增殖性溶瘤腺病毒介导不同抑癌机制miRNA联合作用的胰腺癌靶向治疗实验研究

Pancreatic cancer is one of the most devastating malignant cancers without effective treatments clinically. In our previous study supported by the National Natural Science Foundation of China, we developed a human carcinoembryonic antigen (CEA) promoter-regulated oncolytic adenovirus carrying the Hsp70 gene (AdCEAp-Hsp70) ,which the the adenovirus AdF35 was constructed to be a vector to carry the targeted gene Hsp70 only to express in pancreatic cancer cells. In order to improve the anti-tumoral efficacy of the adenovirus, in this study, we intend to clone both tumor-suppressive miRNA34a and miRNA-let-7 into the AdF35 controlled by CEA promoter which was successfully constructed in our previous study. The generated Ad5F35-miRNA34a-let-7 posseses the potential of strong tumor suppression of the tow miRNAs with different mechanisms and the oncolytic function of adenovirus as well. The anti-tumoral efficacy will be significantly enhanced by the mutiple anti-tumoral mechanisms of the Ad5F35- miRNA34a-let-7. In order to evaluate the toxicity， Ad5F35- miRNA34a-let-7 will be administrated intravenously or intraperitoneally, the time, frequency and dosage of Ad5F35- miRNA34a-let-7 given to the mice will be investigated to provide a theoretical basis for this virus to be applied clinically in the future.

胰腺癌恶性度高，临床缺乏有效的治疗手段。在我们前期完成的国家自然科学基金课题研究中，我们通过CEA基因启动子控制高感染力腺病毒载体AdF35运输Hsp70基因表达，达到靶向胰腺癌治疗的目的。为进一步提高抗肿瘤疗效，增加安全性，本项研究利用前期构建的CEA启动子调控的增殖性靶向性腺病毒Ad5F35为运输载体，克隆入不同抑癌机制的miRNA34a和miRNAlet-7，制备Ad5F35- miRNA34a-let-7治疗系统。使该腺病毒能靶向胰腺癌细胞表达释放不同抑癌作用的miRNA34a和miRNAlet-7，与病毒靶向增殖产生的溶瘤作用一起，多重抗肿瘤机制发挥协同作用，显著提高抗肿瘤疗效。通过静脉注射以及腹腔注射等不同治疗方式，观察Ad5F35- miRNA34a-let-7对小鼠的急性毒性作用，对其用药时机、频率、给药剂量及途径等进行初步研究，为其临床应用提供确切的理论依据。

胰腺癌恶性度高，临床缺乏有效的治疗手段。我们通过CEA基因启动子控制高感染力腺病毒载体AdF35运输Hsp70基因表达，达到靶向胰腺癌治疗的目的。为进一步提高抗肿瘤疗效，增加安全性，本项研究利用前期构建的CEA启动子调控的增殖性靶向性腺病毒Ad5F35为运输载体，克隆入不同抑癌机制的miRNA34a和miRNAlet-7，制备Ad5F35- miRNA34a-let-7治疗系统。使携带双miRNA的腺病毒能靶向胰腺癌细胞表达释放抑癌作用的miRNA34a和miRNAlet-7，与病毒靶向增殖产生的溶瘤作用一起，多重抗肿瘤机制发挥协同作用，显著提高抗肿瘤疗效。我们通过静脉注射以及腹腔注射等不同治疗方式，观察Ad5F35- miRNA34a-let-7对小鼠移植瘤的抗癌作用，收到了很好的疗效，也未发现毒副作用，为其临床应用提供确切的理论依据。我们按照原定计划，完成了既定研究任务，发表SCI论文一篇，中文统计源期刊一篇，另有一篇SCI论著在撰写中。