Role of Wnt inhibitory factor-1 and Wnt/wingless signaling in choroid plexus tumors.

Little is known on pathways involved in the pathogenesis of choroid plexus tumors (CPTs). The finding of overexpression of Wnt inhibitory factor-1 (Wif-1) prompted us to investigate the functional role of Wif-1 as well as nuclear accumulation of beta-catenin in CPT. In Z310 neoplastic choroid plexus epithelial cells, silencing of Wif1 expression increased proliferative activity not associated with increased canonical Wnt signaling. Nuclear beta-catenin accumulation was also lacking in a series of 16 CPT. In conclusion, our data show that Wif-1 inhibits proliferation of neoplastic choroid plexus epithelial cells, but argue against a role of canonical Wnt/wingless signaling in CPT.