Aptamer-ROTAC assembled DNA nanocentipede for specific targeting of HSPA8 in hepatocellular carcinoma therapy

HSPA8 is first identified as a new PROTAC target for targeted protein degradation in HCC. • HCR-assembled multivalent DNA nanocentipede LC-42 overcomes the hook effect with sustained degradation. • LC-42 improves targeting, cellular uptake, stability, and PROTAC efficiency; the platform is modular and extensible. Hepatocellular carcinoma (HCC) remains one of the leading causes of cancer-related mortality worldwide. However, the clinical translation of proteolysis-targeting chimeras (PROTACs) for HCC therapy remains restricted by the hook effect, limited tumor selectivity, and inefficient intracellular delivery. Herein, we developed a modular hybridization chain reaction (HCR)-programmable multivalent nucleic acid PROTAC platform and demonstrated, for the first time, that heat shock protein A8 (HSPA8) can serve as a target for targeted protein degradation in HCC. Using the HSPA8-binding DNA aptamer AS42 as the molecular recognition module, we constructed a monovalent aptamer-PROTAC (AS-42) and a multivalent DNA nanocentipede-based aptamer-PROTAC (LC-42) through enzyme-free HCR self-assembly. Owing to its programmable multivalent architecture, LC-42 efficiently induced HSPA8 degradation in HepG2 cells at 20 nM and maintained comparable activity at 200 nM, effectively overcoming the hook effect while exhibiting significantly enhanced degradation efficiency compared with AS-42. LC-42 further exhibited superior antiproliferative and pro-apoptotic activities in vitro, along with enhanced tumor accumulation and remarkable tumor growth inhibition in HepG2 xenograft models with favorable systemic biocompatibility. Furthermore, replacing AS-42 with an epidermal growth factor receptor (EGFR)-binding aptamer readily generated an EGFR-targeted degrader while preserving efficient degradation, providing proof-of-concept for the modularity and extensibility of this platform. Collectively, this work establishes HSPA8 as a previously unrecognized target for targeted protein degradation and introduces a modular, programmable DNA nanoplatform for engineering next-generation multivalent nucleic acid PROTACs. This platform thus provides a versatile strategy for precision targeted protein degradation in cancer therapy. Download: Download high-res image (153KB) Download: Download full-size image