Enhanced Tumor-Targeted Delivery of Arginine-Rich Peptides via a Positive Feedback Loop Orchestrated by Piezo1/integrin β1 Signaling Axis.

Peptide-based drugs hold great potential for cancer treatment, and their effectiveness is driven by mechanisms on how peptides target cancer cells and escape from potential lysosomal entrapment post-endocytosis. Yet, the mechanisms remain elusive, which hinder the design of peptide-based drugs. Here hendeca-arginine peptides (R11) are synthesized for targeted delivery in bladder carcinoma (BC), investigated the targeting efficiency and elucidated the mechanism of peptide-based delivery, with the aim of refining the design and efficacy of peptide-based therapeutics. It is demonstrated that the over-activated Piezo1/integrin β1 (ITGB1) signaling axis significantly facilitates tumor-targeted delivery of R11 peptides via macropinocytosis. Furthermore, R11 peptides formed hydrogen bonds with integrin β1, facilitating targeting and penetration into tumor cells. Additionally, R11 peptides protected integrin β1 from lysosome degradation, promoting its recycling from cytoplasm to membrane. Moreover, this findings establish a positive feedback loop wherein R11 peptides activate Piezo1 by increasing membrane fusion, promoting Ca releasing and resulting in enhanced integrin β1-mediated endocytosis in both orthotopic models and clinical tissues, demonstrating effective tumor-targeted delivery. Eventually, the Piezo1/integrin β1 signaling axis promoted cellular uptake and transport of peptides, establishing a positive feedback loop, promoting mechanical delivery to cancer and offering possibilities for drug modification in cancer therapy.