Telomeric repeat-containing RNA is dysregulated in acute myeloid leukemia

TERRA (telomeric repeat-containing RNA) is a class of long noncoding RNAs transcribed from subtelomeric and telomeric regions. TERRA binds to the subtelomeric and telomeric DNA-forming R-loops (DNA-RNA hybrids), which are involved in telomere maintenance and telomerase function, but the role of TERRA in human cells is not well characterized. Here, we comprehensively investigated for the first time TERRA expression in primary human hematopoietic cells from an exploratory cohort of patients with acute myeloid leukemia (AML), patients with acute lymphoblastic leukemia (ALL), patients with telomere biology disorder (TBD), and healthy subjects. TERRA expression was repressed in primary human hematopoietic cells, including healthy donors, patients with ALL, and patients with TBD, irrespective of their telomere length, except for AML. A second cohort comprising 88 patients with AML showed that TERRA was overexpressed in an AML subgroup also characterized by higher R-loop formation, low TERT and RNAseH2 expression, and a paucity of somatic splicing factor mutations. Telomere length did not correlate with TERRA expression levels. To assess the role of TERRA R-loops in AML, we induced R-loop depletion by increasing RNAseH1 expression in 2 AML cell lines. Decreased TERRA R-loops in AML cell lines resulted in increased chemosensitivity to cytarabine. Our findings indicate that TERRA is uniformly repressed in primary human hematopoietic cells but abnormally expressed in an AML subset with low telomerase.

Survival benefit of pediatric-based regimen for adults with acute lymphoblastic leukemia: A single-center retrospective cohort

INTRODUCTION

Improving survival of Acute Lymphoblastic Leukemia (ALL) in adult patients has been a challenge. Despite intensive chemotherapy treatment, overall survival is poor. However, several studies demonstrate that young adult patients have better survival when treated with pediatric-based intensive regimens. Considering these results, We decided to treat newly diagnosed ALL patients according to age and risk factors. The goal of this study was to describe the results of this intensive chemotherapy treatment approach for ALL adult patients diagnosed at our institution.

METHODS

Fifty-eight ALL patients, diagnosed from 2004 to 2013, were included in the analysis. Patients were assigned to either the St. Jude Total Therapy XIIIB high-risk arm (St Jude) or the CALGB 8811 (CALGB). The Kaplan-Meier survival curve was used for the survival analyses and the Cox proportional hazard regression, for multivariable analysis.

RESULTS

The overall survival was 22.9% at 10 years. The St. Jude improved survival, compared to the CALGB (p = 0.007), with 32.6% vs. 7.4% survival rate at 10 years. However, no survival benefit was found for patients younger than 20 years old (p = 0.32). The multivariable analysis demonstrated that undetectable minimal residual disease (MRD) and hematopoietic stem cell transplantation (HSCT) had beneficial impact on survival (p = 0.0007 and p = 0.004, respectively).

CONCLUSION

ALL is a disease of poor prognosis for adults. The joint effort to standardize treatment and seek solutions is the way to start improving this scenario.

Bronchiolitis obliterans in patients undergoing allogeneic hematopoietic SCT

Bronchiolitis obliterans (BO) is a severe pulmonary complication of allo-SCT. This study evaluated the incidence of BO in patients undergoing allo-SCT in Hospital Universitário da Universidade Federal do Paraná, risk factors for developing this complication and prognostic factors for those patients who developed this entity. The study included 1286 patients transplanted between 1979 and 2009 who survived for 100 days or more. We diagnosed 53 cases of BO. The cumulative incidence was 2.9% in 1 year and 3.7% in 3 years. Among patients with chronic GVHD, the cumulative incidence at the same intervals was 8.4% and 9.9%, respectively. The median time between transplantation and diagnosis of BO was 260 days (49-3877 days). In the multivariate analysis the risk factors for BO were female donor, older recipients and acute GVHD. The main prognostic factor was the severity of pulmonary impairment. Patients who developed BO earlier than 260 days had a worse prognosis than those who did so later. At least 80% of deaths were directly related to BO.

A multicenter feasibility study of chronic graft-versus-host disease according to the National Institute of Health criteria: efforts to establish a Brazil-Seattle consortium as a platform for future collaboration in clinical trials

BACKGROUND: New criteria for the diagnosis and classification of chronic graft-versus-host disease were developed in 2005 for the purpose of clinical trials with a consensus sponsored by the National Institute of Health. OBJECTIVES: The aim of this study is to present the results of a multicenter pilot study performed by the Brazil-Seattle chronic graft-versus-host disease consortium to determine the feasibility of using these criteria in five Brazilian centers. METHODS: The study was performed after translation of the consensus criteria into Portuguese and training. A total of 34 patients with National Institute of Health chronic graft-versus-host disease were enrolled in the pilot study between June 2006 and May 2009. RESULTS: Of the 34 patients, 26 (76%) met the criteria of overlap syndrome and eight (24%) the classic subcategory. The overall severity of disease was moderate in 21 (62%) and severe in 13 (38%) patients. The median time from transplant to onset of chronic graft-versus-host disease was 5.9 months (Range: 3 - 16 months); the median time for the overlap syndrome subcategory was 5.9 months (Range: 3 - 10 months) and for the classic subcategory, it was 7.3 months (Range: 3 - 16 months). At a median follow up of 16.5 months (Range: 4 - 39 months), overall survival was 75%. CONCLUSIONS: It was feasible to use the National Institute of Health consensus criteria for the diagnosis and scoring of chronic graft-versus-host disease in a Brazilian prospective multicenter study. More importantly, a collaborative hematopoietic cell transplantation network was established in Brazil offering new opportunities for future clinical trials in chronic graft-versus-host disease and in other areas of research involving hematopoietic stem cell transplantation.

Reduction of crotoxin-induced neuromuscular blockade by gamma radiation

A comparative study between crotoxin and gamma irradiated crotoxin was performed on the indirectly evoked twitches and tetani of sciatic nerve-extensor digitorum longus muscle of rats. Crotoxin (3 to 14 microg/ml) decreased the amplitude of twitches and induced a slight tetanic fade, and irradiated crotoxin did not significantly affect either twitch amplitude or tetanic tension. Since gamma radiation reduced the neurotoxicity of crotoxin it may be useful for the production of anticrotalic serum.