5α,6α-epoxy Cholestanol is a cholesterol derivative that can be catalytically generated by the cytochrome P450 enzyme system in mitochondria or induced during lipid peroxidation. 5α,6α-epoxy Cholestanol can regulate the biosynthesis of bile acids and induce the differentiation and death of tumor cells[1]. 5α,6α-epoxy Cholestanol is an epoxide compound generated by the oxidation of cholesterol under specific conditions and is one of the subtypes of 5,6-epoxycholestanol, possessing unique chemical and biological properties[2]. 5α,6α-epoxy Cholestanol can inhibit the 7α-hydroxylation of cholesterol, thereby affecting the synthesis of bile acids. Additionally, 5,6α-EC has a variety of biological functions, including regulating cell differentiation, promoting the death of tumor cells, activating cholesterol esterification, and modulating membrane properties[3, 4].
In vitro, treatment of MCF-7 breast cancer cells with 5α,6α-epoxy Cholestanol (20μM) for 12 hours stimulated the expression of liver X receptor α/β in MCF-7 cells and upregulated the synthesis of triglycerides[5].
References:
[1] Poirot M, Silvente-Poirot S. Cholesterol-5,6-epoxides: chemistry, biochemistry, metabolic fate and cancer. Biochimie. 2013 Mar;95(3):622-31.
[2] Bischoff F. Carcinogenic effects of steroids. Adv Lipid Res. 1969;7:165-244.
[3] Black HS, Lo WB. Formation of a carcinogen in human skin irradiated with ultraviolet light. Nature. 1971 Dec 3;234(5327):306-8.
[4] Black HS, Douglas DR. Formation of a carcinogen of natural origin in the etiology of ultraviolet light-induced carcinogenesis. Cancer Res. 1973 Sep;33(9):2094-6.
[5] Segala G, de Medina P, Iuliano L, et al. 5,6-Epoxy-cholesterols contribute to the anticancer pharmacology of tamoxifen in breast cancer cells. Biochem Pharmacol. 2013 Jul 1;86(1):175-89.
5α,6α-epoxy Cholestanol是一种胆固醇衍生物，可以通过线粒体中的细胞色素P450酶系催化生成或是在脂质过氧化过程中诱导生成，可调节胆汁酸的生物合成、诱导肿瘤细胞的分化和死亡[1]。5α,6α-epoxy Cholestanol是胆固醇在特定条件下氧化生成的一种环氧化合物，是5,6-epoxy Cholestanol的其中一个亚型，具有独特的化学和生物学特性[2]，5α,6α-epoxy Cholestanol 能够抑制胆固醇的7α-羟化，影响胆汁酸的合成，5α,6α-epoxy Cholestanol还具有调节细胞分化、促进肿瘤细胞死亡、激活胆固醇酯化以及调节膜性质等多种生物学功能[3, 4]。
在体外，5α,6α-epoxy Cholestanol（20μM）处理乳腺癌MCF-7 细胞12小时，刺激了MCF-7细胞中肝脏X受体α/β的表达，并上调了三酰甘油的合成[5]。