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GSE33550
Mus musculus, Homo sapiens
66 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The TLX1 and TLX3 transcription factor oncogenes play an important role in the pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL)1,2. Here we used reverse engineering of global transcriptional networks to decipher the oncogenic regulatory circuit controlled by TLX1 and TLX3. This Systems Biology analysis defined TLX1 and TLX3 as master regulators of an oncogenic transcriptional circuit governing T-ALL. Notably, network structure analysis of this hierarchical network identified RUNX1 as an important mediator of TLX1 and TLX3 induced T-ALL, and predicted a tumor suppressor role for RUNX1 in T-cell transformation. Consistent with these results, we identified recurrent somatic loss of function mutations in RUNX1 in human T-ALL. Overall, these results place TLX1 and TLX3 atop of an oncogenic transcriptional network controlling leukemia development, demonstrate power of network analysis to identify key elements in the regulatory circuits governing human cancer and identify RUNX1 as a tumor suppressor gene in T-ALL.
Publication Title
Disregulated expression of the transcription factor ThPOK during T-cell development leads to high incidence of T-cell lymphomas.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 59 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Transgenic expression of key transcritpion factors inducing T-cell leukemias in mice.
Publication Title
Disregulated expression of the transcription factor ThPOK during T-cell development leads to high incidence of T-cell lymphomas.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 4 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The experiment was designed in order to knock down the expression of TLX3 gene in T-ALL cell line
Publication Title
Disregulated expression of the transcription factor ThPOK during T-cell development leads to high incidence of T-cell lymphomas.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 3 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The experiment was designed in order to knock down the expression of TLX1 gene in T-ALL cell line
Publication Title
Disregulated expression of the transcription factor ThPOK during T-cell development leads to high incidence of T-cell lymphomas.
Sample Metadata Fields
Cell line
View Samples- Mus musculus
- 16 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Nonalcoholic fatty liver disease (NAFLD) is the most common form of liver disease and a leading cause of liver transplantation in the United Sates. Hedgehog (Hh) signaling has been implicated in liver lipid metabolism and the early stages of NAFLD; however, its precise role remains unclear. We examined the prevalence of NAFLD in patients with overt or microform holoprosencephaly (HPE), a disorder associated with germline mutations disrupting Hh signaling. To test the hypothesis that Hh signaling attenuation predisposes to liver steatosis, we subjected Gli2 heterozygous null (Gli2+/-) mice to two unique dietary models of fatty liver. Compared to the general population, the prevalence of NAFLD was significantly higher in the HPE cohort independent of obesity, especially among younger individuals. Gli2 heterozygosity caused increased weight gain and liver steatosis on a high fat diet, and increased liver steatosis in the absence of weight gain on a methionine and choline deficient diet. Increased liver steatosis in Gli2+/- mice was associated with decreased expression of pro-fibrotic and pro-inflammatory genes and increased expression of PPAR, a potent anti-fibrogenic and anti-inflammatory regulator. In addition, tumor suppressors p53 and p16INK4 were found to be downregulated in the Gli2+/- mice. Our results indicate that germline mutations affecting Hh signaling predispose to NAFLD with reduced or absent fibrosis, and might increase the risk of hepatocellular carcinoma.
Publication Title
Human germline hedgehog pathway mutations predispose to fatty liver.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
- Affymetrix Mouse Genome 430A 2.0 Array (mouse430a2)
Description
Gamma-secretase inhibitors (GSIs), which block the activation of NOTCH receptors, are being tested in the treatment of T-cell acute lymphoblastic leukemia (T-ALL). Thus far, limited antileukemic cytotoxicity and severe gastrointestinal toxicity have restricted the clinical application of these targeted drugs. Here we show that combination therapy with GSIs plus glucocorticoids can improve the antileukemic effects of GSIs and reduce their gut toxicity in vivo. Inhibition of NOTCH1 signaling in glucocorticoid-resistant T-ALL restored glucocorticoid receptor auto-up-regulation and induced apoptotic cell death through induction of BIM expression. Additionally, cotreatment with glucocorticoids induced Ccnd2 upregulation in the gut which protected mice from the intestinal secretory metaplasia typically induced by loss of NOTCH signaling. These results support a role for glucocorticoids plus GSIs in the treatment of glucocorticoid-resistant T-ALL.
Publication Title
Gamma-secretase inhibitors reverse glucocorticoid resistance in T cell acute lymphoblastic leukemia.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Glucocorticoids are an essential component of the treatment of lymphoid malignancies and resistance to glucocorticoid therapy constitutes a prominent clinical problem in relapsed and refractory lymphoblastic leukemias. Constitutively active NOTCH signaling is involved in the pathogenesis of over 50% of T-cell lymphoblastic leukemia (T-ALL) which harbor activating mutations in the NOTCH1 gene. Aberrant NOTCH1 signaling has been shown to protect normal thymocytes from glucocorticoid induced cell death. Here we analyzed the interaction of glucocorticoid therapy with inhibition of NOTCH signaling in the treatment of T-ALL. Gamma-secretase inhibitors (GSI), which block the activation of NOTCH receptors, amplified the transcriptional changes induced by glucocorticoid treatment, including glucocorticoid receptor autoinduction and restored sensitivity to dexamethasone in glucocorticoid-resistant T-ALL cells. Apoptosis induction upon inhibition of NOTCH signaling and activation of the glucocorticoid receptor was dependent on transcriptional upregulation of BIM and subsequent activation of the mitochondrial/intrinsic cell death pathway. Finally, we used a mouse xenograft model of T-ALL to demonstrate that combined treatment with dexamethasone and a GSI results in improved antileukemic effects in vivo. These studies provide insight in the mechanisms of glucocorticoid resistance and serve as rationale for the use of glucocorticoid and GSIs in combination in the treatment of T-ALL.
Publication Title
Gamma-secretase inhibitors reverse glucocorticoid resistance in T cell acute lymphoblastic leukemia.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 28 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The NOTCH1 signaling pathway directly links extracellular signals with transcriptional responses in the cell nucleus and plays a critical role during T-cell development and in the pathogenesis over 50% of human T-cell lymphoblastic leukemia (T-ALL) cases. However, little is known about the transcriptional programs activated by NOTCH1. Using an integrative systems biology approach we show that NOTCH1 controls a feed-forward loop transcriptional network that promotes cell growth. Inhibition of NOTCH1 signaling in T-ALL cells led to a reduction in cell size and elicited a gene expression signature dominated by downregulated biosynthetic pathway genes. By integrating gene expression array and ChIP-on-chip data, we show that NOTCH1 directly activates multiple biosynthetic routes and induces c-MYC gene expression. Reverse engineering of regulatory networks from expression profiles showed that NOTCH1 and c-MYC govern two directly interconnected transcriptional programs containing common target genes that together regulate the growth of primary T-ALL cells. These results identify c-MYC as an essential mediator of NOTCH1 signaling and integrate NOTCH1 activation with oncogenic signaling pathways upstream of c-MYC.
Publication Title
NOTCH1 directly regulates c-MYC and activates a feed-forward-loop transcriptional network promoting leukemic cell growth.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 40 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Gain-of-function mutations in NOTCH1 are common in T-cell lymphoblastic leukemias making this receptor a promising target for drugs such as gamma-secretase inhibitors (GSI), which block a proteolytic cleavage required for NOTCH1 activation. However, the enthusiasm for these therapies has been tempered by tumor resistance and the paucity of information on the oncogenic programs regulated by oncogenic NOTCH1. Analysis of gene expression in GSI-responsive and GSI-resistant cell lines treated with Compound E identifies differential resopnses to GSI.
Publication Title
Mutational loss of PTEN induces resistance to NOTCH1 inhibition in T-cell leukemia.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 20 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Gain-of-function mutations in NOTCH1 are common in T-cell lymphoblastic leukemias making this receptor a promising target for drugs such as gamma-secretase inhibitors, which block a proteolytic cleavage required for NOTCH1 activation. However, the enthusiasm for these therapies has been tempered by tumor resistance and the paucity of information on the oncogenic programs regulated by oncogenic NOTCH1. Here we show that NOTCH1 regulates PTEN expression and the activity of the PI3K-AKT signaling pathway in normal and leukemic T cells. Notch signaling and the PI3K-AKT pathway synergize in vivo in a Drosophila model of Notch-induced tumorigenesis, and mutational loss of PTEN is associated with increased glycolysis and resistance to NOTCH1 inhibition in human T-ALL. These findings identify the transcriptional regulation of PTEN and the control of cellular metabolism as key elements of the oncogenic program activated by NOTCH1 and provide the basis for the design of new therapeutic strategies for T-ALL.
Publication Title
Mutational loss of PTEN induces resistance to NOTCH1 inhibition in T-cell leukemia.
Sample Metadata Fields
No sample metadata fields
View Samples