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Expression of cell growth and bone phenotypic genes during the cell cycle of normal diploid osteoblasts and osteosarcoma cells
Author(s) -
McCabe Laura R.,
Last T. J.,
Lynch Maureen,
Lian Jane,
Stein Janet,
Stein Gary
Publication year - 1994
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240560221
Subject(s) - osteosarcoma , osteoblast , alkaline phosphatase , cell cycle , osteopontin , cell growth , biology , microbiology and biotechnology , osteocalcin , extracellular matrix , cell , bone cell , cancer research , endocrinology , genetics , biochemistry , in vitro , enzyme
Abstract Establishing reuglatory mechanisms that mediate proliferation of osteoblasts while restricting expression of genes asociated with mature bone cell phenotypic properties to post‐proliferative cells is fundamental to understanding skeletal development. To gain insight into relationships between growth control and the developmental expression of genes during osteblast differentiation, we have examined expression of three classes of genes during the cell cycle of normal diploid rat calvarial‐derived osteoblasts and rat osteosarcoma cells (ROS 17/2.8): cell cycle and growth‐related to the biosynthesis, organization, and mineralization of the bone extracellular matrix (e.g., alkaline phosphatase, collagen l, osteocalcin, and osteopontin). In normal diploid osteoblasts as well as in osteosarcoma cells we found that histone genes, required for cell progression, are selectively expressed during S phase. All other genes studied were constitutively expressed both at the transcriptional and posttranscriptional levels. Alkaline phosphatase, an integral membrane protein in both osteoblasts and osteosarcoma cells, exhibited only minimal changes in activity during the osteoblast and osteosarcoma cell cycles. Our findings clearly indicate that despite the loss of normal proliferation‐differentiation interrelationships in osteosarcoma cells, cell cycle regulatin or constitutive expression of growth and phenotypic genes is maintained.