Figure 6.

RI-3 is stable in human serum and does not affect cell viability. (a) HT1080 cells were allowed to migrate in real time for 18 hr toward DMEM (CTRL), or 10% FBS in the absence (None) or the presence of 10 nM RI-3 or 10 nM RI-3 pre-incubated at 10⁻³ M in bovine serum for 18 hr at 37 °C. Data represent the means from a quadruplicate experiment. (b) HT1080 cells were allowed to invade matrigel in Boyden chambers for 6 hr toward DMEM (CTRL), or 10% FBS in the absence (None) or the presence of 10 nM RI-3 or 10 nM RI-3 pre-incubated at a 10⁻³ M in human serum for 18 hr at 37 °C. The basal value assessed in the absence of FBS (CTRL) was taken as 100% and all values were reported relative to that. Data are the means ± SD three independent experiments, performed in triplicate. *Indicates statistical significance calculated against None, with *P < 0.05, **P < 0.0001. (c) Cell proliferation of HT1080 cells assessed by MTS assay. HT1080 cells were seeded on plates in growth medium plus/minus 10 µM RI-3, and allowed to proliferate at 37 °C in 5% CO₂. Medium with or without RI-3 was replaced every 24 hr. At the indicated times, the absorbance of adherent cells was assessed with a microplate reader. Data are the means ± SD three independent experiments, performed in triplicate.