Expression of chloramphenicol acetyltransferase (CAT) from rodent type I collagen promoters in transfected osteosarcoma cells in vivo.
We examined the osteoblastic phenotype of permanently transfected ROS 17/2.8 cells in culture and in vivo, in order to evaluate their relevance for studies of the regulation of gene expression and gene function in osteoblastic cells. Recent reports indicate that the progeny transfected cells may substantially vary and differ from the parental cell line in their phenotype, particularly in their tumorigenicity. ROS 17/2.8 cells were transfected with genetic constructs expressing the CAT gene from either the rat alpha 1 (I) or the mouse alpha 2 (I) collagen promoters. Forty-four clonal cell lines display a range of CAT expression from the transfected collagen promoters in culture. Four of these cell lines were further characterized. Alkaline phosphatase activity in these four cell lines is higher than in fibroblastic cells. These four cell lines are tumorigenic in immunocompatible ACI rats and form calcified tumors similar to those formed by ROS 17/2.8. CAT expression could be demonstrated in tumor extracts of two of the four cell lines, which also expressed higher CAT levels in culture. We conclude that permanently transfected ROS 17/2.8 derived cell lines maintain their tumorigenicity and their osteoblastic-like phenotype, and thus may provide a useful system for studies of gene function and regulation in osteoblast-like cells and bone-like tissue in vivo.
Zernik
J
J
Department of BioStructure and Function, University of Connecticut Health Center, Farmington 06032.
Angilly
J
J
Upholt
W B
WB
Rowe
D W
DW
D000818:Animals; D001859:Bone Neoplasms / Q000235:genetics*; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis*; D003094:Collagen / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic; D005796:Genes; D012516:Osteosarcoma / Q000235:genetics*; D010641:Phenotype; D011401:Promoter Regions, Genetic; D051381:Rats; D013539:Simian virus 40 / Q000235:genetics; D014162:Transfection; D014407:Tumor Cells, Cultured
D003094:Collagen; D015500:Chloramphenicol O-Acetyltransferase