本文選題：前轉(zhuǎn)移微環(huán)境 + miR-30s��； 參考：《清華大學》2015年博士論文

【摘要】：腫瘤轉(zhuǎn)移已成為實體腫瘤患者死亡的主要誘因。腫瘤的轉(zhuǎn)移過程十分復雜,主要步驟包括:腫瘤細胞從原發(fā)瘤侵入血管進入血液循環(huán),隨后侵出血管進入轉(zhuǎn)移靶器官,最終形成轉(zhuǎn)移灶。實際上,在腫瘤細胞尚未發(fā)生轉(zhuǎn)移前,原發(fā)瘤已經(jīng)對轉(zhuǎn)移靶器官產(chǎn)生影響,促使靶器官形成一個可以支持腫瘤轉(zhuǎn)移和生長的微環(huán)境,稱之為“前轉(zhuǎn)移微環(huán)境”。前轉(zhuǎn)移微環(huán)境的形成需要原發(fā)瘤來源的分泌因子與轉(zhuǎn)移靶器官之間的相互作用,目前,已經(jīng)對原發(fā)瘤來源的分泌因子進行了大量研究,但是關(guān)于轉(zhuǎn)移靶器官對前轉(zhuǎn)移微環(huán)境形成的作用機制尚不清楚。鑒于miRNAs在腫瘤發(fā)生和發(fā)展過程中發(fā)揮了重要作用,本文系統(tǒng)地研究了轉(zhuǎn)移靶器官miRNAs參與腫瘤前轉(zhuǎn)移微環(huán)境形成的分子機制。首先,在B16/F10黑色素瘤誘導的前轉(zhuǎn)移肺微環(huán)境模型中,通過miRNAs芯片篩選出在前轉(zhuǎn)移肺微環(huán)境形成過程中表達水平顯著下調(diào)的miRNAs:miR-30a、30b、30c、30d和30e(miR-30s),隨后研究發(fā)現(xiàn)主要是肺成纖維細胞miR-30s的表達量發(fā)生了下調(diào)。肺成纖維細胞的miR-30s抑制了前轉(zhuǎn)移肺組織血管內(nèi)皮生長因子受體1+(VEGFR1+)骨髓來源細胞的招募,并降低了肺組織血管的通透性。由于骨髓來源細胞的招募和血管通透性的上升是前轉(zhuǎn)移微環(huán)境形成的主要特征,所以上述結(jié)果表明,miR-30s可以抑制前轉(zhuǎn)移肺微環(huán)境的形成。在小鼠肺組織中過表達miR-30s,可以顯著地抑制腫瘤的肺轉(zhuǎn)移并延長荷瘤鼠的生存期。隨后,通過一系列的生物信息學分析和體內(nèi)外實驗篩選策略,我們鑒定出與腫瘤前轉(zhuǎn)移肺微環(huán)境形成相關(guān)的miR-30s靶基因:Klf9、Nedd4l、Rab38、Skp2和Ugt8a。在前轉(zhuǎn)移肺微環(huán)境中,這5個靶基因的表達水平顯著上調(diào)。進一步研究發(fā)現(xiàn),Rab38通過調(diào)節(jié)CCL2、CXCL1和VEGFA的分泌促進了VEGFR1+骨髓來源細胞向前轉(zhuǎn)移肺組織的招募和聚集,而Skp2則通過上調(diào)基質(zhì)金屬蛋白酶9(MMP9)的表達提高肺組織的血管通透性。在小鼠肺組織中分別過表達Rab38和Skp2均顯著地促進了腫瘤的肺轉(zhuǎn)移并縮短荷瘤鼠的生存期。本研究闡明了轉(zhuǎn)移靶器官的miRNAs參與腫瘤前轉(zhuǎn)移微環(huán)境形成的新的分子機制,同時深入理解前轉(zhuǎn)移微環(huán)境的形成過程,為靶向腫瘤轉(zhuǎn)移的臨床應用提供了新的思路。
[Abstract]:Tumor metastasis has become the main cause of death in patients with solid tumors. The process of tumor metastasis is very complicated. The main steps include: tumor cells invade the blood vessels from the primary tumor into the blood circulation, then invade the blood vessels and enter the target organs and eventually form the metastasis. In fact, the primary tumor has been transferred before the tumor cells have been transferred. The effect of the target organ, which causes the target organ to form a microenvironment that can support tumor metastasis and growth, is called the "anterior transfer microenvironment". The formation of the anterior metastatic microenvironment requires the interaction between the secretory factor of the primary tumor source and the target organ of the metastatic target. However, the mechanism of the transfer of target organs to the formation of the anterior metastatic microenvironment is still unclear. In view of the important role of miRNAs in the development and development of tumor, this paper systematically studies the molecular mechanism of the transfer of target organ miRNAs in the formation of pre tumor microenvironment. First, the pre metastasis of B16/F10 melanoma induced by melanoma. In the lung microenvironment model, miRNAs:miR-30a, 30b, 30C, 30d and 30e (miR-30s) were significantly downregulated during the formation of the anterior metastatic lung microenvironment by miRNAs chip. The subsequent study found that the expression of miR-30s in lung fibroblasts was downregulated. Pulmonary fibroblast cell miR-30s inhibited the anterior metastatic pulmonary tissue. The recruitment of bone marrow derived cells from endothelial growth factor receptor 1+ (VEGFR1+) and reducing the permeability of pulmonary tissue. As the recruitment of bone marrow cells and the increase of vascular permeability are the main characteristics of the formation of the anterior metastatic microenvironment, the above results suggest that miR-30s can inhibit the formation of the anterior metastatic lung microenvironment. MiR-30s can significantly inhibit the lung metastasis of tumor and prolong the survival period of the tumor bearing mice. Then, through a series of bioinformatics analysis and in vivo and in vivo screening strategies, we identified the miR-30s target genes related to the formation of pre tumor metastasis lung microenvironment: Klf9, Nedd4l, Rab38, Skp2 and Ugt8a. in the anterior metastatic lung microenvironment The expression level of these 5 target genes is significantly up-regulated. Further studies have found that Rab38 promotes the recruitment and aggregation of forward metastatic lung tissue in VEGFR1+ bone marrow cells by regulating CCL2, CXCL1 and VEGFA, while Skp2 increases the vascular permeability of lung tissue by increasing the expression of matrix metalloproteinase 9 (MMP9). In mice lung tissue The overexpression of Rab38 and Skp2 respectively promoted the lung metastasis of tumor and shortened the survival time of the tumor bearing mice. This study clarified the new molecular mechanism that the miRNAs of the metastatic target organs was involved in the formation of the pre tumor microenvironment, and the formation process of the anterior metastatic microenvironment was deeply understood, which provided the clinical application of the target tumor metastasis. A new idea.

【學位授予單位】：清華大學
【學位級別】：博士
【學位授予年份】：2015
【分類號】：R73-37
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本文編號：1894361