RESUMO
The G-protein-coupled receptor for estrogen (GPER1) is a transmembrane receptor involved in the progression and development of various neoplasms whose ligand is estradiol (E2). 17ß-aminoestrogens (17ß-AEs) compounds, analogs to E2, are possible candidates for use in hormone replacement therapy (HRT), but our knowledge of their pharmacological profile is limited. Thus, we explored the molecular recognition of GPER1 with different synthetic 17ß-AEs: prolame, butolame, and pentolame. We compared the structure and ligand recognition sites previously reported for a specific agonist (G1), antagonists (G15 and G36), and the natural ligand (E2). Then, the biological effects of 17ß-AEs were analyzed through cell viability and cell-cycle assays in two types of female cancer. In addition, the effect of 17ß-AEs on the phosphorylation of the oncoprotein c-fos was evaluated, because this molecule is modulated by GPER1. Molecular docking analysis showed that 17ß-AEs interacted with GPER1, suggesting that prolame joins GPER1 in a hydrophobic cavity, similarly to G1, G15, and E2. Prolame induced cell proliferation in breast (MCF-7) and cervical cancer (SIHA) cells; meanwhile, butolame and pentolame did not affect cell proliferation. Neither 17ß-AEs nor E2 changed the activation of c-fos in MCF-7 cells. Meanwhile, in SIHA cells, E2 and 17ß-AEs reduced c-fos phosphorylation. Thus, our data suggest that butolame and pentolame, but not prolame, could be used for HRT without presenting a potential risk of inducing breast- or cervical-cancer-cell proliferation. The novelty of this work lies in its study of compound analogs to E2 that may represent important therapeutic strategies for women in menopause, with non-significant effects on the cell viability of cancer cells. The research focused on the interactions of GPER1, a molecule recently associated with promoting and maintaining various neoplasms.
Assuntos
Neoplasias da Mama , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Amino Álcoois , Neoplasias da Mama/tratamento farmacológico , Proliferação de Células , Estradiol/farmacologia , Estrenos , Estrogênios/farmacologia , Feminino , Humanos , Ligantes , Simulação de Acoplamento Molecular , Proteínas Oncogênicas/farmacologiaRESUMO
Glioblastoma (GB) is the most frequent primary brain tumor with a very poor prognosis. Sex hormones are crucial players in the development of GBs. 17 ß-estradiol (E2) signaling is involved through its corresponding intracellular receptors [estrogen receptor α (ERα) and ß (ERß)] in GB cell proliferation and progression. E2 activates G-protein coupled estrogen receptor (GPER), leading to rapidly occurring effects, independently of gene transcription. GPER activation is involved in tumor progression in various cancer types. Currently, available data concerning the occurrence and role of GPER in GB are very limited. In the present study, it was observed that GPER was expressed in human brain tumor cell lines [U251 (astrocytoma-derived cell line), U87, LN229 and T98 (glioblastoma-derived cell line)]. Immunofluorescence assays revealed that GPER localizes in the plasma membrane, cytoplasm and nucleus. An in silico analysis identified two potential E2 response elements in the promoter region of the GPER gene. E2 increased GPER expression in the U251, U87 and LN229 cell lines. Molecular modeling data derived from in silico analysis predicted the three-dimensional conformation of GPER, and docking analysis identified potential binding sites of E2 and its specific agonist, G1. Taken together, these results indicate that GPER may be differentially expressed in human GB cell lines with E2 possibly upregulating GPER expression. The present study raises further questions about the implications of GPER-mediated E2 signaling in the biology of GBs.
RESUMO
Glioblastoma is the most frequent primary tumor in the human brain. Glioblastoma cells express aromatase and the classic estrogen receptors ERα and ERß and can produce estrogens that promote tumor growth. The membrane G protein-coupled estrogen receptor (GPER) also plays a significant role in numerous types of cancer; its participation in glioblastoma tumor development is not entirely known. The present study investigated the effect of the agonists [17ß-estradiol (E2) and G1] and antagonist (G15) of GPER on proliferation and apoptosis of C6 glioblastoma cells. GPER expression was evaluated by immunofluorescence, western blotting and reverse transcription-quantitative PCR. Cell proliferation was determined using Ki67 immunopositivity. Cell viability was examined using the MTT assay and apoptosis using caspase-3 immunostaining and ELISA. C6 cells express GPER, and the immunopositivity increased after exposure to E2, G1, or their combination. GPER protein expression increased after treatment with E2 combined with G1. However, GPER mRNA expression decreased in treated cells compared with control. The percentage of Ki67 immunopositive C6 cells increased under the effect of E2 in combination with G1 or G1 alone. G15 significantly reduced Ki67 immunopositivity. Pearson's correlation analysis revealed a positive relationship between GPER and Ki67 immunopositivity across the study conditions. Additionally, the MTT assay showed a significant reduction in C6 cell viability after G15 treatment, alone or in combination with G1. The exposure to G15 increased the percentage of caspase-3 immunopositivity cells and caspase-3 levels. Pearson's correlation analysis demonstrated a negative correlation between GPER and caspase-3 immunopositivity across the study conditions. Glioblastoma C6 cells express GPER, and this receptor modulates cell proliferation and apoptosis. The GPER agonists E2 and G1 favored cell proliferation; meanwhile, the antagonist G15 reduced cell proliferation, viability and favored apoptosis. Therefore, GPER may be used as a biomarker of glioblastoma and as a target to develop new therapeutic strategies for glioblastoma treatment.
RESUMO
Cancer is a major public health issue and represents the second leading cause of death in women worldwide, as female reproductive-related neoplasms are the main cause of incidence and mortality. Female reproductive cancers have a close relationship to estrogens, the principal female sex steroid hormones. Estrogens exert their actions by the nuclear estrogen receptor alpha (ERα) and estrogen receptor beta (ERß). ERα, and ERß act as transcription factors mediating genomic effects. Besides, the G protein-coupled estrogen receptor (GPER, formerly known as GPR30) was recently described as a seven-transmembrane receptor that mediates non-genomic estrogenic signaling, including calcium mobilization, cAMP synthesis, cleavage of matrix metalloproteinases, transactivation of epidermal growth factor receptor (EGFR), and the subsequent activation of PI3K and MAPK signaling pathways, which are the reasons why it is related to cellular processes, such as cell-cycle progression, cellular proliferation, differentiation, apoptosis, migration, and invasion. Since its discovery, selective agonists and antagonists have been found and developed. GPER has been implicated in a variety of hormone-responsiveness tumors, such as breast, endometrial, ovarian, cervical, prostate, and testicular cancer as well as lung, hepatic, thyroid, colorectal, and adrenocortical cancers. Nevertheless, GPER actions in cancer are still debatable due to the conflicting information that has been reported to date, since many reports indicate that activation of this receptor can modulate carcinogenesis. In contrast, many others show that its activation inhibits tumor activity. Besides, estrogens play an essential role in the regulation of the immune system, but little information exists about the role of GPER activation on its modulation within cancer context. This review focuses on the role that the stimulation of GPER plays in female reproductive neoplasms, specifically breast, endometrial, ovarian, and cervical cancers, in its tumor activity and immune response regulation.
Assuntos
Neoplasias dos Genitais Femininos/imunologia , Neoplasias dos Genitais Femininos/patologia , Receptores de Estrogênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Feminino , Neoplasias dos Genitais Femininos/metabolismo , HumanosRESUMO
BACKGROUND: Schizophrenia (SCZ) is a neurodevelopmental disorder influenced by patient sex. Mechanisms underlying sex differences in SCZ remain unknown. A two-hit model of SCZ combines the exposure to perinatal infection (first-hit) with peripubertal unpredictable stress (PUS, second-hit). N-acetylcysteine (NAC) has been tested in SCZ because of the involvement of glutathione mechanisms in its neurobiology. AIMS: We aim to investigate whether NAC administration to peripubertal rats of both sexes could prevent behavioral and neurochemical changes induced by the two-hit model. METHODS: Wistar rats were exposed to polyinosinic:polycytidylic acid (a viral mimetic) or saline on postnatal days (PND) 5-7. On PND30-59 they received saline or NAC 220 mg/kg and between PND40-48 were subjected to PUS or left undisturbed. On PND60 behavioral and oxidative alterations were evaluated in the prefrontal cortex (PFC) and striatum. Mechanisms of hippocampal memory regulation such as immune expression of G protein-coupled estrogen receptor 1 (GPER), α7-nAChR and parvalbumin were also evaluated. RESULTS: NAC prevented sensorimotor gating deficits only in females, while it prevented alterations in social interaction, working memory and locomotor activity in both sexes. Again, in rats of both sexes, NAC prevented the following neurochemical alterations: glutathione (GSH) and nitrite levels in the PFC and lipid peroxidation in the PFC and striatum. Striatal oxidative alterations in GSH and nitrite were observed in females and prevented by NAC. Two-hit induced hippocampal alterations in females, namely expression of GPER-1, α7-nAChR and parvalbumin, were prevented by NAC. CONCLUSION: Our results highlights the influences of sex in NAC preventive effects in rats exposed to a two-hit schizophrenia model.
Assuntos
Acetilcisteína/farmacologia , Esquizofrenia/prevenção & controle , Caracteres Sexuais , Fatores Etários , Animais , Corpo Estriado/metabolismo , Feminino , Glutationa/metabolismo , Hipocampo/metabolismo , Peroxidação de Lipídeos , Locomoção/efeitos dos fármacos , Masculino , Memória de Curto Prazo/efeitos dos fármacos , Nitritos/metabolismo , Parvalbuminas/biossíntese , Poli I-C , Córtex Pré-Frontal/metabolismo , Ratos , Receptores Acoplados a Proteínas G/biossíntese , Esquizofrenia/induzido quimicamente , Esquizofrenia/complicações , Filtro Sensorial/efeitos dos fármacos , Interação Social/efeitos dos fármacos , Estresse Psicológico/complicações , Receptor Nicotínico de Acetilcolina alfa7/biossínteseRESUMO
Aldosterone is the most known mineralocorticoid hormone synthesized by the adrenal cortex. The genomic pathway displayed by aldosterone is attributed to the mineralocorticoid receptor (MR) signaling. Even though the rapid effects displayed by aldosterone are long known, our knowledge regarding the receptor responsible for such event is still poor. It is intense that the debate whether the MR or another receptor-the "unknown receptor"-is the receptor responsible for the rapid effects of aldosterone. Recently, G protein-coupled estrogen receptor-1 (GPER-1) was elegantly shown to mediate some aldosterone-induced rapid effects in several tissues, a fact that strongly places GPER-1 as the unknown receptor. It has also been suggested that angiotensin receptor type 1 (AT1) also participates in the aldosterone-induced rapid effects. Despite this open question, the relevance of the beneficial effects of aldosterone is clear in the kidneys, colon, and CNS as aldosterone controls the important water reabsorption process; on the other hand, detrimental effects displayed by aldosterone have been reported in the cardiovascular system and in the kidneys. In this line, the MR antagonists are well-known drugs that display beneficial effects in patients with heart failure and hypertension; it has been proposed that MR antagonists could also play an important role in vascular disease, obesity, obesity-related hypertension, and metabolic syndrome. Taken altogether, our goal here was to (1) bring a historical perspective of both genomic and rapid effects of aldosterone in several tissues, and the receptors and signaling pathways involved in such processes; and (2) critically address the controversial points within the literature as regarding which receptor participates in the rapid pathway display by aldosterone.