Figure 2

Focal adhesion kinase (FAK)-negative mammary epithelial neoplastic cells show a reduced proliferative capacity. (a) FAK and Neu expression in FAK^wt/wt (left) and FAK^flox/flox (right)/mouse mammary tumour virus (MMTV)-Cre/-NDL2-5 end-stage mammary tumours was determined by immunoblotting. Cytokeratin 8 (CK8) was used as a control for epithelial content. β-actin was used as a loading control. (b) Immunohistochemistry analyses of Cre (left) and FAK (right) expression on paraffin sections of end-stage mammary tumours from FAK^wt/wt (upper) and FAK^flox/flox (lower)/MMTV-Cre/-NDL2-5 animals. Data are representative of at least five animals from each genotype. FAK is co-expressed with Cre throughout the MMTV-Cre/-NDL2-5-derived solid tumour tissue. In FAK^flox/flox tumour sections, Cre-positive/FAK-negative cells are detectable only in small hyperplastic or non-transformed ductal structures. (Scale bars: 100 μm). (c) Paraffin sections of hyperplastic mammary glands from 6-month-old FAK^wt/wt and FAK^flox/flox/MMTV-Cre/-NDL2-5 mice were submitted to immunohistofluorescence analyses of Cre and Ki67 expression. (Scale bars: 20 μm). (d) Graphical representation of the immunostaining shown in (c). Percentages (± standard error of the mean, SEM) were calculated after counting multiple fields from at least five animals from each genotype. P <0.01 vs. FAK^wt/wt mice, Student's t-test.