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1.
Educ Prim Care ; : 1-5, 2024 Apr 14.
Article in English | MEDLINE | ID: mdl-38615345

ABSTRACT

There is need for a greater connection between General Practice and GP trainees in their hospital component of training. Currently, in Scotland, there are no national education programmes specifically designed for GP trainees during their hospital component of training. Our aim was to develop and evaluate the feasibility of a national online 'bitesize' education programme delivered live for GP trainees in their hospital component of training. The study also aims to assess the barriers to attending these teaching sessions and whether they made trainees feel more connected to General Practice. Weekly one hour 'Bitesize' teaching sessions, delivered virtually, were organised by NHS Education for Scotland (NES) GP Medical Education Fellows during a four-week period. Eligible attendees were GP trainees (GPST1s and GPST2s) working in the hospital component of their training. An end of program questionnaire, gathering quantitative and qualitative data, was used for evaluation. There was a strong support for this programme from the attendance numbers and the questionnaire feedback responses, with GP trainees feeling more in touch with general practice and more confident in managing primary care focused topics. GP trainees agreed that a weekly, one-hour, online lunchtime session suits them. The most common barrier to attendance were work commitments and conflicts with local teaching. This pilot has emphasised the need for a structured teaching programme for GP trainees in the hospital component of training.

2.
Cell Rep ; 43(4): 113972, 2024 Apr 23.
Article in English | MEDLINE | ID: mdl-38517892

ABSTRACT

Hypoxia-inducible factor 1 (HIF-1) is a transcriptional activator that mediates cellular adaptation to decreased oxygen availability. HIF-1 recruits chromatin-modifying enzymes leading to changes in histone acetylation, citrullination, and methylation at target genes. Here, we demonstrate that hypoxia-inducible gene expression in estrogen receptor (ER)-positive MCF7 and ER-negative SUM159 human breast cancer cells requires the histone H2A/H2B chaperone facilitates chromatin transcription (FACT) and the H2B ubiquitin ligase RING finger protein 20/40 (RNF20/40). Knockdown of FACT or RNF20/40 expression leads to decreased transcription initiation and elongation at HIF-1 target genes. Mechanistically, FACT and RNF20/40 are recruited to hypoxia response elements (HREs) by HIF-1 and stabilize binding of HIF-1 (and each other) at HREs. Hypoxia induces the monoubiquitination of histone H2B at lysine 120 at HIF-1 target genes in an HIF-1-dependent manner. Together, these findings delineate a cooperative molecular mechanism by which FACT and RNF20/40 stabilize multiprotein complex formation at HREs and mediate histone ubiquitination to facilitate HIF-1 transcriptional activity.


Subject(s)
DNA-Binding Proteins , Hypoxia-Inducible Factor 1 , Ubiquitin-Protein Ligases , Humans , Cell Hypoxia , Cell Line, Tumor , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Histones/metabolism , Hypoxia-Inducible Factor 1/metabolism , MCF-7 Cells , Protein Binding , Response Elements , Transcription Factors/metabolism , Transcriptional Activation , Ubiquitin-Protein Ligases/metabolism , Ubiquitin-Protein Ligases/genetics , Ubiquitination
3.
OTO Open ; 8(1): e117, 2024.
Article in English | MEDLINE | ID: mdl-38420352

ABSTRACT

Objective: The impact of poor sleep on tinnitus has been mainly attributed to central processes. There is an association between sleep disorders and hearing loss, but whether hearing levels mediate the association between sleep disorders and tinnitus is unknown. This study investigates the association between sleep characteristics, tinnitus, and hearing loss. Study Design: Cross-sectional. Setting: National Health and Nutrition Examination Survey (NHANES). Methods: Study cohort includes 9693 adults (≥20 years) from the NHANES 2005 to 2018 who completed audiometric testing and questionnaires on tinnitus and sleep characteristics. Multivariable regression analyses were performed to quantify associations between sleep characteristics, tinnitus, and hearing loss. Results: In this cohort, 29% (95% confidence interval [CI]: 28%-31%) reported trouble sleeping and 9% (95% CI: 8%-10%) reported being diagnosed with sleep disorders. Negative sleep characteristics (less hours of sleep, diagnosis of a sleep disorder, trouble sleeping, or OSA symptoms) were not associated with audiometry-measured hearing loss in multivariable models adjusted for demographics and comorbidities but were significantly associated with bothersome tinnitus. This association remained significant without substantial attenuation in multivariable models additionally adjusting for hearing levels: sleeping <8 h/day (vs ≥8) (odds ratio [OR]: 1.28 [95% CI: 1.08-1.52]), trouble sleeping (OR: 1.78 [95% CI: 1.45-2.19]), diagnosis of sleep disorders (OR: 1.57 [95% CI: 1.14-2.15]), and report of OSA symptoms (OR: 1.42 [95% CI: 1.08-1.88]). Conclusion: Negative sleep characteristics were associated with tinnitus while there was no clinically meaningful association between sleep and hearing loss. Our findings suggest that the relationship between poor sleep and tinnitus is likely contributed by central processes without a major role of mediation via the peripheral auditory system.

4.
Ear Nose Throat J ; : 1455613241230245, 2024 Feb 22.
Article in English | MEDLINE | ID: mdl-38389189

ABSTRACT

Objective: Turicella otitidis and Staphylococcus auricularis have been considered normal aural flora. Their significance in active infection is controversial. We examined a series of patients presenting with acute and chronic otitis media whose ear canal culture isolated T. otitidis and S. auricularis and explored possible pathogenicity, associated factors, and outcomes. Methods: This is a retrospective chart review of patients who presented to a tertiary center outpatient clinic between 2017 and 2022 with otologic microscopic examination of active infection and ear canal culture isolating T. otitidis or S. auricularis only. Clinical course was collected including history, microscopic otoscopy findings, interventions given, outcomes, and sensitivity results. Results: A total of 13 patients (10 with T. otitidis and 3 with S. auricularis) were included. Majority of the patients had a history of otologic surgery (92%) and tympanic membrane perforation (62%). All were treated with combinations of antibiotic otic drops (ie, fluoroquinolone, sulfa, or aminoglycoside based) ± oral antibiotics (ie, penicillin or trimethoprim/sulfamethoxazole). Otorrhea resolved among majority of patients. Otorrhea and mucosalization returned or continued among 4 patients. Sensitivity results demonstrated that 2 of 3 strains of T. otitidis were resistant to clindamycin. There was no resistance against S. auricularis for tested antibiotics. Conclusions: Our findings suggest the potential pathogenicity of T. otitidis and S. auricularis, especially among patients with prior ear surgery and tympanic membrane perforation. Violation of the epithelial barrier from surgery or trauma may contribute to their pathogenicity. Future study is warranted to elucidate pathogenicity of normal aural flora and its mechanisms.

5.
Laryngoscope ; 134(1): 393-396, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37289065

ABSTRACT

OBJECTIVE: There is increased confusion regarding MRI-compatible CIs and BAHAs. This report describes two cases when patients underwent MRIs with non-MRI compatible devices. RESULTS: One patient with bilateral Cochlear Osias experienced dislocation of both internal magnets after 1.5 Tesla MRI. Both magnets were outside the silastic sheath, with the left magnet flipped. A second patient with a legacy CI experienced similar internal magnet dislocation and inversion after 3 Tesla MRI. CONCLUSIONS: This study describes internal magnet dislocation/inversion with the Cochlear Osia and a legacy CI after MRI. Our findings suggest the need for improved patient education and simplified radiology guidelines. Laryngoscope, 134:393-396, 2024.


Subject(s)
Cochlear Implantation , Cochlear Implants , Humans , Cochlear Implantation/adverse effects , Magnetic Resonance Imaging/methods , Magnets , Technology
6.
Ear Hear ; 45(1): 198-206, 2024.
Article in English | MEDLINE | ID: mdl-37563758

ABSTRACT

OBJECTIVES: Congenital cytomegalovirus (cCMV) is the most common cause of nongenetic sensorineural hearing loss (SNHL) in children. We examined the longitudinal hearing outcomes of children with cCMV in relation to their newborn hearing screening findings, and their use of antiviral therapy. DESIGN: The study was based on a retrospective chart review using a database of pediatric patients (N = 445) seen at the University of Minnesota Lions clinic. Chart review identified infants with cCMV, and records were reviewed for information about universal newborn hearing screen (UNHS) results, the clinical course of SNHL, and the use of antiviral therapy. RESULTS: A total of 44 children were identified with cCMV. In this group, 33 (75%) had SNHL of varying degree and age at onset. Notably, 17 (39%) children passed UNHS bilaterally. Of those children, 6 (35%) ultimately acquired bilateral or unilateral SNHL, detected at a mean age of 20 months (median age, 12 months). Five out of 10 children (50%) that did not pass UNHS in one ear acquired late-onset hearing loss in the contralateral ear, identified at a mean age of 24 months (median age, 4 months). Eleven (25%) children passed UNHS bilaterally and continued to demonstrate normal hearing in both ears at their most recent follow-up visit at a mean age of 19 months (SD, 18 months). Of the 33 children with cCMV and SNHL, 18 (55%) received antiviral medication (ganciclovir and/or valganciclovir). While, on average, both treated and untreated ears experienced a progression of hearing loss over time, the group that received antiviral treatment experienced less overall hearing change compared with the untreated group (baseline-adjusted expected mean difference, -10.5 dB; 95% confidence interval, -28.1 to 7.2 dB). CONCLUSIONS: Among children with cCMV included in this study who passed UNHS in both ears, 35% demonstrated delayed-onset SNHL. Notably, of those children who referred unilaterally, 50% later demonstrated SNHL in the contralateral ear. These findings have implications for audiological monitoring, and potentially antiviral therapy, of children with cCMV. As implementation of universal cCMV screening moves forward, a key aspect of follow-up will be appropriate long-term audiologic monitoring.


Subject(s)
Cytomegalovirus Infections , Deafness , Hearing Loss, Sensorineural , Infant , Infant, Newborn , Humans , Child , Child, Preschool , Cytomegalovirus , Retrospective Studies , Hearing Loss, Sensorineural/diagnosis , Hearing , Cytomegalovirus Infections/complications , Cytomegalovirus Infections/drug therapy , Cytomegalovirus Infections/congenital , Deafness/complications , Antiviral Agents/therapeutic use , Neonatal Screening/methods
7.
Perception ; 53(3): 211-214, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38130143

ABSTRACT

For over a quarter-century, the Sky-Tower has dominated the skyline of Auckland Tamaki Makaurau. Despite its imposing height, observers anecdotally report odd fluctuations in how big it appears. From certain angles, it can look positively stumpy. Such misperceptions can be bewildering and perilous when it happens whilst driving. Here, we characterise this strange illusion in the hopes of better understanding its cause.


Subject(s)
Illusions , Humans
8.
Cancers (Basel) ; 15(12)2023 Jun 19.
Article in English | MEDLINE | ID: mdl-37370851

ABSTRACT

Diffuse midline glioma (DMG) is the most lethal of all childhood cancers. DMGs are driven by histone-tail-mutation-mediated epigenetic dysregulation and partner mutations in genes controlling proliferation and migration. One result of this epigenetic and genetic landscape is the overexpression of LIN28B RNA binding protein. In other systems, LIN28B has been shown to prevent let-7 microRNA biogenesis; however, let-7, when available, faithfully suppresses tumorigenic pathways and induces cellular maturation by preventing the translation of numerous oncogenes. Here, we review the current literature on LIN28A/B and the let-7 family and describe their role in gliomagenesis. Future research is then recommended, with a focus on the mechanisms of LIN28B overexpression and localization in DMG.

9.
Plant Physiol ; 192(4): 2687-2702, 2023 08 03.
Article in English | MEDLINE | ID: mdl-37096683

ABSTRACT

Light, temperature, water, and nutrient availability influence how plants grow to maximize access to resources. Axial growth, the linear extension of tissues by coordinated axial cell expansion, plays a central role in these adaptive morphological responses. Using Arabidopsis (Arabidopsis thaliana) hypocotyl cells to explore axial growth control mechanisms, we investigated WAVE-DAMPENED2-LIKE4 (WDL4), an auxin-induced, microtubule-associated protein and member of the larger WDL gene family shown to modulate hypocotyl growth under changing environmental conditions. Loss-of-function wdl4 seedlings exhibited a hyper-elongation phenotype under light conditions, continuing to elongate when wild-type Col-0 hypocotyls arrested and reaching 150% to 200% of wild-type length before shoot emergence. wdl4 seedling hypocotyls showed dramatic hyper-elongation (500%) in response to temperature elevation, indicating an important role in morphological adaptation to environmental cues. WDL4 was associated with microtubules under both light and dark growth conditions, and no evidence was found for altered microtubule array patterning in loss-of-function wdl4 mutants under various conditions. Examination of hormone responses showed altered sensitivity to ethylene and evidence for changes in the spatial distribution of an auxin-dependent transcriptional reporter. Our data provide evidence that WDL4 regulates hypocotyl cell elongation without substantial changes to microtubule array patterning, suggesting an unconventional role in axial growth control.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Hypocotyl , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Arabidopsis/metabolism , Seedlings/metabolism , Indoleacetic Acids/metabolism
10.
Cell Rep ; 42(3): 112164, 2023 03 28.
Article in English | MEDLINE | ID: mdl-36857181

ABSTRACT

Intratumoral hypoxia is a microenvironmental feature that promotes breast cancer progression and is associated with cancer mortality. Plexin B3 (PLXNB3) is highly expressed in estrogen receptor-negative breast cancer, but the underlying mechanisms and consequences have not been thoroughly investigated. Here, we report that PLXNB3 expression is increased in response to hypoxia and that PLXNB3 is a direct target gene of hypoxia-inducible factor 1 (HIF-1) in human breast cancer cells. PLXNB3 expression is correlated with HIF-1α immunohistochemistry, breast cancer grade and stage, and patient mortality. Mechanistically, PLXNB3 is required for hypoxia-induced MET/SRC/focal adhesion kinase (FAK) and MET/SRC/STAT3/NANOG signaling as well as hypoxia-induced breast cancer cell migration, invasion, and cancer stem cell specification. PLXNB3 knockdown impairs tumor formation and lung metastasis in orthotopic breast cancer mouse models.


Subject(s)
Breast Neoplasms , Lung Neoplasms , Animals , Female , Humans , Mice , Breast Neoplasms/pathology , Cell Hypoxia/genetics , Cell Line, Tumor , Cell Movement , Gene Expression Regulation, Neoplastic , Hypoxia/metabolism , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Lung Neoplasms/pathology , Neoplastic Stem Cells/metabolism
11.
Otolaryngol Head Neck Surg ; 168(6): 1477-1484, 2023 06.
Article in English | MEDLINE | ID: mdl-36939593

ABSTRACT

OBJECTIVE: The workforce of neurotology has changed with increasing numbers of accredited programs and diverse representation among trainees over the past several decades. This study aims to describe the characteristics, density, and geographic variation of the current neurotology workforce in the United States. STUDY DESIGN: Cross-sectional study. SETTING: American Board of Otolaryngology-Head and Neck Surgery portal and online search. METHODS: The study cohort included physicians certified in Neurotology by the American Board of Otolaryngology as of 2021 (n = 372). Physician characteristics including years of practice, gender, practice setting, and location were collected. Geographic variation analysis was performed by the state, county, and hospital referral region. Associations between the number of neurotologists per population and socioeconomic characteristics were assessed using multivariable regression analysis. RESULTS: Among 372 neurotologists, 65% practiced in academic settings and 13% were female. The percentage of female neurotologists increased from 0% among neurotologists with ≥30 years of practice to 23% among <10 years of practice. There were no differences in a practice setting by gender. The geographical analysis demonstrated that the average number of neurotologists was 1.1 per 1 million Americans. In a multivariable model, the density of neurotologists was significantly higher within counties with the highest quartiles of college education (ß = .6 [95% confidence interval, CI: 0.3-0.8]) and income (ß = .3 [95% CI: 0.1-0.6]). CONCLUSION: The number of board-certified neurotologists has gradually increased and there have been trends toward greater gender diversity. The geographical distribution of neurotology practice was concentrated in counties with higher socioeconomic status as expected given the referral-based nature of the subspecialty. There should be efforts to reach out to low socioeconomic communities to ensure equivalent access to neurotological care.


Subject(s)
Neurotology , Otolaryngology , Physicians , Humans , Female , United States , Male , Cross-Sectional Studies , Workforce
12.
Cleft Palate Craniofac J ; 60(8): 1029-1031, 2023 08.
Article in English | MEDLINE | ID: mdl-35482357

ABSTRACT

The case series details 2 unusual cases of male newborns with cleft lip and palate (CLP) that later developed formula otorrhea. Both patients underwent bilateral myringotomies with the insertion of pressure equalizing (PE) tubes for chronic otitis media with effusion (OME). Chronic otorrhea associated with feeding occurred post-PE tube insertion and the otorrhea was later confirmed to be due to reflux of formula. Patients were treated with antibiotic ear drops, routine ear cleaning, anti-reflux medication, and reflux precautions. After definite cleft palate repair, formula otorrhea completely resolved. When patients with CLP develop chronic OME or otorrhea following PE tube placement, reflux of formula into the middle ear should be considered and treated accordingly.


Subject(s)
Cleft Lip , Cleft Palate , Otitis Media with Effusion , Child , Humans , Male , Infant, Newborn , Infant , Cleft Palate/complications , Cleft Lip/complications , Otitis Media with Effusion/surgery , Middle Ear Ventilation/adverse effects
13.
Sci Adv ; 8(49): eabo5000, 2022 12 09.
Article in English | MEDLINE | ID: mdl-36490339

ABSTRACT

Hypoxia is a key characteristic of the breast cancer microenvironment that promotes expression of the transcriptional activator hypoxia-inducible factor 1 (HIF-1) and is associated with poor patient outcome. HIF-1 increases the expression or activity of stem cell pluripotency factors, which control breast cancer stem cell (BCSC) specification and are required for cancer metastasis. Here, we identify nuclear prelamin A recognition factor (NARF) as a hypoxia-inducible, HIF-1 target gene in human breast cancer cells. NARF functions as an essential coactivator by recruiting the histone demethylase KDM6A to OCT4 bound to genes encoding the pluripotency factors NANOG, KLF4, and SOX2, leading to demethylation of histone H3 trimethylated at lysine-27 (H3K27me3), thereby increasing the expression of NANOG, KLF4, and SOX2, which, together with OCT4, mediate BCSC specification. Knockdown of NARF significantly decreased the BCSC population in vitro and markedly impaired tumor initiation capacity and lung metastasis in orthotopic mouse models.


Subject(s)
Breast Neoplasms , Hypoxia-Inducible Factor 1 , Animals , Female , Humans , Mice , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Histones/metabolism , Hypoxia/genetics , Hypoxia/metabolism , Neoplastic Stem Cells/metabolism , Neoplastic Stem Cells/pathology , Transcription Factors/genetics , Transcription Factors/metabolism , Tumor Microenvironment/genetics , Tumor Microenvironment/physiology , Hypoxia-Inducible Factor 1/genetics , Hypoxia-Inducible Factor 1/metabolism
14.
Clin Lymphoma Myeloma Leuk ; 22(11): e992-e999, 2022 11.
Article in English | MEDLINE | ID: mdl-35963771

ABSTRACT

INTRODUCTION: The standard of care for early-stage Hodgkin Lymphoma (HL) is combined modality therapy (CMT) consisting of chemotherapy and involved site radiation therapy (ISRT). Recent treatment de-escalation trials have assessed the impact of omitting radiation with the use of positron emission tomography (PET) and have suggested a detriment in progression free survival (PFS) for patients who do not receive radiation therapy (RT) but similar overall survival. The purpose of this study was to compare the cost-effectiveness of PET-directed therapy versus standard of care CMT. METHODS: This study used a cost-effectiveness Markov model simulating 5 year outcomes for 1 million patients with early-stage HL treated with either PET-directed therapy consisting of 2 cycles of ABVD chemotherapy ± ISRT or CMT consisting of 2 cycles of ABVD + ISRT. Patients progressed to no evidence of disease, progression of disease (PD), or death. Patients with PD underwent salvage therapy with high dose chemotherapy and stem cell transplant (HDC-SCT). The primary outcome measured was the incremental cost-effectiveness ratio. Deterministic sensitivity analyses were performed. RESULTS: We found that PET-directed therapy and CMT strategies were associated with costs of $47,362 and $41,167, respectively. The CMT strategy was equally as effective as the PET-directed therapy strategy with QALYs of 3.4. On 1-way sensitivity analyses, the model was most sensitive to CMT and HDC-SCT costs. Two-way sensitivity analyses showed the model was sensitive to the relative costs of these treatments. CONCLUSION: For patients with early-stage HL, CMT is the cost-effective strategy as compared with PET-directed therapy.


Subject(s)
Hodgkin Disease , Humans , Hodgkin Disease/pathology , Cost-Benefit Analysis , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Vinblastine/therapeutic use , Dacarbazine/therapeutic use , Bleomycin/therapeutic use , Doxorubicin/therapeutic use , Combined Modality Therapy , Positron-Emission Tomography , Disease-Free Survival
16.
Sci Adv ; 7(23)2021 06.
Article in English | MEDLINE | ID: mdl-34078608

ABSTRACT

Pediatric high-grade gliomas (pHGGs), including glioblastoma multiforme (GBM) and diffuse intrinsic pontine glioma (DIPG), are morbid brain tumors. Even with treatment survival is poor, making pHGG the number one cause of cancer death in children. Up to 80% of DIPGs harbor a somatic missense mutation in genes encoding histone H3. To investigate whether H3K27M is associated with distinct chromatin structure that alters transcription regulation, we generated the first high-resolution Hi-C maps of pHGG cell lines and tumor tissue. By integrating transcriptome (RNA-seq), enhancer landscape (ChIP-seq), genome structure (Hi-C), and chromatin accessibility (ATAC-seq) datasets from H3K27M and wild-type specimens, we identified tumor-specific enhancers and regulatory networks for known oncogenes. We identified genomic structural variations that lead to potential enhancer hijacking and gene coamplification, including A2M, JAG2, and FLRT1 Together, our results imply three-dimensional genome alterations may play a critical role in the pHGG epigenetic landscape and contribute to tumorigenesis.


Subject(s)
Brain Stem Neoplasms , Glioma , Brain Stem Neoplasms/genetics , Brain Stem Neoplasms/pathology , Child , Chromatin/genetics , Epigenomics , Glioma/genetics , Glioma/pathology , Humans , Mutation
17.
R Soc Open Sci ; 8(4): 190430, 2021 Apr 21.
Article in English | MEDLINE | ID: mdl-33996111

ABSTRACT

Familiarity-based processes such as processing fluency can influence memory judgements in tests of item recognition. Many conventional accounts of source memory assume minimal influence of familiarity on source memory, but recent work has suggested that source memory judgements are affected when test stimuli are processed with greater fluency as a result of priming. The present experiments investigated the relationship between fluency and the accuracy of source memory decisions. Participants studied words presented with different source attributes. During test, they identified words that gradually clarified on screen through progressive demasking, made old/new and source memory judgements, and reported confidence ratings for those words. Response times (RTs) recorded from the item identification task formed the basis of a fluency measure, and identification RTs were compared across categories of item recognition, source accuracy and confidence. Identification RTs were faster in trials with correct retrieval of source information compared with trials for which source could not be accurately retrieved. These findings are consistent with the assumption that familiarity-based processes are related to source memory judgements.

18.
Sci Rep ; 11(1): 5098, 2021 03 03.
Article in English | MEDLINE | ID: mdl-33658570

ABSTRACT

Diffuse midline glioma (DMG) is a highly morbid pediatric brain tumor. Up to 80% of DMGs harbor mutations in histone H3-encoding genes, associated with poor prognosis. We previously showed the feasibility of detecting H3 mutations in circulating tumor DNA (ctDNA) in the liquid biome of children diagnosed with DMG. However, detection of low levels of ctDNA is highly dependent on platform sensitivity and sample type. To address this, we optimized ctDNA detection sensitivity and specificity across two commonly used digital droplet PCR (ddPCR) platforms (RainDance and BioRad), and validated methods for detecting H3F3A c.83A > T (H3.3K27M) mutations in DMG CSF, plasma, and primary tumor specimens across three different institutions. DNA was extracted from H3.3K27M mutant and H3 wildtype (H3WT) specimens, including H3.3K27M tumor tissue (n = 4), CSF (n = 6), plasma (n = 4), and human primary pediatric glioma cells (H3.3K27M, n = 2; H3WT, n = 1). ctDNA detection was enhanced via PCR pre-amplification and use of distinct custom primers and fluorescent LNA probes for c.83 A > T H3F3A mutation detection. Mutation allelic frequency (MAF) was determined and validated through parallel analysis of matched H3.3K27M tissue specimens (n = 3). We determined technical nuances between ddPCR instruments, and optimized sample preparation and sequencing protocols for H3.3K27M mutation detection and quantification. We observed 100% sensitivity and specificity for mutation detection in matched DMG tissue and CSF across assays, platforms and institutions. ctDNA is reliably and reproducibly detected in the liquid biome using ddPCR, representing a clinically feasible, reproducible, and minimally invasive approach for DMG diagnosis, molecular subtyping and therapeutic monitoring.


Subject(s)
Brain Neoplasms/diagnosis , Brain Neoplasms/genetics , Circulating Tumor DNA/genetics , Glioma/diagnosis , Glioma/genetics , Mutation Rate , Polymerase Chain Reaction/methods , Biomarkers, Tumor/blood , Biomarkers, Tumor/genetics , Brain Neoplasms/blood , Brain Neoplasms/pathology , Child , Circulating Tumor DNA/isolation & purification , Feasibility Studies , Glioma/blood , Glioma/pathology , Histones/genetics , Humans , Liquid Biopsy/standards , Prognosis , Reference Standards , Reproducibility of Results , Sensitivity and Specificity
19.
Acta Neuropathol Commun ; 8(1): 219, 2020 12 07.
Article in English | MEDLINE | ID: mdl-33287886

ABSTRACT

Histone H3.3 mutation (H3F3A) occurs in 50% of cortical pediatric high-grade gliomas. This mutation replaces glycine 34 with arginine or valine (G34R/V), impairing SETD2 activity (H3K36-specific trimethyltransferase). Consequently, reduced H3K36me3 is observed on H3.3G34V nucleosomes relative to wild-type, contributing to genomic instability and driving a distinct gene expression signature associated with tumorigenesis. However, it is not known if this differential H3K36me3 enrichment is due to H3.3G34V mutant protein alone. Therefore, we set to elucidate the effect of H3.3G34V mutant protein in pediatric glioma on H3K36me3, H3K27me3 and H3.3 enrichment in vitro. We found that the doxycycline-inducible shRNA knockdown of mutant H3F3A encoding the H3.3G34V protein resulted in loss of H3.3G34V enrichment and increased H3K36me3 enrichment throughout the genome. After knockdown, H3.3G34V enrichment was preserved at loci observed to have the greatest H3.3G34V and H3K36me3 enrichment prior to knockdown. Induced expression of mutant H3.3G34V protein in vitro was insufficient to induce genomic H3K36me3 enrichment patterns observed in H3.3G34V mutant glioma cells. We also observed strong co-enrichment of H3.3G34V and wild-type H3.3 protein, as well as greater H3K27me3 enrichment, in cells expressing H3.3G34V. Taken together, our study demonstrates the effects of H3.3G34V mutant protein on genomic H3K36me3, H3K27me3 and H3.3 enrichment patterns in isogenic cell lines.


Subject(s)
Brain Neoplasms/genetics , Glioma/genetics , Histone Code/genetics , Histones/genetics , Astrocytes , Brain Neoplasms/metabolism , Cell Line, Tumor , Cell Proliferation , Cell Survival , Child , Chromatin Immunoprecipitation , Chromatin Immunoprecipitation Sequencing , Gene Expression Regulation, Neoplastic , Gene Knockdown Techniques , Glioma/metabolism , High-Throughput Nucleotide Sequencing , Humans , Methylation , Mutation, Missense
20.
J Exp Clin Cancer Res ; 39(1): 261, 2020 Nov 25.
Article in English | MEDLINE | ID: mdl-33239043

ABSTRACT

BACKGROUND: Diffuse intrinsic pontine glioma (DIPG) is an aggressive pediatric brainstem tumor. Most DIPGs harbor a histone H3 mutation, which alters histone post-translational modification (PTM) states and transcription. Here, we employed quantitative proteomic analysis to elucidate the impact of the H3.3K27M mutation, as well as radiation and bromodomain inhibition (BRDi) with JQ1, on DIPG PTM profiles. METHODS: We performed targeted mass spectrometry on H3.3K27M mutant and wild-type tissues (n = 12) and cell lines (n = 7). RESULTS: We found 29.2 and 26.4% of total H3.3K27 peptides were H3.3K27M in mutant DIPG tumor cell lines and tissue specimens, respectively. Significant differences in modification states were observed in H3.3K27M specimens, including at H3K27, H3K36, and H4K16. In addition, H3.3K27me1 and H4K16ac were the most significantly distinct modifications in H3.3K27M mutant tumors, relative to wild-type. Further, H3.3K36me2 was the most abundant co-occurring modification on the H3.3K27M mutant peptide in DIPG tissue, while H4K16ac was the most acetylated residue. Radiation treatment caused changes in PTM abundance in vitro, including increased H3K9me3. JQ1 treatment resulted in increased mono- and di-methylation of H3.1K27, H3.3K27, H3.3K36 and H4K20 in vitro. CONCLUSION: Taken together, our findings provide insight into the effects of the H3K27M mutation on histone modification states and response to treatment, and suggest that H3K36me2 and H4K16ac may represent unique tumor epigenetic signatures for targeted DIPG therapy.


Subject(s)
Brain Stem Neoplasms/genetics , Diffuse Intrinsic Pontine Glioma/genetics , Epigenomics/methods , Gene Expression Profiling/methods , Histones/metabolism , Brain Stem Neoplasms/pathology , Diffuse Intrinsic Pontine Glioma/pathology , Female , Humans , Male
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