title: Subclone heterogeneity in a clonally-derived osteoblast-like cell line.
abstract: To analyze the phenotypic diversity of a clonal rat osteosarcoma cell line (ROS 17/2) we have subcloned the cell line and characterized four subclones, ROS 17/2-A.II, A.III, A.V, and A.XIV. The subclones retained many of the characteristics of the parent clone that are considered typical of normal osteoblast-like cells; they responded to parathyroid hormone and isoproterenol, and had a negligible response to prostaglandin E2 as measured by their respective changes in cyclic AMP concentration. In addition up to a 75% decrease in 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) binding was observed over a four-fold increase in cell density. The morphologies of the subclones varied from spindle-shaped, fibroblast-like to cuboidal. Doubling times varied from 24 to 48 hours, and basal alkaline phosphatase (AP) levels differed by as much as 10 times over the initial 3 months in culture. After 6 months (approximately 100 PDL), the population doubling time of subclone A.XIV decreased from approximately 48 to approximately 20 hrs and there was a 2.5 to 3-fold increase in saturation density. This cell line was designated A.XIV.1 and was compared to a thawed sample from frozen stock of the original A.XIV isolate, designated A.XIV.2. These two populations, the parent cell line (ROS 17/2) and subclone A.V had similar growth properties, but differed with respect to changes in their alkaline phosphatase activity (AP) with time in culture: that is, all clones increased AP with time but there was a three to five-fold difference in their respective AP levels at various times in culture. All clones except A.V exhibited decreased AP activity upon reaching their saturation densities.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D002460:Cell Line; D002999:Clone Cells; D010006:Osteoblasts / Q000032:analysis / Q000473:pathology*; D012516:Osteosarcoma / Q000473:pathology*; D051381:Rats; D018167:Receptors, Calcitriol; D011987:Receptors, Steroid / Q000032:analysis
chemical_list: D018167:Receptors, Calcitriol; D011987:Receptors, Steroid; D000469:Alkaline Phosphatase