Related Papers
Cancer research
Intestinal metaplasia of human stomach displays distinct patterns of mucin (MUC1, MUC2, MUC5AC, and MUC6) expression
1999 •
Leonor David
Intestinal metaplasia is a well-established premalignant condition of the stomach that is characterized by mucin carbohydrate modifications defined by histochemical methods. The purpose of the present study was to see whether the expression of mucin core proteins was modified in the different types of intestinal metaplasia and to evaluate the putative usefulness of mucins as "molecular markers" in this setting. We used a panel of monoclonal antibodies with well-defined specificities to MUC1, MUC2, MUC5AC, and MUC6 to characterize the expression pattern of mucins. In contrast to normal gastric mucosa, the complete form or type I intestinal metaplasia (n = 20) displayed little or no expression of MUC1, MUC5AC, or MUC6 in the metaplastic cells and strong expression of the intestinal mucin MUC2 in the goblet cells of all cases. The incomplete forms of intestinal metaplasia, type II (n = 25) and type III (n = 16), expressed MUC1 and MUC5AC in every case, both in goblet and in c...
Virchows Archiv
Mucins as key molecules for the classification of intestinal metaplasia of the stomach
2002 •
Celso Reis
Mucins and mucin-associated carbohydrates have a distinct expression pattern that can be modified under pathological conditions. Normal gastric mucosa expresses MUC1 and MUC5AC in foveolar epithelium and MUC6 in the glands. Lewis type-1 chain antigens (Lea and Leb) are expressed in foveolar epithelium, whereas Lewis type-2 chain antigens (Lex and Ley) are expressed in the glands. In this study we used monoclonal antibodies to evaluate the pattern of mucins and Lewis type-1 carbohydrates in intestinal metaplasia (IM) and compared it with IM types determined using histochemistry. In type-I or complete IM we found expression of MUC2 intestinal mucin and decreased/absent expression of MUC1, MUC5AC and MUC6. In type-II/III or incomplete IM there was co-expression of MUC2 and the mucins expressed in the stomach. No major differences were detected among the three IM types regarding expression of Lewis antigens. Furthermore we observed that sialylated compounds other than sialyl-Lea are responsible for histochemical detection of sialomucins and that sulpho-Lea/c is expressed in the presence or absence of sulphomucins detected using histochemistry. We conclude that mucin immunohistochemistry may replace classic histochemistry for the classification of IM into complete and incomplete types. The present study challenges the distinction of type-II from type-III IM since we did not observe major differences in the expression profile of mucins and Lewis type-1 carbohydrates. Finally, it seems necessary to evaluate the predictive value of IM according to the presence of specific sulphated carbohydrates (e.g. sulpho-Lea/c) rather than histochemically detected sulphomucins.
Molecular cancer
Expression profile of mucins (MUC2, MUC5AC and MUC6) in Helicobacter pylori infected pre-neoplastic and neoplastic human gastric epithelium
2006 •
niranjali devaraj
Helicobacter pylori (H. pylori) causes gastritis and intestinal metaplasia (IM) that may evolve to gastric carcinoma. The objective of this study was to compare the profile of mucins in the progressive stages of H. pylori infected pre-neoplastic and neoplastic human gastric epithelium. We used a panel of monoclonal antibodies with well-defined specificities of MUC2, MUC5AC and MUC6 to characterize the expression pattern of mucins by immunohistochemistry. RUT and ELISA were down for H. pylori confirmation. Human gastric biopsy sections were stained using immunohistochemistry with MUC2, MUC5AC and MUC6 antibodies. MUC5AC was expressed in the superficial epithelium and the upper part of the gastric pits. MUC6 expression was detected in the lower part of the gastric glands. MUC2 was expressed in intestinal metaplasia, mostly in goblet cells. The mucin expression profile in the progressive stages of H. pylori infected human gastric epithelium allows the identification of intestinal metap...
Immunohistochemical Study of the Expression of MUC6 Mucin and Coexpression of Other Secreted Mucins (MUC5AC and MUC2) in Human Gastric Carcinomas
Filipa Carvalho
Journal of Histotechnology
Hematoxylin and eosin staining of mucins of the gastrointestinal tract
2017 •
Tony Henwood
An infrequent observation of assessing hematoxylin and eosin sections is the blue staining of mucins (for example those in goblet cells). This is believed to be due to a low concentration of alum and high pH of the hematoxylin staining solution. This study examines the incidence of blue mucin in various sites of the gastrointestinal tract using a low alum, high pH hematoxylin solution. The results are compared with a conventional hematoxylin solution, iron alum celestine blue method and an alcian blue (pH 2.5)-periodic acid-Schiff (AB-PAS) stain to characterize the type of mucin demonstrated. This study is the first to offer evidence that blue-stained mucin with low alum, high pH hematoxylin corresponds with carboxylated mucins as shown by the AB-PAS stain in the gastrointestinal tract. Iron alum celestine blue was also found to stain the mucin of a proportion of rectal biopsies and appendix as well as the carboxylated mucin of one duodenal biopsy.
PubMed
Biochemical and immunohistochemical characterisation of mucins in 8 cases of colonic disease--a pilot study
2007 •
Anwar Mall
Objectives: To characterise mucins in cancer of the colon and compare these with controls using stringent biochemical measures to avoid endogenous proteolysis. Design: Crude mucus scrapings were collected from 12 specimens obtained by colectomy. Specimens from 3 traumatic colectomies and 1 sigmoid volvulus were used as controls, and compared with 6 specimens from colons resected for adenocarcinoma and 2 irradiated colons. Subjects: The median age of the 4 female patients was 76 years (range 49 - 82 years), and of the 8 male patients 46.5 years (range 16 - 74 years). Results and conclusions: The crude mucus scrapings in the 9 specimens ranged in weight from 353 mg to 7 697 mg (median 4 928 mg). The median of purified mucin in the 9 specimens was 0.72 microg/mg wet weight of scraped material. Eight samples gave non-extractable pellet material, and were treated with DTT to reduce disulphide bonds for further analysis. One of these 8 pellets was resistant to reduction and had to be digested with papain before analysis. Only 5 of these pellets had mucin. Gel filtration and SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis) analysis revealed different populations of mucin based on size and extent of degradation. Western blotting and immunohistochemical analysis confirmed the presence of MUC2 in all samples, MUC5AC in 2 and MUC5B in 5 diseased specimens. Immunohistochemical analysis showed that there was no MUC1 in the normal specimens, MUC1 apoprotein (MUC1 core) in 2 cancer specimens and MUC1 in 1 cancer specimen. Histochemical analysis showed that normal tissue expressed neutral and acidic mucins and diseased specimens predominantly expressed acidic mucins. The electrophoretic behaviour of MUC2 in sigmoid volvulus was different from that in cancer of the colon.
Infection and Immunity
Helicobacter pylori Infection Impairs the Mucin Production Rate and Turnover in the Murine Gastric Mucosa
2013 •
Sara Lindén
ABSTRACTTo protect the surface of the stomach, the epithelial cells secrete a mucus layer, which is mainly comprised of the MUC5AC mucin. Further protection is provided by a thick glycocalyx on the apical surface of the epithelial cell, with the cell surface mucin MUC1 as a major component. Here, we investigate the production rate and turnover of newly synthesized mucin in mice and analyze the effects of early colonization and chronic infection withH. pylori. Metabolic incorporation of an azido GalNAc analog (GalNAz) was used as a nonradioactive method to perform pulse experiments in the whole animal. First, the subcellular movement of newly synthesized mucin and mucin turnover was determined in uninfected mice. Based on the time line for mucin transport and dissemination, 2, 6, and 12 h after GalNAz injection was selected to collect the stomachs from mice infected withH. pyloristrain SS1 during early colonization (7 days) and chronic infection (90 days). The results demonstrated th...
Journal of Clinical Medicine
Helicobacter pylori Infection and the Patterns of Gastric Mucin Expression in Children
Dan Gheban
Background: The updated model for the mechanism of gastric carcinogenesis demonstrates that Helicobacter pylori (H. pylori) is a risk factor in every step of the process. The expression of certain gastric mucins is altered by H. pylori infection in adult patients. The aim of our research was to assess the impact of H. pylori infection on the expression of secretory mucins in the pediatric antral mucosa. Methods: Slides were stained with monoclonal antibodies for MUC5AC, MUC6 and MUC2, digitalized and scored using both a semiquantitative and a quantitative approach. Results: The expression of MUC5AC was significantly lower in infected children. Also, MUC2 expression was more pronounced in infected children. MUC6 expression did not differentiate between infected and noninfected children. Additionally, the presence of chronic inflammation significantly altered the expression of MUC6 and MUC2. The expression of MUC6 was significantly higher in patients with gastric atrophy. Conclusion: ...
IP innovative publication pvt. ltd
Mucin histochemical profile in a variety of human colonic non-neoplastic and neoplastic lesions
2019 •
IP Innovative Publication Pvt. Ltd.
Introduction: Mucin deregulation occurs in gastrointestinal lesions progressing to cancer. Evidences advocate utility of mucin profile to predict malignant transformation in preneoplastic colonic lesions, however data are controversial. Objectives: This clinicopathological descriptive study identifies the histochemical profiles of acidic and neutral mucins in human colonic tissues including inflammatory, non-neoplastic and neoplastic lesions. Mucin alteration in different histological grades of adenocarcinoma is also evaluated. Materials and Methods: After collection of relevant data, tissue samples from a cohort of 88 patients recruited from King Abdul Aziz Specialized Hospital, Taif, Saudi Arabia were examined. Dual Alcian Blue (AB; pH 2.5)/ Diastase (D) Periodic Acid Schiff (PAS) technique was used to differentiate acidic and neutral mucins respectively. Statistical analysis including descriptive statistics, Pearson’s chi-square test and linear regression was performed using SPSS. Results: Acidic and neutral mucins were positive in 67.1 and 46.6% of lesions, respectively. All ulcerative colitis tissues were positive for acidic mucin and 75% for neutral mucin. All non-neoplastic polyps were positive for both mucins. Adenomatous polyps demonstrated reduced mucin but more neutral (59.3%) than acidic one (44.4%). About 86% of adenocarcinomas revealed acidic mucin and 22.2% showed neutral mucin with trends for acidic mucin to decrease with grade and for neutral mucin to increase with grade. Conclusion: Altered both acidic and neutral mucin profiles occur in colonic lesions of different pathologies. As colonic adenocarcinoma progresses from grade 1 to grade 3, acid mucin declines with a corresponding increase in neutral mucin. Mucin profile may be of value in evaluating the preneoplastic colorectal lesions.
International Journal of Colorectal Disease
Characterization of the mucins produced by normal human colonocytes in primary culture
1996 •
Fabio Magliocca, Giovanni Latella, Renato Fonti
