{"title":"Cellular gp96 upregulates AFP expression by blocking NR5A2 SUMOylation and ubiquitination in hepatocellular carcinoma.","authors":"Liyuan Qian, Zhentao Liang, Zihao Wang, Jiuru Wang, Xin Li, Jingmin Zhao, Zihai Li, Lizhao Chen, Yongai Liu, Ying Ju, Changfei Li, Songdong Meng","doi":"10.1093/jmcb/mjad027","DOIUrl":null,"url":null,"abstract":"<p><p>Alpha-fetoprotein (AFP) is the most widely used biomarker for the diagnosis of hepatocellular carcinoma (HCC). However, a substantial proportion of HCC patients have either normal or marginally increased AFP levels in serum, and the underlying mechanisms are not fully understood. In the present study, we provided in vitro and in vivo evidence that heat shock protein gp96 promoted AFP expression at the transcriptional level in HCC. NR5A2 was identified as a key transcription factor for the AFP gene, and its stability was enhanced by gp96. A further mechanistic study by co-immunoprecipitation, GST pull-down, and molecular docking showed gp96 and the SUMO E3 ligase RanBP2 competitively binding to NR5A2 at the sites spanning from aa 507 to aa 539. The binding of gp96 inhibited SUMOylation, ubiquitination, and subsequent degradation of NR5A2. In addition, clinical analysis of HCC patients indicated that gp96 expression in tumors was positively correlated with serum AFP levels. Therefore, our study uncovered a novel mechanism that gp96 regulates the stability of its client proteins by directly affecting their SUMOylation and ubiquitination. These findings will help in designing more accurate AFP-based HCC diagnosis and progression monitoring approaches.</p>","PeriodicalId":16433,"journal":{"name":"Journal of Molecular Cell Biology","volume":" ","pages":""},"PeriodicalIF":5.3000,"publicationDate":"2023-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular Cell Biology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1093/jmcb/mjad027","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Alpha-fetoprotein (AFP) is the most widely used biomarker for the diagnosis of hepatocellular carcinoma (HCC). However, a substantial proportion of HCC patients have either normal or marginally increased AFP levels in serum, and the underlying mechanisms are not fully understood. In the present study, we provided in vitro and in vivo evidence that heat shock protein gp96 promoted AFP expression at the transcriptional level in HCC. NR5A2 was identified as a key transcription factor for the AFP gene, and its stability was enhanced by gp96. A further mechanistic study by co-immunoprecipitation, GST pull-down, and molecular docking showed gp96 and the SUMO E3 ligase RanBP2 competitively binding to NR5A2 at the sites spanning from aa 507 to aa 539. The binding of gp96 inhibited SUMOylation, ubiquitination, and subsequent degradation of NR5A2. In addition, clinical analysis of HCC patients indicated that gp96 expression in tumors was positively correlated with serum AFP levels. Therefore, our study uncovered a novel mechanism that gp96 regulates the stability of its client proteins by directly affecting their SUMOylation and ubiquitination. These findings will help in designing more accurate AFP-based HCC diagnosis and progression monitoring approaches.
期刊介绍:
The Journal of Molecular Cell Biology ( JMCB ) is a full open access, peer-reviewed online journal interested in inter-disciplinary studies at the cross-sections between molecular and cell biology as well as other disciplines of life sciences. The broad scope of JMCB reflects the merging of these life science disciplines such as stem cell research, signaling, genetics, epigenetics, genomics, development, immunology, cancer biology, molecular pathogenesis, neuroscience, and systems biology. The journal will publish primary research papers with findings of unusual significance and broad scientific interest. Review articles, letters and commentary on timely issues are also welcome.
JMCB features an outstanding Editorial Board, which will serve as scientific advisors to the journal and provide strategic guidance for the development of the journal. By selecting only the best papers for publication, JMCB will provide a first rate publishing forum for scientists all over the world.