Development of truncated-itraconazole analogues as potent Hedgehog/GLI pathway inhibitors and potential therapeutic agents for cutaneous squamous cell carcinoma

Cutaneous squamous cell carcinoma (cSCC) is a common and potentially aggressive skin Cancer, with limited therapeutic options for advanced disease. The Hedgehog/Gli (HH/Gli) signaling pathway has emerged as a potential therapeutic target in cSCC. Itraconazole (ITZ), a repurposed Antifungal agent, exhibited HH/Gli pathway inhibition but suffers from unfavorable physicochemical properties. Herein, we report the rational design and evaluation of truncated-ITZ analogues as novel HH/Gli pathway inhibitors for cSCC treatment. Starting from the metabolite-inspired lead compound A-26, two series of analogues were synthesized and optimized through structure-based drug design and ligand-lipophilicity efficiency-driven optimization. Among them, compound 16 demonstrated potent HH/Gli pathway inhibition and enhanced aqueous solubility. Compound 16 selectively inhibited proliferation of A431 SCC cells, suppressed colony formation, and induced cell Apoptosis. In an A431 xenograft model, 16 significantly suppressed tumor growth with downregulation of GLI1, Ki67, and SOX2. Preliminary safety evaluation revealed no significant hematological or organ toxicity. These results established truncated-ITZ analogues as promising HH/Gli pathway inhibitors and support further development of compound 16 as a potential therapeutic agent for cSCC.

Hedgehog/GLI pathway inhibitor; Ligand-lipophilicity efficiency; Squamous cell carcinoma; Structure-based drug design; Truncated-itraconazole.