Arsenic metalloid is a double-edge sword. On the one hand it is a very toxic and powerful carcinogen, and on the other it has been successfully used in the treatment of acute promyelocytic leukemia. In order to prevent the deleterious effects caused by arsenic compounds, almost all living organisms have developed mechanisms to eliminate it. In this study genome-wide response of S. cerevisiae to arsenic shows that this metal interferes with genes involved in the iron homeostasis including those encoding proteins that function in iron uptake, incorporation into FeS clusters, and more. In addition our data indicate that Yap1 transcriptionally controls the iron homeostasis regulator AFT2 as well as its direct target, MRS4. Most importantly in response to arsenate exposure Yap1 strongly regulates the expression of several genes involved in the Fe-S proteins biosynthesis, namely NBP35 and YFH1. Interestingly mRNA levels encoding Fet3, Ferro-O2-oxidoreductase required for high-affinity iron uptake, are drastically destabilized upon arsenic exposure. Such destabilization is due to the 5 to 3 exonuclease Xrn1 localized in the P Bodies. Moreover FET3 mRNA decay is not mediated by Cth2 and is independent on the formation of ROS responsible for the toxic effects of arsenic compounds. Strikingly, in presence of arsenate fet3 mutant shows resistance over the wild-type which leads us to suggest that Fet3 has a role in arsenic toxicity. Unexpectedly arsenic treatment seems to activate the non-reductive iron uptake in order to maintain the cellular iron homeostasis. Furthermore our genetic, biochemical, and physiological analysis demonstrate that aft1 mutant is sensitive to arsenic compounds and such phenotype is reversible upon addition of iron. We also show that arsenic exposure induces iron deficiency in aft1 mutant. In conclusion this work shows for the first time that arsenic, a chemotherapy drug used to treat a specific type of acute promyelocytic leukemia (APL), disrupts iron homeostasis and our results suggest that this disruption is independent on ROS generation. Finally we provide preliminary data confirming that such disruption also takes place in mammalian cells, an observation that can be very relevant in term of clinical applications.
Arsenic stress elicits cytosolic Ca(2+) bursts and Crz1 activation in Saccharomyces cerevisiae.
Time
View SamplesComparison between two vegetative stages of the soybean cultivar BR16: 20 and 80 days after germination (DAG) Overall design: Examination of 2 vegetative stages: 20 and 80 DAGs
Revisiting the Soybean GmNAC Superfamily.
Age, Specimen part, Subject
View SamplesExpression profiling of FACS purified Lin-cKit+ cells from compound URE-/+::Msh2-/- mice with AML and control animals
Minimal PU.1 reduction induces a preleukemic state and promotes development of acute myeloid leukemia.
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View SamplesExpression profiling of FACS purified Lin-cKit+ cells from preleukemic compound URE-/+::Msh2-/- mice and control animals (two separate pools of 3 mice each)
Minimal PU.1 reduction induces a preleukemic state and promotes development of acute myeloid leukemia.
No sample metadata fields
View SamplesAngioimmunoblastic T-cell lymphoma (AITL) is an aggressive lymphoid tumor derived from malignant transformation of T follicular helper (Tfh) cells. Genetically, AITL is characterized by loss of function mutations in the Ten-Eleven Translocation 2 (TET2) epigenetic tumor suppressor and a highly recurrent mutation (p.Gly17Val, G17V) in the RHOA small GTPase gene Moreover, RHOA G17V expression in Tet2 deficient hematopoietic progenitors resulted in the specific development of lymphoid tumors resembling human AITL. Notably, inhibition of ICOS signaling impaired the growth of RHOA G17V-induced mouse lymphomas in vivo, thus providing a potential new rational approach for the treatment of AITL. Overall design: We analyzed mRNA expression profiles of primary tumor cells expressing Rhoa G17V or Rhoa wild type.
RHOA G17V Induces T Follicular Helper Cell Specification and Promotes Lymphomagenesis.
Specimen part, Subject
View SamplesStroke is a brain attack cutting off vital blood, and consequently the nutrients and oxygen vital to the brain cells that control everything we do. Stroke is a complex disease with unclear pathogenesis resulting from environmental and genetic factors.
TTC7B emerges as a novel risk factor for ischemic stroke through the convergence of several genome-wide approaches.
Sex
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Protection afforded by an HIV vaccine candidate in macaques depends on the dose of SIVmac251 at challenge exposure.
Specimen part
View SamplesThe SIVmac251 macaque model has been used to evaluate the efficacy of vaccine for HIV. Exposure of macaques to a single high dose of SIVmac251 results in transmission of multiple viral variants, which contrasts the few HIV variants typically transmitted in humans. In here, we investigated whether the dose of SIVmac251 challenge affected vaccination efficacy and found that exposure of the immunized macaques to single high dose of SIVmac251 resulted in no vaccine efficacy, whereas exposure to a tenfold lower dose resulted in protection from SIVmac251 acquisition and protection from disease in animals that become infected. The dose of challenge did not affect the expression of inflammatory genes in the gut in acute infection, but at set point, a significant down regulation of interferon responsive genes and up regulation of genes involved in B and T-cell responses, was observed only in vaccinated animals exposed to a lower dose of SIVmac251. Accordingly, in these animals, we also found a significant correlation with vaccine induced T-cell responses and protection from disease. These data demonstrate that the evaluation of the efficacy of vaccine candidates for HIV relies on accurate modeling in macaques to better mimic HIV transmission to humans.
Protection afforded by an HIV vaccine candidate in macaques depends on the dose of SIVmac251 at challenge exposure.
Specimen part
View SamplesThe SIVmac251 macaque model has been used to evaluate the efficacy of vaccine for HIV. Exposure of macaques to a single high dose of SIVmac251 results in transmission of multiple viral variants, which contrasts the few HIV variants typically transmitted in humans. In here, we investigated whether the dose of SIVmac251 challenge affected vaccination efficacy and found that exposure of the immunized macaques to single high dose of SIVmac251 resulted in no vaccine efficacy, whereas exposure to a tenfold lower dose resulted in protection from SIVmac251 acquisition and protection from disease in animals that become infected. The dose of challenge did not affect the expression of inflammatory genes in the gut in acute infection, but at set point, a significant down regulation of interferon responsive genes and up regulation of genes involved in B and T-cell responses, was observed only in vaccinated animals exposed to a lower dose of SIVmac251. Accordingly, in these animals, we also found a significant correlation with vaccine induced T-cell responses and protection from disease. These data demonstrate that the evaluation of the efficacy of vaccine candidates for HIV relies on accurate modeling in macaques to better mimic HIV transmission to humans.
Protection afforded by an HIV vaccine candidate in macaques depends on the dose of SIVmac251 at challenge exposure.
Specimen part
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
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