Figure 2

Suppression of AP-2α, AP-2γ, and YY1 expression downregulates ERBB2 transcript levels in BT-474 cells. (a) Cells were transfected on days 0 and 2 by small interfering RNAs (siRNAs) directed against AP-2α (siAP-2α) and/or AP-2γ (siAP-2γ) or against luciferase mRNA as control. Graphic shows real-time reverse transcription-polymerase chain reaction (RT-PCR) for AP-2α transcripts on total RNA extracted after 2, 3, or 4 days of treatment with indicated siRNAs. Results are presented as percentages of mRNA level as compared with control cells transfected with luciferase siRNA. Data are means ± standard deviation of three experiments. (b) RT-PCR for AP-2γ transcripts on total RNA. Cells were transfected like in (a). (c) Detection by Western blotting of AP-2α and AP-2γ levels at day 3. Ku70 protein served as control. Cells were transfected like in (a).(d) RT-PCR for ERBB2 transcripts on total RNA. Cells were transfected like in (a). (e) Cells were transfected on day 0 with 30 nM siRNA directed against YY1 (siYY1) or 100 nM combined siRNAs against AP-2α and AP-2γ transcripts (siAP-2α+γ) or both as indicated. Control cells were transfected with a commercially available negative control siRNA (control). Proteins extracted after 24 hours of treatment were detected by Western blotting. Ku70 protein served as control for the protein amount charged on the gel. The percentage of ERBB2 protein level compared with transfection of control siRNA is shown in brackets. AP-2, activator protein 2; YY1, Yin Yang 1.