Figure 5
Overexpression of MMP-10 results in inhibition of apoptosis. A, Caspase activity assay was performed with HeLa-MMP-10OE and HeLaEmpty cells after exposing the cells to the apoptotic-inducing agent, staurosporine at 1 μM. At least three independent experiments performed in triplicate were used to calculate mean ± SD values. *, p < 0.05. The apoptotic effects of staurosporine were abrogated by MMP-10 overexpression. B, Annexin V apoptotic assays were also performed with HeLa-MMP-10OE and HeLaEmpty cells as described above. Assays confirmed that high expression of MMP-10 was associated with resistance to induced apoptosis. C, Changes in mitochondrial membrane potential (DCm) in HeLa-MMP-10OE and control HeLaEmpty cells were assessed by flow cytometric analysis. At least three independent experiments performed in triplicate wells were used to calculate mean ± SD values. *, p < 0.05. High expression of MMP-10 was associated with a significant increase in DCm compared to control. D, Western blot analysis was performed on the above cell lines confirming MMP-10 overexpression was associated with the expression of apoptosis factors. For example, the expression of key intrinsic apoptotic pathway factors (Bcl-xl, Bax and Bak), and factors in the extrinsic apoptotic pathway (FasL and cleaved caspase-8) were altered when MMP-10 was overexpressed. GAPDH served as controls. E, The expression of the proteins from the Western blot from panel D was quantitated and plotted to illustrate relative expression of the apoptotic associated proteins.