Down-regulating HOXA-AS2/miR-20a pathway promotes apoptosis and inhibits invasion and migration of skin squamous carcinoma cells

Objective To study the effect of down-regulation of long non-coding RNA (lncRNA) HOXA cluster antisense RNA 2 (HOXA-AS2)/miR-20a pathway on apoptosis and invasion of skin squamous cell carcinoma cells in vitro. Methods qRT-PCR was used to detect the expression of HOXA-AS2 and miR-20a in 50 clinical specimens of skin squamous cell carcinoma and paired adjacent tissues. Skin squamous carcinoma cell line A431 was transfected with HOXA-AS2 siRNA, and the changes in cell proliferation, clonogenic ability, apoptosis, migration and invasion were evaluated by using MTT assay, clone formation experiment, flow cytometry, and Transwell assay respectively. Western blotting was performed to detect the expression of MMP-2, MMP-9, and cleaved caspase-3 proteins in the cells. Bioinformatics software predicted that HOXA-AS2 and miR-20a had complementary binding sites, and a luciferase reporter system was employed to verify their targeting relationship. A431 cells were co-transfected with HOXA-AS2 siRNA and miR-20a inhibitor, and the changes in cell proliferation, clone formation, apoptosis, migration and invasion were assessed. Results The expression level of HOXA-AS2 was increased in skin squamous cell carcinoma tissues. Transfection of A431 cells with HOXA-AS2 siRNA significantly suppressed the cell proliferation, clone formation, invasion and migration, promoted cell apoptosis, decreased the expression of MMP-2 and MMP-9 proteins, and increased the expression of cleaved caspase-3 protein. Down-regulation of HOXA-AS2 significantly up-regulated miR-20a expression. The expression level of miR-20a in skin squamous cell carcinoma tissues was negatively correlated with that of HOXA-AS2. In A431 cells, miR-20a inhibitor obviously reversed the effects of HOXA-AS2 siRNA on proliferation, clone formation, invasion, migration and apoptosis of the cells. Conclusion Down-regulation of HOXA-AS2/miR-20a pathway can promote the expression of miR-20a, suppress the proliferation, clone formation, invasion and migration, and induce apoptosis of skin squamous cell carcinoma cells in vitro.