Activation of the PP2A-B56α heterocomplex synergizes with venetoclax therapies in AML through BCL2 and MCL1 modulation.

Venetoclax combination therapies are becoming the standard of care in acute myeloid leukemia (AML). However, the therapeutic benefit of these drugs in older/unfit patients is limited to only a few months, highlighting the need for more effective therapies. Protein phosphatase 2A (PP2A) is a tumor suppressor phosphatase with pleiotropic functions that becomes inactivated in ∼70% of AML cases. PP2A promotes cancer cell death by modulating the phosphorylation state in a variety of proteins along the mitochondrial apoptotic pathway. We therefore hypothesized that pharmacological PP2A reactivation could increase BCL2 dependency in AML cells and, thus, potentiate venetoclax-induced cell death. Here, by using 3 structurally distinct PP2A-activating drugs, we show that PP2A reactivation synergistically enhances venetoclax activity in AML cell lines, primary cells, and xenograft models. Through the use of gene editing tools and pharmacological approaches, we demonstrate that the observed therapeutic synergy relies on PP2A complexes containing the B56α regulatory subunit, of which expression dictates response to the combination therapy. Mechanistically, PP2A reactivation enhances venetoclax-driven apoptosis through simultaneous inhibition of antiapoptotic BCL2 and extracellular signal-regulated kinase signaling, with the latter decreasing MCL1 protein stability. Finally, PP2A targeting increases the efficacy of the clinically approved venetoclax and azacitidine combination in vitro, in primary cells, and in an AML patient-derived xenograft model. These preclinical results provide a scientific rationale for testing PP2A-activating drugs with venetoclax combinations in AML.

Targeting the immune microenvironment in Waldenström macroglobulinemia via halting the CD40/CD40-ligand axis.

Recent investigations have improved our understanding of the molecular aberrations supporting Waldenström macroglobulinemia (WM) biology; however, whether the immune microenvironment contributes to WM pathogenesis remains unanswered. First, we showed how a transgenic murine model of human-like lymphoplasmacytic lymphoma/WM exhibits an increased number of regulatory T cells (Tregs) relative to control mice. These findings were translated into the WM clinical setting, in which the transcriptomic profiling of Tregs derived from patients with WM unveiled a peculiar WM-devoted messenger RNA signature, with significant enrichment for genes related to nuclear factor κB-mediated tumor necrosis factor α signaling, MAPK, and PI3K/AKT, which was paralleled by a different Treg functional phenotype. We demonstrated significantly higher Treg induction, expansion, and proliferation triggered by WM cells, compared with their normal cellular counterpart; with a more profound effect within the context of CXCR4C1013G-mutated WM cells. By investigating the B-cell-to-T-cell cross talk at single-cell level, we identified the CD40/CD40-ligand as a potentially relevant axis that supports WM cell-Tregs interaction. Our findings demonstrate the existence of a Treg-mediated immunosuppressive phenotype in WM, which can be therapeutically reversed by blocking the CD40L/CD40 axis to inhibit WM cell growth.

Adaptive potential of maritime pine under contrasting environments.

BACKGROUND: Predicting the adaptability of forest tree populations under future climates requires a better knowledge of both the adaptive significance and evolvability of measurable key traits. Phenotypic plasticity, standing genetic variation and degree of phenotypic integration shape the actual and future population genetic structure, but empirical estimations in forest tree species are still extremely scarce. We analysed 11 maritime pine populations covering the distribution range of the species (119 families and 8 trees/family, ca. 1300 trees) in a common garden experiment planted at two sites with contrasting productivity. We used plant height as a surrogate of fitness and measured five traits (mean and plasticity of carbon isotope discrimination, specific leaf area, needle biomass, Phenology growth index) related to four different strategies (acquisitive economics, photosynthetic organ size, growth allocation and avoidance of water stress). RESULTS: Estimated values of additive genetic variation would allow adaptation of the populations to future environmental conditions. Overall phenotypic integration and selection gradients were higher at the high productivity site, while phenotypic integration within populations was higher at the low productivity site. Response to selection was related mainly to photosynthetic organ size and drought-avoidance mechanisms rather than to water use efficiency. Phenotypic plasticity of water use efficiency could be maladaptive, resulting from selection for height growth. CONCLUSIONS: Contrary to the expectations in a drought tolerant species, our study suggests that variation in traits related to photosynthetic organ size and acquisitive investment of resources drive phenotypic selection across and within maritime pine populations. Both genetic variation and evolvability of key adaptive traits were considerably high, including plasticity of water use efficiency. These characteristics would enable a relatively fast micro-evolution of populations in response to the ongoing climate changes. Moreover, differentiation among populations in the studied traits would increase under the expected more productive future Atlantic conditions.

The alternative RelB NF-κB subunit is a novel critical player in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is the most frequent lymphoid malignancy affecting adults. The NF-κB transcription factor family is activated by 2 main pathways, the canonical and the alternative NF-κB activation pathway, with different functions. The alternative NF-κB pathway leads to activation of the transcriptionally active RelB NF-κB subunit. Alternative NF-κB activation status and its role in DLBCL pathogenesis remain undefined. Here, we reveal a frequent activation of RelB in a large cohort of DLBCL patients and cell lines, independently of their activated B-cell-like or germinal center B-cell-like subtype. RelB activity defines a new subset of patients with DLBCL and a peculiar gene expression profile and mutational pattern. Importantly, RelB activation does not correlate with the MCD genetic subtype, enriched for activated B-cell-like tumors carrying MYD88L265P and CD79B mutations that cooperatively activate canonical NF-κB, thus indicating that current genetic tools to evaluate NF-κB activity in DLBCL do not provide information on the alternative NF-κB activation. Furthermore, the newly defined RelB-positive subgroup of patients with DLBCL exhibits a dismal outcome after immunochemotherapy. Functional studies revealed that RelB confers DLBCL cell resistance to DNA damage-induced apoptosis in response to doxorubicin, a genotoxic agent used in the front-line treatment of DLBCL. We also show that RelB positivity is associated with high expression of cellular inhibitor of apoptosis protein 2 (cIAP2). Altogether, RelB activation can be used to refine the prognostic stratification of DLBCL and may contribute to subvert the therapeutic DNA damage response in a segment of patients with DLBCL.

Deep MRD profiling defines outcome and unveils different modes of treatment resistance in standard- and high-risk myeloma.

Patients with multiple myeloma (MM) carrying standard- or high-risk cytogenetic abnormalities (CAs) achieve similar complete response (CR) rates, but the later have inferior progression-free survival (PFS). This questions the legitimacy of CR as a treatment endpoint and represents a biological conundrum regarding the nature of tumor reservoirs that persist after therapy in high-risk MM. We used next-generation flow (NGF) cytometry to evaluate measurable residual disease (MRD) in MM patients with standard- vs high-risk CAs (n = 300 and 90, respectively) enrolled in the PETHEMA/GEM2012MENOS65 trial, and to identify mechanisms that determine MRD resistance in both patient subgroups (n = 40). The 36-month PFS rates were higher than 90% in patients with standard- or high-risk CAs achieving undetectable MRD. Persistent MRD resulted in a median PFS of âˆ¼3 and 2 years in patients with standard- and high-risk CAs, respectively. Further use of NGF to isolate MRD, followed by whole-exome sequencing of paired diagnostic and MRD tumor cells, revealed greater clonal selection in patients with standard-risk CAs, higher genomic instability with acquisition of new mutations in high-risk MM, and no unifying genetic event driving MRD resistance. Conversely, RNA sequencing of diagnostic and MRD tumor cells uncovered the selection of MRD clones with singular transcriptional programs and reactive oxygen species-mediated MRD resistance in high-risk MM. Our study supports undetectable MRD as a treatment endpoint for patients with MM who have high-risk CAs and proposes characterizing MRD clones to understand and overcome MRD resistance. This trial is registered at www.clinicaltrials.gov as #NCT01916252.

Straightening the crooked: intraspecific divergence of stem posture control and associated trade-offs in a model conifer.

Although the straightening capacity of the stem is key for light capture and mechanical stability in forest trees, little is known about its adaptive implications. Assuming that stem straightening is costly, trade-offs are expected with competing processes such as growth, maintenance, and defence. We established a manipulative experiment in a common garden of Pinus pinaster including provenances typically showing either straight-stemmed or crooked-stemmed phenotypes. We imposed a bending up to 35º on plants aged 9 years of both provenance groups and followed the straightening kinetics and shoot elongation after releasing. Eight months later, we destructively assessed biomass partitioning, reaction wood, wood microdensity, xylem reserve carbohydrates, and phloem secondary metabolites. The experimental bending and release caused significant, complex changes with a marked difference between straight- and crooked-type plants. The straight-type recovered verticality faster and to a higher degree and developed more compression wood, while displaying a transitory delay in shoot elongation, reducing resource allocation to defence and maintaining the levels of non-structural carbohydrates compared with the crooked type. This combination of responses indicates the existence of intraspecific divergence in the reaction to mechanical stresses that may be related to different adaptive phenotypic plasticity.

The role of maternal age, growth, and environment in shaping offspring performance in an aerial conifer seed bank.

PREMISE: Maternal effects have been demonstrated to affect offspring performance in many organisms, and in plants, seeds are important mediators of these effects. Some woody plant species maintain long-lasting canopy seed banks as an adaptation to wildfires. Importantly, these seeds stored in serotinous cones are produced by the mother plant under varying ontogenetic and physiological conditions. METHODS: We sampled the canopy seed bank of a highly serotinous population of Pinus pinaster to test whether maternal age and growth and the environmental conditions during each crop year affected seed mass and ultimately germination and early survival. After determining retrospectively the year of each seed cohort, we followed germination and early survival in a semi-natural common garden. RESULTS: Seed mass was related to maternal age and growth at the time of seed production; i.e., slow-growing, older mothers had smaller seeds, and fast-growing, young mothers had larger seeds, which could be interpreted either as a proxy of senescence or as a maternal strategy. Seed mass had a positive effect on germination success, but aside from differences in seed mass, maternal age had a negative effect and diameter had a positive effect on germination timing and subsequent survival. CONCLUSIONS: The results highlight the importance of maternal conditions combined with seed mass in shaping seedling establishment. Our findings open new insights in the offspring performance deriving from long-term canopy seed banks, which may have high relevance for plant adaptation.

PD-1/PD-L1 immune checkpoint and p53 loss facilitate tumor progression in activated B-cell diffuse large B-cell lymphomas.

Refractory or relapsed diffuse large B-cell lymphoma (DLBCL) often associates with the activated B-cell-like (ABC) subtype and genetic alterations that drive constitutive NF-κB activation and impair B-cell terminal differentiation. Here, we show that DNA damage response by p53 is a central mechanism suppressing the pathogenic cooperation of IKK2ca-enforced canonical NF-κB and impaired differentiation resulting from Blimp1 loss in ABC-DLBCL lymphomagenesis. We provide evidences that the interplay between these genetic alterations and the tumor microenvironment select for additional molecular addictions that promote lymphoma progression, including aberrant coexpression of FOXP1 and the B-cell mutagenic enzyme activation-induced deaminase, and immune evasion through major histocompatibility complex class II downregulation, PD-L1 upregulation, and T-cell exhaustion. Consistently, PD-1 blockade cooperated with anti-CD20-mediated B-cell cytotoxicity, promoting extended T-cell reactivation and antitumor specificity that improved long-term overall survival in mice. Our data support a pathogenic cooperation among NF-κB-driven prosurvival, genetic instability, and immune evasion mechanisms in DLBCL and provide preclinical proof of concept for including PD-1/PD-L1 blockade in combinatorial immunotherapy for ABC-DLBCL.

Direct and correlated responses to artificial selection for growth and water-use efficiency in a Mediterranean pine.

PREMISE: Persistence of tree populations in the face of global change relies on their capacity to respond to biotic and abiotic stressors through plastic or adaptive changes. Genetic adaptation will depend on the additive genetic variation within populations and the heritability of traits related to stress tolerance. Because traits can be genetically linked, selective pressure acting on one trait may lead to correlated responses in other traits. METHODS: To test direct and correlated responses to selection for growth and drought tolerance in Pinus halepensis, we selected trees in a parental population for higher growth and greater water-use efficiency (WUE) and compared their offspring with the offspring of random trees from the parental population in two contrasting common gardens. We estimated direct responses to selection for growth and WUE and correlated responses for growth and tolerance to abiotic and biotic stressors. RESULTS: We found a strong response to selection and high realized heritability for WUE, but no response to selection for growth. Correlated responses to selection in other life-history traits were not significant, except for concentration of some chemical defenses, which was greater in the offspring of mother trees selected for growth than in the offspring of unselected control trees. CONCLUSIONS: The empirical evidence of direct responses to selection for high WUE suggests that P. halepensis has the potential to evolve in response to increasing drought stress. Contrary to expectations, the results are not conclusive of a potential negative impact of WUE and growth selection on other key life-history traits.

Phenotypic integration and life history strategies among populations of Pinus halepensis: an insight through structural equation modelling.

BACKGROUND AND AIMS: Understanding inter-population variation in the allocation of resources to specific anatomical compartments and physiological processes is crucial to disentangle adaptive patterns in forest species. This work aims to evaluate phenotypic integration and trade-offs among functional traits as determinants of life history strategies in populations of a circum-Mediterranean pine that dwells in environments where water and other resources are in limited supply. METHODS: Adult individuals of 51 populations of Pinus halepensis grown in a common garden were characterized for 11 phenotypic traits, including direct and indirect measures of water uptake at different depths, leaf area, stomatal conductance, chlorophyll content, non-structural carbohydrates, stem diameter and tree height, age at first reproduction and cone production. The population differentiation in these traits was tested through analysis of variance (ANOVA). The resulting populations' means were carried forward to a structural equation model evaluating phenotypic integration between six latent variables (summer water uptake depth, summer transpiration, spring photosynthetic capacity, growth, reserve accumulation and reproduction). KEY RESULTS: Water uptake depth and transpiration covaried negatively among populations, as the likely result of a common selective pressure for drought resistance, while spring photosynthetic capacity was lower in populations originating from dry areas. Transpiration positively influenced growth, while growth was negatively related to reproduction and reserves among populations. Water uptake depth negatively influenced reproduction. CONCLUSIONS: The observed patterns indicate a differentiation in life cycle features between fast-growing and slow-growing populations, with the latter investing significantly more in reproduction and reserves. We speculate that such contrasting strategies result from different arrays of life history traits underlying the very different ecological conditions that the Aleppo pine must face across its distribution range. These comprise, principally, drought as the main stressor and fire as the main ecological disturbance of the Mediterranean basin.

Richter transformation driven by Epstein-Barr virus reactivation during therapy-related immunosuppression in chronic lymphocytic leukaemia.

The increased risk of Richter transformation (RT) in patients with chronic lymphocytic leukaemia (CLL) due to Epstein-Barr virus (EBV) reactivation during immunosuppressive therapy with fludarabine other targeted agents remains controversial. Among 31 RT cases classified as diffuse large B-cell lymphoma (DLBCL), seven (23%) showed EBV expression. In contrast to EBV- tumours, EBV+ DLBCLs derived predominantly from IGVH-hypermutated CLL, and they also showed CLL-unrelated IGVH sequences more frequently. Intriguingly, despite having different cellular origins, clonally related and unrelated EBV+ DLBCLs shared a previous history of immunosuppressive chemo-immunotherapy, a non-germinal centre DLBCL phenotype, EBV latency programme type II or III, and very short survival. These data suggested that EBV reactivation during therapy-related immunosuppression can transform either CLL cells or non-tumoural B lymphocytes into EBV+ DLBCL. To investigate this hypothesis, xenogeneic transplantation of blood cells from 31 patients with CLL and monoclonal B-cell lymphocytosis (MBL) was performed in Rag2-/- IL2γc-/- mice. Remarkably, the recipients' impaired immunosurveillance favoured the spontaneous outgrowth of EBV+ B-cell clones from 95% of CLL and 64% of MBL patients samples, but not from healthy donors. Eventually, these cells generated monoclonal tumours (mostly CLL-unrelated but also CLL-related), recapitulating the principal features of EBV+ DLBCL in patients. Accordingly, clonally related and unrelated EBV+ DLBCL xenografts showed indistinguishable cellular, virological and molecular features, and synergistically responded to combined inhibition of EBV replication with ganciclovir and B-cell receptor signalling with ibrutinib in vivo. Our study underscores the risk of RT driven by EBV in CLL patients receiving immunosuppressive therapies, and provides the scientific rationale for testing ganciclovir and ibrutinib in EBV+ DLBCL. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Targeting the anion exchanger 2 with specific peptides as a new therapeutic approach in B lymphoid neoplasms.

Regulatory T (Treg) cells can weaken antitumor immune responses, and inhibition of their function appears to be a promising therapeutic approach in cancer patients. Mice with targeted deletion of the gene encoding the Cl-/HCO3- anion exchanger AE2 (also termed SLC4A2), a membrane-bound carrier involved in intracellular pH regulation, showed a progressive decrease in the number of Treg cells. We therefore challenged AE2 as a potential target for tumor therapy, and generated linear peptides designed to bind the third extracellular loop of AE2, which is crucial for its exchange activity. Peptide p17AE2 exhibited optimal interaction ability and indeed promoted apoptosis in mouse and human Treg cells, while activating effector T-cell function. Interestingly, this linear peptide also induced apoptosis in different types of human leukemia, lymphoma and multiple myeloma cell lines and primary malignant samples, while it showed only moderate effects on normal B lymphocytes. Finally, a macrocyclic AE2 targeting peptide exhibiting increased stability in vivo was effective in mice xenografted with B-cell lymphoma. These data suggest that targeting the anion exchanger AE2 with specific peptides may represent an effective therapeutic approach in B-cell malignancies.

DNA methylation profiling identifies two splenic marginal zone lymphoma subgroups with different clinical and genetic features.

Splenic marginal zone lymphoma is a rare lymphoma. Loss of 7q31 and somatic mutations affecting the NOTCH2 and KLF2 genes are the commonest genomic aberrations. Epigenetic changes can be pharmacologically reverted; therefore, identification of groups of patients with specific epigenomic alterations might have therapeutic relevance. Here we integrated genome-wide DNA-promoter methylation profiling with gene expression profiling, and clinical and biological variables. An unsupervised clustering analysis of a test series of 98 samples identified 2 clusters with different degrees of promoter methylation. The cluster comprising samples with higher-promoter methylation (High-M) had a poorer overall survival compared with the lower (Low-M) cluster. The prognostic relevance of the High-M phenotype was confirmed in an independent validation set of 36 patients. In the whole series, the High-M phenotype was associated with IGHV1-02 usage, mutations of NOTCH2 gene, 7q31-32 loss, and histologic transformation. In the High-M set, a number of tumor-suppressor genes were methylated and repressed. PRC2 subunit genes and several prosurvival lymphoma genes were unmethylated and overexpressed. A model based on the methylation of 3 genes (CACNB2, HTRA1, KLF4) identified a poorer-outcome patient subset. Exposure of splenic marginal zone lymphoma cell lines to a demethylating agent caused partial reversion of the High-M phenotype and inhibition of proliferation.

Acquired mutations in BCL2 family proteins conferring resistance to the BH3 mimetic ABT-199 in lymphoma.

Acquired resistance to targeted drugs is emerging as an obstacle to successful cancer treatment. Recently, a BCL2-selective BH3 mimetic termed ABT-199 showed promising therapeutic results in BCL2-dependent tumors. Based on its high affinity for BCL2, we studied potential mechanisms conferring resistance upon ABT-199 therapy, aiming to anticipate its occurrence in the clinic. Two models of resistant lymphomas were established by continuous ABT-199 exposure. In resistant Bcl2-expressing mouse lymphoma cells, 2 missense mutations within the Bcl2 BH3 domain were identified. Both F101C and F101L mutations impeded ABT-199 binding to the BH3 domain, therefore suppressing mitochondrial apoptosis. In resistant human lymphoma cells, a missense mutation in the C-terminal transmembrane domain of proapoptotic BAX (G179E) was found, which abrogated BAX anchoring to mitochondria and blocked ABT-199-induced apoptosis both in vitro and in vivo. Importantly, G179E BAX mutation also induced partial cross-resistance to other antineoplastic drugs. Our study reveals the acquisition of mutations in BCL2 family proteins as a novel mechanism of apoptosis resistance in cancer. These results anticipate the potential development of such mutations in patients treated with ABT-199, providing a basis to preventing their occurrence and to designing drugs able to circumvent the acquired resistance.

Life-history correlations with seasonal cold hardiness in maritime pine.

PREMISE OF THE STUDY: Plants have developed mechanisms to withstand stressful environmental conditions, but the high energetic cost of these mechanisms may involve exchanges with other key functions. While trade-offs between cold hardiness and growth rates are a general assumption, we lack information regarding genetically based trade-offs between cold hardiness and other life-history traits. Such information has strong implications for tree conservation and breeding, especially in the context of ongoing climate change. METHODS: We used a common garden progeny test to examine the relationships between seasonal cold hardiness and life-history traits of growth, reproduction, juvenile ontogeny, and phenology in 75 families of six maritime pine (Pinus pinaster Ait.) populations, three of continental and three of coastal origins. KEY RESULTS: We found a clear differentiation among populations with regard to cold hardiness and life-history traits. Two continental Iberian populations showed high cold tolerance and slower growth, but faster ontogenetic development in relation to both vegetative heteroblastic change in juveniles and the onset of female reproduction. The coastal populations displayed the opposite behavior, while the continental Moroccan population presented a unique combination of traits. We confirmed trade-offs between cold-hardiness and growth at the population level, but not within populations. There were no trade-offs with other life-history traits at either level. CONCLUSIONS: Relevant local adaptation syndromes were identified in the relationship between cold hardiness and life-history traits. These should be considered in developing tree management guidelines aimed at increasing productivity or adaptability under the expected conditions of climate change.

Disentangling plasticity of serotiny, a key adaptive trait in a Mediterranean conifer.

PREMISE OF THE STUDY: Serotiny, the maintenance of ripe seeds in closed fruits or cones until fire causes dehiscence, is a key adaptive trait of plants in fire-prone ecosystems, but knowledge of phenotypic plasticity for cone retention in woody plants is extremely scarce. On the basis of published literature and our field observations, we hypothesized that increased aridity might decrease the aerial seed bank as a plastic response, not necessarily adaptive. METHODS: We used a Pinus halepensis common garden replicated in three contrasted sites (mild, cold, and dry) to separate population differentiation from phenotypic plasticity of cone serotiny and canopy cone bank (CCB). Differences in growth among trees of the same provenance allowed us to include size effect as a proxy of ontogenetic age for the same chronological age of the trees. KEY RESULTS: Tree size had a strong negative effect on serotiny, but serotiny degree differed among trial sites even after accounting for size effects. As hypothesized, serotiny was lower at the harsh (dry and cold) sites compared with the mild site. Genetic variation for size-dependent cone serotiny and significant population × site interaction were confirmed, the latter implying different plasticity of serotiny among populations. Population differentiation for CCB showed an ecotypic trend, with positive correlation with temperature oscillation (continentality) and negative correlation with summer rainfall. CONCLUSIONS: Growth-limiting environments exacerbated the precocious release of seeds, contrary to the ecotypic trend found for the aerial cone bank, suggesting a counter-gradient plasticity. This plastic response is potentially maladaptive under a scenario of frequent wildfires.

Combined clinical and genomic signatures for the prognosis of early stage non-small cell lung cancer based on gene copy number alterations.

BACKGROUND: The development of a more refined prognostic methodology for early non-small cell lung cancer (NSCLC) is an unmet clinical need. An accurate prognostic tool might help to select patients at early stages for adjuvant therapies. RESULTS: A new integrated bioinformatics searching strategy, that combines gene copy number alterations and expression, together with clinical parameters was applied to derive two prognostic genomic signatures. The proposed methodology combines data from patients with and without clinical data with a priori information on the ability of a gene to be a prognostic marker. Two initial candidate sets of 513 and 150 genes for lung adenocarcinoma (ADC) and squamous cell carcinoma (SCC), respectively, were generated by identifying genes which have both: a) significant correlation between copy number and gene expression, and b) significant prognostic value at the gene expression level in external databases. From these candidates, two panels of 7 (ADC) and 5 (SCC) genes were further identified via semi-supervised learning. These panels, together with clinical data (stage, age and sex), were used to construct the ADC and SCC hazard scores combining clinical and genomic data. The signatures were validated in two independent datasets (n = 73 for ADC, n = 97 for SCC), confirming that the prognostic value of both clinical-genomic models is robust, statistically significant (P = 0.008 for ADC and P = 0.019 for SCC) and outperforms both the clinical models (P = 0.060 for ADC and P = 0.121 for SCC) and the genomic models applied separately (P = 0.350 for ADC and P = 0.269 for SCC). CONCLUSION: The present work provides a methodology to generate a robust signature using copy number data that can be potentially used to any cancer. Using it, we found new prognostic scores based on tumor DNA that, jointly with clinical information, are able to predict overall survival (OS) in patients with early-stage ADC and SCC.

Downregulation of FOXP1 is required during germinal center B-cell function.

B-cell maturation and germinal center (GC) formation are dependent on the interplay between BCL6 and other transcriptional regulators. FOXP1 is a transcription factor that regulates early B-cell development, but whether it plays a role in mature B cells is unknown. Analysis of human tonsillar B-cell subpopulations revealed that FOXP1 shows the opposite expression pattern to BCL6, suggesting that FOXP1 regulates the transition from resting follicular B cell to activated GC B cell. Chromatin immunoprecipitation-on-chip and gene expression assays on B cells indicated that FOXP1 acts as a transcriptional activator and repressor of genes involved in the GC reaction, half of which are also BCL6 targets. To study FOXP1 function in vivo, we developed transgenic mice expressing human FOXP1 in lymphoid cells. These mice exhibited irregular formation of splenic GCs, showing a modest increase in naïve and marginal-zone B cells and a significant decrease in GC B cells. Furthermore, aberrant expression of FOXP1 impaired transcription of noncoding γ1 germline transcripts and inhibited efficient class switching to the immunoglobulin G1 isotype. These studies show that FOXP1 is physiologically downregulated in GC B cells and that aberrant expression of FOXP1 impairs mechanisms triggered by B-cell activation, potentially contributing to B-cell lymphomagenesis.

Expression of MALT1 oncogene in hematopoietic stem/progenitor cells recapitulates the pathogenesis of human lymphoma in mice.

Chromosomal translocations involving the MALT1 gene are hallmarks of mucosa-associated lymphoid tissue (MALT) lymphoma. To date, targeting these translocations to mouse B cells has failed to reproduce human disease. Here, we induced MALT1 expression in mouse Sca1(+)Lin(-) hematopoietic stem/progenitor cells, which showed NF-κB activation and early lymphoid priming, being selectively skewed toward B-cell differentiation. These cells accumulated in extranodal tissues and gave rise to clonal tumors recapitulating the principal clinical, biological, and molecular genetic features of MALT lymphoma. Deletion of p53 gene accelerated tumor onset and induced transformation of MALT lymphoma to activated B-cell diffuse large-cell lymphoma (ABC-DLBCL). Treatment of MALT1-induced lymphomas with a specific inhibitor of MALT1 proteolytic activity decreased cell viability, indicating that endogenous Malt1 signaling was required for tumor cell survival. Our study shows that human-like lymphomas can be modeled in mice by targeting MALT1 expression to hematopoietic stem/progenitor cells, demonstrating the oncogenic role of MALT1 in lymphomagenesis. Furthermore, this work establishes a molecular link between MALT lymphoma and ABC-DLBCL, and provides mouse models to test MALT1 inhibitors. Finally, our results suggest that hematopoietic stem/progenitor cells may be involved in the pathogenesis of human mature B-cell lymphomas.

Using a brain-machine interface to control a hybrid upper limb exoskeleton during rehabilitation of patients with neurological conditions.

BACKGROUND: As a consequence of the increase of cerebro-vascular accidents, the number of people suffering from motor disabilities is raising. Exoskeletons, Functional Electrical Stimulation (FES) devices and Brain-Machine Interfaces (BMIs) could be combined for rehabilitation purposes in order to improve therapy outcomes. METHODS: In this work, a system based on a hybrid upper limb exoskeleton is used for neurological rehabilitation. Reaching movements are supported by the passive exoskeleton ArmeoSpring and FES. The movement execution is triggered by an EEG-based BMI. The BMI uses two different methods to interact with the exoskeleton from the user's brain activity. The first method relies on motor imagery tasks classification, whilst the second one is based on movement intention detection. RESULTS: Three healthy users and five patients with neurological conditions participated in the experiments to verify the usability of the system. Using the BMI based on motor imagery, healthy volunteers obtained an average accuracy of 82.9 ± 14.5 %, and patients obtained an accuracy of 65.3 ± 9.0 %, with a low False Positives rate (FP) (19.2 ± 10.4 % and 15.0 ± 8.4 %, respectively). On the other hand, by using the BMI based on detecting the arm movement intention, the average accuracy was 76.7 ± 13.2 % for healthy users and 71.6 ± 15.8 % for patients, with 28.7 ± 19.9 % and 21.2 ± 13.3 % of FP rate (healthy users and patients, respectively). CONCLUSIONS: The accuracy of the results shows that the combined use of a hybrid upper limb exoskeleton and a BMI could be used for rehabilitation therapies. The advantage of this system is that the user is an active part of the rehabilitation procedure. The next step will be to verify what are the clinical benefits for the patients using this new rehabilitation procedure.