ENERGY RESTRICTION, CELL SIGNALING AND CANCER PREVENTION

描述：拟议的研究将检验以下假设：饮食 能量限制(ER)升高抑制皮肤肿瘤的发生 糖皮质激素(GCH)可降低选定的表皮蛋白激酶 C(PKCα和Zeta)，并阻断AP-1的诱导。第一个具体目标 将决定是否需要肾上腺来抑制肿瘤的ER GCH对去肾上腺/ER小鼠的促进和如果给药恢复 内质网抑制。皮肤肿瘤将由7，12-二甲基引发 苯并(A)菲(DMBA)和TPA促进。GCH的高程为 假想通过引起抑制皮肤肿瘤的促进作用 抑制信号转导的PKC蛋白水平降低 Raf-1/MAP-Kinase通路及阻断TPA诱导c-jun的能力 蛋白质和AP-1：DNA结合。《特定目标2》将检验这一假设 阻断AP-1的诱导：DNA结合依赖于内质网 AP-1组成蛋白的调控。第三个具体目标是 检验内质网阻断Raf-1/MAP-K信号通路的假说 Raf-1是PKC的已知底物。凝胶迁移率 AP-1 DNA共有序列的移位实验、Western blotts和 AIMS 2和AIMS 3将使用免疫复合体激酶分析。 特定目的，限制饮食能量阻断AP-1的能力 TPA和UVB-LIGHT中荧光素酶的诱导和转录调控 将使用转基因AP-1-荧光素酶小鼠对处理过的小鼠进行研究 模特。AIMS 2-4中修饰的生化事件对 皮质酮将通过SHAM和SHAM的平行研究进行评估 摘除肾上腺的小鼠。

DESCRIPTION: The proposed studies will test the hypothesis that dietary energy restriction (ER) inhibits skin tumor promotion by elevating glucocorticoid hormone (GCH) which reduces selected epidermal protein kinase C (PKC alpha and zeta) and blocks AP-1 induction. The first specific aim will determine if the adrenal gland is required for ER inhibition of tumor promotion and if administration of GCH to adrenalectomized/ER mice restores the ER inhibition. Skin tumors will be initiated with 7,12-dimethyl benz(a)anthracene (DMBA) and promoted with TPA. Elevation of GCH is hypothesized to mediate the inhibition of skin tumor promotion by causing the reduction in PKC protein levels which inhibits signaling down Raf-1/MAP-Kinase pathways and blocks the ability of TPA to induce c-June protein and AP-1:DNA binding. Specific Aim 2 will test the hypothesis that the blockage of the induction of AP-1:DNA binding is dependent upon ER regulation of constituent proteins of AP-1. The third specific aim will test the hypothesis that ER blocks signaling down the Raf-1/MAP-kinase pathway at the level of Raf-1, a well known substrate for PKC. Gel mobility shift experiments with AP-1 DNA consensus sequences, western blots and immune complex kinase assays will be used for Aims 2 and 3. In the fourth specific aim, the ability of dietary energy restriction to block AP-1 induction and transcriptional regulation of luciferase in TPA and UVB-light treated mice will be investigated using the transgenic AP-1-luciferase mouse model. The dependence of the biochemical events modified in Aims 2-4 on corticosterone will be assessed by parallel studies in sham and adrenalectomized mice.