子宫内膜癌胰岛素样生长因子2的表达和印迹状态的改变

Expression level and genomic imprinting status of insulin-like growth factor 2 in endometrial carcinoma

目的基因印迹是目前肿瘤医学领域研究的新热点。胰岛素样生长因子2(insulin-like growth factor 2,IGF2)基因是最早发现的内源性印迹基因之一。肿瘤与IGF2印迹基因表达的关系受到关注。文中通过研究IGF2在子宫内膜癌中的表达及其印迹变化探讨IGF2与子宫内膜癌发生的关系。方法用逆转录-聚合酶链反应(reverse transcription polymerasechain reaction,RT-PCR)半定量检测37例子宫内膜癌组织、25例癌旁组织及20例正常子宫内膜组织中IGF2的相对表达量。根据IGF2第9外显子具有Apa I位点序列设计引物,用PCR、RT-PCR结合限制性片段长度多态性(restrction fragment lengthpolymorphism,RFLP)方法分析IGF2的基因印迹状态。结果子宫内膜癌组织中IGF2的相对表达量明显高于癌旁组织及正常组织,癌旁组织与正常组织中的表达量无显著性差异。IGF2在子宫内膜癌、癌旁组织、正常组织中均存在基因印迹丧失(loss of imprinting,LOI)现象,但3组之间无显著性差异。结论 IGF2的表达增加可能是子宫内膜癌发生的相关因素。IGF2的LOI现象在子宫内膜癌的发生中是否起一定作用尚待进一步研究。

Objective Gene imprinting is a new focus in cancer research, and insulin-like growth factor 2 （IGF2） is one of the earliest endogenous imprinting genes ever found. The relationship between cancer and IGF2 has drawn special attention from the medical world. The purpose of this study was to investigate the association of the expression level of IGF2 with the development of endo- metrial carcinoma. Methods We determined the expression of IGF2 in 37 samples of endometrial carcinoma, 25 samples of para- cancer tissue and 20 samples of normal tissue by RT-PCR semi-quantitative analysis. Based on the polymorphism of the Apa I site in exon 9 of IGF2, we examined the genomic imprinting status of IGF2 by PCR-RFLP and RT-PCR-RFLP. Results The average expression level of IGF2 was significantly higher in endometrial carcinoma than in paracancer and normal tissues, but with no significant difference between the latter two. The loss of imprinting （LOI） of IGF＇2 was found in the samples, but with no significant differences a- mong the three groups. Conclusion The increased expression of IGF2 may be associated with the pathogenesis of endometrial carcinoma. But whether the LOI of IGF2 plays a role in endometrial carcinoma deserves further exploration.