This SuperSeries is composed of the SubSeries listed below.
PI3K inhibition synergizes with glucocorticoids but antagonizes with methotrexate in T-cell acute lymphoblastic leukemia.
Sex, Age, Specimen part, Cell line
View SamplesThe PI3K pathway is frequently hyperactivated in primary T-cell acute lymphoblastic leukemia (T-ALL) cells. Activation of the PI3K pathway has been suggested as one mechanism of glucocorticoid resistance in T-ALL, and patients harboring mutations in the PI3K negative regulator PTEN may be at increased risk of induction failure and relapse. In this study, we identified Myc as an important downstream integrator of PI3K pathway activity in T-ALL and we provide data supportive of an association of higher PI3K activity with glucocorticoid resistance and worse clinical outcome. The PI3K inhibitor AS605240 showed anti-leukemic activity and strong synergism with glucocorticoids both in vitro and in a NOD/SCID xenograft model of T-ALL. In contrast, PI3K inhibition showed antagonism with methotrexate and daunorubicin, drugs that preferentially target dividing cells. This antagonistic interaction, however, could be circumvented by the use of correct drug scheduling schemes. Our data indicate the potential benefits and difficulties for the incorporation of PI3K inhibitors in T-ALL therapy.
PI3K inhibition synergizes with glucocorticoids but antagonizes with methotrexate in T-cell acute lymphoblastic leukemia.
Sex, Age, Specimen part
View SamplesThe PI3K pathway is frequently hyperactivated in primary T-cell acute lymphoblastic leukemia (T-ALL) cells. Activation of the PI3K pathway has been suggested as one mechanism of glucocorticoid resistance in T-ALL, and patients harboring mutations in the PI3K negative regulator PTEN may be at increased risk of induction failure and relapse. In this study, we identified Myc as an important downstream integrator of PI3K pathway activity in T-ALL and we provide data supportive of an association of higher PI3K activity with glucocorticoid resistance and worse clinical outcome. The PI3K inhibitor AS605240 showed anti-leukemic activity and strong synergism with glucocorticoids both in vitro and in a NOD/SCID xenograft model of T-ALL. In contrast, PI3K inhibition showed antagonism with methotrexate and daunorubicin, drugs that preferentially target dividing cells. This antagonistic interaction, however, could be circumvented by the use of correct drug scheduling schemes. Our data indicate the potential benefits and difficulties for the incorporation of PI3K inhibitors in T-ALL therapy.
PI3K inhibition synergizes with glucocorticoids but antagonizes with methotrexate in T-cell acute lymphoblastic leukemia.
Sex, Specimen part
View SamplesThe PI3K pathway is frequently hyperactivated in primary T-cell acute lymphoblastic leukemia (T-ALL) cells. Activation of the PI3K pathway has been suggested as one mechanism of glucocorticoid resistance in T-ALL, and patients harboring mutations in the PI3K negative regulator PTEN may be at increased risk of induction failure and relapse. In this study, we identified Myc as an important downstream integrator of PI3K pathway activity in T-ALL and we provide data supportive of an association of higher PI3K activity with glucocorticoid resistance and worse clinical outcome. The PI3K inhibitor AS605240 showed anti-leukemic activity and strong synergism with glucocorticoids both in vitro and in a NOD/SCID xenograft model of T-ALL. In contrast, PI3K inhibition showed antagonism with methotrexate and daunorubicin, drugs that preferentially target dividing cells. This antagonistic interaction, however, could be circumvented by the use of correct drug scheduling schemes. Our data indicate the potential benefits and difficulties for the incorporation of PI3K inhibitors in T-ALL therapy.
PI3K inhibition synergizes with glucocorticoids but antagonizes with methotrexate in T-cell acute lymphoblastic leukemia.
Specimen part, Cell line
View SamplesLymphotoxin-mediated activation of the lymphotoxin- receptor (LTR) has been implicated in several physiological and pathological processes, including lymphoid organ development, T-cell maturation, and solid and hematopoietic malignancies. Its role in T-cell acute lymphoblastic leukemia (T-ALL) or other T-cell malignancies has remained however to be investigated. Here we show that the genes encoding lymphotoxin (LT)- and LT were expressed in T-ALL patient samples, more abundantly in the TAL/LMO molecular subtype, and in the TEL-JAK2 mouse model of cortical/mature T-ALL. Surface LT12 protein was detected in primary mouse T-ALL cells, but only upon phorbol ester stimulation or absence of microenvironmental LTR interaction. Indeed, in contrast to leukemic cells collected from transplanted Ltbr/ mice or from co-cultures with Ltbr/ mouse embryonic fibroblasts (MEF), those collected from Ltbr+/+ mice or from Ltbr+/+ MEF co-cultures presented no surface LT expression. Supporting the notion that LT signaling plays a role in T-ALL, inactivation of the Ltbr gene in mice resulted in a statistically significant delay in TEL-JAK2-induced leukemia onset. Expression of the Lta and Ltb genes was found to be increased at the early asymtptomatic stages of TEL-JAK2 T-ALL, when only low proportions of malignant thymocytes are present in normal sized thymus. Interestingly, young asymptomatic TEL-JAK2;Ltbr/ mice presented significantly less leukemic thymocytes than TEL-JAK2;Ltbr+/+ mice. Together, these data indicate that early lymphotoxin expression by T-ALL cells activates LTR signaling in thymic stromal cells, thus promoting leukemogenesis.
Lymphotoxin-β receptor in microenvironmental cells promotes the development of T-cell acute lymphoblastic leukaemia with cortical/mature immunophenotype.
Sex, Age, Specimen part
View SamplesWe exploited microarrays to detail the global program of gene expression underlying normal stem cells and cancer stem cells in the cerebellum and in medulloblastomas (MBs).
Gene signatures associated with mouse postnatal hindbrain neural stem cells and medulloblastoma cancer stem cells identify novel molecular mediators and predict human medulloblastoma molecular classification.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A systems analysis identifies a feedforward inflammatory circuit leading to lethal influenza infection.
Sex, Specimen part
View SamplesTranscriptomic comparison of 5 cell types during lethal and non-lethal influenza infection and further use of these signatures in a top-down systems analysis investigating the relative pathogenic contributions of direct viral damage to lung epithelium vs. dysregulated immunity during lethal influenza infection.
A systems analysis identifies a feedforward inflammatory circuit leading to lethal influenza infection.
Sex, Specimen part
View SamplesIntroduction: Sepsis is a complex immunological response to infection characterized by early hyperinflammation followed by severe and protracted immunosuppression, suggesting that a multi-marker approach has the greatest clinical utility for early detection, within a clinical environment focused on SIRS differentiation. Pre-clinical research using an equine sepsis model identified a panel of gene expression biomarkers that define the early aberrant immune activation. Thus, the primary objective was to apply these gene expression biomarkers to distinguish patients with sepsis from those who had undergone major open surgery and had clinical outcomes consistent with systemic inflammation due to physical trauma and wound healing.
Development and validation of a novel molecular biomarker diagnostic test for the early detection of sepsis.
Specimen part
View SamplesAngiogenesis is essential for tissue development, wound healing and tissue perfusion, with its dysregulation linked-to tumorigenesis, rheumatoid arthritis and heart disease. Here we show pro-angiogenic stimuli couple to NADPH oxidase-dependent generation of oxidants that catalyse an activating intermolecular-disulphide between regulatory-RI subunits of protein kinase A (PKA), which stimulates PKA-dependent ERK signalling. This is crucial to blood vessel growth as 'redox-dead' Cys17Ser RI knock-in mice fully resistant to PKA disulphide-activation have deficient angiogenesis in models of hind limb ischaemia and tumour-implant growth. Disulphide-activation of PKA represents a new therapeutic target in diseases with aberrant angiogenesis.
Deficient angiogenesis in redox-dead Cys17Ser PKARIα knock-in mice.
Specimen part
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