alpha-chymotrypsin and Osteosarcoma

Topics: Amylases; Animals; Arginase; Benz(a)Anthracenes; Carcinoma; Carcinoma 256, Walker; Carcinoma, Brown-Pearce; Carcinoma, Ehrlich Tumor; Catalase; Chymotrypsin; Deoxyribonucleases; Enzyme Therapy; Humans; Hyaluronoglucosaminidase; Mammary Neoplasms, Experimental; Mice; Neoplasms, Experimental; Osteosarcoma; Peroxidases; Rats; Ribonucleases; Sarcoma; Sarcoma 180; Sarcoma, Experimental; Trypsin

The interaction of cells with laminin and laminin fragments was studied in short-term cell attachment assays. Neurite-promoting chymotrypsin fragments of laminin were isolated using a monoclonal antibody which blocks neurite outgrowth on laminin. The fragments were shown, by electron microscopy after rotary shadowing and by immunological reactivity with different monoclonal antibodies, to contain only the distal end of the long arm. These fragments promoted the attachment and spreading of glioma, sarcoma, carcinoma, muscle, and endodermal cells to the same extent as intact laminin. The attachment was unaffected by peptides containing the RGD sequence. The morphology of the cells on the chymotrypsin fragments was indistinguishable from that on intact laminin but different from the morphology of the same cells on fibronectin. Light microscopy and scanning electron microscopy showed extensive process formation on laminin but not on fibronectin suggestive of increased cell motility in response to laminin. We conclude that the neurite-promoting domain of laminin contains a major site of interaction for non-neuronal cells and that this site induces a cellular response in certain non-neuronal cells that is unique to laminin.

Topics: Animals; Antibodies, Monoclonal; Axons; Carcinoma; Cell Adhesion; Cell Movement; Chymotrypsin; Endoderm; Glioma; Humans; Immunohistochemistry; Laminin; Microscopy, Electron; Microscopy, Electron, Scanning; Muscles; Osteosarcoma; Peptide Fragments; Rats; Tumor Cells, Cultured

The murine monoclonal antibody 791T/36 cross-reacts with cells other than the immunizing osteogenic sarcoma cell line 791T, upon which the 791T/36-defined epitope is expressed on a protein of apparent molecular weight 72,000. An investigation was performed to determine whether the epitope occurred on similar molecules on other cell lines. Radiolabelled immunoprecipitates, prepared with the 791T/36 antibody, from three osteogenic sarcoma cell lines (2 OS, 788T and 278T), the prostate carcinoma EB33 and the colon carcinoma HcLo each contained a protein with a molecular weight of 72,000 as the major constituent, together with, in some cases, material of lower molecular weight. This heterogeneity was shown by neuraminidase treatment of the immune precipitates to be due to variations in sialic acid content of the antigens since, in five of the six cell lines tested, such treatment produced homogeneous material of apparent molecular weight 55,000. Chymotrypsin treatment of the immune precipitates produced in each instance a major polypeptide of molecular weight 47,000 which displayed no microheterogeneity. Immunoadsorbent-purified antigen from 791T cells was shown to bind strongly to Sepharose-wheat-germ agglutinin and less to Sepharose-concanavalin A, confirming the glycoprotein nature of this antigen. These studies demonstrate that molecules expressing the 791T/36-defined epitopes on different tumour cell lines are glycoproteins which display heterogeneity with respect to apparent molecular weight that is attributable to varying degrees of sialylation. No apparent differences were detected in the polypeptide "backbone" of these antigenic molecules.

Topics: Antigens, Neoplasm; Antigens, Surface; Carcinoma; Cell Line; Chymotrypsin; Humans; Lectins; Melanoma; Molecular Weight; Osteosarcoma; Papain

Topics: Cell Adhesion; Cell Aggregation; Cell Line; Chymotrypsin; Clone Cells; Dose-Response Relationship, Drug; Edetic Acid; Humans; Osteosarcoma; Papain; Peptide Hydrolases; Thrombin

Topics: Cell Adhesion; Cell Separation; Chymotrypsin; Humans; Neuraminidase; Osteosarcoma; Pancreatic Elastase; Serine Endopeptidases; Trypsin; Tumor Cells, Cultured