Protein tyrosine kinase signaling diversity and susceptibility to targeted kinase inhibitors

Design, synthesis and biological evaluation of new potent and highly selective ROS1-tyrosine kinase inhibitor

ROS1 protein is a receptor tyrosine kinase that has been reported mainly in meningiomas and astrocytomas, and until now, there is no selective inhibitor for this kinase. In this study, we illustrate for the synthesis of a highly potent and selective inhibitor for ROS1 kinase. The synthesized compound 1 was tested initially at a single dose concentration of 10 microM over 45 different kinases. At this concentration, a 94% inhibition of the enzymatic activity of ROS1 kinase was observed, while the inhibition in activity was below 30% in all of the other kinases. The pyrazole compound 1 was further tested in a 10-dose IC(50) mode and showed an IC(50) value of 199 nM for ROS1 kinase. The compound 1 can be used as a promising lead for the development of new selective inhibitors for ROS1 kinase, and it may open the way for new selective therapeutics for astrocytomas.

Discovery of 4-azaindoles as novel inhibitors of c-Met kinase

A series of 4-azaindole inhibitors of c-Met kinase is described. The postulated binding mode was confirmed by an X-ray crystal structure and series optimisation was performed on the basis of this structure. Future directions for series development are discussed.