Study Of Targeting Augmentation Of HSV-TK Gene Transfection By Nanoscale Ultrasound Microbubble Of Hepatoma HepG2Cell In Vitro

About500,000new liver cancer cases diagnosed in each year. Livercancer has resulted in the third highest mortality rate among themalignancies, following lung cancer and stomach cancer[1]. Due to theoccult onset, high malignancy degree and high mortality of liver cancer,most patients were already in the middle or late stage of cancer when theystarted to show obvious symptoms, and thus had missed the best time oftreatment. At this stage, removal of tumors by surgery would have poorefficacy due to the high risk of recurrence and metastasis. Therefore, it isextremely important to develop novel strategies for the treatment of livercancer.Suicide gene is one of the best programs in gene therapy of cancer now,HSV-TK gene is the most mature system used in liver cancer[2-3]. Thetreatment of tumors is based on the principle of invertase gene, which canblock the nucleotide metabolism by producing toxic substances, or enhancethe sensitivity to chemotherapeutic drugs of tumor cells, and achieve thepupose of killing tumor cells effectively[4]. But due to the lack of systemsaccuracy, low efficiency of gene transfection cells, It have been restricted its widespread application in clinical and scientific research.Targeted cancer therapy can destroy cancer cells highly specificallyand efficiently, and thus can be widely used for the treatment of tumors. Atpresent, in most targeted binding approaches, the targeting genes,antibodies and peptides are conjugated to the carrier, which can bespecifically delivered to the target tissue or organ and subsequently bind tospecific antigen or receptor via the corresponding antibody or ligand on itssurface. To date, using microbubbles as the carrier has become a hotresearch spot for the diagnosis and treatment of tumors[5-8]. Particularly, theultrasound microbubble has been thought to be an ideal carrier, due to itssafety, wide application and rapid metabolism. At the same time, as a carrierof gene transfection,gene can be better protected by ultrasoundmicrobubbles in the process of gene transfer. With the aid of ultrasoundmicrobubble link on the specificity of the antibodies, aim genes will beleaded into tumor cells more accurately, by using low frequency ultrasonicexpose them, further increase the efficiency of gene transfection, but purposegene itself will not damaged at all.As a result, the principle of this research is the use of ultrasoundmicrobubble targeting to tumor cells enhancing the gene transfection.Itcarrys together with HSV-TK containing EGFP gene and targetedultrasound microbubble cantaining GPC3in the form of electrostaticadsorption,it has built nanoscale targeting ultrasound molecular probes which are cantaining HSV-TK gene and GPC3antibody successfully, thetargeted genes and liver cancer cells will be combined together. Using lowfrequency ultrasonic irradiation to enhance HSV-TK gene transfect HepG2cancer, observation the TK gene transfection and TK protein expression inhepatic carcinoma according flow cytometry、confocal scanning lasermicroscope、WB、Q-PCR and so on, In order to provided experimentalsupport for the application in the treatment of liver cancer in vivo.