Cancer is a prevalent disease and is one of the leading causes of death worldwide driven by mutations at the genetic level. An ideal model organism used for cancer research, specifically melanoma, is ...zebrafish as adult zebrafish display disappearance of their horizontal stripes and emergence of black masses. Zebrafish have highly conserved genes, comparable signaling pathways, and similar tumor development. This research project is designed to identify gene expression changes that are critical for the progression of melanoma in this model system. Wild‐type and heterozygous p53 deficient (M214K) will be exposed to ultraviolet (UV) radiation to promote tumorigenesis. The expression of multiple genes in the p53 pathway will be monitored via qPCR during progression of the melanoma. Genes that are identified as up‐regulated or down‐regulated will be targeted using CRISPR‐Cas9 to determine their role in the progression of the disease.
The RNA-processing exosome contains ribonucleases that degrade aberrant RNAs in archael and eukaryotic cells. In Saccharomyces cerevisiae, the nuclear/nucleolar 3'-5' exoribonuclease Rrp6 ...distinguishes the nuclear exosome from the cytoplasmic exosome. In vivo, the TRAMP complex enhances the ability of the nuclear exosome to destroy some aberrant RNAs. Previous reports showed that purified TRAMP enhanced RNA degradation by the nuclear exosome in vitro. However, the exoribonucleolytic component(s) of the nuclear exosome enhanced by TRAMP remain unidentified. We show that TRAMP does not significantly enhance RNA degradation by purified exosomes lacking Rrp6 in vitro, suggesting that TRAMP activation experiments with nuclear exosome preparations reflect, in part, effects on the activity of Rrp6. Consistent with this, we show that incubation of purified TRAMP with recombinant Rrp6 results in a 10-fold enhancement of the rate of RNA degradation. This increased activity results from enhancement of the hydrolytic activity of Rrp6 because TRAMP cannot enhance the activity of an Rrp6 mutant lacking a key amino acid side chain in its active site. We observed no ATP or polyadenylation dependence for the enhancement of Rrp6 activity by TRAMP, suggesting that neither the poly(A) polymerase activity of Trf4 nor the helicase activity of Mtr4 plays a role in the enhancement. These findings identify TRAMP as an exosome-independent enhancer of Rrp6 activity.
The development of strategies to eradicate primary human acute myelogenous leukemia (AML) cells is a major challenge to the leukemia research field. In particular, primitive leukemia cells, often ...termed leukemia stem cells, are typically refractory to many forms of therapy. To investigate improved strategies for targeting of human AML cells we compared the molecular mechanisms regulating oxidative state in primitive (CD34+) leukemic versus normal specimens. Our data indicate that CD34+ AML cells have elevated expression of multiple glutathione pathway regulatory proteins, presumably as a mechanism to compensate for increased oxidative stress in leukemic cells. Consistent with this observation, CD34+ AML cells have lower levels of reduced glutathione and increased levels of oxidized glutathione compared with normal CD34+ cells. These findings led us to hypothesize that AML cells will be hypersensitive to inhibition of glutathione metabolism. To test this premise, we identified compounds such as parthenolide (PTL) or piperlongumine that induce almost complete glutathione depletion and severe cell death in CD34+ AML cells. Importantly, these compounds only induce limited and transient glutathione depletion as well as significantly less toxicity in normal CD34+ cells. We further determined that PTL perturbs glutathione homeostasis by a multifactorial mechanism, which includes inhibiting key glutathione metabolic enzymes (GCLC and GPX1), as well as direct depletion of glutathione. These findings demonstrate that primitive leukemia cells are uniquely sensitive to agents that target aberrant glutathione metabolism, an intrinsic property of primary human AML cells.
Background: Eradication of primary human leukemia cells represents a major challenge. Therapies have not substantially changed in over 30 years.
Results: Using normal versus leukemia specimens enriched for primitive cells, we document aberrant regulation of glutathione metabolism.
Conclusion: Aberrant glutathione metabolism is an intrinsic property of human leukemia cells.
Significance: Interventions based on modulation of glutathione metabolism represent a powerful means to improve therapy.
We used an in vivo small hairpin RNA (shRNA) screening approach to identify genes that are essential for MLL-AF9 acute myeloid leukemia (AML). We found that Integrin Beta 3 (Itgb3) is essential for ...murine leukemia cells in vivo and for human leukemia cells in xenotransplantation studies. In leukemia cells, Itgb3 knockdown impaired homing, downregulated LSC transcriptional programs, and induced differentiation via the intracellular kinase Syk. In contrast, loss of Itgb3 in normal hematopoietic stem and progenitor cells did not affect engraftment, reconstitution, or differentiation. Finally, using an Itgb3 knockout mouse model, we confirmed that Itgb3 is dispensable for normal hematopoiesis but is required for leukemogenesis. Our results establish the significance of the Itgb3 signaling pathway as a potential therapeutic target in AML.
Display omitted
•In vivo RNAi screening in primary mouse and human AML reveals dependence on Itgb3•Itgb3 depletion impairs leukemia cell growth while sparing normal hematopoiesis•Itgb3 loss downregulates leukemia stem cell programs and induces differentiation•Itgb3 activity in AML is mediated by Syk and amenable to pharmacologic inhibition
Background
Frailty is associated with numerous post‐operative adverse outcomes in older adults. Current pre‐operative frailty screening tools require additional data collection or objective ...assessments, adding expense and limiting large‐scale implementation.
Objective
To evaluate the association of an automated measure of frailty integrated within the Electronic Health Record (EHR) with post‐operative outcomes for nonemergency surgeries.
Design
Retrospective cohort study.
Setting
Academic Medical Center.
Participants
Patients 65 years or older that underwent nonemergency surgery with an inpatient stay 24 hours or more between October 8th, 2017 and June 1st, 2019.
Exposures
Frailty as measured by a 54‐item electronic frailty index (eFI).
Outcomes and Measurements
Inpatient length of stay, requirements for post‐acute care, 30‐day readmission, and 6‐month all‐cause mortality.
Results
Of 4,831 unique patients (2,281 females (47.3%); mean (SD) age, 73.2 (5.9) years), 4,143 (85.7%) had sufficient EHR data to calculate the eFI, with 15.1% categorized as frail (eFI > 0.21) and 50.9% pre‐frail (0.10 < eFI ≤ 0.21). For all outcomes, there was a generally a gradation of risk with higher eFI scores. For example, adjusting for age, sex, race/ethnicity, and American Society of Anesthesiologists class, and accounting for variability by service line, patients identified as frail based on the eFI, compared to fit patients, had greater needs for post‐acute care (odds ratio (OR) = 1.68; 95% confidence interval (CI) = 1.36–2.08), higher rates of 30‐day readmission (hazard ratio (HR) = 2.46; 95%CI = 1.72–3.52) and higher all‐cause mortality (HR = 2.86; 95%CI = 1.84–4.44) over 6 months' follow‐up.
Conclusions
The eFI, an automated digital marker for frailty integrated within the EHR, can facilitate pre‐operative frailty screening at scale.
The RNA exosome processes and degrades RNAs in archaeal and eukaryotic cells. Exosomes from yeast and humans contain two active exoribonuclease components, Rrp6p and Dis3p/Rrp44p. Rrp6p is ...concentrated in the nucleus and the dependence of its function on the nine-subunit core exosome and Dis3p remains unclear. We found that cells lacking Rrp6p accumulate poly(A)+ rRNA degradation intermediates distinct from those found in cells depleted of Dis3p, or the core exosome component Rrp43p. Depletion of Dis3p in the absence of Rrp6p causes a synergistic increase in the levels of degradation substrates common to the core exosome and Rrp6p, but has no effect on Rrp6p-specific substrates. Rrp6p lacking a portion of its C-terminal domain no longer co-purifies with the core exosome, but continues to carry out RNA 3′-end processing of 5.8S rRNA and snoRNAs, as well as the degradation of certain truncated Rrp6-specific rRNA intermediates. However, disruption of Rrp6p–core exosome interaction results in the inability of the cell to efficiently degrade certain poly(A)+ rRNA processing products that require the combined activities of Dis3p and Rrp6p. These findings indicate that Rrp6p may carry out some of its critical functions without physical association with the core exosome.
Function and the independent performance of daily activities are of critical importance to older adults. Although function was once a domain of interest primarily limited to geriatricians, ...transdisciplinary research has demonstrated its value across the spectrum of medical and surgical care. Nonetheless, integrating a functional perspective into medical and surgical therapeutics has yet to be implemented consistently into clinical practice. This article summarizes the presentations and discussions from a workshop, “Embedding/Sustaining a Focus on Function in Specialty Research and Care,” held on January 31 to February 1, 2019. The third in a series supported by the National Institute on Aging and the John A. Hartford Foundation, the workshop aimed to identify scientific gaps and recommend research strategies to advance the implementation of function in care of older adults. Transdisciplinary leaders discussed implementation of mobility programs and functional assessments, including comprehensive geriatric assessment; integrating cognitive and sensory functional assessments; the role of culture, environment, and community in incorporating function into research; innovative methods to better identify functional limitations, techniques, and interventions to facilitate functional gains; and the role of the health system in fostering integration of function. Workshop participants emphasized the importance of aligning goals and assessments and adopting a team science approach that includes clinicians and frontline staff in the planning, development, testing, and implementation of tools and initiatives. This article summarizes those discussions.
See related editorial by Ling et al.
The implementation of Course‐Based Undergraduate Research Experiences (CUREs) has made it possible to expose large undergraduate populations to research experiences. For these research experiences to ...be authentic, they should reflect the increasing collaborative nature of research. While some CUREs have expanded with multiple schools across the nation, it is still unclear how a structured extramural collaboration between students and faculty from an outside institution affects student outcomes. In this study, we established three cohorts of students: 1) no‐CURE 2) single institution CURE (CURE) and 3) external collaborative CURE (ec‐CURE) and assessed academic and attitudinal outcomes. The ec‐CURE differs from a regular CURE in that students work with faculty member from an external institution to refine their hypothesis and discuss their data. The sharing of ideas, data and materials with an external faculty allowed students to experience a level of collaboration not typically found in an undergraduate setting. Students in the ec‐CURE had the greatest gains in experimental design, self‐reported course benefits, scientific skills and STEM importance. Importantly this study occurred in a diverse community of STEM disciplinary faculty from 2‐ and 4‐year institutions illustrating that exposing students to structured external collaboration is both feasible and beneficial to student learning.
To examine whether mental health problems predict incident use of 12 different tobacco products in a nationally representative sample of youth and young adults.
This study analyzed Wave (W) 1 and W2 ...data from 10,533 12- to 24-year-old W1 never tobacco users in the Population Assessment of Tobacco and Health (PATH) Study. Self-reported lifetime internalizing and externalizing symptoms were assessed at W1. Past 12-month use of cigarettes, electronic nicotine delivery systems (ENDS), traditional cigars, cigarillos, filtered cigars, pipe, hookah, snus pouches, other smokeless tobacco, bidis and kreteks (youth only), and dissolvable tobacco was assessed at W2.
In multivariable regression analyses, high-severity W1 internalizing (adjusted odds ratio AOR = 1.5, 95% CI = 1.3-1.8) and externalizing (AOR = 1.3, 95% CI = 1.1-1.5) problems predicted W2 onset of any tobacco use compared to no/low/moderate severity. High-severity W1 internalizing problems predicted W2 use onset across most tobacco products. High-severity W1 externalizing problems predicted onset of any tobacco (AOR = 1.6, 95% CI = 1.3-1.8), cigarettes (AOR = 1.4, 95% CI = 1.0-2.0), ENDS (AOR = 1.8, 95% CI = 1.5-2.1), and cigarillos (AOR = 1.5, 95% CI = 1.0-2.1) among youth only.
Internalizing and externalizing problems predicted onset of any tobacco use. However, findings differed for internalizing and externalizing problems across tobacco products, and by age, gender, and race/ethnicity. In addition to screening for tobacco product use, health care providers should screen for a range of mental health problems as a predictor of tobacco use. Interventions addressing mental health problems may prevent youth from initiating tobacco use.
Abstract
Traditional clinical care models focus on the measurement and normalization of individual organ systems and de-emphasize aspects of health related to the integration of physiologic systems. ...Measures of physical, cognitive and sensory, and psychosocial or emotional function predict important health outcomes like death and disability independently from the severity of a specific disease, cumulative co-morbidity, or disease severity measures. A growing number of clinical scientists in several subspecialties are exploring the utility of functional assessment to predict complication risk, indicate stress resistance, inform disease screening approaches and risk factor interpretation, and evaluate care. Because a substantial number of older adults in the community have some form of functional limitation, integrating functional assessment into clinical medicine could have a large impact. Although interest in functional implications for health and disease management is growing, the science underlying functional capacity, functional limitation, physical frailty, and functional metrics is often siloed among different clinicians and researchers, with fragmented concepts and methods. On August 25–26, 2016, participants at a trans-disciplinary workshop, supported by the National Institute on Aging and the John A. Hartford Foundation, explored what is known about the pathways, contributors, and correlates of physical, cognitive, and sensory functional measures across conditions and disease states; considered social determinants and health disparities; identified knowledge gaps, and suggested priorities for future research. This article summarizes those discussions.
PDF
