Abstract A32: Proteomic signatures of deoxycholic acid and ursodeoxycholic acid treated human colon cancer cells
Autor: | Daniel W. Rosenberg, Antoine Ménoret, Anthony T. Vella, Masako Nakanishi |
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Rok vydání: | 2008 |
Předmět: | |
Zdroj: | Cancer Prevention Research. 1:A32-A32 |
ISSN: | 1940-6215 1940-6207 |
Popis: | A32 Dietary factors play an important role in the pathogenesis of colorectal cancer (CRC), due in part to the influence of the bile acids. While the secondary bile acid, deoxycholic acid (DCA), has been associated with tumor promotion, one tertiary bile acid in particular, ursodeoxycholic acid (UDCA), has been demonstrated to exert chemopreventive properties in the colon. Although its efficacy against high-grade adenomas has already been demonstrated in phase III clinical trials, mechanisms by which UDCA suppresses colon tumorigenesis remain unclear. In order to gain further insight into the tumor modifying properties of the bile acids, we compared the effects of DCA and UDCA on human colon tumor cells (CaCo-2) using proteomic analyses. In the following study, CaCo-2 cells grown at 70% confluence were treated with either 10 µM deoxycholic acid (DCA) or 1 mM ursodeoxycholic acid (UDCA) for 72 hours. For the proteomic analysis, protein was first fractionated by PF2D isochromatofocusing on a Beckman Coulter ProteomeLab PF2D platform. Fractions corresponding to a linear gradient between pH 8.0 and 4.0 were collected and processed through an automated autoloader for further separation by HPRP-PF2D reverse phase chromatography. Two dimensional protein expression maps displaying isoelectric point (pI) versus hydrophobicity were generated by the ProteoView/DeltaVue software package. Pairwise analysis of these complex protein chromatograms demonstrated common peak profiles (signatures) as well as unique peaks (fingerprints) characteristic of UDCA or DCA treatment. One of these protein peaks that exhibited a differential expression pattern between the two drug treatments was identified by MALDI and tandem mass spectrometry sequencing as heat-shock protein 60 (Hsp60). Furthermore, this protein was found to be less oxidized upon treatment with UDCA, suggesting the attenuation of oxidative stress present in cancer cells. Further analyses on the role of Hsp60 as well as resultant diminished oxidative stress will enable the discovery of potential mechanisms by which DCA and UDCA control cellular pathways. Citation Information: Cancer Prev Res 2008;1(7 Suppl):A32. |
Databáze: | OpenAIRE |
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