Platelet-derived growth factor (PDGF) BB acts as a chemoattractant for human malignant mesothelioma cells via PDGF receptor beta integrin alpha 3 beta 1 interaction

Platelet-derived growth factor BE (PDGF BE) and the PDGP receptor beta are expressed on mesothelioma cells, but their biological function has not yet been defined, In the present study we used Boyden chambers fitted,vith filt ers coated with the adhesive matrix proteins fibronectin, laminin, collagen type IV or the nonmatrix adhesive molecule poly-L-Iysine (PLL). Mesothelio ma cells migrated towards PDGF BE at concentrations ranging from 0.78 to 12 .5 ng/ml if matrix proteins were present as adhesive substrates, This migra tion was integrin dependent since the same cells failed to migrate if the a dhesive interactions necessary for migration were provided by molecules oth er than integrins, Migration of mesothelioma cells on fibronectin, laminin or collagen-type TV in response to PDGF BE was inhibited if the cells were pretreated with blocking antibodies to alpha 3 beta 1 integrin, These findi ngs describe for the first time PDGF BE as a chemoattractant for malignant mesothelioma cells and that collaboration between PDGF receptor beta and in tegrin alpha 3 beta 1 is necessary for the motile response of these cells t o PDGF BB.