44 research outputs found
Untargeted Metabolomic Characterization of Glioblastoma Intra-Tumor Heterogeneity Using OrbiSIMS
Glioblastoma (GBM) is an incurable brain cancer with a median survival of less than two years from diagnosis. The standard treatment of GBM is multimodality therapy comprising surgical resection, radiation, and chemotherapy. However, prognosis remains poor, and there is an urgent need for effective anticancer drugs. Since different regions of a single GBM contain multiple cancer subpopulations ("intra-tumor heterogeneity"), this likely accounts for therapy failure as certain cancer cells can escape from immune surveillance and therapeutic threats. Here, we present metabolomic data generated using the Orbitrap secondary ion mass spectrometry (OrbiSIMS) technique to investigate brain tumor metabolism within its highly heterogeneous tumor microenvironment. Our results demonstrate that an OrbiSIMS-based untargeted metabolomics method was able to discriminate morphologically distinct regions (viable, necrotic, and non-cancerous) within single tumors from formalin-fixed paraffin-embedded tissue archives. Specifically, cancer cells from necrotic regions were separated from viable GBM cells based on a set of metabolites including cytosine, phosphate, purine, xanthine, and 8-hydroxy-7-methylguanine. Moreover, we mapped ubiquitous metabolites across necrotic and viable regions into metabolic pathways, which allowed for the discovery of tryptophan metabolism that was likely essential for GBM cellular survival. In summary, this study first demonstrated the capability of OrbiSIMS for in situ investigation of GBM intra-tumor heterogeneity, and the acquired information can potentially help improve our understanding of cancer metabolism and develop new therapies that can effectively target multiple subpopulations within a tumor
Histopathological impact of Redox-responsive methacrylamide based micellar nanoparticles on Orthotopic Models of Triple Negative Breast Cancers
The therapeutic efficacy of anticancer nanocarriers ishighly dependent on their size, shape, targeting ability, and stimuli-responsiveness. Herein, we studied the in vivo therapeutic efficacy ofDoxorubicin (Dox) loaded redox responsive micellar-like nanoparticles (MNPs) based on linear 2-hydroxypropyl methacrylamide (HPMA) via histopathological evaluations. The therapeutic efficacy of DOX-loaded micellar-like Nanoparticles significantly improved while the side effects reduced as confirmed by histopathological examinations. H&E and tunnel staining of tumor tissues indicated the higher population of apoptotic tumor cells in both treatment groups containing DOX. These redox responsive crosslinked HPMA-based micellar-like nanoparticles with acceptable therapeutic efficacy and apoptosis induction in cancerous cells proved to be promising nanomedicine for breast cancer chemotherapy
Antitumor activity and safety of pembrolizumab in patients with advanced recurrent ovarian cancer: results from the phase II KEYNOTE-100 study
BACKGROUND: Advanced recurrent ovarian cancer (ROC) is the leading cause of gynecologic cancer-related death in developed countries and new treatments are needed. Previous studies of immune checkpoint blockade showed low objective response rates (ORR) in ROC with no identified predictive biomarker. PATIENTS AND METHODS: This phase II study of pembrolizumab (NCT02674061) examined two patient cohorts with ROC: cohort A received one to three prior lines of treatment with a platinum-free interval (PFI) or treatment-free interval (TFI) between 3 and 12months and cohort B received four to six prior lines with a PFI/TFI of ≥3months. Pembrolizumab 200mg was administered intravenously every 3weeks until cancer progression, toxicity, or completion of 2years. Primary end points were ORR by Response Evaluation Criteria in Solid Tumors version 1.1 per blinded independent central review by cohort and by PD-L1 expression measured as combined positive score (CPS). Secondary end points included duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Cohort A enrolled 285 patients; the first 100 served as the training set for PD-L1 biomarker analysis. Cohort B enrolled 91 patients. ORR was 7.4% for cohort A and 9.9% for cohort B. Median DOR was 8.2months for cohort A and not reached for cohort B. DCR was 37.2% and 37.4%, respectively, in cohorts A and B. Based on the training set analysis, CPS 1 and 10 were selected for evaluation in the confirmation set. In the confirmation set, ORR was 4.1% for CPS<1, 5.7% CPS ≥1, and 10.0% for CPS ≥10. PFS was 2.1months for both cohorts. Median OS was not reached for cohort A and was 17.6months for cohort B. Toxicities were consistent with other single-agent pembrolizumab trials. CONCLUSIONS: Single-agent pembrolizumab showed modest activity in patients with ROC. Higher PD-L1 expression was correlated with higher response. CLINICAL TRIAL NUMBER: Clinicaltrials.gov, NCT02674061. ispartof: Ann Oncol vol:30 issue:7 pages:1080-1087 ispartof: location:England status: publishe
Method of Analysis of the Resilience and Adaptability in Social Housing Developments through Post-occupancy Evaluation and Co-production. Final research report
The current social and climatic changes observed require an urgent revision of urbanization strategies around the
world, to reduce environmental and social impacts, as well as to develop the resilience of built environments. The
main challenges are the use of constructive systems and appropriate materials, design techniques and construction
for specific climatic zones, besides the existent habitational adaptation with new technologies. In developing
countries, the low level of quality in architecture and urbanism increase the social vulnerability that affects millions
of people who find it difficult to find adequate housing, which in turn is found in precarious conditions. When the
governmental housing programmes try to balance out this deficit, the low quality of defined standards lead to highly
inadequate houses for the residents, obligating them to make modifications to buildings which are not necessarily
prepared for these adaptations, leading to the waste of material and the inefficient use of resources.
This Project will use advanced Post-Occupancy Evaluation (POE) techniques to develop methodological analysis
procedures together with Social Housing Developments. The analysis will focus on the adaptive and transformative
capacities alongside the resilience of the built environment in attendance to the necessities of the residents and the
subsequent environmental impact caused by these ongoing transformations. The analysis will be centred on three
elements: (i) BUILT ENVIRONMENT (building complex, taking into consideration the scales of the district,
neighbourhood and unit, and the relation of impact between the built and natural environments; (ii) AGENTS (agents
that interfere with the local social dynamic); (iii) USERS (residents of the complex). The evaluation will focus on
social, functional, behavioural and environmental issues of the built environment. For verification, the
methodological procedures developed will be applied to a case study in the city of Uberlandia - Brazil, specifically the undertaking of the governmental programme "minha casa, minha vida" located in the western area of the city
Role of Self‐Assembly Conditions and Amphiphilic Balance on Nanoparticle Formation of PEG‐PDLLA Copolymers in Aqueous Environments
The production of well-defined and reproducible poly-meric nanoparticles (NPs), in terms of size and stability in biological environments, is undoubtedly a fundamental challenge in the formulation of novel and more effective nanomedicines. The adoption of PEGylated lactide (LA) block copolymers as biodegradable and biocompatible nanocarriers at different clinical stages has rendered these materials an attractive polymeric platform to be exploited and their formulation is further understood. In the present work, we synthesized a library of linear polyethyl-ene glycol-poly(D,L-lactide) block copolymers with different lengths of LA (15, 25, 50, and 100 LA units) via simple and metal-free ring-opening polymerization, in order to alter the amphi-philic balance of the different macromolecules. The produced polymers were formulated into NPs while varying a series of key parameters in the solvent displacement process, including solvent:nonsolvent ratios and the nature of the two media, and the effect on size and stability was assessed. In addition, stability to protein-NPs interaction and aggregation was studied, highlighting the different NP final properties according to the nature of the amphiphilic balance and nanoformulation conditions. Therefore, we have illustrated a systematic and methodo-logical process to optimize a series of NPs parameters balancing particle size, size distribution, surface charge, and stability to guide future works in the nanoformulation field
Functionalized block co-polymer pro-drug nanoparticles with anti-cancer efficacy in 3D spheroids and in an orthotopic triple negative breast cancer model
Amphiphilic block co-polymers composed of poly(ethylene glycol)-co-poly(lactide)-co-poly(2-((tert-butoxycarbonyl)amino)-3-propyl carbonate) (PEG-pLA-pTBPC) are synthesized in monomer ratios and arrangements to enable assembly into nanoparticles with different sizes and architectures. These materials are based on components in clinical use, or known to be biodegradable, and retain the same fundamental chemistry across 'AB' and 'BAB' block architectures. In MCF7 and MDA-MB-231 breast cancer cells, nanoparticles of < 100 nm are internalized most rapidly, by both clathrin-and caveolin-mediated pathways. In THP-1 cells, polymer architecture and length of the hydrophilic block is the most important factor in the rate of internalization. The organ distributions of systemically injected nanoparticles in healthy mice indicate highest accumulation of the BAB-blocks in lungs and liver and the lowest accumulation in these organs of a methoxyPEG5000-pLA-pTBPC polymer. Conjugation of doxorubicin via a serum-stable urea linker to the carbonate regions of PEG5000-pLA-pTBPC generates self-assembling nanoparticles which are more cytotoxic in 2D, and penetrate further in 3D spheroids of triple negative breast cancer cells, than the free drug. In an aggressive orthotopic triple negative breast cancer mouse model, the methoxyPEG5000-pLA-pTBPC is of similar potency to free doxorubicin but with no evidence of adverse effects in terms of body weight
RHPS4 G-quadruplex ligand induces anti-proliferative effects in brain tumor cells
Background
Telomeric 3’ overhangs can fold into a four-stranded DNA structure termed G-quadruplex (G4), a formation which inhibits telomerase. As telomerase activation is crucial for telomere maintenance in most cancer cells, several classes of G4 ligands have been designed to directly disrupt telomeric structure.
Methods
We exposed brain tumor cells to the G4 ligand 3,11-difluoro-6,8,13-trimethyl-8H-quino[4,3,2-kl]acridinium methosulfate (RHPS4) and investigated proliferation, cell cycle dynamics, telomere length, telomerase activity and activated c-Myc levels.
Results
Although all cell lines tested were sensitive to RHPS4, PFSK-1 central nervous system primitive neuroectodermal cells, DAOY medulloblastoma cells and U87 glioblastoma cells exhibited up to 30-fold increased sensitivity compared to KNS42 glioblastoma, C6 glioma and Res196 ependymoma cells. An increased proportion of S-phase cells were observed in medulloblastoma and high grade glioma cells whilst CNS PNET cells showed an increased proportion of G1-phase cells. RHPS4-induced phenotypes were concomitant with telomerase inhibition, manifested in a telomere length-independent manner and not associated with activated c-Myc levels. However, anti-proliferative effects were also observed in normal neural/endothelial cells in vitro and ex vivo.
Conclusion
This study warrants in vivo validation of RHPS4 and alternative G4 ligands as potential anti-cancer agents for brain tumors but highlights the consideration of dose-limiting tissue toxicities