Disease relevance of PSG1

• Linkage of two human pregnancy-specific beta 1-glycoprotein genes: one is associated with hydatidiform mole [1].
• The evolutionary relationship between CEA and PS beta G points to a possible common function in the control of cell invasion and/or metastasis [2].
• Syncytial trophoblast in choriocarcinoma components and syncytial giant cells were all positive for HCG, SP1 and HPL [3].
• Twenty-one adenocarcinomas (91.3%) reacted for CEA, 14 (60.9%) for Leu-M1, 14 (60.9%) for SC, nine (39.1%) for CA19-9, and eight (34.8%) for SP1; no mesotheliomas stained for any of these markers [4].
• 61 patients with seminoma and 113 with nonseminomatous germ cell tumors of the testis were treated according to the histology, stage of disease, and serum levels of tumor markers (CEA, AFP, hCG, hPL and SP1) [5].

Psychiatry related information on PSG1

• PSG1 was representative of PSGtot and similar to PSG2 only in those patients with rapid eye movement (REM) phase sleep in the first part of the night [6].
• SP1 was detected at low levels in the CSF from 1 patient out of 5 with Creutzfeldt-Jakob disease and from a patient with Behçet's disease [7].

High impact information on PSG1

• Pregnancy-specific beta 1 glycoprotein (SP1) was determined by radioimmunoassay in sera from 27 normal women, 33 women with benign breast disease, and 191 women with carcinoma of the breast, staged for extent of the disease [8].
• SP1 was elevated at 11-440 ng/ml in 3 of 6 men with choriocarcinomas, in 5 of 17 men with teratomas or "teratocarcinomas" (embryonal carcinomas and teratomas), and in 5 of 50 men with embryonal carcinomas; the highest value in 143 patients with nonmalignant diseases was 9.1 ng/ml [9].
• Schwangerschafts (pregnancy) protein No. 1 (SP1), a recently identified beta1-glycoprotein that occurs during pregnancy, was assayed in the sera of 97 men with germ cell tumors of the testis [9].
• None of 24 sera from men with seminomas and none of 5 sera from men with orchitis had elevated SP1 [9].
• Maternal concentrations of pregnancy-specific beta 1-glycoprotein (SP1) were measured in 145 patients with vaginal bleeding in the first trimester of pregnancy [10].

Chemical compound and disease context of PSG1

• Tumors composed of yolk-sac elements alone or mixed with embryonal carcinoma produce AFP: of syncytiotrophoblastic elements - hCG, hPL or SP1; and teratomas with differentiated structures - CEA [11].
• Previous transfection studies of HIV LTR constructs linked to the chloramphenicol acetyltransferase gene indicated that multiple regulatory regions including the enhancer, SP1, TATA and TAR regions were important for HIV gene expression [12].
• To demonstrate the ectopic production of pregnancy-specific beta 1-glycoprotein (PSbetaG) by a nontrophoblastic tumor, the in vitro secretion of this glycoprotein was evaluated in an hCG-producing ovarian cystadenocarcinoma cell line maintained in long term cell culture [13].
• In addition to stimulating PS beta G production, retinoic acid increased the production of hCG and its alpha-subunit (hCG alpha) by choriocarcinoma cells [14].
• Choriocarcinoma cells can be induced to synthesize low levels of PS beta G by retinoic acid, 8-bromo-cAMP (8BrcAMP), cholera toxin, methyl-isobutylxanthine (MIX), and 5-bromo-2'-deoxyuridine (BrdUrd) [14].

Biological context of PSG1

• Depending upon the domains compared, PSGGA and PSGGB share 92-98% nucleotide and 86-95% amino acid sequence identity with PSG93, the most abundant PS beta G transcript [1].
• The coding region of PSG95 is identical to the previously reported cDNA clones PSG1d and FL-NCA, but PSG95 contains an additional 518 and 523 base pairs in the 3' end as compared with PSG1d and FL-NCA, respectively [1].
• The two genes are arranged in the same 5'----3' orientation; the 3' region (including the A2 and B-C exons) of the upstream gene, PSGGA, is linked to the 5' region (including the 5'/L and L/N exons) of PSGGB, the downstream gene [1].
• Three highly homologous cDNAs encoding human pregnancy-specific beta 1-glycoprotein (SP1) were isolated from a human placental cDNA library [15].
• PS beta G gene expression in primary trophoblasts was slightly reduced by 8-bromo-cAMP, but was markedly inhibited by sodium butyrate [16].

Anatomical context of PSG1

• To determine whether human and murine PSGs have similar functions and use the same receptor, we treated wild-type and CD9-deficient macrophages with murine PSG17N and human PSG1 and -11 [17].
• Effect of pregnancy-specific beta 1-glycoprotein on the development of preimplantation embryo [18].
• Placental fibroblasts provide a unique model for the study of the mechanisms responsible for the differential expression of the PS beta G gene [19].
• Expression of the pregnancy-specific beta 1-glycoprotein gene in cultured human trophoblasts [16].
• Effect of human pregnancy-specific beta1-glycoprotein on blood cell regeneration after bone marrow transplantation [20].

Associations of PSG1 with chemical compounds

• The major placental PS beta G is a 72-kDa glycoprotein, while the major fibroblast PS beta G is a 62-kDa species [19].
• Evaluation of five tumor markers (AFP, CEA, hCG, hPL and SP1) in monitoring therapy and follow-up of patients with testicular germ cell tumors [5].
• The positions of the cysteine residues in each domain also are conserved, indicating that PS beta G and CEA are two members of the same gene family [21].
• In addition, the process of calcium phosphate-mediated DNA transfection, as well as treatment with the calcium ionophore A23187 or with phorbol 12-myristate 13-acetate, can also result in heritable changes in the malignant behavior of SP1 cells [22].
• The carbohydrate side-chains are essential for the stability of fibroblast PS beta G, because PS beta G synthesis in these fibroblasts could not be detected in the presence of tunicamycin, a protein glycosylation inhibitor which did not affect PS beta G mRNA expression [23].

Other interactions of PSG1

• PSGGB corresponds to the previously identified cDNA PSG6, which encodes proteins containing a 34-amino acid leader peptide and a 108-amino acid N domain, which is one amino acid shorter than the majority of PS beta G N domains [1].
• These results suggest that PSG1 and PSG3 exhibit embryotropic activity at different stages of development in the mouse model [18].
• Ribonuclease protection analysis showed that butyrate increased the PS beta G mRNAs containing the PSG-5' or PSG93-specific sequence to approximately 20% of human placental levels [19].
• Human fetal liver contains a family of carcinoembryonic antigen related glycoproteins called the pregnancy specific beta 1 glycoprotein/fetal liver non specific cross-reactive antigen (PS beta G/FL-NCA) glycoprotein family [24].
• The calculated molecular masses of the two polypeptides encoded by PSG16 and PSG93 are 46.9 and 47.2 kDa, close to the size of the major nonglycosylated PS beta G of 48 kDa [25].

Analytical, diagnostic and therapeutic context of PSG1

• Twenty nine consecutive OSAS patients, aged 54+/-10 yrs; body mass index (BMI) 40+/-6 kg x m(-2) (mean+/-SD values), were studied by separate analyses of PSG1, PSG2 and PSGtot [6].
• Molecular cloning revealed that PS beta G is an extremely polymorphic protein [16].
• Sequence determination of one of the cloned cDNA inserts revealed a partial cDNA of 773 bp which is 94% homologous at the nucleotide level and 88% homologous at the amino acid level to the placental SP1 cDNA [26].
• Serum levels of AFP, CEA, hCG, hPL and SP1 were measured by specific radioimmunoassays in 111 patients with testicular germ cell tumors [11].
• Specific and sensitive determination of pregnancy-specific beta 1-glycoprotein by radioimmunoassay. A new pregnancy test [27].

References