[Establishment of the drug resistant cell line of choriocarcinoma and the reversal of drug resistance by transfection of human interleukin 2 gene].

OBJECTIVE: To establish the drug-resistant cell line of choriocarcinoma and to study the transfection of the human interleukin 2 (hIL-2) gene into the established drug resistant cell line and investigate the reversal of the multidrug resistance. METHODS: The resistant cell line was established by pulse exposed choriocarcinoma cell line JEG-3 to etopside (VP-16) for ten months. The recombinant plasmid containing pcDNA3.1(+)-hIL-2 gene was constructed. The drug resistant cell line was transfected with the constructed plasmid by lipofectin, and the tumor cell colonies containing the IL-2 sequence were selected by genetin. The expression of hIL-2 and drug resistant-related genes was detected by reverse transcript polymerase chain reaction. The chemosensitivity of the gene-transfected tumor cells and the non transfected cell lines to methetraxate, VP-16, kengshengmycine, paclitaxol and 5-fluorouracil was determined by the methyl thiazolyl tetrazolium cytotoxicity assay. RESULTS: The transfected cells expressed human hIL-2 gene, and showed the reversal of multidrug resistance by methyl thiazolyl tetrazolium assay. The transfected cells expressed no multidrug resistance gene-1 (MDR1) on mRNA level. Drug resistance index to VP-16 decreased from 38.7 to 6.0 and 6.1, the index to methetraxate decreased from 14.5 to 2.6 and 2.5, to methetraxate from 13.0 to 2.0. CONCLUSION: The transfection of hIL-2 gene into the drug resistance cell line of choriocarcinoma can modulate the MDR1 expression on the mRNA level, and reverse the drug resistance.