The Study Of Biological Characteristics And Multiple-drug Resistance Of Taxol-resistant Nasopharyngeal Carcinoma Cells Lines

Objectives to observe the biological characteristics of two paclitaxel-resistance cell lines of nasopharyngeal carcinoma (CNE-1 /Taxol,HNE-2/Taxol) that set up in our laboratory and explore its Multidrug resistance and the role of MDR-1 in acquired Paclitaxel-resistance.Methods Two paclitaxel-resistance nasopharyngeal carcinoma cell lines(CNE-1/Taxol,HNE-2/Taxol) have been successfully established, using large dose paclitaxel attacking the cells then low dose paclitaxel maintaining in the cells. The difference of cell morphology, cell growth curves and the doubling time between the parent cells and the drug-resistant cells was compared. the changes of the cell cycle was detected by flow cytometry; The sensitivity of cell line to paclitaxel, cisplatin,5-fluorouracil, methotrexate and bleomycin was detected by colony formation assay. mRNA expression of MDR-1 of cells were assessed by real-time RT-PCR.Results the cell morphology of Two paclitaxel-resistance nasopharyngeal carcinoma cell lines(CNE-1/Taxol,HNE-2/Taxol) is different from parent cells. The rate of cell proliferation of drug-resistant cells was longer than that of parent cells, the double time of the drug-resistant cells was extended and the rate of cells in G2/M phase was increased, The results of Colony formation assay revealed that the sensitivity to paclitaxel of drug-resistance cell lines(CNE-1/Taxol,HNE-2/Taxol) is significantly lower than its parental cell (CNE-1, HNE-2), the IC50 values of drug-resistance cell lines were 9.59±0.26,7.62±0.21, the parental cells were 1.14±0.08,0.92±0.08; at the same time, the sensitivity to 5-fluorouracil and methotrexate of drug-resistance cells was significantly lower than its parental cells, but the resistance index was significantly lower than its to paclitaxel. However, the sensitivity to cisplatin of drug-resistance cells was significantly higher than its parental cell, the IC50 values of of drug-resistance cells were, the parental cells were; the sensitivity to bleomycin of drug-resistance cells did not change (p>0.05) compared with the parental cell line; real-time RT-PCR results show that MDR-1 in the two parent cells were very low, and no significant increase in drug-resistance cells.Conclusion CNE-1/Taxol and HNE-2/Taxol are two pairs of cell lines resistant to paclitaxel,.it is an important model for studying the mechanisms of paclitaxel-resistance. Two cell lines with the characteristics of multi-drug resistance resistant to 5-fluorouracil and methotrexate; But the sensitivity to cisplatin was inversely increased. The expression of MDR-1 might not contribute to acquired Paclitaxel-resistance in nasopharyngeal carcinoma.