Background/purpose: The S100 protein is part of a Ca(2+) binding protein superfamily that contains an EF hand domain, which is involved in the onset and progression of many human diseases, especially the proliferation and metastasis of tumors. S100A13, a new member of the S100 protein family, is a requisite component of the fibroblast growth factor-1 (FGF-1) protein release complex, and is involved in human tumorigenesis by interacting with FGF-1 and interleukin-1. In this study, experiments were designed to determine the direct role of S100A13 in FGF-1 protein release and transportation.
Methods: We successfully constructed the lentiviral vectors containing shRNA targeting the human S100A13 gene. Human umbilical vein endothelial cells (HUVECs) were transfected with lentiviral RNAi vectors for S100A13. Then immunofluorescence staining, real-time quantitative polymerase chain reaction and Western blotting were used to detect the inhibition efficiency of the vectors and to monitor the release and transportation of FGF-1 protein.
Results: Lentiviral RNAi vectors induced suppression efficiency of S100A13 gene by 90% in HUVECs. FGF-1 protein was found to be transported from the cytoplasm to the cell membrane, and then released from cells when HUVECs were deprived of serum. The release of FGF-1 protein was blocked by the downregulation of S100A13, but the transportation was not affected, suggesting that S100A13 is a key cargo protein for FGF-1 release.
Conclusion: S100A13 promotes the release of FGF-1 protein, but does not affect the transportation of FGF-1 protein in HUVECs.
Copyright © 2010 Formosan Medical Association & Elsevier. Published by Elsevier B.V. All rights reserved.