Sherif Daouti may be contacted via e-mail at Sherif.Daouti@roche.com
Chondrocyte cluster formation in agarose cultures as a functional assay to identify genes expressed in osteoarthritis
Article first published online: 29 MAR 2005
Copyright © 2005 Wiley-Liss, Inc.
Journal of Cellular Physiology
Volume 204, Issue 2, pages 560–566, August 2005
How to Cite
Quintavalla, J., Kumar, C., Daouti, S., Slosberg, E. and Uziel-Fusi, S. (2005), Chondrocyte cluster formation in agarose cultures as a functional assay to identify genes expressed in osteoarthritis. J. Cell. Physiol., 204: 560–566. doi: 10.1002/jcp.20345
- Issue published online: 26 MAY 2005
- Article first published online: 29 MAR 2005
- Manuscript Accepted: 29 NOV 2004
- Manuscript Received: 13 FEB 2004
Understanding altered gene expression in osteoarthritic cartilage can lead to new targets for drug intervention. We established a functional assay based on chondrocyte cluster formation, a phenotype associated with osteoarthritis (OA), to screen an OA cartilage gene library. Previous reports have demonstrated that normal chondrocytes grown in suspension culture maintain their chondrocytic phenotype, however, certain growth factors such as basic fibroblast growth factor (bFGF) will induce the cells to proliferate in tight clusters similar to those seen in osteoarthritic cartilage. In this study we validate that overexpression of bFGF by retrovirally transduced normal chondrocytes would similarly induce the proliferation of tight cell clusters. We then used this approach as a basis to set up a functional screen where an entire OA cartilage cDNA library was tranduced into normal chondrocytes to search for other genes that would also induce cluster formation. Seven potential genes were isolated from the OA gene library, including BPOZ, IL-17 receptor C, NADH ubiquinone oxidoreductase, COMP, Soluble carrier 16 (MCT 3), C1r, and bFGF itself. None of the identified genes were upregulated by bFGF, however, all of them upregulated the expression of bFGF suggesting a common pathway. Although cluster formation is not considered to be destructive in OA cartilage, it is consistent with the disease and could yield answers to the altered phenotype. Further studies are needed to elucidate how these genes are linked to the disease state. © 2005 Wiley-Liss, Inc.