Prevention of skin cancer by phytochemicals via Nrf2 and epigenetics

通过 Nrf2 和表观遗传学使用植物化学物质预防皮肤癌

• 批准号: 9207083
• 负责人: Ah-Ng Tony Kong
• 金额: $ 35.46万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-13 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9207083
• 关键词: Agar; Anti-Inflammatory Agents; Anti-inflammatory; Antioxidants; BCL2 gene; Back; Benchmarking; Berry; Biological Markers; Carcinogenicity Tests; Cell Line; Cells; Chemopreventive Agent; Clinical Trials; Coupled; Cyclin D1; DNA Methylation; Development; Diet; Dietary Phytochemical; Disease; Ear; Edema; Embryo; Environmental Carcinogens; Enzymes; Epigenetic Process; Event; Exposure to; Fibroblasts; Future; Genes; Goals; Healthcare; Human; In Vitro; Incidence; Inflammation; Inflammatory; Inflammatory Response; Investigation; Knock-out; Knowledge; Laboratories; MEKs; Malignant Neoplasms; Mediating; Methylation; Modeling; Modification; Molecular; Morbidity - disease rate; Mus; Oxidative Regulation; Oxidative Stress; Papilloma; Pathogenesis; Pathway interactions; Phytochemical; Play; Prevalence; Prevention strategy; Preventive; Process; Proteins; Publishing; Regimen; Role; Skin; Skin Cancer; Skin Carcinogenesis; Skin Carcinoma; Skin Neoplasms; Sulforaphane; Sunlight; Testing; Transcriptional Activation; Tumor Promotion; UVB carcinogenesis; UVB induced; Ultraviolet B Radiation; United States; Vascular Endothelial Growth Factors; base; beta catenin; c-myc Genes; cancer chemoprevention; cancer type; care burden; dimethylbenzanthracene; epigenetic marker; epigenetic regulation; epigenomics; genome wide methylation; in vivo; in vivo Model; insight; keratinocyte; mouse model; novel; prevent; protective effect; public health relevance; skin cancer prevention; success; transcription factor; tumorigenesis; ursolic acid

 DESCRIPTION (provided by applicant): Non-melanoma skin cancers are the most common types of cancers in the United States, with over 1 million new cases per year, while increasing exposure to sunlight (UV) and environmental carcinogens appear to be the major causative factors. The long term goal of this application is to develop a safe and effective strategy using relatively non-toxic dietary cancer chemopreventive compounds to prevent skin cancer. The rationale for these studies is based on investigation from our laboratory and others, showing that: (1) Sulforaphane (SFN) presents abundantly in these berries and crucifers, respectively, strongly inhibits skin carcinogenesis in various mouse models in vivo; (2) Skin carcinogenesis is greatly enhanced in knockouts of Nrf2, a transcription factor critical in mediating anti-oxidative stress/inflammatory responses, and, importantly, SFN has no cancer protective effect in these Nrf2(-/-) mice; (3) Nrf2 and Nrf2-targeted HO-1 expression is decreased in skin tumors in Nrf2(+/+) mice; (4) Enhanced expression of c-Myc, Bcl-2, cyclin D1, beta-catenin, VEGF, Cox-2, and Bax is seen in all skin tumors; (5) UVB enhanced expression of inflammatory biomarkers in the skin of Nrf2(-/-) mice is substantially decreased compared with Nrf2(+/+) mice; (6) SFN induces cellular antioxidant proteins in MEFs (mouse embryonic fibroblast) and MEKs (mouse epidermal keratinocytes) of Nrf2 (+/+) but not of Nrf2 (- /-); (7) SFN blocks TPA-induced ear inflammation in C57BL/6J mice and not in Nrf2(-/-) mice; (8) Ursolic acid (UA), a natural triterpenoid with potent anti-inflammatory and cancer preventive activities inhibits TPA-induced ear edema and tumor promotion; (9) Increasing evidence suggests that epigenetics plays an important role in cancer development and progression including non-melanoma skin cancer; both UA and SFN modify CpG methylation of Nrf2 in JB6 mouse epidermal cell line; (10) Significant difference are observed in global DNA methylation profiles between DMBA/TPA papilloma vs normal skin and UVB-induced skin tumor vs non- irradiated skin analyzed by MeDIP-Seq analysis; and (11) UA and SFN inhibit TPA-induced JB6 transformation in soft agar. Based on the results summarized above we hypothesize that UA and SFN prevent skin carcinogenesis by altering epigenetic modifications with 3 specific aims: (1) To investigate the epigenetic events during in vivo skin cancer development and progression in B[a]P/TPA-induced skin carcinogenesis in Nrf2(+/+) vs Nrf2(-/-) C57BL6 mice, UVB-induced skin tumorigenesis in SKH-1 mice, and the cancer preventive efficacy coupled with epigenetic changes of UA and SFN; (2) To examine the epigenetic changes during transformation in vitro of mouse epidermal JB6 and human keratinocyte HaCaT cells and the effect of UA and SFN on these epigenetic changes; (3) To elucidate the molecular mechanisms involved in the epigenetic regulation of inflammatory/oxidative stress genes identified in Aims 1 and 2 by UA and SFN in mouse epidermal JB6 and human keratinocyte HaCaT cells. This study will advance our knowledge in developing better chemopreventive compounds for cancer chemoprevention clinical trials in skin cancer.

 描述（由申请人提供）：非黑色素瘤皮肤癌是美国最常见的癌症类型，每年新发病例超过100万例，而暴露于阳光（UV）和环境致癌物的增加似乎是主要的致病因素。本申请的长期目标是开发一种安全有效的策略，使用相对无毒的饮食癌症化学预防化合物来预防皮肤癌。这些研究的基本原理是基于本实验室和其他实验室的研究，表明：（1）萝卜硫素（SFN）分别在这些浆果和十字花科植物中大量存在，强烈抑制各种小鼠体内模型的皮肤致癌作用;（2）皮肤癌发生在Nrf 2的敲除中大大增强，Nrf 2是介导抗氧化应激/炎症反应的关键转录因子，并且重要的是，SFN在这些Nrf 2（-/-）小鼠中没有癌症保护作用;（3）在Nrf 2（+/+）小鼠的皮肤肿瘤中Nrf 2和Nrf 2靶向的HO-1表达降低;（4）在所有皮肤肿瘤中观察到c-Myc、Bcl-2、细胞周期蛋白D1、β-连环蛋白、VEGF、考克斯-2和Bax的表达增强;（5）与Nrf 2（+/+）小鼠相比，UVB增强的Nrf 2（-/-）小鼠皮肤中炎性生物标志物的表达显著降低;（6）SFN诱导MEFs中的细胞抗氧化蛋白（小鼠胚胎成纤维细胞）和MEK（7）SFN在C57 BL/6 J小鼠中阻断TPA诱导的耳部炎症，而在Nrf 2（-/-）小鼠中不阻断TPA诱导的耳部炎症;（8）熊果酸（UA）是一种天然三萜类化合物，具有有效的抗炎和癌症预防活性，可抑制TPA诱导的耳部水肿和肿瘤促进作用;（9）越来越多的证据表明表观遗传学在包括非黑色素瘤皮肤癌在内的癌症发生和进展中起重要作用; UA和SFN均修饰JB 6小鼠表皮细胞系中Nrf 2的CpG甲基化;（10）通过MeDIP-Seq分析，在DMBA/TPA乳头状瘤与正常皮肤之间以及UVB诱导的皮肤肿瘤与未照射的皮肤之间观察到全局DNA甲基化谱的显著差异;以及（11）UA和SFN抑制软琼脂中TPA诱导的JB 6转化。基于以上总结的结果，我们假设UA和SFN通过改变表观遗传修饰来预防皮肤癌发生，具有3个特定目的：（1）研究在Nrf 2（+/+）与Nrf 2（-/-）C57 BL 6小鼠中B[a]P/TPA诱导的皮肤癌发生、UVB诱导的SKH-1小鼠中的皮肤肿瘤发生、（2）研究小鼠表皮JB 6细胞和人角质形成细胞HaCaT细胞体外转化过程中的表观遗传学变化以及UA和SFN对这些表观遗传学变化的影响;（3）阐明炎症/炎症反应的表观遗传调控的分子机制。通过小鼠表皮JB 6和人角质形成细胞HaCaT细胞中的UA和SFN在目的1和2中鉴定的氧化应激基因。这项研究将促进我们的知识，在开发更好的化学预防化合物的癌症化学预防皮肤癌的临床试验。