118 results found
Tsiailanis AD, Renziehausen A, Kiriakidi S, et al., 2020, Enhancement of glioblastoma multiforme therapy through a novel Quercetin-Losartan hybrid., Free Radical Biology and Medicine, Vol: 160, Pages: 391-402, ISSN: 0891-5849
Glioblastoma multiforme (GBM) is the most common and aggressive primary malignant brain tumor. Maximal surgical resection followed by radiotherapy and concomitant chemotherapy with temozolomide remains the first-line therapy, prolonging the survival of patients by an average of only 2.5 months. There is therefore an urgent need for novel therapeutic strategies to improve clinical outcomes. Reactive oxygen species (ROS) are an important contributor to GBM development. Here, we describe the rational design and synthesis of a stable hybrid molecule tethering two ROS regulating moieties, with the aim of constructing a chemopreventive and anticancer chemical entity that retains the properties of the parent compounds. We utilized the selective AT1R antagonist losartan, leading to the inhibition of ROS levels, and the antioxidant flavonoid quercetin. In GBM cells, we show that this hybrid retains the binding potential of losartan to the AT1R through competition-binding experiments and simultaneously exhibits ROS inhibition and antioxidant capacity similar to native quercetin. In addition, we demonstrate that the hybrid is able to alter the cell cycle distribution of GBM cells, leading to cell cycle arrest and to the induction of cytotoxic effects. Last, the hybrid significantly and selectively reduces cancer cell proliferation and angiogenesis in primary GBM cultures with respect to the isolated parent components or their simple combination, further emphasizing the potential utility of the current hybridization approach in GBM.
Diamantis DA, Oblukova M, Chatziathanasiadou MV, et al., 2020, Bioinspired tailoring of fluorogenic thiol responsive antioxidant precursors to protect cells against H2O2-induced DNA damage., Free Radic Biol Med, Vol: 160, Pages: 540-551
Natural antioxidants, like phenolic acids, possess a unique chemical space that can protect cellular components from oxidative stress. However, their polar carboxylic acid chemotype reduces full intracellular antioxidant potential due to limited diffusion through biological membranes. Here, we have designed and developed a new generation of hydrophobic turn-on fluorescent antioxidant precursors that upon penetration of the cell membrane, reveal a more polar and more potent antioxidant core and simultaneously become fluorescent allowing their intracellular tracking. Their activation is stimulated by polarity alteration by sensing intracellular signals and specifically biothiols. In our design, the carboxylic group of phenolic acids that originally restricts cell entrance is derivatized and conjugated through Copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) to a coumarin derivative that its fluorescence properties are quenched with a biothiol activatable element. This more hydrophobic precursor readily penetrates cell membrane and once inside the cell the antioxidant core is revealed upon sensing glutathione, its fluorescence is restored in a turn-on manner and the generation of a more polar character traps the molecule inside the cell. This turn-on fluorescent antioxidant precursor that can be applied to phenolic acids, was developed for rosmarinic acid and the conjugate was named as RCG. The selectivity and responsiveness of RCG towards the most abundant biothiols was monitored through a variety of biophysical techniques including UV-Vis, fluorescence and NMR spectroscopy. The electrochemical behavior and free radical scavenging capacity of the precursor RCG and the active compound (RC) was evaluated and compared with the parent compound (rosmarinic acid) through cyclic voltammetry and EPR spectroscopy, respectively. The stability of the newly synthesized bioactive conjugate RC was found significantly higher than the parent rosmarinic acid when exposed to oxy
Benito A, Hajji N, O'Neill K, et al., 2020, β-Hydroxybutyrate oxidation promotes the accumulation of immunometabolites in activated microglia cells, Metabolites, Vol: 10, ISSN: 2218-1989
Metabolic regulation of immune cells has arisen as a critical set of processes required for appropriate response to immunological signals. While our knowledge in this area has rapidly expanded in leukocytes, much less is known about the metabolic regulation of brain-resident microglia. In particular, the role of alternative nutrients to glucose remains poorly understood. Here, we use stable-isotope (13C) tracing strategies and metabolomics to characterize the oxidative metabolism of β-hydroxybutyrate (BHB) in human (HMC3) and murine (BV2) microglia cells and the interplay with glucose in resting and LPS-activated BV2 cells. We found that BHB is imported and oxidised in the TCA cycle in both cell lines with a subsequent increase in the cytosolic NADH:NAD+ ratio. In BV2 cells, stimulation with LPS upregulated the glycolytic flux, increased the cytosolic NADH:NAD+ ratio and promoted the accumulation of the glycolytic intermediate dihydroxyacetone phosphate (DHAP). The addition of BHB enhanced LPS-induced accumulation of DHAP and promoted glucose-derived lactate export. BHB also synergistically increased LPS-induced accumulation of succinate and other key immunometabolites, such as α-ketoglutarate and fumarate generated by the TCA cycle. Finally, BHB upregulated the expression of a key pro-inflammatory (M1 polarisation) marker gene, NOS2, in BV2 cells activated with LPS. In conclusion, we identify BHB as a potentially immunomodulatory metabolic substrate for microglia that promotes metabolic reprogramming during pro-inflammatory response.
Syed N, Srivastava S, Mukherjee S, et al., 2020, Comprehending meningioma signaling cascades using multipronged proteomics approaches & targeted validation of potential markers, Frontiers in Oncology, Vol: 10, ISSN: 2234-943X
Meningiomas are one of the most prevalent primary brain tumors. Our study aims to obtain mechanistic insights of meningioma pathobiology using mass spectrometry-based label-free quantitative proteome analysis to identifying druggable targets and perturbed pathways for therapeutic intervention. Label-free based proteomics study was done from peptide samples of 21 patients and 8 non-tumor controls which were followed up with Phosphoproteomics to identify the kinases and phosphorylated components of the perturbed pathways. In silico approaches revealed perturbations in extracellular matrix remodeling and associated cascades. To assess the extent of influence of Integrin and PI3K-Akt pathways, we used an Integrin Linked Kinase inhibitor on patient-derived meningioma cell line and performed a transcriptomic analysis of the components. Furthermore, we designed a Targeted proteomics assay which to the best of our knowledge for very first-time enables identification of peptides from 54 meningioma patients via SRM assay to validate the key proteins emerging from our study. This resulted in the identification of peptides from CLIC1, ES8L2, and AHNK many of which are receptors and kinases and are difficult to be characterized using conventional approaches. Furthermore, we were also able to monitor transitions for proteins like NEK9 and CKAP4 which have been reported to be associated with meningioma pathobiology. We believe, this study can aid in designing peptide-based validation assays for meningioma patients as well as IHC studies for clinical applications.
Vrettos E, Valverde IE, Mascarin A, et al., 2020, Single peptide backbone surrogate mutations to regulate Angiotensin GPCR subtype selectivity, Chemistry: A European Journal, Vol: 26, Pages: 10690-10694, ISSN: 0947-6539
Mutating the side‐chains of amino acids in a peptide ligand, with unnatural amino acids, aiming to mitigate its short half‐life is an established approach. However, it is hypothesized that mutating specific backbone peptide bonds with bioisosters can be exploited not only to enhance the proteolytic stability of parent peptides, but also to tune its receptor subtype selectivity. Towards this end, four [Y]6‐Angiotensin II analogues are synthesized where amide bonds have been replaced by 1,4‐disubstituted 1,2,3‐triazole isosteres in four different backbone locations. All the analogues possessed enhanced stability in human plasma in comparison with the parent peptide, whereas only two of them achieved enhanced AT2R/AT1R subtype selectivity. This diversification has been studied through 2D NMR spectroscopy and unveiled a putative more structured microenvironment for the two selective ligands accompanied with increased number of NOE cross‐peaks. The most potent analogue, compound 2, has been explored regarding its neurotrophic potential and resulted in an enhanced neurite growth with respect to the established agent C21.
Birch JL, Coull BJ, Spender LC, et al., 2020, Multifaceted transforming growth factor-beta (TGF beta) signalling in glioblastoma, Cellular Signalling, Vol: 72, Pages: 1-12, ISSN: 0898-6568
Glioblastoma (GBM) is an aggressive and devastating primary brain cancer which responds very poorly to treatment. The average survival time of patients is only 14–15 months from diagnosis so there is a clear and unmet need for the development of novel targeted therapies to improve patient outcomes. The multifunctional cytokine TGFβ plays fundamental roles in development, adult tissue homeostasis, tissue wound repair and immune responses. Dysfunction of TGFβ signalling has been implicated in both the development and progression of many tumour types including GBM, thereby potentially providing an actionable target for its treatment. This review will examine TGFβ signalling mechanisms and their role in the development and progression of GBM. The targeting of TGFβ signalling using a variety of approaches including the TGFβ binding protein Decorin will be highlighted as attractive therapeutic strategies.
Castellano E, Atkinson A, O'Neill K, et al., 2019, THE COLLAGEN-PROLYL HYDROXYLASES PROMOTE PROLIFERATION AND INVASION IN GBM, Meeting of the British-Neuro-Oncology-Society (BNOS), Publisher: OXFORD UNIV PRESS INC, Pages: 12-12, ISSN: 1522-8517
Shahabi L, Shahabi G, Wilcox E, et al., 2019, USING NEURO-ONCOLOGY TO TEACH GCSE STUDENTS STEM-SUBJECTS, Meeting of the British-Neuro-Oncology-Society (BNOS), Publisher: OXFORD UNIV PRESS INC, Pages: 6-6, ISSN: 1522-8517
Benito A, Hajji N, O'Neill K, et al., 2019, KETOGENIC DIET AND METABOLIC REGULATION OF BRAIN MICROGLIA, Meeting of the British-Neuro-Oncology-Society (BNOS), Publisher: OXFORD UNIV PRESS INC, Pages: 8-8, ISSN: 1522-8517
Zeng Q, Stylianou T, Preston J, et al., 2019, THE KETOGENIC DIET ALTERS THE EPIGENETIC LANDSCAPE OF GBM TO POTENTIATE THE EFFECTS OF CHEMOTHERAPY AND RADIOTHERAPY, Meeting of the British-Neuro-Oncology-Society (BNOS), Publisher: OXFORD UNIV PRESS INC, Pages: 8-8, ISSN: 1522-8517
Laaniste L, Srivastava P, Stylianou T, et al., 2019, Integrated systems-genetic analyses reveal a network target for delaying glioma progression, Annals of Clinical and Translational Neurology, Vol: 6, Pages: 1616-1638, ISSN: 2328-9503
ObjectiveTo identify a convergent, multitarget proliferation characteristic for astrocytoma transformation that could be targeted for therapy discovery.MethodsUsing an integrated functional genomics approach, we prioritized networks associated with astrocytoma progression using the following criteria: differential co‐expression between grade II and grade III IDH1‐mutated and 1p/19q euploid astrocytomas, preferential enrichment for genetic risk to cancer, association with patient survival and sample‐level genomic features. Drugs targeting the identified multitarget network characteristic for astrocytoma transformation were computationally predicted using drug transcriptional perturbation data and validated using primary human astrocytoma cells.ResultsA single network, M2, consisting of 177 genes, was associated with glioma progression on the basis of the above criteria. Functionally, M2 encoded physically interacting proteins regulating cell cycle processes and analysis of genome‐wide gene‐regulatory interactions using mutual information and DNA–protein interactions revealed the known regulators of cell cycle processes FoxM1, B‐Myb, and E2F2 as key regulators of M2. These results suggest functional disruption of M2 via gene mutation or altered expression as a convergent pathway regulating astrocytoma transformation. By considering M2 as a multitarget drug target regulating astrocytoma transformation, we identified several drugs that are predicted to restore M2 expression in anaplastic astrocytoma toward its low‐grade profile and of these, we validated the known antiproliferative drug resveratrol as down‐regulating multiple nodes of M2 including at nanomolar concentrations achievable in human cerebrospinal fluid by oral dosing.InterpretationOur results identify M2 as a multitarget network characteristic for astrocytoma progression and encourage M2‐based drug screening to identify new compounds for preventing glioma transformation.
Renziehausen A, Tsiailanis AD, Perryman R, et al., 2019, Encapsulation of temozolomide in a calixarene nanocapsule improves its stability and enhances its therapeutic efficacy against glioblastoma, Molecular Cancer Therapeutics, Vol: 18, ISSN: 1535-7163
The alkylating agent temozolomide (TMZ) is the first-line chemotherapeutic for glioblastoma (GBM), a common and aggressive primary brain tumour in adults. However, its poor stability and unfavourable pharmacokinetic profile limit its clinical efficacy. There is an unmet need to tailor the therapeutic window of TMZ, either through complex derivatization or by utilizing pharmaceutical excipients. To enhance stability and aqueous solubility, we encapsulated TMZ in a p-sulphonatocalixarene (Calix) nanocapsule and employed 1H-NMR, LC-MS and UV-Vis spectroscopy to chart the stability of this novel TMZ@Calix complex according to FDA and EMA guidelines. LC-MS/MS plasma stability assays were conducted in mice to further explore the stability profile of TMZ@Calix in vivo. The therapeutic efficacy of TMZ@Calix was compared to that of unbound TMZ in GBM cell lines and patient derived primary cells with known O6-methylguanine-DNA methyltransferase (MGMT) expression status and in vivo in an intracranial U87 xenograft mouse model. Encapsulation significantly enhanced the stability of TMZ in all conditions tested. TMZ@Calix was more potent than native TMZ at inhibiting the growth of established GBM cell lines and patient derived primary lines expressing MGMT and highly resistant to TMZ. In vivo, native TMZ was rapidly degraded in mouse plasma, whereas the stability of TMZ@Calix was enhanced 3-fold with increased therapeutic efficacy in an orthotopic model. In the absence of new effective therapies, this novel formulation is of clinical importance serving as an inexpensive and highly efficient treatment that could be made readily available to GBM patients and warrants further pre-clinical and clinical evaluation.
Hall PE, Lewis R, Syed N, et al., 2019, A phase I study of pegylated arginine deiminase ( Pegargiminase), cisplatin, and pemetrexed in argininosuccinate synthetase 1-deficient recurrent high-grade glioma, Clinical Cancer Research, Vol: 25, Pages: 2708-2716, ISSN: 1078-0432
Purpose: Patients with recurrent high-grade gliomas (HGG) are usually managed with alkylating chemotherapy ± bevacizumab. However, prognosis remains very poor. Preclinically, we showed that HGGs are a target for arginine depletion with pegargiminase (ADI-PEG20) due to epimutations of argininosuccinate synthetase (ASS1) and/or argininosuccinate lyase (ASL). Moreover, ADI-PEG20 disrupts pyrimidine pools in ASS1-deficient HGGs, thereby impacting sensitivity to the antifolate, pemetrexed.Patients and Methods: We expanded a phase I trial of ADI-PEG20 with pemetrexed and cisplatin (ADIPEMCIS) to patients with ASS1-deficient recurrent HGGs (NCT02029690). Patients were enrolled (01/16–06/17) to receive weekly ADI-PEG20 36 mg/m2 intramuscularly plus pemetrexed 500 mg/m2 and cisplatin 75 mg/m2 intravenously once every 3 weeks for up to 6 cycles. Patients with disease control were allowed ADI-PEG20 maintenance. The primary endpoints were safety, tolerability, and preliminary estimates of efficacy.Results: Ten ASS1-deficient heavily pretreated patients were treated with ADIPEMCIS therapy. Treatment was well tolerated with the majority of adverse events being Common Terminology Criteria for Adverse Events v4.03 grade 1-2. The best overall response was stable disease in 8 patients (80%). Plasma arginine was suppressed significantly below baseline with a reciprocal increase in citrulline during the sampling period. The anti–ADI-PEG20 antibody titer rose during the first 4 weeks of treatment before reaching a plateau. Median progression-free survival (PFS) was 5.2 months (95% confidence interval (CI), 2.5–20.8) and overall survival was 6.3 months (95% CI, 1.8–9.7).Conclusions: In this recurrent HGG study, ADIPEMCIS was well tolerated and compares favorably to historical controls. Additional trials of ADI-PEG20 in HGG are planned.
Atkinson A, Renziehausen A, Wang H, et al., 2019, The collagen prolyl hydroxylases are bifunctional growth regulators in melanoma, Journal of Investigative Dermatology, Vol: 139, Pages: 1118-1126, ISSN: 0022-202X
Appropriate post-translational processing of collagen requires prolyl hydroxylation, catalyzed by the prolyl 3- (C-P3H) and prolyl 4- (C-P4H) hydroxylases is essential for normal cell function. Here we have investigated the expression, transcriptional regulation and function of the C-P3H and C-P4H families in melanoma. We show that the CP3H family exemplified by Leprel1 and Leprel2 are subject to methylation-dependent transcriptional silencing in primary and metastatic melanoma consistent with a tumour suppressor function. In contrast, although there is transcriptional silencing of P4HA3 in a sub-set of melanomas, the CP4H family members P4HA1, P4HA2 and P4HA3 are often over-expressed in melanoma, expression being prognostic of worse clinical outcomes. Consistent with tumour suppressor function, ectopic expression of Leprel1 and Leprel2 inhibits melanoma proliferation, whereas P4HA2 and P4HA3 increase proliferation and particularly invasiveness of melanoma cells. Pharmacological inhibition with multiple selective C-P4H inhibitors reduces proliferation and inhibits invasiveness of melanoma cells. Together, our data identify the C-P3H and C-P4H families as potentially important regulators of melanoma growth and invasiveness and suggest that selective inhibition of C-P4H is an attractive strategy to reduce the invasive properties of melanoma cells.
Rossi AP, Syed N, Wetmore C, et al., 2019, THE KETONE BODY B-HYDROXYBUTYRATE ACTS AS AN EPIGENETIC MODIFIER AND INCREASES RADIATION-INDUCED DNA DAMAGE IN DIFFUSE INTRINSIC PONTINE GLIOMA, 5th Biennial Conference of the Society-for-Neuro-Oncology on Pediatric Neuro-Oncology Basic and Translational Research, Publisher: OXFORD UNIV PRESS INC, Pages: 77-77, ISSN: 1522-8517
Renziehausen A, Wang H, Rao B, et al., 2019, The renin angiotensin system (RAS) mediates bifunctional growth regulation in melanoma and is a novel target for therapeutic intervention, Publisher: NATURE PUBLISHING GROUP, Pages: 2320-2336, ISSN: 0950-9232
Chatziathanasiadou MV, Stylos EK, Giannopoulou E, et al., 2019, Development of a validated LC-MS/MS method for the in vitro and in vivo quantitation of sunitinib in glioblastoma cells and cancer patients, Journal of Pharmaceutical and Biomedical Analysis, Vol: 164, Pages: 690-697, ISSN: 0731-7085
Sunitinib is a multi-targeted tyrosine kinase inhibitor approved for the treatment of renal cell carcinoma and imatinib-resistant gastrointestinal stromal tumor and is currently being investigated against other forms of malignant tumors. Recently great interest has emerged for the application of sunitinib to glioblastoma treatment. In order to have a method with broad applicability it will be of importance to have access to a method that could be applied both in human plasma and cell uptake studies. No method has been reported thus far for the estimation of sunitinib uptake in glioma cells. We therefore set out to develop a method that could be applied for quantifying sunitinib in human plasma and in cell uptake studies. The method was validated and accredited according to ISO 17025:2005 guideline in human plasma and successfully applied to cancer patient plasma. Also, the method was effectively recruited to establish a protocol for the evaluation of sunitinib accumulation into M095K glioma cells. This method could significantly contribute to developmental phases in repurposing this drug in different cancer types.
Przystal JM, Hajji N, Khozoie C, et al., 2018, Efficacy of arginine depletion by ADI-PEG20 in an intracranial model of GBM, Cell Death and Disease, Vol: 9, ISSN: 2041-4889
Glioblastoma multiforme (GBM) remains a cancer with a poor prognosis and few effective therapeutic options. Successful medical management of GBM is limited by the restricted access of drugs to the central nervous system (CNS) caused by the blood brain barrier (BBB). We previously showed that a subset of GBM are arginine auxotrophic because of transcriptional silencing of ASS1 and/or ASL and are sensitive to pegylated arginine deiminase (ADI-PEG20). However, it is unknown whether depletion of arginine in peripheral blood in vivo has therapeutic activity against intracranial disease. In the present work, we describe the efficacy of ADI-PEG20 in an intracranial model of human GBM in which tumour growth and regression are assessed in real time by measurement of luciferase activity. Animals bearing intracranial human GBM tumours of varying ASS status were treated with ADI-PEG20 alone or in combination with temozolomide and monitored for tumour growth and regression. Monotherapy ADI-PEG20 significantly reduces the intracranial growth of ASS1 negative GBM and extends survival of mice carrying ASS1 negative GBM without obvious toxicity. The combination of ADI-PEG20 with temozolomide (TMZ) demonstrates enhanced effects in both ASS1 negative and ASS1 positive backgrounds.Our data provide proof of principle for a therapeutic strategy for GBM using peripheral blood arginine depletion that does not require BBB passage of drug and is well tolerated. The ability of ADI-PEG20 to cytoreduce GBM and enhance the effects of temozolomide argues strongly for its early clinical evaluation in the treatment of GBM.
Syed N, Mubarak M, Stylos E, et al., 2019, Development and validation of simple step protein precipitation UHPLC-MS/MS methods for quantitation of temozolomide in patient plasma samples Journal: Journal of Pharmaceutical and Biomedical Analysis, Journal of Pharmaceutical and Biomedical Analysis
Kiryushko D, Pankratova S, Klingelhofer J, et al., 2018, The S100A4 protein signals through the ErbB4 receptor to promote neuronal survival., Theranostics, Vol: 8, Pages: 3977-3990, ISSN: 1838-7640
Understanding the mechanisms of neurodegeneration is crucial for development of therapies to treat neurological disorders. S100 proteins are extensively expressed in the injured brain but S100's roleand signalling in neural cells remain elusive. We recently demonstrated that the S100A4 protein protects neurons in brain injury and designed S100A4-derived peptides mimicking its beneficial effects. Here we show that neuroprotection by S100A4 involves the growth factor family receptorErbB4 and its ligand Neuregulin 1 (NRG), key regulators of neuronal plasticity and implicated in multiple brain pathologies. The neuroprotective effect of S100A4 depends on ErbB4 expression andthe ErbB4 signalling partners ErbB2/Akt, and is reduced by functional blockade of NRG/ErbB4 in cell models of neurodegeneration. We also detect binding of S100A4 with ErbB1 (EGFR) and ErbB3. S100A4-derived peptides interact with, and signal through ErbB, are neuroprotective inprimary and immortalized dopaminergic neurons, and do not affect cell proliferation/motility - features which make them promising as potential neuroprotectants. Our data suggest that the S100- ErbB axis may be an important mechanism regulating neuronal survival and plasticity
Hajji N, García-Domínguez DJ, Hontecillas-Prieto L, et al., 2018, The bitter side of epigenetics: variability and resistance to chemotherapy, Epigenomics, ISSN: 1750-1911
One of the major obstacles to the development of effective new cancer treatments and the main factor for the increasing number of clinical trial failures appears to be the paucity of accurate, reproducible and robust drug resistance testing methods. Most research assessing the resistance of cancers to chemotherapy has concentrated on genetic-based molecular mechanisms, while the role of epigenetics in drug resistance has been generally overlooked. This is rather surprising given that an increasing body of evidence pointing to the fact that epigenetic mechanism alterations appear to play a pivotal role in cancer initiation, progression and development of chemoresistance. This resulted in a series of clinical trials involving epi-drug as single treatment or combined with cancer conventional drugs. In this review, we provided the main mechanisms by which the epigenetic regulators control the resistance to cancer drugs.
Hall PE, Lewis R, Syed N, et al., 2018, A phase I expansion study of pegargiminase, cisplatin, and pemetrexed in argininosuccinate synthetase 1-negative recurrent high grade gliomas (HGGs)., Journal of Clinical Oncology, Vol: 36, Pages: e14085-e14085, ISSN: 0732-183X
Moren L, Perryman R, Crook T, et al., 2018, Correction to: Metabolomic profiling identifies distinct phenotypes for ASS1 positive and negative GBM (vol 18, 167, 2018), BMC Cancer, Vol: 18, Pages: 1-1, ISSN: 1471-2407
Moren L, Perryman R, Crook T, et al., 2018, Metabolomic profiling identifies distinct phenotypes for ASS1 positive and negative GBM, BMC Cancer, Vol: 18, Pages: 1-16, ISSN: 1471-2407
BackgroundTumour cells have a high demand for arginine. However, a subset of glioblastomas has a defect in the arginine biosynthetic pathway due to epigenetic silencing of the rate limiting enzyme argininosuccinate synthetase (ASS1). These tumours are auxotrophic for arginine and susceptible to the arginine degrading enzyme, pegylated arginine deiminase (ADI-PEG20). Moreover, ASS1 deficient GBM have a worse prognosis compared to ASS1 positive tumours. Since altered tumour metabolism is one of the hallmarks of cancer we were interested to determine if these two subtypes exhibited different metabolic profiles that could allow for their non-invasive detection as well as unveil additional novel therapeutic opportunities.MethodsWe looked for basal metabolic differences using one and two-dimensional gas chromatography-time-of-flight mass spectrometry (1D/2D GC-TOFMS) followed by targeted analysis of 29 amino acids using liquid chromatography-time-of-flight mass spectrometry (LC-TOFMS). We also looked for differences upon arginine deprivation in a single ASS1 negative and positive cell line (SNB19 and U87 respectively). The acquired data was evaluated by chemometric based bioinformatic methods.ResultsOrthogonal partial least squares-discriminant analysis (OPLS-DA) of both the 1D and 2D GC-TOFMS data revealed significant systematic difference in metabolites between the two subgroups with ASS1 positive cells generally exhibiting an overall elevation of identified metabolites, including those involved in the arginine biosynthetic pathway. Pathway and network analysis of the metabolite profile show that ASS1 negative cells have altered arginine and citrulline metabolism as well as altered amino acid metabolism. As expected, we observed significant metabolite perturbations in ASS negative cells in response to ADI-PEG20 treatment.ConclusionsThis study has highlighted significant differences in the metabolome of ASS1 negative and positive GBM which warrants further study to deter
Williams M, Cross H, Jenkinson MD, et al., 2018, THE KETOGENIC DIET FOR PATIENTS WITH BRAIN TUMOURS: TWO PARALLEL RANDOMISED TRIALS, Meeting of the British-Neuro-Oncology-Society (BNOS), Publisher: OXFORD UNIV PRESS INC, Pages: 7-8, ISSN: 1522-8517
Tzouliana S, Hajji N, Perryman R, et al., 2017, THE KETOGENIC DIET ALTERS THE EPIGENETIC LANDSCAPE OF GBM TO POTENTIATE THE EFFECTS OF CHEMO AND RADIOTHERAPY, Joint Conference of 22nd Annual Scientific Meeting and Education Day of the Society-for-Neuro-Oncology / Conference of the Society-for-CNS-Interstitial-Delivery-of-the-Therapeutics (SCIDOT) on Therapeutic Delivery to the CNS, Publisher: OXFORD UNIV PRESS INC, Pages: 96-97, ISSN: 1522-8517
Woolf EC, Bhattacharya A, Rossi AP, et al., 2017, THE KETONE BODY beta-HYDROXYBUTYRATE CHEMO- AND RADIO-SENSITIZES MALIGNANT GLIOMA CELLS BY INHIBITING HISTONE DEACETYLASE ACTIVITY AND DOWNREGULATING EXPRESSION OF RAD51, Joint Conference of 22nd Annual Scientific Meeting and Education Day of the Society-for-Neuro-Oncology / Conference of the Society-for-CNS-Interstitial-Delivery-of-the-Therapeutics (SCIDOT) on Therapeutic Delivery to the CNS, Publisher: OXFORD UNIV PRESS INC, Pages: 83-83, ISSN: 1522-8517
Bassiri K, Ferluga S, Sharma V, et al., 2017, Global proteome and phospho-proteome analysis of Merlin-deficient meningioma and schwannoma identifies PDLIM2 as a novel therapeutic target., EBioMedicine, Vol: 16, Pages: 76-86, ISSN: 2352-3964
Loss or mutation of the tumour suppressor Merlin predisposes individuals to develop multiple nervous system tumours, including schwannomas and meningiomas, sporadically or as part of the autosomal dominant inherited condition Neurofibromatosis 2 (NF2). These tumours display largely low grade features but their presence can lead to significant morbidity. Surgery and radiotherapy remain the only treatment options despite years of research, therefore an effective therapeutic is required. Unbiased omics studies have become pivotal in the identification of differentially expressed genes and proteins that may act as drug targets or biomarkers. Here we analysed the proteome and phospho-proteome of these genetically defined tumours using primary human tumour cells to identify upregulated/activated proteins and/or pathways. We identified over 2000 proteins in comparative experiments between Merlin-deficient schwannoma and meningioma compared to human Schwann and meningeal cells respectively. Using functional enrichment analysis we highlighted several dysregulated pathways and Gene Ontology terms. We identified several proteins and phospho-proteins that are more highly expressed in tumours compared to controls. Among proteins jointly dysregulated in both tumours we focused in particular on PDZ and LIM domain protein 2 (PDLIM2) and validated its overexpression in several tumour samples, while not detecting it in normal cells. We showed that shRNA mediated knockdown of PDLIM2 in both primary meningioma and schwannoma leads to significant reductions in cellular proliferation. To our knowledge, this is the first comprehensive assessment of the NF2-related meningioma and schwannoma proteome and phospho-proteome. Taken together, our data highlight several commonly deregulated factors, and indicate that PDLIM2 may represent a novel, common target for meningioma and schwannoma.
Preston J, Stylianou J, Zeng Q, et al., 2017, THE KETOGENIC DIET INDUCES EPIGENETIC CHANGES THAT PLAY KEY ROLES IN TUMOUR DEVELOPMENT, Meeting of the British-Neuro-Oncology-Society (BNOS), Publisher: OXFORD UNIV PRESS INC, Pages: 128-128, ISSN: 1522-8517
Woolf EC, Syed N, Scheck AC, 2016, Tumor metabolism, the ketogenic diet and beta-hydroxybutyrate: novel approaches to adjuvant brain tumor therapy, Frontiers in Molecular Neuroscience, Vol: 9, ISSN: 1662-5099
Malignant brain tumors are devastating despite aggressive treatments such as surgical resection, chemotherapy and radiation therapy. The average life expectancy of patients with newly diagnosed glioblastoma is approximately ~18 months. It is clear that increased survival of brain tumor patients requires the design of new therapeutic modalities, especially those that enhance currently available treatments and/or limit tumor growth. One novel therapeutic arena is the metabolic dysregulation that results in an increased need for glucose in tumor cells. This phenomenon suggests that a reduction in tumor growth could be achieved by decreasing glucose availability, which can be accomplished through pharmacological means or through the use of a high-fat, low-carbohydrate ketogenic diet (KD). The KD, as the name implies, also provides increased blood ketones to support the energy needs of normal tissues. Preclinical work from a number of laboratories has shown that the KD does indeed reduce tumor growth in vivo. In addition, the KD has been shown to reduce angiogenesis, inflammation, peri-tumoral edema, migration and invasion. Furthermore, this diet can enhance the activity of radiation and chemotherapy in a mouse model of glioma, thus increasing survival. Additional studies in vitro have indicated that increasing ketones such as β-hydroxybutyrate (βHB) in the absence of glucose reduction can also inhibit cell growth and potentiate the effects of chemotherapy and radiation. Thus, while we are only beginning to understand the pluripotent mechanisms through which the KD affects tumor growth and response to conventional therapies, the emerging data provide strong support for the use of a KD in the treatment of malignant gliomas. This has led to a limited number of clinical trials investigating the use of a KD in patients with primary and recurrent glioma.
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