Experimental Study And Clinical Observation About Multiple Drug Combination Preventing The Recurrence Of Bladder Carcimoma After Operation

1.BackgroundsTumor of bladder is the most common categories in the tumors of urinary system.Any operation of remaining bladder almost has the disadvantage of the high recurrence rate.In order to reduce the recurrence rate further,we study the alternate intravesical instillation of three drugs- pirarubicin(THP),Mitomycin(MMC) and Hydroxycamptothecin(HCPT).2.Objectives(1)To establish drug resistance bladder cancer cell line of each drug and assess them. (2)TO study the expression of p53 and bcl-2 and MDR-1 of the drug resistance cell line to address the mechanism of the MDR of bladder tumor.(3)To compare the inhibit rate of each drug in lab.(4)To study the clinical effect of alternate intravesical instillation of the three drugs to reduce the recurrence rate.3.Methods(1)Established drug resistance bladder cancer cell lines named T-24/THP,T-24/HCPT,T-24/MMC respectively and obtained the indexes such as doubling time and growth curve to assess them.(2)Tested these resistance bladder cancer cell lines by immunocytochemistry,PCR-SSCP,RT-PCR.(3)Built such combinations as follow①single drug;②two dugs;③three drugs,which were used T-24,used MTT assay and TUNEL to obtain inhibition ratio and AI and compared the results to obtain the effect difference.Finally,according to the first part,we took the single-drug-resistance -cell-line culture process,for example,to attempt to build the three drug resistance cell line. We treated the T-24 cell line with the three drugs alternately to observe the T-24 cell tolerance to the three drugs combination.(4)We studied the 184 patients treated during 2004-2006 in our hospital.4.Results(1)The drug resistance bladder cancer cell lines named T-24/THP,T-24/HCPT,T-24/MMC respectively are established successfully.The difference of suppressive rate was not significant, except between T-24/MMC and T-24.The result show T-24/MMC exhibited cross-resistance to HCPT.(2)The results of PCR-SSCP show the significant variation of P53 level in the three drugs resistance cell lines.The results of RT-PCR show the significant increase of MDR-1 mRNA level in T-24/THP and T-24/MMC.The immunocytochemistry show the prominent expression of bcl-2.(3)According to the inhibition ratio and AI,two drugs combination is more significant than single drug and less than three drugs.(4)The clinical study showed the three drugs combination reduced the minimum of recurrence rate and the least side-effects. 5.Conclusions(1)The results show T-24/MMC exhibits drug resistance to HCPT and T-24/THP exhibits drug resistance to(t- test p＜0.05) MMC.(2)The of p53 and the prominent expression of MDR-1 and Bcl-2 all take part in the MDR of bladder cancer process and can be overcome to some degree.(3)The alternate intravesical instillation of THP and HCPT and MMC can decrease the MDR of transitional cell carcinoma of bladder.ficantly and have less side effects.