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19
result(s) for
"Das, Sunetra"
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Integrated analysis of canine soft tissue sarcomas identifies recurrent mutations in TP53, KMT genes and PDGFB fusions
2023
Soft tissue sarcomas (STS) are a heterogenous group of mesenchymal tumors representing over 50 distinct types with overlapping histological features and non-specific anatomical locations. Currently, localized sarcomas are treated with surgery + / − radiation in both humans and dogs with few molecularly targeted therapeutic options. However, to improve precision-based cancer therapy through trials in pet dogs with naturally occurring STS tumors, knowledge of genomic profiling and molecular drivers in both species is essential. To this purpose, we sought to characterize the transcriptomic and genomic mutation profiles of canine STS subtypes (fibrosarcoma, undifferentiated pleomorphic sarcoma, and peripheral nerve sheath tumors), by leveraging RNAseq, whole exome sequencing, immunohistochemistry, and drug assays. The most common driver mutations were in cell cycle/DNA repair (31%,
TP53
-21%) and chromatin organization/binding (41%,
KMT2D
-21%) genes. Similar to a subset of human sarcomas, we identified fusion transcripts of platelet derived growth factor B and collagen genes that predict sensitivity to PDGFR inhibitors. Transcriptomic profiling grouped these canine STS tumors into 4 clusters, one PNST group (H1), and 3 FSA groups selectively enriched for extracellular matrix interactions and
PDFGB
fusions (H2), homeobox transcription factors (H3), and elevated T-cell infiltration (H4). This multi-omics approach provides insights into canine STS sub-types at a molecular level for comparison to their human counterparts, to improve diagnosis, and may provide additional targets for chemo- and immuno-therapy.
Journal Article
VDX-111 targets proliferative pathways in canine cancer cell lines
by
Lambert, James R.
,
Das, Sunetra
,
Nordeen, Steven K.
in
1-Phosphatidylinositol 3-kinase
,
AKT protein
,
Alfacalcidol
2024
VDX-111 (also identified as AMPI-109) is a vitamin D derivative which has shown anticancer activity. To further assess the function of this compound against multiple cancer types, we examined the efficacy of VDX-111 against a panel of 30 well characterized canine cancer cell lines. Across a variety of cancer types, VDX-111 induced widely variable growth inhibition, cell death, and migration inhibition, at concentrations ranging from 10 nM to 1 μM. Growth inhibition sensitivity did not correlate strongly with tumor cell histotype; however, it was significantly correlated with the expression of genes in multiple cell signaling pathways, including the MAPK and PI3K-AKT pathways. We confirmed inhibition of these signaling pathways as likely participants in the effects of VDX-111. These results suggest that a subset of canine tumors may be sensitive to treatment with VDX-111, and suggests possible predictive markers of drug sensitivity and pharmacodynamic biomarkers of drug exposure that could be employed in future clinical trials.
Journal Article
Immune pathways and TP53 missense mutations are associated with longer survival in canine osteosarcoma
2021
Osteosarcoma affects about 2.8% of dogs with cancer, with a one-year survival rate of approximately 45%. The purpose of this study was to characterize mutation and expression profiles of osteosarcoma and its association with outcome in dogs. The number of somatic variants identified across 26 samples ranged from 145 to 2,697 with top recurrent mutations observed in TP53 and SETD2. Additionally, 47 cancer genes were identified with copy number variations. Missense TP53 mutation status and low pre-treatment blood monocyte counts were associated with a longer disease-free interval (DFI). Patients with longer DFI also showed increased transcript levels of anti-tumor immune response genes. Although, T-cell and myeloid cell quantifications were not significantly associated with outcome; immune related genes, PDL-1 and CD160, were correlated with T-cell abundance. Overall, the association of gene expression and mutation profiles to outcome provides insights into pathogenesis and therapeutic interventions in osteosarcoma patients.Sunetra Das et al. combine genetic and immunohistochemistry data to characterize mutation and expression profiles of canine osteosarcoma and its association with clinical outcomes. Their results provide further insight into the pathogenesis and potential future therapeutic targets for osteosarcoma.
Journal Article
Morphological, Molecular, and Hormonal Basis of Limb Regeneration across Pancrustacea
2015
Regeneration is a developmental process that allows an organism to re-grow a lost body part. Historically, the most studied aspect of limb regeneration across Pancrustacea is its morphological basis and its dependence on successful molting. Although there are distinct morphological differences in regeneration processes between insects and crustaceans, in both groups the phenomenon is initiated via formation of a blastema, followed by proliferation, dedifferentiation, and redifferentiation of blastemal cells to generate a functional limb. In recent years, with the availability of sequence data and tools to manipulate gene expression, the emphasis of this field has shifted toward the genetic basis of limb regeneration. Among insects this focus is on genes that are known to be required during the development of legs in embryos. RNA interference-mediated functional studies conducted during regeneration of imaginal discs of Drosophila melanogaster, and nymphal legs of Gryllus bimaculatus reveal that several conserved pathways and transcription factors (Wingless, Decapentaplegic, Hedgehog, Dachshund) are required for successful regeneration. In contrast to studies on the regeneration of insects’ limbs, work on crustaceans has focused on the hormonal basis of the re-growth of limbs. Regeneration in decapods, like Uca pugilator and Gecarcinus lateralis, occurs in discrete phases of growth in tandem with the stages of the molt cycle. Recent studies have shown that ecdysteroid hormone signaling is necessary for blastemal proliferation. Although the current research emphases of limb regeneration in insect and crustacean are fairly distinct, the results generated by functional studies of a wide array of regeneration genes will be beneficial for generating testable regeneration models.
Journal Article
Prospective clinical trial testing COXEN-based gene expression models of chemosensitivity in dogs with spontaneous osteosarcoma
2021
BackgroundThis study is a prospective clinical trial in dogs with osteosarcoma testing a gene expression model (GEM) predicting the chemosensitivity of tumors to carboplatin (CARBO) or doxorubicin (DOX) developed using the COXEN method.Patients and methodsSixty dogs with appendicular osteosarcoma were enrolled in this trial. RNA isolation and gene expression profiling were conducted with 2 biopsies for 54/63 screened tumors, and with a single biopsy for 9 tumors. Resulting gene expression data were used for calculation of a COXEN score for CARBO and DOX based on a previous study showing the significance of this predictor on patient outcome utilizing retrospective data (BMC Bioinformatics 17:93). Dogs were assigned adjuvant CARBO, DOX or the combination based on the results of the COXEN score following surgical removal of the tumor via amputation and were monitored for disease progression by chest radiograph every 2 months.ResultsThe COXEN predictor of chemosensitivity to CARBO or DOX was not a significant predictor of progression-free interval or overall survival for the trial participants. The calculation of DOX COXEN score using gene expression data from two independent biopsies of the same tumor were highly correlated (P < 0.0001), whereas the calculated CARBO COXEN score was not (P = 0.3039).ConclusionThe COXEN predictor of chemosensitivity to CARBO or DOX is not a significant predictor of outcome when utilized in this prospective study. This trial represents the first prospective trial of a GEM predictor of chemosensitivity and establishes pet dogs with cancer as viable surrogates for prospective trials of prognostic indicators.
Journal Article
Host–microbe interactions in the nasal cavity of dogs with chronic idiopathic rhinitis
2024
Chronic rhinitis (CR) is a frustrating clinical syndrome in dogs and our understanding of the disease pathogenesis in is limited. Increasingly, host–microbe interactions are considered key drives of clinical disease in sites of persistent mucosal inflammation such as the nasal and oral cavities. Therefore, we applied next generation sequencing tools to interrogate abnormalities present in the nose of dogs with CR and compared immune and microbiome profiles to those of healthy dogs. Host nasal cell transcriptomes were evaluated by RNA sequencing, while microbial communities were assessed by 16S rRNA sequencing. Correlation analysis was then used to identify significant interactions between nasal cell transcriptomes and the nasal microbiome and how these interactions were altered in animals with CR. Notably, we observed significant downregulation of multiple genes associated with ciliary function in dogs with CR, suggesting a previously undetected role for ciliary dysfunction in this syndrome. We also found significant upregulation of immune genes related to the TNF-α and interferon pathways. The nasal microbiome was also significantly altered in CR dogs, with overrepresentation of several potential pathobionts. Interactome analysis revealed significant correlations between bacteria in the genus Porphyromonas and the upregulated host inflammatory responses in dogs with CR, as well as defective ciliary function which was correlated with Streptococcus abundance. These findings provide new insights into host–microbe interactions in a canine model of CR and indicate the presence of potentially causal relationships between nasal pathobionts and the development of nasal inflammation and ciliary dysfunction.
Journal Article
Analysis of Annotation and Differential Expression Methods used in RNA-seq Studies in Crustacean Systems
by
Das, Sunetra
,
Durica, David S.
,
Shyamal, Sharmishtha
in
Animals
,
Crustacea - genetics
,
High-Throughput Nucleotide Sequencing
2016
In the field of crustacean biology, usage of RNA-seq to study gene expression is rapidly growing. Major advances in sequencing technology have contributed to the ability to examine complex patterns of genome activity in a wide range of organisms that are extensively used for comparative physiology, ecology and evolution, environmental monitoring, and commercial aquaculture. Relative to insect and vertebrate model organisms, however, information on the organization of crustacean genomes is virtually nonexistent, making de novo transcriptome assembly, annotation and quantification problematic and challenging. We present here a summary of the methodologies and software analyses employed in 23 recent publications, which describe de novo transcriptome assembly, annotation, and differential gene expression in a variety of crustacean experimental systems. We focus on establishing a series of best practices that will allow for investigators to produce datasets that are understandable, reproducible, and of general utility for related analyses and cross-study comparisons.
Journal Article
A Comparison of Resources for the Annotation of a De Novo Assembled Transcriptome in the Molting Gland (Y-Organ) of the Blackback Land Crab, Gecarcinus lateralis
by
Das, Sunetra
,
Mykles, Donald L.
in
Animals
,
Brachyura - genetics
,
High-Throughput Nucleotide Sequencing
2016
Next-generation sequencing technologies are revolutionizing crustacean biology. De novo assembly of RNA sequencing (RNA-seq) data allows researchers to catalog and quantify genes expressed in tissues of a species that lacks a complete genome sequence. RNA-seq has become an important tool for understanding phenotypic plasticity and the responses of organisms to environmental cues. However, there are challenges with identification of assembled contiguous sequences (contigs) without a reference genome. Thus, the selection of resources for annotating contigs is critical for the downstream analysis of gene functions. A de novo-assembled transcriptome of the Gecarcinus lateralis molting gland, or Y-organ (YO), was used to compare two functional annotation packages, Trinotate and Blast2GO. The assembled transcriptome contained 229,278 contigs derived from YOs from animals in intermolt, premolt (early, mid, and late), and postmolt stages. Gene identification using BLAST against four databases and functional annotation using Gene Ontologies were conducted. The analysis revealed two major limitations of de novo assembly: (1) assembly using Trinity generates redundant contigs and (2) transcripts that encode protein isoforms are not distinguished with current computational tools. It is recommended that the NCBI Non-Redundant, SwissProt, TrEMBL, and Uniref90 databases be used to maximize gene identification. Trinotate is preferred for assigning functions to identified genes, as the package uses multiple databases for annotation. The differences between packages to generate Gene Ontology (GO) terms are attributed to the databases used for inputs: Trinotate uses both Pfam and BLAST databases, while Blast2GO uses only the BLAST database. InterProScan was used to verify the GO terms assigned via BLAST. A comprehensive annotation of de novo assembled transcriptome is necessary for the downstream analysis of differentially expressed transcripts in the YO over the molt cycle.
Journal Article