Li Dawei, Zhou Liang, Huang Jiameng, Xiao Xiyan
Department of Otolaryngology - Head and Neck Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai 200233, P.R. China.
Department of Otolaryngology - Head and Neck Surgery, Affiliated Eye and Ear, Nose and Throat Hospital of Fudan University, Shanghai 200031, P.R. China.
Oncol Lett. 2016 Aug;12(2):1569-1574. doi: 10.3892/ol.2016.4749. Epub 2016 Jun 17.
In a previous study, it was demonstrated that hypoxia upregulated the multidrug resistance (MDR) of laryngeal cancer cells to chemotherapeutic drugs, with multidrug resistance 1 (MDR1)/P-glycoprotein (P-gp) expression also being upregulated. The present study aimed to investigate the role and mechanism of MDR1/P-gp on hypoxia-induced MDR in human laryngeal carcinoma cells. The sensitivity of laryngeal cancer cells to multiple drugs and cisplatin-induced apoptosis was determined by CCK-8 assay and Annexin-V/propidium iodide staining analysis, respectively. The accumulation of rhodamine 123 (Rh123) in the cells served as an estimate of drug accumulation and was evaluated by flow cytometry (FCM). MDR1/P-gp expression was inhibited using interference RNA, and the expression of the MDR1 gene was analyzed using reverse transcription-quantitative polymerase chain reaction and western blotting. As a result, the sensitivity to multiple chemotherapeutic agents and the apoptosis rate of the hypoxic laryngeal carcinoma cells increased following a decrease in MDR1/P-gp expression (P<0.05). Additionally, FCM analysis of fluorescence intensity indicated that the downregulated expression of MDR1/P-gp markedly increased intracellular Rh123 accumulation (P<0.05). Such results suggest that MDR1/P-gp serves an important role in regulating hypoxia-induced MDR in human laryngeal carcinoma cells through a decrease in intracellular drug accumulation.
在先前的一项研究中，已证明缺氧会上调喉癌细胞对化疗药物的多药耐药性（MDR），同时多药耐药蛋白1（MDR1）/P-糖蛋白（P-gp）的表达也会上调。本研究旨在探讨MDR1/P-gp在缺氧诱导的人喉癌细胞多药耐药中的作用及机制。分别通过CCK-8法和膜联蛋白V/碘化丙啶染色分析来测定喉癌细胞对多种药物的敏感性和顺铂诱导的细胞凋亡情况。细胞中罗丹明123（Rh123）的蓄积作为药物蓄积的一个指标，并通过流式细胞术（FCM）进行评估。使用干扰RNA抑制MDR1/P-gp的表达，并通过逆转录-定量聚合酶链反应和蛋白质印迹法分析MDR1基因的表达。结果显示，随着MDR1/P-gp表达的降低，缺氧喉癌细胞对多种化疗药物的敏感性及凋亡率增加（P<0.05）。此外，FCM对荧光强度的分析表明，MDR1/P-gp表达下调显著增加了细胞内Rh123的蓄积（P<0.05）。这些结果表明，MDR1/P-gp通过减少细胞内药物蓄积在调节缺氧诱导的人喉癌细胞多药耐药中发挥重要作用。
