Deregulation of Hedgehog (Hh) pathway signaling has been associated with the pathogenesis of various malignancies, including basal cell carcinomas (BCC). Inhibitors of the Hh pathway currently available or under clinical investigation all bind and antagonize Smoothened (SMO), inducing a marked but transient clinical response. Tumor regrowth and therapy failure were attributed to mutations in the binding site of these small molecule SMO antagonists. The anti-fungal itraconazole was demonstrated to be a potent SMO antagonist with a distinct mechanism of action from that of current SMO inhibitors. However, itraconazole represents a suboptimal therapeutic option due to its numerous drug-drug interactions. Here we show that posaconazole, a second generation triazole anti-fungal with minimal drug-drug interactions and a favorable side effect profile, is also a potent inhibitor of the Hh pathway that functions at the level of SMO. We demonstrate that posaconazole inhibits the Hh pathway by a mechanism distinct from that of cyclopamine and other cyclopamine-competitive SMO antagonists but similar to itraconazole, has robust activity against drug-resistant SMO mutants and inhibits the growth of Hh-dependent basal cell carcinoma in vivo. Our results suggest that posaconazole, alone or in combination with other Hh pathway antagonists, may be readily tested in clinical studies for the treatment of Hh-dependent cancers.
Dysfibrogenemias are characterized by the production of abnormally functioning fibrinogen, occurring in the presence of liver disease, medication toxicity, malignancy, or genetic mutation. Here, we report a patient with multiple, separate episodes of hepatic portal system thromboses associated with dysfibrinogenemia. Molecular studies identified the presence of a 554Arg→Cys mutation in the fibrinogen Aα gene, previously identified as Fibrinogen Dusart (also known as Fibrinogen Paris V and Fibrinogen Chapel Hill). This case further illustrates the association of this dysfibrinogenemia with a unique thrombophilic manifestation.
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