Caveolin-1與FAK分子於大腸直腸癌組織之表達分析

Analysis of Caveolin-1 and FAK Expression in Colorectal Cancer Tissue

目的：大腸癌為國內罹患癌症類型之首，近年癌症研究致力於細胞內的分子機轉，以期發現早期診斷的標記分子，並於臨床治療上應用。Caveolae為細胞內凹所形成的小窩，主要由Caveolin家族調控，Caveolin為內膜蛋白，其中Caveolin1（CAV1）為主要分子，參與內吞、胞器運輸與訊號傳遞。在過去實驗中發現CAV1與某些致癌因子有負相關表達，被認為是抑癌因子，但近年研究顯示CAV1在大腸癌癌症第Ⅲ、Ⅳ期卻有較高表達量，其機制可能更為複雜。Focal adhesion kinase（FAK）在細胞移行及轉移過程中扮演重要的角色，並且與許多致癌因子相互影響，較高FAK表達量與病患生存率的降低有關。本研究欲了解臨床病患之大腸直腸癌腫瘤組織CAV1表達與FAK之關係。方法：實驗以病患之腫瘤、正常周邊組織進行組織石蠟包埋、切片，並以免疫化學組織染色、分析CAV1與FAK在大腸直腸癌的表達情形。結果：以16名病患的周邊組織與腫瘤組織比對，定性結果顯示CAV1在大腸癌腫瘤組織有較高表達量，FAK亦有較高的表達量。結論：本研究定量結果腫瘤組織之CAV1有較高之表達量，CAV1與FAK表達有正相關，可能與癌症分期有關。

Purposes Colorectal cancer is the most common cause of cancer deaths in Taiwan. In recent years, studies have focused on elucidating the cellular and molecular mechanisms underlying cancer pathogenesis, in order to discover novel biomarkers for early diagnosis and treatment of cancer. Caveolae are invaginations present inside the cells and are mainly regulated by members of the caveolin family. Caveolins are integral membrane proteins, of which, caveolin-1 (CAV1) is an important member that participates in endocytosis, organelle transport, and signal transduction. Previous studies have reported that CAV1 expression was negatively correlated with some carcinogenic factors, and it was believed to be a tumor suppressor. However, recent studies revealed that CAV1 was highly expressed in stage III and IV colon cancer and its mechanism of action was highly complex. Focal adhesion kinase (FAK) plays an important role in cell migration and metastasis, and interacts with many carcinogenic factors. It was observed that high FAK expression was associated with a low survival rate in patients. Our study attempted to understand the relationship between CAV1 and FAK expression in colorectal cancer tissues. Methods The present study involved paraffin embedding and sectioning of the tumor samples, as well as the healthy surrounding tissue samples from patients. Subsequently, immunohistochemical staining was performed for analyzing CAV1 and FAK expression in both these tissues. Results Results showed that compared to the healthy surrounding tissue, CAV1 and FAK expression was considerably higher in the colorectal cancer tissue. Conclusions Our study clearly indicated higher CAV1 expression in tumor tissues was positively correlated with that of FAK, which might be associated with the cancer stage.