Wu Xiao, Zhuang Yi-xuan, Hong Chao-qun, Chen Jiong-yu, You Yan-jie, Zhang Fan, Huang Ping, Wu Ming-yao
Department of Pathology, Cancer Hospital of Shantou University Medical College, Shantou, 515031, Guangdong, China,
Med Oncol. 2014 Aug;31(8):100. doi: 10.1007/s12032-014-0100-y. Epub 2014 Jun 29.
E-cadherin (E-cad) is widely expressed in epithelial cells and acts as a pivotal tumor suppressor. The promoter methylation of E-cad has been reported to closely relate to its downregulation in many kinds of cancers. E-cad expression and methylation status were detected by immunohistochemistry (IHC) and methylation-specific polymerase chain reaction (MS-PCR) in 50 ovarian cancer tissues. 5-Aza-2'-deoxycytidine (5-Aza-dC) was used to demethylate E-cad in SKOV3 and ES2 ovarian cancer cell lines, of which the effect was verified by Western blot and MS-PCR. Then MTT and transwell experiments were conducted to detect the capacity of cell proliferation and migration for these cells. Downregulation of E-cad expression was observed in 60 % of ovarian cancer tissues (30/50) by IHC, whereas MS-PCR result indicated that E-cad was methylated in 64 % of (32/50) ovarian cancer specimens. And E-cad expression was significantly correlated with E-cad methylation (P = 0.004). 5-Aza-dC was used to process SKOV3 and ES2 ovarian cancer cell lines. By MTT experiment, we found that the proliferation of 5-Aza-dC-treated SKOV3 and ES2 was significantly suppressed by 28.0 % (P < 0.05) and 32.3 % (P < 0.05). By transwell experiment, the motility of SKOV3 and ES2 was found to be significantly suppressed by 38.2 and 27.4 % (P < 0.05), respectively, after treated with 5-Aza-dC. E-cad methylation is one of the main reasons for the expression reduction in ovarian cancer. 5-Aza-dC treatment could significantly restore the expression of E-cad and suppress growth and invasion of SKOV3 and ES2 cells. These results suggest E-cad methylation may be a promising target for ovarian cancer therapy.
E-钙黏蛋白（E-cad）广泛表达于上皮细胞中，是一种关键的肿瘤抑制因子。据报道，E-cad的启动子甲基化与多种癌症中其表达下调密切相关。采用免疫组织化学（IHC）和甲基化特异性聚合酶链反应（MS-PCR）检测了50例卵巢癌组织中E-cad的表达及甲基化状态。使用5-氮杂-2'-脱氧胞苷（5-Aza-dC）对SKOV3和ES2卵巢癌细胞系中的E-cad进行去甲基化处理，并通过蛋白质免疫印迹法（Western blot）和MS-PCR验证其效果。然后进行MTT和Transwell实验，检测这些细胞的增殖和迁移能力。免疫组化结果显示，60%（30/50）的卵巢癌组织中E-cad表达下调，而MS-PCR结果表明，64%（32/50）的卵巢癌标本中E-cad发生甲基化。并且E-cad表达与E-cad甲基化显著相关（P = 0.004）。使用5-Aza-dC处理SKOV3和ES2卵巢癌细胞系。通过MTT实验发现，5-Aza-dC处理的SKOV3和ES2细胞的增殖分别被显著抑制了28.0%（P < 0.05）和32.3%（P < 0.05）。通过Transwell实验发现，用5-Aza-dC处理后，SKOV3和ES2细胞的迁移能力分别被显著抑制了38.2%和27.4%（P < 0.05）。E-cad甲基化是卵巢癌中其表达降低的主要原因之一。5-Aza-dC处理可显著恢复E-cad的表达，并抑制SKOV3和ES2细胞的生长和侵袭。这些结果表明，E-cad甲基化可能是卵巢癌治疗的一个有前景的靶点。
