Subject(s)
Cell Adhesion , Osteosarcoma/pathology , Cell Aggregation , Cell Line , Clone Cells , HumansABSTRACT
A human osteosarcoma derived cell line was treated with phorbol-12-myristate-13-acetate and was subsequently cloned extensively. 27 clones were examined for their initial rate of aggregation, their attachment to homo- and heterotypic performed cell layers, and the size of their 24-hour aggregates. Quantitative differences for these three adhesive parameters were observed between the clones. Based on these findings five clones were studied in more detail. The adhesive differences between these clones were stable, reproducible, and dependent on the assay system. This human clonal system will be a valuable tool to study the molecular nature of the adhesive properties of these cells.
Subject(s)
Cell Adhesion , Osteosarcoma/pathology , Animals , Cell Line , Clone Cells/drug effects , Humans , Mice , Mice, Nude , Neoplasm Transplantation , Tetradecanoylphorbol Acetate/pharmacologyABSTRACT
EGTA dissociated cell lines could be distinguished on the basis of their dependence on calcium during initial aggregation. However, the calcium-dependent aggregation could not be abolished by low chymotrypsin/EGTA treatment. These differences were not related to any morphogenetic property of the cells and suggest that different aggregation mechanisms are involved.
Subject(s)
Calcium/physiology , Cell Aggregation/drug effects , Egtazic Acid/pharmacology , Ethylene Glycols/pharmacology , Animals , Cell Adhesion , Cell Line , Cell Membrane/physiology , Cell Transformation, Neoplastic , Chymotrypsin/pharmacology , Dogs , HumansSubject(s)
Aminopeptidases/metabolism , Clone Cells/analysis , Osteosarcoma , Receptors, Immunologic/analysis , gamma-Glutamyltransferase/metabolism , CD13 Antigens , Cell Line , Cell Membrane/analysis , Fibronectins/analysis , Genetic Variation , Humans , Low Density Lipoprotein Receptor-Related Protein-1 , Surface PropertiesSubject(s)
Osteosarcoma/physiopathology , Peptide Hydrolases/pharmacology , Cell Adhesion/drug effects , Cell Aggregation/drug effects , Cell Line , Chymotrypsin/pharmacology , Clone Cells/physiology , Dose-Response Relationship, Drug , Edetic Acid/pharmacology , Humans , Papain/pharmacology , Thrombin/pharmacologyABSTRACT
A quantitative analysis was carried out on the dispersion of gene loci over the E. coli genetic map. Therefore, the map was divided into regions characterized by an homogeneous gene density. This created a distribution pattern of gene loci that contained a symmetry axis located near to the origin of DNA replication. The pattern could be subdivided into a set of 22 functional domains containing gene loci whose products revealed a biochemical or functional relatedness. A correlation was found between the boundary positions of these domains and the distribution of F plasmid- and DNA insertion sites over the E. coli chromosome. The structural, functional and evolutionary implications of these findings are discussed.
