Proteolytic release of antigenic fragments corresponding to normal fecal antigen and non‐specific cross‐reacting antigen from carcinoembryonic antigen

Matsuoka, Yoshikazu; Koga, Yoshiko; Maruta, H; Yoshino, Masayasu; Tsuru, Eiko

doi:10.1002/ijc.2910210510

Cited by 44 publications

(10 citation statements)

References 21 publications

(8 reference statements)

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“…These NCAs have been de tected using a variety of methods [17][18][19][20][21][22]. This family of CEA-related molecules is complex and has made the true tissue speci ficity of CEA difficult to interpret.…”

Section: Introductionmentioning

confidence: 99%

Immunophenotypic Analysis of Colorectal Carcinomas with Monoclonal Antibodies 47D10 and Anti-Carcinoembryonic Antigen

Keep¹,

Benson

Sullivan³

et al. 1989

Tumor Biol

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A series of 80 colorectal adenocarcinomas were analyzed immunohistochemically for the antigen recognized by a new monoclonal antibody (MCA) 47D10. These antigens are part of a complex family of substances similar to, yet distinct from carcinoembryonic antigen (CEA), and are termed nonspecific cross-reacting antigens (NCA). Formalin-fixed paraffin-embedded sections of colorectal adenocarcinomas were evaluated for the expression of these antigens and compared to the expression of CEA. Our study shows that 83.8% of the cases were positively stained for NCA while 91.3% were positive for CEA. Both antigens were coexpressed in 80% of the cases. No correlation was found between MCA 47D10 immunoreactivity and tumor grade, stage, size or location within the colon. In 25 cases, the benign colonic mucosa adjacent to the carcinoma stained positively with MCA 47D10. Normal colon does not express NCA as recognized by MCA 47D10, except in rare cells. Forty-eight of these cases had serum available for study. Both NCA and CEA were determined in these serum samples. Forty-two of these sera demonstrated elevated CEA levels, whereas only 8 showed increased levels of the 47D10 antigen(s). These findings suggest that the gene product(s) recognized by MCA 47D10 can be independently expressed or, more commonly, coexpressed with CEA in these tissues.

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Section: Introductionmentioning

confidence: 99%

Immunophenotypic Analysis of Colorectal Carcinomas with Monoclonal Antibodies 47D10 and Anti-Carcinoembryonic Antigen

Keep¹,

Benson

Sullivan³

et al. 1989

Tumor Biol

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“…Mlcroscale immunodlffusion tests were carried out in a 1.2% agarose layer as described previously (47).…”

Section: Western Blotting Analysesmentioning

confidence: 99%

Effective Purification of Nonspecific Cross-Reacting Antigens with Phosphatidylinositol-Specific Phospholipase C

Kuroki

Kuwahara²,

Tsuruta³

et al. 1993

Preparative Biochemistry

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Two molecular species of nonspecific cross-reacting antigens, NCA-90 and NCA-50 with mol. wts. of 90,000 and 50,000, respectively, were effectively extracted with phosphatidylinositol-specific phospholipase C (PI-PLC) from human lung tissues, followed by extraction with perchloric acid, immunoaffinity chromatography with anti-NCA adsorbent, and gel filtration on a TSK G3000SW column. The yields of NCA were about 2 times more than those obtained by the usual method without PI-PLC. Addition of 0.05 unit of PI-PLC to 1 g of lung tissue and incubation at 37 degrees C for 1 h with continuous shaking seem to be practically sufficient for NCA extraction. The immunochemical properties of the NCAs thus obtained were found to be identical to those of NCAs obtained by the ordinary method.

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“…These include blood assays to monitor tumor burden (13,14), immunohistochemical analyses of tissue samples to detect tumor cells (15,16), tumor imaging with radiolabeled MAbs (17,18), and MAb-guided therapy (19,20). Since more than 20 structurally related antigens, such as nonspecific cross-reacting antigen (NCA) (21,22), normal fecal antigen (NFA) (23,24,25,26), or biliary glycoprotein (BGP) (27), have been found in various human tissues or body fluids as products of the CEA gene family members (5), elucidation of the specificity of anti-CEA MAbs is very important. Their specificity has been evaluated by several approaches including the analysis of cross-reactivity with the CEA-related antigens (28,29,30), immuno-histochemical reactivity with a variety of normal or malignant tissues (31,32,33), and competitive binding activity among MAbs (29,30,34).…”

Section: Introductionmentioning

confidence: 99%

Biochemical Characterization of 25 Distinct Carcinoembryonic Antigen (CEA) Epitopes Recognized by 57 Monoclonal Antibodies and Categorized into Seven Groups in Terms of Domain Structure of the CEA Molecule

Kuroki

Haruno²,

Murakami³

et al. 1992

Hybridoma

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The chemical nature of 25 distinct carcinoembryonic antigen (CEA) epitopes, which were recognized by 57 different monoclonal antibodies and categorized into 7 groups (Groups A to G) in terms of domain structure of the CEA molecule, was analyzed and the findings obtained were compared with the results of our previous studies using recombinant CEA proteins. All 21 epitopes of Groups A to F defined by 48 MAbs were resistant to periodate oxidation and were to a greater or lesser extent retained after deglycosylation of CEA, indicating that they are all protein in nature. The 21 epitopes were detected in recombinant CEA proteins expressed in Chinese hamster ovary (CHO) cells. Seven of the 21 epitopes of protein nature were partially or completely sensitive to reduction and alkylation of CEA and not detected or only slightly revealed in the recombinant CEA proteins expressed in E. coli, indicating that those epitopes are dependent on the tertiary structure of the peptide chain, which is formed by disulfide bonds. All 4 epitopes of Group G defined by 9 MAbs were sensitive to mild periodate oxidation and deglycosylation, but resistant to reduction and alkylation and to digestion with pepsin or pronase, indicating that those 4 epitopes are carbohydrate in nature. Although none of the 4 epitopes of Group G were detected in the recombinant CEA proteins expressed in E. coli, two were detected in those expressed in CHO cells. The biochemical studies reported here thus provide information as to the nature of the epitopes on the CEA molecule and help form the basis for selecting the anti-CEA MAbs for use in biological study and potential clinical applications of CEA.

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Proteolytic release of antigenic fragments corresponding to normal fecal antigen and non‐specific cross‐reacting antigen from carcinoembryonic antigen

Cited by 44 publications

References 21 publications

Immunophenotypic Analysis of Colorectal Carcinomas with Monoclonal Antibodies 47D10 and Anti-Carcinoembryonic Antigen

Immunophenotypic Analysis of Colorectal Carcinomas with Monoclonal Antibodies 47D10 and Anti-Carcinoembryonic Antigen

Effective Purification of Nonspecific Cross-Reacting Antigens with Phosphatidylinositol-Specific Phospholipase C

Biochemical Characterization of 25 Distinct Carcinoembryonic Antigen (CEA) Epitopes Recognized by 57 Monoclonal Antibodies and Categorized into Seven Groups in Terms of Domain Structure of the CEA Molecule

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