RESUMEN
A novel SERM (selective estrogen receptor modulators), 1-(R), a chromene-derived bisbenzopyran, was discovered to alleviate hot flushes and effectively increase vaginal fluidity in rats. Moreover, 1-(R) was found to have beneficial effects on plasma cholesterol and bone metabolism while maintaining antiestrogenic activity in the uterus. The biological profile of its enantiomer 1-(S) was also evaluated.
Asunto(s)
Benzopiranos/síntesis química , Líquidos Corporales/efectos de los fármacos , Sofocos/tratamiento farmacológico , Moduladores Selectivos de los Receptores de Estrógeno/síntesis química , Vagina/efectos de los fármacos , Enfermedades Vaginales/tratamiento farmacológico , Animales , Benzopiranos/química , Benzopiranos/farmacología , Densidad Ósea/efectos de los fármacos , Línea Celular , Colesterol/sangre , Femenino , Humanos , Tamaño de los Órganos/efectos de los fármacos , Ovariectomía , Ratas , Moduladores Selectivos de los Receptores de Estrógeno/química , Moduladores Selectivos de los Receptores de Estrógeno/farmacología , Estereoisomerismo , Útero/efectos de los fármacos , Vagina/metabolismoRESUMEN
Deleted in malignant brain tumors 1 (DMBT1) is a candidate suppressor of malignancies of the brain, lung, gut, and breast. We have been studying gene expression in the uterus in the presence of estrogens and their antagonists. Here, we show that DMBT1 RNA levels are robustly increased by estrogen treatment in the uteri of ovariectomized monkeys and rats. In monkeys, the progestin antagonist mifepristone inhibits estrogen-dependent uterine proliferation. As determined by a microarray experiment and quantitative analysis of RNA levels, mifepristone inhibited estrogenic induction of DMBT1. DMBT1 was not expressed in intact monkeys that were treated with a gonadotropin agonist to suppress steroidogenesis. An in vitro transfection study with human DMBT1 promoter constructs showed that an Alu site approximately 3000 nucleotides upstream of the gene mediates estrogenic regulation. Surprisingly, the estrogen antagonists tamoxifen, raloxifene, and ICI 182,780 also induced gene expression via this Alu site. Rodents represent a more convenient model system for studying uterine biology than monkeys. In rats, uterine DMBT1 RNA levels were dramatically up-regulated by estrogen. Consistent with the transfection study, tamoxifen and raloxifene increased DMBT1 RNA levels in vivo, but ICI 182,780 inhibited an estrogen-induced increase. Immunohistochemical studies showed that DMBT1 is specifically induced in glandular and luminal epithelia of the rat endometrium. Our experiments establish that DMBT1 is an estrogen-responsive gene with a possible role in endometrial proliferation or differentiation, and they have implications for the putative tumor suppressive and mucosal protective functions of DMBT1 in the uterus.
Asunto(s)
Aglutininas/fisiología , Endometrio/metabolismo , Epitelio/metabolismo , Estradiol/análogos & derivados , Estrógenos/metabolismo , Regulación de la Expresión Génica , Mucinas/fisiología , Receptores de Superficie Celular/fisiología , Elementos Alu , Animales , Northern Blotting , Proteínas de Unión al Calcio , Diferenciación Celular , Línea Celular , Proteínas de Unión al ADN , Relación Dosis-Respuesta a Droga , Estradiol/farmacología , Antagonistas de Estrógenos/farmacología , Femenino , Fulvestrant , Haplorrinos , Humanos , Inmunohistoquímica , Luciferasas/metabolismo , Mucinas/biosíntesis , Membrana Mucosa/patología , Análisis de Secuencia por Matrices de Oligonucleótidos , Plásmidos/metabolismo , Reacción en Cadena de la Polimerasa , Regiones Promotoras Genéticas , ARN/química , ARN/metabolismo , Clorhidrato de Raloxifeno/farmacología , Ratas , Ratas Sprague-Dawley , Tamoxifeno/farmacología , Transfección , Proteínas Supresoras de Tumor , Regulación hacia Arriba , Útero/metabolismoRESUMEN
As part of a program aimed at the development of selective estrogen receptor modulators (SERMs), novel chromene scaffolds, benzopyranobenzoxapanes, were discovered. Many compounds showed binding affinity as low as 1.6-200 nM, displayed antagonist behaviors in the MCF-7 human breast adenocarcinoma cell line as well in Ishikawa cell line with IC(50) values in the range 0.2-360 nM. On the basis of the side chain substitution, various compounds demonstrated strong inhibitory activity in anti-uterotropic assay. Compound 7-(R) and its major metabolites 5-(R) and 6-(R) were evaluated in several in vivo models of estrogen action. Relative to a full estrogen agonist (ethynyl estradiol) and the SERM raloxifene, 7-(R) was found to be a potent SERM that behaved as antagonist in the uterus and exhibited estrogen agonistic activity on bone, plasma lipids, hot flush, and vagina. The overall pharmacokinetic profile and stability were significantly improved compared to those of the phase 2 development compound 9-(R).