Secreted phosphoprotein 1 is associated with epithelial cell proliferation and PI3K/AKT signalling in sinonasal...

Sinonasal inverted papilloma is a locally aggressive epithelial lesion with a relatively high recurrence rate, yet the molecular basis of its proliferative behaviour remains incompletely understood. This study investigated the clinical relevance of secreted phosphoprotein 1 in sinonasal inverted papilloma and its association with epithelial cell proliferation and related signalling pathways.

Differentially expressed genes were identified from the GSE193016 dataset, followed by gene set enrichment analysis. The expression of secreted phosphoprotein 1 and the cell cycle-related molecules cell division cycle 25C and cyclin A2 in clinical specimens was assessed using quantitative PCR, Western blotting, and immunohistochemistry. Associations between secreted phosphoprotein 1 expression and postoperative recurrence were assessed based on follow-up data. In vitro experiments using human nasal epithelial cells were conducted to examine the effects of altered secreted phosphoprotein 1 expression on cell proliferation-associated phenotypes, and pathway inhibition assays were performed to investigate the involvement of the PI3K/AKT signalling pathway.

Secreted phosphoprotein 1 expression was significantly upregulated in sinonasal inverted papilloma tissues, with higher levels observed in advanced-stage cases (T3-T4), and was associated with postoperative recurrence. The expression of the cell cycle-related molecules cell division cycle 25C and cyclin A2, positively correlated with secreted phosphoprotein 1 expression and increased with disease progression. In vitro epithelial cell models demonstrated that modulation of secreted phosphoprotein 1 expression was accompanied by corresponding changes in cellular proliferative capacity and cell cycle-related protein expression. Pathway inhibition assays further suggested that PI3K/AKT signalling may be involved in secreted phosphoprotein 1-associated alterations in cell cycle regulation.

These findings indicate that secreted phosphoprotein 1 is highly expressed in sinonasal inverted papilloma and may be associated with epithelial cell proliferation and PI3K/AKT signalling. In addition, secreted phosphoprotein 1 expression correlates with disease recurrence, highlighting its potential research value as a biological marker, while the underlying mechanisms warrant further investigation.