Faculty Bibliography

BACKGROUND:The emergency department is a critical juncture in the trajectory of care of patients with serious, life-limiting illness. Implementation of a clinical decision support (CDS) tool automates identification of older adults who may benefit from palliative care instead of relying upon providers to identify such patients, thus improving quality of care by assisting providers with adhering to guidelines. The Primary Palliative Care for Emergency Medicine (PRIM-ER) study aims to optimize the use of the electronic health record by creating a CDS tool to identify high risk patients most likely to benefit from primary palliative care and provide point-of-care clinical recommendations. METHODS:A clinical decision support tool entitled Emergency Department Supportive Care Clinical Decision Support (Support-ED) was developed as part of an institutionally-sponsored value based medicine initiative at the Ronald O. Perelman Department of Emergency Medicine at NYU Langone Health. A multidisciplinary approach was used to develop Support-ED including: a scoping review of ED palliative care screening tools; launch of a workgroup to identify patient screening criteria and appropriate referral services; initial design and usability testing via the standard System Usability Scale questionnaire, education of the ED workforce on the Support-ED background, purpose and use, and; creation of a dashboard for monitoring and feedback. RESULTS:The scoping review identified the Palliative Care and Rapid Emergency Screening (P-CaRES) survey as a validated instrument in which to adapt and apply for the creation of the CDS tool. The multidisciplinary workshops identified two primary objectives of the CDS: to identify patients with indicators of serious life limiting illness, and to assist with referrals to services such as palliative care or social work. Additionally, the iterative design process yielded three specific patient scenarios that trigger a clinical alert to fire, including: 1) when an advance care planning document was present, 2) when a patient had a previous disposition to hospice, and 3) when historical and/or current clinical data points identify a serious life-limiting illness without an advance care planning document present. Monitoring and feedback indicated a need for several modifications to improve CDS functionality. CONCLUSIONS:CDS can be an effective tool in the implementation of primary palliative care quality improvement best practices. Health systems should thoughtfully consider tailoring their CDSs in order to adapt to their unique workflows and environments. The findings of this research can assist health systems in effectively integrating a primary palliative care CDS system seamlessly into their processes of care. TRIAL REGISTRATION/BACKGROUND:ClinicalTrials.gov Identifier: NCT03424109. Registered 6 February 2018, Grant Number: AT009844-01.

Neomorphic mutations in isocitrate dehydrogenase I (IDH1) result in the formation of the oncometabolite 2-hydroxyglutarate (2HG) in a significant subset of gliomas and other tumors including acute myeloid leukemias. Preclinical evidence suggests that gliomas harboring IDH1 mutations undergo widespread, long-lasting modifications to the epigenome that persist following inhibition of 2HG production. However, the exact mechanism underlying gliomagenesis remains unclear. To address difficulties in growing these tumors in culture, our group generated a model of low-grade astrocytoma in human neural stem cells (NSCs). This model, referred to as 3-Hit NSCs, suggested a block in differentiation potential underlies gliomagenesis at the cellular level. This block is rescued by restoration of expression of the transcription factor (sex determining region Y)-box 2 (SOX2), which is transcriptionally downregulated during IDH mutant gliomagenesis. We believe that these changes occur secondary to profound alterations in 3-dimensional chromatin organization around the SOX2 genomic locus. Our preliminary data suggest SOX2 expression in control NSCs depends on 3-dimensional association of its promoter to an uncharacterized, distal enhancer located 600 kb telomeric to the SOX2 gene. We believe this association is disrupted in 3-Hit NSCs due to eviction of chromatin organizer CTCF from its motifs in the SOX2 topologically associating domain (TAD). To test this hypothesis, we used CRISPR-Cas9 technology to excise CTCF motifs immediately upstream of the SOX2 promoter and in the region of the putative enhancer in control NSCs. Excision of such motifs significantly reduced SOX2 mRNA levels and impaired growth of control NSCs. We are currently working on characterizing this novel SOX2-enhancer interaction in native stem cells, as well as tumors that depend on SOX2 expression. This works aims to elucidate the core epigenetic mechanisms underlying IDH mutant gliomagenesis. Our findings will be used to improve therapy in IDH-mutant glioma

The identification of heterozygous neomorphic isocitrate dehydrogenase (IDH) mutations across multiple cancer types including both solid and hematologic malignancies has revolutionized our understanding of oncogenesis in these malignancies and the potential for targeted therapeutics using small molecule inhibitors. The neomorphic mutation in IDH generates an oncometabolite product, 2-hydroxyglutarate (2HG), which has been linked to the disruption of metabolic and epigenetic mechanisms responsible for cellular differentiation and is likely an early and critical contributor to oncogenesis. In the past 2 years, two mutant IDH (mutIDH) inhibitors, Enasidenib (AG-221), and Ivosidenib (AG-120), have been FDA-approved for IDH-mutant relapsed or refractory acute myeloid leukemia (AML) based on phase 1 safety and efficacy data and continue to be studied in trials in hematologic malignancies, as well as in glioma, cholangiocarcinoma, and chondrosarcoma. In this review, we will summarize the molecular pathways and oncogenic consequences associated with mutIDH with a particular emphasis on glioma and AML, and systematically review the development and preclinical testing of mutIDH inhibitors. Existing clinical data in both hematologic and solid tumors will likewise be reviewed followed by a discussion on the potential limitations of mutIDH inhibitor monotherapy and potential routes for treatment optimization using combination therapy.

A methionine substitution at lysine-27 on histone H3 variants (H3K27M) characterizes ~80% of diffuse intrinsic pontine gliomas (DIPG) and inhibits polycomb repressive complex 2 (PRC2) in a dominant-negative fashion. Yet, the mechanisms for this inhibition and abnormal epigenomic landscape have not been resolved. Using quantitative proteomics, we discovered that robust PRC2 inhibition requires levels of H3K27M greatly exceeding those of PRC2, seen in DIPG. While PRC2 inhibition requires interaction with H3K27M, we found that this interaction on chromatin is transient, with PRC2 largely being released from H3K27M. Unexpectedly, inhibition persisted even after PRC2 dissociated from H3K27M-containing chromatin, suggesting a lasting impact on PRC2. Furthermore, allosterically activated PRC2 is particularly sensitive to H3K27M, leading to the failure to spread H3K27me from PRC2 recruitment sites and consequently abrogating PRC2's ability to establish H3K27me2-3 repressive chromatin domains. In turn, levels of polycomb antagonists such as H3K36me2 are elevated, suggesting a more global, downstream effect on the epigenome. Together, these findings reveal the conditions required for H3K27M-mediated PRC2 inhibition and reconcile seemingly paradoxical effects of H3K27M on PRC2 recruitment and activity.

Gliomas are malignant primary tumors of the central nervous system. Their cell-of-origin is thought to be a neural progenitor or stem cell that acquires mutations leading to oncogenic transformation. Thanks to advances in human stem cell biology, it has become possible to derive human cell types that represent putative cells-of-origin in vitro and model the gliomagenesis process by systematically introducing genetic alterations in these human cells. Here, we present methods to derive human neural stem cells (NSCs) from human embryonic stem cells (hESCs). Because these NSCs are genetically unmodified at baseline, they can be used as a cellular platform to study the effects of individual oncogenic hits in a well-controlled manner in the backdrop of a human genetic background. We also present some key applications of these NSCs, which include their transduction with lentiviral vectors, their neuroglial differentiation and xenografting methods into immunocompromised mice to assess in vivo behavior.

Low-grade astrocytomas (LGAs) carry neomorphic mutations in isocitrate dehydrogenase (IDH) concurrently with P53 and ATRX loss. To model LGA formation, we introduced R132H IDH1, P53 shRNA, and ATRX shRNA into human neural stem cells (NSCs). These oncogenic hits blocked NSC differentiation, increased invasiveness in vivo, and led to a DNA methylation and transcriptional profile resembling IDH1 mutant human LGAs. The differentiation block was caused by transcriptional silencing of the transcription factor SOX2 secondary to disassociation of its promoter from a putative enhancer. This occurred because of reduced binding of the chromatin organizer CTCF to its DNA motifs and disrupted chromatin looping. Our human model of IDH mutant LGA formation implicates impaired NSC differentiation because of repression of SOX2 as an early driver of gliomagenesis.