Score 3, a strong complete membrane staining is observed in more than 10% of the cells. Colonies were documented using ACT 1 software connected to an Olympus SZX12 or a Nikon EclipseS100 microscope and analyzed using SIGNATURE software. A two sided t test was used to protocol determine statistical significance. Kaplan Meier analysis was done using the GraphPad Prism software package, and survival statistics were calcu lated using the log rank test. Scatchard analysis of Rh EGF binding was done as described previously. Animal experiments All animal experiments were conducted in accordance with Institutional Animal Care and Use Committee approved protocols. Experimental female mice, Brca1flox flox, MMTV Cre and p53 , were obtained by breeding Brca1 conditional knockout mice from the National Institutes of Health repository, originally generated by Xu et al.
who made these mice available to us via the National Cancer Inhibitors,Modulators,Libraries Institute repository, with MMTV Cre mice 4Mam, Jackson Laboratory, Bar Harbor, ME, USA and p53 knockout Inhibitors,Modulators,Libraries mice. At the time of the study, the mice had been inbred for 2 years. The floxed or wild type status of Brca1, the presence of the MMTV Cre transgene and p53 heterozygosity were determined by PCR as pre viously described. Mice were examined for the occurrence of tumors twice weekly. When tumor metrics were performed, the length and width of the tumor were determined using calipers and the tumor volume was determined by calculating width2 �� length 2. Tumor growth was recorded as the ratio of tumor growth to tumor volume at the time of diagnosis.
Results BRCA1 inhibition results in increased EGFR expression To examine whether EGFR upregulation is directly related to the loss of BRCA1, we suppressed BRCA1 in different MEC lines, including MCF 10A, hMEC hTERT and HMLE. These MEC lines have not yet undergone transformation, and instead are propagated as immortalized cells. hMECs were transfected with control or BRCA1 Inhibitors,Modulators,Libraries directed siRNA and analyzed 72 to 120 hours after transfection. MCF 10A and HMLE cells showed poor transfection efficiency upon transient transfection with siRNA, and therefore these cells were infected with Inhibitors,Modulators,Libraries lentiviruses that expressed shRNAi against BRCA1 and selected for pools of infected cells with puromycin. Asynchronously growing cells were lysed and analyzed for EGFR expression.
Through out these experiments, the effects observed after short term suppression of BRCA1 with transient transfection in hMECs were similar to the results obtained in MCF 10A and HMLE cells with longer term suppression of BRCA1 after lentiviral infection and puromycin selection. In all three cell lines and with either approach, we found that Inhibitors,Modulators,Libraries EGFR protein levels as measured by immu noblotting with anti EGFR antibodies increased when selleck chem BRCA1 was inhibited.