SB-218078

**SB‑218078** is a potent and selective small molecule inhibitor of checkpoint kinase 1 (Chk1), acting as an ATP‑competitive antagonist. It displays high selectivity for Chk1 over other kinases (IC50 values are approximately 15 nM for Chk1 versus much higher for cdc2 and PKC). By inhibiting Chk1 activity and phosphorylation of downstream targets such as cdc25C phosphatase in cells exposed to DNA damage or replication stressors (e.g., γ‑irradiation or topoisomerase I inhibitors), SB‑218078 abrogates G₂ cell cycle arrest. This can sensitize tumor cells to DNA-damaging chemotherapeutics by preventing cell cycle checkpoint-mediated repair responses. The compound has been used extensively in preclinical research but is not approved for clinical use[2][3][5].

Other names

9,10,11,12-tetrahydro-9,12-epoxy-1h-diindolo(1,2,3-fg:3',2',1'-kl)pyrrolo(3,4-i)(1,6)benzodiazocine-1,3(2h)-dione9,12-epoxy-1h-diindolo(1,2,3-fg:3',2',1'-kl)pyrrolo(3,4-i)(1,6)benzodiazocine-1,3(2h)-dioneLSM-1274LSM1274LSM 1274UNII-S6U3J3UP11UNII-S-6U3J3UP11UNII-S 6U3J3UP11DTXSID10392024DTXSID-10392024DTXSID 10392024