子宫内膜癌中PR基因表达缺陷及其启动子区CpG岛甲基化的研究  

RESEARCH ON THE EXPRESS DEFECT AND CPG PROMOTOR REGION METHYLATION OF PROGESTERONE RECEPTOR GENE IN HUMAN UTERINE ENDOMETRIAL CARCINOMA

作　　者：田海侠[1] 刘丽丽[1] 

机构地区：[1]辽宁医学院附属一院妇产科,锦州121001

出　　处：《现代预防医学》2010年第10期1861-1864,1866,共5页Modern Preventive Medicine

摘　　要：[目的]研究子宫内膜癌中孕激素受体亚型PRA、PRB表达与其启动子区甲基化状态的关系,探讨子宫内膜癌组织、细胞分子变化特征及孕激素受体亚型表达下调的机制。[方法](1)应用免疫组化SP法检测子宫内膜癌组织中PRA、PRB蛋白的表达。(2)应用甲基化特异性PCR检测子宫内膜癌组织及经5-杂氮脱氧胞苷(5′-aza-2′-deoxyóytidine ADC)处理前后子宫内膜癌Hec-1-B细胞系中PRA、PRB的甲基化状态。(3)应用免疫印迹法检测ADC处理Hec-1-B细胞系前后PRA、PRB蛋白的表达。[结果](1)与正常子宫内膜组织比较:PRA蛋白在高、中低分化子宫内膜癌组织中表达差异无统计学意义;PRB蛋白在高分化子宫内膜癌组织中表达无明显降低,差异无统计学意义,在中低分化子宫内膜癌组织中表达明显降低,差异有统计学意义。(2)与正常子宫内膜组织比较,子宫内膜癌组织中,PRA启动子区CpG岛甲基化率较低,差异无统计学意义,PRB启动子区CpG岛甲基化率较高,差异有统计学意义,与组织分化程度有关,与病理类型及有无淋巴结转移和有无肌层浸润无关;子宫内膜癌Hec-1-B细胞系中,加入ADC前PRA出现非甲基化条带,PRB出现甲基化条带,加入ADC后,PRA非甲基化条带不变,PRB甲基化条带消失。(3)子宫内膜癌Hec-1-B细胞系中加入不同浓度ADC后,PRA蛋白表达无明显改变,PRB蛋白表达不同程度增加。[结论]子宫内膜癌组织以及Hec-1-B细胞系中,存在PR基因异常甲基化,与PR表达下调关系密切,编码PR基因启动子的选择性B亚型甲基化,导致了PRB的失活,继而PRB蛋白表达下降或消失,可能参与了子宫内膜癌的形成。ADC可通过去甲基化作用使PRB恢复表达,可能提高子宫内膜癌的临床内分泌治疗效果。[Objective] To study the relationship between PRA and PRB expression and promoter emthylation status in the endometrial cancer, and to explore the molecular characteristics and expression of progesterone receptor isoforms downward mechanism. [Methods] （1） Immunohistochemical was applied to detect PRA and PRB protein expression in the endometrial carcinoma tissues. （2） Methylation-specific PCR was used to detect PRA and PRB＇s methylation status in the endometrial carcinoma tissues and cell lines. （3） The Western blotting ADC was applied to detect the ADC to deal with Hec-1-B cell lines before and after the two subtypes of progesterone receptor protein expression. [Results] Comparing with normal endometrial tissues, PRA protein was not significantly reduced, PRB protein in well-differentiated endometrial carcinoma was not significantly lower, and they significantly decreased in poorly differentiated endometrial cancer tissues. （2） PRA prompter region CpG island methylation rate did not present significant difference, PRB was relatively high related with the degree of differentiation, and was unrelated with pathological type and lymph node metastasis and muscularis infiltrates; In Hec-1-B cell lines, unmethylated bands of PRA and methylation bands of PRB appeared before adding ADC, and PRA remained unchanged and PRB methylation bands disappeared after adding ADC. （3） After adding different concentrations of ADC, PRA and PRB protein expression increased in different degrees in the Hec-1-B cell lines. [Conclusion] Endometrial cancer tissues and cell lines existed abnormal methylation of PR gene, and is related with the decrease of PR, and PR genes promoter methylation of selective subtype B induced inactivation of PRB, and then PRB protein expression decreased or disappread, which could involved in the formation of endometrial cancer. ADC demethylation could renew the expression of PRB, and improve the treatment effect of endometrial cancer in clinic.

关 键 词：子宫内膜癌 孕激素受体亚型 甲基化 

分 类 号：R711.4[医药卫生—妇产科学]