The m7G RNA modification in gastrointestinal cancers: mechanisms and therapeutic potential

The N7-methylguanosine (m7G) modification, an epigenetic transcriptional regulatory mechanism, plays a crucial role in the development of gastrointestinal malignant tumors. This modification, mediated by enzyme complexes such as methyltransferase-like 1 (METTL1)/WD repeat domain 4 (WDR4) and williams-beuren syndrome chromosome region 22 (WBSCR22)/tRNA methyl transferase activator subunit 11-2 (TRMT12), is widely distributed in messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), and non-coding RNA. Its abnormal expression is closely associated with the pathogenesis of various gastrointestinal tumors, including hepatocellular carcinoma, colorectal cancer, pancreatic cancer, and esophageal cancer. The METTL1/WDR4 complex enhances the translation efficiency of oncogenes by promoting tRNA m7G modification, thereby facilitating tumor cell proliferation, metastasis, and chemotherapy resistance. More importantly, the m7G modification significantly influences tumor cell resistance to chemotherapy, targeted therapy, and radiation therapy by regulating the epidermal growth factor receptor (EGFR) signaling pathway, autophagy processes, and DNA repair mechanisms. Therefore, m7G modification has dual potential as both a prognostic biomarker and a therapeutic target, and may provide a molecular basis for precision medicine in the treatment of gastrointestinal tumors.