Fig. 6
Cells filling abnormal IKMV ducts are highly proliferative. 6 week old virgin IKMV and control littermates were dox-treated (2 g/L) for 3 days prior to sacrifice. PCNA staining of mammary tissue reveals increased proliferation in the IKMV ducts as compared to controls, shown in both a 10X and b 20X images (positive staining is dark brown). c This increased number of PCNA positive cells/duct was quantified (counts were normalized to area of each duct; n = 3 control, n = 3 IKMV glands were used for quantification and 6 ducts per gland were counted; ***p < 0.0001). d,e qRT-PCR analysis shows increased expression of cyclin b1 and decreased expression of p18INK4c following activation of NF-κB in mammary epithelium (n = 6 control, n = 7 IKMV samples run for cyclin b1; *p = 0.0210; n = 3 control, n = 4 IKMV samples run for p18IKN4c; *p = 0.0064). f Immunofluorescent staining for Ki-67 (green, nuclear) confirms that cells within the IKMV ducts are actively cycling. Many of the proliferating cells co-stain with CK8/18 (red, cytoplasmic), indicating that the luminal epithelium is driven to proliferate upon activation of NF-κB. Note that the far right image is a magnification of the white box in the center image. White arrows indicate double positive Ki-67/CK8/18 cells