Targeted regulation by ROCK2 on bladder carcinoma via Wnt signaling under hypoxia.

ABSTRACT

Bladder cancer is frequently occurred in urinary system and has complicated pathogenesis factors including both genetics and environmental factors that have not been fully illustrated. Hypoxia can further induce tumor progression. ROCK2 has abnormal expression in various tumors but its expression or functional role in bladder cancer have not been illustrated. In vitro cultured bladder cancer cell line T24 was randomly assigned into control group, hypoxia group (prepared under hypoxic culture), and ROCK2 siRNA group (transfected with ROCK2 siRNA after hypoxia treatment). Real-time PCR and Western bot measured ROCK2 expression. MTT assay tested cell proliferation, and cell migration was quantified. Cell apoptosis was measured by caspase3 activity assay kit and Transwell chamber measured cell migration. Western blot quantified expressional change of HIF-1α and E-cadherin, and Wnt signal pathway proteins including Wnt4, and ß-catenin. ROCK2 is up-regulated in bladder cancer T24 cells under hypoxia, and can facilitate cell proliferation, migration and invasion, inhibited Caspase3 activity, enhanced HIF-1α expression, decreased E-cadherin expression, and up-regulated Wnt4 and ß-catenin (p< 0.05 comparing to hypoxia group). Under hypoxia conditions, ROCK2 can facilitate apoptosis of bladder cancer cells via modulating Wnt signal pathway, inhibit cell proliferation, migration, invasion or formation of epithelial mesenchymal transition (EMT).