乳腺癌发生过程中NOEY2基因启动子区甲基化及mRNA表达

Promoter methylation and mRNA expression of NOEY2 gene in the development of breast cancers

目的探讨乳腺癌发生过程中抑癌基因NOEY2启动子区甲基化状态及其对mRNA表达的影响。方法应用甲基化特异性PCR及双亚硫酸钠基因测序技术检测MCF10模型中乳腺增生细胞系MCF10A、癌前细胞系MCF10AT、导管内癌细胞系MCF10DC IS.com、浸润癌细胞系MCF10CA1 a、MCF10CA1d、MCF10CA1h及正常乳腺组织中NOEY2基因启动子区CpG岛I甲基化状态,然后用RT-PCR和实时PCR技术检测上述样品的mRNA表达水平。结果MCF10模型的增生细胞系、癌前细胞系、导管内癌细胞系、浸润癌细胞系均发生该基因启动子区CpG岛I高度甲基化;与正常乳腺组织相比,上述细胞系mRNA表达显著减少。结论NOEY2基因启动子区高度甲基化及相应的mRNA表达减少是乳腺癌发生过程中的早期事件,与乳腺癌发生有关,可能成为早期诊断乳腺癌的潜在分子生物学标记。

Purpose To investigate the methylation status of NOEY2 gene promoter and its effects for expression of mRNA in breast cancer development. Methods Methylation specific PCR and sodium bisufite genomic sequencing were employed to detect methylation status of NOEY2 promoter CpG island I in normal breast tissues and MCF10 model including MCF10A cell line（ breast hyperplastic cell line, non-tumorigenic）, MCF10AT cell line （pre-malignant cell line, forms slowly progressing hyper and dysplastic lesions）, MCF10DCIS. com cell line（ breast ductal carcinoma in situ cell line, forms ductal carcinoma in situ） , MCF10CAla, MCF10CAld, MCF10CAlh cell lines（ invasive breast carcinoma cell line, form aggressive tumors of different morphology and metastatic potential）. Then, mRNA expression of NOEY2 in the samples mentioned above was determined using reverse transcribed PCR and real time PCR assays. Results Hypermethylation of NOEY2 promoter region CpG island I was identified in the breast hyperplastic cell line, pre-ma- lignant cell line, ductal carcinoma in situ cell line and all invasive carcinoma cell lines, mRNA expression of NOEY2 was dramatically reduced in the hypermethylated cell lines with comparison of normal breast tissue. Conclusions Aberrant promoter methylation of NO- EY2 and associated transcription silencing are early events in the development of breast cancers, which implies that promoter methyla- tion of NOEY2 play an important biologic role in breast cancer development and might be one of potential markers for breast diagnosis in early stage.