Fig. 5
Tumor xenografts in an orthotopic mouse model treated by Pac 1. a, b Viability of two breast cancer cell lines as determined using an SRB assay 72 h after treatment with Pac 1 or Pac 2. c Western blot of the expression of PKR and p-PKR protein in the two breast cancer cell lines 72 h after treatment with Pac 1 at various doses. d, e Growth of MDA-MB-231 breast (d) and H1299 lung (e) tumor xenografts in an orthotopic mouse model. Tumor growth in both models was markedly lower in tumors intravenously injected with Pac 1 than in untreated control tumors. Tumor volumes (y-axes) were measured in five to six mice per group over 28 days. The data are presented as means (error bars, standard deviation). f Immunohistochemical analysis of H1299 lung tumors showing that the growth inhibition observed in Pac 1-treated mice was caused by reductions in PKR, p-PKR, and Ki-67 protein expression. g The chemical structures of Pac 1 and Pac 2
