SPP1 is a prognostic related biomarker and correlated with tumor-infiltrating immune cells in ovarian cancer

Background: Secreted phosphoprotein 1 (SPP1) plays a vital role in tumor progression of multiple cancer types However, it still awaits further exploration whether SPP1 is a bystander or an actual player in the modulation of immune infiltration in ovarian cancer. Methods: In this study, the expression level of SPP1 was identified by Oncomine, GEPIA and TIMER databases, and the result of SPP1 immumohistochemical staining was acquired by The HPA database. The impact of SPP1 expression level on the clinical outcome of ovarian cancer patients were evaluated via Kaplan-Meier Plotter and PrognoScan dataset. Immune infiltration analyses were conducted using TIMER and TISIDB dataset. In addition, Functional enrichment analyses were performed with Metascape and GeneMANIA database. To verify these findings from the public database, the results were validated in a cohort of ovarian cancer patients. Results: SPP1 was found to be overexpressed in ovarian tumor tissues and high SPP1 expression was correlated with shorter survivals. Notably, SPP1 expression was positively correlated with infiltrating levels of CD4 + T cells, CD8 + T cells, macrophages, neutrophils, and dendritic cells. Furthermore, SPP1 expression level showed strong correlation with diverse immune cells in ovarian cancer. Of note, functional enrichment analysis suggested that SPP1 was strongly correlated with immune response. Conclusions: These findings imply that SPP1 is correlated with prognosis and immune cell infiltrating, offering a new potential immunotherapeutic target in ovarian cancer.