Abstract
Long non-coding RNA SLC25A25 antisense RNA 1 (SLC25A25-AS1) exerts antitumour activity in colorectal cancer. The present study investigated whether SLC25A25-AS1 is implicated in the aggressiveness of non-small cell lung cancer (NSCLC) and the possible underlying mechanism. SLC25A25-AS1 expression in NSCLC was determined by reverse transcription-quantitative PCR. The proliferation, apoptosis, migration and invasion of NSCLC cells were tested in vitro through cell counting kit-8 assay, flow cytometry analysis, Transwell migration and invasion assays, followed by in vivo validation using animal experiments. Additionally, the competitive endogenous RNA theory for SLC25A25-AS1, microRNA-195-5p (miR-195-5p) and integrin α2 (ITGA2) was identified using subcellular fractionation, bioinformatics analysis, reverse transcription-quantitative PCR, western blotting, a luciferase assay and RNA immunoprecipitation. As compared with normal lung tissues, increased expression of SLC25A25-AS1 was demonstrated in NSCLC tissues using The Cancer Genome Atlas database.. In addition, SLC25A25-AS1 was overexpressed in both NSCLC tissues and cell lines. High SLC25A25-AS1 expression was markedly associated with shorter overall survival time of patients with NSCLC. SLC25A25-AS1 silencing impeded NSCLC cell proliferation and triggered apoptosis, while restricting cell migration and invasion. Tumour growth in vivo was also impaired by SLC25A25-AS1 silencing. Mechanistically, SLC25A25-AS1 was demonstrated to be an miR-195-5p sponge in NSCLC cells. miR-195-5p mimics decreased ITGA2 expression in NSCLC cells by directly targeting ITGA2, and SLC25A25-AS1 interference decreased ITGA2 expression by sequestering miR-195-5p. Furthermore, the antitumour effects of SLC25A25-AS1 silencing on malignant behaviours were counteracted when ITGA2 was restored or when miR-195-5p was silenced. In summary, by controlling the miR-195-5p/ITGA2 axis, SLC25A25-AS1 served tumour-promoting roles in NSCLC cells. Therefore, the SLC25A25-AS1/miR-195-5p/ITGA2 signalling pathway might be an attractive target for future therapeutic options in NSCLC.