RESUMO
MiR-200b, a member of the microRNA-200 family, has been identified to be capable of suppressing glioma cell growth through targeting CREB1 or CD133. However, whether miR-200b affects the biological behavior (proliferation, invasion, and migration) of glioma cells is poorly understood. The aim of this study was to evaluate the effect of miR-200b on the biological behavior of glioma cells in vitro. MiRNA-200b mimics, miRNA-200b inhibitor, and mimic control were transfected into conventionally cultured glioma U251 cells, followed by measuring the expression of miR-200b and CD133 in transfected cells by RT-PCR; effect of miR-200b on CD133 mRNA 3'-UTR luciferase activity by luciferase reporter assay; proliferation activity of transfected U251 cells by MTT method; and changes in U251 cell invasion and migration by Transwell method after transfection. Compared to that in the miRNA-200b inhibitor, mimic control, and blank control groups, miRNA-200b expression was significantly increased and CD133 mRNA expression was significantly decreased in the mimic miRNA-200b group in a time-dependent manner (P < 0.05). Meanwhile, dual luciferase reporter assay showed that miR-200b could inhibit CD133 activity through binding to the 3'-UTR of CD133 mRNA (P < 0.05). Furthermore, the proliferation activity and invasion and migration abilities of U251 cells transfected with miRNA-200b mimic were significantly decreased (P < 0.05). In conclusion, overexpression of miR-200b inhibited the proliferation, invasion, and migration of glioma cells possibly through targeting CD133.
Assuntos
Antígeno AC133/genética , Glioma/genética , MicroRNAs/genética , Regiões 3' não Traduzidas , Antígeno AC133/metabolismo , Apoptose/genética , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Glioma/metabolismo , Glioma/patologia , Humanos , MicroRNAs/biossíntese , MicroRNAs/metabolismo , Neoplasias do Sistema Nervoso/genética , Neoplasias do Sistema Nervoso/metabolismo , Neoplasias do Sistema Nervoso/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , TransfecçãoRESUMO
Polyunsaturated fatty acids (PUFAs) are known to inhibit cell proliferation of many tumour types both in vitro and in vivo. Their capacity to interfere with cell proliferation has been linked to their induction of reactive oxygen species (ROS) production in tumour tissues leading to cell death through apoptosis. However, the exact mechanisms of action of PUFAs are far from clear, particularly in brain tumours. The loss of bound hexokinase from the mitochondrial voltage-dependent anion channel has been directly related to loss of protection from apoptosis, and PUFAs can induce this loss of bound hexokinase in tumour cells. Tumour cells overexpressing Akt activity, including gliomas, are sensitised to ROS damage by the Akt protein and may be good targets for chemotherapeutic agents, which produce ROS, such as PUFAs. Cardiolipin peroxidation may be an initial event in the release of cytochrome c from the mitochondria, and enriching cardiolipin with PUFA acyl chains may lead to increased peroxidation and therefore an increase in apoptosis. A better understanding of the metabolism of fatty acids and eicosanoids in primary brain tumours such as gliomas and their influence on energy balance will be fundamental to the possible targeting of mitochondria in tumour treatment.
Assuntos
Metabolismo dos Lipídeos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Neoplasias do Sistema Nervoso/metabolismo , Neoplasias do Sistema Nervoso/patologia , Animais , Morte Celular , Proliferação de Células , Ácidos Graxos/metabolismo , Humanos , Mitocôndrias/ultraestruturaAssuntos
Biomarcadores Tumorais/metabolismo , Proteínas de Choque Térmico , Proteínas de Neoplasias/metabolismo , Neoplasias/metabolismo , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Neoplasias do Sistema Digestório/metabolismo , Intervalo Livre de Doença , Resistencia a Medicamentos Antineoplásicos , Neoplasias do Endométrio/metabolismo , Feminino , Proteínas de Choque Térmico HSP27 , Neoplasias Hematológicas/metabolismo , Humanos , Masculino , Chaperonas Moleculares , Neoplasias/terapia , Neoplasias do Sistema Nervoso/metabolismo , Neoplasias Ovarianas/metabolismo , Prognóstico , Neoplasias Urogenitais/metabolismo , Neoplasias do Colo do Útero/metabolismoRESUMO
A 31-year-old patient with a clinical picture of obstructive jaundice had surgical treatment, and a primary carcinoid of the ampulla of Vater (VA) was found. The tumor was studied with light microscopy, immunohistochemistry, and electron microscopy. The neoplasm had histopathologic and cytopathologic features similar to those encountered in typical neuroendocrine neoplasms. It is interesting that immunohistochemical techniques disclosed the presence of vasointestinal polypeptide, cholecystokinin, and bombesin; however, unlike most neuroendocrine neoplasms arising in VA, no somatostatin-immunoreactive cells were found.
Assuntos
Ampola Hepatopancreática , Neoplasias do Ducto Colédoco/metabolismo , Doenças do Sistema Endócrino/metabolismo , Neoplasias do Sistema Nervoso/metabolismo , Adulto , Bombesina/metabolismo , Colecistocinina/metabolismo , Neoplasias do Ducto Colédoco/patologia , Doenças do Sistema Endócrino/patologia , Humanos , Masculino , Microscopia Eletrônica , Neoplasias do Sistema Nervoso/patologia , Somatostatina/metabolismo , Peptídeo Intestinal Vasoativo/metabolismoRESUMO
A heterogeneous group of 159 tumours was studied for the presence of S-100 protein by the immunoperoxidase technique in order to determine whether this marker may be of value in facilitating immunocytochemical diagnosis. Among cases of melanocytic and pigmented lesions, S-100 was widely distributed and demonstrated the strongest degrees of reactivity. S-100 protein was identified in virtually all nerve sheath tumours such as schwannomas, neurofibromas, myxoid sheath nerve tumour and also in some tumours of controversial histogenesis such as granular cell tumours. The great majority of carcinomas did not express S-100, with only two cases of breast carcinoma displaying focal S-100 staining. In a miscellaneous group of tumours S-100 was demonstrated in chordomas, myoepitheliomas and Wilms' tumour with Schwann cell differentiation. Despite its presence in a wide array of cell types, S-100 protein continues to be an extremely useful marker especially for soft tissue and peripheral nervous system tumours.