RESUMO
The RASSF family proteins have been implicated in the development of human cancers. To date, the expression pattern and biological significance of RASSF4 in colorectal cancers (CRC) have not been fully investigated. In the current study, we explored expression pattern of RASSF4 in 118 CRC specimens and 30 adjacent 'normal' colon tissues by immunohistochemistry. The results showed that RASSF4 was downregulated in CRC tissues compared with adjacent 'normal' tissues. RASSF4 downregulation significantly associated with advanced tumour-node-metastasis (TNM) stage, T status, positive node status and high Ki-67 index. Analysis of TCGA dataset also supported RASSF4 downregulation in CRC tissues. Ectopically expressed RASSF4 in LoVo cells inhibited cell growth, colony formation, cell cycle progression and increased the sensitivity to 5-FU treatment. Annexin V/PI apoptosis assay showed that RASSF4 overexpression increased 5-FU-induced apoptosis and downregulated the mitochondrial membrane potential. In addition, Western blot demonstrated that RASSF4 overexpression repressed YAP and Bcl-2 while upregulating p21 expression. YAP knockdown abolished the role of RASSF4 on Bcl-2. ChIP assay showed that TEAD4, a major YAP binding transcription factor, could bind to the promoter regions of Bcl-2. In conclusion, our data showed that RASSF4 was downregulated in human CRC. RASSF4 regulated malignant behaviour through YAP/Bcl-2 signalling in CRC cells.
Assuntos
Apoptose , Neoplasias Colorretais , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Proteínas de Ligação a DNA , Fluoruracila/farmacologia , Humanos , Proteínas Musculares , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Fatores de Transcrição de Domínio TEA , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismoRESUMO
OBJECTIVE: Mutations in the high-temperature requirement A serine peptidase 1 (HTRA1) gene were studied in a Chinese family with cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL). METHODS: Exons 1-9 of the HTRA1 gene were amplified and bidirectionally sequenced in a Chinese family with CARASIL. Mutation effects were analysed by three-dimensional modelling of the serine protease HTRA1 protein. RESULTS: The proband was found to be homozygous for a novel missense mutation (c.854 C > T) identified in exon 4 of the HTRA1 gene; the parents of the proband were heterozygous for the same missense mutation. This c.854 C > T mutation resulted in a change from proline to leucine (p.P285L) in serine protease HTRA1, and was absent in 260 control chromosomes. Three-dimensional models showed that the change from proline to leucine (p.P285L) could attenuate the hydrogen bond between S284 and S287 residues, which might affect function of serine protease HTRA1. CONCLUSION: Discovery of a novel missense mutation (c.854C>T) associated with CARASIL expands the known CARASIL-related mutations in HTRA1.
Assuntos
Alopecia/genética , Infarto Cerebral/genética , Leucoencefalopatias/genética , Modelos Moleculares , Mutação de Sentido Incorreto , Serina Endopeptidases/genética , Doenças da Coluna Vertebral/genética , Adulto , Alopecia/enzimologia , Alopecia/etnologia , Alopecia/patologia , Substituição de Aminoácidos , Povo Asiático , Sequência de Bases , Estudos de Casos e Controles , Infarto Cerebral/enzimologia , Infarto Cerebral/etnologia , Infarto Cerebral/patologia , Análise Mutacional de DNA , Éxons , Família , Feminino , Heterozigoto , Serina Peptidase 1 de Requerimento de Alta Temperatura A , Homozigoto , Humanos , Ligação de Hidrogênio , Leucoencefalopatias/enzimologia , Leucoencefalopatias/etnologia , Leucoencefalopatias/patologia , Masculino , Dados de Sequência Molecular , Linhagem , Serina Endopeptidases/química , Serina Endopeptidases/metabolismo , Doenças da Coluna Vertebral/enzimologia , Doenças da Coluna Vertebral/etnologia , Doenças da Coluna Vertebral/patologiaRESUMO
Encapsulated papillary oncocytic neoplasms (EPONs) of the thyroid are rare tumors, whose relationship to other thyroid tumors has not been thoroughly elucidated. Earlier, they have been regarded as variants of papillary thyroid carcinoma (PTC), hyperplastic lesions, and follicular neoplasms. Eighteen EPONs were retrieved from our surgical pathology files and reviewed for defining morphologic features. Cases having the typical nuclear features of PTC were excluded. Immunohistochemistry (IHC) for CK19, HBME1, and CD56 was carried out. Microdissection, polymerase chain reaction, and sequencing of exon 15 of the BRAF gene were completed. Cases were evaluated for rearranged in transformation/papillary thyroid carcinoma RET/PTC rearrangement by fluorescent in situ hybridization (FISH). The majority of the tumors exhibited a distinctive histologic appearance. They were composed of true papillae lined by a single layer of predominantly cuboidal cells with oncocytic cytoplasm; hobnailing was typically prominent. Three tumors showed taller cells with uniformly apical nuclei and no hobnailing. Ten of 18 cases showed vascular and/or capsular invasion; hence, if the diagnostic criteria used to evaluate follicular neoplasms are applied, more than half of the tumors would be considered minimally invasive carcinomas. No cases were immunoreactive with antibodies to HBME1, whereas only 1 of 13 was immunoreactive for CK19. Six of 7 interpretable cases were immunoreactive for CD56. No BRAF point mutations or RET/PTC rearrangements were identified in the examined cases. All patients were alive at the time of last follow-up and no locally recurrent disease had been reported; however, 1 case was remarkable for a lymph node metastasis. Our results confirm that EPONs are histologically, immunohistochemically, and molecularly distinct from papillary thyroid carcinoma and seem to be most related to follicular neoplasms.