Figure 5
Small-molecule inhibitors, FIPI, NOPT (FIPI: 5-fluoro-2-indolyl des-chlorohalopemid; NOPT: N-[2-(4-oxo-1-phenyl-1,3,8-triazaspiro[4,5]dec-8-yl)ethyl]-2-naphthalenecarboxamide) and apigenin, inhibit cell invasion of two breast cancer cell lines, which correlates to a decreased PLD2 activity independent of cell proliferation. Exponentially growing cells in culture were used for these experiments. (a) Relative difference of cell invasiveness of highly invasive MDA-MB-231 compared with less invasive MCF-7 cells in response to 3 nM EGF. (b–d) Effect of small-molecule inhibitors on cell invasion. (b) FIPI dose response. (c) NOPT dose response. (d) Apigenin dose response. Triplicate results are mean ±s.e.m. (b, inset) FIPI schematic. (c, inset) NOPT schematic. (d, inset) Apigenin inset. (e) Time-dependent effect of FIPI or NOPT on endogenous PLD activity after incubation for 5 min or for 30 min with the inhibitors before the enzymatic assay. (f) Time-dependent effects of small-molecule inhibitors (300 nM concentration of each) on MDA-MB-231 cell proliferation. (g) Effect of 300 nM concentration of each inhibitor on cell invasion or lipase assay (at 30 min) of MDA-MB-231 cancer cells overexpressing recombinant PLD2-WT. Triplicate results are mean ±s.e.m. The symbols * and # denote statistically significant (P<0.05) differences (increases or decreases, respectively) between samples and controls.
