Activation of bombesin receptor subtype-3 stimulates adhesion of lung cancer cells

Bombesin receptor subtype-3 (BRS-3) is an orphan G protein-coupled receptor having sequence homologies to gastrin-releasing peptide and neuromedin B receptors. (d-Phe(6), beta-Ala(11), Phe(13), Nle(14)] bombesin (6-14) is known to act as a synthetic receptor agonist for BRS-3. To characterize BRS-3-mediated biological responses, we examined the effect of BRS-3 activation by [d-Phe(6), beta-Ala(11), Phe(13), Nle(14)]Bn(6-14) on the adhesion of the small cell lung cancer NCI-N417 cells that express native BRS-3. We found that the BRS-3 agonist stimulated adhesion of NCI-N417 cells in laminin-coated culture wells. The adhesion of the cells to laminin induced by BRS-3 activation was accompanied by an increase in vinculin-like immunoreactivity and diminished in the presence of an anti-beta(1) integrin antibody, suggesting that the receptor activation stimulates focal adhesion formation. We suggest that BRS-3 may be involved in invasion and metastasis of certain cancer cells, like small cell lung cancer cells, upon attachment to laminin. (C) 2006 Elsevier Ireland Ltd. All rights reserved.