Protein kinase C beta (PKCβ) is an intracellular protein involved in multiple signaling pathways that regulate cell proliferation, differentiation, survival, and apoptosis. PKCβ is known to be closely associated with cancer, for instance, through its overexpression in the early stages of colorectal cancer and the frequent occurrence of its genetic mutations in cancerous tissues. Therefore, elucidating the signaling pathways of mutant PKCβ provides fundamental insights into tumorigenesis and the development of anticancer therapies. Based on this idea, the response of PKCβ and its mutants to pharmaceutical stimuli have been intensively investigated. On the other hand, their responses to mechanical stimuli remain poorly understood. The objective of this study, therefore, is to clarify the spatiotemporal dynamics of wild-type PKCβ and its mutant following mechanical stimulation, represented by the release of intercellular tension. Our live-cell imaging revealed distinct dynamics dependent on either mechanical stimulation or mutation: wild-type PKCβ was rapidly localized to regions near the site of stimulation, whereas the mutant exhibited significantly reduced localization. Since the results were not consistent with those obtained using pharmaceutical stimuli, our findings may provide insights not only into pathological processes such as tumorigenesis but also into the design of new anticancer drugs.
Yamasaki et al. (Wed,) studied this question.