Laminin receptor expression and function in small-cell lung carcinoma.
Interactions between tumor cells and laminin or other components of the extracellular matrix are thought to play a role in tumor invasion and metastasis. To analyze these interactions, we examined the expression of 5 types of laminin receptors on 11 cell lines derived from the highly malignant and metastatic tumor small-cell lung cancer (SCLC). The integrins VLA-1, VLA-3, VLA-6 and the 67 KDa monomeric receptor were expressed at various levels, whereas the VLA-2 receptor was absent on the cell lines. Only one cell line expressed none of these laminin receptors. All cell lines co-expressed alpha 6 beta 1 (VLA-6) and the 67-kDa molecule, the only receptors specific for laminin. Analysis of the ability of SCLC cells to bind radiolabeled laminin and to adhere to laminin substrata revealed a correlation between these 2 parameters and the expression of VLA-6 and the 67-kDa monomeric receptor. Cell adhesion was mediated by alpha 6 beta 1, as indicated by inhibition of adhesion using an anti-VLA-6 monoclonal antibody (MAb). Both VLA-6 and the monomeric receptor were up-regulated in vitro by laminin.
Pellegrini
R
R
Division of Experimental Oncology E, Istituto Nazionale Tumori, Milan, Italy.
Martignone
S
S
Ménard
S
S
Colnaghi
M I
MI
D000906:Antibodies / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D018288:Carcinoma, Small Cell / Q000378:metabolism*; D002448:Cell Adhesion / Q000187:drug effects; D002460:Cell Line; D005455:Fluorescent Antibody Technique; D006801:Humans; D016023:Integrins / Q000096:biosynthesis* / Q000187:drug effects / Q000378:metabolism; D007797:Laminin / Q000378:metabolism*; D008175:Lung Neoplasms / Q000378:metabolism*; D008970:Molecular Weight; D017474:Receptors, Laminin / Q000096:biosynthesis* / Q000378:metabolism; D012044:Regression Analysis; D014407:Tumor Cells, Cultured
D000906:Antibodies; D000911:Antibodies, Monoclonal; D016023:Integrins; D007797:Laminin; D017474:Receptors, Laminin