5-氮-2-脱氧胞苷对前列腺癌细胞株谷胱苷肽-S-转移酶1和维A酸受体β2基因甲基化状态的影响

The effects of 5-Aza-2＇-deoxycytidine, a methylation inhibitor, on the proliferation of androgen-sensitive prostate cancer cell line, and on the regulation of methylation of glutathione s-transferase P1 and retinoicacid receptorβ2 gene

目的研究甲基转移酶抑制剂5-氮-2-脱氧胞苷（5-Aza-dc）对雄激素依赖性前列腺癌细胞株（LNCaP）生长的抑制作用及对谷胱苷肽-S-转移酶1（GSTP1）和维A酸受体β2（RARβ2）基因甲基化状态的影响。方法5-Aza-dc作用LNCaP细胞，观察其生长状态，并应用CCK8法检测5-Aza-dc作用前后LNCaP存活率。巢式甲基化特异性聚合酶链反应方法分析用药后LNCaP的GSTPl和RARe32基因启动子区5’端CpG岛甲基化状态。结果5-Aza-dc抑制LNCaP的生长、增殖，作用LNCaP后，其GSTP1和RARe32基因的甲基化状态出现逆转，以上作用与药物浓度及药物作用时间在一定范围内呈正相关，结果显示小剂量（〈1．0μmol/L）的5-Aza-dc作用48h内对细胞有抑制作用，作用72h后有刺激细胞增长的作用；同样，小剂量的5-Aza-dc作用72h的细胞GSTP1、RAR/32基因甲基化状态较药物作用48h未见明显减弱，即应用相对低浓度药物，作用时间超过48h后其去甲基化效用并无明显增加。结论5-Aza-dc能较好抑制LNCaP的生长增殖并有效地逆转DNA的异常甲基化，低浓度药物应用时其作用的持续性和稳定性有所改变，为临床治疗方案的选择提供一定的研究基础。

Objective To investigate the effects of 5-Aza-2＇-deoxycytidine （5-Aza-dc）, a methylation inhibitor, on the proliferation of androgen-sensitive prostate cancer line （LNCaP）, and on its regulation of methylation on glutathione s-transferaseP1 （GSTP1） and retinoic acid receptorβ2 （RARe2） gene. Methods LNCaP ceils were treated with 5-Aza-dc in different concentration. CCK8 method was used to detect the growth of LNCaP cells. The methylation of GSTP1 and RARβ32 gene in LNCaP cell was detected by nested methylation specific polymerase chain reaction （nMSP）. Results The proliferation of LNCaP cells was inhibited after exposed to 5-Aza-dc. The methylation of GSTP1 and RARβ2 gene was changed from hypermethylation to demethylation by the 5-Aza-dc. These effects were dose- and time- dependent within certain concentration of 5-Aza-dc, but LNCaP cells grew better after 72 h than within 48 h when exposed to 5-Aza-dc below 1.0 μmol/L. Also the methylation of GSTP1 and RARe2 gene changed from hypermethylation to demethylation by the 5-Aza-dc was not different when exposed to 5-Aza-dc below 1.0 gmol/L within 72 h and 48 h. Conclusions 5-Aza-dc may effectively inhibit the growth of LNCaP cells and reverse the DNA methylation damage in some tumor suppressor genes, but the continuity and stability of low-dose 5-Aza-dc is changeable. The studv will nrovide a research basis for clinical treatment.