P38 MAP KINASE SIGNALING IN SKIN

P38 皮肤中的图激酶信号传导

• 批准号: 8461202
• 负责人: Tatiana Efimova
• 金额: $ 28.76万
• 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/8461202
• 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; Health; Human; Immune; Immune system; In Vitro; Inflammation; Inflammatory; Keratin; Kinetics; Knockout Mice; Lead; Letters; MAPK14 gene; MAPK3 gene; Maintenance; Malignant - descriptor; Malignant Conversion; Malignant Neoplasms; Malignant neoplasm of liver; 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; Play; Predisposition; Prevention; Process; Protein Isoforms; Regimen; Research; Resistance; Role; Signal Transduction; Skin; Skin Carcinogenesis; Skin Neoplasms; 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; dimethylbenzanthracene; human MAPK14 protein; improved; in vivo; insight; keratinocyte; macrophage; mitogen-activated protein kinase p38; mouse model; neoplastic cell; outcome forecast; prevent; promoter; recombinase; research study; response; senescence; skin squamous cell carcinoma; therapeutic target; transcription factor; treatment strategy; tumor; tumor growth; tumor initiation; tumor microenvironment; 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.

描述(由申请人提供)： 本研究的主要目的是了解p384丝裂原活化蛋白激酶(MAPK)在上皮细胞癌变中的作用。上皮癌，或癌症，占人类所有癌症的90%以上。皮肤鳞状细胞癌(SCC)是美国第二常见的癌症，在晚期预后较差。P38 MAPK家族成员以特定细胞类型和特定细胞环境的方式发挥作用，调节细胞的增殖、分化、存活、炎症、衰老和转化。P384MAPK亚型在皮肤上皮细胞中含量丰富，在人鳞状细胞癌中表达增加。P384在先天免疫细胞中也大量表达，已知的先天免疫细胞参与了与上皮癌发展相关的慢性炎症的维持。利用p384基因胚系缺失的小鼠，我们最近发现，在两阶段化学致癌过程中，p384在皮肤肿瘤的发生发展中是必需的。在这里，我们描述了p384缺失小鼠的一个重要表型：这些小鼠在动态平衡条件下是正常的表型，但对化学致癌表现出显著的抵抗力，其特征是肿瘤发病延迟，频率降低，多样性降低，肿瘤体积缩小。肿瘤体积减小和发病晚意味着生长缺陷；频率较低和多样性降低表明启动细胞较少，或在促进过程中失去启动细胞，或TPA在p384缺失细胞中的无效促进作用。事实上，我们的数据表明，p384在TPA促进肿瘤的过程中在介导角质形成细胞增殖方面发挥了重要作用，并且在p384缺失的情况下，TPA介导的关键炎症和血管生成介质包括COX2、VEGF1和AP1的诱导以及癌基因转录因子STAT3的激活被取消。最后，鉴于p384消融的全球性，p384可能在天然免疫系统中发挥非细胞自主作用，该系统以其在皮肤癌发生中的促进作用而闻名。我们自上一次应用回顾以来获得的其他初步数据显示，与转化的野生型角质形成细胞相比，在p384完整宿主的原位皮肤移植中，致癌的ras转化的p384缺失的角质形成细胞形成了较小的皮肤肿瘤。尽管在移植后的最初几周，两种基因型的潜伏期间隔相同，肿瘤动力学相似，但由p384缺失的角质形成细胞形成的肿瘤在肿瘤进展的后期显示出明显的大小退化的倾向。此外，与野生型移植物相比，p384缺失移植物显示出更低的恶性转化率。这封信的发现表明，内源性角质形成细胞p384与致癌ras共同发挥作用，促进良性肿瘤细胞的恶性转化。总之，使用全局p384基因敲除小鼠进行的化学致癌研究的数据，以及使用致癌ras基因转化的p384缺失角质形成细胞进行的皮肤移植研究的结果，支持了我们的假设，即p384通过调节角质形成细胞的自主方式，通过调节肿瘤上皮细胞的生存和增殖，以及以非细胞自主方式，通过介导肿瘤微环境中免疫(髓)细胞发出的促癌信号，调节多个阶段的上皮癌变。使用我们产生的小鼠品系来验证这一假设，我们建议：1)通过Cre-lox系统使用有条件的组织特异性p384基因打靶来确定p384缺失对上皮癌变的角质形成细胞特异性和免疫(髓系)细胞特异性的影响。2)通过将p384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，以时间调控的方式利用表皮特异性沉默p384基因，确定p384缺失对肿瘤发展不同阶段的影响。P384依赖于上皮细胞癌变的分子机制将通过生物化学和细胞培养方法进行探索，并在体内得到证实。我们乐观地认为，拟议研究的完成将导致更好地从机制上理解p384在上皮细胞癌变中的作用及其作为抗癌治疗靶点的潜力。