Fig. 1

ATF6 mediated ER stress in PCa cells. (A) Representative immunofluorescence (IF) images of ATF6 (green) in LNCaP cells treated with 1 μM Thapsigargin (Tg) for 4 h or the appropriate amount of DMSO (Ctrl) and non-treated RWPE-1 and PC-3 cells; bars, 10 μm. (B) ATF6 W-B of the nuclear fraction from LNCaP cells treated with DMSO or Tg; lamin B1 is a loading control. (C) Quantification of the ratio of nuclear/cytoplasmic ATF6 IF in cells presented in A (N = 3; **P < 0.001, t test). (D-F) Expression of mRNA for calreticulin (D), HSP90B (E), and HSPA5 (F) in RWPE-1 and LNCaP cells treated with DMSO or Tg, as well as non-treated PC-3 cells (N = 3; **P < 0.001, t test). (G) GRP78 and ATF6 W-B of the lysate from the tumor tissues of PCa patients (T, grade 2) and prostate normal tissues (N); β-actin is a loading control. (H) Examination of intranuclear ATF6 and total GRP78 in the normal prostate and tumor foci of PCa patients with different Gleason (Gl) scores. Shown is IF staining of GRP78 (red) and ATF6 (green); bars, 5 μm. White boxes indicate an area enlarged at the right. (I, J) Quantification of ATF6 (I) and GRP78 (J) in the samples described in H (**P < 0.001; *P < 0.01, pairwise Wilcoxon with Bonferonni-Hochberg multiple test). Data are presented as medians (min – max)