High expression of Fibroblast activation protein (FAP) predicts poor outcome in high-grade serous ovarian cancer
Abstract Background High-grade serous ovarian cancer (HSOC) is a fatal form of ovarian cancer. Previous studies indicated some potential biomarkers for clinical evaluation of HSOC prognosis. However, there is a lack of systematic analysis of different expression genes (DEGs) to screen and detect significant biomarkers of HSOC. Method and materials: TCGA database was conducted to analyze relevant genes expression in HSOC. Outcomes of candidate genes expression, including overall survival (OS) and progression-free survival (PFS), were calculated by Cox regression analysis for hazard rates (HR). Histopathological investigation of the identified genes was carried out in 32 Chinese HSOC patients to validate gene expression in different stages of HSOC. Results Of all 57,331 genes that were analyzed, FAP was identified as the only novel gene that significantly contributed to both OS and PFS of HSOC. In addition, FAP had a consistent expression profile between carcinoma-paracarcinoma and early-advanced stages of HSOC. Immunological tests in paraffin section also confirmed that up-regulation of FAP was present in advanced stage HSOC patients. Prediction of FAP network association suggested that FN1 could be a potential downstream gene which further influenced HSOC survival. Conclusions High-level expression of FAP was associated with poor prognosis of HSOC via FN1 pathway.