Abstract
A single chain glycoprotein with an estimated molecular mass of 160 kD (gp160) was previously identified as a human lung tumor-associated antigen. This tumor marker is shown here to be associated noncovalently with a second 130-kD protein. Sequential immunoprecipitation studies of surface iodinated lung tumor cell lysates reveal that this heterodimeric complex is indistinguishable serologically and structurally from the integrin VLA-2, found originally on activated T lymphocytes and platelets. The VLA-2-like complex expressed on the lung tumors possesses similar characteristic Mg2+ dependent binding of collagen and laminin as observed with VLA-2 on normal cells. RNA analysis indicates that human lung tumors express at least 20 times more VLA-2 alpha chain message than normal adult human lung tissue. The results presented here raise the possibility that the overproduction of VLA-2 may be involved in the pathogenesis of human lung tumors by modulating the invasive and metastatic potential of the tumor.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Antigens, Tumor-Associated, Carbohydrate / analysis*
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Antigens, Tumor-Associated, Carbohydrate / genetics
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Antigens, Tumor-Associated, Carbohydrate / metabolism
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Biomarkers, Tumor / analysis
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Blotting, Northern
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Cell Adhesion Molecules / analysis*
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Cell Adhesion Molecules / genetics
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Cell Adhesion Molecules / metabolism
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Collagen / metabolism
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Electrophoresis, Polyacrylamide Gel
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Extracellular Matrix Proteins / chemistry*
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Extracellular Matrix Proteins / metabolism
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Gene Expression Regulation, Neoplastic / physiology
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Humans
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Laminin / metabolism
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Lung Neoplasms / etiology
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Lung Neoplasms / metabolism
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Lung Neoplasms / pathology*
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Neoplasm Metastasis / physiopathology
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Precipitin Tests
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Receptors, Very Late Antigen / analysis*
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Receptors, Very Late Antigen / genetics
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Receptors, Very Late Antigen / metabolism
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Tumor Cells, Cultured / metabolism
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Tumor Cells, Cultured / pathology
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Tumor Cells, Cultured / ultrastructure
Substances
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Antigens, Tumor-Associated, Carbohydrate
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Biomarkers, Tumor
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Cell Adhesion Molecules
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Extracellular Matrix Proteins
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Laminin
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Receptors, Very Late Antigen
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Collagen