Figure 4

Knock-down of the AhR reduces centriole aberrations in breast cancer cell lines. (A, B) Immunoblot analysis of HCC1806 cells for AhR expression after transient transfection of cells with siRNA targeting the AhR or control siRNA duplexes. Immunoblot for Actin is shown to demonstrate protein loading (A). Quantification of the proportion of HCC1806 cells with aberrant centriole numbers following transfection with siRNA targeting the AhR or control siRNA. Each bar represents mean and standard error of at least three independent experiments with a minimum of 50 cells counted per experiment (B). (C, D) Immunoblot analysis of MCF-7/neo and MCF-7/cyclin E cells for AhR expression after transient transfection of cells with siRNA targeting the AhR or control siRNA duplexes. Immunoblot for actin is shown to demonstrate protein loading (C). Quantification of the proportion of cells with aberrant centriole numbers following transfection with siRNA targeting the AhR or control siRNA. Each bar represents mean and standard error of at least three independent experiments with a minimum of 50 cells counted per experiment (D). (E) Immunoblot analysis of MCF-7/neo and MCF-7/cyclin E cells following transient transfection (72 h) with either control siRNA (siControl) or siRNA targeting the AhR (siAhR). Immunoblots for AhR, cyclin E, cyclin A, p27^Kip1 and actin are shown. (F) Quantification of the proportion of MCF-7/neo cells (open bars) and MCF-7/cyclin E cells (black bars) with n > 4 centrioles following transient transfection with either control siRNA (siControl) or siRNA duplexes targeting CDK2 (siCDK2), cyclin E (siCyclin E), AhR (siAhR), CDK2 and AhR (siCDK2/siAhR) or cyclin E and AhR (siCyclin E/siAhR). Each bar represents mean and stardard error of two independent experiments each with triple quantification of at least 50 cells.