Ding Hongda, Liu Junpeng, Wang Caibin, Su Yang
Department of General Surgery, Shengjing Hospital of China Medical University, No. 36 Sanhao Road, Shenyang, 110004 China.
Cancer Cell Int. 2020 Aug 31;20:425. doi: 10.1186/s12935-020-01520-4. eCollection 2020.
Dysregulation of fatty acid (FA) metabolism is involved in hepatocellular carcinoma (HCC) development. Non-POU domain-containing octamer binding protein (NONO), known as the component of nuclear paraspeckles, has recently been found to promote HCC progression. In this study, we investigated the functions of NONO in regulating de novo FA synthesis and its underling mechanism during HCC development.
The roles of NONO in HCC development by applying gene function loss analysis in HCC cells were detected by quantitative real-time polymerase chain reaction, cell proliferation, and cell invasion assays. The underlying mechanism of NONO in HCC development was examined by western blotting, subcellular fractionation, RNA-binding protein immunoprecipitation-sequencing, chromatin immunoprecipitation, co-immunoprecipitation and mass spectrometry. The effect of NONO on tumorigenesis in vivo was performed with a subcutaneous xenograft mouse model of HCC.
NONO promotes HCC progression by interacting with and increasing ATP-citrate lyase (ACLY) mRNA to enhance FA biosynthesis. Furthermore, NONO promotes ACLY expression through enhancing nuclear ACLY mRNA stability in Diethylnitrosamine-stimulated HCC cells, not related to nuclear paraspeckles. Moreover, we find that NONO/SFPQ (Splicing factor proline and glutamine rich) heterodimer is essential for NONO interacting with ACLY mRNA in DEN stimulated HCC cells. In addition, NONO, Insulin like growth factor 2 mRNA binding protein 1 (IGF2BP1) and ACLY expressions contribute HCC development in mice and are related to poor survival.
NONO promotes HCC progression by enhancing FA biosynthesis through interacting with ACLY mRNA and provide a novel potential target for HCC therapy.
脂肪酸（FA）代谢失调与肝细胞癌（HCC）的发生发展有关。含非POU结构域的八聚体结合蛋白（NONO），作为核旁斑的组成成分，最近被发现可促进HCC进展。在本研究中，我们调查了NONO在HCC发生发展过程中调节从头合成FA的功能及其潜在机制。
通过定量实时聚合酶链反应、细胞增殖和细胞侵袭实验，应用基因功能缺失分析检测NONO在HCC细胞中对HCC发生发展的作用。通过蛋白质免疫印迹、亚细胞分级分离、RNA结合蛋白免疫沉淀测序、染色质免疫沉淀、免疫共沉淀和质谱分析，研究NONO在HCC发生发展中的潜在机制。利用HCC皮下异种移植小鼠模型，研究NONO对体内肿瘤发生的影响。
NONO通过与ATP柠檬酸裂解酶（ACLY）mRNA相互作用并增加其表达，促进FA生物合成，从而促进HCC进展。此外，在二乙基亚硝胺刺激的HCC细胞中，NONO通过增强核ACLY mRNA稳定性促进ACLY表达，这与核旁斑无关。而且，我们发现NONO/SFPQ（富含脯氨酸和谷氨酰胺的剪接因子）异二聚体对于DEN刺激的HCC细胞中NONO与ACLY mRNA相互作用至关重要。此外，NONO、胰岛素样生长因子2 mRNA结合蛋白1（IGF2BP1）和ACLY的表达促进小鼠HCC的发展，且与较差的生存率相关。
NONO通过与ACLY mRNA相互作用增强FA生物合成，促进HCC进展，并为HCC治疗提供了一个新的潜在靶点。
