20,582 research outputs found
The ambitious role of anti angiogenesis molecules: Turning a cold tumor into a hot one
In renal cancer emerging treatment options are becoming available and there is a strong need to combine therapies to reformulate and adjourn clinical practice. We here highlight and discuss the need to take advantage of the common immune targets to design combined strategies to increase clinical responses
Kidney cancer: The next decade
Chris Boshoff, Senior Vice President of Immuno-Oncology, Translational and Early Development at Pfizer, and colleagues Samra Turajlic and Charles Swanton from the Francis Crick Institute and University College London give us their personal point of view on new insights and future therapeutic approaches for renal cancer
Potential role of immunotherapy in advanced non-small-cell lung cancer
Immuno checkpoint inhibitors have ushered in a new era with respect to the treatment of advanced non-small-cell lung cancer. Many patients are not suitable for treatment with epidermal growth factor receptor tyrosine kinase inhibitors (eg, gefitinib, erlotinib, and afatinib) or with anaplastic lymphoma kinase inhibitors (eg, crizotinib and ceritinib). As a result, anti-PD- 1/PD-L1 and CTLA-4 inhibitors may play a novel role in the improvement of outcomes in a metastatic setting. The regulation of immune surveillance, immunoediting, and immunoescape mechanisms may play an interesting role in this regard either alone or in combination with current drugs. Here, we discuss advances in immunotherapy for the treatment of metastatic non-small-cell lung cancer as well as future perspectives within this framework.Pierre Fabr
Inhibition of bromodomain and extra-terminal (BET) proteins increases NKG2D ligand MICA expression and sensitivity to NK cell-mediated cytotoxicity in multiple myeloma cells. role of cMYC-IRF4-miR-125b interplay
Background: Anticancer immune responses may contribute to the control of tumors after conventional chemotherapy and different observations have indicated that chemotherapeutic agents can induce immune responses resulting in cancer cell death and immune-stimulatory side effects. Increasing experimental and clinical evidence highlight the importance of Natural Killer (NK) cells in immune responses toward Multiple Myeloma (MM) and combination therapies able to enhance the activity of NK cells against MM are showing promise in treating this hematologic cancer.
The epigenetic readers of acetylated histones Bromodomain and Extra-Terminal (BET) proteins are critical regulators of gene expression. In cancer, they can upregulate transcription of key oncogenes such as cMYC, IRF4, BCL-2 and others. In addition, the activity of these proteins can regulate the expression of osteoclastogenic cytokines during cancer progression. Here, we investigated the effect of BET-bromodomain proteins inhibition, on the expression of Natural Killer (NK) cell-activating ligands in Multiple Myeloma (MM) cells.
Methods: Five MM cell lines [SKO-007(J3), U266, RPMI-8226, ARP-1, JJN3] and CD138+ MM cells isolated from MM patients were used to investigate the activity of BET bromodomain inhibitors (BETi) (JQ1 and I-BET-151) and of the selective BRD4-degrader PROTAC (Proteolysis Targeting Chimera) (ARV-825), on the expression and function of several NK cell activating ligands (NKG2DLs and DNAM-1Ls), using Flow Cytometry, Real-Time PCR, transient transfections and degranulation assays.
Results: Our results indicate that inhibition of BET proteins via small molecule inhibitors or their degradation via a hetero-bifunctional Proteolysis Targeting Chimera (PROTAC) probe can enhance the expression of MICA, a ligand of the NKG2D receptor, in human MM cell lines and primary malignant plasma cells, rendering myeloma cells more efficient to activate NK cell degranulation. Noteworthy, similar results were obtained using selective CBP/EP300 bromodomain inhibition. Mechanistically, we found that BETi-mediated inhibition of cMYC correlates with the upregulation of miR-125b-5p and the downregulation of the cMYC/miR-125b-5p target gene IRF4, a transcriptional repressor of MICA.
Conclusions: These findings provide new insights on the immuno-mediated antitumor activities of BETi and further elucidate the molecular mechanisms that regulate NK cell-activating ligand expression in MM
Glycosylation of glycolipids in cancer: basis for development of novel therapeutic approaches
Altered networks of gene regulation underlie many pathologies, including cancer. There are several proteins in cancer cells that are turned either on or off, which dramatically alters the metabolism and the overall activity of the cell, with the complex machinery of enzymes involved in the metabolism of glycolipids not being an exception. The aberrant glycosylation of glycolipids on the surface of the majority of cancer cells, associated with increasing evidence about the functional role of these molecules in a number of cellular physiological pathways, has received considerable attention as a convenient immunotherapeutic target for cancer treatment. This has resulted in the development of a substantial number of passive and active immunotherapies, which have shown promising results in clinical trials. More recently, antibodies to glycolipids have also emerged as an attractive tool for the targeted delivery of cytotoxic agents, thereby providing a rationale for future therapeutic interventions in cancer. This review first summarizes the cellular and molecular bases involved in the metabolic pathway and expression of glycolipids, both in normal and tumor cells, paying particular attention to sialosylated glycolipids (gangliosides). The current strategies in the battle against cancer in which glycolipids are key players are then described.Fil: Daniotti, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Vilcaes, Aldo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Torres Demichelis, Vanina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Ruggiero, Fernando Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; ArgentinaFil: Rodríguez Walker, Macarena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigaciones en Química Biológica de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Centro de Investigaciones en Química Biológica de Córdoba; Argentin
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RARE-30. PEDIATRIC GLIOBLASTOMA IN THE POST-TEMOZOLOMIDE ERA: OUTCOMES AND CHARACTERISTICS
Abstract
INTRODUCTION
Glioblastoma (GBM) is the most common brain tumor, however, is a rare occurrence in children and is poorly characterized. We evaluated the characteristics and outcomes of pediatric GBM (pGBM).
METHODS
Retrospective analysis of pediatric (age< 18) patients diagnosed with GBM undergoing first glioblastoma resection at our brain tumor center (2005- 2016).
RESULTS
From 1457 GBM patients, we identified twenty-four (1.65%) pGBMs (Median Age=9 years, Females=45.8%). Median overall survival (OS) was 32.1 months, while the median progression-free survival was 11.5 months. The commonest symptoms at presentation were headaches (54.2%,n=13) and motor symptoms (50%,n=12). Mean tumor diameter was 4.5 cm and 25% of the cohort underwent gross total resection (GTR) of their tumor. Univariate analysis revealed median OS significantly associated with tumor extent of resection (GTR=56.4 months; STR/Biopsy=13.7 months, p=0.001), age at surgery (>10 years=43.9 months, < 10 years= 17.2 months, p=0.01), tumor size (> 4cm= 9.1 months, < 4cm=56.9 months, p=0.01),motor symptoms at presentation (present=14.9 months, absent=41.04 months, p=0.02) and infratentorial tumors (infratentorial=17.4 vs supratentorial=53.4 months, p=0.02). Multivariate analysis revealed GTR (HR 0.2[95% CI 0.07–0.72]; p=0.03), Age >10 years (HR 0.6[95% CI 0.02–0.64]; p=0.002), tumor >4 cm (HR 2.89[95% CI 1.88–4.11]; p=0.001) and EGFR amplification (HR 3.48[95% CI 0.82–17.4]; p=0.005) to be independent predictors of OS. Comparing patients under and over 10 years, we found that older patients had smaller tumors at presentation (4.9 vs 3.6 cms, p=0.03), greater rates of preoperative temozolomide (n=1,7.7% vs n=6, 54.5%) and bevacizumab (n=1,7.7% vs n=4, 36.4%) treatment, and lower rates of EGFR amplification (66.7% vs 11.1%) that could explain survival disparities between groups.
CONCLUSION
Motor symptoms, larger tumors at presentation and tumor EGFR amplification may be indictive of poorer outcomes in pGBM. However, maximal tumor resection, aggressive chemoradiation and tumor presentation at age >10 years may confer better prognosis in these patients
A new monoclonal antibody detects downregulation of protein tyrosine phosphatase receptor type γ in chronic myeloid leukemia patients
Background:
Protein tyrosine phosphatase receptor gamma (PTPRG) is a ubiquitously expressed member of the protein tyrosine phosphatase family known to act as a tumor suppressor gene in many different neoplasms with mechanisms of inactivation including mutations and methylation of CpG islands in the promoter region. Although a critical role in human hematopoiesis and an oncosuppressor role in chronic myeloid leukemia (CML) have been reported, only one polyclonal antibody (named chPTPRG) has been described as capable of recognizing the native antigen of this phosphatase by flow cytometry. Protein biomarkers of CML have not yet found applications in the clinic, and in this study, we have analyzed a group of newly diagnosed CML patients before and after treatment. The aim of this work was to characterize and exploit a newly developed murine monoclonal antibody specific for the PTPRG extracellular domain (named TPγ B9-2) to better define PTPRG protein downregulation in CML patients.
Methods:
TPγ B9-2 specifically recognizes PTPRG (both human and murine) by flow cytometry, western blotting, immunoprecipitation, and immunohistochemistry.
Results:
Co-localization experiments performed with both anti-PTPRG antibodies identified the presence of isoforms and confirmed protein downregulation at diagnosis in the Philadelphia-positive myeloid lineage (including CD34+/CD38bright/dim cells). After effective tyrosine kinase inhibitor (TKI) treatment, its expression recovered in tandem with the return of Philadelphia-negative hematopoiesis. Of note, PTPRG mRNA levels remain unchanged in tyrosine kinase inhibitors (TKI) non-responder patients, confirming that downregulation selectively occurs in primary CML cells.
Conclusions:
The availability of this unique antibody permits its evaluation for clinical application including the support for diagnosis and follow-up of these disorders. Evaluation of PTPRG as a potential therapeutic target is also facilitated by the availability of a specific reagent capable to specifically detect its target in various experimental conditions
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