Changes in the energetic metabolism are generally observed in cancer cells, the so-called Warburg effect31. In agreement, Seahorse analyses demonstrated the clear metabolic reprogramming of transformed iNPCs (Fig. 1f,g). RNA expression analyses highlighted the upregulation of glycolytic genes typically associated with metabolic alterations in GTICs in the transformed iNPCs, including: PKM2; HK; GLUT3 (a gene recently described as critical for glucose uptake in GTICs)6; and LDHB (a gene commonly upregulated in gliomas bearing IDH mutations)32 (Supplementary Fig. 3a). Higher lactate production and lower glucose consumption in transformed iNPCs revealed significant differences in the lactate/glucose ratio (Supplementary Fig. 3b). Non-labelled mass spectrometry highlighted, as before, higher similarities between p53KD- and WTiNPCs, an intermediate profile in Ras/EGFR/SrciNPCs and marked differences in the levels of metabolites involved in carbon and aminoacid metabolism in p53KD-Ras/EGFR/SrciNPCs (Supplementary Fig. 3c). Next, U-13C glucose labelling was used to monitor carbon flux in the transformed iNPCs as compared with WTiNPCs. No significant differences in levels of production of glycolytic metabolites were found among the four lines, except for increased glucose flux into lactate and glycine in p53KD-Ras/EGFR/SrciNPCs, (Supplementary
