Long noncoding RNA TP73-AS1 promotes non-small cell lung cancer progression by competitively sponging miR-449a/EZH2

Long noncoding RNAs (lncRNAs) are a type of noncoding RNA transcript that are characterized by lack of protein-coding capacity. The vital role of lncRNAs in non-small cell lung cancer (NSCLC) is attracting increasingly more attention. In the present study, we investigate the role of lncRNA antisense RNA of the TP73 gene (TP73-AS1) in NSCLC carcinogenesis. The results demonstrate that TP73-AS1 is markedly upregulated in NSCLC tissues, and functional experiments revealed that TP73-AS1 is significantly increased in NSCLC tissue and cell lines, indicating a possible oncogenic role. In loss-of-function assays, the knockdown of TP73-AS1 inhibited NSCLC cell proliferation, tumor growth and cycle progression in vivo and in vitro. Bioinformatic tools predicted that miR-449a both targeted the 3'-UTR of TP73-AS1 and EZH2, which was confirmed using luciferase reporter assay and AGO2-dependent RNA immunoprecipitate (RIP). TP73-AS1 and miR-449a were in the same RNAinduced silencing complex (RISC). In summary, the results indicate an explicit oncogenic role of TP73-AS1 in the NSCLC tumorigenesis, suggesting a TP73-AS1-miR-449a-EZH2 axis and providing new insight for NSCLC tumorigenesis.