Rational Design and Optimization of m 6 A-RNA Demethylase FTO Inhibitors as Anticancer Agents.

Aberrant regulation of N 6 -methyladenosine (m 6 A) RNA modification has been implicated in the progression of multiple diseases, including cancer. Previously, we identified a small molecule inhibitor of the m 6 A demethylase fat mass- and obesity-associated protein (FTO), which removes both m 6 A and N 6 ,2'- O -dimethyladenosine (m 6 A m ) RNA modifications. In this work, we describe the rational design and optimization of a new class of FTO inhibitors derived from our previous lead FTO-04 with nanomolar potency and high selectivity against the homologous m 6 A RNA demethylase ALKBH5. The oxetanyl class of compounds comprise competitive inhibitors of FTO with potent antiproliferative effects in glioblastoma, acute myeloid leukemia, and gastric cancer models where lead FTO-43 demonstrated potency comparable to clinical chemotherapeutic 5-fluorouracil. Furthermore, FTO-43 increased m 6 A and m 6 A m levels in a manner comparable to FTO knockdown in gastric cancer cells and regulated Wnt/PI3K-Akt signaling pathways. The oxetanyl class contains significantly improved anticancer agents with a variety of applications beyond glioblastoma.