Design of chemical probes for hedgehog acyltransferase

Hedgehog （Hh）信号通路是一种保守的旁分泌通路，主要在胚胎发育中起生理作用。然而，在成人中，估计25%的癌症死亡与Hh信号上调有关。靶向“接收”细胞中下游Hh信号的抑制剂是某些Hh依赖性癌症的一线治疗方法。虽然最初非常有效，但由于耐药性，大多数患者在一年内进展，这表明迫切需要可以联合使用的新方法。Hedgehog酰基转移酶（HHAT）是通过“产生”细胞中Hh蛋白的棕榈酰化产生Hh信号所必需的。我们已经发现了多种新的、经过验证的、化学成分多样的HHAT抑制剂系列，它们在体外具有出色的效力（100nM及以下），比以往报道的效力高50倍，具有多种可开发的特性。我们进一步建立了提高效力的合成途径和类似物，首次建立了与每种抑制剂结合的HHAT的低温电镜结构，并进行了一整套HHAT抑制的生化和细胞分析。在药物发现、结构生物学和药代动力学分析方面的科学家团队的支持下，该项目将有助于发现第一个高效和选择性的HHAT抑制剂，作为化学生物学工具，以验证HHAT作为临床前转化性癌症模型的新靶点。

The Hedgehog (Hh) signalling pathway is a conserved paracrine pathway that plays a physiological role primarily in embryonic development. However, in adults upregulated Hh signalling is involved in an estimated 25% of all cancer deaths. Iinhibitors targeting downstream Hh signalling in the 'receiving' cells, are first line therapy in certain Hh-dependent cancers. Although initially highly effective, most patients progress within one year due to resistance indicating the pressing need for new approaches which could be used in combination. Hedgehog acyltransferase (HHAT) is required for generation of the Hh signal through palmitoylation of Hh protein in the 'producing' cell. We have discovered multiple novel, validated and chemically diverse HHAT inhibitor hit series, with outstanding potency (100nM and below) in vitro, up to 50-fold more potent than any previously reported, with varied and developable properties. We have further established synthetic routes and analogues of improved potency, the first cryo-EM structures of HHAT bound to each class of inhibitor, and a full suite of biochemical and cellular assays for HHAT inhibition. Supported by a team of scientists in drug discovery, structural biology and pharmacokinetic analysis, this project will contribute to discovery of the first highly potent and selective HHAT inhibitors as chemical biology tools to validate HHAT as a novel target in preclinical translational cancer models.