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Clinical and Experimental Immunology Sep 2020Cladribine (CdA), an oral prodrug approved for the treatment of relapsing multiple sclerosis, selectively depletes lymphocytes. CdA passes the blood-brain barrier,...
Cladribine (CdA), an oral prodrug approved for the treatment of relapsing multiple sclerosis, selectively depletes lymphocytes. CdA passes the blood-brain barrier, suggesting a potential effect on central nervous system (CNS) resident cells. We examined if CdA modifies the phenotype and function of naive and activated primary mouse microglia, when applied in the concentrations 0·1-1 μM that putatively overlap human cerebrospinal fluid (CSF) concentrations. Primary microglia cultures without stimulation or in the presence of proinflammatory lipopolysaccharide (LPS) or anti-inflammatory interleukin (IL)-4 were treated with different concentrations of CdA for 24 h. Viability was assessed by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Phagocytotic ability and morphology were examined by flow cytometry and random migration using IncuCyte Zoom and TrackMate. Change in gene expression was examined by quantitative polymerase chain reaction (qPCR) and protein secretion by Meso Scale Discovery. We found that LPS and IL-4 up-regulated deoxycytidine kinase (DCK) expression. Only activated microglia were affected by CdA, and this was unrelated to viability. CdA 0·1-1 μM significantly reduced granularity, phagocytotic ability and random migration of activated microglia. CdA 10 μM increased the IL-4-induced gene expression of arginase 1 (Arg1) and LPS-induced expression of IL-1β, tumor necrosis factor (TNF), inducible nitric oxide synthase (iNOS) and Arg1, but protein secretion remained unaffected. CdA 10 μM potentiated the increased expression of anti-inflammatory TNF receptor 2 (TNF-R2) but not TNF-R1 induced by LPS. This suggests that microglia acquire a less activated phenotype when treated with 0·1-1 μM CdA that putatively overlaps human CSF concentrations. This may be related to the up-regulated gene expression of DCK upon activation, and suggests a potential alternative mechanism of CdA with direct effect on CNS resident cells.
Topics: Animals; Anti-Inflammatory Agents; Blood-Brain Barrier; Cell Movement; Cells, Cultured; Cladribine; Gene Expression Regulation; Humans; Lymphocyte Depletion; Mice; Mice, Inbred C57BL; Microglia; Multiple Sclerosis; Phagocytosis; Receptors, Tumor Necrosis Factor, Type II
PubMed: 32492189
DOI: 10.1111/cei.13473 -
Nature Communications May 2023Cancer cells utilize the main de novo pathway and the alternative salvage pathway for deoxyribonucleotide biosynthesis to achieve adequate nucleotide pools....
Cancer cells utilize the main de novo pathway and the alternative salvage pathway for deoxyribonucleotide biosynthesis to achieve adequate nucleotide pools. Deoxycytidine kinase is the rate-limiting enzyme of the salvage pathway and it has recently emerged as a target for anti-proliferative therapies for cancers where it is essential. Here, we present the development of a potent inhibitor applying an iterative multidisciplinary approach, which relies on computational design coupled with experimental evaluations. This strategy allows an acceleration of the hit-to-lead process by gradually implementing key chemical modifications to increase affinity and activity. Our lead compound, OR0642, is more than 1000 times more potent than its initial parent compound, masitinib, previously identified from a drug repositioning approach. OR0642 in combination with a physiological inhibitor of the de novo pathway doubled the survival rate in a human T-cell acute lymphoblastic leukemia patient-derived xenograft mouse model, demonstrating the proof-of-concept of this drug design strategy.
Topics: Mice; Humans; Animals; Drug Repositioning; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Nucleotides; Drug Design; Disease Models, Animal
PubMed: 37248212
DOI: 10.1038/s41467-023-38668-2 -
Porto Biomedical Journal 2017
PubMed: 32258705
DOI: 10.1016/j.pbj.2017.07.093 -
PloS One 2018[18F]FAC (2'-deoxy-2'-[18F]fluoro-β-D-arabinofuranosylcytosine, 1) is a versatile probe for imaging deoxycytidine kinase (dCK) expression levels in vivo. dCK is...
[18F]FAC (2'-deoxy-2'-[18F]fluoro-β-D-arabinofuranosylcytosine, 1) is a versatile probe for imaging deoxycytidine kinase (dCK) expression levels in vivo. dCK is responsible for phosphorylation of deoxycytidine (dC, 2) and other nucleoside analogs, plays a key role in immune activation and has demonstrated to be one of the key enzymes in activating nucleoside based drugs including gemcitabine. Reported synthesis of [18F]FAC is high yielding but is quite challenging requiring bromination using HBr and careful drying of excess HBr which is critical for successful synthesis. Here in we report a simplified trimethylsilyl trifluoromethanesulfonate (TMSOTf) assisted synthesis of [18F]FAC eliminating the need of bromination and drying. [18F]FAC (β-anomer) was synthesized with average isolated decay corrected yield of 10.59 + 4.2% (n = 6) with radiochemical purity of >98% and total synthesis time of 158 + 19 min.
Topics: Cytarabine; Deoxycytidine; Deoxycytidine Kinase; Fluorine Radioisotopes; Mesylates; Radiochemistry; Radiopharmaceuticals; Trimethylsilyl Compounds; Gemcitabine
PubMed: 29715301
DOI: 10.1371/journal.pone.0196784 -
Pharmacogenomics Oct 2009The mainstay of acute myeloid leukemia chemotherapy is the nucleoside analog cytarabine (ara-C). Numerous studies suggest that the intracellular concentrations of the... (Review)
Review
The mainstay of acute myeloid leukemia chemotherapy is the nucleoside analog cytarabine (ara-C). Numerous studies suggest that the intracellular concentrations of the ara-C active metabolite, ara-CTP, vary widely among patients and, in turn, are associated with variability in clinical response to acute myeloid leukemia treatment. Thus, genetic variation in key genes in the ara-C metabolic pathway--specifically, deoxycytidine kinase (a rate-limiting activating enzyme), 5 nucleotidase, cytidine deaminase and deoxycytidylate deaminase (all three are inactivating enzymes), human equilibrative nucleoside transporter (ara-C uptake transporter) and ribonucleotide reductase (RRM1 and RRM2--enzymes regulating intracellular deoxycytidine triphosphate pools)--form the molecular basis of the interpatient variability observed in intracellular ara-CTP concentrations and response to ara-C. Understanding genetic variants in the key candidate genes involved in the metabolic activation of ara-C, as well as the pharmacodynamic targets of ara-C, will provide an opportunity to identify patients at an increased risk of adverse reactions or decreased likelihood of response, based upon their genetic profile, which in future could help in dose optimization to reduce drug toxicity without compromising efficacy. The pharmacogenetic studies on ara-C would also be equally applicable to other nucleoside analogs, such as gemcitabine, decitabine, clofarabine and so on, which are metabolized by the same pathway.
Topics: 5'-Nucleotidase; Antimetabolites, Antineoplastic; Arabinofuranosylcytosine Triphosphate; Cytarabine; Cytidine Deaminase; Deoxycytidine Kinase; Equilibrative Nucleoside Transporter 1; Forecasting; Genetic Variation; Humans; Leukemia, Myeloid, Acute; Nucleoside Deaminases; Pharmacogenetics; Ribonucleotide Reductases
PubMed: 19842938
DOI: 10.2217/pgs.09.118 -
Cancer Research May 2019Deoxycytidine kinase (DCK) is a key enzyme for the activation of a broad spectrum of nucleoside-based chemotherapy drugs (e.g., gemcitabine); low DCK activity is one of...
Deoxycytidine kinase (DCK) is a key enzyme for the activation of a broad spectrum of nucleoside-based chemotherapy drugs (e.g., gemcitabine); low DCK activity is one of the most important causes of cancer drug-resistance. Noninvasive imaging methods that can quantify DCK activity are invaluable for assessing tumor resistance and predicting treatment efficacy. Here we developed a "natural" MRI approach to detect DCK activity using its natural substrate deoxycytidine (dC) as the imaging probe, which can be detected directly by chemical exchange saturation transfer (CEST) MRI without any synthetic labeling. CEST MRI contrast of dC and its phosphorylated form, dCTP, successfully discriminated DCK activity in two mouse leukemia cell lines with different DCK expression. This dC-enhanced CEST MRI in xenograft leukemic cancer mouse models demonstrated that DCK(+) tumors have a distinctive dynamic CEST contrast enhancement and a significantly higher CEST contrast than DCK(-) tumors (AUC = 0.47 ± 0.25 and 0.20 ± 0.13, respectively; = 0.026, paired Student test, = 4) at 1 hour after the injection of dC. dC-enhanced CEST contrast also correlated well with tumor responses to gemcitabine treatment. This study demonstrates a novel MR molecular imaging approach for predicting cancer resistance using natural, nonradioactive, nonmetallic, and clinically available agents. This method has great potential for pursuing personalized chemotherapy by stratifying patients with different DCK activity. SIGNIFICANCE: A new molecular MRI method that detects deoxycytidine kinase activity using its natural substrate deoxycytidine has great translational potential for clinical assessment of tumor resistance and prediction of treatment efficacy.
Topics: Animals; Cell Line, Tumor; Deoxycytidine; Deoxycytidine Kinase; Female; Heterografts; Leukemia; Magnetic Resonance Imaging; Mice; Mice, Inbred NOD; Mice, SCID; Substrate Specificity
PubMed: 30940660
DOI: 10.1158/0008-5472.CAN-18-3565 -
Cancers Jul 2018Antimetabolites, in particular nucleobase and nucleoside analogues, are cytotoxic drugs that, starting from the small field of paediatric oncology, in combination with... (Review)
Review
Antimetabolites, in particular nucleobase and nucleoside analogues, are cytotoxic drugs that, starting from the small field of paediatric oncology, in combination with other chemotherapeutics, have revolutionised clinical oncology and transformed cancer into a curable disease. However, even though combination chemotherapy, together with radiation, surgery and immunotherapy, can nowadays cure almost all types of cancer, we still fail to achieve this for a substantial proportion of patients. The understanding of differences in metabolism, pharmacokinetics, pharmacodynamics, and tumour biology between patients that can be cured and patients that cannot, builds the scientific basis for rational therapy improvements. Here, we summarise current knowledge of how tumour-specific and patient-specific factors can dictate resistance to nucleobase/nucleoside analogues, and which strategies of re-sensitisation exist. We revisit well-established hurdles to treatment efficacy, like the blood-brain barrier and reduced deoxycytidine kinase activity, but will also discuss the role of novel resistance factors, such as SAMHD1. A comprehensive appreciation of the complex mechanisms that underpin the failure of chemotherapy will hopefully inform future strategies of personalised medicine.
PubMed: 30041457
DOI: 10.3390/cancers10070240 -
Scientific Reports Oct 2019The present study investigated the effect of cladribine (CLA) and six of its derivatives containing a formamidine group at position 6 (CLA-FDM, CLA-FPAZ, CLA-FPIR,...
The present study investigated the effect of cladribine (CLA) and six of its derivatives containing a formamidine group at position 6 (CLA-FDM, CLA-FPAZ, CLA-FPIR, CLA-FPIP, CLA-FHEX, and CLA-FMOR) on acute promyelocytic, lymphoblastic, and acute monocytic leukemia cells. The role of ATR kinase in deoxycytidine kinase (dCK) activation in response to DNA damage was assessed. The presence of DNA lesions was assessed by measurement phosphorylation of H2AX and by using the alkaline comet assay with proteinase K post-treatment following assessment of the cell cycle. Apoptotic events such as alterations in intracellular calcium concentration, caspase-3/7 activity and increased sub-G1 cell population were measured. CLA derivatives were highly effective against leukemic cells, showing high cytotoxicity, causing DNA fragmentation, and inducing DNA-protein cross-links in leukemic cells. CLA-FMOR showed the highest efficacy. CLA derivatives increased the levels of intracellular calcium ions, caspase-3/7 and the percentage of sub-G1 apoptotic cells and blocked cells in the S phase of the cell cycle to a greater extent than free CLA. The selective ATR inhibitor VE-821 significantly suppressed the increase in dCK activity and decreased basal dCK activity. The present results suggested that ATR kinase controls dCK activity in response to synthetic CLA derivatives.
Topics: Adenosine; Amidines; Antineoplastic Agents; Apoptosis; Ataxia Telangiectasia Mutated Proteins; Caspases; Cell Line; Cell Line, Tumor; Cladribine; DNA Fragmentation; HL-60 Cells; Humans; Leukemia, Monocytic, Acute; Pyrazines; S Phase; Sulfones; THP-1 Cells
PubMed: 31575977
DOI: 10.1038/s41598-019-50509-1 -
Cell Death & Disease May 2024
PubMed: 38821944
DOI: 10.1038/s41419-024-06628-3 -
International Journal of Clinical and... 2013Rheumatoid arthritis (RA) is a complex, multi-system disease whose primary site of inflammatory tissue damage is the joint. The increasing evidences indicate that...
Rheumatoid arthritis (RA) is a complex, multi-system disease whose primary site of inflammatory tissue damage is the joint. The increasing evidences indicate that activated RA fibroblast-like synoviocytes (FLS) play a critical role in the development of pannus by migrating into cartilage and bone. Furthermore FLS and T cells can activate each other in vitro and in vivo, which is crucial for the progress of RA. Deoxycytidine kinase (DCK) has been linked to peripheral T cell homeostatic proliferation and survival, which is very important for RA. Yet, the function of DCK in FLS is still unknown. Here, we present a story that DCK could regulate the migration and invasion of FLS through AKT pathway in RA patients. Moreover, DCK seems to be the upstream of AKT and FAK, and AKT inhibitor exerted the similar effect on FLS motility. In summary, our study characterized the new role of DCK in human primary FLS cells, and figured out the possible pathway DCK involved in, and these findings might propose DCK as a novel target for controlling joint destruction of RA.
Topics: Adult; Aged; Arthritis, Rheumatoid; Cell Movement; Cells, Cultured; Cytoskeleton; Deoxycytidine Kinase; Female; Fibroblasts; Focal Adhesion Kinase 1; Humans; Male; Matrix Metalloproteinase 1; Matrix Metalloproteinase 3; Middle Aged; Phosphorylation; Protein Kinase Inhibitors; Proto-Oncogene Proteins c-akt; RNA Interference; Signal Transduction; Synovial Membrane; Tissue Inhibitor of Metalloproteinase-2; Transfection
PubMed: 24294360
DOI: No ID Found