Merck, SML3121-5MG, TETi76 diethyl ester

Biochem/physiol Actions
Cell-permeant, α-KG-competitive and hightly selective TET1/2/3 inhibitor with preferential cytotoxicity against TET-deficient cells in vitro and in vivo.
TETi76 diethyl ester is a cell-permeant diester form of the α-KG-competitive and hightly selective TET1/2/3 dioxygenase inhibitor TETi76 acid (TET2 cat. domain Kd = 0.3 μM; no potency against 16 other αKG/Fe2+-dependent enzymes, including closely related RNA dioxygenase FTO). TETi76 ester downregulates cellular 5-hydroxymethylcytosine (5hmC) levels (IC50 = 20-37 μM; K562, MEG01, SIGM5, OCI-AML5, MOLM13), exerts preferential cytotoxicity in TET-deficient cultures (TET2/3-knockout K562 LD50 ~10 μM vs wt K562 LD50 ~40 μM) and significantly reduces TET2-deficient SIGM5 tumor burden in mice in vivo (50 mg/kg p.o.).