LncRNA growth arrest-specific transcript 5 targets miR-21 gene and regulates bladder cancer cell proliferation and apoptosis through PTEN.

The aim of this study was to investigate the mechanism by which growth arrest-specific transcript 5 (GAS5) regulates bladder cancer cells. Bladder cancer samples were collected and tested for experiment. Dual-luciferase reporter assay was used to verify the downstream target genes for GAS5 and miR-21. The expression level of GAS5 was decreased and that of miR-21 was increased, indicating a negative correlation between the two. Patients with high GAS5 level and low miR-21 level had relatively longer survival rates. GAS5 inhibited bladder cancer cells proliferation and promoted apoptosis, and miR-21 had the opposite effects. MiR-21 was a direct target for GAS5, whereas phosphatase and tensin homolog (PTEN) was a direct target gene of miR-21. Low expression of miR-21 could reverse the proliferative and antiapoptotic effects caused by GAS5 silencing. High levels of GAS5 and low levels of miR-21 might be associated with a higher survival rate in bladder cancer patients. GAS5 could exert antiproliferative and proapoptotic effects on bladder cancer cells through miR-21 and PTEN.