METTL3-mediated downregulation of splicing factor SRSF11 is associated with carcinogenesis and poor survival of cancer patients.

OBJECTIVE:N6-methyladenosine (m6A) is one of the most abundant post-transcriptional modifications in eukaryotic RNA. As m6A modifications play an important role in RNA processing, abnormal m6A regulation caused by aberrant expression of m6A regulators is closely related to carcinogenesis. In this study, we aimed to determine the role of METTL3 expression in carcinogenesis, regulation of splicing factor expression by METTL3, and their effects in survival period and cancer-related metabolisms. MATERIALS AND METHODS:We investigated the correlation between each splicing factor and METTL3 in breast invasive ductal carcinoma (BRCA), colon adenocarcinoma (COAD), lung adenocarcinoma (LUAD) and gastric adenocarcinoma (STAD). Survival analysis was performed based on the expression of each splicing factor. To determine the molecular mechanism of SRSF11 in carcinogenesis, gene set enrichment analysis using RNA sequencing data was performed according to SRSF11 expression. RESULTS:Among the 64 splicing factors used for correlation analysis, 13 splicing factors showed a positive correlation with METTL3 in all four cancer types. We found that when METTL3 expression was decreased, the expression of SRSF11 was also decreased in all four types of cancer tissue when compared to that in normal tissue. Decreased SRSF11 expression was associated with poor survival in patients with BRCA, COAD, LUAD, and STAD. Gene set enrichment analysis according to SRSF11 expression showed that the p53/apoptosis, inflammation/immune response, and ultraviolet/reactive oxygen species stimulus-response pathways were enriched in cancers with decreased SRSF11 expression. CONCLUSIONS:These results suggest that METTL3 regulates SRSF11 expression, which could influence mRNA splicing in m6A modified cancer cells. METTL3-mediated downregulation of SRSF11 expression in cancer patients correlates with poor prognosis.