乙型肝炎病毒 (HBV)-DNA 整合到宿主基因组中有助于肝细胞癌 (HCC) 的发展。 KMT2B 是 HCC 中第二常见的 HBV-DNA 整合位点，但其作用和功能仍不清楚。我们的目的是利用人类基因组编辑的诱导多能干细胞（iPSC）模型来阐明 HBV-KMT2B 整合对 HCC 发展的影响。根据 HBV-KMT2B 在 HCC 中整合的遗传信息，我们确定了其完整的 DNA 序列和转录本变体。为了排除其他致癌突变的影响，我们在具有完整基因组的健康供体 iPSC 中重现了 HBV 整合，并使用 iPSC 衍生的肝祖细胞 (HPC) 和肝细胞 (iPS-Heps) 分析了其影响。重现的 HBV-KMT2B 整合显着上调肝细胞增殖。综合转录和表观遗传学分析显示，基于组蛋白 3 赖氨酸 4 三甲基化 (H3K4me3) 扰动的 HBV-KMT2B 整合，肝细胞中细胞周期相关基因的表达增强，与原始 HCC 样本中的情况相似。长读长 RNA 序列检测到 HCC 样本和 HPC 中常见的 KMT2B 转录物变异。截短变体的过度表达显着增强了肝细胞的增殖，而 HBV-KMT2B 融合转录本并没有增强增殖。 HBV-KMT2B 整合的 HPC 表现出复制应激和 DNA 损伤，表明我们的模型由于 KMT2B 功能异常增强而启动了肝癌发生过程。我们使用基因工程 iPSC 的疾病模型首次深入了解 HCC 发展中的 KMT2B 功能和HBV-KMT2B 整合的致癌过程。我们阐明了由于 KMT2B 功能异常而导致 HBV 相关 HCC 的新致癌机制。版权所有 © 2024 作者。由爱思唯尔公司出版。保留所有权利。

Hepatitis B virus (HBV)-DNA integration into the host genome contributes to hepatocellular carcinoma (HCC) development. KMT2B is the second most frequent locus of HBV-DNA integration in HCC, however its role and function remain unclear. We aimed to clarify the impact of HBV-KMT2B integration in HCC development using a human genome-edited induced pluripotent stem cells (iPSCs) model.Based on the genetic information on HBV-KMT2B integration in HCC, we determined its complete DNA sequence and transcript variants. To exclude the effect of other oncogenic mutations, we reproduced HBV integration in healthy donor iPSCs with an intact genome and analyzed its effects using iPSC-derived hepatic progenitor cells (HPCs) and hepatocytes (iPS-Heps).The reproduced HBV-KMT2B integration significantly upregulated the proliferation of hepatic cells. Comprehensive transcriptional and epigenetic analyses revealed enhanced expression of cell cycle-related genes in hepatic cells with HBV-KMT2B integration based on perturbation of histone 3 lysine 4 tri-methylation(H3K4me3), mimicking that in the original HCC sample. Long-read RNA-sequence detected the common KMT2B transcript variants in the HCC sample and HPCs. Overexpression of the truncated variant significantly enhanced proliferation of hepatic cells, whereas HBV-KMT2B fusion transcripts did not enhance proliferation. HBV-KMT2B-integrated HPCs exhibited replication stress and DNA damage, indicating that our model initiated the process of hepatocarcinogenesis due to abnormally promoted KMT2B function.Our disease model using genetically engineered iPSCs provides the first insight into both the KMT2B function in HCC development and the oncogenic processes by HBV-KMT2B integration. We clarified the novel oncogenic mechanism in HBV-related HCC due to aberrant KMT2B function.Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.