Study Of Golgi Membrane Glycoprotein GP73Promoter And Its Application In Targeting Treatment For Liver Cancer Using Adenovirus

Cancer is the second largest killer among all human diseases, which is next tocardiovascular disease, and seriously threats to human life and heath. In China, cancermorbidity increase year by year and became younger in average age. At present, themortality rate of human hepatocellular carcinoma (HCC) rank the second place in alltypes of cancers. The common therapeutic methods for HCC mainly including surgery,chemotherapy and radiotherapy et al. The surgery is feasible for patients who are inthe early phase, but not for most patients with advanced stage of liver cancer. And thetraditional therapeutic methods are difficult to work well. Thus, it is urgent to explorethe novel treatment strategies for improving HCC patients’survival and living quality.Our previous designed cancer targeting gene-virotherapy strategy, which combinedthe superiority of gene therapy and virotherapy, will bring the new hope for tumortherapy.Golgi membrane glycoprotein GP73is one of glycoprotein discovered in recentyears. Many results showed that GP73is a good HCC marker, and its sensitivity andspecificity are better compared with the custom liver cancer marker AFP, which reach75%and97%separately, while58%and85%for AFP. Based on the character ofGP73, we first cloned the GP73promoter sequence, and studied the activity ofGP73promoter by the Dual-Luciferase report system and screened the659bp coresequence of GP73promoter with high activity. Then, based on the Adeasy adenovirussystem and our previous constructed oncolytic adenovirus ZD55, we designed a novelselective replicated oncolytic adenovirus GD55, which is regulated by GP73promotercontrolling E1A replacing the endogenous promoter and has eliminated E1B55KDaand E3regions. Meanwhile, we also constructed the adenovirus GP73-EGFP carriedgreen fluorescent protein (EGFP). The experimental results in vitro showed that theGD55has the better specificity of antitumor proliferation ability than that of ZD55,and exhibits the targeting antitumor effect in HCC cells with the lesser side-effect toliver normal cells. Further animal experiments in vivo showed that GD55has goodsuppression effect on liver cancer growth in xenografted HCC mice. In conclusion, the study has successfully screened the specific GP73promotercore region for HCC， and constructed oncolytic adenovirus vector GD55fortargeting HCC. The preliminary results indicated that GD55has good liver cancerspecific and acts as the candidate of the individual targeting cancer gene-viral therapyfor HCC, which lay on the foundation for future clinical liver cancer individualtherapy.