Input:
Bradycardia-induced coronary angiogenesis is dependent on vascular endothelial growth factor.

A marked coronary angiogenesis is known to occur with chronic bradycardia. We tested the hypothesis that vascular endothelial growth factor (VEGF), an endothelial cell mitogen and a major regulator of angiogenesis, is upregulated in response to low heart rate and consequential increased stroke volume. Bradycardia was induced in rats by administering the bradycardic drug alinidine (3 mg/kg body weight) twice daily. Heart rate decreased by 32% for 20 to 40 minutes after injection and was chronically reduced by 10%, 14%, and 18.5% after 1, 2, and 3 weeks of treatment, respectively. Arterial pressure and cardiac output were unchanged. Left ventricular capillary length density (mm/mm(3)) increased gradually with alinidine administration; a 15% increase after 2 weeks and a 40% increase after 3 weeks of alinidine treatment were documented. Left ventricular weight, body weight, and their ratio were not significantly altered by alinidine treatment. After 1 week of treatment, before an increase in capillary length density, VEGF mRNA increased  greater than 2-fold and then declined to control levels after 3 weeks of treatment. VEGF protein was higher in alinidine-treated rats than in controls after 2 weeks and increased further after 3 weeks of treatment. Injection of VEGF-neutralizing antibodies over a 2-week period completely blocked alinidine-stimulated angiogenesis. In contrast, bFGF mRNA was not altered by alinidine treatment. These data suggest that VEGF plays a key role in the angiogenic response that occurs with chronic bradycardia. The mechanism underlying this VEGF-associated angiogenesis may be an increase in stretch due to enhanced diastolic filling.

angiogenesis

coronary

angiogenesis

coronary

angiogenesis

angiogenesis

angiogenic

angiogenesis

declined

VEGF

blocked

Injection

angiogenesis

administering

rats

alinidine

administration

alinidine

treatment

alinidine

treatment

alinidine

treated

alinidine

rats

Injection

VEGF-neutralizing antibodies

treatment

alinidine

induced

angiogenesis

dependent

angiogenesis

vascular endothelial growth factor

upregulated

vascular endothelial growth factor

increased

Left ventricular capillary

administration

increase

Left ventricular capillary

increase

Left ventricular capillary

increase

capillary

increased

VEGF

increased

VEGF

stimulated

alinidine

angiogenesis

altered

bFGF

treatment

plays a key role

VEGF

angiogenic

associated

VEGF

angiogenesis


Input:
External beam radiotherapy for subretinal neovascularization in age-related macular degeneration: is this treatment efficient?

PURPOSE: Control of the natural course of subretinal neovascularization (SRNV) in age-related macular degeneration (AMD) is difficult. Only a subset of patients is suitable for laser coagulation. This prospective study aimed to determine the efficacy and individual benefit of external beam radiotherapy (EBRT). METHODS AND MATERIALS: The prospective trial included 287 patients with subfoveal neovascularization due to AMD which was verified by fluorescein angiography. Patients have been treated between January 1996 and October 1997. All patients received a total dose of 16 Gy in 2-Gy daily fractions with 5-6 MeV photons based on computerized treatment planning in individual head mask fixation. This first analysis is based on 73 patients (50 women, 23 men, median age 74.3 years), with a median follow-up of 13.3 months and a minimum follow-up of 11 months. RESULTS: All patients completed therapy and tolerability was good. First clinical control with second angiography was performed 6 weeks after irradiation, then in 3-month intervals. Eighteen patients with SRNV refusing radiotherapy served as a control group and were matched with 18 irradiated patients. After 7 months median visual acuity (VA) was 20/160 for the irradiated and 20/400 for the untreated patients. One year after radiotherapy final median VA was 20/400 in both groups. CONCLUSION: These results suggest that 16 Gy of conventionally fractionated external beam irradiation slows down the visual loss in exudative AMD for only a few months. Patients' reading vision could not be saved for a long-term run.

neovascularization

neovascularization

neovascularization

degeneration

macular

degeneration

macular

refusing

radiotherapy

treated

Patients

received

patients

therapy

patients

radiotherapy

patients

irradiated

patients

irradiated

patients

untreated

patients

Control

neovascularization


Input:
Increased serum levels of vascular endothelial growth factor in patients with renal cell carcinoma.

Neovascularization, an essential event for the growth of solid tumors, is regulated by a number of angiogenic factors. One such factor, vascular endothelial growth factor (VEGF), is considered to exert a potent angiogenic activity, as indicated by immunohistochemical and molecular evidence. In this study we investigated the serum VEGF level (s-VEGF) in patients with renal cell carcinoma (RCC). s-VEGF in peripheral blood samples was analyzed in 40 RCC patients and 40 patients without cancer (controls) using a sandwich enzyme-linked immunoassay. In 20 RCC patients, serum samples were obtained separately from the bilateral renal veins. s-VEGF was also measured before, 4 and 8 weeks after nephrectomy in 11 patients. There were significant differences in s-VEGF between the RCC patients and the controls (207.3+/-32.9 vs. 71.5+/-9.1 pg/ml, mean+/-SE) (P less than 0.005), between the tumor-bearing renal veins and the contralateral ones (P less than 0.01), between the pre- and post-nephrectomy situations (P less than 0.01) and among the various parameters of tumor status such as tumor extent (P less than 0.001) and existence of metastasis (P less than 0.001). s-VEGF significantly correlated with the tumor volume obtained by a three-dimensional measurement (r=0.802, P less than 0.0001). The sensitivity and specificity of s-VEGF at the cut-off level of 100 pg/ml, as determined by the receiver-operating-characteristics curve, were 80.0% and 72.5%, respectively. The results indicate that tumor tissue of RCC liberates VEGF into the systemic blood flow and that s-VEGF is a possible marker for RCC.

Neovascularization

angiogenic

angiogenic

growth

solid tumors

liberates

tumor tissue

VEGF

blood

Increased

vascular endothelial growth factor

essential

Neovascularization

growth

regulated

Neovascularization


Input:
Insulin-induced vascular endothelial growth factor expression in retina.

PURPOSE: Clinical studies have demonstrated that intensive insulin therapy causes a transient worsening of retinopathy. The mechanisms underlying the initial insulin-induced deterioration of retinal status in patients with diabetes remain unknown. Vascular endothelial growth factor (VEGF) is known to be operative in the pathogenesis of diabetic retinopathy. The current study was conducted to characterize the effect of insulin on retinal VEGF gene expression in vitro and in vivo. METHODS: The effect of insulin on VEGF expression in vivo was examined by in situ hybridization studies of rat retinal VEGF transcripts. To examine the mechanisms by which insulin regulates VEGF expression, human retinal pigment epithelial (RPE) cells were exposed to insulin, and VEGF mRNA levels were quantified with RNase protection assays (RPAs). Conditioned media from insulin-treated RPE cells were assayed for VEGF protein and capillary endothelial cell proliferation. The capacity of insulin to stimulate the VEGF promoter linked to a luciferase reporter gene was characterized in transient transfection assays. RESULTS: Insulin increased VEGF mRNA levels in the ganglion, inner nuclear, and RPE cell layers. In vitro, insulin increased VEGF mRNA levels in human RPE cells and enhanced VEGF promoter activity without affecting transcript stability. Insulin treatment also increased VEGF protein levels in conditioned RPE cell media in a dose-dependent manner with a median effective concentration of 5 nM. The insulin-conditioned RPE cell media stimulated capillary endothelial cell proliferation, an effect that was completely blocked by anti-VEGF neutralizing antibody. CONCLUSIONS: Insulin increases VEGF mRNA and secreted protein levels in RPE cells through enhanced transcription of the VEGF gene. Intensive insulin therapy may cause a transient worsening of retinopathy in patients with diabetes through increased retinal VEGF gene expression.

proliferation

capillary endothelial cell

proliferation

capillary endothelial cell

expression

vascular endothelial growth factor

expression

VEGF

expression

VEGF

expression

VEGF

expression

VEGF

blocked

stimulated

anti-VEGF neutralizing antibody

therapy

insulin

exposed

retinal pigment epithelial (RPE) cells

insulin

treated

insulin

RPE cells

assayed

RPE cells

linked

promoter

luciferase

treatment

Insulin

therapy

insulin

patients

induced

Insulin

expression

stimulate

insulin

VEGF

promoter

increased

Insulin

VEGF

increased

insulin

VEGF

enhanced

insulin

VEGF

promoter

increased

treatment

VEGF

stimulated

proliferation

increases

VEGF

enhanced

enhanced

Insulin

transcription

increased

therapy

expression

effect

insulin

expression

effect

insulin

expression

regulates

insulin

expression

transcription

VEGF


Input:
The antiangiogenic agent linomide inhibits the growth rate of von Hippel-Lindau paraganglioma xenografts to mice.

The aim of this study was to ascertain the potential usefulness of the antiangiogenic compound linomide for treatment of von Hippel-Lindau (VHL)-related tumors. Paraganglioma tissue fragments obtained at surgery from a VHL type 2a patient were transplanted s.c. to male BALB/c nu/nu (nude) mice: (a) 2-3-mm fragments for "prevention" experiments; and (b) 2-3-mm fragments allowed to grow to 1 cm for "intervention" studies. Both groups received either 0.5 mg/ml linomide in drinking water or acidified water and were followed until tumor diameter reached 3 cm or for 4 weeks. In both the prevention and intervention experiments, a significant diminution of tumor size and weight was observed in the drug-treated animals. In vivo nuclear magnetic resonance analysis of tumor blood flow in linomide-treated animals showed localization of blood vessels almost exclusively to the periphery of the poorly vascularized tumors with a significant reduction of both vascular functionality and vasodilation. Histological examination of tumors from linomide-treated animals revealed marked avascularity. Treated animals also displayed a 2.4-fold reduction of tumor vascular endothelial growth factor mRNA levels. Taken together, our data indicate that in VHL disease, therapy directed at inhibition of constitutively expressed VEGF induction of angiogenesis by VHL tumors may constitute an effective medical treatment.

angiogenic

angiogenic

angiogenesis

expressed

VEGF

growth

von Hippel-Lindau paraganglioma xenografts

localization

blood vessels

inhibits

linomide

growth

diminution

tumor

reduction

vascular endothelial growth factor

inhibition

induction

VHL tumors

treatment

linomide

von Hippel-Lindau (VHL)-related tumors

obtained

Paraganglioma tissue fragments

transplanted

Paraganglioma tissue fragments

BALB/c nu/nu (nude) mice

received

linomide

treated

linomide

treated

linomide

induction

VEGF

angiogenesis


Input:
Vascular proliferation and enhanced expression of endothelial nitric oxide synthase in human peritoneum exposed to long-term peritoneal dialysis.

Long-term peritoneal dialysis (PD) is associated with alterations in peritoneal permeability and loss of ultrafiltration. These changes originate from increased peritoneal surface area, but the morphologic and molecular mechanisms involved remain unknown. The hypothesis that modifications of activity and/or expression of nitric oxide synthase (NOS) isozymes might play a role in these modifications, via enhanced local production of nitric oxide, was tested in this study. NOS activities were measured by the L-citrulline assay in peritoneal biopsies from seven control subjects, eight uremic patients immediately before the onset of PD, and 13 uremic patients on short-term ( less than 18 mo, n = 6) or long-term( greater than 18 mo, n = 7) PD. Peritoneal NOS activity is increased fivefold in long-term PD patients compared with control subjects. In uremic patients, NOS activity is positively correlated with the duration of PD. Increased NOS activity is mediated solely by Ca(2+)-dependent NOS and, as shown by immunoblotting, an upregulation of endothelial NOS. The biologic relevance of increased NOS in long-term PD was demonstrated by enhanced nitrotyrosine immunoreactivity and a significant increase in vascular density and endothelial area in the peritoneum. Immunoblotting and immunostaining studies demonstrated an upregulation of vascular endothelial growth factor (VEGF) mostly along the endothelium lining peritoneal blood vessels in long-term PD patients. In the latter, VEGF colocalized with the advanced glycation end product pentosidine deposits. These data provide a morphologic (angiogenesis and increased endothelial area) and molecular (enhanced NOS activity and endothelial NOS upregulation) basis for explaining the permeability changes observed in long-term PD. They also support the implication of local advanced glycation end product deposits and liberation of VEGF in that process.

angiogenesis

proliferation

Vascular

expression

endothelial nitric oxide synthase

expression

nitric oxide synthase

colocalized

VEGF

pentosidine

liberation

VEGF

enhanced

expression

increased

peritoneal surface area

enhanced

production

increased

NOS

Increased

NOS

upregulation

endothelial NOS

increased

NOS

enhanced

nitrotyrosine

increase

vascular

increase

endothelial area

upregulation

vascular endothelial growth factor

increased

endothelial area

enhanced

NOS

upregulation

endothelial NOS

play a role

enhanced

mediated

NOS

NOS

production

nitric oxide


Input:
Active hair growth (anagen) is associated with angiogenesis.

After the completion of skin development, angiogenesis, i.e., the growth of new capillaries from pre-existing blood vessels, is held to occur in the skin only under pathologic conditions. It has long been noted, however, that hair follicle cycling is associated with prominent changes in skin perfusion, that the epithelial hair bulbs of anagen follicles display angiogenic properties, and that the follicular dermal papilla can produce angiogenic factors. Despite these suggestive observations, no formal proof is as yet available for the concept that angiogenesis is a physiologic event that occurs all over the mature mammalian integument whenever hair follicles switch from resting (telogen) to active growth (anagen). This study uses quantitative histomorphometry and double-immunohistologic detection techniques for the demarcation of proliferating endothelial cells, to show that synchronized hair follicle cycling in adolescent C57BL/6 mice is associated with substantial angiogenesis, and that inhibiting angiogenesis in vivo by the intraperitoneal application of a fumagillin derivative retards experimentally induced anagen development in these mice. Thus, angiogenesis is a physiologic event in normal postnatal murine skin, apparently is dictated by the hair follicle, and appears to be required for normal anagen development. Anagen-associated angiogenesis offers an attractive model for identifying the physiologic controls of cutaneous angiogenesis, and an interesting system for screening the effects of potential antiangiogenic drugs in vivo.

angiogenesis

angiogenesis

skin

angiogenic

epithelial hair bulbs

angiogenic

angiogenesis

angiogenesis

angiogenesis

angiogenesis

hair follicle

angiogenesis

angiogenesis

angiogenic

proliferating

endothelial cells

development

skin

cycling

hair follicle

cycling

hair follicle

growth

hair

growth

capillaries

resting

hair follicles

growth

hair follicles

inhibiting

cycling

angiogenesis

associated

growth

angiogenesis

associated

cycling

associated

cycling

angiogenesis

associated

angiogenesis


Input:
Alpha-melanocyte-stimulating hormone modulates activation of NF-kappa B and AP-1 and secretion of interleukin-8 in human dermal fibroblasts.

Alpha-melanocyte-stimulating hormone (alpha-MSH) has evolved as a mediator of diverse biological activities in an ever-growing number of non-melanocytic cell types. One mechanism by which alpha-MSH exerts its effects is modulation of AP-1 and NF-kappa B. These two transcription factors also play an important role in fibroblasts, in extracellular matrix composition, and in cytokine expression. By use of electric mobility shift assays, we demonstrate that alpha-MSH (10(-6) to 10(-14) M) activates AP-1 in human dermal fibroblasts, whereas coincubation with interleukin-1 beta (IL-1 beta) results in suppression of its activation. alpha-MSH also induces activation of NF-kappa B but does not modulate DNA binding on costimulation with IL-1 beta. Since AP-1 and NF-kappa B are key elements in controlling interleukin-8 (IL-8) transcription, human fibroblasts were treated with alpha-MSH and IL-1 beta for 24 hours, and cytokine levels in the supernatants were measured by ELISA. alpha-MSH alone had little effect, whereas coincubation with IL-1 beta led to marked downregulation of IL-8 secretion (at most 288 +/- 152 ng/mL) when compared to treatment with IL-1 beta alone (919 +/- 157 ng/mL). Our results indicate that alpha-MSH exerts modulatory effects on the activation of NF-kappa B and AP-1, and that it can regulate chemokine secretion in human dermal fibroblasts. These effects of alpha-MSH may have important regulatory functions in extracellular matrix composition, wound healing, or angiogenesis.

binding

NF-kappa B

angiogenesis

growing

non-melanocytic cell

secretion

dermal fibroblasts

secretion

suppression

activates

coincubation

downregulation

secretion

coincubation

alpha-MSH

dermal fibroblasts

interleukin-1 beta

treated

fibroblasts

alpha-MSH

IL-1 beta

coincubation

alpha-MSH

IL-1 beta

treatment

IL-1 beta

activation

NF-kappa B

activation

activates

alpha-MSH

induces

alpha-MSH

activation

activation

NF-kappa B

costimulation

NF-kappa B

IL-1 beta

led

coincubation

downregulation

activation

NF-kappa B

activation

modulates

Alpha-melanocyte-stimulating hormone

activation

modulates

Alpha-melanocyte-stimulating hormone

secretion

mediator

Alpha-melanocyte-stimulating hormone

non-melanocytic cell

modulation

alpha-MSH

modulation

alpha-MSH

NF-kappa B

play an important role

fibroblasts

play an important role

extracellular matrix

modulate

alpha-MSH

binding

controlling

transcription

controlling

NF-kappa B

transcription

effects

alpha-MSH

activation

have important regulatory functions

alpha-MSH

extracellular matrix

transcription


Input:
Vasodilator-stimulated phosphoprotein is involved in stress-fiber and membrane ruffle formation in endothelial cells.

Vasodilator-stimulated phosphoprotein (VASP) is highly expressed in vascular endothelial cells, where it has been implicated in cellular reorganization during angiogenesis, as well as in endothelial retraction and changes in vessel permeability. However, the cellular functions of VASP are not known. In this study, we have expressed wild-type and mutant forms of VASP in endothelial cells to determine in what aspects of cytoskeletal behavior this protein participates. Expression of wild-type VASP induces marked membrane ruffling and formation of prominent stress fibers in bovine aortic endothelial cells. Deletion of the proline-rich domain of VASP abolishes its ability to bind profilin but does not affect ruffling or stress fiber formation. Further deletions reveal a sequence within the carboxy-terminal domain that is responsible for in vivo bundle formation. Ruffling occurs only on the expression of forms of VASP that possess bundling activity and the capacity to bind zyxin/vinculin-derived peptide. The ability of distinct subdomains within VASP to bind adhesion proteins and induce F-actin bundling in vivo suggests that this protein could function in the aggregation and tethering of actin filaments during the formation of endothelial cell-substrate and cell-cell contacts. These data provide a mechanism whereby VASP can influence endothelial migration and organization during capillary formation and modulate vascular permeability via effects on endothelial cell contractility.

bind

VASP

profilin

bind

VASP

zyxin

vinculin

bind

subdomains

VASP

angiogenesis

formation

stress-fiber

formation

membrane ruffle

formation

stress fibers

formation

stress fiber

formation

endothelial cell-substrate

formation

cell-cell contacts

organization

endothelial

formation

capillary

expressed

Vasodilator-stimulated phosphoprotein

Expression

VASP

expression

VASP

migration

endothelial

abolishes

bind

influence

VASP

migration

influence

VASP

organization

expressed

VASP

induces

Expression

ruffling

induces

Expression

formation

induce

VASP

F-actin

involved

Vasodilator-stimulated phosphoprotein

formation

changes

vessel

ruffling

membrane

affect

formation

modulate

vascular

effects

effects

VASP

endothelial cell


Input:
Urokinase receptor: a molecular organizer in cellular communication.

In a variety of cell types, the glycolipid-anchored urokinase receptor (uPAR) is colocalized pericellularly with components of the plasminogen activation system and endocytosis receptors. uPAR is also coexpressed with caveolin and members of the integrin adhesion receptor superfamily. The formation of functional units with these various proteins allows the uPAR to mediate the focused proteolysis required for cell migration and invasion and to contribute both directly and indirectly to cell adhesive processes in a non-proteolytic fashion. This dual activity, together with the initiation of signal transduction pathways by uPAR, is believed to influence cellular behaviour in angiogenesis, inflammation, wound repair and tumor progression/metastasis and open up the way for uPAR-based therapeutic approaches.

adhesive processes

cell

angiogenesis

progression

tumor

coexpressed

uPAR

caveolin

integrin adhesion receptor

colocalized

cell

glycolipid-anchored urokinase receptor

plasminogen

migration

cell

invasion

cell

metastasis

tumor

influence

initiation

angiogenesis

influence

initiation

progression

influence

initiation

metastasis

signal transduction pathways

required

migration

required

invasion

initiation

signal transduction pathways

uPAR

contribute

uPAR

adhesive processes


Input:
RNA damage and inhibition of neoplastic endothelial cell growth: effects of human and amphibian ribonucleases.

Angiogenesis defines the many steps involved in the growth and migration of endothelial cell-derived blood vessels. This process is necessary for the growth and metastasis of tumors, and considerable effort is being expended to find inhibitors of tumor angiogenesis. This usually involves screening of potential anti-angiogenic compounds on endothelial cells. To this end, two candidate anti-angiogenic RNA-damaging agents, onconase and (-4)rhEDN, were screened for their effects on endothelial cell proliferation using three distinct types of endothelial cells in culture: HPV-16 E6/E7-immortalized human umbilical vein endothelial cells (HUVECs), a Kras-transformed HPV-16 E6/E7 HUVEC (Rhim et al., Carcinogenesis 4, 673-681, 1998), and primary HUVECs. Onconase similarly inhibited proliferation in all three cell lines (IC(50) = 0.3-1.0 microM) while (-4)rhEDN was more effective on immortalized HUVEC cell lines (IC(50) = 0.02-0.06 microM) than on primary HUVECs (IC(50) > 0.1 microM). Differential sensitivity to these agents implies that more than one endothelial cell type must be used in proliferation assays to screen for novel anti-angiogenic compounds.

Angiogenesis

angiogenesis

tumor

angiogenic

angiogenic

angiogenic

growth

endothelial cell

proliferation

endothelial cell

proliferation

cell lines

proliferation

endothelial cell type

derived

blood vessels

growth

blood vessels

growth

tumors

migration

blood vessels

metastasis

tumors

inhibition

growth

inhibited

Onconase

proliferation

immortalized

HPV-16 E6

human umbilical vein endothelial cells

immortalized

human umbilical vein endothelial cells

transformed

Kras

HUVEC

immortalized

HUVEC cell lines

effective

HUVEC cell lines

effective

HUVECs

effects

onconase

proliferation

effects

proliferation


Input:
IL-12 inhibition of endothelial cell functions and angiogenesis depends on lymphocyte-endothelial cell cross-talk.

In vivo IL-12-dependent tumor inhibition rests on the ability of IL-12 to activate a CD8-mediated cytotoxicity, inhibit angiogenesis, and cause vascular injury. Although in vivo studies have shown that such inhibition stems from complex interactions of immune cells and the production of IFN-gamma and other downstream angiostatic chemokines, the mechanisms involved are still poorly defined. Here we show that IL-12 activates an anti-angiogenic program in Con A-activated mouse spleen cells (activated spc) or human PBMC (activated PBMC). The soluble factors they release in its presence arrest the cycle of endothelial cells (EC), inhibit in vitro angiogenesis, negatively modulate the production of matrix metalloproteinase-9, and the ability of EC to adhere to vitronectin and up-regulate ICAM-1 and VCAM-1 expression. These effects do not require direct cell-cell contact, yet result from continuous interaction between activated lymphoid cells and EC. We used neutralizing Abs to show that the IFN-inducible protein-10 and monokine-induced by IFN-gamma chemokines are pivotal in inducing these effects. Experiments with nu/nu mice, nonobese diabetic-SCID mice, or activated spc enriched in specific cell subpopulations demonstrated that CD4(+), CD8(+), and NK cells are all needed to mediate the full anti-angiogenetic effect of IL-12.

adhere

EC

vitronectin

contact

cell

cell

interaction

lymphoid cells

EC

angiogenesis

angiogenesis

angiogenic

angiogenesis

angiogenetic

production

IFN-gamma

production

matrix metalloproteinase-9

expression

expression

inhibition

endothelial cell

inhibition

angiogenesis

inhibition

tumor

inhibit

angiogenesis

program

angiogenic

arrest

endothelial cells

inhibit

angiogenesis

negatively modulate

production

negatively modulate

adhere

dependent

inhibition

activates

program

activated

Con A

spleen cells

activated

Con A

PBMC

activated

spc

activated

PBMC

up-regulate

expression

activated

lymphoid cells

activated

EC

activated

spc

require

contact

mediate

effect

effect

angiogenetic


Input:
Effects of morphological patterning on endothelial cell migration.

The migration of vascular endothelial cells (ECs) plays an important role in vascular remodeling. Here we studied the effects of cell morphology on the migration of bovine aortic ECs by culturing cells on micropatterned strips of collagen matrix (60-, 30-, and 15-microm wide). The spreading areas of the cells on 15- and 30-microm wide strips were 30% lower than those on 60-microm wide strips and unpatterned collagen. The cells on 15-microm wide strips completely aligned in the direction of the strip, and had significantly lower shape index than those in all other groups. On strips of all widths, ECs tended to migrate in the direction of strips. ECs on 15-microm wide strips had highest speed, particularly in the direction of the strip. Vinculin staining showed that the leading edge of ECs on 15-microm wide strips had focal adhesions that were oriented with their lamellipodial protrusion and the direction of cell migration; this arrangement of the focal adhesions may promote EC migration. The present study provides direct evidence on the role of cell morphology in EC migration, and will help us to understand the mechanisms of EC migration during angiogenesis and wound healing.

angiogenesis

migration

endothelial cell

migration

vascular endothelial cells

migration

aortic ECs

migrate

ECs

migration

cell

migration

EC

migration

EC

migration

EC

culturing

cells

promote

migration

Effects

migration

plays an important role

migration

remodeling

role

migration

remodeling

vascular


Input:
Thrombospondin-2 plays a protective role in multistep carcinogenesis: a novel host anti-tumor defense mechanism.

The angiogenic switch during tumorigenesis is thought to be induced by a change in the balance of pro- angiogenic and anti-angiogenic factors. To elucidate the biological role of the endogenous angiogenesis inhibitor thrombospondin-2 (TSP-2) during multistep carcinogenesis, we subjected TSP-2-deficient and wild-type mice to a chemical skin carcinogenesis regimen. Surprisingly, TSP-2 expression was strongly upregulated in the mesenchymal stroma of wild-type mice throughout the consecutive stages of tumorigenesis whereas the angiogenesis factor, vascular endothelial growth factor, was induced predominantly in tumor cells. TSP-2 deficiency dramatically enhanced susceptibility to skin carcinogenesis and resulted in accelerated and increased tumor formation. The angiogenic switch occurred in early stages of pre-malignant tumor formation, and tumor angiogenesis was significantly enhanced in TSP-2-deficient mice. While TSP-2 deficiency did not affect tumor differentiation or proliferation, tumor cell apoptosis was significantly reduced. These results reveal upregulation of an endogenous angiogenesis inhibitor during multi step tumorigenesis and identify enhanced stromal TSP-2 expression as a novel host anti-tumor defense mechanism.

angiogenic

angiogenic

angiogenic

angiogenesis

angiogenesis

angiogenic

angiogenesis

tumor

angiogenesis

apoptosis

tumor cell

formation

tumor

formation

tumor

differentiation

tumor

deficient

expression

deficiency

deficient

deficiency

expression

proliferation

tumor

defense

tumor

inhibitor

angiogenesis

reduced

deficiency

apoptosis

defense

tumor

subjected

mice

induced

angiogenic

upregulated

expression

induced

vascular endothelial growth factor

increased

deficiency

formation

enhanced

formation

enhanced

angiogenesis

enhanced

expression

affect

deficiency

differentiation

affect

deficiency

proliferation


Input:
Current prospects for controlling cancer growth with non-cytotoxic agents--nutrients, phytochemicals, herbal extracts, and available drugs.

In animal or cell culture studies, the growth and spread of cancer can be slowed by many nutrients, food factors, herbal extracts, and well-tolerated, available drugs that are still rarely used in the clinical management of cancer, in part because they seem unlikely to constitute definitive therapies in themselves. However, it is reasonable to expect that mechanistically complementary combinations of these measures could have a worthwhile impact on survival times and, when used as adjuvants, could improve the cure rates achievable with standard therapies. The therapeutic options available in this regard include measures that: down-regulate serum free IGF-I; suppress the synthesis of mevalonic acid and/or certain derivatives thereof; modulate arachidonate metabolism by inhibiting 5-lipoxygenase, 12-lipoxygenase, or COX-2; antagonize the activation of AP-1 transcription factors; promote the activation of PPAR-gamma transcription factors; and that suppress angiogenesis by additional mechanisms. Many of these measures appear suitable for use in cancer prevention.

angiogenesis

growth

cancer

growth

cancer

spread

cancer

metabolism

arachidonate

slowed

growth

slowed

spread

down-regulate

IGF-I

suppress

synthesis

inhibiting

inhibiting

inhibiting

antagonize

activation

suppress

angiogenesis

prevention

cancer

culture

cell

activation

promote

activation

activation

PPAR-gamma

controlling

growth

modulate

metabolism

synthesis

mevalonic acid


Input:
Inhibition of PDGF-stimulated and matrix-mediated proliferation of human vascular smooth muscle cells by SPARC is independent of changes in cell shape or cyclin-dependent kinase inhibitors.

Interactions among growth factors, cells, and extracellular matrix regulate proliferation during normal development and in pathologies such as atherosclerosis. SPARC (secreted protein, acidic, and rich in cysteine) is a matrix-associated glycoprotein that modulates the adhesion and proliferation of vascular cells. In this study, we demonstrate that SPARC inhibits human arterial smooth muscle cell proliferation stimulated by platelet-derived growth factor or by adhesion to monomeric type I collagen. Binding studies with SPARC and SPARC peptides indicate specific and saturable interaction with smooth muscle cells that involves the C-terminal Ca2+-binding region of the protein. We also report that SPARC arrests monomeric collagen-supported smooth muscle cell proliferation in the late G1-phase of the cell cycle in the absence of an effect on cell shape or on levels of cyclin-dependent kinase inhibitors. Cyclin-dependent kinase-2 activity, p107 and cyclin A levels, and retinoblastoma protein phosphorylation are markedly reduced in response to the addition of exogenous SPARC and/or peptides derived from specific domains of SPARC. Thus, SPARC, previously characterized as an inhibitor of platelet-derived growth factor binding to its receptor, also antagonizes smooth muscle cell proliferation mediated by monomeric collagen at the level of cyclin-dependent kinase-2 activity.

Interactions

cells

extracellular matrix

associated

SPARC

matrix

adhesion

vascular cells

adhesion

monomeric type I collagen

Binding

SPARC

Binding

SPARC peptides

interaction

SPARC

smooth muscle cells

C-terminal Ca2+-binding region

interaction

SPARC peptides

smooth muscle cells

C-terminal Ca2+-binding region

binding

platelet-derived growth factor

proliferation

vascular smooth muscle cells

proliferation

cells

proliferation

vascular cells

proliferation

arterial smooth muscle cell

proliferation

smooth muscle cell

proliferation

smooth muscle cell

changes

cell

Inhibition

proliferation

SPARC

inhibits

SPARC

proliferation

arrests

SPARC

proliferation

reduced

Cyclin-dependent kinase-2

reduced

reduced

cyclin A

reduced

phosphorylation

antagonizes

proliferation

phosphorylation

retinoblastoma protein

addition

SPARC

stimulated

PDGF

proliferation

mediated

matrix

proliferation

stimulated

proliferation

platelet-derived growth factor

stimulated

proliferation

adhesion

supported

collagen

proliferation

response

reduced

addition

independent

Inhibition

changes

independent

Inhibition

cyclin-dependent kinase inhibitors

regulate

Interactions

proliferation

modulates

SPARC

adhesion

modulates

SPARC

proliferation

effect

cell

effect

cyclin-dependent kinase inhibitors

mediated

proliferation

collagen


Input:
Upregulation of vascular endothelial growth factor receptors is associated with advanced neuroblastoma.

BACKGROUND: Angiogenesis is essential for tumor growth and relies on the production of angiogenic factors. Vascular endothelial growth factor (VEGF) is a major regulator of angiogenesis that binds to tyrosine kinase receptors Flt-1 and KDR. The interaction of VEGF and its receptors at gene and protein levels in neuroblastoma remains widely unknown. METHODS: Tumor biopsy specimens and serum were obtained from 37 neuroblastoma patients; adrenal biopsy sections and sera of 7 normal children served as controls. Biopsy specimens were examined by real-time reverse transcription polymerase chain reaction (RT-PCR) and Western blotting; serum was analyzed by enzyme-linked immunosorbent assay (ELISA). VEGF-A(165), B, C, Flt-1, and KDR were analyzed. RESULTS: VEGF isoforms and its receptors' mRNA were expressed in neuroblastoma and control tissues. Whereas the ligands were increased in stages III and IV, the receptors were upregulated in stage III only. At protein level, VEGF-B and C, Flt-1, and KDR were not detectable in tissue lysates, whereas VEGF-A was increased in stages III and IV. Serum VEGF protein levels were upregulated in stage III. CONCLUSIONS: VEGF-A(165) is one of the major angiogenesis regulators among the ligands' family of VEGF, whereas its receptors KDR, and most probably Flt-1, may contribute to a poor prognosis (angiogenic) phenotype, as indicated by their upregulated MRNA levels in stage III neuroblastoma. VEGF-A(165) mainly contributes to increased serum VEGF levels and may serve as a diagnostic tool in advanced-stage neuroblastoma.

binds

Vascular endothelial growth factor

binds

Vascular endothelial growth factor

KDR

interaction

VEGF

Angiogenesis

angiogenic

angiogenesis

angiogenesis

angiogenic

detectable

VEGF-B

detectable

C

detectable

detectable

KDR

protein levels

VEGF

growth

tumor

Upregulation

vascular endothelial growth factor receptors

essential

Angiogenesis

growth

increased

VEGF-A

upregulated

protein levels

increased

VEGF

contributes

increased

expressed

VEGF


Input:
Optimizing treatment of choroidal neovascularization feeder vessels associated with age-related macular degeneration.

PURPOSE: To optimize the method of treating choroidal neovascularization (CNV) associated with age-related macular degeneration (AMD). DESIGN: Experimental study and interventional case series. METHODS: The parameters associated with locating and then photocoagulating CNV feeder vessels were identified and optimized using published data and data derived from modeling the choroidal vasculature. Based on these optimized parameters, a prototype diagnostic/treatment system was designed that captures high-speed indocyanine green (ICG) angiogram images and facilitates analysis of the images by enhancing visualization of dye movement through CNV feeder vessels (FVs). The system also permits precise aiming and delivery of 810- nm wavelength photocoagulation laser energy to target FVs on a real-time ICG angiogram image of the choroidal vasculature. Target FVs are tracked by a joy-stick controlled laser aiming beam until an intravenously-injected high-concentration ICG dye bolus is observed to enter the target vessel, at which time the laser is fired. Proof of principle of the combined diagnosis/treatment system design for performing dye-enhanced photocoagulation (DEP) in the clinical setting and determination of the minimum DEP laser energy needed to close CNV FVs was made in 11 AMD patients requiring treatment of CNV, but for whom other treatment was not appropriate. RESULTS: Using ICG-DEP, CNV feeder vessels were closed with single pulse laser energy, delivering as little as 0.6 to 1.8 J of energy to the fundus, producing no visible change in the fundus. Successful FV closure was usually indicated immediately by presence of incarcerated ICG dye in the vessel adjacent to the burn site. The prototype system proved relatively easy to operate. After acquiring and interpreting diagnostic angiograms and repositioning a patient in front of the device, feeder vessel DEP and treatment evaluation required 15 to 20 minutes. CONCLUSIONS: Indocyanine green dye-enhanced photocoagulation of CNV feeder vessels, facilitated by use of a device that permits real-time visualization of the choroidal circulation while aiming the treatment laser beam, appears to minimize the amount of energy applied to the fundus and the volume of fundus tissue affected by treatment, compared with other treatment modalities. The combination diagnosis/treatment device should be useful in optimizing FV treatment and in refining and evaluating the efficacy of DEP in future clinical trials.

neovascularization

feeder vessels

neovascularization

CNV

CNV

feeder vessels

CNV

feeder vessels

CNV

FVs

CNV

CNV

feeder vessels

CNV

feeder vessels

degeneration

macular

degeneration

macular

observed

ICG dye

vessel

treatment

neovascularization

treating

neovascularization

photocoagulating

feeder vessels

intravenously-injected

ICG dye

treatment

CNV

closed

ICG

feeder vessels

closure

FV

photocoagulation

feeder vessels

treatment

FV

requiring

patients

treatment

enhanced

Indocyanine green dye

photocoagulation

associated

neovascularization

degeneration

associated

neovascularization

degeneration


Input:
Inhibition of angiogenesis by the cancer chemopreventive agent conjugated linoleic acid.

Dietary conjugated linoleic acid (CLA) has been shown previously to inhibit rat mammary carcinogenesis. In addition to direct effects on mammary epithelial cells,including decreased proliferation and induction of apoptosis, CLA may exert its effects indirectly by inhibiting the differentiation of mammary stromal cells to an endothelial cell type. Specifically, CLA was found to decrease the ability of mammary stromal cells to form complex anastomosing microcapillary networks in vitro on Engelbreth-Holm-Swarm-derived reconstituted basement membrane. This suggested that CLA might inhibit angiogenesis in vivo. To test this possibility, CD2/F(1) mice were placed on synthetic diets containing 0, 1, or 2% CLA for 6 weeks, before angiogenic challenge by s.c. injection with an angiogenic gel substrate (Matrigel pellet assay). After 7 days, the pellets from animals fed the control diet were infiltrated by abundant branching networks of blood vessels with patent lumen-containing RBCs. In contrast, pellets from the CLA-fed animals contained fewer infiltrating cells, which formed limited branching cellular networks, the majority of which had collapsed lumen and no RBCs. Both levels of dietary CLA showed similar effects, with the number of RBC-containing vessels per 20x field decreased to a third of that seen in control. Dietary CLA decreased serum levels of vascular endothelial growth factor (VEGF) and whole mammary gland levels of VEGF and its receptor Flk-1. Both cis-9, trans-11 and trans-10, cis-12 CLA isomers were effective in inhibiting angiogenesis in vitro in a dose-dependent fashion. The ability of CLA to inhibit angiogenesis may contribute to its efficacy as a chemopreventive agent.

angiogenesis

angiogenesis

angiogenic

angiogenic

angiogenesis

angiogenesis

collapsed

lumen

proliferation

mammary epithelial cells

apoptosis

mammary epithelial cells

differentiation

mammary stromal cells

differentiation

endothelial cell

form

microcapillary networks

branching

networks of blood vessels

formed

cellular networks

infiltrating

cells

Inhibition

angiogenesis

conjugated linoleic acid

decreased

proliferation

inhibiting

CLA

differentiation

decrease

CLA

form

inhibit

CLA

angiogenesis

decreased

CLA

vascular endothelial growth factor

decreased

CLA

VEGF

decreased

CLA

inhibiting

angiogenesis

inhibit

CLA

angiogenesis

placed

mice

CLA

s.c. injection

mice

fed

CLA

induction

apoptosis

abundant

branching

effects

decreased

CLA

effects

induction

CLA

effects

mammary epithelial cells

inhibiting

effective

inhibiting

effective

inhibiting

effective

inhibiting

effective

cis-12 CLA isomers

inhibiting


Input:
Molecular characterization of angiogenic properties of human oral squamous cell carcinoma cells.

Little is known about the specificity of angiogenic properties of oral cancer cells and the possible mechanisms. Stimulatory effects on proliferation and migration of human umbilical vein endothelial cells (HUVEC) characterized the angiogenic properties of oral cancer cells but not normal oral keratinocytes (NOK). ELISA found the presence of vascular endothelial growth factors (VEGF) both in the tested oral cancer cells and NOK. Attenuation of the proangiogenic effects by neutralizing VEGF antibodies suggests VEGF play a key role in the acquisition of the angiogenic phenotype in oral cancer cells. Western blotting of p53 and murine double mutant 2 (Mdm2) together with p53 DNA sequencing analysis indicate that p53 function loss by mutation or overexpression of Mdm2 occurred in all tested oral cancer cells regardless of their etiology. In summary, the angiogenic property of oral cancer cells is mediated by many factors in addition to VEGF and the functional status of p53.

angiogenic

angiogenic

angiogenic

angiogenic

angiogenic

angiogenic

proliferation

human umbilical vein endothelial cells

overexpression

migration

human umbilical vein endothelial cells

Attenuation

angiogenic

neutralizing VEGF antibodies

function loss

overexpression

Stimulatory effects

proliferation

Stimulatory effects

migration

play a key role

VEGF

angiogenic

mediated

angiogenic

VEGF

mediated

angiogenic


Input:
Enforced expression of tissue inhibitor of matrix metalloproteinase-3 affects functional capillary morphogenesis and inhibits tumor growth in a murine tumor model.

Homeostasis of the extracellular matrix is a delicate balance between degradation and remodeling, the balance being maintained by the interaction of activated matrix metalloproteinases (MMPs) and specific tissue inhibitors of matrix metalloproteinases (TIMPs). Up-regulation of MMP activity, favoring proteolytic degradation of the basement membrane and extracellular matrix, has been linked to tumor growth and metastasis, as well as tumor-associated angiogenesis, whereas inhibition of MMP activity appears to restrict these processes. We have used retroviral-mediated gene delivery to effect sustained autocrine expression of TIMP-3 in murine neuroblastoma and melanoma tumor cells in order to further examine the ability of TIMPs to inhibit angiogenesis in vivo. Growth of both histologic types of gene-modified tumor cells in severe combined immunodeficiency (SCID) mice was significantly restricted when compared with controls. Grossly, these tumors were small and had few feeding vessels. Histologic evaluation revealed that although tumors overexpressing TIMP-3 had an increased number of CD31(+) endothelial cells, these endothelial cells had not formed functional tubules, as evidenced by decreased vessel continuity and minimal pericyte recruitment. This effect appears to be mediated, in part, by decreased expression of vascular endothelial (VE)-cadherin by endothelial cells in the presence of TIMP-3 as seen both in an in vitro assay and in TIMP-3-overexpressing tumors. Taken together, these results demonstrate that overexpression of TIMP-3 can inhibit angiogenesis and associated tumor growth, and that the antiangiogenic effects of TIMP-3 appear to be mediated through the inhibition of functional capillary morphogenesis.

interaction

matrix metalloproteinases

tissue inhibitors of matrix metalloproteinases

angiogenesis

tumor

angiogenesis

angiogenesis

tumor

angiogenic

degradation

extracellular matrix

degradation

basement membrane

degradation

extracellular matrix

morphogenesis

capillary

formed

tubules

morphogenesis

capillary

expression

tissue inhibitor of matrix metalloproteinase-3

expression

overexpressing

expression

vascular endothelial (VE)-cadherin

overexpressing

overexpression

growth

tumor

growth

tumor

Growth

tumor cells

growth

tumor

metastasis

tumor

recruitment

pericyte

inhibits

expression

growth

inhibition

MMP

restrict

growth

inhibition

restrict

metastasis

inhibition

restrict

angiogenesis

inhibition

inhibit

TIMPs

angiogenesis

restricted

Growth

decreased

vessel

decreased

expression

endothelial cells

inhibit

overexpression

angiogenesis

inhibit

overexpression

growth

effects

angiogenic

inhibition

morphogenesis

Enforced

expression

activated

matrix metalloproteinases

Up-regulation

MMP

effect

expression

affects

expression

morphogenesis

maintained

degradation

interaction

maintained

remodeling

interaction

mediated

effects

inhibition

remodeling

extracellular matrix


Input:
Brn-3a, a neuronal transcription factor of the POU gene family: indications for its involvement in cancer and angiogenesis.

Brn-3a, a member of the POU gene family (so-called because of the similarity with the group of transcription factors Pit, Oct, and Unc), was found in neuronal cells engaged in the transcription activity of the p1 and p2 promoters of the most powerful antiapoptotic gene, namely, Bcl-2. The alternative splicing of Brn-3a mRNA produces two molecular forms: a longer, Bcl-2 transactivating form, and a shorter inactive form, lacking 84 AA in the aminoterminus. In neuronal cells, following Brn-3a gene transfection and superexpression, an increase of 30 fold of the Bcl-2 protein occurs, leading to apoptosis protection. However, recent works demonstrate that Brn-3a expression is not restricted to neuronal cells, as its activity was detected also in cancer cells of non-neuronal nature. Looking for mechanisms linking Brn-3a to carcinogenesis, we discuss the role of this transcription factor in influencing Bcl-2/p53 antagonism and Bcl-2/VEGF induction of tumor angiogenesis, concluding this review with a proposal for the oncogenic nature of Brn-3a.

angiogenesis

angiogenesis

tumor

apoptosis

neuronal cells

produces

superexpression

expression

protection

apoptosis

restricted

expression

influencing

antagonism

influencing

induction

antagonism

antagonism

transfection

neuronal cells

increase

leading

increase

protection

induction

angiogenesis

induction

VEGF

angiogenesis

engaged

transcription

engaged

transcription

p2 promoters

role

influencing

transcription


Input:
Roles of cell adhesion molecules in tumor angiogenesis induced by cotransplantation of cancer and endothelial cells to nude rats.

Roles of cell adhesion molecules mediating the interaction of cancer and endothelial cells in tumor angiogenesis were investigated using new in vitro and in vivo model systems with a cultured murine endothelial cell line (F-2) and human cultured epidermoid cancer cells (A431). The A431 cells exhibited typical in vitro cell adhesion to the endothelial F-2 cells. The initial step of adhesion was mediated by sialyl Lewis(x) (Le(x)) and sialyl Le(a), the carbohydrate determinants expressed on the cancer cells, and E-selectin expressed constitutively on F-2 cells. Prolonged culture led to the implantation of cancer cells into the monolayer of the F-2 cells, which was mediated mainly by alpha(3)beta(1)-integrin. F-2 cells cultured on Matrigel showed evident tube formation, and coculture of F-2 cells with A431 cells led to the formation of A431 cell nests constantly surrounded by tube-like networks consisting of F-2 cells. This in vitro morphogenesis was inhibited by the addition of anti-sialyl Le(x)/Le(a) or anti-beta(1)-integrin antibodies, which led to the formation of cancer cell aggregates that were independent from the F-2 cell networks. This in vitro morphological appearance was exactly reproduced in the in vivo tumors, which were formed when the mixture of A431 and F-2 cells at the ratio of 10:1 were cotransplanted s.c. into the back of nude rats. The tumors of A431 supplemented with F-2 cells were profoundly vascularized throughout by the tubular structures formed by F-2 cells, the lumen of which contained the host rat blood cells. The tumor mass thus formed was an average 5.8-fold as large as control A431 tumors that were grown without F-2 cells. The co-injection of anti-Le(x)/Le(a) or anti-beta(1)-integrin antibodies produced a marked reduction in the size of A431 tumors, which were not vascularized and accompanied an independent tiny remnant clump of F-2 cells. The size of these A431 tumors did not differ significantly from those of control A431 tumors raised without F-2 cells. These results indicate that the interaction of tumor cells and endothelial cells in orderly tumor angiomorphogenesis is highly dependent on the action of cell adhesion molecules mediating the adhesion of cancer cells to endothelial cells, inhibition of which remarkably retards tumor growth and angiogenesis.

interaction

cancer

endothelial cells

adhesion

A431 cells

endothelial F-2 cells

adhesion

A431 cells

endothelial F-2 cells

aggregates

cancer cell

interaction

tumor cells

endothelial cells

adhesion

cancer cells

endothelial cells

angiogenesis

tumor

angiogenesis

tumor

angiomorphogenesis

tumor

angiogenesis

tumor

formation

tube

formed

tumors

formed

tubular structures

formed

tumor

expressed

E-selectin

grown

A431 tumors

raised

A431 tumors

growth

tumor

reduction

A431 tumors

inhibition

interaction

retards

inhibition

growth

retards

inhibition

angiogenesis

cotransplantation

cancer

endothelial cells

nude rats

cultured

cultured

implantation

cancer cells

F-2 cells

cultured

F-2 cells

coculture

F-2 cells

A431 cells

cotransplanted

F-2 cells

back

supplemented

tumors

F-2 cells

co-injection

anti-Le(x)/Le(a)

anti-beta(1)-integrin antibodies

induced

angiogenesis

cotransplantation

mediating

interaction

mediated

adhesion

sialyl Lewis(x)

mediated

adhesion

sialyl Le(a)

mediated

adhesion

expressed

formation

aggregates

produced

co-injection

reduction

dependent

interaction

mediating

mediated

F-2 cells

independent

formation

F-2 cell

mediating

adhesion


Input:
Regulation of transforming growth factor-beta signaling and vascular diseases.

PURPOSE: Members of the transforming growth factor (TGF)-beta superfamily play critical roles in regulation of various cellular functions. Dysregulation of the signaling mechanisms of the TGF-beta superfamily proteins is associated with clinical diseases such as cancer, fibrotic diseases, and vascular disorders. Therefore, understanding these signaling mechanisms may provide us with novel ways to develop strategies for treating clinical diseases induced by these cytokines. METHODS: This review discusses our current understanding of the mechanisms of TGF-beta signaling, focusing on the roles of TGF-beta in regulation of vascular wall cells and on the regulation of TGF-beta superfamily signals by inhibitory Smads.

inhibitory

Smads

signaling

transforming growth factor-beta

signaling

TGF-beta

Regulation

signaling

Dysregulation

TGF-beta

roles

TGF-beta

regulation

regulation

vascular wall cells

regulation

TGF-beta

inhibitory


Input:
Arteriogenesis: the development and growth of collateral arteries.

In patients with atherosclerotic vascular diseases, collateral vessels bypassing major arterial obstructions have frequently been observed. This may explain why some patients remain without symptoms or signs of ischemia. The term "arteriogenesis" was introduced to differentiate the formation of collateral arteries from angiogenesis, which mainly occurs in the ischemic, collateral flow-dependent tissue. Many observations in various animal models and humans support that the remodeling of preexisting collateral vessels is the mechanism of collateral artery formation. This remodeling process seems to be mainly flow-mediated. It involves endothelial cell activation, basal membrane degradation, leukocyte invasion, proliferation of vascular cells, neointima formation (in most species studied), and changes of the extracellular matrix. The contribution of ischemia to arteriogenesis is still unclear, but arteriogenesis clearly can occur in the absence of any significant ischemia. It is questionable, whether collateral arteries also form de novo in ischemic vascular diseases. A better understanding of the mechanisms of arteriogenesis will be important for the design of more effective strategies for the treatment of patients with ischemic vascular diseases.

Arteriogenesis

collateral arteries

arteriogenesis

collateral arteries

angiogenesis

arteriogenesis

arteriogenesis

arteriogenesis

degradation

basal membrane

proliferation

vascular cells

development

collateral arteries

formation

collateral arteries

formation

collateral artery

formation

neointima

form

collateral arteries

growth

collateral arteries

invasion

leukocyte

dependent

tissue

activation

endothelial cell

involves

remodeling

activation

involves

remodeling

degradation

involves

remodeling

invasion

involves

remodeling

proliferation

involves

remodeling

formation

involves

remodeling

changes

changes

extracellular matrix

remodeling

collateral vessels

remodeling

collateral vessels


Input:
Possible role of cyclooxygenase II in the acquisition of ovarian luteal function in rodents.

The development of the corpus luteum (CL), which involves angiogenesis, is essential for the establishment of early pregnancy. We investigated the roles of the prostaglandin synthases cyclooxygenase (COX) I and COX-II in angiogenesis and progesterone production in the newly formed CL, using inhibitors of the COX enzymes and the gonadotropin-induced pseudopregnant rat as a model. Injection of indomethacin, a nonselective COX inhibitor, on the day of ovulation and the following day decreased serum levels of progesterone, as did injection of the selective COX-II inhibitor NS-398. In contrast, a selective COX-I inhibitor, SC-560, had no effect on serum progesterone concentrations. None of the inhibitors had any effect on the weight of the superovulated ovaries or on the synthesis of progesterone by cultured luteal cells. To determine whether changes in angiogenesis are responsible for the decrease in progesterone synthesis, we measured hemoglobin and CD34 levels in luteinized ovaries following injection of COX inhibitors and measured the relative frequency of cells positive for platelet-endothelial cell adhesion molecule as a specific marker for endothelial cells. All of these parameters were reduced by the COX-II inhibitors, suggesting that changes in the vasculature are responsible for the decrease in serum progesterone. Histological examination of ovarian corrosion casts indicated that NS-398 inhibited the establishment of luteal capillary vessels following the injection of hCG. The results are consistent with the hypothesis that the activity of COX-II is associated with the formation of functional CL via its stimulation of angiogenesis.

angiogenesis

angiogenesis

angiogenesis

angiogenesis

development

corpus luteum

formed

CL

luteinized

ovaries

establishment

luteal capillary vessels

formation

CL

decreased

progesterone

decrease

synthesis

decrease

progesterone

inhibited

establishment

pseudopregnant

rat

Injection

indomethacin

injection

injection

hCG

induced

gonadotropin

pseudopregnant

stimulation

COX-II

angiogenesis

roles

cyclooxygenase (COX) I

angiogenesis

roles

cyclooxygenase (COX) I

production

roles

COX-II

angiogenesis

roles

COX-II

production

effect

progesterone

effect

superovulated ovaries

changes

angiogenesis

responsible

changes

decrease

changes

vasculature

responsible

changes

decrease

associated

formation

stimulation

production

progesterone

synthesis

progesterone

synthesis

progesterone


Input:
Tumor angiogenesis modulates leukocyte-vessel wall interactions in vivo by reducing endothelial adhesion molecule expression.

The expression of endothelial cell (EC) adhesion molecules involved in leukocyte-vessel wall interactions is suppressed in malignancies. In the present study, we investigated in vivo the regulation of leukocyte-vessel wall interactions by the presence of a tumor. By means of intravital microscopy, tumor necrosis factor alpha-stimulated leukocyte-vessel wall interactions were studied in ear skin microvessels of nude mice bearing small human LS174T colon carcinomas and in C57Bl/6 mice bearing murine B16F10 melanomas. Leukocyte-vessel wall interactions were studied both within and outside small tumors growing in the ear, and in ear microvessels of mice with a large tumor growing on their flank. Tumor-free mice were used as controls. Compared with values measured at the edge of the ear and in the contralateral ear, leukocyte adhesion was found to be diminished significantly in vessels inside the ear tumor in both mouse models. This reduction disappeared with increasing distance from the tumor. Surprisingly, the level of leukocyte adhesion in ear venules of mice with a large flank tumor was also reduced significantly. Leukocyte rolling, i.e., the step preceding adhesion, was not influenced by the presence of a tumor in nude mice, but was down-regulated in immune-competent C57Bl/6 mice. Treatment of mice bearing a small ear tumor with a humanized antivascular endothelial growth factor antibody prevented the down-regulation of leukocyte-vessel wall interactions inside the tumor vessels compared with the nontreated group. Fluorescence-activated cell sorter analysis showed that isolated tumor ECs have suppressed levels of intercellular adhesion molecule 1 as compared with ECs from normal mouse tissues. In cultured b.END5 cells the tumor necrosis factor alpha-induced up-regulation of intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 was reduced in ECs that were preincubated with basic fibroblast growth factor or vascular endothelial growth factor. The current results may have an impact on the effectiveness of clinical immunotherapeutic treatment protocols, because immune effector cells may not be able to enter tumor tissue.

interactions

leukocyte

vessel wall

interactions

leukocyte

vessel wall

interactions

leukocyte

vessel wall

interactions

leukocyte

vessel wall

interactions

Leukocyte

vessel wall

adhesion

leukocyte

adhesion

leukocyte

interactions

leukocyte

vessel wall

angiogenesis

Tumor

expression

endothelial adhesion molecule

expression

endothelial cell (EC) adhesion molecules

growing

tumors

growing

tumor

enter

immune effector cells

tumor tissue

reducing

angiogenesis

expression

diminished

adhesion

reduction

adhesion

reduced

adhesion

prevented

Treatment

down-regulation

down-regulation

interactions

suppressed

tumor ECs

intercellular adhesion molecule 1

reduced

up-regulation

Treatment

mice

humanized antivascular endothelial growth factor antibody

nontreated

mice

preincubated

ECs

basic fibroblast growth factor

preincubated

ECs

vascular endothelial growth factor

stimulated

tumor necrosis factor alpha

interactions

activated

cell

induced

tumor necrosis factor alpha

up-regulation

up-regulation

intercellular adhesion molecule 1

up-regulation

vascular cell adhesion molecule 1

modulates

interactions

reducing

involved

expression

interactions

regulation

interactions

tumor


Input:
Prognostic value of p53 protein expression and vascular endothelial growth factor expression in resected squamous cell carcinoma of the esophagus.

The most common genetic alterations found in a wide variety of cancers are p53 tumor suppressor gene mutations. p53 appears to be a nuclear transcription factor that plays a role in the control of cell proliferation, apoptosis, and the maintenance of genetic stability. Angiogenesis is a critical process in solid tumor growth and metastasis. Vascular endothelial growth factor (VEGF), a recently identified growth factor with significant angiogenic properties, may be a major tumor angiogenesis regulator. Few studies have investigated the association between p53 and VEGF expressions and prognosis in esophageal carcinoma. Forty-seven specimens resected from patients with stage II and III squamous cell carcinoma (SCC) of the esophagus were studied using immunohistochemical staining. VEGF and p53 expressions were observed in 40% and 53% of the tumors, respectively. The p53 and VEGF staining statuses were coincident in only 21% of the tumors, and no significant correlation was found between p53 and VEGF statuses. No clinicopathologic factors were significantly correlated with p53 or VEGF expression. No significant association between p53 and VEGF expressions and poor prognosis was found. In conclusion, p53 and VEGF were not correlated with prognosis in patients with stage II and III SCC of the esophagus.

Angiogenesis

angiogenic

angiogenesis

tumor

proliferation

cell

apoptosis

cell

expression

expression

vascular endothelial growth factor

expressions

expressions

VEGF

expressions

VEGF

expressions

expression

expression

VEGF

expressions

expressions

VEGF

growth

solid tumor

metastasis

solid tumor

resected

squamous cell carcinoma

resected

squamous cell carcinoma

control

proliferation

control

apoptosis

critical

Angiogenesis

growth

critical

Angiogenesis

metastasis

regulator

Vascular endothelial growth factor

angiogenesis


Input:
The role of organ vascularization and lipoplex-serum initial contact in intravenous murine lipofection.

Following intravenous administration of cationic lipid-DNA complexes (lipoplexes) into mice, transfection (lipofection) occurs predominantly in the lungs. This was attributed to high entrapment of lipoplexes in the extended lung vascular tree. To determine whether lipofection in other organs could be enhanced by increasing the degree of vascularization, we used a transgenic mouse model with tissue-specific angiogenesis in liver. Tail vein injection of N-(1-(2,3-dioleoyloxy)propyl)-N,N,N-trimethylammonium chloride (DOTAP)/cholesterol lipoplexes resulted in increased lipoplex entrapment in hypervascularized liver but did not boost luciferase expression, suggesting that lipoplex delivery is not a sufficient condition for efficient organ lipofection. Because the intravenously injected lipoplexes migrated within seconds to lungs, we checked whether the effects of immediate contact with serum correlate with lung lipofection efficiency of different DOTAP-based formulations. Under conditions mimicking the injection environment, the lipoplex-serum interaction was strongly dependent on helper lipid and ionic strength: lipoplexes prepared in 150 mM NaCl or lipoplexes with high ( greater than 33 mol%) cholesterol were found to aggregate immediately. This aggregation process was irreversible and was inversely correlated with the percentage of lung cells that took up lipoplexes and with the efficiency of lipofection. No other structural changes in serum were observed for cholesterol-based lipoplexes. Dioleoyl phosphatidylethanolamine-based lipoplexes were found to give low expression, apparently because of an immediate loss of integrity in serum, without lipid-DNA dissociation. Our study suggests that efficient in vivo lipofection is the result of cross-talk between lipoplex composition, interaction with serum, hemodynamics, and target tissue "susceptibility" to transfection.

aggregate

lipoplexes

cholesterol

aggregation

lipoplexes

cholesterol

vascularization

organ

vascularization

angiogenesis

liver

expression

luciferase

entrapment

lipoplexes

lung vascular tree

entrapment

lipoplex

liver

delivery

lipoplex

migrated

lipoplexes

lungs

lipofection

lipoplex

murine

administration

lipoplexes

mice

lipofection

organs

injection

Tail vein

N-(1-(2,3-dioleoyloxy)propyl)-N,N,N-trimethylammonium chloride (DOTAP)/cholesterol lipoplexes

lipofection

organ

injected

lipoplexes

lipofection

lung

DOTAP

lipofection

lung cells

lipoplexes

enhanced

lipofection

increasing

increasing

vascularization

resulted

injection

increased

increased

entrapment

boost

injection

expression

sufficient

delivery

lipofection


Input:
Proliferative diabetic retinopathy is associated with a low level of the natural ocular anti-angiogenic agent pigment epithelium-derived factor (PEDF) in aqueous humor. a pilot study.

Retinopathy is the most common microvascular diabetes complication and represents a major threat to the eyesight. The aim of this study was to address the role of pro- and anti-angiogenic molecules in diabetic retinopathy in the aqueous humor of the eye. Aqueous humor was collected at cataract surgery from 19 diabetic patients and from 13 age- and sex-matched normoglycemic controls. Levels of pro-angiogenic vascular endothelial growth factor (VEGF) and angiogenic inhibitor pigment epithelium-derived factor (PEDF) were determined. Angiogenic activity of the aqueous humor was quantified by measuring its effect on the migration of capillary endothelial cells. In the aqueous fluid, VEGF levels were increased in diabetics (mean values: 501 vs. 367 pg/ml; p = 0.05), compared to controls. PEDF was found to be decreased in diabetics (mean values: 2080 vs. 5780 ng/ml; p = 0.04) compared to controls. In seven diabetic patients with proliferative retinopathy, the most profound finding was a significant decrease of the PEDF level (mean value: 237 ng/ml), whereas VEGF levels were comparable to diabetic patients without proliferation (mean value: 3153; p = 0.003). Angiogenic activity in samples of patients from the control group was generally inhibitory due to PEDF, and inhibition was blocked by neutralizing antibodies to PEDF. Likewise, in diabetics without proliferation, angiogenic activity was also blocked by antibodies to PEDF. We will demonstrate here that the level of the natural ocular anti-angiogenic agent PEDF is inversely associated with proliferative retinopathy. PEDF is an important negative regulator of angiogenic activity of aqueous humor. Our data may have implications for the development of novel regimens for diabetic retinopathy.

angiogenic

ocular

angiogenic

angiogenic

angiogenic

Angiogenic

Angiogenic

angiogenic

angiogenic

angiogenic

migration

capillary endothelial cells

decreased

PEDF

decrease

PEDF

inhibitory

Angiogenic

PEDF

inhibition

Angiogenic

blocked

inhibition

neutralizing antibodies to PEDF

blocked

angiogenic

antibodies to PEDF

negative regulator

PEDF

angiogenic

collected

Aqueous humor

increased

VEGF

effect

aqueous humor

migration


Input:
Angiogenesis--biomedical technology.

All of these studies show that angiogenesis research can benefit from new biomedical technology tools currently being developed, as well as contribute by providing new technologies that can be used in other areas of medicine. It is hoped that the chapters in this book in this area will provide the reader with an up-to-date appreciation of some of the exciting research that is currently being pursued.

Angiogenesis

angiogenesis


Input:
Interleukin-1 receptor antagonist inhibits ischaemic and excitotoxic neuronal damage in the rat.

Interleukin-1 (IL-1) synthesis in the brain is stimulated by mechanical injury and IL-1 mimics some effects of injury, such as gliosis and neovascularization. We report that neuronal death resulting from focal cerebral ischaemia (middle cerebral artery occlusion, 24 h) is significantly inhibited (by 50%) in rats injected with a recombinant IL-1 receptor antagonist (IL-1ra, 10 micrograms, icv 30 min before and 10 min after ischaemia). Excitotoxic damage due to striatal infusion of an NMDA-receptor agonist (cis-2,4-methanoglutamate) was also markedly inhibited (71%) by injection of the IL-1ra. These data indicate that endogenous IL-1 is a mediator of ischaemic and excitotoxic brain damage, and that inhibitors of IL-1 action may be of therapeutic value in the treatment of acute or chronic neuronal death.

neovascularization

damage

neuronal

damage

brain

death

neuronal

death

neuronal

synthesis

inhibits

Interleukin-1 receptor antagonist

damage

inhibited

death

injected

rats

IL-1 receptor antagonist

infusion

injection

stimulated

synthesis

mediator

damage


Input:
Transcriptional and post-translation regulation of the Tie1 receptor by fluid shear stress changes in vascular endothelial cells.

The interaction between the vascular endothelium and hemodynamic forces (and more specifically, fluid shear stress), induced by the flow of blood, plays a major role in vascular remodeling and in new blood vessels formation via a process termed arteriogenesis. Tie1 is an orphan tyrosine kinase receptor expressed almost exclusively in endothelial cells and is required for normal vascular development and maintenance. The present study demonstrates that Tie1 expression is rapidly down-regulated in endothelial cells exposed to shear stress, and more so to shear stress changes. This down-regulation is accompanied by a rapid cleavage of Tie1 and binding of the cleaved Tie1 45 kDa endodomain to Tie2. The rapid cleavage of Tie1 is followed by a transcriptional down-regulation in response to shear stress. The activity of the Tie1 promoter is suppressed by shear stress and by tumor necrosis factor alpha. Shear stress-induced transcriptional suppression of Tie1 is mediated by a negative shear stress response element, localized in a region of 250 bp within the promoter. The rapid down-regulation of Tie1 by shear stress changes and its rapid binding to Tie2 may be required for destabilization of endothelial cells in order to initiate the process of vascular restructuring.

binding

45 kDa endodomain

binding

arteriogenesis

cleavage

cleaved

cleavage

formation

blood vessels

development

vascular

expressed

expression

down-regulated

expression

down-regulation

expression

down-regulation

transcriptional

suppressed

promoter

tumor necrosis factor alpha

suppression

transcriptional

down-regulation

destabilization

endothelial cells

exposed

endothelial cells

required

development

required

maintenance

induced

suppression

required

down-regulation

destabilization

required

binding

destabilization

initiate

restructuring

post-translation

Tie1 receptor

regulation

Transcriptional

regulation

post-translation

plays a major role

arteriogenesis

via

remodeling

arteriogenesis

via

formation

arteriogenesis

maintenance

vascular

mediated

suppression

negative shear stress response element

remodeling

vascular

restructuring

vascular

Transcriptional

Tie1 receptor

transcriptional

transcriptional


Input:
Therapeutic angiogenesis: a complex problem requiring a sophisticated approach.

Blood and vascular disorders underlie a plethora of pathologic conditions and are the single most frequent cause of human disease. Ischemia, involving restricted blood flow to tissues is the most common consequence of vessel dysfunction resulting in the disruption of oxygen and nutrient delivery and the accumulation of waste metabolites. Cells cannot survive extended severe ischemia but may be able to adapt to a moderate condition where diffusion to and from bordering nonischemic regions sustains vital functions. Under this condition, the secondary functions of effected cells are likely to be impaired, and a new metabolic equilibrium is established, determined by the level of cross-diffusion and degree of hypoxia. In tissues with a normally high metabolic turnover such as skeletal and cardiac muscle, even mild ischemia causes hypoxia, acidosis, and depressed function (contractility) and eventually threatens myocyte viability and organ function. Ischemic cardiac muscle is additionally vulnerable because reperfusion is essential for survival but reperfusion itself poses additional stress principally from increased production of free radicals during reoxygenation. The latter effect is called reperfusion injury and can cause as much damage as the ischemia. The treatment possibilities for ischemia-related vascular disease are limited. Lipid/cholesterol-lowering agents, diet and antiplatelet adherence (aspirin) therapy may help slow the progression of vessel disease in some instances; but surgical reconstruction may be the only option in advanced stages, and even this is not always an option. An alternative and rather obvious strategy to treat ischemia is to activate endogenous angiogenic or arteriogenic pathways to stimulate revascularization of the tissue. The feasibility of such a strategy has now been established through the results of studies over the past decade, and a new discipline called therapeutic angiogenesis has emerged. This review focuses on the application of therapeutic angiogenesis for treating ischemic muscle disease and includes a critical evaluation of the parameters and limitations of current procedures. The development of this technology has benefited from its application to both peripheral and coronary artery disease and results from both are reviewed here.

angiogenesis

angiogenic

arteriogenic pathways

revascularization

angiogenesis

angiogenesis

dysfunction

vessel

disruption

oxygen

survive

Cells

therapy

aspirin

activate

angiogenic

activate

arteriogenic pathways

stimulate

activate

revascularization

effected

cells


Input:
Expression, regulation, and function of IGF-1, IGF-1R, and IGF-1 binding proteins in blood vessels.

The vascular insulin-like growth factor (IGF)-1 system includes the IGFs, the IGF-1 receptor (IGF-1R), and multiple binding proteins. This growth factor system exerts multiple physiologic effects on the vasculature through both endocrine and autocrine/paracrine mechanisms. The effects of IGF-1 are mediated principally through the IGF-1R but are modulated by complex interactions with multiple IGF binding proteins that themselves are regulated by phosphorylation, proteolysis, polymerization, and cell or matrix association. During the last decade, a significant body of evidence has accumulated, indicating that expression of the components of the IGF system are regulated by multiple factors, including growth factors, cytokines, lipoproteins, reactive oxygen species, and hemodynamic forces. In addition, cross-talk between the IGF system and other growth factors and integrin receptors has been demonstrated. There is accumulating evidence of a role for IGF-1 in multiple vascular pathologies, including atherosclerosis, hypertension, restenosis, angiogenesis, and diabetic vascular disease. This review will discuss the regulation of expression of IGF-1, IGF-1R, and IGF binding proteins in the vasculature and summarize evidence implicating involvement of this system in vascular diseases.

interactions

IGF binding proteins

polymerization

IGF binding proteins

association

IGF binding proteins

cell

association

IGF binding proteins

matrix

angiogenesis

proteolysis

IGF binding proteins

Expression

Expression

Expression

IGF-1 binding proteins

expression

expression

expression

IGF binding proteins

system

insulin-like growth factor (IGF)-1

system

IGF

system

IGF

phosphorylation

IGF binding proteins

regulation

regulation

regulation

IGF-1 binding proteins

mediated

regulated

IGF binding proteins

phosphorylation

regulated

IGF binding proteins

proteolysis

regulated

IGF binding proteins

polymerization

regulated

IGF binding proteins

association

role

angiogenesis

regulation

expression


Input:
Morphogenesis of embryonic CNS vessels.

This chapter focuses on the morphology of blood vessel formation in and around the early central nervous system (CNS, i.e., brain and spinal cord) of avian embryos. We discuss cell lineages, proliferation and interactions of endothelial cells, pericytes and smooth muscle cells, and macrophages. Due to space limitations, we can not review the molecular control of CNS angiogenesis, but refer the reader to other chapters in this book and to recent publications on the assembly of the vasculature (1,2).

interactions

endothelial cells

interactions

pericytes

interactions

smooth muscle cells

interactions

macrophages

angiogenesis

CNS

proliferation

endothelial cells

proliferation

pericytes

proliferation

smooth muscle cells

proliferation

macrophages

Morphogenesis

embryonic CNS vessels

formation

blood vessel

assembly

vasculature

control

angiogenesis


Input:
The candidate tumour suppressor protein ING4 regulates brain tumour growth and angiogenesis.

Gliomas are the most common primary tumours of the central nervous system, with nearly 15,000 diagnosed annually in the United States and a lethality approaching 80% within the first year of glioblastoma diagnosis. The marked induction of angiogenesis in glioblastomas suggests that it is a necessary part of malignant progression; however, the precise molecular mechanisms underlying the regulation of brain tumour growth and angiogenesis remain unresolved. Here we report that a candidate tumour suppressor gene, ING4, is involved in regulating brain tumour growth and angiogenesis. Expression of ING4 is significantly reduced in gliomas as compared with normal human brain tissue, and the extent of reduction correlates with the progression from lower to higher grades of tumours. In mice, xenografts of human glioblastoma U87MG, which has decreased expression of ING4, grow significantly faster and have higher vascular volume fractions than control tumours. We show that ING4 physically interacts with p65 (RelA) subunit of nuclear factor NF-kappaB, and that ING4 regulates brain tumour angiogenesis through transcriptional repression of NF-kappaB-responsive genes. These results indicate that ING4 has an important role in brain tumour pathogenesis.

interacts

angiogenesis

brain tumour

angiogenesis

glioblastomas

angiogenesis

brain tumour

angiogenesis

brain tumour

angiogenesis

brain tumour

malignant progression

glioblastomas

progression

tumours

pathogenesis

brain tumour

Expression

expression

growth

brain tumour

growth

brain tumour

growth

brain tumour

grow

vascular

suppressor

tumour

reduced

Expression

gliomas

reduction

gliomas

decreased

expression

induction

angiogenesis

regulates

growth

regulates

angiogenesis

regulation

growth

regulation

angiogenesis

regulating

growth

regulating

angiogenesis

regulates

angiogenesis

has an important role

pathogenesis


Input:
TGFbeta1, back to the future: revisiting its role as a transforming growth factor.

TGFbeta1 was initially identified in culture media from transformed cells as part of a factor that could produce a transformed phenotype in a nontransformed cell line. Subsequently this activity was separated into TGFbeta and TGFalpha an EGF receptor ligand. With the discovery that TGFbeta1 was a potent growth inhibitor of epithelial cells, and the identification of inactivating mutations within the TGFbeta1 signaling pathway in cancers it became clear that TGFbeta1 signaling is a tumor suppressor pathway for early stages of cancer. However many human carcinomas overexpress TGFbeta1 and this is associated with poor patient prognosis and increased frequency of metastasis. Similar results have been obtained with tumor cell lines and experimental animal models. Thus stage specific duality of function is the emerging paradigm for the role of TGFbeta1 in cancer. This review will focus on the evidence for TGFbeta1 as a tumor promoting and metastasis factor and examine the biological and molecular basis for these effects. It is proposed that the switch from tumor suppressor to oncogene reflects genetic or epigenetic alterations in signaling pathways in tumor cells that alter the readout from the TGFbeta1 pathway.

overexpress

growth

epithelial cells

metastasis

carcinomas

metastasis

tumor

inactivating

signaling pathway

signaling pathway

signaling

pathway

increased

overexpress

metastasis

promoting

tumor

role

cancer

alter

pathway


Input:
Role of thrombin in angiogenesis and tumor progression.

Clinical, laboratory, histopathological, and pharmacological evidence support the notion that the coagulation system, which is activated in most cancer patients, plays an important role in tumor biology. Our laboratory has provided evidence that thrombin activates angiogenesis, a process which is essential in tumor growth and metastasis. This event is independent of fibrin formation. At the cellular level many actions of thrombin can contribute to activation of angiogenesis: (1). Thrombin decreases the ability of endothelial cells to attach to basement membrane proteins. (2). Thrombin greatly potentiates vascular endothelial growth factor- (VEGF-) induced endothelial cell proliferation. This potentiation is accompanied by up-regulation of the expression of VEGF receptors (kinase insert domain-containing receptor [KDR] and fms-like tyrosine kinase [Flt-1]). (3). Thrombin increases the mRNA and protein levels of alpha (v)beta (3) integrin and serves as a ligand to this receptor. Furthermore, thrombin increases the secretion of VEGF and enhances the expression and protein synthesis of matrix metalloprotease-9 and alpha (v)beta (3) integrin in human prostate cancer PC-3 cells. These results could explain the angiogenic and tumor-promoting effect of thrombin and provide the basis for development of thrombin receptor mimetics or antagonists for therapeutic application.

attach

Thrombin

basement membrane

angiogenesis

angiogenesis

angiogenesis

angiogenic

proliferation

endothelial cell

progression

tumor

expression

kinase insert domain-containing receptor

expression

fms-like tyrosine kinase

protein levels

alpha (v)beta (3) integrin

expression

matrix metalloprotease-9

expression

alpha (v)beta (3) integrin

growth

tumor

metastasis

tumor

secretion

VEGF

formation

fibrin

decreases

endothelial cells

attach

coagulation system

activated

coagulation system

activates

thrombin

angiogenesis

essential

angiogenesis

growth

essential

angiogenesis

metastasis

activation

thrombin

angiogenesis

induced

vascular endothelial growth factor

proliferation

up-regulation

expression

increases

Thrombin

mRNA

increases

Thrombin

protein levels

increases

thrombin

secretion

enhances

thrombin

expression

enhances

thrombin

protein synthesis

promoting

tumor

thrombin

Role

thrombin

angiogenesis

Role

thrombin

progression

plays an important role

coagulation system

tumor

potentiates

Thrombin

proliferation

mRNA

alpha (v)beta (3) integrin

protein synthesis

matrix metalloprotease-9

protein synthesis

alpha (v)beta (3) integrin


Input:
Matrix metalloproteinase activity and immunohistochemical profile of matrix metalloproteinase-2 and -9 and tissue inhibitor of metalloproteinase-1 during human dermal wound healing.

Proteolytic activity is required for the turnover of the extracellular matrix during wound healing. Matrix metalloproteinases can collectively cleave all components of the extracellular matrix, with the endogenous tissue inhibitor of metalloproteinase-1 regulating their activity. Breast tissue taken at varying postoperative times (n= 92) or during surgery (controls, n= 17), was used to investigate the temporal and spatial activity of matrix metalloproteinase-2 and -9 and tissue inhibitor of metalloproteinase-1 during human wound healing. Matrix metalloproteinase activity, determined using a quenched fluorescence substrate assay, increased during early healing (3-8 weeks) compared to controls, and then decreased between 24 and 36 weeks after surgery (p  less than  0.05 until 24 weeks, Mann-Whitney U-test). Immunohistochemistry scores for matrix metalloproteinase-9 expression were significantly elevated compared to controls in scar endothelial cells and fibroblasts from 2 until 12 and 20 weeks, respectively. Matrix metalloproteinase-2 staining was observed exclusively in fibroblasts, reaching maximum levels 8-12 weeks after surgery, decreasing by 1.5 years but remaining significantly increased. Tissue inhibitor of metalloproteinase-1 staining was relatively sparse but was significantly increased until 8 weeks after surgery. These results show that matrix metalloproteinases are present at elevated levels during early wound healing, when angiogenesis occurs, and suggest that matrix metalloproteinase-9 may play a significant role. The later expression of matrix metalloproteinase-2 and -9 in fibroblasts suggests a role in extracellular matrix remodeling.

angiogenesis

cleave

extracellular matrix

expression

matrix metalloproteinase-9

present

matrix metalloproteinases

expression

matrix metalloproteinase-2

expression

decreased

Matrix metalloproteinase

decreasing

Matrix metalloproteinase-2

cleave

Matrix metalloproteinases

cleave

increased

Matrix metalloproteinase

elevated

expression

increased

Matrix metalloproteinase-2

increased

Tissue inhibitor of metalloproteinase-1

elevated

present

regulating

Matrix metalloproteinases

tissue inhibitor of metalloproteinase-1

play a significant role

angiogenesis

matrix metalloproteinase-9

role

matrix metalloproteinase-2

remodeling

role

remodeling

turnover

extracellular matrix

remodeling

extracellular matrix


Input:
Enhanced IGF-1 expression improves smooth muscle cell engraftment after cell transplantation.

The functional benefit of cell transplantation after a myocardial infarction is diminished by early cell losses. IGF-1 enhances cell proliferation and survival. We hypothesized that IGF-1-transfected smooth muscle cells (SMCs) would enhance cell survival and improve engraftment after cell transplantation. The IGF-1 gene was transfected into male SMCs and compared with SMCs transfected with a plasmid vector (vector control) and nontransfected SMCs (cell control). IGF-1 mRNA (n=10/group) and protein levels (n=6/group) were higher (P  less than 0.05 for all groups) at 3, 7, and 14 days compared with controls. VEGF was also increased in parallel to enhanced IGF-1 expression. IGF-1-transfected cells demonstrated greater cell proliferation, stimulated angiogenesis, and decreased caspase-3 activity after simulated ischemia and reperfusion (P  less than 0.05 for all groups compared with vector or cell controls). A uniform left ventricular injury was produced in female rats using a cryoprobe. Three weeks later, 2 x 10(6) cells from three groups were implanted into the scar. One week later, IGF-1-transfected SMCs had increased myocardial IGF-1 and VEGF levels, increased Bcl2 expression, limited cell apoptosis, and enhanced vessel formation in the myocardial scar compared with the two control groups (P  less than 0.05 for all groups). The proportion of SMCs surviving in the implanted region was greater (P  less than 0.05) in the IGF-1-transfected group than in the vector or cell controls. Gene enhancement with IGF-1 improved donor cell proliferation, survival, and engraftment after cell transplantation, perhaps mediated by enhanced angiogenesis and reduced apoptosis.

angiogenesis

angiogenesis

proliferation

cell

proliferation

cell

proliferation

donor cell

losses

cell

survival

cell

survival

cell

apoptosis

SMCs

surviving

SMCs

survival

donor cell

engraftment

smooth muscle cell

engraftment

cell

formation

vessel

engraftment

donor cell

expression

expression

expression

decreased

limited

apoptosis

transplantation

smooth muscle cell

cell

transplantation

cell

transfected

smooth muscle cells

transplantation

cell

transfected

SMCs

transfected

SMCs

nontransfected

SMCs

transfected

cells

implanted

cells

transfected

SMCs

implanted

SMCs

transfected

transplantation

cell

Enhanced

expression

improves

expression

engraftment

enhances

proliferation

enhances

survival

enhance

smooth muscle cells

survival

improve

smooth muscle cells

engraftment

increased

VEGF

enhanced

expression

stimulated

angiogenesis

increased

increased

VEGF

increased

expression

enhanced

formation

enhancement

improved

enhancement

proliferation

improved

enhancement

survival

improved

enhancement

engraftment

enhanced

angiogenesis


Input:
[Glaucoma and ocular ischemic syndrome--case report]

PURPOSE: Ocular ischemic syndrome (OIS) is often poorly diagnosed and treated as primary open angle glaucoma or later on, as neovascular glaucoma. We present a 54 year old male, treated topical since 23 years for glaucoma and sent to our clinic for trabeculectomy because of rapid worsening of vision on right eye with bilateral total excavation of optic disc. MATERIAL AND METHODS: Observational case report. RESULTS: Because of typical signs of IOS (iris neovascularization, mid-peripheral dot and blot hemorrhages in both eyes, narrowed arterioles in right eye, following examinations were performed: Doppler ultrasonography of carotid arteries, digital subtractional angiography of the carotid vessels and magnetic resonance angiography. The examinations showed occlusion of the right common carotid artery and with 80% stenosis of the left common carotid artery, occlusion of abdominal aorta. After phacoemulsification with implantation of intraocular lens because of rapid intumescence cataract in the right eye, and endarterectomy of left external carotid artery, the neovascularization of the iris regressed in both eyes. CONCLUSION: In case of iris neovascularization or mid-peripheral hemorrhages the Doppler sonography of carotid arteries should be performed. Quick cooperation between ophthalmologist, radiologist and vascular surgeon following endarterectomy seems to stop progressing changes of ocular ischemic syndrome.

neovascularization

iris

neovascularization

iris

neovascularization

iris

regressed

neovascularization

treated

male

implantation

lens


Input:
Hypoxia-responsive element-mediated soluble Tie2 vector exhibits an anti-angiogenic activity in vitro under hypoxic condition.

Hypoxia-inducible factor-1 (HIF-1) is one of the key mammalian transcription factors and shows increased levels in both protein stability and intrinsic transcriptional activity during low oxygen tension. Hypoxia-activated functional HIF-1 protein binds to hypoxia-responsive elements (HRE) in the enhancers of several genes including VEGF, the major player in angiogenesis, and initiates their mRNA expression. The molecular mechanisms regulating the gene expression under hypoxic conditions could increase the therapeutic window of tumor-specific delivery systems. In this study, to examine hypoxia-specific production of anti-angiogenic therapeutic gene, we constructed 5 copies of HRE (5xHRE) of human VEGF linked to soluble Tie2 (sTie2) driven by minimal SV40 promoter (5xHRE/SV40/sTie2). Our data showed that under hypoxia the secreted sTie2 selectively inhibited tube formation and migration capacities of endothelial cells in vitro. Hence, we propose that the vector system, 5xHRE/SV40/sTie2, might be a useful tool for down-regulating tumor angiogenesis under hypoxic condition.

binds

hypoxia-responsive elements

VEGF

angiogenic

angiogenesis

angiogenic

angiogenesis

tumor

formation

tube

secreted

migration

endothelial cells

activity

angiogenic

inhibited

formation

inhibited

migration

down-regulating

angiogenesis

constructed

HRE

linked

HRE

initiates

expression

mediated

Hypoxia-responsive element

expression

VEGF


Input:
2-methoxyestradiol inhibits hypoxia-inducible factor 1alpha, tumor growth, and angiogenesis and augments paclitaxel efficacy in head and neck squamous cell carcinoma.

PURPOSE: Head and neck squamous cell carcinomas have been reported to overexpress hypoxia-inducible factor (HIF)-1alpha, a transcription factor that promotes expression of angiogenesis factors and resistance to programmed and therapy-induced cell death. 2-Methoxyestradiol (2ME2) is a natural compound with HIF-1alpha inhibitory activity that is currently being evaluated in phase 1 and 2 clinical trials for advanced solid tumors and multiple myeloma. To our knowledge, this is the first study to evaluate the effects of 2ME2 in head and neck squamous cell carcinoma. EXPERIMENTAL DESIGN: In the present study, we investigated the effects of 2ME2 alone and in combination with paclitaxel, an active agent in recurrent or advanced head and neck squamous cell carcinoma. RESULTS: 2ME2 exhibited antiproliferative and cytotoxic effects in a panel of five head and neck squamous cell carcinoma cell lines in the 0.5 to 10 micromol/L range, including induction of G2-M blockade, caspase-3/7 activation, and apoptosis at 48 hours. 2ME2 resulted in decreased nuclear HIF-1alpha-binding activity and affected the expression of downstream genes, such as bid, a proapoptotic bcl-2 family member, and vascular endothelial growth factor, a proangiogenic cytokine. The up-regulation of Bid (57.5% at 12 hours, P  less than  0.0006) and inhibition of vascular endothelial growth factor secretion (57.7% at 24 hours, P  less than  0.015; and 50.3% at 48 hours, P  less than  0.0006) could be partially attributed to the effects on HIF-1alpha, because HIF-1alpha small interfering RNAs produced similar effects. Finally, in vivo, in a xenograft model of head and neck squamous cell carcinoma using UM-SCC-11A cells, 2ME2 exhibited antitumor and antiangiogenic activity, as measured by CD31 immunostaining. CONCLUSIONS: These results provide support for the use of 2ME2 in combination with paclitaxel for the treatment of recurrent or advanced head and neck squamous cell carcinoma.

binding

angiogenesis

head and neck squamous cell carcinoma

angiogenesis

angiogenic

angiogenic

head and neck squamous cell carcinoma

death

cell

apoptosis

head and neck squamous cell carcinoma cell lines

overexpress

hypoxia-inducible factor (HIF)-1alpha

expression

bid

expression

bcl-2 family

expression

vascular endothelial growth factor

growth

tumor

secretion

vascular endothelial growth factor

inhibits

hypoxia-inducible factor 1alpha

inhibits

growth

inhibits

angiogenesis

inhibitory

decreased

binding

inhibition

secretion

activity

tumor

activity

angiogenic

clinical trials

solid tumors

clinical trials

myeloma

treatment

paclitaxel

head and neck squamous cell carcinoma

induced

death

induction

activation

induction

apoptosis

activation

activation

up-regulation

Bid

effects

head and neck squamous cell carcinoma

effects

head and neck squamous cell carcinoma

effects

paclitaxel

head and neck squamous cell carcinoma

exhibited

head and neck squamous cell carcinoma cell lines

affected

expression

effects

up-regulation

effects

inhibition


Input:
Expression and purification of the catalytic domain of human vascular endothelial growth factor receptor 2 for inhibitor screening.

Vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, can act in tumor-induced angiogenesis by binding to specific receptors on the surface of endothelial cells. One such receptor, VEGFR-2/KDR, plays a key role in VEGF-induced angiogenesis. Here, we expressed the catalytic domain of VEGFR-2 as a soluble active kinase using Bac-to-Bac expression system, and investigated correlations between VEGFR-2 activity and enzyme concentration, ATP concentration, substrate concentration and divalent cation type. We used these data to establish a convenient, effective and non-radioactive ELISA screening technique for the identification and evaluation of potential inhibitors for VEGFR-2 kinase. We screened 200 RTK target-based compounds and identified one (TKI-31) that potently inhibited VEGFR-2 kinase activity (IC50=0.596 microM). Treatment of NIH3T3/KDR cells with TKI-31 blocked VEGF-induced phosphorylation of KDR in a dose-dependent manner. Moreover, TKI-31 dose-dependently suppressed HUVEC tube formation. Thus, we herein report a novel, efficient method for identifying VEGFR-2 kinase inhibitors and introduce one, TKI-31, that may prove to be a useful new angiogenesis inhibitor.

binding

Vascular endothelial growth factor

endothelial cells

angiogenesis

angiogenesis

angiogenesis

formation

HUVEC tube

Expression

vascular endothelial growth factor receptor 2

expressed

inhibited

blocked

Treatment

phosphorylation

suppressed

formation

phosphorylation

KDR

Treatment

NIH3T3/KDR cells

induced

tumor

angiogenesis

induced

VEGF

angiogenesis

induced

VEGF

phosphorylation

act

angiogenesis

binding

plays a key role

angiogenesis

plays a key role

KDR

angiogenesis