Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.4.3 (phospholipase C)
 18,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have produced human CEA transgenic mice which were found to express CEA mRNA in all tissues. By immunoblot analysis using anti-CEA polyclonal antibody, we also detected CEA protein in all tissues. However, the molecular size of CEA in the brain was different from that in other tissues, although the mRNA size was same and no deletion nor rearrangement was detected at the DNA level. Immunohistochemical analysis of the lung and the colon showed that the expression sites were the bronchial epithelial cells of the lung and the columnar epithelial cells of the colon. Interestingly, the expression of CEA protein in the transgenic mice was polarised to the luminal side of epithelial cells similar to the normal CEA expression in human tissues. We also detected cell surface expression of human CEA on thymocytes and spleen cells and CEA expression was greatly reduced by the phosphatidylinositol-specific phospholipase C (PI-PLC) treatment.
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PMID:Establishment and characterisation of human carcinoembryonic antigen transgenic mice. 191 Dec 19

Recent studies have shown that, even with a minimal content of carcinoembryonic antigen (CEA), normal human colonic epithelial cells express substantial amounts of CEA mRNA and colonic mucosal fragments cultured in vitro produce CEA quite actively, indicating that CEA should no longer be considered to be of an oncofetal nature. To understand the basis of the usefulness of CEA as a tumor marker, we analyzed the release of CEA, a glycosyl-phosphatidylinositol (GPI)-anchored protein, from colonic epithelial cells, by culturing isolated colonic crypts in collagen gel. The crypts appeared to preserve their morphological and biochemical integrity in the gel for at least 16 hr, and released CEA spontaneously. Three forms of CEA--spontaneously released CEA, CEA liberated with phosphatidylinositol-specific phospholipase C (PI-PLC) and CEA in cell lysates--were indistinguishable on SDS-PAGE. This is in contrast to recombinant CEA spontaneously released from CHO transfectants, which showed a smaller molecular mass than that of PI-PLC-cleaved recombinant CEA. By phase separation using Triton X-114, CEA in the cell lysates of crypts was separated mostly into the detergent phase, while the spontaneously released and the PI-PLC-cleaved CEA were separated into the aqueous phase. When the cells were metabolically labeled with the precursors of the GPI-anchor, 3H-ethanolamine but not 3H-palmitic acid was found in the spontaneously released CEA. These findings suggest that, in contrast to the proteolysis-like release of the recombinant CEA from CHO cells, CEA in normal colonic epithelial cells is released by a non-proteolytic cleavage, which probably occurs through the action of some endogenous phospholipase.
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PMID:Non-proteolytic release of carcinoembryonic antigen from normal human colonic epithelial cells cultured in collagen gel. 801 5