Expressions of PKM2 and PTB and their clinical significance in human bladder transitional cell carcinoma

Objective To explore the expressions of tumor M2 pyruvate kinase (PKM2) and polypyrimidine tract binding protein (PTB) and their clinical significance in bladder transitional cell carcinoma (BTCC). Methods The changes of PKM2 and PTB mRNA levels in different grades of BTCC and cell lines were identified by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR), and the changes of PKM1, PKM2 and PTB protein levels were validated by Western blotting. The expressions of PKM1, PKM2 and PTB were also studied by using the SP method of immunohistochemistry in BTCC samples and normal bladder tissues. Results The mRNA levels and the protein levels of PKM2 and PTB increased in the BTCC tissues, obviously in high-grade tumors and cell lines in comparison with those in normal bladder epithelium. The positive rate of PKM2 was 84.4% (38/45) in BTCC tissues, which was significantly higher than that in normal tissues 60.0% (27/45) ( P ＜ 0. 05 ). The expression of PTB was higher in the BTCC tissues (95.6%, 43/45) than that in normal tissues ( 55.6%, 25/45, P ＜ 0. 05 ).There was a positive correlation between the expressions of PKM2 and PTB. Conclusion PTB may play an important role in the alternative processing of PKM2 to regulate the energy metabolism of bladder cancer cells. Key words: Energy metabolism; Bladder transitional cell carcinoma; PKM2; PTB