Lee M P, Feinberg A P
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Cancer Res. 1998 Mar 1;58(5):1052-6.
Genomic imprinting is an epigenetic modification of the gamete or zygote leading to parental origin-specific gene expression in somatic cells of the offspring. We have previously identified a cluster of imprinted genes on human chromosome 11p15.5, a region involved in Beckwith-Wiedemann syndrome, Wilms' tumor, and ovarian, breast, and lung cancer. Here we show that TSSC3, which is homologous to the mouse apoptosis gene TDAG51 and maps to this region, is imprinted and expressed from the maternal allele in normal development. This result is important for three reasons: (a) TSSC3 is the first apoptosis-related gene in any species found to be imprinted; (b) it is located within the tumor suppressor region of 11p15; and (c) it lies within 15 kb of the nonimprinted gene hNAP2, thus defining a small boundary interval between imprinted and nonimprinted genes on 11p.
基因组印记是配子或受精卵的一种表观遗传修饰，可导致后代体细胞中基因按亲本来源特异性表达。我们之前在人类11号染色体p15.5上鉴定出一组印记基因，该区域与贝克威思-维德曼综合征、威尔姆斯瘤以及卵巢癌、乳腺癌和肺癌有关。在此我们表明，与小鼠凋亡基因TDAG51同源且定位于该区域的TSSC3在正常发育过程中是印记基因，且由母本等位基因表达。这一结果具有重要意义，原因有三点：（a）TSSC3是在任何物种中发现的首个被印记的凋亡相关基因；（b）它位于11p15的肿瘤抑制区域内；（c）它位于非印记基因hNAP2的15 kb范围内，从而确定了11p上印记基因与非印记基因之间的一个小边界区间。
