Biochemical characterization of the long-term culture of Swarm rat chondrosarcoma chondrocytes in agarose

The Swarm rat chondrosarcoma has been used extensively as a model system for the study of proteoglycan structure and biosynthesis. Its application to the study of long-term processes of proteoglycan metabolism has been hampered by lack of a homogenous culture system capable of supporting synthesis of a nondiffusable extracellular matrix.; In this study the author has attempted to establish conditions for long-term culture of the chondrosarcoma chondrocytes in agarose, a medium selective towards growth of anchorage-independent cells and one that allows immobilization of the cells in a solid matrix. Agarose has also been shown to promote expression of cartilage-specific phenotype in cultures of articular cartilage chondrocytes.; Biochemical characterization of an agarose culture of chondrosarcoma chondrocytes over a 20 day period indicates stability of this culture system with respect to the type of proteoglycans and collagens synthesized. The cells synthesize at all times a large chondroitin sulfate proteoglycan capable of forming aggregates with hyaluronic acid. In addition, a small molecular weight proteoglycan is synthesized constituting approximately 10% of the total proteoglycan population. Type II collagen is the predominant type of collagen synthesized by the tumor in vivo with minor collagen types also present. This pattern is maintained under culture conditions in agarose gels.; The half-life of proteoglycans in agarose cultures of the Swarm rat chondrosarcoma is greater than 29 days. The rate of degradation can be significantly enhanced if the cultures are maintained in the presence of retinol. Under those conditions the rate of proteoglycan synthesis is also strongly inhibited.; Analysis of the growth pattern of the chondrosarcoma chondrocytes in agarose indicates this system to be capable of supporting cell division under varied culture conditions.