Biology subjects

Miller, C. A.

Publications and source records attributed to Miller, C. A..

36 records · Page 2Linked to original sources

bioRxiv2021

Clinicopathologic features of a feline SARS-CoV-2 infection model parallel acute COVID-19 in humans

The emergence and ensuing dominance of COVID-19 on the world stage has emphasized the urgency of efficient animal models for the development of therapeutics and assessment of immune responses to SARS-CoV-2 infection. Shortcomings of current animal models for SARS-CoV-2 include limited lower respiratory disease, divergence from clinical COVID-19 disease, and requirements for host genetic modifications to permit infection. This study validates a feline model for SARS-CoV-2 infection that results in clinical disease and histopathologic lesions consistent with severe COVID-19 in humans. Intra-tracheal inoculation of concentrated SARS-CoV-2 caused infected cats to develop clinical disease consistent with that observed in the early exudative phase of COVID-19. A novel clinical scoring system for feline respiratory disease was developed and utilized, documenting a significant degree of lethargy, fever, dyspnea, and dry cough in infected cats. In addition, histopathologic pulmonary lesions such as diffuse alveolar damage, hyaline membrane formation, fibrin deposition, and proteinaceous exudates were observed due to SARS-CoV-2 infection, imitating lesions identified in people hospitalized with ARDS from COVID-19. A significant correlation exists between the degree of clinical disease identified in infected cats and pulmonary lesions. Viral loads and ACE2 expression were quantified in nasal turbinates, distal trachea, lung, and various other organs. Natural ACE2 expression, paired with clinicopathologic correlates between this feline model and human COVID-19, encourage use of this model for future translational studies. Author SummaryIdentifying an ideal animal model to study COVID-19 has been difficult, and current models come with challenges that restrict their potential in translational studies. Few lab animals naturally express the receptors necessary for viral infection (ACE2), and many fail to manifest clinical signs or pathology similar to that seen in humans. Other models (non-human primates, mink) are ideal for disease and transmission studies, but are restricted by cost, husbandry challenges, and scarce availability. Alternatively, cats naturally express ACE2 receptors, are naturally infected with SARS-CoV-2 and can transmit virus from cat-to-cat. Prior to this study, cats infected by oral/nasal routes have not displayed significant clinical disease or lung pathology. However, we demonstrate that direct inoculation of concentrated SARS-CoV-2 virus in the trachea of cats induces analogous clinical and pathologic features to hospitalized patients with acute COVID-19. Our results show that infected cats exhibit significant clinical signs during experimental infection (coughing, increased respiratory effort, lethargy, and fever) and exhibit extensive lung lesions that mimic severe COVID-19 pathology such as diffuse alveolar damage and hyaline membrane formation - highlighting the immeasurable potential for this feline model to address translational approaches for COVID-19 and to better understand the role of cats in transmission and disease.

microbiology↗

bioRxiv2021

The gastrin-releasing peptide regulates stress-enhanced fear and dopamine signaling

Fear extinction is an adaptive behavioral process critical for organisms survival, but deficiency in extinction may lead to PTSD. While the amygdala and its neural circuits are critical for fear extinction, the molecular identity and organizational logic of cell types that lie at the core of these circuits remain unclear. Here we report that mice deficient for amygdala-enriched gastrin-releasing peptide gene (Grp-/-) exhibit enhanced neuronal activity in the basolateral amygdala (BLA) and stronger fear conditioning, as well as deficient extinction in stress-enhanced fear learning (SEFL). rAAV2-retro-based tracing combined with visualization of the GFP knocked in the Grp gene showed that BLA receives GRPergic or conditioned stimulus projections from the indirect auditory thalamus-to-auditory cortex pathway, ventral hippocampus and ventral tegmental area. Transcription of dopamine-related genes was decreased in BLA of Grp-/- mice following SEFL extinction recall, suggesting that the GRP may mediate fear extinction regulation by dopamine. Impact statementMice deficient for the amygdala-enriched gastrin-releasing peptide gene are susceptible to stress-enhanced fear, a behavioral protocol with relevance to PTSD, and show a decrease in dopamine-related gene transcription.

neuroscience↗

bioRxiv2020

Accurate neoantigen prediction depends on mutation position relative to patient allele-specific MHC anchor location

Neoantigens are novel peptide sequences resulting from sources such as somatic mutations in tumors. Upon loading onto major histocompatibility complex (MHC) molecules, they can trigger recognition by T cells. Accurate neoantigen identification is thus critical for both designing cancer vaccines and predicting response to immunotherapies. Neoantigen identification and prioritization relies on correctly predicting whether the presenting peptide sequence can successfully induce an immune response. As the majority of somatic mutations are single nucleotide variants, changes between wildtype and mutated peptides are typically subtle and require cautious interpretation. A potentially underappreciated variable in neoantigen-prediction pipelines is the mutation position within the peptide relative to its anchor positions for the patients specific MHC molecules. While a subset of peptide positions are presented to the T-cell receptor for recognition, others are responsible for anchoring to the MHC, making these positional considerations critical for predicting T-cell responses. We computationally predicted high probability anchor positions for different peptide lengths for 328 common HLA alleles and identified unique anchoring patterns among them. Analysis of 923 tumor samples shows that 6-38% of neoantigen candidates are potentially misclassified and can be rescued using allelespecific knowledge of anchor positions. A subset of anchor results were orthogonally validated using protein crystallography structures. Representative anchor trends were experimentally validated using peptide-MHC stability assays and competition binding assays. By incorporating our anchor prediction results into neoantigen prediction pipelines, we hope to formalize, streamline and improve the identification process for relevant clinical studies. One Sentence SummaryNeoantigen prediction accuracy is significantly influenced by the mutation position within the neoantigen and its relative position to the patients allele-specific MHC anchor locations.

bioinformatics↗

bioRxiv2020

Discovery of a Novel, Selective and Short-Acting Skeletal Myosin II Inhibitor

Myosin IIs, actin-based motors that utilize the chemical energy of ATP to generate force, have potential as therapeutic targets. Their heavy chains differentiate the family into muscle (skeletal [SkMII], cardiac, smooth) and nonmuscle myosin IIs. Despite therapeutic potential for muscle disorders, no SkMII-specific inhibitor has been reported and characterized. Here we present the discovery, synthesis and characterization of "skeletostatins", novel derivatives of the pan-myosin II inhibitor blebbistatin, with selectivity within the myosin IIs for SkMII. In addition, the skeletostatins bear improved potency, solubility and photostability, without cytotoxicity. Based on its optimal in vitro profile, Skeletostatin 1s in vivo tolerability, efficacy and pharmacokinetics were determined. Skeletostatin 1 was well-tolerated in mice, impaired motor performance, and had an excellent muscle to plasma ratio. Skeletostatins are useful probes for basic research and a strong starting point for drug development.

pharmacology and toxicology↗

bioRxiv2020

U2AF1 is a haplo-essential gene required for cancer cell survival

Somatic mutations in the spliceosome gene U2AF1 are common in patients with myelodysplastic syndromes. U2AF1 mutations that code for the most common amino acid substitutions are always heterozygous, and the retained wild-type allele is expressed, suggesting that mutant hematopoietic cells may require the residual wild-type allele to be viable and cause disease. We show that hematopoiesis and RNA splicing in U2af1 heterozygous knock-out mice was similar to control mice, but that deletion of the wild-type allele in U2AF1(S34F) heterozygous mutant expressing hematopoietic cells (i.e., hemizygous mutant) was lethal. These results confirm that U2AF1 mutant hematopoietic cells are dependent on the expression of wild-type U2AF1 for survival in vivo and that U2AF1 is a haplo-essential cancer gene. Mutant U2AF1 (S34F) expressing cells were also more sensitive to reduced, but not absent, expression of wild-type U2AF1 than non-mutant cells. Furthermore, mice transplanted with leukemia cells expressing mutant U2AF1 had significantly reduced tumor burden and improved survival after the wild-type U2af1 allele was deleted compared to when it was not deleted. These results suggest that selectively targeting the wild-type U2AF1 allele in heterozygous mutant cells could induce cancer cell death and be a therapeutic strategy for patients harboring U2AF1 mutations.

cancer biology↗

bioRxiv2020

Human SYNGAP1 Regulates the Development of Neuronal Activity by Controlling Dendritic and Synaptic Maturation

SYNGAP1 is a major genetic risk factor for global developmental delay, autism spectrum disorder, and epileptic encephalopathy. De novo loss-of-function variants in this gene cause a neurodevelopmental disorder defined by cognitive impairment, social-communication disorder, and early-onset seizures. Cell biological studies in mouse and rat neurons have shown that Syngap1 regulates developing excitatory synapse structure and function, with loss-of-function variants driving formation of larger dendritic spines and stronger glutamatergic transmission. However, studies to date have been limited to mouse and rat neurons. Therefore, it remains unknown how SYNGAP1 loss-of-function impacts the development and function of human neurons. To address this, we employed CRISPR/Cas9 technology to ablate SYNGAP1 protein expression in neurons derived from a human induced pluripotent stem cell line (hiPSC). Reducing SynGAP protein expression in developing hiPSC-derived neurons enhanced dendritic morphogenesis, leading to larger neurons compared to those derived from isogenic controls. Consistent with larger dendritic fields, we also observed a greater number of morphologically defined excitatory synapses in cultures containing these neurons. Moreover, neurons with reduced SynGAP protein had stronger excitatory synapses and expressed synaptic activity earlier in development. Finally, distributed network spiking activity appeared earlier, was substantially elevated, and exhibited greater bursting behavior in SYNGAP1 null neurons. We conclude that SYNGAP1 regulates the postmitotic maturation of human neurons made from hiPSCs, which influences how activity develops within nascent neural networks. Alterations to this fundamental neurodevelopmental process may contribute to the etiology of SYNGAP1-related disorders.

neuroscience↗

bioRxiv2020

Syngap1 Dynamically Regulates the Fine-Scale Reorganization of Cortical Circuits in Response to Sensory Experience

Experience induces complex, neuron-specific changes in population activity within sensory cortex circuits. However, the mechanisms that enable neuron-specific changes within cortical populations remain unclear. To explore the idea that synapse strengthening is involved, we studied fine-scale cortical plasticity in Syngap1 mice, a neurodevelopmental disorder model useful for linking synapse biology to circuit functions. Repeated functional imaging of the same L2/3 somatosensory cortex neurons during single whisker experience revealed that Syngap1 selectively regulated the plasticity of a low-active, or "silent", neuronal subpopulation. Syngap1 also regulated spike-timing-dependent synaptic potentiation and experience-mediated in vivo synapse bouton formation, but not synaptic depression or bouton elimination in L2/3. Adult re-expression of Syngap1 restored plasticity of "silent" neurons, demonstrating that this gene controls dynamic cellular processes required for population-specific changes to cortical circuits during experience. These findings suggest that abnormal experience-dependent redistribution of cortical population activity may contribute to the etiology of neurodevelopmental disorders.

neuroscience↗

bioRxiv2020

Splicing of the SynGAP Carboxyl-Terminus Enables Isoform-Specific Tuning of NMDA Receptor Signaling Linked to Cognitive Function

SynGAP-1 is a splice variant of the neurodevelopmental disorder risk gene, SYNGAP1/Syngap1. 1 encodes the C-terminal PDZ binding motif (PBM) that promotes liquid-liquid phase separation, a candidate process for postsynaptic density organization within excitatory synapses. However, it remains unknown how the endogenous SynGAP PBM regulates synapse properties and related cognitive functions. We found that a major PBM function in mice is to limit the mobility of SynGAP-1 in response to NMDA receptor activation. Genetic disruption of the PBM increased SynGAP-1 mobility to levels consistent with other non-PBM-containing C-terminal isoforms. This resulted in a lowering of the threshold for NMDA receptor-dependent signaling required for plasticity, leading to aberrant strengthening of excitatory synapses in spontaneously active neurons. PBM-deficient animals also exhibited a lower seizure threshold, disrupted LTP, and impaired cognition. Thus, the PBM enables isoform-specific SynGAP gating of NMDA receptor function, a mechanism linking synaptic signaling dynamics to network excitability and cognition.

neuroscience↗

bioRxiv2020

A Simple and Robust Cell Based Assay for the Discovery of Novel Cytokinesis Inhibitors

Cytokinesis is the last step of mitotic cell division that separates the cytoplasm of dividing cells. Small molecule inhibitors targeting either the elements of the regulatory pathways controlling cytokinesis, or the terminal effectors have been of interest as potential drug candidates for the treatment of various diseases. Here we have developed a cell-based assay for the discovery of novel cytokinesis inhibitors. The assay is performed in a 96-well plate format in 48 hours. Living cells, nuclei and nuclei of dead cells are revealed by a single staining step with three fluorescent dyes, followed by live cell imaging using an automated fluorescence microscope. The primary signal is the nuclei-to-cell ratio (NCR). In the presence of cytokinesis inhibitors, this ratio is expected to increase over time, as the ratio of multinucleated cells increases in the population. Cytotoxicity is quantified as the ratio of dead nuclei to total nuclei. A screening window coefficient (Z) of 0.65 indicates that the assay is suitable for screening purposes, as the positive and negative controls are well-separated. EC50 values for four compounds can be reliably determined in a single 96-well plate by using only six different compound concentrations. An excellent test-retest reliability (R2=0.998) was found for EC50 values covering a [~]1500-fold range of potencies. The robustness, simplicity and flexibility of the assay is demonstrated here by using modulators of actin dynamics with different mechanisms of action (jasplakinolide, cytochalasin D and swinholide A) and derivatives of the nonmuscle myosin II inhibitor blebbistatin.

cell biology↗

bioRxiv2019

Homologous laminar organization of the mouse and human subiculum

The subiculum is the major output structure of the hippocampal formation and one of the brain regions most affected by Alzheimers disease. Our previous work revealed a hidden laminar architecture within the mouse subiculum. However, the rotation of the hippocampal longitudinal axis across species makes it unclear how the laminar organization is represented in human subiculum. Using in situ hybridization data from the Allen Human Brain Atlas, we demonstrate that the human subiculum also contains complementary laminar gene expression patterns similar to the mouse. In addition, we provide evidence that the molecular domain boundaries in human subiculum correspond to microstructural differences observed in high resolution MRI and fiber density imaging. Finally, we show both similarities and differences in the gene expression profile of subiculum pyramidal cells within homologous lamina. Overall, we present a new 3D model of the anatomical organization of human subiculum and its evolution from the mouse.

neuroscience↗

bioRxiv2019

Methamphetamine learning induces persistent nonmuscle myosin II-dependent spine motility in the basolateral amygdala

Nonmuscle myosin II inhibition (NMIIi) in the basolateral amygdala (BLA) selectively disrupts memories associated with methamphetamine (METH) days after learning, without retrieval. However, the molecular mechanisms underlying this selective vulnerability remain poorly understood. A known function of NMII is to transiently activate dendritic spine actin dynamics with learning. Therefore, we hypothesized that METH-associated learning perpetuates NMII-driven actin dynamics in dendritic spines, leading to an extended window of vulnerability for memory disruption. Two-photon imaging of actin-mediated spine motility in neurons from memory-related structures, BLA and CA1, revealed a persistent increase in spine motility after METH-associated learning that was restricted to BLA neurons. METH-induced changes to BLA spine dynamics were reversed by a single systemic injection of an NMII inhibitor. Thus, a perpetual form of NMII-driven spine actin dynamics in BLA neurons may contribute to the unique susceptibility of METH-associated memories.

neuroscience↗

bioRxiv2019

microRNA mir-598-3p mediates susceptibility to stress-enhancement of remote fear memory

microRNAs (miRNAs) have emerged as potent regulators of learning, recent memory and extinction. However, our understanding of miRNAs directly involved in regulating complex psychiatric conditions perpetuated by aberrant memory, such as in posttraumatic stress disorder (PTSD), remains limited. To begin to address the role of miRNAs in persistent memory, we performed small-RNA sequencing on basolateral amygdala (BLA) tissue to identify miRNAs altered by auditory fear conditioning (FC) one month after training. mir-598-3p, a highly conserved miRNA previously unstudied in the brain, was downregulated in the BLA. Further decreasing BLA mir-598-3p levels did not alter the expression or extinction of the remote fear memory. Given that stress is a critical component in PTSD, we next assessed the impact of stress-enhanced fear learning (SEFL) on mir-598-3p levels, finding the miRNA is elevated in the BLA of male, but not female, mice susceptible to the effects of stress in SEFL. Accordingly, intra-BLA inhibition of mir-598-3p interfered with expression and extinction of the remote fear memory in male, but not female, mice. This effect could not be attributed to an anxiolytic effect of miRNA inhibition. Finally, bioinformatic analysis following quantitative proteomics on BLA tissue collected 30 days post-SEFL training identified putative mir-598-3p targets and related pathways mediating the differential susceptibility, with evidence for regulation of the actin cytoskeleton.

neuroscience↗

bioRxiv2018

pVACtools: a computational toolkit to select and visualize cancer neoantigens

The elucidation of neoantigens is a critical step in predicting response to checkpoint blockade therapy and design of personalized cancer vaccines. We have developed an in silico sequence analysis method - pVACtools, to facilitate comprehensive neoantigen characterization. This modular workflow consists of tools for neoantigen prediction from somatic alterations (pVACseq and pVACfuse), prioritization and selection using a graphical web-based interface (pVACviz), and determining the optimal order of neoantigen candidates in a DNA vector-based vaccine(pVACvector).

bioinformatics↗

bioRxiv2018

Bioinformatic analysis of long-lasting transcriptional and translational changes in the basolateral amygdala following acute stress

Stress profoundly impacts the brain and increases the risk of developing a psychiatric disorder. The brains response to stress is mediated by a number of pathways that affect gene expression and protein function throughout the cell. Understanding how stress achieves such dramatic effects on the brain requires an understanding of the brains stress response pathways. The majority of studies focused on molecular changes have employed repeated or chronic stress paradigms to assess the long-term consequences of stress and have not taken an integrative genomic and/or proteomic approach. Here, we determined the lasting impact of a single stressful event (restraint) on the broad molecular profile of the basolateral amygdala complex (BLC), a key brain region mediating emotion, memory and stress. Molecular profiling performed thirty days post-restraint consisted of small RNA sequencing, RNA sequencing and quantitative mass spectrometry and identified long-lasting changes in microRNA (miRNA), messenger RNA (mRNA) and proteins. Alignment of the three datasets further delineated the regulation of stress-specific pathways which were validated by qPCR and Western Blot analysis. From this analysis, mir-29a-5p was identified as a putative regulator of stress-induced adaptations in the BLC. Further, a number of predicted mir-29a-5p targets are regulated at the mRNA and protein level. The concerted and long-lasting disruption of multiple molecular pathways in the amygdala by a single stress event is expected to be sufficient to alter behavioral responses to a wide array of future experiences, including exposure to additional stressors.

neuroscience↗

bioRxiv2018

Re-expression of SynGAP Protein in Adulthood Improves Translatable Measures of Brain Function and Behavior in a Model of Neurodevelopmental Disorders

BackgroundNeurodevelopmental disorder (NDD) risk genes have pleiotropic biological functions, such as control over both developmental and non-developmental processes that influence disease-related phenotypes. Currently, it remains unclear how developmental versus non-developmental processes influence the duration and/or effectiveness of permissive treatment windows for NDDs. SYNGAP1 haploinsufficiency causes an NDD defined by autistic traits, cognitive impairment, and epilepsy. Syngap1 heterozygosity in mice disrupts a developmental critical period, and, consistent with this, certain behavioral abnormalities are resistant to gene therapy initiated in adulthood. However, the Syngap1 endophenotype is extensive and this protein has diverse cell biological functions. Therefore, SynGAP pleiotropy may influence the permissive treatment window for previously untested disease-relevant phenotypes.\n\nMethodsA whole-body gene restoration technique was used to determine how restoration of SynGAP protein in adult heterozygous mice impacted previously untested phenotypes, such as memory, seizure susceptibility, systems-level cortical hyperexcitability, and hippocampal oscillations linked to mnemonic processes.\n\nResultsAdult restoration of SynGAP protein in haploinsufficient mice reversed long-term contextual memory deficits and behavioral measures of seizure susceptibility. Moreover, SynGAP re-expression in adult mice eliminated brain state-dependent, patient-linked paroxysmal interictal spiking and increased the amplitude of hippocampal theta oscillations.\n\nConclusionsSynGAP protein in the mature brain dynamically regulates neural circuit function and influences disease-relevant phenotypes. The impact of these findings is that treatments targeting certain debilitating aspects of SYNGAP1-related disorders may be effective throughout life. Moreover, the efficacy of experimental treatments for SYNGAP1 patients may be quantifiable through changes in species-conserved, state-dependent pathological electroencephalogram signals.

neuroscience↗

bioRxiv2018

Mutation detection in thousands of acute myeloid leukemia cells using single cell RNA-sequencing

Virtually all tumors are genetically heterogeneous, containing subclonal populations of cells that are defined by distinct mutations1. Subclones can have unique phenotypes that influence disease progression2, but these phenotypes are difficult to characterize: subclones usually cannot be physically purified, and bulk gene expression measurements obscure interclonal differences. Single-cell RNA-sequencing has revealed transcriptional heterogeneity within a variety of tumor types, but it is unclear how this expression heterogeneity relates to subclonal genetic events - for example, whether particular expression clusters correspond to mutationally defined subclones3,4,5,6-9. To address this question, we developed an approach that integrates enhanced whole genome sequencing (eWGS) with the 10x Genomics Chromium Single Cell 5 Gene Expression workflow (scRNA-seq) to directly link expressed mutations with transcriptional profiles at single cell resolution. Using bone marrow samples from five cases of primary human Acute Myeloid Leukemia (AML), we generated WGS and scRNA-seq data for each case. Duplicate single cell libraries representing a median of 20,474 cells per case were generated from the bone marrow of each patient. Although the libraries were 5 biased, we detected expressed mutations in cDNAs at distances up to 10 kbp from the 5 ends of well-expressed genes, allowing us to identify hundreds to thousands of cells with AML-specific somatic mutations in every case. This data made it possible to distinguish AML cells (including normal-karyotype AML cells) from surrounding normal cells, to study tumor differentiation and intratumoral expression heterogeneity, to identify expression signatures associated with subclonal mutations, and to find cell surface markers that could be used to purify subclones for further study. The data also revealed transcriptional heterogeneity that occurred independently of subclonal mutations, suggesting that additional factors drive epigenetic heterogeneity. This integrative approach for connecting genotype to phenotype in AML cells is broadly applicable for analysis of any sample that is phenotypically and genetically heterogeneous.

cancer biology↗

bioRxiv2017

The prognostic effects of somatic mutations in ER-positive breast cancer

More than 50 genes are recurrently affected by somatic mutation in estrogen receptor positive (ER+) breast cancer but prognostic effects have not been definitively established. Primary tumor DNA was therefore subjected to targeted sequencing from 625 postmenopausal (UBC-TAM series) and 328 premenopausal (MA12 trial) hormone receptor-positive (HR+) patients. Independent validation of prognostic interactions was achieved using independent data from the METABRIC study. Associations between MAP3K1 and PIK3CA with luminal A status and TP53 mutations with Luminal B/non-luminal tumors were observed, validating the methodological approach. In UBC-TAM, NF1 frame-shift nonsense (FS/NS) mutation was validated as a poor outcome driver. For MA12, poor outcome associated with PIK3R1 mutation was similarly validated. DDR1 mutations were strongly associated with poor prognosis in UBC-TAM despite stringent false-discovery correction (q=0.0003). In conclusion, uncommon recurrent somatic mutations should be further explored to create a more complete explanation of the highly variable outcomes that typify ER+ breast cancer.

genomics↗

bioRxiv2017

Temporal and Clonal Progression in a Pediatric Ependymoma Patient Through Multiple Treatments

BackgroundMultiple recurrences after complete resection and irradiation of supratentorial ependymoma are common and frequently result in patient death. However, the molecular basis for treatment resistance, the impact that radiation and other adjuvant therapies have in promoting recurrence, and the use of this information to rationally design effective approaches to treat recurrent ependymoma are unknown. Due to the rarity of these tumors and the even less likely banking of multiple recurrent samples from the same patient, we initiated a study to characterize the evolution of a single patients ependymoma in response to therapy.\n\nMethods and FindingsA combination of high depth, whole genome and exome-based DNA sequencing of germline and tumor specimens, RNA sequencing of tumor specimens, and advanced computational analyses were employed to reconstruct the natural history of a supratentorial ependymoma case in which there were four local recurrences. The findings reveal the extent to which treatment with radiation and chemotherapies resulted in the diversification of the tumor subclonal architecture and shaped the neo-antigen landscape, and provide new insights into possible molecular mechanisms of oncogenesis, treatment response and recurrence.\n\nConclusionsAlthough the recurrent tumors we studied were clearly shaped by therapy, the founding clone was never eradicated by any treatment. We conclude that DNA and RNA sequencing may provide critical prognostic indicators to identify ependymoma patients that should be observed, rather than irradiated, post gross total resection.

cancer biology↗