摘要
Prox1 屬於homeobox gene family，其功能為轉錄因子，並發現和Drosophila的 prospero 有同源性，因此命名為 prospero- related homeobox 1。Prox1 被發現在生物體生長發育中扮演重要角色，目前發現 prox1會參與角膜、肝臟、胰，以及神經系統發育的調控中。除此之外，prox1被認為在淋巴管發育中，是主要的調控因子之一。在腫瘤研究中，prox1 在 hepatocellular carcinoma 和乳癌中，被認為是扮演抑制腫瘤的角色。但是，在大腸癌中 prox1 卻有大量表現的情形，並且會促進腫瘤惡化。在研究中發現，於低表現 prox1的 DLD-1 大腸癌細胞中，prox1 大量表現 E-cadherin 轉錄後修飾會受到影響，降低 E-cadherin 的表現量，進而引發 epithelia- mesenchymal transition，同時也會讓細胞貼附能力下降，以及細胞侵犯性增加。另一方面，在SW620大腸癌細胞中，抑制prox1表現，則增加E-cadherin表現量，並且增加細胞貼附能力，以及降低細胞侵犯性。因此，轉錄因子prox1在大腸癌中，參與腫瘤轉移過程的調控，被認為是一個oncogene。

Abstract
The homeobox gene prox1 is a transcription factor related to the Drosophila gene Prospero. It play an essential role in the development of central nervous system, lens, liver and pancreas. In addition, prox1 is a master gene controlling the early development of the lymphatic vasculature. In tumorigenesis, prox1 has been shown to function as a tumor suppressor gene in hepatocellular carcinoma and breast cancer. Conversely, prox1 is over-expressed in the majority of colorectal cancer (CRC) and it promotes dysplasia, tumor growth and malignant progression. I report the findings here and show that ectopic expression of prox1 in prox1-null DLD-1 colon cancer cells will increase cell invasion but decrease cell adhesion. In addition, prox1 may induce epithelia- mesenchymal transition (EMT) by attenuating E-cadherin expression and up-regulating other EMT markers. On the contrary, knockdown of prox1 increases E-cadherin expression in SW620 cells; reduction of prox1 increases cell adhesion but decreases invasion. In short, the transcription factor prox1 plays an oncogenic role and promotes cancer metastasis in CRC.

目錄
中文摘要 --------------------------------------1
英文摘要 --------------------------------------2
縮寫語 --------------------------------------3
研究背景 --------------------------------------4
研究目的 --------------------------------------8
實驗材料與方法 ---------------------------------9
實驗結果 --------------------------------------32
討論 --------------------------------------37
圖 --------------------------------------40
表 --------------------------------------60
參考文獻 --------------------------------------62
附件 --------------------------------------66

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