Hormone catalysis: role of protecting and modifying reagents of sulfhydryl groups on estrogen receptor in breast cancer.

We have studied the modulation and differential sensitivity of the estrogen receptor (ER) in breast cancer in the presence of protecting or modifying agents of disulfide bonds and sulfhydryl groups present in the ER steroid-binding domain. Protecting agents such as mercaptoethanol and dithiotreitol increased the [(3)H]estradiol binding to ER by 25% and 50%, respectively. Modifying agents such as p-chloromercuribenzensulfonate decreased the [(3)H]estradiol binding by 70% and this was nearly completely abolished by N-ethylmaleimide (94%). These data indicate that disulfide bonds and sulfhydryl groups in the steroid-binding domain are intimately involved in the maintenance of a receptor structure necessary for estradiol binding.

The role of progesterone in endometrial estradiol- and progesterone-receptor synthesis in women with menstrual disorders and habitual abortion.

The objective of this comparative study was to determine the influence of changes in estradiol and progesterone during ovulatory vs. anovulatory cycles on levels of estradiol receptor (ER) and progesterone receptor (PgR) in endometrium. Thirty women (range age 20-35 years) were divided into three groups: women with a history of habitual abortion, obese women with menstrual disorders, and women with regular ovulatory cycles as well as proven fertility. A single venous blood sample and an endometrial sample were simultaneously obtained during the secretory phase of the menstrual cycle, in order to measure estradiol and progesterone levels and ER and PgR concentrations in cytosol and salt-extracted nucleosol. Plasma estradiol levels were not different between groups. Plasma progesterone was two times higher in fertile women than in habitual aborters. In endometrial tissue, progesterone content was 200 times higher in fertile women than in habitual aborters. ER and PgR were lower in the cytosol than in the nuclear fraction in fertile and obese women. Both receptors were at their lowest level in the cytosol and nuclear compartment of women with recurrent miscarriage. Fluctuations mainly in the sex hormone progesterone, in plasma and endometrium tissue, could interfere with ER and PgR levels.

Endometrium estradiol receptors type I and type II during early pregnancy of rat.

By centrifugation in a sucrose density gradient we studied the citosol 17beta-estradiol binding sites of blastocyst receptive and non-receptive endometrial zones, as well as uterine horn endometrium whose ovary was extirpated three weeks before pregnancy. The cytosol was prelabelled with [3H]-17beta-estradiol 2 and 25 nM. In this work two incubation temperatures were studied. On the other hand, at 4 degrees C unoccupied receptors were identified as different from the classic receptor 8S type I. At the same time, we found that 25 degrees C is the optimal temperature for the assay of total receptors to achieve complete exchange of [3H]-17beta-estradiol by 17beta-estradiol in the binding sites. In these conditions, the major component was the 4S type II receptor, mainly in the endometrium from ovariectomized uteri. Furthermore, 17beta-estradiol content was determined in the total homogenized by radioimmunoassay and the results were: 1.42+/-0.16, 1.22+/-0.15 and 1.75+/-0.27 pmol/g wet tissue for receptive, non-receptive and ovariectomized uteri, respectively.

Human papillomavirus hpv-16 DNA as an epitheliotropic virus that induces hyperproliferation in squamous penile tissue.

The prevalence of human papillomavirus HPV-16DNA sequences in 57 penile carcinoma biopsies was examined using the polymerase chain reaction (PCR) with type specific internal probes, employing HPV consensus primers from the L1 region. The cases comprised 39 typical squamous cell carcinoma and 18 specimens with different subtype. PCR products were analyzed and HPV-16DNA was detected in a high percentage of specimens. Thirty-eight biopsies were HPV-16DNA positive. This determination was correlated with cellular differentiation and growth pattern. Our data corroborates that squamous cell carcinoma was invariably associated with HPV-16DNA.

Prostatic cancer/benign prostatic hypertrophy. Subcellular distribution of estradiol/androgen receptors.

Six microsomal population of estradiol and androgen receptors have been characterized in human benign prostatic hypertrophy (BPH) and prostate cancer (PCa). Estradiol receptor (ER) and androgen receptors (AR) were extracted using 0.6 M KCL and determined by the dextran-coated charcoal method. ER and AR levels were smaller in BPH plasma membranes (PM) than in Pca cases. For functions 3, 4, 6, the ER values in PCa were 25-38% less with regard to BPH ER values. Whereas in PCa, AR values obtained in all fractions were higher when compared to BPH AR values. In benign prostatic hypertrophy and prostatic cancer, ER and AR levels were significantly higher in the nuclear fraction. In the nuclear fraction, ER and AR levels in BPH and PCa were significantly different. The subcellular distribution of AR and ER in BPH and PCa constitutes a reservation mechanism and processing a receptors for their continued growth.

Endometrial thickness of postmenopausal breast cancer patients treated with tamoxifen.

The effect of administration time of tamoxifen was assessed in 52 postmenopausal patients with mammary cancer in order to evaluate its effect on endometrium and serum levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and estradiol. Mean age of the patients was 61.5 years, 23% had a history of smoking, mean body mass index (BMI) was 26.9 kg/m(2), and mean age at menarche, menopause and administration time of tamoxifen was 12.9, 48 and 3.5 years, respectively. Serum FSH and LH concentrations were decreased by 41.8% and 44.9%, respectively, compared with mean normal postmenopausal levels. The FSH decrement was associated with BMI and LH level, whereas the LH decrement was associated with patient age and FSH concentration. Endometrium thickness <5 mm was reported in 60.5% of the patients, while endometrium thickness >/=5 mm was found in 39.5% of the cases. Histology revealed that 75% of the patients had atrophic endometrium; the remaining patients (25%) did not show atrophic changes. Administration time of tamoxifen was not associated with endometrial thickness or with serum FSH and LH concentrations.