m6A Regulator-Mediated Methylation Modification Patterns and Characterisation of Tumour Microenvironment Infiltration in Non-Small Cell Lung Cancer

Purpose: The role of RNA N6-methyladenosine (m(6)A) modification in the progression of multiple tumours and the tumour microenvironment (TME) has been progressively demonstrated and promises a new direction for tumour therapy. However, there have been no reports on systematic analyses of RNA m(6)A modification in TME in non-small cell lung cancer (NSCLC). Patients and Methods: In this study, we used unsupervised cluster analysis to identify three m(6)A modification patterns of 28 m(6)A regulators and three m(6)A gene signature subgroups of commonly differentially expressed genes (co-DEGs) in the three m(6)A modification patterns. Quantifying these subtypes using the ssGSEA and ESTIMATE algorithms to characterise the tumour immune microenvironment (TIME) in NSCLC. Based on the principal component analysis (PCA), we used co-DEGs to construct m(6)A scores to analyse the characteristics of m(6)A modifications in individual patients and assessed the practical clinical utility of m(6)A scores using a nomogram for survival prediction. Results: A total of 28 m(6)A regulators in 1210 NSCLC samples were mainly enriched in RNA modification and metabolic biological processes. The three following m(6)A modification patterns were identified based on the role of the 28 m(6)A regulators in TME: immune inflammation, immune evasion and immune desert. The m(6)A scores calculated based on co-DEGs in these modification patterns were significantly positively correlated with immune infiltration and significantly negatively correlated with tumour mutational burden (TMB). Survival was significantly better in the high-m(6)A-score group than in the low-m(6)A-score group, and the m(6)A score could be used as an independent favourable prognostic factor. In addition, assessment of both immune checkpoint inhibitors (ICIs) and immunophenoscore (IPS) revealed a better immunotherapeutic effect in the high-m(6)A-score group. Conclusion: The modification characteristics of 28 m(6)A regulators in the TIME of NSCLC were analysed from a comprehensive to an individual basis, which may facilitate the development of more effective clinical immunotherapeutic strategies.