Knockdown of LncRNA DLX6-AS1 Inhibits Cell Proliferation, Migration and Invasion While Promotes Apoptosis by Downregulating PRR11 Expression and Upregulating MiR-144 in Non-small Cell Lung Cancer

Background: Long non-coding RNA (lncRNA) distal-less homeobox 6 antisense 1 (DLX6-AS1) was reported to be dysregulated in lung cancer. However, detailed roles of DLX6-AS1 in the pathogenesis of non-small cell lung cancer (NSCLC) were largely unknown.

Methods: The expression of DLX6-AS1 was measured in NSCLC tissues and cells by quantitative real-time PCR (qRT-PCR). The abundance of proline rich 11 (PRR11) were detected by qRT-PCR and western blot, respectively. The effects of DLX6-AS1 and PRR11 on cell proliferation, migration, invasion and apoptosis were explored by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), transwell and flow cytometry analysis, respectively. Luciferase reporter assay, qRT-PCR and western blot were performed to confirm the interaction between miR-144 and DLX6-AS1 or PRR11. Tumor xenograft assay was performed to verify the role of DLX6-AS1 in NSCLC in vivo.

Results: DLX6-AS1 and PRR11 were elevated in NSCLC tissues and cells. DLX6-AS1 was positively correlated with PRR11 mRNA expression in NSCLC tissues. Knockdown of DLX6-AS1 and PRR11 significantly suppressed cell proliferation, migration and invasion and induced apoptosis in NSCLC cells, which was reversed by PRR11 overexpression. In addition, DLX6-AS1 and PRR11 were demonstrated to interact with microRNA-144 (miR-144) and DLX6-AS1 upregulated PRR11 expression by acting as a competing endogenous RNA (ceRNA) of miR-144 in NSCLC cells. Furthermore, DLX6-AS1 knockdown suppressed tumor growth in NSCLC in vivo by upregulating miR-144 and downregulating PRR11.

Conclusion: Knockdown of DLX6-AS1 inhibited cell proliferation, migration, invasion and promoted apoptosis by downregulating PRR11 expression and upregulating miR-144 in NSCLC.