... is involved in claudin-1 expression and localization. Indeed, a study shows that increasing β-catenin in- creases the expression of claudin-1 in colorectal cancer cells, and that claudin-1 ... expression of claudin-1 in the cytoplasm, with some nuclear expression of claudin-1. B) Treatment of these cells with PKA inhibitor results in nuclear translocation of claudin-1 in as little as 15 minutes, ... cancer. J Clin Invest 2005;115(7): 1765-1776 18. Miwa N., Furuse M., Tsukita S., Niikawa N., Nakamura Y., and Furukawa Y. Involvement of claudin-1 in the beta-catenin/Tcf signaling pathway and its...