2015-01-012024-05-13https://scholars.lib.ntu.edu.tw/handle/123456789/650986摘要：在西方國家，攝護腺癌 (prostate cancer)是主要發生在男性身上之癌症。在台灣，攝護腺癌發生率高居第七名，其致死率也再逐年增高中。正常攝護腺組織主要由上皮腺體和肌纖維性基質所組成，大部分攝護腺病變會發生在上皮腺體，進而導致攝護腺惡性腺瘤 (prostate adenocarcinomas)。在攝護腺癌化和癌症進展的過程中，通常會伴隨著細胞生長速度、侵襲和轉移的能力增加。癌症細胞具有侵襲能力是一個惡性的指標，通常和其微環境(microenvironment)有關。癌細胞會和一些腫瘤相關的基質細胞有交互作用，例如:癌細胞會促使肌纖維母細胞 (myofiberblast) 分泌產物來啟動腫瘤細胞生長且促進轉移。因此，腫瘤細胞之微環境在癌症的進程中扮演非常重要之角色。然而其詳細分子機制以及腫瘤細胞之微環境在攝護腺癌進程中如何作用仍有許多未知。因此，在此計畫中我們想要了解細胞周圍之絲胺酸蛋白酶：第二型間質蛋白酶 (Matriptase-2) 在攝護腺癌進程和轉移中扮演的角色和機制。細胞周圍的蛋白酶活性失調的會藉由改變其癌症細胞侵襲之能力和腫瘤周圍之微環境，而導致癌症惡化進展。第二型間質蛋白酶，又稱第二型膜上絲胺酸蛋白酶六，是近年來新被鑑定的嵌膜型絲胺酸蛋白酶，研究指出，其主要功能為肝臟對鐵代謝中重要的調控者，維持鐵的恆定。而在癌症細胞中，第二型間質蛋白酶可降低乳癌和攝護腺癌細胞的侵襲和轉移能力，以及生長。然而，第二型間質蛋白酶如何抑制癌細胞侵襲及惡化的分子機制目前仍未清楚。我們的初步研究顯示在攝護腺癌細胞 (PC3及DU-145) 過量表達第二型間質蛋白酶可明顯抑制其移動能力，然而在正常之攝護腺上皮細胞(PNT2)中降低第二型間質蛋白酶表現卻促進其侵襲能力。此外，第二型間質蛋白酶表現會降低細胞上皮-間質轉型 (Epithelial Mesenchymal Transition, EMT) 的現象，以及抑制由轉化表皮生長因子β1 [Transforming growth factor beta1 , (TGF-β1)]所引起的攝護腺癌轉移。我們的研究結果顯示，過量表達第二型間質蛋白酶會增加第三型TGF-β接受器 (TGF-beta receptor)，又稱細胞膜糖蛋白 (Endoglin)，但第一、二型TGF-β接受器則無顯著差異，此外，間質蛋白酶 (Matriptase) 的活性以及表達量也會下降，細胞間質蛋白酶已被報導可促進癌細胞侵襲、生長和移動。因此我們將會更加深入探討第二型間質蛋白酶抑制攝護腺癌之機制。我們假設第二型間質蛋白可以藉由正向調控细胞膜糖蛋白的表現或降低細胞間質蛋白酶的表現和活性來抑制攝護腺癌細胞的侵襲、腫瘤生長及轉移。為了釐清問題，我們設定以下之四項執行目標：1) 驗證第二型間質蛋白酶是否會藉由正向調控細胞膜醣蛋白或是負向調控間質蛋白酶來抑制攝護腺癌細胞之侵襲能力。 2) 藉由鑑定出第二型間質蛋白酶在攝護腺癌細胞中之受質或是其有交互作用之分子，來了解第二型間質蛋白酶下游之訊息如何調控細胞膜醣蛋白和間質蛋白酶。3) 了解第二型間質蛋白酶和細胞膜醣蛋白在攝護腺腫瘤新生及轉移中所扮演之角色。 4) 分析第二型間質蛋白酶、間質蛋白酶、細胞膜醣蛋白及以在2)中鑑定出分子在攝護腺癌病患切片組織的表現量，是否有相關性。這些實驗結果可以幫助我們更加了解第二型間質蛋白酶在抑制攝護腺癌症上之分子機制，進一步可望找出有用的標的來治療攝護腺癌。<br> Abstract: Prostate cancer is a major leading cause of male cancers in the western countries. In Taiwan, prostate cancer is the seventh leading cause of cancer-related deaths with increasing incidence annually. Prostate tissue is primarily consisted of epithelial glands and fibromuscular stroma. Most cancer lesions often occur in the glandular epithelia that give rise to prostate adenocarcinomas. During the development and progression of prostate cancer, an increase of cell growth, invasion and metastatic ability is often observed. Cancer cell invasion is a hallmark of malignancy and occurs within a microenvironment where cancer cells communicate with tumor-associated stromal cells such as myofiberblasts via secretory products to initiate invasive tumor growth and metastasis. Thus, the tumor microenvironment plays an important role in cancer progression and metastasis. However, the detailed molecular mechanisms of cancer metastasis and how the tumor microenvironment provides a role in prostate cancer progression and metastasis are largely unknown. The focus of this research proposal is on addressing the role and molecular mechanisms of pericellular serine protease matriptase-2 in prostate cancer progression and metastasis. Dysregulation of pericellular proteolysis has been strongly implicated in the development of metastasis via alteration of cancer cell invasion and tumor microenvironment. Matriptase-2 (also named as TMPRSS6) is a newly identified membrane-anchored serine protease as a regulator for iron homeostasis in liver and can decrease breast and prostate cancer cell invasion and tumor growth. However, the molecular mechanisms how matriptase-2 reduces prostate cancer cell invasion and progression remain largely unknown. Our preliminary study showed that overexpression of matriptase-2 decreased prostate cancer PC3 and DU145 cell migration and invasion, while silencing of matriptase-2 in prostate epithelial PNT2 cells promoted the cell invasion. Moreover, matriptase-2 overexpression suppressed the epithelial mesenchymal transition and TGF-β1-induced prostate cancer PC3 cell invasion. The preliminary results further showed that overexpression of matriptase-2 increased the expression of endoglin, a TGF-β coreceptor, with no significant effect on TGF-β receptor I or II, and reduced the expression and activity of matriptase, a serine protease able to promote prostate cancer progression and metastasis. Thus, in this study, we will explore the molecular mechanisms how matriptase-2 inhibits prostate cancer progression. Our hypothesis is that matriptase-2 signaling can up-regulate the expression of endoglin or down-regulate the expression and activity of matriptase, leading to inhibition of prostate cancer cell invasion, tumor growth and metastasis. To answer this question, several specific aims will be carried out as follows: 1) To examine whether the up-regulation of endoglin or down-regulation of matriptase by matriptase-2 results in reduction of prostate cancer cell invasion, 2) To identify the in vivo substrates or interacting proteins of matriptase-2 that execute matriptase-2 signaling to modulate the expression of endoglin and matriptase in prostate cancer cells, 3) To examine the role of matriptase-2 and endoglin in tumorigenicity and metastasis of prostate cancer, 4) To analyze the expression levels of matriptase-2, matriptase, endoglin and the identified proteins in Aim 2 in archival specimens of prostate cancer patients. The results of these experiments will help us to understand the molecular mechanism in which matriptase-2 plays inhibitory roles in prostate cancer progression. The information generated from the study may be useful for developing a novel strategy for prostate cancer therapy.攝護腺癌癌轉移腫瘤生成絲胺酸蛋白酶第二型間質蛋白酶prostate cancermetastasistumor growthserine proteasematriptase-2