c-peptide and Adenomatous-Polyps

Blueberries may lower relative risk for cancers of the gastrointestinal tract. Previous work indicated an inhibitory effect of consumed blueberry (BB) on formation of aberrant crypt foci (ACF) in colons of male Fisher F344 rats (inbred strain). However, effects of BB on colon tumors and in both genders are unknown.. We examined efficacy of BB in inhibition of azoxymethane (AOM)-induced colon ACF and intestine tumors in male and female Sprague-Dawley rats (outbred strain). Pregnant rats were fed a diet with or without 10% BB powder; progeny were weaned to the same diet as their dam and received AOM as young adults.. Male and female rats on control diet had similar numbers of ACF at 6 weeks after AOM administration. BB increased (P < 0.05) ACF numbers within the distal colon of female but not male rats. There was a significant (P < 0.05) diet by gender interaction with respect to total colon ACF number. Colon and duodenum tumor incidences were less in females than males at 17 weeks after AOM. BB tended (0.1 > P > 0.05) to reduce overall gastrointestinal tract tumor incidence in males, however, tumor incidence in females was unaffected (P > 0.1) by BB. There was a tendency (0.1 > P > 0.05) for fewer adenocarcinomas (relative to total of adenomatous polyps plus adenocarcinomas) in colons of female than male tumor-bearing rats; in small intestine, this gender difference was significant (P < 0.05). BB favored (P < 0.05) fewer adenocarcinomas and more adenomatous polyps (as a proportion of total tumor number) in female rat small intestine.. Results did not indicate robust cancer-preventive effects of BB. Blueberry influenced ACF occurrence in distal colon and tumor progression in duodenum, in gender-specific fashion. Data indicate the potential for slowing tumor progression (adenomatous polyp to adenocarcinoma) by BB.

Topics: Adenocarcinoma; Adenomatous Polyps; Animals; Azoxymethane; Blueberry Plants; C-Peptide; Colonic Neoplasms; Disease Models, Animal; Disease Progression; Duodenal Neoplasms; Female; Incidence; Male; Nutrition Therapy; Rats; Rats, Sprague-Dawley

Colon carcinogenesis is a multi-steps process in which many growth factors are involved. In some studies the increased risk of colon cancer development was observed in patients with diabetes mellitus type 2 with accompanying hyperinsulinemia. It is also known that insulin-like growth factor I (IGF-I) plays an important role in proliferation, growth, differentiation and inhibiting apoptosis of both epithelial and carcinoma cells. The aim of the study was to evaluate the serum concentration of insulin, C-peptide and IGF-I in patients with colon adenomas and colorectal cancer.. In 17 patients with colon cancer, 32 patients with colon adenomas and in 12 healthy persons the serum concentration of insulin, C-peptide and IGF-I was determined using ELISA kits.. In patients with colon cancer significantly higher serum IGF-I concentration comparing to the control group was observed (85.66 ng/ml vs. 60.96 ng/ml; p < 0.05). Higher IGF-I concentration was also observed in patients with distal tumors comparing to the proximal localisation (95.40 ng/ml vs. 64,65 ng/ml, p < 0.05) and in more differentiated tumors (84.36 ng/ml vs. 75.24 ng/ml). Similarly, higher C-peptide concentrations were observed in distal tumors (635.64 pmol/ I vs. 578.69 pmol/l) and in well-differentiated carcinoma (671.32 pmol/ I vs. 575.66 pmol/l). In patients with colon adenomatous polyps we also observed higher serum IGF-I concentrations I comparing to the control group (82.1 ng/ml vs. 60.96 ng/ml), in high dysplasia adenomas (84.12 ng/ml vs. 79.67 ng/ml) and in smaller adenomas to 1 cm diameter (97.98 ng/ml vs. 73.28 ng/ml), but the differences were not significant. We also observed higher concentration of C-peptide in patients with low grade dysplasia adenomas (665.24 pmol/l vs. 498.13 pmol/l) and with small polyps (611.51 pmol/l vs. 514.89 pmol/l). There were no differences in serum concentration of IGF-I and C-peptide between patients with tubular and villous adenomas. There was no statistical difference observed in insulin serum concentration in all groups of patients.. IGF-I is probably involved particularly in the early stage of colon carcinogenesis.

Topics: Adenoma; Adenomatous Polyps; Adult; Aged; Aged, 80 and over; Biomarkers, Tumor; C-Peptide; Colonic Polyps; Colorectal Neoplasms; Diabetes Mellitus, Type 2; Female; Humans; Hyperinsulinism; Insulin; Insulin-Like Growth Factor I; Male; Middle Aged