CD24, or heat stable antigen, is a cell surface sialoglycoprotein expressed on immature cells that disappears after the cells have reached their final differentiation stage. CD24 may be important in human embryonic kidney epithelial cell differentiation. In mice, CD24 expression is up-regulated in the early metanephros and localized to developing epithelial structures but the role and expression of CD24 in the developing human kidney has not been well described. In normal human fetal kidneys from 8 to 38 weeks gestation, CD24 expression was up-regulated and restricted to the early epithelial aggregates of the metanephric blastema and to the committed proliferating tubular epithelia of the S-shape nephron; however individual CD24+ cells were identified in the interstitium of later gestation and postnatal kidneys. In freshly isolated cells, FACS analysis demonstrated distinct CD24+ and CD24+133+ cell populations, constituting up to 16% and 14% respectively of the total cells analyzed. Isolated and expanded CD24+ clones displayed features of an epithelial progenitor cell line. Early fetal urinary tract obstruction resulted in an upregulation of CD24 expression, both in developing epithelial structures of early gestation kidneys and in the cells of the injured tubular epithelium of the later gestation kidneys. These results highlight the cell specific expression of CD24 in the developing human kidney and dysregulation in fetal urinary tract obstruction.
Ontogeny of CD24 in the human kidney.
Age, Specimen part
View SamplesDrug resistance remains a major obstacle to successful cancer treatment. Here we use a novel approach to identify rapamycin as a glucocorticoid resistance reversal agent. A database of drug-associated gene expression profiles was screened for molecules whose profile overlapped with a gene expression signature of glucocorticoid (GC) sensitivity/resistance in Acute Lymphoblastic Leukemia (ALL) cells. The screen indicated the mTOR inhibitor rapamycin profile matched the signature of GC-sensitivity. We thus tested the hypothesis that rapamycin would induce GC sensitivity in lymphoid malignancy cells, and found that it sensitized cells to glucocorticoid induced apoptosis via modulation of antiapoptotic MCL1. These data indicate that MCL1 is an important regulator of GC-induced apoptosis, and that the combination of rapamycin and glucocorticoids has potential utility in ALL. Furthermore this approach represents a novel strategy for identification of promising combination therapies for cancer.
Gene expression-based chemical genomics identifies rapamycin as a modulator of MCL1 and glucocorticoid resistance.
No sample metadata fields
View SamplesHutchinsonGilford progeria syndrome (HGPS) is a rare genetic disease with widespread phenotypic features resembling premature aging. HGPS was recently shown to be caused by dominant mutations in the LMNA gene, resulting in the in-frame deletion of 50 amino acids near the carboxyl terminus of the encoded lamin A protein. Children with this disease typically succumb to myocardial infarction or stroke caused by severe atherosclerosis at an average age of 13 years. To elucidate further the molecular
Genome-scale expression profiling of Hutchinson-Gilford progeria syndrome reveals widespread transcriptional misregulation leading to mesodermal/mesenchymal defects and accelerated atherosclerosis.
Cell line
View SamplesDrug resistance remains a major obstacle to successful cancer treatment. Here we use a novel approach to identify rapamycin as a glucocorticoid resistance reversal agent. A database of drug-associated gene expression profiles was screened for molecules whose profile overlapped with a gene expression signature of glucocorticoid (GC) sensitivity/resistance in Acute Lymphoblastic Leukemia (ALL) cells. The screen indicated the mTOR inhibitor rapamycin profile matched the signature of GC-sensitivity. We thus tested the hypothesis that rapamycin would induce GC sensitivity in lymphoid malignancy cells, and found that it sensitized cells to glucocorticoid induced apoptosis via modulation of antiapoptotic MCL1. These data indicate that MCL1 is an important regulator of GC-induced apoptosis, and that the combination of rapamycin and glucocorticoids has potential utility in ALL. Furthermore this approach represents a novel strategy for identification of promising combination therapies for cancer.
Gene expression-based chemical genomics identifies rapamycin as a modulator of MCL1 and glucocorticoid resistance.
No sample metadata fields
View SamplesLeukemias and other cancers possess a rare population of cells capable of self-renewal, and eradication of these cancer stem cells is likely necessary for long-term cancer-free survival. Given that both normal and cancer stem cells are capable of self-renewal the extent to which cancer stem cells resemble normal tissue stem cells is a critical issue if targeted therapies are to be developed. We introduced the MLL-AF9 fusion protein encoded by the t(9;11)(p22;q23) found in human acute myelogenous leukemia (AML) into murine committed granulocyte-macrophage progenitors (GMP). The resultant leukemias contained cells with an immunophenotype similar to normal GMP that were highly enriched for leukemia stem cells (LSC). Detailed gene expression comparisons between normal hematopoietic stem cells (HSC), committed progenitors, and the LSC population demonstrated the LSC were globally more similar to the normal GMP than any other population. However, a subset of genes highly expressed in normal stem cells was re-activated in the LSC. These data demonstrate LSC can be generated from committed progenitors without widespread reprogramming of gene expression, and a leukemia self-renewal associated signature is activated in the process. Our findings define progression from normal hematopoietic progenitor to leukemia stem cell, and suggest that targeting a self-renewal program expressed in an abnormal context may be possible.
Transformation from committed progenitor to leukaemia stem cell initiated by MLL-AF9.
No sample metadata fields
View SamplesLeukemias and other cancers possess a rare population of cells capable of self-renewal, and eradication of these cancer stem cells is likely necessary for long-term cancer-free survival. Given that both normal and cancer stem cells are capable of self-renewal the extent to which cancer stem cells resemble normal tissue stem cells is a critical issue if targeted therapies are to be developed. We introduced the MLL-AF9 fusion protein encoded by the t(9;11)(p22;q23) found in human acute myelogenous leukemia (AML) into murine committed granulocyte-macrophage progenitors (GMP). The resultant leukemias contained cells with an immunophenotype similar to normal GMP that were highly enriched for leukemia stem cells (LSC). Detailed gene expression comparisons between normal hematopoietic stem cells (HSC), committed progenitors, and the LSC population demonstrated the LSC were globally more similar to the normal GMP than any other population. However, a subset of genes highly expressed in normal stem cells was re-activated in the LSC. These data demonstrate LSC can be generated from committed progenitors without widespread reprogramming of gene expression, and a leukemia self-renewal associated signature is activated in the process. Our findings define progression from normal hematopoietic progenitor to leukemia stem cell, and suggest that targeting a self-renewal program expressed in an abnormal context may be possible.
Transformation from committed progenitor to leukaemia stem cell initiated by MLL-AF9.
No sample metadata fields
View SamplesWe generated MLL-AF9 mediated murine leukemias that originate either from hematopoietic stem or committed progenitors cells. The luekemia stem cell fraction in these two type of leukemias shared exactly the same immunophenotype but their genetic programs differ.
No associated publication
Specimen part
View SamplesHuman iPS cells derived from normal and Fragile-X fibroblasts in order to assess the capability of Fragile-X iPS cells to be used as a model for different aspects of Fragile-X syndrome. Microarry analysis used to compare global gene expression between human ES cells, the normal and the mutant iPS cells and the original fibroblasts, to demonstrate that the overall reprogramming process succeeded, and that the FX-iPS cells are fully reprogrammed cells.
Differential modeling of fragile X syndrome by human embryonic stem cells and induced pluripotent stem cells.
Specimen part, Disease, Cell line
View SamplesLeukemias and other cancers possess a rare population of cells capable of self-renewal, and eradication of these cancer stem cells is likely necessary for long-term cancer-free survival. Given that both normal and cancer stem cells are capable of self-renewal the extent to which cancer stem cells resemble normal tissue stem cells is a critical issue if targeted therapies are to be developed. We introduced the MLL-AF9 fusion protein encoded by the t(9;11)(p22;q23) found in human acute myelogenous leukemia (AML) into murine committed granulocyte-macrophage progenitors (GMP). The resultant leukemias contained cells with an immunophenotype similar to normal GMP that were highly enriched for leukemia stem cells (LSC). Detailed gene expression comparisons between normal hematopoietic stem cells (HSC), committed progenitors, and the LSC population demonstrated the LSC were globally more similar to the normal GMP than any other population. However, a subset of genes highly expressed in normal stem cells was re-activated in the LSC. These data demonstrate LSC can be generated from committed progenitors without widespread reprogramming of gene expression, and a leukemia self-renewal associated signature is activated in the process. Our findings define progression from normal hematopoietic progenitor to leukemia stem cell, and suggest that targeting a self-renewal program expressed in an abnormal context may be possible.
Transformation from committed progenitor to leukaemia stem cell initiated by MLL-AF9.
No sample metadata fields
View SamplesLeukemias and other cancers possess a rare population of cells capable of self-renewal, and eradication of these cancer stem cells is likely necessary for long-term cancer-free survival. Given that both normal and cancer stem cells are capable of self-renewal the extent to which cancer stem cells resemble normal tissue stem cells is a critical issue if targeted therapies are to be developed. We introduced the MLL-AF9 fusion protein encoded by the t(9;11)(p22;q23) found in human acute myelogenous leukemia (AML) into murine committed granulocyte-macrophage progenitors (GMP). The resultant leukemias contained cells with an immunophenotype similar to normal GMP that were highly enriched for leukemia stem cells (LSC). Detailed gene expression comparisons between normal hematopoietic stem cells (HSC), committed progenitors, and the LSC population demonstrated the LSC were globally more similar to the normal GMP than any other population. However, a subset of genes highly expressed in normal stem cells was re-activated in the LSC. These data demonstrate LSC can be generated from committed progenitors without widespread reprogramming of gene expression, and a leukemia self-renewal associated signature is activated in the process. Our findings define progression from normal hematopoietic progenitor to leukemia stem cell, and suggest that targeting a self-renewal program expressed in an abnormal context may be possible.
Transformation from committed progenitor to leukaemia stem cell initiated by MLL-AF9.
No sample metadata fields
View Samples