  Background: RNA guanine-7 methyltransferase (RNMT) is one of the main
regulators of N7-methylguanosine, and the deregulation of RNMT correlated with
tumor development and immune metabolism. However, the specific function of RNMT
in pan-cancer remains unclear.
  Methods: RNMT expression in different cancers was analyzed using multiple
databases, including Cancer Cell Line Encyclopedia (CCLE), Genotype-Tissue
Expression Project (GTEx), and The Cancer Genome Atlas (TCGA). Cox regression
analysis and Kaplan-Meier analysis were used to estimate the correlation of
RNMT expression to prognosis. The data was also used to research the
relationship between RNMT expression and common immunoregulators, tumor
mutation burden (TMB), microsatellite instability (MSI), mismatch repair (MMR),
and DNA methyltransferase (DNMT). Additionally, the cBioPortal website was used
to evaluate the characteristics of RNMT alteration. The TISDB database was used
to obtain the expression of different subtypes. The Tumor Immune Estimation
Resource (TIMER) database was used to analyze the association between RNMT and
tumor immune infiltration. Gene set enrichment analysis (GSEA) was used to
identify the relevant pathways.
  Results: RNMT was ubiquitously highly expressed across cancers and survival
analysis revealed that its expression was highly associated with the clinical
prognosis of various cancer types. Remarkably, RNMT participates in immune
regulation and plays a crucial part in the tumor microenvironment. A positive
association was found between RNMT expression and six immune cell types
expression in colon adenocarcinoma, kidney renal clear cell carcinoma, and
liver hepatocellular carcinoma. Moreover, RNMT expression was highly associated
with immunoregulators in most cancer types, and correlated to TMB, MSI, MMR,
and DNMT. Finally, GSEA indicated that RNMT may correlate with tumor immunity.

Genomics