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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Members of the carcinoembryonic antigen (CEA) family include CEA, non-specific cross reacting antigen (NCA), and biliary glycoprotein (BGP), and appear to function as cell adhesion molecules. Immunoprecipitation and subsequent gel electrophoresis of proteins from several colon cancer cell lines labeled with [gamma-32P]ATP, under conditions designed to detect ecto-kinase-catalyzed phosphorylation of cellular proteins, revealed that polyclonal anti-CEA antiserum recognized a 175-190 kDa phosphoprotein on the surface of colon cancer cells. The ability to detect this phosphoprotein did not correlate with CEA production, and immunoprecipitation studies suggested that the phosphoprotein is BGP. Phosphoamino acid analysis of the 175-190 kDa protein showed that it contained predominantly phosphotyrosine.
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PMID:Antiserum to carcinoembryonic antigen recognizes a phosphotyrosine-containing protein in human colon cancer cell lines. 768 8

A total of 22 genes have been identified in the carcinoembryonic antigen (CEA) gene family. The protein products of this family are highly homologous and include CEA, biliary glycoprotein, nonspecific cross-reacting antigen 50/90 (NCA 50/90), NCA 95, and pregnancy-specific beta-glycoprotein. We used a monoclonal antibody with high affinity to develop a specific enzyme-linked immunosorbent assay (ELISA) method for NCA 50/90 in serum and plasma. Our calibrators were based on affinity-purified recombinant protein from a baculovirus expression system. No significant reactivity with purified CEA, recombinant NCA 95, or recombinant biliary glycoprotein was found by Western blot analysis or in the ELISA method. Only 1 of 15 sera from pregnant women (chorionic gonadotropin > 1000 ng/ml) was positive in the NCA 50/90 ELISA, suggesting that this method does not detect pregnancy-specific glycoprotein. A cutoff value of 18 ng/ml was established based on the 95% value of serum and plasma from 147 healthy volunteers. Only 3 of 31 serum and plasma samples from patients with clinically inactive breast cancer were elevated above the cutoff value, but 44% of 136 samples from patients with clinically active breast cancer were positive. NCA 50/90 measurements were elevated in 7 of 25 patients with active breast cancer whose CEA and CA 15-3 values were below cutoff, and NCA 50/90 values do not correlate with CEA in breast cancer. In addition, we found sensitivities of 70, 39, and 42% for lung cancer, colon cancer, and leukemia, respectively. The sensitivity for non-small cell lung cancer was 85%, however, compared to 50% for small cell lung cancer. Serum from leukemia patients showed an overall sensitivity of 43%, but 71% (10 of 14) sera from patients with chronic myelogenous leukemia were positive compared to, for example, chronic lymphocytic leukemia where 0 of 7 sera had NCA 50/90 values above the cutoff. These studies suggest that NCA 50/90 may have clinical utility in the management of patients with a variety of cancers.
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PMID:Nonspecific cross-reacting antigen 50/90 is elevated in patients with breast, lung, and colon cancer. 811 11

A two-component tissue architecture assay system has been devised that tests the ability of human colon carcinoma cells to conform to the specific three-dimensional cell-cell and cell-substratum interactions characteristic of normal colonic tissues. Dissociated fetal rat colonic cells (FRCC) were allowed to reaggregate in suspension with or without the addition of different proportions (0.1%, 1%, and 10% of the total cells) of the human colon carcinoma cell lines, SW-1222 and LS-174T. Cellular aggregates obtained after 36 hours, incubation exhibited cell sorting by the formation of recognizable epithelial colonic crypt-like structures with glandular lumens in a mesenchyme-like background. Carcinoembryonic antigen (CEA)-positive SW-1222 cells in 10% mixed aggregates were organized into numerous well-formed glandular structures with a polarized apical distribution of CEA. LS-174T cells, on the other hand, were self-sorted but structurally disorganized with a continuous cell surface CEA distribution. Pure FRCC and mixed aggregates were implanted under the kidney capsules of Swiss nu/nu (nude) or CD-1 nu/nu mice and allowed to grow for a period of 7-10 days. Whereas the normal FRCC readily formed colonic tissue, the SW-1222 cells exhibited a capacity for differentiation into colonic crypts which became progressively less normal and more tumor-like as the proportion of carcinoma cells in the aggregates was increased. The LS-174T cells demonstrated poor differentiation at all concentrations. Cell surface levels of CEA and the CEA family member nonspecific crossreacting antigen (NCA), both overexpressed in colon cancer, were higher in LS-174T than in SW-1222 cells, whereas family member biliary glycoprotein (BGP), downregulated in colon carcinoma was higher in the SW-1222 cells. These results thus support the suggestion that deregulated expression of CEA family members can be involved in the ability of colonocytes to differentiate and conform to normal tissue architecture as assessed by the assay. The assay is therefore amenable to genetic analysis of normal and perturbed architectural phenotypes.
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PMID:A colonic tissue architecture assay applied to human colon carcinoma cells. 902 35

Neisseria gonorrhoeae (GC) is a human pathogen that adheres to and invades genital surfaces. Although pili are required for the initial adherence, the interaction of GC with epithelial cells is also promoted by a family of outer membrane proteins, the opacity (Opa) proteins such as OpaA protein from strain MS11. Studies have demonstrated that the interaction of the OpaA GC with epithelial cells involves binding to heparan sulfate attached to syndecan receptors. However, other Opa proteins interact with CEA gene family member 1 (CGM1) or biliary glycoprotein (BGP), members of the CD66 antigen family. In this study, we demonstrate that, in addition, the 180-kD carcinoembryonic antigen (CEA) is a receptor for Opa proteins. This conclusion was based on the following observations. First, transfected HeLa cells expressing CEA (HeLa-CEA) and the CEA-expressing colon cancer cell line (LS 174T) bound and subsequently engulfed the Opa+ bacteria. These interactions were inhibited by anti-CEA antibody, but could not be inhibited by addition of heparin. Furthermore, OpaI E. coli directly bound purified CEA. We also compared the adherence and invasion by Opa+ bacteria of CD66 transfected HeLa cells: HeLa-BGPa, HeLa-CGM6, HeLa-NCA, HeLa-CGM1a, HeLa-CEA, and HeLa-Neo serving as negative control. Using OpaI as the prototype, the relative ability of the transfected HeLa cell lines to support adherence was (CEA = BGPa >CGM1a >NCA >>CGM6 = Neo). The ability to mediate invasion of the transfectant cells was (CGM1a >CEA >BGPa >NCA >CGM6 = Neo). Among the Opa proteins tested, OpaC proved to be bifunctional, able to mediate adherence to both syndecan receptors and to CD66 antigens.
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PMID:Several carcinoembryonic antigens (CD66) serve as receptors for gonococcal opacity proteins. 915 93

Human carcinoembryonic antigen (CEA) is overexpressed in a wide variety of epithelial malignancies including colon cancer. CEA can function in vitro as a homotypic intercellular adhesion molecule and can block the terminal differentiation of rodent myoblasts, thus raising the possibility that deregulated expression of CEA might directly contribute to malignant progression. To address this question, the expression pattern and cell-surface levels of CEA were studied during malignant transformation of the colonic epithelium in sporadic and familial adenomatous polyposis-related neoplasms. The level of immunohistochemically detected CEA was higher in 30% to 62% of microadenomas and small adenomas from familial adenomatous polyposis patients compared with adjacent normal mucosa, and this proportion was positively correlated with lesion size and degree of dysplasia. Cytofluorometric analysis of highly purified single epithelial cell suspensions from freshly excised carcinomas versus adjacent normal tissue demonstrated up to a 20-fold increase of mean cell-surface CEA in a group of colon carcinomas representative of the overall majority of such tumors--from Dukes' stages A to D and ranging mainly from well to moderately differentiated, the degree of overproduction was inversely correlated with tumor differentiation and directly correlated with stage. A marked tendency toward nonpolarized versus apical cell-surface expression with progression was also noted. Nonspecific cross-reacting antigen (NCA), a CEA family member, is also a homotypic adhesion molecule and blocks terminal myogenic differentiation, whereas biliary glycoprotein is a CEA family adhesion molecule that does not. Cell-surface NCA showed even greater overexpression (up to 70-told) in dedifferentiated tumors, whereas total-cell biliary glycoprotein showed approximately 2-fold lower levels than was normal in more differentiated tumors and approximately 2-fold higher levels than in further progressed tumors. These results therefore support the suggestion that CEA and NCA can directly contribute to colon carcinogenesis by inhibiting colonocyte differentiation.
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PMID:Cell-surface levels of human carcinoembryonic antigen are inversely correlated with colonocyte differentiation in colon carcinogenesis. 916 89

Carcinoembryonic antigen (CEA) has been recently implicated in the process of human colon cancer liver metastasis by means of an adhesion mechanism. Based on the strong sequence and structural homology of biliary glycoprotein (BGP) to CEA, we hypothesized that BGP might be overexpressed at the RNA and protein level in tumor cells with high metastatic potential. We have found the BGP messenger RNA derived from highly metastatic colon cancer cells is constitutively overexpressed-nearly fourfold greater than poorly metastatic cells-and that BGP expression is induced by interferon-gamma. Similarly, we have demonstrated that BGP protein levels were constitutively elevated in highly metastatic human colon cancer cells when compared to poorly metastatic cells. Collectively these results suggest that the basal and interferon-stimulated expression of BGP transcripts may be regulated in a manner similar to CEA and that a potential role in the process of metastasis may be inferred.
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PMID:Biliary glycoprotein is overexpressed in human colon cancer cells with high metastatic potential. 983 61