Promoter-hypermethylation associated defective expression of E-cadherin in primary non-small cell lung cancer
Promoter-hypermethylation associated defective expression of E-cadherin in primary non-small cell lung cancer
复制标题
原发性非小细胞肺癌中启动子高甲基化相关 E-钙粘蛋白表达缺陷。
DOI：
10.1016/j.lungcan.2008.03.023
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发表时间：
2008-11-01
期刊：
影响因子：
5.3
通讯作者：
Luo, Z. W.
中科院分区：
文献类型：
--
作者：
Wang, Guiying;Hu, Xiaohua;Luo, Z. W.
CpG岛的高甲基化是肿瘤抑制基因失活的主要机制。e -钙粘蛋白（E-cad）作为肿瘤侵袭抑制因子已被报道用于几种侵袭性和转移性肿瘤。然而，其在原发性非小细胞癌（NSCLC）癌变中的意义尚未得到很好的证实。本研究旨在通过精心收集的95对非小细胞肺癌肿瘤和相应的非恶性组织样本来评估其意义。我们进行了PCR-SSCP（单链构象多态性）和PCR-RFLP（限制性片段长度多态性）筛选DNA变异，亚硫酸盐转化特异性MSP进行甲基化分析，逆转录(RT)-PCR进行mRNA和免疫组织化学（IHC）进行蛋白质表达分析。为了研究启动子超甲基化对E-cad表达的影响，我们还在6个细胞系中进行了去甲基化实验。首先，我们发现，与健康志愿者的DNA相比，-160A携带者（E-cod启动子区域的单核苷酸多态性（SNP））患肺癌的风险增加(OR（优势比）= 2.81；95% CI（置信区间），1.36-5.86)。E-cad甲基化在肿瘤中的发生频率明显高于相应的正常瘤周。组织（p < 10(-5)）。与相应的肿瘤相比，E-cad的表达降低是肿瘤的一个明显的分子特征。此外，甲基化改变在低分化肿瘤中比在高分化肿瘤中更常见。经5-Aza-dC （5-aza-2′-脱氧胞苷）处理后，甲基化细胞系中E-cad的缺陷表达明显恢复。因此，E-cad的启动子高甲基化与其缺陷表达和肿瘤分化显著相关，去甲基化观察提出了一种通过恢复E-cad的正常表达来逆转肿瘤恶性的治疗策略。(C) 2008年由爱思唯尔爱尔兰有限公司出版
Hypermethylation of CpG islands is well known as a major inactivation mechanism of tumor suppressor genes. E-cadherin (E-cad) as a tumor invasion suppressor has been reported in several invasive and metastatic carcinomas. However, its significance in carcinogenesis of primary non-small cell tung cancer (NSCLC) is not well documented. This study was designed to assess the significance with 95 pairs of carefully collected NSCLC tumors and corresponding nonmalignant tissue samples. We carried out PCR-SSCP (single-strand conformation polymorphism) and PCR-RFLP (restriction fragment length polymorphism) screening for DNA variants, bisulfite conversion-specific MSP for methylation analysis, reverse transcription (RT)-PCR for mRNA and immunohistochemistry (IHC) for protein expression assays. To investigate effect of promoter-hypermethylation on E-cad expression, we also did demethylation experiment in six cell lines. First, we found that the -160A carriers (a single nucteotide polymorphism (SNP) in the promoter region of E-cod) had an increased risk for lung cancer development when compared to DNA from healthy volunteers (OR (odds ratio) = 2.81; 95% CI (confidence interval), 1.36-5.86). Methylation of E-cad occurred with a significantly higher frequency in tumors than corresponding normal peritumoral. tissues (p < 10(-5)). Reduced expression of E-cad was detected as a distinct molecular feature of tumors in comparison to corresponding counterparts. Moreover, the methylation alteration was detected more frequently in low-differentiated tumors than in well-differentiated ones. Defective expression of E-cad in methylated cell lines was markedly recovered after treated with 5-Aza-dC (5-aza-2'-deoxycytidine). Thus, promoter-hypermethytation of E-cad is significantly associated with its defective expression and tumor differentiation, and the demethylating observation proposes a therapeutic strategy to reverse the tumor's malignancy by restoring normal expression of E-cad. (C) 2008 Published by Elsevier Ireland Ltd.