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.
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).
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).
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.
BMC cancer. 2018 Nov 15*** epublish ***
Kazuhiro Nagao, Nachi Shinohara, Frank Smit, Mirjam de Weijert, Sander Jannink, Yuji Owada, Peter Mulders, Egbert Oosterwijk, Hideyasu Matsuyama
Department of Urology, Graduate School of Medicine, Yamaguchi University, 1-1-1, Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan. ., Department of Urology, Graduate School of Medicine, Yamaguchi University, 1-1-1, Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan., Department of Urology, Radboud University Medical Center, Nijmegen 267 Experimental Urology, Geert Grooteplein, 26-28, P.O. Box 9101, NL-6525, GA, Nijmegen, The Netherlands., Department of Organ Anatomy, Tohoku University Graduate School of Medicine, 2-1, Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.