Role of the angiogenic components, VEGFA, FGF2, OPN and RHOC, in urothelial cell carcinoma of the urinary bladder

Abstract

The objective of this study was to analyze the expression profile of the angiogenic components, vascular endothelial growth factor-A (VEGFA), basic fibroblast growth factor-2 (FGF2), osteopontin (OPN) and ras homolog gene family, member C (RHOC), in urothelial cell carcinoma (UCC) of the urinary bladder and to examine their role as candidate diagnostic biomarkers. Using qPCR, 77samples of UCC of the urinary bladder and 77 matched tumor-associated normal samples were investigated to determine the expression of the four angiogenic components. The correlation between gene expression, patient survival and pathological features of the tumors was also examined. The VEGFA and OPN transcript levels were greater in the bladder cancer tissue than in the normal urothelium (P<0.001). Patients with higher VEGFA mRNA levels showed a tendency towards shorter cancer-specific survival. OPN levels showed a gradual increase, the lowest levels being found in non-invasive carcinoma and the highest in muscle invasive tumors. Elevated OPN levels indicated poor prognosis in connection with advanced disease stage (P<0.001). Both superficially invasive and muscle invasive tumors had significantly higher FGF2 levels compared to the control tissues (P=0.018 and P=0.050, respectively). Moreover, FGF2 was significantly higher in the metastatic vs. the non-metastatic tumors (P=0.0097). FGF2 levels exhibited a trend towards a correlation with worse patient survival. RHOC mRNA levels were higher in muscle invasive compared to superficially invasive tumors, as well as in gradeIII vs. gradeI/II tumors. Furthermore, we detected worse overall survival for patients with high RHOC expression levels. VEGFA and FGF2 exhibited the best linear combination in the ROC curves for specificity and sensitivity. Thus, VEGFA and FGF2 may serve as candidate biomarkers for diagnostic purposes. Higher OPN expression may be used as a potential biomarker to predict patient survival relative to advanced tumor stage. However, further studies are required to investigate its role in urinary bladder carcinogenesis.