Inhibition of topoisomerase II α activity and induction of apoptosis in mammalian cells by semi-synthetic andrographolide analogues
作者:Jintapat Nateewattana、Rungnapha Saeeng、Sakkasem Kasemsook、Kanoknetr Suksen、Suman Dutta、Surawat Jariyawat、Arthit Chairoungdua、Apichart Suksamrarn、Pawinee Piyachaturawat
DOI:10.1007/s10637-012-9868-9
日期:2013.4
Topoisomerase II α enzyme plays a critical role in DNA replication process. It controls the topologic states of DNA during transcription and is essential for cell proliferation. Human DNA topoisomerase II α (hTopo II α) is a promising chemotherapeutic target for anticancer agents against a variety of cancer types. In the present study, andrographolide and its structurally modified analogues were investigated for their inhibitory activities on hTopo II α enzyme. Five out of nine andrographolide analogues potently reduced hTopo II α activity and inhibited cell proliferation in four mammalian cell lines (Hela, CHO, BCA-1 and HepG2 cells). IC50 values for cytotoxicity of analogues 3A.1, 3A.2, 3A.3, 1B and 2C were 4 to 7 μM. Structure-activity relationship studies revealed that both core structure of andrographolide and silicon based molecule of functional group were important for the inhibition of hTopo II α activity whereas position C-19 of analogues was required for anti-proliferation. In addition, the analogue 2C at 10 μM concentration inhibited hTopo II α, and induced apoptosis with nuclear fragmentation and formation of apoptotic bodies in HepG2 cells. The analogue 2C may, therefore, have a therapeutic potential as effective anticancer agent targeting the hTopo II α functions.
拓扑异构酶 II α 在 DNA 复制过程中发挥着关键作用。它在转录过程中控制 DNA 的拓扑状态,对细胞增殖至关重要。人类DNA拓扑异构酶II α(hTopo II α)是一种很有前景的抗癌化疗靶点。本研究研究了穿心莲内酯及其结构修饰类似物对 hTopo II α 酶的抑制活性。九种穿心莲内酯类似物中有五种能有效降低 hTopo II α 的活性,并抑制四种哺乳动物细胞系(Hela、CHO、BCA-1 和 HepG2 细胞)的细胞增殖。类似物 3A.1、3A.2、3A.3、1B 和 2C 的细胞毒性 IC50 值为 4 至 7 μM。结构-活性关系研究表明,穿心莲内酯的核心结构和功能基团的硅基分子对抑制 hTopo II α 的活性非常重要,而类似物的 C-19 位则是抗增殖的必要条件。此外,类似物 2C 在 10 μM 浓度下可抑制 hTopo II α,并诱导 HepG2 细胞凋亡,使细胞核破碎并形成凋亡体。因此,类似物 2C 可能具有治疗潜力,可作为针对 hTopo II α 功能的有效抗癌剂。