Publications by authors named "Abhinav B Nagulapally"

5 Publications

  • Page 1 of 1

Genomic and Transcriptomic Analysis of Relapsed and Refractory Childhood Solid Tumors Reveals a Diverse Molecular Landscape and Mechanisms of Immune Evasion.

Cancer Res 2021 12 5;81(23):5818-5832. Epub 2021 Oct 5.

Translational Genomics Research Institute (TGen), Phoenix, Arizona.

Children with treatment-refractory or relapsed (R/R) tumors face poor prognoses. As the genomic underpinnings driving R/R disease are not well defined, we describe here the genomic and transcriptomic landscapes of R/R solid tumors from 202 patients enrolled in Beat Childhood Cancer Consortium clinical trials. Tumor mutational burden (TMB) was elevated relative to untreated tumors at diagnosis, with one-third of tumors classified as having a pediatric high TMB. Prior chemotherapy exposure influenced the mutational landscape of these R/R tumors, with more than 40% of tumors demonstrating mutational signatures associated with platinum or temozolomide chemotherapy and two tumors showing treatment-associated hypermutation. Immunogenomic profiling found a heterogenous pattern of neoantigen and MHC class I expression and a general absence of immune infiltration. Transcriptional analysis and functional gene set enrichment analysis identified cross-pathology clusters associated with development, immune signaling, and cellular signaling pathways. While the landscapes of these R/R tumors reflected those of their corresponding untreated tumors at diagnosis, important exceptions were observed, suggestive of tumor evolution, treatment resistance mechanisms, and mutagenic etiologies of treatment. SIGNIFICANCE: Tumor heterogeneity, chemotherapy exposure, and tumor evolution contribute to the molecular profiles and increased mutational burden that occur in treatment-refractory and relapsed childhood solid tumors.
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http://dx.doi.org/10.1158/0008-5472.CAN-21-1033DOI Listing
December 2021

Molecular Guided Therapy Provides Sustained Clinical Response in Refractory Choroid Plexus Carcinoma.

Front Pharmacol 2017 25;8:652. Epub 2017 Sep 25.

Pediatric Oncology Translational Research Program, Helen DeVos Children's Hospital at Spectrum HealthGrand Rapids, MI, United States.

Choroid plexus carcinomas (CPCs) are rare, aggressive pediatric brain tumors with no established curative therapy for relapsed disease, and poor survival rates. Mutation or dysfunction correlates with poor or no survival outcome in CPCs. Here, we report the case of a 4 month-old female who presented with disseminated CPC. After initial response to tumor resection and adjuvant-chemotherapy, the tumor recurred and metastasized with no response to aggressive relapse therapy suggesting genetic predisposition. This patient was then enrolled to a Molecular Guided Therapy Clinical Trial. Genomic profiling of patient tumor and normal sample identified a germline mutation with loss of heterozygosity, somatic mutations including , and aberrant activation of biological pathways. The mutations were not targetable for therapy. However, targeting the altered biological pathways (mTOR, PDGFRB, FGF2, HDAC) guided identification of possibly beneficial treatment with a combination of sirolimus, thalidomide, sunitinib, and vorinostat. This therapy led to 92% reduction in tumor size with no serious adverse events, excellent quality of life and long term survival.
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http://dx.doi.org/10.3389/fphar.2017.00652DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5622196PMC
September 2017

BKM120 induces apoptosis and inhibits tumor growth in medulloblastoma.

PLoS One 2017 29;12(6):e0179948. Epub 2017 Jun 29.

Pediatric Oncology Translational Research Program, Helen DeVos Children's Hospital, Grand Rapids, MI, United States of America.

Medulloblastoma (MB) is the most common malignant brain tumor in children, accounting for nearly 20 percent of all childhood brain tumors. New treatment strategies are needed to improve patient survival outcomes and to reduce adverse effects of current therapy. The phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) intracellular signaling pathway plays a key role in cellular metabolism, proliferation, survival and angiogenesis, and is often constitutively activated in human cancers, providing unique opportunities for anticancer therapeutic intervention. The aim of this study was to evaluate the pre-clinical activity of BKM120, a selective pan-class I PI3K inhibitor, on MB cell lines and primary samples. IC50 values of BKM120 in the twelve MB cell lines tested ranged from 0.279 to 4.38 μM as determined by cell viability assay. IncuCyte ZOOM Live-Cell Imaging system was used for kinetic monitoring of cytotoxicity of BKM120 and apoptosis in MB cells. BKM120 exhibited cytotoxicity in MB cells in a dose and time-dependent manner by inhibiting activation of downstream signaling molecules AKT and mTOR, and activating caspase-mediated apoptotic pathways. Furthermore, BKM120 decreased cellular glycolytic metabolic activity in MB cell lines in a dose-dependent manner demonstrated by ATP level per cell. In MB xenograft mouse study, DAOY cells were implanted in the flank of nude mice and treated with vehicle, BKM120 at 30 mg/kg and 60 mg/kg via oral gavage daily. BKM120 significantly suppressed tumor growth and prolonged mouse survival. These findings help to establish a basis for clinical trials of BKM120, which could be a novel therapy for the treatment of medulloblastoma patients.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0179948PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5491106PMC
September 2017

Tolcapone induces oxidative stress leading to apoptosis and inhibition of tumor growth in Neuroblastoma.

Cancer Med 2017 Jun 21;6(6):1341-1352. Epub 2017 Apr 21.

Pediatric Oncology Translational Research Program, Helen DeVos Children's Hospital, Grand Rapids, Michigan.

Catechol-O-methyltransferase (COMT) is an enzyme that inactivates dopamine and other catecholamines by O-methylation. Tolcapone, a drug commonly used in the treatment of Parkinson's disease, is a potent inhibitor of COMT and previous studies indicate that Tolcapone increases the bioavailability of dopamine in cells. In this study, we demonstrate that Tolcapone kills neuroblastoma (NB) cells in preclinical models by inhibition of COMT. Treating four established NB cells lines (SMS-KCNR, SH-SY5Y, BE(2)-C, CHLA-90) and two primary NB cell lines with Tolcapone for 48 h decreased cell viability in a dose-dependent manner, with IncuCyte imaging and Western blotting indicating that cell death was due to caspase-3-mediated apoptosis. Tolcapone also increased ROS while simultaneously decreasing ATP-per-cell in NB cells. Additionally, COMT was inhibited by siRNA in NB cells and showed similar increases in apoptotic markers compared to Tolcapone. In vivo xenograft models displayed inhibition of tumor growth and a significant decrease in time-to-event in mice treated with Tolcapone compared to untreated mice. These results indicate that Tolcapone is cytotoxic to neuroblastoma cells and invite further studies into Tolcapone as a promising novel therapy for the treatment of neuroblastoma.
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http://dx.doi.org/10.1002/cam4.1065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5463066PMC
June 2017

Functional analysis of a chromosomal deletion associated with myelodysplastic syndromes using isogenic human induced pluripotent stem cells.

Nat Biotechnol 2015 Jun 23;33(6):646-55. Epub 2015 Mar 23.

1] Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, USA. [2] The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA. [3] The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA. [4] Division of Hematology, Department of Medicine, University of Washington, Seattle, Washington, USA. [5] Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, Washington, USA. [6] Department of Pathology, University of Washington, Seattle, Washington, USA. [7] Division of Hematology and Medical Oncology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA.

Chromosomal deletions associated with human diseases, such as cancer, are common, but synteny issues complicate modeling of these deletions in mice. We use cellular reprogramming and genome engineering to functionally dissect the loss of chromosome 7q (del(7q)), a somatic cytogenetic abnormality present in myelodysplastic syndromes (MDS). We derive del(7q)- and isogenic karyotypically normal induced pluripotent stem cells (iPSCs) from hematopoietic cells of MDS patients and show that the del(7q) iPSCs recapitulate disease-associated phenotypes, including impaired hematopoietic differentiation. These disease phenotypes are rescued by spontaneous dosage correction and can be reproduced in karyotypically normal cells by engineering hemizygosity of defined chr7q segments in a 20-Mb region. We use a phenotype-rescue screen to identify candidate haploinsufficient genes that might mediate the del(7q)- hematopoietic defect. Our approach highlights the utility of human iPSCs both for functional mapping of disease-associated large-scale chromosomal deletions and for discovery of haploinsufficient genes.
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http://dx.doi.org/10.1038/nbt.3178DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4464949PMC
June 2015
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