Study on the different biological characteristics of a multi-drug resistant nasopharyngeal carcinoma cell line CNE2/DDP and its parental cell line CNE2 / 肿瘤

ABSTRACT

Objective: To observe the biological difference of multi-drug resistant nasopharyngeal carcinoma (NPC) cell line CNE2/DDP and its parental cell line CNE2, as well as analyze the characteristics of multi-drug resistant cells. Methods: The difference in morphological features, growth characteristics and colony formation rate in vitro were examined and compared under light microscope. Flow cytometry was used to evaluate the cell cycle distribution and the expression of P-170 and ABCG2 proteins. Drug sensitivity was measured by MTT assay. Tumorigenicity was evaluated after subcutaneous injection of 1 × 106 CNE2/DDP or CNE2 cells into BALB/c nude mice. Results: Under light microscope CNE2/DDP cells were smaller and showed a round shape and the CNE2 cells appeared polygonal cell bodies. CNE2/DDP cells had relatively longer colony doubling time than CNE2 cells (29.46 h vs 21.03 h) indicating that the growth of CNE2/DDP cells was slower. There was significant difference in the cell cycle distribution between CNE2/DDP and CNE2 cells [ (65.12 ± 1.67) % vs (44.9 ± 2.2) % in G0/G1 phase, (23.63 ± 0.42)% vs (39.67 ± 1.27) % in S phase, and (10.93 ± 0.25) % vs (13.23 ± 0.31)% in G2/M phase, P < 0.01]. Expression of P-170 and ABCG2 proteins in CNE2/DDP cells were significantly higher than that in CNE2 cells [(75.93 ± 0.86)% vs (2.83 ± 0.40)%, (43.37 ± 0.42) % vs (4.07 ± 0.59)% P < 0.01]. There was no significant difference in the resistance indexes of CNE2/DDP cells to DDP,5-FU and VCR before and after transplantation. The tumorigenicity time was (17.17 ± 1.17) d and (10.00 ± 2.68) d respectively for CNE2/DDP and CNE2 cells after being transplanted into BALB/c nude mice. Conclusion: CNE2/DDP has typical multi-drug resistance features and could be used for the research of drug-resistant NPC.