Abstract:
To investigate the relationship between drug resistance and the lung resistance protein ( LRP ) by establishing a human nasopharyngeal carcinoma drug-resistant cell line. Methods: Cisplatin resistance was induced in human nasopharyngeal carcinoma cell line TW03 by continuous exposure to gradually increasing doses of cisplatin. The resistance index of the resulting cell line, TW03/DDP, was estimated by the MTT assay. The cell cycle was examined by flow cytometry. Cell growth, doubling time, and cellular appearance were also investigated. LRP expression was measured by immunocytochemisty, Western blot, and reverse transcriptase polymerase chain reaction. Results: The resistance indices of TW03/DDP to cisplatin, 5-fluorouracil, adriamycin, cytrarabine, and vincristine were 40.85, 5.65, 26.68, 1.60, and 28.19, respectively. The proliferation of TW03/DDP was slower than TW03. The doubling time lengthened. The cell number of the G2/M-phase increased, whereas that of the G1/M-phase decreased, compared with TW03. LRP mRNA and LRP were both up-regulated in TW03/DDP compared with TW03. Conclusion: Cisplatin-resistant cell line TW03/DDP was established, and exhibited a typical phenotype resistant to anti-cancer drugs. LRP expression in TW03/DDP was higher than in TW03. The drug resistance of TW03/DDP correlated with the up-regulation of LRP.