In Vitro And In Vivo Study On Reversing The Drug Resistance Of Choriocarcinoma Cell Line JEG-3/VP2 By Transfected With HTNF-α

Objective Choriocarcinoma is one of curable tumors, which occurs at very high frequencies in pregnant women and sensitive to chemotherapy. Chemotherapy is the main treatment modality of choriocarcinoma, but a major obstacle to successful chemotherapy is drug resistance. The mortality of drug-resistant choriocarcinoma patients is about 60% and novel strategies need developing. Because the drug resistance of choriocarcinoma cells is mostly acquired, it will be effective to improve the chemotherapy results by reversing it. This study is designed to transfect huTNF-α gene into a drug-resistant choriocarcinoma cell line using gene engineering technology and observe the changes of its drug resistance in vitro and in vivo.Methods Human TNF-α gene was obtained by PCR amplification and cloned into pcDNA3.1-myc-his(-) expression vector. The constructed vector was transfected into a drug-resistant choriocarcinoma cell line JEG-3/VP2 with lipofectinmin. The positive clones were screened out by G418 and their drug-resistant indexes for VP-16 were examined. The expression levels of MDR1 mRNA in positive cells and control cells were analyzed by RT-PCR. The nude mouse model for transfected cells was constructed and the weight of plant tumors was weighted. The expression levels of MDR1 mRNA and MDR1 protein in plant tumors were tested by RT-PCR and immunohistochemisty.Results The mRNA of huTNF-α was detected in the transfected carcinoma cells. The resistance to VP-16 and the mRNA level of MDR1 in transfected cells dramatically decreased compared with the control cells. The weight of the plant tumors of the transfected group was obviously lower than that of the control group and the difference was significant (P<0.05). The drug resistance of the plant tumors of the transfected cells clearly reduced relative to the control as well as their expression levels of MDR1 mRNA and MDR1 protein.Conclusion Transfecting huTNF-α gene into a drug-resistant choriocarcinoma cell line was able to reverse its drug resistance at both mRNA level and protein level, increase its sensitivity to cytotoxic drugs and reduce its tumorigenesity.