Abstract：
The c-ros oncogene 1 (ROS1), an oncogenic driver, is known to induce non-small cell lung cancer (NSCLC) when overactivated, particularly through the formation of fusion proteins. Traditional targeted therapies focus on inhibiting ROS1 activity with ROS 1 inhibitors to manage cancer progression. However, a new strategy involving the design of protein degraders offers a more potent approach by completely degrading ROS1 fusion oncoproteins, thereby effectively blocking their kinase activity and enhancing anti-tumour potential. Utilizing PROteolysis-TArgeting Chimera (PROTAC) technology and informed by molecular docking and rational design, we report the first ROS1-specific PROTAC, SIAIS039. This degrader effectively targets multiple ROS1 fusion oncoproteins (CD74-ROS1, SDC4-ROS1 and SLC34A2-ROS1) in engineered Ba/F3 cells and HCC78 cells, demonstrating anti-tumour effects against ROS1 fusion-driven cancer cells. It suppresses cell proliferation, induces cell cycle arrest, and apoptosis, and inhibits clonogenicity. The anti-tumour efficacy of SIAIS039 surpasses two approved drugs, crizotinib and entrectinib, and matches that of the top inhibitors, including lorlatinib and taletrectinib. Mechanistic studies confirm that the degradation induced by 039 requires the participation of ROS1 ligands and E3 ubiquitin ligases, and involves the proteasome and ubiquitination. In addition, 039 exhibited excellent oral bioavailability in a mouse xenograft model, highlighting its potential for clinical application. In conclusion, our study presents a promising and novel therapeutic strategy for ROS1 fusion-positive NSCLC by targeting ROS1 fusion oncoproteins for degradation, laying the foundation for the development of further PROTAC and offering hope for patients with ROS1 fusion-positive NSCLC.
摘要：
c-ros癌基因1（ROS1），一个致癌司机,已知过度激活时会诱导非小细胞肺癌（NSCLC），特别是通过融合蛋白的形成。传统的靶向治疗侧重于用ROS1抑制剂抑制ROS1活性以控制癌症进展。然而,一种涉及蛋白质降解物设计的新策略通过完全降解ROS1融合癌蛋白提供了一种更有效的方法，从而有效地阻断它们的激酶活性并增强抗肿瘤潜力。利用PROteasoly-Togeting嵌合体（PROTAC）技术，通过分子对接和合理设计，我们报告了第一个ROS1特定的PROTAC，SIAIS039.这种降解剂有效地靶向工程Ba/F3细胞和HCC78细胞中的多种ROS1融合癌蛋白（CD74-ROS1，SDC4-ROS1和SLC34A2-ROS1），证明了对ROS1融合驱动的癌细胞的抗肿瘤作用。它抑制细胞增殖，诱导细胞周期停滞，和细胞凋亡，并抑制克隆性。SIAIS039的抗肿瘤功效超过了两种已批准的药物，克唑替尼和恩替替尼，和顶级抑制剂的匹配，包括洛拉替尼和他列替尼。机理研究证实，039诱导的降解需要ROS1配体和E3泛素连接酶的参与，涉及蛋白酶体和泛素化。此外,039在小鼠异种移植模型中表现出优异的口服生物利用度，突出其临床应用潜力。总之,我们的研究通过靶向ROS1融合癌蛋白降解，为ROS1融合阳性NSCLC提供了一种有希望的新治疗策略，为进一步发展PROTAC奠定基础，并为ROS1融合阳性NSCLC患者提供希望。
