New Horizons in hCG Detection

Hussa, Robert O.; Cole, Laurence A.

doi:10.1007/978-1-4684-4811-5_13

Cited by 8 publications

(2 citation statements)

References 60 publications

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“…Antisera H2 and H93 were gifts from Dr. R. O. Hussa (Hybritech, San Diego, CA) and from Dr. H. C. Chen (National Institute of Child Health and Human Development, Bethesda, MD), respectively. H2 recognizes conformation-specific determinants in regions of hCG/3 not involving the CTP (core directed) (12), while H93 is the hCG,8-CTP directed antiserum (13). Double staining with different kinds of the antisera was also performed as previously described (7).…”

Section: Western Blot Analysismentioning

confidence: 99%

Fragmentation of the β-Subunit of Human Chorionic Gonadotropin Produced by Choriocarcinoma*

et al. 1988

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When human chorionic gonadotropin (hCG) was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions with dithiothreitol (DTT), a smaller weight material (CTP'), in addition to the beta-subunit, could be detected by Western blot analysis using antiserum for hCG beta-carboxy-terminal peptide (CTP). The CTP' band was much more apparent with urinary hCG from a patient with choriocarcinoma than with that from normal pregnant women. Second-dimensional electrophoresis of the choriocarcinoma hCG (c-hCG) after reduction with DTT indicated that the CTP', Mr 25,000, was released from the beta-subunit. The carbohydrate structure of the CTP' was analyzed by affinity with lectin-peroxidase on a nitrocellulose membrane. The CTP' did not interact with Concanavalin A, but exhibited strong interaction with both RCA120 and Arachis hypogaea after removal of sialic acid, indicating that it was released as a fragment containing an O-linked sugar chain as was found in the hCG beta carboxy-terminal portion. Western blot analysis using the antisera for hCG alpha, hCG beta, and hCG beta-CTP showed that the CTP' contains not only the carboxy-terminal portion but also a part of the internal (core) portion of the beta-subunit molecule. This dissociation of the c-hCG beta was further supported by the presence of a faster moving component (FMC) which may correspond to the NH2-terminal side counterpart. The desialylated FMC could be detected by Concanavalin A and RCA120 but not by Arachis hypogaea, indicating that it contains N-linked rather than O-linked sugar chains. The FMC does not contain any of the epitopes for the antisera examined in Western blot. These results indicate that the beta-subunit of the choriocarcinoma urine hCG has an unusual site which is dissociated into two components of Mr 25,000 (CTP') and Mr 18,000 (FMC) by DTT reduction.

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Section: Western Blot Analysismentioning

confidence: 99%

Fragmentation of the β-Subunit of Human Chorionic Gonadotropin Produced by Choriocarcinoma*

et al. 1988

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“…areas of intensive investigation (9,10). Indeed, the molecular polymorphism of hCG and the presence of hCGrelated proteins in biological fluids and tissues have presented major difficulties in understanding its synthesis during pregnancy and mechanisms of presumed hCG genome depression in both normal and malignant nontrophoblastic cells.…”

mentioning

confidence: 99%

Physiological Studies of Human Chorionic Gonadotropin (hCG), αhCG, and βhCG as Measured by Specific Monoclonal Immunoradiometric Assays*

et al. 1987

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Several libraries of monoclonal antibodies have been produced against epitopes that reside on hCG, alpha hCG, and beta hCG. Having characterized them physically, we explored their use in the construction of highly specific and sensitive immunoradiometric assays. There were several important immunochemical considerations with respect to developing assays that accurately detect low levels of free subunits in serum in the presence of high concentrations of the native hormone. These include physical properties and specificities of the monoclonal antibodies, choice of capture antibody on the solid phase support, assay design, and purity of hormone standards. Using such assays, we found early pregnancy (in vitro fertilization) to be characterized by the sequential appearance of hCG, followed by beta hCG and then alpha hCG. Molar ratios of beta hCG to alpha hCG and beta hCG to hCG were highest in early gestation. However, there was a reversal of the beta hCG to alpha hCG ratio at 12-13 weeks gestation, and an excess of free alpha hCG was observed thereafter. Except for values obtained in very early pregnancy, the beta hCG to hCG ratio remained remarkably constant at approximately 0.5% throughout gestation. In contrast, choriocarcinoma was distinguished by absolute serum beta hCG concentrations 3-100 times greater than the maximum values observed during pregnancy and, more importantly, by exceedingly high beta hCG to hCG ratios. For comparison, we studied hCG, alpha hCG, and beta hCG levels in an additional 178 patients with nontrophoblastic tumors. Ectopic production of alpha hCG and beta hCG was rare (3%), and thus far, we have been unable to demonstrate the presence of hCG in such patients. Therefore, hCG and the free subunits appear not to be useful as serological markers for nontrophoblastic tumors.

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A novel tumor-associated protein: clinical significance of serum levels in various clinical conditions with special reference to gynecological malignant diseases

Nakai¹,

Kawauchi²,

Atsumi³

et al. 1992

European Journal of Obstetrics & Gynecology and Reproductiv

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New Horizons in hCG Detection

Cited by 8 publications

References 60 publications

Fragmentation of the β-Subunit of Human Chorionic Gonadotropin Produced by Choriocarcinoma*

Fragmentation of the β-Subunit of Human Chorionic Gonadotropin Produced by Choriocarcinoma*

Physiological Studies of Human Chorionic Gonadotropin (hCG), αhCG, and βhCG as Measured by Specific Monoclonal Immunoradiometric Assays*

A novel tumor-associated protein: clinical significance of serum levels in various clinical conditions with special reference to gynecological malignant diseases

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