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Cellular Signalling Feb 2023A point mutation (V617F) in the Janus kinase 2 (JAK2) gene results in the production of disorderly activated tyrosine kinase, which causes myeloproliferative neoplasms...
A point mutation (V617F) in the Janus kinase 2 (JAK2) gene results in the production of disorderly activated tyrosine kinase, which causes myeloproliferative neoplasms (MPN). We herein demonstrated that the RNA helicase DDX5 was highly expressed at the mRNA and protein levels through the activation of signal transducer and activator of transcription 5 (STAT5) in Ba/F3 cells expressing a JAK2V617F mutant and erythropoietin receptor (V617F/EpoR cells) and MPN patient-derived HEL cells. A treatment with the JAK1/2 inhibitor, ruxolitinib and STAT5 inhibitor, pimozide significantly inhibited DDX5 mRNA expression and enhanced the degradation of DDX5 in these cells, suggesting that the JAK2V617F mutant positively regulates DDX5 mRNA expression and DDX5 protein stability by activating STAT5. The knockdown of DDX5 specifically inhibited the activation of mechanistic target of rapamycin (mTOR) in V617F/EpoR cells and HEL cells and significantly suppressed the proliferation of these cells. Furthermore, the knockdown of DDX5 markedly suppressed tumorigenesis, splenomegaly, and liver hypertrophy caused by an inoculation of V617F/EpoR cells in nude mice. Collectively, these results revealed that JAK2V617F exhibits transforming activity by inducing the expression of DDX5 in a STAT5-dependent manner, indicating the potential of the JAK2V617F/STAT5/DDX5 axis as a therapeutic target in the treatment of MPN.
Topics: Animals; Mice; Carcinogenesis; Cell Transformation, Neoplastic; Janus Kinase 2; Mice, Nude; Mutation; Myeloproliferative Disorders; Receptors, Erythropoietin; RNA, Messenger; STAT5 Transcription Factor; DEAD-box RNA Helicases
PubMed: 36442590
DOI: 10.1016/j.cellsig.2022.110537 -
Leukemia Jan 2023The patients with relapsed and refractory diffuse large B-cell lymphoma (DLBCL) have poor prognosis, and a novel and effective therapeutic strategy for these patients is...
The patients with relapsed and refractory diffuse large B-cell lymphoma (DLBCL) have poor prognosis, and a novel and effective therapeutic strategy for these patients is urgently needed. Although ubiquitin-specific protease 1 (USP1) plays a key role in cancer, the carcinogenic effect of USP1 in B-cell lymphoma remains elusive. Here we found that USP1 is highly expressed in DLBCL patients, and high expression of USP1 predicts poor prognosis. Knocking down USP1 or a specific inhibitor of USP1, pimozide, induced cell growth inhibition, cell cycle arrest and autophagy in DLBCL cells. Targeting USP1 by shRNA or pimozide significantly reduced tumor burden of a mouse model established with engraftment of rituximab/chemotherapy resistant DLBCL cells. Pimozide significantly retarded the growth of lymphoma in a DLBCL patient-derived xenograft (PDX) model. USP1 directly interacted with MAX, a MYC binding protein, and maintained the stability of MAX through deubiquitination, which promoted the transcription of MYC target genes. Moreover, pimozide showed a synergetic effect with etoposide, a chemotherapy drug, in cell and mouse models of rituximab/chemotherapy resistant DLBCL. Our study highlights the critical role of USP1 in the rituximab/chemotherapy resistance of DLBCL through deubiquitylating MAX, and provides a novel therapeutic strategy for rituximab/chemotherapy resistant DLBCL.
Topics: Animals; Mice; Humans; Rituximab; Pimozide; Lymphoma, Large B-Cell, Diffuse; Lymphoma, Non-Hodgkin; Ubiquitin-Specific Proteases; Antineoplastic Combined Chemotherapy Protocols
PubMed: 36352191
DOI: 10.1038/s41375-022-01747-2 -
Diabetes Jan 2023Despite significant progress in understanding the pathogenesis of type 2 diabetes (T2D), the condition remains difficult to manage. Hence, new therapeutic options...
Despite significant progress in understanding the pathogenesis of type 2 diabetes (T2D), the condition remains difficult to manage. Hence, new therapeutic options targeting unique mechanisms of action are required. We have previously observed that elevated skeletal muscle succinyl CoA:3-ketoacid CoA transferase (SCOT) activity, the rate-limiting enzyme of ketone oxidation, contributes to the hyperglycemia characterizing obesity and T2D. Moreover, we identified that the typical antipsychotic agent pimozide is a SCOT inhibitor that can alleviate obesity-induced hyperglycemia. We now extend those observations here, using computer-assisted in silico modeling and in vivo pharmacology studies that highlight SCOT as a noncanonical target shared among the diphenylbutylpiperidine (DPBP) drug class, which includes penfluridol and fluspirilene. All three DPBPs tested (pimozide, penfluridol, and fluspirilene) improved glycemia in obese mice. While the canonical target of the DPBPs is the dopamine 2 receptor, studies in obese mice demonstrated that acute or chronic treatment with a structurally unrelated antipsychotic dopamine 2 receptor antagonist, lurasidone, was devoid of glucose-lowering actions. We further observed that the DPBPs improved glycemia in a SCOT-dependent manner in skeletal muscle, suggesting that this older class of antipsychotic agents may have utility in being repurposed for the treatment of T2D.
Topics: Animals; Mice; Antipsychotic Agents; Coenzyme A-Transferases; Diabetes Mellitus, Type 2; Dopamine; Fluspirilene; Hyperglycemia; Mice, Obese; Penfluridol; Pimozide; Receptors, Dopamine
PubMed: 36256885
DOI: 10.2337/db22-0221 -
Journal of Pharmaceutical Sciences Dec 2022Pimozide, an antipsychotic drug, is a potent inhibitor of the hERG channel. A case of death due to cardiac arrest has been reported in a boy who received pimozide...
Pimozide, an antipsychotic drug, is a potent inhibitor of the hERG channel. A case of death due to cardiac arrest has been reported in a boy who received pimozide together with sertraline and aripiprazole. In this study, we focused on drug-drug interactions and investigated the relationships between transporter-mediated intracellular accumulation and the hERG inhibitory effect of pimozide. The accumulation of pimozide in cardiomyocyte-derived AC16 cells was significantly increased by sertraline and aripiprazole, which are thought to have a P-glycoprotein (P-gp) inhibitory effect, and under P-gp siRNA conditions. These results suggest P-gp inhibition increases pimozide accumulation in AC16 cells. We introduced the hERG plasmid into AC16 cells and investigated the concentration-dependent hERG inhibitory effect of pimozide from within AC16 cells. Addition of 10 nM or more pimozide significantly inhibited the hERG current with concentration dependence. These results indicate P-gp-mediated pharmacokinetic interaction increases pimozide accumulation in AC16 cells, and the subsequent elevated pimozide levels within the cells may result in an increased risk of hERG channel inhibition. Our present study calls attention to the risks associated with the combined use of cardiotoxic P-gp substrate(s) and P-gp inhibitory medicines.
Topics: Humans; Male; Pimozide; Aripiprazole; Sertraline; Antipsychotic Agents; ATP Binding Cassette Transporter, Subfamily B; Potassium Channel Blockers
PubMed: 36181876
DOI: 10.1016/j.xphs.2022.09.025 -
Cell Death & Disease Sep 2022Ubiquitin-specific protease 1 (USP1) is a deubiquitinase involved in DNA damage repair by modulating the ubiquitination of major regulators, such as PCNA and FANCD2....
Ubiquitin-specific protease 1 (USP1) is a deubiquitinase involved in DNA damage repair by modulating the ubiquitination of major regulators, such as PCNA and FANCD2. Because USP1 is highly expressed in many cancers, dysregulation of USP1 contributes to cancer therapy. However, the role of USP1 and the mechanisms underlying chemotherapy remain unclear. In this study, we found high USP1 expression in tumor tissues and that it correlated with poor prognosis in RCC. Mechanistically, USP1 enhanced survivin stabilization by removing ubiquitin. Pharmacological inhibitors (ML23 and pimozide) and siRNA targeting USP1 induced downregulation of survivin expression. In addition, ML323 upregulated DR5 expression by decreasing miR-216a-5p expression at the post-transcriptional level, and miR-216a-5p mimics suppressed the upregulation of DR5 by ML323. Inhibition of USP1 sensitized cancer cells. Overexpression of survivin or knockdown of DR5 markedly prevented the co-treatment with ML323 and TRAIL-induced apoptosis. These results of in vitro were proved in a mouse xenograft model, in which combined treatment significantly reduced tumor size and induced survivin downregulation and DR5 upregulation. Furthermore, USP1 and survivin protein expression showed a positive correlation, whereas miR-216a-5p and DR5 were inversely correlated in RCC tumor tissues. Taken together, our results suggest two target substrates of USP1 and demonstrate the involvement of survivin and DR5 in USP1-targeted chemotherapy.
Topics: Animals; Antineoplastic Agents; Apoptosis; Carcinoma, Renal Cell; Cell Line, Tumor; Deubiquitinating Enzymes; Down-Regulation; Humans; Kidney Neoplasms; Mice; MicroRNAs; Pimozide; Proliferating Cell Nuclear Antigen; RNA, Small Interfering; Receptors, TNF-Related Apoptosis-Inducing Ligand; Survivin; Ubiquitin-Specific Proteases; Ubiquitins; Up-Regulation
PubMed: 36153316
DOI: 10.1038/s41419-022-05271-0 -
Cancer Research Dec 2022Mutant isocitrate dehydrogenase 1 (IDH1) and IDH2 block the differentiation of acute myeloid leukemia (AML) cells through production of R-2-hydroxyglutarate (R-2-HG)....
UNLABELLED
Mutant isocitrate dehydrogenase 1 (IDH1) and IDH2 block the differentiation of acute myeloid leukemia (AML) cells through production of R-2-hydroxyglutarate (R-2-HG). IDH inhibitors can induce differentiation of AML cells by lowering R-2-HG but have limited clinical efficacy as single agents. Here, we performed a genome-wide CRISPR knockout screen in an Idh1-mutated hematopoietic progenitor cell line to identify genes that increased the differentiation response to ivosidenib, an IDH1 inhibitor. The screen identified C-type lectin member 5a (Clec5a), which encodes a spleen tyrosine kinase (SYK)-coupled surface receptor, as one of the top hits. Knockout of Clec5a and Syk rendered cells more sensitive to ivosidenib-induced differentiation through a reduction in STAT5-dependent expression of stemness-related genes, including genes in the homeobox (HOX) family. Importantly, direct inhibition of STAT5 activity was sufficient to increase the differentiation response to IDH inhibitors in primary human IDH1- and IDH2-mutated AML cells, including those harboring mutations in receptor tyrosine kinase (RTK) and MAPK genes that have been linked to drug resistance. In patient-derived xenograft models of IDH1-mutated AML, combination treatment with ivosidenib and the STAT5 inhibitor pimozide was superior to each agent alone in inducing differentiation in leukemic cells without compromising normal hematopoiesis. These findings demonstrate that STAT5 is a critical mediator of resistance to IDH inhibitors and provide the rationale for combining STAT5 and IDH inhibitors in the treatment of IDH-mutated AML.
SIGNIFICANCE
A CRISPR knockout screen identifies a mechanism of resistance to IDH inhibitors in AML involving activated STAT5 signaling, suggesting a potential strategy to improve the clinical efficacy of IDH inhibitors.
Topics: Humans; Isocitrate Dehydrogenase; STAT5 Transcription Factor; Leukemia, Myeloid, Acute; Enzyme Inhibitors; Mutation; Receptors, Cell Surface; Lectins, C-Type
PubMed: 36150062
DOI: 10.1158/0008-5472.CAN-22-1293 -
European Journal of Medicinal Chemistry Dec 2022T-type Ca channels (T-channels), particularly Ca3.2 and Ca3.1 isoforms, are promising targets for treating various diseases including intractable pain. Given the potent...
Discovery of pimozide derivatives as novel T-type calcium channel inhibitors with little binding affinity to dopamine D receptors for treatment of somatic and visceral pain.
T-type Ca channels (T-channels), particularly Ca3.2 and Ca3.1 isoforms, are promising targets for treating various diseases including intractable pain. Given the potent inhibitory activity of pimozide, an antipsychotic, against T-channels, we conducted structure-activity relationship studies of pimozide derivatives, and identified several compounds including 3a, 3s, and 4 that had potency comparable to that of pimozide in inhibiting T-channels, but little binding affinity to dopamine D receptors. The introduction of a phenylbutyl group on the benzoimidazole nuclei of pimozide was considered a key structural modification to reduce the binding affinity to D receptors. Those pimozide derivatives potently suppressed T-channel-dependent somatic and visceral pain in mice, without causing any motor dysfunctions attributable to D receptor blockade, including catalepsy. The present study thus provides an avenue to develop novel selective T-channel inhibitors available for pain management via the structural modification of existing medicines.
Topics: Mice; Animals; Pimozide; Calcium Channels, T-Type; Visceral Pain; Dopamine; Calcium Channel Blockers; Receptors, Dopamine
PubMed: 36075145
DOI: 10.1016/j.ejmech.2022.114716 -
Journal of Biomolecular Structure &... 2023In the present study, we screened eighty seven novel phytochemical compounds from four popular herbs, such as, and identified the best three for targeting the main...
In the present study, we screened eighty seven novel phytochemical compounds from four popular herbs, such as, and identified the best three for targeting the main protease (M) receptor of SARS-CoV-2. After categorizing all the phytochemicals based upon LibDock scores and hydrogen bonding interactions, the top ranked 26 compounds were further subjected for detailed Molecular dynamics (MD) study. From these screening we identified that Aegelinosides B leads the list with a high LibDock value of 142.50 (binding energy: -8.54 kcal/mol), which is better than several popular reference compounds namely, Tipranavir (LibDock score, 141.50), Saquinavir (125.34), Zopicole (122.9), Pirenepine (122.70), (115.37), Metixene (109.18), Oxiconazole Pimozide (138.00) and Rimonabant (91.88). Detailed analysis for structural stability (RMSD), Cα fluctuations (RMSF), intermolecular hydrogen bond interactions, effect of solvent accessibility (SASA) and compactness (Rg) factors were performed for the best six compounds and it is found that they are very stable and exhibit folding behavior. Apart from the docking and MD tests, through further drug-likeness and toxicity tests, three compounds, such as, Aegelinosides B, Epicatechin, and Feruloyltyramine (LibDock scores, respectively, 142.50, 124.33 and 129.06) can be suggested for fighting SARS-CoV-2.Communicated by Ramaswamy H. Sarma.
PubMed: 35930306
DOI: 10.1080/07391102.2022.2107573 -
Cancers Jul 2022Monoclonal antibodies targeting the PD-1/PD-L1 immune checkpoint have considerably improved the treatment of some cancers, but novel drugs, new combinations, and... (Review)
Review
Monoclonal antibodies targeting the PD-1/PD-L1 immune checkpoint have considerably improved the treatment of some cancers, but novel drugs, new combinations, and treatment modalities are needed to reinvigorate immunosurveillance in immune-refractory tumors. An option to elicit antitumor immunity against cancer consists of using approved and marketed drugs known for their capacity to modulate the expression and functioning of the PD-1/PD-L1 checkpoint. Here, we have reviewed several types of drugs known to alter the checkpoint, either directly via the blockade of PD-L1 or indirectly via an action on upstream effectors (such as STAT3) to suppress PD-L1 transcription or to induce its proteasomal degradation. Specifically, the repositioning of the approved drugs liothyronine, azelnidipine (and related dihydropyridine calcium channel blockers), niclosamide, albendazole/flubendazole, and a few other modulators of the PD-1/PD-L1 checkpoint (repaglinide, pimozide, fenofibrate, lonazolac, propranolol) is presented. Their capacity to bind to PD-L1 or to repress its expression and function offer novel perspectives for combination with PD-1 targeted biotherapeutics. These known and affordable drugs could be useful to improve the therapy of cancer.
PubMed: 35884428
DOI: 10.3390/cancers14143368