Antineoplastic effects of pharmacological inhibitors of aurora kinases in CSF3RT618I-driven cells.

Myeloproliferative neoplasms (MPN) are consolidated as a relevant group of diseases derived from the malfunction of the hematopoiesis process and have as a particular attribute the increased proliferation of myeloid lineage. Among these, chronic neutrophilic leukemia (CNL) is distinguished, caused by the T618I mutation of the CSF3R gene, a trait that generates ligand-independent receptor activation and downstream JAK2/STAT signaling. Previous studies reported that mutations in BCR::ABL1 and JAK2V617F increased the expression of the aurora kinase A (AURKA) and B (AURKB) in Ba/F3 cells and their pharmacological inhibition displays antineoplastic effects in human BCR::ABL1 and JAK2V617F positive cells. Delimiting the current scenario, aspects related to the AURKA and AURKB as a potential target in CSF3RT618I-driven models is little known. In the present study, the cellular and molecular effects of pharmacological inhibitors of aurora kinases, such as aurora A inhibitor I, AZD1152-HQPA, and reversine, were evaluated in Ba/F3 expressing the CSF3RT618I mutation. AZD1152-HQPA and reversine demonstrated antineoplastic potential, causing a decrease in cell viability, clonogenicity, and proliferative capacity. At molecular levels, all inhibitors reduced histone H3 phosphorylation, aurora A inhibitor I and reversine reduced STAT5 phosphorylation, and AZD1152-HQPA and reversine induced PARP1 cleavage and γH2AX expression. Reversine more efficiently modulated genes associated with cell cycle and apoptosis compared to other drugs. In summary, our findings shed new insights into the use of AURKB inhibitors in the context of CNL.

AD80, a multikinase inhibitor, exhibits antineoplastic effects in acute leukemia cellular models targeting the PI3K/STMN1 axis.

Despite the great advances in the understanding of the molecular basis of acute leukemia, very little of this knowledge has been translated into new therapies. Stathmin 1 (STMN1), a phosphoprotein that regulates microtubules dynamics, is highly expressed in acute leukemia cells and promotes cell cycle progression and proliferation. GDP366 has been described as a STMN1 and survivin inhibitor in solid tumors. This study identified structural GDP366 analogs and the cellular and molecular mechanisms underlying their suppressive effects on acute leukemia cellular models. STMN1 mRNA levels were higher in AML and ALL patients, independent of risk stratification (all p < 0.001). Cheminformatics analysis identified three structural GDP366 analogs, with AD80 more potent and effective than GSK2606414 and GW768505A. In acute leukemia cells, GDP366 and AD80 reduced cell viability and autonomous clonal growth in a dose- and/or time-dependent manner (p < 0.05) and induced apoptosis and cell cycle arrest (p < 0.05). At the molecular level, GDP366 and AD80 reduced Ki-67 (a proliferation marker) expression and S6 ribosomal protein (a PI3K/AKT/mTOR effector) phosphorylation, and induced PARP1 (an apoptosis marker) cleavage and γH2AX (a DNA damage marker) expression. GDP366 induced STMN1 phosphorylation and survivin expression, while AD80 reduced survivin and STMN1 expression. GDP366 and AD80 modulated 18 of the 84 cytoskeleton regulators-related genes. These results indicated that GDP366 and AD80 reduced the PI3K/STMN1 axis and had cytotoxic effects in acute leukemia cellular models. Our findings further highlight STMN1-mediated signaling as a putative anticancer target for acute leukemia.

AD80, a multikinase inhibitor, as a potential drug candidate for colorectal cancer therapy.

AIMS: Colorectal cancer (CRC) is a very heterogeneous disease. One of its hallmarks is the dysregulation of protein kinases, which leads to molecular events related to carcinogenesis. Hence, kinase inhibitors have been developed and are a new strategy with promising potential for CRC therapy. This study aims to explore AD80, a multikinase inhibitor, as a drug option for CRC, with evaluation of the PI3K/AKT/mTOR and MAPK (ERK1/2) status of CRC cells' panel and the cytotoxicity of AD80 in those cells, as well as in normal colon cells. MAIN METHODS: Cellular and molecular mechanisms, such as clonogenicity, cell cycle, morphology, protein and mRNA expression, were investigated in CRC cells after AD80 exposure. KEY FINDINGS: Results show that PI3K/AKT/mTOR and MAPK signaling pathways are upregulated in CRC cellular models, with increased phosphorylation of mTOR, P70S6K, S6RP, 4EBP1, and ERK1/2. Hence, AD80 selectively reduces cell viability of CRC cells. Therefore, the antitumor mechanisms of AD80, such as clonogenicity inhibition (reduction of colony number and size), G2/M arrest (increased G2/M population, and CDKN1B mRNA expression), DNA damage (increased H2AX and ERK1/2 phosphorylation, and CDKN1A and GADD45A mRNA expression), apoptosis (increased PARP1 cleavage, and BAX, PMAIP1, BBC3 mRNA expression) and inhibition of S6RP phosphorylation were validated in CRC model. SIGNIFICANCE: Our findings reinforce kinases as promising cancer therapeutic targets for the treatment of colorectal cancer, suggesting AD80 as a drug candidate.

Reversine exerts cytotoxic effects through multiple cell death mechanisms in acute lymphoblastic leukemia.

PURPOSE: Acute lymphoblastic leukemia (ALL) is an aggressive hematological cancer with limited therapeutic options for adult patients. Aurora kinases have drawn attention as potential targets in hematological neoplasms due to their high expression and biological functions. Aurora kinase A (AURKA) and AURKB are essential for a successful mitosis, acting in spindle mitotic organization and cytokinesis. Reversine is a synthetic purine analog that acts as a multi-kinase inhibitor with anti-neoplastic activity by targeting AURKA and AURKB. METHODS: ALL patient gene expression data were retrieved from the Amazonia! DATABASE: For functional assays, Jurkat (T-ALL) and Namalwa (B-ALL) cells were exposed to increasing concentrations of reversine and submitted to various cellular and molecular assays. RESULTS: We found that AURKB expression was higher in ALL patient samples compared to normal lymphocytes (p < 0.0001). The ALL cell lines tested displayed aberrant AURKA and AURKB expression. In Jurkat and Namalwa cells, reversine reduced cell viability in a dose- and time-dependent manner (p < 0.05). Reversine also significantly reduced the viability of primary ALL cells. Reversine induced apoptosis and autophagy, and reduced cell proliferation in both cell lines (p < 0.05). Mitotic catastrophe markers, including cell cycle arrest at G2/M, increased cell size and DNA damage, were observed upon reversine exposure. Short- and long-term treatment with reversine inhibited autonomous clonogenicity (p < 0.05). At the molecular level, reversine reduced AURKB activity, induced SQSTM1/p62 consumption, and increased LC3BII and γ-H2AX levels. In Namalwa cells, reversine modulated 25 out of 84 autophagy-related genes, including BCL2, BAD, ULK1, ATG10, IRGM and MAP1LC3B, which indicates that reversine acts by initiating and sustaining autophagy signals in ALL cells. CONCLUSIONS: From our data we conclude that reversine reduces the viability of ALL cells by triggering multiple cell death mechanisms, including apoptosis, mitotic catastrophe, and autophagy. Our findings highlight reversine as a potential anticancer agent for ALL.

Reversine exhibits antineoplastic activity in JAK2V617F-positive myeloproliferative neoplasms.

JAK2/STAT signaling participates in the Ph-negative myeloproliferative neoplasms (MPN) pathophysiology and has been targeted by ruxolitinib, a JAK1/2 inhibitor. In the present study, the impact of ruxolitinib treatment on cytoskeleton-related genes expression was explored. In SET2 cells, AURKA and AURKB expression/activity were downregulated in a dose- and time-dependent manner by ruxolitinib. Reversine, a multikinase inhibitor selective for aurora kinases, reduced cell viability in a dose- and/or time-dependent manner in JAK2V617F cells. Reversine significantly increased apoptosis and mitotic catastrophe, and reduced cell proliferation and clonogenic capacity in SET2 and HEL cells. In the molecular scenario, reversine induced DNA damage and apoptosis markers, as well as, reduced AURKA and AURKB expression/activity. In SET2 cells, reversine modulated the expression of 32 out of 84 apoptosis-related genes investigated, including downregulation of antiapoptotic (BCL2, BCL2L1, and BIRC5) and upregulation of proapoptotic (BIK, BINP3, and BNIP3L) genes. Synergism experiments indicated that low dose of reversine had a potentiating effect under ruxolitinib treatment at low doses in SET2 cells. In summary, our exploratory study establishes new targets, related to the regulation of the cellular cytoskeleton, for potential pharmacological intervention in MPN. These findings indicate that AURKA and AURKB participate in the JAK2/STAT signaling pathway and contribute to the MPN phenotype.