Objective: To study the expression of OCT4 protein in bladder cancer and its correlation to the clinicopathologic features and prognosis of bladder cancer.
Methods: OCT4 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.
Results: All 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.
Conclusion: OCT4 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.