%0 Journal Article %A ULISSE CUCCHI %A LAURA M. GIANELLINI %A ANNA DE PONTI %A FRANCESCO SOLA %A RACHELE ALZANI %A VERONICA PATTON %A ALICE PEZZONI %A SONIA TROIANI %A MARIA B. SACCARDO %A SIMONA RIZZI %A MARIA L. GIORGINI %A PAOLO CAPPELLA %A ITALO BERIA %A BARBARA VALSASINA %T Phosphorylation of TCTP as a Marker for Polo-like Kinase-1 Activity In Vivo %D 2010 %J Anticancer Research %P 4973-4985 %V 30 %N 12 %X Polo-like kinase 1 (PLK1) is the master regulator of mitosis and a target for anticancer therapy. To develop a marker of PLK1 activity in cells and tumour tissues, this study focused on translational controlled tumour protein (TCTP) and identified serine 46 as a site phosphorylated by PLK1 in vitro. Using an antibody raised against phospho-TCTP-Ser46, it was demonstrated that phosphorylation at this site correlates with PLK1 level and kinase activity in cells. Moreover, PLK1 depletion by siRNA or inactivation by specific inhibitors caused a correspondent decrease in phospho-TCTP-Ser46 signal validating this site as a direct marker of PLK1. Using this marker, the study characterized PLK1 inhibitors in cells by setting up a high-content assay and finally immunohistochemical assay suitable for following inhibitor activity in preclinical tumour models and possibly in clinical studies was developed. %U https://ar.iiarjournals.org/content/anticanres/30/12/4973.full.pdf