The cytidine nucleoside analogs azacitidine (AZA) and decitabine (DAC) are used for the treatment of patients with myelodysplastic syndromes and acute myeloid leukemia (AML). Few non-clinical studies ...have directly compared the mechanisms of action of these agents in a head-to-head fashion, and the agents are often viewed as mechanistically similar DNA hypomethylating agents. To better understand the similarities and differences in mechanisms of these drugs, we compared their in vitro effects on several end points in human AML cell lines.
Both drugs effected DNA methyltransferase 1 depletion, DNA hypomethylation, and DNA damage induction, with DAC showing equivalent activity at concentrations 2- to 10-fold lower than AZA. At concentrations above 1 microM, AZA had a greater effect than DAC on reducing cell viability. Both drugs increased the sub-G1 fraction and apoptosis markers, with AZA decreasing all cell cycle phases and DAC causing an increase in G2-M. Total protein synthesis was reduced only by AZA, and drug-modulated gene expression profiles were largely non-overlapping.
These data demonstrate shared mechanisms of action of AZA and DAC on DNA-mediated markers of activity, but distinctly different effects in their actions on cell viability, protein synthesis, cell cycle, and gene expression. The differential effects of AZA may be mediated by RNA incorporation, as the distribution of AZA in nucleic acid of KG-1a cells was 65:35, RNA:DNA.
Patients with multiple chronic conditions, especially cancer survivors, face challenges in medical decision making. Previous research demonstrates how patient values can guide medical decisions, ...however facilitating patient values elicitation remains a challenge. This study aims to evaluate the psychometric properties of and refine the What Matters Most (WMM) Survey, a self-reported values elicitation tool, in a cohort of older veteran cancer survivors.
An observational cohort study was conducted to evaluate the psychometric properties of the WMM Survey in older, multimorbid cancer survivors. 262 patients were administered the assessment at two timepoints, between 14 and 30 days apart.
Exploratory factor analyses revealed four factors for assessing healthcare values among older adults with good internal consistency for all factors: Functioning (Cronbach’s alpha coefficient, α = 0.88), Enjoying Life (α = 0.79), Connecting (α = 0.84), and Managing Health (α = 0.88). Demographic and clinical characteristics were not uniformly associated with specific healthcare values.
Future studies are required to refine the proposed assessment and to evaluate its application in a general patient population.
The WMM Survey is an innovative resource in health values elicitation, allowing for facilitation of patient-clinician communication for whole-person medical approaches and measurement of health values for research.
•Developed a self-reported health values assessment tool for older patients.•Evaluated the tool’s psychometric properties in older, multimorbid cancer survivors.•Analyses revealed four values domains, consistent with previous studies.•Applications in patient-driven values elicitation and clinical decision making.•Further work is required to optimize assessment and evaluate in general population.
Trainees, drawn from across healthcare professions, are the future clinical workforce caring for older adults in a variety of healthcare settings. For these trainees, clinical training and education ...in the evidence-based principles of Geriatric Medicine are critical. The Age Friendly Health Systems (AFHS) initiative, developed by the John A. Hartford Foundation and the Institute for Healthcare Improvement (IHI), classifies these principles into the 4 Ms Framework (What Matters, Mentation, Mobility, Medications). For older adults, the current disease-based, siloed approach often results in fragmented care with a burdensome assortment of medications, diagnostic tests, and specialist visits.1 The benefits and harms of complex treatment plans are often uncertain, as older adults with multiple chronic conditions (MCCs) are often excluded from clinical trials. When faced with tradeoffs between possible outcomes, older adults with MCCs vary in their health outcome goals and in what they are willing to do to achieve these outcomes.2 The uncertainty of benefits and harms of many interventions and variability in goals and preferences among older adults with MCCs makes “What Matters” the core of Age Friendly care.National experts engaged key stakeholders in the care of multimorbid older adults (clinicians, patients, caregivers, and payer sources) to develop Patient Priorities Care (PPC).1 PPC is a frameshift in clinical decision-making from addressing each chronic condition in isolation to providing the care that best achieves the priorities of each individual older adult, that is, the health outcomes they most desire given the treatments and healthcare tasks that they are willing and able to accept.3 PPC provides a systematic and evidence-based framework for addressing the “What Matters” of the 4 Ms frameworks and an approach to care that aligns decision-making with older patients' health priorities. PPC reduces overall treatment burden, improves patient satisfaction and increases priorities-aligned care.3, 4Virtual education methods, which rapidly expanded across health professions in response to COVID-19 pandemic restrictions, allow for wide spread dissemination of training in asking about and acting on What Matters. Virtual training also expands the reach of clinician–educators with expertise in PPC. This study details the outcomes of a PPC virtual training session pilot with an interprofessional group of health professional trainees from three institutions.
Anti-CD20 antibody treatments, such as obinutuzumab, have been associated with infusion-related reactions (IRRs). In the phase 3 iLLUMINATE study of ibrutinib-obinutuzumab versus ...chlorambucil-obinutuzumab in first-line chronic lymphocytic leukemia/small lymphocytic lymphoma, IRRs were substantially reduced with ibrutinib-obinutuzumab versus chlorambucil-obinutuzumab. We prospectively analyzed inflammatory cytokines to evaluate the impact of ibrutinib on circulating cytokine levels following obinutuzumab infusion. In iLLUMINATE, ibrutinib or chlorambucil was given approximately 30–120 min before the first obinutuzumab infusion. Cytokines evaluated were IFNγ, IL-6, IL-8, IL-10, IL-18, MCP-1, MIP-1α, MIP-1β, and TNFα. Changes in peak cytokine levels from baseline (immediately before obinutuzumab) to post-obinutuzumab infusion were compared between arms and between patients with versus without IRRs using Wilcoxon rank sum test. Of 228 treated patients, 95 on ibrutinib-obinutuzumab (15 with IRRs, 80 without) and 88 on chlorambucil-obinutuzumab (45 with IRRs, 43 without) with cytokine data were included. Irrespective of IRR occurrence, median increase in cytokines was lower with ibrutinib-obinutuzumab versus chlorambucil-obinutuzumab for all cytokines (
P
< 0.01) except MIP-1β. Across treatment arms, post-obinutuzumab median increase in all cytokines except MIP-1β was greater in patients with versus without IRRs (
P
< 0.001). IL-6 and IL-8 elevations were associated with IRRs in both treatment arms. Among patients with IRRs, those receiving ibrutinib-obinutuzumab had lower post-obinutuzumab increases in IL-6, IL-8, IL-10, and MCP-1 (
P
< 0.04) than patients receiving chlorambucil-obinutuzumab. For patients in the ibrutinib-treatment arm, we observed a reduction in both the rate of clinically apparent IRRs and the levels of IRR-related cytokines and chemokines. This observation supports an immunomodulatory mechanism of action for ibrutinib. Clinical Trial Registration: NCT02264574
MDS is characterized by ineffective hematopoiesis that leads to peripheral cytopenias. Development of effective treatments has been impeded by limited insight into pathogenic pathways governing ...dysplastic growth of hematopoietic progenitors. We demonstrate that smad2, a downstream mediator of transforming growth factor–β (TGF-β) receptor I kinase (TBRI) activation, is constitutively activated in MDS bone marrow (BM) precursors and is overexpressed in gene expression profiles of MDS CD34+ cells, providing direct evidence of overactivation of TGF-β pathway in this disease. Suppression of the TGF-β signaling by lentiviral shRNA-mediated down-regulation of TBRI leads to in vitro enhancement of hematopoiesis in MDS progenitors. Pharmacologic inhibition of TBRI (alk5) kinase by a small molecule inhibitor, SD-208, inhibits smad2 activation in hematopoietic progenitors, suppresses TGF-β–mediated gene activation in BM stromal cells, and reverses TGF-β–mediated cell-cycle arrest in BM CD34+ cells. Furthermore, SD-208 treatment alleviates anemia and stimulates hematopoiesis in vivo in a novel murine model of bone marrow failure generated by constitutive hepatic expression of TGF-β1. Moreover, in vitro pharmacologic inhibition of TBRI kinase leads to enhancement of hematopoiesis in varied morphologic MDS subtypes. These data directly implicate TGF-β signaling in the pathobiology of ineffective hematopoiesis and identify TBRI as a potential therapeutic target in low-risk MDS.
Neural crest cells (NCCs) are a migratory, transient, and multipotent stem cell population essential to vertebrate embryonic development, contributing to numerous cell lineages in the adult organism. ...While great strides have been made in elucidating molecular and cellular events that drive NCC specification, comprehensive knowledge of the genetic factors that orchestrate NCC developmental programs is still far from complete. We discovered that elevated Hoxb5b levels promoted an expansion of zebrafish NCCs, which persisted throughout multiple stages of development. Correspondingly, elevated Hoxb5b also specifically expanded expression domains of the vagal NCC markers
and
. Increases in NCCs were most apparent after pulsed ectopic Hoxb5b expression at early developmental stages, rather than later during differentiation stages, as determined using a novel transgenic zebrafish line. The increase in vagal NCCs early in development led to supernumerary Phox2b
enteric neural progenitors, while leaving many other NCC-derived tissues without an overt phenotype. Surprisingly, these NCC-derived enteric progenitors failed to expand properly into sufficient quantities of enterically fated neurons and stalled in the gut tissue. These results suggest that while Hoxb5b participates in vagal NCC development as a driver of progenitor expansion, the supernumerary, ectopically localized NCC fail to initiate expansion programs in timely fashion in the gut. All together, these data point to a model in which Hoxb5b regulates NCCs both in a tissue specific and temporally restricted manner.
The myelodysplastic syndromes (MDSs) are collections of heterogeneous hematologic diseases characterized by refractory cytopenias as a result of ineffective hematopoiesis. Development of effective ...treatments has been impeded by limited insights into any unifying pathogenic pathways. We provide evidence that the p38 MAP kinase is constitutively activated or phosphorylated in MDS bone marrows. Such activation is uniformly observed in varied morphologic subtypes of low-risk MDS and correlates with enhanced apoptosis observed in MDS hematopoietic progenitors. Most importantly, pharmacologic inhibition of p38α by a novel small molecule inhibitor, SCIO-469, decreases apoptosis in MDS CD34+ progenitors and leads to dose-dependant increases in erythroid and myeloid colony formation. Down-regulation of the dominant p38α isoform by siRNA also leads to enhancement of hematopoiesis in MDS bone marrow progenitors in vitro. These data implicate p38 MAPK in the pathobiology of ineffective hematopoiesis in lowrisk MDS and provide a strong rationale for clinical investigation of SCIO-469 in MDS.
Although PS-341 (bortezomib) is a promising agent to improve multiple myeloma (MM) patient outcome, 65% of patients with relapsed and refractory disease do not respond. We have previously shown that ...heat shock protein (Hsp)27 is upregulated after PS-341 treatment, that overexpression of Hsp27 confers PS-341 resistance, and that inhibition of Hsp27 overcomes PS-341 resistance. Since Hsp27 is a downstream target of p38 mitogen-activated protein kinase (MAPK)/MAPK-mitogen-activated protein kinase-2 (MAPKAPK2), we hypothesized that inhibition of p38 MAPK activity could augment PS-341 cytotoxicity by downregulating Hsp27. Although p38 MAPK inhibitor SCIO-469 (Scios Inc, CA, USA) alone did not induce significant growth inhibition, it blocked baseline and PS-341-triggered phosphorylation of p38 MAPK as well as upregulation of Hsp27, associated with enhanced cytotoxicity in MM.1S cells. Importantly, SCIO-469 enhanced phosphorylation of c-Jun NH2-terminal kinase (JNK) and augmented cleavage of caspase-8 and poly(ADP)-ribose polymerase. Moreover, SCIO-469 downregulated PS-341-induced increases in G2/M-phase cells, associated with downregulation of p21Cip1 expression. Importantly, SCIO-469 treatment augmented cytotoxicity of PS-341 even against PS-341-resistant cell lines and patient MM cells. These studies therefore provide the framework for clinical trials of SCIO-469 to enhance sensitivity and overcome resistance to PS-341, thereby improving patient outcome in MM.
Transforming growth factors (TGFs) have pleiotropic biological effects on tumor cells and their environment. In multiple myeloma (MM), we have reported that bone marrow stromal cells (BMSCs) from MM ...patients produce more TGF-beta1 than BMSCs from healthy donors, which in turn induces interleukin (IL)-6 secretion. We show here that the TGF-beta receptor I kinase inhibitor SD-208 significantly decreases secretion of both IL-6 and vascular endothelial growth factor (VEGF) from BMSCs, as well as tumor cell growth triggered by MM cell adhesion to BMSCs.
Cytokine production and MM cell proliferation triggered by TGF-beta1 or adhesion to BMSCs were examined in the presence or absence of SD-208. Effects of SD-208 on TGF-beta1-induced signaling pathways triggering IL-6 and VEGF transcription in BMSCs were also delineated.
SD-208 significantly inhibits not only transcription but also secretion of both IL-6 and VEGF from BMSCs triggered by either TGF-beta1 or adhesion of MM cells to BMSCs. Moreover, SD-208 decreased tumor cell growth triggered by MM cell adhesion to BMSCs. SD-208 works, at least in part, by blocking TGF-beta1-triggered nuclear accumulation of Smad2/3 and hypoxia-inducible factor 1alpha, as well as related production of IL-6 and VEGF, respectively.
These studies indicate that SD-208 inhibits production of cytokines mediating MM cell growth, survival, drug resistance, and migration in the BM milieu, thereby providing the preclinical rationale for clinical evaluation of SD-208 to improve patient outcome in MM.
Hydrogen (H2) gas is an obligatory byproduct of nitrogen (N2) reduction during biological nitrogen fixation by the metalloenzyme nitrogenase. Despite significant efforts, diazotrophic H2 production ...rates remain too low to compete with fossil fuel-derived H2. Here, we investigate the role of temperature (14, 19, 30 °C), carbon metabolism (acetate or succinate as carbon source), and nitrogenase isoform (molybdenum, vanadium, iron-only nitrogenase) in controlling N2 reduction and H2 production rates in the model anaerobic photoheterotroph Rhodopseudomonas palustris.
Rates of H2 production are primarily controlled by growth rate and secondarily by nitrogenase enzymology. The iron-only nitrogenase exhibits the highest H2:N2 stoichiometries (6.3–12.7); H2:N2 stoichiometries for molybdenum and vanadiumnitrogenases are similarly lower (2.5–4.1 and 2.6–4.3, respectively) and uncorrelated with growth rate or temperature. Hydrogen inhibition of growth is lower than H2 inhibition of purified nitrogenase. These results help provide a framework for optimizing physical and metabolic conditions in diazotroph-based biohydrogen production efforts.
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•H2 production rates controlled primarily by growth rate and nitrogenase enzymology.•Mo- and V-nitrogenase have similar H2:N2 ratios uncorrelated with temperature.•H2:N2 ratios <4 decoupled from growth rate over a range of conditions.•Lower biomass N content associated with higher H2 production rates and H2:N2 ratios.•In vivo H2 inhibition of N2 reduction is minimal (∼15% at 0.3 atm, Mo- and V-Nase).
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