中文摘要：

目的：探讨 ABC 转运体家族在鼻咽癌肿瘤干细胞表达及对顺铂耐药机制的作用。方法通过罗丹明123外排实验及钠钾 ATP 酶活性检测,观察鼻咽癌细胞 CNE-2与鼻咽癌肿瘤干细胞 CNE-2S 之间药物外排能力的差异。运用实时定量 RT-PCR 技术,测定两种细胞在顺铂作用下6个 ABC 转运体家族成员 mRNA 的表达情况,并采用 Western blot 检测 ABCA3、ABCC1、ABCC2及 ABCG2的蛋白表达水平。利用小分子 RNA 干扰技术沉默 ABCA3基因后,观察两种细胞药物外排及顺铂诱导的凋亡情况。结果顺铂对 CNE-2S 的半数抑制浓度（IC50）为 CNE-2的4.1倍（P〈0.05）,同时CNE-2S 的相对药物外排活性为 CNE-2的4.8倍（P〈0.05）。 CNE-2S 较 CNE-2高表达 ABCA3、ABCB1、ABCC1及 ABCG2（P〈0.05）。1μmol.L^－1顺铂作用48 h 后,ABCA3在 CNE-2S 中特异性高表达,沉默 ABCA3后能显著抑制 CNE-2S 的药物外排能力（P〈0.05）,并增强顺铂对 CNE-2S 及 CNE-2的诱导凋亡能力（P〈0.05）。结论鼻咽癌肿瘤干细胞对顺铂耐药与高表达 ABCA3、ABCC1及 ABCG2有关,抑制 ABCA3的表达能逆转肿瘤干细胞对顺铂的杀伤作用。

英文摘要：

Objective To investigate the role of ATP-binding cassette （ ABC ） family on the resistance of nasopharyngeal carcinoma （NPC） stem cells （CSCs） to cisplatin. Methods We compared the differences between the drug extravasation capability of CNE-2 and CNE-2S by using Rhodamine-123 efflux assay. We determined the mRNA and protein expression levels of ABC transport family members, including ABCA3,ABCB1,ABCB5,ABCC1,ABCC2 and ABCG2,after 48 h being treated with 1 μmol.L-1 cisplatin by RT-PC and Western blotting.Rhoamine-123 efflux and apoptosis by cisplatin in two kinds of cells was examined by ABCA3 gene silencing with specific small-interfering RNA. Results The IC50 of cisplatin on CNE-2S was 4.1 fold to that on CNE-2（P〈0.05）.For the relative drug effluent activity and Na^＋K^＋ ATPase activity,CNE-2S was 4.8 fold to CNE-2（P〈0.05）,suggested that CNE-2S expressed more ABCA3,ABCB1,ABCC1 and ABCG2 in comparison to CNE-2（P〈0.05）.After 48 h treatment with 1 μmol.L^-1 cisplatin,ABCA3 specifically highly expressed in CNE-2S （P〈0.05）, and knocking down of ABCA3 resulted in reduction of rhodamine-123 efflux and increase of apoptosis. Conclusion The cisplatin resistance of NPC CSCs is associated with enhanced expression of ABCA3,ABCC1 and ABCG2, suppression of ABCA3 could reverse the resistance of NPC CSCs to cisplatin.