Identification of a metastasis related gene in colon cancer

• Main Authors: Ching-Han Tsao, 曹經漢
• Other Authors: Jason C. Huang
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/67757645579260197286

碩士 === 國立陽明大學 === 醫學生物技術暨檢驗學系暨研究所 === 97 === Colorectal cancer（CRC）is one of the most common malignant neoplasms in Taiwan and the world. About half of patients with colorectal cancer can be cured by surgery and multimodal treatment. But metastasis is the most important cause for cure failure. We used microarray to analyze the gene expression profiles in colorectal cancer specimens. By comparing primary and metastatic carcinomas, we obtained 262 metastasis related genes. RT-PCR and real-time PCR were used to verify 11 of the 262 genes. We further narrowed down to four possible candidates：ADFP, SDC4, ENPEP and ANLN. First, we focused on adipose differential related protein (ADFP). So far, the function of ADFP is not clear. According to previous studies, it was involved in adipocyte differentiation, but its relationship with cancer is unknown. Based on real-time PCR result, we found that the expression level of ADFP is higher in patients’biopsies of more advanced tumor grade. This implied that the amounts of ADFP are increased during cancer progression and metastasis. In order to prove the hypothesis, we expressed ADFP in suitable colon cancer cell line. For the purpose, we utilized qPCR to quantify endogenous ADFP expression level in SW480, SW620, HCT-15 and HT-29. SW480 has lower endogenous mRNA expression level of ADFP than the others, so SW480 is an appropriate cell line for overexpressing ADFP. Besides, we also optimize the time point for ADFP expression. Our results showed that the maximum expression of ADFP could be detected 24 to 36 hours post-transfection. Combining the two results, we used wound healing and invasion assay to validate whether ADFP overexpression will increase in vitro cell mobility and invasive ability of cancer cells. We used wound healing to verify that cancer cells mobility was enhanced in SW480 overexpressing ADFP. In wound healing assay, we found that the gap was filled up faster with SW480 transfected with ADFP expression plasmid compared with vector control plasmid in 48 hours. In invasion assay, when ADFP was overexpressed in SW480, the number of migrating cells crossing coated matrigel was more than that of vector control. Taken together, our findings shows that ADFP can enhance in vitro cells mobility and invasive ability of colon cancer cells, but more evidence will be needed to support our assumption that the ADFP gene expression can promote tumor metastasis.