Plasma steroid-binding proteins in the cysts of gross cystic disease of the breast

A novel, functional, and highly divergent sex hormone-binding globulin that may participate in the local control of ovarian functions in salmonids

A cDNA encoding for a novel rainbow trout SHBG was identified and characterized. Phylogenetic analysis showed that this novel SHBG, named SHBGb, was a highly divergent paralog of the classical SHBG (SHBGa) form previously known in vertebrates including zebrafish, seabass, and rainbow trout. Using all available sequences, no SHBGb-like sequence could be identified in any fish species besides Atlantic salmon. Rainbow trout SHBGa and SHBGb share only 26% sequence identity at the amino acid level and exhibit totally distinct tissue distribution, thus demonstrating a functional shift of SHBGb. Indeed, shbga mRNA was predominantly expressed in liver and spleen but could not be detected in the ovary, whereas shbgb had a predominant ovarian expression but could not be detected in liver. Despite its high divergence, rainbow trout SHBGb expressed in COS-7 cells could bind estradiol and testosterone with high affinity and specificity. Both rainbow trout shbgb mRNA and proteins were localized to the granulosa cells of vitellogenic ovarian follicles, whereas SHBGb immunoreactivity was also found in theca cells. Finally, shbgb ovarian mRNA expression exhibited a significant drop between late vitellogenesis and oocyte maturation at a time when ovarian aromatase (cyp19a) gene expression and estradiol circulating levels exhibited a dramatic decrease. Together, these observations show that SHBGb is a functional and highly divergent SHBG paralog probably arising from a salmonid-specific duplication of the shbg gene.

Human gross cyst breast disease and cystic fluid: bio-molecular, morphological, and clinical studies

For more than one and a half century the cystic disease of the breast has been recognized as the most frequent female benign breast lesion. Although some conundrums and controversies exist about the relation between gross cysts and breast cancer, recent evidence suggests that the multidisciplinary study of gross cystic breast disease (GCBD) may be a powerful tool for predicting the natural history of the multifaceted gross cyst pathology. A lot of papers have been published on breast cyst fluids (BCF) concerning biochemical, hormonal and morphological aspects, demonstrating that the intracystic fluid contains a wide variety of components (such as ions, lipids, proteins, enzymes, growth factors and antigens) and suggesting that their profile provides additional knowledge on both physiopathology and etiologic pathways of human gross cystic breast disease. The aim of this overview is the critical evaluation of all data accumulated in the last thirty years, in order to highlight the utility of biochemical and epidemiological studies to identify gross cysts, if any, at higher breast cancer risk.

Ultrastructural characterization and biochemical profile of human gross cystic breast disease

Human gross cystic breast disease is a benign condition affecting about 7-10% of adult women occurring with the highest incidence in the premenopausal decade. Although breast cysts do not represent a preneoplastic condition per se, several studies indicate an increased breast cancer risk in women affected by this pathology. In this report we study 115 breast cystic fluid samples obtained by needle-aspiration from women with gross cystic breast disease. The samples were analysed biochemically and the cells contained therein were observed at the electron microscope. According to their biochemical profiles, the cysts were subdivided into three types: Type I, showing a Na/K ratio < 0.5 and a typical protein content; Type II, showing a Na/K ratio >10 and a protein content quite similar to plasma; Type III, showing a Na/K ratio between 1 and 7 and an intermediate protein content. The electron microscopic examination demonstrated that Type I cystic fluid cells exhibit morphological features typical of actively synthesising and secreting cells, while the characteristics of Type II cells indicate a low metabolic activity. Type III cells have characteristics typical of both Type I and Type II cells, thereby confirming the intermediate nature of this cyst type. We hypothesise that these cyst types could represent different developmental stages of a structural evolution pathway, during which the biosynthetically active 'apocrine stage' would be the key step to cell neoplastic transformation.

Longitudinal evaluation of serum androgen levels in men with and without prostate cancer

Androgens are thought to play a role in the pathogenesis of prostate cancer. We evaluated androgen levels in 3 age-matched groups of men who were part of the Baltimore Longitudinal Study of Aging: 1) 16 men with no prostatic disease by urologic history and exam (control group); 2) 20 men with a histologic diagnosis of benign prostatic hyperplasia (BPH) who had undergone simple prostatectomy; and 3) 20 men with a histologic diagnosis of prostate cancer (16 with local/regional cancer, and 4 with metastatic cancer). Luteinizing hormone (LH), total testosterone (T), and free T were measured on stored AM sera by radioimmunoassay (RIA). Free T was also calculated from the measured concentrations of total T and sex hormone binding globulin (SHBG). The median number of repeated sex steroid measurements ranged from 6-9 over a period from 7-25 years prior to the diagnosis of prostate disease. There were no significant differences in age-adjusted LH, total T, SHBG, or calculated free T levels among the groups at 0-5, 5-10, and 10-15 years before diagnosis. These data suggest that there are no measurable differences in serum testosterone levels among men who are destined to develop prostate cancer and those without the disease.

Steroid biochemistry and categorization of breast cyst fluid: relation to breast cancer risk

Patients bearing macrocysts of the breast are at higher risk of later developing cancer. The fluid filling the cysts (breast cysts fluid, BCF) contains unusual amounts of steroid conjugates, first androgen and estrogen sulfates. Measuring BCF cations (K+,Na+) allows categorization of cysts into two major subsets (type I and type II) that are associated with a different degree and/or turnover of apocrine metaplastic cells in the lining epithelium. Type I cysts (high K+/Na+ ratio) accumulate hugh amounts of dehydroepiandrosterone sulfate, estrone sulfate, androstane-3 alpha,17 beta-diol glucuronide, androsterone glucuronide and contain more testosterone and dihydrotestosterone than type II. Conversely, type II cysts (low K+/Na+ ratio) contain more progesterone and pregnenolone. A cohort study was started in 1983 at the Cancer Prevention Center, Ravenna, Italy, with the aim of evaluating the relationships between the biochemistry of BCF and the incidence of breast cancer in women with gross cystic disease (GCD) of the breast. The bimodal distribution of the cationic pattern has been confirmed from data obtained in 798 patients aspirated. The risk of cyst relapse was significantly higher among women with type I cysts or with multiple cysts at presentation. Twelve incident cases of breast cancer have been diagnosed among women whose BCF was categorized. Eleven out of 12 cases had type I or multiple cysts. The cumulative incidence of breast cancer among patients bearing type I cysts was 2.5%. We conclude that women with GCD bearing type I cysts have an increased breast cancer risk when compared with the counterpart bearing type II cysts or the general population.

Biochemical study of cyst fluid in human breast cystic disease: a review

Gross cystic disease of the breast may sometimes indicate an increased risk of breast cancer. Biochemical analysis of the cyst fluid could suggest which cysts are associated with breast cancer risk, as well as providing insights into the pathophysiology of this condition. The Na+/K+ ratio appears to be associated with the histological classification of the cyst. Sulfoconjugated estrogens and androgens, especially DHEA-S, are often found at high levels. A number of gross cystic disease fluid proteins (GCDFPs) have been described, and several polypeptide growth factors including EGF and IGF-I are frequently found. It is hoped that biochemical analysis of these components of breast cyst fluids will shed further light on the role of gross cysts in relation to breast cancer.

Effects of sex hormone binding globulin (SHBG) on human prostatic carcinoma

The purpose of this study was to determine what effects sex hormone binding globulin (SHBG) might have on the growth and steroid content of human prostate carcinoma. Two human prostate carcinoma cell lines were used for this study, ALVA-41 and ALVA-101. The first part of the study was to determine the effect of SHBG or albumin on the uptake of [3H]DHT in the cells. In this experiment both SHBG and albumin inhibits the uptake of [3H]DHT into each of the cell lines when studied in vitro. The degree of inhibition was dependent on the binding capacity of the protein. When [3H]thymidine uptake was measured in each of the cell lines following either the addition of SHBG or albumin to the culture media, an increase in uptake and presumably DNA synthesis was noted in the ALVA-41 and ALVA-101 cells for SHBG additions but not for albumin. Further, this stimulation was increased when testosterone was added to the media, however, [3H]thymidine uptake was decreased by high concentrations of dihydrotestosterone (DHT) or if the SHBG was saturated with DHT prior to being added to the media. The cells also demonstrate high affinity cell membrane receptors for SHBG. Finally, using a 3', 550 bp cDNA or SHBG, 1.9 and 2.8 kb mRNAs were detected on Northern analysis of the ALVA-101 and ALVA-41 cells. These data indicate SHBG can inhibit uptake of steroids into the prostate, but also it may act as a stimulus for growth through a SHBG cell surface receptor. In addition, the growth effect may be through an autocrine effect from SHBG or a SHBG-related peptide.

Unconjugated and glucuronide steroid levels in human breast cyst fluid

The present report deals with the concentrations of C-21, C-19 and C-18 steroids as well as steroid glucuronides, namely androstane-3 alpha,17 beta-diol glucuronide, androsterone glucuronide, estradiol glucuronide, and estrone glucuronide (E1-G) in breast cyst fluid (BCF). The concentration of the gross breast cystic disease protein 15 (GCDFP-15) was also measured and its value was correlated with concentrations of unconjugated steroids as well as steroid conjugates. The present data indicate that for a large number of unconjugated steroids (namely pregnenolone, progesterone, dehydroepiandrosterone (DHEA), androsterone, androstane-3 alpha,17 beta-diol, estrone and estradiol) there is an important accumulation in BCF. Our data permit us to demonstrate a statistical relationship between the concentrations of DHEA and its metabolites (namely, androstenedione [4-ene-Dione]), thus suggesting an activity of the enzyme 3 beta-hydroxysteroid dehydrogenase-4-ene-5-ene-isomerase in the breast tissue. Further examination of the relationship between the concentrations of 4-ene-Dione and its metabolites, namely testosterone and 5 alpha-reduced steroid metabolites, as well as their glucuronide derivatives, strongly suggests that the metabolism of androgens in the breast tissue occurs mainly via 5 alpha-reductase and glucuronyl transferase activities. The concentration of GCDFP-15 in BCF found in the present investigation was 2745 +/- 234 micrograms/ml and we have shown that a negative relationship exists in the BCF between E1-G and GCDFP-15 levels.

Levels of eighteen non-conjugated and conjugated steroids in human breast cyst fluid: relationships with cyst type

The present study investigates the levels of a large series of 18 non-conjugated or conjugated steroids in 71 samples of human breast cyst fluid (BCF) as divided into three groups corresponding to different electrolyte composition. In the type 1 group, the K+/Na+ ratio was higher than 1.5, while in type 2 it was lower than 0.66 and finally type 3 had an intermediate ratio. Pregnenolone (PREG) and progesterone (PROG) levels were approximately 2-fold higher (P less than 0.05) in the type 2 than in the type 1 group while both 17-OH-pregnenolone (17-OH-PREG) and 17-OH-progesterone (17-OH-PROG) concentrations were similar in these two groups. Most of the C-19 steroids analyzed, namely dehydroepiandrosterone sulfate (DHEAS), androst-5-ene-3 beta, 17 beta-diol (5-ene-DIOL), testosterone (TESTO), dihydrotestosterone (DHT), androstane-3 alpha, 17 beta-diol (3 alpha-DIOL), androsterone (ADT), androstane-3 alpha, 17 beta-diol glucuronide (3 alpha-DIOL-G) and androsterone glucuronide (ADT-G) were 180-360% (P less than 0.05) higher in type 1 than in type 2 cysts while no difference in C-18 steroid and C-18 steroid glucuronide levels was observed. A small or no difference was seen in steroid levels between types 2 and 3. We conclude that the arbitrary division according to the electrolyte composition of BCF permits identification of different patterns of steroid concentrations in BCF. However, the mechanism responsible for both sets of parameters remain unclear.

The endocrine basis of benign breast disorders

There is sound clinical evidence that many benign breast conditions, especially pain, nodularity, and cysts, are likely to have their pathogenesis in hormonal events during reproductive life. Yet the classical theories of persisting hyperestrogenism and luteal progestogen deficiency have not stood up to detailed investigation. Recent work has demonstrated the importance of dynamic hormonal changes and of chronobiological rhythms--daily, menstrual, and seasonal. Recent developments and findings are reviewed to point to the directions in which the basic etiology of these conditions is likely to be discovered.

Size isomers of testosterone-estradiol-binding globulin exist in the plasma of individual men and women

We isolated testosterone-estradiol-binding globulin TeBG rapidly and in high yield from pooled pregnancy plasma. It showed two bands on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE). Both bands stained with three different monoclonal antibodies to TeBG, thus demonstrating their immunological similarity. Freshly drawn, individual sera, from men, women, and pregnant patients were submitted to microaffinity chromatography, a procedure which partially purifies TeBG in approximately 4 hr. The partially purified plasma was submitted to SDS PAGE, followed by immunoblotting. The blotted TeBG exhibited the same two bands seen in the isolated, purified protein. The size heterogeneity observed in TeBG purified to: proteolysis occurring during isolation; a peculiarity of pregnancy plasma; or heterogeneity attendant upon the use of pooled plasma for isolation.