Target validation and biomarker identification in oncology : the example of aurora kinases

Innovative strategies for measuring kinase activity to accelerate the next wave of novel kinase inhibitors

The development of protein kinase inhibitors (PKIs) has gained significance owing to their therapeutic potential for diseases like cancer. In addition, there has been a rise in refining kinase activity assays, each possessing unique biological and analytical characteristics crucial for PKI development. However, the PKI development pipeline experiences high attrition rates and approved PKIs exhibit unexploited potential because of variable patient responses. Enhancing PKI development efficiency involves addressing challenges related to understanding the PKI mechanism of action and employing biomarkers for precision medicine. Selecting appropriate kinase activity assays for these challenges can overcome these attrition rate issues. This review delves into the current obstacles in kinase inhibitor development and elucidates kinase activity assays that can provide solutions.

Mitosis is not a key target of microtubule agents in patient tumors

Mitosis-specific agents have, to date, not been clinically successful. By contrast, microtubule-targeting agents (MTAs) have a long record of success, usually attributed to the induction of mitotic arrest. Indeed, it was this success that led to the search for mitosis-specific inhibitors. We believe the clinical disappointment of mitosis-specific inhibitors stands as evidence that MTAs have been successful not only by interfering with mitosis but, more importantly, by disrupting essential interphase cellular mechanisms. In this Perspective we will review literature that supports a paradigm shift in how we think about one of our most widely used classes of chemotherapeutics-MTAs. We believe that the steady presence and constant physiological role of microtubules are responsible for the overall success of MTAs. While mitosis-specific inhibitors are effective on only a small fraction of the tumor mass (dividing cells), MTAs target tubulin, a protein that has crucial roles in both mitotic and non-mitotic cells.