P38 MAP KINASE SIGNALING IN SKIN

P38 皮肤中的图激酶信号传导

• 批准号: 7986195
• 负责人: Tatiana Efimova
• 金额: $ 31.54万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-07-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7986195
• 关键词: Ablation; Address; Benign; Biochemical; Carcinoma; Cell Culture Techniques; Cell Lineage; Cell Proliferation; Cells; Cellular Structures; Chemicals; Chronic; Cutaneous; Data; Defect; Development; Diagnostic Neoplasm Staging; Disease; Epithelial; Epithelial Neoplasms; Epithelium; Exhibits; Family member; Frequencies; Gene Deletion; Gene Targeting; Genes; Genotype; Goals; Growth; Head and neck structure; Human; Immune; Immune system; In Vitro; Inflammation; Inflammatory; Keratin; Kinetics; Knockout Mice; Lead; Letters; MAPK14 gene; Maintenance; Malignant - descriptor; Malignant Conversion; Malignant Neoplasms; Malignant neoplasm of liver; Maps; Mediating; Mediator of activation protein; Methods; Mitogen-Activated Protein Kinases; Modeling; Molecular; Mouse Strains; Mus; Myeloid Cells; Nature; Neoplastic Epithelial Cell; Null Lymphocytes; Oncogenic; PTGS2 gene; Papilloma; Pathway interactions; Phenotype; Phosphotransferases; Play; Predisposition; Prevention; Process; Protein Isoforms; Regimen; Research; Resistance; Role; Signal Transduction; Skin; Skin Carcinogenesis; Skin Neoplasms; Skin Transplantation; Skin graft; Squamous cell carcinoma; Staging; System; Tamoxifen; Testing; Tissues; Transcription Factor AP-1; Transgenic Mice; Tumor Promotion; Tumor stage; United States; anti-cancer therapeutic; cancer therapy; carcinogenesis; cell type; chemical carcinogenesis; human MAPK14 protein; improved; in vivo; insight; keratinocyte; macrophage; mouse model; neoplastic cell; outcome forecast; prevent; promoter; public health relevance; recombinase; research study; response; senescence; skin squamous cell carcinoma; therapeutic target; transcription factor; treatment strategy; tumor; tumor growth; tumor initiation; tumor progression; tumorigenesis

DESCRIPTION (provided by applicant): The major goal of this proposal is to understand the role of p384 mitogen-activated protein kinase (MAPK) in epithelial carcinogenesis. Epithelial cancers, or carcinomas, comprise over 90% of all human cancers. Cutaneous squamous cell carcinoma (SCC) is the second most common cancer in the United States that exhibits poor prognosis in advanced stages. The p38 MAPK family members function in a cell type-specific and cell context-specific manner to regulate cell proliferation, differentiation, survival, inflammation, senescence and transformation. p384 MAPK isoform is highly abundant in cutaneous epithelia, and its expression is increased in human SCC. p384 is also abundantly expressed in innate immune cells known to be involved in maintenance of chronic inflammation associated with epithelial cancer development. Using mice with germline deletion of p384 gene, we recently discovered that p384 is required for de-novo skin tumor development during two-stage chemical carcinogenesis. Here we describe an important phenotype of p384-null mice: these mice are normal phenotypically under homeostatic conditions, but display a significant resistance to chemical carcinogenesis as characterized by delayed tumor onset, reduced frequency, reduced multiplicity and reduced tumor size. Reduced tumor size and late onset suggest growth defects; lower frequency and reduced multiplicity suggest less initiation, or loss of initiated cells during promotion, or ineffective promotion by TPA in p384-null cells. Indeed, our data show that p384 plays an essential role in mediating keratinocyte proliferation during tumor promotion by TPA, and the TPA-mediated induction of key inflammatory and angiogenic mediators, including COX2, VEGF1, and AP1, as well as activation of oncogenic transcription factor Stat3, are abrogated in p384-null setting. Lastly, given the global nature of p384 ablation, p384 may act non cell autonomously, for instance, in the innate immune system, known for its promoting role in skin carcinogenesis. Our additional preliminary data, obtained since the previous review of this application, show that oncogenic ras-transformed p384-null keratinocytes formed smaller skin tumors in orthotopic skin grafts to p384 intact hosts, compared with transformed wild-type keratinocytes. Despite identical latency intervals and similar tumor kinetics during initial weeks after grafting in both genotypes, tumors formed by p384-null keratinocytes exhibited a marked predisposition to regress in size at a late stage of tumor progression. Furthermore, p384-null grafts displayed a reduced rate of malignant conversion compared with their wild-type counterparts. The letter finding suggests that endogenous keratinocyte p384 functions in concert with oncogenic ras to promote malignant conversion of benign tumor cells. Together, the data from chemical carcinogenesis studies, using global p384 knockout mice, and the results from skin graft studies using oncogenic ras-transformed p384-null keratinocytes, support our hypothesis that p384 regulates multiple stages of epithelial carcinogenesis both in a keratinocyte cell autonomous manner, by regulating survival and proliferation of neoplastic epithelial cells, and in a non- cell autonomous manner, by mediating tumor promoting signals emanating from the immune (myeloid) cell component of tumor microenvironment. Using mouse strains we generated to test this hypothesis, we propose to: 1) Determine keratinocyte-specific and immune (myeloid) cell-specific effects of p384 loss on epithelial carcinogenesis by using conditional tissue-specific p384 gene targeting via the Cre-lox system. 2) Determine the impact of p384 loss on distinct stages of tumor development by using epidermal-specific silencing of p384 gene in a temporally regulated fashion, by means of crossing p384flox mice to transgenic mice in which a tamoxifen-regulated CreERT recombinase is expressed under the control of keratinocyte-specific human keratin 14 promoter. The molecular mechanisms underlying p384-dependent contributions to epithelial carcinogenesis will be explored using biochemical and cell culture methods and confirmed in vivo. We are optimistic that the completion of the proposed studies will result in a better mechanistic understanding of the p384 role in epithelial carcinogenesis and its potential as an anti-cancer therapeutic target. PUBLIC HEALTH RELEVANCE: Our recent findings demonstrate a fundamental in vivo importance of p384 mitogen-activated protein kinase signaling in epithelial carcinogenesis. Our proposed research will build on these findings and determine: i) how p384 signaling contributes to specific stages of epithelial carcinogenesis, including initiation, promotion, and malignant progression; and ii) whether p384 promotes tumorigenesis by means of keratinocyte cell autonomous or non cell autonomous mechanisms, or both. Understanding the mechanisms underlying cell-type-specific and tumor stage-specific functions of this newly discovered mediator of epithelial carcinogenesis will have direct and important implications for our understanding of the disease process and will potentially provide an improved strategy for cancer therapy.

描述（由申请人提供）： 该提案的主要目标是了解p384有丝分裂原活化蛋白激酶（MAPK）在上皮致癌作用中的作用。上皮癌或癌占所有人类癌症的90%以上。皮肤鳞状细胞癌（SCC）是美国第二常见的癌症，晚期预后不良。p38 MAPK家族成员以细胞类型特异性和细胞环境特异性的方式起作用，以调节细胞增殖、分化、存活、炎症、衰老和转化。p384 MAPK亚型在皮肤上皮中高度丰富，并且在人SCC中表达增加。p384还在已知参与维持与上皮癌发展相关的慢性炎症的先天免疫细胞中大量表达。利用p384基因缺失的小鼠，我们最近发现，p384是在两阶段化学致癌过程中从头皮肤肿瘤发展所必需的。在这里，我们描述了p384缺失小鼠的一个重要表型：这些小鼠在稳态条件下表型正常，但对化学致癌作用表现出显着的抵抗力，其特征是肿瘤发病延迟、频率降低、多样性降低和肿瘤大小减小。肿瘤大小减小和迟发提示生长缺陷;较低的频率和降低的多样性提示较少的起始，或在促进过程中起始细胞的损失，或TPA在p384无效细胞中的无效促进。事实上，我们的数据表明，p384在TPA促进肿瘤过程中介导角质形成细胞增殖中起着重要作用，TPA介导的关键炎症和血管生成介质（包括COX 2、VEGF 1和AP 1）的诱导以及致癌转录因子Stat 3的激活在p384无效的情况下被废除。最后，考虑到p384消融的全局性质，p384可以非细胞自主地起作用，例如，在先天免疫系统中，已知其在皮肤癌发生中的促进作用。自上次审查本申请以来获得的额外初步数据表明，与转化的野生型角质形成细胞相比，致癌ras转化的p384缺失角质形成细胞在p384完整宿主的原位皮肤移植物中形成了更小的皮肤肿瘤。尽管相同的潜伏期间隔和类似的肿瘤动力学在移植后的最初几周内，在两种基因型，由p384-空角质形成细胞形成的肿瘤表现出显着的倾向，在肿瘤进展的晚期阶段的大小倒退。此外，与野生型移植物相比，p384-null移植物显示恶性转化率降低。这封信的发现表明，内源性角质形成细胞p384的功能与致癌ras共同促进良性肿瘤细胞的恶性转化。总之，来自使用全局p384敲除小鼠的化学致癌作用研究的数据和来自使用致癌ras转化的p384无效角质形成细胞的皮肤移植研究的结果支持我们的假设，即p384通过调节赘生性上皮细胞的存活和增殖以角质形成细胞自主方式和以非细胞自主方式调节上皮致癌作用的多个阶段，通过介导从肿瘤微环境的免疫（髓样）细胞成分发出的肿瘤促进信号。使用我们产生的小鼠品系来检验这一假设，我们提出：1）通过使用条件性组织特异性p384基因靶向经由Cre-lox系统来确定p384缺失对上皮癌发生的角质形成细胞特异性和免疫（髓样）细胞特异性作用。2)通过将p384 flox小鼠与在角质形成细胞特异性人角蛋白14启动子控制下表达他莫昔芬调节的CreERT重组酶的转基因小鼠杂交，以时间调节的方式使用表皮特异性p384基因沉默，确定p384缺失对肿瘤发展不同阶段的影响。p384依赖性上皮细胞癌变的分子机制将使用生物化学和细胞培养方法进行探索，并在体内证实。我们乐观地认为，完成拟议的研究将导致更好地了解p384在上皮癌发生中的作用及其作为抗癌治疗靶点的潜力。 公共卫生关系： 我们最近的研究结果表明，p384丝裂原活化蛋白激酶信号在上皮癌发生中的重要性。我们提出的研究将建立在这些发现的基础上，并确定：i）p384信号如何有助于上皮癌变的特定阶段，包括启动，促进和恶性进展; ii）p384是否通过角质形成细胞自主或非细胞自主机制促进肿瘤发生，或两者兼而有之。了解这种新发现的上皮癌变介质的细胞类型特异性和肿瘤阶段特异性功能的机制将对我们理解疾病过程产生直接和重要的影响，并可能为癌症治疗提供改进的策略。