Faculty Opinions recommendation of Siglec-15 recognition of sialoglycans on tumor cell lines can occur independently of sialyl Tn antigen expression.

2020 ◽  
Author(s):  
Peng Wu
Keyword(s):  
Tumor Cell ◽  
Cell Lines ◽  
Antigen Expression ◽  
Tumor Cell Lines ◽  
Tn Antigen ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn

scholarly journals Siglec-15 recognition of sialoglycans on tumor cell lines can occur independently of sialyl Tn antigen expression

Glycobiology ◽  
2020 ◽  
Author(s):  
Gavuthami Murugesan ◽  
Viviana G Correia ◽  
Angelina S Palma ◽  
Wengang Chai ◽  
Chunxia Li ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Cell Lines ◽  
Antigen Expression ◽  
Mapk Signaling ◽  
Breast Cancer Cell Lines ◽  
Cross Linking ◽  
Monocytic Cell ◽  
Immunosuppressive Microenvironment ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn

Abstract Siglec-15 is a conserved sialic acid-binding Ig-like lectin expressed on osteoclast progenitors, which plays an important role in osteoclast development and function. It is also expressed by tumor-associated macrophages and by some tumors, where it is thought to contribute to the immunosuppressive microenvironment. It was shown previously that engagement of macrophage-expressed Siglec-15 with tumor cells expressing its ligand, sialyl Tn (sTn), triggered production of TGF-β. In the present study, we have further investigated the interaction between Siglec-15 and sTn on tumor cells and its functional consequences. Based on binding assays with lung and breast cancer cell lines and glycan-modified cells, we failed to see evidence for recognition of sTn by Siglec-15. However, using a microarray of diverse, structurally defined glycans, we show that Siglec-15 binds with higher avidity to sialylated glycans other than sTn or related antigen sequences. In addition, we were unable to demonstrate enhanced TGF-β secretion following co-culture of Siglec-15-expressing monocytic cell lines with tumor cells expressing sTn or following Siglec-15 cross-linking with monoclonal antibodies. However, we did observe activation of the SYK/MAPK signaling pathway following antibody cross-linking of Siglec-15 that may modulate the functional activity of macrophages.

scholarly journals Terminal α1,4-linked N-acetylglucosamine in Helicobacter pylori-associated Intestinal Metaplasia of the Human Stomach and Gastric Carcinoma Cell Lines

2006 ◽  
Vol 54 (5) ◽  
pp. 585-591 ◽  
Author(s):  
Bibiana Ferreira ◽  
Nuno T. Marcos ◽  
Leonor David ◽  
Jun Nakayama ◽  
Celso A. Reis
Keyword(s):  
Helicobacter Pylori ◽  
Gastric Carcinoma ◽  
Cell Lines ◽  
Carcinoma Cell ◽  
Tn Antigen ◽  
Gastric Carcinoma Cell ◽  
Carcinoma Cell Lines ◽  
Gastric Carcinoma Cell Lines ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn

Helicobacter pylori (Hp) infection is associated with the development of gastric lesions including gastritis, intestinal metaplasia (IM), and gastric carcinoma. In humans, Hp is found almost exclusively in the foveolar epithelium of the gastric mucosa and rarely colonizes the deeper portions where mucous cells of the glands produce mucins with terminal α1, 4-GlcNAc O-glycans. This structure exerts antimicrobial activity against Hp. The development of IM in the stomach is characterized by Hp clearance from the metaplastic glands and by major alterations in the expression of mucins and mucin-carbohydrates. The present work evaluated whether terminal α1,4-GlcNAc and sialyl-Tn antigen are implicated in the process of Hp clearance from metaplastic glands by analyzing the expression of these antigens in different types of IM—complete ( n=12) and incomplete ( n=8)—and in gastric cell lines. Terminal α1,4-GlcNAc was not detected in IM except in a single foci of one case, indicating that this structure is not implicated in the clearance of Hp from IM, in contrast to what is observed in normal gastric mucosa. None of the gastric carcinoma cell lines studied showed terminal α1,4-GlcNAc, suggesting that they do not display a gastric gland mucous cell phenotype and therefore are useful models for in vitro Hp studies. Finally, sialyl-Tn antigen colocalizes with MUC2 mucin and is present in all cases of complete and incomplete IM, suggesting that either or both can be implicated in Hp clearance from IM. (J Histochem Cytochem 54:585-591, 2006)

scholarly journals Polypeptide GalNAc-transferases, ST6GalNAc-transferase I, and ST3Gal-transferase I Expression in Gastric Carcinoma Cell Lines

2003 ◽  
Vol 51 (6) ◽  
pp. 761-771 ◽  
Author(s):  
Nuno T. Marcos ◽  
Andrea Cruz ◽  
Filipe Silva ◽  
Raquel Almeida ◽  
Leonor David ◽  
...  
Keyword(s):  
Cell Lines ◽  
Control Cell ◽  
T Antigen ◽  
Tn Antigen ◽  
Gastric Carcinoma Cell ◽  
Aberrant Expression ◽  
Peptide Epitopes ◽  
Gastric Cell ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn

Mucin O-glycosylation in cancer is characterized by aberrant expression of immature carbohydrate structures leading to exposure of simple mucin-type carbohydrate antigens and peptide epitopes. Glycosyltransferases controlling the initial steps of mucin O-glycosylation are responsible for the altered glycosylation observed in cancer. We studied the expression in gastric cell lines of six UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases (GalNAc-T1, T2, T3, T4, T6, T11) that catalyze the initial key step in the regulation of mucin O-glycosylation, the transfer of GalNAc from UDP-GalNAc to serine and threonine residues. We also studied the expression of ST6GalNAc-I, the enzyme responsible for the synthesis of Sialyl-Tn antigen (NeuAcα2,6GalNAc) and the ST3Gal-I, the enzyme responsible for the synthesis of Sialyl-T antigen (NeuAcα2,3Galβ1,3GalNAc). This study was done using specific monoclonal antibodies, enzymatic assays, and RT-PCR. Our results showed that GalNAc-T1, -T2, and -T3 have an ubiquitous expression in all gastric cell lines, whereas GalNAc-T4, -T6, and -T11 show a restricted expression pattern. The immunoreactivity with MAb VU-2-G7 suggests that, apart from GalNAc-T4, another GalNAc transferase is involved in the glycosylation of the Thr in the PDTR region of the MUC1 tandem repeat. The expression of ST3Gal-I correlates with the expression of the Sialyl-T antigen in gastric cell lines and in the control cell lines studied. The expression of ST6GalNAc-I is low in gastric cell lines, in accordance with the low/absent expression of the Sialyl-Tn antigen.

scholarly journals Sialyl-Tn Antigen Expression in Crohnʼs Colitis

1997 ◽  
Vol 3 (4) ◽  
pp. 254-259 ◽  
Author(s):  
Alyssa Ta ◽  
Noam Harpaz ◽  
Carol Bodian ◽  
Alfred Roston ◽  
Lee Oberman ◽  
...  
Keyword(s):  
Antigen Expression ◽  
Tn Antigen ◽  
Sialyl Tn Antigen ◽  
Sialyl Tn
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