Investigation of Tankyrase Inhibitors to Block Wnt Signalling as a TherapeuticStrategy for Sarcomas (360G-Wellcome-099713_Z_12_Z)

Sarcoma sensitivity to tankyrase inhibitors will be investigated by screening a panel of sarcoma cell lines covering diverse histologies with compounds fromthe lead series of ICR tankyrase inhibitors. Sensitivity will be compared to activity of the Wnt pathway to confirm if tankyrase inhibitors are more effective in cells with high Wnt pathway activity. Pathway activity will be measured using immunoblots for active ?-catenin, TOPFLASH reporter assays and Wnt target gene expression profiling. Sensitivity will also be compared to cell line dependence on the Wnt pathway using dominant negative TCF4 expression to block expression of Wnt target genes. Biomarkers that predict sensitivity will be found by correlating the data for drug sensitivity to mutation and gene expression profiles available from online databases, and potential biomarkers will be confirmed by RT-PCR and immunoblots. Further investigation of the involvement of validated biomarkers in determining sensitivity will be performed using RNAi knockdown and cDNA overexpression of the gene in question. Mechanisms of resistance will be investigated using combinations of clinically relevant drugs with tankyrase inhibitors to identify compounds that act synergistically to increase the effect of tankyrase inhibitors.