Linked Life Data

11308020

Source:http://linkedlifedata.com/resource/pubmed/id/11308020

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2001-4-18
pubmed:abstractText
The Sialyl-Tn antigen (Sialyl alpha-Ser/Thr) is expressed as a cancer-associated antigen on the surface of cancer cells. Its presence is associated with a poor prognosis in patients with colorectal and other cancers. We previously reported that Sialyl-Tn expression in LSC human colon cancer cells could be explained by a specific lack of the activity of core 1 beta3-Gal-transferase (Brockhausen et al., Glycoconjugate J. 15, 595-603, 1998) and an inability to synthesize the common O-glycan core structures. To support this mechanism, or find other mechanisms to explain Sialyl-Tn antigen expression, we investigated the O-glycosylation pathways in clonal rat colon cancer cell lines that were selected for positive or negative expression of Sialyl-Tn antigen, and compared these pathways to those in normal rat colonic mucosa. Normal rat colonic mucosa had very active glycosyltransferases synthesizing O-glycan core structures 1 to 4. Several sialyl-, sulfo- and fucosyltransferases were also active. An M type core 2 beta6-GlcNAc-transferase was found to be present in rat colon mucosa and all of the rat colon cancer cells. O-glycosylation pathways in rat colon cancer cells were significantly different from normal rat colonic mucosa; for example, rat colon cancer cells lost the ability to synthesize O-glycan core 3. All rat colon cancer cell lines, regardless of the Sialyl-Tn phenotype, expressed glycosyltransferases assembling complex O-glycans of core 1 and core 2 structures (unlike human LSC colon cancer cells which lack core 1 beta3-Gal-transferase activity). It was the activity of CMP-sialic acid:GalNAc-mucin alpha6-sialyltransferase that coincided with Sialyl-Tn expression. Sialyl-Tn negative cells had a several fold higher activity of core 2 beta6-GlcNAc-transferase which synthesizes complex O-glycans that may mask adjacent Sialyl-Tn epitopes. The results suggest a new mechanism controlling Sialyl-Tn expression in cancer cells.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1431-6730
pubmed:author
pubmed:issnType
Print
pubmed:volume
382
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
219-32
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:11308020-Amino Acid Sequence, pubmed-meshheading:11308020-Animals, pubmed-meshheading:11308020-Antigens, Tumor-Associated, Carbohydrate, pubmed-meshheading:11308020-Carbohydrate Sequence, pubmed-meshheading:11308020-Cell Division, pubmed-meshheading:11308020-Colonic Neoplasms, pubmed-meshheading:11308020-Epithelial Cells, pubmed-meshheading:11308020-Gastric Mucosa, pubmed-meshheading:11308020-Glycosylation, pubmed-meshheading:11308020-Molecular Sequence Data, pubmed-meshheading:11308020-Mucins, pubmed-meshheading:11308020-N-Acetylglucosaminyltransferases, pubmed-meshheading:11308020-Polysaccharides, pubmed-meshheading:11308020-Rats, pubmed-meshheading:11308020-Reference Values, pubmed-meshheading:11308020-Sialyltransferases, pubmed-meshheading:11308020-Tumor Cells, Cultured
pubmed:year
2001
pubmed:articleTitle
Pathways of mucin O-glycosylation in normal and malignant rat colonic epithelial cells reveal a mechanism for cancer-associated Sialyl-Tn antigen expression.
pubmed:affiliation
Department of Medicine, Queen's University, Kingston, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't