Fig. 4

Nrf2 increases proliferation of benign, premalignant and malignant pancreatic ductal epithelial cells. Representative Ki67 stainings of (a) H6c7-pBp and H6c7-kras cells that were transfected with a control vector (pcDNA3.1) or Nrf2-HA and left untreated or were treated with 10 ng/ml TGF-β1 for 48 h, and (b) H6c7-pBp, H6c7-kras and (c) Colo357 cells that were transfected either with control siRNA or Nrf2 siRNA and left untreated or were treated with 10 ng/ml TGF-β1 for 48 h. Magnification x280 (magnification of images in frames x540). Quantification of Ki67 positive cells was performed at a 200-fold magnification by choosing 5 representative visual fields, in each counting positively stained as well as negative cells along a diagonal line using Microsoft Powerpoint 2007 in order to calculate the percentage of Ki67 positive cells. If less than ten cells touched the line, all captured cells of the visual field were counted. Data are expressed as mean ± SD of counted cells from 5 visual fields. * = p < 0.05