本文選題：EMX2基因 + 結(jié)直腸癌　； 參考：《北京協(xié)和醫(yī)學(xué)院》2017年博士論文

【摘要】：·背景EMX2基因是同源框基因中的一員,在神經(jīng)系統(tǒng)及泌尿生殖系統(tǒng)的胚胎發(fā)育中有廣泛的作用。該基因在多癌種中均有表達(dá)調(diào)低,且表達(dá)抑制與預(yù)后不良或治療耐藥相關(guān)。該基因在腫瘤中突變較為少見(jiàn),其表達(dá)降低主要是啟動(dòng)子區(qū)過(guò)甲基化的結(jié)果。EMX2有抑制腫瘤細(xì)胞增殖和侵襲的能力,可通過(guò)抑制經(jīng)典Wnt通路發(fā)揮作用。本研究選擇結(jié)直腸癌為研究對(duì)象,旨在探索EMX2基因在結(jié)直腸癌中的表觀遺傳學(xué)調(diào)控及其臨床意義,并對(duì)該基因在結(jié)直腸癌中的功能及作用通路做進(jìn)一步驗(yàn)證。·方法臨床研究方面:研究對(duì)象為2012年于中國(guó)醫(yī)學(xué)科學(xué)院腫瘤醫(yī)院進(jìn)行手術(shù)治療的原發(fā)結(jié)直腸癌患者170例。應(yīng)用甲基化特異性PCR(MSP)技術(shù)檢測(cè)EMY2基因啟動(dòng)子區(qū)甲基化狀態(tài),并分析其與各項(xiàng)臨床因素、預(yù)后及治療的相關(guān)性。機(jī)制研究方面:檢測(cè)該基因在結(jié)直腸癌細(xì)胞系中的表達(dá)情況,以及加入去甲基化試劑后表達(dá)水平的變化以明確其調(diào)控機(jī)制。在結(jié)直腸癌細(xì)胞系中過(guò)表達(dá)EMX2或用shRNA抑制其表達(dá),檢測(cè)細(xì)胞增殖和遷移能力的改變以及Wnt經(jīng)典通路活性的改變,以明確該基因的功能和發(fā)揮作用的分子通路�！そY(jié)果對(duì)1例正常結(jié)直腸組織和3例結(jié)直腸癌組織進(jìn)行免疫組化染色的結(jié)果顯示:EMX2基因在結(jié)直腸癌組織中有表達(dá)降低的趨勢(shì)。對(duì)18例結(jié)直腸癌及相應(yīng)正常組織的MSP結(jié)果顯示:該基因在結(jié)直腸癌組織中有過(guò)甲基化的趨勢(shì)(甲基化比例為83.3%vs 53.3%)。在170例結(jié)直腸癌標(biāo)本中,61例(35.9%)EMX2基因甲基化陽(yáng)性。甲基化陽(yáng)性與年齡≥65歲(P=0.029)和KRAS基因突變(P=0.045)顯著相關(guān)。預(yù)后方面,該基因甲基化陽(yáng)性與總生存期的縮短有相關(guān)趨勢(shì),且甲基化陽(yáng)性的患者傾向于出現(xiàn)遠(yuǎn)期復(fù)發(fā)和進(jìn)展,對(duì)II期患者的單獨(dú)分析中也顯示類(lèi)似的趨勢(shì)。該基因甲基化陰性組靶向治療可延長(zhǎng)總生存期,陽(yáng)性組治療效果不明顯。EMX2基因在結(jié)直腸癌細(xì)胞系中表達(dá)顯著降低,且用去甲基化試劑處理后基因表達(dá)上調(diào)。過(guò)表達(dá)EMX2基因的HCT116細(xì)胞系增殖速度顯著降低,而轉(zhuǎn)染shRNA的低表達(dá)細(xì)胞系中細(xì)胞遷移能力有顯著上調(diào)。此外,EMX2過(guò)表達(dá)細(xì)胞系中Wnt經(jīng)典通路活性抑制,低表達(dá)細(xì)胞系中通路活性增強(qiáng)�！そY(jié)論EMX2基因在結(jié)直腸癌中表達(dá)降低,主要是啟動(dòng)子區(qū)過(guò)甲基化的結(jié)果。該基因表達(dá)降低與總生存期縮短和病變的遠(yuǎn)期復(fù)發(fā)進(jìn)展存在相關(guān)趨勢(shì),有作為II期腫瘤預(yù)后因子的可能性。該基因可抑制結(jié)直腸癌細(xì)胞的增殖和遷移,通過(guò)Wnt經(jīng)典通路發(fā)揮作用,與EGFR等結(jié)直腸癌中常見(jiàn)致癌分子通路的關(guān)系有待進(jìn)一步探索。
[Abstract]:Background EMX2 gene is a member of homobox gene and plays an important role in embryonic development of nervous system and genitourinary system. The expression of the gene was down-regulated in multiple carcinomas, and its inhibition was associated with poor prognosis or drug resistance. The decrease of the gene expression is mainly due to the hypermethylation of promoter region. EMX2 has the ability to inhibit the proliferation and invasion of tumor cells, which can play a role by inhibiting the classical Wnt pathway. The purpose of this study was to explore the epigenetic regulation of EMX2 gene in colorectal cancer and its clinical significance. Methods: 170 patients with primary colorectal cancer underwent surgical treatment in 2012 at the Cancer Hospital of the Chinese Academy of Medical Sciences. The methylation status of promoter region of EMY2 gene was detected by methylation specific PCR, and the correlation between methylation and clinical factors, prognosis and treatment was analyzed. Mechanism study: the expression of this gene in colorectal cancer cell line and the change of expression level after adding demethylation reagent were detected to clarify its regulatory mechanism. EMX2 was overexpressed or inhibited by shRNA in colorectal cancer cell lines. The changes of cell proliferation and migration ability and the activity of Wnt classic pathway were detected. Results Immunohistochemical staining of 1 normal colorectal tissue and 3 colorectal cancer tissues showed that the expression of the 1% EMX2 gene decreased in colorectal cancer tissues. The MSP results of 18 cases of colorectal cancer and the corresponding normal tissues showed that there was a tendency of hypermethylation of the gene in colorectal cancer tissues (83.3%vs 53.3%). EMX2 gene methylation was positive in 61 of 170 colorectal cancer specimens. There was a significant correlation between methylation positive and age 鈮，

本文編號(hào)：1903340