TNF Alpha in PKC Epsilon Signaling to Carcinogenesis

PKC Epsilon 信号传导中的 TNF Alpha 致癌作用

• 批准号: 6883185
• 负责人: AJIT K VERMA
• 金额: $ 26.84万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-12 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6883185
• 关键词: biological signal transduction; carcinogenesis; disease /disorder etiology; environment related neoplasm /cancer; enzyme activity; enzyme mechanism; genetically modified animals; isozymes; keratinocyte; laboratory mouse; metalloendopeptidases; metastasis; molecular oncology; oxidative stress; pathologic process; phorbols; prohormone convertase; protein kinase C; skin neoplasms; squamous cell carcinoma; transfection; tumor necrosis factor alpha; tumor promoters; ultraviolet radiation

DESCRIPTION (provided by applicant): The objectives of this proposal are to determine how protein kinase Cepsilon (PKCepsilon) signals tumor necrosis factor alpha (TNFalpha) release and whether this TNFalpha release mediates the development of metastatic squamous cell carcinoma (mSCC) in PKCepsilon-overexpressing transgenic mice. PKC is not only the major intracellular receptor for the mouse skin tumor promoter 12-0-tetradecanoylphorbol-13-acetate (TPA) but also is activated by a variety of stress factors including ultraviolet irradiation (UVR). PKCepsilon is among the six PKC isoforms (alpha, delta, epsilon, eta, mu, delta) expressed in the mouse skin. To determine the in vivo functional specificity of PKCe in mouse skin carcinogenesis, we generated PKCepsilon transgenic mouse (FVB/N) lines 224 and 215 that overexpress approximately 8- and 18-fold respectively PKCepsilon protein over endogenous levels in basal epidermal cells. PKCepsilon transgenic mice were observed to be highly sensitive to the development of mSCC elicited either by the repeated exposure to UVR or by the DMBA (100 nmol) - TPA (5nmol) tumor promotion protocol. During studies to find clues about how PKCe overexpression mediates development of mSCC, we found that PKCepsilon transgenic mice have dramatically elevated TNFalpha serum levels relative to their wild-type littermates either following UVR exposure or during skin tumor promotion by TPA. TPA-stimulated serum TNFalpha levels were proportional to the level of expression of epidermal PKCe in transgenic mouse lines 224 and 215. Preliminary results indicate that mouse keratinocytes are the primary source of serum TNFalpha levels, and TPA affects ectodomain shedding of TNFalpha. The release of soluble TNFalpha is catalyzed by the TNFalpha converting enzyme (TACE), a transmembrane metalloproteinase. We hypothesize that: 1) UVR- or TPA-stimulated TNFalpha release is the key downstream component of the PKCepsilon signal transduction pathway to development of mSCC in PKCe transgenic mice and 2) PKCepsilon mediates UVR/TPA-stimulated TNFalpha release by regulating TACE activity. We propose two specific aims to test this hypothesis: Specific Aim #1: To determine whether TNFalpha is essential for the development of mSCC in PKCepsilon transgenic mice. Specific Aim #2: To determine how PKCe mediates UVR- or TPA-stimulated release of TNFalpha.

描述（由申请人提供）：该提案的目的是确定蛋白激酶Cepsilon（PKCEPSILON）如何发出肿瘤坏死因子alpha（TNFalpha）的释放，以及该TNFALPHA释放是否介导了pkcepsilon-overextermextemencressing Mitecressing Mitectressing Mitectressing Mitectressing trendegressing trancicsing rice。 PKC不仅是小鼠皮肤肿瘤启动子的主要细胞内受体，12-0-四甲基氯醇13-乙酸酯（TPA），而且还被包括紫外线照射（UVR）在内的多种应力因素激活。 PKCEPSILON是在小鼠皮肤中表达的六种PKC同工型（Alpha，delta，Epsilon，Eta，Mu，Mu，Delta）之一。为了确定PKCE在小鼠皮肤癌变中的体内功能特异性，我们生成了PKCEPSILON转基因小鼠（FVB/N）线224和215，在基础表皮细胞中，在内源性水平上过度表达了约8倍和18倍PKCepsilon蛋白。观察到PKCEPSILON转基因小鼠对通过反复暴露于UVR或DMBA（100 nmol）-TPA（5nmol）肿瘤促进方案而引起的MSCC的发展高度敏感。在研究有关PKCE过表达如何介导MSCC发展的线索的研究期间，我们发现PKCepsilon转基因小鼠相对于其野生型乱立立与UVR暴露，或者在TPA促进皮肤鼻鼻毛期间，TNFalpha血清水平显着升高。 TPA刺激的血清TNFALPHA水平与转基因小鼠系224和215中表皮PKCE的表达水平成比例。初步结果表明，小鼠角化形成细胞是血清TNFALPHA水平的主要来源，TPA影响了Tnfalpha的胞质分子。可溶性tnfalpha的释放是由跨膜金属蛋白酶转化酶（TACE）催化的。我们假设：1）uvr-或tpa刺激的tnfalpha释放是pKcepsilon信号转导途径的关键下游组成部分，用于在PKCE转基因小鼠中开发MSCC和2）PKCepsilon介导UVR/TPA刺激的TNFALPHA通过调节的TACE TACE TACE TACE ACTIONS介导UVR/TPA刺激的Tnfalpha。我们提出了两个特定的目的来检验这一假设：具体目的＃1：确定tnfalpha对于在pkcepsilon转基因小鼠中发展MSCC是否至关重要。特定目的＃2：确定PKCE如何介导tnfalpha的UVR-或TPA刺激的释放。