University of Zagreb

School of Medicine

Acute myeloid leukemia (AML) is a heterogeneous group of diseases characterized by clonal proliferation of blasts that are blocked at an early stage of differentiation. The most successful pharmacological therapy of AML is differentiation therapy with all-trans-retinoic acid (ATRA); however, ATRA-based therapy is restricted to acute promyelocytic leukemia (APL), a particular subtype that carries t(15;17) translocation. All other AMLs are treated with intensive chemotherapy, which have not significantly improved the disease-free or overall survival. Our recent study demonstrated that 5-aminoimidazole-4-carboxamide ribonucleoside (AICAR, acadesine) induces apoptosis and enhances differentiation of non-APL AML cell lines, but the mechanism is still unknown. Therefore, proposed studies are aimed to determine the mechanism responsible for beneficial effects of AICAR in non-APL AML cells and to further elucidate signaling mechanisms and metabolic changes responsible for monocytic and granulocytic differentiation of AML cells. We will use commercially available AML cell lines to define: a) the role and the mechanism of autophagy in monocytic/macrophage and granulocytic differentiation, b) the changes in metabolism during differentiation and cell cycle progression, and to determine c) the role of Sirt deacetylase in monocytic/macrophage and granulocytic differentiation of AML cell lines. In addition, in vitro profiling of the sensitivity of primary AML samples to AICAR will be performed. The proposed project aims to define signaling mechanisms responsible for differentiation of leukemia cells, which may eventually lead to the development of an improved therapy, thus contributing to well-being of AML patients.

Scientific project leader

Dora Višnjić, M.D., Ph.D., Professor
Department of Physiology, University of Zagreb School of Medicine, Zagreb, Croatia
Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia

Project team members

Drago Batinić, M.D., Ph.D., Professor
Department of Laboratory Immunology, University Hospital Centre Zagreb, Zagreb, Croatia
Department of Physiology, University of Zagreb School of Medicine, Croatia

Antonio Bedalov, M.D., Ph.D., Professor
Clinical Research Division, Fred Hutchinson Cancer Research Centre, Seattle, WA, USA

Hrvoje Lalić, M.D., Ph.D., Assistant professor
Department of Physiology, University of Zagreb School of Medicine, Zagreb, Croatia
Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia

Josip Batinić, M.D., Ph.D., Assistant professor
Division of Hematology, Department of Internal Medicine, University Hospital Centre Zagreb, Zagreb, Croatia

Vilma Dembitz, M.D., Ph.D., Assistant professor
Department of Physiology, University of Zagreb School of Medicine, Zagreb, Croatia
Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia

Barbara Tomić, M.D., Ph.D. student, HRZZ project associate (DOK-2018-01-9599)
Department of Physiology, University of Zagreb School of Medicine, Zagreb, Croatia
Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia

Tomislav Smoljo, M.D., Ph.D. student, HRZZ project associate (DOK-2020-01-2873)
Department of Physiology, University of Zagreb School of Medicine, Zagreb, Croatia
Croatian Institute for Brain Research, University of Zagreb School of Medicine, Zagreb, Croatia

Klara Dubravčić, M.Sc.
Department of Laboratory Immunology, University Hospital Center Zagreb, Zagreb, Croatia

Marijana Andrijašević, technician
Croatian Institute for Brain Research, Zagreb, Croatia

Tomic B, Smoljo T, Lalic H, Dembitz V, Batinic J, Batinic D, Bedalov A, Visnjic D. Cytarabine-induced differentiation of AML cells depends on Chk1 activation and shares the mechanism with inhibitors of DHODH and pyrimidine synthesis. Sci Rep. 2022;12(1):11344. doi: 10.1038/s41598-022-15520-z.

Dembitz V, Lalic H, Tomic B, Smoljo T, Batinic J, Dubravcic K, Batinic D, Bedalov A, Visnjic D. All-trans retinoic acid induces differentiation in primary acute myeloid leukemia blasts carrying an inversion of chromosome 16. Int J Hematol. 2022;115(1):43-53. doi: 10.1007/s12185-021-03224-5.

Višnjić D, Lalić H, Dembitz V, Tomić B, Smoljo T. AICAr, a Widely Used AMPK Activator with Important AMPK-Independent Effects: A Systematic Review. Cells. 2021;10(5):1095. doi: 10.3390/cells10051095.

Klionsky DJ, et al. Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1. Autophagy. 2021;17(1):1-382. doi: 10.1080/15548627.2020.1797280.

Dembitz V, Lalic H, Kodvanj I, Tomic B, Batinic J, Dubravcic K, Batinic D, Bedalov A, Visnjic D. 5-aminoimidazole-4-carboxamide ribonucleoside induces differentiation in a subset of primary acute myeloid leukemia blasts. BMC Cancer. 2020;20(1):1090. doi: 10.1186/s12885-020-07533-6.

Dembitz V, Tomic B, Kodvanj I, Simon JA, Bedalov A, Visnjic D. The ribonucleoside AICAr induces differentiation of myeloid leukemia by activating the ATR/Chk1 via pyrimidine depletion. J Biol Chem. 2019;294(42):15257-15270. doi: 10.1074/jbc.RA119.009396.

Visnjic D, Dembitz V, Lalic H. The Role of AMPK/mTOR Modulators in the Therapy of Acute Myeloid Leukemia. Curr Med Chem. 2019;26(12):2208-2229. doi: 10.2174/0929867325666180117105522.

Dembitz V, Lalic H, Visnjic D. 5-Aminoimidazole-4-carboxamide ribonucleoside-induced autophagy flux during differentiation of monocytic leukemia cells. Cell Death Discov. 2017;3:17066. doi: 10.1038/cddiscovery.2017.66.