Id proteins in UV-mediated keratinocyte apoptosis

描述（由申请人提供）：人类最常见的恶性肿瘤是皮肤癌，其发病率接近所有其他癌症亚型的总和。人乳头瘤病毒（HPV）和紫外线（UV）照射都是这种疾病的危险因素。HPV的永生化可能是癌发生的早期阶段，而UV可能通过诱导进一步的突变以及选择致瘤细胞来诱导后续事件。HPV-16 E6/7永生化的人角质形成细胞对UVB诱导的细胞凋亡非常敏感，与载体转导或早期传代（p7）E6/7细胞相比。DNA微阵列分析表明，在监测的16，000个基因中，Id蛋白家族的三个成员在UVB暴露后表现出显着变化;每个Id在原代细胞与永生化细胞中受到UV的差异调节。Id蛋白在许多其他类型细胞的分化、凋亡和肿瘤发生中起重要作用。因此，特定目的将检验Id基因在调节细胞培养物和移植的人表皮中由急性UVB暴露诱导的角质形成细胞凋亡和分化中起核心作用的假设。 具体目的我将研究的遗传因素，负责初级和永生化HFK的Id 2和Id 3的差异调节。 具体目标II将描绘Id 2和Id 3在人角质形成细胞凋亡调节中的作用。将通过研究优先与Id 2和Id 3相互作用的因素来研究基因和细胞类型特异性反应的机制。 Specific Aim III将产生来自过度表达Id 2或Id 3的角质形成细胞的移植人表皮，以检查对UVB或局部致癌物的短期（分化和凋亡）和长期（转化）反应。

DESCRIPTION (provided by applicant): The most common malignancy occurring in humans is skin cancer, with an incidence that approaches that of all other cancer subtypes combined. Both human papillomavirus (HPV) and ultraviolet (UV) irradiation are risk factors for this disease. Immortalization by HPV may be an early stage in carcinogenesis, while UV may induce subsequent events both by inducing further mutations, as well as selecting for tumorigenic cells. HPV-16 E6/7-immortalized human keratinocytes were exquisitely sensitive to UVB-induced apoptosis compared to either vector-transduced or early passage (p7) E6/7 cells. DNA microarray analysis showed that, out of 16,000 genes monitored, three members of the Id protein family exhibit significant changes following UVB exposure; each Id was differentially regulated by UV in primary versus immortalized cells. Id proteins play important roles in differentiation, apoptosis, and tumorigenesis in a variety of other cell types. The Specific Aims will therefore test the hypothesis that Id genes play a central role in modulating keratinocyte apoptosis and differentiation induced by acute UVB exposure both in cell culture and grafted human epidermis. Specific Aim I will examine the genetic elements that are responsible for the differential regulation of Id2 and Id3 in primary and immortalized HFK. Specific Aim II will delineate the roles of Id2 and Id3 in the regulation of apoptosis in human keratinocytes. The mechanism(s) of the gene- and cell-type specific response will be studied by investigating the factors that interact preferentially with Id2 and Id3. Specific Aim III will generate a grafted human epidermis derived from keratinocytes that overexpress Id2 or Id3 to examine both the short-term (differentiation and apoptosis) and long-term (transformation) responses to UVB or topical carcinogens.