HL-60细胞内DNA甲基化作用与RNA聚合酶活力的关系

以 S-腺苷酰 - L-甲硫氨酸 ( SAM)为诱导物 ,在 1 0 μmol/L最佳浓度下可诱导 HL- 60细胞分化达 1 6%左右 .HPLC测定结果证明 ,诱导物处理后 HL- 60细胞 DNA甲基化水平升高 .通过 3 H-UTP同位素参入法 ,测定了不同处理时间和不同浓度 SAM对 HL- 60细胞 DNA模板体外转录活性的影响 ,发现体外活力下降 .比较了不同浓度α-鹅膏蕈碱存在下 RNA聚合酶活力的变化 ,结果表明 SAM处理后细胞中不同 RNA转录产物所占份额改变

Relationship between DNA Methylation and Activities of RNA Polymerases in HL-60 Cells

The differentiation index of HL 60 cells was measured after being treated with S Adenosyl L Methionine(SAM) by using the NBT staining method.The value of differentiation index is 16% or so when the concentration of SAM was 10 μmol/L.The methylation level of genomic DNA of HL 60 cells was analysed by HPLC.It was found that the DNA methylation level of HL 60 cells after being treated with SAM was increased in comparing with that control cells.The RNA polymerase activities of HL 60 cells in vitro by means of incorporation of 3H UTP,and results showed that RNA polymerase activities of SAM treated HL 60 cells were no higher than that of control cells.It was found that the sensitivity of RNA polymerase to the α amanitin,a specific inhibitor of RNA polmerase,was also obviously changed.This suggested that SAM may result in the different expression of various RNA in HL 60 cells.