BACKGROUND: The Polycomb Group protein EZH2 is implicated in prostate cancer 
progression. EZH2 promotes prostate cancer cell proliferation and invasiveness. 
We describe a link between EZH2 function and actin polymerization in prostate 
cancer cells.
METHODS: Nuclear and cytoplasmic EZH2 expression in benign and malignant 
prostate tissue samples was assessed. An association between EZH2 function and 
actin polymerization in prostate cancer cells was investigated using 
siRNA-mediated knock-down of EZH2. Effects of EZH2 knock-down on actin 
polymerization dynamics were analyzed biochemically using immunoblot analysis of 
cell lysate fractions, and morphologically using immunocytochemistry.
RESULTS: Cytoplasmic EZH2 is expressed at low levels in benign prostate 
epithelial cells and over-expressed in prostate cancer cells. Cytoplasmic EZH2 
expression levels correlate with nuclear EZH2 expression in prostate cancer 
samples. Knock-down of EZH2 in PC3 prostate cancer cells increases the amount of 
F-actin polymerization, cell size, and formation of actin-rich filaments.
CONCLUSIONS: Cytoplasmic EZH2 is over-expressed in prostate cancer cells. EZH2 
function promotes a reduction in the pool of insoluble F-actin in invasive 
prostate cancer cells. EZH2 may regulate actin polymerization dynamics and 
thereby promote prostate cancer cell motility and invasiveness.