[Combination of cytosine arabinoside and cisplatin enhances inhibition of cell proliferation and promotes apoptosis of resistant nasopharyngeal carcinoma cells].

Objective: To investigate the synergistic cytotoxicity of cisplatin and cytosine arabinoside (Ara-C) on nasopharyngeal carcinoma (NPC) cell lines TW03 and cisplatin-resistant TW03/DDP which is cisplatin-induced drug-resistant cell line.

Methods: The TW03/DDP cells was established by gradually increasing the dose of cisplatin, and then examined by real-time quantitative PCR (qRT-PCR) and semi-quantitative Western blotting for the expression level of lung resistance-related protein (LRP). Effects of DDP and Ara-C combined treatment or alone on proliferation and apoptosis of TW03/DDP cells and TW03 cells were detected by CCK-8 assay and flow cytometry, respectively.

Results: Compared with TW03 cells, TW03/DDP cells expressed higher level of LRP. After treatments for 24 hours, both cisplatin and Ara-C inhibited proliferation and caused apoptosis of TW03/DDP and TW03 cells, and DDP showed minor effect on the proliferation of TW03/DDP cells. Compared with Ara-C or DDP treatment alone, combination of Ara-C and DDP showed a more remarkable inhibition of proliferation and promotion of apoptosis in both TW03 and TW03/DDP cells.

Conclusion: Ara-C and DDP have a synergistic killing effect on NPC cell lines with and without DDP-caused drug resistance, and show better effects on proliferation inhibition and apoptosis promotion than Ara-C or DDP treatment alone, which provides a novel and prospective strategy for NPC chemotherapy.