Relaxation of IGF2 Imprinting in Human Gynecologic Tumors

为了验证基因组印迹在人妇科肿瘤中的存在，我们分析了人胰岛素样生长因子2 （IGF2）基因的等位基因表达。基因组印迹是基因的亲本等位基因特异性表达，最近IGF2的印迹已经证明亲本IGF2是单等位基因表达的。为了研究IGF2基因印迹是否发生在人类妇科肿瘤中，我们利用ApaI多态性检测了IGF2基因外显子9 3'非翻译区等位基因的特异性表达。我们使用了19个妇科肿瘤细胞系和66个人类妇科肿瘤。19个细胞系中有4个（21%）信息丰富，这4个细胞系中有3个（75%）显示印迹丢失（LOI）。妇科肿瘤66例中有24例信息丰富（36%），5例（21%）有LOI。因此，IGF2在一些妇科肿瘤中是双等位表达的。我们认为IGF2的LOI参与了一些妇科肿瘤的发生发展。

To test for the existence of of genomic imprinting in human gynecologic tumors, we analyzed the allelic expression of human insulin-like growth factor 2 (IGF2) genes. Genomic imprinting is the parental allele-specific expressions of genes, and recently imprinting of IGF2 has demonstrated that parental parental IGF2 was monoallelically expressed. To study whether IGF2 gene imprinting occurs in human gynecologic tumors, We examined allele-specific expression using ApaI poymorphism in the 3' untranslated region of IGF2 gene exon 9. We used 19 gynecologic tumor cell lines, and 66 human gynecologic tumors. Four of 19 cell lines (21%) were informative, and three of these four cell lines (75%) revealed loss of imprinting (LOI). For gynecologic tumors, 24 of 66 were were informative (36%), and 5 of the 24 (21%) had LOI.Thus, IGF2 is expressed biallelically in some gynecologic tumors. We suggest LOI of IGF2 is involved in the developement of some gynecologic tumors.