Targeting NOTCH1 in combination with antimetabolite drugs prolongs life span in relapsed pediatric and adult T-acute lymphoblastic leukemia xenografts.

T-cell acute lymphoblastic leukemia (T-ALL) is a hematologic tumor, characterized by several genetic alterations, that constitutes 15% of pediatric and 25% of adult ALL. While with current therapeutic protocols children and adults' overall survival (OS) rates reach 85-90% and 40-50%, respectively, the outcome for both pediatric and adult T-ALL patients that relapse or are refractory to induction therapy, remains extremely poor, achieving around 25% OS for both patient groups. About 60% of T-ALL patients show increased NOTCH1 activity, due to activating NOTCH1 mutations or alterations in its ubiquitin ligase FBXW7.

Dissecting molecular mechanisms of resistance to NOTCH1-targeted therapy in T-cell acute lymphoblastic leukemia xenografts.

Despite substantial progress in treatment of T-cell acute lymphoblastic leukemia (T-ALL), mortality remains relatively high, mainly due to primary or acquired resistance to chemotherapy. Further improvements in survival demand better understanding of T-ALL biology and development of new therapeutic strategies. The Notch pathway has been involved in the pathogenesis of this disease and various therapeutic strategies are currently under development, including selective targeting of NOTCH receptors by inhibitory antibodies.

Involvement of NADPH Oxidase 1 in Liver Kinase B1-Mediated Effects on Tumor Angiogenesis and Growth.

The liver kinase B1 () gene is a tumor suppressor with an established role in the control of cell metabolism and oxidative stress. However, whether dis-regulated oxidative stress promotes growth of LKB1-deficient tumors remains substantially unknown. Through studies, we observed that loss of LKB1 perturbed expression of several genes involved in reactive oxygen species (ROS) homeostasis.

Histone deacetylase 6 controls Notch3 trafficking and degradation in T-cell acute lymphoblastic leukemia cells.

Several studies have revealed that endosomal sorting controls the steady-state levels of Notch at the cell surface in normal cells and prevents its inappropriate activation in the absence of ligands. However, whether this highly dynamic physiologic process can be exploited to counteract dysregulated Notch signaling in cancer cells remains unknown. T-ALL is a malignancy characterized by aberrant Notch signaling, sustained by activating mutations in Notch1 as well as overexpression of Notch3, a Notch paralog physiologically subjected to lysosome-dependent degradation in human cancer cells.

AKR1C enzymes sustain therapy resistance in paediatric T-ALL.

Background: Despite chemotherapy intensification, a subgroup of high-risk paediatric T-cell acute lymphoblastic leukemia (T-ALL) patients still experience treatment failure. In this context, we hypothesised that therapy resistance in T-ALL might involve aldo-keto reductase 1C (AKR1C) enzymes as previously reported for solid tumors.

Methods: Expression of NRF2-AKR1C signaling components has been analysed in paediatric T-ALL samples endowed with different treatment outcomes as well as in patient-derived xenografts of T-ALL.

Reconstruction of gene regulatory modules from RNA silencing of IFN-α modulators: experimental set-up and inference method.

Background: Inference of gene regulation from expression data may help to unravel regulatory mechanisms involved in complex diseases or in the action of specific drugs. A challenging task for many researchers working in the field of systems biology is to build up an experiment with a limited budget and produce a dataset suitable to reconstruct putative regulatory modules worth of biological validation.

Results: Here, we focus on small-scale gene expression screens and we introduce a novel experimental set-up and a customized method of analysis to make inference on regulatory modules starting from genetic perturbation data, e.

DLL4 regulates NOTCH signaling and growth of T acute lymphoblastic leukemia cells in NOD/SCID mice.

Activation of the NOTCH pathway occurs commonly in T acute lymphoblastic leukemia (T-ALL) mainly due to mutations in NOTCH1 or alterations in FBW7 and is involved in the regulation of cell proliferation and survival. Since mutations hit different domains of the receptor, they are predicted to heterogeneously perturb ligand-induced NOTCH1 activity. Moreover, T-ALL cells also co-express NOTCH3 receptors which could be triggered by different ligands.