We modeled human Trisomy 21 primitive hematopoiesis using induced pluripotent stem cells (iPSCs). Primitive multipotent progenitor populations generated from Trisomy 21 iPSCs showed normal proliferative capacity and megakaryocyte production, enhanced erythropoiesis and reduced myeloid development compared to euploid iPSCs.
Trisomy 21-associated defects in human primitive hematopoiesis revealed through induced pluripotent stem cells.
Specimen part
View SamplesKeloids are benign tumors of the dermis that form during a protracted wound healing process. Susceptibility to keloid formation occurs predominantly in people of African and Asian descent. The key alteration(s) responsible for keloid formation has not been identified and there is no satisfactory treatment for this disorder. The altered regulatory mechanism is limited to dermal wound healing, although several diseases characterized by an exaggerated response to injury are prevalent in individuals of African ancestry. We have observed a complex pattern of phenotypic differences in keloid fibroblasts grown in standard culture medium or induced by hydrocortisone. In this study Affymetrix-based microarray was performed on RNA obtained from fibroblasts cultured from normal scars and keloids grown in the absence and presence of hydrocortisone. We observed differential regulation of approximately 500 genes of the 38,000 represented on the Affymetrix chip. Of particular interest was increased expression of several IGF-binding and IGF-binding related proteins and decreased expression of a subset of Wnt pathway inhibitors and multiple IL-1-inducible genes. Increased expression of CTGF and IGFBP-3 was observed in keloid fibroblasts only in the presence of hydrocortisone. These findings support a role for multiple fibrosis-related pathways in the pathogenesis of keloids
Gene profiling of keloid fibroblasts shows altered expression in multiple fibrosis-associated pathways.
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View SamplesFrom preliminary experiments, HSP70 deficient MEF cells display moderate thermotolerance to a severe heatshock of 45.5 degrees after a mild preshock at 43 degrees, even in the absence of hsp70 protein. We would like to determine which genes in these cells are being activated to account for this thermotolerance.
Microarray analysis of cellular thermotolerance.
No sample metadata fields
View SamplesDnmt3a catalyzes DNA methylation of gDNA, which contributes to the transriptional regulations of genes and genomic stability.
Methylation-independent repression of Dnmt3b contributes to oncogenic activity of Dnmt3a in mouse MYC-induced T-cell lymphomagenesis.
Age, Specimen part
View SamplesIdentification of genetic/cytogenetic alterations and differentially expressed cellular genes in HPV16 E6, E7 and E6/E7 positive human foreskin keratinocytes
Complementation of non-tumorigenicity of HPV18-positive cervical carcinoma cells involves differential mRNA expression of cellular genes including potential tumor suppressor genes on chromosome 11q13.
No sample metadata fields
View SamplesIdentification of genes differentially expressed in tumorigenic compared to non-tumorigenic, HPV18 positive cells
Complementation of non-tumorigenicity of HPV18-positive cervical carcinoma cells involves differential mRNA expression of cellular genes including potential tumor suppressor genes on chromosome 11q13.
No sample metadata fields
View SamplesDnmt3b is a DNA methytransferase which is an enzyme that methylated genomic DNA which contributes to genomic stability and transcriptional regulation.
Loss of Dnmt3b function upregulates the tumor modifier Ment and accelerates mouse lymphomagenesis.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gfi1b: a key player in the genesis and maintenance of acute myeloid leukemia and myelodysplastic syndrome.
Specimen part
View SamplesDifferentiation of hematopoietic stem cells (HSCs) is regulated by a concert of different transcription factors (TFs). A disturbed function of TFs can be the basis of (pre)malignancies such as myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Growth Factor Independence 1b (Gfi1b) is a repressing TF with a key role in quiescence of HSCs and emergence and maturation of erythrocytes and platelets. Here, we show that low expression of GFI1B in blast cells is associated with inferior prognosis of MDS and AML patients. Using mouse models with either reduced expression or conditional deletion of Gfi1b, crossed with a mouse model reflecting human MDS or AML, we demonstrate that AML development was accelerated with heterozygous loss of Gfi1b, and latency was further decreased when Gfi1b was conditionally deleted. Loss of Gfi1b significantly enhanced stemness of leukemic cells with upregulation of genes fundamentally involved in leukemia development. On a molecular level, we found that loss of Gfi1b not only increased the levels of reactive oxygen species (ROS) but also induced gene expression changes of key AML pathways such as the p38/AKT pathway. These results demonstrate that Gfi1b functions as an oncosuppressor in MDS/AML development.
Gfi1b: a key player in the genesis and maintenance of acute myeloid leukemia and myelodysplastic syndrome.
Specimen part
View SamplesTo understand molecular mechanisms underlying the synergy of Rb loss and E2F8 loss, we used gene expression profiling to assess molecular changes in Mx1-Cre-mediated knockout (KO) mice using RNA isolated from sorted Ter119+CD71high Erythroblasts.
Inactivation of Rb and E2f8 synergizes to trigger stressed DNA replication during erythroid terminal differentiation.
Specimen part
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