BackgroundDespite great efforts to identify druggable molecular targets for AML, there remains an unmet need for more effective therapies.MethodsAn in silico screening was performed using Connectivity Maps to identify FDA-approved drugs that may revert an early leukaemic transformation gene signature. Hit compounds were validated in AML cell lines. Cytotoxic effects were assessed both in primary AML patient samples and healthy donor blood cells. Xenotransplantation assays were undertaken to determine the effect on engraftment of hit compounds. The mechanism of action responsible for the antileukaemic effect was studied focussing on lysosomes and mitochondria.FindingsWe identified a group of antihistamines (termed ANHAs) with distinct physicochemical properties associated with their cationic-amphiphilic nature, that selectively killed leukaemic cells. ANHAs behaved as antileukaemic agents against primary AML samples ex vivo, sparing healthy cells. Moreover, ANHAs severely impaired the in vivo leukaemia regeneration capacity. ANHAs' cytotoxicity relied on simultaneous mitochondrial and lysosomal disruption and induction of autophagy and apoptosis. The pharmacological effect was exerted based on their physicochemical properties that permitted the passive targeting of both organelles, without the involvement of active molecular recognition.InterpretationDual targeting of lysosomes and mitochondria constitutes a new promising therapeutic approach for leukaemia treatment, supporting the further clinical development.FundThis work was funded by the (RMR), (RMR), the (RMR), the (RMR), (RMR), and (IJC).

This study was supported in part by a grant from FIS-PI11/01560 and FIS-PI11/00977 within the 'Plan Nacional de I + D + I' and co-funded by the 'ISCIII-Subdirección General de Evaluación' and 'Fondo Europeo de Desarrollo Regional (FEDER)' and by the grant 'Premi Fi de Residència Emili Letang 2015' from the Hospital Clínic of Barcelona. The authors have no competing interests to disclose.

BackgroundTreatment for acute myeloid leukemia (AML) has not significantly changed in the last decades and new therapeutic approaches are needed to achieve prolonged survival rates. Leukemia stem cells (LSC) are responsible for the initiation and maintenance of AML due to their stem-cell properties. Differentiation therapies aim to abrogate the self-renewal capacity and diminish blast lifespan.MethodsAn in silico screening was designed to search for FDA-approved small molecules that potentially induce differentiation of AML cells. Bromocriptine was identified and validated in an in vitro screening. Bromocriptine is an approved drug originally indicated for Parkinson’s disease, acromegaly, hyperprolactinemia and galactorrhoea, and recently repositioned for diabetes mellitus.ResultsTreatment with bromocriptine reduced cell viability of AML cells by activation of the apoptosis program and induction of myeloid differentiation. Moreover, the LSC-enriched primitive AML cell fraction was more sensitive to the presence of bromocriptine. In fact, bromocriptine decreased the clonogenic capacity of AML cells. Interestingly, a negligible effect is observed in healthy blood cells and hematopoietic stem/progenitor cells.ConclusionsOur results support the use of bromocriptine as an anti-AML drug in a repositioning setting and the further clinical validation of this preclinical study.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-016-1007-5) contains supplementary material, which is available to authorized users.

Diffuse large B cell lymphoma (DLBCL) patients carrying hepatitis C virus (HCV) have higher risk of treatment toxicity and complications. The aim of this study was to assess the impact of HCV in a series of DLBCL patients treated with immunochemotherapy. 321 patients (161 M/160F; median age, 66 years) diagnosed with de novo DLBCL in a single center between 2002 and 2013 were included. Immunodeficiency-related lymphomas were excluded. HCV+ cases were defined by the presence of IgG anti-HCV. Main clinico-biological characteristics and outcome were analyzed according to the viral status. Two hundred ninety patients were HCV- and 31 HCV+. HCV+ patients were older (median age 71 vs. 64 years, P = 0.03), had more often B symptoms (P = 0.013), spleen (P = 0.003), and liver (P = 0.011) involvement, higher rate of early death (<4 months, P = .001), and shorter overall survival (OS). Eleven HCV+ patients had cirrhosis criteria. HCV+ patients with impaired liver function before or during treatment showed inferior OS. Elevated pre-treatment bilirubin correlated also with higher liver toxicity. In a multivariate analysis that included R-IPI score, serum beta2-microglobulin (β2m), HCV status, and presence of cirrhosis, only R-IPI, β2m, and cirrhosis showed independent prognostic impact on OS. The presence of HCV in DLBCL patients entails higher number of complications and early deaths; however, liver impairment and not the hepatitis viral status was the key feature in the outcome of the patients.

Acute myeloid leukemia (AML) is a clinically and molecularly heterogeneous neoplasia with poor outcome, organized as a hierarchy initiated and maintained by a sub-population with differentiation and self-renewal capacities called leukemia stem cells (LSCs). Although currently used chemotherapy is capable of initially reducing the tumor burden producing a complete remission, most patients will ultimately relapse and will succumb to their disease. As such, new therapeutic strategies are needed. AML cells differentially expressed serotonin receptor type 1 (HTR1) compared with healthy blood cells and the most primitive hematopoietic fraction; in fact, HTR1B expression on AML patient samples correlated with clinical outcome. Inhibition of HTR1s activated the apoptosis program, induced differentiation and reduced the clonogenic capacity, while minimal effect was observed on healthy blood cells. In vivo regeneration capacity of primary AML samples was disrupted upon inhibition of HTR1. The self-renewal capacity remaining in AML cells upon in vivo treatment was severely reduced as demonstrated by serial transplantation. Thus, treatment with HTR1 antagonists showed antileukemia effect, especially anti-LSC activity while sparing healthy blood cells. Our results highlight the importance of HTR1 in leukemogenesis and LSC survival and identify this receptor family as a new target for therapy in AML with prognostic value.

Myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML) are chronic myeloid clonal neoplasms. To date, the only potentially curative therapy for these disorders remains allogeneic hematopoietic progenitor cell transplantation (HCT), although patient eligibility is limited due to high morbimortality associated with this procedure coupled with advanced age of most patients. Dopamine receptors (DRs) and serotonin receptors type 1 (HTR1s) were identified as cancer stem cell therapeutic targets in acute myeloid leukemia. Given their close pathophysiologic relationship, expression of HTR1s and DRs was interrogated in MDS and CMML. Both receptors were differentially expressed in patient samples compared to healthy donors. Treatment with HTR1B antagonists reduced cell viability. HTR1 antagonists showed a synergistic cytotoxic effect with currently approved hypomethylating agents in AML cells. Our results suggest that HTR1B constitutes a novel therapeutic target for MDS and CMML. Due to its druggability, the clinical development of new regimens based on this target is promising.

Pineal cell aggregates in 5, 10 and 15 day-old chick embryos have been studied. Cell aggregates were classified into rosettes or vesicles and spheroid and ellipsoid vesicles distinguished. The number of pineal vesicles per unit of surface (vesicle density) was determined in three pineal portions: apical, anterior and posterior. By day 5, only cellular rosettes were found, mainly in the apical portion. After 10 and 15 days, the presence of rosettes was occasional. The posterior wall showed only small spheroid vesicles, while in the apical and anterior areas ellipsoid vesicles were also observed. Moreover, the spheroid/ellipsoid vesicle ratio increased from the 10th to the 15th day of incubation. The vesicle density decreased between the 10th and 15th day because of the increase in both vesicle and pineal size, without changes in the total number of vesicles. The results suggest that changes in vesicle morphology and density could be related to the functional activity of the pineal gland during embryonic development.

Inbred athymic nulnu BALB/c mice were injected subcutaneously with the highly oncogenic polyomavirus A2 strain, and the sites of viral DNA replication were determined by whole mouse section hybridization (T. W.