Regulation of creatine kinase activity in rat osteogenic sarcoma cell clones by parathyroid hormone, prostaglandin E2, and vitamin D metabolites.

We have previously shown that both parathyroid hormone (PTH) and prostaglandin E2 (PGE2) stimulate the activity of creatine kinase BB (CKBB) in rat bone cells in culture. Therefore, morphologically distinct rat osteogenic sarcoma cells in culture were tested for stimulation of CKBB activity by hormones that regulate skeletal tissues. PTH stimulated CKBB in the osteoblast-like clone ROS 17/2; 1 alpha,25(OH)2D3 inhibited this activity while PGE2, CT and 24R,25(OH)2D3 had no significant effect. PGE2 stimulated CKBB activity in the fibroblast-like clone ROS 24/1, which was unresponsive to PTH, CT and Vitamin D metabolites. 24R,25(OH)2D3 as well as PGE2 (but not PTH, CT or 1 alpha 25(OH)2D3) stimulated CKBB in clone ROS 25/1, suggesting that this fibroblast-like clone has some chondroblast-like character. Both PTH and PGE2 stimulated the brain type isoenzyme of CK (CKBB), although the osteogenic sarcoma cell clones contain a significant proportion of the muscle type of CK (CKMM). Thus, increased CKBB activity can serve as an additional characteristic marker for the action of steroid and polypeptide hormones and for prostaglandins.