<i>In vivo</i> effect of StSPL on angiogenesis in the chicken chorioallantoic membrane (CAM).

<p>MCF-7 cell spheroids containing 5×10⁵ cells in 50 µl were placed on E8 CAMs, and either treated with PBS (control), WT StSPL (StSPL, 20 µg/ml), or K311A (20 µg/ml) for 4 d. CAMs were analysed for vessel formation as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022436#s4" target="_blank">Materials and Methods</a> section, and the density of vessels per µm² of area around the tumor was determined. Representative CAMs that were PBS-treated (A), WT StSPL-treated (B), and K311A mutant-treated (C) were photographed under a stereomicroscope and vessel density was determined using the Vessel_tracer software <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0022436#pone.0022436-Sofka1" target="_blank">[58]</a> (D). Results are expressed as vessel density per µm2 and are means +/− S.D. (n = 5). *p<0.05 considered statistically significant when compared to the control treated samples.