Binding of the sulfates of estradiol-17beta to human serum albumin and plasma.

The binding of the 3 estradiol-17beta sulfates in solutions of human serum albumin (HSA) and in plasma has been studied by the method of centrifugal ultrafiltration. HSA has one binding site for the 17-sulfate with association constants of about 10(5) to 10(6)M-1 at either 4 degrees or 37 degrees and several sites with association constants of 10(3) to 10(4) M-1. HSA has 3 groups of binding sites for estradiol-17beta disulfate, one binding site with association constants of about 10(6) M-1 at either 4 C or 37 C, about 2 binding sites with association constants of about 10(4)M-1 and several sites with association constants of about 10(3)M-1. The binding data of the 3-sulfate of estradiol-17beta are best interpreted by the postulate of the existence of a tetramer in addition to the monomer of the sulfate in solution. With this postulate, HSA has one binding site with an association constant of about 5-10(5)M-1 and seven binding sites with association constants of about 10(3)M-1 at either 4 C or 37 C. More than 99% of the 17-sulfate or the disulfate of estradiol-17beta is bound in plasma at 37 degrees, with all of the binding accounted for by HSA. The estradiol-17beta sulfates compete with one another for binding to HSA. Strong displacement has also been found by androgen sulfates and, less, by estrogen glucosiduronates.

p53 mutant His175 identified in a newly established fallopian tube carcinoma cell line secreting interleukin 6.

Fallopian tube carcinoma is a lethal gynecologic malignancy. Etiologic factors are unknown. No experimental data on molecular alterations exist so far. For an in vitro model, we established the permanent human tubal carcinoma cell line FT-MZ-1. The median doubling time was 14 days with 24.2% in S phase. A point missense mutation of the p53 tumor suppressor gene resulting in the His175 mutant was identified. Aberrant p53 protein accumulated in nucleus and cytoplasm. FT-MZ-1 substantially secreted interleukin 6 (Il-6) coinciding with the inactivation of p53 as a transrepressor on the Il-6 gene promoter.

Chicken ovalbumin upstream promoter--transcription factor (COUP-TF) expression in human endometrial cancer cell lines.

COUP-TF is an orphan member of the steroid receptor superfamily. COUP-TF down-regulates hormonal induction by other steroid receptors involved in cell proliferation and differentiation. Previous study has suggested a role in gynecological adenocarcinoma. In the present study we evaluated COUP-TF expression in endometrial cancer. Fourteen permanent endometrial cancer cell lines were established front the primary site of 14 endometrial cancer patients. Immunocytochemistry for COUP-TF-like activity was performed using an affinity selected polyclonal rabbit-derived antibody in an immunoperoxidase staining technique. The staining intensity and cell surface area were quantified by image analysis. By immunostain 2 cell lines were COUP-TF (+), 6 (+ +) and 6 (+ + +). Quantitative differences in staining intensity and cell surface area were not significant in these groups. All cell lines tested were immunocytochemically negative for estrogen and progesterone receptors. COUP-TF is a new factor involved in endometrial cancer cell differentiation and growth, especially in estrogen receptor negative tumors.

Transcortin: a corticosteroid-binding protein of plasma-XIV. Effects of time of equilibration of serum with cortisol on transcortin determinations by gel filtration.

The results of determination of plasma transcortin levels by gel filtration are subject to assay conditions such as duration of incubation and the amount of cortisol added. We investigated the cause for the dependency of results on assay conditions by incubating samples over prolonged periods of time. Transcortin concentration and the rate of dissociation of the cortisol-transcortin complex remained constant over many weeks of storage at 4 degree C, while irreversible binding to unidentified macromolecules increased continuously. Irreversible binding occurs faster at 37 degrees C than at 4 degrees C. In addition, with time, an ether-extractable, less polar metabolite of cortisol appears in the serum. The data suggest that a highly reactive metabolite of cortisol enters into covalent binding with macromolecules during prolonged incubations.

Correlation of histochemical and biochemical analyses of androgen binding in prostatic cancer: relation to therapeutic response.

A histochemical technique for the detection of androgen binding in prostatic cancer was performed on specimens from 108 patients and compared with a biochemical method in a double blind study of 77. Statistical analyses showed a significant agreement between the two assay systems for the qualitative and quantitative presence or absence of specific androgen binding, as well as for the subcellular localization of binding in nucleus and/or cytoplasm. Although the number of cases studied was too small for statistical analysis, there appeared to be good correlation between histochemical androgen binding results and clinical response, or lack of response to hormonal manipulation in 20 patients with State C and Stage D carcinoma. No correlation was evident between androgen binding and tumor grade or clinicopathologic stage of disease of either histochemistry or biochemistry.