Deciphering and targeting a non-genetic driver pathway in hepatocellular carcinoma

破译和靶向肝细胞癌的非遗传驱动途径

• 批准号: 10350679
• 负责人: Narendra Wajapeyee
• 金额: $ 47.8万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-02-12 至 2026-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10350679
• 关键词: American; American Cancer Society; BCL6 gene; BTB/POZ Domain; Biochemical; Biological Assay; Cell Culture Techniques; Cell-Mediated Cytolysis; Cessation of life; Characteristics; Cirrhosis; Clinical; Data; Development; Diagnosis; Disease; Distal; Environment; Erinaceidae; Follow-Up Studies; Genes; Genetic; Growth; Hepatic; Hepatocyte; Human; Immune system; Immunocompetent; Immunocompromised Host; Immunosuppression; Lead; Liver Fibrosis; Liver neoplasms; Malignant Epithelial Cell; Mediating; Modeling; Molecular; Mus; Names; Neoplasm Metastasis; Oncogenic; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacology; Prevalence; Primary carcinoma of the liver cells; Probability; Property; Proteins; RNA analysis; Role; Series; Solubility; Survival Rate; T-Lymphocyte; Testing; Therapeutic; Transcription Repressor; Tumor Suppressor Genes; Tumor Suppressor Proteins; United States; Validation; Xenograft procedure; analog; base; cell growth; design; effective therapy; epigenetic silencing; experimental study; follow-up; gene repression; genetic corepressor; genome-wide; growth promoting activity; humanized mouse; improved; inhibitor; innovation; knock-down; liver cancer model; mouse model; mutant; new therapeutic target; non-genetic; novel; novel strategies; novel therapeutics; patient derived xenograft model; pre-clinical; rational design; small hairpin RNA; small molecule; small molecule inhibitor; subcutaneous; transcriptome; transcriptome sequencing; tumor; tumor growth; tumor progression; tumorigenesis; zinc-binding protein

PROJECT SUMMARY Hepatocellular carcinoma (HCC) accounts for nearly 31,000 deaths annually in the United States alone. Factors that epigenetically silence an HCC tumor suppressor gene have the potential to promote tumorigenesis and thus may provide novel drug targets for HCC therapies. Using a genome-scale shRNA screen, we identified BCL6 as a putative and novel HCC driver gene. BCL6 is a transcriptional repressor with no previously documented role in HCC development and progression. We found that BCL6 was sufficient to transform cultured immortalized hepatocytes and promote HCC tumor growth in mouse subcutaneous xenografts. These oncogenic effects of BCL6 were dependent upon the ability of BCL6 to cause transcriptional repression because a transcriptional repression activity defective mutant of BCL6 failed to transform hepatocytes and promote tumor growth in mice. Based on our preliminary results, in this application we will establish the role of BCL6 as a driver of HCC, determine the mechanism by which BCL6 promotes tumor growth, and evaluate novel BCL6 targeting small-molecule inhibitors for HCC therapy. In Aim 1, we will establish the role of BCL6 in initiation and progression of hepatic tumorigenesis using a series of complementary mouse models that recapitulate characteristic features of HCC, including a mouse model of liver fibrosis (cirrhosis). This model recapitulates cirrhosis which is a cardinal feature of HCC. Additionally, based on our preliminary results that BCL6 inhibition in HCC cells increases their probability of getting cleared by T-cells, we will also use a mouse model with humanized immune system to study the impact of BCL6 in HCC progression in the context of a functional human immune system. In Aim 2, based upon the results of our RNA-seq and further follow up analysis, we will determine if epigenetic silencing of tumor suppressor HHIP and the zinc transporter ZIP14 by BCL6 is necessary for it to drive hepatic tumor growth. In Aim 3, we will evaluate our novel BCL6 inhibitors in pre-clinical mouse models of HCC, including HCC patient-derived xenograft (PDX) models for HCC therapeutics. In preliminary experiments, we have developed a novel small-molecule inhibitor designed to target the BTB domain of BCL6 and thereby disrupt its interaction with its co-repressors SMRT, NCOR and BCOR. We found that this novel BCL6 inhibitor L2-12019 inhibited the HCC cell growth in culture and in a human HCC xenograft-based mouse model. In Aim 3 studies, we will rationally design and evaluate new L2-12019 analogs to improve drug-like properties. The lead analog (with improved potency, selectivity, stability and solubility) will be tested with L2-12019 in pre-clinical mouse models of HCC and its efficacy will be compared with existing BCL6 inhibitors. Collectively, the results of the experiments proposed in this application will elucidate a novel non-genetic druggable pathway that promotes HCC tumor growth and progression and evaluate a new approach for treating HCC.

项目摘要 仅在美国，肝细胞癌（HCC）每年就造成近31，000例死亡。 表观遗传学沉默HCC肿瘤抑制基因的因素有可能促进HCC的发生。 肿瘤发生，因此可能为HCC治疗提供新的药物靶点。使用基因组规模的shRNA 筛选，我们确定BCL 6作为一个推定的和新的HCC驱动基因。BCL 6是一种转录抑制因子， 以前没有记录在HCC发展和进展中的作用。我们发现BCL 6足以 转化培养的永生化肝细胞并促进小鼠皮下HCC肿瘤生长 异种移植BCL 6的这些致癌作用依赖于BCL 6引起转录抑制的能力。 抑制，因为BCL 6的转录抑制活性缺陷突变体不能转化 肝细胞并促进小鼠肿瘤生长。根据我们的初步结果，在本申请中，我们将 确定BCL 6作为HCC驱动因素的作用，确定BCL 6促进肿瘤的机制， 生长，并评估用于HCC治疗的新型BCL 6靶向小分子抑制剂。在目标1中，我们 使用一系列的方法来确定BCL 6在肝肿瘤发生的起始和进展中的作用。 互补的小鼠模型，其概括HCC的特征性特征，包括HCC的小鼠模型， 肝纤维化（肝硬化）。该模型概括了肝硬化，肝硬化是HCC的主要特征。此外，本发明还 基于我们的初步结果，即肝癌细胞中的BCL 6抑制增加了它们被清除的可能性， 通过T细胞，我们还将使用具有人源化免疫系统的小鼠模型来研究BCL 6在 在功能性人类免疫系统的背景下HCC进展。在目标2中，根据我们的结果， 通过RNA-seq和进一步的后续分析，我们将确定肿瘤抑制因子HHIP的表观遗传沉默和 BCL 6的锌转运蛋白ZIP 14是其驱动肝肿瘤生长所必需的。在目标3中，我们将评估 我们的新型BCL 6抑制剂在HCC临床前小鼠模型中的应用，包括HCC患者来源的异种移植物（PDX） 肝癌治疗模型。在初步实验中，我们开发了一种新型的小分子抑制剂， 设计为靶向BCL 6的BTB结构域，从而破坏其与其辅阻遏物SMRT的相互作用， NCOR和BCOR。我们发现这种新型BCL 6抑制剂L2-12019在培养中抑制HCC细胞的生长， 以及在基于人HCC异种移植物的小鼠模型中。在目标3研究中，我们将合理设计和评估 新的L2-12019类似物，以改善药物样性质。先导类似物（具有改善的效力、选择性， 稳定性和溶解性）将在HCC的临床前小鼠模型中用L2-12019进行测试， 与现有的BCL 6抑制剂相比。总的来说，本申请中提出的实验的结果 将阐明促进HCC肿瘤生长和进展的新的非遗传药物途径， 评估治疗HCC的新方法。