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.

项目概要/摘要慢性紫外线 (UV) 辐射不仅会诱发基因突变，还会导致表观遗传异常影响转录因子、癌基因和肿瘤抑制因子表达的修饰，导致皮肤鳞状细胞癌 (cSCC) 的发展，这是美国第二常见的癌症更好地了解与紫外线相关的表观遗传异常的机制。提供抑制皮肤恶性肿瘤的新方法。引人注目的是，慢性紫外线照射会诱导 CDKN2A 基因启动子处的 DNA 高甲基化，从而导致编码肿瘤抑制因子 p16INK4A 和 p14ARF 这种表观遗传改变使 CDKN2A 沉默，从而促进肿瘤发生。然而，目前尚不清楚这种表观遗传畸变是否可以逆转。重新激活 CDKN2A 并抑制 cSCC 的恶性表型在目标 1 中，我们将使用基于 CRISPR-Cas9 的技术。表观基因组编辑工具可特异性去甲基化 CDKN2A 启动子并研究靶向的效果 DNA 去甲基化对癌症表型的影响。紫外线辐射会增加 Myc 的表达，Myc 是一种致癌转录因子。 Myc 癌基因家族在许多人类癌症中过度表达时会失调。 Myc 与非规范（低亲和力）基序结合，入侵增强子，并可能激活超级增强子（由异常高水平的 H3K27 乙酰化定义的非编码基因组区域）。增强子强烈上调癌基因，导致恶性肿瘤发生，但其异常程度仍然难以捉摸。过度表达的 Myc 与低亲和力 Myc 结合形成超级增强子。位点，招募组蛋白乙酰转移酶 p300，并产生导致恶性肿瘤的异常超级增强子。在目标 2 中，我们将确定过度表达的 Myc 在 cSCC 超级增强子形成中的作用。 cSCC 的一个子集表现出较差的分化，这与患者生存率较低有关，但它仍然存在。尚不清楚是什么赋予了低分化 cSCC 的侵袭性。 DNA 甲基化和/或 Myc 抑制剂通过重新激活 CDKN2A 抑制体内低分化 cSCC 和/或抑制 Myc 相关超级增强子在目标 3 中，我们将使用低分化的 cSCC 患者。衍生的异种移植物作为临床前模型来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学分析：“PIXUL-ChIP”（高通量染色质剪切以获得强大的 ChIP 信号）和“EVA”（检测特定 DNA 的表观遗传可视化分析）通过我们的表观基因组编辑工具，拟议的研究将阐明单细胞水平的甲基化。表观遗传异常对 cSCC 侵袭性的贡献并揭示调节的治疗潜力表观遗传标记可抑制 cSCC。