Goblet cell changes during intestinal adaptation to azoxymethane and enteric bypass in the rat

Gastro-Intestinal Tract Cancers Following Bariatric Surgery: a Narrative Review

The association between obesity and malignancies has been identified epidemiologically. Meanwhile, the increasing global number of bariatric surgeries is reported annually; bariatric surgery's effect on different types of cancers is not well understood. Unfortunately, nonspecific presentations and difficulties regarding investigations make diagnosis challenging. The aim of this study is to compile available data about gastro-intestinal (GI) cancers, occurring after different bariatric surgeries. Although GI cancers are considered a rare complication of obesity surgery, they do exist, and diagnosis needs a high index of suspicion.

Could Mycobacterium avium subspecies paratuberculosis cause Crohn's disease, ulcerative colitis…and colorectal cancer?

Infectious agents are known causes of human cancers. Schistosoma japonicum and Schistosoma mansoni cause a percentage of colorectal cancers in countries where the respective Schistosoma species are prevalent. Colorectal cancer is a complication of ulcerative colitis and colonic Crohn’s disease, the two main forms of idiopathic inflammatory bowel disease (IIBD). Mycobacterium avium subspecies paratuberculosis (MAP), the cause of a chronic intestinal disease in domestic and wild ruminants, is one suspected cause of IIBD. MAP may therefore be involved in the pathogenesis of IIBD-associated colorectal cancer as well as colorectal cancer in individuals without IIBD (sporadic colorectal cancer) in countries where MAP infection of domestic livestock is prevalent and MAP’s presence in soil and water is extensive. MAP organisms have been identified in the intestines of patients with sporadic colorectal cancer and IIBD when high magnification, oil immersion light microscopy (×1000 total magnification rather than the usual ×400 total magnification) is used. Research has demonstrated MAP’s ability to invade intestinal goblet cells and cause acute and chronic goblet cell hyperplasia. Goblet cell hyperplasia is the little-recognized initial pathologic lesion of sporadic colorectal cancer, referred to as transitional mucosa, aberrant crypt foci, goblet cell hyperplastic polyps or transitional polyps. It is the even lesser-recognized initial pathologic feature of IIBD, referred to as hypermucinous mucosa, hyperplastic-like mucosal change, serrated epithelial changes, flat serrated changes, goblet cell rich mucosa or epithelial hyperplasia. Goblet cell hyperplasia is the precursor lesion of adenomas and dysplasia in the classical colorectal cancer pathway, of sessile serrated adenomas and serrated dysplasia in the serrated colorectal cancer pathway, and of flat and elevated dysplasia and dysplasia-associated lesions or masses in IIBD-associated intestinal cancers. MAP’s invasion of intestinal goblet cells may result in the initial pathologic lesion of IIBD and sporadic colorectal cancer. MAP’s persistence in infected intestines may result in the eventual development of both IIBD-associated and sporadic colorectal cancer.

Overexpression of glycine-extended gastrin in transgenic mice results in increased colonic proliferation

Gastrin is a peptide hormone involved in the growth of both normal and malignant gastrointestinal tissue. Recent studies suggest that the glycine-extended biosynthetic intermediates mediate many of these trophic effects, but the in vivo relevance of glycine-extended gastrin (G-Gly) has not been tested. We have generated mice (MTI/G-GLY) that overexpress progastrin truncated at glycine-72 to evaluate the trophic effects of G-Gly in an in vivo model. MTI/G-GLY mice have elevated serum and colonic mucosal levels of G-Gly compared with wild-type mice. MTI/G-GLY mice had a 43% increase in colonic mucosal thickness and a 41% increase in the percentage of goblet cells per crypt. MTI/G-GLY mice exhibited increased colonic proliferation compared with wild-type controls, with an expansion of the proliferative zone into the upper third of the colonic crypts. Continuous infusion of G-Gly into gastrin-deficient mice for two weeks also resulted in elevated G-Gly levels, a 10% increase in colonic mucosal thickness, and an 81% increase in colonic proliferation when compared with gastrin-deficient mice that received saline alone. To our knowledge, these studies demonstrate for the first time that G-Gly's contribute to colonic mucosal proliferation in vivo.

Histochemistry of mucins of pig intestinal secretory epithelial cells before and after weaning

Two histochemical staining techniques, Alcian blue/PAS and high-iron-diamine/Alcian blue, which differentiated neutral from sulphated and sialylated acid mucins were applied to sections of duodenum, ileum, caecum, colon and rectum from pigs aged one day, 3 weeks and 10 weeks. In each age group, sulphated-acid mucins predominated at all sites, particularly in the large intestine. In both the small and the large intestine, non-sulphated mucins occurred mainly at the bases of the crypts. Neutral mucins occurred in a few goblet cells in crypts and villi, either alone or together with acid mucins; neutral mucins increased away from the bases of the crypts. No changes were noted in the caecum, colon or rectum of pigs one, two, 5 or 13 days after weaning onto a diet containing soya protein. In the small intestine, there was a transient increase in the numbers of goblet cells in the crypts and villi, a relative increase in sulphated and a decrease in non-sulphated acid mucins and a change in the distribution of sulphated mucins in the crypts. No change in proportions of neutral and acid mucins was detected.

Influence of sialomucin at the resection margin on local tumour recurrence and survival of patients with colorectal cancer: a multivariate analysis

In a multicentre prospective trial 358 patients undergoing curative surgery for colorectal cancer were followed for a median 18.0 months (+/- 7.2 months). The presence or absence of sialomucin in either resection margin was studied using the high iron diamine-alcian blue stain. There was evidence of excess sialomucin at one or other resection margin in 106 patients (29.6 per cent). Apart from sigmoid carcinomas occurring more often in the sialomucin positive group, there were no significant differences in any histological or clinical parameters between groups. Survival analysis for the events 'death', 'local recurrence', and 'all recurrence' was undertaken using the Cox regression model. The best prognostic variables selected in a stepwise fashion for death and all recurrence were 'Dukes' classification', 'sialomucin present' and 'histological differentiation'. The best prognostic variables selected for local recurrence were 'sialomucin present', 'Dukes' classification' and 'histological differentiation'. Sialomucin in a resection margin is an important independent prognostic variable for the development of local tumour recurrence and of subsequent survival for patients with colorectal carcinoma.

Elevated plasma enteroglucagon alone fails to alter distal colonic carcinogenesis in rats

The effect of physiologic increases of plasma enteroglucagon, induced by massive bypass or resection of small bowel, on large bowel cell turnover and carcinogenesis was studied in rats in which the distal colon was isolated as a mucous fistula. After injections of azoxymethane, either 85% end-to-side jejunoileal bypass, 85% jejunoileal resection, or sham bypass was performed. Controls underwent colonic transection and resuture, azoxymethane treatment, and then sham bypass. Thirty weeks later the plasma enteroglucagon level had almost trebled after jejunoileal bypass (p less than 0.001) and almost doubled after jejunoileal resection (p less than 0.002) when compared with sham bypass; sham values did not differ from controls. The median number of tumors per rat in the distal (defunctioned) colon fell from 2 to 0 (p less than 0.05). Segmental weight fell by 45% (p less than 0.001) and crypt cell production rate by 75% (p less than 0.001). Neither tumor yield nor adaptation was affected by jejunoileal bypass or jejunoileal resection. Plasma enteroglucagon has no effect on colonic cell turnover or carcinogenesis in the absence of luminal content.

Sialomucins at resection margin and likelihood of recurrence in colorectal carcinoma

Oncogenic transformation of colonic epithelium is accompanied by changes in surface carbohydrate, notably an increased secretion of sialomucins at the expense of the normally predominant sulphomucins. In a multicentre prospective trial the correlation between the presence of sialomucins at the resection margin and the subsequent development of local recurrence was studied in 250 patients who had undergone "curative" resection for colorectal carcinoma with a mean follow up period of 14 months. Nineteen of 70 patients (27.1%) with a sialomucin predominant pattern at either resection margin developed local recurrence compared with 15 of 180 patients (8.3%) with a mixed or sulphomucin predominant pattern (p less than 0.01). Increased sialomucin staining at the resection margins was associated with reduced survival in these patients (p less than 0.01). At a mean of 14 months of follow up 153 patients (85%) were alive in the sulphomucin group and 53 patients (76%) were alive in the sialomucin group. Regression analysis predicted five year survivals of 32.8% and 18.9% for the sulphomucin and sialomucin groups respectively. Abnormal mucus production at the resection margin in patients treated for colorectal carcinoma appears to identify those with a higher risk of local recurrence and reduced survival.