54 research outputs found

    Nickel and chromium in wastewater - The Malaysian experience

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    Heavy metals in natural water bodies pose a serious problem in Malaysia.Ni and Cr have drawn particular attention owing to their prevalence in various industrial effluents. While efforts are being made by industries to control discharges by recycling the metals, a lack of cost effective technologies appear to be a constraint, This paper discusses these issues in Malaysian and global perspectives

    Explorative Role of miR-216a/217 as a Tumor Suppressor in Pancreatic Cancer

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    Pancreatic cancer (PC) is a lethal malignancy with a 5-year survival rate of 10.8%. Gemcitabine, in combination with Abraxane and Folfirinox, are current treatments available for metastatic PC, however, all these therapies provided limited patient survival benefit, often resulting in high toxicity. Therefore, there is a need to identify novel therapeutic targets and combination therapies to combat this lethal cancer. MicroRNAs (miRNAs or miRs) have been shown to regulate PC proliferation and metastasis. Recently, miRNA therapies have shown promising results as a single miRNA is predicted to target more than 200 genes, involved in multiple pathways. The objective of this study is to understand the role of miR-216a/217 in PC growth and its progression. We and others have shown that miR-216a/217 was progressively downregulated during PC progression. PC patients with higher miR-216a/217 had better survival. Our In-situ hybridization data showed reduced expression of miR-216a/217 in PC patient samples (TMA - 196 core). Further, over-expression of miR-216a/217 in Capan-1 PC cells in vitro resulted in inhibition of cell proliferation and the epithelial-mesenchymal transition (EMT). In silico analysis have identified protein tyrosine phosphatase type IVA member 1 (PTP4A1) as a direct downstream target of miR-216a/217 in PC. Furthermore, our data indicates that miR-216a/217 inhibits PC metastasis by targeting PTP4A1 and may serve as a prospective therapeutic target in PC.https://digitalcommons.unmc.edu/surp2022/1022/thumbnail.jp

    Ferromagnetism in the Periodic Anderson Model - a Modified Alloy Analogy

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    We introduce a new aproximation scheme for the periodic Anderson model (PAM). The modified alloy approximation represents an optimum alloy approximation for the strong coupling limit, which can be solved within the CPA-formalism. Zero-temperature and finite-temperature phase diagrams are presented for the PAM in the intermediate-valence regime. The diversity of magnetic properties accessible by variation of the system parameters can be studied by means of quasiparticle densities of states: The conduction band couples either ferro- or antiferromagneticaly to the f-levels. A finite hybridization is a necessary precondition for ferromagnetism. However, too strong hybridization generally suppresses ferromagnetism, but can for certain system parameters also lead to a semi-metallic state with unusual magnetic properties. By comparing with the spectral density approximation, the influence of quasiparticle damping can be examined.Comment: 20 pages, 13 figure

    MiR-1253 Potentiates Cisplatin Response in Pediatric Medulloblastoma by Regulating Ferroptosis

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    Introduction Among CNS tumors, medulloblastoma (MB) is the most common malignant pediatric brain tumor. Of the four subgroups, group 3 (G3MB) tumors fare the worst. Haploinsufficiency of 17p13.3 is a hallmark of these high-risk tumors; included within this locus is miR-1253, which has tumor suppressive properties in medulloblastoma. Therapeutic strategies capitalizing on the anti-neoplastic properties of miRNAs can provide promising adjuncts that can improve efficacy while mitigating toxicity of current chemotherapeutic drugs. Objective In this study, we explored the potentiation of miR-1253 on cisplatin cytotoxicity in group 3 MB. Methods We used RNA Sequencing to isolate a putative target for miR-1253 that is upregulated in G3MB, has a poor prognostic profile, and is involved in iron balance/ferroptosis. Calein AM quenching, COX IV staining and multiple stains for iron were used to study mitochondrial vs. free cytosolic iron generation. Confocal microscopy and FACs analyses were used to examine ROS generation and lipid peroxidation. Using 2 classical group 3 MB cell lines, possessing c-Myc amplification and i17q, we determined the IC50 of cisplatin in the presence of miR-1253 expression using MTT assay. We also studied colony formation, apoptosis and oxidative stress, as cisplatin is an inducer of both. Finally, ROS and ferroptosis inhibitors were used to study effects on tumor cell rescue from miR-1253 and cisplatin therapy. Results In silico and in vitro analyses revealed upregulation of ABCB7 in G3MB cancer cells and tumors. Overexpressing miR-1253, in turn, suppressed ABCB7, revealing it as a putative target with poor survival in high-expressing MB tumors. Overexpression also led to a suppression of GPX4, a ferroptosis regulator, consequently increasing labile iron pool within the mitochondria and resulting in mtROS induction. Cisplatin is reported as an inducer of both apoptosis and ferroptosis-mediated cancer cell death. In miR-1253-overexpressing cancer cells, we observed a cumulative effect on cell death and colony formation with cisplatin; treatment with ROS and ferroptosis inhibitors abrogated these effects. Conclusions We conclude that miR-1253 potentiates the ferroptotic effects of cisplatin via targeting miR-1253/ABCB7/GPX4 axis.https://digitalcommons.unmc.edu/chri_forum/1010/thumbnail.jp

    Ubiquitous Aberration in Cholesterol Metabolism Across Pancreatic Ductal Adenocarcinoma

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    Pancreatic cancer (PC) is characterized by metabolic deregulations that often manifest as deviations in metabolite levels and aberrations in their corresponding metabolic genes across the clinical specimens and preclinical PC models. Cholesterol is one of the critical metabolites supporting PC, synthesized or acquired by PC cells. Nevertheless, the significance of the de novo cholesterol synthesis pathway has been controversial in PC, indicating the need to reassess this pathway in PC. We utilized preclinical models and clinical specimens of PC patients and cell lines and utilized mass spectrometry-based sterol analysis. Further, we also performed in silico analysis to corroborate the significance of de novo cholesterol synthesis pathway in PC. Our results demonstrated alteration in free sterol levels, including free cholesterol, across in vitro, in vivo, and clinical specimens of PC. Especially, our sterol analyses established consistent alterations in free cholesterol across the different PC models. Overall, this study demonstrates the significance and consistency in deviation of cholesterol synthesis pathway in PC while showing the aberrations in sterol metabolite intermediates and the related genes using preclinical models, in silico platforms, and the clinical specimens

    CAD-centric Computation Management System for a Virtual TBM

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    HyPerComp Inc. in research collaboration with TEXCEL has set out to build a Virtual Test Blanket Module (VTBM) computational system to address the need in contemporary fusion research for simulating the integrated behavior of the blanket, divertor and plasma facing components in a fusion environment. Physical phenomena to be considered in a VTBM will include fluid flow, heat transfer, mass transfer, neutronics, structural mechanics and electromagnetics. We seek to integrate well established (third-party) simulation software in various disciplines mentioned above. The integrated modeling process will enable user groups to interoperate using a common modeling platform at various stages of the analysis. Since CAD is at the core of the simulation (as opposed to computational meshes which are different for each problem,) VTBM will have a well developed CAD interface, governing CAD model editing, cleanup, parameter extraction, model deformation (based on simulation,) CAD-based data interpolation. In Phase-I, we built the CAD-hub of the proposed VTBM and demonstrated its use in modeling a liquid breeder blanket module with coupled MHD and structural mechanics using HIMAG and ANSYS. A complete graphical user interface of the VTBM was created, which will form the foundation of any future development. Conservative data interpolation via CAD (as opposed to mesh-based transfer), the regeneration of CAD models based upon computed deflections, are among the other highlights of phase-I activity

    MiR-212-3p Functions as a Tumor Suppressor Gene in Group 3 Medulloblastoma via Targeting Nuclear Factor I/B (NFIB)

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    Haploinsufficiency of chromosome 17p and c-Myc amplification distinguish group 3 medulloblastomas which are associated with early metastasis, rapid recurrence, and swift mortality. Tumor suppressor genes on this locus have not been adequately characterized. We elucidated the role of miR-212-3p in the pathophysiology of group 3 tumors. First, we learned that miR-212-3p undergoes epigenetic silencing by histone modifications in group 3 tumors. Restoring its expression reduced cancer cell proliferation, migration, colony formation, and wound healing in vitro and attenuated tumor burden and improved survival in vivo. MiR-212-3p also triggered c-Myc destabilization and degradation, leading to elevated apoptosis. We then isolated an oncogenic target of miR-212-3p, i.e. NFIB, a nuclear transcription factor implicated in metastasis and recurrence in various cancers. Increased expression of NFIB was confirmed in group 3 tumors and associated with poor survival. NFIB silencing reduced cancer cell proliferation, migration, and invasion. Concurrently, reduced medullosphere formation and stem cell markers (Nanog, Oct4, Sox2, CD133) were noted. These results substantiate the tumor-suppressive role of miR-212-3p in group 3 MB and identify a novel oncogenic target implicated in metastasis and tumor recurrence

    Blocking c-MET/ERBB1 Axis Prevents Brain Metastasis in ERBB2+ Breast Cancer

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    Brain metastasis (BrM) remains a significant cause of cancer-related mortality in epidermal growth factor receptor 2-positive (ERBB2+) breast cancer (BC) patients. We proposed here that a combination treatment of irreversible tyrosine kinase inhibitor neratinib (NER) and the c-MET inhibitor cabozantinib (CBZ) could prevent brain metastasis. To address this, we first tested the combination treatment of NER and CBZ in the brain-seeking ERBB2+ cell lines SKBrM3 and JIMT-1-BR3, and in ERBB2+ organoids that expressed the c-MET/ERBB1 axis. Next, we developed and characterized an orthotopic mouse model of spontaneous BrM and evaluated the therapeutic effect of CBZ and NER in vivo. The combination treatment of NER and CBZ significantly inhibited proliferation and migration in ERBB2+ cell lines and reduced the organoid growth in vitro. Mechanistically, the combination treatment of NER and CBZ substantially inhibited ERK activation downstream of the c-MET/ERBB1 axis. Orthotopically implanted SKBrM3+ cells formed primary tumor in the mammary fat pad and spontaneously metastasized to the brain and other distant organs. Combination treatment with NER and CBZ inhibited primary tumor growth and predominantly prevented BrM. In conclusion, the orthotopic model of spontaneous BrM is clinically relevant, and the combination therapy of NER and CBZ might be a useful approach to prevent BrM in BC

    Disruption of FDPS/Rac1 Axis Radiosensitizes Pancreatic Ductal Adenocarcinoma by Attenuating DNA Damage Response and Immunosuppressive Signalling

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    BACKGROUND: Radiation therapy (RT) has a suboptimal effect in patients with pancreatic ductal adenocarcinoma (PDAC) due to intrinsic and acquired radioresistance (RR). Comprehensive bioinformatics and microarray analysis revealed that cholesterol biosynthesis (CBS) is involved in the RR of PDAC. We now tested the inhibition of the CBS pathway enzyme, farnesyl diphosphate synthase (FDPS), by zoledronic acid (Zol) to enhance radiation and activate immune cells. METHODS: We investigated the role of FDPS in PDAC RR using the following methods: in vitro cell-based assay, immunohistochemistry, immunofluorescence, immunoblot, cell-based cholesterol assay, RNA sequencing, tumouroids (KPC-murine and PDAC patient-derived), orthotopic models, and PDAC patient\u27s clinical study. FINDINGS: FDPS overexpression in PDAC tissues and cells (P \u3c 0.01 and P \u3c 0.05) is associated with poor RT response and survival (P = 0.024). CRISPR/Cas9 and pharmacological inhibition (Zol) of FDPS in human and mouse syngeneic PDAC cells in conjunction with RT conferred higher PDAC radiosensitivity in vitro (P \u3c 0.05, P \u3c 0.01, and P \u3c 0.001) and in vivo (P \u3c 0.05). Interestingly, murine (P = 0.01) and human (P = 0.0159) tumouroids treated with Zol+RT showed a significant growth reduction. Mechanistically, RNA-Seq analysis of the PDAC xenografts and patients-PBMCs revealed that Zol exerts radiosensitization by affecting Rac1 and Rho prenylation, thereby modulating DNA damage and radiation response signalling along with improved systemic immune cells activation. An ongoing phase I/II trial (NCT03073785) showed improved failure-free survival (FFS), enhanced immune cell activation, and decreased microenvironment-related genes upon Zol+RT treatment. INTERPRETATION: Our findings suggest that FDPS is a novel radiosensitization target for PDAC therapy. This study also provides a rationale to utilize Zol as a potential radiosensitizer and as an immunomodulator in PDAC and other cancers. FUNDING: National Institutes of Health (P50, P01, and R01)
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