搜索结果: 'methocult media formulations for human hematopoietic cells serum containing'

BACKGROUND Induced pluripotent stem cells (iPSCs) hold tremendous potential,both as a biological tool to uncover the pathophysiology of disease by creating relevant human cell models and as a source of cells for cell-based therapeutic applications. Studying the reprogramming process will also provide significant insight into tissue development. OBJECTIVE We sought to characterize the derivation of iPSC lines from nasal epithelial cells (NECs) isolated from nasal mucosa samples of children,a highly relevant and easily accessible tissue for pediatric populations. METHODS We performed detailed comparative analysis on the transcriptomes and methylomes of NECs,iPSCs derived from NECs (NEC-iPSCs),and embryonic stem cells (ESCs). RESULTS NEC-iPSCs express pluripotent cell markers,can differentiate into all 3 germ layers in vivo and in vitro,and have a transcriptome and methylome remarkably similar to those of ESCs. However,residual DNA methylation marks exist,which are differentially methylated between NEC-iPSCs and ESCs. A subset of these methylation markers related to epithelium development and asthma and specific to NEC-iPSCs persisted after several passages in vitro,suggesting the retention of an epigenetic memory of their tissue of origin. Our analysis also identified novel candidate genes with dynamic gene expression and DNA methylation changes during reprogramming,which are indicative of possible roles in airway epithelium development. CONCLUSION NECs are an excellent tissue source to generate iPSCs in pediatric asthmatic patients,and detailed characterization of the resulting iPSC lines would help us better understand the reprogramming process and retention of epigenetic memory. View Publication

Purpose: The bone marrow microenvironment is considered a critical component in the dissemination and fate of cancer cells in the metastatic process. We explored the possible correlation between bone marrow mesenchymal stem cells (BM-MSC) and disseminated breast cancer-initiating cells (BCIC) in primary breast cancer patients. Experimental design: Bone marrow mononuclear cells (BM-MNC) were collected at the time of primary surgery in 12 breast cancer patients. BM-MNC was immunophenotyped and BCIC was defined as epithelial cells (CD326+CD45-) with a stem-like" phenotype (CD44+CD24low/-� View Publication

Green tea has shown remarkable anti-inflammatory and cancer chemopreventive effects in many animal tumor bioassays,cell culture systems,and epidemiological studies. Many of these biological effects of green tea are mediated by epigallocatechin 3-gallate (EGCG),the major polyphenol present therein. We have earlier shown that EGCG treatment results in apoptosis of several cancer cells,but not of normal cells (J. Natl. Cancer Inst. 89,1881-1886 (1997)). The mechanism of this differential response of EGCG is not known. In this study,we investigated the involvement of NF-kappaB during these differential responses of EGCG. EGCG treatment resulted in a dose-dependent (i) inhibition of cell growth,(ii) G0/G1-phase arrest of the cell cycle,and (iii) induction of apoptosis in human epidermoid carcinoma (A431) cells,but not in normal human epidermal keratinocytes (NHEK). Electromobility shift assay revealed that EGCG (10-80 microM) treatment results in lowering of NF-kappaB levels in both the cytoplasm and nucleus in a dose-dependent manner in both A431 cells and NHEK,albeit at different concentrations. EGCG treatment was found to result in a dose-based differential inhibition of TNF-alpha- and LPS-mediated activation of NF-kappaB in these cells. The inhibition of NF-kappaB constitutive expression and activation in NHEK was observed only at high concentrations. The immunoblot analysis also demonstrated a similar pattern of inhibition of the constitutive expression as well as activation of NF-kappaB/p65 nuclear protein. This inhibition of TNF-alpha-caused NF-kappaB activation was mediated via the phosphorylative degradation of its inhibitory protein IkappaBalpha. Taken together,EGCG was found to impart differential dose-based NF-kappaB inhibitory response in cancer cells vs normal cells; i.e.,EGCG-mediated inhibition of NF-kappaB constitutive expression and activation was found to occur at much higher dose of EGCG in NHEK as compared to A431 cells. This study suggests that EGCG-caused cell cycle deregulation and apoptosis of cancer cells may be mediated through NF-kappaB inhibition. View Publication

The cell surface marker CD133 has been proposed as a brain tumor stem cell marker. However,there have been substantial controversies regarding the necessity and role of CD133 in tumorigenesis. This study aimed to characterize CD133(+) cells in brain tumors. Human brain tumor specimens and whole blood were collected from the same patients (N=12). We carried out dual FACS staining for CD133/CD34 and functional tumorigenesis and angiogenesis analyses of CD133(+) cells from different origins. We also investigated the in vivo tumorigenic potential and histological characteristics of four distinct groups on the basis of expression of CD133/CD34 markers (CD133(+),CD133(+)/CD34(+),CD133(+)/CD34(-),and CD133(-)). CD133(+) brain tumor cells coexpressed significantly higher positivity for CD34 (70.7±5.2% in CD133(+) vs. 12.3±4.2% in CD133(-) cells,P<0.001). CD133(+) brain tumor cells formed neurosphere-like spheroids and differentiated into multiple nervous system lineages unlike CD133(+) blood cells. They showed biological characteristics of endothelial cells,including vWF expression,LDL uptake and tube formation in vitro,unlike CD133(-) brain tumors cells. Pathologic analysis of brains implanted with CD133(+) cells showed large,markedly hypervascular tumors with well-demarcated boundary. CD133(+)/CD34(-) cells produced smaller but highly infiltrative tumors. Notably,pure angiogenic cell fractions (CD133(+)/CD34(+)) and CD133(-) tumor cells did not generate tumors in vivo. Our data suggest the presence of a distinct subpopulation of CD133(+) cells isolated from human brain tumors,with characteristics of endothelial progenitor cells (EPCs). View Publication