Importance of brain-type fatty acid binding protein for cell-biological processes in human renal carcinoma cells

The molecular mechanisms underlying renal cell carcinoma (RCC) development and progression are still not completely understood. The importance of fatty acid binding proteins (FABP) for the progression of carcinomas has been shown for several tumors. However, the importance of brain-type FABP (B-FABP) in cell-biological processes in renal carcinoma cells is unknown. Therefore, it was the aim of this study to evaluate the role of B-FABP in processes such as proliferation, migration and invasion. By using the approach of down- and up-regulation of B-FABP in human kidney carcinoma cells Caki-2 and Caki-1, the potential participation of B-FABP in proliferation, migration and invasion was demonstrated. B-FABP was down-regulated at both mRNA and protein levels following treatment of Caki-2 cells with B-FABP siRNA. Down-regulation of B-FABP decreased cell proliferation and migration but did not affect invasion. The transfection of Caki-1 cells with human B-FABP cDNA generated an increment of B-FABP mRNA but the protein was not detectable. Transfected Caki-1 cells developed a faster proliferation compared to untreated cells. An effect on the process of invasion was not observed. Our data suggest that B-FABP is involved in cell proliferation and migration of human renal carcinoma cells. The detailed molecular mechanisms remain to be elucidated.