Cutaneous melanoma (CM) is an aggressive cancer; given that initial and specific signs are lacking, diagnosis is often late and the prognosis is poor. RNA modification has been widely studied in tumour progression. Nevertheless, little progress has been made in the signature of N1‐methyladenosine (m1A), 5‐methylcytosine (m5C), N6‐methyladenosine (m6A)‐related regulators and the tumour microenvironment (TME) cell infiltration in CM. Our study identified the characteristics of m1A‐, m5C‐ and m6A‐related regulators based on 468 CM samples from the public database. Using univariate, multivariate and LASSO Cox regression analysis, a risk model of regulators was established and validated by a nomogram on independent prognostic factors. The gene set variation analysis (GSVA) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) clarified the involved functional pathways. A combined single‐sample gene set enrichment analysis (ssGSEA) and CIBERSORT approach revealed TME of regulator‐related prognostic signature. The nine‐gene signature stratified the patients into distinct risk subgroups for personalized prognostic assessment. Additionally, functional enrichment, immune infiltration and immunotherapy response analysis indicated that the high‐risk group was correlated with T‐cell suppression, while the low‐risk group was more sensitive to immunotherapy. The findings presented here contribute to our understanding of the TME molecular heterogeneity in CM. Nine m1A‐, m5C‐ and m6A‐related regulators may also be promising biomarkers for future research.

Background and Aims: Crohn's disease (CD) is a chronic and refractory intestinal inflammatory disease. The 3′ untranslated region (3′ UTR) of mRNA transcript can regulate its own translational process post-transciptionally, and its role in CD remains unclear. The aim of this study was to identify the critical genes influencing CD phenotype via the regulation of mRNA 3′ UTR. Methods:Isoform Structural Change Model (IsoSCM) was used to evaluate the length of 3′ UTR of the whole transciptome from a RNA-seq based online CD database. Correlations between 3′ UTR length status and mRNA level were analyzed by Spearman coefficients. Correlated genes list was overlapped with published critical CD related gene list. Univariate and multivariate analysis were performed to identify the genes associated with CD phenotype. Results:Compared with normal control, 3′ UTR of 34192 genes were shortened and 57389 were lengthened among 432784 genes in CD patients. The 3′ UTR changes of 255 genes were found significantly correlated with their mRNA level. Furthermore, 8 overlapped genes were shared by above 255 correlated genes and known CD related gene list (ABCB1, FAF1, TUT2, IL27, JAK2, LTB, NAGLU and PTPN2). The mRNA level of ABCB1 and JAK2, and shortened 3′ UTR length of JAK2 transcript were found to be correlated with deep ulcer in CD patients by univariate and multivariate analysis. Conclusions:The 3′ UTR changes of CD related genes were confirmed to be related to the phenotype of CD. Our findings may provide further insight into the epigenetic mechanisms and therapeutic strategies for CD.