MicroRNA-573 inhibits cell proliferation, migration and invasion and is downregulated by PICSAR in cutaneous squamous cell carcinoma.

The incidence of cutaneous squamous cell carcinoma (cSCC) has been increasing in recent years. Meanwhile, microRNAs (miRNAs) have been found to play vital roles in various cancers, including cSCC. This study aimed to investigate the expression of microRNA-573 (miR-573) in cSCC, its relationship with long non-coding RNA PICSAR and analyze its biological role. The relationship between PICSAR and miR-573 was confirmed by dual-luciferase reporter assay and Pearson's correlation coefficient analysis. The levels of PICSAR and miR-573 were measured using quantitative Real-Time PCR. Cell Counting Kit-8 assay was used to evaluate the cSCC cell proliferation ability. The migration and invasion abilities of cSCC cells were evaluated by Transwell assay. PICSAR expression was increased and miR-573 was decreased in tumor tissues and cSCC cell lines. PICSAR and miR-573 can bind directly, and miR-573 expression was downregulated by PICSAR in cSCC. Overexpression of miR-573 significantly inhibited the proliferation, migration and invasion abilities of A431 and SCC13 cells. Additionally, miR-573 overexpression reversed the promotion effects of PICSAR overexpression on cSCC cell proliferation, migration and invasion abilities. In conclusion, our findings indicated that miR-573 expression was decreased in tumor tissues and cSCC cells and was downregulated by PICSAR in cSCC. Additionally, miR-573 overexpression inhibited cSCC cell proliferation, migration and invasion, and reversed the promotion effects of PICSAR overexpression on cSCC cell biological functions. Thus, miR-573 might function as a tumor suppressor and might be involved in the regulatory effects of PICSAR on tumorigenesis in cSCC.