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1.
Arch Dis Child ; 109(2): 130-137, 2024 01 22.
Article in English | MEDLINE | ID: mdl-38041663

ABSTRACT

OBJECTIVE: To compare and contrast the perceived care needs of children with life-limiting conditions (CLLC) from the perspectives of the children, parents and healthcare providers. DESIGN: A qualitative case study method using semistructured interviews was employed with a within-case and across-case analysis. Themes and subthemes emerging from the cases were compared and contrasted in the across-case analysis to explore the similarities and variations in participant perceptions. SETTING/PARTICIPANTS: The setting was the paediatric departments of five regional hospitals in Hong Kong. Twenty-five sets of informants (CLLC-parent-healthcare provider) were recruited, with 65 individual interviews conducted. RESULTS: A total of 3784 units of analysis were identified, resulting in three themes with subthemes. 'Living with the disease' (55.8%) occupied the largest proportion, followed by 'information and understanding about the disease' (27.4%), and 'care support and palliative care' (16.8%). Healthcare provider support mainly focused on physical concerns. Family and social support were present, but carer stress created tension between couples. Doctors were the primary source of medical information, but the parents had to seek further information via the internet and support from patient groups. There was a perceived need for better coordination and collaboration of care. The palliative care approach coordinated by nurses was seen as helpful in addressing the care needs of the CLLC. CONCLUSIONS: This original study identified the importance of palliative care with active engagement of parents which can address the service gap for CLLC.


Subject(s)
Palliative Care , Parents , Child , Humans , Hong Kong , Social Support , Qualitative Research
2.
Nat Commun ; 13(1): 2965, 2022 05 26.
Article in English | MEDLINE | ID: mdl-35618699

ABSTRACT

Development of the gastrointestinal system occurs after gut tube closure, guided by spatial and temporal control of gene expression. However, it remains unclear what forces regulate these spatiotemporal gene expression patterns. Here we perform single-cell chromatin profiling of the primitive gut tube to reveal organ-specific chromatin patterns that reflect the anatomical patterns of distinct organs. We generate a comprehensive map of epigenomic changes throughout gut development, demonstrating that dynamic chromatin accessibility patterns associate with lineage-specific transcription factor binding events to regulate organ-specific gene expression. Additionally, we show that loss of Sox2 and Cdx2, foregut and hindgut lineage-specific transcription factors, respectively, leads to fate shifts in epigenomic patterns, linking transcription factor binding, chromatin accessibility, and lineage fate decisions in gut development. Notably, abnormal expression of Sox2 in the pancreas and intestine impairs lineage fate decisions in both development and adult homeostasis. Together, our findings define the chromatin and transcriptional mechanisms of organ identity and lineage plasticity in development and adult homeostasis.


Subject(s)
Chromatin , Gastrula , Adult , Chromatin/genetics , Endoderm , Epigenomics , Humans , Transcription Factors
3.
Pediatr Pulmonol ; 57(7): 1799-1801, 2022 07.
Article in English | MEDLINE | ID: mdl-35419994

ABSTRACT

INTRODUCTION: Spinal muscular atrophy is a congenital condition associated with mutations in the SMN1 gene. Patients have normal intellectual development, but the natural history is progressive respiratory failure resulting in premature death. CASE: Diagnosed with spinal muscular atrophy type 2 in early primary school, the wheelchair-bound girl developed severe pneumonia on one occasion, when she became critically ill and was admitted to the paediatric intensive care unit with multiorgan dysfunction, requiring mechanical ventilation and high inotropic support. Parents and the patient expressed strong desire for full respiratory and intensive care support to be given. Survived the episode, she is wheelchair ambulatory and continues to pursue a creative artistic career. DISCUSSION: Children with SMA and their families need to be supported by a comprehensive multi-disciplinary team to manage this illness. Pediatricians and healthcare givers must provide up-to-date health advice on COVID-19 prophylaxis and management to special groups of patients with respiratory and neurological risks.


Subject(s)
COVID-19 , Muscular Atrophy, Spinal , Respiratory Insufficiency , Spinal Muscular Atrophies of Childhood , Child , Critical Care , Female , Humans , Respiratory Insufficiency/etiology , Respiratory Insufficiency/therapy , Spinal Muscular Atrophies of Childhood/complications , Spinal Muscular Atrophies of Childhood/therapy
4.
Catheter Cardiovasc Interv ; 99(3): 583-592, 2022 02.
Article in English | MEDLINE | ID: mdl-34478233

ABSTRACT

OBJECTIVES: To compare clinical outcomes in high bleeding risk (HBR) patients with and without complex percutaneous coronary intervention (PCI) treated with Resolute Onyx zotarolimus-eluting stents (ZES) after 1-month dual antiplatelet therapy (DAPT). BACKGROUND: PCI with 1-month DAPT has been demonstrated to be safe in HBR patients treated with Resolute Onyx ZES. Whether these outcomes are consistent in patients with complex lesions is uncertain. METHODS: Among HBR patients who were event-free 1 month after PCI with ZES and treated thereafter with single antiplatelet therapy (SAPT), the clinical outcomes between 1 month and 1 year were compared after complex PCI (3 vessels treated, ≥ 3 lesions treated, total stent length > 60 mm, bifurcation with ≥ 2 stents implanted, atherectomy, or left main, surgical bypass graft or chronic total occlusion PCI) versus noncomplex PCI. Propensity score adjustment was performed to adjust for baseline differences among complex and noncomplex patients. RESULTS: Complex patients (N = 401, 26.6% of total) had a higher prevalence of hyperlipidemia, diabetes mellitus and previous myocardial infarction (MI). Between 1 month and 1 year, rates of MI (7.1% vs. 4.0%, p = 0.02) and cardiac death/MI (9.3% vs. 6.1%, p = 0.04) were higher among complex versus noncomplex patients, although stent thrombosis rates were similar. After adjustment for baseline characteristics, differences in outcomes were no longer significant between groups. CONCLUSIONS: Higher rates of ischemic outcomes in complex PCI patients were largely explained by baseline clinical differences, rather than lesion complexity, among HBR patients treated with 1-month DAPT following PCI with Resolute Onyx ZES.


Subject(s)
Coronary Artery Disease , Drug-Eluting Stents , Percutaneous Coronary Intervention , Coronary Artery Disease/drug therapy , Coronary Artery Disease/therapy , Drug-Eluting Stents/adverse effects , Dual Anti-Platelet Therapy/adverse effects , Humans , Percutaneous Coronary Intervention/adverse effects , Platelet Aggregation Inhibitors , Treatment Outcome
5.
Nat Commun ; 12(1): 979, 2021 02 12.
Article in English | MEDLINE | ID: mdl-33579912

ABSTRACT

Glioblastoma (GBM) is a deadly cancer in which cancer stem cells (CSCs) sustain tumor growth and contribute to therapeutic resistance. Protein arginine methyltransferase 5 (PRMT5) has recently emerged as a promising target in GBM. Using two orthogonal-acting inhibitors of PRMT5 (GSK591 or LLY-283), we show that pharmacological inhibition of PRMT5 suppresses the growth of a cohort of 46 patient-derived GBM stem cell cultures, with the proneural subtype showing greater sensitivity. We show that PRMT5 inhibition causes widespread disruption of splicing across the transcriptome, particularly affecting cell cycle gene products. We identify a GBM splicing signature that correlates with the degree of response to PRMT5 inhibition. Importantly, we demonstrate that LLY-283 is brain-penetrant and significantly prolongs the survival of mice with orthotopic patient-derived xenografts. Collectively, our findings provide a rationale for the clinical development of brain penetrant PRMT5 inhibitors as treatment for GBM.


Subject(s)
Antineoplastic Agents/pharmacology , Brain Neoplasms/metabolism , Glioblastoma/metabolism , Protein-Arginine N-Methyltransferases/metabolism , Animals , Apoptosis , Brain Neoplasms/drug therapy , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Cell Cycle , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Discovery , Epigenomics , Female , Gene Expression Regulation, Neoplastic , Glioblastoma/drug therapy , Glioblastoma/genetics , Glioblastoma/pathology , Humans , Mice , Neoplastic Stem Cells/metabolism , Protein-Arginine N-Methyltransferases/drug effects , Protein-Arginine N-Methyltransferases/genetics , RNA Splicing , Xenograft Model Antitumor Assays
6.
Ear Nose Throat J ; 100(3_suppl): 204S-206S, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33459563

ABSTRACT

Mechanical feedback is one of the most common difficulties encountered when fitting hearing aids for toddlers and young children. We described the use of 3D printing to tailor a protective cap for a toddler with bilateral microtia/canal atresia to facilitate bone-anchoring hearing aid use.


Subject(s)
Hearing Aids , Hearing Loss, Conductive/rehabilitation , Printing, Three-Dimensional , Prosthesis Fitting/instrumentation , Protective Devices , Bone Conduction , Child, Preschool , Congenital Microtia/rehabilitation , Ear Canal/abnormalities , Equipment Design , Female , Hearing Loss, Conductive/congenital , Humans , Medical Illustration , Prostheses and Implants
7.
Nat Cancer ; 2(2): 157-173, 2021 02.
Article in English | MEDLINE | ID: mdl-35122077

ABSTRACT

Glioblastomas harbor diverse cell populations, including rare glioblastoma stem cells (GSCs) that drive tumorigenesis. To characterize functional diversity within this population, we performed single-cell RNA sequencing on >69,000 GSCs cultured from the tumors of 26 patients. We observed a high degree of inter- and intra-GSC transcriptional heterogeneity that could not be fully explained by DNA somatic alterations. Instead, we found that GSCs mapped along a transcriptional gradient spanning two cellular states reminiscent of normal neural development and inflammatory wound response. Genome-wide CRISPR-Cas9 dropout screens independently recapitulated this observation, with each state characterized by unique essential genes. Further single-cell RNA sequencing of >56,000 malignant cells from primary tumors found that the majority organize along an orthogonal astrocyte maturation gradient yet retain expression of founder GSC transcriptional programs. We propose that glioblastomas grow out of a fundamental GSC-based neural wound response transcriptional program, which is a promising target for new therapy development.


Subject(s)
Brain Neoplasms , Glioblastoma , Brain Neoplasms/genetics , Carcinogenesis/genetics , Glioblastoma/genetics , Humans , Neoplastic Stem Cells/metabolism
8.
Circ Cardiovasc Interv ; 13(11): e009565, 2020 11.
Article in English | MEDLINE | ID: mdl-33167705

ABSTRACT

BACKGROUND: Despite treatment guidance endorsing shortened dual antiplatelet therapy (DAPT) duration in high bleeding risk (HBR) patients after drug-eluting stents, limited evidence exists to support these recommendations. The present study was designed to examine the safety and effectiveness of 1-month DAPT duration following percutaneous coronary intervention with zotarolimus-eluting stents in HBR patients. METHODS: Onyx ONE Clear was a prospective, multicenter, nonrandomized study evaluating the safety and effectiveness of 1-month DAPT followed by single antiplatelet therapy in HBR patients undergoing percutaneous coronary intervention with Resolute Onyx drug-eluting stents. The primary analysis of cardiac death or myocardial infarction between 1 month and 1 year was performed in the prespecified one-month clear population of patients pooled from the Onyx ONE US/Japan study and Onyx ONE randomized controlled trial. One-month clear was defined as DAPT adherence and without major adverse events during the first month following percutaneous coronary intervention. RESULTS: Among patients enrolled in Onyx ONE US/Japan (n=752) and Onyx ONE randomized controlled trial (n=1018), 1506 patients fulfilled one-month clear criteria. Mean HBR characteristics per patient was 1.6 with 44.7% having multiple risks. By 2 months and 1 year, respectively, 96.9% and 89.3% of patients were taking single antiplatelet therapy. Between 1 month and 1 year, the rate of the primary end point was 7.0%. The 1-sided upper 97.5% CI was 8.4%, less than the performance goal of 9.7% (P<0.001). CONCLUSIONS: Among HBR patients who were event free before DAPT discontinuation at 1 month, favorable safety and effectiveness through 1 year support treatment with Resolute Onyx drug-eluting stents as part of an individualized strategy for shortened DAPT duration following percutaneous coronary intervention. Registration: URL: https://www.clinicaltrials.gov; Unique identifier NCT03647475.


Subject(s)
Cardiovascular Agents/administration & dosage , Coronary Artery Disease/therapy , Drug-Eluting Stents , Dual Anti-Platelet Therapy , Percutaneous Coronary Intervention/instrumentation , Platelet Aggregation Inhibitors/administration & dosage , Sirolimus/analogs & derivatives , Aged , Aged, 80 and over , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/mortality , Drug Administration Schedule , Dual Anti-Platelet Therapy/adverse effects , Female , Hemorrhage/chemically induced , Humans , Japan , Male , Middle Aged , Percutaneous Coronary Intervention/adverse effects , Percutaneous Coronary Intervention/mortality , Platelet Aggregation Inhibitors/adverse effects , Prospective Studies , Prosthesis Design , Randomized Controlled Trials as Topic , Risk Assessment , Risk Factors , Sirolimus/administration & dosage , Time Factors , Treatment Outcome , United States
9.
Circ., cariovasc. interv. (Print) ; 13(11): 222-232, Nov. 2020. tab, graf
Article in English | CONASS, Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1150552

ABSTRACT

BACKGROUND: Despite treatment guidance endorsing shortened dual antiplatelet therapy (DAPT) duration in high bleeding risk (HBR) patients after drug-eluting stents, limited evidence exists to support these recommendations. The present study was designed to examine the safety and effectiveness of 1-month DAPT duration following percutaneous coronary intervention with zotarolimus-eluting stents in HBR patients. METHODS: Onyx ONE Clear was a prospective, multicenter, nonrandomized study evaluating the safety and effectiveness of 1-month DAPT followed by single antiplatelet therapy in HBR patients undergoing percutaneous coronary intervention with Resolute Onyx drug-eluting stents. The primary analysis of cardiac death or myocardial infarction between 1 month and 1 year was performed in the prespecified one-month clear population of patients pooled from the Onyx ONE US/Japan study and Onyx ONE randomized controlled trial. One-month clear was defined as DAPT adherence and without major adverse events during the first month following percutaneous coronary intervention. RESULTS: Among patients enrolled in Onyx ONE US/Japan (n=752) and Onyx ONE randomized controlled trial (n=1018), 1506 patients fulfilled one-month clear criteria. Mean HBR characteristics per patient was 1.6 with 44.7% having multiple risks. By 2 months and 1 year, respectively, 96.9% and 89.3% of patients were taking single antiplatelet therapy. Between 1 month and 1 year, the rate of the primary end point was 7.0%. The 1-sided upper 97.5% CI was 8.4%, less than the performance goal of 9.7% (P<0.001). CONCLUSIONS: Among HBR patients who were event free before DAPT discontinuation at 1 month, favorable safety and effectiveness through 1 year support treatment with Resolute Onyx drug-eluting stents as part of an individualized strategy for shortened DAPT duration following percutaneous coronary intervention.


Subject(s)
Drug-Eluting Stents , Risk , Percutaneous Coronary Intervention
10.
J. Am. Coll. Cardiol ; 76(17 suppl. b): 24-24, Oct., 2020. tab.
Article in English | CONASS, Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1343418

ABSTRACT

BACKGROUND Safety and effectiveness outcomes were examined at 1 year among high bleeding risk (HBR) patients treated with 1 month of dual antiplatelet therapy (DAPT) following PCI with zotarolimus eluting stents (ZES) (Resolute Onyx, Medtronic, Santa Rosa, Califor nia) according to lesion complexity (Table). METHODS The 1-year clinical outcomes were evaluated in HBR pa tients treated with ZES who were event-free following 1-month DAPT post-procedure with planned single antiplatelet therapy thereafter. Propensity score adjustment was performed to account for baseline differences (Table). RESULTS A total of 1,506 patients were stratified by complex (n » 395) or noncomplex (n » 1,111) PCI criteria (Table). Complex patients were more frequently men (72.2% vs. 66.1%; p » 0.03) and had higher rates of prior myocardial infarction (MI) (34.4% vs. 23.4%), prior CABG (24.1% vs. 8.9%), multivessel disease (78.2% vs. 39.8%), and B2/C lesion classification (84.2% vs. 75.6%), all p < 0.001. Complex patients had more lesions treated (1.7 vs. 1.2), longer stent length per patient (65.1 mm vs. 26.9 mm), and longer procedure time (58.8 min vs. 35.3 min), all p < 0.001. Procedural success was higher among noncomplex patients (90.8% vs. 82.0%; p < 0.001). In unadjusted analysis, the rate of MI was higher in patients with complex lesions (p » 0.04). How ever, no significant differences in any outcomes between patients with and without complex lesions were present after propensity score adjustment (Table). CONCLUSION Despite greater anatomic and procedural complexity, similar safety and effectiveness were observed in complex and noncomplex patients treated with 1-month DAPT following PCI with Resolute Onyx ZES after propensity score adjustment. These findings support 1-month DAPT among selected HBR patients undergoing PCI with Resolute Onyx ZES irrespective of lesion and procedural complexity.


Subject(s)
Stents , Myocardial Infarction
11.
Cell Rep ; 31(2): 107511, 2020 04 14.
Article in English | MEDLINE | ID: mdl-32294450

ABSTRACT

Medulloblastoma (MB) is a neoplasm linked to dysregulated cerebellar development. Previously, we demonstrated that the Sonic Hedgehog (SHH) subgroup grows hierarchically, with Sox2+ cells at the apex of tumor progression and relapse. To test whether this mechanism is rooted in a normal developmental process, we studied the role of Sox2 in cerebellar development. We find that the external germinal layer (EGL) is derived from embryonic Sox2+ precursors and that the EGL maintains a rare fraction of Sox2+ cells during the first postnatal week. Through lineage tracing and single-cell analysis, we demonstrate that these Sox2+ cells are within the Atoh1+ lineage, contribute extensively to adult granule neurons, and resemble Sox2+ tumor cells. Critically, constitutive activation of the SHH pathway leads to their aberrant persistence in the EGL and rapid tumor onset. We propose that failure to eliminate this rare but potent developmental population is the tumor initiation mechanism in SHH-subgroup MB.


Subject(s)
Medulloblastoma/etiology , Medulloblastoma/metabolism , SOXB1 Transcription Factors/metabolism , Animals , Cell Lineage/genetics , Cells, Cultured , Cerebellar Neoplasms/pathology , Cerebellum/embryology , Female , Hedgehog Proteins/metabolism , Humans , Male , Mice, Knockout , Mice, Transgenic , Neoplasm Recurrence, Local/pathology , Neural Stem Cells/metabolism , Neurogenesis , Neurons/metabolism , SOXB1 Transcription Factors/physiology , Signal Transduction/physiology , Single-Cell Analysis/methods
12.
J Clin Invest ; 130(6): 3069-3086, 2020 06 01.
Article in English | MEDLINE | ID: mdl-32182224

ABSTRACT

Glioblastoma multiforme (GBM) contains a subpopulation of cells, GBM stem cells (GSCs), that maintain the bulk tumor and represent a key therapeutic target. Norrin is a Wnt ligand that binds Frizzled class receptor 4 (FZD4) to activate canonical Wnt signaling. Although Norrin, encoded by NDP, has a well-described role in vascular development, its function in human tumorigenesis is largely unexplored. Here, we show that NDP expression is enriched in neurological cancers, including GBM, and its levels positively correlated with survival in a GBM subtype defined by low expression of ASCL1, a proneural factor. We investigated the function of Norrin and FZD4 in GSCs and found that it mediated opposing tumor-suppressive and -promoting effects on ASCL1lo and ASCL1hi GSCs. Consistent with a potential tumor-suppressive effect of Norrin suggested by the tumor outcome data, we found that Norrin signaling through FZD4 inhibited growth in ASCL1lo GSCs. In contrast, in ASCL1hi GSCs Norrin promoted Notch signaling, independently of WNT, to promote tumor progression. Forced ASCL1 expression reversed the tumor-suppressive effects of Norrin in ASCL1lo GSCs. Our results identify Norrin as a modulator of human brain cancer progression and reveal an unanticipated Notch-mediated function of Norrin in regulating cancer stem cell biology. This study identifies an unanticipated role of Norrin in human brain cancer progression. In addition, we provide preclinical evidence suggesting Norrin and canonical Wnt signaling as potential therapeutic targets for GBM subtype-restricted cancer stem cells.


Subject(s)
Brain Neoplasms/metabolism , Eye Proteins/metabolism , Glioblastoma/metabolism , Neoplasm Proteins/metabolism , Nerve Tissue Proteins/metabolism , Receptors, Notch/metabolism , Wnt Proteins/metabolism , Wnt Signaling Pathway , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Cell Line, Tumor , Eye Proteins/genetics , Glioblastoma/genetics , Glioblastoma/pathology , Humans , Neoplasm Proteins/genetics , Nerve Tissue Proteins/genetics , Receptors, Notch/genetics , Wnt Proteins/genetics
13.
Genes Dev ; 33(9-10): 498-510, 2019 05 01.
Article in English | MEDLINE | ID: mdl-30842215

ABSTRACT

Developmental signal transduction pathways act diversely, with context-dependent roles across systems and disease types. Glioblastomas (GBMs), which are the poorest prognosis primary brain cancers, strongly resemble developmental systems, but these growth processes have not been exploited therapeutically, likely in part due to the extreme cellular and genetic heterogeneity observed in these tumors. The role of Wnt/ßcatenin signaling in GBM stem cell (GSC) renewal and fate decisions remains controversial. Here, we report context-specific actions of Wnt/ßcatenin signaling in directing cellular fate specification and renewal. A subset of primary GBM-derived stem cells requires Wnt proteins for self-renewal, and this subset specifically relies on Wnt/ßcatenin signaling for enhanced tumor burden in xenograft models. In an orthotopic Wnt reporter model, Wnthi GBM cells (which exhibit high levels of ßcatenin signaling) are a faster-cycling, highly self-renewing stem cell pool. In contrast, Wntlo cells (with low levels of signaling) are slower cycling and have decreased self-renewing potential. Dual inhibition of Wnt/ßcatenin and Notch signaling in GSCs that express high levels of the proneural transcription factor ASCL1 leads to robust neuronal differentiation and inhibits clonogenic potential. Our work identifies new contexts for Wnt modulation for targeting stem cell differentiation and self-renewal in GBM heterogeneity, which deserve further exploration therapeutically.


Subject(s)
Cell Differentiation/genetics , Neoplastic Stem Cells/cytology , Signal Transduction , Cell Line, Tumor , Cell Self Renewal/genetics , Gene Expression Regulation, Neoplastic/genetics , Glioblastoma/physiopathology , Humans , Receptors, Notch/genetics , Receptors, Notch/metabolism , Wnt Proteins/genetics , Wnt Proteins/metabolism
15.
Nature ; 549(7671): 227-232, 2017 09 14.
Article in English | MEDLINE | ID: mdl-28854171

ABSTRACT

Human glioblastomas harbour a subpopulation of glioblastoma stem cells that drive tumorigenesis. However, the origin of intratumoural functional heterogeneity between glioblastoma cells remains poorly understood. Here we study the clonal evolution of barcoded glioblastoma cells in an unbiased way following serial xenotransplantation to define their individual fate behaviours. Independent of an evolving mutational signature, we show that the growth of glioblastoma clones in vivo is consistent with a remarkably neutral process involving a conserved proliferative hierarchy rooted in glioblastoma stem cells. In this model, slow-cycling stem-like cells give rise to a more rapidly cycling progenitor population with extensive self-maintenance capacity, which in turn generates non-proliferative cells. We also identify rare 'outlier' clones that deviate from these dynamics, and further show that chemotherapy facilitates the expansion of pre-existing drug-resistant glioblastoma stem cells. Finally, we show that functionally distinct glioblastoma stem cells can be separately targeted using epigenetic compounds, suggesting new avenues for glioblastoma-targeted therapy.


Subject(s)
Cell Differentiation , Cell Lineage , Cell Tracking , Glioblastoma/pathology , Neoplastic Stem Cells/pathology , Animals , Cell Differentiation/drug effects , Cell Lineage/drug effects , Cell Proliferation , Clone Cells/drug effects , Clone Cells/pathology , Epigenesis, Genetic , Female , Glioblastoma/drug therapy , Heterografts , Humans , Mice , Neoplasm Invasiveness , Neoplasm Transplantation , Neoplastic Stem Cells/drug effects , Phenotype , Stochastic Processes
16.
Cell Stem Cell ; 21(2): 209-224.e7, 2017 08 03.
Article in English | MEDLINE | ID: mdl-28712938

ABSTRACT

Glioblastomas exhibit a hierarchical cellular organization, suggesting that they are driven by neoplastic stem cells that retain partial yet abnormal differentiation potential. Here, we show that a large subset of patient-derived glioblastoma stem cells (GSCs) express high levels of Achaete-scute homolog 1 (ASCL1), a proneural transcription factor involved in normal neurogenesis. ASCL1hi GSCs exhibit a latent capacity for terminal neuronal differentiation in response to inhibition of Notch signaling, whereas ASCL1lo GSCs do not. Increasing ASCL1 levels in ASCL1lo GSCs restores neuronal lineage potential, promotes terminal differentiation, and attenuates tumorigenicity. ASCL1 mediates these effects by functioning as a pioneer factor at closed chromatin, opening new sites to activate a neurogenic gene expression program. Directing GSCs toward terminal differentiation may provide therapeutic applications for a subset of GBM patients and strongly supports efforts to restore differentiation potential in GBM and other cancers.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/metabolism , Brain Neoplasms/pathology , Carcinogenesis/pathology , Cell Lineage , Chromatin/metabolism , Glioblastoma/pathology , Neurons/pathology , Base Sequence , Basic Helix-Loop-Helix Transcription Factors/genetics , Brain Neoplasms/genetics , Carcinogenesis/genetics , Cell Differentiation/genetics , Disease Progression , Enhancer Elements, Genetic/genetics , Gene Expression Regulation, Neoplastic , Glioblastoma/genetics , Humans , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Neurons/metabolism , Promoter Regions, Genetic/genetics , Protein Binding , Sequence Analysis, RNA , Up-Regulation/genetics
17.
Lab Chip ; 17(3): 511-520, 2017 01 31.
Article in English | MEDLINE | ID: mdl-28092382

ABSTRACT

There is a growing awareness that complex 3-dimensional (3D) organs are not well represented by monolayers of a single cell type - the standard format for many drug screens. To address this deficiency, and with the goal of improving screens so that drugs with good efficacy and low toxicity can be identified, microphysiological systems (MPS) are being developed that better capture the complexity of in vivo physiology. We have previously described an organ-on-a-chip platform that incorporates perfused microvessels, such that survival of the surrounding tissue is entirely dependent on delivery of nutrients through the vessels. Here we describe an arrayed version of the platform that incorporates multiple vascularized micro-organs (VMOs) on a 96-well plate. Each VMO is independently-addressable and flow through the micro-organ is driven by hydrostatic pressure. The platform is easy to use, requires no external pumps or valves, and is highly reproducible. As a proof-of-concept we have created arrayed vascularized micro tumors (VMTs) and used these in a blinded screen to assay a small library of compounds, including FDA-approved anti-cancer drugs, and successfully identified both anti-angiogenic and anti-tumor drugs. This 3D platform is suitable for efficacy/toxicity screening against multiple tissues in a more physiological environment than previously possible.


Subject(s)
Cell Culture Techniques/instrumentation , Drug Evaluation, Preclinical/instrumentation , Microfluidic Analytical Techniques/instrumentation , Tissue Array Analysis/instrumentation , Antineoplastic Agents/pharmacology , Drug Evaluation, Preclinical/methods , Equipment Design , Gene Expression Profiling , Gene Expression Regulation, Neoplastic/drug effects , Humans , Neoplasms, Experimental/metabolism , Neovascularization, Pathologic/metabolism , Tissue Array Analysis/methods
18.
Cancer Cell ; 29(6): 859-873, 2016 06 13.
Article in English | MEDLINE | ID: mdl-27300435

ABSTRACT

Glioblastomas (GBM) grow in a rich neurochemical milieu, but the impact of neurochemicals on GBM growth is largely unexplored. We interrogated 680 neurochemical compounds in patient-derived GBM neural stem cells (GNS) to determine the effects on proliferation and survival. Compounds that modulate dopaminergic, serotonergic, and cholinergic signaling pathways selectively affected GNS growth. In particular, dopamine receptor D4 (DRD4) antagonists selectively inhibited GNS growth and promoted differentiation of normal neural stem cells. DRD4 antagonists inhibited the downstream effectors PDGFRß, ERK1/2, and mTOR and disrupted the autophagy-lysosomal pathway, leading to accumulation of autophagic vacuoles followed by G0/G1 arrest and apoptosis. These results demonstrate a role for neurochemical pathways in governing GBM stem cell proliferation and suggest therapeutic approaches for GBM.


Subject(s)
Brain Neoplasms/drug therapy , Glioblastoma/drug therapy , Neural Stem Cells/drug effects , Receptors, Dopamine D4/metabolism , Small Molecule Libraries/administration & dosage , Animals , Autophagy , Brain Neoplasms/metabolism , Cell Differentiation/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Screening Assays, Antitumor , Gene Expression Regulation, Neoplastic/drug effects , Glioblastoma/metabolism , Humans , Mice , Neoplastic Stem Cells/cytology , Neoplastic Stem Cells/drug effects , Neural Stem Cells/cytology , Neural Stem Cells/pathology , Receptors, Dopamine D4/antagonists & inhibitors , Signal Transduction/drug effects , Small Molecule Libraries/pharmacology , Survival Analysis , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
19.
Cancer Cell ; 28(6): 715-729, 2015 Dec 14.
Article in English | MEDLINE | ID: mdl-26626085

ABSTRACT

Mutations in the histone 3 variant H3.3 have been identified in one-third of pediatric glioblastomas (GBMs), but not in adult tumors. Here we show that H3.3 is a dynamic determinant of functional properties in adult GBM. H3.3 is repressed by mixed lineage leukemia 5 (MLL5) in self-renewing GBM cells. MLL5 is a global epigenetic repressor that orchestrates reorganization of chromatin structure by punctuating chromosomes with foci of compacted chromatin, favoring tumorigenic and self-renewing properties. Conversely, H3.3 antagonizes self-renewal and promotes differentiation. We exploited these epigenetic states to rationally identify two small molecules that effectively curb cancer stem cell properties in a preclinical model. Our work uncovers a role for MLL5 and H3.3 in maintaining self-renewal hierarchies in adult GBM.


Subject(s)
Brain Neoplasms/metabolism , Cell Self Renewal , Chromatin Assembly and Disassembly , DNA-Binding Proteins/metabolism , Glioblastoma/metabolism , Histones/metabolism , Neoplastic Stem Cells/metabolism , Adolescent , Adult , Animals , Antineoplastic Agents/pharmacology , Brain Neoplasms/drug therapy , Brain Neoplasms/genetics , Brain Neoplasms/mortality , Brain Neoplasms/pathology , Cell Differentiation , Cell Proliferation , Cell Self Renewal/drug effects , Child , Child, Preschool , Chromatin Assembly and Disassembly/drug effects , DNA Methylation , DNA-Binding Proteins/genetics , Drug Design , Epigenesis, Genetic , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Glioblastoma/drug therapy , Glioblastoma/genetics , Glioblastoma/mortality , Glioblastoma/pathology , Histones/genetics , Humans , Kaplan-Meier Estimate , Mice, Inbred NOD , Mice, SCID , Molecular Targeted Therapy , Mutation , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/pathology , Prognosis , RNA Interference , Signal Transduction , Time Factors , Transfection , Tumor Cells, Cultured , Xenograft Model Antitumor Assays , Young Adult
20.
J Am Soc Hypertens ; 9(10): 769-779, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26362830

ABSTRACT

SYMPLICITY HTN-3, the first trial of renal denervation (RDN) versus sham, enrolled 26% African Americans, a prospectively stratified cohort. Although the 6-month systolic blood pressure (SBP) reduction in African Americans (AAs) was similar in the RDN group (-15.5 ± 25.4 mm Hg, n = 85 vs. -17.8 ± 29.2, n = 49, P = .641), the sham SBP response was 9.2 mm Hg greater (P = .057) in AAs than non-AAs. In multivariate analyses, sham SBP response was predicted by an interaction between AA and a complex antihypertensive regimen (at least one antihypertensive medication prescribed ≥3 times daily), while in the RDN group, SBP response was predicted by an interaction between AA race and baseline BP ≥ 180 mm Hg. AA race did not independently predict SBP response in either sham or RDN. There appears to be effect modification by race with individual-level patient characteristics in both treatment arms that affect the observed pattern of SBP responses.


Subject(s)
Hypertension/physiopathology , Hypertension/surgery , Kidney/innervation , Sympathetic Nervous System/surgery , Adult , Black or African American , Aged , Antihypertensive Agents/therapeutic use , Blood Pressure Monitoring, Ambulatory , Catheter Ablation , Cohort Studies , Female , Humans , Hypertension/ethnology , Male , Medication Adherence , Middle Aged , Multivariate Analysis , Prospective Studies , Sympathectomy/methods , Treatment Outcome
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