Li Chen, Sun Shuaishuai, Kong Hao, Xie Xiangqian, Liang Gaolin, Zhang Yan, Wang Huan, Li Jinbo
State Key Laboratory of Analytical Chemistry for Life Sciences, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University Nanjing 210023 China
State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Chemistry and Biomedicine Innovation Center (ChemBIC), Nanjing University Nanjing 210023 China
RSC Chem Biol. 2024 Nov 25;6(1):73-80. doi: 10.1039/d4cb00247d. eCollection 2025 Jan 2.
Strategies allowing tumor-selective siRNA delivery while minimizing off-tumor gene silencing effects are highly demanded to advance cancer gene therapy, which however still remain challenging. We herein report a dual-locking bioconjugation approach to address this challenge. A dual-locked cyclopeptide-siRNA conjugate (DPRC) was designed to simultaneously endow siRNA with tumor-targeting properties and tumor-biomarker/visible-light dually controllable action. The DPRC consisted of a programmed death-ligand 1 (PD-L1)-targeting cyclopeptide as a tumor-homing ligand and B-cell lymphoma-2 (Bcl-2)-targeting siRNA as a payload. They were conjugated a tandem-responsive cleavable linker containing a photocleavable coumarin moiety quenched by naphthylamide through a disulfide linkage. Owing to the interaction between cell-membrane PD-L1 and the cyclopeptide, the DPRC was efficiently taken up by PD-L1-positive cancer cells. Notably, the internalized DPRC could only release and restore the gene silencing activity of siBcl-2 upon GSH-mediated disulfide bond breakage followed by visible light irradiation on the coumarin moiety to induce photo-cleavage. The released siBcl-2 further silenced the expression of anti-apoptotic Bcl-2 to suppress cancer cell growth. We demonstrated the tumor-targeting and dual-locked action of siRNA by the DPRC in both two-dimensional and three-dimensional cancer cell cultures. This study thus presents a novel strategy for precise tumor-specific gene silencing by siRNA.
为推进癌症基因治疗，迫切需要能够实现肿瘤选择性siRNA递送并将肿瘤外基因沉默效应降至最低的策略，然而这仍然具有挑战性。我们在此报告一种双锁生物共轭方法来应对这一挑战。设计了一种双锁环肽-siRNA共轭物（DPRC），以同时赋予siRNA肿瘤靶向特性以及肿瘤生物标志物/可见光双重可控作用。DPRC由作为肿瘤归巢配体的靶向程序性死亡配体1（PD-L1）的环肽和作为有效载荷的靶向B细胞淋巴瘤-2（Bcl-2）的siRNA组成。它们通过二硫键与一个串联响应可裂解连接子共轭，该连接子包含一个被萘酰胺淬灭的光可裂解香豆素部分。由于细胞膜上的PD-L1与环肽之间的相互作用，DPRC被PD-L1阳性癌细胞有效摄取。值得注意的是，内化的DPRC只有在谷胱甘肽介导的二硫键断裂，随后对香豆素部分进行可见光照射以诱导光裂解后，才能释放并恢复siBcl-2的基因沉默活性。释放的siBcl-2进一步使抗凋亡蛋白Bcl-2的表达沉默，从而抑制癌细胞生长。我们在二维和三维癌细胞培养中证明了DPRC对siRNA的肿瘤靶向和双锁作用。因此，本研究提出了一种通过siRNA实现精确肿瘤特异性基因沉默 的新策略。
