E3 ligase ZFP91 inhibits Hepatocellular Carcinoma Metabolism Reprogramming by regulating PKM splicing
E3 ligase ZFP91 inhibits Hepatocellular Carcinoma Metabolism Reprogramming by regulating PKM splicing
复制标题
E3连接酶ZFP91通过调节PKM剪接抑制肝细胞癌代谢重编程
DOI：
10.7150/thno.44873
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发表时间：
2020-01-01
期刊：
影响因子：
12.4
通讯作者：
Yan, Guang-Rong
中科院分区：
文献类型：
--
作者：
Chen, De;Wang, Yanjie;Yan, Guang-Rong
理由：肝细胞癌（HCC）是最致命的癌症之一，很少有分子靶向抗癌疗法被开发出来治疗它。因此，寻找新的治疗靶点迫在眉睫。代谢重编程是癌症的一个重要标志。然而，对于泛素连接酶是如何参与肿瘤代谢调控的，我们仍然知之甚少。方法：采用RT-PCR、western blot和免疫组化法检测ZFP91的表达。采用RNAi、细胞增殖、集落形成和transwell检测ZFP91的体外功能。采用小鼠异种移植模型研究ZFP91在体内的作用。利用Co-IP联合质谱或western blot来研究蛋白质之间的相互作用。用免疫印迹法和western blot分析泛素化。采用RT-PCR和限制性酶切法评估RNA剪接。乳酸生成和葡萄糖摄取测定用于分析肿瘤代谢。结果：我们发现E3连接酶锌指蛋白91 （ZFP91）在体外和体内抑制HCC代谢重编程、细胞增殖和转移。在机制上，ZFP91促进lys48相关的癌蛋白hnRNP A1在赖氨酸8和蛋白酶体降解处的泛素化，从而抑制hnRNP A1依赖的PKM剪接，从而导致PKM1异构体形成增加，PKM2异构体形成降低，抑制HCC糖代谢重编程、细胞增殖和转移。此外，ZFP91水平较低的HCC患者预后较差，ZFP91是HCC患者的独立预后因素。结论：我们的研究确定ZFP91是肝癌发生和HCC代谢重编程的抑癌因子，并提出其作为HCC预后的新生物标志物和治疗靶点。
Rationale: Hepatocellular carcinoma (HCC) is one of the most lethal cancers, and few molecularly targeted anticancer therapies have been developed to treat it. Thus, the identification of new therapeutic targets is urgent. Metabolic reprogramming is an important hallmark of cancer. However, how ubiquitin ligases are involved in the regulation of cancer metabolism remains poorly understood. Methods: RT-PCR, western blot and IHC were used to determine ZFP91 expression. RNAi, cell proliferation, colony formation and transwell assays were used to determine the in vitro functions of ZFP91. Mouse xenograft models were used to study the in vivo effects of ZFP91. Co-IP together with mass spectrometry or western blot was utilized to investigate protein-protein interaction. Ubiquitination was analyzed using IP together with western blot. RNA splicing was assessed by using RT-PCR followed by restriction digestion. Lactate production and glucose uptake assays were used to analyze cancer metabolism. Results: We identified that an E3 ligase zinc finger protein 91 (ZFP91) suppressed HCC metabolic reprogramming, cell proliferation and metastasis in vitro and in vivo. Mechanistically, ZFP91 promoted the Lys48-linked ubiquitination of the oncoprotein hnRNP A1 at lysine 8 and proteasomal degradation, thereby inhibiting hnRNP A1-dependent PKM splicing, subsequently resulting in higher PKM1 isoform formation and lower PKM2 isoform formation and suppressing HCC glucose metabolism reprogramming, cell proliferation and metastasis. Moreover, HCC patients with lower levels of ZFP91 have poorer prognoses, and ZFP91 is an independent prognostic factor for patients with HCC. Conclusions: Our study identifies ZFP91 as a tumor suppressor of hepatocarcinogenesis and HCC metabolism reprogramming and proposes it as a novel prognostic biomarker and therapeutic target of HCC.