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Xu L, Xiang W, Yang J, Gao J, Wang X, Meng L, Ye K, Zhao XH, Zhang XD, Jin L, Ye Y. PHB2 promotes SHIP2 ubiquitination via the E3 ligase NEDD4 to regulate AKT signaling in gastric cancer. J Exp Clin Cancer Res 2024; 43:17. [PMID: 38200519 PMCID: PMC10782615 DOI: 10.1186/s13046-023-02937-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND Prohibitin 2 (PHB2) exhibits opposite functions of promoting or inhibiting tumour across various cancer types. In this study, we aim to investigate its functions and underlying mechanisms in the context of gastric cancer (GC). METHODS PHB2 protein expression levels in GC and normal tissues were examined using western blot and immunohistochemistry. PHB2 expression level associations with patient outcomes were examined through Kaplan-Meier plotter analysis utilizing GEO datasets (GSE14210 and GSE29272). The biological role of PHB2 and its subsequent regulatory mechanisms were elucidated in vitro and in vivo. GC cell viability and proliferation were assessed using MTT cell viability analysis, clonogenic assays, and BrdU incorporation assays, while the growth of GC xenografted tumours was measured via IHC staining of Ki67. The interaction among PHB2 and SHIP2, as well as between SHIP2 and NEDD4, was identified through co-immunoprecipitation, GST pull-down assays, and deletion-mapping experiments. SHIP2 ubiquitination and degradation were assessed using cycloheximide treatment, plasmid transfection and co-immunoprecipitation, followed by western blot analysis. RESULTS Our analysis revealed a substantial increase in PHB2 expression in GC tissues compared to adjacent normal tissues. Notably, higher PHB2 levels correlated with poorer patient outcomes, suggesting its clinical relevance. Functionally, silencing PHB2 in GC cells significantly reduced cell proliferation and retarded GC tumour growth, whereas overexpression of PHB2 further enhanced GC cell proliferation. Mechanistically, PHB2 physically interacted with Src homology 2-containing inositol 5-phosphatase 2 (SHIP2) in the cytoplasm of GC cells, thus leading to SHIP2 degradation via its novel E3 ligase NEDD4. It subsequently activated the PI3K/Akt signaling pathway and thus promoted GC cell proliferation. CONCLUSIONS Our findings highlight the importance of PHB2 upregulation in driving GC progression and its association with adverse patient outcomes. Understanding the functional impact of PHB2 on GC growth contributes valuable insights into the molecular underpinnings of GC and may pave the way for the development of targeted therapies to improve patient outcomes.
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Affiliation(s)
- Liang Xu
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, Newcastle, NSW, 2308, Australia
| | - Wanying Xiang
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Jiezhen Yang
- Department of Pathology, Zhongshan Hospital (Xiamen Branch), Fudan University, Xiamen, 361015, China
| | - Jing Gao
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Xinyue Wang
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Li Meng
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China
| | - Kaihong Ye
- Translational Research Institute, Henan Provincial and Zhengzhou City Key Laboratory of Non-Coding RNA and Cancer Metabolism, Henan International Join Laboratory of Non-Coding RNA and Metabolism in Cancer, Henan Provincial People's Hospital, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450053, Henan, China
| | - Xiao Hong Zhao
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, Newcastle, NSW, 2308, Australia
| | - Xu Dong Zhang
- School of Biomedical Sciences and Pharmacy, The University of Newcastle, Newcastle, NSW, 2308, Australia.
- Translational Research Institute, Henan Provincial and Zhengzhou City Key Laboratory of Non-Coding RNA and Cancer Metabolism, Henan International Join Laboratory of Non-Coding RNA and Metabolism in Cancer, Henan Provincial People's Hospital, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450053, Henan, China.
| | - Lei Jin
- Translational Research Institute, Henan Provincial and Zhengzhou City Key Laboratory of Non-Coding RNA and Cancer Metabolism, Henan International Join Laboratory of Non-Coding RNA and Metabolism in Cancer, Henan Provincial People's Hospital, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, 450053, Henan, China.
- School of Medicine and Public Health, The University of Newcastle, Newcastle, NSW, 2308, Australia.
| | - Yan Ye
- Department of Immunology, School of Basic Medical Sciences, Anhui Medical University, Hefei, 230032, Anhui, China.
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Structural Insights into the Binding Propensity of Human SHIP2 SH2 to Oncogenic CagA Isoforms from Helicobacter pylori. Int J Mol Sci 2022; 23:ijms231911299. [PMID: 36232599 PMCID: PMC9569640 DOI: 10.3390/ijms231911299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/20/2022] [Accepted: 09/20/2022] [Indexed: 11/30/2022] Open
Abstract
SHIP2 is a multi-domain inositol 5-phosphatase binding to a variety of phosphotyrosine (pY)-containing proteins through its SH2 domain, so as to regulate various cell signaling pathways by modulating the phosphatidylinositol level in the plasma membrane. Unfavorably, Helicobacter pylori can hijack SHIP2 through the CagA protein to induce gastric cell carcinogenesis. To date, the interaction between SHIP2 and CagA was not analyzed from a structural point of view. Here, the binding of SHIP2-SH2 with Tyr-phosphorylated peptides from four EPIYA motifs (A/B/C/D) in CagA was studied using NMR spectroscopy. The results showed that EPIYA-C and -D bind to a similar interface of SHIP2-SH2, including a pY-binding pocket and a hydrophobic pocket, to achieve high affinity, while EPIYA-A and -B bind to a smaller interface of SHIP2-SH2 with weak affinity. By summarizing the interface and affinity of SHIP2-SH2 for CagA EPIYA-A/B/C/D, c-MET and FcgR2B ITIM, it was proposed that, potentially, SHIP2-SH2 has a selective preference for L > I > V for the aliphatic residues at the pY+3 position in its ligand. This study reveals the rule of the ligand sequence bound by SHIP2-SH2 and the mechanism by which CagA protein hijacks SHIP2, which will help design a peptide inhibitor against SHIP2-SH2.
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