Sialosyl Tn Research Articles

Search for Amniotic Fluid-Specific Markers: Novel Biomarker Candidates for Amniotic Fluid Embolism

Objective: Amniotic fluid embolism (AFE) is a catastrophic syndrome. The amniotic fluid (AF)-specific antigens might be assessed in maternal serum when these proteins abruptly enter maternal circulation. The aims of this study were 1) to review a conventional marker for diagnosis of AFE, and 2) to find AF-specific proteins. Study design: This article reviews the English language literature for identification of proteins specifically or exclusively present in AF. The genome-wide gene expression profiling studies and proteomics-based approaches have been reported to identify the AF-specific proteins. Results: Maternal serum sialosyl Tn (STN), zinc-coproporphyrin-1 (ZnCP-1), tryptase and complement activation are clinically used as biomarkers for detecting AFE. However, these tests are quite limited. With advances in proteomics technology, together with the considerable efforts to find novel diagnostic biomarkers, many candidate proteins have been discovered and reported. Among 44 candidate markers identified in the present review, interleukin(IL)-6, squamous cell carcinoma (SCC), insulin-like growth factor-binding protein (IGFBP)-1, CA125 and osteopontin may be unique AF-

Immunoelectron microscopic analysis of lysosomal deposits in α- N-acetylgalactosaminidase deficiency with angiokeratoma corporis diffusum

α- N-Acetylgalactosaminidase (α-NAGA) deficiency with angiokeratoma corporis diffusum (AKCD) is one of the lysosomal storage diseases. GalNAcα1- O-Ser/Thr (Tn) is theoretically deposited in lysosomes, but substances with attached galactose and neuraminic (sialic) acid (T and sialosyl Tn, respectively) are excreted in patients’ urine. In this study, in two Japanese cases we analyzed the material accumulated in lysosomes using immunoelectron microscopy with mouse antibodies to Tn, sialosyl Tn and T (Thomsen–Friedenreich) antigens in order to find out what substance(s) is really deposited in lysosomes. We found that only GalNAcα1- O-Ser/Thr (Tn) was actually accumulated in vacuolated lysosomes of vascular endothelial cells, eccrine sweat gland cells, fibroblasts and pericytes. Galactosylation and sialylation of Tn appears to occur in cells other than those in the skin. The results suggest that this disease is caused by a single enzyme deficiency.

Expression of MUC1 and MUC2 and carbohydrate antigen Tn change during malignant transformation of biliary papillomatosis.

Biliary papillomatosis is characterized by papillary proliferations of biliary lining cells without invasion or metastasis. The neoplastic character and biological behaviour of this disease remain still speculative. These issues were examined in this study. Mucin core protein MUC1, MUC2, MUC3, MUC5AC and carbohydrate antigens (T, Tn and sialosyl Tn) were immunohistochemically examined, using 11 lesions of biliary papillomatosis from seven patients, and five lesions of biliary papillomatosis with foci of carcinoma from four patients. Five cases of papillary intrahepatic cholangiocarcinoma and 12 histologically normal livers were used as a control. Patients with biliary papillomatosis alone or with carcinoma were middle-aged or elderly (five men and six women). Microscopically, biliary papillomatosis showed a villous, papillo-tubular, papillary, or papillo-villous pattern with a thin fibrovascular core. Cytologically, they were classifiable into biliary epithelial or pyloric gland-like type. The former was frequent in the cases associated with carcinoma. Expression of MUC1, Tn antigen and sialosyl Tn antigen was frequent and marked in biliary papillomatosis alone and with carcinoma and also intrahepatic papillary carcinoma. In addition, marked expression of MUC1 and Tn antigen were rather frequent in biliary papillomatosis with carcinoma and intrahepatic biliary papillary carcinoma compared with biliary papillomatosis. MUC2 was rather frequent and marked in biliary papillomatosis alone compared to other two disease groups. Focal expression of MUC5AC and MUC2 was rather frequent and infrequent irrespective of disease group, respectively. Focal expression of T antigen was frequent in papillary ICC. Biliary papillomatosis could undergo overt malignant transformation along with altered phenotypic expression of MUC proteins and mucin carbohydrate antigens.

Diagnostic Utility of Sialosyl-Tn in Discriminating Carcinomatous Cells from Benign Mesothelium in Body Cavity Effusions

Detecting malignant cells in the setting of reactive mesothelium can be difficult. Several techniques have been tried but without widespread acceptance. Sialosyl-Tn (STn) is an aberrantly glycosylated precursor of the MN blood group antigen frequently expressed in carcinomas and dysplastic epithelium. We investigated the STn monoclonal antibody for its clinical utility as an isolated stain to discriminate benign mesothelium from malignant cells. Cell block material from 72 cases of body cavity fluids were immunostained for STn using the avidin-biotin complex method without antigen retrieval. Slides were incubated overnight at 4 degrees C in a humidified chamber. Strong immunoreactivity was noted in 31/40 (77%) carcinomatous cases. Only moderate staining was noted in 1 of 28 (4%) benign effusions and weak staining in 5 (18%) additional benign cases. Specificity was 100%, sensitivity 78%, positive predictive value 100% and negative predictive value 76%. No staining was noted in four noncarcinomatous malignant effusions. STn may have diagnostic value in this cytologic setting as part of a diagnostic panel but not as an isolated stain.

Histopathological Subtypes and Prognosis of Gastric Cancer Are Correlated with the Expression of Mucin-Associated Sialylated Antigens: Sialosyl-Lewisa, Sialosyl-Lewisx and Sialosyl-Tn

The expression of three sialylated mucin-associated antigens – sialosyl-Lewis^a (SLEA), sialosyl-Lewis^x (SLEX) and sialosyl-Tn (STN) – and their correlation with the TNM stage, histopathological growth pattern and prognosis was investigated in a series of 127 gastric carcinomas. Various classification systems (pTNM, WHO and Laurén) did not display any correlation with an expression of the sialomucin antigens under study. SLEA reactivity was strongly associated with an unfavorable outcome of the total population, whereas SLEX and STN did not exert such an impact. However, in the subgroups of pTNM stage I as well as pN0 patients, SLEA and SLEX reactivity of the tumors was associated with a worse prognosis. In the subgroup of diffuse-type cancers as defined according to Laurén’s classification, the expression of all three antigens indicated a worsening of the prognosis.

Glycopathological study of eyelid tumors and pseudotumors

The expression of MUC1, Tn (GalNAc α 1-O-Ser/Thr) and sialosyl Tn (STn) (NeuAc α 2,6 GalNAc α 1-O-Ser/Thr) antigens, which are useful markers for the prognosis of cancer in other organs, was examined immunohistochemically in a series of 45 eyelid tumors and 5 pseudotumors: basal cell carcinoma, 18; squamous cell carcinoma, 11; sebaceous gland carcinoma, 6; seborrheic keratosis, 4; papilloma, 3; verruca vulgaris, 2; nevus, 1; and granuloma, 5. The MUC1 antigen was identified in all squamous cell and sebaceous gland carcinomas, but not in basal cell carcinoma or the benign tumors. The Tn antigen was expressed in all the sebaceous gland, half of the squamous cell, and only rarely in the basal cell carcinomas. The STn antigen was expressed in all seborrheic keratosis and in the majority of squamous cell carcinomas, but only rarely in sebaceous gland and basal cell carcinomas. Eyelid tumors are frequently associated with apomucin and mucin-carbohydrate antigens: the MUC1 glycoprotein appears to be related to the malignant potential of eyelid tumors, and may be a useful marker for the differential diagnosis of invasive tumors, including sebaceous gland and squamous cell carcinomas.

Reciprocal control of colon-specific sulfomucin and sialosyl-Tn antigen expression in human colorectal neoplasia.

Histochemical reports claim that sulfomucins decrease and sialylated mucins increase during colon carcinogenesis. We examined the expression of colon-specific sulfomucins and sialosyl Tn antigen (STN) in normal small intestine, normal colorectal mucosa and colorectal tumours at different stages of progression immunohistochemically, using MAb 91.9H specific for colonic sulfomucins and MAb TKH-2 for STN. No expression of sulfomucins recognized by MAb 91.9H was found in normal small intestine, whereas STN staining was pronounced. The converse was the case in normal colorectal mucosa. Sulfomucins were still found in adenomas, but the amounts decreased with depth of invasion in cancers (P < 0.001). In contrast, no STN could be detected in benign lesions, but staining became increasingly evident with invasion (P < 0.001). This reciprocal control of expression of colon-specific sulfomucins and STN evident in tumour progression indicates that the mucous phenotype shifts from the colonic to the small intestinal type.

Correlative histochemical study providing evidence for the dual nature of human colorectal cancer mucin.

Luminal secretions within colorectal cancers have been assumed to be the counterpart of normal goblet cell mucin. The aim of this study was to establish whether secretory material within colorectal cancers may in fact be traced to different lineages: goblet cells and columnar cells. The distribution of the apomucins MUC1 and MUC2, non-O-acetylated sialic acid and the carbohydrate structures sialosyl Tn, Tn, Lewis(x), sialosyl Lewis(x) and Lewis(y) was studied in normal colorectal mucosa and colorectal cancer specimens using standard histochemical techniques. Unmasking of MUC1 and MUC2 was achieved using periodic acid and saponification-neuraminidase-periodic acid pretreatment respectively. Within normal and malignant epithelium, correlations and/or co-localization could be demonstrated for goblet cells with MUC2, non-O-acetylated sialic acid, sialosyl Tn, Tn (Golgi region) and sialosyl Lewis(x), and for columnar cells with MUC1, Lewis(x), sialosyl Le(x), Tn (cytoplasm) and Lewis(y) (UEA-1). The goblet cell spectrum was associated with mucin-like (type I) luminal secretions within cancers, whereas the columnar cell spectrum characterized non-mucin-like (type II) secretions and intracytoplasmic lumina. These data indicate that colorectal cancer mucin can be broadly separated into two types: secretory mucin linked to cells of goblet lineage and up-regulated membrane-associated mucin of presumed columnar cell origin.

Sialosyl Tn antigen expression is associated with the prognosis of patients with advanced gastric cancer

Sialosyl Tn antigen expression is associated with the prognosis of patients with advanced gastric cancer

Sialosyl Tn antigen expression is associated with the prognosis of patients with advanced gastric cancer

Sialosyl Tn antigen expression is associated with the prognosis of patients with advanced gastric cancer

Characterisation of the tumour‐associated carbohydrate epitope recognised by monoclonal antibody 4D3

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 α-1-anti-chymotrypsin. This glycoprotein was subsequently deglycosylated to yield 5 forms corresponding to α-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 α-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. © 1996 Wiley-Liss, Inc.

Prognostic implications of Sialosyl-Tn antigen expression in sinonasal intestinal-type adenocarcinoma.

The expression of the mucin antigen sialosyl-Tn (S-Tn) was evaluated immunohistochemically in a series of 30 intestinal type adenocarcinomas of the nasal cavities and paranasal sinuses to assess the relationship between the histological features of the lesions and their clinical behaviour. In grades 1 and 2 adenocarcinomas, the staining localised at the apical pole or within the cytoplasm of neoplastic cells, and in the content of glandular structures. Grade 3 adenocarcinomas had a very scanty expression of the antigen. Mucinous adenocarcinomas showed an intense immunoreaction within the cell cytoplasm and in the extracellular mucous pools. Conversely, non-neoplastic sinonasal mucosa had a very focal distribution of the antigen. Immunostaining was scored according to the percentage of low power microscopic fields showing positivity. Twenty-one adenocarcinomas (70%) were considered positive. No significant relationship was found between S-Tn positivity and the histological degree of differentiation of the lesion. The 5-year survival rate and disease-free interval of patients with S-Tn positive adenocarcinomas were significantly lower than those with negative adenocarcinomas (17.8% versus 72%, P = 0.0001; 16.6% versus 40%, P = 0.0001, respectively). These results indicate that S-Tn immunostaining appears to be a significant prognostic factor in patients with sinonasal intestinal type adenocarcinoma.

Sialosyl-Tn antigen is prevalent and precedes dysplasia in ulcerative colitis: A retrospective case-control study

BACKGROUND & AIMS: Expression of the carbohydrate-associated sialosyl- Tn (STn) antigen has been correlated with carcinogenesis in sporadic colon cancer. This retrospective study analyzed surveillance colonoscopy biopsy specimens to determine whether STn antigen could serve as a marker for neoplasia risk in patients with long-standing ulcerative colitis. METHODS: Eleven patients who developed dysplasia or cancer and who had undergone at least three surveillance colonoscopies were matched with 11 controls who had not developed neoplasia. Sections from 969 available surveillance biopsy specimens were stained immunohistochemically with monoclonal antibody TKH2 and were interpreted blindly. RESULTS: Compared with controls, patients expressed STn antigen more frequently in their biopsy specimens (44% patient biopsy specimens vs. 11% control biopsy specimens). Patients were also more likely to undergo colonoscopies with two or more colonic segments expressing STn antigen (73% vs. 22%), repeated STn antigen expression in two or more consecutive colonoscopies (91% vs. 27%), and STn antigen expression proximal to the hepatic flexure (64% vs. 0%). STn antigen appearance preceded the detection of neoplasia by 7 or fewer years, and its preferential expression in patients was not confounded by the degree of active inflammation. CONCLUSIONS: Repeated STn antigen expression in nondysplastic colonic mucosa may presage the development of neoplasia in long-standing ulcerative colitis and may be a useful adjunct to dysplasia during colonoscopic surveillance. (Gastroenterology 1996 Mar;110(3):694-704)

Sialosyl Tn antigen expression is associated with the prognosis of patients with advanced gastric cancer.

Several studies have revealed a correlation between sialosyl Tn antigen (STN) and certain clinicopathologic features of various cancers, and that STN is an independent prognostic factor. However, the clinical significance of the expression of STN in gastric cancer has not been reported. Thus, the purpose of this study was to evaluate immunohistochemically the clinical significance of expression of STN in gastric cancer. The expression of STN in surgically resected specimens of human gastric cancer was evaluated immunohistochemically using a monoclonal antibody (TKH-2), in 60 patients whose serum STN levels were measured and in 54 patients with advanced cancer who had been followed for more than 5 years after gastrectomy. The correlations between the level of STN expression and clinicopathologic factors were analyzed. The staining intensity was graded as follows: (-), less than 5% of the cancer cells expressed STN; (+), 5-50%; (++), more than 50%. Sialosyl TN antigen staining was detected mainly on the cell membrane, in the cytoplasm, and in the luminal contents, and 57.2% of the 60 specimens expressed STN, whereas the corresponding value for positive serum levels was 15%. A higher percentage of advanced tumors expressed STN than did the early cases, but the difference was not statistically significant. All cases with strong staining, the (++) cases, were advanced cases either with lymph node metastases or with cancer invading in or beyond the muscle layer proper. The expression of STN appeared to be related to the clinical stage, the extent of cancer invasion, and the presence of lymph node metastases. Sialosyl TN antigen was detected in the serum in less than 6% of the patients whose tumors were (-) or (+) for STN expression, and in 86.7% of the patients whose tumors expressed high levels of STN (++). The estimated 5-year survival in advanced cases (Stage III) was significantly better in those with negative STN expression than in those with positive STN expression (P < 0.01). These results suggest that STN may be a useful marker associated with the prognosis of patients with advanced gastric cancer.

Sialosyl-Tn antigen: Initial report of a new marker of malignant progression in long-standing ulcerative colitis

Background & Aims: Expression of the mucin-associated carbohydrate antigen sialosyl-Tn (STn) correlates with malignant transformation in sporadic colonic neoplasms. The aim of this study was to analyze STn antigen expression in patients with long-standing ulcerative colitis (UC). Methods: STn antigen was assessed by immunohistochemistry in archival tissues. Study A was a retrospective chronological case-control study. Serial surveillance colonoscopic biopsy specimens without inflammation or dysplasia were analyzed in 7 patients who developed colon cancer and in 8 controls who did not develop colon cancer. Study B analyzed the anatomic distribution of STn expression in 17 cancer-bearing (case) and 6 cancer-free (control) colectomy specimens from patients with UC. In some colectomy specimens, STn was compared with aneuploidy, which was determined by flow cytometry. Results: In study A, among the 7 patients with UC who developed cancer, 6 patients (86%) expressed STn in at least one prior nondysplastic surveillance biopsy specimen from the same site. Only 3 of 8 control patients (38%) expressed STn. In study B, STn was expressed in 40 of 82 specimens (49%) from cancer-bearing colons but only 8 of 62 specimens (13%) from cancer-free colons. STn was expressed in most aneuploid areas but was also found in diploid, nondysplastic mucosa. Conclusions: STn antigen seems to be a promising marker of cancer risk in patients with UC.

Distribution of sialosyl Tn and Tn antigens within normal and malignant colorectal epithelium

Expression of the core blood group structures sialosyl Tn (STn) and Tn is regarded as a colorectal cancer-specific change reflecting truncated synthesis of the oligosaccharide component of goblet cell mucin. The distribution of STn and Tn in normal and malignant epithelium has been studied in detail by a combination of mucin-, lectin-, and immunohistochemistry with and without pretreatment with potassium hydroxide (KOH), neuraminidase, and KOH-neuraminidase. When O-acetylated sialic acid (neuraminidase-resistant) is converted by saponification to non-O-acetylated sialic acid (neuraminidase-sensitive), normal colorectal goblet cells (mainly of the lower two-thirds of crypts) are immunoreactive with the monoclonal antibody TKH2 (specific for STn). This immunoreactivity is abolished by the interposition of neuraminidase, but goblet cells then become immunoreactive with Hb-Tn1 (specific for Tn). While colorectal cancer mucin expresses STn, expression of Tn is not seen in either goblet cell mucin or extracellular material showing the morphological and histochemical characteristics of secretory mucin. Tn expression in cancers is mainly limited to the Golgi zone and in a proportion of cases to cytoplasm and apical membrane (glycocalyx) of columnar cells and inspissated material within lumina. The material reacting with Hb-Tn1 may be upregulated, membrane-associated MUC1 glycoprotein rather than MUC2 or MUC4 goblet cell mucin. The presence of STn and cryptic Tn within normal colorectal goblet cells and the absence of Tn expression within colorectal cancer secretory mucin contradicts the generally accepted concept of cancer-specific incomplete glycoprotein synthesis within these neoplasms.

Sialosyl-Tn (STn) antigen is prevalent and precedes dysplasia in ulcerative colitis (UC): A retrospective case-control study: [formula omitted], Derek Dubois, Noam Harpaz, Anli Chen, Carol Bodian, Steven Itzkowitz. GI Research Lab, Depts of Medicine, Pathology & Biomath Sciences, Mount Sinai School of Med, New York City, NY

Sialosyl-Tn (STn) antigen is prevalent and precedes dysplasia in ulcerative colitis (UC): A retrospective case-control study: [formula omitted], Derek Dubois, Noam Harpaz, Anli Chen, Carol Bodian, Steven Itzkowitz. GI Research Lab, Depts of Medicine, Pathology & Biomath Sciences, Mount Sinai School of Med, New York City, NY

Sialosyl-Tn (STn) antigen expression compared to dysplasia and DNA-aneuploidy in prospective colonoscopic surveillance biopsies from patients with longstanding ulcerative colitis (UC): [formula omitted], Olle Broström, Robert Löfberg, Eric Young, Åke Öst, Bernhard Tribukait, Steven Itzkowitz. Units of Gastroenterology, South and Huddinge Hospitals; Dept of Radiobiology, Karolinska Institute, Stockholm, Sweden & Gl Res Lab, Dept of Med, Mt Sinai School of

Sialosyl-Tn (STn) antigen expression compared to dysplasia and DNA-aneuploidy in prospective colonoscopic surveillance biopsies from patients with longstanding ulcerative colitis (UC): [formula omitted], Olle Broström, Robert Löfberg, Eric Young, Åke Öst, Bernhard Tribukait, Steven Itzkowitz. Units of Gastroenterology, South and Huddinge Hospitals; Dept of Radiobiology, Karolinska Institute, Stockholm, Sweden & Gl Res Lab, Dept of Med, Mt Sinai School of

Is the carbohydrate sialosyl-Tn a marker for altered, non-malignant activity in squamous epithelium in the head and neck region?

Cell surface carbohydrates are involved in many cell functions such as cellular differentiation, adhesion, and invasion. A carbohydrate, sialosyl-Tn (STn), is expressed in many human carcinomas but generally not in normal epithelia. In the oral mucosa, however, STn has recently been observed on basal cells in some lesions with epithelial hyperplasia and dysplasia. The aim of this study was to carry out a systematic investigation of STn expression on epithelial basal cells in hyperplastic, 'borderline' malignant, and malignant head and neck lesions, to see if the expression of STn is associated specifically with hyperplastic conditions. Using the primary monoclonal antibody TKH2, normal controls did not reveal STn. STn was detected on probably post-mitotic basal cells in hyperplastic head and neck lesions and on basal cells adjacent to cancers, but not within the carcinomas. A Ki67 antibody reacted with basal cells in other locations. The most highly differentiated lesions, such as focal epithelial hyperplasia and verrucous hyperplasia, revealed a high percentage (86 per cent in both cases) of STn reactivity. The least-differentiated verrucous carcinomas (VCs) and keratoacanthomas (KAs) did not express STn, in contrast to the highly differentiated VCs and KAs. These findings indicate that STn-negative cases may have a greater malignant potential that the STn-positive cases. In conclusion, STn expressed on basal cells is possibly a marker for non-malignant conditions with altered basal cell activity and for highly differentiated verrucous carcinomas.

Mucin-associated T antigens in benign and malignant epithelium of the gall bladder, extrahepatic bile ducts and ampulla of Vater

The mucin-associated antigens Tn, sialosyl-Tn (STn), T and sialosyl-T (STAg) antigens accumulate through aberrant and incomplete glycosylation in malignant epithelial cells. Their diagnostic and prognostic significance in tumours of the colon and cervix has been described, and a possible role for Tn antigen in cell-to-cell adhesion has been suggested. These antigens have been demonstrated through peanut agglutinin (PNA) lectin binding and more recently using specific monoclonal antisera. Differences between the two methods have been described, which may be due to fixation schedules and/or specificity. We have investigated the effect of fixation on the binding of biotinylated PNA lectin and compared its reactivity with the immunoreactivity of monoclonal antisera to Tn, STn, T and STAg antigens in benign and malignant epithelium of the gall bladder, extrahepatic bile ducts and ampulla of Vater. We found that short-term fixation in formol sublimate resulted in poor PNA binding. All other tested fixation schedules showed strong perinuclear binding, similar to that found on cryostat sections. When compared with monoclonal antisera, PNA binding demonstrated the lowest specificity in benign epithelium. In both benign and malignant epithelium, the two methods cannot substitute for each other. STn and STAg antigens were found to be oncodevelopmental throughout the extrahepatic biliary tract. When used in a panel, they are useful as diagnostic markers of malignancy in gall bladder epithelium.