The Role of CtBP1 in UV-mediated Melanoma Carcinogenesis

CtBP1 在紫外线介导的黑色素瘤癌变中的作用

• 批准号: 8974368
• 负责人: DAVID A. NORRIS
• 金额: --
• 依托单位: VA EASTERN COLORADO HEALTH CARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2018-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8974368
• 关键词: Affect; Area; Binding; Binding Proteins; Binding Sites; Biological Markers; Biotin; Cessation of life; Cutaneous Melanoma; DNA; DNA Damage; DNA Repair; Data; Development; Diagnosis; Diet; Disease; Down-Regulation; Engineering; Environmental Carcinogens; Functional disorder; Future; Genes; Genetic Transcription; Goals; Growth; Health; Human; Immune; Immunosuppression; In Vitro; Incidence; Inflammation; Inflammatory; Knockout Mice; Link; Mediating; Mediator of activation protein; Melanoma Cell; Military Personnel; Molecular; Mus; NADH; National Cancer Institute; Nucleotide Excision Repair; Pathogenesis; Pathway interactions; Play; Population; Prevention; Preventive; Production; Regulation; Repression; Role; Sampling; Services; Skin; Skin Cancer; Soldier; Sun Exposure; Testing; Therapeutic; Therapeutic Intervention; Transcription Coactivator; Transcription Repressor/Corepressor; Transcriptional Regulation; Transgenes; Transgenic Mice; Tumor Suppressor Proteins; UV Radiation Exposure; UV induced; United States; angiogenesis; base; carcinogenesis; chromatin immunoprecipitation; combat; cytokine; design; gene repression; improved; in vivo; insight; keratinocyte; knock-down; melanocyte; melanoma; novel; novel strategies; overexpression; paracrine; prevent; repaired; research study; subcutaneous; tempol; therapeutic target; treatment strategy; tumor; ultraviolet; ultraviolet irradiation

DESCRIPTION (provided by applicant): Summary The incidence of melanoma is rapidly increasing in the United States including in VA populations, and sun exposure during US military service has been linked to increased melanoma incidence. Even though melanoma is not the most common skin cancer, it is the most deadly form. The National Cancer Institute predicted 76,690 melanoma diagnoses and 9,480 deaths for 2013. Identification of the molecules and pathways responsible for melanoma is critical to the rational development of novel preventive and therapeutic strategies. CtBP1 (Carboxyl-terminal Binding Protein 1) is an NADH-dependent transcriptional regulator shown to repress transcription of multiple tumor suppressors in vitro. This proposal focuses on understanding the role of CtBP1 over expression in ultraviolet (UV)-mediated melanoma carcinogenesis. Our long-term goal is to develop CtBP1-based novel preventative/therapeutic approaches for melanoma. Our preliminary data show that CtBP1 is over expressed in human melanomas, which represses transcription of key players involved in the nucleotide excision repair (NER) pathway, thus inhibiting DNA damage repair following UV irradiation. Furthermore, CtBP1 over expression in keratinocytes causes production of several cytokines commonly seen during UV carcinogenesis. Based on our preliminary data, we hypothesize: CtBP1 over expression suppresses genes critical for repairing UV-mediated DNA damage in melanocytes and activates UV signature cytokines in keratinocytes involved in immune suppression, inflammation, and angiogenesis, thus contributing to UV carcinogenesis. To test our hypotheses, Aim 1 will assess the role of CtBP1 in UV carcinogenesis in vivo. The Tyr-H-rasG12V/Ink4a-null mice develop spontaneous cutaneous melanomas, highly resemble the UV-induced malignant melanoma. We will cross the Tyr-H-rasG12V/Ink4a-null mice with CtBP1 knockout mice to assess whether decreasing CtBP1 inhibits UV carcinogenesis and if any pathological alterations associated with CtBP1 over expression contributes to melanoma development. In addition, we have generated the K5.CtBP1 transgenic mice, which over express CtBP1 in keratinocytes and display subcutaneous inflammation and angiogenesis. We will cross the Tyr-H-rasG12V/Ink4a-null mice with our K5.CtBP1 mice to study the impact of the CtBP1-induced immune suppressive, inflammatory, and angiogenic cytokines on UV-mediated melanoma carcinogenesis. Our preliminary study shows that UV irradiation of the skin increases CtBP1 and NADH levels. We are the first to identify the NADH-dependent activation of CtBP1 and have recently shown the inhibition of CtBP1 function by the NADH-blocker Tempol. Therefore, we will determine if UV-mediated melanoma carcinogenesis can be inhibited by Tempol. These analyses will pave the road for developing the preventative or therapeutic approaches for UV-mediated melanoma by targeting CtBP1. Aim 2 will examine the molecular mechanisms by which CtBP1 represses key mediators of the NER pathway. We will assess the impact of CtBP1-mediated repression of NER genes in the pathogenesis of melanoma, define the molecular mechanism of CtBP1 transcriptional regulation of NER genes, and identify CtBP1 transcriptional co-factors of NER genes. We will also test if CtBP1 regulation of NER genes is altered during UV carcinogenesis. These analyses will determine how CtBP1 hyperfunction suppresses the NER genes and inhibits UV-induced DNA damage repair in melanocytes. Aim 3 will identify UV signature cytokines produced in keratinocytes, which are CtBP1 transcriptional targets that affect melanoma microenvironment. Our preliminary data revealed that several UV signature cytokines involved in immune suppression, inflammation, and angiogenesis in the stroma could be directly transactivated by CtBP1 in keratinocytes. Samples generated in Aim 1 will be used to identify these CtBP1 transcriptional targets. In vivo knockdown of candidate CtBP1 targets will be used to validate their roles in UV carcinogenesis.

描述（由申请人提供）： 黑色素瘤的发病率在美国（包括VA人群）迅速增加，美国军队服役期间的阳光照射与黑色素瘤发病率增加有关。尽管黑色素瘤不是最常见的皮肤癌，但它是最致命的形式。国家癌症研究所预测2013年有76,690例黑色素瘤诊断和9,480例死亡。鉴定负责黑色素瘤的分子和途径对于合理开发新的预防和治疗策略至关重要。CtBP 1（羧基末端结合蛋白1）是一种NADH依赖性转录调节因子，在体外可抑制多种肿瘤抑制因子的转录。该建议的重点是了解CtBP 1过表达在紫外线（UV）介导的黑色素瘤癌变中的作用。我们的长期目标是开发基于CtBP 1的新的黑色素瘤预防/治疗方法。我们的初步数据表明，CtBP 1在人类黑色素瘤中过度表达，抑制参与核苷酸切除修复（NER）途径的关键参与者的转录，从而抑制紫外线照射后的DNA损伤修复。此外，角化细胞中CtBP 1的过表达导致UV致癌过程中常见的几种细胞因子的产生。基于我们的初步数据，我们假设：CtBP 1过表达抑制基因修复紫外线介导的DNA损伤的黑素细胞和激活紫外线信号细胞因子参与免疫抑制，炎症和血管生成，从而有助于紫外线致癌。为了验证我们的假设，目的1将评估CtBP 1在体内UV致癌作用中的作用。Tyr-H-rasG 12 V/Ink 4a-null小鼠发生自发性皮肤黑色素瘤，高度类似于UV诱导的恶性黑色素瘤。我们将Tyr-H-rasG 12 V/Ink 4a缺失小鼠与CtBP 1敲除小鼠杂交，以评估CtBP 1的降低是否抑制UV致癌作用，以及与CtBP 1过度表达相关的任何病理学改变是否有助于黑色素瘤的发展。此外，我们已经产生了K5.CtBP1转基因小鼠，其在角质形成细胞中过表达CtBP 1并显示皮下炎症和血管生成。我们将Tyr-H-rasG 12 V/Ink 4a缺失小鼠与我们的K5.CtBP1小鼠杂交，以研究CtBP 1诱导的免疫抑制、炎症和血管生成细胞因子对UV介导的黑素瘤致癌作用的影响。我们的初步研究表明，皮肤的紫外线照射会增加CtBP 1和NADH水平。我们是第一个鉴定CtBP 1的NADH依赖性激活的人，并且最近显示了NADH阻断剂Tempol对CtBP 1功能的抑制。因此，我们将确定Tempol是否可以抑制UV介导的黑色素瘤致癌作用。这些分析将为通过靶向CtBP 1开发UV介导的黑色素瘤的预防或治疗方法铺平道路。目的2将研究CtBP 1抑制NER途径关键介质的分子机制。我们将评估CtBP 1介导的抑制NER基因在黑色素瘤发病机制中的影响，确定CtBP 1转录调节NER基因的分子机制，并确定CtBP 1转录辅助因子NER基因。我们还将测试在紫外线致癌过程中，NER基因的CtBP 1调控是否发生改变。这些分析将确定CtBP 1功能亢进如何抑制NER基因并抑制黑素细胞中UV诱导的DNA损伤修复。目的3将鉴定角质形成细胞中产生的UV信号细胞因子，其是影响黑色素瘤微环境的CtBP 1转录靶点。我们的初步数据显示，参与免疫抑制，炎症和血管生成的基质中的几个UV签名细胞因子可以直接反式激活角质形成细胞中的CtBP 1。Aim 1中生成的样品将用于鉴定这些CtBP 1转录靶标。候选CtBP 1靶标的体内敲低将用于验证它们在UV致癌作用中的作用。