1
|
Abstract
Early studies of changes in mucin expression in disorders of the gastrointestinal tract focused on alterations in the carbohydrate chain. This review briefly considers the various mechanisms by which such alterations may come about: (a) normal variation, (b) sialic acid alterations, (c) defective assembly of carbohydrate side-chains, (d) changed expression of core proteins and (e) epithelial metaplasia. The availability of monoclonal antibodies to mucin core proteins adds a new dimension to mucin histochemistry. It is now possible to offer explanations for traditional mucin histochemical findings on the basis of lineage-specific patterns of mucin core protein expression. Changes in core protein expression are described in inflammatory, metaplastic and neoplastic disorders of the gastrointestinal tract. The possibility that mucin change could be important in the aetiology of some diseases such as ulcerative colitis and H. pylori gastritis is considered. It is more probable, however, that changes in mucin expression are secondary to reprogramming of cellular differentiation and altered cell turnover. As such they may serve as markers to explain pathogenesis and provide novel diagnostic and prognostic information.
Collapse
Affiliation(s)
- J R Jass
- Department of Pathology, University of Queensland School of Medicine, Herston Road, Queensland 4006, Australia.
| | | |
Collapse
|
2
|
Buisine MP, Devisme L, Savidge TC, Gespach C, Gosselin B, Porchet N, Aubert JP. Mucin gene expression in human embryonic and fetal intestine. Gut 1998; 43:519-24. [PMID: 9824580 PMCID: PMC1727278 DOI: 10.1136/gut.43.4.519] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND The intestinal epithelium is covered by a continuous layer of mucus which is secreted by well differentiated epithelial cells. Disregulation of the expression of mucins has been reported to have possible implications in the neoplastic process which affects intestinal mucosae. It is well known that preneoplastic and neoplastic tissues can express fetal phenotypic characteristics. AIMS To assess whether the expression of mucin genes in the intestinal tract is linked to the stage of cellular differentiation and tissue development, by studying the expression of six mucin genes in human fetal small intestine and colon, and also adult tissues. METHODS In situ hybridisation was used to study mRNA expression of MUC2, MUC3, MUC4, MUC5B, MUC5AC, and MUC6 in 32 human embryos and fetuses (6.5-27 weeks gestation). Normal adult mucosae were used as controls. RESULTS Three mucin genes, MUC2, MUC4, and MUC5AC, were differently expressed in fetal intestine compared with expression in normal adults. CONCLUSION These differences in mucin gene expression suggest a possible regulatory role for these products in intestinal epithelial cell differentiation.
Collapse
Affiliation(s)
- M P Buisine
- Unité 377 INSERM and Laboratoire de Biochimie et de Biologie Moléculaire, Hôpital C Huriez, 59045 Lille Cedex, France
| | | | | | | | | | | | | |
Collapse
|
3
|
Affiliation(s)
- J R Jass
- Department of Pathology, University of Queensland Medical School, Brisbane, Australia
| |
Collapse
|
4
|
Pinczower GD, Williams RP, Gianello RD, Robinson HC, Preston BN, Linnane AW. Characterisation of the tumour-associated carbohydrate epitope recognised by monoclonal antibody 4D3. Int J Cancer 1996; 66:636-44. [PMID: 8647626 DOI: 10.1002/(sici)1097-0215(19960529)66:5<636::aid-ijc10>3.0.co;2-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The tumour-associated epitope recognised by monoclonal antibody (MAb) 4D3 is expressed on a high m.w. mucin glycoprotein preparation known as small intestinal mucin antigen (SIMA). This epitope is detected in tissue from a high proportion of patients with colorectal cancer, and elevated levels occur in serum from a significant number of such patients, highlighting the potential clinical utility of MAb 4D3. In the present study, insight into the composition and structure of the carbohydrate epitope recognised by MAb 4D3 was gained following characterisation of 2 glycopeptides that co-purified with SIMA. Sequence analysis of 1 of these glycopeptides revealed that it was identical to the glycoprotein alpha-1-anti-chymotrypsin. This glycoprotein was subsequently deglycosylated to yield 5 forms corresponding to alpha-1-anti-chymotrypsin substituted with 4, 3, 2, 1 or no branched glycans. MAb 4D3 was reactive with each of the glycosylated forms, including the form carrying only 1 branched glycan, but did not react with fully deglycosylated alpha-1-anti-chymotrypsin. MAb 4D3 also reacted to different extents with ovine, bovine or porcine submaxillary mucins, each of which has a different amount of the O-linked sialylated disaccharide known as sialosyl Tn. Of these mucins, MAb 4D3 was most reactive with ovine submaxillary mucin, in which almost all of the carbohydrate chains are sialosyl Tn. Reactivity of MAb 4D3 towards isolated glycans, sialosyl Tn and related structures led to the conclusion that the preferred MAb 4D3 epitope involves the sialylated N-acetyl galactosamine disaccharide as well as an additional monosaccharide present on a neighbouring carbohydrate chain. Although the preferred epitope recognised by MAb 4D3 involves this sialylated disaccharide, the specificity of MAb 4D3 was different from that of other MAbs with a reported specificity for sialosyl Tn.
Collapse
Affiliation(s)
- G D Pinczower
- Centre for Molecular Biology and Medicine, Monash University, Clayton, Victoria, Australia
| | | | | | | | | | | |
Collapse
|
5
|
Abstract
Neoplastic, inflammatory and regenerative processes affecting colorectal mucosa are associated with alterations in structure of epithelial mucin. This review collates mucin-, lectin-, and immuno-histochemical observations on colorectal mucins and introduces recent molecular genetic insights into the structure of the protein backbone of mucins. The numerous structural modifications uncovered by the various technical approaches have been reduced to a few manageable principles that are of relevance to both researcher and diagnostic pathologist. Particular attention is drawn to the need to appreciate the limited specificities of probes, the confounding influences of anatomical site and genetic factors (necessitating the use of appropriate positive and negative control tissues) and the precise location of secretory material. In the past, insufficient attention has been given to the effects of altered differentiation including metaplasia and differing lineage expression in epithelial disorders of growth. It is likely that certain changes loosely ascribed to goblet cell mucin, such as neo-expression of blood group antigens and anomalous expression of core carbohydrate structures, do not occur at all. Critical examination of available data point to only two consistent and unequivocal changes affecting goblet cell mucin in pathological processes: loss of O-acetyl substituents at sialic acid C4 and C7,8,9 and increased sialylation. Furthermore, there are no neoplasia-specific alterations in mucins documented to date. All neoplasia-associated changes have been described in non-neoplastic lesions also.
Collapse
Affiliation(s)
- J R Jass
- Department of Pathology, School of Medicine, University of Auckland, New Zealand
| | | |
Collapse
|
6
|
Pinczower GD, Gianello RD, Williams RP, Preston BN, Preston H, Linnane AW. Monoclonal antibody 4D3 detects small intestinal mucin antigen (SIMA)--glycoprotein in the serum of patients with colorectal cancer. Int J Cancer 1993; 54:391-6. [PMID: 8509213 DOI: 10.1002/ijc.2910540307] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have developed a sensitive ELISA using MAb 4D3 for the detection of a novel epitope on Small Intestinal Mucin Antigen (SIMA) and report here that SIMA is present in the serum of patients with colorectal cancer. SIMA has been shown to occur in tissue from a high proportion of patients with colorectal cancer. SIMA derived from serum was similar to tissue-derived SIMA: both eluted in the void volume of a Superose 6 column indicating a molecular weight above 5,000 kDa and they exhibited similar buoyant densities on CsCl gradients. The ELISA was most reliable after pre-treatment of serum with 0.4 M perchloric acid to remove interfering substances. The upper limit for SIMA in normal serum was set as the mean plus 2 standard deviations determined from a group of 97 healthy control subjects. In a sample of 113 patients with colorectal cancer, SIMA serum levels were elevated in 15% of patients with Dukes' Stage A, 38% with Stage B, 32% with Stage C and 75% with Stage D colorectal cancer. SIMA serum levels were compared with those of the widely used tumor marker, carcinoembryonic antigen (CEA). The SIMA assay detected a significant number of sera that were not detected by the test for CEA. We propose that SIMA will prove to be a valuable serological tumor marker, in combination with CEA and other tumor markers, for the detection of colorectal cancer.
Collapse
Affiliation(s)
- G D Pinczower
- Biochemistry Department, Monash University, Clayton, Victoria, Australia
| | | | | | | | | | | |
Collapse
|
7
|
Pilbrow SJ, Hertzog PJ, Pinczower GD, Linnane AW. Expression of large intestinal mucin antigen (LIMA) epitopes in the normal and neoplastic gastrointestinal tract. J Pathol 1993; 169:361-73. [PMID: 7684076 DOI: 10.1002/path.1711690314] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
This study has identified the expression in normal and neoplastic gastrointestinal (GI) tract of epitopes on the colonic mucin LIMA (large intestinal mucin antigen), which are unique markers of normal colonic differentiation. Six anti-LIMA monoclonal antibodies (MAbs) (22D4, 9B5, 2C3, 23B2, 46A2, and 10B3) were studied immunohistochemically in normal GI tract, colorectal adenomas, and colorectal and gastric cancers. All MAbs showed specificities consistent with distinct epitopes, five of which were neuraminidase-resistant and four periodate-sensitive. Each reacted with mucin in 60-100 per cent normal colons--MAbs 10B3 and 23B2 also with small intestinal mucin--but none with gastric mucin. Five MAbs showed crypt and regional gradients in normal colon, MAbs, 22D4, 9B5, and 2C3 showing a hierarchy of reactivities in the crypt. Individual adenomas showed decreasing goblet cell (GC) LIMA expression with increasing size. However, 30 per cent of familial adenomatous polyposis (FAP) patients had generalized background losses of 9B5 and 2C3 GC reactivity, retaining 22D4, whilst 44 per cent of non-FAP patients lost 22D4 GC reactivity, regaining 9B5 and 2C3--evidence for polymorphism of mucin expression. All colorectal cancers expressed LIMA epitopes (frequently weaker than normal), and three MAbs (22D4, 9B5, and 2C3) showed deeper than normal staining in adjacent crypts. Eighty-five per cent of gastric cancers also expressed LIMA epitopes.
Collapse
Affiliation(s)
- S J Pilbrow
- Biochemistry Department, Monash University, Clayton, Victoria, Australia
| | | | | | | |
Collapse
|
8
|
Pilbrow SJ, Hertzog PJ, Linnane AW. Differentiation-associated changes in mucin glycoprotein antigenicity in mucosa adjacent to rare gastrointestinal tract tumours of non-mucosal origin. J Pathol 1993; 169:259-67. [PMID: 8445491 DOI: 10.1002/path.1711690214] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We have investigated changes in mucin antigenicity and morphology in the perineoplastic mucosa adjacent to rare, predominantly non-mucosal gastrointestinal (GI) tumours. Twenty-nine tumours of small and large intestine, including primary mesenchymal and ectodermal tumours, were examined immunohistochemically using 11 monoclonal antibodies (MAbs) raised against SIMA and LIMA (small and large intestinal mucin antigens). Non-epithelial GI tumours were essentially non-reactive, while adjacent mucosa showed altered mucin expression and morphology, in particular, features of transitional mucosa (TM). Combinations of different SIMA epitopes were detected adjacent to all colorectal tumours, and, similarly, LIMA epitopes adjacent to small intestinal tumours. Specific patterns adjacent to certain tumours may reflect influences of factors produced by individual tumours on mucin composition. Altered antigenicity and morphology in TM thus appear to be reactive changes in response to a wide range of GI tumours, presumably as a consequence of factors secreted by the tumour and/or a host response to the tumour.
Collapse
Affiliation(s)
- S J Pilbrow
- Biochemistry Department, Monash University, Clayton, Victoria, Australia
| | | | | |
Collapse
|
9
|
Klingel R, Real FX, Meyer zum Büschenfelde KH, Dippold WG. Expression of epithelial antigens EPM-1 and EXO-1 in normal, transitional, inflammatory and neoplastic colorectal mucosa. Eur J Cancer 1993; 29A:1723-8. [PMID: 8398302 DOI: 10.1016/0959-8049(93)90113-t] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
EPM-1 (a high molecular weight glycoprotein) and EXO-1 (a carbohydrate epitope expressed on polar neutral glycolipids and mucins) are two developmental antigens of normal and neoplastic human epithelia and were characterised by monoclonal antibodies. Their distribution was investigated in normal and pathological human colorectal mucosa. In normal mucosa, EPM-1 and EXO-1 showed characteristic expression patterns. EPM-1 was differentially expressed along the crypt villus axis with maximum at the crypt basis. EXO-1 was present throughout the whole mucosa. The characteristic gradient of EPM-1 expression along the crypt axis in normal mucosa was no longer detectable in benign polyps. Intact gradient of EPM-1 staining discriminated between neoplastic changes of the benign adenomatous polyp and mucosal inflammation. Neoplastic mucosa in benign polyps and especially atypical glands in highly differentiated tumours showed essentially identical expression patterns. In colorectal carcinomas the overall reactivities for EPM-1 and EXO-1 were independently associated with the histopathological grade of tumour differentiation.
Collapse
Affiliation(s)
- R Klingel
- First Department of Internal Medicine, University of Mainz, Germany
| | | | | | | |
Collapse
|
10
|
Pilbrow SJ, Hertzog PJ, Linnane AW. The adenoma-carcinoma sequence in the colorectum--early appearance of a hierarchy of small intestinal mucin antigen (SIMA) epitopes and correlation with malignant potential. Br J Cancer 1992; 66:748-57. [PMID: 1419617 PMCID: PMC1977410 DOI: 10.1038/bjc.1992.351] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The colorectal adenoma-carcinoma sequence was examined in relation to the ectopic expression of the oncofoetal Small Intestinal Mucin Antigen (SIMA), to the development of morphologic changes in the adenoma and perineoplastic mucosa and to indices of malignant potential. Four anti-SIMA MAbs, which define a novel hierarchy of SIMA epitopes in the normal small intestine and adjacent to colorectal cancers, were used in a retrospective immunohistochemical study of Familial Adenomatous Polyposis (FAP, n = 183) and non-familial (n = 44) adenomas. Inappropriate expression of SIMA epitopes was first detected in mucosa adjacent to minute microadenomas larger than three glands, and with increase in size, in increasing amounts within adenomas themselves, but not with microadenomas smaller than three glands or regions of flat mucosa free of adenomas. SIMA epitope expressed in mucosa adjacent to adenomas preceded changes in perineoplastic morphology, which progressed with adenoma growth to resemble transitional mucosa (TM) adjacent to cancers. Thus, the onset of both SIMA expression and morphological changes in TM were consistent with reactive rather than pre-existing field change phenomena. The previously reported hierarchy of four SIMA epitopes (5C5, 3D4, 4D3, 6C5) was also consistently observed in the adenoma-carcinoma sequence, and applied to (i) the order of epitope detection, (ii) the number of positive adenomas and (iii) extent of staining; (iv) the height in the crypt and (v) distance from the adenoma to which epitopes were expressed in perineoplastic mucosa. These observations are consistent with a progression of changes in mucin composition with adenoma development. The percentage of positive adenomas and reactivity scores for each anti-SIMA MAb correlated with increasing adenoma size, degree of dysplasia and growth pattern. SIMA expression appears to predate the earliest reported oncogene and tumour suppressor gene changes, was persistent and increased throughout adenoma development. SIMA epitopes are thus markers of very early neoplastic change, whose expression correlates with malignant potential and may contribute to the accumulation of changes necessary for tumourigenesis.
Collapse
Affiliation(s)
- S J Pilbrow
- Biochemistry Department, Monash University, Clayton, Victoria, Australia
| | | | | |
Collapse
|