Hepatitis B virus integrations in KMT2B drive hepatocellular carcinoma

KMT2B 中的乙型肝炎病毒整合驱动肝细胞癌

• 批准号: 10661827
• 负责人: Jian Cao
• 金额: $ 46.26万
• 依托单位: RUTGERS BIOMEDICAL AND HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-15 至 2027-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10661827
• 关键词: Affect; Alleles; Amino Acids; Animals; Automobile Driving; Binding; Binding Sites; Biochemical; Bioinformatics; C-terminal; Cancer Etiology; Cancer Histology; Cell Line; Cell Proliferation; Cells; Cessation of life; Chromatin; Chromosomal translocation; Chromosomes; Clinical; Complex; Data; Development; Disease; Early Diagnosis; Enzymes; Epigenetic Process; Event; Exons; Gene Expression; Genes; Genetic Engineering; Genome; Goals; Hepatitis B Infection; Hepatitis B Virus; Hepatocarcinogenesis; Hepatocyte; Histones; Homologous Gene; Hot Spot; Human; Image; Immigrant; In Vitro; Individual; Infant; Injections; KDR gene; Knock-in; Knock-out; Lead; Length; Liver; Liver neoplasms; Lysine; MLL gene; Malignant Neoplasms; Malignant neoplasm of liver; Measures; Methyltransferase; Minority Groups; Mixed-Lineage Leukemia; Modeling; Monitor; Multiple Endocrine Neoplasia Type 1; Mutation; Oncogenes; Oncogenic; Oncornaviruses; Patients; Phenotype; Phosphotransferases; Prevention approach; Preventive; Primary carcinoma of the liver cells; Protein Truncation; RNA-Directed DNA Polymerase; Tail; Telomerase; Testing; Therapeutic; Tumor Promotion; Tumor Suppressor Proteins; Variant; Vascular Endothelial Growth Factors; Veins; Virus Integration; advanced disease; cancer genome; cancer site; cancer type; carcinogenesis; chronic infection; detection assay; experience; gain of function; genome-wide analysis; genomic locus; hepatocellular carcinoma cell line; histone demethylase; histone methyltransferase; histone modification; in vivo; in vivo Model; inhibitor; insight; integration site; lens epithelium-derived growth factor; leukemia; liver cancer model; loss of function; mouse model; mutant; new therapeutic target; novel; overexpression; pharmacologic; targeted agent; targeted treatment; transcriptome sequencing; tumor; tumor growth; tumor initiation; tumorigenesis; viral DNA; whole genome

ABSTRACT Chronic infection by hepatitis B virus (HBV) is the leading cause of hepatocellular carcinoma (HCC). HBV alone is responsible for more than 3% of worldwide cancer deaths of all cancer sites combined. How HBV promotes carcinogenesis is not fully understood, leading to limited therapeutic options for advanced diseases. We previously revealed that 10% of HBV-associated HCC tumors carry clonal integrations of HBV in the KMT2B gene locus in cancer cell genomes. All these integrations are located between exons 3 and 6 of the KMT2B gene. KMT2B is the only close homolog of KMT2A (also known as MLL1). It has been well established that the chromosomal translocations affecting KMT2A are the primary drivers of infant mixed lineage leukemia. HBV integrations in KMT2B in HCC may mirror KMT2A rearrangements in leukemia, but its function has not been studied. We have identified patient-derived HCC cell lines carrying HBV integrations in KMT2B. Using these cell lines and RNA-seq data of HCC tumors with HBV integrations in KMT2B, we found that these integrations lead to expression of truncated KMT2B from the N-terminus to 697 to 906 amino acid residues. Knockout of the KMT2B truncation in an integration-carrying cell line suppressed cell proliferation in vitro. Overexpression of a KMT2B truncation transformed normal human hepatocytes in vitro and induced tumor growth in vivo in hydrodynamic injection-based mouse models. Mechanistically, we found the KMT2B truncation sequestered the tumor suppressor MENIN from the KMT2A/B histone methyltransferase complex and chromosome. A KMT2B truncation carrying a mutation that blocks MENIN binding failed to promote tumor formation in vivo. Based on these preliminary data, our central hypothesis is that HBV integrations in KMT2B produce truncations, which sequester MENIN from KMT2B complex and promote hepatocellular carcinoma. To test this hypothesis, we will determine the oncogenic function of KMT2B truncations, using various in vitro and in vivo models (Aim 1), and determine the mechanism of KMT2B truncation-triggered tumorigenesis (Aim2). Specifically, a new genetic engineered mouse model of HCC will be generated and a potential targeted agent for HCC with HBV integrations in KMT2B will be tested. The proposed studies aim to establish the oncogenic driving function and mechanism of HBV integrations in KMT2B in HCC, which cause 35,000 HCC cases every year. It is among the most common cancer-causing genetic alterations but it is significantly understudied. The completion of the proposed studies will discover a novel oncovirus-driving, epigenetic mechanism of HCC development and provide information for developing prevention approaches, early detection assays, and targeted therapeutics for affected individuals.

抽象的 丙型肝炎病毒（HBV）慢性感染是肝细胞癌（HCC）的主要原因。仅HBV 负责所有癌症部位的全球癌症死亡中超过3％的总和。 HBV如何促进 致癌作用尚未完全理解，从而导致晚期疾病的治疗选择有限。我们 以前显示，HBV相关的HCC肿瘤中有10％在KMT2B中携带HBV的克隆整合 癌细胞基因组中的基因基因座。所有这些集成位于KMT2B的外显子3和6之间 基因。 KMT2B是KMT2A的唯一亲密同源物（也称为MLL1）。已经确定了 影响KMT2A的染色体易位是婴儿混合谱系白血病的主要驱动因素。 HBV HCC中的KMT2B集成可能会反映白血病中的KMT2A重排，但其功能尚未 研究。我们已经确定了在KMT2B中携带HBV积分的患者衍生的HCC细胞系。使用这些单元格 在KMT2B中具有HBV积分的HCC肿瘤的线和RNA-seq数据，我们发现这些集成率很高 从N末端到697至906个氨基酸残基的截短的KMT2B表达。淘汰 在携带的细胞系中，KMT2B截断在体外抑制了细胞增殖。 a的过表达 KMT2B截断在体外转化了正常的人肝细胞，并诱导体内肿瘤生长 基于流体动力注射的小鼠模型。从机械上讲，我们发现KMT2B截断隔离了 来自KMT2A/B组蛋白甲基转移酶复合酶复合物和染色体的肿瘤抑制Menin。 KMT2B 携带阻断梅宁结合的突变的截短无法在体内促进肿瘤形成。基于 这些初步数据，我们的中心假设是KMT2B中的HBV整合会产生截断，这是 来自KMT2B复合物的Menin隔离并促进肝细胞癌。为了检验这一假设， 我们将使用各种体外和体内模型来确定KMT2B截断的致癌功能（AIM 1），并确定KMT2B截断触发的肿瘤发生的机理（AIM2）。具体来说，一个新的 将生成HCC的基因工程小鼠模型，并具有HBV的HCC的潜在靶向剂 KMT2B中的集成将进行测试。拟议的研究旨在建立致癌驾驶功能和 HCC中KMT2B中HBV集成的机制，每年导致35,000个HCC病例。这是 最常见的引起癌症的遗传改变，但已大量研究。完成 拟议的研究将发现一种新型的癌症驾驶，HCC发育的表观遗传机制和 为开发预防方法，早期检测测定法和有针对性的治疗剂提供信息 受影响的人。