Background: To identify potential therapeutic target in clear cell renal cell carcinoma (ccRCC), we performed a transcriptome analysis. Our analysis showed that fatty acid binding protein 7 (FABP7) has the highest mean differential overexpression in ccRCC compared to normal kidney. We aimed to investigate the significance of FABP7 in ccRCC.
Methods: Immunohistochemical staining for 40 advanced ccRCC cases was performed to investigate correlation between clinicopathological parameters and FABP7. They were composed of 40-83 years old cases with 33 male, 22 cases with pT ≥ 3, 19 cases with M1, and 16 cases with grade 3. The effect of gene knockdown was analysed by a cell viability assay and invasion assay in FABP7-overexpressing cell lines (SKRC7 and SKRC10).
Results: Our immunohistochemical analysis showed that higher FABP7 expression significantly correlated with distant metastasis and poor cancer-specific survival (CSS; both p < 0.05). Functional suppression of FABP7 significantly inhibited SKRC10 cell growth (p < 0.05) and resulted in a significant reduction of the invasive potential (p < 0.01), but did not cause growth inhibition of SKRC7 cells. We found that The Cancer Genome Atlas Research Network (TCGA) database shows FABP6 and 7 as equally overexpressed in the FABP family. Functional suppression of fatty acid binding protein 6 (FABP6) resulted in significant growth inhibition of SKRC7 cells (p < 0.005).
Conclusions: Functional suppression of FABP7 significantly reduced cell viability and invasive potential in a ccRCC cell line. FABP7 may play a role in progression in some metastatic ccRCCs. The suppressed function may be compensated by another FABP family member.
Keywords: Clear cell renal cell carcinoma; Fatty acid binding protein 6; Fatty acid binding protein 7; Prognostic marker; Therapeutic target.