Pan-cancer analysis reveals CHRM2 as a biomarker for cancer prognosis and immunotherapy

Background: CHRM2 is a member of the muscarinic acetylcholine receptor gene, which plays an important role in many cancers. Methods: Differential expression of CHRM2 across cancers was analyzed using The Cancer Genome Atlas (TCGA) database, and survival analysis of CHRM2 was performed using the Kaplan-Meier method. Spearman correlation analysis was used to study the correlation between CHRM2 and tumor mutation burden and microsatellite instability, and immune cell infiltration in tumor tissues were analyzed by the ESTIMATE and CIBERSORT algorithms. The biological role of CHRM2 in cancer was investigated by gene set enrichment analysis, and drug sensitivity analysis was conducted using the CellMiner database. Results: CHRM2 expression was downregulated in most cancers, and low CHRM2 expression was associated with better prognosis, especially in BLCA and COAD. CHRM2 expression correlated significantly with clinical stage, TMB, MSI, and a variety of immune cells and immune factors. GSEA showed that CHRM2 was enriched in many functions and pathways, and drug sensitivity analysis showed that CHRM2 correlated positively with several c-Met inhibitors. Conclusion: CHRM2 may be a prognostic indicator, a potential biomarker and a therapeutic target for pan-cancer, especially BLCA and COAD.