Figure 4

IGF-1 antagonizes estradiol-induced activation of PAX2 in luminal breast cancer cells. MCF-7 cells were cultivated in a steroid- and serum-depleted growth medium and treated with 10 nM estradiol and/or 30 ng/mL IGF-1, as indicated. A) Following 30 min-treatment with estradiol and/or IGF-1, PAX2 phosphorylation on ser393 residue and total levels of PAX2 protein were determined using western blot. GAPDH was used as a control to normalize for protein content. B) Following 24 h-treatment with estradiol and/or IGF-1, total levels of ERBB2 protein were assessed, using western blot. GAPDH was used as a control to normalize for protein content. C) Following 24 h-treatment with estradiol and/or IGF-1, cells were subjected to Matrigel invasion assay. All results are representative or mean values +/- SD of three independent experiments. Different subscript letters indicate a statistically significant difference.