Small-Molecule Targeting of Oncogenic FTO Demethylase in Acute Myeloid Leukemia

Abstract

Graphical AbstractHighlights d Structure-guided design and optimization yield potent FTO inhibitors d mRNA m 6 A acts as the major effector of the inhibitor/FTO axis in AML cells d FTO inhibitor FB23-2 displays therapeutic effects in PDX AML models d Targeting epitranscriptomic RNA methylation holds potential to treat AML SUMMARY FTO, an mRNA N 6 -methyladenosine (m 6 A) demethylase, was reported to promote leukemogenesis. Using structure-based rational design, we have developed two promising FTO inhibitors, namely FB23 and FB23-2, which directly bind to FTO and selectively inhibit FTO's m 6 A demethylase activity. Mimicking FTO depletion, FB23-2 dramatically suppresses proliferation and promotes the differentiation/apoptosis of human acute myeloid leukemia (AML) cell line cells and primary blast AML cells in vitro. Moreover, FB23-2 significantly inhibits the progression of human AML cell lines and primary cells in xeno-transplanted mice. Collectively, our data suggest that FTO is a druggable target and that targeting FTO by small-molecule inhibitors holds potential to treat AML. SignificanceAs the most abundant internal mRNA modification, m 6 A impacts various biological processes. As a major m 6 A demethylase, FTO is overexpressed in certain subtypes of AMLs and promotes leukemogenesis. Thus, the development of effective inhibitors to target FTO's aberrant m 6 A demethylase activity is urgently needed for leukemia therapy. Here we report two selective FTO inhibitors that efficiently reverse/suppress FTO-mediated aberrant epitranscriptome in AML cells and significantly inhibit AML progression in vivo. Our studies provide the proof-of-concept evidence demonstrating that small-molecule inhibitors targeting oncogenic FTO represent a promising targeted therapeutic strategy for the effective treatment of AML. Moreover, given the overexpression of FTO in various cancers, our work may have a broad impact on cancer therapy by targeting the FTO-mediated epitranscriptome.

Epitranscriptomic profiling of N6-methyladenosine-related RNA methylation in rat cerebral cortex following traumatic brain injury

“…Behavioral testing: modified neurological severity score and Morris water maze FTO inhibitor FB23-2 (MedChemExpress, USA) was used to block FTO demethylase function by intraperitoneal injection (1.4 mg/kg) 15 min after CCI [33]. The 25 rats were randomly divided into 4 groups: TBI + FB23-2 (n = 7), TBI + DMSO (n = 8), Sham+FB23-2 (n = 5), and Sham+DMSO (n = 5).…”

N6-Methyladenosine: A Novel RNA Imprint in Human Cancer

“…Meanwhile, R-2HG also has synergistic effect with first-line chemotherapy drugs such as decitabine and daunorubicin, which was validated in mouse models. Later on, Huang et al utilized structure-guided design and developed two small-molecule FTO inhibitors, FB23 and its derivative FB23-2 (85). In comparison, the latter shows significantly improved antiproliferative activity in AML cells and induces cell differentiation.…”

Hydrazines as versatile chemical biology probes and drug-discovery tools for cofactor-dependent enzymes

“…lysine-specific histone demethylase 1A (KDM1A) and ribosyldihydronicotinamide dehydrogenase [quinone] (NQO2)) are also highest-reactivity targets of 3, implying that it can directly covalently couple to the enzymes themselves in addition to the FAD cofactor. Iron(II)and 2-oxoglutarate-dependent (Fe/2OG) enzymes -including fat mass and obesity-associated dioxygenase (FTO), the O2dependent RNA demethylase that is critical for an array of cellular processes and disease states, including CNS function 22 , obesity 23 and cancer 24 -were also identified as specific probe targets, with 2 being more selective than 3 toward these enzymes. To the best of our knowledge, this represents the first report of the targeting of an Fe/2OG enzyme with a covalent inactivator.…”