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Science Translational Medicine Jun 2024In chronic myeloid leukemia (CML), the persistence of leukemic stem cells (LSCs) after treatment with tyrosine kinase inhibitors (TKIs), such as imatinib, can lead to...
In chronic myeloid leukemia (CML), the persistence of leukemic stem cells (LSCs) after treatment with tyrosine kinase inhibitors (TKIs), such as imatinib, can lead to disease relapse. It is known that therapy-resistant LSCs rely on oxidative phosphorylation (OXPHOS) for their survival and that targeting mitochondrial respiration sensitizes CML LSCs to imatinib treatment. However, current OXPHOS inhibitors have demonstrated limited efficacy or have shown adverse effects in clinical trials, highlighting that identification of clinically safe oxidative pathway inhibitors is warranted. We performed a high-throughput drug repurposing screen designed to identify mitochondrial metabolism inhibitors in myeloid leukemia cells. This identified lomerizine, a US Food and Drug Administration (FDA)-approved voltage-gated Ca channel blocker now used for the treatment of migraines, as one of the top hits. Transcriptome analysis revealed increased expression of voltage-gated and receptor-activated Ca channels in CML LSCs (CD34CD38) compared with normal counterparts. This correlated with increased endoplasmic reticulum (ER) mass and increased ER and mitochondrial Ca content in CML stem/progenitor cells. We demonstrate that lomerizine-mediated inhibition of Ca uptake leads to ER and mitochondrial Ca depletion, with similar effects seen after and knockdown. Through stable isotope-assisted metabolomics and functional assays, we observe that lomerizine treatment inhibits mitochondrial isocitrate dehydrogenase activity and mitochondrial oxidative metabolism and selectively sensitizes CML LSCs to imatinib treatment. In addition, combination treatment with imatinib and lomerizine reduced CML tumor burden, targeted CML LSCs, and extended survival in xenotransplantation model of human CML, suggesting this as a potential therapeutic strategy to prevent disease relapse in patients.
Topics: Drug Repositioning; Humans; Mitochondria; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Animals; Cell Line, Tumor; Endoplasmic Reticulum; Piperazines; Mice; Neoplastic Stem Cells; Calcium; Oxidative Phosphorylation; Imatinib Mesylate
PubMed: 38865484
DOI: 10.1126/scitranslmed.adi5336 -
ELife Jun 2024Philadelphia chromosome-positive (Ph) leukemia is a fatal hematological malignancy. Although standard treatments with tyrosine kinase inhibitors (TKIs) have achieved...
Philadelphia chromosome-positive (Ph) leukemia is a fatal hematological malignancy. Although standard treatments with tyrosine kinase inhibitors (TKIs) have achieved remarkable success in prolonging patient survival, intolerance, relapse, and TKI resistance remain serious issues for patients with Ph leukemia. Here, we report a new leukemogenic process in which RAPSYN and BCR-ABL co-occur in Ph leukemia, and RAPSYN mediates the neddylation of BCR-ABL. Consequently, neddylated BCR-ABL enhances the stability by competing its c-CBL-mediated degradation. Furthermore, SRC phosphorylates RAPSYN to activate its NEDD8 E3 ligase activity, promoting BCR-ABL stabilization and disease progression. Moreover, in contrast to in vivo ineffectiveness of PROTAC-based degraders, depletion of RAPSYN expression, or its ligase activity decreased BCR-ABL stability and, in turn, inhibited tumor formation and growth. Collectively, these findings represent an alternative to tyrosine kinase activity for the oncoprotein and leukemogenic cells and generate a rationale of targeting RAPSYN-mediated BCR-ABL neddylation for the treatment of Ph leukemia.
Topics: Animals; Humans; Mice; Cell Line, Tumor; Fusion Proteins, bcr-abl; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; NEDD8 Protein; Ubiquitin-Protein Ligases; Muscle Proteins
PubMed: 38865175
DOI: 10.7554/eLife.88375 -
The Egyptian Heart Journal : (EHJ) :... Jun 2024Myeloproliferative disorders, including monoclonal gammopathy of undetermined significance (MGUS), are often associated with amyloid light-chain (AL)-type cardiac...
BACKGROUND
Myeloproliferative disorders, including monoclonal gammopathy of undetermined significance (MGUS), are often associated with amyloid light-chain (AL)-type cardiac amyloidosis (CA) but occasionally with wild-type transthyretin (ATTR) CA. In recent years, ATTR amyloidosis has attracted necessity for its reliable diagnosis with the addition of new treatments. Usually, both wild-type ATTR CA and AL-type CA present with marked cardiac hypertrophy, but renal dysfunction is milder in wild-type ATTR amyloidosis than in AL-type amyloidosis. Peripheral neurologic and autonomic symptoms such as numbness and dysesthesia are moderately present in AL-type amyloidosis, but less so in wild-type ATTR amyloidosis. Furthermore, the prognosis of ATTR-type amyloidosis is better than that of AL-type amyloidosis.
CASE PRESENTATION
A 72-year-old man with cardiac hypertrophy presented with New York Heart Association functional class III dyspnea and leg edema. He had no history of carpal tunnel syndrome. An electrocardiogram showed atrial fibrillation and low voltage. The N-terminal pro-B-type natriuretic peptide level was 3310 pg/mL, and troponin T was elevated to 0.073 ng/mL. However, the glomerular filtration rate was only slightly decreased at 69.0 mL/min/1.73 m. The serum free light-chain assay revealed a significant increase in the kappa chain, with positive results in Bence Jones proteins and serum immunoelectrophoresis. Bone marrow examination confirmed the diagnosis of monoclonal gammopathy of undetermined significance (MGUS). AL-type amyloidosis associated with a myeloproliferative disorder was suspected, and the prognosis was initially predicted to be poor, classified as Mayo stage IV. Contrary to this prognosis, the patient showed a slow progression of heart failure. Further imaging modalities and cardiac tissue findings confirmed the diagnosis as transthyretin type amyloidosis, and a favorable prognosis was established with the use of tafamidis.
CONCLUSIONS
MGUS occasionally coexists with wild-type ATTR CA. Scant autonomic symptoms, mild renal dysfunction, and slow progression of heart failure might be clues that the CA associated with the myeloproliferative disease is wild-type ATTR amyloidosis.
PubMed: 38856864
DOI: 10.1186/s43044-024-00499-x -
Journal of Hematology & Oncology Jun 2024Neutrophils play a crucial role in inflammation and in the increased thrombotic risk in myeloproliferative neoplasms (MPNs). We have investigated how neutrophil-specific...
BACKGROUND
Neutrophils play a crucial role in inflammation and in the increased thrombotic risk in myeloproliferative neoplasms (MPNs). We have investigated how neutrophil-specific expression of JAK2-V617F or CALRdel re-programs the functions of neutrophils.
METHODS
Ly6G-Cre JAK2-V617F and Ly6G-Cre CALRdel mice were generated. MPN parameters as blood counts, splenomegaly and bone marrow histology were compared to wild-type mice. Megakaryocyte differentiation was investigated using lineage-negative bone marrow cells upon in vitro incubation with TPO/IL-1β. Cytokine concentrations in serum of mice were determined by Mouse Cytokine Array. IL-1α expression in various hematopoietic cell populations was determined by intracellular FACS analysis. RNA-seq to analyse gene expression of inflammatory cytokines was performed in isolated neutrophils from JAK2-V617F and CALR-mutated mice and patients. Bioenergetics of neutrophils were recorded on a Seahorse extracellular flux analyzer. Cell motility of neutrophils was monitored in vitro (time lapse microscopy), and in vivo (two-photon microscopy) upon creating an inflammatory environment. Cell adhesion to integrins, E-selectin and P-selection was investigated in-vitro. Statistical analysis was carried out using GraphPad Prism. Data are shown as mean ± SEM. Unpaired, two-tailed t-tests were applied.
RESULTS
Strikingly, neutrophil-specific expression of JAK2-V617F, but not CALRdel, was sufficient to induce pro-inflammatory cytokines including IL-1 in serum of mice. RNA-seq analysis in neutrophils from JAK2-V617F mice and patients revealed a distinct inflammatory chemokine signature which was not expressed in CALR-mutant neutrophils. In addition, IL-1 response genes were significantly enriched in neutrophils of JAK2-V617F patients as compared to CALR-mutant patients. Thus, JAK2-V617F positive neutrophils, but not CALR-mutant neutrophils, are pathogenic drivers of inflammation in MPN. In line with this, expression of JAK2-V617F or CALRdel elicited a significant difference in the metabolic phenotype of neutrophils, suggesting a stronger inflammatory activity of JAK2-V617F cells. Furthermore, JAK2-V617F, but not CALRdel, induced a VLA4 integrin-mediated adhesive phenotype in neutrophils. This resulted in reduced neutrophil migration in vitro and in an inflamed vessel. This mechanism may contribute to the increased thrombotic risk of JAK2-V617F patients compared to CALR-mutant individuals.
CONCLUSIONS
Taken together, our findings highlight genotype-specific differences in MPN-neutrophils that have implications for the differential pathophysiology of JAK2-V617F versus CALR-mutant disease.
Topics: Animals; Neutrophils; Janus Kinase 2; Mice; Myeloproliferative Disorders; Humans; Inflammation; Calreticulin; Mice, Transgenic; Mice, Inbred C57BL; Cytokines
PubMed: 38853260
DOI: 10.1186/s13045-024-01562-5 -
Orvosi Hetilap Jun 2024
Review
Topics: Humans; Janus Kinase 2; Cardiovascular Diseases; Mutation; Risk Factors; Myeloproliferative Disorders
PubMed: 38852144
DOI: 10.1556/650.2024.33055 -
Cell Communication and Signaling : CCS Jun 2024Abnormally expressed BCR/ABL protein serves as the basis for the development of chronic myeloid leukaemia (CML). The F-actin binding domain (FABD), which is a crucial...
BACKGROUND
Abnormally expressed BCR/ABL protein serves as the basis for the development of chronic myeloid leukaemia (CML). The F-actin binding domain (FABD), which is a crucial region of the BCR/ABL fusion protein, is also located at the carboxyl end of the c-ABL protein and regulates the kinase activity of c-ABL. However, the precise function of this domain in BCR/ABL remains uncertain.
METHODS
The FABD-deficient adenovirus vectors Ad-BCR/ABL△FABD, wild-type Ad-BCR/ABL and the control vector Adtrack were constructed, and 32D cells were infected with these adenoviruses separately. The effects of FABD deletion on the proliferation and apoptosis of 32D cells were evaluated by a CCK-8 assay, colony formation assay, flow cytometry and DAPI staining. The levels of phosphorylated BCR/ABL, p73, and their downstream signalling molecules were detected by western blot. The intracellular localization and interaction of BCR/ABL with the cytoskeleton-related protein F-actin were identified by immunofluorescence and co-IP. The effect of FABD deletion on BCR/ABL carcinogenesis in vivo was explored in CML-like mouse models. The degree of leukaemic cell infiltration was observed by Wright‒Giemsa staining and haematoxylin and eosin (HE) staining.
RESULTS
We report that the loss of FABD weakened the proliferation-promoting ability of BCR/ABL, accompanied by the downregulation of BCR/ABL downstream signals. Moreover, the deletion of FABD resulted in a change in the localization of BCR/ABL from the cytoplasm to the nucleus, accompanied by an increase in cell apoptosis due to the upregulation of p73 and its downstream proapoptotic factors. Furthermore, we discovered that the absence of FABD alleviated leukaemic cell infiltration induced by BCR/ABL in mice.
CONCLUSIONS
These findings reveal that the deletion of FABD diminished the carcinogenic potential of BCR/ABL both in vitro and in vivo. This study provides further insight into the function of the FABD domain in BCR/ABL.
Topics: Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Fusion Proteins, bcr-abl; Animals; Humans; Mice; Cell Proliferation; Apoptosis; Actins; Carcinogenesis; Protein Domains; Cell Line, Tumor
PubMed: 38849885
DOI: 10.1186/s12964-024-01694-8 -
Cell Biochemistry and Biophysics Jun 2024Essential thrombocythemia (ET) is a type of myeloproliferative neoplasm that increases the risk of thrombosis. To diagnose this disease, the analysis of mutations in the...
Essential thrombocythemia (ET) is a type of myeloproliferative neoplasm that increases the risk of thrombosis. To diagnose this disease, the analysis of mutations in the Janus Kinase 2 (JAK2), thrombopoietin receptor (MPL), or calreticulin (CALR) gene is recommended. Disease poses diagnostic challenges due to overlapping mutations with other neoplasms and the presence of triple-negative cases. This study explores the potential of Raman spectroscopy combined with machine learning for ET diagnosis. We assessed two laser wavelengths (785, 1064 nm) to differentiate between ET patients and healthy controls. The PCR results indicate that approximately 50% of patients in our group have a mutation in the JAK2 gene, while only 5% of patients harbor a mutation in the ASXL1 gene. Additionally, only one patient had a mutation in the IDH1 and one had a mutation in IDH2 gene. Consequently, patients having no mutations were also observed in our group, making diagnosis challenging. Raman spectra at 1064 nm showed lower amide, polysaccharide, and lipid vibrations in ET patients, while 785 nm spectra indicated significant decreases in amide II and C-H lipid vibrations. Principal Component Analysis (PCA) confirmed that both wavelengths could distinguish ET from healthy subjects. Support Vector Machine (SVM) analysis revealed that the 800-1800 cm range provided the highest diagnostic accuracy, with 89% for 785 nm and 72% for 1064 nm. These findings suggest that FT-Raman spectroscopy, paired with multivariate and machine learning analyses, offers a promising method for diagnosing ET with high accuracy by detecting specific molecular changes in serum. Principal Component Analysis (PCA) confirmed that both wavelengths could distinguish ET from healthy subjects. Support Vector Machine (SVM) analysis revealed that the 800-1800 cm range provided the highest diagnostic accuracy, with 89% for 785 nm and 72% for 1064 nm. These findings suggest that FT-Raman spectroscopy, paired with multivariate and machine learning analyses, offers a promising method for diagnosing ET with high accuracy by detecting specific molecular changes in serum.
PubMed: 38847941
DOI: 10.1007/s12013-024-01333-6 -
Frontiers in Immunology 2024The Philadelphia chromosome-negative myeloproliferative neoplasms are a group of slowly progressing haematological malignancies primarily characterised by an...
INTRODUCTION
The Philadelphia chromosome-negative myeloproliferative neoplasms are a group of slowly progressing haematological malignancies primarily characterised by an overproduction of myeloid blood cells. Patients are treated with various drugs, including the JAK1/2 inhibitor ruxolitinib. Mathematical modelling can help propose and test hypotheses of how the treatment works.
MATERIALS AND METHODS
We present an extension of the Cancitis model, which describes the development of myeloproliferative neoplasms and their interactions with inflammation, that explicitly models progenitor cells and can account for treatment with ruxolitinib through effects on the malignant stem cell response to cytokine signalling and the death rate of malignant progenitor cells. The model has been fitted to individual patients' data for the V617F variant allele frequency from the COMFORT-II and RESPONSE studies for patients who had substantial reductions (20 percentage points or 90% of the baseline value) in their V617F variant allele frequency ( = 24 in total).
RESULTS
The model fits very well to the patient data with an average root mean square error of 0.0249 (2.49%) when allowing ruxolitinib treatment to affect both malignant stem and progenitor cells. This average root mean square error is much lower than if allowing ruxolitinib treatment to affect only malignant stem or only malignant progenitor cells (average root mean square errors of 0.138 (13.8%) and 0.0874 (8.74%), respectively).
DISCUSSION
Systematic simulation studies and fitting of the model to the patient data suggest that an initial reduction of the malignant cell burden followed by a monotonic increase can be recapitulated by the model assuming that ruxolitinib affects only the death rate of malignant progenitor cells. For patients exhibiting a long-term reduction of the malignant cells, the model predicts that ruxolitinib also affects stem cell parameters, such as the malignant stem cells' response to cytokine signalling.
Topics: Nitriles; Humans; Pyrazoles; Pyrimidines; Myeloproliferative Disorders; Janus Kinase 2; Neoplastic Stem Cells; Models, Theoretical; Protein Kinase Inhibitors
PubMed: 38846951
DOI: 10.3389/fimmu.2024.1384509 -
Platelets Dec 2024Thromboembolic events are common in patients with essential thrombocythemia (ET). However, the pathophysiological mechanisms underlying the increased thrombotic risk...
Thromboembolic events are common in patients with essential thrombocythemia (ET). However, the pathophysiological mechanisms underlying the increased thrombotic risk remain to be determined. Here, we perform the first phenotypical characterization of platelet expression using single-cell mass cytometry in six ET patients and six age- and sex-matched healthy individuals. A large panel of 18 transmembrane regulators of platelet function and activation were analyzed, at baseline and after stimulation with thrombin receptor-activating peptide (TRAP). We detected a significant overexpression of the activation marker CD62P (p-Selectin) ( = .049) and the collagen receptor GPVI ( = .044) in non-stimulated ET platelets. In contrast, ET platelets had a lower expression of the integrin subunits of the fibrinogen receptor GPIIb/IIIa CD41 ( = .036) and CD61 ( = .044) and of the von Willebrand factor receptor CD42b ( = .044). Using the FlowSOM algorithm, we identified 2 subclusters of ET platelets with a prothrombotic expression profile, one of them (cluster 3) significantly overrepresented in ET (22.13% of the total platelets in ET, 2.94% in controls, = .035). Platelet counts were significantly increased in ET compared to controls ( = .0123). In ET, MPV inversely correlated with platelet count (=-0.96). These data highlight the prothrombotic phenotype of ET and postulate GPVI as a potential target to prevent thrombosis in these patients.
Topics: Humans; Thrombocythemia, Essential; Blood Platelets; Male; Female; Thrombosis; Middle Aged; Aged; Flow Cytometry; Platelet Activation; Case-Control Studies; Adult
PubMed: 38845541
DOI: 10.1080/09537104.2024.2358244 -
BMJ Case Reports Jun 2024Extramedullary lesions in patients with chronic myeloid leukaemia (CML) suggest progression to the blast phase because such lesions generally consist of immature...
Extramedullary lesions in patients with chronic myeloid leukaemia (CML) suggest progression to the blast phase because such lesions generally consist of immature granulocytes. We here report a case of an extramedullary mass formed by mature granulocytes during the chronic phase of CML. A 60-year-old woman who had discontinued treatment for CML with dasatinib of her own accord several years ago presented to our hospital with a complaint of right thigh pain. She had a mass on her right leg, which was located on her right thigh and was elastic, soft and fist-sized. Blood tests and the bone marrow findings were compatible with the chronic phase of CML, and a CT-guided needle biopsy showed an infiltrate containing numerous mature neutrophils and foam cells. The mass disappeared with dasatinib alone, without antibacterial agents or drainage.Although the detailed pathogenesis of mass formation with mature granulocytes in the chronic phase of CML has not been elucidated, the clinical course of the current case highlights the importance of prompt biopsy, pathological examination and the early initiation of appropriate treatment.
Topics: Humans; Female; Middle Aged; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Granulocytes; Dasatinib; Soft Tissue Neoplasms; Antineoplastic Agents; Thigh
PubMed: 38844352
DOI: 10.1136/bcr-2023-258700