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13 result(s) for "Fowles, Jared S."
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RSK1 is an exploitable dependency in myeloproliferative neoplasms and secondary acute myeloid leukemia
Myeloid malignancies are heterogenous disorders characterized by distinct molecular drivers but share convergence of oncogenic signaling pathways and propagation by ripe pro-inflammatory niches. Here, we establish a comprehensive transcriptional atlas across the spectrum of myeloproliferative neoplasms (MPN) and secondary acute myeloid leukemia (sAML) through RNA-sequencing of 158 primary samples encompassing CD34+ hematopoietic stem/progenitor cells and CD14+ monocytes. Supported by mass cytometry (CyTOF) profiling, we reveal aberrant networks of PI3K/AKT/mTOR signalling and NFκB-mediated hyper-inflammation. Combining ATAC-Seq, CUT&Tag, RNA-seq, and CyTOF, we demonstrate that targeting of ribosomal protein S6 kinase A1 (RSK1) suppresses NFκB activation and diminishes pro-inflammatory mediators including tumor necrosis factor (TNF) associated with MPN disease severity and transformation. We further evaluate a therapeutic approach utilizing a first-in-class RSK inhibitor, PMD-026, currently in Phase 2 development for breast cancer, for use in myeloid malignancies. Treatment with PMD-026 suppressed disease burden across seven syngeneic and patient-derived xenograft leukemia mouse models spanning the spectrum of driver and disease-modifying mutations. These findings uncover a therapeutic avenue for a conserved dependency across MPN and sAML. Secondary acute myeloid leukemias (sAMLs) evolving from myeloproliferative neoplasms (MPNs) associate with poor prognosis. Here authors identify RSK1 as a vulnerability for MPN and sAML and show the efficacy of a first-in-class RSK inhibitor, PMD-026, against these types of myeloid malignancies.
Intra- and interspecies gene expression models for predicting drug response in canine osteosarcoma
Background Genomics-based predictors of drug response have the potential to improve outcomes associated with cancer therapy. Osteosarcoma (OS), the most common primary bone cancer in dogs, is commonly treated with adjuvant doxorubicin or carboplatin following amputation of the affected limb. We evaluated the use of gene-expression based models built in an intra- or interspecies manner to predict chemosensitivity and treatment outcome in canine OS. Models were built and evaluated using microarray gene expression and drug sensitivity data from human and canine cancer cell lines, and canine OS tumor datasets. The “COXEN” method was utilized to filter gene signatures between human and dog datasets based on strong co-expression patterns. Models were built using linear discriminant analysis via the misclassification penalized posterior algorithm. Results The best doxorubicin model involved genes identified in human lines that were co-expressed and trained on canine OS tumor data, which accurately predicted clinical outcome in 73 % of dogs ( p  = 0.0262, binomial). The best carboplatin model utilized canine lines for gene identification and model training, with canine OS tumor data for co-expression. Dogs whose treatment matched our predictions had significantly better clinical outcomes than those that didn’t ( p  = 0.0006, Log Rank), and this predictor significantly associated with longer disease free intervals in a Cox multivariate analysis (hazard ratio = 0.3102, p  = 0.0124). Conclusions Our data show that intra- and interspecies gene expression models can successfully predict response in canine OS, which may improve outcome in dogs and serve as pre-clinical validation for similar methods in human cancer research.
Immune pathways and TP53 missense mutations are associated with longer survival in canine osteosarcoma
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.
Of Elephants and Other Mammals: A Comparative Review of Reproductive Tumors and Potential Impact on Conservation
Reproductive tumors can impact conception, pregnancy, and birth in mammals. These impacts are well documented in humans, while data in other mammals are limited. An urgent need exists to understand the reproductive impact of these lesions in endangered species, because some endangered species have a documented high prevalence of reproductive tumors. This article documents that the prevalence of both benign and malignant neoplasia differs between African and Asian elephants, with Asian elephants more frequently diagnosed and negatively affected by both. The prevalence of these tumors across mammalian species is compared, and impact plus treatment options in human medicine are reviewed to inform decision making in elephants. Evidence suggests that reproductive tumors can negatively impact elephant conservation. Future studies that document reproductive outcomes, including the success of various treatment approaches in elephants with tumors will benefit conservation efforts.
Co-evolution of tumor and immune cells during progression of multiple myeloma
Multiple myeloma (MM) is characterized by the uncontrolled proliferation of plasma cells. Despite recent treatment advances, it is still incurable as disease progression is not fully understood. To investigate MM and its immune environment, we apply single cell RNA and linked-read whole genome sequencing to profile 29 longitudinal samples at different disease stages from 14 patients. Here, we collect 17,267 plasma cells and 57,719 immune cells, discovering patient-specific plasma cell profiles and immune cell expression changes. Patients with the same genetic alterations tend to have both plasma cells and immune cells clustered together. By integrating bulk genomics and single cell mapping, we track plasma cell subpopulations across disease stages and find three patterns: stability (from precancer to diagnosis), and gain or loss (from diagnosis to relapse). In multiple patients, we detect “B cell-featured” plasma cell subpopulations that cluster closely with B cells, implicating their cell of origin. We validate AP-1 complex differential expression (JUN and FOS) in plasma cell subpopulations using CyTOF-based protein assays, and integrated analysis of single-cell RNA and CyTOF data reveals AP-1 downstream targets (IL6 and IL1B) potentially leading to inflammation regulation. Our work represents a longitudinal investigation for tumor and microenvironment during MM progression and paves the way for expanding treatment options. Clonal evolution in multiple myeloma (MM) needs to be understood in both the tumor and its microenvironment. Here the authors perform single-cell multi-omics profiling of samples from MM patients at different stages, finding transitions in the immune cell composition throughout progression.
DUSP6 mediates resistance to JAK2 inhibition and drives leukemic progression
Myeloproliferative neoplasms (MPNs) exhibit a propensity for transformation to secondary acute myeloid leukemia (sAML), for which the underlying mechanisms remain poorly understood, resulting in limited treatment options and dismal clinical outcomes. Here, we performed single-cell RNA sequencing on serial MPN and sAML patient stem and progenitor cells, identifying aberrantly increased expression of DUSP6 underlying disease transformation. Pharmacologic dual-specificity phosphatase (DUSP)6 targeting led to inhibition of S6 and Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling while also reducing inflammatory cytokine production. DUSP6 perturbation further inhibited ribosomal S6 kinase (RSK)1, which we identified as a second indispensable candidate associated with poor clinical outcome. Ectopic expression of DUSP6 mediated JAK2-inhibitor resistance and exacerbated disease severity in patient-derived xenograft (PDX) models. Contrastingly, DUSP6 inhibition potently suppressed disease development across Jak2 and MPL MPN mouse models and sAML PDXs without inducing toxicity in healthy controls. These findings underscore DUSP6 in driving disease transformation and highlight the DUSP6-RSK1 axis as a vulnerable, druggable pathway in myeloid malignancies.
Prospective clinical trial testing COXEN-based gene expression models of chemosensitivity in dogs with spontaneous osteosarcoma
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.
Utilization of a canine cancer cell line (FACC) panel in comparative and translational studies of gene expression and drug sensitivity
Canine cancer is the leading cause of death in adult dogs. The use of the canine cancer model in translational research is growing in popularity due to the many biologic and genetic similarities it shares with human cancers. Cancer cell tissue culture has long been an established tool for expanding our understanding of cancer processes and for development of novel cancer treatments. With the high rate of genomic advancements in cancer research over the last decade human cancer cell line panels that combine pharmacologic and genomic information have proven very helpful in elucidating the complex relationships between gene expression and drug response in cancer. We have assembled a panel of canine cancer cell lines at the Flint Animal Cancer Center (FACC) at Colorado State University to be utilized in a similar fashion as a tool to advance canine cancer research. The purpose of these studies is to describe the characteristics of the FACC panel with the available genomic and drug sensitivity data we have generated, and to show its utility in comparative and translational oncology by focusing specifically on canine melanoma and osteosarcoma. We were able to confirm our panel of cell lines as being of canine origin and determined their genetic fingerprint through PCR and microsattelite analyses, creating a point of reference for validation in future studies and collaborations. Gene expression microarray analysis allowed for further molecular characterization of the panel, showing that similar tumor types tended to cluster together based on general as well as cancer specific gene expression patterns. In vitro studies that measure phenotypic differences in the panel can be coupled with genomic data, resulting in the identification of potential gene targets worthy of further exploration. We also showed that human and canine cancer cells are similarly sensitive to common chemotherapy. Next we utilized the FACC panel in a comparative analysis to determine if signaling pathways important in human melanoma were also activated and sensitive to targeted inhibition in canine melanoma. We were able to show that despite apparent differences in the mechanism of pathway activation, human and canine melanoma tumors and cell lines shared constitutive signaling of the MAPK and PI3K/AKT pathways, and responded similarly to targeted inhibition. These data suggest that studies involving pathway-targeted inhibition in either canine or human melanoma could potentially be directly translatable to each other. Evidence of genetic similarities between human and canine cancers led us to ask whether or not non-pathway focused gene expression models for predicting drug sensitivity could be developed in an interspecies manner. We were able to show that models built on canine datasets using human derived gene signatures successfully predicted response to chemotherapy in canine osteosarcoma patients. When compared to a large historical cohort, dogs that received the treatement our models predicted them to be sensitive to lived significantly longer disease-free. Taken together, these studies show that human and canine cancers share strong molecular similarities that can be used advantageously to develop better treatment strategies in both species.
DUSP6 mediates resistance to JAK2 inhibition and drives leukemic progression
Myeloproliferative neoplasms (MPNs) exhibit a propensity for transformation to secondary acute myeloid leukemia (sAML), for which the underlying mechanisms remain unclear, resulting in limited treatment options and dismal clinical outcomes. Here, we performed bulk and single cell RNA-sequencing on CD34+ stem/progenitor cells from serial patient samples at MPN and sAML phases, and identified elevated DUSP6 expression underlying disease transformation. Targeting DUSP6 led to inhibition of S6 and JAK/STAT signaling, which suppressed cell proliferation and inflammatory cytokine production. Furthermore, ectopic DUSP6 expression mediated JAK2 inhibitor resistance, while DUSP6 inhibition reduced JAK2 inhibitor-persistent cells. Mechanistically, DUSP6 perturbation inhibited RSK1, which we identified as a second indispensable candidate associated with poor clinical outcome. Lastly, DUSP6 inhibition potently suppressed disease development across Jak2 V617F and MPL W515L mouse models, and sAML patient-derived xenografts. These findings underscore DUSP6 in driving disease transformation and therapeutic resistance, and highlight the DUSP6-RSK1 axis as a novel, druggable pathway. Competing Interest Statement S.T.O. has served as a consultant for Kartos Therapeutics, CTI BioPharma, Celgene/Bristol Myers Squibb, Disc Medicine, Blueprint Medicines, PharmaEssentia, Constellation, Geron, Abbvie, Sierra Oncology, and Incyte. All other authors disclose no competing interests.