Targeting epigenetic abnormalities to inhibit cutaneous squamous cell carcinoma

针对表观遗传异常抑制皮肤鳞状细胞癌

基本信息

批准号：
10705718
负责人：
Masaoki Kawasumi
金额：
$ 39.57万
依托单位：
UNIVERSITY OF WASHINGTON
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-09-15 至 2027-08-31
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10705718
关键词：
Acetylation Affect Affinity Automobile Driving Binding Binding Sites CDKN2A gene CRISPR/Cas technology Carcinogens Cell Cycle Proteins Cell Line Cells Cessation of life Chromatin Chronic Communities Cyclin-Dependent Kinase Inhibitor 2A DNA DNA Methylation DNA Methylation Inhibition DNA Modification Process DNA Sequence Alteration Data Development Drug Combinations EP300 gene Enhancers Environmental Risk Factor Enzymes Epigenetic Process Genes Genetic Induction Genomic Segment Genomics Goals Guide RNA Histone Acetylation Histones Human Hypermethylation Inhibition of Cell Proliferation Invaded Laboratories Large Cell Carcinoma MYC gene MYC-Family Oncogene Malignant Neoplasms Measures Methylation Modification Neoplasm Metastasis Oncogenes Oncogenic Patients Phenotype Play Positioning Attribute Pre-Clinical Model Proliferating RNA Polymerase II Risk Role Sampling Signal Transduction Skin Skin Cancer Specimen Testing Therapeutic Tumor Promotion Tumor Suppressor Proteins UV Radiation Exposure UV induced Ultraviolet Rays United States Untranslated RNA Visualization demethylation detection assay driver mutation epigenome editing epigenomics genome editing genomic locus histone modification in vivo inhibitor innovative technologies malignant phenotype migration new technology novel strategies novel therapeutic intervention overexpression p14ARF Protein patient derived xenograft model promoter rational design recruit skin organogenesis skin squamous cell carcinoma small molecule inhibitor targeted treatment tool transcription factor tumor tumor growth ultraviolet

项目摘要

Project Summary/Abstract Chronic ultraviolet (UV) radiation induces not only genetic mutations but also aberrant epigenetic modifications that affect the expression of transcription factors, oncogenes, and tumor suppressors, leading to the development of cutaneous squamous cell carcinoma (cSCC), the second most common cancer in the United States. A better understanding of the mechanisms underlying UV-associated epigenetic abnormalities will provide novel approaches to inhibit skin malignancies. Strikingly, chronic UV exposure induces DNA hypermethylation at the promoter of CDKN2A gene, which encodes tumor suppressors p16INK4A and p14ARF. This epigenetic alteration silences CDKN2A, promoting tumor growth and metastasis. However, it remains unclear whether the reversal of this epigenetic aberration can reactivate CDKN2A and inhibit malignant phenotypes of cSCC. In Aim 1, we will use our CRISPR-Cas9-based epigenome editing tools to specifically demethylate the CDKN2A promoter and investigate the effect of targeted DNA demethylation on cancer phenotypes. UV radiation increases the expression of Myc, which is an oncogenic transcription factor. Myc activation is a cancer hallmark, and the Myc oncogene family is deregulated in many human cancers. When overexpressed, Myc binds to noncanonical (low-affinity) motifs, invading enhancers, and potentially activates super-enhancers (noncoding genomic regions defined by unusually high levels of H3K27 acetylation). Cancer-specific super- enhancers strongly upregulate oncogenes, driving malignancies. However, it remains elusive how aberrant super-enhancers are formed in cSCC. We hypothesize that overexpressed Myc binds to low-affinity Myc binding sites, recruits histone acetyltransferase p300, and generates aberrant super-enhancers that drive malignancy. In Aim 2, we will determine the role of overexpressed Myc in super-enhancer formation in cSCC. A subset of cSCC displays poor differentiation, which correlates with poor patient survival. However, it remains unclear what confers the aggressiveness of poorly differentiated cSCC. We hypothesize that small-molecule inhibitors of DNA methylation and/or Myc suppress poorly differentiated cSCC in vivo by reactivating CDKN2A and/or inhibiting Myc-associated super-enhancers. In Aim 3, we will use poorly differentiated cSCC patient- derived xenografts as preclinical models to assess the effects of these inhibitors on tumor growth and metastasis. Innovative technologies will be used for epigenetic analyses: “PIXUL-ChIP” (high-throughput chromatin shearing for robust ChIP signals) and “EVA” (epigenetic visualization assay that detects specific DNA methylation at the single-cell level). With our epigenome editing tools, the proposed study will elucidate the contribution of epigenetic abnormalities to cSCC aggressiveness and reveal therapeutic potential of modulating epigenetic marks to suppress cSCC.

项目摘要/摘要慢性紫外线（UV）辐射不仅会影响遗传突变，而且会影响异常表观遗传学影响转录因子，癌基因和肿瘤补充剂表达的修饰，导致皮肤鳞状细胞癌（CSCC）的发展，美国第二大最常见的癌症国家。更好地理解与紫外线相关的表观遗传异常的机制提供新颖的方法来抑制皮肤恶性肿瘤。令人惊讶的是，慢性紫外线暴露在CDKN2A基因的启动子上诱导DNA高甲基化，该基因编码肿瘤补充剂P16INK4A和P14ARF。这种表观遗传改变沉默CDKN2A，促进肿瘤生长和转移。但是，尚不清楚这种表观遗传畸变的相反重新激活CDKN2A并抑制CSCC的恶性表型。在AIM 1中，我们将使用基于CRISPR-CAS9的表观基因组编辑工具专门将CDKN2A启动子脱甲基并研究靶向的效果 DNA在癌症表型上的脱甲基化。紫外线辐射增加了MYC的表达，MYC是一种致癌转录因子。 MYC激活是癌症标志和MYC Oncogene家族在许多人类癌症中受到放松管制。过表达时， MYC与非宗教（低亲和力）基序结合，入侵增强剂，并可能激活超级增强剂（由异常高的H3K27乙酰化定义的非编码基因组区域）。癌症特异性超级增强剂强烈上调癌基因，驱动恶性肿瘤。但是，仍然难以捉摸超级增强剂是在CSCC中形成的。我们假设过表达的MYC与低亲和力MYC结合结合站点，招募组蛋白乙酰转移酶P300，并产生驱动恶性肿瘤的异常超级增强剂。在AIM 2中，我们将确定过表达MYC在CSCC中超增强剂形成中的作用。 CSCC的一部分显示出差的分化，这与患者的生存差有关。但是，它仍然是尚不清楚是什么赋予了分化不善的CSCC的侵略性。我们假设小分子 DNA甲基化和/或MYC的抑制剂通过重新激活CDKN2A抑制了分化较差的CSCC 和/或抑制与MYC相关的超级增强剂。在AIM 3中，我们将使用差异化的CSCC患者 - 衍生Xenographictics作为临床前模型，以评估这些抑制剂对肿瘤生长和转移的影响。创新技术将用于表观遗传分析：“ Pixul-Chip”（高通量染色质剪切可用于健壮的芯片信号）和“ eva”（表观遗传可视化测定法检测特定的DNA 单细胞水平的甲基化）。借助我们的表观基因组编辑工具，拟议的研究将阐明表观遗传异常对CSCC侵略性的贡献并揭示了调节的治疗潜力表观遗传标记抑制CSCC。