Silencing of PKCη induces cycle arrest of EBV+ B lymphoma cells by upregulating expression of p38-MAPK/TAp73/GADD45α and increases susceptibility to chemotherapeutic agents

PKCη is involved in proliferation, differentiation, and drug resistance. However, PKCη function in EBV+ B lymphoma remains poorly understood. Gene silencing of PKCη through siRNA knockdown inhibited cellular proliferation, induced cell cycle arrest in G0/G1 and G2/M phases, and sensitized cells to chemotherapeutic drugs. Upon PKCη knockdown, expression levels of p21, GADD45α, and TAp73 were all increased, whereas expression levels of CDK2, CDK4, CDK6, cyclin E, cyclin B1, and cdc2 were all downregulated. PKCη silencing also activated p38-MAPK, which in turn contributed to the expression of cell cycle arrest-related molecules. These results suggest that siRNA-mediated silencing of PKCη can be a potent tool to complement existing chemotherapy regimens for treating EBV+ B lymphoma.