Abstract B22: Modulation of insulin-like growth factor binding proteins expression in human prostate cancer cells in vitro by american cranberry (Vaccinium macrocarpon) extract

Abstract

Abstract American cranberry (Vaccinium macrocarpon) extract has been previously shown to affect cell cycle, apoptosis, and proliferative ability in prostate cancer cells in vitro. The insulin-like growth factors (IGFs) and their modulators the insulin-like growth factor binding proteins (IGFBPs) may play roles in these events. IGFBPs act by regulating IGF action but also exhibit many IGF-independent activities. IGFBP expression in response to cranberry extract [50 & 100 ug/mL for 3 and 24 hours] was determined via Western blot analysis in DU145 and in PC3 androgen-refractory human prostate cancer cells. Cranberry extract treatment decreased the expression levels of both IGFBP-2 and IGFBP-5 and increased the expression levels of IGFBP-4. IGFBP-3 protein expression levels were apparently unaffected by cranberry extract suggesting that IGFBP-3 is likely not involved in this cellular response to cranberry extract. A reduction in IGFBP-2/-5 expression suggests a reduction in IGF through loss of IGF-stabilization by the IGFBPs suggesting an inhibition of the cell cycle due to this restriction in IGF. Increases in IGFBP-4 levels in response to cranberry would also inhibit IGFs and thereby inhibit cellular growth and proliferation. Increased IGFBP-2/-5 expression has been associated with progression from androgen-sensitivity to androgen-insensitivity in prostate cancer cells. Decreased IGFBP-2/-5 expression levels in response to cranberry extract could counteract this progression in vitro. [funded by The Cranberry Institute (Wisconsin Board) and Jeanne & J.-Louis Levesque Foundation] Citation Format: Robert Hurta, Brendan McKeown, Ravi Boddeti, Catherine Neto. Modulation of insulin-like growth factor binding proteins expression in human prostate cancer cells in vitro by american cranberry (Vaccinium macrocarpon) extract. [abstract]. In: Proceedings of the Third AACR International Conference on Frontiers in Basic Cancer Research; Sep 18-22, 2013; National Harbor, MD. Philadelphia (PA): AACR; Cancer Res 2013;73(19 Suppl):Abstract nr B22.