Kobe2602 is a small-molecule inhibitor of Ras with Ki value of 149 μM [1].
Kobe2602 is a compound screened out by a computer-assisted search of about 160,000 compounds. It dose-dependently inhibited the binding of H-RasG12V to c-Raf-1 in NIH 3T3 cells with a rough IC50 value of 10 μM. 20 μM of Kobe2602 effectively suppressed the phosphorylation of down-stream kinases of Raf, including MEK and ERK. Besides that, in NIH 3T3 cells transfected with H-rasG12V, Kobe2602 inhibited the colony formation with IC50 value of 1.4 μM. Kobe2602 also showed effect on other cancer cells carrying activated ras oncogenes, such as PANC-1(K-rasG12V), HT1080 (N-rasQ61L) and HCT116 (H-rasG13D). Moreover, in mice bearing SW480 xenografts, administration of Kobe2602 resulted in 40-50% inhibition of the tumor growth at dose of 80 mg/kg [1].
References:
[1] Shima F, Yoshikawa Y, Ye M, et al. In silico discovery of small-molecule Ras inhibitors that display antitumor activity by blocking the Ras–effector interaction. Proceedings of the National Academy of Sciences, 2013, 110(20): 8182-8187.