Comprehensive analyses of molecular features, prognostic values, and regulatory functionalities of m6A-modified long non-coding RNAs in lung adenocarcinoma.

Background: Lung adenocarcinoma (LUAD) has a high incidence and recurrence rate. N6-methyladenosine (m6A) modification of RNA has become a promising epigenetic marker in tumors. The dysregulation of both RNA m6A levels and m6A regulator expression levels reportedly affects essential biological processes in various tumors. Long non-coding RNAs (lncRNAs), a subgroup of RNAs over 200 nucleotides in length that do not code for protein, can be modified and regulated by m6A, but the relevant profile in LUAD remains unclear. Results: The m6A levels of total RNA were decreased in LUAD tumor tissues and cells. Multiple m6A regulators were abnormally expressed at both the RNA and protein levels, and were related in expression patterns and functionally synergistic. Our microarray revealed 2846 m6A-modified lncRNA transcripts as well as its molecular features, 143 of which were differentially m6A-modified and manifested a negative correlation between expression levels and m6A modification levels. More than half of the differentially m6A-modified lncRNAs associated with dysregulated expression. The 6-MRlncRNA risk signature was a reliable indicator for assessing survival time of LUAD patients. The competitive endogenous regulatory network suggested a potential m6A-induced pathogenicity in LUAD. Conclusions: These data have demonstrated that differential RNA m6A modification and m6A regulator expression levels were identified in LUAD patients. In addition, this study provides evidence increasing the understanding of molecular features, prognostic values, and regulatory functionalities of m6A-modified lncRNAs in LUAD. [ABSTRACT FROM AUTHOR]