Silencing of PIGU inhibits the progression of esophageal squamous cell carcinoma through the PI3K/AKT signaling pathway

Abstract

Abstract Phosphatidylinositol glycan anchor biosynthesis class U (PIGU), a crucial subunit of the glycosylphosphatidylinositol transamidase (GPI-T) complex, is an oncogene in hepatocellular carcinoma. However, its role in esophageal squamous cell carcinoma (ESCC) remains poorly understood. This study aims to clarify PIGU’s role and mechanisms in ESCC by analyzing its expression across pan-cancer datasets, clinical relevance in TCGA-ESCA samples, and effects on cell behavior (migration, invasion, proliferation) and signaling pathways, validated via immunohistochemistry. To examine cell behavior, we used Transwell, colony-formation, CCK-8, and wound-healing assays to assess migration, invasion, proliferation, and wound healing.The epithelial-mesenchymal transition marker levels were measured using Western blot analysis, and the cell cycle and apoptosis were assessed using flow cytometry in conjunction with western blotting. Furthermore, we used western blotting to examine proteins implicated in the PI3K/AKT signaling pathway.To further confirm PIGU’s role in ESCC progression, a subcutaneous xenograft mouse model was employed. Our findings suggest that PIGU is highly expressed in ESCC and is strongly associated with tumor growth, lymphatic metastasis and poor prognosis, and is an independent prognostic factor for ESCC patients.PIGU knockdown not only arrested the cell cycle and induced apoptosis, but also significantly reduced migration, invasion, and proliferation in ESCC cells. Additionally, vimentin and N-cadherin were downregulated when PIGU expression was silenced, although E-cadherin expression was simultaneously increased.Moreover, PIGU knockdown decreased the amount of phosphorylated Akt and PI3K. In vivo, PIGU knockdown inhibited ESCC cell proliferation and promoted apoptosis. These findings imply that targeting PIGU may represent a promising therapeutic approach, and that PIGU could potentially serve as both a diagnostic and prognostic biomarker for esophageal squamous cell carcinoma (ESCC).

Keywords

• PIGU
• Esophageal squamous cell carcinoma
• PI3K/AKT
• Cell cycle
• Apoptosis