GPD inhibits both anchorage-dependent and -independent growth in SK-MEL-28 human melanoma cells.

(A) GPD inhibits the proliferation of SK-MEL-28 cells whereas Rb1 exhibits no significant effect. BrdU-incorporated cells were treated with various concentrations of GPD (20, 40, 60 µM) or Rb1 (60 µM). Results are shown as % of control ±SD (n = 4). The asterisks (**) and (***) indicate statistical significance (pC) The effect of GPD on anchorage-independent cell growth inhibition is dose-dependent. The soft agar assay was repeated with various concentrations of GPD. Results are shown as means ±SE (n = 3). The asterisk (*) indicates statistical significance (p