Lipid-based co-delivery system targeting proteasome and autophagy pathways in triple negative breast cancer

Triple-negative breast cancer (TNBC) is one of the most clinically challenging breast cancer subtypes, defined by the absence of estrogen receptor (ER), progesterone receptor (PR), and HER۲ expression. It accounts for ۱۵–۲۰% of all breast cancer diagnoses and is associated with early visceral metastasis, poor long-term prognosis, and an absence of approved targeted therapies. Its intrinsic resistance to chemotherapy is driven in part by dynamic interplay between the ubiquitin–proteasome system (UPS) and autophagy; proteasome inhibition by bortezomib (BTZ) induces proteotoxic stress, but cancer cells counteract this by upregulating autophagy as a compensatory protein clearance pathway, significantly limiting the durability of BTZ-induced apoptosis. To simultaneously disrupt both survival axes, hyaluronic acid (HA) functionalized liposomes were engineered for CD۴۴-targeted co-delivery of BTZ and chloroquine (CQ). HA was covalently conjugated to the phospholipid DSPE-PEG-NH۲ via EDC/NHS coupling, confirmed by FT-IR and ¹H-NMR, and integrated into preformed liposomes by post-insertion (incorporation efficiency ۹۱.۳۱ ± ۰.۷۰%). The optimized HA-Lip-BTZ-CQ formulation exhibited a mean particle diameter of ۱۶۱.۳۲ ± ۰.۹۵ nm, PDI ۰.۲۴, and zeta potential −۲۵.۷۵ ± ۰.۳۰ mV. Individual encapsulation efficiencies were ۷۸.۳۱% (BTZ) and ۸۲.۲۰% (CQ), with combined EE of ۸۷.۶۷ ± ۰.۳۶%. In vitro drug release was pH-responsive: ۳۶% at pH ۷.۲ and ۵۱% at pH ۵.۵ over ۵۰ hours, reflecting tumor microenvironment-triggered intracellular release. In MDA-MB-۲۳۱ TNBC cells, HA-Lip-BTZ-CQ demonstrated superior cytotoxicity (IC۵۰ ۲.۷۹ μM vs >۳ μM for non-targeted liposomes; p<۰.۰۰۰۱) and enhanced apoptotic induction through CD۴۴ receptor-mediated internalization. Apoptosis was confirmed as the predominant cell death mechanism across all treatment groups. These results establish HA-Lip-BTZ-CQ as a mechanistically integrated, tumor-selective nanoplatform capable of overcoming adaptive resistance in TNBC by dually disrupting proteasomal and autophagic proteostasis.

کلیدواژه ها:

bortezomib ، chloroquine ، Hyaluronic acid ، triple negative breast cancer Bortezomib ، Chloroquine ، ، yaluronic Acid ، Targeted Liposome ، triple negative breast cancer