Molecular mechanism underlying long non-coding RNA AFAP1-AS1 inhibition of proliferation, invasion and metastasis of oral squamous cell carcinoma via targeting miR-545-3p

Abstract

Objective To investigate the mechanism underlying long-chain non-coding RNA (lncRNA) actin filament-associated protein 1-antisense RNA1 (AFAP1-AS1) regulation of proliferation, invasion and metastasis of oral squamous cell carcinoma by targeting microRNA-545-3p (miR-545-3p) . Methods Thirty patients with oral squamous cell carcinoma, who underwent resection in our hospital between March 2017 and May 2018, were included in the study, and the corresponding normal tissues adjacent to the carcinoma were collected. Real-time fluorescent quantitative PCR (qRT-PCR) was used to determine the expression of AFAP1-AS1 and miR-545-3p in oral squamous cell carcinoma and adjacent normal tissues. The oral squamous cell carcinoma SCC15 cells were included as the subject in the study, and the dual luciferase reporter gene assay was used to examine the effect of miR-545-3p on AFAP1-AS1 activity. The SCC15 cells with suppressed AFAP1-AS1 and overexpressed miR-545-3p. CCK-8 assay, scratch test and Transwell assay were used to determine the cell proliferation, migration and invasion, respectively. Results Compared with the normal tissues adjacent to the carcinoma, the expression level of AFAP1-AS1 increased in the oral squamous cell carcinoma tissues (5.15±1.79 vs. 1.00±0.16, P<0.01) , whereas the expression level of miR-545-3p decreased (0.35±0.07 vs. 1.00±0.11, P<0.05) . The findings of dual luciferase reporter gene assay showed that AFAP1-AS1 targeted and negatively regulated miR-545-3p expression. Knockdown of AFAP1-AS1 significantly inhibited the proliferation, migration and invasion of SCC15 cells, and promoted the expression of miR-545-3p in SCC15 cells. After overexpression of AFAP1-AS1, the proliferation, migration and invasion of SCC15 cells were significantly inhibited. At the same time, the proliferation, migration and invasion of SCC15 cells were significantly enhanced after knockdown of AFAP1-AS1 and inhibition of miR-545-3p expression. Conclusions LncRNA AFAP1-AS1 is highly expressed in oral squamous cell carcinoma and may inhibit the proliferation, migration and invasion of oral squamous cell carcinoma by targeting inhibition of miR-545-3p. Key words: Oral squamous cell carcinoma; Long non-coding RNA; AFAP1-AS1; MicroRNA-545-3p