The Multifunctional Protein Kinase C-ε in Cancer Development and Progression

The protein kinase C (PKC) family proteins are important signal transducers and have long been the focus of cancer research. PKC epsilon, a member of this family, is overexpressed in most solid tumors and plays critical roles in different processes that lead to cancer development. Studies using cell lines and animal models demonstrated the transforming potential of PKC epsilon. While earlier research established the survival functions of PKC epsilon, recent studies revealed its role in cell migration, invasion and cancer metastasis. PKC epsilon has also been implicated in epithelial to mesenchymal transition (EMT), which may be the underlying mechanism by which it contributes to cell motility. In addition, PKC epsilon affects cell-extracellular matrix (ECM) interactions by direct regulation of the cytoskeletal elements. Recent studies have also linked PKC epsilon signaling to cancer stem cell functioning. This review focuses on the role of PKC epsilon in different processes that lead to cancer development and progression. We also discussed current literatures on the pursuit of PKC epsilon as a target for cancer therapy.