Treatment Of Bladder Cancer By Oncolytic Virus And Sodium Butyrate

Aim:Bladder cancer is a commonly occurring cancer.Existing local therapies for transitional cell carcinoma(TCC)of the bladder include local resection for nonmuscle-invasive disease and cystectomy for muscle-invasive disease.These strategies are effective but far from satisfactory.Thus,novel treatments need to be developed.The aim of this study is to construct a dual specific vector which contains prostate stem cell antigen enhancer(PSCAE)and UroplakinⅡ(UPⅡ)promoter targeted bladder cancer.Methods:UPⅡpromoter and PSCAE were amplified by polymerase chain reaction (PCR).Luciferase gene(Luc)was obtained from plasmid pBK-CMV-Luc.E1A was abtained from RpS-TOAD-PSE-PBN-E1A.PSCAE,UPⅡpromoter,Luc and E1A were inserted into shuttle plasmid to create RpS-UPⅡ-E1A,RpS-E-UPⅡ-E1A, RpS-UPⅡ-Luc,RpS-E—UPⅡ—Luc;RpS-UPⅡ-Null;RpS-E—UPⅡ-Null. Rp-UPⅡ-Luc and Rp-E-UPⅡ-Luc were cotransfected with pCMV-β-gal into various cell lines at the presence or absence of androgen receptor agonist R1881 and androgen receptor antagonist Flutamide.Luminescence was detected with Luciferase assay kit and counted on liquid scintillation counter.The plasmids were cotransfected with pAdEasy-1 by electroporation in electrocompetent E.coli BJ5183 cells respectively to form Ad-RpS-UPⅡ-E1A,Ad-RpS-E-UPⅡ-E1A,Ad-RpS-UPⅡ-Null,Ad-RpS-E—UPⅡ-Null. The plasmids were transfected into 293 cells by Lipofectamine 2000. Recombinant adenovirus Ad-E-UPⅡ-E1A was tested for its inhibition in bladder cancer cell line T24.Results:Bladder cancer cells showed higher Luc activity than non-bladder cancer cells after transfected with plasmids Rp-UPⅡ-Luc and Rp-E-UPⅡ-Luc.PSCAE can improve the Luc activity in both AR positive and AR negative bladder cancer cells but not in non-bladder cancer cells and normal human urothelial(NHU)cells.R1881 can increase the Luc activity in AR positive bladder cancer cells but not in AR negative bladder cancer cells and non-bladder cancer cells.Flutamide can not inactivate PSCAE in bladder cancer cells.Recombinant adenovirus Ad-E-UPⅡ-E1A can induce T24 cells lysis,but Ad-E-UPⅡ-Null can not induce T24 cell lysis. Conclusion:UPⅡpromoter can drive target gen expression in bladder cancer cells.PSCAE can improve target gene expression in bladder cancer cells but not in non-bladder cancer cells and NHU cells.PSCAE maintains a certain level of androgen independent activity in bladder cancer cells.PSCAE is active in both AR positive and AR negative bladder cancer cells.Recombinant adenovirus Ad-E-UPⅡ-E1A can induce T24 cells lysis. Objectives:To investigate the inhibitory effect of sodium butyrate(NAB)on the proliferation of human bladder cancer cell lines and its synergetic effect with anticancer drugs in treating bladder cancer in vitro and in vivo.Methods:The inhibitory effects of NaB on human bladder cancer cell lines in vitro and the synergetic effect of NaB with mitomycin c,cisplatin(CDDP)and adriamycin were detected by the 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay.Hoechst staining and electron microscopy were used to observe morphology for apoptotic cells after NaB treatment.Fas,bcl-2 and caspase-3 were determined with flow cytometry.In vivo synergetic effects were detected in N-methyl-N-nitrosourea induced bladder cancer model rats.Results:NaB significantly inhibited the growth of bladder cancer cell lines in a concentration and time dependent manner.Better results of tumor inhibition have been achieved when NaB was combined with CDDP,mitomycin c and adriamycin, rather than used alone.Furthermore,2 h exposure to NaB can sensitize bladder cancer to chemotherapy agents.The Bcl-2 expression in bladder cancer cells is decreased and caspase-3 expression increased after NaB treatment.Intravesical application of NaB combined with CDDP can significantly inhibit tumor growth and progression.Conclusions:NaB has a direct anticancer effect and can markedly enhance the action of several chemotherapy agents.2 h expose to NaB can also sensitize bladder cancer to anticancer drugs.NaB may be an excellent candidate agent for intravesical application in treating bladder cancer.