ABSTRACT
Objective To study the relationship between the intervals of Mitomycin C treatment and cytotoxicity, apoptosis and drug resistance for bladder cancer cells.Methods The bladder transitional cell cancer line BIU-87 was treated for two hours every time for five times with intervals of 24, 48, 72 and 96 hours respectively.Cytotoxicity was measured by MTT.p53,bcl-2,Bax and p170 expression were analyzed by Western blot.Results The IC_(50)(?g/ml)were 4.41,0.71,2.83,4.51and 6.16 with treatment intervals of 24, 48, 72 and 96 hours respectively, p53 and bcl-2 were significantly down-regulated and bcl-2/Bax was re- duced at 24 hour treatment interval but not changed at 48,72 and 96 hour intervals,p170 was not detected at 24 hour treatment interval but increasingly expressed at 48,72 and 96 hours intervals.Conclusion The in- terval of Mitomycin C treatment is closely related with cytotoxieity and apoptosis and drug resistance of blad- der cancer cells.The intervals of intravesical instillations may play an important role in the effect of chemotherapy.