Polymer lipid hybrid nanoparticles encapsulated with Emodin combined with DOX reverse multidrug resistance of breast cancer via IL-6/JAK2/STAT3 signaling pathway

Abstract

Multidrug resistance (MDR) is one of the main reasons affecting the efficacy of chemotherapy in breast cancer (BC). Our previous studies constructed polymer lipid hybrid nanoparticles encapsulated with Emodin (EMO) (E-PLNs) and proved that they can inhibit epithelial mesenchymal transition (EMT) and reverse MDR in BC. This study aims to explore the mechanisms by which the EMT involved in MDR and the E-PLNs exerted effects. The prepared E-PLNs were characterized by Dynamic light scattering, infrared spectroscopy, X-ray, and differential scanning calorimetry. The effects of drugs or treatments were evaluated by detecting cell viability, apoptosis, invasion, EMT markers, and MDR related proteins in vitro. The results showed that IL-6 could promote proliferation, EMT, invasion and MDR of MCF-7/ADR cells (induced from MCF-7 cells) by activating the JAK2/STAT3 signaling pathway, and these effects could be reversed by AG490 (JAK2 inhibitor) or E-PLNs combined with Doxorubicin (DOX). E-PLNs might be an effective MDR reversal agent for BC. Polymer lipid hybrid nanoparticles encapsulated with Emodin had good physical and chemical properties, improving the bioavailability and efficacy of Emodin. Compared with parental MCF-7 cells, MCF-7/ADR cells overexpressed markers of epithelial mesenchymal transition (EMT), and Galunisertib (EMT inhibitor) inhibited EMT and reversed MDR. Compared with parental MCF-7 cells, MCF-7/ADR cells secreted high level of IL-6. Exogenous IL-6 promoted proliferation, invasion, EMT, and MDR of MCF-7/ADR cells by activating the JAK2/STAT3 pathway. AG490 (JAK2 inhibitor) and/or E-PLNs combined with DOX downregulated the IL-6/JAK2/STAT3 pathway and inhibited its mediated proliferation, invasion, EMT, and MDR in MCF-7/ADR cells.