Department of Anesthesia, Stanford University School of Medicine, Stanford, CA 94305.
Department of Medicine, Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA 94305.
J Hepatol. 2020 Apr;72(4):746-760. doi: 10.1016/j.jhep.2019.11.007. Epub 2019 Nov 22.
BACKGROUND & AIMS: Since human induced pluripotent stem cells (iPSCs) develop into hepatic organoids through stages that resemble human embryonic liver development, they can be used to study developmental processes and disease pathology. Therefore, we examined the early stages of hepatic organoid formation to identify key pathways affecting early liver development.
Single-cell RNA-sequencing and metabolomic analysis was performed on developing organoid cultures at the iPSC, hepatoblast (day 9) and mature organoid stage. The importance of the phosphatidylethanolamine biosynthesis pathway to early liver development was examined in developing organoid cultures using iPSC with a CRISPR-mediated gene knockout and an over the counter medication (meclizine) that inhibits the rate-limiting enzyme in this pathway. Meclizine's effect on the growth of a human hepatocarcinoma cell line in a xenotransplantation model and on the growth of acute myeloid leukemia cells in vitro was also examined.
Transcriptomic and metabolomic analysis of organoid development indicated that the phosphatidylethanolamine biosynthesis pathway is essential for early liver development. Unexpectedly, early hepatoblasts were selectively sensitive to the cytotoxic effect of meclizine. We demonstrate that meclizine could be repurposed for use in a new synergistic combination therapy for primary liver cancer: a glycolysis inhibitor reprograms cancer cell metabolism to make it susceptible to the cytotoxic effect of meclizine. This combination inhibited the growth of a human liver carcinoma cell line in vitro and in a xenotransplantation model, without causing significant side effects. This drug combination was also highly active against acute myeloid leukemia cells.
Our data indicate that phosphatidylethanolamine biosynthesis is a targetable pathway for cancer; meclizine may have clinical efficacy as a repurposed anti-cancer drug when used as part of a new combination therapy.
The early stages of human liver development were modeled using human hepatic organoids. We identified a pathway that was essential for early liver development. Based upon this finding, a novel combination drug therapy was identified that could be used to treat primary liver cancer and possibly other types of cancer.
由于人类诱导多能干细胞（iPSC）通过类似于人类胚胎肝脏发育的阶段发育成肝类器官，因此它们可用于研究发育过程和疾病病理学。因此，我们检查了肝类器官形成的早期阶段，以确定影响早期肝脏发育的关键途径。
对 iPSC、肝前体细胞（第 9 天）和成熟类器官阶段的发育类器官培养物进行单细胞 RNA 测序和代谢组学分析。在发育类器官培养物中，使用 CRISPR 介导的基因敲除和一种抑制该途径限速酶的市售药物（美克洛嗪）来研究磷脂酰乙醇胺生物合成途径对早期肝脏发育的重要性。还研究了美克洛嗪在异种移植模型中对人肝癌细胞系生长的影响以及在体外对急性髓性白血病细胞生长的影响。
类器官发育的转录组和代谢组学分析表明，磷脂酰乙醇胺生物合成途径对早期肝脏发育至关重要。出乎意料的是，早期的肝前体细胞对美克洛嗪的细胞毒性作用特别敏感。我们证明，美克洛嗪可被重新用于原发性肝癌的新协同联合治疗：一种糖酵解抑制剂重新编程癌细胞代谢，使其易受美克洛嗪的细胞毒性作用影响。这种组合在体外和异种移植模型中抑制了人肝癌细胞系的生长，而没有引起明显的副作用。这种药物组合对急性髓性白血病细胞也具有高度活性。
我们的数据表明，磷脂酰乙醇胺生物合成是一种可靶向的癌症途径；当用作新联合治疗的一部分时，美克洛嗪可能具有作为重新定位的抗癌药物的临床疗效。
使用人类肝类器官模拟人类肝脏的早期发育阶段。我们确定了一个对早期肝脏发育至关重要的途径。基于这一发现，确定了一种新的联合药物治疗方法，可用于治疗原发性肝癌，可能还有其他类型的癌症。
