RNA-sequencing of alpha beta hydrolase domain 6 (ABHD6) wild type (WT) versus knockout (KO) Huh7 hepatoma cells with or without palmitic acid treatment.

Primary liver cancer accounts for approximately 700,000 deaths worldwide annually ranking third in cancer-related mortality, with hepatocellular carcinoma (HCC) comprising the great majority of these tumors. Recently there has been an emphasis on the role of metabolic syndrome in the development of cirrhosis and HCC, as non-alcoholic fatty liver disease (NAFLD) is currently a leading cause of HCC in the United States. We previously identified the lipid hydrolase alpha/beta hydrolase domain 6 (ABHD6) as a key mediator of the development of metabolic syndrome and intimately involved in cell signaling, making it a prime target for investigation in NAFLD-related HCC. ABHD6 displays higher expression within HCC tumor cores when compared to adjacent non-tumor tissue in human subjects. Using an in vivo antisense oligonucleotide (ASO)-driven knockdown approach, we have shown the inhibition of ABHD6 prevents the development and progression of HCC in an obesity/NAFLD-driven mouse model. Additionally, a xenograft model of using the human Huh7 cell line displayed reduced tumor engraftment and growth with ABHD6 genetic deletion and small molecule inhibition. ABHD6 knockout cells demonstrated increased levels of bis(monoacylglycerol)phosphates (BMPs), lipids relevant to high fat diet-induced lysosomal dysfunction, and knockout cells also demonstrated altered autophagy and lysosomal activity using in vitro model of saturated fatty acid-induced lipotoxicity. These studies reveal novel lipid signaling mechanisms by which NAFLD progresses towards HCC and provide support for ABHD6 as a potential therapeutic target in HCC. RNA from HUH7 WT and ABHD6 KO cells was harvested before (i.e. in basal media) and after 24 and 48 hours of palmitic acid treatment.

原发性肝癌每年在全球造成约70万例死亡，位列癌症相关死亡病因的第三位，其中肝细胞癌（hepatocellular carcinoma, HCC）占此类肿瘤的绝大多数。近年来，代谢综合征在肝硬化与肝细胞癌发生发展中的作用受到学界广泛关注，因为非酒精性脂肪性肝病（non-alcoholic fatty liver disease, NAFLD）目前已是美国肝细胞癌的首要致病因素。我们此前已确认脂质水解酶α/β水解酶结构域6（alpha/beta hydrolase domain 6, ABHD6）是代谢综合征发生发展的关键介质，并深度参与细胞信号转导，使其成为非酒精性脂肪性肝病相关肝细胞癌研究的核心靶点。在人类受试者中，肝细胞癌肿瘤核心区域的ABHD6表达水平高于邻近非肿瘤组织。我们采用体内反义寡核苷酸（antisense oligonucleotide, ASO）介导的基因敲低方法，证实抑制ABHD6可阻止肥胖/非酒精性脂肪性肝病诱导的小鼠模型中肝细胞癌的发生与进展。此外，使用人Huh7细胞系构建的异种移植模型中，ABHD6基因敲除或小分子抑制剂处理可降低肿瘤定植与生长能力。ABHD6敲除细胞在饱和脂肪酸诱导的脂毒性体外模型中，表现为双(单酰甘油)磷酸酯（bis(monoacylglycerol)phosphates, BMPs）水平升高——这类脂质与高脂饮食诱导的溶酶体功能障碍密切相关——同时自噬与溶酶体活性发生改变。本研究揭示了非酒精性脂肪性肝病进展为肝细胞癌的全新脂质信号机制，并支持ABHD6作为肝细胞癌潜在治疗靶点的可能性。研究人员从基础培养基（即未处理状态）及经棕榈酸处理24、48小时的Huh7野生型与ABHD6敲除细胞中提取了RNA。