三氧化二砷诱导人骨髓增生异常综合征细胞株MUTZ-1细胞p15INK4B基因表达的研究

目的 探讨三氧化二砷（As2O3)去甲基化作用的机制。方法 采用甲基化特异PCR（MSP）检测p15INK4B基因甲基化，RT－PCR方法检测p15，甲基转移酶（DNMT）1，DNMT3A，DNMT3B的表达，MTT法检测As2O3对MUTZ－1细胞的生长抑制。结果 MUTZ－1细胞有p15INK4B基因甲基化，p15基因弱表达，As2O3作用后p15INK4B基因甲基化程度明显下降，p15基因表达增强，DNMT3A，DNMT3B mRNA的表达下降并呈浓度依赖性。结论 As2O3可能通过抑制甲基转移酶DNMT3A，DNMT3B，或（和）直接对p15INK4B基因去甲基化，使p15基因表达上调，恢复共活性。

Arsenic trioxide induced p15INK4B gene expression in myelodysplastic syndrome cell line MUTZ-1

Objective To investigate the mechanisms of arsenic trioxide (As 2O 3) induced demethylation. Method Methylation of p15INK4B gene in MUTZ 1 cell was detected by PCR using a methylation specific primer (MSP), the expression of P15,DNA methyltransferase(DNMT)1,DNMT3A and DNMT3B gene by RT PCR, the As 2O 3 induced growth inhibition of MUTZ 1 cell by MTT method. Results P15 gene failed to express in MUTZ 1 cells after methylation. The expression was recovered after the cells exposed to As 2O 3. As 2O 3could significantly down regulate DNMT3A and DNMT3B but not DNMT1 gene on mRNA level in a dose dependent manner. Conclusion As 2O 3 could activate the expression of p15 gene by demethylation or/and by inhibiting DNMT3A and DNMT3B gene.