Vázquez Salgado Alexandra M, Cai Chunmiao, Lee Markcus, Yin Dingzi, Chrystostome Marie-Lise, Gefre Adrienne F, He Shirui, Kieckhaefer Julia E, Wangensteen Kirk J
Department of Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota; Pharmacology Graduate Program, University of Pennsylvania, Philadelphia, Pennsylvania.
Department of Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
Cell Mol Gastroenterol Hepatol. 2025;19(5):101460. doi: 10.1016/j.jcmgh.2025.101460. Epub 2025 Jan 4.
BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) frequently undergoes regional chromosomal amplification, resulting in elevated gene expression levels. We aimed to elucidate the role of these poorly understood genetic changes by using CRISPR activation (CRISPRa) screening in mouse livers to identify which genes within these amplified loci are cancer driver genes.
We used data from The Cancer Genome Atlas to identify that frequently copy number-amplified and up-regulated genes all reside on human chromosomes 1q and 8q. We generated CRISPRa screening transposons that contain oncogenic Myc to drive tumor formation. We conducted CRISPRa screens in vivo in the liver to identify tumor driver genes. We extensively validated the findings in separate mice and performed RNA sequencing analysis to explore mechanisms driving tumorigenesis.
We targeted genes that frequently undergo amplification in human HCC using an in vivo CRISPRa screening system in mice, which induced extensive liver tumorigenesis. Human chromosome 1q genes Zbtb7b, Vps72, Gba1, and Mrpl9 emerged as drivers of liver tumorigenesis. In human HCC there is a trend in correlation between levels of MRPL9, VPS72, or GBA1 and poor survival. In validation assays, activation of Vps72, Gba1, or Mrpl9 resulted in extensive liver tumorigenesis and decreased survival in mice. RNA sequencing revealed different mechanisms driving HCC, with Mrpl9 activation altering genes functionally related to mitochondrial function, Vps72 levels altering phospholipid metabolism, and Gba1 activation enhancing endosomal-lysosomal activity, all leading to promotion of cellular proliferation. Analysis of human tumor tissues with high levels of MRPL9, VPS72, or GBA1 revealed congruent results, indicating conserved mechanisms driving HCC.
This study reveals chromosome 1q genes Vps72, Gba1, and Mrpl9 as drivers of HCC. Future efforts to prevent or treat HCC can focus on these new driver genes.
肝细胞癌（HCC）常发生局部染色体扩增，导致基因表达水平升高。我们旨在通过在小鼠肝脏中进行CRISPR激活（CRISPRa）筛选，以阐明这些尚不清楚的基因变化的作用，从而确定这些扩增位点内的哪些基因是癌症驱动基因。
我们利用癌症基因组图谱的数据，确定经常发生拷贝数扩增且上调的基因都位于人类染色体1q和8q上。我们构建了包含致癌性Myc的CRISPRa筛选转座子，以驱动肿瘤形成。我们在肝脏中进行了体内CRISPRa筛选，以确定肿瘤驱动基因。我们在单独的小鼠中广泛验证了这些发现，并进行了RNA测序分析，以探索驱动肿瘤发生的机制。
我们使用小鼠体内CRISPRa筛选系统，靶向人类HCC中经常发生扩增的基因，该系统诱导了广泛的肝脏肿瘤发生。人类染色体1q基因Zbtb7b、Vps72、Gba1和Mrpl9成为肝脏肿瘤发生的驱动基因。在人类HCC中，MRPL9、VPS72或GBA1水平与较差的生存率之间存在相关性趋势。在验证试验中，激活Vps72、Gba1或Mrpl9会导致小鼠广泛的肝脏肿瘤发生并降低生存率。RNA测序揭示了驱动HCC的不同机制，Mrpl9激活改变了与线粒体功能相关的基因，Vps72水平改变了磷脂代谢，Gba1激活增强了内体-溶酶体活性，所有这些都导致细胞增殖的促进。对MRPL9、VPS72或GBA1水平高的人类肿瘤组织的分析得出了一致的结果，表明驱动HCC的机制具有保守性。
本研究揭示了染色体1q基因Vps72、Gba1和Mrpl9是HCC的驱动基因。未来预防或治疗HCC的努力可以聚焦于这些新的驱动基因。
