免疫治疗联合化疗治疗膀胱肿瘤的基础研究

The Combination of Immunotherapy and Chemotherapy in Treating Bladder Tumor

目的通过体外和动物研究,探讨免疫治疗联合化疗对膀胱肿瘤的治疗效果。方法培养EJ膀胱癌细胞后,脂质体转染白细胞介素12(IL-12)至EJ细胞内,ELISA法测定培养液中IL-12水平。吡柔比星(THP)加入细胞培养液中,测定各组细胞死亡率(DR),电镜观察E.J细胞微结构的改变。建立裸鼠的膀胱肿瘤模型,腹腔内注射IL-12基因质粒和THP,观察肿瘤体积和血清IL-12水平变化。结果体外实验发现IL-12联合THP治疗组的DR值最高为58.2%±15.8%,明显高于THP组(12.2%±5.6%,P=0.01)和IL-12组(33.4%±7.8%,P=0.046)。并且电镜下发现联合治疗组的肿瘤细胞坏死和凋亡改变最为明显。动物实验中发现IL-12联合THP治疗后,肿瘤体积明显减小,其血清IL-12水平也较其他组明显增高(P<0.01)。结论 IL-12联合THP化疗对膀胱肿瘤生长有明显的抑制作用,免疫基因联合化疗可能作为一种理想的膀胱肿瘤治疗方法。

Objective To evaluate the treatment effect of combined chemotherapy and interleukin-12(IL- 12)gene therapy in experimental urothelial bladder cancer(UBC)models both in vitro and in vivo.Methods EJ UBC cells were transfected with recombinant IL-12 genes using a liposomal transfection agent.Pirarubicin (THP)was added to the experimental samples at a final concentration of 20 mg/L.Death rates(DR)and cellular micromorphologic changes were evaluated.Bladder tumor model was established by subcutaneous injection of EJ cells to the nude mice.Following the combinant therapy of THP and IL-12 gene injection,Tumor size and IL-12 levels were tested.Results In vitro study:DR in the THP& IL-12 gene therapy group(58.2%±15.8%)was significantly higher than groups 1(12.2%±5.6%;P=0.01)and 2(33.4%±7.8%;P= 0.046).The highest amount of apoptosis changes and necrosis was observed in group 3 under electron microscope. In vivo study:A significant tumor attenuation was found in IL-12& THP group compared with any other groups(P<0.05).Serum IL-12 levels were significantly higher in IL-12 gene groups(P<0.01).Conclusions The combination of chemotherapy and IL-12 gene therapy demonstrated a synergistic suppression on bladder tumor cells both in vitro or in vivo.Further investigations should be focused on the high sufficent transgene protocols in vivo.