cytellin and Adenoma

The rate of APC mutations in the intestine increases in middle-age. At the same period of life, plant sterol and stanol enriched functional foods are introduced to diet to lower blood cholesterol. This study examined the effect of plant stanol enriched diet on intestinal adenoma formation in the Apc(Min) mouse. Apc(Min) mice were fed 0.8% plant stanol diet or control diet for nine weeks. Cholesterol, plant sterols and plant stanols were analyzed from the caecum content and the intestinal mucosa. Levels of β-catenin, cyclin D1, epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase 1/2 (ERK1/2) were measured from the intestinal mucosa by Western blotting. Gene expression was determined from the intestinal mucosa using Affymetrix and the data were analyzed for enriched categories and pathways. Plant stanols induced adenoma formation in the small intestine, however, the adenoma size was not affected. We saw increased levels of nuclear β-catenin, phosphorylated β-catenin (Ser675 and Ser552), nuclear cyclin D1, total and phosphorylated EGFR and phosphorylated ERK1/2 in the intestinal mucosa after plant stanol feeding. The Affymetrix data demonstrate that several enzymes of cholesterol synthesis pathway were up-regulated, although the cholesterol level in the intestinal mucosa was not altered. We show that plant stanols induce adenoma formation by activating Wnt and EGFR signaling. EGFR signaling seems to have promoted β-catenin phosphorylation and its translocation into the nucleus, where the expression of cyclin D1 was increased. Up-regulated cholesterol synthesis may partly explain the increased EGFR signaling in the plant stanol-fed mice.

Topics: Adenoma; Animals; beta Catenin; Cecum; Cholesterol; Cyclin D1; ErbB Receptors; Female; Gene Expression Regulation; Genes, APC; Intestinal Mucosa; Intestinal Neoplasms; Male; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Mitogen-Activated Protein Kinase 3; Phytosterols; Proto-Oncogene Proteins c-akt; Serine; Sitosterols; Sterol Regulatory Element Binding Protein 2; Up-Regulation; Wnt Signaling Pathway

This study examined the effects of lyophilized black raspberries (BRB) on azoxymethane (AOM)-induced aberrant crypt foci (ACF), colon tumors, and urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels in male Fischer 344 rats. AOM was injected (15 mg/kg body wt i.p.) once per week for 2 wk. At 24 h after the final injection, AOM-treated rats began consuming diets containing 0%, 2.5%, 5%, or 10% (wt/wt) BRB. Vehicle controls received 5% BRB or diet only. Rats were sacrificed after 9 and 33 wk of BRB feeding for ACF enumeration and tumor analysis. ACF multiplicity decreased 36%, 24%, and 21% (P < 0.01 for all groups) in the 2.5%, 5%, and 10% BRB groups, respectively, relative to the AOM-only group. Total tumor multiplicity declined 42%, 45%, and 71% (P < 0.05 for all groups). Although not significant, a decrease in tumor burden (28%, 42%, and 75%) was observed in all BRB groups. Adenocarcinoma multiplicity decreased 28%, 35%, and 80% (P < 0.01) in the same treatment groups. Urinary 8-OHdG levels were reduced by 73%, 81%, and 83% (P < 0.01 for all groups). These results indicate that BRB inhibit several measures of AOM-induced colon carcinogenesis and modulate an important marker of oxidative stress in the Fischer 344 rat.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Adenocarcinoma; Adenoma; Animals; Anthocyanins; Anticarcinogenic Agents; Azoxymethane; Calcium; Cholesterol; Colonic Neoplasms; Coumaric Acids; Deoxyguanosine; Diet; Ellagic Acid; Freeze Drying; Fruit; Oxidative Stress; Rats; Rats, Inbred F344; Rosaceae; Sitosterols

Topics: Adenoma; Humans; Male; Plant Extracts; Prostatic Hyperplasia; Sitosterols; Urination Disorders; Urodynamics

Topics: Adenoma; Humans; Male; Prostaglandins; Prostaglandins E; Prostaglandins F; Prostatic Neoplasms; Sitosterols

Topics: Adenoma; Humans; Male; Plants, Medicinal; Prostatic Neoplasms; Sitosterols