ABSTRACT
Objective To explore the investigate of X-chromosome-linked inhibitor of apoptosis pro- tein(XIAP)and its effect on chemotherapeutic sensitivity in bladder carcinoma.Methods Using immu- nohistochemistry methods,the expression of XIAP was evaluated in 47 bladder carcinomas and 6 normal bladder tissues.The XIAP gene was transfected into bladder cancer cell line T24 by liposome and the positive clone was screened by G418.Cellular XIAP mRNA level was detected by RT-PCR.The apoptosis of T24 cells was induced by low-dose of mitocycin C(0.005 mg/ml and 0.05 mg/ml,respectively).The in vitro cellular growth activities were assayed by MTT color imetry;and the apoptosis rate was assayed by TUNEL methods. Results The expression rate of XIAP was 78.7%(37/47)in bladder carcinoma samples,with no corre- lation with carcinoma stages and grades(P＞0.05).XIAP mRNA level in transfected T24 ceils was signifi- cantly increased by 3.8 times.Treated with 0.005 mg/ml and 0.05 mg/ml of mitomycin C,the growth rates of XIAP transfected T24 cells were increased [(11.60?0.25)% and(16.51?0.87)% ,respectively,P＜0.05];and the apoptosis rates were decreased [(10.1?0.2)% and( 11.9?0.2)% ,respectively,P＜0.05]compared with those in control cells.Conclusions XIAP is highly expressed in humun bladder car- cinoma samples.Overexpression of XIAP in T24 cells results in decrease in bladder carcinoma cell apoptosis induced by MMC,which may decrease the chemotherapeutic sensitivity of T24 cells.