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1.
Asian J Neurosurg ; 18(2): 396-399, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37397046

RESUMO

Astroblastoma is a rare tumor, which is mostly found in pediatric population. Due to scarcity of literature, the data about treatment is lacking. We are reporting case of brainstem astroblastoma in an adult female. A 45-year-old lady presented with complaint of headache, vertigo, vomiting, and nasal regurgitation for 3 months. On examination, she had weak gag, left hemiparesis. Magnetic resonance imaging brain reported medulla oblongata mass, dorsally exophytic. She underwent suboccipital craniotomy and decompression of mass. Histopathology confirmed diagnosis of astroblastoma. She underwent radiotherapy and recovered well. Brainstem astroblastoma is an extremely rare entity. The surgical resection is possible due to well-defined plane. For best outcome, maximum resection and radiation are indicated.

2.
Cell Genom ; 3(7): 100340, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37492101

RESUMO

Pediatric brain and spinal cancers are collectively the leading disease-related cause of death in children; thus, we urgently need curative therapeutic strategies for these tumors. To accelerate such discoveries, the Children's Brain Tumor Network (CBTN) and Pacific Pediatric Neuro-Oncology Consortium (PNOC) created a systematic process for tumor biobanking, model generation, and sequencing with immediate access to harmonized data. We leverage these data to establish OpenPBTA, an open collaborative project with over 40 scalable analysis modules that genomically characterize 1,074 pediatric brain tumors. Transcriptomic classification reveals universal TP53 dysregulation in mismatch repair-deficient hypermutant high-grade gliomas and TP53 loss as a significant marker for poor overall survival in ependymomas and H3 K28-mutant diffuse midline gliomas. Already being actively applied to other pediatric cancers and PNOC molecular tumor board decision-making, OpenPBTA is an invaluable resource to the pediatric oncology community.

3.
Artigo em Inglês | MEDLINE | ID: mdl-36307212

RESUMO

Angiosarcomas are rare, malignant soft tissue tumors in children that arise in a wide range of anatomical locations and have limited targeted therapies available. Here, we report a rare case of a pediatric angiosarcoma (pAS) with Li-Fraumeni syndrome (LFS) expressing a novel NOTCH1-ROS1 gene fusion. Although both NOTCH1 and ROS1 are established proto-oncogenes, our study is the first to describe the mechanistic role of NOTCH1-ROS1 fusion arising via intrachromosomal rearrangement. NOTCH1-ROS1 displayed potent neoplastic transformation propensity in vitro, and harbors tumorigenic potential in vivo, where it induced oncogenic activation of the MAPK, PI3K/mTOR, and JAK-STAT signaling pathways in a murine allograft model. We found an unexpected contribution of the NOTCH1 extracellular region in mediating NOTCH1-ROS1 activation and oncogenic function, highlighting the contribution of both NOTCH1 and ROS1 fusion partners in driving tumorigenicity. Interestingly, neither membrane localization nor fusion protein dimerization were found to be essential for NOTCH1-ROS1 fusion oncogenicity. To target NOTCH1-ROS1-driven tumors, we tested both NOTCH1-directed inhibitors and ROS1-targeted tyrosine kinase inhibitors (TKI) in heterologous models (NIH3T3, Ba/F3). Although NOTCH1 inhibitors did not suppress NOTCH1-ROS1-driven oncogenic growth, we found that oral entrectinib treatment effectively suppressed the growth of NOTCH-ROS1-driven tumors. Taken together, we report the first known pAS case with a novel NOTCH1-ROS1 alteration along with a detailed report on the function and therapeutic targeting of NOTCH1-ROS1. Our study highlights the importance of genomic profiling of rare cancers such as pAS to reveal actionable drivers and improve patient outcomes.


Assuntos
Hemangiossarcoma , Proteínas Tirosina Quinases , Criança , Humanos , Camundongos , Animais , Proteínas Tirosina Quinases/genética , Proteínas Tirosina Quinases/metabolismo , Hemangiossarcoma/tratamento farmacológico , Hemangiossarcoma/genética , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas/genética , Células NIH 3T3 , Fusão Gênica , Receptor Notch1/genética
4.
Clin Cancer Res ; 28(18): 3965-3978, 2022 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-35852795

RESUMO

PURPOSE: PNOC003 is a multicenter precision medicine trial for children and young adults with newly diagnosed diffuse intrinsic pontine glioma (DIPG). PATIENTS AND METHODS: Patients (3-25 years) were enrolled on the basis of imaging consistent with DIPG. Biopsy tissue was collected for whole-exome and mRNA sequencing. After radiotherapy (RT), patients were assigned up to four FDA-approved drugs based on molecular tumor board recommendations. H3K27M-mutant circulating tumor DNA (ctDNA) was longitudinally measured. Tumor tissue and matched primary cell lines were characterized using whole-genome sequencing and DNA methylation profiling. When applicable, results were verified in an independent cohort from the Children's Brain Tumor Network (CBTN). RESULTS: Of 38 patients enrolled, 28 patients (median 6 years, 10 females) were reviewed by the molecular tumor board. Of those, 19 followed treatment recommendations. Median overall survival (OS) was 13.1 months [95% confidence interval (CI), 11.2-18.4] with no difference between patients who followed recommendations and those who did not. H3K27M-mutant ctDNA was detected at baseline in 60% of cases tested and associated with response to RT and survival. Eleven cell lines were established, showing 100% fidelity of key somatic driver gene alterations in the primary tumor. In H3K27-altered DIPGs, TP53 mutations were associated with worse OS (TP53mut 11.1 mo; 95% CI, 8.7-14; TP53wt 13.3 mo; 95% CI, 11.8-NA; P = 3.4e-2), genome instability (P = 3.1e-3), and RT resistance (P = 6.4e-4). The CBTN cohort confirmed an association between TP53 mutation status, genome instability, and clinical outcome. CONCLUSIONS: Upfront treatment-naïve biopsy provides insight into clinically relevant molecular alterations and prognostic biomarkers for H3K27-altered DIPGs.


Assuntos
Astrocitoma , Neoplasias do Tronco Encefálico , DNA Tumoral Circulante , Glioma Pontino Intrínseco Difuso , Glioma , Biologia , Biomarcadores , Neoplasias do Tronco Encefálico/genética , Neoplasias do Tronco Encefálico/metabolismo , Neoplasias do Tronco Encefálico/terapia , Criança , DNA Tumoral Circulante/genética , Glioma Pontino Intrínseco Difuso/genética , Feminino , Instabilidade Genômica , Glioma/genética , Glioma/metabolismo , Glioma/terapia , Humanos , Adulto Jovem
5.
Saudi J Anaesth ; 16(2): 194-199, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35431746

RESUMO

Background: Facial area is one of the most frequently injured area of the body, accounting for 23-97% of all facial fractures. Treatments under general anesthesia as those for maxillofacial fractures or infections is a highly complicated and a major challenging task in trismus associated patients. The main culprit in trismus is the increase muscle tone of masticatory muscles which are supplied via the mandibular nerve, blocking which could help increase the mouth opening thus, changing the whole of airway management. Material and Method: A prospective study was done on 50 patients of ASA grade I-II with unilateral mandibular fracture with trismus posted for maxillofacial surgery. Mandibular nerve block was given via extraoral approach with 5 ml of 0.5% bupivacaine using peripheral nerve stimulator to determine the difference in Pre block and Post block mouth opening and the VAS score at 2, 5, 10, 15, 20, 25, and 30 minutes. Results: The Interincisor distance measured Pre block was 1.20 ± 0.32 mm and was significantly increased after 5 mins onwards from the block (P < 0.005). The VAS score determined Pre block was 5.14 ± 1.37 which significantly decreased just 2 minutes after the application of block (P < 0.005). Conclusion: Mandibular nerve block decreases the pain and will aid in the decision making by an anesthetist regarding airway management as it helps in increasing the inter incisor distance significantly. Moreover, given the feasibility and effectiveness of the block it could be included in standard of care protocol for mandibular fracture patients.

6.
Indian J Anaesth ; 65(Suppl 4): S149-S155, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34908566

RESUMO

BACKGROUND AND AIMS: The pain following total abdominal hysterectomy (TAH), a very commonly performed gynaecological surgery, is usually taken care of by various opioids, non-opioids, regional and peripheral nerve blocks. Erector spinae plane block (ESPB) under ultrasound guidance is a relatively new approach for postoperative analgesia in thoracic and abdominal surgeries. Ultrasound availability and expertise to use it is a limitation at times. The primary aim of this study was to determine the analgesic efficacy of ESPB using peripheral nerve stimulation (PNS) technique in patients undergoing TAH. METHODS: A total of 60 American Society of Anesthesiologists physical status I and II female patients were posted for abdominal hysterectomy after obtaining ethical committee clearance in a tertiary care centre. Group I (n = 30) received spinal anaesthesia, whereas Group II (n = 30) received ESPB under peripheral nerve stimulator (PNS) guidance with 20 mL of 0.375% ropivacaine before spinal anaesthesia. Post-operative pain intensity reported using the Visual Analogue Scale (VAS) was considered as the primary outcome. The haemodynamic variables, total duration before the first rescue analgesia, total consumption of tramadol, level of satisfaction regarding analgesia and any complications were considered as secondary outcomes. The data were recorded in an excel sheet, and analysis was performed using the Statistical Package for the Social Sciences version 23.0. RESULTS: VAS score was significantly lower (P < 0.001) in Group II at 0, 1, 2, 3, 4, 6, 12, 18 and 24 h post-operatively. The total dose of rescue analgesia was significantly reduced in the ESPB group. CONCLUSION: PNS-guided ESPB is effective in relieving pain in patients undergoing TAH.

7.
Pediatr Blood Cancer ; 68(6): e28933, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33565241

RESUMO

Pediatric histiocytic neoplasms are hematopoietic disorders frequently driven by the BRAF-V600E mutation. Here, we identified two BRAF gene fusions (novel MTAP-BRAF and MS4A6A-BRAF) in two aggressive histiocytic neoplasms. In contrast to previously described BRAF fusions, MTAP-BRAF and MS4A6A-BRAF do not respond to the paradox breaker RAF inhibitor (RAFi) PLX8394 due to stable fusion dimerization mediated by the N-terminal fusion partners. This highlights a significant and clinically relevant shift from the current dogma that BRAF-fusions respond similarly to BRAF-inhibitors. As an alternative, we show suppression of fusion-driven oncogenic growth with the pan-RAFi LY3009120 and MEK inhibition.


Assuntos
Histiocitose , Neoplasias , Linhagem Celular Tumoral , Criança , Humanos , Mutação , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/genética
8.
BMC Bioinformatics ; 21(1): 577, 2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33317447

RESUMO

BACKGROUND: Gene fusion events are significant sources of somatic variation across adult and pediatric cancers and are some of the most clinically-effective therapeutic targets, yet low consensus of RNA-Seq fusion prediction algorithms makes therapeutic prioritization difficult. In addition, events such as polymerase read-throughs, mis-mapping due to gene homology, and fusions occurring in healthy normal tissue require informed filtering, making it difficult for researchers and clinicians to rapidly discern gene fusions that might be true underlying oncogenic drivers of a tumor and in some cases, appropriate targets for therapy. RESULTS: We developed annoFuse, an R package, and shinyFuse, a companion web application, to annotate, prioritize, and explore biologically-relevant expressed gene fusions, downstream of fusion calling. We validated annoFuse using a random cohort of TCGA RNA-Seq samples (N = 160) and achieved a 96% sensitivity for retention of high-confidence fusions (N = 603). annoFuse uses FusionAnnotator annotations to filter non-oncogenic and/or artifactual fusions. Then, fusions are prioritized if previously reported in TCGA and/or fusions containing gene partners that are known oncogenes, tumor suppressor genes, COSMIC genes, and/or transcription factors. We applied annoFuse to fusion calls from pediatric brain tumor RNA-Seq samples (N = 1028) provided as part of the Open Pediatric Brain Tumor Atlas (OpenPBTA) Project to determine recurrent fusions and recurrently-fused genes within different brain tumor histologies. annoFuse annotates protein domains using the PFAM database, assesses reciprocality, and annotates gene partners for kinase domain retention. As a standard function, reportFuse enables generation of a reproducible R Markdown report to summarize filtered fusions, visualize breakpoints and protein domains by transcript, and plot recurrent fusions within cohorts. Finally, we created shinyFuse for algorithm-agnostic interactive exploration and plotting of gene fusions. CONCLUSIONS: annoFuse provides standardized filtering and annotation for gene fusion calls from STAR-Fusion and Arriba by merging, filtering, and prioritizing putative oncogenic fusions across large cancer datasets, as demonstrated here with data from the OpenPBTA project. We are expanding the package to be widely-applicable to other fusion algorithms and expect annoFuse to provide researchers a method for rapidly evaluating, prioritizing, and translating fusion findings in patient tumors.


Assuntos
Fusão Gênica , Neoplasias/genética , RNA/metabolismo , Software , Algoritmos , Humanos , Neoplasias/patologia , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , RNA/genética
9.
Elife ; 92020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32155117

RESUMO

The Polycomb-like protein PHF19/PCL3 associates with PRC2 and mediates its recruitment to chromatin in embryonic stem cells. PHF19 is also overexpressed in many cancers. However, neither PHF19 targets nor misregulated pathways involving PHF19 are known. Here, we investigate the role of PHF19 in prostate cancer cells. We find that PHF19 interacts with PRC2 and binds to PRC2 targets on chromatin. PHF19 target genes are involved in proliferation, differentiation, angiogenesis, and extracellular matrix organization. Depletion of PHF19 triggers an increase in MTF2/PCL2 chromatin recruitment, with a genome-wide gain in PRC2 occupancy and H3K27me3 deposition. Transcriptome analysis shows that PHF19 loss promotes deregulation of key genes involved in growth, metastasis, invasion, and of factors that stimulate blood vessels formation. Consistent with this, PHF19 silencing reduces cell proliferation, while promotes invasive growth and angiogenesis. Our findings reveal a role for PHF19 in controlling the balance between cell proliferation and invasiveness in prostate cancer.


Assuntos
Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica/fisiologia , Neoplasias da Próstata/metabolismo , Fatores de Transcrição/metabolismo , Fosfatos de Cálcio/metabolismo , Diferenciação Celular , Linhagem Celular , Proteínas de Ligação a DNA/genética , Técnicas de Silenciamento de Genes , Estudo de Associação Genômica Ampla , Humanos , Masculino , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Neoplasias da Próstata/genética , Fatores de Transcrição/genética
10.
J Neuropathol Exp Neurol ; 78(12): 1100-1111, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31617914

RESUMO

Dysembryoplastic neuroepithelial tumors (DNT) lacking key diagnostic criteria are challenging to diagnose and sometimes fall into the broader category of mixed neuronal-glial tumors (MNGT) or the recently described polymorphous low-grade neuroepithelial tumor of the young (PLNTY). We examined 41 patients with DNT, MNGT, or PLNTY for histologic features, genomic findings, and progression-free survival (PFS). Genomic analysis included sequence and copy number variants and RNA-sequencing. Classic DNT (n = 26) was compared with those with diffuse growth without cortical nodules (n = 15), 6 of which exhibited impressive CD34 staining classifying them as PLNTY. Genomic analysis was complete in 33, with sequence alterations recurrently identified in BRAF, FGFR1, NF1, and PDGFRA, as well as 7 fusion genes involving FGFR2, FGFR1, NTRK2, and BRAF. Genetic alterations did not distinguish between MNGTs, DNTs, or PLNTYs; however, FGFR1 alterations were confined to DNT, and PLNTYs contained BRAF V600E or FGFR2 fusion genes. Analysis of PFS showed no significant difference by histology or genetic alteration; however, numbers were small and follow-up time short. Further molecular characterization of a PLNTY-related gene fusion, FGFR2-CTNNA3, demonstrated oncogenic potential via MAPK/PI3K/mTOR pathway activation. Overall, DNT-MNGT spectrum tumors exhibit diverse genomic alterations, with more than half (19/33) leading to MAPK/PI3K pathway alterations.


Assuntos
Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Sistema de Sinalização das MAP Quinases , Neoplasias Neuroepiteliomatosas/genética , Neoplasias Neuroepiteliomatosas/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Adolescente , Adulto , Encéfalo/patologia , Neoplasias Encefálicas/metabolismo , Criança , Pré-Escolar , Feminino , Genômica , Humanos , Masculino , Neoplasias Neuroepiteliomatosas/metabolismo , Intervalo Livre de Progressão , Adulto Jovem
11.
Pediatr Dev Pathol ; 22(6): 594-598, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31335288

RESUMO

Sclerosing epithelioid fibrosarcoma (SEF) is an uncommon neoplasm that rarely presents in bone. It is characterized by epithelioid cells arranged in nests and single-file cords within a sclerotic stromal background which may mimic neoplastic bone. SEF harbors an EWSR1 translocation, which may complicate its distinction from Ewing sarcoma in cases with histomorphologic overlap. We present a diagnostically challenging case of SEF in the mandible of a 16-year-old girl. Our experience highlights the lack of specificity of traditional morphology and EWSR1 break-apart fluorescent in situ hybridization. Open-ended RNA-based fusion gene testing coupled with MUC4 immunohistochemistry aided the eventual diagnosis in this case. Herein, we report the third case of SEF with EWSR1-CREB3L3 translocation and show that this fusion leads to aberrant upregulation of the phosphoinositide 3-kinase/mammalian target of rapamycin signaling pathway in heterologous cell models.


Assuntos
Biomarcadores Tumorais/genética , Fibrossarcoma/genética , Neoplasias Mandibulares/genética , Proteínas de Fusão Oncogênica/genética , Fosfatidilinositol 3-Quinase/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Translocação Genética , Adolescente , Feminino , Fibrossarcoma/diagnóstico , Fibrossarcoma/metabolismo , Fibrossarcoma/patologia , Humanos , Neoplasias Mandibulares/diagnóstico , Neoplasias Mandibulares/metabolismo , Neoplasias Mandibulares/patologia , Transdução de Sinais , Regulação para Cima
12.
Int J Cancer ; 145(7): 1889-1901, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30861105

RESUMO

This clinical trial evaluated whether whole exome sequencing (WES) and RNA sequencing (RNAseq) of paired normal and tumor tissues could be incorporated into a personalized treatment plan for newly diagnosed patients (<25 years of age) with diffuse intrinsic pontine glioma (DIPG). Additionally, whole genome sequencing (WGS) was compared to WES to determine if WGS would further inform treatment decisions, and whether circulating tumor DNA (ctDNA) could detect the H3K27M mutation to allow assessment of therapy response. Patients were selected across three Pacific Pediatric Neuro-Oncology Consortium member institutions between September 2014 and January 2016. WES and RNAseq were performed at diagnosis and recurrence when possible in a CLIA-certified laboratory. Patient-derived cell line development was attempted for each subject. Collection of blood for ctDNA was done prior to treatment and with each MRI. A specialized tumor board generated a treatment recommendation including up to four FDA-approved agents based upon the genomic alterations detected. A treatment plan was successfully issued within 21 business days from tissue collection for all 15 subjects, with 14 of the 15 subjects fulfilling the feasibility criteria. WGS results did not significantly deviate from WES-based therapy recommendations; however, WGS data provided further insight into tumor evolution and fidelity of patient-derived cell models. Detection of the H3F3A or HIST1H3B K27M (H3K27M) mutation using ctDNA was successful in 92% of H3K27M mutant cases. A personalized treatment recommendation for DIPG can be rendered within a multicenter setting using comprehensive next-generation sequencing technology in a clinically relevant timeframe.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias do Tronco Encefálico/tratamento farmacológico , Glioma Pontino Intrínseco Difuso/tratamento farmacológico , Sequenciamento do Exoma/métodos , Análise de Sequência de RNA/métodos , Sequenciamento Completo do Genoma/métodos , Adolescente , Adulto , Neoplasias do Tronco Encefálico/genética , Criança , Pré-Escolar , DNA Tumoral Circulante , Glioma Pontino Intrínseco Difuso/genética , Estudos de Viabilidade , Feminino , Histonas/genética , Humanos , Masculino , Terapia de Alvo Molecular/métodos , Projetos Piloto , Medicina de Precisão , Adulto Jovem
13.
Hum Gene Ther ; 30(2): 168-178, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30024272

RESUMO

T cells made with messenger RNA (mRNA) encoding chimeric antigen receptor (CAR) offer a safe alternative to those transduced with viral CARs by mitigating the side effects of constitutively active T cells. Previous studies have shown that mRNA CAR T cells are transiently effective but lack persistence and potency across tumor types. It was hypothesized that the efficacy of mRNA CARs could be improved by utilizing recent advancements in RNA technology, such as incorporating a modified nucleoside, 1-methylpseudouridine, into the mRNA and applying a novel purification method using RNase III to eliminate dsRNA contaminants. T cells electroporated with nucleoside-modified and purified mRNA encoding CD19 CAR showed an initial twofold increase in CAR surface expression, as well as a twofold improvement in cytotoxic killing of leukemia cells that persisted up to 5 days. T cells generated with nucleoside-modified and purified CAR mRNA also showed reduced expression of checkpoint regulators and a differential pattern of genetic activation compared to those made with conventional mRNA. In vivo studies using a leukemia mouse model revealed that the most robust 100-fold suppression of leukemic burden was achieved using T cells electroporated with purified mRNAs, regardless of their nucleoside modification. The results provide a novel approach to generate mRNA for clinical trials, and poise mRNA CAR T cells for increased efficacy during testing as new CAR targets emerge.


Assuntos
Transferência Adotiva , Eletroporação , Leucemia , RNA Mensageiro , Receptores de Antígenos Quiméricos , Linfócitos T/imunologia , Animais , Antígenos CD19/genética , Antígenos CD19/imunologia , Linhagem Celular Tumoral , Humanos , Leucemia/genética , Leucemia/imunologia , Leucemia/patologia , Leucemia/terapia , Camundongos , Camundongos Endogâmicos NOD , Camundongos Knockout , Camundongos SCID , RNA Mensageiro/genética , RNA Mensageiro/imunologia , RNA Mensageiro/isolamento & purificação , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/imunologia , Linfócitos T/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Bone ; 109: 91-100, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28780023

RESUMO

Gain-of-function mutations in the Type I Bone Morphogenic Protein (BMP) receptor ACVR1 have been identified in two diseases: Fibrodysplasia Ossificans Progressiva (FOP), a rare autosomal dominant disorder characterized by genetically driven heterotopic ossification, and in 20-25% of Diffuse Intrinsic Pontine Gliomas (DIPGs), a pediatric brain tumor with no effective therapies and dismal median survival. While the ACVR1 mutation is causal for FOP, its role in DIPG tumor biology remains under active investigation. Here, we discuss cross-fertilization between the FOP and DIPG fields, focusing on the biological mechanisms and principles gleaned from FOP that can be applied to DIPG biology. We highlight our current knowledge of ACVR1 in both diseases, and then describe the growing opportunities and barriers to effectively investigate ACVR1 in DIPG. Importantly, learning from other seemingly unrelated diseases harboring similar mutations may uncover novel mechanisms or processes for future investigation.


Assuntos
Receptores de Ativinas Tipo I/genética , Neoplasias do Tronco Encefálico/genética , Glioma/epidemiologia , Miosite Ossificante/genética , Humanos , Mutação/genética , Doenças Raras
16.
Oncotarget ; 8(49): 84697-84713, 2017 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-29156677

RESUMO

Pediatric low-grade gliomas (PLGGs) are frequently associated with activating BRAF gene fusions, such as KIAA1549-BRAF, that aberrantly drive the mitogen activated protein kinase (MAPK) pathway. Although RAF inhibitors (RAFi) have been proven effective in BRAF-V600E mutant tumors, we have previously shown how the KIAA1549-BRAF fusion can be paradoxically activated by RAFi. While newer classes of RAFi, such as PLX8394, have now been shown to inhibit MAPK activation by KIAA1549-BRAF, we sought to identify alternative MAPK pathway targeting strategies using clinically relevant MEK inhibitors (MEKi), along with potential escape mechanisms of acquired resistance to single-agent MAPK pathway therapies. We demonstrate effectiveness of multiple MEKi against diverse BRAF-fusions with novel N-terminal partners, with trametinib being the most potent. However, resistance to MEKi or PLX8394 develops via increased RTK expression causing activation of PI3K/mTOR pathway in BRAF-fusion expressing resistant clones. To circumvent acquired resistance, we show potency of combinatorial targeting with trametinib and everolimus, an mTOR inhibitor (mTORi) against multiple BRAF-fusions. While single-agent mTORi and MEKi PLGG clinical trials are underway, our study provides preclinical rationales for using MEKi and mTORi combinatorial therapy to stave off or prevent emergent drug-resistance in BRAF-fusion driven PLGGs.

17.
Anesth Essays Res ; 11(1): 206-210, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28298786

RESUMO

INTRODUCTION: Postoperative pain is a major cause of fear and anxiety in hospitalized patients and so if patients remain pain-free during this period, they can cooperate with the circumstances well, leading to early recovery. Over the last two decades, there has been considerable revival of interest in the use of regional anesthesia techniques for surgery and pain management. As very few studies have been conducted using ropivacaine with dexmedetomidine and magnesium sulfate (MgSO4) as adjuvants, the present study was undertaken with primary aims to compare the hemodynamic stability, onset and duration of sensory and motor block and with secondary aims of the postoperative analgesic effect of dexmedetomidine and MgSO4 along with ropivacaine. MATERIALS AND METHODS: After getting the Institutional Ethics Committee approval, this study was conducted on fifty patients of the American Society of Anesthesiologists physical Status I and II aged between 20 and 65 years of either sex and scheduled to undergo infraumbilical surgeries under spinal anesthesia. They were divided into two groups of 25 each. Group D patients received 3 ml of 0.75% isobaric ropivacaine hydrochloride with 10 µg of dexmedetomidine whereas Group M patients received 75 mg of MgSO4 in the place of dexmedetomidine. The quality of surgical analgesia and quality of intraoperative muscle relaxation were assessed and graded. RESULTS: We found out that onset of sensory and motor block was earlier in Group D in comparison to Group M. There was a significant reduction in the time to the first rescue analgesia in group receiving intrathecal dexmedetomidine. CONCLUSION: It is concluded from our study that ropivacaine plus dexmedetomidine group are better than ropivacaine plus MgSO4 in providing early onset of sensory and motor block as well as in providing postoperative analgesia.

19.
Bioessays ; 38(5): 446-54, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27000413

RESUMO

The Polycomb group of proteins (PcGs) are transcriptional repressor complexes that regulate important biological processes and play critical roles in cancer. Mutating or deleting EZH2 can have both oncogenic and tumor suppressive functions by increasing or decreasing H3K27me3. In contrast, mutations of SUZ12 and EED are reported to have tumor suppressive functions. EZH2 is overexpressed in many cancers, including prostate cancer, which can lead to silencing of tumor suppressors, genes regulating epithelial to mesenchymal transition (EMT), and interferon signaling. In some cases, EZH2 overexpression also leads to its use of non-histone substrates. Lastly, PRC2 associated factors can influence the progression of cancer through progressive mutations or by specific binding to certain target genes. Here, we discuss which mutations and deletions of the PRC2 complex have been detected in different cancers, with a specific focus on the overexpression of EZH2 in prostate cancer.


Assuntos
Proteína Potenciadora do Homólogo 2 de Zeste/genética , Epigênese Genética , Complexo Repressor Polycomb 2/genética , Neoplasias da Próstata/genética , Linhagem Celular Tumoral , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Transição Epitelial-Mesenquimal/genética , Histonas/genética , Histonas/metabolismo , Humanos , Masculino , Mutação , Proteínas de Neoplasias , Complexo Repressor Polycomb 2/metabolismo , Próstata/metabolismo , Próstata/patologia , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Transdução de Sinais , Fatores de Transcrição , Transcrição Gênica
20.
Nat Genet ; 48(3): 273-82, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26829751

RESUMO

Angiocentric gliomas are pediatric low-grade gliomas (PLGGs) without known recurrent genetic drivers. We performed genomic analysis of new and published data from 249 PLGGs, including 19 angiocentric gliomas. We identified MYB-QKI fusions as a specific and single candidate driver event in angiocentric gliomas. In vitro and in vivo functional studies show that MYB-QKI rearrangements promote tumorigenesis through three mechanisms: MYB activation by truncation, enhancer translocation driving aberrant MYB-QKI expression and hemizygous loss of the tumor suppressor QKI. To our knowledge, this represents the first example of a single driver rearrangement simultaneously transforming cells via three genetic and epigenetic mechanisms in a tumor.


Assuntos
Glioma/genética , Proteínas Oncogênicas v-myb/genética , Proteínas de Fusão Oncogênica/genética , Proteínas de Ligação a RNA/genética , Carcinogênese/genética , Linhagem Celular Tumoral , Criança , Hibridização Genômica Comparativa , Exoma/genética , Regulação Neoplásica da Expressão Gênica , Rearranjo Gênico , Glioma/patologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação , Proteínas Oncogênicas v-myb/biossíntese , Proteínas de Fusão Oncogênica/biossíntese , Proteínas de Ligação a RNA/biossíntese
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