Uyeno S, Aoki Y, Nata M, Sagisaka K, Kayama T, Yoshimoto T, Ono T
Department of Radiation Research, Tohoku University School of Medicine, Aoba-ku, Sendai, Japan.
Cancer Res. 1996 Dec 1;56(23):5356-9.
Genomic imprinting is a gamete-specific modification resulting in the allele-specific expression of genes in somatic cells. A loss of imprinting (LOI) has been found in many embryonal and adult tumors, suggesting that it plays a role in tumor development. The incidence of LOI, however, does not seem to be ubiquitous among tumors because neuroblastoma and colorectal cancer revealed no LOI. We examined the involvement of LOI of IGF2 and H19 genes in human gliomas. The two genes were imprinted in normal brain subcortex tissues. In glioma, 8 of 14 informative cases (57%) revealed LOI in IGF2. The frequency did not depend on the tumor grade. For H19, in contrast, all 13 informative cases maintained imprinting. These results suggest that LOI of IGF2 but not H19 plays a role in the development of human glioma.
基因组印记是一种配子特异性修饰，导致体细胞中基因的等位基因特异性表达。在许多胚胎和成体肿瘤中都发现了印记丢失（LOI），这表明它在肿瘤发展中起作用。然而，LOI的发生率在肿瘤中似乎并不普遍，因为神经母细胞瘤和结直肠癌未显示出LOI。我们研究了IGF2和H19基因的LOI在人类胶质瘤中的作用。这两个基因在正常脑皮质下组织中是印记的。在胶质瘤中，14例信息充分的病例中有8例（57%）显示IGF2存在LOI。该频率不取决于肿瘤分级。相比之下，对于H19，所有13例信息充分的病例均保持印记。这些结果表明，IGF2而非H19的LOI在人类胶质瘤的发展中起作用。
