Fig. 6.

HIF-1α and PDGF-B expression correlate with LV area and predict histological grade of human breast cancers. (A) IHC for HIF-1α, PDGF-B, and podoplanin in biopsy sections from an invasive ductal carcinoma (grade 2). Deconvoluted images were thresholded and pseudocolored for HIF-1α (red), PDGF-B (green), HIF-1α and PDGF-B (yellow), and podoplanin (white). (Scale bar, 500 μm.) (B) Linear regression analysis of HIF-1α and PDGF-B staining intensity in grade 1 (G1, Left), 2 (G2, Center), and 3 (G3, Right) breast cancer biopsies. Correlation coefficient (r) and P values are indicated above each plot. (C) Staining intensity Z-score for HIF-1α (Left) or PDGF-B (Right) in biopsies according to histological grade. (D) LVs before and after digital deconvolution for podoplanin signal. Photomicrograph (Left) shows IHC for podoplanin (brown). Digital image (Right) shows luminal LV area (black). (Scale bar, 500 μm) (E) Quantification of LV area measured by podoplanin IHC according to histological grade. (F) Multiple linear regression analysis of HIF-1α and PDGF-B expression and LV area (LVA). Correlation coefficients for HIF-1α (α), PDGF-B (β), and LVA (γ) are indicated by orange bars (left y-axis), whereas the t statistic for each coefficient is shown in black bars (right y-axis). The three factors were positively correlated with histological grade (G), and the overall linear model equation is shown below the graph (LVA was normalized using a square root transform). *P < 0.05 by F test or Bonferroni post hoc comparisons after one-way ANOVA. P values indicate overall statistical significance. Data are expressed as mean ± SEM.