本文選題：乳腺癌　切入點：紫杉醇　出處：《中國科學技術大學》2017年博士論文　論文類型：學位論文

【摘要】：腫瘤轉移是臨床治療失敗和死亡的主要原因,研究其分子機制是開發(fā)治療措施,提高存活率的關鍵。上皮間質轉換(Epithelial-mesenchymal transition,EMT)是一個多基因參與的生物過程,在腫瘤細胞轉移和化療耐藥中發(fā)揮重要的作用,探討EMT的內(nèi)在調(diào)控機制具有重要的科學價值。紫杉醇(Paclitaxel,Taxol)為治療復發(fā)性或轉移性乳腺癌單藥及聯(lián)合用藥的一線化療藥物,其耐藥是導致乳腺癌化療失敗的巨大障礙。本研究旨在揭示乳腺癌化療耐藥的分子機制,克服化療耐藥性,以獲得更好的臨床療效。趨化因子受體CXCR4與其配體基質細胞源性因子-1 alpha(stromal cell-derived factor-1 alpha,SDF-1α)相互作用能有效促進腫瘤細胞的增殖和侵襲,在乳腺癌器官特異性,如淋巴以及肺和骨髓的轉移中發(fā)揮重要的調(diào)控作用。CXCR4信號通路與紫杉醇耐藥、EMT形成機制存在Cross-talking,可作為臨床輔助化療的靶點。來源于病毒巨噬細胞炎性蛋白Ⅱ(Virus macrophage inflammatory protein-Ⅱ,vMIP-Ⅱ)N 末端 21 個氨基酸的多肽(NT21MP),通過與SDF-1α競爭結合CXCR4受體,在乳腺癌細胞凋亡誘導和增殖抑制中發(fā)揮重要的作用。但其調(diào)控EMT的效應和機制尚不清楚。血小板源性生長因子(The platelet-derived growth factor,PDGF)信號途徑通過調(diào)控細胞增殖、凋亡、遷移、趨化及EMT誘導,促進了惡性腫瘤的發(fā)生發(fā)展。血小板源性生長因子受體-alpha(Platelet-derived growth factor receptor-alpha,PDGFRα)在乳腺癌中異常高表達,與EMT誘導相關,賦予腫瘤細胞耐藥表型和侵襲能力。本研究首先利用生物信息學技術分析NT21MP結合CXCR4的關鍵氨基酸和理化性質;其次,以乳腺癌親本細胞株MCF-7,SKBR-3和MDA-MB-231,以及其紫杉醇耐藥細胞株(SKBR-3/PR和MCF-7/PR)為研究對象,采用體外實驗和聯(lián)合免疫缺陷小鼠體內(nèi)乳腺癌耐藥模型進行研究。體內(nèi)實驗以SKBR-3/PR細胞構建乳腺癌紫杉醇耐藥裸鼠模型,NT21MP通過尾靜脈注射,紫杉醇和生理鹽水通過腹腔注射;分析腫瘤重量、增殖凋亡活性、肺轉移和EMT標志物等蛋白表達改變;體外實驗中,利用熒光定量技術,Western blot法檢測基因表達,利用增殖、凋亡、遷移和趨化等實驗檢測生物學活性。結果顯示SDF-1αN端Lys1和Ser4以疏水作用力和氫鍵分別與CXCR4的關鍵活性位點的氨基酸Asp262和Arg188結合,對阻斷CXCR4信號可能發(fā)揮關鍵的作用。NT21MP可部分逆轉紫杉醇誘導的EMT表型,并可下調(diào)耐藥細胞中PDGFA,PDGFB及其受體PDGFRα的表達,隨之抑制后續(xù)AKT和ERK1/2的信號通路活性,從而逆轉EMT。
[Abstract]:Tumor metastasis is the main cause of failure and death in clinical treatment. Studying its molecular mechanism is the key to develop therapeutic measures and improve survival rate. Epithelial-mesenchymal transition (EMTT) is a multigene involved biological process. Paclitaxel Taxol is a first-line chemotherapeutic agent for the treatment of recurrent or metastatic breast cancer, which plays an important role in tumor cell metastasis and chemotherapeutic resistance. The aim of this study was to reveal the molecular mechanism of chemoresistance in breast cancer and to overcome chemoresistance. The interaction between chemokine receptor CXCR4 and its ligand stromal cytokine 1 alpha(stromal cell-derived factor-1 alphaSDF-1 偽 can effectively promote the proliferation and invasion of tumor cells. CXCR4 signaling pathway and paclitaxel resistant EMT formation mechanism exist Cross-talking.It can be used as a target of clinical adjuvant chemotherapy. It is derived from viral macrophage inflammatory protein 鈪，

本文編號：1570418