5－氮－2＇－脱氧胞苷（5－aza－CdR）对HL－60细胞分化和DNA甲基化酶的影响

以５－氮－２＇－脱氧胞苷（５－ａｚａ－ＣｄＲ）为诱导物，在０．５μｍｏｌ／Ｌ的最佳浓度下，可诱导ＨＬ－６０细胞分化达１５％左右。同时，用［￣３Ｈ］－ｍｅｔｈｙｌ－ｓ－ａｄｅｎｏｓｙｌｍｅｔｈｉｏｎｉｎｅ（￣３Ｈ－ＳＡＭ）为底物，通过同位素参入法，测定了不同浓度诱导物对ＨＬ－６０细胞ＤＮＡ甲基化酶活力的影响，发现在最佳诱导物浓度下，可使ＨＬ－６０细胞ＤＮＡ甲基化酶活力明显下降，此外，也比较了不同分化水平的ＨＬ－６０细胞中具有不同甲基化水平的ＤＮＡ在体外接受甲基的能力，从而证明５－ａｚａ－ＣｄＲ诱导ＨＬ－６０细胞分化与其ＤＮＡ甲基化状态密切相关。

The Effect of 5-Aza-2'-deoxycytidine (5-Aza-CdR)on Cell Differentiation and DNA Methylase of HL-60 Cells

The differentiation index of HL-60 cells was measured after being treated with 5-aza-CdR by using The NBT staining method. The value of differentiation index is 15% or so when the concentration of 5-aza-CdR is 0. 5μmol/L. The DNA methylase activities of HL-60 cells treated with the drug were assayed by using 3H-methyl-S-adenosylmethionine (3H-SAM) as methyl donor. The DNA methylase activities of HL-60 cells were obviously decreased by the treatment of 5-aza-CdR. This change was related to the concentration of 5-aza-CdR. The DNA methylase activities of different HL-60 cells were also compared by using different DNA substrates in vitro. All these results showed that the 5-aza-CdR could induce the differentiation of HL-60 cells and it was closely related to the activity of DNA methylase of HL-60 cells.