Cytarabine-induced differentiation of AML cells depends on Chk1 activation and shares the mechanism with inhibitors of DHODH and pyrimidine synthesis

Tomić, Barbara; Smoljo, Tomislav; Lalić, Hrvoje; Dembitz, Vilma; Batinić, Josip; Batinić, Drago; Bedalov, Antonio; Višnjić, Dora

doi:10.1038/s41598-022-15520-z

Cited by 10 publications

(15 citation statements)

References 47 publications

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“…Pathway analysis revealed the activation of treatment-relevant processes, including chemotaxis, leukocyte migration, differentiation, and migration. Along with its cytotoxic effect, cytarabine has been known to induce AML cell differentiation at lower doses [ 20 ]. We also identified certain pathways which were treatment-specific.…”

Section: Discussionmentioning

confidence: 99%

Transcriptional Response to Standard AML Drugs Identifies Synergistic Combinations

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Ngaffo,

Goedtel-Armbrust

et al. 2023

IJMS

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Unlike genomic alterations, gene expression profiles have not been widely used to refine cancer therapies. We analyzed transcriptional changes in acute myeloid leukemia (AML) cell lines in response to standard first-line AML drugs cytarabine and daunorubicin by means of RNA sequencing. Those changes were highly cell- and treatment-specific. By comparing the changes unique to treatment-sensitive and treatment-resistant AML cells, we enriched for treatment-relevant genes. Those genes were associated with drug response-specific pathways, including calcium ion-dependent exocytosis and chromatin remodeling. Pharmacological mimicking of those changes using EGFR and MEK inhibitors enhanced the response to daunorubicin with minimum standalone cytotoxicity. The synergistic response was observed even in the cell lines beyond those used for the discovery, including a primary AML sample. Additionally, publicly available cytotoxicity data confirmed the synergistic effect of EGFR inhibitors in combination with daunorubicin in all 60 investigated cancer cell lines. In conclusion, we demonstrate the utility of treatment-evoked gene expression changes to formulate rational drug combinations. This approach could improve the standard AML therapy, especially in older patients.

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Section: Discussionmentioning

confidence: 99%

Transcriptional Response to Standard AML Drugs Identifies Synergistic Combinations

More,

Ngaffo,

Goedtel-Armbrust

et al. 2023

IJMS

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“…At the end of experiment, 50,000 AML cells per sample were cytospun on microscopic slides (1,000 rpm, 2 min) using StatSpin Cytofuge 2 (BeckmanCoulter, Marseille, France) and left to dry overnight. Adherent stromal cells were washed with PBS and left to dry for at least 2 h. Air-dried slides were stained with May-Grünwald Giemsa stain, as previously described (Tomic et al, 2022). Morphology was examined using AxioVert 200 microscope and images were obtained using AxioCam MRc 5 camera and ZEN software, blue edition (Carl Zeiss AG, Oberkochen, Germany).…”

Section: Morphological Analysismentioning

confidence: 99%

“…Cytotoxic effect of high doses of cytarabine on AML cells is ascribed to apoptosis, but the effects of LDAC remained incompletely understood. In AML cell lines, LDAC induces granulocytic or monocytic differentiation (Wang et al, 2000;Chen et al, 2017) that depends on the activation of DNA damage signaling pathway (Tomic et al, 2022;Wang et al, 2022). However, terminal differentiation in patients treated with LDAC are rarely described so that cytarabine has been used in differentiation therapy mostly to enhance the effects of other differentiation-inducing agents (Madan and Koeffler, 2020).…”

Section: Introductionmentioning

confidence: 99%

Bone marrow stromal cells reduce low-dose cytarabine-induced differentiation of acute myeloid leukemia

Smoljo,

Tomic,

Lalic

et al. 2023

Front. Pharmacol.

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Low-dose cytarabine (LDAC) is a standard therapy for elderly acute myeloid leukemia (AML) patients unfit for intensive chemotherapy. While high doses of cytarabine induce cytotoxicity, the precise mechanism of action of LDAC in AML remains elusive. In vitro studies have demonstrated LDAC-induced differentiation; however, such differentiation is seldom observed in vivo. We hypothesize that this discrepancy may be attributed to the influence of bone marrow (BM) stromal cells on AML cells. Thus, this study aimed to investigate the impact of BM stromal cells on LDAC-induced differentiation of AML cell lines and primary samples. Our results demonstrate that the presence of MS-5 stromal cells prevented LDAC-induced cell cycle arrest, DNA damage signaling and differentiation of U937 and MOLM-13 cell lines. Although transcriptomic analysis revealed that the stroma reduces the expression of genes involved in cytokine signaling and oxidative stress, data obtained with pharmacological inhibitors and neutralizing antibodies did not support the role for CXCL12, TGF-β1 or reactive oxygen species. The presence of stromal cells reduces LDAC-induced differentiation in primary samples from AML-M4 and myelodysplastic syndrome/AML patients. In conclusion, our study demonstrates that BM stroma reduces differentiation of AML induced by LDAC. These findings provide insights into the limited occurrence of terminal differentiation observed in AML patients, and suggest a potential explanation for this observation.

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“…Thus, inhibiting de novo pyrimidine synthesis would interfere with numerous metabolic and anabolic cell survival processes, explaining the cytotoxic response of tumor cells to DHODH inhibitors (DHODHi). In AML, the differentiating effect of DHODHi has recently been attributed to inducing replicative stress, an expected response of pyrimidine depletion (21)(22)(23)(24).The earlier clinical application of a relatively potent DHODHi, such as brequinar (BRQ), in solid tumor malignancies was halted because of lack of efficacy and significant dose-limiting stomatitis, gastrointestinal toxicity, and hematologic toxicity (25,26). This contrasts with less potent DHODHi, such as leflunomide and teriflunomide, that are used to treat rheumatoid arthritis and multiple sclerosis and lack these toxicities associated with BRQ.…”

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confidence: 99%

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confidence: 99%

Pyrimidine depletion enhances targeted and immune therapy combinations in acute myeloid leukemia

Elgamal,

Fobare,

Vibhute

et al. 2024

JCI Insight

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Acute myeloid leukemia (AML) represents the most commonly diagnosed and lethal adult leukemia, with a 5-year survival of less than 15% in patients over the age of 60 (1, 2). AML originates from a leukemia-initiating hematopoietic stem cell and is characterized by uncontrolled proliferation of dysfunctional, immature hematopoietic myeloid cells (blasts). AML-initiating cells have features that resemble normal hematopoietic stem cells and are highly immune suppressive, making it quite challenging to treat with either targeted or immune-based therapies (outside of allogeneic stem cell transplant). Until recently, effective therapies for AML were limited to intensive chemotherapy followed by allogeneic stem cell transplant, which provided curative potential for a minority of patients. More recently, several therapies targeting select mutations, including IDH1 (ivosidenib) (3), IDH2 (enasidenib) (4), and FLT3 (gilteritinib) (5), have been approved for AML treatment and demonstrate a unique differentiating phenotype. By differentiating early AML progenitor cells, these therapies may further separate their phenotype from normal hematopoietic cells and in some cases can promote durable remissions. However, these targeted therapeutics are limited to AML patients with IDH1, IDH2, or FLT3 mutations, and resistance mechanisms have been reported (6, 7). Another example of mutation-specific, targeted differentiation therapy is all-trans retinoic acid (ATRA) for acute promyelocytic leukemia (APL) AML subtype. Despite the high response rate, there is a lack of durable response in most patients in the absence of combination therapy (8-10). This collective experience suggests that successful therapy will involve differentiation agents that can be used in a broader AML population and identifying combination strategies likely to result in durable remissions. The need for combination strategies is supported by murine model data of AML, where a combination of differentiation and targeted therapies is required to eliminate clonal AML stem cells (11). Broadly affecting AML with differentiation therapy will require a therapeutic target that is effective in AML subtypes independent of mutation subtype.One such target for broad differentiation of AML cells demonstrated by Sykes and Scadden et al. ( 12) and later corroborated by others is dihydroorotate dehydrogenase (DHODH) (13-15). DHODH is a mitochondrial membrane flavoprotein that catalyzes the rate-limiting step of the de novo pyrimidine nucleotide biosynthesis pathway (16,17). DHODH catalyzes the oxidation of dihydroorotate (DHO) to orotate, which is further converted downstream by uridine monophosphate synthetase to uridine monophosphate (18, 19), the biosynthetic precursor of thymidine and cytidine (20). Rapidly proliferating cells and most cancer cells rely predominantly on this de novo synthesis pathway (20) as opposed to the salvage pathway, which re-cycles degraded intracellular nucleic acids (17) or shuttles extracellular nucleosides using nucleoside transporters (12,17,20). Th...

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Cytarabine-induced differentiation of AML cells depends on Chk1 activation and shares the mechanism with inhibitors of DHODH and pyrimidine synthesis

Cited by 10 publications

References 47 publications

Transcriptional Response to Standard AML Drugs Identifies Synergistic Combinations

Transcriptional Response to Standard AML Drugs Identifies Synergistic Combinations

Bone marrow stromal cells reduce low-dose cytarabine-induced differentiation of acute myeloid leukemia

Pyrimidine depletion enhances targeted and immune therapy combinations in acute myeloid leukemia

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