Figure 2

The engrafment potential of LP-1K and LP-1D1b does not rely on exacerbated proliferation properties. a) In a second set of engraftment assay, mice were monitored for tumor appearance, and the volume of the tumor evaluated. In the histograms are indicated the number of mice bearing tumors four or eight weeks post-injection and the mean volume of tumors at that time. b) Fixed tumor sections were studied by conventional IHC for CD138 (brown staining) expression (40× magnification). Anti-CD138 Ab was purchased from Dako (Trappes, France). Sequential sections were incubated with the secondary Ab alone as negative control. c) LP-1 derived clones were plated at a density of 5 × 10⁵ cells/ml, cells were harvested 24 h later, fixed in EtOH, stained with PI and analyzed with an Epics XL flow cytometer and Expo™32 software (Beckman Coulter). For each series, 10,000 to 20,000 events were gated. The percentage of cells within each cell cycle phase (G0/G1, S, G2/M) is indicated on the graph, the apoptotic cells (ap) are in the sub-G1 fraction.