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Figure 1 | BMC Cancer

Figure 1

From: Genistein inhibits proliferation of colon cancer cells by attenuating a negative effect of epidermal growth factor on tumor suppressor FOXO3 activity

Figure 1

Genistein inhibits EGF-induced proliferation and FOXO3 phosphorylation and translocation in colon cancer cells. (A) HT-29 cells were stimulated with EGF in presence of genistein (10, 50, 100, and 150 μM) and assayed for proliferation 48 hours later by MTS. This experiment was repeated three independent times and graphed data are mean ± sd (n = 24, *p < 0.001). (B) Genistein inhibits EGF-induced FOXO3 phosphorylation. HT-29 cells treated with EGF, with and without genistein, were examined for phosphorylated FOXO3 at Thr32. Genistein inhibits EGF induced FOXO3 phosphorylation. Immunoblots were performed three independent times and graphs represent densitometric analysis means ± sd (n = 3, *p < 0.05). (C) Genistein inhibits EGF-induced translocation of FOXO3. Immunofluorescent staining of experimental monolayers revealed that EGF-induced FOXO3 translocation from the nucleus to the cytosol was inhibited by genistein. This experiment was repeated two times in triplicate. (D) Genistein inhibits FOXO3 phosphorylation in colon cancer cells. Equal amounts of protein extracted from 70% confluent (proliferative) and 100% confluent HT-29 monolayers were separated and immunoblotted with antibodies against phosphorylated FOXO3, total FOXO3, and actin. In proliferative HT-29 cells (70% confluent), the phosphorylated form of FOXO3 is increased relative to non-proliferative cells (100% confluent). HT-29 cells (70% confluent) were incubated with genistein for 24 hours and the status of phosphorylated FOXO3 was examined. Genistein attenuates phosphorylated FOXO3 in sub-confluent HT-29 cells. These experiments were repeated three times and graphs represent densitometric analysis (n = 8, *p < 0.05).

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