Clustering of the Membrane Protein by Molecular Self-Assembly Downregulates the Signaling Pathway for Cancer Cell Inhibition

This work reports a cyclic peptide appended self-assembled scaffold that recognizes the membrane protein EGFR and arrests the EGFR signaling through multivalent interactions by assembly-induced aggregation. When incubated with cells, the oligomers of <b>PAD-1</b> first recognize the overexpressed EGFR on cancer cell membranes for arresting EGFR, which then initiates cellular uptake through endocytosis. The accumulation of <b>PAD-1</b> and EGFR in the lysosome results in the formation of nanofibers, leading to the lysosomal membrane permeabilization (LMP). These processes disrupt the homeostasis of EGFR and inhibit the downstream signaling transduction of EGFR for cancer cell survival. Moreover, LMP induced the release of protein aggregates that could generate endoplasmic reticulum (ER) stress, resulting in cancer cell death selectively. In vivo studies indicate the efficient antitumor efficiency of <b>PAD-1</b> in tumor-bearing mice. As a first example, this work provides an alternative strategy for controlling protein behavior for tuning cellular events in living cells.