Long noncoding RNA TMPO-AS1 promotes progression of non-small cell lung cancer through regulating its natural antisense transcript TMPO.

Long noncoding RNAs (lncRNAs), a large group of RNAs with limited or no protein-coding capacity, have been demonstrated to play critical roles in human malignancy. The aim of this study is to examine the expression and function TMPO antisense transcript 1 (TMPO-AS1) in non-small cell lung cancer (NSCLC). Here, we found that the expression of both TMPO-AS1 and TMPO mRNA levels were overexpressed in NSCLC cells lines and tissues. A significant positive correlation was observed between TMPO-AS1 and TMPO mRNA levels. The upregulation of TMPO-AS1, TMPO mRNA and protein levels were associated with tumor progression of NSCLC. More importantly, through antisense pairing with TMPO mRNA, TMPO-AS1 regulates TMPO mRNA stability. Knockdown of TMPO-AS1 decreased the mRNA and protein levels of TMPO in NSCLC cells. An overlapping (OL) region was found between TMPO-AS1 and TMPO exon 1 and overexpression of TMPO-AS1-OL elevated the mRNA and protein levels of TMPO. Functionally, the downregulation of TMPO-AS1 significantly inhibited cells proliferation, colony formation, migration and invasiveness in vitro, and tumor growth in vivo. In contrast, overexpression of TMPO could promote the aggressive behaviors of NSCLC cells in vitro. Our findings indicate that TMPO-AS1 contributes to lung carcinogenesis, which may be partially through upregulation TMPO.