Abstract
LncRNA growth arrest specific 5 (GAS5) has been confirmed to play an essential role in a number of biological processes, such as tumor regulation and gene transcription. GAS5 has been shown to be a tumor suppressor gene in many types of cancer, but its specific mechanism of action in bladder cancer (BC) remains to be elucidated. In this study, we explored the biological properties of GAS5 in BC and its mechanism of action in BC. We analyzed the expression of GAS5 in 50 pairs of BC tissues and found that GAS5 was low expressed in BC tissues compared with normal mucosal tissues. In vitro and in vivo experiments showed that GAS5 could affect the proliferation and migration of BC cells. Nucleoplasmic isolation assays and fluorescence in situ hybridization (FISH) assays demonstrated the localization of GAS5 in cell cytoplasm. Chromatin isolation by RNA purification (ChIRP), RNA immunoprecipitation (RIP) and luciferase assay demonstrated the target binding relationship of GAS5 with miR-18a-5p. Rescue experiments demonstrated that GAS5 promoted the proliferation and migration of BC cells through target binding of miR-18a-5p. Moreover, miR-18a-5p bound to its targets AXIN2 and GSK3β, which in turn affected the expression of Wnt/β-catenin pathway-related proteins. Our findings demonstrate that GAS5 regulates Wnt/β-catenin pathway activity by regulating the miR-18a-5p/AXIN2/GSK3β axis to modulate BC progression, providing a new potential therapeutic strategy for the treatment of BC.