INTEGRIN-DEPENDENT MIGRATION OF LUNG-CANCER CELLS TO EXTRACELLULAR-MATRIX COMPONENTS

Since tumour progression is dependent on the ability of malignant cell s to interact with the extracellular matrix (ECM), we have investigate d the significance of beta 1 and beta 3 integrins for migration of lun g cancer cells to components of the ECM. In an in vitro hapto- and che motactic assay system, five cell lints representing the major types of lung cancer were examined: adenocarcinoma (WART); squamous cell carci noma (U-1752); small cell lung cancer (SCLC) (U-1906, 054 A) and large cell lung cancer (LCLC) (U-1810), Flow cytometric analyses were perfo rmed to characterize their integrin expression, U-1906, 054 A, WART an d U-1752 all expressed beta 1 integrins whereas U-1810 did not, Howeve r, U-1810 and U-1752 expressed beta 3 integrins, All cell Lines except U-1810 and U-1752 showed hapto- and chemotactic motility to fibronect in, laminin and type IV collagen and this motility was beta 1 integrin -dependent except in the case of U-1810, However, the hapto- and chemo tactic responses differed markedly between the separate cell lines and there was no distinct pattern to separate non-small cell lung cancer (NSCLC) from SCLC, No or very little migration nas seen in control exp eriments with bo cine serum albumin (BSA) or serum-free medium alone, indicating that the migration of the lung cancer cells require adhesio n molecules, soluble or substratum bound. We have found the involvemen t of beta 1 integrins in lung cancer cell migration in vitro ton;ards fibronectin, laminin and type IV collagen except in the case of U-1810 . The U-1810 cell line clearly differed from the rest of the cell line s by larking expression of beta 1 integrins.