PHB2 promotes SHIP2 ubiquitination via the E3 ligase NEDD4 to regulate AKT signaling in gastric cancer

作者：Liang Xu, Wanying Xiang, Jiezhen Yang, Jing Gao, Xinyue Wang, Meng Li, Kaihong Ye, Xiao Hong Zhao, Xu Dong Zhang, Lei Jin, Yan Ye · 发表于：Journal of Experimental & Clinical Cancer Research · 年份：2024 · DOI：10.1186/s13046-023-02937-1 · 被引用次数：12 · 研究领域：Ubiquitin and proteasome pathways、Nuclear Structure and Function、RNA Research and Splicing

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...