1. |
- Malyukova, Alena, et al.
(author)
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Combination of tyrosine kinase inhibitors and the MCL1 inhibitor S63845 exerts synergistic antitumorigenic effects on CML cells
- 2021
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In: Cell Death and Disease. - : Springer Nature. - 2041-4889. ; 12:10
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Journal article (peer-reviewed)abstract
- Tyrosine kinase inhibitor (TKI) treatment has dramatically improved the survival of chronic myeloid leukemia (CML) patients, but measurable residual disease typically persists. To more effectively eradicate leukemia cells, simultaneous targeting of BCR-ABL1 and additional CML-related survival proteins has been proposed. Notably, several highly specific myeloid cell leukemia 1 (MCL1) inhibitors have recently entered clinical trials for various hematologic malignancies, although not for CML, reflecting the insensitivity of CML cell lines to single MCL1 inhibition. Here, we show that combining TKI (imatinib, nilotinib, dasatinib, or asciminib) treatment with the small-molecule MCL1 inhibitor S63845 exerted strong synergistic antiviability and proapoptotic effects on CML lines and CD34+ stem/progenitor cells isolated from untreated CML patients in chronic phase. Using wild-type BCR-ABL1-harboring CML lines and their T315I-mutated sublines (generated by CRISPR/Cas9-mediated homologous recombination), we prove that the synergistic proapoptotic effect of the drug combination depended on TKI-mediated BCR-ABL1 inhibition, but not on TKI-related off-target mechanisms. Moreover, we demonstrate that colony formation of CML but not normal hematopoietic stem/progenitor cells became markedly reduced upon combination treatment compared to imatinib monotherapy. Our results suggest that dual targeting of MCL1 and BCR-ABL1 activity may efficiently eradicate residual CML cells without affecting normal hematopoietic stem/progenitors.
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2. |
- Ujvari, Dorina, et al.
(author)
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IFNγ directly counteracts imatinib-induced apoptosis of primary human CD34+ CML stem/progenitor cells potentially through the upregulation of multiple key survival factors
- 2022
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In: Oncoimmunology. - : Taylor & Francis. - 2162-4011 .- 2162-402X. ; 11:1
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Journal article (peer-reviewed)abstract
- Tyrosine kinase inhibitors (TKIs) have dramatically improved the survival in chronic myeloid leukemia (CML), but residual disease typically persists even after prolonged treatment. Several lines of evidence suggest that TKIs administered to CML patients upregulate interferon γ (IFNγ) production, which may counteract the anti-tumorigenic effects of the therapy. We now show that activated T cell-conditioned medium (TCM) enhanced proliferation and counteracted imatinib-induced apoptosis of CML cells, and addition of a neutralizing anti-IFNγ antibody at least partially inhibited the anti-apoptotic effect. Likewise, recombinant IFNγ also reduced imatinib-induced apoptosis of CML cells. This anti-apoptotic effect of IFNγ was independent of alternative IFNγ signaling pathways, but could be notably diminished by STAT1-knockdown. Furthermore, IFNγ upregulated the expression of several anti-apoptotic proteins, including MCL1, PARP9, and PARP14, both in untreated and imatinib-treated primary human CD34+ CML stem/progenitor cells. Our results suggest that activated T cells in imatinib-treated CML patients can directly rescue CML cells from imatinib-induced apoptosis at least partially through the secretion of IFNγ, which exerts a rapid, STAT1-dependent anti-apoptotic effect potentially through the simultaneous upregulation of several key hematopoietic survival factors. These mechanisms may have a major clinical impact, when targeting residual leukemic stem/progenitor cells in CML.
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4. |
- Yektaei-Karin, Elham, et al.
(author)
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Modulation of leukotriene signaling inhibiting cell growth in chronic myeloid leukemia
- 2017
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In: Leukemia and Lymphoma. - : Informa UK Limited. - 1042-8194 .- 1029-2403. ; 58:8, s. 1903-1913
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Journal article (peer-reviewed)abstract
- Although tyrosine kinase inhibitors (TKIs) have dramatically improved clinical outcome in chronic myeloid leukemia (CML), cure rarely occurs. This may be due to BCR-ABL-independent, aberrant signaling pathways, one of which leads to leukotriene (LT) formation. Well-recognized as inflammatory mediators, LT can also affect oncogenic mechanisms of several tumors. We have previously discovered elevated LT-synthesis and up-regulated cysteinyl-LT-inducing enzyme in CML. Here we report on dose-dependent inhibition of CML cell growth exerted by specific blockers of LT-signaling. Thus, the cysteinyl-LT1-receptor-antagonist montelukast significantly reduced the growth of K562, KCL22, and KU812 cells, as well as primary CD34(+) blood cells from two CML patients. Adding montelukast to the TKI imatinib caused combined inhibition. No effect was seen on normal bone marrow cells. Similarly, growth inhibition was also observed with the 5-lipoxygenase (LO)-inhibitor BWA4C, the 5-LO-activating-protein-(FLAP)-inhibitor licofelone and the LTB4(BLT1)-receptor-antagonist LY293111. Thus, blocking of aberrant LT-signaling may provide an additional, novel therapeutic possibility in CML.
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5. |
- Zovko, Ana, et al.
(author)
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Compounds from the marine sponge Cribrochalina vasculum offer a way to target IGF-1R mediated signaling in tumor cells
- 2016
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In: Oncotarget. - : Impact Journals, LLC. - 1949-2553. ; 7:31, s. 50258-50276
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Journal article (peer-reviewed)abstract
- In this work two acetylene alcohols, compound 1 and compound 2, which were isolated and identified from the sponge Cribrochalina vasculum, and which showed antitumor effects were further studied with respect to targets and action mechanisms. Gene expression analyses suggested insulin like growth factor receptor (IGF-1R) signaling to be instrumental in controlling anti-tumor efficacy of these compounds in non-small cell lung cancer (NSCLC). Indeed compounds 1 and 2 inhibited phosphorylation of IGF-1R beta as well as reduced its target signaling molecules IRS-1 and PDK1 allowing inhibition of pro-survival signaling. In silico docking indicated that compound 1 binds to the kinase domain of IGF-1R at the same binding site as the well known tyrosine kinase inhibitor AG1024. Indeed, cellular thermal shift assay (CETSA) confirmed that C. vasculum compound 1 binds to IGF-1R but not to the membrane localized tyrosine kinase receptor EGFR. Importantly, we demonstrate that compound 1 causes IGF-1R beta but not Insulin Receptor degradation specifically in tumor cells with no effects seen in normal diploid fibroblasts. Thus, these compounds hold potential as novel therapeutic agents targeting IGF-1R signaling for anti-tumor treatment.
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6. |
- Zovko, Ana, et al.
(author)
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Marine Sponge Cribrochalina vasculum Compounds Activate Intrinsic Apoptotic Signaling and Inhibit Growth Factor Signaling Cascades in Non-Small Cell Lung Carcinoma
- 2014
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In: Molecular Cancer Therapeutics. - 1535-7163 .- 1538-8514. ; 13:12, s. 2941-2954
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Journal article (peer-reviewed)abstract
- Marine-derived compounds have been explored and considered as possible antitumor agents. In this study, we analyzed extracts of the sponge Cribrochalina vasculum for their ability to inhibit tumor cell proliferation. Screening identified two acetylenic compounds of similar structure that showed strong tumor-specific toxicity in non-small cell lung carcinoma (NSCLC) cells and small-cell lung carcinoma cells, and less prominent toxicity in ovarian carcinoma, while having no effect on normal cells. These acetylenic compounds were found to cause a time-dependent increase in activation of apoptotic signaling involving cleavage of caspase-9, caspase-3, and PARP, as well as apoptotic cell morphology in NSCLC cells, but not in normal fibroblasts. Further analysis demonstrated that these compounds caused conformational change in Bak and Bax, and resulted in loss of mitochondrial potential and cytochrome c release in NSCLC cells. Moreover, a decreased phosphorylation of the growth factor signaling kinases Akt, mTOR, and ERK was evident and an increased phosphorylation of JNK was observed. Thus, these acetylenic compounds hold potential as novel therapeutic agents that should be further explored for NSCLC and other tumor malignancies.
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7. |
- Zovko, Ana, et al.
(author)
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Montelukast, a cysteinyl leukotriene receptor antagonist, inhibits the growth of chronic myeloid leukemia cells through apoptosis
- 2018
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In: Oncology Reports. - : Spandidos Publications. - 1021-335X .- 1791-2431. ; 40:2, s. 902-908
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Journal article (peer-reviewed)abstract
- The clinical outcome for patients with chronic myeloid leukemia (CML) has improved significantly with the introduction of tyrosine kinase inhibitors (TKIs). However, their curative potential appears limited, probably as a consequence of TKI-resistant leukemic stem cells (LSCs) that persist as a result of aberrant pathways independent of the well-established oncoprotein Bcr-Abl. One such pathway involves signaling through leukotrienes (LTs), bioactive compounds that have been suggested to play a role in several other malignancies. Cysteinyl LT1 receptor (CysLT1R) has been reported to be overexpressed in a number of solid cancers, and blocking of this receptor with the antagonist montelukast (treatment approved for bronchial asthma) has resulted in the killing of cancer cells. We recently demonstrated that montelukast, alone or in combination with imatinib, can effectively reduce the growth of CML cells, while normal bone marrow cells were left unaffected. Herein, we further investigated the importance of CysLT1R for the survival of CML cells and the mechanisms by which montelukast induces cell death. Knockdown of the CysLT1R of K562 cells with siRNA reduced their growth by 25%. Montelukast had no effect on these cells, while it killed more than 50% of CysLT1R-expressing cells. Growth inhibition exerted by imatinib was unaffected by CysLT1R status. Montelukast-induced killing of K562/JURL-MK1 CML cells was paralleled by Bax overexpression, cytochrome c release, PARP-1 cleavage, and caspase-3 activation, an event further increased in a setting where montelukast was added to imatinib. Wnt/-catenin signaling was activated by CysLT1R and we observed that montelukast could induce proteins in this pathway, a finding of relevance for LSC survival. Thus, montelukast, employed at in vivo-like concentrations, induces the killing of CML cells through apoptotic pathways and may provide an additional, novel therapeutic possibility in CML.
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