RESUMO
BACKGROUND: The phosphatidylinositol 3'-kinase (PI3K)-AKT pathway is activated in many human cancers and plays a key role in cell proliferation and survival. A mutation (E17K) in the pleckstrin homology domain of the AKT1 results in constitutive AKT1 activation by means of localisation to the plasma membrane. The AKT1 (E17K) mutation has been reported in some tumour types (breast, colorectal, ovarian and lung cancers), and it is of interest which tumour types other than those possess the E17K mutation. METHODS: We analysed the presence of the AKT1 (E17K) mutation in 89 endometrial cancer tissue specimens and in 12 endometrial cancer cell lines by PCR and direct sequencing. RESULTS: We detected two AKT1 (E17K) mutations in the tissue samples (2 out of 89) and no mutations in the cell lines. These two AKT1 mutant tumours do not possess any mutations in PIK3CA, PTEN and K-Ras. INTERPRETATION: Our results and earlier reports suggest that AKT1 mutations might be mutually exclusive with other PI3K-AKT-activating alterations, although PIK3CA mutations frequently coexist with other alterations (such as HER2, K-Ras and PTEN) in several types of tumours.
Assuntos
Proteínas Sanguíneas/genética , Neoplasias do Endométrio/genética , Mutação de Sentido Incorreto , Fosfoproteínas/genética , Proteínas Proto-Oncogênicas c-akt/genética , Linhagem Celular Tumoral , Metilação de DNA , Neoplasias do Endométrio/enzimologia , Feminino , Humanos , PTEN Fosfo-Hidrolase/biossíntese , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Polimorfismo de Nucleotídeo Único , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-akt/metabolismoAssuntos
Autoanticorpos/imunologia , Doenças Autoimunes/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Proteinose Alveolar Pulmonar/imunologia , Autoanticorpos/sangue , Doenças Autoimunes/sangue , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/imunologia , Ensaios Clínicos Fase II como Assunto , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Humanos , Pulmão/efeitos dos fármacos , Pulmão/fisiopatologia , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/imunologia , Estudos Multicêntricos como Assunto , Oxigênio/sangue , Proteinose Alveolar Pulmonar/sangue , Proteinose Alveolar Pulmonar/fisiopatologia , Estudos RetrospectivosRESUMO
Two cases of undifferentiated tumours were found in cows. Electron microscopy revealed that one was an undifferentiated squamous cell carcinoma of unknown primary site and the other an undifferentiated adenocarcinoma of the lung.
Assuntos
Adenocarcinoma/veterinária , Carcinoma de Células Escamosas/veterinária , Doenças dos Bovinos/patologia , Neoplasias Pulmonares/veterinária , Adenocarcinoma/diagnóstico , Adenocarcinoma/ultraestrutura , Animais , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/ultraestrutura , Bovinos , Doenças dos Bovinos/diagnóstico , Feminino , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/ultraestrutura , Microscopia EletrônicaRESUMO
The DNA mismatch repair gene is a key regulator in the elimination of base-base mismatches and insertion/deletion loops (IDLs). Human MutS homologue 2 (hMSH2), originally identified as a human homologue of the bacterial MutS, is a tumour suppressor gene frequently mutated in hereditary non-polyposis colorectal cancer. Hereditary non-polyposis colorectal cancer is characterised by the early onset of colorectal cancer and the development of extracolonic cancers such as endometrial, ovarian, and urological cancers. Oestrogen receptor (ER) alpha and beta are members of a nuclear receptor (NR) superfamily. Ligand-dependent transcription of ER is regulated by the p160 steroid receptor coactivator family, the thyroid hormone receptor-associated proteins/the vitamin D receptor-interacting proteins (TRAP/DRIP) mediator complex, and the TATA box-binding protein (TBP)-free TBP associated factor complex (TFTC) type histone acetyltransferase complex. Here, we report the interaction between ER alpha/beta and hMSH2. Immunoprecipitation and glutathione-S-transferase pull-down assay revealed that ER alpha and hMSH2 interacted in a ligand-dependent manner, whereas ER beta and hMSH2 interacted in a ligand-independent manner. Oestrogen receptor alpha/beta bound to hMSH2 through the hMSH3/hMSH6 interaction domain of hMSH2. In a transient expression assay, hMSH2 potentiated the transactivation function of liganded ER alpha, but not that of ER beta. These results suggest that hMSH2 may play an important role as a putative coactivator in ER alpha dependent gene expression.
Assuntos
Pareamento Incorreto de Bases/genética , Reparo do DNA/genética , Proteínas de Ligação a DNA/genética , Receptor alfa de Estrogênio/genética , Proteínas Proto-Oncogênicas/genética , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Mapeamento Cromossômico , Neoplasias do Endométrio/genética , Receptor beta de Estrogênio/genética , Feminino , Expressão Gênica , Genes Supressores de Tumor , Humanos , Proteína 2 Homóloga a MutS , Ativação TranscricionalRESUMO
Freezing patterns and post-thaw survival of cells varies with different cooling rates. The optimal cooling rates, indicating the highest percentage survival, were different in yeast and red blood cells. A difference of freezing patterns was also noticed in preparations frozen above and below the optimal cooling rate for each cell, namely, cell shrinkage at lower rates and intracellular ice formation at higher rates which showed similar trends in both the cells, even though there was some shifting of the optimum. Ultra-rapid freezing and addition of cryoprotectants are useful ways to minimize ice crystal formation and to cause such ice formations to approach the vitreous state. Ice crystals are hardly detectable in yeast cells as well as in erythrocytes, when these cells are frozen ultra-rapidly in the presence of cryoprotective agents in moderate concentration.
Assuntos
Eritrócitos/ultraestrutura , Congelamento , Saccharomyces cerevisiae/ultraestrutura , Sobrevivência Celular/efeitos dos fármacos , Crioprotetores , Eritrócitos/fisiologia , Glicerol/farmacologia , Hemólise/efeitos dos fármacos , Humanos , Saccharomyces cerevisiae/fisiologiaRESUMO
Over the past few decades, numerous studies have been done on the freeze-drying of biological materials from a physical, chemical and biological point of view. Morphological observation of the freeze-drying process of specimens, however, has been tried by only a few investigators. In those studies, thin-layered aqueous specimens, which were sandwiched between two cover slips, were mostly observed with an optical microscope. For ultrastructural and stereoscopic observation, the scanning electron microscope has a great advantage, unlike that of the optical microscope. A specially designed cryo-scanning electron microscope, employed in the present study, made it possible to observe the freezing patterns of the specimens and also the sublimation process of ice in frozen specimens under vacuum. With this specially designed microscope, shrinkage of some specimens due to dehydration during the freeze-drying process was revealed and the extent of such shrinkage was quantitatively determined.
Assuntos
Liofilização , Microscopia Eletrônica de Varredura , Animais , Eritrócitos/ultraestrutura , Feminino , Humanos , Microscopia Eletrônica de Varredura/instrumentação , Óvulo/ultraestrutura , Plantas/ultraestrutura , Ouriços-do-Mar , Leveduras/ultraestruturaRESUMO
The effect of freeze-thawing on the yeast respiratory system was studied at rapid rates of cooling. Freezing of whole cells with liquid nitrogen induced decrease of respiratory activity to under 20% of that of original cells. Mitochondria harvested from freeze-thawed cells have markedly decreased succinate oxidizing activity. Activity of succinate cytochrome c reductase was reduced significantly after freeze-thawing of whole cells while activities of succinate dehydrogenase and cytochrome c oxidase were reduced slightly. By spectrophotometric analysis it was found that about one-half the amount of cytochrome c + c1 was eluted from mitochondria to cytosol after freeze-thawing of cells. The activities of succinate oxidation in mitochondria from freeze-thawed cells were restored to normal levels by the addition of cytochrome c. Freeze-thawing of isolated mitochondria did not induce deactivation of succinate oxidizing activities and succinate cytochrome c reductase, and no elution of cytochrome c was observed. It was concluded that the decreased respiratory activities of yeast cells by freezing of cells with liquid nitrogen can be attributed primarily to the elution of cytochrome c from mitochondria.
Assuntos
Mitocôndrias/metabolismo , Consumo de Oxigênio , Saccharomyces cerevisiae/metabolismo , Fracionamento Celular , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Congelamento , Mitocôndrias/ultraestrutura , Succinato Citocromo c Oxirredutase/metabolismo , Succinato Desidrogenase/metabolismoRESUMO
The DNP fibres gamma-irradiated under aerobic condition showed a reduction of their diameter, while no remarkable changes were observed in the DNP fibres irradiated under hypoxic condition by scanning electron microscopy.