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Allogeneic hematopoietic stem cell transplantation is the treatment of choice for autosomal recessive osteopetrosis caused by defects in the TCIRG1 gene. Despite recent progress in conditioning, an important number of patients are not eligible for allogeneic stem cell transplantation because of the severity of the disease and significant transplant-related morbidity. We exploited peripheral CD34(+) cells, known to circulate at high frequency in the peripheral blood of TCIRG1-deficient patients, as a novel cell source for autologous transplantation of gene corrected cells. Detailed phenotypical analysis showed that circulating CD34(+). cells have a cellular composition that resembles bone marrow (BM), supporting their use in gene therapy protocols. Transcriptomic profile revealed enrichment in genes expressed by hematopoietic stem and progenitor cells (HSPC). To overcome the limit of BM harvest/HSPC mobilization and serial blood drawings in TCIRG1 patients, we applied UM171-based ex vivo expansion of HSPC coupled with lentiviral gene transfer. Circulating CD34(+). cells from TCIRG1-defective patients were transduced with a clinically-optimized lentiviral vector expressing TCIRG1 under the control of phosphoglycerate promoter and expanded ex vivo. Expanded cells maintained long-term engraftment capacity and multi-lineage repopulating potential when transplanted in vivo both in primary and secondary NOD scid gamma common chain (NSG) recipients. Moreover, when CD34(+) cells were differentiated in vitro, genetically corrected osteoclasts resorbed the bone efficiently. Overall, we provide evidence that expansion of circulating HSPC coupled to gene therapy can overcome the limit of stem cell harvest in osteopetrotic patients, thus opening the way to future gene-based treatment of skeletal diseases caused by BM fibrosis.

Forest ecosystems are important providers of ecosystem functions and services belonging to four categories: supporting, provisioning, regulating and cultural ecosystem services. Forest management, generally focused on timber production, has consequences on the ability of the system to keep providing services. Silviculture, in fact, may affect the ecological structures and processes from which services arise. In particular, the removal of biomass causes a radical change in the stocks and flows of energy characterizing the system. Aiming at the assessment of differences in stored natural capital and ecosystem functions and services provision, three differently managed temperate forests of common beech (Fagus sylvatica) were considered: (1) a forest in semi-natural condition, (2) a forest carefully managed to get timber in a sustainable way and (3) a forest exploited without management. Natural capital and ecosystem functions and services are here accounted in biophysical terms. Specifically, all the resources used up to create the biomass (stock) and maintain the production (flow) of the different components of the forest system were calculated. Both stored emergy and empower decrease with increasing human pressure on the forest, resulting in a loss of natural capital and a diminished ability of the natural system to contribute to human well-being in terms of ecosystem services provision.

Terricolous lichen communities in lowlands occur especially in open dry habitats. Such communities are often dominated by species of the genus Cladonia, which are very variable in morphology, reproduction strategies, and secondary metabolites. In this work, we investigated traits-environment relationships considering vegetation dynamics, substrate pH, disturbance, and climate. A total of 122 plots were surveyed in 41 acidic dry grasslands in the western Po Plain (Northern Italy). Relationships between Cladonia traits and environmental variables were investigated by means of a model-based Fourth Corner Analysis. Thallus morphology and metabolites responded to vegetation dynamics, substrate pH, disturbance, and climate, whereas reproduction strategies responded only to vegetation dynamics. Traits’ correlations with vegetation dynamics elucidate their colonization patterns in open dry habitats or suggest biotic interactions with bryophytes and vascular plants. In addition, correlations between metabolites and environmental factors support interpretations of their ecological roles. Our results also stress the importance of studying traits’ relationships with climatic factors as an alert towards lichen reactions to climate change.

In this contribution, new data concerning bryophytes, fungi and lichens of the Italian flora are presented. It includes new records, confirmations or exclusions for the bryophyte genera Acaulon, Campylopus, Entosthodon, Homomallium, Pseudohygrohypnum, and Thuidium, the fungal genera Entoloma, Cortinarius, Mycenella, Oxyporus, and Psathyrella and the lichen genera Anaptychia, Athallia, Baeomyces, Bagliettoa, Calicium, Nephroma, Pectenia, Phaeophyscia, Polyblastia, Protoparmeliopsis, Pyrenula, Ramalina, and Sanguineodiscus.

Epiphytic lichens were surveyed in the “Bosco Siro Negri” Integral Nature State Reserve (province of Pavia, Lombardy, NW Italy), which hosts a well-preserved fragment of oak-elm floodplain forest (Natura 2000 Habitat 91F0). The core woodland fragment hosted only four species on the tree boles, i.e. Lepraria finkii plus the forest specialists Coenogonium pineti, Diarthonis spadicea, and Opegrapha vermicellifera. An additional eight nitro- and photophytic species were recorded on the highest twigs of the canopy. The whole Reserve, including the neighbouring degraded woodlands and poplar plantations, hosted 27 epiphytic lichen taxa. The lower Ticino River valley between Vigevano and Pavia, in which the Reserve is located, was surveyed for epiphytic lichens in an additional 45 sites, including 15 wellpreserved oak-elm/hornbeam woodlands (Habitat 91F0), 15 degraded broadleaved woodlands with high occurrence of black locust and 15 poplar plantations. Overall, 32 species were recorded. Well-preserved woodlands had a lower species richness, but they hosted forest specialists not occurring in the other two habitats. Graphis pulverulenta and Lecania cyrtellina are new to Lombardy. Anisomeridium polypori, Diarthonis spadicea, Lecanora expallens and Pseudoschismatomma rufescens are reported from Lombardy for the second time.

Rubinstein-Taybi syndrome (RSTS) is a rare multisystem developmental disorder with moderate to severe intellectual disability caused by heterozygous mutations of either CREBBP or EP300 genes encoding CBP/p300 chromatin regulators. We explored the gene programs and processes underlying the morphological and functional alterations shown by iPSC-derived neurons modeling RSTS to bridge the molecular changes resulting from defective CBP/p300 to cognitive impairment. By global transcriptome analysis, we compared the differentially expressed genes (DEGs) marking the transition from iPSC-derived neural progenitors to cortical neurons (iNeurons) of five RSTS patients carrying private CREBBP/EP300 mutations and manifesting differently graded neurocognitive signs with those of four healthy controls. Our data shows a defective and altered neuroprogenitor to neuron transcriptional program in the cells from RSTS patients. First, transcriptional regulation is weaker in RSTS as less genes than in controls are modulated, including genes of key processes of mature functional neurons, such as those for voltage-gated channels and neurotransmitters and their receptors. Second, regulation is subverted as genes acting at pre-terminal stages of neural differentiation in cell polarity and adhesive functions (members of the cadherin family) and axon extension/guidance (members of the semaphorins and SLIT receptors families) are improperly upregulated. Impairment or delay of RSTS neuronal differentiation program is also evidenced by decreased modulation of the overall number of neural differentiation markers, significantly impacting the initial and final stages of the differentiation cascade. Last, extensive downregulation of genes for RNA/DNA metabolic processes confirms that RSTS is a global transcription disorder, consistent with a syndrome driven by chromatin dysregulation. Interestingly, the morphological and functional alterations we have previously appointed as biomarkers of RSTS iNeurons provide functional support to the herein designed transcriptome profile pointing to key dysregulated neuronal genes as main contributors to patients’ cognitive deficit. The impact of RSTS transcriptome may go beyond RSTS as comparison of dysregulated genes across modeled neurodevelopmental disorders could unveil convergent genes of cognitive impairment., This work was supported by ERA-NET NEURON JTC2015 “Chromisyn” (to L.L.) and by Italian MOH RC 08C921 to IRCSS Istituto Auxologico Italiano. A.B. and R.M-V. research is supported by grants SAF2017-87928-R and PCIN-2015-192-C02-01 from MICINN co-financed by ERDF, and PROMETEO/2016/026 from the Generalitat Valenciana. The Instituto de Neurociencias is a “Centre of Excellence Severo Ochoa.”

Hemorrhagic shock is a leading cause of morbidity and mortality worldwide. Significant blood loss may lead to decreased blood pressure and inadequate tissue perfusion with resultant organ failure and death, even after replacement of lost blood volume. One reason for this high acuity is that the fundamental mechanisms of shock are poorly understood. Proteomic and metabolomic approaches have been used to investigate the molecular events occurring in hemorrhagic shock but, to our knowledge, a systematic analysis of the transcriptomic profile is missing. Therefore, a pilot analysis using paired-end RNA sequencing was used to identify changes that occur in the blood transcriptome of rats subjected to hemorrhagic shock after blood reinfusion. Hemorrhagic shock was induced using a Wigger’s shock model. The transcriptome of whole blood from shocked animals shows modulation of genes related to inflammation and immune response (Tlr13, Il1b, Ccl6, Lgals3), antioxidant functions (Mt2A, Mt1), tissue injury and repair pathways (Gpnmb, Trim72) and lipid mediators (Alox5ap, Ltb4r, Ptger2) compared with control animals. These findings are congruent with results obtained in hemorrhagic shock analysis by other authors using metabolomics and proteomics. The analysis of blood transcriptome may be a valuable tool to understand the biological changes occurring in hemorrhagic shock and a promising approach for the identification of novel biomarkers and therapeutic targets. Impact statement This study provides the first pilot analysis of the changes occurring in transcriptome expression of whole blood in hemorrhagic shock (HS) rats. We showed that the analysis of blood transcriptome is a useful approach to investigate pathways and functional alterations in this disease condition. This pilot study encourages the possible application of transcriptome analysis in the clinical setting, for the molecular profiling of whole blood in HS patients.

BACKGROUND The authors describe a family with a high penetrance of plasma cell dyscrasias, suggesting inheritance of an autosomal dominant risk allele. METHODS The authors performed whole-exome sequencing and reported on a combined approach aimed at the identification of causative variants and risk loci, using the wealth of data provided by this approach. RESULTS The authors identified gene mutations and single-nucleotide polymorphisms of potential significance, and pinpointed a known risk locus for myeloma as a potential area of transmissible risk in the family. CONCLUSIONS To the authors' knowledge, the current study is the first to provide a whole-exome sequencing approach to such cases, and a framework analysis that could be applied to further understanding of the inherited risk of developing plasma cell dyscrasias. Cancer 2017. © 2017 American Cancer Society.

Persistent alteration of plasma neuroactive steroid levels associated with major depression has been recently reported in men after the suspension of the treatment for androgenetic alopecia with finasteride, an inhibitor of the enzyme 5alpha-reductase. Observations in male rats confirmed persistent alterations in neuroactive steroid levels also in the brain. In the present study, we have ascertained possible effects on depressive-like behavior, neurogenesis, gliosis, neuroinflammation and gut microbiota in male rats after subchronic treatment for 20 days with finasteride and after one month of its withdrawal. At the end of treatment there was an increase in the number of pH3 immunoreactive cells in the subgranular zone of the dentate gyrus together with an increase in the mRNA levels of TNF-α in the hippocampus. By one month after the end of finasteride treatment, rats showed depressive-like behavior coupled with a decrease in the number of pH3 immunoreactive cells in the subgranular zone of the dentate gyrus, a decrease in granule cell density in the granule cell layer and an increase in the number of GFAP immunoreactive astrocytes in the dentate gyrus. Finally, alteration of gut microbiota (i.e., an increase in Bacteroidetes phylum and in Prevotellaceae family at the end of the treatment and a decrease in Ruminococcaceae family, Oscillospira and Lachnospira genus at the end of the withdrawal period) was detected. In conclusion, finasteride treatment in male rats has long term effects on depressive-like behavior, hippocampal neurogenesis and neuroinflammation and gut microbiota composition., This research was supported by grants from MIUR Progetto Eccellenza. We also thank the Post-Finasteride Foundation for the financial support to R.C. Melcangi; Ministerio de Economía, Industria y Competitividad (MINECO), Spain (grant number BFU2017-82754-R), Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Instituto de Salud Carlos III, Madrid, Spain and Fondos Feder for the financial support to L.M. Garcia-Segura.

Current understanding of acute myeloid leukemia (AML) assumes a developmental hierarchy, in which a minor fraction of primitive and quiescent leukemia stem cells (LSC) sustain clonal propagation of disease. These therapy-resistant LSC may be the basis of relapse, as supported by data correlating the presence of LSC gene expression signatures at diagnosis with poor prognosis (Ng et al, Nature 2016). Novel approaches tracing LSC fates at single cell level before, during and after chemotherapy (CTX) are needed to confirm their biological relevance and derive new, LSC-focused diagnostic and therapeutic strategies. We and others have previously linked key LSC properties, such as quiescence and therapy resistance, to complex transcriptional regulation orchestrated by miR-126 (Lechman et al, Cancer Cell 2016). Furthermore, we provided proof of concept that LSCs could be prospectively isolated as miR-126(high) cells exploiting a lentiviral reporter vector capturing miR-126 bioactivity in live cells with single cell resolution. To extend these studies, we transduced primary blasts from n=3 AML patients (pts) carrying NPM1 and FLT3-ITD mutations with the miR-126 reporter, followed by xenografting (PDX). Blasts showed intra-tumor heterogeneity (ITH) in terms of miR-126 activity, with a minor fraction identified as miR-126(high). Limiting dilution secondary transplantation of FACS sorted miR-126(high) and -(low) blasts proved strong enrichment of repopulating activity within the miR-126(high) compartment in all 3 pts. On the contrary, no LSC enrichment could be verified in the CD34+CD38- fraction in 1 patient, suggesting that high miR-126 activity represents a more robust LSC identifier than commonly used surface markers. Next, we investigated the impact of daunorubicin and cytarabine CTX on miR-126-reporter+ blasts (n=3 AML) in PDX. Surprisingly, overall miR-126 activity diminished in post CTX residual AML compared to controls, compatible with a loss of blast quiescence. CTX accentuated ITH by uncovering a subset of blasts with very high levels of miR-126, distinct from the bulk population, which may correspond to residual quiescent LSC (Fig A). We then performed bulk RNA sequencing on miR-126(high) and miR-126(low) subsets from CTX and control PDX. While miR-126(low) blasts from both groups expressed markers of myeloid differentiation, miR-126(high) blasts were enriched for published hematopoietic stem cell hallmark signatures. Integrating differentially expressed genes between miR-126(high) and-(low) subsets at steady state and post CTX, we extrapolated a novel 8 gene signature associated with miR-126(high) blasts. Of note, patients from the AML TCGA PanCancer Atlas Cohort (n=161) harboring overexpression in one or more of these 8 genes had significantly decreased overall survival (10 vs 19 months, Logrank test p-value = 0.018). To further test whether our 8-gene miR-126(high) signature reveals ITH in patients, we performed single cell RNA sequencing (scRNAseq) of AML patient BM aspirates at diagnosis (n= 6). Blasts were identified based on the detection of mutated NPM1 transcripts in single cells. In 5 out of 7 patients expression of the miR-126 signature mapped to specific clusters of blasts identified by unsupervised shared nearest neighbor algorithm, confirming that it identifies ITH in patient samples. Interestingly, we detected miR-126 signature(high) blasts in pts with poor prognosis (n=4) and not in those with favorable outcome (n=2) (Fig B). To investigate ITH across longitudinal samples, we next performed scRNAseq of residual AML from a representative patient assessed early after CTX. In line with our PDX CTX model displaying increased miR-126 ITH, blasts on day14 of induction CTX segregated into 2 different clusters: cluster 1 containing LSC-like cells with miR-126(high) signature and similar transcriptional profile to the diagnosis counterpart; cluster 2, instead, was composed of actively cycling blasts. Residual blasts at day30, in addition to uniformly expressing the miR-126(high) signature, differed from diagnosis and day14 blasts by displaying cell cycle quiescence and induction of oxidative phosphorylation genes (Fig C). In summary, we have set up and applied PDX LSC modeling to clinically relevant patient samples to address AML intra-tumor heterogeneity and to pinpoint novel relevant transcriptomic features of LSC at diagnosis and after chemotherapy. Figure Disclosures Gentner: Genenta Science: Consultancy, Equity Ownership, Research Funding.

Gheza, G., Nascimbene, J., Mayrhofer, H., Barcella, M. & Assini, S. 2018. Two Cladonia species new to Italy from dry habitats in the Po Plain. - Herzogia 31: 293–303.Cladonia conista and C. pulvinata occur at several sites in dry lowland habitats in the Po Plain (northern Italy). Vegetation releves are provided in order to characterize the main lichen associations (Cladonietum rei, Cladonietum foliaceae, Pycnothelio-Cladonietum cervicornis) and vascular plant communities in which the two species were found in Thero-Airion dry acidic grasslands and in dry open Calluna heathlands.

Summary Sex impacts on liver physiology with severe consequences for energy metabolism and response to xenobiotic, hepatic, and extra-hepatic diseases. The comprehension of the biology subtending sex-related hepatic differences is therefore very relevant in the medical, pharmacological, and dietary perspective. The extensive application of metabolomics paired to transcriptomics here shows that, in the case of short-term fasting, the decision to maintain lipid synthesis using amino acids (aa) as a source of fuel is the key discriminant for the hepatic metabolism of male and female mice. Pharmacological and genetic interventions indicate that the hepatic estrogen receptor (ERα) has a key role in this sex-related strategy that is primed around birth by the aromatase-dependent conversion of testosterone into estradiol. This energy partition strategy, possibly the result of an evolutionary pressure enabling mammals to tailor their reproductive capacities to nutritional status, is most important to direct future sex-specific dietary and medical interventions.

Nature Communications 8: Article number: 15805 (2017); Published: 14 June 2017; Updated: 2 August 2017 In Supplementary Fig. 10 of this Article, images for panels a and b were inadvertently omitted. The correct version of Supplementary Fig. 10 is provided as Supplementary Information associated withthis Erratum.

Reduced cardiac vagal control reflected in low heart rate variability (HRV) is associated with greater risks for cardiac morbidity and mortality. In two-stage meta-analyses of genome-wide association studies for three HRV traits in up to 53,174 individuals of European ancestry, we detect 17 genome-wide significant SNPs in eight loci. HRV SNPs tag non-synonymous SNPs (in NDUFA11 and KIAA1755), expression quantitative trait loci (eQTLs) (influencing GNG11, RGS6 and NEO1), or are located in genes preferentially expressed in the sinoatrial node (GNG11, RGS6 and HCN4). Genetic risk scores account for 0.9 to 2.6% of the HRV variance. Significant genetic correlation is found for HRV with heart rate (−0.74, Heart rate variability (HRV) describes the individual variation in cardiac cycle duration and is a measure of vagal control of heart rate. Here, the authors identify seventeen single-nucleotide polymorphisms associated with HRV, lending new insight into the vagal regulation of heart rhythm.

In this contribution, new data concerning bryophytes, fungi and lichens and of the Italian flora are presented. It includes new records and confirmations for the bryophyte generaDicranodontium,Fontinalis,LophocoleaandRiccia, the fungal genusDiplolaeviopsis, the lichen generaAgonimia,Cladonia,Protoparmelia,Rhizocarpon, andScytinium.

Conservation of species is often focused either only on those that are endangered, or on maximising the number recorded on species lists. However, species share space and time with others, thus interacting and building frameworks of relationships that can be unravelled by community-level network analysis. It is these relationships that ultimately drive ecosystem function via the transfer of energy and nutrients. However interactions are rarely considered in conservation planning. Network analysis can be used to detect key species ("hubs") that play an important role\ud in cohesiveness of networks. We applied this approach to plant-pollinator communities on two montane Northern Apennine grasslands, paying special attention to the modules and the identity of hubs. We performed season-wide sampling and then focused the network analyses on time units consistent with plant phenology. After testing for significance of modules, only some modules were found to be significantly segregated from others. Thus, networks were organized around a structured core of modules with a set of companion species that were not organized into compartments. Using a network approach we obtained a list of important plant and pollinator species, including three Network Hubs of utmost importance, and other hubs of particular biogeographical interest. By having a lot of links and high partner diversity, hubs should convey stability to networks. Due to their role in the networks, taking into account such key species when considering the management of sites could help to preserve the greatest number of interactions and thus support many other species.

Cancer has been proposed as an example of systems biology disease or network disease. Accordingly, tumor cells differ from their normal counterparts more in terms of intracellular network dynamics than single markers. Here we shall focus on a recently recognized hallmark of cancer, the deregulation of cellular energetics. The constitutive activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway has been confirmed as an essential step toward cell transformation. We will consider how the effects of Akt activation are connected with cell metabolism; more precisely, we will review existing metabolic models and discuss the current knowledge available to construct a kinetic model of the most relevant metabolic processes regulated by the PI3K/Akt pathway. The model will enable a systems biology approach to predict the metabolic targets that may inhibit cell growth under hyper activation of Akt. (C) 2011 Elsevier Inc. All rights reserved.

Background In mice MEOX2/TCF15 heterodimers are highly expressed in heart endothelial cells and are involved in the transcriptional regulation of lipid transport. In a general population, we investigated whether genetic variation in these genes predicted coronary heart disease (CHD). Results In 2027 participants randomly recruited from a Flemish population (51.0 % women; mean age 43.6 years), we genotyped six SNPs in MEOX2 and four in TCF15. Over 15.2 years (median), CHD, myocardial infarction, coronary revascularisation and ischaemic cardiomyopathy occurred in 106, 53, 78 and 22 participants. For SNPs, we contrasted CHD risk in minor-allele heterozygotes and homozygotes (variant) vs. major-allele homozygotes (reference) and for haplotypes carriers (variant) vs. non-carriers. In multivariable-adjusted analyses with correction for multiple testing, CHD risk was associated with MEOX2 SNPs (P ≤ 0.049), but not with TCF15 SNPs (P ≥ 0.29). The MEOX2 GTCCGC haplotype (frequency 16.5 %) was associated with the sex- and age-standardised CHD incidence (5.26 vs. 3.03 events per 1000 person-years; P = 0.036); the multivariable-adjusted hazard ratio [HR] of CHD was 1.78 (95 % confidence interval, 1.25–2.56; P = 0.0054). For myocardial infarction, coronary revascularisation, and ischaemic cardiomyopathy, the corresponding HRs were 1.96 (1.16–3.31), 1.87 (1.20–2.91) and 3.16 (1.41–7.09), respectively. The MEOX2 GTCCGC haplotype significantly improved the prediction of CHD over and beyond traditional risk factors and was associated with similar population-attributable risk as smoking (18.7 % vs. 16.2 %). Conclusions Genetic variation in MEOX2, but not TCF15, is a strong predictor of CHD. Further experimental studies should elucidate the underlying molecular mechanisms. Electronic supplementary material The online version of this article (doi:10.1186/s12863-015-0272-2) contains supplementary material, which is available to authorized users.

INTRODUCTION: Allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) represents an effective form of adoptive immunotherapy for Acute Myeloid Leukemia (AML), thanks to the antitumor effect mediated by donor immune cells infused as part of the graft. Unfortunately, post-transplantation relapses remain a frequent observation, warranting further investigation on AML immunobiology. Our group demonstrated that relapses after partially HLA-incompatible HSCT are frequently due to the outgrowth of immune-resistant mutant AML clones characterized by genomic loss the mismatched histocompatibility determinants targeted by alloreactive donor T cells, and have thus gained a selective advantage upon pressure from the transplanted immune system, in a process called “leukemia immunoediting” (Vago et al., N Engl J Med, 2009). In the present study, we took advantage of high-throughput technologies to profile post-transplantation AML relapses with no genomic loss of HLA, to identify novel targets of the leukemia immunoediting process. METHODS: Serial AML samples were collected and FACS-purified from 9 patients at diagnosis, relapse after sole chemotherapy and relapse after allo-HSCT, and employed for whole transcriptome profiling using Illumina HumanHT12 microarrays. Deregulated genes were identified by pair-wise LIMMA analysis, and unsupervised enrichment analysis was performed interrogating the Gene Ontology database. High-throughput results were confirmed in a validation cohort of 12 patients by ad hoc designed qPCR assays, immunophenotypic analyses and functional experiments. In particular, co-cultures were performed using as responders peripheral blood lymphocytes harvested from patients after allo-HSCT, and as stimulators and targets their respective AML blasts collected at diagnosis or at relapse: read-outs included antigen-specific T cell activation, cytotoxicity, and cytokine release. RESULTS: Amongst all the genes expressed by purified AML blasts, a 110-gene signature (p CONCLUSIONS: Our results demonstrate that the deregulation of immune-related processes, and in particular of molecules and pathways involved in T cell-mediated allo-recognition, are pervasive and distinctive features of AML relapses after allo-HSCT. Identification of patient-specific mechanisms of immune evasion might be translated into personalized therapeutic approaches, tailored to restore or circumvent inefficient antigen presentation and T cell costimulation. Disclosures Bonini: MolMed S.p.A.: Consultancy.

In Italy, Corynephorus communities are distributed along the medium course of the Ticino river and Sesia river and the internal sand dunes of Lomellina (through the Vercelli, Novara and Pavia provinces); these stations represent the southern limit of European distribution of this habitat. A phytosociological study was carried out to gain better knowledge of their composition; of their affinity or diversity against the central European communities; of their distribution and of the main threats to their conservation. Original and literature relevés (114) were elaborated producing a cluster analysis; correspondence analysis (CA), principal component analysis and Kruskal–Wallis test were carried on to characterize the clusters of relevés taking into consideration biological forms, chorological groups, Ellenberg indicator values and floristic groups. Italian Corynephorus communities can be attributed to the following syntaxa: Spergulo vernalis-Corynephoretum canescentis, Spergulo vernalis-Corynephoretum canescentis cladonietosum, Spergulo vernalis-Corynephoretum canescentis silenetosum nutantis and Spergulo vernalis-Corynephoretum canescentis artemisietosum campestris. Italian Corynephorus communities are included in the Habitat 2330 of the EU Habitat Directive. They are threatened by different factors (such as restricted areas of occurrence, alien plant invasion and natural dynamics) and they need to be managed if we want to conserve them.

Introduction Imatinib mesylate (IM) is the first line therapy against Chronic Myeloid Leukemia (CML), effectively prolonging overall survival. Because discontinuation of treatment is associated with molecular relapse, IM is required indefinitely to maintain operational cure. To evaluate the degree of response to therapy and to highlight the persistence of the disease after treatment, patients should be monitored routinely. The gold standard for diagnosing CML is the cytogenetic analysis, a direct not-sensitive method to detect Ph-positive cells. Quantitative real-time RT-PCR (qRT-PCR) provides highly sensitive detection of BCR-ABL1 transcripts, but mRNA levels are not directly related to the number of leukemic cells and cannot detect transcriptionally silent leukemic stem cells. Methods Here we will propose a new sensitive approach to directly detect the number of leukemic cells using a DNA-based biomarker specific for each patient. We applied targeted next-generation sequencing for the identification of genomic BCR-ABL1 fusion junctions, and we developed a sensitive new approach to detect the number of leukemic cells by a DNA Q-PCR assay based on the genomic break-point, with a formula to calculate the number of Ph+ cells. The percentage of the leukemic cells (LC) was calculated using the following formula: %LC= (2/(2Δct+1))*100, where ΔCt is the difference between the amplification cycles of the BCR-ABL1 and BCR reactions. The number of LC was calculated by multiplying the total number of cells analyzed in each sample by the percentage of LC calculated by the ΔCt formula. We then defined a limit of quantization and a limit of sensitivity in the evaluation of minimal residual disease (MRD), as described by guidelines for the detection of MRD by genomic Q-PCR in acute lymphoblastic leukemia (ALL). We defined a “quantitative range” of detection, the portion of the standard curve in which the MRD levels can be quantified reproducibly and accurately, and we defined the “limit of sensitivity”, the lowest MRD level that still can be detected, although not in all replicates. We thus calculated the exact number of leukemic cells only when the MRD fell within the range of quantization. The detection of MRD at the limit of sensitivity was indicated as positive but not quantified. Results We monitored eight CML patients treated with Imatinib for 8 years. We tested the same samples by patient specific Q-PCR, and in parallel by cytogenetic analysis and by standard qRT-PCR. In all samples positive for chimeric transcripts we measured corresponding chimeric genomic DNA (gDNA) by Q-PCR, confirming the sensitivity of the Q-PCR method. According to conventional criteria, undetectable levels of BCR-ABL1 mRNA assessed by qRT-PCR are indicative of complete molecular response (CMR), but in 33.3% (45/135) samples with undetectable levels of mRNA, we detected the persistence of transcriptionally-silent leukemic cells. However, we never found samples negative by gDNA Q-PCR and positive by RNA-based qRT-PCR (Figure 1). Thirty-six of 135 samples were also analyzed cytogenetically until the achievement of CCyR. As expected, Ph+cells were detected only in 25% (9/36) and 22,2% (8/36) of samples by CBA and I-FISH, respectively, whereas BCR-ABL1 mRNA was detected by qRT-PCR in 83.3% (30/36) of samples and Ph+ cells were detected by genomic Q-PCR in 91.7% (33/36) of samples (Figure 1). Finally, the separation of different cell populations from blood and bone marrow revealed the presence of a population of transcriptionally silent cancer stem cells. The gDNA based Q-PCR analysis performed on highly purified (immunomagnetically selected ) CD34+and CD3+ cells confirmed the presence of a population of transcriptionally silent cancer stem cells. Conclusions The demonstration of positive gDNA Q-PCR in 33.3% of samples negative for the RNA qRT-PCR could partially explain why some patients lose MMR and CMR and others do not, when IM is discontinued for brief periods. The gDNA based Q-PCR could be used to supplement conventional techniques, providing clinicians with additional information about disease status and response in determining whether to stop or alter therapy. Acknowledgments to AIRC and AIL. Disclosures: No relevant conflicts of interest to declare.

Introduction Allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) is the most effective therapy for many patients with Acute Myeloid Leukemia (AML). Still, post-transplantation relapse remains an unmet clinical need, and our insights into its biological determinants are limited. Based on the “leukemia immunoediting” hypothesis, post-transplantation relapse may result from the outgrowth of immune-resistant leukemic variants upon the selective pressure of the transplanted immune system, verging on the intrinsic ability of tumor cells to alter their genomic and transcriptional profile. Our group provided a compelling proof of this model, demonstrating that upon partially HLA-incompatible allo-HSCT, AML blasts frequently undergo genomic loss of the mismatched HLA, evading donor immune control and resulting in clinical relapse (Vago et al, N Engl J Med, 2009). Besides its biological and medical relevance, this proof-of-principle discovery paved the way to the identification of novel mechanisms of leukemia relapse. Methods Serial AML samples at time of diagnosis, relapse after sole chemotherapy, and relapse after allo-HSCT were collected longitudinally in 9 patients. AML blasts were FACS-purified and gene expression profile was performed using Illumina HumanHT12 v4.0 Expression Bead chips. Deregulated genes and signatures were identified by pairwise LIMMA analysis. Gene Ontology and Gene Set Enrichment Analysis curated databases were interrogated to identify deregulated processes. Validation of high-throughput results was performed by molecular HLA typing, ad hoc designed locus- and allele-specific qPCR, immunophenotypic analysis and functional ex vivo assays. Results Pairwise enrichment analysis of the patient samples demonstrated that 18/29 (62%) biological processes significantly deregulated in AML at post-transplantation relapse were immune-related, whereas after sole chemotherapy no immune-related process resulted deregulated. Pairwise analysis of triplicate samples at diagnosis and post-transplantation relapse allowed the identification of a 149 gene signature (p Conclusions Our data demonstrate that not only genomic HLA haplotype loss, but also transcriptional HLA Class II downregulation can be at the basis of AML relapse after partially mismatched HSCT, and provide further evidence on how tightly post-transplantation relapse and immune evasion may be linked. Moreover, the novel mechanism we described depends on CIITA downregulation, and may in turn be linked to methylation of its promoter, potentially providing a novel biological rationale for the documented efficacy of demethylating agents as salvage therapy for relapses after allo-HSCT. Disclosures: Bonini: MolMed SpA: Consultancy.