UMR-106 cell line was chosen as a model in our study as it was a rat osteosarcoma cell with more mature osteoblastic phenotypes that were commonly used by others for studying the effects of different hormonal agents (PTH, prostaglandins, and bone resorbing steroids) on signal transduction (Partridge et al., 1983; Forrest et al., 1985; Mitchell and Goltzman, 1990; Armbrecht et al., 1998). This evidence concerns the gene PTH and osteosarcoma.