O-GlcNAcylation participates in initiation of SHH-type medulloblastoma by regulating Rack1 protein stability
10.12354/j.issn.1000-8179.2025.20241573
- VernacularTitle:O-GlcNAcylation通过调节Rack1蛋白稳定性参与SHH型髓母细胞瘤的形成
- Author:
Luo JINGYA
1
;
Gao TANGQING
;
Yang MENGMENG
;
Yang HAIHONG
Author Information
1. 西南交通大学医学院(成都市 610031);中国人民解放军西部战区总医院麻醉科
- Publication Type:Journal Article
- Keywords:
receptor for activated C kinase 1(Rack1);
O-GlcNAcylation;
cell proliferation;
SHH-type medulloblastoma(SHH-MB)
- From:
Chinese Journal of Clinical Oncology
2025;52(2):55-63
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the role of O-GlcNAcylation in the regulation of the stability of receptor for activated C kinase 1(Rack1)during SHH-type medulloblastoma(SHH-MB)initiation.Methods:SHH-MB tumors and adjacent tissues were selected from the clinical tu-mor specimen library of the Department of Pathology at The General Hospital of Western Theater Command.Rack1 expression and O-GlcNAcylation(O-GlcNAc)levels in these tumor tissues were analyzed.The human medulloblastoma cell line Daoy was treated with a glyc-osyltransferase(OGT)inhibitor(OSMI-1)and adeglycosyltransferase(OGA)inhibitor(TM-G),and their impact on tumor cell proliferation was assessed using a Cell Counting Kit-8(CCK-8)and immunofluorescence staining.The O-GlcNAc enzyme labeling system co-immunoprecipita-tion(Co-IP)and Western blot were used to correlate Rack1 protein levels with O-GlcNAc levels.The impact of O-GlcNAcon Rack1 stability was confirmed using cycloheximide(CHX)and ubiquitination modification experiments.In a medulloblastoma mouse model with Rack1 knockdown,tumor cell proliferation was detected using a Cell Counting Kit-8(CCK-8),immunofluorescence staining,and a scratch assay.Xenograft tumors were transplanted into immunodeficient mice and SHH signaling was detected by Western blot in the obtained tissue samples(sh-NC and sh-Rack1)to verify the role of Rack1 protein in SHH-MB.Results:Rack1 and O-GlcNAcylation levels were significantly in-creased in SHH-MB tumor samples,and a negative correlation was observed between Rack1 levels and patient survival rates.Treatment of Daoy cells with OGT and TM-G revealed that O-GlcNAc significantly promotes Daoy cell proliferation,while inhibiting O-GlcNAc impedes tu-mor cell proliferation.Molecular experiments have confirmed that O-GlcNAc modification of Rack1 protein can regulate tumor cell stability,thereby promoting tumor cell proliferation.When Rack1 expression was knocked down in Daoy cells,cell proliferation was significantly re-duced relative to control cells.Accordingly,proliferation was significantly inhibited in tumor tissues with Rack1 protein knockdown in mouse models,suggesting that Rack1 can participate in the initiation of SHH-MB by regulating SHH signaling.Conclusions:O-GlcNAcylation particip-ates in SHH-MB initiation by regulating Rack1 stability.
