Repression of TRIM13 by chromatin assembly factor CHAF1B is critical for AML development.

Acute myeloid leukemia (AML) is an aggressive blood cancer that stems from the rapid expansion of immature leukemic blasts in the bone marrow. Mutations in epigenetic factors represent the largest category of genetic drivers of AML. The chromatin assembly factor CHAF1B is a master epigenetic regulator of transcription associated with self-renewal and the undifferentiated state of AML blasts. Upregulation of CHAF1B, as observed in almost all AML samples, promotes leukemic progression by repressing the transcription of differentiation factors and tumor suppressors. However, the specific factors regulated by CHAF1B and their contributions to leukemogenesis are unstudied. We analyzed RNA sequencing data from mouse MLL-AF9 leukemic cells and bone marrow aspirates, representing a diverse collection of pediatric AML samples and identified the E3 ubiquitin ligase TRIM13 as a target of CHAF1B-mediated transcriptional repression associated with leukemogenesis. We found that CHAF1B binds the promoter of TRIM13, resulting in its transcriptional repression. In turn, TRIM13 suppresses self-renewal of leukemic cells by promoting pernicious entry into the cell cycle through its nuclear localization and catalytic ubiquitination of cell cycle-promoting protein, CCNA1. Overexpression of TRIM13 initially prompted a proliferative burst in AML cells, which was followed by exhaustion, whereas loss of total TRIM13 or deletion of its catalytic domain enhanced leukemogenesis in AML cell lines and patient-derived xenografts. These data suggest that CHAF1B promotes leukemic development, in part, by repressing TRIM13 expression and that this relationship is necessary for leukemic progression.

Combination of treosulfan, fludarabine and cytarabine as conditioning in patients with acute myeloid leukemia, myelodysplastic syndrome and myeloproliferative neoplasms.

PURPOSE: Treosulfan and fludarabine (Treo/Flu) were successfully introduced into toxicity-reduced conditioning for SCT. However, the risk of post-SCT relapse remains a matter of concern. We report the results of a novel individual treatment approach with Treo/Flu and cytarabine (Treo/Flu/AraC) conditioning prior to allogeneic SCT in patients with acute myeloid leukemia (AML), myelodysplastic syndrome (MDS), or myeloproliferative neoplasms (MPN). METHODS: Seventy-seven patients (median age 54 years) at high risk of disease relapse due to unfavorable cytogenetics or failure to achieve complete remission prior to SCT were included. Median follow-up was 3.2 years. RESULTS: The 1-, 2- and 3-year RFS rates were 49.4%, 41.7%, and 37.6% and OS rates were 59.3%, 49.3%, and 45.4%, respectively. Cumulative incidence of NRM was 10% at 100 days, 18.8% at 1 year and 20.1% at 2 years. The cumulative incidence of relapse increased from 31% at 1 year to 38.5% after 3 years. The cumulative incidences of engraftment, chimerism, graft-versus-host disease (GvHD) and toxicities were acceptable and comparable with similar patients conditioned with Treo/Flu or FLAMSA-RIC. CONCLUSION: In conclusion, Treo/Flu/AraC provides tolerable, feasible, and effective conditioning for patients with AML, MDS or MPN, even in advanced disease states. The incidence of NRM and relapse is acceptable in this heavily pre-treated population with high-risk disease. Future research will aim to confirm these initial findings and include a larger number of participants in a prospective trial.

Relationship of Head Circumference and Age in the Prediction of the Real-Ear-to-Coupler Difference (RECD).

BACKGROUND: Pediatric hearing instrument fitting is optimally performed with individually obtained real-ear-to-coupler difference (RECD) measurements. If these measurements cannot be obtained, predicted values based on age are used. Recent evidence obtained from children aged 3-11 years suggests that head circumference (HC) may be a viable alternative or addition to age for use in RECD prediction. PURPOSE: The purpose of the present study was to determine if HC can be used to predict RECDs in infants, children, and adults. RESEARCH DESIGN: A correlational design was used. HC and RECD values were measured in all participants. STUDY SAMPLE: Participants were 278 North American infants and children (136 males and 142 females) aged 1.6 months to 11 years and 109 adults (42 males and 67 females) aged 18 years to 83 years. DATA COLLECTION AND ANALYSIS: After otoscopic inspection and immittance measurements were performed to assess candidacy for inclusion in the study, HC was measured twice for all participants and a single RECD measure was obtained for each participant at twelve frequencies (250 through 12500 Hz). The reliability of HC measurements was assessed with an intraclass correlation analysis. Linear regression analyses were performed with age and HC as predictor variables and RECDs as the dependent variable. RESULTS: Analysis indicated good reliability of the HC measurement. The relationships between RECD and HC were comparable with the relationships between RECD and age. Combining HC and age did not improve predictive accuracy. CONCLUSIONS: HC can be used in children and adults as an alternative metric in the prediction of RECDs when individual RECDs cannot be obtained.

A Prospective Study of Circulating Tumor DNA to Guide Matched Targeted Therapy in Lung Cancers.

BACKGROUND: Liquid biopsy for plasma circulating tumor DNA (ctDNA) next-generation sequencing (NGS) is commercially available and increasingly adopted in clinical practice despite a paucity of prospective data to support its use. METHODS: Patients with advanced lung cancers who had no known oncogenic driver or developed resistance to current targeted therapy (n = 210) underwent plasma NGS, targeting 21 genes. A subset of patients had concurrent tissue NGS testing using a 468-gene panel (n = 106). Oncogenic driver detection, test turnaround time (TAT), concordance, and treatment response guided by plasma NGS were measured. All statistical tests were two-sided. RESULTS: Somatic mutations were detected in 64.3% (135/210) of patients. ctDNA detection was lower in patients who were on systemic therapy at the time of plasma collection compared with those who were not (30/70, 42.9% vs 105/140, 75.0%; OR = 0.26, 95% CI = 0.1 to 0.5, P < .001). The median TAT of plasma NGS was shorter than tissue NGS (9 vs 20 days; P < .001). Overall concordance, defined as the proportion of patients for whom at least one identical genomic alteration was identified in both tissue and plasma, was 56.6% (60/106, 95% CI = 46.6% to 66.2%). Among patients who tested plasma NGS positive, 89.6% (60/67; 95% CI = 79.7% to 95.7%) were also concordant on tissue NGS and 60.6% (60/99; 95% CI = 50.3% to 70.3%) vice versa. Patients who tested plasma NGS positive for oncogenic drivers had tissue NGS concordance of 96.1% (49/51, 95% CI = 86.5% to 99.5%), and directly led to matched targeted therapy in 21.9% (46/210) with clinical response. CONCLUSIONS: Plasma ctDNA NGS detected a variety of oncogenic drivers with a shorter TAT compared with tissue NGS and matched patients to targeted therapy with clinical response. Positive findings on plasma NGS were highly concordant with tissue NGS and can guide immediate therapy; however, a negative finding in plasma requires further testing. Our findings support the potential incorporation of plasma NGS into practice guidelines.

Antibiotic resistance in Aeromonas upstream and downstream of a water resource recovery facility.

Aeromonas strains isolated from sediments upstream and downstream of a water resource recovery facility (WRRF) over a two-year time period were tested for susceptibility to 13 antibiotics. Incidence of resistance to antibiotics, antibiotic resistance phenotypes, and diversity (based on resistance phenotypes) were compared in the two populations. At the beginning of the study, the upstream and downstream Aeromonas populations were different for incidence of antibiotic resistance (p < 0.01), resistance phenotypes (p < 0.005), and diversity. However, these differences declined over time and were not significant at the end of the study. These results (1) indicate that antibiotic resistance in Aeromonas in stream sediments fluctuates considerably over time and (2) suggest that WRRF effluent does not, when examined over the long- term, affect antibiotic resistance in Aeromonas in downstream sediment.

Unfolding the relationship between secreted molecular chaperones and macrophage activation states.

Over the last 20 years, it has emerged that many molecular chaperones and protein-folding catalysts are secreted from cells and function, somewhat in the manner of cytokines, as pleiotropic signals for a variety of cells, with much attention being focused on the macrophage. During the last decade, it has become clear that macrophages respond to bacterial, protozoal, parasitic and host signals to generate phenotypically distinct states of activation. These activation states have been termed 'classical' and 'alternative' and represent not a simple bifurcation in response to external signals but a range of cellular phenotypes. From an examination of the literature, the hypothesis is propounded that mammalian molecular chaperones are able to induce a wide variety of alternative macrophage activation states, and this may be a system for relating cellular or tissue stress to appropriate macrophage responses to restore homeostatic equilibrium.