摘要：在台灣胃癌是致死癌症中的第五名，約占所有本國癌症死亡病例之百分之六點三。極差的預後通常是因癌細胞轉移至腹膜、淋巴結、及其他器官如肝臟等。雖然手術治療是胃癌治癒的希望，但癌細胞在手術過程中常游離擴散使癌細胞附著於腹膜，而造成腹膜轉移，目前並無更令人滿意的治療方法，是胃癌治療的重大問題。腹膜轉移過程首先癌細胞須貼附於腹膜間皮細胞(peritoneal mesothelial cells)、使其萎縮、進而侵入基底膜(basement membrane)、並使細胞外間質降解、癌細胞增生及血管新生。許多因子參與了這些步驟，而我們需要針對這些因子來癌研究致病轉機並研發更新的方法以提升胃癌腹膜轉移的治療成效。結締組織生長因子(Connective Tissue Growth Factor; CTGF)屬CCN 家族，具有傷口癒合，發炎，細胞貼附及移動，細胞凋亡，以及癌細胞生長及纖維化的功能。前人研究發現CTGF 在肺癌內扮演著抑制癌細胞轉移的角色，在大腸結腸癌中亦發現CTGF 之高表現與癌細胞的侵襲及轉移下降有關，而病人預後較佳。所以認為CTGF 可能與癌細胞在腹膜貼附，生長及血管新生有關。腹膜間皮細胞是癌細胞最先接觸的部位，癌細胞成功的貼附在間皮細胞上，決定是否會成功的腹膜轉移。我們認為CTGF 與癌細胞貼附在腹膜的能力是具有相關性的，並會造成後續的癌細胞增生與血管新生。因此，我們在先期實驗中利用反轉錄聚合酶連鎖反應及西方墨點法測試了AGS、N87、TSGH、及MKN45 等胃癌細胞株中CTGF 的表現量並利用免疫染色來證實病人胃癌組織中亦有CTGF 的表現。再來我們測試了這些細胞貼附性，發現不同的CTGF 表現，細胞貼附的能力亦不同。所以我們利用載體將CTGF 送入細胞株內測試CTGF 對貼附性的影響，發現CTGF 的增加會造成貼附性下降。基於先期研究結果，我們認為CTGF 與腹膜轉移之癌細胞貼附有關，值得後續研究。所以在此計畫內我們預計以三年時間研究CTGF 在細胞層面及動物中所扮演的角色並探討是否與病患預後及腹膜轉移有相關性，同時進行以CTGF 治療腹膜轉移的動物研究。第一年: 探討CTGF 高度穩定表現細胞株在活體外(in vitro)與細胞貼附功能、細胞增生、或血管新生與腹膜轉移的關係。第二年: 探討CTGF 重組蛋白是否會在體外及動物體內影響胃癌細胞的貼附性，同時利用微陣列尋找相關基因。第三年: 探討CTGF 的表現量是否與病患之臨床病理因子、存活率與術後腹膜轉移有相關性，同時研究以CTGF 重組蛋白治療老鼠胃癌腹膜轉移之效果。
Abstract: For the past 50 years, gastric cancer has been one of the ten most frequent cancers andthe second leading cause of cancer-related death in the world. In Taiwan, it is the fifthmost common cause of cancer-related deaths, accounting for 6.3% of all cancer deaths.The poor prognosis of gastric cancer is mostly caused by the extensive metastasis tothe lymph nodes, liver, and peritoneal dissemination even if curative resection wasperformed. The main cause of recurrence after curative or noncurative resection ofadvanced tumors is peritoneal metastasis because of possible direct spillage anddissemination of tumor cells as a result of surgical manipulation, and it is associatedwith a poor prognosis. As yet, no effective treatment has been developed for thiscondition. The development of peritoneal metastasis is a multistep process, beginningwith attachment to peritoneal mesothelial cells, retraction of the mesothelial cells andexposure of the basement membrane, attachment to the basement membrane,degradation in the extracellular matrix, proliferation by the cancer cells, andangiogenesis, and it is clear that many types of agents are involved at the variousstages of this process. Developing a new therapeutic method for this mode ofmetastasis is very important for improvement of gastric cancer treatment.CTGF is a secretory protein belonging to the CCN family (one among the threeoriginally discovered members: cysteine-rich61, CTGF, andnephroblastoma-overexpressed gene). It is a multifunctional growth factor involved inwound healing, inflammation, cell adhesion, chemotaxis, apoptosis, tumor growth,and fibrosis. Recent studies showed that overexpression of CTGF in human oralsquamous cell carcinoma reduces cell growth and tumorigenecity. Similar tumorgrowth inhibitory effects were observed in lung cancer cells in which CTGFoverexpression was less angiogenic and metastatic due to blocking of the VEGF Asignaling pathway. CTGF was also reported to be a key regulator of colorectal cancerinvasion and metastasis, and it appears to be a better prognostic factor. These studiessuggest that CTGF may involve the processes of peritoneal metastasis which includescancer cell adhesion in peritoneum, proliferation and angiogenesis. Peritonealmesothelium is the first surface encountered by disseminated tumor cells andsuccessful adhesion is, therefore, of paramount importance in metastasis formation.Therefore, we hypothesized that CTGF is a potential molecule target, which may berelated to cell adhesion to peritoneum, the first step of peritoneal metastasis, and itsexact mechanism may includes proliferation and angiogenesis.In order to answer these important questions, first, we have performed the preliminarystudies to prove CTGF did express in different gastric cancer cell lines including AGS,N87, TSGH, and MKN-45 by using RT-PCR and Western blotting, and gastric cancertissues by using immunohistochemical method. Second, we demonstrated differentlevels of CTGF expression in different cell lines pose different adhesion ability inin-vitro adhesion assay. Third, we conducted a transient CTGF-overexpressedMKN45 gastric cancer cell line, and CTGF-overexpressed cell line had loweradhesive ability compared to the control.
