背景与目的:榄香烯(elemene,ELE)是传统抗肿瘤中药制剂,目前药效机制尚不明确.本研究旨在探讨ELE对人肝癌HepG-2细胞增殖及DNA拓扑异构酶Ⅰ(topoisomerase Ⅰ,TOPO Ⅰ)的影响.方法:采用四甲基偶氯唑蓝还原法(MTT)观察ELE对HepG-2细胞增殖的影响;采用流式细胞术(FCM)检测ELE对HepG-2细胞周期的影响;采用RT-PCR法检测ELE对HepG-2细胞TOPO Ⅰ mRNA表达的影响;采用TOPO Ⅰ介导的负超螺旋PBR322DNA 解旋反应检测ELE对TOPO Ⅰ酶活性的影响;采用负超螺旋PBR322DNA检测ELE对DNA的直接抑制作用.结果:ELE能抑制HepG-2细胞增殖,其抑制效应具有时间和剂量依赖性;阻滞HepG-2细胞于S期,呈剂量依赖性;下调TOPO Ⅰ mRNA表达,呈剂量依赖特性;对TOPO Ⅰ介导的负超螺旋PBR322DNA解旋反应有抑制作用;对负超螺旋PBR322DNA没有直接抑制作用.结论:ELE能够抑制HepG-2细胞增殖;影响TOPO Ⅰ的表达及活性可能是其作用机制之一.%Background and purpose: The elemene (ELE) is a traditional Chinese antitumor drug. However,its mechanism is still unclear. The purpose of this study was to investigate the effects of ELE on the proliferation and topoisomerase Ⅰ (TOPOⅠ ) of hepatocarcinoma HepG-2 cells. Methods: The cells proliferation were assessed by MTT assay. Cell cycles were shown through FCM. TOPOⅠ mRNA expression was analyzed by RT-PCR. The activity of TOPOⅠ was measured by a TOPOⅠ mediated supercoiled PBR322 relaxation. The supercoiled PBR322 was also used to determine the direct DNA breakages. Results: ELE siguificantly inhibited HepG-2 cells proliferation in doseand time-dependent ways, induced tumor cells arrested at the S-phase. Decreased TOPOⅠ mRNA expression in dosedependent ways, inhibited the TOPOⅠ mediated DNA relaxations, but could not directly induce DNA breakage at any concentrations. Conclusion: ELE could inhibit the proliferation of human hepatocellular carcinoma HepG-2 cells. The regulation of TOPOⅠ activity and mRNA expression might be one of the mechanisms of ELE anti-tumor.
展开▼
