Hypermethylated Colorectal Cancer Patients Present a Myc-Driven Hypermetabolism with a One-Carbon Signature Associated to Worsen Prognosis

• DOI: 10.20944/preprints202402.0487.v1
• Publication Date: 2024-02-09T10:23:16Z
• Authors: Christophe Desterke; Emmanuel Dornier

Colorectal cancer (CRC) is the second cause of cancer-related death where the CpG-island methylation pathways (CIMP) is associated to KRAS/BRAF mutations, two oncogenes rewiring cell metabolism, worst prognosis and resistance to classical chemotherapies. Despite this, the question of a possible metabolic rewiring in CIMPs has never been asked. Here we asked if metabolic dysregulations were associated to the methylation status of tumours by evaluating the transcriptome of CRC tumours. CIMP-high patients were found to present a hyper-metabolism activating mainly carbohydrates, folates, sphingolipids and arachidonic acid metabolic pathways. A third of these genes had epigenetic targets of Myc in their proximal promoter, activating carboxylic acid, tetrahydrofolate interconversion, nucleobase, and oxoacid metabolisms. Amongst the Myc signature, the expression of GAPDH, TYMS, DHFR, TK1 was enough to predict methylation levels, microsatellite instability (MSI) and mutations in the mismatch repair (MMR) machinery, which are strong indicators of responsiveness to immunotherapies. Finally, we discovered that CIMP patients harboured an increase in genes involved in the one-carbon metabolism, a pathway critical to provide nucleotides for cancer growth and methyl donors for DNA methylation which was associated to worse prognosis. Transcriptomics could hence become a tool to help clinicians stratify their patients better.