PI3K/mTOR dual-inhibition with VS-5584 enhances anti-leukemic efficacy of ponatinib in blasts and Ph-negative LSCs of chronic myeloid leukemia

Autor: Roya Gasimli, Sunde Yilmaz Susluer, Güray Saydam, Fatma Sogutlu, Tugce Balci Okcanoglu, Cagla Kayabasi, Cigir Biray Avci, Aycan Asik, Cumhur Gündüz, Besra Ozmen Yelken
Rok vydání: 2021
Předmět:
mTOR inhibitor
Stem-Cells
Resistance
Apoptosis
PI3K
chemistry.chemical_compound
Phosphatidylinositol 3-Kinases
Antineoplastic Combined Chemotherapy Protocols
Kinase Inhibitor
Phosphoinositide-3 Kinase Inhibitors
Stem Cells
TOR Serine-Threonine Kinases
Ponatinib
Chronic myeloid leukemia
Imidazoles
NF-kappa B
Myeloid leukemia
Drug Synergism
Pyridazines
Leukemia
STAT Transcription Factors
Differentiation
Combination
Stem cell
Mitogen-Activated Protein Kinases
Bcr-Abl
Signal Transduction
Cell Survival
Mtor
Morpholines
Leukemia stem cell
Antineoplastic Agents
Inhibitory Concentration 50
Leukemia
Myelogenous
Chronic
BCR-ABL Positive
medicine
Humans
Viability assay
Protein kinase B
Biology
PI3K/AKT/mTOR pathway
Janus Kinases
Pharmacology
medicine.disease
G1 Phase Cell Cycle Checkpoints
chemistry
C/Ebp-Alpha
Purines
Imatinib
Cancer research
K562 Cells
Proto-Oncogene Proteins c-akt
Transcription Factors
Zdroj: European journal of pharmacology. 910
ISSN: 1879-0712
Popis: Ponatinib is used for advanced treatment of chronic myeloid leukemia (CML), although low doses to prevent side effects do not suppress survival pathways and eradicate leukemia stem cells (LSCs). We evaluated the potential of ponatinib and PI3K/mTOR dual-inhibitor VS-5584 combination (PoVS) therapy to increase the anti-leukemic effects of ponatinib and investigated the underlying mechanisms at the molecular level. We measured the cytotoxicities of ponatinib, VS-5584, and PoVS (CCK-8 assay), and used the median-effect equation for combination analyses. We investigated the effects of inhibitory concentrations on apoptosis, cell viability and cell-cycle regulation (flow cytometry), protein levels (ELISA, Western blot), transcriptional activities (dual-luciferase reporter assay), gene expressions (qRT-PCR). VS-5584 exerted selective cytotoxic effects against CML and LSC cell lines. VS-5584 inhibited the PI3K/Akt/mTOR pathway, resulting in reduced cell viability, slightly induced caspase-independent apoptosis, prominent G0/G1 cell-cycle blockade that is not a consequence of quiescence. Normal hematopoietic stem cell line was the least affected. Moreover, ponatinib and VS-5584 mediated synergistic anti-leukemic effects on leukemic cells. VS-5584 reduced the ponatinib dose required to target leukemic cells. PoVS treatment inhibited PI3K/Akt/mTOR pathway more consistently than either of the two agents alone through reducing p-Akt, p-mTOR, p-S6K, p-PRAS40, p-S6. The subsequent downstream effects were an increase in C/EBP transcriptional activity and decreases in activities of E2F/DP1, Myc/Max, CREB, STAT3, NF kappa B, AP-1, Elk-1/SRF. Transcriptional regulation resulted in alterations in the expression levels of target mRNAs. Our results highlight PoVS can be a promising treatment strategy for eliminating CML cells and LSCs selectively, with the reduced ponatinib doses.
Ege University Scientific Research Projects (BAP) Department [15-TIP-019, 2015-TIP-063]
This work was supported by Ege University Scientific Research Projects (BAP) Department (Grand no. 15-TIP-019, 2015-TIP-063).
Databáze: OpenAIRE
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