Abstract
The molecular forms of human chorionic gonadotropin (hCG) were assessed in parallel serum and urine samples from a choriocarcinoma patient by gel chromatography, isoelectric focusing, and Western blot analysis. There were significant qualitative differences in the molecular forms of hCG between the serum and the urine. The serum hCG had a greater molecular weight and a stronger acidic charge than the urinary hCG. These results may be attributed to differences of sialic acid contents. Affinity chromatography using Ricinus communis agglutinin‐conjugated Sepharose showed that the serum hCG was completely sialylated, while the urinary hCG was partially desialylated. In addition to the complete hCG molecule, two kinds of hCGβ‐related fragments were detected in the urine of the patient, but not in the serum. In the Western blot using anti‐hCGβ or anti‐hCGβ‐CTP under reducing conditions, the urine presented a new band (CTP′) with Mr 23,000 in addition to the β‐subunit, while the serum revealed a single band of the β‐subunit with or without a reducing reagent. The present data revealed striking qualitative differences in the molecular forms of hCG between serum and urine of a patient with choriocarcinoma.
Keywords: Human chorionic gonadotropin, Trophobiastic disease, Glycoprotein, Molecular heterogeneity, Lectin
Full Text
The Full Text of this article is available as a PDF (383.0 KB).
REFERENCES
- 1. ) Hussa , R. O.Human chorionic gonadotropin; a clinical marker: review of its biosynthesis . Ligand Rev. , 3 , 1 – 48 ( 1981. ). [Google Scholar]
- 2. ) Ashitaka , Y. , Nishimura , R. , Futamura , K. , Ohashi , M. and Tojo , S.Serum and chorionic tissue concentrations of human chorionic gonadotropin and its subunits during pregnancy . Endocrinol. Jpn. , 21 , 547 – 550 ( 1974. ). [DOI] [PubMed] [Google Scholar]
- 3. ) Nishimura , R. , Ashitaka , Y. and Tojo , S.The clinical evaluation of the simultaneous measurements of human chorionic gonadotropin and its alpha‐subunit in sera of patients with trophoblastic diseases . Endocrinol. Jpn. , 26 , 575 – 583 ( 1979. ). [DOI] [PubMed] [Google Scholar]
- 4. ) Franchimont , P. , Gaspard , U. , Reuter , A. and Heynen , G.Polymorphism of protein and polypeptide hormones . Clin. Endocrinol. , 1 , 315 – 336 ( 1972. ). [DOI] [PubMed] [Google Scholar]
- 5. ) Amr , S. , Wehmann , R. E. , Birken , S. and Canfield , R. E.Characterization of a carboxyterminal peptide fragment of the human chorionic gonadotropin β‐subunit excreted in the urine of a woman with choriocarcinoma . J. Clin. Invest. , 71 , 329 – 339 ( 1983. ). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6. ) Papapetrou , P. D. , Sakarelou , N. P. , Braouzi , H. and Fessa , P. H.Ectopic production of human chorionic gonadotropin (hCG) by neoplasms . Cancer , 45 , 2583 – 2592 ( 1980. ). [DOI] [PubMed] [Google Scholar]
- 7. ) Papapetrou , P. D. and Nicopoulou , S. C.The origin of a human chorionic gonadotropin β‐subunit‐core fragment excreted in the urine of patients with cancer . Ada Endocrinol. , 112 , 415 – 422 ( 1986. ). [DOI] [PubMed] [Google Scholar]
- 8. ) Birken , S. , Armstrong , E. G. , Kolks , M. A. G. , Cole , L. A , Agosto , G. M. , Krichevsky , A. , Vaitukaitis , J. L. and Canfield , R. E.Structure of human chorionic gonadotropin β‐subunit fragment from pregnancy urine . Endocrinology , 123 , 572 – 583 ( 1988. ). [DOI] [PubMed] [Google Scholar]
- 9. ) Wehmann , R. E. and Nisula , B. C.The metabolic and renal clearance rates of purified human chorionic gonadotropin . J. Clin. Invest , 68 , 184 – 194 ( 1981. ). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10. ) Amir , S. , Rosa , C. , Birken , S. , Canfield , R. E. and Nisula , B.Carboxyterminal peptide fragments of the beta‐subunit are urinary products of the metabolism of desialylated human choriogonadotropin . J. Clin. Invest. , 76 , 350 – 356 ( 1985. ). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11. ) Nishimura , R. , Ide , K. , Utsunomiya , T. , Kitajima , T. , Yuki , Y. and Mochizuki , M.Fragmentation of the β‐subunit of human chorionic gonadotropin produced by choriocarcinoma . Endocrinology , 123 , 420 – 425 ( 1988. ). [DOI] [PubMed] [Google Scholar]
- 12. ) Nishimura , R. , Utsunomiya , T. , Ide , K. , Kitajima , T. , Chen , H. C. , Strobel , J. L. , Hussa , R. O. and Mochizuki , M.Characterization of human chorionic gonadotropin in urine of patients with trophoblastic diseases by Western blotting using specific antibodies . Jpn. J. Cancer Res. , 78 , 833 – 839 ( 1987. ). [PubMed] [Google Scholar]
- 13. ) Hussa , R. O. and Cole , L. A.New horizons in hCG detection . In “ Human Trophoblast Neoplasms,” ed. Patillo R. A. and Hussa R. O. , pp. 217 – 243 ( 1984. ). Plenum Press; , New York ). [DOI] [PubMed] [Google Scholar]
- 14. ) Chen , H. C. , Hodgen , G. D. , Matsuura , S. , Lin , J. L. , Gross , E. , Reichert , L. E. , Jr. , Birken , S. , Canfield , R. E. and Ross , G. T.Evidence for a gonadotropin from nonpregnant subjects that has physical and biological similarities to human chorionic gonadotropin . Proc. Natl. Acad. Sci. USA , 73 , 2885 – 2889 ( 1976. ). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15. ) Catt , K. J. , Dufau , M. L. and Tsuruhara , T.Radioligand‐receptor assay of luteinizing hormone and chorionic gonadotropin . J. Clin. Endocrinol. Metab. , 34 , 123 – 132 ( 1972. ). [DOI] [PubMed] [Google Scholar]
- 16. ) Nishimura , R. , Hamamoto , T. , Utsunomiya , T. and Mochizuki , M.Heterogeneity of free alpha‐subunit in term placenta . Endocrinol. Jpn. , 30 , 663 – 669 ( 1973. ). [DOI] [PubMed] [Google Scholar]
- 17. ) Towbin , H. , Stoehelin , T. and Gordon , J.Electric transfer of proteins from acrylamide gels to nitrocellulose sheets: procedure and some applications . Proc. Natl. Acad. Sci. USA , 76 , 4350 – 4354 ( 1979. ). [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18. ) Kato , Y. and Braunstein , G. D.β‐Core fragment is a major form of immunoreactive urinary chorionic gonadotropin in human pregnancy . J. Clin. Endocrinol. Metab. , 66 , 1197 – 1201 ( 1988. ). [DOI] [PubMed] [Google Scholar]
- 19. ) Irimura , T. , Kawaguchi , T. , Terao , T. and Osawa , T.Carbohydrate‐binding specificity of the so‐called galactose specific phytohemagglutinins . Carbohydr, Res. , 39 , 317 – 327 ( 1975. ). [DOI] [PubMed] [Google Scholar]
- 20. ) Yazaki , K. , Yazaki , C. , Wakabayashi , K. and Igarashi , M.Isoelectric heterogeneity of human chorionic gonadotropin: presence of choriocarcinoma specific components . Am. J. Obstet. Gynecol. , 138 , 189 – 194 ( 1980. ). [DOI] [PubMed] [Google Scholar]
- 21. ) Mizuochi , T. , Nishimura , R. , Taniguchi , T. , Utsunomiya , T. , Mochizuki , M. , Derappe , C. and Kobata , A.Comparison of carbohydrate structure between human chorionic gonadotropin in urine of the patients with trophoblastic diseases and healthy individuals . Jpn. J. Cancer Res. , 76 , 752 – 759 ( 1985. ). [PubMed] [Google Scholar]
- 22. ) Nishimura , R. , Endo , Y. , Tanabe , K. , Ashitaka , Y. and Tojo , S.The biological properties of urinary human chorionic gonadotropin from the patients with trophoblastic diseases . J. Endocrinol. Invest. , 4 , 349 – 358 ( 1981. ). [DOI] [PubMed] [Google Scholar]
- 23. ) Mizuochi , T. , Nishimura , R. , Derappe , C. , Taniguchi , T. , Hamamoto , T. , Mochizuki , M. and Kobata , A.Structures of the asparagine‐linked sugar chains of human chorionic gonadotropin produced in choriocarcinoma . J. Biol, Chem. , 258 , 14126 – 14129 ( 1983. ). [PubMed] [Google Scholar]
- 24. ) Blithe , D. L. , Akar , A. H. , Wehmann , R. E. and Nisula , B. D.Purification of β‐core fragment from pregnancy urine and demonstration that its carbohydrate moieties differ from those of native human chorionic gonadotropin‐β . Endocrinology , 122 , 173 – 180 ( 1988. ). [DOI] [PubMed] [Google Scholar]