The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

CGA  -  glycoprotein hormones, alpha polypeptide

Homo sapiens

Synonyms: Anterior pituitary glycoprotein hormones common subunit alpha, CG-ALPHA, CG-alpha, Choriogonadotropin alpha chain, Chorionic gonadotrophin subunit alpha, ...
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of CGA


Psychiatry related information on CGA

  • Increased permissiveness, however, was not due to decreased discrimination because females could discriminate between calls even at the highest HCG doses [4].
  • On the second day of this treatment, pregnant mares' serum gonadotrophin was administered and human chorionic gonadotrophin (HCG) 48 h later, after which copulation occurred [5].
  • Phonotaxis assays were conducted to measure three aspects of mate choice behavior before and after HCG administration; receptivity (response to a conspecific mate signal), permissiveness (response to a signal that is less attractive than conspecific signals) and discrimination (ability to discern signal differences) [4].
  • When estrus was terminated with human chorionic gonadotropin (HCG), predatory behavior did not further regress as it did in control runs [6].
  • Serum samples for AFP and HCG should be obtained before orchiectomy in any patient with a testicular tumour, as the pre-orchiectomy titres may represent important information for the subsequent clinical decision making [7].

High impact information on CGA

  • In one family, a homozygous point mutation leading to a premature stop codon (CGA to TGA) was identified in exon 3 of the gene [8].
  • Seventeen of 27 patients with functioning islet-cell carcinomas had elevated plasma levels of hCG or one of its subunits (hCG-alpha and hCG-beta) [9].
  • In one patient responding to streptozocin, changes in hCG-alpha correlated with the clinical course [9].
  • A further intriguing finding is the striking similarity between the direct, inhibitory effects of LHRH and LH/HCG on the gonads; for example, both treatments reduce LH receptor numbers and the steroidogenic responsiveness of rat Leydig cells [10].
  • It is well established that the administration of high doses of luteinizing hormone (LH) or human chorionic gonadotropin (HCG) to animals can impair gonadal function in both the male and female [10].

Chemical compound and disease context of CGA


Biological context of CGA


Anatomical context of CGA


Associations of CGA with chemical compounds

  • CGA gene (coding for the alpha subunit of glycoprotein hormones) overexpression in ER alpha-positive prostate tumors [1].
  • After modified VAC chemotherapy (vincristine, dactinomycin, and cyclophosphamide), AFP and HCG levels in the serum were reduced significantly, while serum CEA increased gradually to the level of 6.5 ng/ml [24].
  • HCG, hPL, and estriol and the coagulation profile remained within the normal range throughout the pregnancy [25].
  • The location of the cystine-containing peptides in human FSH alpha- and beta-subunits was established by amino acid composition, end-group analysis and determination of the amino acid sequence by Edman degradation [26].
  • Serial sections of tissue specimens were repeatedly stained, mainly with hematoxylin and eosin (H-E) stain, HCG immunostain, and AFP immunostain [27].

Physical interactions of CGA

  • With the exception of anti-22-39, all of the remaining antisera bound to hFSH alpha r/a. None of the antisera bound to hFSH beta [28].
  • HCG binding to the testicular LH receptor is similar in fertile, subfertile, and infertile stallions [29].

Regulatory relationships of CGA

  • Flow cytometry showed that the expression of LH-R on the cell surface of luteinizing granulosa cells was enhanced by HCG, but was unaffected by TNFalpha [30].
  • Significant correlations were found for AFP and UE3 in the controls and for intHCG and F beta HCG in both the control and the Down's syndrome pregnancies [31].
  • We conclude that VIP rapidly increases cAMP content and activates hCG-alpha gene expression in JEG-3 cells, but sustained elevations in cAMP are necessary for maximal accumulation of this CRE-regulated gene product [32].
  • The present study demonstrates that the proto-oncogene c-jun represses transcription of the human CG alpha and CG beta promoters. c-Jun repressed the CG alpha promoter through a canonical cAMP response element (CRE) that is known to bind c-Jun and other members of the B-Zip transcription factor family [33].
  • EGF also stimulates secretion of human chorionic gonadotropin (hCG) and to a lesser extent the secretion of free hCG-alpha [34].

Other interactions of CGA

  • In the current study we demonstrate that bLH, hCG, hCG beta, hCG alpha, and FSH alpha are recognized by the pituitary GalNAc-transferase in vitro, whereas oFSH, hFSH, and hFSH beta are not (b-, h-, and o-indicate bovine, human, and ovine) [16].
  • In germinomas, HCG positive cells were occasionally demonstrated in cells presenting as syncytiotrophoblastic giant cells (STGC), and GFAP and S-100 positive cells were found in the surrounding gliotic lesions [35].
  • Tumours markers of poor prognosis in the multivariate analysis were serum beta HCG > or = 4 IU/l [hazard ratio (HR) 1.7; 95% confidence interval (CI) 2.8-1.1] and CA125 > or = 350 U/ml (HR 2.2; CI 4.2-1.2) [36].
  • This high rate was primarily due to the simultaneous measurement of CEA, betaHCG, HCG, and casein [37].
  • Positive reaction was shown in 44% of the cases for keratin, 77% for CEA, and 58% for HCG [38].

Analytical, diagnostic and therapeutic context of CGA

  • This is the largest prognostic study of each tumour marker in advanced disease and demonstrates that serum beta HCG and CA125 in gastric cancer prior to chemotherapy do convey an independent poor prognosis which may reflect not just tumour burden but aggressive biology [36].
  • By the indirect immunoperoxidase technique, the antigens AFP, HCG, and CEA were stained in the immature glandular tissues of teratoma [24].
  • On the other hand, noncompetitive binding tests and immunoblotting results showed that one of the MCAs against FSH alpha (BF3A20) bound strongly to intact LH and FSH and their alpha subunits, but not their beta subunits [39].
  • 170 patients with testicular germ cell tumours (88 seminomas and 82 non-seminomas) were examined with immunologic techniques for the presence of the tumour markers alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) in tumour tissue and preoperative serum samples [40].
  • The resulting 510 bp PCR product for the CGA-subunit included the full coding sequence for the 96 amino acid mature subunit preceded by a 24 amino acid signal peptide [41].


  1. CGA gene (coding for the alpha subunit of glycoprotein hormones) overexpression in ER alpha-positive prostate tumors. Bièche, I., Latil, A., Parfait, B., Vidaud, D., Laurendeau, I., Lidereau, R., Cussenot, O., Vidaud, M. Eur. Urol. (2002) [Pubmed]
  2. Immunocytochemical evaluation of human esophageal neoplasms and preneoplastic lesions for beta-chorionic gonadotropin, placental lactogen, alpha-fetoprotein, carcinoembryonic antigen, and nonspecific cross-reacting antigen. Burg-Kurland, C.L., Purnell, D.M., Combs, J.W., Hillman, E.A., Harris, C.C., Trump, B.F. Cancer Res. (1986) [Pubmed]
  3. Patterns of seminoma tissue markers and deletions. Yamamoto, H., Rudén, U., Ljungdahl-Ståhle, E., Brehmer-Andersson, E., Hirano, K., Hisazumi, H., Stigbrand, T., Wahren, B. Int. J. Cancer (1987) [Pubmed]
  4. Hormonal state influences aspects of female mate choice in the Túngara Frog (Physalaemus pustulosus). Lynch, K.S., Crews, D., Ryan, M.J., Wilczynski, W. Hormones and behavior. (2006) [Pubmed]
  5. Effect of platelet activating factor on embryonic development and implantation in the mouse. Fukuda, A.I., Breuel, K.F. Hum. Reprod. (1996) [Pubmed]
  6. Annual rhythm and hormonal control of predatory behavior in female ferrets. Harrer, S., Schmidt, W.J. Physiol. Behav. (1986) [Pubmed]
  7. Serum tumour markers in testicular and extragonadal germ cell malignancies. Klepp, O. Scand. J. Clin. Lab. Invest. Suppl. (1991) [Pubmed]
  8. Herlitz's junctional epidermolysis bullosa is linked to mutations in the gene (LAMC2) for the gamma 2 subunit of nicein/kalinin (LAMININ-5). Aberdam, D., Galliano, M.F., Vailly, J., Pulkkinen, L., Bonifas, J., Christiano, A.M., Tryggvason, K., Uitto, J., Epstein, E.H., Ortonne, J.P. Nat. Genet. (1994) [Pubmed]
  9. Ectopic production of chorionic gonadotropin and its subunits by islet-cell tumors. A specific marker for malignancy. Kahn, C.R., Rosen, S.W., Weintraub, B.D., Fajans, S.S., Gorden, P. N. Engl. J. Med. (1977) [Pubmed]
  10. HCG stimulation of testicular LHRH-like activity. Sharpe, R.M., Fraser, H.M. Nature (1980) [Pubmed]
  11. The CGA gene as new predictor of the response to endocrine therapy in ER alpha-positive postmenopausal breast cancer patients. Bièche, I., Parfait, B., Noguès, C., Andrieu, C., Vidaud, D., Spyratos, F., Lidereau, R., Vidaud, M. Oncogene (2001) [Pubmed]
  12. The role of radioimmunodetection in the management of testicular cancer. Javadpour, N., Kim, E.E., DeLand, F.H., Salyer, J.R., Shah, U., Goldenberg, D.M. JAMA (1981) [Pubmed]
  13. The prognostic value of CEA, beta HCG, AFP, CA125, CA19-9 and C-erb B-2, beta HCG immunohistochemistry in advanced colorectal cancer. Webb, A., Scott-Mackie, P., Cunningham, D., Norman, A., Andreyev, J., O'Brien, M., Bensted, J. Ann. Oncol. (1995) [Pubmed]
  14. HCG, HPL, oestradiol, progesterone and AFP in serum in patients with threatened abortion. Kunz, J., Keller, P.J. British journal of obstetrics and gynaecology. (1976) [Pubmed]
  15. False-positive and false-negative alpha-feto protein and human chorionic gonadotropin assays in testicular cancer: a double blind study. Javadpour, N., Soares, T. Cancer (1981) [Pubmed]
  16. Recognition by the glycoprotein hormone-specific N-acetylgalactosaminetransferase is independent of hormone native conformation. Smith, P.L., Baenziger, J.U. Proc. Natl. Acad. Sci. U.S.A. (1990) [Pubmed]
  17. Assignment of disulfide bonds in the alpha subunit of human chorionic gonadotropin. Mise, T., Bahl, O.P. J. Biol. Chem. (1980) [Pubmed]
  18. Purification and characterization of recombinant human thyrotropin (TSH) isoforms produced by Chinese hamster ovary cells: the role of sialylation and sulfation in TSH bioactivity. Szkudlinski, M.W., Thotakura, N.R., Bucci, I., Joshi, L.R., Tsai, A., East-Palmer, J., Shiloach, J., Weintraub, B.D. Endocrinology (1993) [Pubmed]
  19. Trophoblastic cells expressing human chorionic gonadotropin genes in peripheral blood of patients with trophoblastic disease. Taniguchi, R., Koizumi, T., Das, H., Chakraborty, S., Sugimoto, T., Hasegawa, K., Kono, M., Nishimura, R. Life Sci. (2000) [Pubmed]
  20. In silico identification of breast cancer genes by combined multiple high throughput analyses. Shen, D., He, J., Chang, H.R. Int. J. Mol. Med. (2005) [Pubmed]
  21. Alpha-fetoprotein and beta-human chorionic gonadotropin: their clinical significance as tumour markers. Gregory, J.J., Finlay, J.L. Drugs (1999) [Pubmed]
  22. Distribution of tumor-associated antigens in the various histologic components of germ cell tumors of the testis. Jacobsen, G.K., Jacobsen, M., Clausen, P.P. Am. J. Surg. Pathol. (1981) [Pubmed]
  23. Markers and characteristics of human SCLC cell lines. Neuroendocrine markers, classical tumor markers, and chromosomal characteristics of permanent human small cell lung cancer cell lines. Bepler, G., Jaques, G., Koehler, A., Gropp, C., Havemann, K. J. Cancer Res. Clin. Oncol. (1987) [Pubmed]
  24. alpha-Fetoprotein (AFP), human chorionic gonadotropin (HCG), and carcinoembryonic antigen (CEA) demonstrated in the immature glands of mediastinal teratocarcinoma: a case report. Irie, T., Watanabe, H., Kawaoi, A., Takeuchi, J. Cancer (1982) [Pubmed]
  25. Maternal serum alpha-fetoprotein levels in a triplet pregnancy with 2 papyraceous fetuses. Taubert, H.D., Bastert, G., Dericks-Tan, J.S. Arch. Gynecol. (1986) [Pubmed]
  26. Studies on the disulfide bonds in human pituitary follicle-stimulating hormone. Fujiki, Y., Rathnam, P., Saxena, B.B. Biochim. Biophys. Acta (1980) [Pubmed]
  27. Morphologic features of human chorionic gonadotropin- or alpha-fetoprotein-producing germ cell tumors of the central nervous system: histological heterogeneity and surgical meaning. Sugiyama, K., Arita, K., Tominaga, A., Hanaya, R., Taniguchi, E., Okamura, T., Itoh, Y., Yamasaki, F., Kurisu, K. Brain tumor pathology. (2001) [Pubmed]
  28. Topographic analysis of the alpha-subunit of human follicle-stimulating hormone using site-specific antipeptide antisera. Weiner, R.S., Andersen, T.T., Dias, J.A. Endocrinology (1990) [Pubmed]
  29. HCG binding to the testicular LH receptor is similar in fertile, subfertile, and infertile stallions. Motton, D.D., Roser, J.F. J. Androl. (1997) [Pubmed]
  30. Immunohistochemical localization of the LH/HCG receptor in human ovary: HCG enhances cell surface expression of LH/HCG receptor on luteinizing granulosa cells in vitro. Takao, Y., Honda, T., Ueda, M., Hattori, N., Yamada, S., Maeda, M., Fujiwara, H., Mori, T., Wimalasena, J. Mol. Hum. Reprod. (1997) [Pubmed]
  31. First-trimester biochemical screening for fetal chromosome abnormalities and neural tube defects. Aitken, D.A., McCaw, G., Crossley, J.A., Berry, E., Connor, J.M., Spencer, K., Macri, J.N. Prenat. Diagn. (1993) [Pubmed]
  32. Vasoactive intestinal peptide increases intracellular cAMP and gonadotropin-alpha gene activity in JEG-3 syncytial trophoblasts. Constraints posed by desensitization. Deutsch, P.J., Sun, Y., Kroog, G.S. J. Biol. Chem. (1990) [Pubmed]
  33. c-Jun represses transcription of the human chorionic gonadotropin alpha and beta genes through distinct types of CREs. Pestell, R.G., Hollenberg, A.N., Albanese, C., Jameson, J.L. J. Biol. Chem. (1994) [Pubmed]
  34. Epidermal growth factor stimulates secretion of human chorionic gonadotropin by cultured human choriocarcinoma cells. Benveniste, R., Speeg, K.V., Carpenter, G., Cohen, S., Lindner, J., Rabinowitz, D. J. Clin. Endocrinol. Metab. (1978) [Pubmed]
  35. An immunohistochemical study of intracranial germ cell tumours. Yamagami, T., Handa, H., Yamashita, J., Okumura, T., Paine, J., Haebara, H., Furukawa, F. Acta neurochirurgica. (1987) [Pubmed]
  36. The prognostic value of serum and immunohistochemical tumour markers in advanced gastric cancer. Webb, A., Scott-Mackie, P., Cunningham, D., Norman, A., Andreyev, J., O'Brien, M., Bensted, J. Eur. J. Cancer (1996) [Pubmed]
  37. Simultaneous assays of cancer-associated antigens in various neoplastic disorders. Franchimont, P., Zangerle, P.F., Nogarede, J., Bury, J., Molter, F., Reuter, A., Hendrick, J.C., Collette, J. Cancer (1976) [Pubmed]
  38. An immunohistochemical study of keratin, carcinoembryonic antigen, human chorionic gonadotropin and alpha-fetoprotein in lung cancer. Kimura, N., Ghandur-Mnaymen, L. Tohoku J. Exp. Med. (1985) [Pubmed]
  39. Immunocytochemical localization of the subunits of glycoprotein hormones (LH, FSH, and TSH) in the bullfrog pituitary gland using monoclonal antibodies and polyclonal antiserum. Tanaka, S., Park, M.K., Hayashi, H., Hanaoka, Y., Wakabayashi, K., Kurosumi, K. Gen. Comp. Endocrinol. (1990) [Pubmed]
  40. Alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) in testicular germ cell tumours. A comparison of histologic and serologic occurrence of tumour markers. Jacobsen, G.K. Acta pathologica, microbiologica, et immunologica Scandinavica. Section A, Pathology. (1983) [Pubmed]
  41. Cloning and sequencing of feline thyrotropin (fTSH): heterodimeric and yoked constructs. Rayalam, S., Eizenstat, L.D., Hoenig, M., Ferguson, D.C. Domest. Anim. Endocrinol. (2006) [Pubmed]
WikiGenes - Universities