Jahns F, Wilhelm A, Jablonowski N, Mothes H, Greulich KO, Glei M. Butyrate modulates antioxidant enzyme expression in malignant and non-malignant human colon tissues.
Mol Carcinog 2014;
54:249-60. [PMID:
24677319 DOI:
10.1002/mc.22102]
[Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 09/21/2013] [Accepted: 10/11/2013] [Indexed: 01/27/2023]
Abstract
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; P < 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 (P < 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 H2 O2 -mediated DNA damage. Despite a significantly lowered SOD2 transcript (0.51-fold, P < 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, P < 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: r = -0.49, P = 0.09; SOD2: r = -0.58, P = 0.049). In conclusion, butyrate exhibited potential antioxidant features ex vivo but cellular consequences need to be investigated more in depth.
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