CLDN1 and Familial prostate cancer: In the present study, we demonstrated that ATP and BzATP treatment both led to a significant up-regulation of Snail as well as a dramatic down-regulation of E-cadherin and Claudin-1 in prostate cancer cells in vitro, and P2X7 knockdown remarkably inhibited expression of Snail and promoted expressions of E-cadherin and Claudin-1 in vitro and in vivo.