Figure 4.

Higher levels of MMP2 than MMP9 were detected in the conditioned media of A549 cells upon treatment with the p53 inhibitor, pifithrin-α. Cells (0.2 × 10⁵) were grown in 10% FBS-supplemented media for 24 h. The following day, the cell monolayers were incubated in serum-free media for 24 h, then treated as indicated for 72 h with the inhibitors without and with 600 µM 4-MU as described in the “Methods” section. The media was collected then the same amount of protein (3 µL of 600 µg/mL total protein) of each sample was used to quantitate MMPs (“Methods” section). Data from five independent assays, each carried out in triplicate, were quantitated, averaged, normalized, and expressed as fold change relative to cells not treated with 4-MU using the GraphPad 8.4.3 software. The graphs summarize the results expressed as means ± SD (n = 5). Asterisks (*) indicate a statistically significant difference from the corresponding samples without 4-MU treatment for each cell line, Mann–Whitney test. Statistical differences between different groups were analyzed by an ordinary one-way analysis of variance (ANOVA) followed by Tukey’s post-hoc multiple comparison test. *p < 0.05, **p < 0.01.