The Research For Immunotherapeutic Effect Of CpG-ODN Combine With Epirubicin To Treat Bladder Tumor Rat

Objective: Bladder cancer rats model were established by N-methyl-N-nitrosourea(MNU)via bladder instillation.The changes of biological characteristics was observed by naked eye,the changes of pathological grading evaluated by HE stain,the expression of p53 and Survivin analyzed by immunohistochemistry,and the changes of cytokine level evaluated by ELISA in bladder tumor tissue after treatment.To explore the immune sensitization of CpG oligomeric deoxyribonucleotide(CpG-ODN)for chemotherapy with Epirubicin(EPI),and compared with Bacillus Calmette Guerin(BCG),which was the “gold standard treatment”for bladder tumor instillation,to explored the possibility of CpG-ODN replaced BCG.Methods: 116 SD rats were randomly divided into two groups:the blank control group(n=24)and the experimental group(n=82).In 8th week,after established the rats model,the experimental group(n=82)was randomly divided into four groups,namely the model group(n=10),the EPI group(n=24),the EPI+BCG group(n=24),and the EPI+ CpG-ODN group(n=24).HE staining was used to observe the pathological features,and calculate the incidence of bladder tumor.After the successful establishment of bladder cancer rat model,EPI,EPI+BCG and EPI+CpG-ODN were instilled into bladder for four time treatment,and the blank control group was instilled 0.9% normal saline(NS).The end of animal experiments,the bladder tissues and serum were collected and evaluated as followed:(1)pathological changes of bladder tumor tissues were analyzed by HE staining;(2)changes of p53,Survivin expression in bladder tumor were detected by immunohistochemistry;(3)changes of IL-2 and IFN-? level were evaluated by ELISA.Results: The inner wall of the bladder in EPI+BCG group and EPI+CpG-ODN group obviously changed from brown-red to white,the bladder wall gradually became normal,and the tumor gradually disappeared.Moreover,compared with EPI group,the number of cancer cells in the EPI+BCG group and EPI+CpG-ODN group decreased and showed significantly different(P<0.05).The positive expression of p53 and Survivin between the EPI+BCG group and the EPI+ CpG-ODN group with significantly different(P<0.05).After four instillation treatments,the level of IL-2 and IFN-? in EPI group was lower than that in the EPI+BCG group and EPI+CpG-ODN group(P<0.05).In this study,the dose of CpG-ODN was 4 ?M/ml and BCG was 2mg/ml and we found that cystolith were observed in the bladder of the EPI+BCG group,but no observed in the EPI+ CpG-ODN group.Conclusion: CpG-ODN can enhanced the anti-tumor effect of EPI,and effectively inhibited the development of tumor.Moreover,CpG-ODN can effectively stimulate the cellular immune response,and significantly down-regulate the expression of p53,Survivin.Compared with BCG,the dose of CpG-ODN was significantly lower than BCG,but the anti-tumor effect was relatively stable,and no significantly side-effect.Therefore,CpG-ODN is expected to be an adjuvant to enhance the sensitivity of chemotherapy and to treat bladder malignancy.Furthermore,CpG-ODN has the potential to replace BCG for bladder tumor treatment.