Critical roles for DNA methylation in embryonic development are well established, but less is known about the roles of DNA methylation during trophoblast development, the extraembryonic lineage that gives rise to the placenta. Here we dissected the role of DNA methylation in trophoblast development by performing mRNA and DNA methylation profiling of Dnmt3a/3b-null trophoblast. We find that most gene deregulation is explained by an erasure of maternal methylation in the oocyte, but partially independent of loss of imprinting of the trophoblast-essential Ascl2 gene. Our results reveal that maternal DNA methylation controls multiple differentiation and physiological processes in trophoblast via both imprinting-dependent and -independent mechanisms. Overall design: mRNA-seq and WGBS-seq of maternal Dnmt3a/3b-null trophoblast; mRNA-seq of maternal Ascl2 KO trophoblast
Maternal DNA Methylation Regulates Early Trophoblast Development.
No sample metadata fields
View SamplesMissense FBXW7 mutations are prevalent in various tumors, including T-cell acute lymphoblastic leukemia (T-ALL). To study the effects of such lesions, we generated animals carrying regulatable Fbxw7 mutant alleles. We show here that these mutations specifically bolster cancer-initiating cell activity in collaboration with Notch1 oncogenes, but spare normal hematopoietic stem cell function. We were also able to show that FBXW7 mutations specifically affect the ubiquitylation and half-life of c-Myc protein, a key T-ALL oncogene. Using animals carrying c-Myc fusion alleles, we connected Fbxw7 function to c-Myc abundance and correlated c-Myc expression to leukemia-initiating activity.
The ubiquitin ligase FBXW7 modulates leukemia-initiating cell activity by regulating MYC stability.
Age, Specimen part
View SamplesTo formally address the tumor suppressor activity of Sh2b3 in vivo, we tested the interaction between oncogenic NOTCH1 and Sh2b3 loss in a retroviral- transduction bone marrow transplantation model of NOTCH-induced T-ALL
Genetic loss of SH2B3 in acute lymphoblastic leukemia.
Specimen part
View SamplesEarly immature T-cell acute lymphoblastic leukemias (T-ALLs) account for about 5-10% of pediatric T-ALLs and are associated with poor prognosis. However, the genetic defects that drive the biology of these tumors remain largely unknown. Analysis of microarray gene expression signatures in adult T-ALL demonstrated a high prevalence of early immature leukemias and revealed a close relationship between these tumors and myeloid leukemias. Consistently, adult immature T- ALLs showed characteristic mutations in myeloid specific oncogenes and tumor suppressors including IDH1, IDH2, DNMT3A, FLT3 and NRAS. Moreover, we identified ETV6 mutations as a novel genetic lesion uniquely present in immature adult T-ALL. All together, our results demonstrate that early immature adult T- ALL represents a heterogeneous category of leukemias characterized by the presence of overlapping myeloid and T-ALL characteristics and highlight the role of ETV6 mutations in these tumors.
ETV6 mutations in early immature human T cell leukemias.
Specimen part
View SamplesThe ubiquitin-proteasome system (UPS) has recently emerged as a major target for drug development in cancer therapy. The proteasome inhibitor bortezomib has clinical activity in multiple myeloma and mantle cell lymphoma. Here we report that Eeyarestatin I (EerI), a chemical inhibitor that blocks ER-associated protein degradation (ERAD), has anti-tumor and biologic activities similar to bortezomib, and can synergize with bortezomib. Like bortezomib, EerI-induced cytotoxicity requires the upregulation of the BH3 only pro-apoptotic protein NOXA. We further demonstrate that both EerI and bortezomib activate NOXA via an unanticipated mechanism that requires cooperation between two processes: First, these agents elicit an integrated stress response program at the ER to activate the CREB/ATF transcription factors ATF3 and ATF4. We show that ATF3 and ATF4 form a complex capable of binding to the NOXA promoter, which is required for NOXA activation. Second, EerI and bortezomib also block ubiquitination of histone H2A to relieve its inhibition on NOXA transcription. Our results identify a class of anti-cancer agents that integrate ER stress response with an epigenetic mechanism to induce cell death.
ERAD inhibitors integrate ER stress with an epigenetic mechanism to activate BH3-only protein NOXA in cancer cells.
No sample metadata fields
View SamplesGlucocorticoid resistance is a major driver of therapeutic failure in T-cell acute lymphoblastic leukemia (T-ALL). Here we used a systems biology approach, based on the reverse engineering of signaling regulatory networks, which identified the AKT1 kinase as a signaling factor driving glucocorticoid resistance in T-ALL. Indeed, activation of AKT1 in T-ALL lymphoblasts impairs glucocorticoid-induced apoptosis. Mechanistically, AKT1 directly phosphorylates the glucocorticoid receptor NR3C1 protein at position S134 and blocks glucocorticoid-induced NR3C1 translocation to the nucleus. Consistently, inhibition of AKT1 with MK-2206 increases the response of T-ALL cells to glucocorticoid therapy both in T-ALL cell lines and in primary patient samples thus effectively reversing glucocorticoid resistance in vitro and in vivo. These results warrant the clinical testing of ATK1 inhibitors and glucocorticoids, in combination, for the treatment of T-ALL.
Direct reversal of glucocorticoid resistance by AKT inhibition in acute lymphoblastic leukemia.
Specimen part
View SamplesGlucocorticoid resistance is a major driver of therapeutic failure in T-cell acute lymphoblastic leukemia (T-ALL). Here we identify the AKT1 kinase as a signaling factor driving glucocorticoid resistance in T-ALL. Mechanistically, AKT1 directly phosphorylates the glucocorticoid receptor NR3C1 protein and blocks glucocorticoid-induced NR3C1 transcription by inhibiting glucocorticoid-induced NT3C1 translocation to the nucleus. Consistently, pharmacologic inhibition of AKT1 increases the response of T-ALL cells to glucocorticoid therapy and effectively reverses glucocorticoid resistance in vitro and in vivo. These results warrant the clinical testing of AKT1 inhibitors and glucocorticoids in combination for the treatment of T-ALL.
Direct reversal of glucocorticoid resistance by AKT inhibition in acute lymphoblastic leukemia.
Cell line
View SamplesStem cell development requires selection of specific genetic programs to direct cellular fate. Using microarray technology, we profile expression trends at selected timepoints during stem cell differentiation to characterize these changes.
Genomic chart guiding embryonic stem cell cardiopoiesis.
Specimen part
View SamplesTranscriptome of S. cerevisiae in shifts between glucose and maltose media with different re-growth conditions Overall design: Cells are pregrown in maltose, then grown for different durations in glucose and then washed back to maltose
A new protocol for single-cell RNA-seq reveals stochastic gene expression during lag phase in budding yeast.
Subject
View SamplesWe investigate the role of Snf2l in ovaries by characterizing a mouse bearing an inactivating deletion on the ATPase domain of Snf2l (Ex6DEL). Snf2l mutant mice produce significantly fewer eggs than control mice when superovulated. Thus, gonadotropin stimulation leads to a significant deficit in secondary follicles and an increase in abnormal antral follicles. We profiled the expression of granulosa cells from Snf2l WT and Ex6DEL mice treated with pregnant mares' serum gonadotropin followed by human chorionic gonadotropin
The imitation switch ATPase Snf2l is required for superovulation and regulates Fgl2 in differentiating mouse granulosa cells.
Specimen part
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