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Autism Spectrum Disorder (ASD) is characterized by differences in social communication and interaction, as well as areas of focused interests and/or repetitive behaviors. Recent studies have highlighted a higher prevalence of endocrine and reproductive disturbances among females on the autism spectrum, hinting at potential disruptions within the hypothalamus-pituitary-ovary (HPO) axis. This research aims to explore the reproductive health disparities in ASD using an animal model of autism, the C58/J inbred mouse strain, with a focus on reproductive performance and hormonal profiles compared to the C57BL/6J control strain. Our findings revealed that the estrous cycle in C58/J females is disrupted, as evidenced by a lower frequency of complete cycles and a lack of cyclical release of estradiol and progesterone compared to control mice. C58/J females also exhibited poor performance in several reproductive parameters, including reproductive lifespan and fertility index. Furthermore, estrogen receptor alpha content showed a marked decrease in the hypothalamus of C58/J mice. These alterations in the estrous cycle, hormonal imbalances, and reduced reproductive function imply dysregulation in the HPO axis. Additionally, our in-silico study identified a group of genes involved in infertility carrying single-nucleotide polymorphisms (SNPs) in the C58/J strain, which also have human orthologs associated with autism. These findings could offer valuable insights into the molecular underpinnings of neuroendocrine axis disruption and reproductive issues observed in ASD.
Assuntos
Modelos Animais de Doenças , Hipotálamo , Camundongos Endogâmicos C57BL , Animais , Feminino , Camundongos , Hipotálamo/metabolismo , Ciclo Estral/fisiologia , Saúde Reprodutiva , Transtorno Autístico/metabolismo , Transtorno Autístico/genética , Transtorno do Espectro Autista/metabolismo , Transtorno do Espectro Autista/genética , Reprodução/fisiologia , Reprodução/genética , Progesterona/sangue , Progesterona/metabolismo , Estradiol/sangue , Estradiol/metabolismo , Masculino , Hormônios Esteroides Gonadais/metabolismo , Hormônios Esteroides Gonadais/sangueRESUMO
BACKGROUND: Ulipristal acetate (UPA) and levonorgestrel are used as emergency hormonal contraceptives. Although both are highly effective in preventing pregnancy, UPA shows efficacy even when taken up to 120 h after unprotected sexual intercourse. AIMS: To investigate whether the mechanism of UPA's contraceptive action involves post-fertilization effects. METHODS: In vitro and in vivo studies using cultured human endometrial cells and a pre-clinical rat model. RESULTS: Endometrial cells treated with UPA showed changes in the expression of receptivity gene markers and a significant decrease in trophoblast spheroids attached to the cultured cells. In addition, administration of UPA to female unmated rats decreased the expression of implantation-related genes in the endometrium and inhibited the number of implantation sites in the mated group compared to the non-treated group. CONCLUSIONS: These results support that UPA as an emergency contraceptive might have post-fertilization effects that may affect embryo implantation.
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HER2-positive breast cancer is associated with aggressive behavior and reduced survival rates. Calcitriol restores the antiproliferative activity of antiestrogens in estrogen receptor (ER)-negative breast cancer cells by re-expressing ERα. Furthermore, calcitriol and its analog, EB1089, enhance responses to standard anti-cancer drugs. Therefore, we aimed to investigate EB1089 effects when added to the combined treatment of lapatinib and antiestrogens on the proliferation of HER2-positive breast cancer cells. BT-474 (ER-positive/HER2-positive) and SK-BR-3 (ER-negative/HER2-positive) cells were pre-treated with EB1089 to modulate ER expression. Then, cells were treated with EB1089 in the presence of lapatinib with or without the antiestrogens, and proliferation, phosphorylation array assays, and Western blot analysis were performed. The results showed that EB1089 restored the antiproliferative response to antiestrogens in SK-BR-3 cells and improved the inhibitory effects of the combination of lapatinib with antiestrogens in the two cell lines. Moreover, EB1089, alone or combined, modulated ERα protein expression and reduced Akt phosphorylation in HER2-positive cells. EB1089 significantly enhanced the cell growth inhibitory effect of lapatinib combined with antiestrogens in HER2-positive breast cancer cells by modulating ERα expression and Akt phosphorylation suppression. These results highlight the potential of this therapeutic approach as a promising strategy for managing HER2-positive breast cancer.
Assuntos
Neoplasias da Mama , Calcitriol/análogos & derivados , Humanos , Feminino , Lapatinib/farmacologia , Lapatinib/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Calcitriol/farmacologia , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Moduladores de Receptor Estrogênico/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor ErbB-2/metabolismo , Antagonistas de Estrogênios/uso terapêutico , Linhagem Celular TumoralRESUMO
Breast cancer is the most prevalent neoplasia among women worldwide. For the estrogen receptor-positive (ER+) phenotype, tamoxifen is the standard hormonal therapy; however, it carries the risk of promoting endometrial carcinoma. Hence, we aimed to evaluate the antiproliferative effect of the phytochemical α-mangostin (AM) as a co-adjuvant alongside tamoxifen on breast cancer cells to improve its efficacy while reducing its adverse effects on endometrium. For this, ER+ breast cancer cells (MCF-7 and T-47D) and endometrial cells (N30) were treated with AM, 4-hydroxytamoxifen (4-OH-TMX), and their combination. Cell proliferation was evaluated using sulforhodamine B assay, and the pharmacological interaction was determined through the combination index and the dose reduction index calculation. The genes KCNH1, CCDN1, MKI67, and BIRC5 were amplified by real-time PCR as indicators of oncogenesis, cell cycle progression, cell proliferation, and apoptosis, respectively. Additionally, genes involved in ER signaling were analyzed. In breast cancer cells, the combination of AM with 4-OH-TMX showed a synergistic antiproliferative effect and favorable dose reduction. AM and 4-OH-TMX decreased KCNH1, CCND1, and BIRC5 gene expression. In endometrial cells, AM decreased MKI-67 gene expression, while it reverted the 4-OH-TMX-dependent CCND1 upregulation. This study establishes the benefits of incorporating AM as a co-adjuvant for first-line ER+ breast cancer therapy.
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Medulloblastoma (MB) is the most common and aggressive pediatric intracranial tumor. Estrogen receptor ß (ERß) expression correlates with MB development and its phosphorylation modifies its transcriptional activity in a ligand-dependent or independent manner. Using in silico tools, we have identified several residues in ERß protein as potential targets of protein kinases C (PKCs) α and δ. Using Daoy cells, we observed that PKCα and PKCδ associate with ERß and induce its phosphorylation. The activation of ERß promotes MB cells proliferation and invasion, and PKCs downregulation dysregulates these steroid receptor mediated processes. Our data suggest that these kinases may play a crucial role in the regulation of the ERß transcriptional activity. Overexpression of both PKCα and PKCδ in MB biopsies samples supports their relevance in MB progression.
Assuntos
Neoplasias Cerebelares , Receptor beta de Estrogênio , Meduloblastoma , Proteína Quinase C-alfa/metabolismo , Proteína Quinase C-delta/metabolismo , Proteína Quinase C , Linhagem Celular Tumoral , Proliferação de Células , Criança , Receptor alfa de Estrogênio , Receptor beta de Estrogênio/genética , Receptor beta de Estrogênio/metabolismo , Humanos , Meduloblastoma/genética , Meduloblastoma/metabolismoRESUMO
PURPOSE: Histone deacetylases (HDACs) play a vital role in the epigenetic regulation of gene expression due to their overexpression in several cancer forms. Therefore, these enzymes are considered as a potential anticancer drug target. Different synthetic and natural structures have been studied as HDACs inhibitors; based on available structural design information, the capping group is important for the biological activity due to the different interactions in the active site entrance. The present study aimed to analyze high substituted pyridine as a capping group, which included carrying out the synthesis, antiproliferative activity analysis, and docking studies of these novel compounds. METHODS: To achieve the synthesis of these derivatives, four reaction steps were performed, generating desired products 15a-k. Their effects on cell proliferation and gene expression of p21, cyclin D1, and p53 were determined using the sulphorhodamine B (SRB) method and quantitative real-time polymerase chain reaction. The HDAC1, HDAC6, and HDAC8 isoforms were used for performing docking experiments with our 15a-k products. RESULT: The products 15a-k were obtained in overall yields of 40-71%. Compounds 15j and 15k showed the highest antiproliferative activity in the breast (BT-474 and MDA-MB-231) and prostate (PC3) cancer cell lines at a concentration of 10 µM. These compounds increased p21 mRNA levels and decreased cyclin D1 and p53 gene expression. The docking study showed an increment in the strength, and in the number of interactions performed by the capping moiety of the tested molecules compared with SAHA; interactions displayed are mainly van der Waals, π-stacking, and hydrogen bond. CONCLUSION: The synthesized compounds 2-thiophene (15j) and 2-furan (15k) pyridine displayed cell growth inhibition, regulation of genes related to cell cycle progression in highly metastatic cancer cell lines. The molecular coupling analysis performed with HDAC1, HDAC6 and HDAC8 showed an increment in the number of interactions performed by the capping moiety and consequently in the strength of the capping group interaction.
Assuntos
Neoplasias da Mama/genética , Ciclina D1/genética , Inibidor de Quinase Dependente de Ciclina p21/genética , Furanos/síntese química , Inibidores de Histona Desacetilases/síntese química , Neoplasias da Próstata/genética , Piridinas/química , Tiofenos/síntese química , Proteína Supressora de Tumor p53/genética , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Epigênese Genética/efeitos dos fármacos , Feminino , Furanos/química , Furanos/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/farmacologia , Humanos , Masculino , Simulação de Acoplamento Molecular , Células PC-3 , Gravidez , Neoplasias da Próstata/tratamento farmacológico , Tiofenos/química , Tiofenos/farmacologiaRESUMO
Patients with estrogen receptor (ER) α-negative breast tumors have a poor prognosis and are not suitable for hormone therapy. Previously, we demonstrated that calcitriol, the active metabolite of vitamin D, induces ERα expression and re-establishes the response to antiestrogens in ER-negative breast cancer cells. However, the mechanisms involved in this process have not been elucidated. Therefore, the present study was undertaken to investigate the mechanisms implicated in the calcitriol-induced ERα expression in ER-negative breast cancer cells. Using EMSA and ChIP assays, we found that the calcitriol/vitamin D receptor (VDR)/retinoic X receptor (RXR) complex binds to putative vitamin D response elements (VDREs) in the ERα gene promoter region. In addition, we established by a fluorometric assay that calcitriol decreased DNA-methyltransferase and histone deacetylase activities. Flow cytometry and qPCR analyses showed that co-treatment of calcitriol with inhibitors of the histone deacetylase and DNA methyltransferase, and genistein significantly increased ERα expression, compared to that observed with the compounds alone. In conclusion, the calcitriol-dependent ERα induction in ER-negative breast cancer cells results from binding of the VDR-RXR complex to VDREs in the ERα gene promoter region, including the downregulation of enzymes with chromatin-remodeling activities. These results may bring forth novel mechanistic knowledge into the actions of calcitriol in ERα-negative breast cancer.
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Coumarin-hydroxamic acid derivatives 7a-k were herein designed with a dual purpose: as antiproliferative agents and fluorescent probes. The compounds were synthesized in moderate yields (30-87%) through a simple methodology, biological evaluation was carried out on prostate (PC3) and breast cancer (BT-474 and MDA-MB-231) cell lines to determine the effects on cell proliferation and gene expression. For compounds 7c, 7e, 7f, 7i and 7j the inhibition of cancer cell proliferation was similar to that found with the reference compound at a comparable concentration (10 µM), in addition, their molecular docking studies performed on histone deacetylases 1, 6 and 8 showed strong binding to the respective active sites. In most cases, antiproliferative activity was accompanied by greater levels of cyclin-dependent kinase inhibitor p21, downregulation of the p53 tumor suppressor gene, and regulation of cyclin D1 gene expression. We conclude that compounds 7c, 7e, 7f, 7i and 7j may be considered as potential anticancer agents, considering their antiproliferative properties, their effect on the regulation of the genes, as well as their capacity to dock to the active sites. The fluorescent properties of compound 7j and 7k suggest that they can provide further insight into the mechanism of action.
Assuntos
Neoplasias da Mama , Proliferação de Células/efeitos dos fármacos , Cumarínicos , Corantes Fluorescentes , Inibidores de Histona Desacetilases , Ácidos Hidroxâmicos , Simulação de Acoplamento Molecular , Neoplasias da Próstata , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Cumarínicos/síntese química , Cumarínicos/química , Cumarínicos/farmacologia , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Corantes Fluorescentes/química , Corantes Fluorescentes/farmacologia , Inibidores de Histona Desacetilases/síntese química , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/farmacologia , Humanos , Ácidos Hidroxâmicos/química , Ácidos Hidroxâmicos/farmacologia , Masculino , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/metabolismo , Células PC-3 , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Relação Estrutura-AtividadeRESUMO
Calcitriol is a multitarget anticancer hormone; however, its effects on angiogenesis remain contradictory. Herein, we tested whether the antiangiogenic phytochemicals curcumin or resveratrol improved calcitriol antitumorigenic effects in vivo. Triple-negative breast cancer tumoral cells (MBCDF-T) were xenografted in nude mice, maintaining treatments for 3 weeks. Tumor onset, volume and microvessel density were significantly reduced in mice coadministered with calcitriol and curcumin (Cal+Cur). Vessel count was also reduced in mice simultaneously treated with calcitriol and resveratrol (Cal+Rsv). Cal+Cur and Cal+Rsv treatments resulted in less tumor activated endothelium, as demonstrated by decreased tumor uptake of integrin-targeted biosensors in vivo. The renal gene expression of Cyp24a1 and Cyp27b1 suggested increased calcitriol bioactivity in the combined regimens. In vitro, the phytochemicals inhibited both MBCDF-T and endothelial cells proliferation, while potentiated calcitriol's ability to reduce MBCDF-T cell-growth and endothelial cells migration. Resveratrol induced endothelial cell death, as deduced by increased sub-G1 cells accumulation, explaining the reduced tumor vessel number in resveratrol-treated mice, which further diminished when combined with calcitriol. In conclusion, the concomitant administration of calcitriol with curcumin or resveratrol synergistically promoted anticancer effects in vitro and in vivo in human mammary tumor cells. Whereas the results suggest different mechanisms of action of the phytochemicals when coadministered with calcitriol, the converging biological effect was inhibition of tumor neoangiogenesis.
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BACKGROUND: Expression and activity of the potassium channel ether-à-go-go-1 (EAG1) are strongly related to carcinogenesis and tumor progression, which can be exploited for therapeutic purposes. EAG1 activity may be reduced by preventing its phosphorylation with epidermal growth factor receptor (EGFR) kinase inhibitors and by astemizole, which blocks the channel pore and downregulates its gene expression. OBJECTIVE: We aimed to study the potential cooperative antiproliferative effect of the EGFR inhibitor gefitinib and the EAG1-blocker astemizole, in breast cancer cells. MATERIALS AND METHODS: The cells were characterized by immunocytochemistry. Inhibitory concentrations were determined by non-linear regression analysis using dose-response curves. The nature of the pharmacological effect was evaluated by the combination index equation while cell cycle analysis was studied by flow cy-tometry. RESULTS: Astemizole and gefitinib inhibited cell proliferation in a concentration-dependent manner, with inhibitory concentrations (IC 50) values of 1.72 µM and 0.51 µM, respectively. All combinations resulted in a synergistic antiproliferative effect. The combination of astemizole and gefitinib diminished the percentage of cells in G2/M and S phases, while increased accumulation in G0/G1 of the cell cycle. CONCLUSIONS: Astemizole and gefitinib synergistically inhibited proliferation in breast cancer cells expressing both EGFR and EAG1. Our results suggest that the combined treatment increased cell death by targeting the oncogenic activity of EAG1.
Assuntos
Antineoplásicos/farmacologia , Astemizol/farmacologia , Neoplasias da Mama/tratamento farmacológico , Gefitinibe/farmacologia , Antineoplásicos/administração & dosagem , Astemizol/administração & dosagem , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Canais de Potássio Éter-A-Go-Go/genética , Feminino , Gefitinibe/administração & dosagem , Regulação Neoplásica da Expressão Gênica , Humanos , Concentração Inibidora 50 , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologiaRESUMO
Abstract Background Expression and activity of the potassium channel ether-à-go-go-1 (EAG1) are strongly related to carcinogenesis and tumor progression, which can be exploited for therapeutic purposes. EAG1 activity may be reduced by preventing its phosphorylation with epidermal growth factor receptor (EGFR) kinase inhibitors and by astemizole, which blocks the channel pore and downregulates its gene expression. Objective We aimed to study the potential cooperative antiproliferative effect of the EGFR inhibitor gefitinib and the EAG1-blocker astemizole, in breast cancer cells. Materials and Methods The cells were characterized by immunocytochemistry. Inhibitory concentrations were determined by non-linear regression analysis using dose-response curves. The nature of the pharmacological effect was evaluated by the combination index equation while cell cycle analysis was studied by flow cytometry. Results Astemizole and gefitinib inhibited cell proliferation in a concentration-dependent manner, with inhibitory concentrations (IC 50) values of 1.72 µM and 0.51 µM, respectively. All combinations resulted in a synergistic antiproliferative effect. The combination of astemizole and gefitinib diminished the percentage of cells in G2/M and S phases, while increased accumulation in G0/G1 of the cell cycle. Conclusions Astemizole and gefitinib synergistically inhibited proliferation in breast cancer cells expressing both EGFR and EAG1. Our results suggest that the combined treatment increased cell death by targeting the oncogenic activity of EAG1.
Assuntos
Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Astemizol/farmacologia , Gefitinibe/farmacologia , Antineoplásicos/farmacologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica , Astemizol/administração & dosagem , Concentração Inibidora 50 , Linhagem Celular Tumoral , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/farmacologia , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Canais de Potássio Éter-A-Go-Go/genética , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Gefitinibe/administração & dosagem , Antineoplásicos/administração & dosagemRESUMO
Factors affecting vitamin D metabolism may preclude anti-carcinogenic effects of its active metabolite calcitriol. Chronic ethanol consumption is an etiological factor for breast cancer that affects vitamin D metabolism; however, the mechanisms underlying this causal association have not been fully clarified. Using a murine model, we examined the effects of chronic moderate ethanol intake on tumoral and renal CYP27B1 and CYP24A1 gene expression, the enzymes involved in calcitriol synthesis and inactivation, respectively. Ethanol (5% w/v) was administered to 25-hydroxyvitamin D3-treated or control mice during one month. Afterwards, human breast cancer cells were xenografted and treatments continued another month. Ethanol intake decreased renal Cyp27b1 while increased tumoral CYP24A1 gene expression.Treatment with 25-hydroxyvitamin D3 significantly stimulated CYP27B1 in tumors of non-alcohol-drinking mice, while increased both renal and tumoral CYP24A1. Coadministration of ethanol and 25-hydroxyvitamin D3 reduced in 60% renal 25-hydroxyvitamin D3-dependent Cyp24a1 upregulation (P<0.05). We found 5 folds higher basal Cyp27b1 than Cyp24a1 gene expression in kidneys, whereas this relation was inverted in tumors, showing 5 folds more CYP24A1 than CYP27B1. Tumor expression of the calcitriol target cathelicidin increased only in 25-hydroxyvitamin D3-treated non-ethanol drinking animals (P<0.05). Mean final body weight was higher in 25-hydroxyvitamin D3 treated groups (P<0.001). Overall, these results suggest that moderate ethanol intake decreases renal and tumoral 25-hydroxyvitamin D3 bioconversion into calcitriol, while favors degradation of both vitamin D metabolites in breast cancer cells. The latter may partially explain why alcohol consumption is associated with vitamin D deficiency and increased breast cancer risk and progression.
Assuntos
25-Hidroxivitamina D3 1-alfa-Hidroxilase/genética , Consumo de Bebidas Alcoólicas/genética , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Etanol/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Vitamina D3 24-Hidroxilase/genética , Consumo de Bebidas Alcoólicas/metabolismo , Animais , Neoplasias da Mama/complicações , Calcifediol/farmacologia , Calcitriol/metabolismo , Etanol/metabolismo , Feminino , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Rim/efeitos dos fármacos , Rim/metabolismo , Camundongos , Camundongos Nus , Vitaminas/farmacologiaRESUMO
Pregnane derivatives are studied as agents for the treatment of different hormone-dependent diseases. The biological importance of these steroids is based on their potential use against cancer. In this study, we report the synthesis, characterization and biological activity of two pregnane derivatives with a triazole (3ß-hydroxy-21-(1H-1,2,4-triazol-1-yl)pregna-5,16-dien-20-one; T-OH) or imidazole (3ß-hydroxy-21-(1H-imidazol-1-yl)pregna-5,16-dien-20-one; I-OH) moieties at C-21. These derivatives were synthesized from 16-dehydropregnenolone acetate. The activity on cell proliferation of the compounds was measured on three human cancer cells lines: prostate cancer (PC-3), breast cancer (MCF7) and lung cancer (SK-LU-1). The cytotoxic and antiproliferative effects of T-OH and I-OH were assessed by using SBR and XTT methods, respectively. The gene expressions were evaluated by real time PCR. In addition, results were complemented by docking studies and transactivation assays using an expression vector to progesterone and androgen receptor. Results show that the two compounds inhibited the three cell lines proliferation in a dose-dependent manner. Compound I-OH downregulated the gene expression of the cyclins D1 and E1 in PC-3 and MFC7 cells; however, effect upon Ki-67, EAG1, BIM or survivin genes was not observed. Docking studies show poor interaction with the steroid receptors. Nevertheless, the transactivation assays show a weak antagonist effect of I-OH on progesterone receptor but not androgenic or antiandrogenic actions. In conclusion, the synthesized compounds inhibited cell proliferation as well as genes key to cell cycle of PC-3 and MCF7 cell lines. Therefore, these compounds could be considered a good starting point for the development of novel therapeutic alternatives to treat cancer.
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Antineoplásicos/síntese química , Imidazóis/síntese química , Pregnadienos/síntese química , Triazóis/síntese química , Antineoplásicos/farmacologia , Apoptose , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Imidazóis/farmacologia , Concentração Inibidora 50 , Simulação de Acoplamento Molecular , Pregnadienos/farmacologia , Triazóis/farmacologia , Vitamina D3 24-Hidroxilase/metabolismoRESUMO
About 90% of insulinomas are benign and 5%-15% are malignant. Benign insulinomas express the glucagon-like peptide-1 receptor (GLP-1R) and low levels of somatostatin receptors (SSTR), while malignant insulinomas over-express SSTR or GLP-1R in low levels. A kit for the preparation of Lys(27)((99m)Tc-EDDA/HYNIC)-Exendin(9-39)/(99m)Tc-EDDA/HYNIC-Tyr(3)Octreotide was formulated to detect 100% of insulinomas. The formulation showed radiochemical purity of 97±1%, high stability in human serum, and GLP-1R and SSTR affinity. The biodistribution and imaging studies demonstrated properties suitable for its use as a target-specific agent for the simultaneous molecular imaging of GRP-1R- and/or SSTR-positive tumors.
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Ácido Edético/análogos & derivados , Insulinoma/diagnóstico por imagem , Compostos de Organotecnécio/química , Compostos de Organotecnécio/farmacocinética , Neoplasias Pancreáticas/diagnóstico por imagem , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/farmacocinética , Animais , Ácido Edético/química , Liofilização , Humanos , Insulinoma/patologia , Masculino , Camundongos , Camundongos Nus , Neoplasias Pancreáticas/patologia , Radioquímica , Cintilografia , Ratos , Distribuição Tecidual , Células Tumorais CultivadasRESUMO
C6 rat glioma cells are one of the most aggressive carcinogenic tumors, due to its high mortality rate in human beings and animals. The current treatment for this illness includes surgery, radio and chemotherapy, showing relapse in patients treated with those therapies. Since the ozone was found to be an effective bioreactive to inhibit growth of several carcinoma cells in vitro and in vivo. In this research, therapeutic peritoneum insufflation of ozone/oxygen dissolved in the physiological solution of NaCl 0.9% was dosed for fifteen days on different female mice groups in an advanced stage of C6 tumor (n=6). The first of them was the control group which had no treatment, the second group was dosage with oxygen every second day, the third group was dosed with ozone every second day, and finally the fourth group was dosed with ozone dissolved every fifth day. The size of the tumor was higher in both groups dosage by ozone, nevertheless tumor activity measured by microPET was 98% less in the fourth group compared with the control group. That result proves that ozone provokes an increase in the tumor volume even though the decrease of the cell activity. Those results were confirmed by the quantification of hydroperoxides, total cholesterol and total triglycerides.
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Neoplasias Encefálicas/patologia , Glioma/patologia , Ozônio/farmacologia , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Técnicas In Vitro , Masculino , Camundongos , Camundongos Nus , RatosRESUMO
17ß-amino-1,3,5(10)estratrien-3-ol (17ßAE2), is the 17ß-aminoestrogens prototype possessing anticoagulant activity, contrasting with the procoagulant effects of 17ß-estradiol (17ßE2). Its estrogenicity profile has not been reported, and it was evaluated by uterotrophic assay, estrogen receptor binding affinity and its ability to induce gene transcription of the human estrogen receptor (hER)α mediated in a Saccharomyces cerevisiae yeast expression system. Additionally, 17ßAE2 and 17αAE2 were compared with 17ßE2 in HeLa cells co-transfected with expression vectors for hERα or hERß subtypes and for an estrogen-responsive reporter gene. Immature female CD1 mice and Wistar rats (21 days old) were treated for three days with 17ßAE2 (10-5000 µg/kg), 17ßE2 (0.001-1000 µg/kg) or vehicle (propylenglycol 10 ml/kg) and uterine weights were estimated. 17ßAE2 increased uterine weight in a dose-dependent manner. The effective dose (ED)50 uterine weight values: 17ßAE2=552 and 764 µg/kg (17ßE2=4.8 and 16 µg/kg) and their relative uterotrophic potency were 0.86 and 2.1 (17ßE2=100) in mice and rats, respectively. 17ßAE2 competed with [(3)H]E2 for the estrogen receptor. The 17ßAE2 relative binding affinities (RBAs) were: 0.074; Ki=2.2×10(-6)M (17ßE2=100; Ki=1.6×10(-9)M); 0.029 and Ki=3.8×10(-6)M (17ßE2=100; Ki=1.1×10(-9)M) for mice and rats uteri respectively. 17ßAE2 activated hERα-mediated ß-galactosidase transcription activity in the yeast system co-transfected with hERα gene. 17ßAE2 effective concentration (EC)50=1.82 µM (17ßE2=2.14 nM) with a relative potency of 0.12 (17ßE2=100). These transactivation effects were abolished by the antagonist fulvestrant (ICI 182,780), similarly to 17ßE2. 17ßAE2 and 17αAE2 bind with low relative affinity to hERα and hERß. Both induced hER-mediated reporter gene transactivation in a dose-response manner. The overall results provide evidence that 17ßAE2 has a weak agonist estrogenic action greatly mediated through the hERß and to a lesser extent the hERα at genomic level.
Assuntos
Anticoagulantes/farmacologia , Estradiol/análogos & derivados , Estrogênios/farmacologia , Receptores de Estrogênio/metabolismo , Ativação Transcricional/efeitos dos fármacos , Útero/efeitos dos fármacos , Animais , Estradiol/farmacologia , Feminino , Células HeLa , Humanos , Camundongos , Ratos , Ratos Wistar , Receptores de Estrogênio/genética , Elementos de Resposta/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genéticaRESUMO
BACKGROUND: The oncogenic ether-à-go-go-1 potassium channel (EAG1) activity and expression are necessary for cell cycle progression and tumorigenesis. The active vitamin D metabolite, calcitriol, and astemizole, a promising antineoplastic drug, target EAG1 by inhibiting its expression and blocking ion currents, respectively. We have previously shown a synergistic antiproliferative effect of calcitriol and astemizole in breast cancer cells in vitro, but the effect of this dual therapy in vivo has not been studied. METHODS: In the present study, we explored the combined antineoplastic effect of both drugs in vivo using mice xenografted with the human breast cancer cell line T-47D and a primary breast cancer-derived cell culture (MBCDF). Tumor-bearing athymic female mice were treated with oral astemizole (50 mg/kg/day) and/or intraperitoneal injections of calcitriol (0.03 µg/g body weight twice a week) during 3 weeks. Tumor sizes were measured thrice weekly. For mechanistic insights, we studied EAG1 expression by qPCR and Western blot. The expression of Ki-67 and the relative tumor volume were used as indicators of therapeutic efficacy. RESULTS: Compared to untreated controls, astemizole and calcitriol significantly reduced, while the coadministration of both drugs further suppressed, tumor growth (P < 0.05). In addition, the combined therapy significantly downregulated tumoral EAG1 and Ki-67 expression. CONCLUSIONS: The concomitant administration of calcitriol and astemizole inhibited tumor growth more efficiently than each drug alone, which may be explained by the blocking of EAG1. These results provide the bases for further studies aimed at testing EAG1-dual targeting in breast cancer tumors expressing both EAG1 and the vitamin D receptor.
Assuntos
Antineoplásicos/administração & dosagem , Astemizol/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Calcitriol/administração & dosagem , Canais de Potássio Éter-A-Go-Go/antagonistas & inibidores , Animais , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica , Astemizol/uso terapêutico , Calcitriol/uso terapêutico , Linhagem Celular Tumoral , Sinergismo Farmacológico , Canais de Potássio Éter-A-Go-Go/genética , Canais de Potássio Éter-A-Go-Go/metabolismo , Feminino , Humanos , Camundongos , Camundongos Nus , Transplante de NeoplasiasRESUMO
The sodium-coupled neutral amino acid transporter 2 (SNAT2) translocates small neutral amino acids into the mammary gland to promote cell proliferation during gestation. It is known that SNAT2 expression increases during pregnancy, and in vitro studies indicate that this transporter is induced by 17ß-estradiol. In this study, we elucidated the mechanism by which 17ß-estradiol regulates the transcription of SNAT2. In silico analysis revealed the presence of a potential estrogen response element (ERE) in the SNAT2 promoter. Reporter assays showed an increase in SNAT2 promoter activity when cotransfected with estrogen receptor alpha (ER-α) after 17ß-estradiol stimulation. Deletion of the ERE reduced estradiol-induced promoter activity by 63%. Additionally, EMSAs and supershift assays showed that ER-α binds to the SNAT2 ERE and that this binding competes with the interaction of ER-α with its consensus ERE. An in vivo ChIP assay demonstrated that the binding of ER-α to the SNAT2 promoter gradually increased in the mammary gland during gestation and that maximal binding occurred at the highest 17ß-estradiol serum concentration. Liquid chromatography-elevated energy mass spectrometry and Western blot analysis revealed that the SNAT2 ER-α-ERE complex contained poly(ADP-ribose) polymerase 1, Lupus Ku autoantigen protein p70, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) proteins and that the silencing of each of these proteins nearly abolished 17ß-estradiol-stimulated SNAT2 promoter activity. Nuclear levels of GAPDH increased progressively during gestation in the mammary gland, and GAPDH binding was nucleotide-specific for the SNAT2 ERE. Thus, this study provides new insights into how the mammary epithelium adapts to control amino acid uptake through the transcriptional regulation of the SNAT2 transporter via 17ß-estradiol.
Assuntos
Sistemas de Transporte de Aminoácidos/genética , Estradiol/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Transcrição Gênica/efeitos dos fármacos , Sistema A de Transporte de Aminoácidos , Sistemas de Transporte de Aminoácidos/metabolismo , Animais , Antígenos Nucleares/metabolismo , Sequência de Bases , Núcleo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Epitélio/metabolismo , Receptor alfa de Estrogênio/metabolismo , Feminino , Gliceraldeído-3-Fosfato Desidrogenases/metabolismo , Células HeLa , Humanos , Autoantígeno Ku , Glândulas Mamárias Animais/metabolismo , Dados de Sequência Molecular , Fragmentos de Peptídeos/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Gravidez , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Ratos , Elementos de Resposta/genéticaRESUMO
BACKGROUND: Approximately 30% of breast tumors do not express the estrogen receptor (ER) α, which is necessary for endocrine therapy approaches. Studies are ongoing in order to restore ERα expression in ERα-negative breast cancer. The aim of the present study was to determine if calcitriol induces ERα expression in ER-negative breast cancer cells, thus restoring antiestrogen responses. METHODS: Cultured cells derived from ERα-negative breast tumors and an ERα-negative breast cancer cell line (SUM-229PE) were treated with calcitriol and ERα expression was assessed by real time PCR and western blots. The ERα functionality was evaluated by prolactin gene expression analysis. In addition, the effects of antiestrogens were assessed by growth assay using the XTT method. Gene expression of cyclin D1 (CCND1), and Ether-à-go-go 1 (EAG1) was also evaluated in cells treated with calcitriol alone or in combination with estradiol or ICI-182,780. Statistical analyses were determined by one-way ANOVA. RESULTS: Calcitriol was able to induce the expression of a functional ERα in ER-negative breast cancer cells. This effect was mediated through the vitamin D receptor (VDR), since it was abrogated by a VDR antagonist. Interestingly, the calcitriol-induced ERα restored the response to antiestrogens by inhibiting cell proliferation. In addition, calcitriol-treated cells in the presence of ICI-182,780 resulted in a significant reduction of two important cell proliferation regulators CCND1 and EAG1. CONCLUSIONS: Calcitriol induced the expression of ERα and restored the response to antiestrogens in ERα-negative breast cancer cells. The combined treatment with calcitriol and antiestrogens could represent a new therapeutic strategy in ERα-negative breast cancer patients.
Assuntos
Neoplasias da Mama/patologia , Calcitriol/farmacologia , Moduladores de Receptor Estrogênico/farmacologia , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Neoplasias da Mama/tratamento farmacológico , Calcitriol/análogos & derivados , Linhagem Celular Tumoral , Ciclina D1/metabolismo , Estradiol/análogos & derivados , Estradiol/farmacologia , Feminino , Fulvestranto , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Receptores de Calcitriol/metabolismoRESUMO
Calcitriol, a potent antineoplastic vitamin D metabolite, inhibits proliferation, induces apoptosis and slows the growth of tumors. Calcitriol also may exert either antiangiogenic or proangiogenic effects depending on the tissue. Vascular endothelial growth factor (VEGF) and thrombospondin-1 (Tsp-1) are key factors involved in promoting and inhibiting angiogenesis, respectively. The effects of calcitriol on Tsp-1 have not been studied in the mammary gland, while VEGF regulation is not clear, since opposite outcomes have been demonstrated. Therefore, the present study was undertaken to investigate the effects of calcitriol on VEGF and Tsp-1 expression in primary breast tumor-derived cells and a panel of established breast cancer cell lines. In vivo studies in athymic mice were also performed in order to gain further insight into the biological effects of calcitriol on angiogenesis. Real time-PCR and ELISA analyses showed that calcitriol stimulated VEGF mRNA expression and protein secretion while elicited the opposite effect on Tsp-1 in 7 out of 8 cell lines studied, independently of the cell phenotype (P<0.05 in n=5). In vivo, calcitriol significantly inhibited the relative tumoral volume after 4 weeks of treatment; however, serum VEGF was higher in calcitriol-treated animals compared to controls (P<0.05). The integrated fluorescence intensity analysis of CD31, a vessel marker, showed that xenografted breast cancer cells developed tumors with similar vascular density regardless of the treatment. Nevertheless, larger necrotic areas were observed in the tumors of calcitriol-treated mice compared to controls. Since the antineoplastic activity of calcitriol has been consistently demonstrated in several studies including this one, our results suggest that the antitumoral effect of calcitriol in vivo involve different mechanisms not necessarily related to the inhibition of tumor vascularization. Overall, our findings indicate that calcitriol can impact the angiogenic process in breast cancer by regulating VEGF and Tsp-1 expression. This article is part of a Special Issue entitled '16th Vitamin D Workshop'.