本文關(guān)鍵詞： NKD2 DNA甲基化 Wnt信號(hào)通路 表觀遺傳學(xué) 乳腺癌　出處：《中國(guó)人民解放軍醫(yī)學(xué)院》2015年博士論文　論文類型：學(xué)位論文

【摘要】：背景：乳腺癌是全世界女性中最常見(jiàn)的惡性腫瘤,并且死亡率位居第二位。在中國(guó),乳腺癌的發(fā)病率較西方國(guó)家低。這種差異可能與生活習(xí)慣及環(huán)境因素有關(guān),表觀遺傳改變常常受到環(huán)境因素的影響。異常的基因甲基化在乳腺癌中頻繁發(fā)生,與乳腺癌的發(fā)生發(fā)展相關(guān)。Naked cuticle homolog 1 (NKD1) 和 2 (NKD2)是果蠅naked cuticle基因在哺乳動(dòng)物的同源基因。NKD1位于染色體16q12.1, NKD2位于染色體5p15.3。已發(fā)現(xiàn)許多腫瘤包括乳腺癌中,這些區(qū)域頻繁發(fā)生雜合性缺失(Loss of heterozygosity, LOH)。NKD1和NKD2已被報(bào)道通過(guò)與Dishevelled相互作用負(fù)調(diào)控經(jīng)典Wnt信號(hào)通路。在人和鼠的骨肉瘤細(xì)胞中發(fā)現(xiàn)NKD2可以抑制腫瘤的增殖和遷移,且在惡性膠質(zhì)瘤細(xì)胞中NKD2發(fā)生啟動(dòng)子區(qū)的甲基化改變。目的：研究NKD2在乳腺癌中的表觀遺傳改變及其在乳腺癌中的作用和作用機(jī)制。方法：本研究在6株乳腺癌細(xì)胞系和68例乳腺癌組織中,采用甲基化特異PCR,半定量RT-PCR,免疫組織化學(xué)分析NKD2在細(xì)胞系和組織中的甲基化狀態(tài)及表達(dá)水平的改變。MTT,克隆形成實(shí)驗(yàn)和流式細(xì)胞術(shù)的方法分析NKD2對(duì)乳腺癌細(xì)胞增殖、侵襲遷移能力的影響。雙熒光素酶實(shí)驗(yàn)，western blot和siRNA的方法,并結(jié)合裸鼠成瘤模型探討NKD2對(duì)乳腺癌的作用及其在Wnt信號(hào)通路中的作用機(jī)制。結(jié)果：NKD2啟動(dòng)子區(qū)在MDA-MB-231和MDA-MB-468細(xì)胞中呈甲基化狀態(tài),且其表達(dá)缺失,經(jīng)5-AZA處理后表達(dá)恢復(fù)。在MCF7, ZR75-1, BT474和T47D細(xì)胞中NKD2呈低表達(dá),啟動(dòng)子區(qū)呈半甲基化狀態(tài),經(jīng)5-AZA處理后表達(dá)增加。在原發(fā)性乳腺癌組織中,NKD2的甲基化率為51.4%(35/68),其甲基化與NKD2的表達(dá)沉默或降低有關(guān)(p0.05)。體內(nèi)、外實(shí)驗(yàn)發(fā)現(xiàn)NKD2可以抑制乳腺癌細(xì)胞的增殖。NKD2誘導(dǎo)G0/1期阻滯并且抑制Wnt信號(hào)通路的活性。結(jié)語(yǔ),NKD2在乳腺癌中頻繁發(fā)生甲基化,NKD2的表達(dá)受啟動(dòng)子區(qū)甲基化調(diào)控。NKD2通過(guò)抑制Wnt信號(hào)通路而抑制乳腺癌細(xì)胞的生長(zhǎng)。
[Abstract]:Background: breast cancer is the most common malignant tumor among women in the world, with the second highest mortality rate. In China, the incidence of breast cancer is lower than that in western countries. This difference may be related to lifestyle and environmental factors. Epigenetic changes are often affected by environmental factors. Abnormal gene methylation occurs frequently in breast cancer. Naked cuticle homolog 1 and 2 NKD2) are the homologous genes of naked cuticle gene in Drosophila melanogaster. NKD1 is located on chromosome 16q12.1 and NKD2 is located at chromosome 5p15.3.Many tumors including breast cancer have been found. Loss of heterozygosity occurs frequently in these regions. LOH).NKD1 and NKD2 have been reported to negatively regulate classical Wnt signaling pathways through interaction with Dishevelled. NKD2 has been found to inhibit tumor proliferation and migration in human and mouse osteosarcoma cells. And methylation of NKD2 promoter in malignant glioma cells. Objective: to study the epigenetic change of NKD2 in breast cancer and its role and mechanism in breast cancer. Methods: this study was carried out in 6 breast cancer strains. Cell lines and 68 breast cancer tissues, Methylation specific PCR, semi-quantitative RT-PCR, immunohistochemical analysis of methylation status and expression level of NKD2 in cell lines and tissues, clone formation assay and flow cytometry were used to analyze the proliferation of NKD2 in breast cancer cells. Methods of Western blot and siRNA for double luciferase assay, The effect of NKD2 on breast cancer and its mechanism in Wnt signaling pathway were studied in nude mice. Results: the promoter region of NKD2 D 2 was methylated in MDA-MB-231 and MDA-MB-468 cells, and its expression was absent. In MCF7, ZR75-1, BT474 and T47D cells, the expression of NKD2 was low and the promoter was semi-methylated. In primary breast cancer, the methylation rate of NKD2 was 51.4% 35 / 68, and its methylation was related to the silencing or lowering of NKD2 expression. It was found that NKD2 could inhibit the proliferation of breast cancer cells. NKD2 induced G0 / 1 arrest and inhibited the activity of Wnt signaling pathway. The expression of NKD2 was regulated by promoter methylation in breast cancer. The growth of breast cancer cells was inhibited by inhibiting Wnt signaling pathway.
【學(xué)位授予單位】：中國(guó)人民解放軍醫(yī)學(xué)院
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類號(hào)】：R737.9

【參考文獻(xiàn)】

相關(guān)期刊論文 前1條

1 Jeong Mo Bae;Tae Hun Lee;Nam-Yun Cho;Tae-You Kim;Gyeong Hoon Kang;;Loss of CDX2 expression is associated with poor prognosis in colorectal cancer patients[J];World Journal of Gastroenterology;2015年05期

，

本文編號(hào)：1516259