Flufenamic acid: growth modulating effects on human aortic smooth muscle cells in vitro

The aim of the study was to examine the effects of flufenamic acid on proliferation, clonogenic activity, migratory ability, cell-cycle distribution, and p44/42-mitogen-activated protein kinase (MAPK) expression on serum-stimulated human aortic smooth muscle cells (haSMCs) in vitro.

HaSMCs were treated with flufenamic acid in three different doses (40 micromol/L, 200 micromol/L, 400 micromol/L) for 4 days, and then flufenamic-acid-free culture medium was supplemented every 4 days until day 20 after initial treatment. The growth kinetics were assessed. Cell-cycle analysis was performed by flow cytometry. The clonogenic activity was evaluated with use of colony formation assays. The migratory ability was investigated by stimulation with platelet derived growth factor (PDGF-BB) in 24 well plates with 8-microm pore membrane inserts. The p44/42 MAPK was detected by Western blot technique.

Flufenamic acid inhibited the proliferation (400 micromol/L treatment over 4 d; 179,700 +/- 49,800 vs 747,900 +/- 144,000; P <.001), clonogenic activity (400 micromol/L treatment over 4 d; 1 +/- 0.3 vs 50 +/- 1.4; P <.001) and migratory ability (400 micromol/L treatment over 4 d; 8 cells +/- 2 vs 48 cells +/- 15; P <.001) of haSMCs in a dose-dependent manner. Cell-cycle analysis revealed a G2/M-phase block (400 micromol/L treatment over 4 d; 28.9 +/- 1.5 vs 9.5 +/- 3.2; P <.001). The expression of p44/42 MAPK was reduced for a treatment with 400 micromol/L flufenamic acid (controls, 427 BLU +/- 0.305 vs treatment group, 190 BLU +/- 106; P <.05)

Flufenamic acid inhibits the proliferation and migration of haSMCs. Further experiments with animal models concerning stenosis and restenosis are necessary to evaluate the potential of this promising drug.