Cytogenetics of swarm rat chondrosarcoma.

The Swarm rat chondrosarcoma is a tumor tissue line derived from a tumor that arose spontaneously in a Sprague-Dawley rat. The original tissue has given rise to several tissue lines and cell lines that have been prepared in different laboratories. It has been observed that these lines differed in their growth rates and biochemical characteristics. We have characterized our Swarm rat chondrosarcoma tissue and cell lines currently in use in terms of their cytogenetic profiles and their tumorigenic properties in vivo. We found a wide variety of chromosomal abnormalities among cell lines, including translocations, deletions and polyploidy. There were also significant differences in their growth properties in vivo, giving rise to tumors of a few milligrams in the case of Ng cells, to 35 grams in the tissue line JWS. The cytogenetic complexity of the Swarm rat chondrosarcoma between and among different lines makes it very suitable to address questions about the changes that occur as a result of karyotypic abnormalities and to provide links between cytogenetic abnormalities and the dynamic oncogenic machinery.