Linked Life Data

7688074

Source:http://linkedlifedata.com/resource/pubmed/id/7688074

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1993-8-30
pubmed:abstractText
Carcinoembryonic antigen (CEA) is a well-known tumor marker, consisting of a single heavily glycosylated polypeptide chain (mol. wt 200 kD), bound to the cell surface by a phosphatidylinositol-glycan anchor. The hydrophobic domain, encoded by the 3' end of the open reading frame of the CEA gene is not present in the mature protein. This domain is assumed to play an important role in the targeting and attachment of CEA to the cell surface. To verify this hypothesis, a recombinant CEA cDNA lacking the 78 b.p. of the 3' region, encoding the 26 a.a. hydrophobic domain, was prepared in a Rc/CMV expression vector containing a neomycin resistance gene. The construct was transfected by the calcium phosphate technique into CEA-negative human and rat colon carcinoma cell lines. Geneticin-resistant transfectants were screened for the presence of CEA in the supernatant and positive clones were isolated. As determined by ELISA, up to 13 micrograms of recombinant CEA per 10(6) cells was secreted within 72 hr by the human transfected cells and about 1 microgram by the rat cells. For comparison, two human carcinoma cell lines, CO112 and LS174T, selected for high CEA expression, shed about 45 and 128 ng per 10(6) cells within 72 hr, respectively. Western blot analysis showed that the size of the recombinant CEA secreted by the transfected human cells is identical to that of reference CEA purified from human colon carcinomas metastases (about 200 kD). The recombinant CEA synthesized by the transfected rat carcinoma cells has a smaller size (about 144 kD, possibly due to incomplete glycosylation), as has already been observed for CEA produced by rat colon carcinoma cells transfected with full-length CEA cDNA. The 100-fold increase in secretion of rCEA encoded by truncated CEA cDNA transfected in human cells confirms the essential role of this domain in the targeting and anchoring of the glycoprotein. These results suggest a new approach for the in vitro production of large amounts of CEA needed in research laboratories and for immunoassay kits.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0161-5890
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:geneSymbol
CEA
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
921-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Marked increase in the secretion of a fully antigenic recombinant carcinoembryonic antigen obtained by deletion of its hydrophobic tail.
pubmed:affiliation
Institute of Biochemistry, University of Lausanne, Epalinges, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't