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1.
ATS Sch ; 1(1): 11-19, 2020 Feb 21.
Article in English | MEDLINE | ID: mdl-33870265

ABSTRACT

Background: Leadership and teamwork are critical to the performance of a multidisciplinary team responding to emergencies in the intensive care unit; yet, these skills are variably taught to pulmonary and critical care trainees. Currently, there is no standardized leadership curriculum in critical care training. Objective: We developed a longitudinal crisis leadership curriculum for first-year pulmonary and critical care fellows using high-fidelity simulation as a medium to practice and solidify skills. The goal was to improve leadership skills and trainee confidence when leading a team during life-threatening emergencies. Methods: Guided by a needs assessment of current and recently graduated fellows, we developed a leadership curriculum from a review of the available literature and local expert opinion. Four sessions were conducted over the academic years of 2016 to 2017 and 2017 to 2018, each including small-group teaching on effective leadership behaviors, followed by simulation with postsession leadership debriefing to review performance. Fellows were surveyed regarding their experiences with the curriculum. Results: Over two academic years, 100% of targeted fellows (N = 13) completed every session. Participants reported improved understanding of key elements of effective leadership, greater confidence in leading a multidisciplinary team, and increased preparedness to lead during a crisis. Simulation with debriefing was viewed as an effective medium for learning leadership skills, and fellows provided positive feedback regarding the experience. Conclusion: Implementation of a longitudinal crisis leadership curriculum within the first year of pulmonary and critical care fellowship was feasible and highly valued by learners. More research is needed to determine effective methods for teaching and assessing leadership skills.

2.
Front Physiol ; 10: 1321, 2019.
Article in English | MEDLINE | ID: mdl-31681022

ABSTRACT

Sepsis is a debilitating condition associated with a high mortality rate that greatly strains hospital resources. Though advances have been made in improving sepsis diagnosis and treatment, our understanding of the disease is far from complete. Mathematical modeling of sepsis has the potential to explore underlying biological mechanisms and patient phenotypes that contribute to variability in septic patient outcomes. We developed a comprehensive, whole-body mathematical model of sepsis pathophysiology using the BioGears Engine, a robust open-source virtual human modeling project. We describe the development of a sepsis model and the physiologic response within the BioGears framework. We then define and simulate scenarios that compare sepsis treatment regimens. As such, we demonstrate the utility of this model as a tool to augment sepsis research and as a training platform to educate medical staff.

5.
J Grad Med Educ ; 11(4): 389-401, 2019 Aug.
Article in English | MEDLINE | ID: mdl-31440332

ABSTRACT

BACKGROUND: Management of mechanical ventilation (MV) is an important and complex aspect of caring for critically ill patients. Management strategies and technical operation of the ventilator are key skills for physicians in training, as lack of expertise can lead to substantial patient harm. OBJECTIVE: We performed a narrative review of the literature describing MV education in graduate medical education (GME) and identified best practices for training and assessment methods. METHODS: We searched MEDLINE, PubMed, and Google Scholar for English-language, peer-reviewed articles describing MV education and assessment. We included articles from 2000 through July 2018 pertaining to MV education or training in GME. RESULTS: Fifteen articles met inclusion criteria. Studies related to MV training in anesthesiology, emergency medicine, general surgery, and internal medicine residency programs, as well as subspecialty training in critical care medicine, pediatric critical care medicine, and pulmonary and critical care medicine. Nearly half of trainees assessed were dissatisfied with their MV education. Six studies evaluated educational interventions, all employing simulation as an educational strategy, although there was considerable heterogeneity in content. Most outcomes were assessed with multiple-choice knowledge testing; only 2 studies evaluated the care of actual patients after an educational intervention. CONCLUSIONS: There is a paucity of information describing MV education in GME. The available literature demonstrates that trainees are generally dissatisfied with MV training. Best practices include establishing MV-specific learning objectives and incorporating simulation. Next research steps include developing competency standards and validity evidence for assessment tools that can be utilized across MV educational curricula.


Subject(s)
Clinical Competence/standards , Internship and Residency , Learning , Respiration, Artificial/standards , Simulation Training/standards , Education, Medical, Graduate , Emergency Medicine/education , Humans , Internal Medicine/education , Physicians
7.
MedEdPORTAL ; 15: 10813, 2019 03 15.
Article in English | MEDLINE | ID: mdl-31139732

ABSTRACT

Introduction: The management of neurologic emergencies is an important component of critical care fellowship training. Additional training in neurocritical care has been demonstrated to improve clinical outcomes, though exposure to these emergencies during training can be limited. Methods: Three simulation cases are presented as part of a comprehensive neurologic emergencies curriculum for critical care trainees. The cases represent neurologic catastrophes encountered in the intensive care unit consisting of symptomatic hyponatremia, severe alcohol withdrawal syndrome, and brain herniation syndrome. The case descriptions are complete with learning objectives, critical actions checklists, and debriefing material for facilitators, as well as all necessary personnel briefs and required equipment. Results: The scenarios were completed over the course of the 2016-2017 academic year by first-year critical care fellows. Following curriculum implementation, there was an improvement in self-perceived confidence of fellows in neurologic emergency management skills. Discussion: The cases were felt to be realistic and beneficial and led to perceived improvement in management of neurologic emergencies and leadership during clinical crises.


Subject(s)
Critical Care , Emergencies , Fellowships and Scholarships , Intensive Care Units/organization & administration , Simulation Training , Alcohol Withdrawal Delirium/diagnosis , Alcohol Withdrawal Delirium/therapy , Curriculum , Education, Medical, Graduate , Humans , Hyponatremia/diagnosis , Hyponatremia/therapy
8.
CPT Pharmacometrics Syst Pharmacol ; 8(1): 12-25, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30411537

ABSTRACT

BioGears is an open-source, lumped parameter, full-body human physiology engine. Its purpose is to provide realistic and comprehensive simulations for medical training, research, and education. BioGears incorporates a physiologically based pharmacokinetic/pharmacodynamic (PK/PD) model that is designed to be applicable to a diversity of drug classes and patients and is extensible to future drugs. In addition, BioGears also supports drug interactions with various patient insults and interventions allowing for a realistic research framework and accurate dose-patient responses. This tutorial will demonstrate how the generic BioGears PK/PD model can be extended to a new substance for prediction of drug administration outcomes.

10.
Respir Med ; 144S: S13-S19, 2018 11.
Article in English | MEDLINE | ID: mdl-30249376

ABSTRACT

INTRODUCTION: The diagnosis of cardiac sarcoidosis (CS) is difficult to ascertain due to the insensitivity of endomyocardial biopsy. Current diagnostic criteria require a positive endomyocardial biopsy or extra-cardiac biopsy with clinical features suggestive of CS. Common tests for diagnosis of pulmonary sarcoidosis include bronchoalveolar lavage (BAL), lung and mediastinal lymph node (MLN) biopsies. Our objective was to determine the diagnostic utility of these tests in patients with suspected CS and without prior history of pulmonary involvement. METHODS: This retrospective cohort study included 37 patients without history of extra-cardiac sarcoidosis referred for suspected CS. All patients underwent chest computed tomography (CT) staged using the modified Scadding criteria, and had BAL, and/or lung or MLN biopsy. BAL cellular analyses with lymphocytes>15% and/or CD4/CD8 ratio≥ 4 were considered suggestive of sarcoidosis. The number of positive biopsies and BALs were compared between normal CT (Scadding stage 0) and abnormal CT (Scadding stage 1-4) groups. RESULTS: A definitive diagnosis of sarcoidosis was ascertained in 18/31 (58%) patients undergoing lung or lymph node biopsy, and a potential diagnosis in 18/27 (67%) patients with BAL CD4/CD8>4 or lymphocytes>15%. Of the 12 patients in the normal CT group, 4/10 (40%) had positive lung biopsies, and 9/12 (75%) patients had either positive biopsy or BAL criteria. CONCLUSIONS: In suspected cardiac sarcoidosis, a diagnosis of extra-cardiac sarcoidosis was ascertained in a majority of patients irrespective of degree of lung involvement on chest CT. Our results support referral for pulmonary biopsy/bronchoalveolar lavage in suspected CS to confirm the diagnosis of sarcoidosis.


Subject(s)
Biopsy/methods , Bronchoalveolar Lavage/methods , Cardiomyopathies/diagnosis , Lung/pathology , Sarcoidosis/diagnosis , Adult , Aged , Bronchoalveolar Lavage Fluid/cytology , Bronchoalveolar Lavage Fluid/immunology , Bronchoscopy/methods , CD4-CD8 Ratio/statistics & numerical data , Cardiomyopathies/pathology , Female , Humans , Lung/diagnostic imaging , Lymph Nodes/pathology , Male , Mediastinoscopy/methods , Mediastinum/diagnostic imaging , Mediastinum/pathology , Middle Aged , Retrospective Studies , Sarcoidosis/complications , Sarcoidosis/pathology , Tomography, X-Ray Computed/methods
11.
JAMA Surg ; 153(5): 464-470, 2018 05 01.
Article in English | MEDLINE | ID: mdl-29299602

ABSTRACT

Importance: Clinician miscommunication contributes to an estimated 250 000 deaths in US hospitals per year. Efforts to standardize handoff communication may reduce errors and improve patient safety. Objective: To determine the effect of a standardized handoff curriculum, UW-IPASS, on interclinician communication and patient outcomes. Design, Setting, and Participants: This cluster randomized stepped-wedge randomized clinical trial was conducted from October 2015 to May 2016 at 8 medical and surgical intensive care units at 2 hospital systems within an academic tertiary referral center. Participants included residents, fellows, advance-practice clinicians, and attending physicians (n = 106 clinicians, with 1488 handoff events over 8 months) and data were collected from daily text message-based surveys and patient medical records. Exposures: The UW-IPASS standardized handoff curriculum. Main Outcomes and Measures: The primary aim was to assess the effect of the UW-IPASS handoff curriculum on perceived adequacy of interclinician communication. Patient days of mechanical ventilation, intensive care unit length of stay, reintubations within 24 hours, and order workflow patterns were also analyzed. Mixed-effects logistic regression was used to compute odds ratios and confidence intervals with adjustment for location, time period, and clinician. Results: A total of 63 residents and advance practice clinicians, 13 fellows, and 30 attending physicians participated in the study. During the control period, clinicians reported being unprepared for their shift because of a poor-quality handoff in 35 of 343 handoffs (10.2%), while UW-IPASS-period residents reported being unprepared in 53 of 740 handoffs (7.2%) (odds ratio, 0.19; 95% CI, 0.03-0.74; P = .03). Compared with the control phase, the perceived duration of handoffs among clinicians using UW-IPASS was unchanged (+5.5 minutes; 95% CI, 0.34-9.39; P = .30). Early morning order entry decreased from 106 per 100 patient-days in the control phase to 78 per 100 patient-days in the intervention period (-28 orders; 95% CI, -55 to -4; P = .04). Overall, UW-IPASS was not associated with any changes in intensive care unit length of stay, duration of mechanical ventilation, or the number of reintubations. Conclusions and Relevance: The UW-IPASS standardized handoff curriculum was perceived to improve intensive care provider preparedness and workflow. IPASS-based curricula represent an important step forward in communication standardization efforts and may help reduce communication errors and omissions. Trial Registration: isrctn.org Identifier: ISRCTN14209509.


Subject(s)
Curriculum/standards , Intensive Care Units , Internship and Residency/methods , Medical Errors/prevention & control , Patient Handoff/standards , Practice Patterns, Physicians' , Communication , Humans , Intensive Care Units/standards , Patient Safety , Surveys and Questionnaires
12.
MedEdPORTAL ; 14: 10744, 2018 08 24.
Article in English | MEDLINE | ID: mdl-30800944

ABSTRACT

Introduction: Management of airway emergencies is a core skill for critical care fellows. There is no standardized training mechanism for difficult airway management among critical care fellowships, although fellows frequently cite management of airway catastrophes as an area of educational need. Methods: Three simulation cases that are each approximately 15 minutes in length are presented. The cases represent airway emergencies encountered in the intensive care unit consisting of angioedema, endotracheal tube dislodgement, and endotracheal tube occlusion. Incorporated into the scenarios are planned incidents of interpersonal conflict requiring negotiation by the learner during a crisis event. The case descriptions are complete, with learning objectives and critical actions as well as all necessary personnel briefs and required equipment. Results: The cases were completed over multiple simulation sessions on different days by 11 first-year critical care fellows during the 2016-2017 academic year. All participants demonstrated improvement in self-perceived confidence in airway management skills. Discussion: The cases were felt to be realistic and beneficial and led to perceived improvement in management of airway emergencies and leadership during crisis scenarios.


Subject(s)
Airway Management/methods , Internal Medicine/education , Simulation Training/methods , Airway Management/instrumentation , Critical Care/methods , Curriculum , Education, Medical, Graduate/methods , Humans , Intensive Care Units/organization & administration , Intensive Care Units/statistics & numerical data , Internal Medicine/methods , Intubation, Intratracheal/instrumentation , Intubation, Intratracheal/methods
13.
Clin Cancer Res ; 22(24): 6204-6216, 2016 Dec 15.
Article in English | MEDLINE | ID: mdl-27267852

ABSTRACT

PURPOSE: The conversion of tumor cells from an epithelial to a mesenchymal-like phenotype, via a process designated as the epithelial-mesenchymal transition (EMT), is known to mediate tumor resistance to a variety of cell death inducers, including cytotoxic effector immune cells. The goal of this study was to identify and potentially repurpose FDA-approved compounds capable of reducing mesenchymal features of human lung carcinoma cells, which could be used in combination with immunotherapies or chemotherapeutic strategies to improve clinical responses. EXPERIMENTAL DESIGN: In the current report, we have utilized a quantitative high-throughput screening (qHTS) of a pharmaceutical collection of more than 2,000 compounds to identify clinically approved drugs capable of augmenting the sensitivity of mesenchymal-like, lung cancer cells to immune- and chemotherapy-mediated lysis, both in vitro and in vivo RESULTS: The estrogen receptor antagonist fulvestrant was shown to reduce mesenchymal features of lung carcinoma cells, resulting in tumor sensitization to the cytotoxic effect of antigen-specific T cells, natural killer (NK) effector cells, and chemotherapy both in vivo and in vitro CONCLUSIONS: To our knowledge, this is the first report defining a potential role for estrogenic signaling in promoting tumor resistance to immune-mediated cytotoxicity and chemotherapy in lung cancer. Our data demonstrate a robust association between the acquisition of mesenchymal attributes, therapeutic resistance of lung carcinoma cells, and the expression of estrogen receptor 1 (ESR1), supporting further investigations on the role of estrogen signaling in lung cancer progression via the induction of EMT. Clin Cancer Res; 22(24); 6204-16. ©2016 AACR.


Subject(s)
Estradiol/analogs & derivatives , Estrogen Receptor alpha/metabolism , Lung Neoplasms/drug therapy , Lung Neoplasms/immunology , Signal Transduction/drug effects , Cell Line, Tumor , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/immunology , Epithelial-Mesenchymal Transition/drug effects , Epithelial-Mesenchymal Transition/immunology , Estradiol/pharmacology , Fulvestrant , Humans , Killer Cells, Natural/drug effects , Killer Cells, Natural/immunology , Lung Neoplasms/metabolism , Signal Transduction/immunology , T-Lymphocytes/drug effects , T-Lymphocytes/immunology
14.
J Biomol Screen ; 21(9): 942-55, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27112173

ABSTRACT

Synthetic lethal screens are used to discover new combination treatments for cancer. In traditional high-throughput synthetic lethal screens, compounds are tested at a single dose, and hit selection is based on threshold activity values from the variance of the efficacy of the compounds tested. The limitation of the single-dose screening for synthetic lethal screens is that it does not allow for the robust detection of differential activities from compound collections with a broad range of potencies and efficacies. There is therefore a need to develop screening approaches that enable the identification of compounds with synthetic lethal effects based on changes in both potency and efficacy. Here we describe the implementation of a dose response-based synthetic lethal screen to find drugs that enhance or mitigate the cytotoxic effect of an immunotoxin protein (HA22). We developed a data analysis framework for the selection of compounds with enhancing or mitigating cytotoxic activities based on the use of dose-response parameters. The data analysis framework includes an ensemble ranking approach that allows the use of multiple dose-response parameters in a nonparametric fashion. Quantitative high-throughput screening (HTS) enables the identification of compounds with synthetic lethal activity not identified by single-dose HTS.


Subject(s)
High-Throughput Screening Assays/methods , Neoplasms/drug therapy , Small Molecule Libraries/pharmacology , Synthetic Lethal Mutations/genetics , Bacterial Toxins/antagonists & inhibitors , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Exotoxins/antagonists & inhibitors , Humans , Neoplasms/genetics , Small Molecule Libraries/isolation & purification , Small Molecule Libraries/therapeutic use
15.
Oncotarget ; 6(34): 35247-62, 2015 Nov 03.
Article in English | MEDLINE | ID: mdl-26497213

ABSTRACT

Despite advances in multimodal treatment, neuroblastoma (NB) is often fatal for children with high-risk disease and many survivors need to cope with long-term side effects from high-dose chemotherapy and radiation. To identify new therapeutic targets, we performed an siRNA screen of the druggable genome combined with a small molecule screen of 465 compounds targeting 39 different mechanisms of actions in four NB cell lines. We identified 58 genes as targets, including AURKB, in at least one cell line. In the drug screen, aurora kinase inhibitors (nine molecules) and in particular the AURKB-selective compound, barasertib, were the most discriminatory with regard to sensitivity for MYCN-amplified cell lines. In an expanded panel of ten NB cell lines, those with MYCN-amplification and wild-type TP53 were the most sensitive to low nanomolar concentrations of barasertib. Inhibition of the AURKB kinase activity resulted in decreased phosphorylation of the known target, histone H3, and upregulation of TP53 in MYCN-amplified, TP53 wild-type cells. However, both wild-type and TP53 mutant MYCN-amplified cell lines arrested in G2/M phase upon AURKB inhibition. Additionally, barasertib induced endoreduplication and apoptosis. Treatment of MYCN-amplified/TP53 wild-type neuroblastoma xenografts resulted in profound growth inhibition and tumor regression. Therefore, aurora B kinase inhibition is highly effective in aggressive neuroblastoma and warrants further investigation in clinical trials.


Subject(s)
Aurora Kinase B/antagonists & inhibitors , Neuroblastoma/enzymology , Neuroblastoma/therapy , Animals , Apoptosis/physiology , Aurora Kinase B/genetics , Aurora Kinase B/metabolism , Cell Line, Tumor , Female , Gene Knockdown Techniques , High-Throughput Nucleotide Sequencing/methods , Humans , Mice , Mice, Inbred NOD , Mice, SCID , Molecular Targeted Therapy , Neuroblastoma/genetics , Neuroblastoma/metabolism , Protein Kinase Inhibitors/pharmacology , RNA Interference , Small Molecule Libraries/pharmacology , Xenograft Model Antitumor Assays
16.
Proc Natl Acad Sci U S A ; 111(31): 11365-70, 2014 Aug 05.
Article in English | MEDLINE | ID: mdl-25049379

ABSTRACT

In the activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL), NF-κB activity is essential for viability of the malignant cells and is sustained by constitutive activity of IκB kinase (IKK) in the cytoplasm. Here, we report an unexpected role for the bromodomain and extraterminal domain (BET) proteins BRD2 and BRD4 in maintaining oncogenic IKK activity in ABC DLBCL. IKK activity was reduced by small molecules targeting BET proteins as well as by genetic knockdown of BRD2 and BRD4 expression, thereby inhibiting downstream NF-κB-driven transcriptional programs and killing ABC DLBCL cells. Using a high-throughput platform to screen for drug-drug synergy, we observed that the BET inhibitor JQ1 combined favorably with multiple drugs targeting B-cell receptor signaling, one pathway that activates IKK in ABC DLBCL. The BTK kinase inhibitor ibrutinib, which is in clinical development for the treatment of ABC DLBCL, synergized strongly with BET inhibitors in killing ABC DLBCL cells in vitro and in a xenograft mouse model. These findings provide a mechanistic basis for the clinical development of BET protein inhibitors in ABC DLBCL, particularly in combination with other modulators of oncogenic IKK signaling.


Subject(s)
I-kappa B Kinase/antagonists & inhibitors , Lymphoma, Large B-Cell, Diffuse/enzymology , Nuclear Proteins/antagonists & inhibitors , Protein Kinase Inhibitors/pharmacology , Protein Serine-Threonine Kinases/antagonists & inhibitors , Transcription Factors/antagonists & inhibitors , Adenine/analogs & derivatives , Animals , Azepines/pharmacology , Azepines/toxicity , Cell Cycle Proteins , Cell Death/drug effects , Cell Line, Tumor , Cell Survival , Drug Synergism , Humans , I-kappa B Kinase/chemistry , I-kappa B Kinase/metabolism , Lymphoma, Large B-Cell, Diffuse/pathology , Mice , Mice, SCID , Nuclear Proteins/metabolism , Piperidines , Protein Serine-Threonine Kinases/metabolism , Protein Structure, Tertiary , Pyrazoles/pharmacology , Pyrimidines/pharmacology , Signal Transduction/drug effects , Transcription Factors/metabolism , Triazoles/pharmacology , Triazoles/toxicity , Xenograft Model Antitumor Assays
17.
Proc Natl Acad Sci U S A ; 111(6): 2349-54, 2014 Feb 11.
Article in English | MEDLINE | ID: mdl-24469833

ABSTRACT

The clinical development of drug combinations is typically achieved through trial-and-error or via insight gained through a detailed molecular understanding of dysregulated signaling pathways in a specific cancer type. Unbiased small-molecule combination (matrix) screening represents a high-throughput means to explore hundreds and even thousands of drug-drug pairs for potential investigation and translation. Here, we describe a high-throughput screening platform capable of testing compounds in pairwise matrix blocks for the rapid and systematic identification of synergistic, additive, and antagonistic drug combinations. We use this platform to define potential therapeutic combinations for the activated B-cell-like subtype (ABC) of diffuse large B-cell lymphoma (DLBCL). We identify drugs with synergy, additivity, and antagonism with the Bruton's tyrosine kinase inhibitor ibrutinib, which targets the chronic active B-cell receptor signaling that characterizes ABC DLBCL. Ibrutinib interacted favorably with a wide range of compounds, including inhibitors of the PI3K-AKT-mammalian target of rapamycin signaling cascade, other B-cell receptor pathway inhibitors, Bcl-2 family inhibitors, and several components of chemotherapy that is the standard of care for DLBCL.


Subject(s)
Antineoplastic Agents/pharmacology , Apoptosis/drug effects , B-Lymphocytes/immunology , Lymphoma, Large B-Cell, Diffuse/pathology , Pyrazoles/pharmacology , Pyrimidines/pharmacology , Adenine/analogs & derivatives , Cell Line, Tumor , High-Throughput Screening Assays , Humans , Lymphoma, Large B-Cell, Diffuse/immunology , Phosphatidylinositol 3-Kinases/metabolism , Piperidines
18.
Clin Geriatr Med ; 30(1): 79-93, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24267604

ABSTRACT

Clostridium difficile-associated illness is an increasingly prevalent and morbid condition. The elderly population is at a disproportionate risk of developing symptomatic disease and associated complications, including progression to severe or fulminant disease, and development of recurrent infections. This article analyzes the factors that influence C difficile disease propensity and severity, with particular attention directed toward features relevant to the rapidly aging population.


Subject(s)
Anti-Bacterial Agents , Clostridioides difficile , Clostridium Infections , Metronidazole , Vancomycin , Aged , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/adverse effects , Clostridioides difficile/drug effects , Clostridioides difficile/isolation & purification , Clostridioides difficile/pathogenicity , Clostridium Infections/epidemiology , Clostridium Infections/etiology , Clostridium Infections/physiopathology , Clostridium Infections/therapy , Cross Infection , Diarrhea/physiopathology , Disease Management , Humans , Metronidazole/administration & dosage , Metronidazole/adverse effects , Outcome Assessment, Health Care , Prevalence , Risk Factors , Severity of Illness Index , Vancomycin/administration & dosage , Vancomycin/adverse effects
19.
PLoS One ; 8(1): e54525, 2013.
Article in English | MEDLINE | ID: mdl-23342165

ABSTRACT

The identification of novel combinations of effective cancer drugs is required for the successful treatment of cancer patients for a number of reasons. First, many "cancer specific" therapeutics display detrimental patient side-effects and second, there are almost no examples of single agent therapeutics that lead to cures. One strategy to decrease both the effective dose of individual drugs and the potential for therapeutic resistance is to combine drugs that regulate independent pathways that converge on cell death. BCL2-like family members are key proteins that regulate apoptosis. We conducted a screen to identify drugs that could be combined with an inhibitor of anti-apoptotic BCL2-like proteins, ABT-263, to kill human leukemia cells lines. We found that the combination of D,L-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) hydrochloride, an inhibitor of glucosylceramide synthase, potently synergized with ABT-263 in the killing of multiple human leukemia cell lines. Treatment of cells with PDMP and ABT-263 led to dramatic elevation of two pro-apoptotic sphingolipids, namely ceramide and sphingosine. Furthermore, treatment of cells with the sphingosine kinase inhibitor, SKi-II, also dramatically synergized with ABT-263 to kill leukemia cells and similarly increased ceramides and sphingosine. Data suggest that synergism with ABT-263 requires accumulation of ceramides and sphingosine, as AMP-deoxynojirimycin, (an inhibitor of the glycosphingolipid pathway) did not elevate ceramides or sphingosine and importantly did not sensitize cells to ABT-263 treatment. Taken together, our data suggest that combining inhibitors of anti-apoptotic BCL2-like proteins with drugs that alter the balance of bioactive sphingolipids will be a powerful combination for the treatment of human cancers.


Subject(s)
Ceramides/metabolism , Aniline Compounds/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Enzyme Inhibitors/pharmacology , Glucosyltransferases/antagonists & inhibitors , Glucosyltransferases/metabolism , Humans , Morpholines/pharmacology , Sulfonamides/pharmacology
20.
Curr Protoc Chem Biol ; 5(3): 195-212, 2013.
Article in English | MEDLINE | ID: mdl-24391083

ABSTRACT

High-content flow (HCF) screening systems, such as the iQue Screener and HTFC Screening System from IntelliCyt, have facilitated the implementation of flow cytometry assays for high-throughput screening. HCF screening systems enable the use of smaller sample volumes and multiplexed assays to simultaneously assess different cellular parameters from a single well. This becomes invaluable when working with cells or compounds that are available in limited quantities or when conducting large-scale screens. When assays can be miniaturized to a 384- or 1536-well microplate format, it is possible to implement dose-response-based high-throughput screens, also known as quantitative HTS or qHTS. This article describes how qHTS at the new National Center for Advancing Translational Science (NCATS) has been systematically coupled with the HTFC Screening System and Multimetric Apoptosis Screening Kit from IntelliCyt to biologically validate active compounds from primary cell proliferation screens using a model of diffuse large B cell lymphoma (DLBCL).


Subject(s)
Annexin A5/biosynthesis , Caspase 3/metabolism , Caspase 7/metabolism , Cell Survival/drug effects , Enzyme Activation/drug effects , High-Throughput Screening Assays/methods , Mitochondrial Membranes/drug effects , Apoptosis/drug effects , Cell Proliferation/drug effects , Dose-Response Relationship, Drug , Flow Cytometry , Humans
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