Deng Changping, Ma Jiacheng, Liu Yuping, Tong Xikui, Wang Lei, Dong Jiayi, Shi Ping, Wang Meiyan, Zheng Wenyun, Ma Xingyuan
State Key Laboratory of Bioreactor Engineering East China University of Science and Technology Shanghai P. R. China.
Key Laboratory of Systems Biomedicine (Ministry of Education) Shanghai Center for Systems Biomedicine Shanghai Jiao Tong University Shanghai P. R. China.
MedComm (2020). 2025 Jan 19;6(2):e70068. doi: 10.1002/mco2.70068. eCollection 2025 Feb.
Proteolysis targeting chimeras (PROTACs) are pivotal in cancer therapy for their ability to degrade specific proteins. However, their non-specificity can lead to systemic toxicity due to protein degradation in normal cells. To address this, we have integrated a nanobody into the PROTACs framework and leveraged the tumor microenvironment to enhance drug specificity. In this study, we engineered BumPeD, a novel bispecific nanobody-targeted PROTACs-like platform, by fusing two nanobodies with a Furin protease cleavage site (RVRR) and a degron sequence (ALAPYIP or KIGLGRQKPPKATK), enabling the tumor microenvironment to direct the degradation of intracellular proteins. We utilized KN035 and Nb4A to target PD-L1 (programmed death ligand 1) on the cell surface and intracellular Survivin, respectively. In vitro experiments showed that BumPeD triggers Survivin degradation via the ubiquitin-proteasome pathway, inducing tumor apoptosis and suppressing bladder tumor cell proliferation and migration. In vivo experiments further confirmed BumPeD's robust anti-tumor efficacy, underscoring its potential as a precise protein degradation strategy for cancer therapy. Our platform provides a systematic approach to developing effective and practical protein degraders, offering a targeted theoretical basis and experimental support for the development of novel degradative drugs, as well as new directions for cancer therapy.
靶向蛋白降解嵌合体（PROTACs）因其降解特定蛋白质的能力而在癌症治疗中发挥着关键作用。然而，由于其非特异性，会导致正常细胞中的蛋白质降解，进而引发全身毒性。为了解决这一问题，我们将一个纳米抗体整合到PROTACs框架中，并利用肿瘤微环境来提高药物特异性。在本研究中，我们通过将两个纳米抗体与一个弗林蛋白酶切割位点（RVRR）和一个降解子序列（ALAPYIP或KIGLGRQKPPKATK）融合，构建了一个新型双特异性纳米抗体靶向的类PROTACs平台BumPeD，使肿瘤微环境能够指导细胞内蛋白质的降解。我们分别利用KN035和Nb4A靶向细胞表面的程序性死亡配体1（PD-L1）和细胞内的生存素。体外实验表明，BumPeD通过泛素-蛋白酶体途径触发生存素降解，诱导肿瘤细胞凋亡，并抑制膀胱肿瘤细胞的增殖和迁移。体内实验进一步证实了BumPeD强大的抗肿瘤疗效，突显了其作为一种精确的癌症治疗蛋白质降解策略的潜力。我们的平台为开发有效且实用的蛋白质降解剂提供了一种系统方法，为新型降解药物的开发提供了有针对性的理论基础和实验支持，也为癌症治疗提供了新方向。
