ELL-associated factor 2 regulates proliferation and migration of prostate cancer cells via extracellular regulated protein phosphorylation

Objective To investigate whether ELL-associated factor 2 (EAF2) inhibits prostate cancercell proliferation and migration by regulating level of extracellular regulated protein (ERK) phosphorylation. Methods After inhibiting expression of EAF2 by interfering RNA (RNAi) in C4-2 and 22Rv1 cells, the expression level of phosphorylation of ERK was assessed by Western blotting. After transfecting myc-EAF2 into 293T cells according to the manufacturer’s instruction, the expression level of phosphorylation of E RK was assessed by Western blotting. After knockdown of EAF2 by RNAi in C4-2 cells, proliferation and migration abilities were tested by either Bromodeoxyuridine incorporation assay (BrdU) or Transwell migration assay. To detect whether EAF2 affects cells proliferation and migration by targeting ERK phosphorylation, ERK inhibitor (PD184352) was used to inhibit ERK phosphorylation, then the BrdU and Transwell assays were repeated. Results The expression of phosphorylation-ERK (p-ERK) was significantly increased after transfection of small interfering RNA (siRNA) against EAF2, not total-ERK (t-ERK). The expression of p-ERK was significantly decreased after transfection with myc-EAF2 plasmid. Moreover, proliferation was further decreased from (30.8±0.8)% to (21.9±0.5)% (P=0.001) after combined transfection of siRNA targeting EAF2 and ERK inhibitor (PD184352) compared to knockdown of EAF2 cells (P=0.013). The migration was decreased from (203±17) cells to (123±11) cells (P=0.002) after combined transfection of siRNA targeting EAF2 and inhibitor of ERK (PD184352) compared to single knockdown of cells (P=0.011). Conclusion These findings suggest that EAF2 regulates p-ERK level in prostate cancer cells and that EAF2 regulates cells’ proliferation and migration abilities via ERK phosphorylation. Key words: Prostate cancer; ELL-associated factor 2; Extracellular regulated protein