Carcinoembryonic antigen (CEA) is a glycoprotein found in the fetal gastrointestinal tract during the first six months of gestation. In the normal adult small amounts of CEA are present in serum. Serum levels increase in case of malignant tumours associated with various cancers e.g. of the colon, rectum, stomach, pancreas, ovaries. The CEA test is particularly useful to monitor the response to therapy in patients with diagnosed malignancies. CEA is the most widely used among the tumour marker tests.
The aim of the project is to investigate means to improve the reliability of assays of serum CEA. The project will comprise studies to produce a purified, well characterised CEA material, while examining and improving the specificity of monoclonal antibodies (mAbs) used for the immunological assay of CEA in serum. Techniques of cell culture and genetic engineering will be employed for these purposes. The next step might include the certification of serum reference samples.
The work to purify CEA from the human colon adenocarcinoma cell line LS 174 T is completed. The purification scheme first included the treatment of the cell line by a phosphatidylinositol phospholipase-C to release CEA from the cell membrane. Further steps comprised anion exchange, immunoaffinity and gel filtration chromatographies. The purified material is currently examined for its immunological properties.
In parallel, work was undertaken to prepare a synthetic peptide (77 aminoacid residues long) as an immunogenic material. The peptide was selected as representing the portion of the CEA molecule that is the most characteristic of it, i.e. presenting the least homology with other CEA-like proteins. The preparation was to be made by genetic engineering and was successful. The procedure is at present optimized to increase the production yield. The project should be completed in 1994.
Funding SchemeCSC - Cost-sharing contracts