Search

Breast cancer incidence and mortality rates are markedly lower in the south than in the north of Europe. This has been ascribed to differences in lifestyle and, notably, dietary habits across European countries. However, little information exists on the influence of different dietary regimens on estrogens and, hence, on breast cancer risk. Here we report results of our MeDiet Project, a randomized, dietary intervention study aimed to assess the effect of a Mediterranean diet on the profiles of endogenous estrogens in healthy postmenopausal women. Out of the 230 women who initially volunteered to participate in the study, 115 were found to be eligible and were enrolled. Women were then randomly assigned into an intervention (n = 58) and a control (n = 57) group. Women in the intervention group adhered to a traditional, restricted Mediterranean diet for 6 mo, whereas women in the control group continued to follow their regular diet. Women in the intervention group changed their dietary regimen substantially, and this eventually led to a shift from a prevalent intake of animal fat and proteins to a prevalent intake of vegetable fat and proteins. Regarding urinary estrogens, no significant difference was observed between the intervention and control groups at baseline. After 6 mo, however control women did not show any major change but women in the intervention group exhibited a significant decrease (over 40%) of total estrogen levels (P < 0.02). The largest part of this modification was based on a marked decrease of specific estrogen metabolites, including hydroxyand keto- derivatives of estradiol or estrone. To our knowledge, this is the first report to show that a traditional Mediterranean diet significantly reduces endogenous estrogen. This may eventually lead to identify selected dietary components that more effectively decrease estrogens levels and, hence, provide a basis to develop dietary preventive measures for breast cancer. [ABSTRACT FROM AUTHOR]

Introduction: Congenital hypothyroidism is an endocrine disease with a significant incidence in the general population (1:2000-1:3000 newborns in Italy) and a different geographical distribution, partially explained by endemic iodine deficiency, genetic traits and autoimmune thyroid diseases., Objectives: Aims of this study are: to evaluate the incidence of positive neonatal blood spot screening for CH in western Sicily, identified by the screening centre of the Children Hospital "G. Di Cristina", ARNAS, Palermo; to evaluate the impact of a lower TSH cutoff in the neonatal blood spot screening for CH., Materials and Methods: The TSH threshold of the neonatal screening was established as ≥6 mU/L of whole blood. We analysed the screening centre data in the period January 2013-April 2018, for a total number of 85.373 babies (45.7% males; 54.3% females)., Results: 4.082 Babies (4.8%) required a second screening. Among these, 372 (0.44%) were out of range. The diagnosis of congenital hypothyroidism (CH) was confirmed in 182 babies (0.21%). 77/372 newborns (20.7%) with confirmed high TSH levels showed whole blood TSH levels ≥6 - < 7 mU/L. In synthesis, 48.9% of the out of range re-testing had a confirmed diagnosis of CH., Conclusion: The reduction of TSH cutoff to 6 mU/L allowed to identify 77/372 neonates (20.7%) with confirmed out of range TSH, otherwise not recruited by the previously employed TSH cutoff.

The product of neurofibromatosis type 2 (NF2) gene, also known as Merlin/neurofibromin 2, homeostatically regulates liver stem cells by controlling abundance and signaling of epidermal growth factor receptor (EGFR), with a mechanism independent of the Hippo pathway. We have reported that locally elevated estrogen formation, driven by abnormally high expression and function of aromatase, may be implicated in development and progression of human hepatocellular carcinoma (HCC) through activation of a rapid signaling pathway mediated by amphiregulin (AREG) and EGFR. We have recently presented a model by which the aromatase-estrogen-amphiregulin-EGFR axis is activated in response to tissue injury and/or inflammatory disease, with its alteration eventually leading to development of major human tumors (liver, breast, prostate) and other chronic diseases (diabetes, obesity, Alzheimer's and heart disease). In this study, we investigated NF2 expression in liver cancer cells and tissues in relation to aromatase expression/function, estrogen receptor (ER) status and amphiregulin. Our data indicate that NF2 expression is associated with aromatase and AREG expression, being elevated in HCC tissues and HepG2 cells, intermediate in cirrhotic tissues and Huh7 cells, and lower in nontumoral liver and HA22T cells. In addition, NF2 expression is inversely related to wild type hERα66 and proportional to the expression of the membrane-associated hERα36 splice variant, as measured by exon-specific RT-PCR analysis, both in vivo and in vitro. Furthermore, incubation with estradiol induced a significant decrease of NF2 expression in both HA22T and Huh7 cells (over 54% and 22%, respectively), while no change could be observed in HepG2 cells, this effect being inversely related to aromatase expression and activity in HCC cell lines. Based on the above combined evidence, we hypothesize that NF2 behaves as a protein sensing tissue damage and aromatase-driven local estrogen formation, eventually leading to regulation of stem cells differentiation and tissue repair., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

There is convincing epidemiological and clinical evidence that, independent of aging, lifestyle and, notably, nutrition are associated with development or progression of major human cancers, including breast, prostate, colorectal tumors, and an increasingly large collection of diet-related cancers. Mechanisms underlying this association are mostly related to the distinct epigenetic effects of different dietary patterns. In this context, Mediterranean diet has been reported to significantly reduce mortality rates for various chronic illnesses, including cardiovascular diseases, neurodegenerative diseases and cancer. Although many observational studies have supported this evidence, dietary intervention studies using a Mediterranean dietary pattern or its selected food components are still limited and affected by a rather large variability in characteristics of study subjects, type and length of intervention, selected end-points and statistical analysis. Here we review data of two of our intervention studies, the MeDiet study and the DiMeSa project, aimed at assessing the effects of traditional Mediterranean diet and/or its component(s) on a large panel of both plasma and urine biomarkers. Both published and unpublished results are presented and discussed.

Although estrogen receptors (ERs) are expressed in human hepatocellular carcinoma (HCC), several clinical trials have failed to demonstrate the efficacy of antiestrogen treatment in HCC patients. Recently, the identification of several ER splicing variants has enlightened the complex nature of estrogen signaling in peripheral tissues; this may help understanding estrogen role in either nontumoral or malignant nonclassical target organs, including liver. In this work we have investigated mRNA expression of wild-type and splice variants of ERα in nontumoral, cirrhotic, and malignant human liver, as well as in HCC cell lines, using an exon-specific reverse transcription polymerase chain reaction (RT-PCR). In particular, ERα66 was detected in nontumoral and, to a lesser extent, in cirrhotic liver tissues, whereas its expression decreased or became undetectable in HCC tissues and cell lines. The ERα46 splicing variant was detected ubiquitously in all samples; interestingly, however, the ERα36 variant was inversely expressed with respect to ERα66, being highest in HepG2 cells, intermediate in Huh7 cells, and lowest in HA22T cells. It is noteworthy that aromatase was correspondingly expressed with ERα36 and inversely related to ERα66. This observation suggests that a switch from ERα66 to a predominant expression of ERα36 may be associated with development and/or progression of human HCC.

Background: We investigated aromatase (Aro)-driven estrogen formation in non-tumoral and malignant liver tissues and cells, also in relation to expression of the estrogen receptors α and β (ERα and ERβ) and amphiregulin (AREG), aiming to gain insights into the potential role of estrogens in human hepatocellular carcinoma (HCC)., Materials and Methods: Chromatographic and reverse transcriptase polymerase chain reaction (RT-PCR) analyses were used to assess activity and expression of the Aro enzyme and AREG as well as the expression of wild-type and variant ERs, both in vivo and in vitro., Results: Following 24 h and 72 h incubation of liver tissues or cells with testosterone, human HCC tissues and HepG2 hepatoma cells showed elevated Aro activity (estrogen formation, respectively, of 20% and 52%-99%). By contrast, no Aro activity could be detected in non-tumoral tissues and HA22T liver cancer cells. Cirrhotic samples and Huh7 cells exhibited intermediate enzyme activity, with estrogen formation of 4% and 34%, respectively. Markedly lower or undetectable Aro mRNA levels were observed in HA22T cells and non-tumoral liver tissues compared with HepG2 cells and HCC samples. Cirrhotic specimens displayed variable transcript levels. Interestingly, no or low expression of wild-type ERα and ERβ could be observed in liver cancer cells and malignant tissues. However, ubiquitous expression of the hERα46 variant and occasional expression of the hERβ2/Cx variant were observed in cancer tissues and cells., Conclusions: It is noteworthy that the pattern of wild-type ERα was inversely related to Aro, whilst AREG expression was consistently associated with that of Aro. This combined evidence suggests that locally elevated Aro activity may increase malignant cell proliferation also through AREG signalling.

This study compares the survival of breast cancer patients who are metastatic at diagnosis (DMBC) and of recurrent metastatic breast cancer (RMBC) patients. We analyzed retrospectively the population-based data of Breast Cancer Registry of Palermo and collected a total of 4459 breast cancer cases in the years 1999-2005. Survival analysis did not show statistically significant differences between DMBC and RMBC patients (P= 0.882). Endocrine manipulation is the treatment of choice in the case of hormone receptor-positive breast tumors. In 91 receptor-positive DMBC patients the endocrine treatment was associated with a prolonged overall survival (OS) (median survival 33.5 months compared to 29 months for receptor-positive patients who did not receive hormone treatment). Receptor-negative patients who underwent endocrine therapy (76% of cases) survived longer than receptor-negative patients who did not receive hormone treatment (median survival 28.5 months vs. 15 months, respectively). This evidence supports the concept that endocrine therapies impinging upon molecular targets other than hormone receptors may increase survival rates of breast cancer patients.

There is indirect multiple evidence that hints at a potential role of sex steroids in development and progression of human hepatocellular carcinoma (HCC). In the present study, we have investigated androgen metabolism in a panel of human liver cancer cell lines (HA22T, Huh7, HepG2) and in normal, cirrhotic and malignant human liver tissues aiming to dissect the potential impact of individual enzyme activities and their products in normal and diseased human liver, both in vivo and in vitro. Using our intact cell analysis we were able to assess rates and pathways of androgen metabolism in living conditions. Overall, incubation of cultured cells or tissue minces with either testosterone (T) or androstenedione (Ad) used as precursor resulted in a large extent of 17betaoxidation of T to Ad (cells: 28-77%; tissues: 35-50%). In malignant liver cell lines, both HA22T and Huh7 cells showed consistent amounts of the 5alpha-reductase enzyme products (18% and 15%, respectively), while 5beta-reductase activity was more pronounced in Huh7 cells (18%) than in HA22T cells (1.8%). Interestingly, a significant extent of estrogen formation could be observed in Huh7 cells (5.4-11.5%), while no aromatase activity could be detected in HA22T cells. In HepG2 cells, along with a relatively high proportion of Ad, estrogens represented the most prominent (50-55%) end product of androgen metabolism, regardless of the precursor used. In liver tissues, equivalent results could be obtained, with a consistent proportion of 17betaoxidation of T to Ad (35-50%) being observed in the majority of samples. However, while normal liver tissue samples exhibited a minor proportion of bioactive androgens (3.4%) with no aromatase products, HCC tissues showed a significant extent of aromatase activity (nearly 20%) with estrogen representing the most prominent metabolic product after 24h incubation with either T or Ad. HCV and alcoholic cirrhotic tissues displayed different patterns of androgen metabolism. The former produced limited amounts of bioactive androgens (5.3%) and considerable levels of the intermediate aromatase product 19OH-Ad (up to 28%), the latter exhibited a prevalence of androgen degradation through the 5beta-reductase pathway (9.8%) and a significant extent of aromatase activity (16% as a whole). In conclusion, three major metabolic states could be depicted, depending on prevalent pathways of androgen metabolism and steroid receptor status: estrogenic, androgenic, and mixed. This model supports the idea that local estrogen biosynthesis may be implicated in human HCC and provides a basis for the exploitation of aromatase inhibitors and/or ER antagonists or selective estrogen receptor modulators (SERMs) as a new therapeutic strategy in HCC patients.

In this study we investigated the impact of estrogen antagonists and of 16alpha-OHE1 (an estrogen derivative that binds to and induces transactivation of estrogen receptors) on estrogen metabolism in malignant HepG2 human liver cells featured by high estrogen sulfotransferase (EST); our aim was to clarify the potential correlation of EST and ER. As expected, the HepG2 cells exhibited a very high EST activity, with the majority of estrogen metabolites (over 86%) being detected as sulfates by 24 h. The coincubation of E2 and the antiestrogen tamoxifen induced a weak inhibition of EST activity (from 85.4% to 81.5%), while the coincubation with the pure antagonist ICI-182 and with 16alpha-OHE1 produced a 50% and 90% decrease of EST, respectively. Interestingly, both selective estrogen receptor modulators (SERMs) TAM and ICI-182, along with the same 16alpha-OHE1, gave rise respectively to a 2.8%, 3.2%, and 4.6% of de novo 16alpha-OHE1 formation. The inhibition of EST and the increase of 16alpha-OHE1 formation were both time- and dose-dependent. Our results suggest that EST activity is tightly associated with ER transactivation and can be regulated by selective estrogen receptor modulators (SERMs), including antiestrogens and 16alpha-OHE1. In this framework, 16alpha-OHE1 may have a potential role in human liver carcinogenesis, also through the inhibition of EST and the production of unconjugated, bioavailable estrogens.

In this randomized dietary intervention study (DI) we analyzed levels of androgens, phytoestrogens, and estrogens in 12-h urine samples of 69 healthy postmenopausal women, 37 of whom followed a traditional Mediterranean diet for 6 months (intervention group) as compared to 32 women who followed their regular diet (control group). Circulating levels of both insulin and testosterone (T) were also assayed. Overall, enterolactone (ENL) was the most prominent phytoestrogen in urines of both control and intervention women, and its levels increased by a 20% after DI. At the baseline the ENL levels were seen to be significantly associated with both the total androgens (TOT-A) (r= 0.371, P= 0.002) and the TOT-A/total estrogen (TOT-E) ratio (r= 0.351, P= 0.005) in all 69 postmenopausal women. Furthermore, the DI resulted in a more pronounced negative association of both ENL with insulin (r=-0.321, P= 0.05) and insulin with TOT-A (r=-0.421, P= 0.01). Regarding urinary androgens, ENL associated with both 3alpha-androsterone (5alpha-androgen, r= 0.363, P= 0.002) and 3alpha-etiocholanolone (5beta-androgen, r= 0.295, P= 0.01) at baseline, while after DI, circulating insulin and T exhibited a significant negative association with the 5beta-androgen metabolite etiocholanolone (r=-0.487, P= 0.002; and r=-0.336, P= 0.042, respectively). We conclude that lignan components of the Mediterranean diet, notably ENL, are associated with urinary levels of products of androgen metabolism, including both 5alpha- and 5beta-reductase enzymes, in healthy postmenopausal women. Further studies are necessary to better understand the interplay of sex hormones with dietary phytoestrogens.

The seeming impairment of retinoid metabolism in human breast tumor cells has been attributed to the lower expression of cellular retinol binding proteins (CRBPs), of alcohol/retinol dehydrogenases, or aldehyde/retinaldehyde dehydrogenases. In a previous study we indicated that xanthine dehydrogenase (XDH) is able to oxidize actively both all-trans-retinol (t-ROL) bound to the CRBP (holo-CRBP) and all-trans-retinaldehyde (t-RAL) to all-trans-retinoic acid (t-RA) in human mammary epithelial cells (HMEC). Since both XDH and CRBP are required for the biosynthesis of t-RA, we have inspected their bioavailability in both estrogen-responsive and nonresponsive human mammary epithelial cancer cells. The XDH activity, as assessed in the crude and purified extracts of both MCF7 and MDA-MB 231 cells by measuring the substrate t-RAL (that unlike t-ROL does not need CRBP), was 6 to 10 times lower than that previously encountered in normal HMEC. In addition, CRBP expression was absent in either cell line. Based on this preliminary evidence, we propose here that the low levels of XDH activity and the associated absence of CRBP in both MCF7 and MDA-MB 231 human breast cancer cells might be responsible for the retinoic acid deficiency observed in these cell model systems. This defect may be the crux of the impairment to stem cell differentiation and, hence, may be primarily implicated in human mammary carcinogenesis.

In this study we have investigated androgen (testosterone and androstenedione) metabolism in malignant HepG2, Huh-7, and HA22T human liver cell lines. Following 72-h incubation with testosterone or androstenedione, estrogen formation through aromatase activity was consistently higher in HepG2 cells (being nearly 100%) and moderate in Huh7 cells (34%), while it was undetectable in HA22T cells. The produced estrogens are completely conjugated by estrogen sulpho-transferase (EST) in HepG2 cells, while nearly 25% remains in the free form in Huh-7 cells. The HA22T and Huh-7 cells show a markedly different balance of 5alpha- versus 5beta-reduced androgens (65.7% vs. 2.5% and 2.6% vs. 22.2%, respectively), while no detectable 5alpha/5beta-reduced androgen is formed in HepG2 cells. These divergent metabolic profiles, coupling aromatase to EST, and to 5alpha/5beta-reductase, hint at a differential regulation of androgen metabolic pathways that may ultimately lead to a distinct impact of biologically active metabolites on growth and function of human liver cancer cells.

The relationship between sex steroids and cancer has been studied for more than a century. Using an original intact cell analysis, we investigated sex steroid metabolism in a panel of human cancer cell lines, either hormone responsive or unresponsive, originating from human breast, endometrium, and prostate. We found that highly divergent patterns of steroid metabolism exist and that the catalytic preference (predominantly reductive or oxidative) is strictly associated with the steroid receptor status of cells. We explored intratissue concentrations and profiles of estrogens in a set of human breast tumors as compared to normal mammary tissues, also in relation to their estrogen receptor status. In particular, we showed that, with hydroxyestrogens representing the majority of all tissue estrogens, concentrations of individual metabolites, as well as their ratios, significantly differ when comparing normal tissue with cancer tissues or when they are related to the overall survival of cancer patients.

Objective: It has been proposed that physiologic levels of estrogens stimulate immune responses whereas androgens suppress inflammatory reactions. Thus, prevalence of synovial androgens relative to estrogens would be favorable in rheumatoid arthritis (RA). We investigated synovial fluid (SF) concentrations of several estrogens and androgens and conversion products of the sex steroid precursor dehydroepiandrosterone (DHEA) in supernatants of mixed synoviocytes., Methods: SF steroid concentrations were measured by high performance liquid chromotography and mass spectrometry in 12 patients with RA and 8 subjects with traumatic knee injury (noninflammatory controls). Conversion of DHEA to downstream hormones was measured by thin-layer chromatography and phosphorimaging detection in 3 patients with RA and 3 patients with osteoarthritis (OA)., Results: Overall, SF concentration of free estrogens tended to be higher in RA patients versus controls (p < 0.06). Molar ratio of free SF estrogens/free SF androgens was elevated in RA compared to controls (1.17 +/- 0.32 vs 0.29 +/- 0.08, without unit; p = 0.017). The free SF concentration of the precursor androstenedione was significantly higher in RA patients than in controls (104.6 +/- 32.6 vs 30.4 +/- 0.4 ng/ml; p = 0.011), and SF estrone the aromatase conversion product of androstenedione was also elevated in RA compared to controls (13.6 +/- 2.6 vs 6.6 +/- 0.8 ng/ml; p = 0.035). The biologically active estrogen derivatives, 16a-hydroxyestrone and 4-hydroxyestradiol, were both higher in RA compared to controls (p = 0.085 and p = 0.044, respectively). In mixed RA synoviocytes, DHEA conversion yielded high local levels of 17beta-estradiol (708 pmol/l = 0.193 ng/ml) compared to testosterone (88 pmol/l = 0.026 ng/ml)., Conclusion: SF levels of estrogens relative to androgens are significantly elevated, while those of androgens are markedly reduced, in patients with RA compared to controls. This imbalance is most probably due to increased aromatase activity. Thus, an available steroid precursor, such as DHEA, may be rapidly converted to proinflammatory estrogens in the synovial tissue, which may in turn stimulate the inflammatory process in patients with RA.

Purpose: The main goal of our study was to assess estrogen contents of breast tumor tissues, having different estrogen receptor status, in relation to long-term follow-up of patients., Experimental Design: Twenty-one breast cancer cases, all collected from January 1986 to January 1988 at the M. Ascoli Cancer Hospital Centre in Palermo, were included in the study and compared with 6 healthy women as a control group. Average follow-up time of patients was 144 +/- 10 months. The estrogen receptor status of tissues was determined by both ligand binding and immunohistochemical assays. A high performance liquid chromatography-based approach, jointly with gas chromatography/mass spectrometry, was used to identify and measure main estrogens, various hydroxyestrogens, and their methoxy derivatives in both normal and tumor tissues., Results: Although variable concentrations of hydroxylated estrogens were detected, they consistently accounted for >80% of all of the estrogens. Significantly greater amounts of both 2- and 4-hydroxyestradiol, along with a marked increase of 16 alpha-hydroxyestrone (OHE(1)), were observed in cancer with respect to normal breast tissues. A significant positive association was observed with elevated 16 alpha OHE(1) (P = 0.015) in patients alive, leading to significantly lower (P = 0.043) 2OHE(1):16 alpha OHE(1) ratio values. Conversely, ratio values of 4:2 hydroxy+methoxy estrogens was significantly lower (P = 0.006) in deceased patients. Using cutoff values of 1.2 for 4:2 hydroxy+methoxy ratio and 150 fmol/mg tissue for 16 alpha OHE(1) we achieved a clear-cut separation of patients, with over-cutoff patients having 147 months and under cutoff patients showing only 47 months median survival time (P = 0.00008)., Conclusions: Our data imply that individual hydroxyestrogens may have a distinct role in the onset and the clinical progression of breast cancer, with greater 16 alpha OHE(1) levels being in turn associated to cancer with respect to normal tissues and to a prolonged survival of breast cancer patients.

Sex steroid hormones are thought, among several other risk factors, to play a role in liver malignancies. For example, from epidemiological studies in hepatocellular carcinoma (HCC), a clear disadvantage for male sex is evident. In addition, elevated levels of serum testosterone (T) and increased T to Estradiol (E(2)) ratio have been reported to predict an increased risk of HCC for male cirrhotic patients. On the other hand, palliative treatment of liver cancer patients with anti-hormones has been widely used in the past. However, the molecular mechanism(s) underlying sex steroid action on either normal or transformed liver cells, have not yet been fully clarified, nor endocrine discriminants have been satisfactorily assessed for an adequate characterization of liver cancer tissues. In this paper, we report studies on hormonal status of human liver tissues and cells, especially focusing on androgens, to better define endocrine end-points of interest for HCC. A consistent evidence from ex vivo or in vitro systems strongly suggests that high affinity binding sites of androgens are expressed at sufficient concentrations to induce a biological response in either normal or phenotipically transformed hepatocytes; in the latter, however, high heterogeneity and/or more scattering concentrations were encountered. Further, experimental data seem to suggest that lack of response to androgens may be due to a rapid metabolic conversion of steroids by neoplastic tissues and cells. Cancer hepatocytes privilege in fact 5beta more than 5alpha metabolic pathway of androgens. This may eventually lead biologically active androgens to be transformed into less active derivatives, as it occurs for T which is massively converted (>90% at 6 h) thus hindering the whole mechanism of action of androgens., (Copyright 2002 Elsevier Science Ireland Ltd.)

Preliminary evidence from a case control study of healthy postmenopausal women living in Palermo, Sicily, is presented to investigate the potential impact of a traditional Mediterranean diet on the risk of developing breast cancer. Of the 230 women who fulfilled specific eligibility criteria, 115 were enrolled in the study based on serum testosterone values equal to or greater than the median population value (0.14 microg/ml). Women were then individually randomized into a diet intervention (n = 58) and a control (n = 55) group. Women in the intervention group attended a weekly "cooking course" for 1 year, being trained by professional chefs in the correct use of the natural ingredients of the traditional Mediterranean diet, including whole cereals, legumes, seeds, fish, cruciferous vegetables, and many others. The intervention group was subsequently instructed to follow the learned diet at home, while the control group was only advised to increase the consumption of fruits and vegetables, as recommended by WHO. The following measures were taken at the beginning, middle, and end of the study: (a) fasting blood and 12-hour urine samples to assay defined hormonal endpoints; (b) height, weight, and circumference of the waist and hip; and (c) a food frequency and computerized 24-hour dietary recall questionnaire. After 1 year, both the control and the intervention groups showed satisfactory compliance rates (81 and 85%, respectively). In addition, preliminary results so far obtained reveal an unequivocal trend towards weight loss, a strong reduction in cholesterol levels, and a psychophysical feeling of well-being by women adopting the Mediterranean diet. The study is currently ongoing to verify the association of changes in serum and urine hormone levels and breast cancer risk in the intervention group.

In recent years there has been a continuingly increasing interest in novel research subjects, as yet poorly explored, either because they relate to aspects previously thought to be marginal with respect to classical fields of investigation, or because they require both specialized competence and intense cross-talk by researchers from disparate areas. The potential interaction between immunity and cancer has generated a remarkable number of studies, including those related to the newly explored immune-neuro-endocrine system. In this paper, we review a few autoimmune diseases as examples of a mutual relationship between immune diseases and malignancies. We also review our previous studies on patients with rheumatoid arthritis (RA). In particular, aiming to define the hormone-responsive or -sensitive status of synovial tissues and cells, we have inspected different endocrine end-points, including (1) high- and low-affinity sites of androgen and estrogen binding; (2) the activity of key enzymes of steroid metabolism; and (3) the hormonal profile of synovial fluids as an indication of local endocrine milieu. Overall, our data provide convincing evidence for synovial macrophage-like cells and a subset of T lymphocytes to be considered as target cells for gonadal steroids. This provides a basis for developing new strategies for alternative treatments of RA and possibly unveils novel perspectives in both research and the clinic for other autoimmune diseases as well. In addition, the association of autoimmunity and cancer may disclose promising new avenues of research linking steroid hormones, the immune system, and malignant transformation.

Our previous studies are reviewed and at the same time preliminary experimental observation to the topic of endocrine end-points in autoimmune disease is introduced. To this end, we have used rheumatoid arthritis (RA), including synovial fluids and primary cultures of synovial macrophages, as a model system in order to investigate (a) expression and subcellular localization of high-affinity sites of steroid binding in immune effector cells; (b) steroid metabolic profiles in both male and female RA patients, as compared to healthy subjects; and (c) activities of key steroid enzymes that govern intratissue accumulation of sex hormones. In RA tissues and cells, the concurrent evidence for (1) androgen and/or estrogen receptors, (2) high concentrations of biologically active steroids, (3) key enzymes of steroid metabolism, and (4) significant changes of estrogen to androgen ratio, all strongly suggests that individual immune cells, including synovial macrophages, may behave as steroid-sensitive cells, namely, they may represent a target for sex steroids, supporting the hypothesis of a potential endocrine regulation of the immune response also in RA disease. In this respect, definition of several endocrine end-points may have important implications for the treatment of rheumatic disease and other immunological disorders.

The 17beta-hydroxysteroid dehydrogenase (17betaHSD) enzyme system governs important redox reactions at the C17 position of steroid hormones. Different 17betaHSD types (no. 1-4) have been identified to date in peripheral human tissues, such as placenta, testis, and breast. However, there is little information on their expression and activity in either normal or malignant prostate. In the present work, we have inspected pathways of 17beta-oxidation of either androgen or estrogen in human prostate cancer cells (LNCaP, DU145, and PC3) in relation to the expression of messenger RNAs (mRNAs) for 17betaHSD types 1-4. These cell systems feature distinct steroid receptor status and response to hormones. We report here that high expression levels of 17betaHSD4 were consistently observed in all three cell lines, whereas even greater amounts of 17betaHSD2 mRNA were detected solely in PC3 cells. Neither 17betaHSD1 nor 17betaHSD3 mRNAs could be detected in any cell line. From a metabolic standpoint, intact cell analysis showed a much lower extent of 17beta-oxidation of both androgen [testosterone (T)] and estrogen [estradiol (E2)] in LNCaP and DU145 cells compared to PC3 cells, where a greater precursor degradation and higher formation rates of oxidized derivatives (respectively, androstenedione and estrone) were observed. Using subcellular fractionation, we have been able to differentiate among 17betaHSD types 1-4 on the basis of their distinct substrate specificities and subcellular localization. This latter approach gave rise to equivalent results. PC3 cells, in fact, displayed a high level of microsomal activity with a low E2/T activity ratio and approximately equal apparent Km values for E2 and T, suggesting the presence of 17betaHSD2. Dehydrogenase specific activity with both E2 and T was also detected, although at lower levels, in LNCaP and DU145 cells. No evidence for reductase activity could be obtained in either the soluble or microsomal fraction of any cell line. As comparable expression levels of 17betaHSD4 were seen in the three cell lines, 17betaHSD2 is a likely candidate to account for the predominant oxidative activity in PC3 cells, whereas 17betaHSD4 may account for the lower extent of E2 oxidation seen in both LNCaP and DU145 cells. This is the first report on the expression of four different 17betaHSD types in human prostate cancer cells. It ought to be emphasized that for the first time, analysis of different 17betaHSD activities in either intact or fractionated cells harmonizes with the expression of relevant mRNAs species.

We investigated conversion rates of androgens to estrogens in cultured, hormone-responsive prostate (LNCaP) and breast (MCF-7) human cancer cells. For this purpose, we adopted an intact cell analysis, whereby cells were incubated for different incubation times in the presence of close-to-physiological (1 nM) or supraphysiological (1 microM) concentrations of labelled androgen precursors, i.e. testosterone (T) and androstenedione (delta4Ad). The aromatase activity, as measured by estrogen formation, was detected in LNCaP cells (0.5 pmol/ml), even though to a significantly lower extent than in MCF-7 cells (5.4 pmol/ml), using 1 microM T after 72 h incubation. Surprisingly, LNCaP cells displayed a much higher aromatase activity when T was used as a substrate with respect to delta4Ad. In either cell line, T transformation to delta4Ad was relatively low, attaining only 2.8% in LNCaP and 7.5% MCF-7 cells. However, T was mostly converted to conjugates (over 95%), glucuronides and some sulphates, in LNCaP cells, whereas it was only partly converted to sulphates (<10%) in MCF-7 cells. Aromatase activity seems to be inconsistent in LNCaP cells, being strongly affected by culture conditions, especially by fetal calf serum (FCS). Further studies should assess the regulation of aromatase expression by serum or growth factors in different human cancer cells, also using anti-aromatase and/or anti-estrogen compounds, in different culture conditions.

This paper summarizes our most recent results of steroid enzyme studies on cultured breast and endometrial cancer cells. It deals mainly with estrogen 17 beta-hydroxysteroid oxidoreductase (17 beta HSOR) activity, which presides over estradiol (E2) and estrone (E1) interconversion, a major metabolic pathway of estrogens. Assessment of either the oxidative or reductive component of 17 beta HSOR was carried out on intact cells by means of an original approach based on reverse phase-high performance liquid chromatography and radioactive detection on line. This system allows the continuous monitoring of both precursor degradation and formation of several radiometabolites to assess rates and direction of steroid metabolism. Overall, hormone-responsive, estrogen receptor (ER)-positive cells, regardless of whether they were derived from breast (MCF7) or endometrial (Ishikawa) tumor tissues, showed a prevalence for reductive metabolism (E1-->E2), whilst oxidative pathways (E2-->E1) were largely dominant in non-responsive, ER-poor mammary (MDA-MB231) and endometrial (HEC-1A) cells. The above estimates of 17 beta HSOR activity were at variance with those obtained using the classical enzymology approach, not only in quantitative terms (being markedly lower using intact cell analysis), but also because the prevalent direction of estrogen metabolism was often reversed. Although striking methodological differences may well account for this discrepancy, intact cell analysis is undoubtedly more similar to the in vivo state than the artificial requirements of classical enzymology procedures.

The ability of human prostate cancer cells to metabolize androgens was assessed through administration of physiological concentration (0.5-10 nM) of tritiated testosterone (T) as precursor and one-step analysis of both T degradation and products' formation by reverse-phase HPLC and on-line radioactive detection after either 24 h or 72 h incubation. Overall, different prostate cancer cells degraded T quite differently, favoring alternatively reductive or oxidative metabolic pathways. In particular, both LNCaP and DU145 cells retained high levels of unconverted T, with a limited production of androstenedione and its 17-keto derivatives and relatively high amounts of dihydrotestosterone (DHT) and 3 alpha-androstanediol (3 alpha-diol). In contrast, PC3 cells quickly degraded T and exhibited high formation rates of androstenedione and 17-keto metabolites, while neither dihydrotestosterone nor 3 alpha-diol were detected after short or longer incubation times. The effects of both TGF alpha (50 ng/mL) and TGF beta 1 (5 ng/mL) on rates and direction of T metabolism were also explored. In LNCaP cells TGF alpha induced a significant (P < 0.04) decrease of the reductive metabolism of T with a corresponding enhancement of the oxidative pathway (P < 0.002), while TGF beta 1 did not significantly affect T metabolism. On the other hand, both reductive and oxidative pathways were only partially influenced by either growth factor in DU145 and PC3 cells, although TGF alpha significantly raised 5 alpha-androstanedione formation and reduced androsterone production in DU145 cells. All the above evidence was confirmed at both 24 h and 72 h or using increasing doses of TGF alpha and TGF beta 1, a peak activity of 50 ng/mL and 5 ng/mL, respectively, being generally encountered. Overall, our data suggest that TGFs may have a role in the growth regulation of hormone-responsive prostate tumor cells through changes of the intracellular contents of biologically active androgen metabolites.

In this paper we report that two human long-term endometrial cancer cell lines, Ishikawa and HEC-1A, exhibit quite different abilities in metabolizing estrogens. As a matter of fact, incubation of Ishikawa cells with close-to-physiological concentrations of estradiol (E2) as precursor resulted in: (1) elevated formation (up to 90%) of E2-sulphate (E2-S), using lower precursor concentrations; (2) very limited conversion to estrone (E1) (< 10% at 24 h incubation), as either free or sulphate; and (3) low but consistent production of other estrogen derivatives, such as 2-hydroxy-estrogens and estriol. Conversely, scant amounts (if any) of E2-S were found in HEC-1A cells, while no detectable formation of other estrogen metabolites could be observed after 24 h. On the other hand, E1 production was significantly greater (nearly 60% at 24 h) than in Ishikawa cells, a large proportion of E1 (over 50% of the total) being formed after only 6 h incubation using time-course experiments. The hypothesis that E2 metabolism could be minor in Ishikawa cells as a consequence of the high rate of E2-S formation encountered is contradicted by the evidence that conversion to E1 also remains limited in the presence of much lower E2-S amounts, seen using higher molar concentrations of precursor. Overall, we observe that 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) activity diverges significantly in intact Ishikawa and HEC-1A endometrial cancer cells. This difference could not merely be accounted for by the diverse amounts of substrate (E2) available to the cells, nor may it be imputed to different levels of endogenous estrogens. It should rather be sought in different mechanisms controlling 17 beta-HSD activity or, alternatively, in the presence of distinct isoenzymes in the two different cell types.

In order to measure the formation and degradation rates of estradiol by human breast cancer cells, after assessing the biochemical basis of hormone responsiveness and growth response to estrogens, we considered both responsive, estrogen receptor (ER) positive, and non-responsive, ER-negative, breast cancer cell lines, i.e. MCF7, ZR75-1 and MDA-MB231. To this end, we employed a novel "intact cell" approach which allows us, after 24 h incubation, to analyze several enzyme activities in sequence, concurrently with the monitoring of labeled precursor degradation. Our investigations led to the following evidence: (a) the reductive activity of the 17 beta-hydroxysteroid oxoreductase (17 beta-HSOR) appears to be higher than the oxidative only in responsive, ER-rich MCF7 and ZR75-1 cells, as also previously observed by others; (b) this activity is, on the contrary, much lower in MDA-MB231 cells and other unresponsive, ER-poor breast cancer cell lines; (c) conversely, the oxidative activity shows an opposite pattern, being limited in MCF7 and ZR75-1 cells and much higher in MDA-MB231 cells. Overall, a 17 beta-HSOR reductive pathway prevails in both MCF7 and ZR75-1 cells, whilst the oxidative pathway is prevalent in MDA-MB231 cells, leading to a large formation of estrone that is no further metabolized, at least in the experimental conditions used. Our results may provide a likely explanation of previous data on the different estrogen content of breast tumor tissues.

The presence of androgen receptors on synovial macrophages in human normal and rheumatoid synovial tissues has been described previously. It is now reported that primary cultured human macrophages obtained from normal and rheumatoid synovia express functional androgen receptors. We have investigated the capacity of cultured macrophages to metabolize androgens and have found that these cells were capable of metabolizing testosterone to the bioactive metabolite dihydrotestosterone. Therefore, macrophages contain the key enzymes of steroidogenesis, in particular the 5alpha-treductase. Furthermore, interleukin-1beta production by primary cultured rheumatoid macrophages was analysed, following exposure to physiological concentrations of testosterone (10(-8) M). A significant decrease of IL-1beta levels in conditioned media after 24 h (p < 0.05) was observed. It is concluded that androgens may act directly on human macrophages and may interfere with some of their functions via receptor-dependent mechanisms.

The main goal of the present work was to compare the ability of human prostate cancer (PCa) cells to metabolize testosterone (T) in living conditions. To this end we studied three different human PCa cell lines (LNCaP, DU145 and PC3) having different hormone-sensitive status and capability of response to androgens. We used an original approach which allows the evaluation of conversion metabolic rates in growing cells after administration of labeled steroid precursor (presently T), at physiological concentrations (1-10 nM). Analysis of both precursor degradation and formation of several products was carried out using reverse phase-high performance liquid chromatography (RP-HPLC) and "on line" radioactive detection. Comparison of the three human PCa cells revealed that their metabolic aptitude differed in many respects: (i) rates of precursor degradation, (ii) different products' formation, and (iii) extent of conjugate production. In detail, PC3 cells quickly degraded T and exhibited high formation rates of androstenedione (A-4-ene-Ad); both DU145 and LNCaP cells mostly retained high levels of unconverted T, with a limited production of A-4-ene-Ad and its 17-keto derivatives (if any). Either LNCaP or DU145 cells generated a relatively high amount of dihydrotestosterone (DHT). In contrast, neither DHT nor its main metabolites were detected in PC3 cells at both short and longer incubation times. As expected, T degradation and A-4-ene-Ad production were highly correlated (r = 0.97; P < 0.03); similarly, A-4-ene-Ad and DHT formation showed a negative, significant correlation. Negligible production of conjugates was noted in both PC3 and DU145 cells, whilst it was remarkable in LNCaP cells (ranging from 43 to 57%). Overall, our data indicate that human PCa cells degrade T quite differently, favoring alternatively reductive or oxidative patterns of androgen metabolism.

The purpose of this study was to establish the estrogen receptor (ER) expression and content in human aorta fragments removed at the time of by-pass surgery. To this end, we adopted a radioligand binding assay to evaluate either soluble (S) or nuclear (N) ER using dextran-coated charcoal (DCC) and filtration methods, respectively. To better define the intratissular distribution and content of ER, we also measured the presence of a 27 kDa heat shock protein (HSP27), a well established ER-associated protein, using D5 monoclonal antibody. Finally, we analysed the different molecular isoforms of both S and N ER using size exclusion-high performance liquid chromatography (SE-HPLC). High affinity (type I) sites of estrogen binding were detected in 17 out of 19 samples in either S or N fraction, although only 9 out of 19 cases displayed site 1 ER in both cell compartments. ER levels in aortic tissues, detected by radioligand method, compare well with those we have found in other hormone-sensitive human cancer tissues and cells. SE-HPLC analysis revealed two main receptor isoforms in the soluble fraction, having 65 kDa and 18 kDa molecular mass, while a minor component of 29 kDa was also found; the nuclear fraction displayed again two major components of 38 and 23 kDa. Using the HSP27 immunohistochemistry we observed a major staining occurring in smooth muscle cells (SMC), with an increasing intensity towards the lumen. All samples, including the ER negative ones, exhibited some degree of histochemical staining. Using an arbitrary cut-off value, 7 out of 12 samples displayed a highly positive staining, 6 of which showed nuclear ER. Furthermore, SE-HPLC separation indicated the presence of a 64.9 kDa component in the soluble fraction, according to the well known relative molecular mass of ER. Following HSP27 immunohistochemistry, the overall staining intensity in aortic SMC approaches that seen in endometrial and breast epithelia, whilst the muscle ER content is generally lower. Although our data are compatible with a direct role of estrogens in arterial function, the extent of the link with arterial disease remains to be established.

Estriol-3-sulfate (E3S) is present in human breast cyst fluid (BCF) in median levels of 8.7-10.4 nmol/L, yet is barely detectable in the serum (less than 0.034 nmol/L). The source of this huge concentration of E3S is unknown. It may accumulate from blood by active transport or be synthesized and concentrated within the cyst. Since estrone sulfate (E1S) and its possible precursor, dehydroepiandrosterone sulfate (DHEAS) are elevated in BCF, E3S may originate via 16 alpha-hydroxylation of E1S. The present study examined the correlations between the levels of DHEAS and E1S with those of E3S in BCF. The sodium and potassium ions were also quantified and related to the steroid concentrations. By linear regression analysis of log-normalized data there was a highly significant correlation between the concentrations of E1S and E3S (n = 355, r = 0.690, P less than 0.001) and between DHEAS and E3S (n = 361, r = 0.577, P less than 0.001). The BCF were classified according to their K/Na ion ratios: type 1, greater than 1.0, type II, less than 0.25, and type III, 0.25-1.0. By Student's t test, the concentrations of E3S differed between each BCF Type (P less than 0.002). This was also true for E1S and DHEAS. Type 1 cysts were associated with the highest estrogen sulfate levels and type II with the lowest levels. The possible physiological importance of this observation resides in reports that the BCF type expressing the highest steroid concentrations has been related to an aporcine-like epithelial lining of the cyst wall and a somewhat higher risk for developing breast cancer. The results suggest that E3S in BCF may originate from E1S, but alternate mechanisms are not precluded.

Catecholestrogens (CCEs), namely 2- or 4-hydroxyestradiol and hydroxyestrone, are highly polar, reactive, and extremely labile estrogen metabolites in many experimental conditions. For these reasons, indirect assay methods mainly have been used. Some experimental evidence suggests that CCEs are synthesized and biologically active mostly in target cells. At this level, unfortunately, the indirect assays cannot be used. We present a method of gas chromatographic/mass spectral (GC/MS) analysis for the identification of individual CCEs; the major fragmentation ions of authentic estrogen standards as trimethylsilylether derivatives, and the MS patterns of the major CCEs, namely, 2-hydroxyestradiol and hydroxyestrone, are included. Few examples of CCEs detected in human breast cancer tissues and in breast cyst fluids are reported. Sample extracts were submitted to reversed-phase, high-performance liquid chromatography (RP-HPLC) and were quantified by "on line" electrochemical (EC) detection; thereafter, either crude extracts or single eluted peaks were submitted to GC/MS, by which detection limits of less than 5 pmol were attained. As expected, the molecular ion was the most relevant molecule in all but one case. On the contrary, the other relative intensities of major fragmentation ions M -15, M -30, M -90, and M -15 + (-90) were unevenly distributed, although represented in the majority of cases. In all cases, the GC/MS of peak fractions, purified by RP-HPLC and UV detection, confirmed the results of liquid chromatographic analysis combined with EC detection. In contrast, GC/MS of crude extracts was not equally satisfactory. Comparison of a liquid chromatography system with EC detection and the GC/MS approach revealed some inconsistency in quantitation of individual CCEs.(ABSTRACT TRUNCATED AT 250 WORDS)

A simple, rapid approach to the study of conversion rates and metabolic patterns of the steroids testosterone and estradiol is presented. It includes an optimized isocratic high-performance liquid chromatographic procedure in the reversed-phase mode and radioactive on-line detection. The purpose was to estimate the activity of key enzymes of steroid pathways, such as 17 beta-hydroxysteroid dehydrogenase and 5 alpha-reductase, in in vivo conditions. Using this system, we obtained good efficiency and linearity of radio detection, under continuous flow conditions. Sensitivity limits were of the order of 50 and 70 cpm for [3H]estradiol and [14C]estrone, respectively, even though the efficiency was quite dissimilar (17.3% versus 56.2%). The applicability of this approach to studies of steroid metabolic pathways in growing cancer cells in culture is illustrated with examples of the conversion rates of both testosterone and estradiol. The high reproducibility (coefficients of variation of 2.7 and 5.1% for 3H and 14C, respectively) and good extraction efficiency (ranging from 86 to 94%) indicate the feasibility and reliability of this approach.

This review reports studies on long-term prostate cell lines using multiple experimental approaches. The main goal was to investigate the metabolism of testosterone (T) through in vitro conversion rates. Extensive studies were also carried out on growth curves, tritiated thymidine incorporation, and morphometry by either hormone-responsive or hormone-unresponsive, normal and neoplastic human (PC3 and DU-145) and canine (CAPE and CPA) cell lines. All of them were characterized for their content of both soluble and nuclear androgen receptors. Receptor studies at site I binding in both soluble and nuclear fractions were carried out to establish the hormone sensitivity status of cells. In two prostate epithelial cells, steroid metabolic conversions in vitro show predominantly an oxidative metabolism of T, forming mainly androstenedione. Conversion rates were greater than 50% in the first 24 hours and still higher after 72 hours. At the same time and under exactly the same experimental conditions, the other cells showed metabolic pathways in which reductive metabolism prevails, dihydrotestosterone (DHT) being the prevalent metabolite. Different metabolic patterns of steroids of several cell lines relate to the hormone sensitivity status of the cells; steroid receptor-endowed cells are maintaining higher levels of unconverted precursor than are receptor-empty cells. In fact, hormone-sensitive cells, such as cancer canine CPA and human DU-145, produced DHT early through slowly converting T. On the contrary, unresponsive cells such as human cancer cells PC3 and normal canine CAPE quickly metabolize T, but DHT formation was not observed. These significant differences between cells are highly reproducible provided the proportion between cell number and molar concentration of precursors is constant. Differences we observe cannot be attributed to different experimental conditions. Cell viability, extraction efficiency, and all other parameters used for monitoring cell growth kinetics do not substantiate these reported significant differences in metabolic abilities of cells. The divergent steroid metabolic pathway we observe in different prostate long-term cells appears to be an intrinsic, consistent, highly reproducible property of each cell line.

We briefly review some biochemical aspects of benign breast disease (BBD), mainly focusing on free and conjugate estrogen content of breast cyst fluid (BCF), also in relation to cyst type. Evidence is reported that high K(+)-type I-cysts clearly associate with low Cl- levels and accumulate significantly higher quantities of dehydroepiandrosterone sulfate (DHAS) and estrone-3-sulfate (E1S). In spite of the limited number of cases, both increasing DHAS and E1S levels correlate with the increment of K+ to Na+ ratio. A positive correlation was also found between DHAS and E1S. Using electrochemical detection (ECD) on-line to high performance liquid chromatography (HPLC) in the reverse phase mode, we also studied the free estrogen profile. We observed that in type I BCF there are significantly increased amounts of free estrone (E1). The E1S to E1 ratio was significantly different in the two cyst subpopulations; again, a positive correlation was found between free and sulfated E1 (r = 0.820, p less than 10(-6). This last, together with other experimental observations, allows us to hypothesize that in BCF a main pathway of steroids should be E1S----E1. Besides, high specific activity of sulfatase, as well as beta-glucuronidase enzymes, has been demonstrated for BBD. Preliminary information is also reported concerning the BCF pattern of free estrogens, including the highly polar ones, i.e., catecholestrogens (CCE) and the parent methoxy (MeO) conjugates, which represent, in BCF, a predominant portion of all free estrogens. Both CCE levels and ratios appear unevenly distributed in the two different cyst types. In addition, some BCFs show very high concentrations of 16 alpha-OH-E1. Further studies are needed to answer the main question: whether estrogen patterns could represent additive parameters to further categorize breast cystic disease (BCD) or whether they are of minor interest to determine patients' risk of developing breast cancer.

This paper presents a short review of the results obtained to date in our laboratory, with respect to the studies of steroid excretion profiles in both breast and endometrial cancer patients, by using gas-liquid chromatographic analysis. These data demonstrate the importance of minor estrogens, including catechol estrogens, and of their ratios with the classical ones, in studies of steroid metabolism in both breast and endometrial cancer. New data concerning postmenopausal endometrial cancer are consistent with our previous observations and demonstrate the necessity of measuring these steroids directly in tumors and examining patterns of metabolism in vitro. In order to analyze steroid metabolic patterns in vitro, however, high-performance liquid chromatography rather than gas-liquid chromatography methods are preferable on account of their selectivity, specificity, sensitivity and capacity to handle labile materials. With the aim of providing methods suitable for the complete resolution and analysis of these complex natural mixtures a method of computer-aided optimization of HPLC has been developed and its practical utility has been tested.

Studies on estrone metabolism by long term human endometrial cancer HEC-1A and Ishikawa cell lines are reported. These cell lines grow well in epithelial mono or plurilayer form, as previously reported. Ishikawa cells appear to be estrogen responsive whereas HEC-1A appear non responsive. In our experience Ishikawa cells show high affinity--low capacity estrogen binding sites in both soluble and nuclear fractions of the same range of ZR 75-1 and of MCF7, but HEC-1A cytosols gave Kd values in the order of 10(-8)-10(-9). These values are probably more representative of estrogen receptors of low affinity-high capacity (site II) and this is in agreement with previous results regarding their poor response to estrogens. These two different endometrial cancer cell lines exhibit at the same time, common and quite dissimilar metabolic patterns of estrogens. In fact, metabolic conversion studies carried out after 24th incubation at not far from physiological concentrations by using high pressure liquid chromatography in reverse phase mode plus "on line" radioactive detection showed: Both these well established cell lines are fast growing in culture with sufficient morphological or biochemical stability, at least during a limited number of passages and appear a useful material for studies on steroid metabolism. In both, estradiol (E2) and estrone (E1) were most part of converted products (more than 95%); negligible amounts of other radio-metabolites were observed. Quite different conversion rates of E1 to E2 have been shown by HEC-1A cells (6 times or more), with respect to Ishikawa.