AbstractProteolysis Targeting Chimeras (PROTACs) represent a promising therapeutic modality to address undruggable and resistant issues in drug discovery. However, potential on‐target toxicity remains clinically challenging. We developed a generalized caging strategy to synthesize a series of stimuli‐responsive PROTACs (sr‐PROTACs) with diverse molecular blocks bearing robust and cleavable linkers, presenting “turn on” features in manipulating protein degradation. By leveraging pathological cues, such as elevated ROS, phosphatase, H2S, or hypoxia, and external triggers, such as ultraviolet light, X‐Ray, or bioorthogonal reagents, we achieved site‐specific activation and traceless release of original PROTACs through de‐caging and subsequent self‐immolative cleavage, realizing selective uptake and controlled protein degradation in vitro. An in vivo study revealed that two sr‐PROTACs with phosphate‐ and fluorine‐containing cages exhibited high solubility and long plasma exposure, which were specifically activated by tumor overexpressing phosphatase or low dosage of X‐Ray irradiation in situ, leading to efficient protein degradation and potent tumor remission. With more reactive biomarkers to be screened from clinical practice, our caging library could provide a general tool to design activatable PROTACs, prodrugs, antibody‐drug conjugates, and smart biomaterials for personalized treatment, tissue engineering or regenerative medicine.
摘要 蛋白质溶解靶向嵌合体(PROTACs)是一种很有前景的治疗方法,可用于解决药物发现过程中不可药用和耐药的问题。然而,潜在的靶向毒性在临床上仍具有挑战性。我们开发了一种通用笼化策略,合成了一系列刺激响应型 PROTACs(sr-PROTACs),它们具有不同的分子模块,带有坚固且可裂解的连接体,在操纵蛋白质降解方面具有 "开启 "功能。通过利用病理线索(如高浓度 ROS、磷酸酶、H2S 或缺氧)和外部触发器(如紫外线、X 射线或生物正交试剂),我们通过去钙化和随后的自惰性裂解实现了原始 PROTACs 的特定位点激活和无痕释放,实现了体外选择性吸收和可控蛋白质降解。体内研究发现,两种含磷酸和氟笼的 sr-PROTACs 具有高溶解度和长时间血浆暴露的特点,能被肿瘤过表达的磷酸酶或低剂量的 X 射线原位照射特异性激活,从而导致高效的蛋白质降解和强效的肿瘤缓解。随着临床实践中更多反应性生物标记物的筛选,我们的笼式库可为设计可激活的 PROTACs、原药、抗体-药物共轭物和智能生物材料提供通用工具,用于个性化治疗、组织工程或再生医学。