FIG. 5.

IRF6 reexpression promotes cell cycle arrest in cancer cells. (A) Proliferation assay of poorly invasive (MCF-7) or highly invasive (MDA-MB-231) breast cancer cells infected with IRF6-expressing adenovirus (Ad IRF6) in the presence or absence of maspin, compared to Ad controls. Cells were counted 6 days postinfection. (B) Western blot analysis depicting the relative expression of Ad-transfected IRF6 or stably transfected maspin-green fluorescent protein (GFP) in MCF-7 and MDA-MB-231 cells. +, present; −, absent; p, phosphorylated; np, nonphosphorylated. (C) Real-time PCR results demonstrating the inverse correlation between IRF6 reexpression in MCF-7 breast cancer cells and the cellular proliferation marker Ki-67. Error bars represent the standard deviations of the results of three independent experiments. **, P ≤ 0.01 based on Student's t test.