PKD1 and prostate cancer: Since PKD1 modulates the subcellular localization of β-catenin and since curcumin mediated PKD1 activation enhanced the membrane localization of β-catenin, we analyzed the effect of this activation on nuclear β-catenin expression using immunoblotting and on β-catenin transcription activity using a luciferase reporter system in C4-2 prostate cancer cells (Figures 5B and 5C).