Bmi-1在丁酸钠诱导肿瘤细胞凋亡过程中的作用机制

Research advances: the role of Bmi-1 in the mechanism of sodium butyrate-induced apoptosis in tumor cells

丁酸钠(Sodium butyrate,NaB)是一种组蛋白去乙酰化酶抑制剂(histone deacetylase inhibitors,HDACi),通过增加组蛋白的乙酰化,使染色质处于开放状态,便于基因转录与表达。多梳基因家族(Polycomb group genes,PcG)的成员Bmi-1蛋白可以对染色体组蛋白进行修饰,使一些抑癌基因如p14、P16和P21基因等表达沉默,同时Bmi-1蛋白通过Wnt信号通路激活原癌基因c-Myc,使Bmi-1、Wnt信号通路、c-Myc组成一个正反馈循环,还可以上调端粒酶的表达,导致肿瘤的发生。HDACi可以下调Bmi-1蛋白的表达,并通过上调p14、p16和p2l等的表达以及线粒体通路和Wnt信号通路抑制肿瘤细胞的增殖、分化,诱导肿瘤细胞凋亡。HDACi将可能为肿瘤的治疗提供一个广阔的前景,本研究将对Bmi-1在丁酸钠诱导肿瘤细胞凋亡过程中的作用机制作一综述。

Sodium butyrate is a histone deacetylase inhibitor （histone deacetylase inhibitors, HDACi ）, which makes the chromatin in an open state to facilitate the transcription and expression of genes by increasing histone acctylation. Bmi-1 is a member of the polycomb gene family （ Polycomb group genes, PcG） that can be used to modify histone, to make the expression of some tumor suppressor genes silencing such as P14, P16 and P21 gene, while the oncogenes c-Myc can be activated by Bmi-1 through Wnt signal pathway, resulting in a positive feedback loop composed of Bmi-1, Wnt pathway and c-Mye. It can also upregulate the expression of telomerase, resulting in tumor genesis. HDACi can downregulate the expression of Bmi-1 protein to inhibit tumor cell proliferation and dif- ferentiation, and induce tumor cell apoptosis by up-regulating the expressions of p14, p16 and p21 as well as mito- chondrial pathways and Wnt sigaling pathway. HDACi may offer a promising prospect for the treatment of cancer. This paper will give an overview of the role of Bmi-1 in the mechanism of sodium butyrate-induced apoptosis in tumor cells.