Integrated Analysis of the Immune Infiltrates and PD-L1 Expression of N6-Methyladenosine-Related Long Non-Coding RNAs in Colorectal Cancer

BACKGROUND: N6-methyladenosine-related long non-coding RNAs (m6A-related lncRNAs) are involved in the occurrence and progression of various cancers. However, it remains unclear whether m6A-related lncRNAs have potential roles in tumor immune microenvironment (TIME). METHODS: Herein, we investigated correlations of prominent m6A-related lncRNAs with immune infiltrates and PD-L1 expression and the prognostic value of m6A-related lncRNAs in colorectal cancer from The Cancer Genome Atlas (TCGA) cohort, systematically. RESULTS: Firstly, we conducted Pearson correlation analysis to screen the m6A-related lncRNAs, and then univariate Cox regression analysis was performed to identify 72 prognostic m6A-related lncRNAs in CRC patients. Moreover, two molecular subtypes (cluster 1/2) were identified by consensus clustering for 72 m6A-related lncRNAs. The cluster 1 preferentially associated with favorable prognosis, upregulated PD-L1 expression, higher immunoscore, and distinct immune cell infiltration. Furthermore, a prognostic risk score was calculated using 19 m6A-related lncRNAs based signatures which represented an independent prognostic factor for CRC. Patients with low-risk score showed higher PD-L1 expression than patients with high-risk score. Further analysis revealed that m6A-related lncRNAs based signatures were associated with tumor-infiltrating immune cells. CONCLUSION: Our study indicated the essential roles of m6A-related lncRNAs in TIME of CRC and provide novel insights in our understanding of m6A-related lncRNAs function in colorectal cancer.