Theron Anne, Prudent Renaud, Nolte Elsie, van den Bout Iman, Punchoo Rivak, Marais Sumari, du Toit Peet, Hlophe Yvette, van Papendorp Dirk, Lafanechère Laurence, Joubert Annie
Department of Physiology, Faculty of Health Sciences, University of Pretoria, Private Bag X323, Arcadia, Pretoria, Gauteng, 0007, South Africa,
Cancer Chemother Pharmacol. 2015 Feb;75(2):431-7. doi: 10.1007/s00280-014-2653-z. Epub 2014 Dec 30.
2-Methoxyestradiol (2ME) is a promising anti-cancer agent that disrupts the integrity and dynamics of the spindle network. In order to overcome the pharmacokinetic constraints of this compound, a panel of sulphamoylated estradiol analogues were in silico-designed by our laboratory. In this study, we analysed the potential of each analogue to induce cell death on a panel of cancer cell lines. Moreover, the mechanism of action of the most effective compounds was determined.
Cytotoxicity screening of the compounds and intermediates was performed on five different cancer cell lines to determine IG50 values. An in vitro tubulin polymerization assay was done to determine the effect of the drugs on tubulin polymerization while their intracellular effects on the microtubule network were assessed by immunofluorescence microscopy.
IG50 calculations showed that the sulphamoylated analogues induce cytotoxicity at nanomolar concentrations in all cell lines, including the P-glycoprotein pump overexpressing multidrug-resistant uterine sarcoma cell line. The non-sulphamoylated compounds were only cytotoxic at micromolar ranges, if at all. The sulphamoylated compounds inhibited pure tubulin polymerization in a dose-dependent manner and induced microtubule destruction in cells after 24-h exposure.
Results revealed that the novel sulphamoylated 2ME derivatives have potential as anti-cancer drugs, possibly even against chemoresistant cancer cells. These compounds disrupt the intracellular microtubule integrity which leads to mitotic block of the cells.
2-甲氧基雌二醇（2ME）是一种很有前景的抗癌药物，它会破坏纺锤体网络的完整性和动态性。为了克服该化合物的药代动力学限制，我们实验室通过计算机辅助设计了一组氨磺酰化雌二醇类似物。在本研究中，我们分析了每种类似物在一组癌细胞系上诱导细胞死亡的潜力。此外，还确定了最有效化合物的作用机制。
对化合物及中间体在五种不同癌细胞系上进行细胞毒性筛选，以确定半数抑制浓度（IG50）值。进行体外微管蛋白聚合试验，以确定药物对微管蛋白聚合的影响，同时通过免疫荧光显微镜评估其对细胞内微管网络的影响。
IG50计算表明，氨磺酰化类似物在纳摩尔浓度下就能在所有细胞系中诱导细胞毒性，包括过表达P-糖蛋白泵的多药耐药子宫肉瘤细胞系。非氨磺酰化化合物即使有细胞毒性，也仅在微摩尔范围内。氨磺酰化化合物以剂量依赖方式抑制纯微管蛋白聚合，并在暴露24小时后诱导细胞内微管破坏。
结果表明，新型氨磺酰化2ME衍生物有作为抗癌药物的潜力，甚至可能对抗化疗耐药癌细胞。这些化合物破坏细胞内微管完整性，导致细胞有丝分裂阻滞。
