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Figure 1 | Breast Cancer Research

Figure 1

From: Insulin-like growth factor 1 attenuates antiestrogen- and antiprogestin-induced apoptosis in ER+ breast cancer cells by MEK1 regulation of the BH3-only pro-apoptotic protein Bim

Figure 1

IGF-1 attenuates the cytotoxicity of hormonal treatments in ER+ breast cancer cells. (a) Cell number for the adherent versus detached cell population treated with hormones in the presence or absence of various concentrations of IGF-1. (b) Relative levels of active, dephosphorylated Rb110 protein, designated Rb, relative to levels of the inactive, phosphorylated Rb110, designated pRb (top panel), cleaved PARP (middle panel), and cleaved lamin A (bottom panel) in cells undergoing hormonal treatments in the presence and absence of IGF-1. Protein was isolated from cells undergoing the designated treatments at 48, 72, and 120 hours, and immunoblot analysis determined the levels of Rb, pRb, cleaved PARP, and cleaved lamin A; β-actin served as a loading control. (c) Relative levels of cleaved cytokeratin 18 after 72 hours of the hormonal treatments in the presence and absence of IGF-1. (d) The percentage of mitochondrial membrane depolarization in cells undergoing hormonal treatments in the presence or absence of IGF-1. Adherent and detached cells were combined, stained with JC-1 mitochondrial membrane dye, and examined by using flow cytometry. (a, c, d) Data are expressed as mean ± SD (n = 3). Comparisons were made between treatment groups, and a statistically significant difference was identified in cell number when compared with groups treated with aE2; bE2 + IGF-1; cE2 + 4-OHT + IGF-1; dE2 + MIF + IGF-1; eE2 + 4-OHT; and fE2 + MIF. *Significance at P < 0.001.

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