Effects of gene therapy by rAAV-Endostatin in treatment of bladder cancer:an experimental study

Abstract

Objective To investigate the effect of gene therapy by using recombinant adeno-associated virus endostatin(ES)(rAAV-ES)for bladder cancer.Methods Bladder cancer cell line T24 was cultured and transfected with rAAV-ES and rAAV-MCS(vehicle control).72 hours after transfection,the level of ES in the supernatants was measured by ELISA and Annexin V apoptosis test kit was used to examine the apoptosis.Human umbilical vein endothelial cells(HUVECs)were transfected with rAAV-ES and rAAV-MCs.MTT method and flow cytometry were used to detect the apoptosis of the HUVECs.Balb/c nude mice were inoculated subcutaneously with T24 cells.Fifteen mice with tumor were randomly divided into 3 groups to be treated by rAAV-MCS and rAAV-ES,and 5 mice were used as control group.Four weeks after treatment,blood samples were collected to detect the ES level by ELISA.The tumors were taken out for microscopy to calculate the microvessel density (MVD).Results Seventy-two h after transfection,ES could be detected in the supernatants of the T24 cells transfected with rAAV-ES.The apoptotic rates of the T24 cells transfected with rAAV-ES was 37.02%,significantly higher than those of the T24 cells transfected with rAAV-MCS and of the control group(P＜0.05).Transfection of rAAV-ES increased the apoptotic rate of the HUVECs time-dependently.Four weeks after the transfection,the tumor volumes of the rAAV-ES group was (0.75±0.08)cm~3,significantly lower than those of the rAAV-MCS(1.27±0.13)cm~3 group and control group(1.24±0.17)cm~3(P＜0.05).Conclusions rAAV-ES could effectively inhibits the tumor growth and angiogenesis in bladder cancer. Key words: Bladder neoplasms; Gene therapy; ndostatins; Adeno-associated virus