Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Cell Tissue Res ; 375(3): 697-707, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30284085

RESUMO

Cancer stem cells (CSCs) are specific targets for therapeutic applications, but the rarity of CSCs within tumors makes the isolation of CSCs difficult. To overcome these problems, we generated CSCs in vitro using established reprogramming techniques. We transduced four previously established reprogramming factors, Oct3/4, Sox2, Klf4, and L-myc, into the colon cancer cell lines LoVo and OUMS-23, and investigated the biological characteristics of these lines. Tra-1-60+ cells were obtained from reprogrammed induced pluripotent stem (iPS) cell-like colonies and showed CSC properties, including colony formation, maintenance of colonies by repeated passages, and feeder cell dependency, as well as increased expressions of CSC markers such as CD133 and ALDH1. The CSC-like cells showed increased chemoresistance to 5-fluorouracil and elevated tumorigenicity upon transplantation into kidneys of immune-deficient mice. These tumors shifted to a poorly differentiated stage with many atypical cells, cytoplasmic mucin, and focal papillary components, with demonstrated dedifferentiation. The principal component analysis from DNA microarrays showed that though both cell lines moved to iPS cells after reprogramming, they were not completely identical to iPS cells. Significantly elevated gene expression of Decorin and CD90 was observed in CSC-like cells. Together, these results show that reprogramming of cancer cells produced not pluripotent stem cells but CSC-like cells, and these findings will provide biological information about genuine CSCs and help establish new CSC-targeted therapies.


Assuntos
Reprogramação Celular , Neoplasias do Colo/patologia , Células-Tronco Neoplásicas/metabolismo , Animais , Biomarcadores Tumorais/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Fator 4 Semelhante a Kruppel , Camundongos SCID , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
2.
Biochem Biophys Res Commun ; 482(4): 549-555, 2017 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-27856246

RESUMO

Retinoblastoma is the most common intraocular malignancy in pediatric patients. It develops rapidly in the retina and can be fatal if not treated promptly. It has been proposed that a small population of cancer cells, termed cancer stem cells (CSCs), initiate tumorigenesis from immature tissue stem cells or progenitor cells. Reprogramming technology, which can convert mature cells into pluripotent stem cells (iPS), provides the possibility of transducing malignant cancer cells back to CSCs, a type of early stage of cancer. We herein took advantage of reprogramming technology to induce CSCs from retinoblastoma cancer cells. In the present study, the 4 Yamanaka transcription factors, Oct4, Sox2, Klf4 and c-myc, were transduced into retinoblastoma cells (Rbc51). iPS-like colonies were observed 15 days after transduction and showed significantly enhanced CSC properties. The gene and protein expression levels of pluripotent stem cell markers (Tra-1-60, Oct4, Nanog) and cancer stem cell markers (CD133, CD44) were up-regulated in transduced Rbc51 cells compared to control cells. Moreover, iPS-like CSCs could be sorted using the Magnetic-activated cell sorting (MACS) method. A sphere formation assay demonstrated spheroid formation in transduced Rbc51 cells cultured in serum free media, and these spheroids could be differentiated into Pax6-, Nestin-positive neural progenitors and rhodopsin- and recoverin-positive mature retinal cells. The cell viability after 5-Fu exposure was higher in transduced Rbc51 cells. In conclusion, CSCs were generated from retinoblastoma cancer cells using reprogramming technology. Our novel method can generate CSCs, the study of which can lead to better understanding of cancer-specific initiation, cancer epigenetics, and the overlapping mechanisms of cancer development and pluripotent stem cell behavior.


Assuntos
Técnicas de Reprogramação Celular/métodos , Reprogramação Celular , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Neoplásicas/citologia , Neoplasias da Retina/genética , Retinoblastoma/genética , Linhagem Celular Tumoral , Regulação da Expressão Gênica no Desenvolvimento , Regulação Neoplásica da Expressão Gênica , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Fator 4 Semelhante a Kruppel , Células-Tronco Neoplásicas/metabolismo , Retina/citologia , Retina/metabolismo , Fatores de Transcrição/genética , Transdução Genética
3.
Cell Tissue Res ; 354(3): 751-9, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23996199

RESUMO

The major molecular signals of pancreatic exocrine development are largely unknown. We examine the role of fibroblast growth factor 7 (FGF7) in the final induction of pancreatic amylase-containing exocrine cells from induced-pancreatic progenitor cells derived from human embryonic stem (hES) cells. Our protocol consisted in three steps: Step I, differentiation of definitive endoderm (DE) by activin A treatment of hES cell colonies; Step II, differentiation of pancreatic progenitor cells by re-plating of the cells of Step I onto 24-well plates at high density and stimulation with all-trans retinoic acid; Step III, differentiation of pancreatic exocrine cells with a combination of FGF7, glucagon-like peptide 1 and nicotinamide. The expression levels of pancreatic endodermal markers such as Foxa2, Sox17 and gut tube endoderm marker HNF1ß were up-regulated in both Step I and II. Moreover, in Step III, the induced cells expressed pancreatic markers such as amylase, carboxypeptidase A and chymotrypsinogen B, which were similar to those in normal human pancreas. From day 8 in Step III, cells immunohistochemically positive for amylase and for carboxypeptidase A, a pancreatic exocrine cell product, were induced by FGF7. Pancreatic progenitor Pdx1-positive cells were localized in proximity to the amylase-positive cells. In the absence of FGF7, few amylase-positive cells were identified. Thus, our three-step culture protocol for human ES cells effectively induces the differentiation of amylase- and carboxypeptidase-A-containing pancreatic exocrine cells.


Assuntos
Amilases/biossíntese , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/efeitos dos fármacos , Fator 7 de Crescimento de Fibroblastos/metabolismo , Pâncreas Exócrino/citologia , Pâncreas Exócrino/efeitos dos fármacos , Ativinas/farmacologia , Comunicação Celular/efeitos dos fármacos , Comunicação Celular/fisiologia , Contagem de Células , Técnicas de Cultura de Células/métodos , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Células Cultivadas , Técnicas Citológicas , Células-Tronco Embrionárias/metabolismo , Fator 7 de Crescimento de Fibroblastos/genética , Fator 7 de Crescimento de Fibroblastos/farmacologia , Peptídeo 1 Semelhante ao Glucagon/farmacologia , Humanos , Niacinamida/farmacologia , Pâncreas Exócrino/enzimologia , Pâncreas Exócrino/metabolismo , Tretinoína/farmacologia
4.
PLoS One ; 11(9): e0162693, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27632182

RESUMO

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are potential resources for the regeneration of defective organs, including the liver. However, some obstacles must be overcome before this becomes reality. Undifferentiated cells that remain following differentiation have teratoma-forming potential. Additionally, practical applications require a large quantity of differentiated cells, so the differentiation process must be economical. Here we describe a DNA microarray-based global analysis of the gene expression profiles of differentiating human pluripotent stem cells. We identified differences and commonalities among six human pluripotent stem cell lines: the hESCs KhES1, KhES2, KhES3, and H1, and the iPSCs 201B7 and 243G1. Embryoid bodies (EBs) formed without requiring supplementation with inducing factors. EBs also expressed some liver-specific metabolic genes including the ammonia-metabolizing enzymes glutamine synthetase and carbamoyl-phosphate synthase 1. Real-time PCR analysis revealed hepatocyte-like differentiation of EBs treated with ammonia in Lanford medium. Analysis of DNA microarray data suggested that hepatocyte-like cells were the most abundant population in ammonia-treated cells. Furthermore, expression levels of undifferentiated pluripotent stem cell markers were drastically reduced, suggesting a reduced teratoma-forming capacity. These results indicate that treatment of EBs with ammonia in Lanford medium may be an effective inducer of hepatic differentiation in absence of expensive inducing factors.


Assuntos
Amônia/farmacologia , Hepatócitos/efeitos dos fármacos , Células-Tronco Pluripotentes/efeitos dos fármacos , Animais , Diferenciação Celular , Linhagem da Célula , Hepatócitos/citologia , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Células-Tronco Pluripotentes/citologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA