Human lung tumor-associated antigen identified as an extracellular matrix adhesion molecule.
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.
Chen
F A
FA
Roswell Park Cancer Institute, (Unit of New York State Department of Health), Department of Molecular Immunology, Buffalo, New York 14263.
Repasky
E A
EA
Bankert
R B
RB
D015295:Antigens, Tumor-Associated, Carbohydrate / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000032:analysis; D015152:Blotting, Northern; D015815:Cell Adhesion Molecules / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D003094:Collagen / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D016326:Extracellular Matrix Proteins / Q000737:chemistry* / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D006801:Humans; D007797:Laminin / Q000378:metabolism; D008175:Lung Neoplasms / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D009362:Neoplasm Metastasis / Q000503:physiopathology; D011233:Precipitin Tests; D016029:Receptors, Very Late Antigen / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000378:metabolism / Q000473:pathology / Q000648:ultrastructure
D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; D015815:Cell Adhesion Molecules; D016326:Extracellular Matrix Proteins; D007797:Laminin; D016029:Receptors, Very Late Antigen; D003094:Collagen