ABSTRACT
Recent studies indicate that signaling molecules traditionally associated with central nervous system function play critical roles in cancer. Dopamine receptor signaling is implicated in various cancers including glioblastoma (GBM) and it is a recognized therapeutic target, as evidenced by recent clinical trials with a selective dopamine receptor D2 (DRD2) inhibitor ONC201. Understanding the molecular mechanism(s) of the dopamine receptor signaling will be critical for development of potent therapeutic options. Using the human GBM patient-derived tumors treated with dopamine receptor agonists and antagonists, we identified the proteins that interact with DRD2. DRD2 signaling promotes glioblastoma (GBM) stem-like cells and GBM growth by activating MET. In contrast, pharmacological inhibition of DRD2 induces DRD2-TRAIL receptor interaction and subsequent cell death. Thus, our findings demonstrate a molecular circuitry of oncogenic DRD2 signaling in which MET and TRAIL receptors, critical factors for tumor cell survival and cell death, respectively, govern GBM survival and death. Finally, tumor-derived dopamine and expression of dopamine biosynthesis enzymes in a subset of GBM may guide patient stratification for DRD2 targeting therapy.
Subject(s)
Glioblastoma , Humans , Cell Line, Tumor , Dopamine , Glioblastoma/pathology , Receptors, TNF-Related Apoptosis-Inducing Ligand , Signal Transduction , Receptors, Dopamine D2/metabolismABSTRACT
Glioblastoma (GBM) displays marked cellular and metabolic heterogeneity that varies among cellular microenvironments within a tumor. Metabolic targeting has long been advocated as a therapy against many tumors including GBM, but how lipid metabolism is altered to suit different microenvironmental conditions and whether cancer stem cells (CSCs) have altered lipid metabolism are outstanding questions in the field. We interrogated gene expression in separate microenvironments of GBM organoid models that mimic the transition between nutrient-rich and nutrient-poor pseudopalisading/perinecrotic tumor zones using spatial-capture RNA-sequencing. We revealed a striking difference in lipid processing gene expression and total lipid content between diverse cell populations from the same patient, with lipid enrichment in hypoxic organoid cores and also in perinecrotic and pseudopalisading regions of primary patient tumors. This was accompanied by regionally restricted upregulation of hypoxia-inducible lipid droplet-associated (HILPDA) gene expression in organoid cores and pseudopalisading regions of clinical GBM specimens, but not lower-grade brain tumors. CSCs have low lipid droplet accumulation compared to non-CSCs in organoid models and xenograft tumors, and prospectively sorted lipid-low GBM cells are functionally enriched for stem cell activity. Targeted lipidomic analysis of multiple patient-derived models revealed a significant shift in lipid metabolism between GBM CSCs and non-CSCs, suggesting that lipid levels may not be simply a product of the microenvironment but also may be a reflection of cellular state. CSCs had decreased levels of major classes of neutral lipids compared to non-CSCs, but had significantly increased polyunsaturated fatty acid production due to high fatty acid desaturase (FADS1/2) expression which was essential to maintain CSC viability and self-renewal. Our data demonstrate spatially and hierarchically distinct lipid metabolism phenotypes occur clinically in the majority of patients, can be recapitulated in laboratory models, and may represent therapeutic targets for GBM.
Subject(s)
Brain Neoplasms/metabolism , Glioblastoma/metabolism , Lipid Metabolism/physiology , Neoplastic Stem Cells/metabolism , Organoids/metabolism , Tumor Microenvironment/physiology , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Glioblastoma/genetics , Glioblastoma/pathology , Humans , Neoplastic Stem Cells/pathology , Organoids/pathology , Tumor Cells, CulturedABSTRACT
Technology is transforming societies worldwide. A major innovation is the emergence of robotics and autonomous systems (RAS), which have the potential to revolutionize cities for both people and nature. Nonetheless, the opportunities and challenges associated with RAS for urban ecosystems have yet to be considered systematically. Here, we report the findings of an online horizon scan involving 170 expert participants from 35 countries. We conclude that RAS are likely to transform land use, transport systems and human-nature interactions. The prioritized opportunities were primarily centred on the deployment of RAS for the monitoring and management of biodiversity and ecosystems. Fewer challenges were prioritized. Those that were emphasized concerns surrounding waste from unrecovered RAS, and the quality and interpretation of RAS-collected data. Although the future impacts of RAS for urban ecosystems are difficult to predict, examining potentially important developments early is essential if we are to avoid detrimental consequences but fully realize the benefits.
Subject(s)
Biodiversity , Ecosystem , Cities , Forecasting , HumansABSTRACT
[This corrects the article DOI: 10.1371/journal.ppat.1002776.].
ABSTRACT
BACKGROUND: A step change in the night environment is taking place, with the large-scale installation of bright, broad-spectrum road lighting such as white light-emitting diodes (LEDs). One justification for this is a reduction in road traffic collisions (RTCs). This study aimed to estimate the effect of new lighting on personal injury RTCs within a large UK city. METHODS: We analysed a 9-year time series of weekly RTC personal injury counts in 132 areas of the city using multilevel modelling. The RTC rate over a full 24-hour period was the primary outcome; darkness and daylight RTC rates were secondary. The background change in RTC rate was separated from the change associated with the number of newly installed bright lamps by including a polynomial underlying time trend for the logarithm of the mean number of collisions per week for each area. The study was based on a rigorous, predesigned and archived protocol. RESULTS: Within-area coefficients for the broad lighting effect were positive; as the number of bright lamps in an area increased, so did the RTC rate. The estimate for the increase in the within-area 24-hour RTC rate is 11% (95% CI 2% to 20%). The estimate of darkness-only RTCs is 16% (95% CI 2% to 32%). If the effect of lighting on darkness RTC rate is adjusted by that for daylight, one obtains 4% (95% CI -12% to +23%). CONCLUSION: No evidence was found for bright lamps leading to an improvement in road safety in any of the analyses. For this city, introducing brighter road lighting may have compromised safety rather than reducing harm.
Subject(s)
Accidents, Traffic/prevention & control , Lighting , Safety , Humans , Multilevel Analysis , United KingdomABSTRACT
Glioblastomas (GBM) are lethal brain tumors where poor outcome is attributed to cellular heterogeneity, therapeutic resistance, and a highly infiltrative nature. These characteristics are preferentially linked to GBM cancer stem cells (GSC), but how GSCs maintain their stemness is incompletely understood and the subject of intense investigation. Here, we identify a novel signaling loop that induces and maintains GSCs consisting of an atypical metalloproteinase, ADAMDEC1, secreted by GSCs. ADAMDEC1 rapidly solubilizes FGF2 to stimulate FGFR1 expressed on GSCs. FGFR1 signaling induces upregulation of ZEB1 via ERK1/2 that regulates ADAMDEC1 expression through miR-203, creating a positive feedback loop. Genetic or pharmacologic targeting of components of this axis attenuates self-renewal and tumor growth. These findings reveal a new signaling axis for GSC maintenance and highlight ADAMDEC1 and FGFR1 as potential therapeutic targets in GBM. SIGNIFICANCE: Cancer stem cells (CSC) drive tumor growth in many cancers including GBM. We identified a novel sheddase, ADAMDEC1, which initiates an FGF autocrine loop to promote stemness in CSCs. This loop can be targeted to reduce GBM growth.This article is highlighted in the In This Issue feature, p. 1469.
Subject(s)
ADAM Proteins/metabolism , Brain Neoplasms/metabolism , Glioblastoma/metabolism , Neoplastic Stem Cells/metabolism , Signal Transduction , Animals , Brain Neoplasms/genetics , Cell Line, Tumor , Feedback, Physiological , Female , Fibroblast Growth Factor 2/metabolism , Glioblastoma/genetics , Humans , MicroRNAs/genetics , Neoplasm Transplantation , Receptor, Fibroblast Growth Factor, Type 1/metabolism , Zinc Finger E-box-Binding Homeobox 1/metabolismABSTRACT
Bacteria and archaea make up most of natural diversity, but the mechanisms that underlie the origin and maintenance of prokaryotic species are poorly understood. We investigated the speciation history of the genus Salmonella, an ecologically diverse bacterial lineage, within which S. enterica subsp. enterica is responsible for important human food-borne infections. We performed a survey of diversity across a large reference collection using multilocus sequence typing, followed by genome sequencing of distinct lineages. We identified 11 distinct phylogroups, 3 of which were previously undescribed. Strains assigned to S. enterica subsp. salamae are polyphyletic, with two distinct lineages that we designate Salamae A and B. Strains of the subspecies houtenae are subdivided into two groups, Houtenae A and B, and are both related to Selander's group VII. A phylogroup we designate VIII was previously unknown. A simple binary fission model of speciation cannot explain observed patterns of sequence diversity. In the recent past, there have been large-scale hybridization events involving an unsampled ancestral lineage and three distantly related lineages of the genus that have given rise to Houtenae A, Houtenae B and VII. We found no evidence for ongoing hybridization in the other eight lineages, but detected subtler signals of ancient recombination events. We are unable to fully resolve the speciation history of the genus, which might have involved additional speciation-by-hybridization or multi-way speciation events. Our results imply that traditional models of speciation by binary fission and divergence are not sufficient to account for Salmonella evolution.
Subject(s)
Salmonella enterica/genetics , Salmonella/classification , Salmonella/genetics , Bacterial Typing Techniques/methods , Biological Evolution , Classification/methods , Evolution, Molecular , Genetic Speciation , Multilocus Sequence Typing/methods , Nucleic Acid Hybridization/methods , Phylogeny , Salmonella enterica/metabolismABSTRACT
Breast cancer is the most prevalent malignancy and second leading cause of death in women worldwide, with hormone receptor-positive luminal breast cancers being the most widespread subtype. While these tumors are generally amenable to endocrine therapy, cellular heterogeneity and acquired ability of tumor cells to undergo cell state switching makes these populations difficult to be fully targeted and eradicated through conventional methods. We have leveraged a quality-by-design (QbD) approach that integrates biological responses with predictive mathematical modeling to identify key combinations of commercially available drugs to induce estrogen receptor expression for therapeutic targeting. This technology utilizes a high level of automation through a custom-built platform to reduce bias as well as design-of-experiments methodology to minimize the experimental iterations required. Utilizing this approach, we identified a combination of clinical compounds, each at concentrations well below their efficacious dose, able to induce the expression of estrogen receptor alpha (ESR1) in hormone-positive breast cancer cells. Induction of ESR1 in luminal cells leads to chemosensitization. These findings provide proof of concept for the utility of the QbD strategy and identify a unique drug cocktail able to sensitize breast cancer cells to tamoxifen.
Subject(s)
Antineoplastic Combined Chemotherapy Protocols/pharmacology , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Estrogen Receptor alpha/biosynthesis , Tamoxifen/pharmacology , Antineoplastic Agents, Hormonal/pharmacology , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Drug Resistance, Neoplasm , Estradiol/pharmacology , Estrogen Receptor alpha/metabolism , Everolimus/administration & dosage , Female , Humans , Hydroxamic Acids/administration & dosage , Indazoles/administration & dosage , MCF-7 Cells , Paclitaxel/administration & dosage , Sulfonamides/administration & dosage , Tamoxifen/analogs & derivatives , Tumor Cells, CulturedABSTRACT
Gap-junction-mediated cell-cell communication enables tumor cells to synchronize complex processes. We previously found that glioblastoma cancer stem cells (CSCs) express higher levels of the gap junction protein Cx46 compared to non-stem tumor cells (non-CSCs) and that this was necessary and sufficient for CSC maintenance. To understand the mechanism underlying this requirement, we use point mutants to disrupt specific functions of Cx46 and find that Cx46-mediated gap-junction coupling is critical for CSCs. To develop a Cx46 targeting strategy, we screen a clinically relevant small molecule library and identify clofazimine as an inhibitor of Cx46-specific cell-cell communication. Clofazimine attenuates proliferation, self-renewal, and tumor growth and synergizes with temozolomide to induce apoptosis. Although clofazimine does not cross the blood-brain barrier, the combination of clofazimine derivatives optimized for brain penetrance with standard-of-care therapies may target glioblastoma CSCs. Furthermore, these results demonstrate the importance of targeting cell-cell communication as an anti-cancer therapy.
Subject(s)
Connexin 43/physiology , Glioblastoma/pathology , Neoplastic Stem Cells/metabolism , Animals , Cell Communication/drug effects , Clofazimine/pharmacology , Connexin 43/antagonists & inhibitors , Connexin 43/genetics , DNA Mutational Analysis , Gap Junctions/physiology , Glioblastoma/metabolism , HeLa Cells , Humans , Mice , NIH 3T3 Cells , Xenograft Model Antitumor AssaysABSTRACT
Glioblastoma (GBM) remains uniformly lethal, and despite a large accumulation of immune cells in the microenvironment, there is limited antitumor immune response. To overcome these challenges, a comprehensive understanding of GBM systemic immune response during disease progression is required. Here, we integrated multiparameter flow cytometry and mass cytometry TOF (CyTOF) analysis of patient blood to determine changes in the immune system among tumor types and over disease progression. Utilizing flow cytometry analysis in a cohort of 259 patients ranging from benign to malignant primary and metastatic brain tumors, we found that GBM patients had a significant elevation in myeloid-derived suppressor cells (MDSCs) in peripheral blood but not immunosuppressive Tregs. In GBM patient tissue, we found that increased MDSC levels in recurrent GBM portended poor prognosis. CyTOF analysis of peripheral blood from newly diagnosed GBM patients revealed that reduced MDSCs over time were accompanied by a concomitant increase in DCs. GBM patients with extended survival also had reduced MDSCs, similar to the levels of low-grade glioma (LGG) patients. Our findings provide a rationale for developing strategies to target MDSCs, which are elevated in GBM patients and predict poor prognosis.
Subject(s)
Brain Neoplasms/immunology , Cell Line/immunology , Glioblastoma/immunology , Myeloid-Derived Suppressor Cells/immunology , Brain Neoplasms/mortality , Brain Neoplasms/pathology , Brain Neoplasms/secondary , Cell Line/drug effects , Disease Progression , Female , Flow Cytometry/methods , Glioblastoma/pathology , Humans , Longitudinal Studies , Male , Myeloid-Derived Suppressor Cells/drug effects , Neoplasm Metastasis , Neoplasm Staging , Prognosis , Survival Analysis , Tumor Microenvironment/drug effectsABSTRACT
Tumors adapt their phenotypes during growth and in response to therapies through dynamic changes in cellular processes. Connexin proteins enable such dynamic changes during development, and their dysregulation leads to disease states. The gap junction communication channels formed by connexins have been reported to exhibit tumor-suppressive functions, including in triple-negative breast cancer (TNBC). However, we find that connexin 26 (Cx26) is elevated in self-renewing cancer stem cells (CSCs) and is necessary and sufficient for their maintenance. Cx26 promotes CSC self-renewal by forming a signaling complex with the pluripotency transcription factor NANOG and focal adhesion kinase (FAK), resulting in NANOG stabilization and FAK activation. This FAK/NANOG-containing complex is not formed in mammary epithelial or luminal breast cancer cells. These findings challenge the paradigm that connexins are tumor suppressors in TNBC and reveal a unique function for Cx26 in regulating the core self-renewal signaling that controls CSC maintenance.
Subject(s)
Cell Self Renewal , Connexins/metabolism , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Nanog Homeobox Protein/metabolism , Neoplastic Stem Cells/metabolism , Triple Negative Breast Neoplasms/metabolism , Animals , Cell Line, Tumor , Connexin 26 , Female , Humans , MCF-7 Cells , Mammary Glands, Human/metabolism , Mice , Mice, SCID , Neoplasm TransplantationABSTRACT
This data article presents the UK City LIFE1 data set for the city of Birmingham, UK. UK City LIFE1 is a new, comprehensive and holistic method for measuring the livable sustainability performance of UK cities. The Birmingham data set comprises 346 indicators structured simultaneously (1) within a four-tier, outcome-based framework in order to aid in their interpretation (e.g., promote healthy living and healthy long lives, minimize energy use, uncouple economic vitality from CO2 emissions) and (2) thematically in order to complement government and disciplinary siloes (e.g., health, energy, economy, climate change). Birmingham data for the indicators are presented within an Excel spreadsheet with their type, units, geographic area, year, source, link to secondary data files, data collection method, data availability and any relevant calculations and notes. This paper provides a detailed description of UK city LIFE1 in order to enable comparable data sets to be produced for other UK cities. The Birmingham data set is made publically available at http://epapers.bham.ac.uk/3040/ to facilitate this and to enable further analyses. The UK City LIFE1 Birmingham data set has been used to understand what is known and what is not known about the livable sustainability performance of the city and to inform how Birmingham City Council can take action now to improve its understanding and its performance into the future (see "Improving city-scale measures of livable sustainability: A study of urban measurement and assessment through application to the city of Birmingham, UK" Leach et al. [2]).
ABSTRACT
Effective targeting of cancer stem cells (CSCs) requires neutralization of self-renewal and chemoresistance, but these phenotypes are often regulated by distinct molecular mechanisms. Here we report the ability to target both of these phenotypes via CD55, an intrinsic cell surface complement inhibitor, which was identified in a comparative analysis between CSCs and non-CSCs in endometrioid cancer models. In this context, CD55 functions in a complement-independent manner and required lipid raft localization for CSC maintenance and cisplatin resistance. CD55 regulated self-renewal and core pluripotency genes via ROR2/JNK signaling and in parallel cisplatin resistance via lymphocyte-specific protein tyrosine kinase (LCK) signaling, which induced DNA repair genes. Targeting LCK signaling via saracatinib, an inhibitor currently undergoing clinical evaluation, sensitized chemoresistant cells to cisplatin. Collectively, our findings identify CD55 as a unique signaling node that drives self-renewal and therapeutic resistance through a bifurcating signaling axis and provides an opportunity to target both signaling pathways in endometrioid tumors.
Subject(s)
Antineoplastic Agents/therapeutic use , CD55 Antigens/physiology , Cell Self Renewal/physiology , Cisplatin/therapeutic use , Endometrial Neoplasms/physiopathology , Animals , Cell Line, Tumor , Drug Resistance, Neoplasm , Endometrial Neoplasms/drug therapy , Female , Mice , Mice, SCID , Neoplasm Transplantation , Neoplastic Stem Cells/physiology , Signal TransductionABSTRACT
Brain tumors represent some of the most malignant cancers in both children and adults. Current treatment options target the majority of tumor cells but do not adequately target self-renewing cancer stem cells (CSCs). CSCs have been reported to resist the most aggressive radiation and chemotherapies, and give rise to recurrent, treatment-resistant secondary malignancies. With advancing technologies, we now have a better understanding of the genetic, epigenetic and molecular signatures and microenvironmental influences which are useful in distinguishing between distinctly different tumor subtypes. As a result, efforts are now underway to identify and target CSCs within various tumor subtypes based on this foundation. This review discusses progress in CSC biology as it relates to targeted therapies which may be uniquely different between pediatric and adult brain tumors. Studies to date suggest that pediatric brain tumors may benefit more from genetic and epigenetic targeted therapies, while combination treatments aimed specifically at multiple molecular pathways may be more effective in treating adult brain tumors which seem to have a greater propensity towards microenvironmental interactions. Ultimately, CSC targeting approaches in combination with current clinical therapies have the potential to be more effective owing to their ability to compromise CSCs maintenance and the mechanisms which underlie their highly aggressive and deadly nature.
Subject(s)
Brain Neoplasms/physiopathology , Brain Neoplasms/therapy , Neoplastic Stem Cells/physiology , Adult , Brain Neoplasms/genetics , Child , Child, Preschool , Drug Resistance, Neoplasm , Epigenesis, Genetic , Humans , Tumor MicroenvironmentABSTRACT
Researchers have explored the concept of attachment in multiple ways, from animal studies examining imprinting to abnormal attachment in psychopathology. However, until recently, few have considered how neural circuitry develops the effective social bonds that are subsequently replicated in relationships across the lifespan. This current cross-sectional study undertook a fMRI Activation Likelihood Estimation (ALE) meta-analyses to examine the neurocircuitry that governs emotional and behavioural functions critical for building effective social relationships in children and adults. Results suggest that dissociable dorsal cognitive ("cool") and ventral - affective ("hot") frontal-subcortical circuits (FSC) work together to govern social relationships, with repeated social consequences leading to potentially adaptive - or maladaptive - relationships that can become routinized in the cerebellum. Implications for forming stable, functional, social bonds are considered, followed by recommendations for those who struggle with cool and hot FSC functioning that can hinder the development of adaptive prosocial relationships.
Subject(s)
Brain Mapping/methods , Brain/physiology , Empathy/physiology , Executive Function/physiology , Object Attachment , Reward , Social Behavior , Adult , Brain/diagnostic imaging , Child , Humans , Magnetic Resonance ImagingABSTRACT
Tumors contain hostile inflammatory signals generated by aberrant proliferation, necrosis, and hypoxia. These signals are sensed and acted upon acutely by the Toll-like receptors (TLRs) to halt proliferation and activate an immune response. Despite the presence of TLR ligands within the microenvironment, tumors progress, and the mechanisms that permit this growth remain largely unknown. We report that self-renewing cancer stem cells (CSCs) in glioblastoma have low TLR4 expression that allows them to survive by disregarding inflammatory signals. Non-CSCs express high levels of TLR4 and respond to ligands. TLR4 signaling suppresses CSC properties by reducing retinoblastoma binding protein 5 (RBBP5), which is elevated in CSCs. RBBP5 activates core stem cell transcription factors, is necessary and sufficient for self-renewal, and is suppressed by TLR4 overexpression in CSCs. Our findings provide a mechanism through which CSCs persist in hostile environments because of an inability to respond to inflammatory signals.
Subject(s)
Cell Self Renewal/immunology , Glioblastoma/immunology , Glioblastoma/pathology , Immune Evasion , Immunity, Innate , Neoplastic Stem Cells/pathology , Toll-Like Receptor 4/metabolism , Animals , Cell Line, Tumor , Cell Proliferation , DNA-Binding Proteins , Female , Humans , Mice , Models, Biological , Nuclear Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Signal TransductionABSTRACT
OBJECTIVES: Tracheal intubation is the cornerstone of advanced emergency airway management in children and adults and there is good-quality data characterizing intubation in both groups. There are, however, few published studies on emergency tracheal intubation in adolescents. We carried out an observational study to characterize tracheal intubation in adolescents. METHODS: We analysed data from a previously collected Emergency Department Intubation Registry. We included all attempts at tracheal intubation performed in our adult emergency department between 1999 and 2011. We recorded the indication for intubation, the staff involved, the technique and drugs used, and the rates of successful intubation and adverse events. We classified patients into three age groups: 13-16 years (adolescent), 17-24 years (young adult) and at least 25 years (older adult). RESULTS: Trauma was the most common indication for intubation in adolescents, and rapid sequence induction was used in 88% of cases. Ninety-nine percent of tracheal intubations in adolescent patients were successful on the first or the second attempt, no adolescent underwent more than three attempts and none required a surgical airway. The initial intubation attempt in adolescents was more likely to be performed by an anaesthetist (P<0.005). The first attempt success rate was higher (P<0.01) and adverse event rate was lower (P<0.05) in adolescents than in adults. Hypotension was the only adverse event recorded in adolescents; this occurred in three patients (4.5%). CONCLUSION: Our findings suggest that the airway in adolescent patients can be managed successfully and safely in an adult emergency department where there is close collaboration between anaesthetists and emergency physicians.
Subject(s)
Emergency Medical Services/methods , Emergency Service, Hospital/statistics & numerical data , Hospitals, Urban , Intubation, Intratracheal/methods , Outcome Assessment, Health Care , Patient Safety , Adolescent , Adult , Age Factors , Airway Management/methods , Cohort Studies , Female , Humans , Intubation, Intratracheal/adverse effects , Male , Registries , Retrospective Studies , Risk Assessment , Treatment Outcome , United KingdomABSTRACT
Shifting the balance away from tumor-mediated immune suppression toward tumor immune rejection is the conceptual foundation for a variety of immunotherapy efforts currently being tested. These efforts largely focus on activating antitumor immune responses but are confounded by multiple immune cell populations, including myeloid-derived suppressor cells (MDSCs), which serve to suppress immune system function. We have identified immune-suppressive MDSCs in the brains of GBM patients and found that they were in close proximity to self-renewing cancer stem cells (CSCs). MDSCs were selectively depleted using 5-flurouracil (5-FU) in a low-dose administration paradigm, which resulted in prolonged survival in a syngeneic mouse model of glioma. In coculture studies, patient-derived CSCs but not nonstem tumor cells selectively drove MDSC-mediated immune suppression. A cytokine screen revealed that CSCs secreted multiple factors that promoted this activity, including macrophage migration inhibitory factor (MIF), which was produced at high levels by CSCs. Addition of MIF increased production of the immune-suppressive enzyme arginase-1 in MDSCs in a CXCR2-dependent manner, whereas blocking MIF reduced arginase-1 production. Similarly to 5-FU, targeting tumor-derived MIF conferred a survival advantage to tumor-bearing animals and increased the cytotoxic T cell response within the tumor. Importantly, tumor cell proliferation, survival, and self-renewal were not impacted by MIF reduction, demonstrating that MIF is primarily an indirect promoter of GBM progression, working to suppress immune rejection by activating and protecting immune suppressive MDSCs within the GBM tumor microenvironment. Stem Cells 2016;34:2026-2039.
Subject(s)
Brain Neoplasms/immunology , Glioblastoma/immunology , Immune Evasion , Macrophage Migration-Inhibitory Factors/metabolism , Myeloid-Derived Suppressor Cells/metabolism , Neoplastic Stem Cells/metabolism , Animals , Arginase/metabolism , Brain Neoplasms/pathology , Carcinogenesis/metabolism , Carcinogenesis/pathology , Cell Line, Tumor , Cell Survival/drug effects , Culture Media, Conditioned/pharmacology , Female , Glioblastoma/pathology , Humans , Immune Evasion/drug effects , Mice, Inbred C57BL , Mice, Nude , Myeloid-Derived Suppressor Cells/drug effects , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/pathology , Tumor Microenvironment/drug effectsABSTRACT
The mainstay of treatment for ovarian cancer is platinum-based cytotoxic chemotherapy. However, therapeutic resistance and recurrence is a common eventuality for nearly all ovarian cancer patients, resulting in poor median survival. Recurrence is postulated to be driven by a population of self-renewing, therapeutically resistant cancer stem cells (CSCs). A current limitation in CSC studies is the inability to interrogate their dynamic changes in real time. Here we utilized a GFP reporter driven by the NANOG-promoter to enrich and track ovarian CSCs. Using this approach, we identified a population of cells with CSC properties including enhanced expression of stem cell transcription factors, self-renewal, and tumor initiation. We also observed elevations in CSC properties in cisplatin-resistant ovarian cancer cells as compared to cisplatin-naïve ovarian cancer cells. CD49f, a marker for CSCs in other solid tumors, enriched CSCs in cisplatin-resistant and -naïve cells. NANOG-GFP enriched CSCs (GFP+ cells) were more resistant to cisplatin as compared to GFP-negative cells. Moreover, upon cisplatin treatment, the GFP signal intensity and NANOG expression increased in GFP-negative cells, indicating that cisplatin was able to induce the CSC state. Taken together, we describe a reporter-based strategy that allows for determination of the CSC state in real time and can be used to detect the induction of the CSC state upon cisplatin treatment. As cisplatin may provide an inductive stress for the stem cell state, future efforts should focus on combining cytotoxic chemotherapy with a CSC targeted therapy for greater clinical utility.
Subject(s)
Cell Self Renewal/genetics , Cisplatin/pharmacology , Gene Expression Regulation, Neoplastic/drug effects , Neoplastic Stem Cells/metabolism , Ovarian Neoplasms/genetics , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Female , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Humans , Mice, Inbred NOD , Mice, Knockout , Mice, SCID , Nanog Homeobox Protein/genetics , Nanog Homeobox Protein/metabolism , Ovarian Neoplasms/metabolism , Ovarian Neoplasms/pathology , Promoter Regions, Genetic/genetics , Time-Lapse Imaging/methods , Transplantation, HeterologousABSTRACT
Children with specific learning disabilities (SLD) have disparate neuropsychological processing deficits that interfere with academic achievement in spelling, writing fluency, and/or written expression (WE). Although there are multiple potential causes of WE SLD, there is a paucity of research exploring this critical academic skill from a neuropsychological perspective. This study examined the neuropsychological profiles of WE SLD subtypes defined using the concordance-discordance model (C-DM) of SLD identification. Participants were drawn from a sample of 283 children (194 boys, 89 girls) aged 6 years to 16 years old (M(age) = 9.58 years, SD = 2.29 years) referred for comprehensive neuropsychological evaluations in school settings and subsequently selected based on C-DM determined spelling, writing fluency, and WE SLD. WE SLD subtypes differed on several psychomotor, memory, and executive function measures (F range = 2.48-5.07, p range = .049 to <.001), suggesting that these children exhibit distinct patterns of neuropsychological processing strengths and weaknesses. Findings have relevance for differential diagnosis of WE subtypes, discriminating WE SLD subtypes from low WE achievement, and developing differentiated evidence-based instruction and intervention for children with WE SLD. Limitations and future research will be addressed.