TAK-243 (MLN7243)

TAK-243 treatment causes depletion of cellular ubiquitin conjugates, resulting in disruption of signaling events, induction of proteotoxic stress, and impairment of cell cycle progression and DNA damage repair pathways. TAK-243 has weaker inhibitory activity against other closely related E1 ubiquitin-like activating enzymes such as Fat10-activating enzyme (UBA6; 7 ± 3 nM), NEDD8-activating enzyme (NAE; 28 ± 11 nM), SUMO-activating enzyme (SAE; 850 ± 180 nM), ISG15-activating enzyme (UBA7; 5,300 ± 2,100 nM) and autophagy-activating enzyme (ATG7; >10,000 nM) than it does against UAE. TAK-243 inhibits UAE from transferring ubiquitin to an E2 enzyme. TAK-243 shows equally potent inhibition of the two E1 enzymes capable of activating ubiquitin (UBA6 and UAE), as indicated by comparable decreases in levels of charged USE1 and UBCH10. Downstream UAE pathway inhibition by TAK-243 is evident, as shown by a dose- and time-dependent loss of both polyubiquitin chains and mono-ubiquitylated histone H2B; however, TAK-243 treatment does not affect UAE (UBE1) protein levels. TAK-243 treatment also causes accumulation of short-lived proteins such as c-Jun, c-Myc, MCL1 and p53^[1].

HCT-116 and WSU-DLCL2 cells are maintained in log-phase growth in McCoy's 5A modified or RPMI-1460 medium, respectively supplemented with 10% fetal bovine serum at 37℃ in a 5% CO2 incubator. Cells are grown in 6-well cell culture dishes and treated with DMSO (0.1%) or with 0.01, 0.10 or 1.00 μM TAK-243 for the times indicated. Whole-cell extracts are prepared using RIPA buffer.

TAK-243 treatment causes death of cancer cells and, in primary human xenograft studies. TAK-243 demonstrates broad antitumor activity in models of solid and hematological tumors^[1].