A Novel m6A-Related LncRNA Signature for Predicting Prognosis, Chemotherapy and Immunotherapy Response in Patients with Lung Adenocarcinoma

N6-methyladenosine (m6A) and long non-coding RNA (lncRNA) have been associated with cancer prognosis and the effect of immunotherapy. However, the roles of m6A-related lncRNAs in the prognosis and immunotherapy in lung adenocarcinoma (LUAD) patients remain unclear. We evaluated the m6A modification patterns of 695 samples based on m6A regulators, and prognostic m6A-related lncRNAs were identified via a weighted gene co-expression network analysis. Twelve abnormal m6A regulators and nine prognostic lncRNAs were identified. The tumor microenvironment cell-infiltrating characteristics of three m6A-related lncRNA clusters were highly consistent with the three immune phenotypes of tumors, including immune-excluded, immune-inflamed and immune-desert phenotypes. The lncRNA score system was established, and high lncRNA score patients were associated with better overall survival. The lncRNA score was correlated with the expression of the immune checkpoints. Two immunotherapy cohorts supported that the high lncRNA score enhanced the response to anti-PD-1/L1 immunotherapy and was remarkably correlated with the inflamed immune phenotype, showing significant therapeutic advantages and clinical benefits. Furthermore, the patients with high lncRNA scores were more sensitive to erlotinib and axitinib. The lncRNA score was associated with the expression of miRNA and the regulation of post-transcription. We constructed an applied lncRNA score-system to identify eligible LUAD patients for immunotherapy and predict the sensitivity to chemotherapeutic drugs.