Figure 1

Knockdown of αv integrin in breast cancer cells. (A) Oncomine™ box plots of αv expression levels in normal breast and breast cancer data [29]. Normal versus ductal breast carcinoma in situ epithelia, P = 0.04; Normal versus invasive ductal breast carcinoma epithelia, P = 0.02. (B) Kaplan-Meier curves for the overall survival of breast carcinoma patients with high and low αv integrin expression; data obtained from the Kaplan-Meier plotter database [30]. P-values were calculated by log-rank test. (C) mRNA expression profile of αv integrin in breast cancer cell lines of different molecular subtypes (basal A, basal B and luminal) [31]. (D) FACS analysis of the αv integrin protein levels on the surface of control and αv integrin knockdown MDA-MB-231 cells, generated by stable infection with lentiviral vectors expressing two independent αv integrin targeting short hairpins (KD 1 and KD 2) or a control short hairpin (Co. sh). The percentage of αv⁺ cells was analyzed by flow cytometry. (E) Real-time quantitative PCR detection of αv integrin mRNA levels in control and αv integrin knockdown MDA-MB-231 cells. All samples were analyzed in triplicate and normalized to GAPDH (P <0.001). (F) Left, representative FACS profiles of propidium iodine (PI)-stained control MDA-MB-231 cells, αv knockdown cells and doxorubicin-treated MDA-MB-231 cells, a positive control (Co. Pos) for apoptosis detection. P2: subG1 cells. Right, percentage of sub G1 cells calculated by FACS. Co. Pos versus Co.sh or αv KD cells: P <0.01. Average ± SD of three independent experiments.