Methylation Status of SFRP1 Gene Promoter of Colorectal Cancer Cells

大腸直腸癌細胞SFRP1基因啟動子甲基化研究

葉建志(Chien-Chih Yeh) ； 何敬之(Ching-Chih Ho) ； 鍾明宗(Ming-Tzeung Chung)

《北市醫學雜誌》 8卷2期 (2011/06) Pp. 91-96

https://doi.org/10.6200/TCMJ.2011.8.2.01

摘要

目的：在台灣，大腸直腸癌的死亡率佔國人十大癌症的第三名，學者認為發生大腸直腸癌的機轉除了與西化飲食及缺乏運動有關之外，也有致癌及抗癌的基因異常的因素參與其中，Wnt signaling傳導路徑就是促發大腸直腸癌的重要因子，而抑制Wnt signaling傳導路徑的SFRP抑癌基因也就成為抑制大腸直腸癌的守護者，近年來西方學者發現了基因甲基化會影響基因的表現，一旦抑癌基因甲基化將會失去抑癌能力，所以基因甲基化也就扮演了癌症發生與否的重要角色，我們之前已經發現SFRP1基因在大腸直腸癌組織有過度甲基化的現象，為了釐清SFRP1基因在大腸直腸癌細胞的作用，我們將檢視大腸直腸癌細胞株的甲基化現象，以作為後續研究之準備。方法：我們將大腸直腸癌細胞株（HT29和CT26）培養後抽取去氧核糖核酸進行甲基化專一性之聚合酵素鏈鎖反應。結果：SFRP1基因啟動子在大腸直腸癌細胞株CT26發現有部份甲基化的現象，而在HT29則呈現完全甲基化的現象，顯示不同細胞株可能有不同的致癌機制。結論：不同的大腸直腸癌細胞株可能有不同的致癌機制，SFRP1的基因甲基化有可能是HT29細胞株重要的致癌機制，將來會針對HT29細胞株進行進一步的實驗來確認SFRP1基因甲基化是否為大腸直腸癌關鍵之致癌機制。

關鍵字

大腸直腸癌 ； 甲基化 ； 甲基化專一性之聚合酵素鏈鎖反應

並列摘要

Objectives: Cancers of the colon and rectum are the third most frequent malignancy in Taiwan and were responsible for 2555 deaths in 2003. In a review article, Jones et al. emphasized the importance of Wnt pathway in carcinogenesis. Therefore, the interaction of Wnt pathway and antagonists of the pathways during colon/rectal tumorogenesis needs more detail investigation. We have previously reported that frequent methylation of the secreted frizzled-related protein 1 (SFRP1) promoter occurs during colorectal cancer. To clarify the real role of the SFRP1 gene in the development of colorectal cancer, we further explored the methylation status of the SFRP1 gene promoter in colorectal cancer cells. Methods: SFRP1 promoter methylation was evaluated in two cancer cell lines of the colon and rectum, HT29 and CT26, by methylation specific polymerase chain reaction (MS-PCR). Results: Semimethylation of the promoter was found in CT26 cell line, while the HT29 cell line showed aberrant methylation at the promoter region. Conclusions: The MS-PCR result revealed the presence of aberrant SFRP1 promoter methylation in HT29 cells and therefore the HT29 cell line was chosen to be the candidate for further experiments in this area.

並列關鍵字

colorectal cancer ； epigenetics ； methylation ； methylation-specific PCR MSPCR