Figure 5

VPA sensitizes pancreatic cancer cells to NK cell-mediated lysis in vivo by upregulating the expression of MICA and MICB. (A, B) Excised xenograft tumors and growth curves for the xenografts; VPA enhanced the growth inhibitory effect of NK cells in vivo; this effect was attenuated by the PI3K inhibitor LY294002. Data are mean ± SD of five mice per group; * P < 0.05 for NK-92 vs. NK-92 + VPA; Δ P < 0.05 for NK-92 + VPA + LY294002 vs. NK-92 + VPA. (C) Immunohistochemical staining and quantification of MICA and MICB expression in the xenograft tumors; VPA significantly upregulated the expression of MICA and MICB in the pancreatic cancer xenograft tumors in vivo, this effect was attenuated by the PI3K inhibitor LY294002.