Calcium affects biomarkers of colon carcinogenesis after right hemicolectomy

Comparison between Organic and Inorganic Zinc Forms and Their Combinations with Various Dietary Fibers in Respect of the Effects on Electrolyte Concentrations and Mucosa in the Large Intestine of Pigs

This study aimed to determine the effects of Zn sources, used with potato fiber (PF) or lignocellulose (LC), on electrolyte concentration and the mucus layer in the large intestine of pigs. The experiment involved 24 barrows with an initial body weight of 10.8 ± 0.82 kg, divided into four groups fed the following diets: LC and ZnSO4, LC and Zn glycinate (ZnGly), PF and ZnSO4, or PF and ZnGly. Fiber supplements provided 10 g crude fiber/kg diet, while Zn additives introduced 120 mg Zn/kg diet. After four weeks of feeding, the pigs were sacrificed and digesta and tissue samples were taken from the cecum and colon. PF increased the water content and decreased the phosphorus concentration in the large intestine in comparison with LC. PF also increased calcium, iron, and chloride concentrations in the descending colon. Mucus layer thickness and histological parameters of the large intestine were not affected. ZnGly diets increased MUC12 expression in the cecum as compared to the LC-ZnSO4 group. In the ascending colon, the PF-ZnGly diet increased MUC5AC expression, while both PF groups had greater MUC20 expression in comparison with the LC-ZnSO4 group. In the transverse colon, the LC-ZnGly group and both PF groups had higher MUC5AC expression in comparison with the LC-ZnSO4 group, and both ZnGly groups had higher MUC20 expression than ZnSO4 groups. PF and ZnGly increased MUC4 and MUC5AC expression in the descending colon. PF and ZnGly may exert a beneficial effect on colon health in pigs by upregulating the expression of the MUC5AC and MUC20 genes and are more effective than LC and ZnSO4.

Effects of vitamin d and calcium on proliferation and differentiation in normal colon mucosa: a randomized clinical trial

To investigate the potential efficacy of calcium and vitamin D in reducing risk for colorectal neoplasms and to develop "treatable" phenotypic biomarkers of risk for colorectal neoplasms, we conducted a pilot, randomized, double-blind, placebo-controlled, 2 x 2 factorial clinical trial to test the effects of these agents on cell cycle markers in the normal colorectal mucosa. Ninety-two men and women with at least one pathology-confirmed colorectal adenoma were treated with 2 g/day calcium and/or 800 IU/day vitamin D(3) versus placebo over 6 months. Overall expression and distributions of p21(waf1/cip1) (marker of differentiation), MIB-1 (marker of short-term proliferation), and hTERT (marker of long-term proliferation) in colorectal crypts in the normal-appearing rectal mucosa were detected by automated immunohistochemistry and quantified by image analysis. In the calcium, vitamin D, and calcium plus vitamin D groups relative to the placebo, p21 expression increased by 201% (P = 0.03), 242% (P = 0.005), and 25% (P = 0.47), respectively, along the full lengths of colorectal crypts after 6 months of treatment. There were no statistically significant changes in the expression of either MIB-1 or hTERT in the crypts overall; however, the proportion of hTERT, but not MIB-1, expression that extended into the upper 40% of the crypts was reduced by 15% (P = 0.02) in the vitamin D plus calcium group relative to the placebo. These results indicate that calcium and vitamin D promote colorectal epithelial cell differentiation and may "normalize" the colorectal crypt proliferative zone in sporadic adenoma patients, and support further investigation of calcium and vitamin D as chemopreventive agents against colorectal neoplasms.

Diet, fecal water, and colon cancer--development of a biomarker

Colorectal cancer (CRC) is a leading cause of cancer incidence worldwide. Lifestyle factors, especially dietary intake, affect the risk of CRC development. Suitable risk biomarkers are required in order to assess the effect that specific dietary components have on CRC risk. The relationship between dietary intake and indicators of fecal water activity has been assessed using cell and animal models as well as human studies. This review summarizes the literature on fecal water and dietary components with a view to establishing further the potential role of fecal water as a source of CRC risk biomarkers. The literature indicates that fecal water activity markers are affected by specific dietary components linked with CRC risk: red meat, saturated fats, bile acids, and fatty acids are associated with an increase in fecal water toxicity, while the converse appears to be true for calcium, probiotics, and prebiotics. However, it must be acknowledged that the study of fecal water is still in its infancy and a number of issues need to be addressed before its usefulness can be truly gauged.

Colorectal cancer chemoprevention--an overview of the science

The development and dissemination of sophisticated detection technologies have recently exposed the high prevalence of preinvasive colorectal neoplasia in the adult U.S. population. Although cancer screening and surveillance provide opportunities for risk stratification, they achieve risk reduction only when coupled with effective interventions. This review surveys the lead compounds for colorectal cancer prevention and the measures by which they may be prioritized for clinical testing. Clinical trials remain the rate-limiting step in agent development, and novel trial designs are needed to hasten agent identification and testing for cancer prevention. Innovative research models include the nesting of prevention end points within cancer treatment trials and within trials testing promising preventive compounds intended for nononcologic indications.