SETDB2 Links E2A-PBX1 to Cell-Cycle Dysregulation in Acute Leukemia through CDKN2C Repression

Acute lymphoblastic leukemia (ALL) is associated with significant morbidity and mortality, necessitating further improvements in diagnosis and therapy. Targeted therapies directed against chromatin regulators are emerging as promising approaches in preclinical studies and early clinical trials. Here, we demonstrate an oncogenic role for the protein lysine methyltransferase SETDB2 in leukemia pathogenesis. It is overexpressed in pre-BCR+ ALL and required for their maintenance in vitro and in vivo. SETDB2 expression is maintained as a direct target gene of the chimeric transcription factor E2A-PBX1 in a subset of ALL and suppresses expression of the cell-cycle inhibitor CDKN2C through histone H3K9 tri-methylation, thus establishing an oncogenic pathway subordinate to E2A-PBX1 that silences a major tumor suppressor in ALL. In contrast, SETDB2 was relatively dispensable for normal hematopoietic stem and progenitor cell proliferation. SETDB2 knockdown enhances sensitivity to kinase and chromatin inhibitors, providing a mechanistic rationale for targeting SETDB2 therapeutically in ALL

Correction: Circumvention of common labelling artefacts using secondary nanobodies

Correction for ‘Circumvention of common labelling artefacts using secondary nanobodies’ by Shama Sograte-Idrissi et al., Nanoscale, 2020, 12, 10226–10239, DOI: 10.1039/D0NR00227E

Hair cells use active zones with different voltage dependence of Ca²⁺ influx to decompose sounds into complementary neural codes.

For sounds of a given frequency, spiral ganglion neurons (SGNs) with different thresholds and dynamic ranges collectively encode the wide range of audible sound pressures. Heterogeneity of synapses between inner hair cells (IHCs) and SGNs is an attractive candidate mechanism for generating complementary neural codes covering the entire dynamic range. Here, we quantified active zone (AZ) properties as a function of AZ position within mouse IHCs by combining patch clamp and imaging of presynaptic Ca2+ influx and by immunohistochemistry. We report substantial AZ heterogeneity whereby the voltage of half-maximal activation of Ca2+ influx ranged over ∼20 mV. Ca2+ influx at AZs facing away from the ganglion activated at weaker depolarizations. Estimates of AZ size and Ca2+ channel number were correlated and larger when AZs faced the ganglion. Disruption of the deafness gene GIPC3 in mice shifted the activation of presynaptic Ca2+ influx to more hyperpolarized potentials and increased the spontaneous SGN discharge. Moreover, Gipc3 disruption enhanced Ca2+ influx and exocytosis in IHCs, reversed the spatial gradient of maximal Ca2+ influx in IHCs, and increased the maximal firing rate of SGNs at sound onset. We propose that IHCs diversify Ca2+ channel properties among AZs and thereby contribute to decomposing auditory information into complementary representations in SGNs

Overloaded adeno-associated virus as a novel gene therapeutic tool for otoferlin-related deafness

Hearing impairment is the most common sensory disorder in humans. So far, rehabilitation of profoundly deaf subjects relies on direct stimulation of the auditory nerve through cochlear implants. However, in some forms of genetic hearing impairment, the organ of Corti is structurally intact and therapeutic replacement of the mutated gene could potentially restore near natural hearing. In the case of defects of the otoferlin gene (OTOF), such gene therapy is hindered by the size of the coding sequence (~6 kb) exceeding the cargo capacity (<5 kb) of the preferred viral vector, adeno-associated virus (AAV). Recently, a dual-AAV approach was used to partially restore hearing in deaf otoferlin knock-out (Otof-KO) mice. Here, we employed in vitro and in vivo approaches to assess the gene-therapeutic potential of naturally-occurring and newly-developed synthetic AAVs overloaded with the full-length Otof coding sequence. Upon early postnatal injection into the cochlea of Otof-KO mice, overloaded AAVs drove specific expression of otoferlin in ~30% of all IHCs, as demonstrated by immunofluorescence labeling and polymerase chain reaction. Recordings of auditory brainstem responses and a behavioral assay demonstrated partial restoration of hearing. Together, our results suggest that viral gene therapy of DFNB9—using a single overloaded AAV vector—is indeed feasible, reducing the complexity of gene transfer compared to dual-AAV approaches

Avaliação clínica, radiográfica e histológica de cáries de fissura

Objetivo: com o intuito de auxiliar a determinação do plano de tratamento mais conservador, o presente estudo avaliou in vitro a eficácia dos métodos clinico (visual), radiográfico e histológico no diagnóstico das lesões incipientes. Materiais e métodos: foram avaliados 20 dentes molares permanentes humanos que apresentavam superfície oclusal aparentemente íntegra ou escurecida, porém sem cavitação. Estes dentes foram submetidos ao exame radiográfico, através de radiografias periapicais e exame visual, por três examinadores previamente calibrados, com o auxílio de refletores odontológicos. As superfícies oclusais dos dentes foram fotografadas e em seguida os mesmos foram seccionados com disco diamantados em uma máquina de corte, obtendo-se cortes com 0,375mm de espessura. Foram confeccionadas lâminas histológicas para avaliação da desmineralização em esmalte e dentina dos dentes através de microscopia óptica. Escores foram utilizados para a classificação dos métodos diagnósticos avaliados e os mesmos obtidos foram avaliados pela estatística Gamma, com índice de significância de 0,05. Resultados: tanto o diagnóstico clínico quanto o radiográfico foram falhos na determinação da presença, extensão e localização da cárie dentária, não ocorrendo uma correlação entre os três métodos utilizados (p0,05). Conclusão: é imprescindível que o Cirurgião-Dentista associe as informações derivadas dos métodos complementares de diagnóstico aos seus conhecimentos prévios, a fim de optar ou não pelo tratamento restaurador destas lesões

Malignant lymphoma of the oral cavity and the maxillofacial region: overall survival prognostic factors

Objective: To identify the overall survival and prognostic factors of malignant lymphoma of the oral cavity and the maxillofacial region. Study Design: Clinical records data were obtained in order to determine overall survival at 2 and 5 years, the individual survival percentage of each possible prognostic factor with the actuarial technique, and the survival regarding the possible prognostic factors with the actuarial technique and the Log-rank and Cox's regression tests. Results: Of 151 subjects, an overall survival was 60% at 2 years, and 45% at 5 years. The multivariate analysis demonstrated statistically significant differences for clinical stage (p=0.002), extranodal involvement (p=0.030), presence of human immunodeficiency virus (p=0.032), and presence of Epstein-Barr virus (p=0.010). Conclusion: The advanced clinical stage and the larger number of involved extranodular sites are related to a lower overall survival, as well as, the presence of previous infections such as the human immunodeficiency and the Epstein-Barr virus

Comparison of fludarabine-melphalan and fludarabine-treosulfan as conditioning prior to allogeneic hematopoietic cell transplantation-a registry study on behalf of the EBMT Acute Leukemia Working Party

In recent years considerable variations in conditioning protocols for allogeneic hematopoietic cell transplantation (allo-HCT) protocols have been introduced for higher efficacy, lower toxicity, and better outcomes. To overcome the limitations of the classical definition of reduced intensity and myeloablative conditioning, a transplantation conditioning intensity (TCI) score had been developed. In this study, we compared outcome after two frequently used single alkylator-based conditioning protocols from the intermediate TCI score category, fludarabine/melphalan 140 mg/m(2) (FluMel) and fludarabine/treosulfan 42 g/m(2) (FluTreo) for patients with acute myeloid leukemia (AML) in complete remission (CR). This retrospective analysis from the registry of the Acute Leukemia Working Party (ALWP) of the European Society of Bone Marrow Transplantation (EBMT) database included 1427 adult patients (median age 58.2 years) receiving either Flu/Mel (n = 1005) or Flu/Treo (n = 422). Both groups showed similar 3-year overall survival (OS) (54% vs 51.2%, p value 0.49) for patients conditioned with FluMel and FluTreo, respectively. However, patients treated with FluMel showed a reduced 3-year relapse incidence (32.4% vs. 40.4%, p value < 0.001) and slightly increased non-relapse mortality (NRM) (25.7% vs. 20.2%, p value = 0.06) compared to patients treated with FluTreo. Our data may serve as a basis for further studies examining the role of additional agents/ intensifications in conditioning prior to allo-HCT.Peer reviewe