Nordling M M, Glinghammar B, Karlsson P C, Rafter J J
a Dept. of Medical Nutrition Karolinska Institutet Novum Huddinge Sweden.
b King Gustav V Research Institute Karolinska Hospital Stockholm Sweden.
Scand J Gastroenterol. 2003;38(5):549-555. doi: 10.1080/00365520310002913.
The free water phase of feces (fecal water) may mediate the effects of diet on colon carcinogenesis. We examined the effects of fecal water from adenoma patients and controls on three parameters in colonocytes believed to be relevant to tumorigenesis, i.e. genotoxicity in intact cells and on isolated DNA, proliferative activity and activator protein-1 (AP-1) activity.
Genotoxicity in intact colonic cells was assayed using the single-cell gel electrophoresis assay (comet' assay) and on isolated DNA using double-stranded DNA from the X-174 RF plasmid. Cell proliferation was assessed using the commercially available alamar blue' proliferation kit and AP-1 activity using cells transiently transfected with an AP-1-luciferase reporter construct.
The data showed that lipid extracts of fecal water samples from the adenoma patients had a significantly higher capacity to induce cell proliferation than those from controls, and that this effect could be explained to a large extent by the concentrations of deoxycholic and chenodeoxycholic acids in the fecal water using regression models. No difference between patients and controls was observed for induction of AP-1 activity or induction of DNA strand breaks in intact cells. However, induction of DNA strand breaks in isolated DNA was significantly higher for the fecal waters from patients than for those from controls, which could be explained in part in a regression model by concentrations of lithocholic acid in fecal water and fecapentaene-12 in feces.
Our results support the hypothesis that the biochemistry of fecal waters from adenoma patients and controls differs.
粪便中的自由水相（粪水）可能介导饮食对结肠癌发生的影响。我们研究了腺瘤患者和对照组的粪水对结肠细胞中三个被认为与肿瘤发生相关参数的影响，即完整细胞和分离DNA的遗传毒性、增殖活性以及激活蛋白-1（AP-1）活性。
使用单细胞凝胶电泳试验（“彗星”试验）检测完整结肠细胞的遗传毒性，使用来自X-174 RF质粒的双链DNA检测分离DNA的遗传毒性。使用市售的“alamar blue”增殖试剂盒评估细胞增殖，使用瞬时转染AP-1荧光素酶报告构建体的细胞评估AP-1活性。
数据显示，腺瘤患者粪水样本的脂质提取物诱导细胞增殖的能力显著高于对照组，并且使用回归模型，这种效应在很大程度上可以由粪水中脱氧胆酸和鹅脱氧胆酸的浓度来解释。在诱导AP-1活性或完整细胞中DNA链断裂方面，未观察到患者与对照组之间的差异。然而，患者粪水诱导分离DNA中DNA链断裂的程度显著高于对照组，在回归模型中，这部分可以由粪水中石胆酸的浓度和粪便中粪戊烯-12的浓度来解释。
我们的结果支持腺瘤患者和对照组粪水生物化学不同的假设。
