Wnt signaling pathway

Cellular responses to TP53 activation include cell-cycle arrest, apoptosis, DNA repair, senescence and differentiation. Approximately 50% of all human cancers show mutation in TP53. Newly, a functional cross-talk between TP53 and the WNT signaling pathway was observed. TP53 transactivates SIAH-1 leading to ubiquitin-mediated proteasome degradation of oncogenic (unphosphorylated) b -catenin. Presently, it is unknown if TP53 mutations substitute for oncogenic activation of CTNNB1 during tumor development. However, in HCC CTNNB1 mutations and TP53 mutations are mutually exclusive.