Biomimetic Nano-delivery of Small-Molecule Piceatannol Modulates Tumor Stemness and Suppresses Colorectal Cancer Metastasis via Hippo/YAP1/SOX9 Signaling.

Suppressing tumor metastasis is a crucial strategy for improving survival rates in patients with colorectal cancer (CRC), with cancer stem cells (CSCs) being the primary drivers of metastasis. Current therapeutic approaches targeting CSCs are limited, and their molecular mechanisms remain unclear. To address this challenge, a biomimetic nanoparticle delivery system, CMD-BHQ3-PTL/DOX@RBCM is developed, to deliver the stem cell regulator, piceatannol (PTL). This system used carboxymethyl dextran (CMD) and Black Hole Quencher 3 (BHQ3) to encapsulate PTL and the cytotoxic drug doxorubicin (DOX) within a red blood cell membrane (RBCm), enhancing stability and biocompatibility while allowing gradual drug release under hypoxic conditions. The effects of PTL are investigated on CSCs using molecular biology experiments, plasmid construction, and high-throughput sequencing and elucidated the molecular mechanisms underlying this biomimetic nanoparticle delivery system. The therapeutic efficacy of PTL is validated at the tissue level using subcutaneous and metastatic tumor models in human and murine systems. The results demonstrated that CMD-BHQ3-PTL/DOX@RBCM effectively addressed the challenges of specificity and biocompatibility in vivo, significantly inhibiting CSC-related tumor metastasis. This inhibitory effect is closely associated with the Hippo/YAP1/SOX9 pathway. This study highlights the effectiveness of the pH-responsive biomimetic nanoparticle system CMD-BHQ3-PTL/DOX@RBCm in delivering PTL to tumor sites, with SOX9 and its upstream Hippo/YAP1 pathway playing a critical role in the underlying mechanism.