JWZ-5-13

JWZ-5-13 is a highly selective and potent PROTAC degrader that fulfils probe criteria, offering a robust strategy for CDK7 targeting with significant potential in cancer treatment. The PROTAC degrader is derived from the potent CDK7 inhibitor YKL-5-167 that was linked by an aliphatic alkyne-containing linker to VHL. The high in-vitro potency towards CDK7 inhibition was maintained in the PROTAC, JWZ-5-13 (IC50 = 20 nM). With a DC50 of less than 100 nM and a Dmax of 100%, JWZ-5-13 rapidly degrades CDK7 within 6 hours of treatment, which was verified in five different cancer cell lines (Jurkat, OVCAR3, SUDHL, and Molt4 cells). The compound exhibits selectivity over other CDK family members and high proteome-wide selectivity, as demonstrated by an unbiased multiplexed quantitative mass-spectrometry-based proteomics approach in OVCAR3 cells. A corresponding negative control (17-Neg.) for the PROTAC degrader JWZ-5-13 is available that shows intact binding to CDK7 but exhibits a >100-fold weaker activity on the E3 ligase in Jurkat cells. Rescue experiments with proteasome inhibitors further confirmed that the degradation is proteasome-dependent. Moreover, JWZ-5-13 was tested for cell proliferation, where a 7-fold stronger inhibition effect on cell growth than the parent compound was observed in Jurkat, SUDHL5, Molt4, and A549 cells. Bioavailability studies in mice also confirmed that JWZ-5-13 is a valuable chemical probe for investigating the effects of CDK7 degradation in vivo.