基因甲基化做為卵巢亮細胞癌與類子宮內膜癌之區分及預後指標

Abstract

本論文的研究目的是為了分析卵巢亮細胞癌（Ovarian clear cell adenocarcinoma, OCCA）與卵巢類子宮內膜癌（Ovarian endometrioid adenocarcinoma, OEA）之間不同基因的甲基化情形，並進一步評估基因甲基化是否可以當作預測病人化療反應與預後的生物指標。透過甲基化特異聚合酶連鎖反應（Methylation-Specific Polymerase Chain Reaction, MS-PCR）及毛細電泳等方法，我們在66個OCCA與51個OEA病人中，分析8個候選基因（RASSF1A、E-cadherin、DLEC1、RUNX3、SFRP1、SFRP5、PAX與LMX1A）中的甲基化情形，並收集與分析這些病人的臨床病理參數和預後。研究結果顯示，在OCCA的病人中，包括RASSF1A、E-cadherin、DLEC1這三個基因的甲基化頻率皆高於OEA的病人；而對化療藥有抗藥性的組別中，E-cadherin基因的甲基化比例相對於對化療藥敏感的組別明顯高出許多；另外，我們針對這117位病患進行多變量分析，發現疾病處於晚期及SFRP5基因的甲基化是與致死相關的危險因子。再進一步的分析中顯示，包括E-cadherin、DLEC1與SFRP5這三個基因中如果有兩個以上發生基因甲基化的情形，比起只有一個或沒有甲基化的組別，有較短的無病存活期（disease-free survival, DFS）和整體存活期（overall survival, OS）；針對57個癌症處於晚期的婦女分析，使用紫杉醇（paclitaxel）進行化療之組別的整體存活期也比沒使用紫杉醇的患者來的長。綜合以上結果，我們認為OCCA與OEA的甲基化型態確實不同，而E-cadherin、DLEC1和SFRP5這三個基因甲基化的情形，未來或許有發展為卵巢癌OCCA及OEA病患之預後生物指標的潛力。

The purpose of the thesis was to investigate the methylation of various genes between patients with ovarian clear cell adenocarcinoma (OCCA) and ovarian endometrioid adenocarcinoma (OEA). In addition, we evaluated if methylation could be biomarkers in the chemo-response and outcome of the patients. The methylation statuses of eight candidate genes (RASSF1A, E-cadherin, DLEC1, RUNX3, SFRP1, SFRP5, PAX and LMX1A) were evaluated by methylation-specific polymerase chain reactions and capillary electrophoreses in 66 OCCA and 51 OEA patients. The clinico-pathologic parameters and outcomes of these patients were collected and analyzed. The frequencies of gene methylation in RASSF1A, E-cadherin, and DLEC1 were higher in the OCCA than in OEA. The chemo-resistant group had a significantly higher percentage of E-cadherin methylation than the chemo-sensitive group. Advanced stage and SFRP5 gene methylation were two death risk factors by multi-variate analyses in a total of 117 patients. In further analyses, gene methylation of E-cadherin, DLEC1, and SFRP5 were observed. Those with more than two out of the three gene methylations had shorter DFS and OS than those without any or with only one gene methylation. For 57 advance-staged women, paclitaxel chemotherapeutic group had longer OS than those without. As a result, we believe OCCA and OEA differed in gene methylation patterns. Methylation of E-cadherin, DLEC1, and SFRP5 genes appears to have the potential to become the specific biomarkers for OCCA and OEA patients.