Moving upstream in the war on WNTs.

Cholangiocarcinoma is a relatively rare cancer of the biliary ducts that is highly refractory to treatment. The factors that drive cholangiocarcinoma are poorly understood, though chronic liver fluke infection is a risk factor for disease. In this issue of the JCI, Boulter and colleagues demonstrate that the WNT/β-catenin signaling pathway is upregulated in patients with sporadic cholangiocarcinoma. The authors determined that macrophages generate WNT ligands in cholangiocarcinomas and depletion or inhibition of this cell population in animal models of cholangiocarcinoma reduced tumor burden and proliferation. Moreover, pharmacological inhibition of WNT secretion or β-catenin activity was efficacious in animal models. Together the results of this study suggest that targeting WNT has potential as a therapeutic strategy for cholangiocarcinoma.