Mechanisms of Induction of Skin Cancers By UV Light

描述(申请人提供)：本资助拟修读的课程 应用程序集中于研究涉及到的机制 CD1基因敲除小鼠对紫外线致癌的抵抗力。这样做的理由是 这项研究基于一项新颖而有趣的观察，CD1基因敲除小鼠 对紫外线致癌和光毒性具有极强的抵抗力，它们的皮肤 与CD1+/+小鼠相比，含有大量的凋亡角质形成细胞。我们的 最近的研究表明，紫外线可诱导CD1蛋白的表达。 野生型小鼠皮肤，表明CD1是紫外线的目标。基于这些 结果：我们假设CD1-/-小鼠对紫外线致癌的抵抗力 可能与持续消除紫外线损害有关，潜在地 恶性角质形成细胞。将使用以下具体目标来测试这一点 假设：(1)确定CD1基因是否转入CD1-/- 小鼠角质形成细胞恢复对紫外线诱导的凋亡和 对肿瘤转化的敏感性，(2)决定是否 CD1-/-小鼠对紫外线致癌的抵抗力增强是由于持续性 从皮肤中清除紫外线损伤的角质形成细胞，以及(3)确定 CD1-/-小鼠皮肤是否对紫外线诱导的P53突变具有抵抗力 CD1+/+小鼠皮肤。 特异靶1：新生儿CD1-/-和+/+角质形成细胞培养 将建立并测试它们对紫外线诱导的敏感性 细胞凋亡、终末分化和肿瘤转化。在……里面 此外，将对CD1-/-和+/+小鼠的成纤维细胞进行测试，以确定 这种缺陷是普遍的或仅限于角质形成细胞。更重要的是，CD1基因 将其导入CD1-/-角质形成细胞，研究CD1在角质形成细胞中的作用 紫外线诱导细胞凋亡、终末分化和肿瘤转化。 为了研究特异性AIMS 2和3，CD1-/-和+/+小鼠将暴露于急性或 慢性紫外线照射及其皮肤分析(I)晒伤和 TUNEL阳性细胞：(II)细胞周期表达与细胞凋亡相关 P53、p21Waf1/Cip1、Fas、Fas-L、Bax、Bcl一2等蛋白及(Ii) 紫外线特异性P53诱导的动力学(发生率、潜伏期和持久性) 等位基因特异性聚合酶链式反应的突变。 从这些研究中产生的数据应该会为CD1在 光致癌。这些信息对于理解 紫外线、CD1基因与皮肤癌的相互作用。尽管重要的是 CD1分子在抗原提呈和免疫调节中的作用 众所周知，关于它在皮肤癌中的作用，人们几乎一无所知 发展。我们的初步发现，对紫外线致癌的抵抗力和 CD1-/-小鼠细胞凋亡率增加，提示CD1在细胞周期中的作用 监管。因为紫外线会导致免疫抑制和诱发皮肤癌，而且 CD1蛋白在抗原提呈和免疫调节中发挥作用， 了解CD1-/-小鼠对紫外线的抗性机制 癌变也可能有助于理解两者之间的关系。 紫外线致癌和紫外线诱导免疫抑制之间的关系。此外， 结果可能表明皮肤癌与类似的机制有关。 人类的发展。

DESCRIPTION (provided by applicant): The studies proposed in this grant application are focused on investigating the mechanisms involved in the resistance of CD1 knockout mice to UV carcinogenesis. The rationale for these studies is based on a novel and interesting observation that CD1 knockout mice are extremely resistant to UV carcinogenesis and phototoxicity, and their skin contains a high number of apoptotic keratinocytes compared to CD1+/+ mice. Our recent studies indicate that UV induces the expression of CD1 protein in wild-type mouse skin, suggesting that CD1 is a target for UV. Based on these results, we hypothesize that the resistance of CD1-/- mice to UV carcinogenesis may be associated with persistent elimination of UV damaged, potentially malignant keratinocytes. The following specific aims will be used to test this hypothesis: (1) Determine whether transfection of the CD1 gene into CD1-/- mouse keratinocytes restores resistance to UV-induced apoptosis and susceptibility to neoplastic transformation, (2) Determine whether the increased resistance of CD1-/- mice to UV carcinogenesis is due to persistent elimination of UV-damaged keratinocytes from the skin, and (3) Determine whether CD1-/-mouse skin is resistant to UV-induced p53 mutations compared to CD1+/+ mouse skin. To study Specific Aim 1, keratinocyte cultures from neonatal CD1-/- and +/+ will be established and tested for their susceptibility to UV-induced apoptosis, terminal differentiation, and neoplastic transformation. In addition, fibroblasts from CD1-/- and +/+ mice will be tested to determine if the defect is general or limited to keratinocytes. More importantly, CD1 gene will be transfected into CD1-/- keratinocytes to investigate the role of CD1 in UV-induced apoptosis, terminal differentiation and neoplastic transformation. To study Specific Aims 2 and 3, CD1-/- and +/+ mice will be exposed to acute or chronic UV irradiation and their skin analyzed for (i) sunburn and TUNEL-positive cells, (ii) expression of cell cycle and apoptosis-associated proteins such as p53, p21 Waf1/Cip1, Fas, Fas-L, Bax, and Bcl-2, and (ii) kinetics (incidence, latency, and persistence) of induction of UV-specific p53 mutations by allele-specific polymerase chain reaction. Data generated from these studies should shed new light on the role of CD1 in photocarcinogenesis. This information is important for understanding the interactions between UV, the CD1 gene, and skin cancer. Although the important role of CD1 molecule in antigen presentation and immune regulation is well known, virtually nothing is known in regard to its role in skin cancer development. Our preliminary findings, resistance to UV carcinogenesis and increased apoptosis in CD1-/- mice, suggest a role for CD1 in cell cycle regulation. Because UV causes immunosuppression and induces skin cancer, and CD1 protein plays a role in antigen presentation and immune regulation, understanding the mechanisms involved in the resistance of CD1-/- mice to UV carcinogenesis may also contribute to the understanding of the relationship between UV carcinogenesis and UV-induced immunosuppression. In addition, the results may suggest that similar mechanisms be involved in skin cancer development in humans.