Nano‐LYTACs for Degradation of Membrane Proteins and Inhibition of CD24/Siglec‐10 Signaling Pathway

Lysosome‐targeting chimeras (LYTACs) are an emerging therapeutic modality that effectively degrade cancer cell membranes and extracellular target proteins. In this study, a nanosphere‐based LYTAC degradation system is developed. The amphiphilic peptide‐modified N‐acetylgalactosamine (GalNAc) can self‐assemble into nanospheres with a strong affinity for asialoglycoprotein receptor targets. They can degrade different membranes and extracellular proteins by linking with the relevant antibodies. CD24, a heavily glycosylated glycosylphosphatidylinositol‐anchored surface protein, interacts with Siglec‐10 to modulate the tumor immune response. The novel Nanosphere‐AntiCD24, synthesized by linking nanospheres with CD24 antibody, accurately regulates the degradation of CD24 protein and partially restores the phagocytic function of macrophages toward tumor cells by blocking the CD24/Siglec‐10 signaling pathway. When Nanosphere‐AntiCD24 is combined with glucose oxidase, an enzyme promoting the oxidative decomposition of glucose, the combination not only effectively restores the function of macrophages in vitro but also suppresses tumor growth in xenograft mouse models without detectable toxicity to normal tissues. The results indicate that GalNAc‐modified nanospheres, as a part of LYTACs, can be successfully internalized and are an effective drug‐loading platform and a modular degradation strategy for the lysosomal degradation of cell membrane and extracellular proteins, which can be broadly applied in the fields of biochemistry and tumor therapeutics.