Butyrate modulates antioxidant enzyme expression in malignant and non‐malignant human colon tissues. Issue 4 (28th March 2014)

• Record Type: Journal Article
• Authors: Jahns, Franziska; Wilhelm, Anne; Jablonowski, Nadja; Mothes, Henning; Greulich, Karl Otto; Glei, Michael
• Is Part Of: Molecular carcinogenesis. Volume 54:Issue 4(2015:Apr.)
• Page Start: 249
• Page End: 260
• Publication Date: 2014-03-28
• Subjects: Carcinogenesis -- Molecular aspects -- Periodicals; 616.994071
• DOI: 10.1002/mc.22102
• Languages: English
• ISSNs: 0899-1987

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="mc22102-sec-0001" sec-type="section"> <p>The induction of antioxidant enzymes is an important mechanism in colon cancer chemoprevention, but the response of human colon tissue to butyrate, a gut fermentation product derived from dietary fiber, remains largely unknown. Therefore, our study investigated the effect of a butyrate treatment on catalase (CAT) and superoxide dismutase (SOD2) in matched human colon tissues of different transformation stages (n = 3–15 in each group) ex vivo. By performing quantitative real‐time PCR, Western blot, and spectrophotometric measurements, we found an increase in SOD2 at expression and activity level in colonic adenocarcinomas (mRNA: 1.96‐fold; protein: 1.41‐fold, activity: 1.8‐fold; <italic>P</italic> < 0.05). No difference was detectable for CAT between normal, adenoma, and carcinoma colon tissues. Treatment of normal colon epithelium (12 h) with a physiologically relevant concentration of butyrate (10 mM) resulted in a significant increase (<italic>P</italic> < 0.05) in CAT mRNA (1.24‐fold) and protein (1.39‐fold), without affecting the enzymatic activity. Consequently, preliminary experiments failed to show any protective effect of butyrate against H<sub>2</sub>O<sub>2</sub>‐mediated DNA damage. Despite a significantly lowered SOD2 transcript (0.51‐fold, <italic>P</italic> < 0.01) and, to a lesser extent, protein level (0.86‐fold) after butyrate exposure of normal colon cells, the catalytic activity was significantly enhanced (1.19‐fold, <italic>P</italic> < 0.05), suggesting an increased protection against tissue superoxide radicals. In malignant tissues, greater variations in response to butyrate were observed. Furthermore, both enzymes showed an age‐dependent decrease in activity in normal colon epithelium (CAT: <italic>r</italic> = −0.49, <italic>P</italic> = 0.09; SOD2: <italic>r</italic> = −0.58, <italic>P</italic> = 0.049). In conclusion, butyrate exhibited potential antioxidant features ex vivo but cellular consequences need to be investigated more in depth. © 2014 Wiley Periodicals, Inc.</p> </sec> </abstract>