Wright J T, Hansen L, Mahler J, Szczesniak C, Spalding J W
Department of Pediatric Dentistry, School of Dentistry, University of North Carolina at Chapel Hill 27599-7450, USA.
Arch Oral Biol. 1995 Jul;40(7):631-8. doi: 10.1016/0003-9969(95)00017-j.
A line of homozygous transgenic mice (TG.AC) carrying a v-Ha-ras gene fused to the promoter of the zeta globin gene produces a variety of mesenchymal and epithelial neoplasms including odontogenic tumours. The 1-year incidence of odontogenic tumour formation in these mice was approx. 35%. Tumours formed more often in the mandible than maxilla. The various types of tumours frequently presented with: (1) primarily mesenchymal cells in a dense fibrous-like matrix, or (2) loose stroma surrounded by anastomosing cords of epithelial cells that exhibited squamous differentiation, or (3) odontomas forming mineralized tooth structures by well-differentiated odontoblasts and ameloblasts. Some tumours had areas with all three of these characteristics. Mineralized dentine and enamel in the odontomas were morphologically similar to those of normal murine teeth. Odontogenic tumours expressed the v-Ha-ras transgene that was primarily localized to the mesenchymal cells. Proliferating-cell nuclear antigen immunohistochemistry showed that the mesenchymal cells adjacent to the epithelial cords not only expressed the ras transgene but were also actively proliferating. The TG.AC mouse provides an excellent model for the study of odontogenic tumours and tooth development.
携带与ζ珠蛋白基因启动子融合的v-Ha-ras基因的纯合转基因小鼠品系（TG.AC）会产生多种间充质和上皮肿瘤，包括牙源性肿瘤。这些小鼠中牙源性肿瘤形成的1年发生率约为35%。肿瘤在下颌骨中比在上颌骨中更常形成。各种类型的肿瘤常表现为：（1）主要是位于致密纤维样基质中的间充质细胞，或（2）由表现出鳞状分化的上皮细胞吻合索包围的疏松基质，或（3）由分化良好的成牙本质细胞和成釉细胞形成矿化牙齿结构的牙瘤。一些肿瘤具有这三种特征的区域。牙瘤中的矿化牙本质和釉质在形态上与正常小鼠牙齿相似。牙源性肿瘤表达主要定位于间充质细胞的v-Ha-ras转基因。增殖细胞核抗原免疫组织化学显示，与上皮索相邻的间充质细胞不仅表达ras转基因，而且还在积极增殖。TG.AC小鼠为牙源性肿瘤和牙齿发育的研究提供了一个极好的模型。
