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荷卵巢癌裸鼠肿瘤E-cad启动子去甲基化的研究

曲芃芃1,钱林华2,徐娟1   

  1. 1. 天津市中心妇产科医院
    2. 天津医科大学
  • 收稿日期:2011-07-19 修回日期:2011-12-23 出版日期:2012-06-15 发布日期:2012-06-15
  • 通讯作者: 曲芃芃

The Study of E-cadherin Gene PromoterDemethylation in Nude Mice Burdended -ovarian Cancer

  • Received:2011-07-19 Revised:2011-12-23 Published:2012-06-15 Online:2012-06-15

摘要: 目的:观察DNA甲基化转移酶(DNA methyltransferase,DNMT)抑制剂5-氮杂-2'-脱氧胞苷(5-Aza-2'-deoxycytidine,5-Aza-CdR)联合组蛋白去乙酰化酶(histone deacetylase,HDAC)抑制剂苯丁酸钠(Sodium 4-Phenylbutyrate,SPB)对荷卵巢癌细胞系SKOV3裸鼠上皮性钙黏素(epithelial cadherin,E-cad)表达的影响。 方法:在已建立的卵巢癌裸鼠腹腔移植瘤模型上,分别应用或二者联合应用5-Aza-CdR、SPB,免疫组化法检测腹腔移植瘤中DNMT1、HDAC1以及E-cad的表达变化情况;检测各组移植瘤E-cad基因启动子区5’CpG岛甲基化状况及各组移植瘤E-cad mRNA和蛋白的表达变化情况。 结果:①在移植瘤组织中,DNMT1和HDAC1呈高表达,5-Aza-CdR能抑制DNMT1的表达,SPB能抑制HDAC1的表达,与对照组相比,差异显著(P<0.05)。②5-Aza-CdR能够诱导甲基化的E-cad基因去甲基化,从而mRNA及E-cad蛋白恢复表达或者表达增强,联合应用5-Aza-CdR和SPB可更大程度上诱导甲基化的E-cad基因去甲基化而恢复mRNA和E-cad蛋白的表达。 结论:5-Aza-CdR能够降低E-cad基因启动子区的甲基化,可恢复其表达;联合应用5-Aza-CdR和SPB可产生协同效应,显著增强甲基化的E-cad基因的表达,对卵巢癌的治疗有重要作用。

关键词: 卵巢癌, E-钙粘素, 5-氮杂脱氧胞苷, 苯丁酸钠, 去甲基化

Abstract: Objective: To evaluate the effect of the DNA methyltransferase (DNMT) inhibitor 5 - aza -2 '- deoxycytidine (5-Aza-CdR) combined histone acetylation Enzymes (HDAC) inhibitor Sodium 4-Phenylbutyrate (SPB) on the expression of epithelial cadherin (E-cad) expression of nude mice models with ovarian cancer cell lineSKOV3. Methods: 40 nude mice were implanted ovarian cancer cell lineSKOV3 into abdominal cavity as animal model. The models were randomly divided into four groups. Controlled group was injected phosphate-buffered saline into abdominal cavity, 5-Aza-CdR and SPB were used respectively in other two groups, and 5-Aza-CdR plus SPB were used in the fourth group. After two weeks of injection, the expressions of DNMT1, HDAC1 and E-cad in the ovarian cancer xenograft tumors by immunohistochemical staining. The CpG island methylation status of E-cadherin promoter region in xenograft tumors were analyzed by methylation specific PCR (MSP). The mRNA and the protein expressions of E-cad were also compared among the four groups. Results: DNMT1 and HDAC1 were highly expressed in xenograft tumors. 5-Aza-CdR can inhibit the expression of DNMT1 and SPB can inhibit the expression of HDAC1 which were indicated by comparison with controlled group (P <0.05). The combining 5-Aza-CdR with SPB have no obvious synergistic effect on the inhibition of DNMT1 and HDAC1. 5-Aza-CdR can induce methylated E-cad gene demethylation which made E-cad mRNA and protein expressions recovered or even better. 5-Aza-CdR combined with SPB can induce methylated E-cad gene demethylation and recover the E-cad mRNA and protein expressions compared with other groups. Conclusion: 5-Aza-CdR can reduce the E-cad gene promoter methylation and make E-cad mRNA and protein expressions recovered. 5-Aza-CdR combined with SPB can accomplish synergetic effect and enhance the expression of methylated E-cad gene significantly which played an important role in the treatment of ovarian cancer

Key words: Ovarian cancer, E-cadherin, 5-Aza-2'-deoxycytidine, Sodium 4-Phenylbutyrate , Demethylation