Metabolic Reprogramming by MYCN Confers Dependence on the Serine-Glycine-One-Carbon Biosynthetic Pathway.

Abstract

<i>MYCN</i> amplification drives the development of neuronal cancers in children and adults. Given the challenge in therapeutically targeting MYCN directly, we searched for MYCN-activated metabolic pathways as potential drug targets. Here we report that neuroblastoma cells with <i>MYCN</i> amplification show increased transcriptional activation of the serine-glycine-one-carbon (SGOC) biosynthetic pathway and an increased dependence on this pathway for supplying glucose-derived carbon for serine and glycine synthesis. Small molecule inhibitors that block this metabolic pathway exhibit selective cytotoxicity to <i>MYCN</i>-amplified cell lines and xenografts by inducing metabolic stress and autophagy. Transcriptional activation of the SGOC pathway in <i>MYCN</i>-amplified cells requires both MYCN and ATF4, which form a positive feedback loop, with MYCN activation of ATF4 mRNA expression and ATF4 stabilization of MYCN protein by antagonizing FBXW7-mediated MYCN ubiquitination. Collectively, these findings suggest a coupled relationship between metabolic reprogramming and increased sensitivity to metabolic stress, which could be exploited as a strategy for selective cancer therapy. SIGNIFICANCE: This study identifies a MYCN-dependent metabolic vulnerability and suggests a coupled relationship between metabolic reprogramming and increased sensitivity to metabolic stress, which could be exploited for cancer therapy.<i>See related commentary by Rodriguez Garcia and Arsenian-Henriksson, p. 3818</i>.