RESUMEN
Testolactone is a potent steroid aromatase (CYP19A1) inhibitor, and its main effect is a reduction in estradiol and estrone and an increase in testosterone and androstenedione levels. In this work, we evaluated a zebrafish water tank (ZWT) as a model to investigate testolactone biotransformation and the possibility to increase knowledge regarding the applicability of the ZWT on steroid hormone elimination research, as well as on the impact of steroid hormones on the endogenous metabolism of zebrafish. High-resolution mass spectrometry combined with SIEVE software was used to discriminate the peaks of interest based on significant changes in the relative signal intensity of the m/z values between different ZWT experiments. The metabolites, 4,5-dihydrotestolactone and 1,2,4,5-tetrahydrotestolactone, the same metabolites as those described in humans, were detected in ZWT, both in quite similar proportions. The presence of testolactone in the ZWT caused a rise in testosterone and androstenedione in the water tank, similar to that in human serum. These data suggest that, while the concentration of testolactone was high enough to inhibit the aromatase enzyme, an accumulation of androgens in the water occurred, indicating that the ZWT can be considered a model to investigate the impact of steroids on live organisms.
Asunto(s)
Inhibidores de la Aromatasa/metabolismo , Testolactona/metabolismo , Pez Cebra/metabolismo , Animales , Biotransformación , Hormonas Esteroides Gonadales , Testolactona/análogos & derivadosRESUMEN
Microbiological synthesis of 7α- and 7ß-hydroxy derivatives of testololactone and testolactone was developed based on bioconversion of dehydroepiandrosterone (DHEA) by fungus of Isaria fumosorosea VKM F-881 with subsequent modification of the obtained stereoisomers by actinobacteria. The first stage included obtaining of the stereoisomers of 3ß,7(α/ß)-dihydroxy-17a-oxa-D-homo-androst-5-en-17-ones in the preparative amounts. Then the conversion of 7-hydroxylated D-lactones obtained by selected actinobacteria of Nocardioides simplex VKM Ac-2033D, Saccharopolyspora hirsuta VKM Ac-666, and Streptomyces parvulus MTOC Ac-21v was studied. Under the transformation of 3ß,7α-dihydroxy-17a-oxa-D-homo-androst-5-en-17-one and its corresponding 7ß-stereoisomer by N. simplex VKM Ac-2033D and S. hirsuta VKM Ac-666 the 7α- and 7ß-hydroxy-17a-oxa-D-homo-androst-4-ene-3,17-dione (7α- and 7ß-hydroxytestololactone), 7α- and 7ß-hydroxy-17a-oxa-D-homo-androsta-1,4-diene-3,17-dione (7α- and 7ß-hydroxytestolactone) were obtained with molar yields in a range of 60.3-90.9 mol%. The crystalline products of 7α-hydroxytestololactone, 7α-hydroxytestolactone, and their corresponding 7ß-hydroxy stereoisomers were isolated, and their structures were confirmed by mass spectrometry and 1H-NMR spectroscopy analyses. The strain of Str. parvulus MTOC Ac-21v transformed 3ß,7(α/ß)-dihydroxy-17a-oxa-D-homo-androst-5-en-17-ones into the corresponding 3-keto-4-ene analogs and did not show 3-ketosteroid 1(2)-dehydrogenase activity. The activity of actinobacteria towards steroid D-lactones was hitherto unreported.The results contribute to the knowledge of metabolic versatility of actinobacteria capable of transforming steroid substrates and may be applied in the synthesis of potential aromatase inhibitors.
Asunto(s)
Hongos/metabolismo , Hidroxitestosteronas/metabolismo , Testolactona/análogos & derivados , Actinobacteria/metabolismo , Hidroxilación , Hidroxitestosteronas/química , Microbiología Industrial , Estructura Molecular , Saccharopolyspora/metabolismo , Estereoisomerismo , Streptomyces/metabolismo , Testolactona/química , Testolactona/metabolismoRESUMEN
Using ß-sitosterol and stigmasterol as precursor materials, a concise and efficient hemisynthesis of aromatase inhibitors: testololactone and testolactone was accomplished in a well-established reaction scheme. It involves highly effective Oppaneur oxidation of both ß-sitosterol as well as stigmasterol to generate the required enone moiety in ring 'A' of the desired steroid system. The Oppaneur oxidation products of both ß-sitosterol and stigmasterol were then subjected to oxidative cleavage of the side chain to produce 4-androstene-3,17-dione. Baeyer-Villiger oxidation of 4-androstene-3,17-dione using m-CPBA yielded testololactone. Dehydrogenation of 4-androstene-3,17-dione using phenylselenyl chloride in ethyl acetate followed by selenoxide elimination with H2O2 in dichloromethane furnished androstenedienone. Baeyer-Villiger oxidation of the resulting androstenedienone yielded the desired testolactone (overall yield 33%). This expeditious reaction scheme may be exploited for the bulk production of aromatase inhibitors (especially testolactone marketed under the brand name Teslac) from the most abundant and naturally occurring phytosterols like ß-sitosterol.
Asunto(s)
Inhibidores de la Aromatasa/síntesis química , Sitoesteroles/química , Estigmasterol/química , Testolactona/análogos & derivados , Inhibidores de la Aromatasa/química , Técnicas de Química Sintética , Oxidación-Reducción , Fitosteroles , Testolactona/síntesis química , Testolactona/químicaRESUMEN
Nerve growth factor (NGF) has been reported to be involved in male reproductive physiology. However, few reports have described the activity of NGF during Leydig cell development. The objective of the present study was to examine the role of NGF during stem-Leydig-cell (SLC) regeneration. We investigated the effects of NGF on Leydig-cell (LC) regeneration by measuring mRNA levels in the adult rat testis after ethane dimethanesulfonate (EDS) treatment. Furthermore, we used the established organ culture model of rat seminiferous tubules to examine the regulation of NGF during SLC proliferation and differentiation using EdU staining, real-time PCR and western blotting. Progenitor Leydig cells (PLCs) and immature Leydig cells (ILCs) were also used to investigate the effects of NGF on LCs at different developmental stages. NGF mRNA levels changed significantly during Leydig-cell regeneration in vivo. In vitro, NGF significantly promoted the proliferation of stem Leydig cells and also induced steroidogenic enzyme gene expression and 3ß-HSD protein expression. The data from PLCs and ILCs showed that NGF could increase Cyclin D1 and Hsd 17b3 mRNA levels in PLCs and Cyclin D1 mRNA levels in ILCs. These results indicate that NGF may play an important role during LC regeneration by regulating the proliferation and differentiation of LCs at different developmental stages, from SLCs to PLCs and from PLCs to ILCs. The discovery of this effect of NGF on Leydig cells will provide useful information for developing new potential therapies for PADAM (Partial Androgen Deficiency in the Aging Male).
Asunto(s)
Diferenciación Celular/genética , Proliferación Celular , Células Intersticiales del Testículo/metabolismo , Factor de Crecimiento Nervioso/genética , Regeneración/genética , Células Madre/metabolismo , Animales , Western Blotting , Diferenciación Celular/efectos de los fármacos , Células Cultivadas , Ciclina D1/genética , Ciclina D1/metabolismo , Expresión Génica/efectos de los fármacos , Células Intersticiales del Testículo/citología , Células Intersticiales del Testículo/efectos de los fármacos , Masculino , Mesilatos/farmacología , Complejos Multienzimáticos/genética , Complejos Multienzimáticos/metabolismo , Factor de Crecimiento Nervioso/metabolismo , Factor de Crecimiento Nervioso/farmacología , Técnicas de Cultivo de Órganos , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Progesterona Reductasa/genética , Progesterona Reductasa/metabolismo , Ratas , Ratas Sprague-Dawley , Regeneración/efectos de los fármacos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Túbulos Seminíferos/citología , Túbulos Seminíferos/efectos de los fármacos , Túbulos Seminíferos/metabolismo , Células Madre/citología , Células Madre/efectos de los fármacos , Esteroide Isomerasas/genética , Esteroide Isomerasas/metabolismo , Testolactona/análogos & derivados , Testolactona/sangre , Testolactona/metabolismo , Factores de TiempoRESUMEN
The Baeyer-Villiger monooxygenase (BVMO) produced by Penicillium lilacinum AM111, in contrast to other enzymes of this group known in the literature, is able to process 3beta-hydroxy-5-ene steroid substrates. Transformation of DHEA and pregnenolone yielded, as a sole or main product, 3beta-hydroxy-17a-oxa-d-homo-androst-5-en-17-one, a new metabolite of these substrates; pregnenolone was transformed also to testololactone. Testololactone was the only product of oxidation of androstenedione by P. lilacinum AM111. Investigations of the time evolution of reaction progress have indicated that the substrates stimulate activity of BVMO(s) of P. lilacinum AM111.
Asunto(s)
Androstenodiona/metabolismo , Deshidroepiandrosterona/metabolismo , Penicillium/metabolismo , Pregnenolona/metabolismo , Testolactona/análogos & derivados , Androstenodiona/química , Biotransformación , Deshidroepiandrosterona/química , Espectroscopía de Resonancia Magnética , Oxidación-Reducción , Pregnenolona/química , Testolactona/química , Testolactona/metabolismoRESUMEN
Traditional methods for cancer treatment have been aimed at killing the cancer cells. Unfortunately this approach all too often is accompanied by harmful killing of normal cells. The present paper describes an experimental program in our laboratory in which cancer cells are treated so as to revert to normal cell behavior. This process, which we have named reverse transformation, appears to offer considerable hope in the treatment of a large number of malignancies.
Asunto(s)
Bucladesina/farmacología , Transformación Celular Neoplásica/efectos de los fármacos , AMP Cíclico/metabolismo , Testolactona/análogos & derivados , Animales , Encéfalo/citología , Células CHO , Tamaño de la Célula , Cricetinae , AMP Cíclico/análogos & derivados , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Humanos , Células Híbridas/citología , Células Híbridas/efectos de los fármacos , Células Híbridas/metabolismo , Estructura Molecular , Fosforilación , Testolactona/farmacologíaRESUMEN
To determine whether the inhibition of estrogen-related effect in the prostate would be of value in the management of benign prostate hyperplasia (BPH), we examined the effect of TZA-2209, a new steroidal aromatase inhibitor, on the prostate in three of six castrated beagles that received 75 mg/week androstenedione. The three other animals served as controls. Sequential measurements of prostate volume by transrectal ultrasonography showed that the volume in TZA-treated dogs was significantly decreased compared with that in the controls. Prostatic aromatase activity was suppressed by TZA administration. Histopathologically, the stromal component was increased and glands were atrophied by androstenedione treatment. TZA administration increased the volume of the glands. Immunohistochemical detection of estramustine-binding protein showed more positive staining of the protein in the glands that were increased in volume by TZA administration. We concluded that the aromatase inhibitor effectively antagonized the estrogen-related stromal changes, however, this action was accompanied by stimulation of the glandular component due to the accumulation of androgens, the substrate of the aromatase. In the light of these findings, we suggest the simultaneous treatment for the androgen-glandular component route in the prostate is necessary for the effective management of BPH.
Asunto(s)
Androstenodiona/antagonistas & inhibidores , Inhibidores de la Aromatasa , Próstata/efectos de los fármacos , Próstata/patología , Hiperplasia Prostática/tratamiento farmacológico , Hiperplasia Prostática/patología , Proteínas de Secreción Prostática , Testolactona/análogos & derivados , Animales , Proteínas Portadoras/inmunología , Castración , Perros , Estramustina , Técnicas para Inmunoenzimas , Masculino , Tamaño de los Órganos , Próstata/enzimología , Hiperplasia Prostática/enzimología , Células del Estroma/efectos de los fármacos , Testolactona/química , Testolactona/farmacologíaRESUMEN
A 76-year-old man with advanced carcinoma of the breast who had not been orchiectomized underwent sequential hormonal treatment. The tumour progressed during monotherapy with dexamethasone. Objective regression of the tumour followed sequential administration of tamoxifen (twice) and the two aromatase inhibitors, aminoglutethimide and testololactone. In addition, his condition remained stable on two progestogens in high doses, medroxyprogesterone acetate and megestrol acetate.
Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Aminoglutetimida/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Tamoxifeno/uso terapéutico , Testolactona/análogos & derivados , Congéneres de la Testosterona/uso terapéutico , Adenocarcinoma/cirugía , Anciano , Axila , Neoplasias de la Mama/cirugía , Dexametasona/uso terapéutico , Evaluación de Medicamentos , Humanos , Metástasis Linfática , Masculino , Medroxiprogesterona/análogos & derivados , Medroxiprogesterona/uso terapéutico , Acetato de Medroxiprogesterona , Megestrol/análogos & derivados , Megestrol/uso terapéutico , Acetato de Megestrol , Testolactona/uso terapéuticoRESUMEN
The inhibitory effects of miconazole, an antimycotic agent, on aromatase activity for androstenedione in human placenta (105,000 X g pellet fraction) and ovary (800 X g supernatant fraction) were investigated. Various concentrations (0.1-100 microM) of miconazole, aminoglutethimide or delta 1-testololactone were added to the human placental preparation (1 mg protein) and then the mixture was incubated with [1 beta-3 H]-androstenedione (300 pmol) and NADPH (0.5 mg), at 37 degrees C for 30 minutes in air. The reaction was stopped by 10%-trichloroacetic acid (0.8 ml) and the mixture was extracted with chloroform (3 ml). The residual aqueous phase was subjected to Amberlite XAD-II resin-charcoal column chromatography. The amount of 3H2O obtained was regarded as aromatase activity for androstenedione. The effects of miconazole on aromatase activity in human ovarian preparation was also investigated. Aromatase activity in human placenta was suppressed concentration-dependently by miconazole. The inhibition of aromatase activity by miconazole was significantly higher than that by aminoglutethimide and delta 1-testololactone. The I50 values for the inhibition of aromatase activity by miconazole, aminoglutethimide and delta 1-testololactone were 0.60 microM, 15 microM and 34 microM, respectively. The apparent Km value for androstenedione was 320 nM and the apparent Ki value was 120 nM in this assay. The inhibition of aromatase by miconazole in human ovary was also significantly higher than that by aminoglutethimide (I50 value for miconazole = 0.98 microM; I50 value for delta 1-testololactone = 15 microM). These results indicate that miconazole suppresses aromatase activity for androstenedione reversibly in human placenta and ovaries in vitro.
Asunto(s)
Androstenodiona , Inhibidores de la Aromatasa , Miconazol/farmacología , Ovario/enzimología , Placenta/enzimología , Aminoglutetimida/farmacología , Femenino , Humanos , Técnicas In Vitro , Embarazo , Testolactona/análogos & derivados , Testolactona/farmacologíaRESUMEN
This report describes the induction of cell-type-specific maturation, by dibutyryl-cAMP and testololactone, of neuronal and glial properties in a family of cell lines derived from a rat peripheral neurotumor, RT4. This maturation allows further understanding of the process of determination because of the close lineage relationship between the cell types of the RT4 family. The RT4 family is characterized by the spontaneous conversion of one of the cell types, RT4-AC (stem-cell type), to any of three derivative cell types, RT4-B, RT4-D, or RT4-E, with a frequency of about 10(-5). The RT4-AC cells express some properties characteristic of both neuronal and glial cells. Of these neural properties expressed by RT4-AC cells, only the neuronal properties are expressed by the RT4-B and RT4-E cells, and only the glial properties are expressed by the RT4-D cells. This in vitro cell-type conversion of RT4-AC to three derivative cell types is a branch point for the coordinate regulation of several properties and seems to resemble determination in vivo. In our standard culture conditions, several other neuronal and glial properties are not expressed by these cell types. However, addition of dibutyryl-cAMP induces expression of additional properties, in a cell-type-specific manner: formation of long cellular processes in the RT4-B8 and RT4-E5 cell lines and expression of high-affinity uptake of gamma-aminobutyric acid, by a glial-cell-specific mechanism, in the RT4-D6-2 cell line. These new properties are maximally expressed 2-3 days after addition of dibutyryl-cAMP. This indicates that conversion of RT4-AC to the derivative cell types is also a branch point for the regulation of cell-type-specific properties whose expression is responsive to cAMP. Thus, the potential for maturation in response to increased cAMP is a property that segregates in a cell-type-specific manner and is activated at the determinational level in this system.
Asunto(s)
Bucladesina/farmacología , Neuronas/citología , Autorradiografía , Línea Celular , Cinética , Neuronas/efectos de los fármacos , Testolactona/análogos & derivados , Testolactona/farmacología , Tritio , Ácido gamma-Aminobutírico/metabolismoRESUMEN
A steroid monooxygenase of Cylindrocarpon radicicola was found to catalyze oxygenative lactonization of 17-ketosteroid, androstenedione, to yield D-homo-17 alpha-oxasteroid, testololactone, i.e., the androstenedione monooxygenase reaction, in addition to catalyzing the progesterone monooxygenase reaction. The reaction product was identified by TLC, GLC, and mass spectrometry. The oxygenation proceeded with unitary stoichiometry for 17-ketosteroid, NADPH, and molecular oxygen, indicating that it is a typical monooxygenase reaction of the external electron donor type. The enzyme catalyzed successively the side chain cleavage reaction of 17 alpha-hydroxy-20-ketosteroid to produce its 17-keto derivative and the lactonization of the product. The effects of pH and of the concentration of substrate steroids on the androstenedione monooxygenase reaction were different from those on the progesterone monooxygenase reaction. Progesterone is a strong and competitive inhibitor of the lactonization of 17-ketosteroids. The steroid monooxygenase is concluded to have the activities of both oxygenative esterification of 20-ketosteroids and oxygenative lactonization of 17-ketosteroids.
Asunto(s)
Androstenodiona/metabolismo , Hongos Mitospóricos/enzimología , Esteroide 17-alfa-Hidroxilasa/farmacología , Esteroide Hidroxilasas/farmacología , Testolactona/análogos & derivados , Concentración de Iones de Hidrógeno , Cinética , NADP/metabolismo , Oxidación-Reducción , Pregnenolona/farmacología , Progesterona/farmacología , Testolactona/metabolismoRESUMEN
One-third of the cases of breast cancer in postmenopausal women are hormone-dependent and the lesions regress upon treatment with antiestrogens or inhibition of estrogen biosynthesis. In these patients, estrogens are synthesized in extraglandular tissues from adrenal precursors and re-enter plasma to produce estrone levels of 52 +/- 6.5 pg/ml (mean +/- SEM) and estradiol concentrations of 13.1 +/- 0.7 pg/ml. However, the fact that the levels of estrogen in breast tumor tissue are an order of magnitude higher than plasma levels suggested the possibility of in situ estrogen production. To address this possibility, we measured several enzymes involved in estradiol biosynthesis in human tumors. Forty-eight of 61 tumors contained aromatase (estrogen synthetase) activity ranging from 5-80 pg/gm protein per hour. By comparison, the levels of estrone sulfatase were 10(6) higher, ranging from 0.8-125 micrograms/gm protein per hour. Because the sulfatase enzyme was of lower affinity (i.e., Km = 27 microM) than that of aromatase (i.e., 0.027 microM), the amount of estrogen formed under conditions of similar substrate concentrations was compared and found to be 10-fold higher via the sulfatase enzyme. In 41 additional tumors, the 17 beta-hydroxysteroid dehydrogenase enzyme, catalyzing the conversion of estrone to estradiol, was uniformly present. To test the biologic relevance of the estrone sulfate to estrone to estradiol pathway, estrogen-dependent nitrosomethylurea rat mammary tumors were grown in soft agar in the presence of estrone sulfate. Concentrations of estrone sulfate of 10(-6) microM significantly (p less than 0.01) stimulated colony formation in this system in which 75.5-98.6% of estrone sulfate was converted to estrone and 0.2 to 6% to estradiol. These data support the hypothesis that mammary carcinomas can synthesize estradiol in situ from circulating estrogen precursor and that local conversion is biologically important. On the basis of comparative data, the estrone sulfate to estrone to estradiol pathway is quantitatively more important than that involving androstenedione to estrone to estradiol.
Asunto(s)
Aromatasa/metabolismo , Neoplasias de la Mama/metabolismo , Estrógenos/biosíntesis , Sulfatasas/metabolismo , 17-Hidroxiesteroide Deshidrogenasas/análisis , Adrenalectomía , Aminoglutetimida/uso terapéutico , Androstenodiona/análogos & derivados , Androstenodiona/farmacología , Animales , Estradiol/análisis , Estrona/análogos & derivados , Estrona/análisis , Femenino , Humanos , Hidrocortisona/uso terapéutico , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Hormono-Dependientes/metabolismo , Ratas , Testolactona/análogos & derivados , Testolactona/farmacologíaAsunto(s)
Diferenciación Celular , Células Madre Neoplásicas/patología , Neuroglía/patología , Neuronas/citología , Células Madre/patología , Animales , Bucladesina/farmacología , Línea Celular , Regulación de la Expresión Génica , Potasio/metabolismo , Ratas , Sodio/metabolismo , Testolactona/análogos & derivados , Testolactona/farmacologíaRESUMEN
In vitro p450 spectral data suggested that combinations of aromatase inhibitors might produce enhanced biologic effects. If correct, two clinically available aromatase inhibitors, aminoglutethimide (AG) and testololactone (TL) could potentially be given together at lower than usual dosage with reduction of patient side effects and preservation of aromatase inhibition. Using a [3H]water aromatase assay and a placental microsomal system, AG and TL were tested individually and in combination over their respective dose response ranges. Additive effects of these two compounds were observed. Another inhibitor, 4-hydroxyandrostenedione, given with AG produced similar additive inhibition. These data provide a basis for a future trial of AG and TL in combination in patients with breast carcinoma.
Asunto(s)
Aminoglutetimida/farmacología , Androstenodiona/análogos & derivados , Inhibidores de la Aromatasa , Oxidorreductasas/antagonistas & inhibidores , Placenta/enzimología , Testolactona/análogos & derivados , Congéneres de la Testosterona/farmacología , Androstenodiona/farmacología , Femenino , Humanos , Cinética , Microsomas/enzimología , Embarazo , Especificidad por Sustrato , Testolactona/farmacologíaRESUMEN
A rapid, sensitive, and selective assay is described for the quantitation of both testolactone and its recently identified metabolite, 4,5-dihydrotestolactone, in plasma and urine using high-performance liquid chromatography. The procedure includes a methylene chloride extraction prior to chromatography and quantitation using peak height ratios (ultraviolet absorbance detection, 242 nm) of testolactone and 4,5-dihydrotestolactone to the internal standard, testosterone. A sensitivity of 20 ng/ml for both testolactone and 4,5-dihydrotestolactone is easily achieved using only 0.5 ml of sample. Mean recoveries for testolactone and its metabolite are 95.0% and 81.8%, respectively, and the mean coefficient of variation of the procedure is 3.5% for the drug and 7.1% for the metabolite. This method is currently being used to study the pharmacokinetics of testolactone and 4,5-dihydrotestolactone in male patients. A steady-state plasma concentration versus time profile from a representative patient is included.
Asunto(s)
Testolactona/análogos & derivados , Testolactona/análisis , Cromatografía Líquida de Alta Presión/métodos , Humanos , Masculino , Testolactona/sangre , Testolactona/orina , Factores de TiempoRESUMEN
The effect on serum PRL levels of lowering serum oestradiol (E2) concentration by short-term administration of an aromatase activity inhibitor, hydrotestolactone (HT), was studied in six healthy male subjects. After HT administration serum E2 levels decreased from 68 +/- 5.8 to 26 +/- 2.5 pmol/l (mean +/- SE, P less than 0.05). These E2 changes were accompanied by a significant decrease in mean 2-h PRL levels from 11.2 +/- 2.1 to 6.5 +/- 1.6 ng/ml mean +/- SE, P less than 0.05). The evaluation of individual percentage change from basal concentrations showed a varying decrease in all subjects. These findings suggest that under physiological conditions E2 may be one of the factors which control blood PRL concentrations in men.
Asunto(s)
Estradiol/sangre , Prolactina/sangre , Testolactona/análogos & derivados , Congéneres de la Testosterona/farmacología , Adulto , Humanos , Masculino , Persona de Mediana Edad , Adenohipófisis/efectos de los fármacos , Prolactina/metabolismo , Testolactona/farmacologíaRESUMEN
A total of 53 tumors have been examined for estrogen synthesis from androstenedione and assayed for estradiol receptors. It was found that of the 40 tumors that metabolized androstenedione to estrogens, 17 tumors were estradiol receptor negative and 23 tumors were estradiol receptor positive. Of the 13 tumors that did not synthesize estrogens, 7 tumors were receptor negative and 6 tumors were receptor positive. No correlation was found between the ability of the tumor to synthesize estrogens and the presence or absence of estradiol receptors. The inhibition of aromatase enzyme in human breast tumors by delta 1-testololactone, testololactone, and 6 alpha- and 6 beta-bromoandrostenedione was investigated. Estrone and estradiol synthesis from androstenedione was reduced in five tumor incubations by the presence of 0.2 mM delta 1-testololactone and testololactone, 6 alpha- and 6 beta-bromoandrostenedione (2.0 microM) were also shown to block estrogen synthesis in 5 tumors. Furthermore, Lineweaver-Burk plots revealed that all four compounds were competitive inhibitors of androstenedione aromatization. An apparent Km of the aromatase enzyme for androstenedione of 0.08 microM and a Vmax of 23 pmol of estrone synthesized per g tumor per hr were determined for one human breast tumor specimen. The use of an aromatase inhibitor such as delta 1-testololactone in the treatment of breast cancer should be reconsidered. Data from one patient with advanced cancer of the breast, responding to previous oophorectomy and adrenalectomy and treated with large doses of delta 1-testololactone, are presented to illustrate the significance of successful treatment by scientific approaches.
Asunto(s)
Androstenodiona/análogos & derivados , Inhibidores de la Aromatasa , Neoplasias de la Mama/enzimología , Estrógenos/biosíntesis , Oxidorreductasas/antagonistas & inhibidores , Testolactona/análogos & derivados , Adrenalectomía , Androstenodiona/metabolismo , Androstenodiona/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/cirugía , Castración , Femenino , Humanos , Cinética , Recurrencia Local de Neoplasia , Receptores de Estrógenos/análisis , Testolactona/farmacologíaRESUMEN
To evaluate the in vivo effect of delta 1-testololactone on peripheral aromatization, studies were performed on seven postmenopausal women with metastatic breast cancer. Analysis of variance indicated that there were significant increases of circulating androstenedione (p less than 0.05) and estradiol (p less than 0.001) during administration of different doses of testololactone. Androstenedione levels were increased with all doses of testololactone tested (50, 100, 250, and 500 mg every 6 hr for 14 days each), while estradiol rose with only the 250- and 500-mg dosages. With administration, there was a significant decrease of estrone (p less than 0.001) with the mean level falling from 26 +/- 3 (S.E.) to 11 +/- 2 pg/ml. The addition of adrenal suppression (dexamethasone, 1 mg nightly at 11 p.m.) significantly lowered androstenedione (p less than 0.05) but had no effect on estrone or estradiol levels. Long-term therapy (up to 6 months) with the 250-mg dosage showed continual suppression of estrone with no escape being observed. Studies to determine the reason for the increase of estradiol with testololactone suggested cross-reactivity of the antibody with in vivo metabolites of the drug. However, these possible metabolites did not bind to uterine cytosol estrogen receptors. The decrease in estrone with testololactone administration presumably explains its antitumor properties.