OBJECTIVETo study the expression of OCT4 protein in bladder cancer and its correlation to the clinicopathologic features and prognosis of bladder cancer.

METHODSOCT4 mRNA and protein expression was detected in 5 bladder cancer cell lines (RT-4, Tcc-Sup, KK47, T24, and 5637) and 1 normal bladder cell lines by real-time PCR and Western blotting, respectively. Immunohistochemical analysis was used to detect the expression of OCT4 protein in 46 bladder cancer samples.

RESULTSAll the 5 bladder cancer cell lines expressed detectable levels of OCT4 mRNA and proteins, whereas the normal bladder cell line SV-HUC-1 was negative for OCT4 expression. The clinical bladder cancer tissues showed a high positivity rate of OCT4 expression (76.1%), which was not detected in normal bladder tissues. Specific OCT-4 signals were localized mainly in the nuclei of the cancer cells. The expression rate of OCT4 protein was significantly higher in bladder cancer tissue than in normal bladder epithelium (P<0.05), and showed a positive correlation to the grade of tumor differentiation and metastasis (P<0.05) but not to the patients' age, gender or TNM stage.

CONCLUSIONOCT4 protein expression is associated with tumor differentiation and metastasis in bladder cancer and may play an important role in the early diagnosis and prognostic evaluation of bladder cancer.