GR IMPAIRMENT IN CARCINOGENESIS--ROLE OF NF KAPPA BETA

拟议研究的主要目标是确定 糖皮质激素受体（GR）在小鼠皮肤癌变过程中的作用。 我们实验室和其他实验室的早期工作表明， 糖皮质激素是DNA合成的非常有效的抑制剂， 正常的角质形成细胞，但转化的角质形成细胞变得抵抗 糖皮质激素的生长抑制作用以及 这些荷尔蒙。 我们实验室的进一步研究表明， 尽管对糖皮质激素耐药，但GR水平和GR基因 结构在转化的角质形成细胞中没有改变，这表明， GR功能的改变而不是表达的改变起着重要的作用， 在小鼠皮肤癌发生中的作用。目前的证据表明， 来自转录因子NF-κ B家族的蛋白质p65相互作用 在蛋白质-蛋白质水平上与GR结合， GR功能的负抑制剂。 最近我们发现p65是 在小鼠皮肤肿瘤和转化的角质形成细胞中过表达 线 我们建议检验GR功能改变 是肿瘤促进阶段的关键事件， 转化的角质形成细胞的不受控制的生长。 另外这款 该项目需要分析p65作为GR的显性负性抑制剂 在角质形成细胞中。 此外，该项目还需要分析p65作为 角质形成细胞中GR的显性负性抑制剂。 具体目标 目的：1）进一步研究皮肤GR功能的动态变化 2）确定在癌发生过程中， NF-κ B和IkappaB蛋白在多阶段癌变过程中的表达; 3） 为了检测NF-κ B蛋白p65对GR功能的影响， 角质形成细胞的糖皮质激素反应性; 4）开发转基因 表皮中GR表达缺陷或过表达GR的动物 阐明GR在皮肤癌发生中的肿瘤抑制作用; 5） 为了开发过表达NF-κ B蛋白p65的转基因小鼠， 进一步研究p65/GR在多阶段皮肤癌发生中的相互作用。

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.