Effect of curcumol on proliferation, apoptosis and enhancer of zeste homolog 2 expression in bladder cancer EJ cells

Abstract

Objective To observe the effect of curcumol on proliferation, apoptosis and enhancer of zeste homolog 2 (EZH2) expression in human bladder cancer line cell EJ, and to explore its molecular mechanism. Methods The bladder cancer EJ cells were treated with different concentrations of curcumol (12.5, 25.0, 50.0, and 100.0 mg/L) and the control group was given 1% anhydrous ethanol. The inhibitory effect of curcumol on the growth of EJ cells was evaluated by cell counting kit-8 (CCK-8) assay. Special morphological changes of apoptosis were observed by Hoechst 33258 flourescence staning. Flow cytometry technique was used to detect the apoptosis rate of each experimental group. The expression of EZH2 mRNA and protein was examined with reverse transcriptase-polymerase chain reaction (RT-PCR) and Western boltting. Results EJ cells proliferation was obviously inhibited by curcumol in a time- and concentration-dependent manner. The inhibiton rate was (32.94±0.93)%, (46.75±1.28)%, (58.16±0.76)% and (69.13±1.94)%, and the apoptosis rate was (3.60±0.46)%, (6.70±1.83)%, (16.20±1.61)% and (28.70±2.65)% in curcumol-treated (12.5, 25.0, 50.0, and 100.0 mg/L) groups respectively. A typical form of apoptosis was detected in the high concentration of curcumol by fluorescent inverted phase contrast microscope. As compared with the control group, with the increases in concentrations of curcumenol, the expression of EZH2 mRNA and protein was gradually declined. Conclusion Curcumol could significantly inhibit the growth of EJ cells and induce the apoptosis, which may be related to the down-regulation of EZH2. Key words: Curcumol; Bladder cancer; Enhancer of zeste homolog 2