Relation between DNA mismatch repair abnormality and sensitivity of anti-cancer drugs and progesterone receptor in endometrial cancer

为了使晚期子宫内膜癌患者术后辅助治疗更加个体化，我们利用组织学和细胞学标本分析了DNA错配修复基因的遗传/表观遗传变化，并检测了抗癌药物和孕激素的敏感性。我们获得了如下重要发现：(1)微卫星不稳定性(MSI)；1.子宫内膜癌组织中存在MSI高表达(MSI-H)。2.免疫组织化学研究显示，在MSI阳性的子宫内膜癌中，hMLH1、hMSH2、hMSH6的低表达分别占54%、12%、18%。在73%的MSI阳性病例中，这三种MMR蛋白的任何一种都被认为是减少的。其中，hMLH1的表达降低与微卫星感染密切相关，并且hMLH1基因启动子高度甲基化(92%)。3.对mmr基因进行胚系突变分析，发现微卫星阳性病例中hMLH1和hMSH6基因有高突变率的趋势。4.在手术标本的分析中，…子宫内膜癌多见，hMLH1、apc、E-钙粘素、PAR-β-、p16基因启动子异常甲基化参与了子宫内膜癌的发生。特别是，hMLH1启动子损伤的高甲基化(40%)涉及(Banno K，等人)。(2)抗癌药物的敏感性；1.用CDDST法检测子宫内膜癌患者胸腹水对顺铂、紫杉醇和多西紫杉醇的敏感性。2.在细胞周期检查点基因CHFR基因高甲基化与子宫内膜癌细胞系对紫杉烷类药物敏感性的研究中，CHFR基因高甲基化与紫杉烷类药物敏感性降低有关。我们首次认识到CHFR基因甲基化可能调节子宫内膜癌患者对紫杉烷类药物的敏感性(Yanokura M，et al.3.采用免疫组织化学方法检测细胞毒性CD8阳性淋巴细胞渗入癌巢(TIL)，发现MSI-H肿瘤中TIL数(>15/HPF)显著增加，TIL>15/HPF者预后明显好于TIL减低者。此外，TIL升高的患者对顺铂的敏感性有升高的趋势。(3)对孕酮的敏感性：1.对67例早期子宫内膜癌患者采用大剂量醋酸甲羟孕酮(MPA)治疗，以保持生育能力。非典型子宫内膜增生症、复杂性子宫内膜样腺癌和1级子宫内膜样腺癌缓解率分别为100%和93.7%。在某些情况下，子宫内膜腔复发后再次进行甲孕酮治疗。2.双色FISH检测到持续性基因组改变的病例中hMLH1表达降低者，子宫内膜腔复发发生率高(Susumu N，et al.INJ妇科癌症，2005年)，在甲孕酮治疗终止时。较少

In order to indivisualize the post-operative adjuvant treatment of patients with advanced endometrial cancers, we analyzed genetic/epigenetic change of DNA mismatch repair genes using histologic and cytologic specimens and checked sensitivities of anti-cancer drugs and progesterone hormone. We obtained some important findings as described below.(1)Microsatellite instability (MSI) ;1.MSI-high (MSI-H) was recognized in 28.5% cases of endometrial cancer.2.Immunohistochemical study revealed that decreased expression of hMLH1, hMSH2, hMSH6 was recognized in 54%, 12%, 18% in MSI-positive endometrial cancers. Either decrease of the three MMR proteins was recognized in 73% of MSI-positive cases. Especially, decreased expression of hMLH1 is significantly related to MSI, and promoter of hMLH1 gene is highly (92%) methylated.3.Analysis of germ-line mutation of MMR genes revealed tendency of high mutation rates in hMLH1 and hMSH6 genes in MSI-positive cases.4.In the analysis of surgical specimens … More of endometrial cancers, hypermethylation of promoter lesions of hMLH1, APC, E-cadherin, PAR- β-, p16 genes is involved in the carcinogenesis of endometrium. Especially, hypermethylation of promoter lesions of hMLH1 is highly (40%) involved (Banno K, et al. Oncol Rep. 2006).(2)Sensitivity of anti-cancer drugs ;1.Using CDDST method with pleural effusions and ascites of patients with endometrial cancers, we could judge sensitivity to cisplatin, paclitaxel and docetaxel.2.In the investigation of hypermethylation of CHFR gene, one of the cell cycle check point gene, with cell lines derived from endometrial cancers, hypermethylation of CHFR gene was related to high sensitivity to taxanes and demethylation caused decrease in sensitivity to taxanes. We recognized for the first time that methylation of CHFR gene may regulate the sensitivity to taxanes in endometrial cancer (Yanokura M, et al. Oncol Rep. 2007).3.Using immunohistochemistry about cytotoxic CD8-positive lymphocytes infiltrating into the cancer nests (TIL), we recognized that the number of TILs (more than 15/HPF) is significant increased in MSI-H tumors and found that prognosis of the cases with increased TILs (more than 15/HPF) was significantly better than that with decrease TILs. In addition, there was a tendency that sensitivity to cisplatin was high in increased TILs cases.(3)Sensitivity to Progesterone ;1.Sixty-seven cases with early stage endometrial cancer were treated by high-dose medroxyprogesterone acetate (MPA) in order to preserve fertility. Remission rates in atypical endometrial hyperplasia, complex, and grade 1 endometrioid adenocarcinoma were 100% and 93.7%, respectively. In some cases, repeated MPA therapy was performed after recurrence in endometrial cavity. Six cases got pregnant and delivered.2.Recurrence in endometrial cavity tended to occur in high rates in cases with decreased expression of hMLH1 of in cases with persistent genomic alterations detected by two-color FISH (Susumu N, et al. Int J Gynecol Cancer 2005) at the time of termination of MPA therapy. Less