Lubensky I A, Debelenko L V, Zhuang Z, Emmert-Buck M R, Dong Q, Chandrasekharappa S, Guru S C, Manickam P, Olufemi S E, Marx S J, Spiegel A M, Collins F S, Liotta L A
Laboratory of Pathology, National Cancer Institute, NIH, Bethesda, Maryland 20892, USA.
Cancer Res. 1996 Nov 15;56(22):5272-8.
Familial multiple endocrine neoplasia type 1 is an autosomal dominant hereditary disorder characterized by multiple parathyroid, pancreatic, duodenal, and pituitary tumors. The parathyroid tumors may arise as diffuse areas of hyperplasia, whereas the pancreatic and duodenal tumors usually form as discrete nodules. Except for a single report, tumor loss of heterozygosity (LOH) mapping of the putative MEN1 suppressor gene on chromosome 11q13 in the past has been restricted by analysis of a single tumor from individual patients and somatic cellular contamination. For this reason, it has not been possible to analyze the clonality of the emerging MEN1 neoplasms. Furthermore, it has been previously unknown whether the LOH pattern varies between individual MEN1 tumors in a given patient or among tumors of different histological origins within unrelated patients. To address these previous limitations, the present study introduces a refinement in microdissection in which endothelial cells are stained and selectively excluded. Tissue microdissection was applied to study LOH patterns on chromosome 11q13 using 8 polymorphic DNA markers in 44 different MEN1 tumors from parathyroid, pancreas, and duodenum in nine unrelated patients. In addition, X-chromosome inactivation clonal analysis was applied to 16 individual microdissected regions from seven parathyroid glands in three female patients. The LOH rates of parathyroid lesions (100%) and endocrine tumors of the pancreas (83%) were strikingly different from the LOH rate of gastrinomas (21%), suggesting that the mechanism that drives LOH may be influenced by the tissue context. Moreover, combined LOH and X-chromosome inactivation scoring of the same microdissected region revealed that parathyroid MEN1 neoplasms can consist of more than one clone. In this study, the centromeric boundary of the putative MEN1 gene was PYGM. Analysis of differential LOH patterns in multiple microdissected tumors in the same patient constitutes a novel approach to suppressor gene mapping.
家族性多发性内分泌腺瘤病1型是一种常染色体显性遗传性疾病，其特征为多个甲状旁腺、胰腺、十二指肠和垂体肿瘤。甲状旁腺肿瘤可能以弥漫性增生区域的形式出现，而胰腺和十二指肠肿瘤通常形成离散的结节。除了一份单独的报告外，过去对位于11号染色体q13上的假定MEN1抑癌基因进行肿瘤杂合性缺失（LOH）定位时，受到了对个体患者单个肿瘤的分析以及体细胞污染的限制。因此，无法分析新出现的MEN1肿瘤的克隆性。此外，此前尚不清楚在给定患者的个体MEN1肿瘤之间，或者在无关患者中不同组织学起源的肿瘤之间，LOH模式是否存在差异。为了解决这些先前的局限性，本研究引入了一种改进的显微切割方法，其中内皮细胞被染色并被选择性排除。应用组织显微切割技术，使用8个多态性DNA标记，对9名无关患者的甲状旁腺、胰腺和十二指肠中的44个不同MEN1肿瘤进行11号染色体q13上的LOH模式研究。此外，对3名女性患者7个甲状旁腺的16个单独显微切割区域进行了X染色体失活克隆分析。甲状旁腺病变（100%）和胰腺内分泌肿瘤（83%）的LOH率与胃泌素瘤的LOH率（21%）显著不同，这表明驱动LOH的机制可能受组织背景影响。此外，对同一显微切割区域进行联合LOH和X染色体失活评分显示，甲状旁腺MEN1肿瘤可能由多个克隆组成。在本研究中，假定MEN1基因的着丝粒边界为PYGM。分析同一患者多个显微切割肿瘤中的差异LOH模式构成了一种新的抑癌基因定位方法。
