{"title":"Cholesterol suppresses AMFR-mediated PDL1 ubiquitination and degradation in HCC.","authors":"Wei-Qing Shao, Yi-Tong Li, Xu Zhou, Sheng-Guo Zhang, Ming-Hao Fan, Dong Zhang, Zhen-Mei Chen, Chen-He Yi, Sheng-Hao Wang, Wen-Wei Zhu, Ming Lu, Ji-Song Chen, Jing Lin, Yu Zhou","doi":"10.1007/s11010-024-05106-w","DOIUrl":null,"url":null,"abstract":"<p><p>The degradation of proteasomes or lysosomes is emerging as a principal determinant of programmed death ligand 1 (PDL1) expression, which affects the efficacy of immunotherapy in various malignancies. Intracellular cholesterol plays a central role in maintaining the expression of membrane receptors; however, the specific effect of cholesterol on PDL1 expression in cancer cells remains poorly understood. Cholesterol starvation and stimulation were used to modulate the cellular cholesterol levels. Immunohistochemistry and western blotting were used to analyze the protein levels in the samples and cells. Quantitative real-time PCR, co-immunoprecipitation, and confocal co-localization assays were used for mechanistic investigation. A xenograft tumor model was constructed to verify these results in vivo. Our results showed that cholesterol suppressed the ubiquitination and degradation of PDL1 in hepatocellular carcinoma (HCC) cells. Further mechanistic studies revealed that the autocrine motility factor receptor (AMFR) is an E3 ligase that mediated the ubiquitination and degradation of PDL1, which was regulated by the cholesterol/p38 mitogenic activated protein kinase axis. Moreover, lowering cholesterol levels using statins improved the efficacy of programmed death 1 (PD1) inhibition in vivo. Our findings indicate that cholesterol serves as a signal to inhibit AMFR-mediated ubiquitination and degradation of PDL1 and suggest that lowering cholesterol by statins may be a promising combination strategy to improve the efficiency of PD1 inhibition in HCC.</p>","PeriodicalId":18724,"journal":{"name":"Molecular and Cellular Biochemistry","volume":" ","pages":"1807-1818"},"PeriodicalIF":3.5000,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11842428/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Molecular and Cellular Biochemistry","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1007/s11010-024-05106-w","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/9/4 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"CELL BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The degradation of proteasomes or lysosomes is emerging as a principal determinant of programmed death ligand 1 (PDL1) expression, which affects the efficacy of immunotherapy in various malignancies. Intracellular cholesterol plays a central role in maintaining the expression of membrane receptors; however, the specific effect of cholesterol on PDL1 expression in cancer cells remains poorly understood. Cholesterol starvation and stimulation were used to modulate the cellular cholesterol levels. Immunohistochemistry and western blotting were used to analyze the protein levels in the samples and cells. Quantitative real-time PCR, co-immunoprecipitation, and confocal co-localization assays were used for mechanistic investigation. A xenograft tumor model was constructed to verify these results in vivo. Our results showed that cholesterol suppressed the ubiquitination and degradation of PDL1 in hepatocellular carcinoma (HCC) cells. Further mechanistic studies revealed that the autocrine motility factor receptor (AMFR) is an E3 ligase that mediated the ubiquitination and degradation of PDL1, which was regulated by the cholesterol/p38 mitogenic activated protein kinase axis. Moreover, lowering cholesterol levels using statins improved the efficacy of programmed death 1 (PD1) inhibition in vivo. Our findings indicate that cholesterol serves as a signal to inhibit AMFR-mediated ubiquitination and degradation of PDL1 and suggest that lowering cholesterol by statins may be a promising combination strategy to improve the efficiency of PD1 inhibition in HCC.
期刊介绍:
Molecular and Cellular Biochemistry: An International Journal for Chemical Biology in Health and Disease publishes original research papers and short communications in all areas of the biochemical sciences, emphasizing novel findings relevant to the biochemical basis of cellular function and disease processes, as well as the mechanics of action of hormones and chemical agents. Coverage includes membrane transport, receptor mechanism, immune response, secretory processes, and cytoskeletal function, as well as biochemical structure-function relationships in the cell.
In addition to the reports of original research, the journal publishes state of the art reviews. Specific subjects covered by Molecular and Cellular Biochemistry include cellular metabolism, cellular pathophysiology, enzymology, ion transport, lipid biochemistry, membrane biochemistry, molecular biology, nuclear structure and function, and protein chemistry.