Downregulated Long Noncoding RNA PART1 Inhibits Proliferation and Promotes Apoptosis in Bladder Cancer

OBJECTIVE: In this study, we aimed to clarify the effects of long noncoding ribonucleic acid prostrate androgen-regulated transcript-1 on bladder cancer cell proliferation and apoptosis. METHODS: Microarrays were implemented to investigate the long noncoding ribonucleic acid expression profiles in bladder cancer tissue (N = 9) and in noncancer bladder tissue (N = 5). Relative prostrate androgen-regulated transcript-1 expression levels in tissue samples or cell lines were detected by real-time quantitative reverse transcription-polymerase chain reaction. Prostrate androgen-regulated transcript-1 expression was enhanced by the transfection of pcDNA3.1-prostrate androgen-regulated transcript-1 and downregulated by the infection with pcMV-sh prostrate androgen-regulated transcript-1. Additionally, cell proliferation and apoptosis were measured by the cell counting kit-8 assay and flow cytometry, respectively. Cell invasion was determined by a Transwell assay. RESULTS: Prostrate androgen-regulated transcript-1 expression was upregulated in bladder cancer tissues compared to adjacent nontumor tissues. Furthermore, prostrate androgen-regulated transcript-1 levels were successfully upregulated by pcDNA3.1-prostrate androgen-regulated transcript-1 and depleted by pCMV-sh prostrate androgen-regulated transcript-1 in bladder cancer cell lines (5637, T24). Enhanced prostrate androgen-regulated transcript-1 expression promoted cell proliferation and invasion and inhibited cell apoptosis. However, knockdown of prostrate androgen-regulated transcript-1 expression inhibited cell proliferation and invasion and induced cell apoptosis. CONCLUSION: In summary, these data suggest that the knockdown of prostrate androgen-regulated transcript-1 represents a tumor suppressor player in bladder cancer and contributes to the inhibition of tumor proliferation, the promotion of cell apoptosis, and the suppression of cell invasion. Prostrate androgen-regulated transcript-1 may function as a new prognostic biomarker and as a feasible therapeutic target for patients with bladder cancer.