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Title: | 外質體在胃癌進展中所扮演的角色 The Roles of Exosomes in Gastric Cancer Progression |
Authors: | Er-Yen Yen 顏爾言 |
Advisor: | 賴逸儒(I-Rue Lai) |
Keyword: | 外質體,胃癌,調節型T 細胞,轉化生長因子-β1, exosome,gastric cancer,Treg,TGF-β1, |
Publication Year : | 2015 |
Degree: | 碩士 |
Abstract: | 外質體是大小介於30-150奈米的膜狀微囊泡,由上皮細胞、血小板和癌細胞等許多種類的細胞分泌。它存在於大部分的生物體液之中,並扮演著細胞間訊息傳遞的媒介。我們利用差速離心來分離胃癌病人周邊血液中的外質體,以研究它們在胃癌進展中所扮演的角色。首先,藉由穿透式電子顯微鏡和免疫電子顯微鏡觀察所游離外質體的外觀型態,也應用西方墨點法來確認他們會表現在外質體的標記物HSC70、CD9和CD63,並以奈米粒子追蹤分析(nanoparticle tracking analysis, NTA)進行外質體數量及大小分布的分析。接著,藉由免疫組織化學染色,確認胃癌組織中會表現轉化生長因子β1 (transforming growth factor-β1, TGF-β1)這種和癌症進展相關的分子。同時也利用酵素免疫分析法 (enzyme-linked immunosorbent assay, ELISA)來測量胃癌病人血液所分離出的外質體中TGF-β1的表現量。我們發現晚期胃癌病人的外質體會比早期胃癌或者沒有淋巴轉移的病人含有更多的TGF-β1。我們也利用了FOXP3的免疫組織化學染色來測量胃癌引流淋巴結中調節T細胞(regulatory T cell, Treg)的百分比。結果發現調節T細胞的比例,會和腫瘤大小、Borrmann type、淋巴轉移、腫瘤深度和胃癌分期等臨床病理參數有顯著相關。 除此之外,單位外質體所含TGF-β1的量,也被發現和淋巴結中的調節T細胞比例有相關性。這顯示胃癌病人的外質體所攜帶的TGF-β1也許和誘導調節T細胞的分化可能有所關連。關於胃癌外質體是否能誘導調節T細胞的分化,仍須進一步的實驗。 Exosomes are 30–150 nm nanovesicles secreted by various cells, including epithelial cells, platelets and tumor cells. Exosomes are present in most biological fluids and serve as mediators for cell-to-cell communication. To study their biological role in gastric cancer progression, the exosomes from the peripheral blood of gastric cancer patients were isolated by differential ultracentrifugation. The morphology of the isolated microvesicles was examined by Transmission electron microscopy (TEM) and immuno-EM. The expression of specific exosomal markers including HSC70, CD9 and CD63 in the microvesicles was confirmed by Western blot analysis. The number of exosomes was measured by means of Nanoparticle Tracking Analysis (NTA), which can determine the concentration and size of the isolated exosomes. The expression of transforming growth factor-β1 (TGF-β1), a molecule involved in cancer progression, was identified by immunohistochemical staining in gastric cancer. Furthermore, TGF-β1 levels in exosomes isolated from gastric cancer patients was determined by enzyme-linked immunosorbent assay (ELISA), which showed the amount TGF-β1 per exosome of advanced-stage patients was significantly higher than those in early stage or node-negative patients. We also examined the percentage of regulatory T (Treg) cells in draining lymph node by FOXP3 immunohistochemistry. Higher levels of Treg cells were significantly associated with larger tumor size, Borrmann types III and IV, lymph node metastasis, tumor depth and advanced TNM stage. Moreover, TGF-β1 levels in exosomes were correlated with Treg cell percentage in LNs, which established the possible link between TGF-β1 induction and Treg differentiation. The effect and mechanisms of isolated exosomes from gastric cancers on Treg differentiation is under investigation. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/53124 |
Fulltext Rights: | 有償授權 |
Appears in Collections: | 解剖學暨細胞生物學科所 |
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ntu-104-1.pdf Restricted Access | 2.5 MB | Adobe PDF |
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