Linked Life Data

7588808

Source:http://linkedlifedata.com/resource/pubmed/id/7588808

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-12-18
pubmed:abstractText
The product of the MUC1 gene, the polymorphic epithelial mucin (PEM) is aberrantly glycosylated in breast and other carcinomas, resulting in exposure of normally cryptic peptide epitopes. PEM expressed by breast cancer cells contains more sialylated O-glycans and has a lower GlcNAc content than that expressed by normal cells. The exposure of peptide epitopes is thus thought to be due to the sugar side chains being shorter on the tumour-associated mucin. To investigate possible mechanisms underlying the different pattern of glycosylation in breast cancer cells, we analysed the pathways involved in the biosynthesis of O-glycan chains of mucins in normal and cancerous mammary epithelial cells. An immortalized mammary epithelial cells line originating from normal human milk. MTSV1-7, and three human breast cancer cell lines, BT20, MCF-7 and T47D, were studied. Glycosyltransferase activities assembling, elongating and terminating O-glycan core-1 [Gal beta 1-3GalNAc alpha-R] and core-2 [GlcNac beta 1-6 (Gal beta 1-3) GalNAc alpha-R] were present in the normal mammary cell line. Many of the glycosyltransferase activities were also expressed at variable levels in breast cancer cells. However, a sialyltransferase activity (CMP-sialic acid Gal beta 1-3GalNAc alpha 3-sialyltransferase) was increased several fold in all three cancer cell lines. Moreover, mammary cancer cell lines BT20 and T47D have lost the ability to synthesize core-2, as shown by the lack of UDP-GlcNAc: Gal beta 1-3GalNAc (GlcNAc to GalNAc) beta 6-GlcNAc-transferase activity, which corresponded to the absence of the mRNA transcript. However, MCF-7 breast cancer cells expressed this enzyme. Thus, the mechanism for the exposure of peptide epitopes in BT20 and T47D cells is proposed to be the loss of core-2 branching leading to shorter, sialylated O-glycan chains. A different mechanism is proposed for MCF-7 breast cancer cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
233
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
607-17
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:7588808-Amino Acid Sequence, pubmed-meshheading:7588808-Animals, pubmed-meshheading:7588808-Base Sequence, pubmed-meshheading:7588808-Breast Neoplasms, pubmed-meshheading:7588808-Cell Line, pubmed-meshheading:7588808-Female, pubmed-meshheading:7588808-Fucosyltransferases, pubmed-meshheading:7588808-Glycosylation, pubmed-meshheading:7588808-Glycosyltransferases, pubmed-meshheading:7588808-Humans, pubmed-meshheading:7588808-Mice, pubmed-meshheading:7588808-Molecular Sequence Data, pubmed-meshheading:7588808-Mucin-1, pubmed-meshheading:7588808-N-Acetylgalactosaminyltransferases, pubmed-meshheading:7588808-N-Acetylglucosaminyltransferases, pubmed-meshheading:7588808-Neoplasm Proteins, pubmed-meshheading:7588808-Sialyltransferases, pubmed-meshheading:7588808-Sulfotransferases
pubmed:year
1995
pubmed:articleTitle
Mechanisms underlying aberrant glycosylation of MUC1 mucin in breast cancer cells.
pubmed:affiliation
Biochemistry Department, Hospital for Sick Children, Toronto, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't