MicroRNA-1246 regulates the radio-sensitizing effect of curcumin in bladder cancer cells via activating P53.
OBJECTIVES
Radiotherapy is the primary option for bladder cancer patients, but it does not have obvious curative effects. This study was to investigate how to increase radiosensitivity in bladder cancer.


MATERIALS AND METHODS
The curcumin and irradiation treated T24 cells were used for analysis of microRNA expression (miRNA microarray), cell viability (Cell Proliferation Assay Kit), colony formation, apoptosis (Annexin V-FITC/7-AAD flow cytometry), miR-1246 and p53 mRNA (real-time PCR) and protein (Western blot) expression.


RESULTS
Microarray assay identified 17 differentially expressed miRNAs (twofold change) in curcumin treated cells compared to control cells. Among them, miR-1246 was the miRNA with the largest change in expression after curcumin treatment. Curcumin significantly decreased T24 cell viability and colony formation in a concentration-dependent manner compared to control cells. miR-1246 expression was significantly higher in T24 cells than in SV-HUC-1 cells and the higher concentrations (10 or 20 μM) of curcumin significantly down-regulated miR-1246 expression in T24 and HT-1376 cells. The combination of 10 µM curcumin and irradiation was more effective in decreasing miR-1246 expression, cell viability and colony formation than curcumin or irradiation alone. Inhibition of miR-1246 significantly decreased cell viability and colony formation in T24 and HT-1376 cells. Transfection with antagomiR-1246 significantly increased the G0/G1-phase of T24 cells and induced apoptosis compared to cells transfected with antagomiR-NC. Luciferase reporter assay showed that the overexpression of miR-1246 suppressed the luciferase activity of the P53 3'-UTR reporter genes.


CONCLUSION
miR-1246 is involved in the anti-cancer effects of curcumin and irradiation through targeting the inhibition of p53 gene translation in bladder cancer cells.
['Xu|Ran|R|', 'Li|Huabing|H|', 'Wu|Shuiqing|S|', 'Qu|Jian|J|', 'Yuan|Haiyan|H|', 'Zhou|Yangang|Y|', 'Lu|Qiong|Q|']
D000970:Antineoplastic Agents D003474:Curcumin D006801:Humans D035683:MicroRNAs D011838:Radiation-Sensitizing Agents D014407:Tumor Cells, Cultured D016159:Tumor Suppressor Protein p53 D001749:Urinary Bladder Neoplasms
Curcumin Bladder cancer p53 MicroRNA Radiation