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1.
Biol Trace Elem Res ; 202(4): 1612-1627, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37500819

RESUMO

Heavy metal toxicity is an exponentially growing health problem. In this study, we aimed to assess the protective properties of propolis and royal jelly against cadmium adverse effects. Thirty-two adult male rats were included in our study; kidney and liver functions, histopathological changes, and the level of oxidative stress were evaluated in rats exposed to a daily dose of 4.5 mg cadmium per kilogram of body weight for 1 month and those cotreated simultaneously with either propolis (50 mg/kg/day) or royal jelly (200 mg/kg/day) with cadmium compared to control animals. Cadmium-mediated hepatorenal toxicity was manifested as per the increased oxidative stress, function deterioration, and characteristic histopathological aberrations. The supplementation of royal jelly or propolis restores most of the affected parameters to a level similar to the control group. However, the parameters describing the grade of DNA damage and the interleukin-1ß expression in the liver, as well as the levels of malondialdehyde and metallothionein, were slightly elevated compared to controls, despite the regular use of royal jelly or propolis. It is worth noting that better results were found in the case of royal jelly compared to propolis administration. Most likely, the ability of both products to chelate cadmium and contribute in reducing oxidative stress is of great importance. However, further investigations are needed to complement the knowledge about the expected nutritional and medicinal values.


Assuntos
Intoxicação por Cádmio , Própole , Ratos , Masculino , Animais , Própole/farmacologia , Cádmio/toxicidade , Estresse Oxidativo , Intoxicação por Cádmio/tratamento farmacológico , Ácidos Graxos
2.
Tissue Cell ; 85: 102244, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37856936

RESUMO

OBJECTIVE: Herein, we compare the features of neoplastic cancer cells in invasive ductal carcinoma (IDC) grade II and III patients to their corresponding normal cells both in breast and axillary lymph node (ALN) tissues. METHODS: A retrospective cohort of 70 female breast cancer patients enrolled between 2018 and 2020 at Medical Research Institute, Alexandria University, Egypt, was analyzed for clinicopathological features presentation. Fresh tiny pieces of breast tissue and its associated ALN tissues were then processed to investigate the morphological appearance by scanning electron microscopy. Moreover, the histological architecture of tissue sections stained with hematoxylin and eosin was studied by light microscope, while the characterization of the ultrastructure features of breast and ALN tissues was analyzed by transmission electron microscopy. RESULTS: Clinicopathological presentation of patients revealed that the Egyptian female breast cancer population adhered to the global trends of breast cancer disease with elevated incidence rate among postmenopausal women (61.3%), high frequency of IDC (95.7%), and increased ALN metastasis (65.7%). The percentage of estrogen receptor alpha (ERα) and human epidermal growth factor receptor 2 (HER2) expression, as key indicators for carcinogenesis and disease progression was 87.1% and 55.8%, respectively. The present study points to the observed discrepancies among the investigated variables in the diagnostic separation between IDC grade II and grade III. Ductal epithelial cells organization, nuclei size and irregularity, chromatin amount and uniformity, mitochondrial abundance and dysfunction were differentially manifested in IDC grades. Moreover, aberrations in the cellular organelles like lysosomes, endoplasmic reticulum, and lipid droplets vary according to the grade of IDC and the aggressiveness of the invasive breast cancer. CONCLUSIONS: To sum up, this study emphasizes the importance of accurate specimen evaluation for treatment choice and decision.


Assuntos
Neoplasias da Mama , Carcinoma Ductal de Mama , Feminino , Humanos , Egito , Estudos Retrospectivos , Neoplasias da Mama/patologia , Linfonodos/metabolismo , Linfonodos/patologia
3.
Tissue Cell ; 82: 102101, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37141749

RESUMO

OBJECTIVE: Assessing the beneficial effects of silk sericin against hepatic injury induced by diethylnitrosamine (DEN). METHODS: Aiming at promoting sericin as a natural product able to counteract the hazards of toxic elements, HPLC profile was conducted on the extracted sericin sample versus the standard one to qualitatively identify it. Following sericin treatment on human HepG2 liver cancer cells, many parameters were analyzed in vitro including cell viability, cell cycle, and cell apoptosis. Hepatic pro-inflammatory cytokines as well as histopathological and ultrastructure changes were evaluated in vivo in the different experimental groups. RESULTS: Sericin exhibited a dose-dependent cytotoxic effect on HepG2 cells with an IC50 of 14.12 + 0.75 µg/mL. The hepatotoxicity of DEN was manifested in mice by increased pro-inflammatory markers (IL-2, IL-6, and TNF-α), decreased IL-10, liver structure deterioration, and characteristic histopathological and ultrastructure changes. Sericin administration reversed most of the observed alterations inflected by DEN. CONCLUSIONS: Our results substantiate the sericin's powerful apoptotic impact in vitro. In experimental mice, combination treatment using sericin together with melatonin appears to be more potent in mitigating the adverse effects of DEN. However, further investigations are needed to identify the underlying mechanism of action and complement the knowledge about the expected medicinal values of sericin.


Assuntos
Neoplasias Hepáticas , Sericinas , Camundongos , Humanos , Animais , Sericinas/farmacologia , Sericinas/química , Citocinas , Fator de Necrose Tumoral alfa , Seda
4.
Antioxidants (Basel) ; 12(3)2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36978901

RESUMO

In this study, we shed light for the first time on the usage of migratory locusts (Locusta migratoria) as an insect model to investigate the nanotoxicological influence of aluminum oxide (Al2O3) nanoparticles at low doses on testes, and evaluate the capacity of a whole-body extract of American cockroaches (Periplaneta americana) (PAE) to attenuate Al2O3 NPs-induced toxicity. Energy dispersive X-ray microanalyzer (EDX) analysis verified the bioaccumulation of Al in testicular tissues due to its liberation from Al2O3 NPs, implying their penetration into the blood-testis barrier. Remarkably, toxicity with Al engendered disorders of antioxidant and stress biomarkers associated with substantial DNA damage and cell apoptosis. Furthermore, histopathological and ultrastructural analyses manifested significant aberrations in the testicular tissues from the group exposed to Al2O3 NPs, indicating the overproduction of reactive oxygen species (ROS). Molecular docking analysis emphasized the antioxidant capacity of some compounds derived from PAE. Thus, pretreatment with PAE counteracted the detrimental effects of Al in the testes, revealing antioxidant properties and thwarting DNA impairment and cell apoptosis. Moreover, histological and ultrastructural examinations revealed no anomalies in the testes. Overall, these findings substantiate the potential applications of PAE in preventing the testicular impairment of L. migratoria and the conceivable utilization of locusts for nanotoxicology studies.

5.
Chem Biol Interact ; 367: 110166, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36087814

RESUMO

Silver nanoparticles (AgNPs) have long been materials of great interest in numerous fields; however, there is escalating alarm over their toxicity to public health since exposure to these particles is inevitable. This study sheds light on the deleterious impacts of AgNPs on the midgut tissues of beetles (Blaps polychresta) collected from Egypt as a biological model. The investigations were conducted on the beetles administered with a sublethal dose of AgNPs (0.03 mg/g body weight) after 30 days. Oxidative stress parameters and antioxidant enzyme activities were assessed, which exposed critical disruption in the antioxidant defense system of treated beetles. Remarkably, metallothionein (MT) gene expression was significantly increased, while reduced glutathione (GSH) level was notably decreased in midgut tissues subjected to AgNPs. These findings manifestly imply the presence of overproduction in terms of reactive oxygen species (ROS) inside the cells. Additionally, DNA impairment and apoptosis of midgut cells were appraised employing comet and flow cytometry analyses, respectively. The comet results revealed a significant increase in comet cells for the AgNPs treated beetles compared with the control group. Furthermore, the apoptosis results demonstrated a substantial diminution in viable cells with significant growth in apoptotic cells in midgut cells exposed to AgNPs, manifesting their striking correlation with comet and biochemical findings. Noticeably, the histopathological and ultrastructural inspections revealed substantial aberrations in the midgut tissues in the AgNPs treated group, substantiating the previous results. As far as we know, no research has been found that surveyed how the AgNPs at low doses affect the midgut tissues of beetles. Overall, these findings evince the aberrant influences of AgNPs on living organisms.


Assuntos
Besouros , Nanopartículas Metálicas , Animais , Antioxidantes/metabolismo , Besouros/metabolismo , Glutationa/metabolismo , Nanopartículas Metálicas/química , Nanopartículas Metálicas/toxicidade , Metalotioneína/genética , Metalotioneína/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Prata/química , Prata/toxicidade
6.
Sci Rep ; 12(1): 8358, 2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-35589839

RESUMO

Assessing the time of death based on the growth and development of insects is a critical task in forensic entomology. The rate of larvae development can be affected by a variety of toxins, including pesticides. Aluminum phosphide (AlP) is a low-cost insecticide that has yet to be tested for entomotoxicological significance, despite the fact that it is frequently the cause of fatal poisoning. In this study, we measured the body length of Chrysomya albiceps larvae reared on the carcasses of rabbits poisoned with AlP and analyzed the morphological changes of the larvae reared on the carcasses of rabbits poisoned with AlP. The concentration of AlP in the body of the larvae was significantly lower than in rabbit tissues. Insects from the AlP group had a significantly lower gain in body length. Furthermore, deformities in the larvae were found. Smaller respiratory spiracles were found, as well as a deformed small posterior end with hypogenesis of the posterior respiratory spiracles. Thus, disturbed growth and development of carrion flies found at a crime scene could indicate pesticide poisoning, such as aluminum phosphide.


Assuntos
Dípteros , Entomologia Forense , Compostos de Alumínio , Animais , Calliphoridae , Larva , Fosfinas , Coelhos
7.
Nutrients ; 15(1)2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36615776

RESUMO

Honeybee products arouse interest in society due to their natural origin and range of important biological properties. Propolis (P) and royal jelly (RJ) attract scientists' attention because they exhibit antioxidant, anti-inflammatory, anti-bacterial, anti-tumor, and immunomodulatory abilities. In this study, we tested whether P and RJ could mitigate the adverse effects of cadmium (Cd) exposure, with particular emphasis on the reproductive function in female rats. In this line, one week of pretreatment was established. Six experimental groups were created, including (i) the control group (without any supplementation), (ii) the Cd group (receiving CdCl2 in a dose of 4.5 mg/kg/day), (iii) the P group (50 mg of P/kg/day), (iv) RJ group (200 mg of RJ/kg/day), (v) P + Cd group (rats pretreated with P and then treated with P and Cd simultaneously), (vi) RJ + Cd group (animals pretreated with RJ before receiving CdCl2 simultaneously with RJ). Cd treatment of rats adversely affected a number of measured parameters, including body weight, ovarian structure and ultrastructure, oxidative stress parameters, increased ovarian Cd content and prolonged the estrous cycle. Pretreatment and then cotreatment with P or RJ and Cd alleviated the adverse effects of Cd, transferring the clusters in the PCA analysis chart toward the control group. However, clusters for cotreated groups were still distinctly separated from the control and P, or RJ alone treated groups. Most likely, investigated honeybee products can alter Cd absorption in the gut and/or increase its excretion through the kidneys and/or mitigate oxidative stress by various components. Undoubtedly, pretreatment with P or RJ can effectively prepare the organism to overcome harmful insults. Although the chemical composition of RJ and P is relatively well known, focusing on proportion, duration, and scheme of treatment, as well as the effects of particular components, may provide interesting data in the future. In the era of returning to natural products, both P and RJ seem valuable materials for further consideration as anti-infertility agents.


Assuntos
Cádmio , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Ratos , Abelhas , Feminino , Animais , Cádmio/toxicidade , Cromatografia Líquida , Espectrometria de Massas em Tandem , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Estresse Oxidativo , Ácidos Graxos/farmacologia
8.
Pharmacol Res ; 170: 105749, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34214630

RESUMO

This review summarizes the four processes of wound healing in the human body (hemostasis, inflammatory, proliferation, and remodeling) and the most current research on the most important factors affecting cutaneous wound healing and the underlying cellular and/or molecular pathways. Local factors, including temperature, oxygenation, and infection, and systemic factors, such as age, diabetes, sex hormones, genetic components, autoimmune diseases, psychological stress, smoking and obesity are also addressed. A better understanding of the role of these factors in wound repair could result in the development of therapeutics that promote wound healing and resolve affected wounds. Additionally, natural products obtained from plants and animals are critical targets for the discovery of novel biologically significant pharmacophores, such as medicines and agrochemicals. This review outlines the most recent advances in naturally derived targeted treatment for wound healing. These are plant-derived natural products, insect-derived natural products, marine-derived natural products, nanomaterial-based wound-healing therapeutics (metal- and non-metal-based nanoparticles), and natural product-based nanomedicine to improve the future direction of wound healing. Natural products extracted from plants and animals have advanced significantly, particularly in the treatment of wound healing. As a result, the isolation and extraction of bioactive compounds from a variety of sources can continue to advance our understanding of wound healing. Undescribed bioactive compounds or unexplored formulations that could have a role in today's medicinal arsenal may be contained in the abundance of natural products and natural product derivatives.


Assuntos
Organismos Aquáticos , Produtos Biológicos/uso terapêutico , Insetos , Preparações de Plantas/uso terapêutico , Pele/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Ferimentos e Lesões/tratamento farmacológico , Animais , Organismos Aquáticos/química , Produtos Biológicos/efeitos adversos , Produtos Biológicos/isolamento & purificação , Humanos , Insetos/química , Nanomedicina , Fitoterapia , Preparações de Plantas/efeitos adversos , Preparações de Plantas/isolamento & purificação , Pele/metabolismo , Pele/patologia , Ferimentos e Lesões/metabolismo , Ferimentos e Lesões/patologia
9.
EMBO J ; 40(3): e105784, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33411331

RESUMO

High-risk neuroblastoma (NB) is responsible for a disproportionate number of childhood deaths due to cancer. One indicator of high-risk NB is amplification of the neural MYC (MYCN) oncogene, which is currently therapeutically intractable. Identification of anaplastic lymphoma kinase (ALK) as an NB oncogene raised the possibility of using ALK tyrosine kinase inhibitors (TKIs) in treatment of patients with activating ALK mutations. 8-10% of primary NB patients are ALK-positive, a figure that increases in the relapsed population. ALK is activated by the ALKAL2 ligand located on chromosome 2p, along with ALK and MYCN, in the "2p-gain" region associated with NB. Dysregulation of ALK ligand in NB has not been addressed, although one of the first oncogenes described was v-sis that shares > 90% homology with PDGF. Therefore, we tested whether ALKAL2 ligand could potentiate NB progression in the absence of ALK mutation. We show that ALKAL2 overexpression in mice drives ALK TKI-sensitive NB in the absence of ALK mutation, suggesting that additional NB patients, such as those exhibiting 2p-gain, may benefit from ALK TKI-based therapeutic intervention.


Assuntos
Citocinas/genética , Citocinas/metabolismo , Proteína Proto-Oncogênica N-Myc/metabolismo , Neuroblastoma/patologia , Inibidores de Proteínas Quinases/farmacologia , Regulação para Cima , Quinase do Linfoma Anaplásico/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Mutação com Ganho de Função , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Camundongos , Proteína Proto-Oncogênica N-Myc/genética , Neuroblastoma/genética , Neuroblastoma/metabolismo , Análise de Sequência de RNA , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Vet Med Sci ; 7(2): 357-361, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32979302

RESUMO

This study describes a simple method for the large-scale isolation of pure Toxoplasma gondii tachyzoites and bradyzoites. T. gondii tachyzoites were obtained from infected human foreskin fibroblasts (HFFs) and peritoneal exudates of mice, while tissue cysts containing bradyzoites were collected from chronically infected mice. Harvested cells and brain tissues were incubated in Hanks balanced salt solution (HBSS), containing 0.25% trypsin and 0.5% taurodeoxycholic acid (TDC) for 5 min. Subsequent washes in phosphate buffered saline (PBS) were conducted, and the cell viability of the preparations was good, as determined by flow cytometry and ability to reinfect HFF cells and propagate in mice. The purification procedure allowed for a rapid preparation of pure T. gondii tachyzoites and bradyzoites in sufficient quantity that can be used for downstream procedures. The advantage of the new method is that it is convenient and inexpensive.


Assuntos
Parasitologia/métodos , Toxoplasma/isolamento & purificação , Medicina Veterinária/métodos , Animais , Humanos , Camundongos
11.
PLoS One ; 10(5): e0123542, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25955180

RESUMO

Mice lacking ALK activity have previously been reported to exhibit subtle behavioral phenotypes. In this study of ALK of loss of function mice we present data supporting a role for ALK in hypogonadotropic hypogonadism in male mice. We observed lower level of serum testosterone at P40 in ALK knock-out males, accompanied by mild disorganization of seminiferous tubules exhibiting decreased numbers of GATA4 expressing cells. These observations highlight a role for ALK in testis function and are further supported by experiments in which chemical inhibition of ALK activity with the ALK TKI crizotinib was employed. Oral administration of crizotinib resulted in a decrease of serum testosterone levels in adult wild type male mice, which reverted to normal levels after cessation of treatment. Analysis of GnRH expression in neurons of the hypothalamus revealed a significant decrease in the number of GnRH positive neurons in ALK knock-out mice at P40 when compared with control littermates. Thus, ALK appears to be involved in hypogonadotropic hypogonadism by regulating the timing of pubertal onset and testis function at the upper levels of the hypothalamic-pituitary gonadal axis.


Assuntos
Hipogonadismo/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Quinase do Linfoma Anaplásico , Animais , Técnicas de Inativação de Genes , Hormônio Liberador de Gonadotropina/sangue , Hormônio Liberador de Gonadotropina/metabolismo , Hipogonadismo/sangue , Hipogonadismo/genética , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores Proteína Tirosina Quinases/genética , Contagem de Espermatozoides , Espermatozoides/citologia , Espermatozoides/metabolismo , Testosterona/sangue , Testosterona/metabolismo
12.
Sci Signal ; 7(349): ra102, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-25351247

RESUMO

Anaplastic lymphoma kinase (ALK) is an important molecular target in neuroblastoma. Although tyrosine kinase inhibitors abrogating ALK activity are currently in clinical use for the treatment of ALK-positive (ALK(+)) disease, monotherapy with ALK tyrosine kinase inhibitors may not be an adequate solution for ALK(+) neuroblastoma patients. Increased expression of the gene encoding the transcription factor MYCN is common in neuroblastomas and correlates with poor prognosis. We found that the kinase ERK5 [also known as big mitogen-activated protein kinase (MAPK) 1 (BMK1)] is activated by ALK through a pathway mediated by phosphoinositide 3-kinase (PI3K), AKT, MAPK kinase kinase 3 (MEKK3), and MAPK kinase 5 (MEK5). ALK-induced transcription of MYCN and stimulation of cell proliferation required ERK5. Pharmacological or RNA interference-mediated inhibition of ERK5 suppressed the proliferation of neuroblastoma cells in culture and enhanced the antitumor efficacy of the ALK inhibitor crizotinib in both cells and xenograft models. Together, our results indicate that ERK5 mediates ALK-induced transcription of MYCN and proliferation of neuroblastoma, suggesting that targeting both ERK5 and ALK may be beneficial in neuroblastoma patients.


Assuntos
Regulação Neoplásica da Expressão Gênica/fisiologia , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Neuroblastoma/fisiopatologia , Proteínas Nucleares/metabolismo , Proteínas Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Quinase do Linfoma Anaplásico , Animais , Linhagem Celular Tumoral , Primers do DNA/genética , Imunofluorescência , Regulação Neoplásica da Expressão Gênica/genética , Proteínas de Fluorescência Verde , Humanos , Processamento de Imagem Assistida por Computador , Immunoblotting , Imuno-Histoquímica , Imunoprecipitação , Imageamento por Ressonância Magnética , Proteína Quinase 7 Ativada por Mitógeno/genética , Proteína Proto-Oncogênica N-Myc , Neuroblastoma/metabolismo , Células PC12 , Interferência de RNA , Ratos , Reação em Cadeia da Polimerase em Tempo Real
13.
Endocrinology ; 155(7): 2349-54, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24712878

RESUMO

SF-1 (NR5A1) overexpression can induce adrenocortical tumor formation in transgenic mice and is associated with more severe prognosis in patients with adrenocortical cancer. In this study we have identified Vanin-1 (Vnn1), a SF-1 target gene, as a novel modulator of the tumorigenic effect of Sf-1 overexpression in the adrenal cortex. Vanin-1 is endowed with pantetheinase activity, releasing cysteamine in tissues and regulating cell response to oxidative stress by modulating the production of glutathione. Sf-1 transgenic mice developed adrenocortical neoplastic lesions (both dysplastic and nodular) with a frequency increasing with age. Genetic ablation of the Vnn1 gene in Sf-1 transgenic mice significantly reduced the severity of neoplastic lesions in the adrenal cortex. This effect could be reversed by treatment of Sf-1 transgenic/Vnn1 null mice with cysteamine. These data show that alteration of the mechanisms controlling intracellular redox and detoxification mechanisms is relevant to the pathogenesis of adrenocortical neoplasia induced by SF-1 overexpression.


Assuntos
Neoplasias do Córtex Suprarrenal/metabolismo , Amidoidrolases/metabolismo , Transformação Celular Neoplásica/metabolismo , Fator Esteroidogênico 1/metabolismo , Córtex Suprarrenal/efeitos dos fármacos , Córtex Suprarrenal/metabolismo , Córtex Suprarrenal/patologia , Neoplasias do Córtex Suprarrenal/genética , Amidoidrolases/genética , Animais , Transformação Celular Neoplásica/genética , Cisteamina/metabolismo , Cisteamina/farmacologia , Progressão da Doença , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Glutationa/metabolismo , Hiperplasia , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Modelos Biológicos , Espécies Reativas de Oxigênio/metabolismo , Fator Esteroidogênico 1/genética , Fatores de Tempo
14.
Mol Cell Endocrinol ; 371(1-2): 154-9, 2013 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-23168267

RESUMO

Steroidogenic Factor-1 (SF-1) is a nuclear receptor transcription factor that has an essential role in the development of adrenal glands and gonads and in the regulation of steroidogenic gene expression. Recent studies using genomic approaches have revealed that SF-1 also has an important role in regulating proliferation of adrenocortical cells and have revealed its role in the control of a variety of biological processes as diverse as angiogenesis, adhesion to the extracellular matrix, cytoskeleton dynamics, transcriptional and post-transcriptional regulation of gene expression and apoptosis in the adrenal cortex. The identification of the complete set of SF-1 target genes will be of great importance to open new avenues for therapeutic intervention in adrenal diseases.


Assuntos
Córtex Suprarrenal/metabolismo , Gônadas/metabolismo , Fator Esteroidogênico 1/metabolismo , Neoplasias do Córtex Suprarrenal/genética , Apoptose/genética , Adesão Celular , Proliferação de Células , Matriz Extracelular/genética , Matriz Extracelular/metabolismo , Dosagem de Genes , Regulação da Expressão Gênica , Genômica , Humanos , MicroRNAs/genética , Neovascularização Fisiológica/genética , Fator Esteroidogênico 1/genética , Esteroides/biossíntese
15.
Mol Cell Endocrinol ; 336(1-2): 169-73, 2011 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-21094206

RESUMO

Adrenocortical tumors in children are usually diagnosed because of signs of virilization and their prognosis is poor. They possess several distinct pathological features compared to adrenocortical tumors in adults and have an exceptional prevalence in southern Brazil, where they are nearly invariably linked to the presence of a germline specific TP53 (R337H) mutation. Other important factors in childhood adrenocortical tumor pathogenesis are overexpression of the Steroidogenic Factor-1 transcription factor and imprinting defects in the 11p15 genomic region, causing overexpression of Insulin-like Growth Factor-2. Genomic studies have revealed the prognostic relevance of the expression of some Major Histocompatibility Complex genes and the deregulation of the Insulin-like Growth Factor/mammalian Target Of Rapamycin pathway by microRNAs in these tumors. Our hope is that these findings will constitute the basis for the development of novel therapies that will be more active against these tumors and less toxic for the patients.


Assuntos
Neoplasias do Córtex Suprarrenal/genética , Genômica , Criança , Cromossomos Humanos Par 11/genética , Perfilação da Expressão Gênica , Impressão Genômica/genética , Humanos , Transdução de Sinais/genética , Somatomedinas/genética , Somatomedinas/metabolismo , Fator Esteroidogênico 1/genética , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Proteína Supressora de Tumor p53/genética
16.
Mol Cell Endocrinol ; 332(1-2): 32-7, 2011 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-21094679

RESUMO

Signaling by the Wnt family of secreted glycolipoproteins plays key roles in embryonic development of organisms ranging from nematodes to mammals and is also implicated in several types of human cancers. Canonical Wnt signaling functions by regulating the translocation of ß-catenin to the nucleus, where it controls key gene expression programs through interaction with Tcf/Lef and other families of transcription factors. Wnts can also act through non-canonical pathways that do not involve ß-catenin activation, but implicate small GTPases/JNK kinase and intracellular calcium. Here we review recent studies that have revealed the expression of several components of Wnt/ß-catenin signaling in the adrenal cortex and discovered a key role for this pathway in the regulation of proliferation/differentiation of progenitor cells and in tumorigenesis of that endocrine organ.


Assuntos
Transdução de Sinais/fisiologia , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Córtex Suprarrenal/citologia , Córtex Suprarrenal/metabolismo , Neoplasias das Glândulas Suprarrenais/metabolismo , Neoplasias das Glândulas Suprarrenais/patologia , Animais , Diferenciação Celular , Proliferação de Células , Humanos , Células-Tronco/citologia , Células-Tronco/fisiologia , Fator Esteroidogênico 1/metabolismo
17.
Cancer Res ; 70(11): 4666-75, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20484036

RESUMO

MicroRNAs (miRNAs) act at the posttranscriptional level to control gene expression in virtually every biological process, including oncogenesis. Here, we report the identification of a set of miRNAs that are differentially regulated in childhood adrenocortical tumors (ACT), including miR-99a and miR-100. Functional analysis of these miRNAs in ACT cell lines showed that they coordinately regulate expression of the insulin-like growth factor-mammalian target of rapamycin (mTOR)-raptor signaling pathway through binding sites in their 3'-untranslated regions. In these cells, the active Ser(2448)-phosphorylated form of mTOR is present only in mitotic cells in association with the mitotic spindle and midbody in the G(2)-M phases of the cell cycle. Pharmacologic inhibition of mTOR signaling by everolimus greatly reduces tumor cell growth in vitro and in vivo. Our results reveal a novel mechanism of regulation of mTOR signaling by miRNAs, and they lay the groundwork for clinical evaluation of drugs inhibiting the mTOR pathway for treatment of adrenocortical cancer.


Assuntos
Neoplasias do Córtex Suprarrenal/metabolismo , Adenoma Adrenocortical/metabolismo , Carcinoma Adrenocortical/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , MicroRNAs/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Somatomedinas/metabolismo , Neoplasias do Córtex Suprarrenal/genética , Neoplasias do Córtex Suprarrenal/patologia , Adenoma Adrenocortical/genética , Adenoma Adrenocortical/patologia , Carcinoma Adrenocortical/genética , Carcinoma Adrenocortical/patologia , Animais , Processos de Crescimento Celular/fisiologia , Everolimo , Feminino , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , MicroRNAs/genética , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Sirolimo/análogos & derivados , Sirolimo/farmacologia , Serina-Treonina Quinases TOR , Transplante Heterólogo
18.
Development ; 133(11): 2155-65, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16672344

RESUMO

Postmitotic neurons are produced from a pool of cycling progenitors in an orderly fashion that requires proper spatial and temporal coordination of proliferation, fate determination, differentiation and morphogenesis. This probably relies on complex interplay between mechanisms that control cell cycle, specification and differentiation. In this respect, we have studied the possible implication of GATA2, a transcription factor that is involved in several neuronal specification pathways, in the control of the proliferation of neural progenitors in the embryonic spinal cord. Using gain- and loss-of-function manipulations, we have shown that Gata2 can drive neural progenitors out of the cycle and, to some extent, into differentiation. This correlates with the control of cyclin D1 transcription and of the expression of the p27/Kip1 protein. Interestingly, this functional aspect is not only associated with silencing of the Notch pathway but also appears to be independent of proneural function. Consistently, GATA2 also controls the proliferation capacity of mouse embryonic neuroepithelial cells in culture. Indeed, Gata2 inactivation enhances the proliferation rate in these cells. By contrast, GATA2 overexpression is sufficient to force such cells and neuroblastoma cells to stop dividing but not to drive either type of cell into differentiation. Furthermore, a non-cell autonomous effect of Gata2 expression was observed in vivo as well as in vitro. Hence, our data have provided evidence for the ability of Gata2 to inhibit the proliferation of neural progenitors, and they further suggest that, in this regard, Gata2 can operate independently of neuronal differentiation.


Assuntos
Fator de Transcrição GATA2/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Células-Tronco/citologia , Células-Tronco/metabolismo , Animais , Animais Recém-Nascidos , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Embrião de Galinha , Ciclina D1/metabolismo , Ciclina D2 , Ciclinas/metabolismo , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Fator de Transcrição GATA2/deficiência , Fator de Transcrição GATA2/genética , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores Notch/metabolismo , Transdução de Sinais
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