O-GlcNAc 转移酶通过对真核起始因子 4E 的 O-GlcNAc 化激活肝癌中的干细胞样细胞潜能。
O-GlcNAc transferase activates stem-like cell potential in hepatocarcinoma through O-GlcNAcylation of eukaryotic initiation factor 4E.
机构信息
Key Laboratory of Glycoconjuates Research, Ministry of Public Health, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan, Shanghai, People's Republic of China.
Department of Liver Surgery and Transplantation, Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory of Carcinogenesis and Cancer Invasion of Ministry of Education, Shanghai, People's Republic of China.
出版信息
J Cell Mol Med. 2019 Apr;23(4):2384-2398. doi: 10.1111/jcmm.14043. Epub 2019 Jan 24.
O-GlcNAcylation catalysed by O-GlcNAc transferase (OGT) is a reversible post-translational modification. O-GlcNAcylation participates in transcription, epigenetic regulation, and intracellular signalling. Dysregulation of O-GlcNAcylation in response to high glucose or OGT expression has been implicated in metabolic diseases and cancer. However, the underlying mechanisms by which OGT regulates hepatoma development remain largely unknown. Here, we employed the lentiviral shRNA-based system to knockdown OGT to analyse the contribution of OGT in hepatoma cell proliferation and stem-like cell potential. The sphere-forming assay and western blot analysis of stem-related gene expression were used to evaluate stem-like cell potential of hepatoma cell. We found that the level of total O-GlcNAcylation or OGT protein was increased in hepatocellular carcinoma. OGT activated stem-like cell potential in hepatoma through eukaryotic initiation factor 4E (eIF4E) which bound to stem-related gene Sox2 5'-untranslated region. O-GlcNAcylation of eIF4E at threonine 168 and threonine 177 protected it from degradation through proteasome pathway. Expression of eIF4E in hepatoma was determined by immunostaining in 232 HCC patients, and Kaplan-Meier survival analysis was used to determine the correlation of eIF4E expression with prognosis. High glucose promoted stem-like cell potential of hepatoma cell through OGT-eIF4E axis. Collectively, our findings indicate that OGT promotes the stem-like cell potential of hepatoma cell through O-GlcNAcylation of eIF4E. These results provide a mechanism of HCC development and a cue between the pathogenesis of HCC and high glucose condition.
O-GlcNAc 转移酶 (OGT) 催化的 O-GlcNAc 酰化是一种可逆的翻译后修饰。O-GlcNAc 酰化参与转录、表观遗传调控和细胞内信号转导。高糖或 OGT 表达引起的 O-GlcNAc 酰化失调与代谢疾病和癌症有关。然而,OGT 调节肝癌发展的潜在机制在很大程度上仍不清楚。在这里,我们使用基于慢病毒 shRNA 的系统敲低 OGT,以分析 OGT 在肝癌细胞增殖和干细胞样细胞潜能中的作用。采用球体形成实验和 Western blot 分析干细胞相关基因表达来评估肝癌细胞的干细胞样细胞潜能。我们发现,肝细胞癌中总 O-GlcNAc 酰化或 OGT 蛋白水平增加。OGT 通过真核起始因子 4E(eIF4E)激活肝癌中的干细胞样细胞潜能,eIF4E 结合于干细胞相关基因 Sox2 的 5'非翻译区。O-GlcNAc 化的 eIF4E 在苏氨酸 168 和苏氨酸 177 位通过蛋白酶体途径保护其免受降解。通过对 232 例 HCC 患者的免疫染色检测肝癌中的 eIF4E 表达,并进行 Kaplan-Meier 生存分析以确定 eIF4E 表达与预后的相关性。高糖通过 OGT-eIF4E 轴促进肝癌细胞的干细胞样细胞潜能。总之,我们的研究结果表明,OGT 通过 O-GlcNAc 化的 eIF4E 促进肝癌细胞的干细胞样细胞潜能。这些结果为 HCC 的发展机制以及 HCC 的发病机制与高糖条件之间的联系提供了依据。