GR IMPAIRMENT IN CARCINOGENESIS--ROLE OF NF KAPPA BETA

这项拟议研究的主要目标是确定 糖皮质激素受体(GR)在多阶段小鼠皮肤癌发生中的作用 我们实验室和其他实验室的早期工作表明 糖皮质激素是一种非常有效的DNA合成抑制剂 正常角质形成细胞但转化的角质形成细胞对 糖皮质激素对肿瘤生长的抑制及其他作用 这些荷尔蒙。我们实验室的其他研究表明，在 尽管对糖皮质激素耐药，但GR水平和GR基因 转化的角质形成细胞的结构没有改变，这表明 GR功能的改变，而不是表达，起着重要的作用 在小鼠皮肤癌发生中的作用。目前的证据表明 核因子-kappaB转录因子家族中的蛋白p65相互作用 与GR在蛋白质-蛋白质水平上，并发挥显性作用 GR功能的负抑制。最近我们发现P65是 小鼠皮肤肿瘤和转化角质形成细胞中高表达 台词。我们建议检验GR函数改变的假设 是肿瘤促进阶段的关键事件，它允许 转化的角质形成细胞生长失控。此外，这一点 该项目需要分析P65作为GR的主要负面抑制物 在角质形成细胞中。此外，该项目还需要分析P65 AS 角质形成细胞中GR的显性负抑制因子。具体目标 1)进一步观察皮肤GR功能的时序性变化 癌变；2)确定表达的顺序变化 核因子-kappaB和IkappaB蛋白在多阶段癌变过程中的表达 探讨核转录因子-kappaB蛋白p65对糖皮质激素受体功能的影响。 角质形成细胞对糖皮质激素的反应性；4)开发转基因 GR表达不足的动物表皮过度表达GR 阐明GR在皮肤癌发生中的抑癌作用；5) 开发过表达核因子-kappaB蛋白p65的转基因小鼠 进一步研究p65/GR相互作用在多阶段皮肤癌发生中的作用。

The primary goals of the proposed research is to determine the role of glucocorticoid receptor (GR) in multistage mouse skin carcinogenesis. Earlier work from our laboratory as well as others has shown that glucocorticoid hormones are very potent inhibitors of DNA synthesis in normal keratinocytes but transformed keratinocytes become resistant to the growth inhibition by glucocorticoids as well as to other effects of these hormones. Additional studies from our laboratory showed that in spite of the resistance to glucocorticoids, GR levels and GR gene structure are not changed in transformed keratinocytes, suggesting that an alteration of GR function rather than expression plays an important role in mouse skin carcinogenesis. Current evidence indicates that protein p65 from the NF-kappaB family of transcription factors interacts with GR at a protein-protein level and plays a role as a dominant negative inhibitor of GR function. Recently we discovered that p65 is overexpressed in mouse skin tumors and transformed keratinocyte cell lines. We propose to test the hypothesis that alteration of GR function is a critical event during the tumor promotion stage that allows uncontrolled growth of transformed keratinocytes. In addition, this project entails analysis of p65 as a dominant negative inhibitor of GR in keratinocytes. In addition, this project entails analysis of p65 as a dominant negative inhibitor of GR in keratinocytes. The Specific Aims are: 1) To further examine the sequential changes of GR function in skin carcinogenesis; 2) To determine the sequential changes in the expression of NF-kappaB and IkappaB proteins during multistage carcinogenesis; 3) To examine the effect of NF-kappaB protein p65 on GR function and glucocorticoid-responsiveness in keratinocytes; 4) To develop transgenic animals deficient in the GR expression of overexpressing GR in epidermis to address the tumor suppressor role of GR in skin carcinogenesis; 5) To develop transgenic mice that overexpress NF-kappaB protein p65 to further study p65/GR interaction in multistage skin carcinogenesis.