The presence of females induces elevated cortisol levels in an alpha male: Experimental evidence in chimpanzees.

OBJECTIVES: In group-living primates, it has been reported that the alpha male exhibits high concentrations of cortisol and testosterone in the context of mating competition. We investigated how the presence of females affected salivary cortisol and testosterone levels in males from a small captive group of chimpanzees (Pan troglodytes). Specifically, we assessed whether the presence of females resulted in a rapid increase in salivary cortisol and testosterone levels in the alpha male. MATERIALS AND METHODS: We compared the social behavior and salivary hormone concentrations of four males before and after the presentation of receptive females. Three times a day, we collected saliva samples, a useful matrix for investigating short-term hormonal changes, and measured cortisol and testosterone concentration by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: The frequency of inter-male aggression increased in the presence of females, indicating intense competition among males. Salivary cortisol levels increased in all males in the presence of females; however, the increase was significantly more pronounced in the alpha male. We found a complex three-way interaction among the presence of females, sampling timings, and male dominance rank in the analysis of salivary testosterone. Contrary to our prediction, a post hoc analysis revealed that salivary testosterone levels decreased after female introduction and that the alpha male did not show a higher level of salivary testosterone. CONCLUSIONS: Our study provides experimental evidence suggesting that the presence of females plays a significant role in the rank-related variation in the cortisol levels in male chimpanzees. Furthermore, our findings demonstrate the usefulness of salivary hormones for detecting short-term physiological changes in studies of socioendocrinology.

Low serum dehydroepiandrosterone examined by liquid chromatography-tandem mass spectrometry correlates with poor prognosis in hormone-naïve prostate cancer.

BACKGROUND: There is no consensus on blood adrenal androgen concentrations in men with different stages and pathological grades of prostate cancer. In this study, dehydroepiandrosterone (DHEA) concentrations in blood were examined by ultrasensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS). We analyzed the correlation between DHEA concentrations in blood and clinicopathological findings of prostate cancer. METHODS: We analyzed 196 men (mean age 70 years) with prostate cancer. The patients underwent systematic needle biopsy, and peripheral blood sampling was conducted for measurement of DHEA. DHEA concentrations in blood were determined using LC-MS/MS method. Patient age, serum prostate-specific antigen, prostate volume measured by ultrasound, and DHEA levels in blood were compared with Gleason score and clinical stage by multivariate analyses. RESULTS: Median value of PSA and prostate volume were 11.5 ng/ml and 27.7 ml, respectively. Median concentration of DHEA in blood was 1,506.4 pg/ml. There was no correlation between serum DHEA and clinical variables such as age, serum PSA, and prostate volume. In multivariate analysis, low serum DHEA levels in prostate cancer patients were significantly related to high Gleason score and advanced clinical stage. Serum PSA levels in prostate cancer patients were also significantly associated with high Gleason score and advanced clinical stage. High serum PSA and low serum DHEA levels were significantly associated with poor prognosis factors in men with hormone-naïve prostate cancer. CONCLUSIONS: DHEA concentrations in blood were examined by newly developed ultrasensitive LC-MS/MS. We confirmed that low serum DHEA levels in prostate cancer patients were related to high Gleason score and advanced clinical stage. These results suggest that serum DHEA level may be a useful prognostic factor in prostate cancer patients.

High testosterone levels in prostate tissue obtained by needle biopsy correlate with poor-prognosis factors in prostate cancer patients.

BACKGROUND: There is currently no consensus on the correlations between androgen concentrations in prostate tissue and blood and stage and pathological grade of prostate cancer. In this study, we used a newly-developed ultra-sensitive liquid-chromatography tandem mass spectrometry method to measure testosterone (T) and dihydrotestosterone (DHT) concentrations in blood and needle biopsy prostate specimens from patients with prostate cancer. METHODS: We analyzed androgen levels in 196 men diagnosed with prostate cancer. All patients had undergone systematic needle biopsy, and an additional needle biopsy from the peripheral zone was conducted for the simultaneous determination of T and DHT. We analyzed the relationships between T and DHT levels in tissue and blood and Gleason score, clinical stage, and percentage of positive biopsy cores, using multivariate analysis. RESULTS: The median T and DHT levels in blood were 3551.0 pg/mL and 330.5 pg/mL, respectively. There was a strong correlation between serum T and DHT. The median T and DHT levels in prostate tissue were 0.5667 pg/mg and 7.0625 pg/mg, respectively. In multivariate analysis, serum prostate-specific antigen and tissue T levels were significantly associated with poor prognosis; high T levels in prostate tissue were significantly related to high Gleason score (p = 0.041), advanced clinical stage (p = 0.002), and a high percentage of positive biopsy cores (p = 0.001). CONCLUSIONS: The results of this study indicate that high T levels in prostate tissue are related to high Gleason score, advanced clinical stage, and a high percentage of positive biopsy cores in patients with prostate cancer. T level in needle biopsy specimens may therefore be a useful prognostic factor in prostate cancer patients.

Relationship between dioxin and steroid hormones in sera of Vietnamese men.

A recent study found an inverse correlation between serum TCDD levels and serum testosterone in the US veterans, while there is little known on the dioxin and steroid hormones about Vietnamese men. We collected blood samples from 48 men who had resided in a hotspot when exposure happened and 38 men in a non-sprayed area. Some steroid hormones levels showed significant differences between two areas. There were no correlations between steroid hormones and dioxin TEQ, after ajusting for age and other factors. Our findings indicate that steroid hormones of Vietnamese men did not correlate with dioxin TEQ in two areas.

Serum dioxin levels in Vietnamese men more than 40 years after herbicide spraying.

Recent studies have found elevated dioxin levels inside some U.S. military former air bases in Vietnam, known as hotspots. Many studies of Agent Orange have been done in U.S. veterans; however, there is little known about Vietnamese men. In 2010, we collected blood samples from 97 men in a hotspot and 85 men in an unsprayed area in Northern Vietnam. Serum concentrations of not only TCDD but also other dioxins (PCDDs), furans (PCDFs), and nonortho polychlorinated biphenyls (PCBs) were significantly higher in the hotspot than in the unsprayed area. In the hotspot, three subareas were demarcated, based on their proximity to the air base. The total toxic equivalents (TEQ) of PCDDs/PCDFs+PCBs was 41.7 pg/g lipid in the area closest to the air base, while it was around 29 pg/g lipid in the other two subareas. In the unsprayed area, the dioxin levels were no different between men who went to the South during the Vietnam War and those who remained in the North, with TEQs PCDDs/PCDFs+PCBs of around 13.6 pg/g lipid. Our findings suggested that people living close to the former U.S. air bases might have been exposed to both Agent Orange and other sources of dioxin-like compounds.

Effect of saponins in Panax notoginseng (Burkill) F. H. Chen on the steroid hormone levels in the chronic unpredictable mild stress model of depression in rats.

Recent research has indicated that Panax notoginseng saponins (PNS) extracted from the radix of Panax notoginseng (Burkill) F. H. Chen exert antidepressant effects. This study aimed to assess the antidepressive effects of ginsenoside Rg1 and PNS in a depression model induced by chronic unpredictable mild stress (CUMS). Over a period of three weeks, rats were administered ginsenoside Rg1 at a dose of 30 mg/kg and PNS at dosages ranging from 100 to 200 mg/kg body weight per day. To assess how ginsenoside Rg1 and PNS influence depression-like behaviours in rats, various assessments were conducted, including coat state evaluation, forced swim test, and elevated plus maze test. The levels of cortisol and testosterone in serum samples were analysed using the liquid chromatography-electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS) method. LC-ESI-MS/MS method provides precise and accurate results. The lower limit of quantification values for cortisol and testosterone were determined as 100 and 2 pg/mL, respectively. Our data demonstrated that both ginsenoside Rg1 and PNS significantly reversed depression-like behaviour in rats by improving coat condition, reducing immobility time in the forced swim test, and increasing time spent in the open arms of the elevated plus maze test. Furthermore, ginsenoside Rg1 and PNS exhibited a regulatory effect on cortisol and testosterone levels in plasma. These findings suggest that ginsenoside Rg1 and PNS may be potential antidepressants in clinical treatment.

Biphasic time course of the changes in aldosterone biosynthesis under high-salt conditions in Dahl salt-sensitive rats.

OBJECTIVE: The comorbidity of excess salt and elevated plasma aldosterone has deleterious effects in cardiovascular disease. We evaluated the mechanisms behind the paradoxical increase in aldosterone biosynthesis in relation to dietary intake of salt. METHODS AND RESULTS: Dahl salt-sensitive (Dahl-S) and salt-resistant (Dahl-R) rats were fed a high-salt diet, and plasma and tissue levels of aldosterone in the adrenal gland and heart were quantified by liquid chromatography-electrospray ionization-tandem mass spectrometry. In Dahl-S rats, we found that the delayed and paradoxical increase in aldosterone biosynthesis after the initial and appropriate response to high salt. The late rise in aldosterone biosynthesis was accompanied by upregulation of CYP11B2 expression in the zona glomerulosa and increased adrenal angiotensin II levels and renin-angiotensin system components. It preceded the appearance of left ventricular systolic dysfunction and renal insufficiency. Blockade of angiotensin AT(1) receptors reversed the paradoxical increase in aldosterone biosynthesis. In contrast, Dahl-R rats maintained the initial suppression of aldosterone biosynthesis. Aldosterone levels in the heart closely paralleled those in the plasma and adrenal gland and disappeared after bilateral adrenalectomy. CONCLUSIONS: Chronic salt overload in Dahl-S rats stimulates aberrant aldosterone production via activation of the local renin-angiotensin system in the adrenal gland, thereby creating the comorbidity of excess salt and elevated plasma aldosterone.

The relationship between dioxins and salivary steroid hormones in Vietnamese primiparae.

OBJECTIVE: Nearly 40 years after Agent Orange was last sprayed, we conducted a cross-sectional study to evaluate the impact of dioxin exposure on salivary hormones in Vietnamese primiparae. Our previous studies found higher levels of salivary cortisol and cortisone in one of the most highly dioxin-contaminated areas, known as a "hot-spot", than in a non-exposed area. As a result, we suggested that further research with a larger number of participants would be needed to confirm whether dioxin affects steroid hormone levels in Vietnamese primiparae. METHODS: The concentration of steroid hormones in saliva was determined by liquid chromatography (electrospray ionization tandem mass spectrometry), whereas the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in breast milk were determined by gas chromatography-high resolution mass spectrometry, for a sample of the population from a "hot-spot" (n = 16) and a non-exposed area (n = 10). All subjects were aged between 20 and 30 years and had children aged between 4 and 16 weeks. RESULTS: The mean toxic equivalence of PCDDs, PCDFs and PCDDs + PCDFs in breast milk in the hot-spot area was found to be significantly higher than in the non-exposed area (p < 0.001). Likewise, salivary cortisol, cortisone and dehydroepiandrosterone (DHEA) levels were significantly higher in the hotspot area than in the non-exposed area (p < 0.05). As a result, herein we report, for the first time, that salivary DHEA levels in primiparae are higher in a hot-spot than in a non-exposed area, and that this may be the result of dioxin exposure. CONCLUSIONS: Our findings highlight the long-term effects of Agent Orange/dioxin on steroid hormones in Vietnamese primiparae in the post-war period.

Liquid chromatography-tandem mass spectrometry analysis of human adrenal vein corticosteroids before and after adrenocorticotropic hormone stimulation.

CONTEXT: Although steroid hormones produced by the adrenal gland play critical roles in human physiology, a detailed quantitative analysis of the steroid products has not been reported. The current study uses a single methodology (liquid chromatography-tandem mass spectrometry, LC-MS/MS) to quantify ten corticosteroids in adrenal vein (AV) samples pre- and post-adrenocorticotropic hormone (ACTH) stimulation. DESIGN/METHODS: Three men and six women with a diagnosis of an adrenal aldosterone-producing adenoma (APA) were included in the study. Serum was collected from the iliac vein (IV) and the AV contralateral to the diseased adrenal. Samples were collected, before and after administration of ACTH. LC-MS/MS was then used to quantify serum concentrations of unconjugated corticosteroids and their precursors. RESULTS: Prior to ACTH stimulation, the four most abundant steroids in AV were cortisol (90%), cortisone (4%), corticosterone (3%) and 11-deoxycortisol (0.8%). Post-ACTH administration, cortisol remained the major adrenal product (79%); however, corticosterone became the second most abundantly produced adrenal steroid (11%) followed by pregnenolone (2.5%) and 17α-hydroxypregnenolone (2%). ACTH significantly increased the absolute adrenal output of all ten corticosteroids measured (P < 0.05). The four largest post-ACTH increases were pregnenolone (300-fold), progesterone (199-fold), 17α-hydroxypregnenolone (187-fold) and deoxycorticosterone (82-fold). CONCLUSION: Using LC-MS/MS, we successfully measured 10 corticosteroids in peripheral and AV serum samples under pre- and post-ACTH stimulation. This study demonstrates the primary adrenal steroid products and their response to ACTH.

Decreased serum testosterone levels associated with 17ß-hydroxysteroid dehydrogenase activity in 7-year-old children from a dioxin-exposed area of Vietnam.

Since 2008, we have conducted epidemiological cohort studies on the relationship between dioxin exposure and disruption with children in the area sprayed with defoliants during the Vietnam War. In a long-term survey of children through the age of five, we observed androgen disruption due to decreased dehydroepiandrosterone (DHEA) and testosterone levels. In this study of 7-year-old, we separately elucidated androgen disruption for boys and girls, and discussed with respect to hormone disruption with sex differences on the steroid hormone biosynthesis process. This follow-up was conducted with 96 mother-child pairs in Vietnam (hotspot area: 45, non-sprayed area: 51). We took a questionnaire, the physical measurement and assayed 7 steroid hormones in their serum by LC-MS/MS. We examined the relationship between the hormone levels in the serum and dioxin levels in the maternal breast milk. The results showed that the serum DHEA level in the 7-year-old children in the hotspot recovered to levels in the non-sprayed area. The testosterone level of 66.5 pg/mL for boys in the non-sprayed area was 1.5 times the girls level of 44.6 pg/mL, a male-dominant effect. The testosterone level in boys and girls from the hotspot were significantly lower than in the non-sprayed area with no sex difference. The 17ß-hydroxysteroid dehydrogenase (17ß-HSD) activity was significantly higher in boys than in the girls from the non-sprayed area, but was significantly lower in the hotspot boys than in the non-sprayed area boys. Both the testosterone level and 17ß-HSD activity in the boys were inversely correlated with the TEQ total PCDD/Fs in the maternal breast milk. These results indicated that dioxin delayed the expression of the testosterone level and 17ß-HSD activity with growth in the 7-year-old boys. The serum DHEA in the 7-year-old children recovered to the levels of the children in the non-sprayed area.

5alphaDH-DOC (5alpha-dihydro-deoxycorticosterone) activates androgen receptor in castration-resistant prostate cancer.

Prostate cancer often relapses during androgen-depletion therapy, even under the castration condition in which circulating androgens are drastically reduced. High expressions of androgen receptor (AR) and genes involved in androgen metabolism indicate a continued role for AR in castration-resistant prostate cancers (CRPCs). There is increasing evidence that some amounts of 5alpha-dihydrotestosterone (DHT) and other androgens are present sufficiently to activate AR within CRPC tissues, and enzymes involved in the androgen and steroid metabolism, such as 5alpha-steroid reductases, are activated in CRPCs. In this report, we screened eight natural 5alphaDH-steroids to search for novel products of 5alpha-steroid reductases, and identified 11-deoxycorticosterone (DOC) as a novel substrate for 5alpha-steroid reductases in CRPCs. 11-Deoxycorticosterone (DOC) and 5alpha-dihydro-deoxycorticosterone (5alphaDH-DOC) could promote prostate cancer cell proliferation through AR activation, and type 1 5alpha-steroid reductase (SRD5A1) could convert from DOC to 5alphaDH-DOC. Sensitive liquid chromatography-tandem mass spectrometric analysis detected 5alphaDH-DOC in some clinical CRPC tissues. These findings implicated that under an extremely low level of DHT, 5alphaDH-DOC and other products of 5alpha-steroid reductases within CRPC tissues might activate the AR pathway for prostate cancer cell proliferation and survival under castration.

Immunolocalization of estrogen-producing and metabolizing enzymes in benign breast disease: comparison with normal breast and breast carcinoma.

It is well known that estrogens play important roles in the cell proliferation of breast carcinoma. Benign breast disease (BBD) contains a wide spectrum of diseases, and some are considered an important risk factor for subsequent breast carcinoma development. However, the significance of estrogens in BBD has remained largely unknown. Therefore, in this study, we examined tissue concentrations of estrogens and immunolocalization of estrogen-producing/metabolizing enzymes in BBD, and compared these findings with those in the normal breast and ductal carcinoma in situ (DCIS). Tissue concentration of estradiol in BBD (n = 9) was significantly (3.4-fold) higher than normal breast (n = 9) and nearly the same (0.7-fold) as in DCIS (n = 9). Immunoreactivity of estrogen sulfotransferase in BBD was significantly lower (n = 82) than normal breast (n = 28) but was not significantly different from DCIS (n = 28). Aromatase and steroid sulfatase immunoreactivities tended to be higher (P = 0.07) in BBD than in normal breast, and 17ß-hydroxysteroid dehydrogenase type 1 immunoreactivity was significantly higher in BBD than normal breast in the postmenopausal tissues. Immunoreactivity of estrogen and progesterone receptors was also significantly higher in BBD than normal breast. These results suggest that tissue concentration of estradiol is increased in BBD at a level similar to DCIS, which is considered mainly due to loss of estrogen sulfotransferase expression. Increased local estradiol concentration in BBD due to aberrant expression of estrogen-producing/metabolizing enzymes may play important roles in the accumulation of estradiol-mediated growth and/or subsequent development of breast carcinoma.

Association of dioxin in maternal breast milk and salivary steroid hormone levels in preschool children: A five-year follow-up study of a Vietnam cohort.

Recent studies have found elevated dioxin levels inside some former US military air bases in Vietnam, known as hotspots. The aim of the present study was to evaluate the association of dioxin exposure and steroid hormone in preschool children in Vietnam. In 2010, 2011, 52 primiparae mother-infant pairs in the hotspot and 52 pairs in a non-exposure region were enrolled. For the final analysis, 26 vs 26 pairs were selected, who participated at all three surveys. Univariable and multivariable linear regressions were used to evaluate associations between hormone and dioxin congeners. Geometric mean total TEQ of PCDD/DFs in the hotspot were significantly higher than in the non-exposure region, 8.7 and 3.4 pg TEQ/g lipid, respectively. In the hotspot, salivary dehydroepiandrosterone (DHEA) was significantly higher in 1-year-old children (Boys = 123 pg/mL, Girls = 120 pg/mL) than in the non-exposure region (Boys = 28 pg/mL, Girls = 27 pg/mL). In contrast, DHEA was significantly lower in 5-year-old children (Boys = 70 pg/mL, Girls = 106 pg/mL) in the hotspot than in the non-exposure region (Boys = 496 pg/mL, Girls = 654 pg/mL). Salivary testosterone was significantly lower in the hotspot (Boys = 1.9 pg/mL, Girls = 1.9 pg/m; Boys = 1.0 pg/mL, Girls = 1.1 pg/mL, respectively) than in the non-exposure region (Boys = 3.7 pg/mL, Girls = 3.8 pg/m; Boys = 5.7 pg/mL, Girls = 7.0 pg/mL, respectively) at 3 years and 5 years of age. Higher levels of highly chlorinated dioxins in breast milk were associated with higher DHEA in 1-year-old and lower DHEA and testosterone levels in 5-year-old children. Our findings indicated that dioxins were associated with changes of DHEA and testosterone levels in preschool Vietnamese children.

Intratumoral estrogens and estrogen receptors in human non-small cell lung carcinoma.

PURPOSE: The possible involvement of gender-dependent factors has been suggested in human non-small cell lung carcinomas (NSCLC), but their precise roles remain largely unclear. Therefore, we examined intratumoral estradiol concentrations in NSCLC to examine local actions of estrogens in NSCLC. EXPERIMENTAL DESIGN: Fifty-nine frozen specimens of NSCLC were available for liquid chromatography/electrospray tandem mass spectrometry to study intratumoral estradiol concentrations. In addition, A549 NSCLC cells stably expressing estrogen receptor (ER) alpha (A549 + ERalpha) or ERbeta (A549 + ERbeta) were used in vitro studies. RESULTS: Forty-three (73%) of 59 NSCLC showed higher concentration of estradiol in carcinoma tissues than the corresponding nonneoplastic lung tissues from the same patient, and intratumoral estradiol concentrations were significantly (P = 0.0002 and 2.2-fold) higher than the corresponding nonneoplastic lungs. The intratumoral concentration of estradiol was positively correlated with aromatase expression, tumor size, and Ki-67 status in ERalpha- or ERbeta-positive cases. In in vitro studies, estradiol significantly increased cell proliferation of A549 + ERalpha or A549 + ERbeta, which was significantly suppressed by selective ER modulators, tamoxifen or raloxifene. Both A549 + ERalpha and A549 + ERbeta cells expressed aromatase. The cell proliferation level in these cells was significantly increased under treatment with testosterone, and it was inhibited by addition of the aromatase inhibitor letrozole. CONCLUSIONS: These results suggest that estradiol is locally produced in NSCLC mainly by aromatase and plays an important role in the growth of ERalpha- or ERbeta-positive NSCLC. Therefore, use of selective ER modulators and/or aromatase inhibitors may be clinically effective in NSCLC that are positive for both ER and aromatase.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay for simultaneous measurement of salivary testosterone and cortisol in healthy men for utilization in the diagnosis of late-onset hypogonadism in males.

It is well known that late-onset hypogonadism in males can cause a variety of symptoms, and the differential diagnosis is relatively difficult, including psychological disorders, stress, and mood disturbances. The level of serum cortisol can be measured to reflect a patient's level of stress. Salivary hormones facilitate the evaluation of physiological hormonal actions based on free hormone assay. For the simultaneous measurement of testosterone and cortisol levels in saliva, we validate a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay. Concerning accuracy and precision, the lower limit of quantification of salivary testosterone and cortisol were established as 5 and 10 pg/mL, respectively. Testosterone and cortisol in saliva is stable for 2 days, 14 days, and 28 days at room temperature, refrigeration and frozen, respectively. Freezing and thawing for 3 cycles and stimulation of salivation with gum chewing do not alter the measured values of testosterone and cortisol. Total, bioavailable, and free serum testosterone showed slight diurnal changes, but total and bioavailable serum cortisol showed marked diurnal changes. Salivary testosterone levels negatively correlate with age, regardless of the time of saliva collection (r=0.64, p<0.05). However, there is no relationship between salivary cortisol and age (r=0033, p>0.05). LC-MS/MS allows rapid, simultaneous, sensitive, and accurate quantification of testosterone and cortisol in saliva for the diagnosis late-onset hypogonadism or other hormone related disease.

Validation of salivary cortisol and testosterone assays in chimpanzees by liquid chromatography-tandem mass spectrometry.

Owing to its high temporal sensitivity, saliva has distinct advantages for measuring steroids, compared with other noninvasive samples such as urine and feces. Here, we report the validity of assaying salivary cortisol (C) and testosterone (T) using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in captive male chimpanzees, Pan troglodytes. For both the C and T concentrations, we found positive relationships between saliva and plasma. The concentrations of C and T in saliva showed clear patterns of diurnal fluctuation, whereas those in urine and feces did not. These results suggest that the salivary steroid concentrations can be regarded as good indicators of circulating steroid levels. We also developed and validated an efficient method for collecting saliva samples from cotton rope. Although rope includes inherent steroid-like compounds and may affect the accuracy of steroid measurements, our rope-washing procedures effectively removed intrinsic steroidal materials. There was a significant association between the C and T concentrations measured from saliva collected from rope licked by the chimpanzees and those measured from saliva collected directly from the mouth. Salivary T values estimated by LC/MS-MS were similar to those measured by radioimmunoassay. The results indicate the usefulness of saliva as a noninvasive steroid measure and that steroids in the saliva of chimpanzees can be accurately measured by LC-MS/MS.

Aromatase localization in human breast cancer tissues: possible interactions between intratumoral stromal and parenchymal cells.

Aromatase is a key enzyme in intratumoral estrogen production required for the production of estrogens through the conversion of serum androgens in postmenopausal breast cancer patients. There have been, however, controversies regarding the intratumoral localization of aromatase in human breast carcinoma tissues. Therefore, we have first examined the intratumoral localization of aromatase mRNA/protein in 19 breast carcinomas using laser capture microdissection/quantitative reverse transcription-PCR (RT-PCR) and immunohistochemistry. Aromatase mRNA and protein were detected in both intratumoral stromal and parenchymal cells in breast carcinoma tissues. Subsequent microarray expression profiling and clustering analyses, in addition to quantitative RT-PCR studies, showed a significant positive correlation between aromatase and estrogen-related receptor alpha mRNA expression in isolated carcinoma cells. We further examined an interaction between stromal cells isolated from human breast carcinoma tissues and breast carcinoma cell lines using a coculture system to study the biological characteristic of aromatase expression in carcinoma cells. Aromatase mRNA and enzyme activity and 17beta-hydroxysteroid dehydrogenase type 1 mRNA in breast carcinoma cell lines, including MCF-7 and SK-BR-3 cells, were up-regulated in the presence of patient-derived 32N or 74T intratumoral stromal cells. The results from steroid conversion assays were also consistent with the findings above. The results of our study also showed that aromatase inhibitors were more effective in inhibiting aromatization induced by coculture in MCF-7 than that in stromal 32N. The examination of the localization of aromatase and its regulation, including the interactions existing between different cell types in human breast carcinoma tissues, may provide important information as to achieving better clinical response to aromatase inhibitors in breast cancer patients.

Novel 5 alpha-steroid reductase (SRD5A3, type-3) is overexpressed in hormone-refractory prostate cancer.

Prostate cancer often relapses during androgen-depletion therapy, even under conditions in which a drastic reduction of circulating androgens is observed. There is some evidence that androgens remain present in the tissues of hormone-refractory prostate cancers (HRPC), and enzymes involved in the androgen and steroid metabolic pathway are likely to be active in HRPC cells. We previously carried out a genome-wide gene expression profile analysis of clinical HRPC cells by means of cDNA microarrays in combination with microdissection of cancer cells and found dozens of transactivated genes. Among them, we here report the identification of a novel gene, SRD5A2L, encoding a putative 5 alpha-steroid reductase that produces the most potent androgen, 5 alpha-dihydrotestosterone (DHT), from testosterone. Liquid chromatography-tandem mass spectrometry analysis following an in vitro 5 alpha-steroid reductase reaction validated its ability to produce DHT from testosterone, similar to type 1 5 alpha-steroid reductase. Because two types of 5 alpha-steroid reductase were previously reported, we termed this novel 5 alpha-steroid reductase 'type 3 5 alpha-steroid reductase' (SRD5A3). Reverse transcription-polymerase chain reaction and northern blot analyses confirmed its overexpression in HRPC cells, and indicated no or little expression in normal adult organs. Knockdown of SRD5A3 expression by small interfering RNA in prostate cancer cells resulted in a significant decrease in DHT production and a drastic reduction in cell viability. These findings indicate that a novel type 3 5 alpha-steroid reductase, SRD5A3, is associated with DHT production and maintenance of androgen-androgen receptor-pathway activation in HRPC cells, and that this enzymatic activity should be a promising molecular target for prostate cancer therapy.

Development of sensitive derivatization method for aldosterone in liquid chromatography-electrospray ionization tandem mass spectrometry of corticosteroids.

A highly sensitive quantification method of aldosterone by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) was investigated in a positive mode using recently developed picolinyl derivatization. Aldosterone was smoothly and quantitatively converted to the ethyl ether-picolinyl derivative by treatment with HCl-ethanol followed by the esterification with picolinic acid in the presence of 2-methyl-6-nitrobenzoic anhydride and 4-dimethylaminopyridine. The positive ion-ESI mass spectrum of the ethyl ether-picolinyl derivative was characterized by an appearance of protonated molecule ([M+H](+)) as a base peak. The ethyl ether-picolinyl derivatization gave a successful result in a separation of aldosterone from corticosterone, dehydrocorticosterone and cortexolone, and also provided an approximately 10-fold higher ESI response in the positive-LC-ESI-MS/MS (selected reaction monitoring; SRM) when compared to that of underivatized molecule (negative mode). The limit of quantification of aldosterone by SRM using ethyl ether-picolinyl derivatization (m/z 494-->m/z 448) was 1 pg/0.2 ml serum with accuracy and precision of 92.6% and 5.6%, respectively.

Simultaneous determination of tetrahydrocortisol, allotetrahydrocortisol and tetrahydrocortisone in human urine by liquid chromatography-electrospray ionization tandem mass spectrometry.

Simultaneous quantification method of three major metabolites of cortisone and cortisol, tetrahydrocortisol, allotetrahydrocortisol and tetrahydrocortisone by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) was investigated in a positive mode using a recently developed picolinyl derivatization. Conversion of each steroid into the corresponding picolinyl derivatives (1b, 2b or 3b) was performed by mixed anhydride method using picolinic acids and 2-methyl-6-nitrobenzoic anhydride. Derivatization proceeded smoothly to afford the corresponding 3, 21-dipicolinyl derivatives. Positive ion-ESI mass spectra of the picolinyl derivatives were dominated by an appearance of [M+H](+) as base peaks in all cases. The picolinyl derivatives provided 15 to 80-fold higher ESI response in the LC-ESI-MS/MS (selected reaction monitoring: SRM) when compared to those of underivatized molecules in a positive LC-ESI mode. The use of the picolinyl ester, solid-phase extraction, and deuterium labeled internal standards enabled the concentrations of these metabolites in human urine to be determined simultaneously by LC-ESI-MS/MS (SRM) with a small sample volume of less than 1microl urine.