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PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Scale bars, 50 μm.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
d, Summary of treatment effects.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Cell cycle and MYCN programmes are downregulated at the protein level owing to translation inhibition and immature cancer cells are driven into neuronal differentiation.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
In a,c, RNA-seq: ProArg-free DFMO: n = 5; CD: n = 4.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Ribo-seq: n = 5.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Proteomics: ProArg-free DFMO: n = 6; CD: n = 5.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Panel d created in BioRender.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Morscher, R. (2025) https://BioRender.com/kk9n051.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Source data Given the essential role of MYCN in the development and maintenance of neuroblastoma and its positive feedback loop with ODC1 and eIF5A, we explored whether the loss of MYC targets indicates a disruption of the core oncogenic regulatory circuit.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Both MYCN mRNA expression and MYCN protein were preferentially downregulated in tumours under combined ProArg-free diet plus DFMO treatment (Fig. 6b and Extended Data Fig. 9c).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Other core transcription factors were also suppressed, supporting a broad disruption of the MYCN-driven core regulatory circuit (Extended Data Fig. 9d,e).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Despite MYCN downregulation, its transcriptional targets in the polyamine pathway remained unchanged or were upregulated in response to polyamine depletion in vivo (Extended Data Fig. 9f–h) or pharmacological inhibition in vitro (Extended Data Fig. 9i).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Further, TP53 expression remained unaffected on the protein or ribosome level (Extended Data Fig. 9j,k).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
On the mechanistic level, modulating MYC or MYCN activity by genetic or pharmacological means showed no pausing of ribosomes at codons with adenosine in the third position, suggesting a MYC-independent translation phenotype as a driver (Supplementary Fig. 7a–h).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Evaluating tumour differentiation status according to clinical pathological criteria showed that tumours in the CD and ProArg-free groups were uniformly undifferentiated (<5% cytologic differentiated with absent neuropil).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
By contrast, we observed a strong differentiation phenotype upon polyamine-depleting treatment, with one-third of CD plus DFMO-treated tumours being differentiated (more than 5% cytologic differentiated with absent neuropil) and two thirds of ProArg-free diet plus DFMO-treated tumours differentiating or partially differentiating with abundant neuropil (a feature of neural differentiation; Fig. 6c and Extended Data Fig. 10a).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Thus, combining a ProArg-free diet with DFMO therapy led to marked reductions in polyamines, inducing selective translation defects that suppressed tumour cell proliferation and induced tumour differentiation (Fig. 6d).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The therapeutic relevance of combining dietary amino acid depletion with DFMO was further emphasized in a model using established patient-derived neuroblastoma cell line xenografts in mice (Extended Data Fig. 10b–e).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Replicating the genetic model, long-term survival beyond 100 days and apparent cures were observed in one-quarter of the ProArg-free diet plus DFMO-treated mice and treatment was well tolerated without weight changes (Extended Data Fig. 10f,g).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Whereas on the gene-expression level MYCN and ODC1 were unchanged, MYCN protein expression was decreased independently of ODC1 (Extended Data Fig. 10h,i).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Mechanistically decreased proliferation was confirmed by histology, along with a pro-differentiation phenotype (Extended Data Fig. 10j,k), highlighting the role of enhanced polyamine depletion inducing differentiation for treatment of neuroblastoma.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Here we find that neuroblastoma, a highly malignant childhood cancer, is vulnerable to polyamine depletion achieved by the combination of a diet free of proline and arginine to deplete the polyamine precursor ornithine, and pharmacological inhibition of ODC, the committed step of polyamine synthesis, with high-dose DFMO.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The diet plus drug combination markedly enhanced polyamine depletion and exerted a strong anti-cancer effect in a highly lethal transgenic mouse neuroblastoma model, and a human neuroblastoma mouse xenograft model, with durable complete responses in both.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Use of defined diet and drug combinations is emerging as a clinically viable strategy for cancer treatment.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Ketogenic diet can synergize with classical chemotherapy and targeted agents, and can be achieved, with proper support, by patients making careful food choices (NCT05300048 and NCT01535911).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Diets lacking certain amino acids require laboratory formulation, but show acceptable taste and desired metabolic effects in humans, and are also entering cancer efficacy trials (NCT05078775).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Such diets show effects resembling enzyme-based treatments that catabolize particular amino acids, such as asparaginase, a long-standing standard of care for treating childhood leukaemias.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
In some cases, however, diets have important advantages.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
For example, dietary arginine depletion decreases both arginine and ornithine, whereas arginase therapy depletes arginine by converting it into the polyamine precursor ornithine.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Conversely, refeeding has been shown to induce polyamine biosynthesis in intestinal stem cells, triggering tumorigenicity.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Thus, preventing intestinal interconversion of substrates through a dietary approach or alternative interventions suitable for achieving ornithine depletion offer an effective combination with DFMO to deplete polyamines.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Arrested cellular differentiation by retained embryonal gene-expression circuits is a hallmark of paediatric cancers.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Neuroblastoma is a prime example, with hyperactive MYCN driving embryonal programmes.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Induction of differentiation through transcriptional reprogramming is a validated therapeutic strategy, exemplified by the nuclear hormone receptor agonist retinoic acid.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Here we provide evidence for the feasibility of triggering differentiation in paediatric cancers through proteome reprogramming.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Specifically, we find that polyamine depletion promotes the translation of pro-differentiation proteins and suppresses that of cell cycle proteins, leading to neuronal differentiation of neuroblastoma.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Whether similar benefits could be achieved in other MYC-driven cancers merits investigation.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The selective effect of polyamine depletion on translation of certain genes was unexpected, and was not driven by genetic ablation of eIF5A hypusination.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The underlying biochemistry involves polyamine deficiency shifting codon optimality by impairing translation of codons with adenosine at the wobble base by position 34-modified tRNAs, and codons being thus preferentially enriched (or depleted) in different gene sets.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
This mechanism raises the possibility that codon usage has evolved in tandem with metabolism, such that metabolic limitation acts on translation of specific codons to rewire the proteome.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Specifically, our data point to polyamine depletion suppressing proliferation and promoting differentiation via utilization of codons with adenosine in the third position.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
This programme may have evolved to support proper developmental decisions, but using diet and pharmacology, it has therapeutic potential in treating neuroblastoma.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Flash-frozen primary neuroblastoma tumour samples were provided by the Children’s Oncology Group (COG) under study number ANBL16B2 Q. International Neuroblastoma Pathology Classification histologic parameters, MYCN amplification status, age and stage for every patient was obtained centrally via the COG Statistics and Data Center.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Tumour cell content of samples was confirmed over 80% percent.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Patient and tumour characteristics are given in Supplementary Table 1.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Water-soluble metabolites were extracted and analysed as described below.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Animal studies followed protocols approved by Princeton University and Children’s Hospital of Philadelphia Institutional Animal Care and Use Committees.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
For xenografts used for metabolomics, cancer cell lines were grown in RPMI supplemented with 10% FBS and 0.01% insulin/transferrin solution.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Cell lines were provided by the COG Cell Culture Repository: LA-N-5, SMS-SAN, CHLA-90 and SK-N-SH.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
All cell lines repeatedly tested negative for Mycoplasma.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Subcutaneous xenografts were established on 6-week-old female CD1-nu mice by injection of 100 μl 50/50 RPMI/Matrigel solution containing 10 cells of the respective cell line.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
For xenografts used in therapeutic trials, tumours were established on 4- to 6-week-old female NCr-nu mice (Charles River) by injection of 100 μl 50/50 RPMI/Matrigel solution containing 3 × 10 IMR5 cells (MYCN amplified, ALK amplified).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Mice were randomized to specific treatment when tumours were ≥200 mm.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Mice were sacrificed when tumours were 2,000 mm.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Tumour mass was inferred using tumour volume using volume to mass of xenograft conversion described in McLean et al.. The Th-MYCN mouse model was used to investigate the functional changes of metabolism driven by MYCN.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
129×1/SvJ mice transgenic for the Th-MYCN construct were originally obtained from B. Weiss.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Th-MYCN hemizygous mice were bred and litters randomized to assigned therapy.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Mice were genotyped from tail-snip-isolated DNA using quantitative PCR and only transgene-homozygous mice (Th-MYCN) were included in these studies.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
In this model, MYCN expression is targeted to the mouse neural crest under the tyrosine hydroxylase promoter, recapitulating hallmark features of human neuroblastoma.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Tumours arise at autochthonous sites in an immunocompetent host with histologic, genomic, and immune similarities to human neuroblastoma.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Tumours are fully penetrant with onset prior to day 14 in >75% based on histologic audits and are lethal by 7 weeks.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Mice were maintained with 12 h of dark daily (18:00 to 06:00).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The rodent holding rooms were maintained at a temperature range of 18.9 °C–25.6 °C with an ideal setpoint of 22.2 °C.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The humidity was maintained within a range of 30–70% with an ideal setpoint of 50%.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Tissues and tumours were collected from mice in fed state and immediately clamped into liquid nitrogen using Wollenberger clamp.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
All tissues were stored in −80 °C.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Frozen tissues were transferred to 2 ml Eppendorf tubes, which were precooled on dry ice, and then pulverized using Cyromill.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The resulting tissue powder was weighed (around 10 mg) and mixed well by vortexing in extraction buffer (40 μl extraction buffer per mg tissue).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The extraction solution was neutralized with NH4HCO3 as above and centrifuged in a microfuge at maximum speed for 30 min at 4 °C.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Supernatant was transferred to LC–MS vials for analysis.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Blood samples were drawn from mouse tail veins using a microvette and kept on ice.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
After centrifugation (10 min, benchtop microfuge maximum speed, 4 °C), serum was collected in a 1.5 ml tube and stored at −80 °C.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Five microlitres of serum were mixed with 200 μl extraction buffer (40:40:20 acetonitrile: methanol: water with 0.5% formic acid) and neutralized with 15% NH4HCO3.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
After centrifugation (30 min, benchtop microfuge maximum speed, 4 °C), supernatant was transferred to LC–MS vials for analysis.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Metabolomics was performed on the following systems.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
A quadrupole-orbitrap mass spectrometer (Q Exactive, Thermo Fisher Scientific), operating in positive or negative mode was coupled to hydrophilic interaction chromatography (HILIC) via electrospray ionization.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Scans were performed from m/z 70 to 1,000 at 1 Hz and 140,000 resolution.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Liquid chromatography separation was on a XBridge BEH Amide column using a gradient of solvent A (20 mM ammonium acetate, 20 mM ammounium hydroxide in 95:5 water:acetonitrile, pH 9.45) and solvent B (acetonitrile).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Flow rate was 150 μl min.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The liquid chromatography gradient was: 0 min, 85% B; 2 min, 85% B; 3 min, 80% B; 5 min, 80% B; 6 min, 75% B; 7 min, 75% B; 8 min, 70% B; 9 min, 70% B; 10 min, 50% B; 12 min, 50% B; 13 min, 25% B; 16 min, 25% B; 18 min, 0% B; 23 min, 0% B; 24 min, 85% B. Autosampler temperature was 5 °C, and injection volume was 5–10 μl.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Complementary, primary samples analysed on an Exactive (Thermo Fisher Scientifc) operating in negative ion mode.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Liquid chromatography separation was achieved on a Synergy Hydro-RP column (100 mm × 2 mm, 2.5 μm particle size, Phenomenex), using reversed-phase chromatography with the ion pairing agent tributylamine in the aqueous mobile phase to enhance retention and separation.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
An adaptive scan range was used with an m/z from 85–1,000.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Resolution was 100,000 at 1 Hz.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The total run time was 25 min with a flow rate at 200 μl min.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Solvent A is 97:3 water/methanol with 10 mM tributylamine and 15 mM acetic acid; solvent B is methanol.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The gradient is 0 min, 0% B; 2.5 min, 0% B; 5 min, 20% B; 7.5 min, 20% B; 13 min, 55% B; 15.5 min, 95% B; 18.5 min, 95% B; 19 min, 0% B; 25 min, 0% B. Metabolomics data analysis was performed using ElMaven software (https://github.com/ElucidataInc/ElMaven).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
For labelling experiments, correction for natural abundance of C was performed using Accucor (https://github.com/XiaoyangSu/AccuCor).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Th-MYCN mice were housed in groups and food was supplied without restriction to guarantee sufficient supply.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Mice weights were recorded every day.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
During experiments mice were freely moving and tissues and serum were analysed following the above-mentioned method.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Tumour and inter organ cooperativity in proline, arginine and ornithine biosynthesis was analysed on the whole-body level.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The mice were on normal light cycle (06:00–18:00).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
In vivo infusion was performed on 6- to 7-week-old normal Th-MYCN mice pre-catheterized in the right jugular vein and C metabolite tracers were infused for 2.5–5 h to achieve isotopic pseudo-steady state.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
The mouse infusion setup included a tether and swivel system, connecting to the button pre-implanted under the back skin of mice.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Mice were fasted from 09:00 to 14:00 and infused from 14:00 to 16:30.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Tracers were dissolved in saline and infused via the catheter at a constant rate (0.1 μl min per g mouse weight) using a Just infusion Syringe Pump.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
One-hundred millimolar [U-C]glutamine was dissolved and infused for 2.5 h, 40 mM [U-C]arginine was infused for 5 h, 200 mM [U-C]glucose was infused for 5 h, 10 mM [U-C]proline for was infused 5 h and 5 mM [U-C]ornithine was infused for 5 h. At the end of infusion, mice were dissected and tissues were clamped in aluminium foil and stored in liquid nitrogen.
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
ArgPro-free diet was purchased from TestDiet Baker (1812426 (5CC7) for CD, 1816284-203 (5WYF) for ProArg-free diet, 1819015-203 (5WZ3) for arginine-free diet and 1816284-203 (5BDL) for proline-free diet).
PMC12527938
Reprogramming neuroblastoma by diet-enhanced polyamine depletion
Detailed makeup is given in Supplementary Table 2.