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HCT-116 Cells (hct-116 + cell)
Selected AbstractsAnticancerogenic effect of a novel chiroinositol-containing polysaccharide from Bifidobacterium bifidum BGN4FEMS MICROBIOLOGY LETTERS, Issue 2 2004Hyun Ju You Abstract Strains of bifidobacteria have many health-promotion effects. Whole cells or cytoplasm extracts of Bifidobacterium bifidum BGN4, isolated from human feces, inhibited the growth of several cancer cell lines. The polysaccharide fraction (BB-pol) extracted from B. bifidum BGN4 had a novel composition, comprising chiroinositol, rhamnose, glucose, galactose, and ribose. Three human colon cancer cell lines were treated with BB-pol: HT-29, HCT-116, and Caco-2. Trypan blue exclusion assay and BrdU incorporation assay showed that BB-pol inhibited the growth of HT-29 and HCT-116 cells but did not inhibit the growth of Caco-2 cells. [source] Linear relationship between Wnt activity levels and apoptosis in colorectal carcinoma cells exposed to butyrateINTERNATIONAL JOURNAL OF CANCER, Issue 4 2004Darina L. Lazarova Abstract We have reported that butyrate, a fatty acid produced by dietary fiber that induces cell cycle arrest, differentiation and/or apoptosis in colorectal carcinoma (CRC) cells in vitro, modulates Wnt activity in 2 CRC cell lines (Bordonaro et al., Int. J. Cancer, 2002; 97:42,51). Our study determines how changes in the levels of Wnt activity induced by butyrate relate to the effects of butyrate on apoptosis, cell cycle arrest and differentiation of CRC cells. In 10 human CRC cell lines a direct relationship was shown between apoptosis and butyrate-induced increase in Wnt activity, as well as between suppressed clonal growth and increased Wnt activity. No correlation existed between butyrate-induced increase in Wnt activity and differentiation. The direct relationship between apoptosis and Wnt activity was supported by analyses of DLD-1 and HCT-116 cells expressing a dominant negative form of Tcf4, and therefore, with repressed Wnt activity, as well as by measuring the ratio of apoptotic to live cells in flow cytometry-sorted cell fractions with high and low Wnt activity. Novel flow cytometric methodology was utilized to show that butyrate differentially increases the number of cells with Wnt activity in different CRC cell lines. Thus, CRC cell lines in which butyrate upregulated Wnt activity to relatively high levels were most susceptible to the apoptotic effects of butyrate, whereas cell lines in which butyrate modestly modulated Wnt activity were less affected. © 2004 Wiley-Liss, Inc. [source] The 15-lipoxygenase-1 expression may enhance the sensitivity to non-steroidal anti-inflammatory drug-induced apoptosis in colorectal cancers from patients who are treated with the compoundsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 12 2007Masahiro Yoshinaga Abstract Background and Aim:, Non-steroidal anti-inflammatory drugs (NSAIDs) can prevent colorectal cancer (CRC), but their effect is limited. Recent studies have shown the involvement of 15-lipoxygenase-1 (15-LOX-1) in NSAID-induced apoptosis in colorectal carcinoma cells. We evaluate whether 15-LOX-1 expression influences the sensitivity of NSAID-induced apoptosis in CRCs. Methods:, In 22 CRC surgical samples from NSAID users who had been constant for more than 5 years and 28 CRC surgical samples from NSAID non-users, the expressions of 15-LOX-1, cyclooxygenase-2 (COX-2), beta-catenin, and p53 were analyzed using immunohistochemistry. TUNEL assay was also performed for samples. The effects of the transient transfection of 15-LOX-1 cDNA on indomethacin-induced apoptosis were certified in HCT-116 cells. The effects of adding 13-S-hydroxyoctadecadinoic acid (13-S-HODE) on indomethacin-induced apoptosis were also examined in HCT-116 cells. The levels of apoptosis were determined by the analysis of the floating-cells ratio and DNA gel electrophoresis. Results:, The expression of 15-LOX-1 on CRCs from NSAID users was significantly decreased compared with those from NSAID non-users; however, the expressions of other molecules were not significantly different between two groups. The levels of TUNEL scoring in samples from NSAID users were similar to those from NSAID non-users. Indomethacin (100 ,M) induced less apoptosis in mocked cells, whereas the same concentrations of indomethacin enhanced the level of apoptosis in 15-LOX-1-transfected cells. 13-S-HODE also increased the level of indomethacin-induced apoptosis in cells. Conclusion:, Results suggest that 15-LOX-1 expression may be one of the mechanisms which enhance the sensitivity to NSAID-induced apoptosis in CRCs from patients who are treated with the compounds. [source] Differential apoptosis by gallotannin in human colon cancer cells with distinct p53 statusMOLECULAR CARCINOGENESIS, Issue 3 2007Sahar Al-Ayyoubi Abstract Gallotannin (GT), a plant polyphenol, has shown anticarcinogenic activities in several animal models including colon cancer. In our previous study, we showed that GT inhibits 1,2-dimethylhydrazine-induced colonic aberrant crypt foci and tumors in Balb/c mice, thus supporting a role for GT as a chemopreventive agent in colon cancer. However, at the molecular level, GT's mechanism of chemoprevention is still unclear. In this study, we aim at identifying GT's potential molecular mechanisms of action in in vitro studies. We show that GT differentially inhibits the growth of two isogenic HCT-116 (p53+/+, p53,/,) human colon cancer cells versus normal human intestinal epithelial cells (FHs 74Int). DNA flow cytometric analysis showed that GT induced S-phase arrest in both HCT-116 cell lines. Cell-cycle arrest in p53 (+/+) cells was associated with an increase in p53 protein levels and p21 transcript and protein levels. The inhibition of cell-cycle progression of HCT-116 p53 (+/+) cells by GT correlated with a reduction in the protein levels of cyclin D1, pRb, and the Bax/Bcl-2 ratio. Although GT did not induce apoptosis in p53 (+/+) cells, a significant induction of apoptosis was observed in p53 (,/,) cells as shown by TUNEL staining and flow cytometry analysis. Apoptosis induction in p53 (,/,) cells was associated with a significant increase in Bax/Bcl-2 protein levels. Our results demonstrate that GT inhibits the growth of HCT-116 colon cancer cells in a p53-independent manner but exhibits differential sensitivity to apoptosis induction in HCT-116 cells with distinct p53 status. © 2006 Wiley-Liss, Inc. [source] | ||||||||||