8226/S myeloma cells adhered to FN have a survival advantage over nonadhered cells following acute doxorubicin exposure (A) but not following melphalan exposure (B) in cell growth based cytotoxicity assays. FN-adhered cells (---) were bound to FN-coated plates 24 hours before 1-hour drug exposure and control cells were grown in suspension (—). Response to doxorubicin was 12.6-fold lower in FN-adhered cells compared to nonadhered controls (IC50 values for adhered and nonadhered cells were of 4.85 × 10−7 mol/L and 8.5 × 10−8 mol/L, respectively). Data points are presented as cell viability determined by MTT cytotoxicity assay compared with untreated controls. Graphs are representative experiments that were repeated three times in replicates of four.
