Ma Lianshun, Yang Yaping, Yin Zizhang, Liu Mei, Wang Liwei, Chen Lixin, Zhu Linyan, Yang Haifeng
Department of Pharmacology, School of Medicine, Jinan University, Guangzhou 510632, China; Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
Analysis and Test Center, Jinan University, Guangzhou 510632, China.
Biomed Pharmacother. 2017 Jun;90:615-625. doi: 10.1016/j.biopha.2017.03.088. Epub 2017 Apr 12.
Emodin is a natural anthraquinone derivative isolated from the Rheum palmatum. Recent studies demonstrated that emodin has anti-cancer activity in different kinds of human cancer cell lines. However, the underlying mechanism has not been very well studied. Our previous studies showed chloride channels is an important target of anti-cancer drugs. Therefore, the purpose of this research was aimed to explore the role of chloride channels involving in the anti-cancer activity of emodin. The proliferation, cell cycle arrest and apoptosis of poorly differentiated human nasopharyngeal carcinoma cells (CNE-2Z) and normal nasopharyngeal epithelial cells (NP69-SV40T) were detected by 3-(4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide(MTT)and flow cytometry. The results indicated that emodin inhibited the CNE-2Z cell growth more significantly than NP69-SV40T cells and induced cell cycle arrest and apoptosis in CNE-2Z cells but not in NP69-SV40T cells. Chloride channel blocker 5-nitro-2-(3-phenylprop ylamino)-benzoate (NPPB) or tamoxifen both can prevent the apoptosis of CNE-2Z cells induced by emodin. Optical microscope and atomic force microscope (AFM) demonstrated that emodin can induce apoptotic volume decrease (AVD) and ultrastructure changes in CNE-2Z cell and inhibited by chloride channel blocker. These data could be a further evidence of chloride channel for preventing CNE-2Z cells from apoptosis induced by emodin. Whole cell patch clamp study also demonstrated that emodin can activate chloride channel in CNE-2Z cells but not in NP69-SV40T cells. Furthermore, the activated chloride currents can also be inhibited by chloride channel blockers indicating that chloride channel may be the potential target molecular of emodin exerting its anti-tumor efficiency in CNE-2Z cells.
大黄素是从掌叶大黄中分离得到的一种天然蒽醌衍生物。最近的研究表明，大黄素在不同种类的人类癌细胞系中具有抗癌活性。然而，其潜在机制尚未得到很好的研究。我们之前的研究表明氯离子通道是抗癌药物的一个重要靶点。因此，本研究的目的是探讨氯离子通道在大黄素抗癌活性中的作用。采用3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐(MTT)法和流式细胞术检测低分化人鼻咽癌细胞(CNE-2Z)和正常鼻咽上皮细胞(NP69-SV40T)的增殖、细胞周期阻滞和凋亡情况。结果表明，大黄素对CNE-2Z细胞生长的抑制作用比对NP69-SV40T细胞更显著，并诱导CNE-2Z细胞的细胞周期阻滞和凋亡，但对NP69-SV40T细胞无此作用。氯离子通道阻滞剂5-硝基-2-(3-苯丙基氨基)-苯甲酸酯(NPPB)或他莫昔芬均可阻止大黄素诱导的CNE-2Z细胞凋亡。光学显微镜和原子力显微镜(AFM)显示，大黄素可诱导CNE-2Z细胞凋亡体积减小(AVD)和超微结构改变，并被氯离子通道阻滞剂抑制。这些数据可能进一步证明氯离子通道可防止大黄素诱导的CNE-2Z细胞凋亡。全细胞膜片钳研究还表明，大黄素可激活CNE-2Z细胞中的氯离子通道，但不能激活NP69-SV40T细胞中的氯离子通道。此外，激活的氯离子电流也可被氯离子通道阻滞剂抑制，这表明氯离子通道可能是大黄素在CNE-2Z细胞中发挥抗肿瘤作用的潜在靶点分子。
