The Emerging Function of PKCtheta in Cancer

Protein Kinase C theta (PKCA) is a serine/threonine kinase that belongs to the novel PKC subfamily. In normal tissue, its expression is restricted to skeletal muscle cells, platelets and T lymphocytes in which PKCA controls several essential cellular processes such as survival, proliferation and differentiation. Particularly, PKCA has been extensively studied for its role in the immune system where its translocation to the immunological synapse plays a critical role in T cell activation. Beyond its physiological role in immune responses, increasing evidence implicates PKCA in the pathology of various diseases, especially autoimmune disorders and cancers. In this review, we discuss the implication of PKCA in various types of cancers and the PKCA-mediated signaling events controlling cancer initiation and progression. In these types of cancers, the high PKCA expression leads to aberrant cell proliferation, migration and invasion resulting in malignant phenotype. The recent development and application of PKCA inhibitors in the context of autoimmune diseases could benefit the emergence of treatment for cancers in which PKCA has been implicated.