p53 in Melanomagenesis

p53 在黑色素瘤发生中的作用

基本信息

批准号：
9186994
负责人：
Tamara G Terzian
金额：
$ 7.78万
依托单位：
UNIVERSITY OF COLORADO DENVER
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-01-01 至 2018-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9186994
关键词：
Ablation Affect Apoptosis Apoptosis Promoter BRAF gene Back Behavior CDK4 gene CDKN1A gene Carcinogens Clinical Clonal Expansion Culture Media Cutaneous Melanoma Development Dose Endothelin-1 Ensure Etiology Event Exhibits FGF2 gene Fibroblasts Gene Expression Profiling Genetic Goals Growth Growth Factor Histologic Human Hyperpigmentation Immunocompromised Host Incidence Induced Mutation KITLG gene Lead Lesion Link Long-Term Effects Malignant - descriptor Manuscripts Melanocytic nevus Metastatic Melanoma Modeling Molecular Molecular Models Monitor Mus Mutate Mutation Neoplasm Metastasis Nevi and Melanomas Oncogenes Oncogenic Pathway interactions Pharmaceutical Preparations Phenotype Pigmentation physiologic function Pigments Play Premalignant Preparation Prevention Process Protein p53 Protocols documentation Reporting Role Signal Transduction Skin Skin Cancer Stem Cell Factor Subfamily lentivirinae Sun Exposure Sunburn Sunlight System TP53 gene Testing Time Tissues Transcriptional Regulation Tumor Initiators Tumor Promotion Tumor Suppression Tumor Suppressor Proteins Tumorigenicity UV Radiation Exposure Ultraviolet Rays Up-Regulation Viral Western World Xenograft procedure base cancer type carcinogenesis cytokine in vivo insight keratinocyte knock-down melanocyte melanoma migration molecular modeling mouse model mutant novel paracrine public health relevance radiation response response senescence small hairpin RNA transcription factor tumor tumorigenic ultraviolet irradiation

项目摘要

DESCRIPTION (provided by applicant): Invasive and deadly metastatic melanoma is associated with excessive exposure to ultraviolet radiation (UVR). UVR induces activating mutations in oncogenes such as BRAF which initiates the development of pigmented lesions (nevi) and melanoma; however it is also believed that UVR promotes melanomagenesis independently of its mutagenic action. Recently, a molecular model of UVR tumor promotion has emerged where melanocyte proliferation seems to be up-regulated by keratinocyte-derived melanocyte growth factors under the control of the transcription factor and key tumor suppressor p53 in response to UVR. Moreover, in melanoma prone mice that carry mutations in Braf (BrafV600E) or CDK4 (CDK4R24C/R24C), increased expression of melanocyte growth factors accelerated the formation of pigmented lesions and promoted melanoma. In line with this, our unique mouse model with constitutively high expression of keratinocyte-specific p53 displayed a propensity to develop nevi and melanoma when subjected to a carcinogenesis protocol. These findings lead us to the hypothesis that keratinocyte p53 releases paracrine melanocyte growth factors that cooperate with oncogenic mutations such as BRAFV600E in melanocytes to promote proliferation of initiated melanocytes and thus melanoma. This novel and important concept provides for the first time a molecular pathway explaining UVR tumor promotion, and extends the role of p53 beyond its canonical tumor suppression to include a tissue- specific function in melanomagenesis. To test this hypothesis we will use intricate human melanocyte and keratinocyte culture systems (Aim 1) and a 3D human skin equivalent xenografted mouse model (Aim 2). In Aim 1, primary human keratinocytes will be UV-irradiated or treated with a specific p53 activating drug, Nutlin- 3a, to generate keratinocyte-conditioned melanocyte growth media. Primary human melanocytes transduced with a control GFP and a GFP-tagged BRAFV600E lentivirus will be grown in the presence or absence of the UVR- or Nutlin 3a-conditioned media. We will monitor the impact of UVR- and p53- conditioned media on the behavior of transduced melanocytes (proliferation, apoptosis, senescence, migration and pigmentation). We expect that paracrine factors in the conditioned media will increase the proliferation and migration potential of BRAF-mutated melanocytes, and decrease their oncogene-induced senescence in culture. Using lentiviral shRNAs, we will identify the most crucial growth factors for melanocytic proliferation and transformation. In Aim 2, human 3D skin equivalent xenografts will be generated that contain the BRAFV600E-GFP and GFP control melanocytes. These grafts will be UV-irradiated or treated with Nutlin-3a to examine the in vivo impact of p53-dependent growth factors on melanocyte behavior as explored in Aim 1. In longer term studies, grafts will be examined for histological melanocytic changes, melanocytic lesions or melanoma. Together, these aims will explore a link that is still not well defined between UVR, BRAF mutations and melanomagenesis which is imperative for our understanding of this deadly tumor. Our findings will demonstrate the involvement of a paracrine p53 signaling in melanoma development and may lead to new strategies for melanoma prevention and treatment.

描述（由申请人提供）：侵袭性和致命性转移性黑色素瘤与过度暴露于紫外线辐射（UVR）有关，UVR 会诱导致癌基因（例如 BRAF）的激活突变，从而引发色素性病变（痣）和黑色素瘤的发展；认为UVR促进黑色素瘤形成与其诱变作用无关。最近，出现了一种UVR肿瘤促进的分子模型，其中黑色素细胞增殖似乎是这样的。此外，在携带 Braf (BrafV600E) 或 CDK4 (CDK4R24C/R24C) 突变的黑色素瘤易感小鼠中，在转录因子和关键肿瘤抑制因子 p53 的控制下，角化细胞衍生的黑色素细胞生长因子上调。黑色素细胞生长因子的表达加速了色素性病变的形成并促进黑色素瘤的形成，与此相一致的是，我们独特的小鼠模型具有组成性高表达。角质形成细胞特异性 p53 在接受致癌方案时表现出形成痣和黑色素瘤的倾向，这些发现使我们得出这样的假设：角质形成细胞 p53 释放旁分泌黑色素细胞生长因子，与黑色素细胞中的致癌突变（如 BRAFV600E）配合，促进起始黑色素细胞的增殖。因此，这个新颖而重要的概念首次提供了解释 UVR 肿瘤促进的分子途径，并扩展了 UVR 肿瘤的作用。 p53 超越其典型的肿瘤抑制功能，在黑色素瘤生成中包含组织特异性功能。为了检验这一假设，我们将使用复杂的人类黑色素细胞和角质形成细胞培养系统（目标 1）和 3D 人类皮肤等效异种移植小鼠模型（目标 2）。 1、原代人角质形成细胞将经过紫外线照射或用特定的p53激活药物Nutlin-3a处理，以产生角质细胞条件黑素细胞生长培养基。用对照 GFP 和 GFP 标记的 BRAFV600E 慢病毒转导的原代人黑素细胞将在存在或不存在 UVR 或 Nutlin 3a 条件培养基的情况下生长。我们将监测 UVR 和 Nutlin 3a 条件培养基的影响。 p53-条件培养基对转导黑素细胞行为（增殖、凋亡、衰老、迁移和色素沉着）的影响。条件培养基中的旁分泌因子将增加 BRAF 突变黑素细胞的增殖和迁移潜力，并减少培养物中癌基因诱导的衰老。在目标 2 中，我们将鉴定黑素细胞增殖和转化最关键的生长因子。，将生成包含 BRAFV600E-GFP 和 GFP 对照黑素细胞的人类 3D 皮肤等效异种移植物。紫外线照射或用 Nutlin-3a 处理，以检查 p53 依赖性生长因子对黑素细胞行为的体内影响，如目标 1 中所述。在长期研究中，将一起检查移植物的组织学黑素细胞变化、黑素细胞病变或黑素瘤。，这些目标将探索 UVR、BRAF 突变和黑色素瘤发生之间尚未明确定义的联系，这对于我们了解这种致命肿瘤至关重要。黑色素瘤发展中的旁分泌 p53 信号传导可能会导致黑色素瘤预防和治疗的新策略。