Bean (Phaseolus vulgaris L.) polysaccharides modulate gene expression in human colon cancer cells (HT-29)

Colorectal cancer is one of the most commonly diagnosed cancers in the United States and the third cause of cancer mortality in México. We present the results of molecular changes involved in p53 pathway in HT-29 cells evaluated by PCR array after 24 h exposure to in vitro fermented bean (cv. Bayo Madero) polysaccharide extract with human gut flora (FE-hgf). Significant differences were detected in 72 of 84 human p53-mediated signal transduction response genes involved in apoptosis, cell cycle and cell proliferation showed significant expression changes. Apoptosis genes, SIAH1, PRKCA and negative regulation of the cell cycle gene MSH2 were the highest up-regulated genes (30.5-, 18.4- and 9.8-fold, respectively), whereas cell cycle genes CHEK1 and GADD45A were markedly down regulated (21.4- and 9.1-fold, respectively). We demonstrate that common beans and or/it´s polysaccharides modulate gene expression profiles in HT-29 cells, providing insight about the mechanism underlying its overall chemoprotective function against colon carcinogenesis.