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1.
Int J Mol Sci ; 24(14)2023 Jul 21.
Article in English | MEDLINE | ID: mdl-37511490

ABSTRACT

Colorectal carcinoma (CRC) is a prevalent cancer worldwide with a high mortality rate. Evidence suggests that increased expression of Cyclin-dependent kinase 5 (CDK5) contributes to cancer progression, making it a promising target for treatment. This study examined the efficacy of selectively inhibiting CDK5 in colorectal carcinoma using TP5, a small peptide that selectively inhibits the aberrant and hyperactive CDK5/p25 complex while preserving physiological CDK5/p35 functions. We analyzed TP5's impact on CDK5 activity, cell survival, apoptosis, the cell cycle, DNA damage, ATM phosphorylation, and reactive oxygen species (ROS) signaling in mitochondria, in CRC cell lines, both alone and in combination with chemotherapy. We also assessed TP5's efficacy on a xenograft mouse model with HCT116 cells. Our results showed that TP5 decreased CDK5 activity, impaired cell viability and colony formation, induced apoptosis, increased DNA damage, and led to the G1 phase arrest of cell cycle progression. In combination with irinotecan, TP5 demonstrated a synergy by leading to the accumulation of DNA damage, increasing the γH2A.X foci number, and inhibiting G2/M arrest induced by Sn38 treatment. TP5 alone or in combination with irinotecan increased mitochondrial ROS levels and inhibited tumor growth, prolonging mouse survival in the CRC xenograft animal model. These results suggest that TP5, either alone or in combination with irinotecan, is a promising therapeutic option for colorectal carcinoma.


Subject(s)
Colorectal Neoplasms , Cyclin-Dependent Kinase 5 , Mice , Humans , Animals , Cyclin-Dependent Kinase 5/metabolism , Irinotecan/pharmacology , Irinotecan/therapeutic use , Apoptosis , Reactive Oxygen Species/metabolism , Cell Line, Tumor , G2 Phase Cell Cycle Checkpoints , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics
2.
J Biol Chem ; 297(5): 101292, 2021 11.
Article in English | MEDLINE | ID: mdl-34627839

ABSTRACT

Zinc deficiency has been linked to human diseases, including cancer. MDMX, a crucial zinc-containing negative regulator of p53, has been found to be amplified or overexpressed in various cancers and implicated in the cancer initiation and progression. We report here that zinc depletion by the ion chelator TPEN or Chelex resin results in MDMX protein degradation in a ubiquitination-independent and 20S proteasome-dependent manner. Restoration of zinc led to recovery of cellular levels of MDMX. Further, TPEN treatment inhibits growth of the MCF-7 breast cancer cell line, which is partially rescued by overexpression of MDMX. Moreover, in a mass-spectrometry-based proteomics analysis, we identified TRPM7, a zinc-permeable ion channel, as a novel MDMX-interacting protein. TRPM7 stabilizes and induces the appearance of faster migrating species of MDMX on SDS-PAGE. Depletion of TRPM7 attenuates, while TRPM7 overexpression facilitates, the recovery of MDMX levels upon adding back zinc to TPEN-treated cells. Importantly, we found that TRPM7 inhibition, like TPEN treatment, decreases breast cancer cell MCF-7 proliferation and migration. The inhibitory effect on cell migration upon TRPM7 inhibition is also partially rescued by overexpression of MDMX. Together, our data indicate that TRPM7 regulates cellular levels of MDMX in part by modulating the intracellular Zn2+ concentration to promote tumorigenesis.


Subject(s)
Cell Cycle Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Proteolysis , Proto-Oncogene Proteins/metabolism , TRPM Cation Channels/metabolism , Zinc/metabolism , Animals , Cell Cycle Proteins/genetics , Humans , MCF-7 Cells , Mice , Mice, Knockout , PC-3 Cells , Protein Serine-Threonine Kinases/genetics , Proto-Oncogene Proteins/genetics , TRPM Cation Channels/genetics
3.
Int J Mol Sci ; 22(7)2021 Mar 26.
Article in English | MEDLINE | ID: mdl-33810617

ABSTRACT

The foundation of precision immunotherapy in oncology is rooted in computational biology and patient-derived sample sequencing to enrich for and target immunogenic epitopes. Discovery of these tumor-specific epitopes through tumor sequencing has revolutionized patient outcomes in many types of cancers that were previously untreatable. However, these therapeutic successes are far from universal, especially with cancers that carry high intratumoral heterogeneity such as glioblastoma (GBM). Herein, we present the technical aspects of Mannan-BAM, TLR Ligands, Anti-CD40 Antibody (MBTA) vaccine immunotherapy, an investigational therapeutic that potentially circumvents the need for in silico tumor-neoantigen enrichment. We then review the most promising GBM vaccination strategies to contextualize the MBTA vaccine. By reviewing current evidence using translational tumor models supporting MBTA vaccination, we evaluate the underlying principles that validate its clinical applicability. Finally, we showcase the translational potential of MBTA vaccination as a potential immunotherapy in GBM, along with established surgical and immunologic cancer treatment paradigms.


Subject(s)
Brain Neoplasms/immunology , Brain Neoplasms/therapy , CD40 Antigens/immunology , Glioblastoma/immunology , Glioblastoma/therapy , Immunotherapy/methods , Animals , Antigen-Presenting Cells/chemistry , Cancer Vaccines , Computational Biology , Epitopes/chemistry , Humans , Immunophenotyping , Ligands , Medical Oncology/trends , Mice , Neoplasm Metastasis , Peptides/chemistry , Treatment Outcome
4.
Biophys J ; 119(12): 2378-2390, 2020 12 15.
Article in English | MEDLINE | ID: mdl-33189686

ABSTRACT

We have developed a novel, to our knowledge, in vitro instrument that can deliver intermediate-frequency (100-400 kHz), moderate-intensity (up to and exceeding 6.5 V/cm pk-pk) electric fields (EFs) to cell and tissue cultures generated using induced electromagnetic fields (EMFs) in an air-core solenoid coil. A major application of these EFs is as an emerging cancer treatment modality. In vitro studies by Novocure reported that intermediate-frequency (100-300 kHz), low-amplitude (1-3 V/cm) EFs, which they called "tumor-treating fields (TTFields)," had an antimitotic effect on glioblastoma multiforme (GBM) cells. The effect was found to increase with increasing EF amplitude. Despite continued theoretical, preclinical, and clinical study, the mechanism of action remains incompletely understood. All previous in vitro studies of "TTFields" have used attached, capacitively coupled electrodes to deliver alternating EFs to cell and tissue cultures. This contacting delivery method suffers from a poorly characterized EF profile and conductive heating that limits the duration and amplitude of the applied EFs. In contrast, our device delivers EFs with a well-characterized radial profile in a noncontacting manner, eliminating conductive heating and enabling thermally regulated EF delivery. To test and demonstrate our system, we generated continuous, 200-kHz EMF with an EF amplitude profile spanning 0-6.5 V/cm pk-pk and applied them to exemplar human thyroid cell cultures for 72 h. We observed moderate reduction in cell density (<10%) at low EF amplitudes (<4 V/cm) and a greater reduction in cell density of up to 25% at higher amplitudes (4-6.5 V/cm). Our device can be readily extended to other EF frequency and amplitude regimes. Future studies with this device should contribute to the ongoing debate about the efficacy and mechanism(s) of action of "TTFields" by better isolating the effects of EFs and providing access to previously inaccessible EF regimes.


Subject(s)
Electric Stimulation Therapy , Glioblastoma , Electric Conductivity , Electromagnetic Fields , Glioblastoma/therapy , Humans
5.
J Neurooncol ; 148(2): 231-244, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32342332

ABSTRACT

PURPOSE: Glioblastoma (GBM) carries a dismal prognosis despite standard multimodal treatment with surgery, chemotherapy and radiation. Immune checkpoint inhibitors, such as PD1 blockade, for treatment of GBM failed to show clinical benefit. Rational combination strategies to overcome resistance of GBM to checkpoint monotherapy are needed to extend the promise of immunotherapy to GBM management. Emerging evidence suggests that protein phosphatase 2A (PP2A) plays a critical role in the signal transduction pathways of both adaptive and innate immune cells and that inhibition of PP2A could enhance cancer immunity. We investigated the use of a PP2A inhibitor, LB-100, to enhance antitumor efficacy of PD1 blockade in a syngeneic glioma model. METHODS: C57BL/6 mice were implanted with murine glioma cell line GL261-luc or GL261-WT and randomized into 4 treatment arms: (i) control, (ii) LB-100, (iii) PD1 blockade and (iv) combination. Survival was assessed and detailed profiling of tumor infiltrating leukocytes was performed. RESULTS: Dual PP2A and PD1 blockade significantly improved survival compared with monotherapy alone. Combination therapy resulted in complete regression of tumors in about 25% of mice. This effect was dependent on CD4 and CD8 T cells and cured mice established antigen-specific secondary protective immunity. Analysis of tumor lymphocytes demonstrated enhanced CD8 infiltration and effector function. CONCLUSION: This is the first preclinical investigation of the effect of combining PP2A inhibition with PD1 blockade for GBM. This novel combination provided effective tumor immunotherapy and long-term survival in our animal GBM model.


Subject(s)
Antineoplastic Agents, Immunological/administration & dosage , Brain Neoplasms/immunology , Glioblastoma/immunology , Piperazines/administration & dosage , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Protein Phosphatase 2/antagonists & inhibitors , Animals , Brain Neoplasms/prevention & control , Cell Line, Tumor , Drug Therapy, Combination/methods , Female , Glioblastoma/prevention & control , Mice, Inbred C57BL , Programmed Cell Death 1 Receptor/immunology , Protein Phosphatase 2/immunology
6.
Cancer ; 125(8): 1258-1266, 2019 04 15.
Article in English | MEDLINE | ID: mdl-30644531

ABSTRACT

BACKGROUND: Somatic mutations in hypoxia-inducible factor 2α (HIF2A) are associated with polycythemia-paraganglioma syndrome. Specifically, the classic presentation of female patients with recurrent paragangliomas (PGLs), polycythemia (at birth or in early childhood), and duodenal somatostatinomas has been described. Studies have demonstrated that somatic HIF2A mutations occur as postzygotic events and some to be associated with somatic mosaicism affecting hematopoietic and other tissue precursors. This phenomenon could explain the development of early onset of polycythemia in the absence of erythropoietin-secreting tumors. METHODS: Correlation analysis was performed between mosaicism of HIF2A mutant patients and clinical presentations. RESULTS: Somatic HIF2A mutations (p.A530V, p.P531S, and p.D539N) were identified in DNA extracted from PGLs of 3 patients. No somatic mosaicism was detected through deep sequencing of blood genomic DNA. Compared with classic syndrome, both polycythemia and PGL in all 3 patients developed at an advanced age with polycythemia at age 30, 30, and 17 years and PGLs at age 34, 30, and 55 years, respectively. Somatostatinomas were not detected, and 2 patients had ophthalmic findings. The biochemical phenotype in all 3 patients was noradrenergic with 18 F-fluorodopa PET/CT as the most sensitive imaging modality. All patients demonstrated multiplicity, and none developed metastatic disease. CONCLUSION: These findings suggest that newer techniques need to be developed to detect somatic mosaicism in patients with this syndrome. Absence of HIF2A mosaicism in patients with somatic HIF2A mutations supports association with late onset of the disease, milder clinical phenotype, and an improved prognosis compared with patients who have HIF2A mosaicism.


Subject(s)
Basic Helix-Loop-Helix Transcription Factors/genetics , Paraganglioma/classification , Point Mutation , Polycythemia/classification , Adolescent , Adult , Age of Onset , High-Throughput Nucleotide Sequencing , Humans , Middle Aged , Mosaicism , Paraganglioma/diagnostic imaging , Paraganglioma/genetics , Polycythemia/diagnostic imaging , Polycythemia/genetics , Positron Emission Tomography Computed Tomography , Sequence Analysis, DNA
7.
J Pathol ; 245(3): 361-372, 2018 07.
Article in English | MEDLINE | ID: mdl-29704241

ABSTRACT

Oncocytomas represent a subset of benign pituitary adenomas that are characterized by significant mitochondrial hyperplasia. Mitochondria are key organelles for energy generation and metabolic intermediate production for biosynthesis in tumour cells, so understanding the mechanism underlying mitochondrial biogenesis and its impact on cellular metabolism in oncocytoma is vital. Here, we studied surgically resected pituitary oncocytomas by using multi-omic analyses. Whole-exome sequencing did not reveal any nuclear mutations, but identified several somatic mutations of mitochondrial DNA, and dysfunctional respiratory complex I. Metabolomic analysis suggested that oxidative phosphorylation was reduced within individual mitochondria, and that there was no reciprocal increase in glycolytic activity. Interestingly, we found a reduction in the cellular lactate level and reduced expression of lactate dehydrogenase A (LDHA), which contributed to mitochondrial biogenesis in an in vitro cell model. It is of note that the hypoxia-response signalling pathway was not upregulated in pituitary oncocytomas, thereby failing to enhance glycolysis. Proteomic analysis showed that 14-3-3η was exclusively overexpressed in oncocytomas, and that 14-3-3η was capable of inhibiting glycolysis, leading to mitochondrial biogenesis in the presence of rotenone. In particular, 14-3-3η inhibited LDHA by direct interaction in the setting of complex I dysfunction, highlighting the role of 14-3-3η overexpression and inefficient oxidative phosphorylation in oncocytoma mitochondrial biogenesis. These findings deepen our understanding of the metabolic changes that occur within oncocytomas, and shine a light on the mechanism of mitochondrial biogenesis, providing a novel perspective on metabolic adaptation in tumour cells. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Subject(s)
14-3-3 Proteins/metabolism , Adenoma, Oxyphilic/enzymology , Energy Metabolism , L-Lactate Dehydrogenase/metabolism , Mitochondria/enzymology , Organelle Biogenesis , Pituitary Neoplasms/enzymology , 14-3-3 Proteins/genetics , Adenoma, Oxyphilic/genetics , Adenoma, Oxyphilic/pathology , Adult , DNA, Mitochondrial/genetics , DNA, Mitochondrial/metabolism , Electron Transport Complex I/metabolism , Female , Glycolysis , HEK293 Cells , HeLa Cells , Humans , L-Lactate Dehydrogenase/genetics , Male , Middle Aged , Mitochondria/pathology , Mutation , Oxidative Phosphorylation , Pituitary Neoplasms/genetics , Pituitary Neoplasms/pathology , Signal Transduction , Tumor Microenvironment
8.
Cell Physiol Biochem ; 50(1): 317-331, 2018.
Article in English | MEDLINE | ID: mdl-30282066

ABSTRACT

BACKGROUND/AIMS: Protein phosphatase 2A (PP2A) is a ubiquitous serine/threonine phosphatase that mediates cell cycle regulation and metabolism. Mounting evidence has indicated that PP2A inhibition exhibits considerable anticancer potency in multiple types of human cancers. However, the efficacy of PP2A inhibition remains unexplored in mucoepidermoid carcinoma (MEC), especially in locally advanced and metastatic cases with limited systemic treatment. In this study, we demonstrated the therapeutic potency of LB100 in mucoepidermoid carcinoma. METHODS: In this study, the expression of PP2A was evaluated using immunohistochemical (IHC) staining. The effects associated with LB100 alone and in combination with cisplatin for the treatment of mucoepidermoid carcinoma were investigated both in vitro, regarding metabolism, proliferation, and migration, and in vivo in a mucoepidermoid carcinoma xenograft model. In addition, with LB100 treatment and in response to an insulin stimulus, the expression levels and phosphorylation levels of targets in the PI3K-AKT pathway were determined using western blot analysis and immunoblotting. RESULTS: The expression of protein phosphatase 2A was significantly upregulated in the clinical specimens of high-grade MECs compared with those of low-/medium-grade MECs and normal controls. In this article, we report that a small molecule PP2A inhibitor, LB100, decreased cellular viability and glycolytic activity and induced G2/M cell cycle arrest. Importantly, LB100 enhanced the efficacy of cisplatin in mucoepidermoid carcinoma cells both in vitro and in vivo. PP2A inhibition by LB100 increased the phosphorylation of insulin receptor substrate 1(IRS-1) on serine residues, downregulated the expression of phosphatidylinositol 3-kinase (PI3K) p110 alpha subunit and dephosphorylated AKT at Ser473 and Thr308 in mucoepidermoid carcinoma cells in response to insulin stimulus. CONCLUSION: These results highlight the translational potential of PP2A inhibition to synergize with cisplatin in mucoepidermoid carcinoma treatment.


Subject(s)
Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Carcinoma, Mucoepidermoid/pathology , Insulin/metabolism , Piperazines/pharmacology , Protein Phosphatase 2/metabolism , Signal Transduction/drug effects , Adult , Animals , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Carcinoma, Mucoepidermoid/drug therapy , Carcinoma, Mucoepidermoid/metabolism , Cell Cycle Checkpoints/drug effects , Cell Line, Tumor , Cisplatin/pharmacology , Cisplatin/therapeutic use , Female , Humans , Insulin Receptor Substrate Proteins/metabolism , Male , Mice , Mice, Nude , Middle Aged , Phosphatidylinositol 3-Kinases/metabolism , Protein Phosphatase 2/antagonists & inhibitors , Proto-Oncogene Proteins c-akt/metabolism
9.
BMC Cancer ; 18(1): 286, 2018 03 13.
Article in English | MEDLINE | ID: mdl-29534684

ABSTRACT

BACKGROUND: The role of the hypoxia signaling pathway in the pathogenesis of pheochromocytoma/paraganglioma (PPGL)-polycythemia syndrome has been elucidated. Novel somatic mutations in hypoxia-inducible factor type 2A (HIF2A) and germline mutations in prolyl hydroxylase type 1 and type 2 (PHD1 and PHD2) have been identified to cause upregulation of the hypoxia signaling pathway and its target genes including erythropoietin (EPO) and its receptor (EPOR). However, in a minority of patients presenting with this syndrome, the genetics and molecular pathogenesis remain unexplained. The aim of the present study was to uncover novel genetic causes of PPGL-polycythemia syndrome. CASE PRESENTATION: A female presented with a history of JAK2V617F positive PV, diagnosed in 2007, and right adrenal pheochromocytoma diagnosed and resected in 2011. Her polycythemia symptoms and hematocrit levels continued to worsen from 2007 to 2011, with an increased frequency of phlebotomies. Postoperatively, until early 2013, her hematocrit levels remained normalized. Following this, the hematocrit levels ranged between 46.4 and 48.9% [35-45%]. Tumor tissue from the patient was further tested for mutations in genes related to upregulation of the hypoxia signaling pathway including iron regulatory protein 1 (IRP1), which is a known regulator of HIF-2α mRNA translation. Functional studies were performed to investigate the consequences of these mutations, especially their effect on the HIF signaling pathway and EPO. Indel mutations (c.267-1_267delGGinsTA) were discovered at the exon 3 splicing site of IRP1. Minigene construct and splicing site analysis showed that the mutation led to a new splicing site and a frameshift mutation of IRP1, which caused a truncated protein. Fluorescence in situ hybridization analysis demonstrated heterozygous IRP1 deletions in tumor cells. Immunohistochemistry results confirmed the truncated IRP1 and overexpressed HIF-2α, EPO and EPOR in tumor cells. CONCLUSIONS: This is the first report which provides direct molecular genetic evidence of association between a somatic IRP1 loss-of-function mutation and PHEO and secondary polycythemia. In patients diagnosed with PHEO/PGL and polycythemia with negative genetic testing for mutations in HIF2A, PHD1/2, and VHL, IRP1 should be considered as a candidate gene.


Subject(s)
Adrenal Gland Neoplasms/genetics , Germ-Line Mutation , Iron Regulatory Protein 1/genetics , Janus Kinase 2/genetics , Pheochromocytoma/genetics , Polycythemia Vera/genetics , RNA Splicing , Adrenal Gland Neoplasms/complications , Adrenal Gland Neoplasms/pathology , Adult , Female , Humans , Pheochromocytoma/complications , Pheochromocytoma/pathology , Polycythemia Vera/complications , Polycythemia Vera/pathology , Prognosis
10.
Proc Natl Acad Sci U S A ; 112(4): 1137-42, 2015 Jan 27.
Article in English | MEDLINE | ID: mdl-25583479

ABSTRACT

Gaucher disease is caused by mutations of the GBA1 gene, which encodes the lysosomal anchored gluococerebrosidase (GCase). GBA1 mutations commonly result in protein misfolding, abnormal chaperone recognition, and premature degradation, but are less likely to affect catalytic activity. In the present study, we demonstrate that the Hsp90/HOP/Cdc37 complex recruits Hsp27 after recognition of GCase mutants with subsequent targeting of GCase mutant peptides to degradation mechanisms such as VCP and the 26S proteasome. Inhibition of Hsp27 not only increased the quantity of enzyme but also enhanced GCase activity in fibroblasts derived from patients with Gaucher disease. These findings provide insight into a possible therapeutic strategy for protein misfolding diseases by correcting chaperone binding and altering subsequent downstream patterns of protein degradation.


Subject(s)
Gaucher Disease/metabolism , Glucosylceramidase/metabolism , HSP27 Heat-Shock Proteins/metabolism , HSP90 Heat-Shock Proteins/metabolism , Proteolysis , Proteostasis Deficiencies/metabolism , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Chaperonins/genetics , Chaperonins/metabolism , Fibroblasts/metabolism , Gaucher Disease/genetics , Glucosylceramidase/genetics , HSP27 Heat-Shock Proteins/genetics , HSP90 Heat-Shock Proteins/genetics , HeLa Cells , Heat-Shock Proteins , Homeodomain Proteins/genetics , Homeodomain Proteins/metabolism , Humans , Molecular Chaperones , Mutation , Proteasome Endopeptidase Complex/genetics , Proteasome Endopeptidase Complex/metabolism , Protein Folding , Proteostasis Deficiencies/genetics , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolism
12.
J Neurooncol ; 130(1): 111-122, 2016 10.
Article in English | MEDLINE | ID: mdl-27568035

ABSTRACT

Transcription factors that induce epithelial-mesenchymal transition (EMT) promote invasion, chemoresistance and a stem-cell phenotype in epithelial tumors, but their roles in central nervous system tumors are not well-understood. We hypothesized these transcription factors have a functional impact in grades II-III gliomas. Using the National Cancer Institute (NCI) Repository for Molecular Brain Neoplasia Data (REMBRANDT) and the Cancer Genome Atlas (TCGA) Lower-Grade Glioma (LGG) data, we determined the impact of EMT-promoting transcription factors (EMT-TFs) on overall survival in grades II-III gliomas, compared their expression across common genetic subtypes and subsequently validated these findings in a set of 31 tumors using quantitative real-time polymerase chain reaction (PCR) and immunohistochemistry. Increased expression of the gene coding for the transcriptional repressor Zinc Finger E box-binding Homeobox 1 (ZEB1) was associated with a significant increase in overall survival (OS) on Kaplan-Meier analysis. Genetic subtype analysis revealed that ZEB1 expression was relatively increased in IDH1/2-mutant gliomas, and IDH1/2-mutant gliomas expressed significantly lower levels of many ZEB1 transcriptional targets. Similarly, IDH1/2-mutant tumors expressed significantly higher levels of targets of microRNA 200C (MIR200C), a key regulator of ZEB1. In a validation study, ZEB1 mRNA was significantly increased in IDH1-mutant grades II-III gliomas, and ZEB1 protein expression was more pronounced in these tumors. Our findings demonstrate a novel relationship between IDH1/2 mutations and expression of ZEB1 and its transcriptional targets. Therapy targeting ZEB1-associated pathways may represent a novel therapeutic avenue for this class of tumors.


Subject(s)
Brain Neoplasms/metabolism , Gene Expression Regulation, Neoplastic/genetics , Glioma/metabolism , Isocitrate Dehydrogenase/genetics , Mutation/genetics , Zinc Finger E-box-Binding Homeobox 1/metabolism , Brain Neoplasms/genetics , Brain Neoplasms/mortality , Databases, Factual/statistics & numerical data , Female , Glioma/genetics , Glioma/mortality , Humans , Isocitrate Dehydrogenase/metabolism , Kaplan-Meier Estimate , Male , RNA, Messenger/metabolism , Statistics as Topic
13.
J Neurooncol ; 119(1): 71-8, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24844311

ABSTRACT

Recent genome-wide association studies have identified several leukocyte telomere length (LTL)-related single nucleotide polymorphisms (SNPs). Our previous data demonstrated that two SNPs (rs398652 on 14q21 and rs621559 on 1p34.2) were associated with LTL and risk of esophageal squamous cell carcinoma in Chinese. However, the role of these genetic variants on glioma risk is still unknown. Therefore, we examined if these genetic variants have impact on the genetic susceptibility of glioma in Chinese. On the basis of analyzing 404 glioma patients and frequency-matched 820 controls, we found that subjects having the 1p34.2 rs621559 AG or GG genotype had an OR of 1.82 (95 % CI = 1.07-3.09, P = 0.026) or 2.12 (95 % CI = 1.26-3.56, P = 0.005) for developing glioma, respectively, compared with subjects having the rs621559 AA genotype. Similarly, the 14q21 rs398652 AG or GG genotype was associated with increased glioma risk (OR = 1.39, 95 % CI = 1.07-1.80, P = 0.012; OR = 1.52, 95 % CI = 1.04-2.20, P = 0.029) compared to AA genotype. In all, our results highlight the possible role of telomere in carcinogenesis.


Subject(s)
Brain Neoplasms/genetics , Chromosomes, Human, Pair 14 , Chromosomes, Human, Pair 1 , Genetic Predisposition to Disease , Glioma/genetics , Telomere Homeostasis/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Case-Control Studies , Child , Child, Preschool , Female , Genetic Association Studies , Genotype , Glioma/metabolism , Glioma/pathology , Haplotypes , Humans , Leukocytes/metabolism , Male , Middle Aged , Polymorphism, Single Nucleotide , Telomere , Young Adult
14.
Mater Horiz ; 11(11): 2657-2666, 2024 Jun 03.
Article in English | MEDLINE | ID: mdl-38597197

ABSTRACT

Metal-CO2 batteries, which use CO2 as the active species at cathodes, are particularly promising, but device design for mass-producible CO2 reduction and energetic power supply lag behind, limiting their potential benefits. In this study, an aqueous reversible flow-type Zn-CO2 battery using a Pd/SnO2@C cathode catalyst has been assembled and demonstrates an ultra-high discharge voltage of 1.38 V, a peak power density of 4.29 mW cm-2, high-energy efficiency of 95.64% and remarkable theoretical energy density (827.3 W h kg-1). In the meantime, this optimized system achieves a high formate faradaic efficiency of 95.86% during the discharge process at a high rate of 4.0 mA cm-2. This energy- and chemical-conversion technology could store and provide electricity, eliminate CO2 and produce valuable chemicals, addressing current energy and environment issues simultaneously.

15.
Am J Cancer Res ; 14(2): 562-584, 2024.
Article in English | MEDLINE | ID: mdl-38455403

ABSTRACT

Previous studies reported that alternating electric fields (EFs) in the intermediate frequency (100-300 kHz) and low intensity (1-3 V/cm) regime - termed "Tumor Treating Fields" (TTFields) - have a specific, anti-proliferative effect on glioblastoma multiforme (GBM) cells. However, the mechanism(s) of action remain(s) incompletely understood, hindering the clinical adoption of treatments based on TTFields. To advance the study of such treatment in vitro, we developed an inductive device to deliver EFs to cell cultures which improves thermal and osmolar regulation compared to prior devices. Using this inductive device, we applied continuous, 200 kHz electromagnetic fields (EMFs) with a radial EF amplitude profile spanning 0-6.5 V/cm to cultures of primary rat astrocytes and several human GBM cell lines - U87, U118, GSC827, and GSC923 - for a duration of 72 hours. Cell density was assessed via segmented pixel densities from GFP expression (U87, U118) or from staining (astrocytes, GSC827, GSC923). Further RNA-Seq analyses were performed on GSC827 and GSC923 cells. Treated cultures of all cell lines exhibited little to no change in proliferation at lower EF amplitudes (0-3 V/cm). At higher amplitudes (> 4 V/cm), different effects were observed. Apparent cell densities increased (U87), decreased (GSC827, GSC923), or showed little change (U118, astrocytes). RNA-Seq analyses on treated and untreated GSC827 and GSC923 cells revealed differentially expressed gene sets of interest, such as those related to cell cycle control. Up- and down-regulation, however, was not consistent across cell lines nor EF amplitudes. Our results indicate no consistent, anti-proliferative effect of 200 kHz EMFs across GBM cell lines and thus contradict previous in vitro findings. Rather, effects varied across different cell lines and EF amplitude regimes, highlighting the need to assess the effect(s) of TTFields and similar treatments on a per cell line basis.

16.
Adv Sci (Weinh) ; 11(14): e2308280, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38298111

ABSTRACT

Despite strides in immunotherapy, glioblastoma multiforme (GBM) remains challenging due to low inherent immunogenicity and suppressive tumor microenvironment. Converting "cold" GBMs to "hot" is crucial for immune activation and improved outcomes. This study comprehensively characterized a therapeutic vaccination strategy for preclinical GBM models. The vaccine consists of Mannan-BAM-anchored irradiated whole tumor cells, Toll-like receptor ligands [lipoteichoic acid (LTA), polyinosinic-polycytidylic acid (Poly (I:C)), and resiquimod (R-848)], and anti-CD40 agonistic antibody (rWTC-MBTA). Intracranial GBM models (GL261, SB28 cells) are used to evaluate the vaccine efficacy. A substantial number of vaccinated mice exhibited complete regression of GBM tumors in a T-cell-dependent manner, with no significant toxicity. Long-term tumor-specific immune memory is confirmed upon tumor rechallenge. In the vaccine-draining lymph nodes of the SB28 model, rWTC-MBTA vaccination triggered a major rise in conventional dendritic cell type 1 (cDC1) 12 h post-treatment, followed by an increase in conventional dendritic cell type 2 (cDC2), monocyte-derived dendritic cell (moDC), and plasmacytoid dendritic cell (pDC) on Day 5 and Day 13. Enhanced cytotoxicity of CD4+ and CD8+ T cells in vaccinated mice is verified in co-culture with tumor cells. Analyses of immunosuppressive signals (T-cell exhaustion, myeloid-derived suppressor cells (MDSC), M2 macrophages) in the GBM microenvironment suggest potential combinations with other immunotherapies for enhanced efficacy. In conclusion, the authors findings demonstrate that rWTC-MBTA induces potent and long-term adaptive immune responses against GBM.


Subject(s)
Glioblastoma , Vaccines , Mice , Animals , Glioblastoma/metabolism , CD8-Positive T-Lymphocytes , Vaccines/metabolism , Dendritic Cells , Immunity , Tumor Microenvironment
17.
bioRxiv ; 2024 Jan 02.
Article in English | MEDLINE | ID: mdl-37786680

ABSTRACT

Isocitrate dehydrogenase (IDH)-mutant gliomas have distinctive metabolic and biological traits that may render them susceptible to targeted treatments. Here, by conducting a high-throughput drug screen, we pinpointed a specific susceptibility of IDH-mutant gliomas to zotiraciclib (ZTR). ZTR exhibited selective growth inhibition across multiple IDH-mutant glioma in vitro and in vivo models. Mechanistically, ZTR at low doses suppressed CDK9 and RNA Pol II phosphorylation in IDH-mutant cells, disrupting mitochondrial function and NAD+ production, causing oxidative stress. Integrated biochemical profiling of ZTR kinase targets and transcriptomics unveiled that ZTR-induced bioenergetic failure was linked to the suppression of PIM kinase activity. We posit that the combination of mitochondrial dysfunction and an inability to adapt to oxidative stress resulted in significant cell death upon ZTR treatment, ultimately increasing the therapeutic vulnerability of IDH-mutant gliomas. These findings prompted a clinical trial evaluating ZTR in IDH-mutant gliomas towards precision medicine ( NCT05588141 ). Highlights: Zotiraciclib (ZTR), a CDK9 inhibitor, hinders IDH-mutant glioma growth in vitro and in vivo . ZTR halts cell cycle, disrupts respiration, and induces oxidative stress in IDH-mutant cells.ZTR unexpectedly inhibits PIM kinases, impacting mitochondria and causing bioenergetic failure.These findings led to the clinical trial NCT05588141, evaluating ZTR for IDH-mutant gliomas.

18.
Nat Commun ; 15(1): 4163, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38755145

ABSTRACT

TAR DNA-binding protein 43 (TDP-43) proteinopathy in brain cells is the hallmark of amyotrophic lateral sclerosis (ALS) but its cause remains elusive. Asparaginase-like-1 protein (ASRGL1) cleaves isoaspartates, which alter protein folding and susceptibility to proteolysis. ASRGL1 gene harbors a copy of the human endogenous retrovirus HML-2, whose overexpression contributes to ALS pathogenesis. Here we show that ASRGL1 expression was diminished in ALS brain samples by RNA sequencing, immunohistochemistry, and western blotting. TDP-43 and ASRGL1 colocalized in neurons but, in the absence of ASRGL1, TDP-43 aggregated in the cytoplasm. TDP-43 was found to be prone to isoaspartate formation and a substrate for ASRGL1. ASRGL1 silencing triggered accumulation of misfolded, fragmented, phosphorylated and mislocalized TDP-43 in cultured neurons and motor cortex of female mice. Overexpression of ASRGL1 restored neuronal viability. Overexpression of HML-2 led to ASRGL1 silencing. Loss of ASRGL1 leading to TDP-43 aggregation may be a critical mechanism in ALS pathophysiology.


Subject(s)
Amyotrophic Lateral Sclerosis , DNA-Binding Proteins , Neurons , TDP-43 Proteinopathies , Amyotrophic Lateral Sclerosis/metabolism , Amyotrophic Lateral Sclerosis/genetics , Amyotrophic Lateral Sclerosis/pathology , Animals , Humans , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Mice , Female , TDP-43 Proteinopathies/metabolism , TDP-43 Proteinopathies/pathology , TDP-43 Proteinopathies/genetics , Neurons/metabolism , Neurons/pathology , Brain/metabolism , Brain/pathology , Male , Motor Cortex/metabolism , Motor Cortex/pathology
19.
Endocr Relat Cancer ; 30(10)2023 10 01.
Article in English | MEDLINE | ID: mdl-37450881

ABSTRACT

This article is a summary of the plenary lecture presented by Jared Rosenblum that was awarded the Manger Prize at the Sixth International Symposium on Pheochromocytoma/Paraganglioma held on 19-22 October 2022 in Prague, Czech Republic. Herein, we review our initial identification of a new syndrome of multiple paragangliomas, somatostatinomas, and polycythemia caused by early postzygotic mosaic mutations in EPAS1, encoding hypoxia-inducible factor 2 alpha (HIF-2α), and our continued exploration of new disease phenotypes in this syndrome, including vascular malformations and neural tube defects. Continued recruitment and close monitoring of patients with this syndrome as well as the generation and study of a corresponding disease mouse model as afforded by the pheochromocytoma/paraganglioma translational program at the National Institutes of Health has provided new insights into the natural history of these developmental anomalies and the pathophysiologic role of HIF-2α. Further, these studies have highlighted the importance of the timing of genetic defects in the development of related disease phenotypes. The recent discovery and continued study of this syndrome has not only rapidly evolved our understanding of pheochromocytoma and paraganglioma but also deepened our understanding of other developmental tumor syndromes, heritable syndromes, and sporadic diseases.


Subject(s)
Adrenal Gland Neoplasms , Paraganglioma , Pheochromocytoma , Animals , Mice , Pheochromocytoma/genetics , Pheochromocytoma/pathology , Syndrome , Paraganglioma/genetics , Paraganglioma/pathology , Basic Helix-Loop-Helix Transcription Factors/genetics , Adrenal Gland Neoplasms/genetics , Adrenal Gland Neoplasms/pathology
20.
Nat Commun ; 14(1): 2843, 2023 May 18.
Article in English | MEDLINE | ID: mdl-37202405

ABSTRACT

Acidic CO2-to-HCOOH electrolysis represents a sustainable route for value-added CO2 transformations. However, competing hydrogen evolution reaction (HER) in acid remains a great challenge for selective CO2-to-HCOOH production, especially in industrial-level current densities. Main group metal sulfides derived S-doped metals have demonstrated enhanced CO2-to-HCOOH selectivity in alkaline and neutral media by suppressing HER and tuning CO2 reduction intermediates. Yet stabilizing these derived sulfur dopants on metal surfaces at large reductive potentials for industrial-level HCOOH production is still challenging in acidic medium. Herein, we report a phase-engineered tin sulfide pre-catalyst (π-SnS) with uniform rhombic dodecahedron structure that can derive metallic Sn catalyst with stabilized sulfur dopants for selective acidic CO2-to-HCOOH electrolysis at industrial-level current densities. In situ characterizations and theoretical calculations reveal the π-SnS has stronger intrinsic Sn-S binding strength than the conventional phase, facilitating the stabilization of residual sulfur species in the Sn subsurface. These dopants effectively modulate the CO2RR intermediates coverage in acidic medium by enhancing *OCHO intermediate adsorption and weakening *H binding. As a result, the derived catalyst (Sn(S)-H) demonstrates significantly high Faradaic efficiency (92.15 %) and carbon efficiency (36.43 %) to HCOOH at industrial current densities (up to -1 A cm-2) in acidic medium.

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