Itraconazole inhibits invasion and migration of pancreatic cancer cells by suppressing TGF-β/SMAD2/3 signaling.

Pancreatic cancer is the fourth leading cause of cancer-associated mortality worldwide, with an overall 5-year survival rate <8%. We studied the therapeutic effect of itraconazole (ITZ), a commonly used broad-spectrum anti-fungal agent, in the treatment of pancreatic cancer, and to reveal the underlying anticancer mechanisms. Effects of ITZ on cell proliferation, apoptosis, invasion and migration were observed by MTT assays and colony formation assays, flow cytometry, wound scratch assays and transwell assays, respectively. Western blotting and immunofluorescence were performed to investigate the effect of ITZ on the epithelial to mesenchymal transition (EMT) of pancreatic cancer cells. Recombinant transforming growth factor-β (TGF-β) and TGF-β neutralizing antibody were used to study the effect of ITZ on the TGF-β/SMAD2/3 signaling. Transgenic engineered mice which harboring the spontaneous pancreatic cancer was applied to investigate the therapeutic role of ITZ in vivo. We report that ITZ inhibited the viability and induced apoptosis of pancreatic cancer cells. Furthermore, ITZ suppressed the invasion and migration of pancreatic cancer cells. We found that ITZ treatment was efficient in suppressing EMT and that the effect of ITZ was partially mediated by impaired TGF-β/SMAD2/3 signaling. The role of TGF-β/SMAD2/3 signaling in mediating the effect of ITZ was confirmed based on the results that recombinant TGF-β induced, but the TGF-β neutralizing antibody inhibited EMT as well as the invasion and migration of pancreatic cancer cells. Also, the anticancer effect of ITZ could be partially reversed by recombinant TGF-β. Furthermore, treatment with ITZ suppressed growth of tumor in vivo. Taken together, we suggest that ITZ may potentially serve as a new chemotherapeutic agent for the treatment of pancreatic cancer.