Matriptase-mediated loose spheroids are dependent on MMP-9 activity. (A) ES-2 and NCI/ADR-Res Vec and Mat hanging drop spheroids were formed in the presence of MMP-2 inhibitor SB-3CT (2 μM) for 4 d. At least five representative images were taken from three independent experiments and the average percentage of loose morphology was quantified (error bars are ± SEM, **P < 0.01, ***P < 0.005, ns = not significant). (B) mRNA was collected from ES-2 and NCI/ADR-Res Vec and Mat cells and analyzed by qPCR for α5-integrin expression. Data represents average fold change relative to Vec controls normalized to GAPDH from three independent experiments performed in triplicate (error bars are ± SEM; ns = not significant). All P values were calculated according to two-tailed, unpaired Student’s t tests.