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PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
FOXF1 loss results in decreased ETV1 protein, and global loss of ETV1 chromatin binding.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Therefore, FOXF1 inhibition causes the reduction of KIT approximately by 2-to-eightfold than ETV1 inhibition does, while ETV1 knockdown showed no impact on FOXF1 expression.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
These data indicate that the regulation of FOXF1 in GIST may be pre-determined in ICCs precursors .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Heart and Neural Crest Derivatives Expressed 1 (HAND1) is a key TF involved in the placentation and morphogenesis of the heart , and its deficiency during embryogenesis can cause congenital cardiac defects or adult heart failure .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Similarly, HAND1 is involved in the transcriptional amplification of the KIT oncogene via its influence on the expression or protein interactions of the core TF network of KIT , including ETV1, HIC1 (hypermethylated in cancer 1), FOXF1 and other GIST-correlated protein, and G protein-coupled receptor 20(GPR20) .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Physiologically, Homeobox protein BarH-like 1 (BARX1) controls the development of gastric smooth muscle and spleen, as well as intestinal rotation .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Similar to HAND1, BARX1 is a TF localized in the nucleus, which is closely correlated with indolent and micro-GIST, albeit the underlying mechanism remaining unclear .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The c-Abl Src homology 3 domain-binding protein-2 (SH3BP2) has 561 amino acids, containing an SH3-binding proline-rich region, an N-terminal pleckstrin homology (PH) domain, and a C-terminal SH2 domain .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
It serves as a cytoplasmic adaptor protein, which is generally expressed in GIST cells.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The epigenetic silencing of SH3BP2 leads to decreased oncogenic KIT and PDGFRA expression at both mRNA and protein levels .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
SH3BP2 promotes the expression of mutant KIT via up-regulation of the expression of microphthalmia-associated transcription factors (MITF) and ETV1.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Conversely, KIT can expedite the expression of SH3BP2 and MITF, demonstrating a positive feedback loop that exists in these molecules .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Silencing of SH3BP2 induces miRNAs (miR-1246 and miR-5100) expression which targets MITF and ETV1, thus decreasing KIT expression .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
A recent study found that reconstitution/recombination of MITF restored KIT expression levels in SH3BP2-silenced cells and restored cell viability in mesenchymal tumors, while also reducing MITF and ETV1 expressions .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Meanwhile, SH3BP2 silence can also attenuate PI3K activation induced by KIT kinase .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
In GIST, TFs such as HAND and the core TF network constitutes a large positive feedback system for KIT mutant gene expression, and this positive feedback promotes the development of mesenchymal tumors.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The common regulatory mechanism of these transcription factors in the regulation of KIT-encoding genes is unclear warranted to be further investigated.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Epigenetic modifications are closely associated with genome-wide transcriptional regulation in cancer, and it has also been extensively studied in GIST pathogenesis, including progression and drug resistance.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
It refers to a stable heritable change in biological phenotype or gene expression without a change in nucleotide sequence .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The key molecular mechanisms of epigenetic modification of DNA and chromatin can be divided into four main categories: DNA and RNA methylation ; non-coding RNA; covalent post-translational histone modifications and non-covalent mechanisms .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
All epigenetic changes and regulation are mediated through epigenetic enzymes (EEs), the functions of which can be divided into three categories: writers (responsible for modifications); erasers (remove modifications); and readers (identify and direct these modifications to the correct location) .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
In KIT-mutated GIST, chromosomes are frequently lost at 1q, 13q, 14q, 22q, etc.,
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
involving Protein phosphatase 1A (PPM1A), kinesin family member 1B (KIF1B) and neurofibromin 2 (NF2) gene, but this loss does not occur in WT GIST, which show the alternative epigenetic alterations .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Therefore, in this section we explore the role of several epigenetic modifications in relation to KIT and the possible implications for future development.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
DNA methylation is generally the 5-methylcytosine that occurs on the CpG islands and is often described as a "silent" epigenetic marker that plays important role in the maintenance of imprinting, genomic stability, development, and gene regulation in cancer .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Endoglin (ENG, CD105), a transmembrane glycoprotein expressed on activated vascular endothelium and other cells, is a co-protein of the transforming growth factor-h (TGF-h) receptor system.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
High expression of the ENG gene has been demonstrated in human as well as in mouse model of GIST.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
And the elevated ENG expression in KIT oncogenic mutants appears to be indirectly mediated by DNA hypomethylation, but the mechanism of this DNA methylation regulation is not fully understood .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The DNA-binding insulator protein CCCTC-binding factor (CTCF) and cohesion define the boundaries of chromosomal domains, also called topologically associated domains (TADs) [99–101].
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
It is reported that the super-enhancer was shared by Anoctamin 1(ANO1), which encodes the GIST clinical biomarker also known as DOG-1 (‘Discovered on GIST-1’) and FGF3/4, which reside in a ~ 250 kb TAD flanked by boundaries that contain CTCF binding sites, and the adjacent TAD on the 11q side contains a large cluster of super enhancer (SE), was recently observed in SDH-defcient GIST.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
In SDH-defcient GIST, DNA CpG methylation replaced CTCF binding in the FGF and KIT locus leading to abnormal contact between the starter switch and oncogenes .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
So, it is postulated that in GIST, continuation of IM-based therapy for IM-resistant GIST might facilitate disease progression by promoting the malignant behavior of tumors in an FGF2-dependent manner.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Epi-transcriptional modifications are emerging as promising therapeutic targets in cancers.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The most important classification of RNA methylation is the modification of RNA , including N6-methyladenosine (m6A) and 5-Methylcytosine, etc. .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
As the most important classification of RNA methylation, the mechanism of MA modification has been described in the development and treatment of different tumors, such as liver cancer, breast cancer and non-small cell lung cancer [105–107].
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
N-methyladenosine of messenger RNA (mRNA), mainly occurring around the coding region or the stop codon of the 3´UTR, is the most abundant internal modification in mRNA.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The levels of methyltransferase-like 3 (METTL3) is elevated and confer to Imatinib resistance in GIST patients, because METTL3 mediate the mA modification on the 5’UTR of the multidrug transporter MRP1 mRNA, which facilitating MRP1 mRNA translation .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Besides, METTL3-mediated N6-methyladenosine (mA) modifications facilitate miR-25-3p maturation which progression of GIST .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The fat mass- and obesity-associated (FTO) gene, termed as obesity-related gene, is located on chromosome 16q12.2 and is repurposed as a mRNA N-methyladenosine (mA) demethylase.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
A series of small-molecule compounds targeting FTO is developing therapeutic option in acute myeloid leukemia (AML) .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Epigenetic modifications of histones, including methylation, phosphorylation, ubiquitination and acetylation, are the key processes for genes expression in GIST oncogenesis.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Lysine (K)-specific demethylase 4D (KDM4D), as a histone demethylase, is overexpressed in GIST and promotes the progression of GIST via HIF1β/VEGFA signaling .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Bromodomain-containing protein 4 (BRD4) is a member of bromodomain and extra-terminal domain-containing (BET) family that include the proteins of BRD2, BRD3, BRD4, and BRDT.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
These proteins function as “readers” that tether acetylated lysine residues to both histone and non-histone proteins such as TF, and control genes expression.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Accumulating evidences showed that BRD4 can regulate the nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) signaling, as a determinant in the progression of various cancers .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
In GIST, BRD4 binds the acetylated lysine in histones or TF in enhancer or recruited pTEFb to initiate NFκB-dependent acetylated histones, promoting the transcription of c-KIT and C–C motif chemokine ligand 2 (CCL2), which is a chemokine recruiting macrophages to tumor functions as an immunosuppressor .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Monocytic zinc finger (MOZ) is a histone acetyltransferase that mediate the activation of histone acetylation in a complex with other molecules .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Using Genome-scale CRISP screening, the chromatin modifying enzymes, KAT6A/MOZ and KMT2A/MLL1 was found to be co-dependent and co-localized with GIST-associated genes and regulate oncogenic transcription and cell cycle progression by regulating transcription factor gene expression programs .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
KMT2A/MLL1 combined with Menin-MLL complex, is responsible for H3K4 methylation and transcription activation.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Small molecules against MOZ or Menin remarkably reduced GIST tumor growth with synergistic toxicity in vivo and in vitro with the combination of KIT inhibitors .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Non-coding RNAs (ncRNAs) are functional RNAs that is not be translated to proteins but as messager RNAs(mRNAs) functioning as regulators .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Micro-RNAs (miRNAs), a subtype of ncRNAs, are small endogenous RNAs of 19 ~ 22 nucleotides (nt) that regulate post-transcriptional silencing of target genes, usually in the 3′UTR .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Long non-coding RNAs (lncRNAs) are another important ncRNAs with more than 200nt transcripts.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
LncRNAs can fine-tune the expression of neighbor genes in a distinct context-dependent way via multifaceted mechanisms .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The largest study on miRNAs on primary tumors and metastases highlighted perpetuation of miRNAs features in metastatic lesions and that the primary origin appears to be the main determinant of the metastases miRNA profile .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
miR-218 which is a tumor suppressor directly bind to the 3’-UTR domain of relevant mRNA in lung cancer .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Similarly, in KIT-mutant GIST cells, miR-218 can exert its silencing effect on KIT expression by the direct bond to the 3′UTR of the KIT mRNA .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The Imatinib-resistant cell line, GIST430, can be re-sensitized to imatinib when the cells are transfected with miR-218, which possibly targets the PI3K/AKT pathway, KIT, or/and STAT3 molecules .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
MiR-148b-3p was largely described in the constraints of neoplastic transformation .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
By binding to the nucleotides 1378–1393 and 1639–1656 of the 3’-UTR of KIT mRNA, miR-148b-3p can directly down-regulate the level of KIT transcript.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
However, a negative feedback loop causing KIT overexpression with an unknown mechanism offset the inhibitory role of miR-148b-3p.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Therefore, miR-148b-3p alone shows no impact on the GIST cells, although it can synergize with IM to suppress the invasion and proliferation of GIST cells.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The correlation between downregulation of miRNA-221/222 and KIT expression was reported in several studies, indicating a tumor suppressor-miR in GIST .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
In vitro, the over-expression of miRNA-221/222 causes cell cycle arrest, apoptosis induction, and the inhibition of cell proliferation via decreasing KIT expression in erythroleukemic cells and erythropoiesis .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
It binds to 3’UTR of KIT mRNA, where the rs17084733 variant interrupts the binding site of miR-221/222 in GIST cells .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
In addition, the expression of other miRNAs, including miR-142-5p , miR-9, miR-370, miR-494, and miR-501 , was negatively associated with the expression of the KIT gene in GIST cells.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
MiR-494 overexpression caused KIT downregulation and the reduction of its downstream p-AKT and p-STAT3 proteins via decreasing the expression of survivin (BIRC5), an important TF for KIT, which phenotype the KIT inhibition in GIST 882 .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Additionally, miR-17–92, miR-200b-3p and miR20a cluster strongly downregulate the mRNA levels of the ETV1, which is the key TF in the regulation of the KIT gene .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
The lncRNA coiled-coil domain-containing 26 (CCDC26) was identified as a retinoic acid-dependent modulator and plays an important role in the pathogenesis of glioblastoma .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
CCDC26 can inhibit cell proliferation via directly decreasing the KIT expression in myeloid leukemia .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
It also interacts with c-KIT as shown by the assay of RNA pull-down.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
CCDC26 knockdown increases the level of c-KIT mRNA, up-regulates insulin-like growth factor 1 (IGF-1R) expression, resulting in IM resistance, whereas IGF-1R inhibition reversed IM resistance .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
H19 and FOXF1 adjacent non-coding developmental regulatory RNA (FENDRR) are oncogenic lncRNAs that are associated with cancer invasion, proliferation, and migration in various types of cancers .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Their expressions vary in GIST tissue, where H19 is 25.8-fold while FENDRR is 4.7-fold, both were in comparison to normal adjacent tissues .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Highly positive correlations between H19 and ETV1 were found in GIST cells, maybe via MEK and ERK pathways, as detected in colorectal cancer , and the mechanism underlining the regulation of FENDRR on the expression of KIT is not yet fully explored (Table 2).
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Table 2Non-coding RNA associated with c-KITncRNACell linesMechanism of actionFunctionRefmiR-218H1975, A549, GIST882,GIST48, GIST-T1, GIST430Targeting IL-6/STAT3 signaling pathway,Targeting PI3K/AKT signaling pathwaySuppress[122–125]miR-148b-3pGIST882Directly binding to the 3’-UTR of the KIT mRNASuppressmiR-221/222TF-1, HL60, GIST882, GIST48, GIST-T1Targeting KIT/AKT signaling pathwayDirectly binding to the 3’-UTR of the KIT mRNASuppress[47, 127–129]miR-142-5pGIST882, GIST-T1miR-9miR-370miR-501miR-494GIST430, GIST882Downregulate surviving (BIRC5)SuppressmiR17-92GIST882, GIST-T1Directly binding to the 3’-UTR of the KIT mRNADownregulate ETV1SuppressmiR-20amiR-375-3pGIST-T1Directly binding to the 3’-UTR of the KIT mRNADownregulate ETV1miR-200b-3pCCDC26HL60, GIST882,GIST-T1Suppress[137–139]H19FENDRR Non-coding RNA associated with c-KIT H1975, A549, GIST882, GIST48, GIST-T1, GIST430 Targeting IL-6/STAT3 signaling pathway, Targeting PI3K/AKT signaling pathway Targeting KIT/AKT signaling pathway Directly binding to the 3’-UTR of the KIT mRNA Directly binding to the 3’-UTR of the KIT mRNA Downregulate ETV1 Directly binding to the 3’-UTR of the KIT mRNA Downregulate ETV1 HL60, GIST882, GIST-T1 The vast majority (95%) of GIST express KIT protein which is usually higher in the GIST with KIT mutations than those without KIT mutations .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Upon the IM treatment, c-KIT oncoprotein was substantially up-regulated, hinting as a protective mechanism for GIST cells to escape from TKIs, which was widely accepted as one of the major resistance mechanisms (Fig. 2).Fig.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
2Regulations in KIT protein and signaling pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
LMTK3 directly promotes KIT protein translation, but also inhibit the expression of PKC (PKC-θ) and KIT phosphorylation.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
LIX1 controls MAPK pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Hedgehog pathway has two activate models: with ligands, HHs binding to the receptors, Patched-1/2, initiate the Hh pathway and inhibit SMO; without ligands, SMO starts to activate different GLIs, GLI1/2 up-regulate the KIT mRNA level, while GLI3 down-regulates KIT mRNA levels via the proteasome pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
There are three classic intracellular signaling pathways for KIT activation, respectively Ras-Erk pathway, PI3K-AKT pathway and JAK-STAT pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Ras-Erk pathway and PI3K-AKT pathway have crosstalk with Hh pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
FGF2 binds to and activates its receptors FGFR (FGFR3), mediating the reactivation of mutant KIT and JAK-STAT pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
AMPD3 also promotes the JAK-STAT pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
FGFR3 and AMPD3 both form a positive protein–protein feedback loop with mutant KIT.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
MiRNA-218 can inhibit JAK-STAT pathway and P55PIK can promote PI3K-AKT pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
ACK1 activates the MAPK pathway and the PI3K pathway, whereas lix1 may only regulates the MAPK pathway Regulations in KIT protein and signaling pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
LMTK3 directly promotes KIT protein translation, but also inhibit the expression of PKC (PKC-θ) and KIT phosphorylation.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
LIX1 controls MAPK pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Hedgehog pathway has two activate models: with ligands, HHs binding to the receptors, Patched-1/2, initiate the Hh pathway and inhibit SMO; without ligands, SMO starts to activate different GLIs, GLI1/2 up-regulate the KIT mRNA level, while GLI3 down-regulates KIT mRNA levels via the proteasome pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
There are three classic intracellular signaling pathways for KIT activation, respectively Ras-Erk pathway, PI3K-AKT pathway and JAK-STAT pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Ras-Erk pathway and PI3K-AKT pathway have crosstalk with Hh pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
FGF2 binds to and activates its receptors FGFR (FGFR3), mediating the reactivation of mutant KIT and JAK-STAT pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
AMPD3 also promotes the JAK-STAT pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
FGFR3 and AMPD3 both form a positive protein–protein feedback loop with mutant KIT.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
MiRNA-218 can inhibit JAK-STAT pathway and P55PIK can promote PI3K-AKT pathway.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
ACK1 activates the MAPK pathway and the PI3K pathway, whereas lix1 may only regulates the MAPK pathway Protein translation was another rate-limiting process of KIT expression.
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Lemur tyrosine kinase-3 (LMTK3) is a kind of serine/threonine kinase that regulates genes transcription, translation, and the stability of proteins via chromatin condensation and binding of the chromatin to the nuclear periphery, or tethers to DNA region for its function as tumorigenesis-promoting .
PMC10898159
KIT mutations and expression: current knowledge and new insights for overcoming IM resistance in GIST
Intriguingly, LMTK3 specifically modulates KIT gene-specific translation in GIST and melanoma cells, but not in the mast cell line and primary leukemia.