EXPERIMENTAL TRANSFORMATION OF HUMAN MELANOCYTES IN VIVO

人类黑色素瘤发展的实验动物模型已经被 由于其独特的建筑风格和 人体皮肤的功能特性阻碍了对 病因学、诊断和预防疾病。流行病学 观察表明，紫外线（UV）照射在 人类黑色素瘤的病因学，但直接证据仍然缺失。的 前体发育不良痣组织学诊断及生物学 早期原发性黑色素瘤一直是困难和有争议的， 即使在专家中，目前对基因的了解也很少。 畸变及其对黑素瘤发展的重要性。 为了更好地了解人类黑色素瘤的发展， 在最早期用新的分子标记检测黑素细胞损伤， 我们在免疫缺陷的RAG-1小鼠中建立了人类皮肤移植模型， 从新生儿开始的人类技能暴露在化学致癌物中， 7，12-二甲基（a）苯并蒽（DMBA），然后UV照射， 到10个月。对该模型的初步研究表明， 黑素细胞增生、雀斑、发育不良和黑色素瘤。使用 我们现在能够移植成人皮肤， 将选择那些对发展中国家的高敏感性的捐赠者， 发育不良痣和/或黑色素瘤，以确定最佳的UV波长 用于诱导黑素细胞病变，并开发新的标准， 体内黑素细胞转化，包括增殖，逃逸， 角质形成细胞控制的黑素细胞，黑素细胞接触丧失 从基底膜和形态学变化相关 黑素细胞发育不良然后我们将定义新的分子标记， 使用微阵列进行转化，用于分析 来自显微解剖病变或短期培养物的细胞。这些初始 筛选方法之后是免疫组织化学和原位 杂交分析提供了基因表达的信息， 分别在RNA和蛋白质水平上的单个细胞。探讨 主要检查点基因的作用，我们将研究黑色素细胞在 用E6基因或人乳头瘤病毒对p53进行体外检测 螯合或与H-ra一起用于ras激活。转导黑素细胞 然后将被包括在由真皮组成的皮肤重建中， 表皮移植前在体内和长期紫外线照射。我们 独特的体外/体内模型适合于研究病因， 早期发现和预防人类黑色素瘤。

Experimental animal models for human melanoma development have been difficult to establish because of the unique architectural and functional characteristics of human skin hampering investigations on etiology, diagnosis, and prevention of the disease. Epidemiological observations suggest a role for ultraviolet (UV) light irradiation in the etiology of human melanoma but direct evidence is still missing. The histological diagnosis of precursor dysplastic nevi and biologically early primary melanomas continuous to be difficult and controversial, even among experts, and there is currently little understanding of gene aberrations and their importance for melanoma development. To better understand development of human melanoma and to detect melanocytic lesions at the earliest stages with new molecular markers, we have developed a human skin graft model in immunodeficient RAG-1 mice in which human skill from newborns is exposed to the chemical carcinogen 7,12-dimethyl(a)benzanthracene (DMBA) followed by UV irradiation for up to 10 months. Preliminary studies with this model have revealed melanocytic hyperplasia, lentigo, dysplasia, and melanoma. Using a refined grafting technique we are now able to graft skin from adults and will select donors who have a high susceptibility for developing dysplastic nevi and/or melanomas to determine the optimal UV wavelength for induction of melanocytic lesions and to develop new criteria for melanocyte transformation in vivo, including proliferation, escape of melanocytes from control by keratinocytes, loss of melanocyte contact from basement membrane and morphological changes associated with melanocytic dysplasia. We will then define new molecular markers for transformation using microarrays for analyses of mRNA expression in cells from microdissected lesions or short-term cultures. These initial screening approaches are followed by immunohistochemistry and in situ hybridization analyses to provided information on gene expression in single cells at the RNA and protein levels, respectively. To investigate the role of major check point genes, we will transduce melanocytes in vitro with either the E6 gene or human papilloma virus for p53 sequestration or with H-ra for ras activation. Transduced melanocytes will then be included into skin reconstructs consisting of dermis and epidermis prior to grafting in vivo and long-term UV irradiation. Our unique in vitro/in vivo models are suitable to investigate etiology, early detection, and prevention of human melanoma.