罗勒多糖对缺氧条件下肝癌细胞组蛋白H3K9me2甲基化及G9a、JMJD1A表达的影响

Effect of Basil Polysaccharide on Histone H3K9me2 Methylation and Expression of G9a and JMJD1A in Hepatoma Cells Under Hypoxic Conditions

目的:研究罗勒多糖对缺氧条件下肝癌细胞MHCC97H和MHCC97L低氧诱导因子1α(HIF-1α)组蛋白甲基转移酶G9a、去甲基化酶JMJD1A的表达及组蛋白H3K9me2甲基化水平的影响,探讨罗勒多糖对肝癌细胞表观遗传学的调节作用。方法:采用二氯化钴(Co Cl2)模拟细胞缺氧,建立肝癌细胞MHCC97H和MHCC97L体外缺氧模型,通过不同浓度罗勒多糖干预24 h,实时荧光定量PCR法检测各组肝癌细胞中HIF-1α、G9a和JMJD1A mRNA表达水平,Western-blot法检测各组肝癌细胞中HIF-1α、G9a、JMJD1A蛋白表达情况及组蛋白H3K9me2甲基化水平。结果:罗勒多糖能下调MHCC97H细胞缺氧条件下HIF-1α、G9a、JMJD1A mRNA和蛋白的表达和组蛋白H3K9me2甲基化水平以及MHCC97L细胞缺氧条件下HIF-1αmRNA和蛋白的表达和组蛋白H3K9me2甲基化水平(P<0.05)。结论:罗勒多糖对缺氧条件下不同转移潜能肝癌细胞MHCC97H和MHCC97L组蛋白H3K9me2甲基化水平均有有调节作用,其中对高转移潜能肝癌细胞MHCC97H组蛋白H3K9me2甲基化的调节与组蛋白甲基转移酶G9a和去甲基化酶JMJD1A有关,而对低转移潜能肝癌细胞MHCC97L组蛋白H3K9me2甲基化的调节可能是通过其他通路发挥作用。

Objective： To study the effect of basil polysaccharide on the expression of histone methyltransferase G9 a,demethylase JMJD1 A and histone H3K9me2 methylation level in hepatoma cells MHCC97 H and MHCC97 L under hypoxic conditions,in order to explore the regulatory effect of basil polysaccharide on the epigenetics of hepatoma cells. Methods： Cobalt chloride（ Co Cl2） was used to simulate hypoxic,MHCC97 H and MHCC97 L hepatoma cells hypoxia model was established in vitro,and then intervened with different concantration of basil polysaccharide intervened 24 h. The expression of HIF-1α,G9 a and JMJD1 A mRNA in hepatoma cells were detected by real time fluorescent quantitative PCR. The expression of HIF-1α,G9 a,JMJD1A protein and histone H3K9me2 methylation level was detected by Western-blot method. Results： Basil polysaccharide down-regulated the expression of HIF-1α,G9 a,JMJD1A mRNA and protein and histone H3K9me2 methylation level in MHCC97 H cells under hypoxic condition,and down-regulated the expression of HIF-1α mRNA and protein and histone H3K9me2 methylation level in MHCC97 L cells under hypoxic condition（ P〈 0. 05）. Conclusion： Basil polysaccharide can regulate histone H3K9me2 methylation levels in hepatoma cells MHCC97 H and MHCC97 L which have different metastatic potential under hypoxic conditions. On hepatoma cell MHCC97 H,the regulation of histone H3K9me2 methylation is associated with histone methyltransferase G9 a and demethylase JMJD1 A. In hepatoma cell MHCC97 L,the regulation of histone H3K9me2 methylation was probably through other pathways.