Potentiation of the Effect of Erlotinib by Genistein in Pancreatic Cancer: The Role of Akt and Nuclear Factor- B

Division of Hematology/Oncology, Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, Michigan 48201, USA.
Cancer Research (Impact Factor: 9.33). 11/2006; 66(21):10553-9. DOI: 10.1158/0008-5472.CAN-06-2333
Source: PubMed


The epidermal growth factor receptor (EGFR) is a target of new therapies in most nonhematologic cancers. EGFR blockade alone may not be sufficient for the control of growth and invasion of human pancreas cancer because of the independent activation of Akt and nuclear factor-kappaB (NF-kappaB). The expression of EGFR, Akt, and NF-kappaB was determined in six human pancreatic cancer cell lines. Selected cells for specific expression were treated with erlotinib, genistein, gemcitabine, or the combination. Growth inhibition was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and apoptosis was assayed by ELISA. EGFR, phosphorylated EGFR, phosphorylated Akt, and survivin expressions were determined by immunoblotting. Electrophoretic mobility shift assay was used to evaluate the DNA binding activity of NF-kappaB. Genistein significantly increased (P < 0.05) erlotinib-induced growth inhibition and apoptosis in BxPC-3, CAPAN-2, and AsPC-1 cells. In the BxPC-3 cell line, significant down-regulation of EGFR, phosphorylated Akt, NF-kappaB activation, and survivin was observed in the cells treated with the combination compared with the erlotinib-treated cells. In the HPAC and MIAPaCa cell line, no potentiation of the effects of erlotinib by genistein on cell growth or inhibition of the EGFR/Akt/NF-kappaB was observed. Genistein potentiated growth inhibition and apoptosis of the gemcitabine and erlotinib combination in COLO-357 cell line. Genistein potentiates the growth inhibition and apoptosis induced by erlotinib and gemcitabine in certain pancreatic cancer cells. Akt and NF-kappaB inhibition represents one of the mechanisms for the potentiation of erlotinib- and gemcitabine-induced cell death by genistein.

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    • "Inhibition of Nuclear Factor-kappa B (NF-κB) and attenuation of Akt pathways by genistein have been shown in various cancer types [13–16]. NF-κB not only controls the expression of genes involved in survival and proliferation, but also plays a key role in apoptosis [17]. Moreover, NF-κB inhibition in tumor cells may result in increased activity of topoisomerase II inhibitors and, hence, this inhibition can be used in anticancer therapy [18]. "
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