Browsing by Subject "leukemia"

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  • Mechchate, Hamza; Costa de Oliveira, Regiane; Es-safi, Imane; Vasconcelos Mourao, Emmily Myrella; Bouhrim, Mohamed; Kyrylchuk, Andrii; Soares Pontes, Gemilson; Bousta, Dalila; Grafov, Andriy (2021)
    Leukemia is a group of hematological neoplastic disorders linked to high mortality rates worldwide, but increasing resistance has led to the therapeutic failure of conventional chemotherapy. This study aimed to evaluate in vitro the antileukemic activity and potential mechanism of action of a polyphenolic extract obtained from the seeds of Coriandrum sativum L. (CSP). A methylthia-zoletetrazolium assay was performed to assess the CSP cytotoxicity on chronic (K562) and acute (HL60) myeloid leukemia cell lines and on normal Vero cell line. CSP toxicity was also evaluated in vivo using the OECD 423 acute toxicity model on Swiss albino mice. The results demonstrated a remarkable antitumoral activity against K562 and HL60 cell lines (IC50 = 16.86 mu M and 11.75 mu M, respectively) although no cytotoxicity was observed for the Vero cells or mice. A silico study was performed on the following receptors that are highly implicated in the development of leukemia: ABL kinase, ABL1, BCL2, and FLT3. The molecular docking demonstrated a high affinity interaction between the principal CSP components and the receptors. Our findings demonstrated that CSP extract has remarkable antileukemic activity, which is mainly mediated by the flavonoids, catechins, and rutin, all of which showed the highest binding affinity for the targeted receptors. This study revealed a promising active compound alternative research-oriented biopharmacists to explore.
  • Lindholm, Dan; Pham, Dan D.; Cascone, Annunziata; Eriksson, Ove; Wennerberg, Krister; Saarma, Mart (2016)
    Parkinson's disease (PD) is a progressive neurodegenerative disorder causing movement disabilities and several non-motor symptoms in afflicted patients. Recent studies in animal models of PD and analyses of brain specimen from PD patients revealed an increase in the level and activity of the non-receptor tyrosine kinase Abelson (c-Abl) in dopaminergic neurons with phosphorylation of protein substrates, such as alpha-synuclein and the E3 ubiquitin ligase, Parkin. Most significantly inhibition of c-Abl kinase activity by small molecular compounds used in the clinic to treat human leukemia have shown promising neuroprotective effects in cell and animal models of PD. This has raised hope that similar beneficial outcome may also be observed in the treatment of PD patients by using c-Abl inhibitors. Here we highlight the background for the current optimism, reviewing c-Abl and its relationship to pathophysiological pathways prevailing in PD, as well as discussing issues related to the pharmacology and safety of current c-Abl inhibitors. Clearly more rigorously controlled and well-designed trials are needed before the c-Abl inhibitors can be used in the neuroclinic to possibly benefit an increasing number of PD patients.
  • Shishido, Tania Keiko; Popin, Rafael Vicentini; Jokela, Jouni; Wahlsten, Matti; Fiore, Marli Fatima; Fewer, David P.; Herfindal, Lars; Sivonen, Kaarina (2020)
    Cyanobacteria are photosynthetic organisms that produce a large diversity of natural products with interesting bioactivities for biotechnological and pharmaceutical applications. Cyanobacterial extracts exhibit toxicity towards other microorganisms and cancer cells and, therefore, represent a source of potentially novel natural products for drug discovery. We tested 62 cyanobacterial strains isolated from various Brazilian biomes for antileukemic and antimicrobial activities. Extracts from 39 strains induced selective apoptosis in acute myeloid leukemia (AML) cancer cell lines. Five of these extracts also exhibited antifungal and antibacterial activities. Chemical and dereplication analyses revealed the production of nine known natural products. Natural products possibly responsible for the observed bioactivities and five unknown, chemically related chlorinated compounds present only in Brazilian cyanobacteria were illustrated in a molecular network. Our results provide new information on the vast biosynthetic potential of cyanobacteria isolated from Brazilian environments.
  • Raivola, Juuli; Hammaren, Henrik M.; Virtanen, Anniina T.; Bulleeraz, Vilasha; Ward, Alister C.; Silvennoinen, Olli (2018)
    Janus kinase 3 (JAK3) tyrosine kinase has a central role in the control of lymphopoiesis, and mutations in JAK3 can lead to either severe combined immunodeficiency or leukemia and lymphomas. JAK3 associates with the common gamma chain (yc) receptor and functions in a heteromeric signaling pair with JAK1. In IL-2 signaling JAK1 is the effector kinase for STAT5 phosphorylation but the precise molecular regulatory mechanisms of JAK1 and JAK3 and their individual domains are not known. The pseudokinase domain (JAK homology 2, JH2) of JAK3 is of particular interest as approximately half of clinical JAK3 mutations cluster into it. In this study, we investigated the role of JH2s of JAK1 and JAK3 in IL-2R signaling and show that STAT5 activation requires both JH1 and JH2 of JAK1, while both JH1 and JH2 in JAK3 are specifically required for the cytokine-induction of cellular signaling. Characterization of recombinant JAK3 JH2 in thermal shift assay shows an unstable protein domain, which is strongly stabilized by ATP binding. Unexpectedly, nucleotide binding to JAK3 JH2 was found to be cation-independent. JAK3 JH2 showed higher nucleotide binding affinity in MANT-ATP and fluorescent polarization competition assays compared to the other JAK JH2s. Analysis of the functional role of ATP binding in JAK3 JH2 in cells and in zebrafish showed that disruption of ATP binding suppresses ligand-independent activation of clinical JAK3 gain-of-function mutations residing in either JH2 or JH1 but does not inhibit constitutive activation of oncogenic JAK1. ATP-binding site mutations in JAK3 JH2 do not, however, abrogate normal IL-2 signaling making them distinct from JH2 deletion or kinase-deficient JAK3. These findings underline the importance of JAK3 JH2 for cellular signaling in both ligand-dependent and in gain-of-function mutation-induced activation. Furthermore, they identify the JH2 ATP-binding site as a key regulatory region for oncogenic JAK3 signaling, and thus a potential target for therapeutic modulation.
  • Raivola, Juuli; Haikarainen, Teemu; Abraham, Bobin George; Silvennoinen, Olli (2021)
    Simple Summary Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway is a crucial cell signaling pathway that drives the development, differentiation, and function of immune cells and has an important role in blood cell formation. Mutations targeting this pathway can lead to overproduction of these cell types, giving rise to various hematological diseases. This review summarizes pathogenic JAK/STAT activation mechanisms and links known mutations and translocations to different leukemia. In addition, the review discusses the current therapeutic approaches used to inhibit constitutive, cytokine-independent activation of the pathway and the prospects of developing more specific potent JAK inhibitors. Janus kinases (JAKs) transduce signals from dozens of extracellular cytokines and function as critical regulators of cell growth, differentiation, gene expression, and immune responses. Deregulation of JAK/STAT signaling is a central component in several human diseases including various types of leukemia and other malignancies and autoimmune diseases. Different types of leukemia harbor genomic aberrations in all four JAKs (JAK1, JAK2, JAK3, and TYK2), most of which are activating somatic mutations and less frequently translocations resulting in constitutively active JAK fusion proteins. JAKs have become important therapeutic targets and currently, six JAK inhibitors have been approved by the FDA for the treatment of both autoimmune diseases and hematological malignancies. However, the efficacy of the current drugs is not optimal and the full potential of JAK modulators in leukemia is yet to be harnessed. This review discusses the deregulation of JAK-STAT signaling that underlie the pathogenesis of leukemia, i.e., mutations and other mechanisms causing hyperactive cytokine signaling, as well as JAK inhibitors used in clinic and under clinical development.
  • Tiderman, Anette (Helsingin yliopisto, 2020)
    Cancer är en mycket sällsynt sjukdom hos barn. Leukemi är den vanligaste cancerformen hos barn och den vanligaste leukemin hos barn är ALL (akut lymfatisk leukemi). Kliniska fynd eller avvikelser i blodbilden kan väcka misstanken om leukemi. Vården av leukemi hos barn har gått framåt med storm steg, och i dag är prognosen relativt bra. Leukemi hos barn vårdas i Finland enligt nordiska behandlingsprotokoller. Stamcellstransplantation används vid svår behandlade leukemier, då behandlingsresultatet efter de första behandlingarna varit otillräckligt eller ifall återfall förekommer snabbt efter det första behandlings perioden. Immunförsvaret är nedsatt hos leukemi patienter på grund av själva sjukdomen samt på grund av behandlingarna som används för att vårda sjukdomen. Efter en stamcellstransplantation är patientens immunförsvar svårt nedsatt. Det tar till och med år för immunförsvaret att återhämta sig efter en stamcellstransplantation. Syftet med denna studie var att kartlägga rekonstruktionen av T-lymfocyterna efter stamcellstransplantation, samt vilken inverkan T-lymfocyternas rekonstruktion har på patientens prognos. T-lymfocyternas rekonstruktion uppföljdes med hjälp av blodprov med 1, 3, 6, 9, 12, 18 och 24 månaders mellanrum efter stamcellstransplantationen. Enligt studien rekonstrueras CD8 positiva lymfocyterna snabbare än CD4 positiva lymfocyterna. En långsam rekonstruktion av CD4 positiva lymfocyter korrelerar med en högre mortalitet enligt vår studie.
  • Schiffer, Charles A.; Cortes, Jorge E.; Hochhaus, Andreas; Saglio, Giuseppe; le Coutre, Philipp; Porkka, Kimmo; Mustjoki, Satu; Mohamed, Hesham; Shah, Neil P. (2016)
    BACKGROUNDThe proliferation of clonal cytotoxic T-cells or natural killer cells has been observed after dasatinib treatment in small studies of patients with chronic myeloid leukemia (CML). METHODSThe incidence of lymphocytosis and its association with response, survival, and side effects were assessed in patients from 3 large clinical trials. Overall, 1402 dasatinib-treated patients with newly diagnosed CML in chronic phase (CML-CP), CML-CP refractory/intolerant to imatinib, or with CML in accelerated or myeloid-blast phase were analyzed. RESULTSLymphocytosis developed in 32% to 35% of patients and persisted for >12 months. This was not observed in the patients who received treatment with imatinib. Dasatinib-treated patients in all stages of CML who developed lymphocytosis were more likely to achieve a complete cytogenetic response, and patients who had CML-CP with lymphocytosis were more likely to achieve major and deep molecular responses. Progression-free and overall survival rates were significantly longer in patients with CML-CP who were refractory to or intolerant of imatinib and had lymphocytosis. Pleural effusions developed more commonly in patients with lymphocytosis. CONCLUSIONSOverall, lymphocytosis occurred and persisted in many dasatinib-treated patients in all phases of CML. Its presence was associated with higher response rates, significantly longer response durations, and increased overall survival, suggesting an immunomodulatory effect. Prospective studies are warranted to characterize the functional activity of these cells and to assess whether an immunologic effect against CML is detectable. Cancer 2016;122:1398-1407. (c) 2016 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. Lymphocytosis develops frequently after treatment of chronic myeloid leukemia with dasatinib and is associated with higher response rates, significantly longer response durations, and increased overall survival. Prospective studies are warranted to assess whether dasatinib produces an immunomodulatory effect against chronic myeloid leukemia.
  • Rebane, Anni (Helsingin yliopisto, 2015)
    Given the success of first-line treatment in chronic myeloid leukemia (CML), the prevalence of the disease is estimated to increase and more patients are expected to develop resistance to therapy. Thus, even relatively rare point mutations are likely to become more common. In CML, the uncontrollable division of myeloid cells is caused by a reciprocal translocation of chromosomes 9 and 22, resulting in the Philadelphia chromosome. At the meeting point of the two chromosomes, breakpoint cluster region (BCR) and Abelson proto-oncogene 1 (ABL1) fuse together to form the chimeric fusion oncogene BCR-ABL1, the latter of which, the non-receptor tyrosine kinase ABL1, is the driver of the disease. Since the tyrosine kinase inhibitor (TKI) imatinib became available in 2001, the success of first-line therapy has significantly improved the prognosis of CML patients. However, up to 50% of patients with imatinib-refractory disease develop resistance due to point mutations in ABL1, and the most common mutation to emerge is BCR-ABL1 T315I. The broad-range TKI ponatinib is the only approved TKI that inhibits the kinase activity of BCR-ABL1 T315I, but adverse side effects leave patients with this mutation in need of a better, safer, and more effective treatment. The kinase inhibitor axitinib was shown to be selective for BCR-ABL1 T315I, but mutations that emerge as a consequence of axitinib-resistance have yet to be explored. Moreover, patients with the T315I mutation treated with ponatinib have been reported to develop highly drug-resistant mutations in BCR-ABL1 such as T315M and the E255V/T315I compound mutation. The purpose of this study was to identify mutations that enable cells to develop resistance to the kinase inhibitor axitinib and to find new, potential inhibitors for cells expressing the drug-resistant mutations BCR-ABL1 T315I, BCR-ABL1 T315M, and BCR-ABL1 E255V/T315I. To this end, mouse hematopoietic cell lines were constructed prior to determining cell viability in response to inhibitors in combinations and as independent agents. As a novel finding, cells stably expressing T315M were found to exhibit sensitivity to inhibitors of topoisomerase II and mTOR. Moreover, synthetic lethality occurred in these cells in response to the combined treatment of the allosteric inhibitor asciminib and the TKI ponatinib, although not in clinically relevant doses. The highly resistant cells expressing BCR-ABL1 E255V/T315I, like cells expressing T315I and T315M, showed sensitivity to conventional chemotherapy. Notably, however, three SMAC mimetics displayed selectivity to cells expressing BCR-ABL1 E255V/T315I over cells expressing only the single T315I mutation. Considering that CML is expected to become increasingly prevalent, more patients are estimated to develop resistance to therapy. As even relatively rare mutations in BCR-ABL1 become more common, finding an effective treatment for cells expressing these highly resistant mutations takes us one step closer to identifying a safe and effective treatment for CML patients carrying those mutations.
  • Peltonen, Sirkku; Kallionpaa, Roope A.; Rantanen, Matti; Uusitalo, Elina; Lähteenmäki, Päivi M.; Pöyhönen, Minna; Pitkäniemi, Janne; Peltonen, Juha (2019)
    Neurofibromatosis type 1 (NF1) is a cancer predisposition syndrome with an incidence of 1:2,000. Patients with NF1 have an increased cancer risk and mortality, but there are no population-based cohort studies specifically investigating the risk of childhood malignancies. We used the Finnish NF1 cohort to analyze the incidence, risk and prognosis of malignancies in NF1 patients
  • Korkama, Eva-Stina; Armstrong, Anna-Elina; Jarva, Hanna; Meri, Seppo (2018)
    Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired syndrome characterized by intravascular hemolysis, thrombosis, and bone marrow failure. The disease is caused by a mutation in the PIG-A gene that leads to the lack of glycosylphosphatidylinositol-anchored complement regulatory molecules CD55 and CD59 on affected blood cell surfaces. In previous studies, spontaneous clinical remissions have been described. The disease manifestations are very heterogeneous, and we wanted to examine if true remissions and disappearance of the clone occur. In a follow-up of a nation-wide cohort of 106 Finnish patients with a PNH clone, we found six cases, where the clone disappeared or was clearly diminished. Two of the patients subsequently developed leukemia, while the other four are healthy and in clinical remission. According to our data, spontaneous remissions are not as frequent as described earlier. Since the disappearance of the PNH cell clone may indicate either a favorable or a poor outcome-remission or malignancy-careful clinical monitoring in PNH is mandatory. Nevertheless, true remissions occur, and further studies are needed to understand the immunological background of this phenomenon and to obtain a better understanding of the natural history of the disease.