Work

Intracellular redistribution of cell-penetrating peptide p28: A mechanism for enhanced anti-cancer activity

Year: 2025

Type: article

Abstract: Cell-penetrating peptides (CPPs) have been studied as they provide an efficient strategy for the intracellular delivery of bioactive molecules in various biomedical applications such as cancer diagnosis and therapy. We have developed an anionic CPP, p28, that can preferentially enter cancer cells and induce cell cycle arrest and apoptotic cell death preclinically and that showed preliminary efficacy in humans. Yet, the underlying intracellular fate after cell entry remains largely uncharacterized. To better understand the intracellular trafficking of p28, we investigated more closely the role of endosomal acidification and retrograde transport in cancer cells. Here, we show that agents such as chloroquine (CQ), NH 4 Cl, and nordihydroguaiaretic acid (NDGA) that alter discrete steps of endocytosis or Golgi-mediated transport remarkably increased p28 access to the cytosol and nucleus. Moreover, CQ significantly improved the antiproliferative effects induced by p28. Our findings suggest that inadequate intracellular localization is the major limiting factor for the efficacy of CPPs such as p28. Taken together, these results indicate that the effective and adequate alternation of intracellular localization of CPPs can be a promising drug-delivery strategy to specifically deliver the therapeutic molecule to its intracellular therapeutic active site or organelle that leads to potentiate the efficacy for cancer diagnosis and therapy. Enhancing the antiproliferative effects of p28 through redistribution by specific inhibitors. ① The cellular entry of p28 occurs through the caveolae-mediated endocytosis pathway. ② The intracellular localization of p28 involves caveolae-mediated transport pathways, including lysosome and Golgi localization. ③ Chloroquine (CQ) and NH 4 Cl enhance the antiproliferative effects of p28 by increasing the pH inside vesicles. ④ Nordihydroguaiaretic acid (NDGA) induces the redistribution of p28 to the nucleus, significantly enhancing its nuclear localization. • p28 can deliver various types of macromolecules with a wide range of molecular weight. • Inadequate intracellular localization limits CPP efficacy. • p28 is redistributed by disrupting distinct steps of endocytosis. • Combining p28 with a redistribution-inducing inhibitor enhances its anticancer efficacy.

Source: Journal of Controlled Release

DOI: 10.1016/j.jconrel.2025.113660