Layered double hydroxide-loaded si-NEAT1 regulates paclitaxel resistance and tumor-associated macrophage polarization in breast cancer by targeting miR-133b/PD-L1

ZHANG Zhaojun; WU Qiong; XIE Miaomiao; YE Ruyin; GENG Chenchen; SHI Jiwen; YANG Qingling; WANG Wenrui; SHI Yurong

doi:10.12122/j.issn.1673-4254.2025.08.16

Abstract：Objective To study the molecular mechanisms of LDH-loaded si-NEAT1 for regulating paclitaxel resistance and tumor-associated macrophage(TAM)polarization in breast cancer.Methods qRT-PCR and Western blotting were used to detect the expression of lncRNA NEAT1,miR-133b,and PD-L1 in breast cancer SKBR3 cells and paclitaxel-resistant SKBR3 cells(SKBR3-PR).The effects of transfection with si-NEAT1 and miR-133b mimics on MRP,MCRP and PD-L1 expressions and cell proliferation,migration and apoptosis were investigated using qRT-PCR,Western blotting,scratch and Transwell assays,and flow cytometry.Rescue experiments were conducted using si-NEAT1 and miR-133b inhibitor.Human THP-1 macrophages were cultured in the presence of conditioned media(CM)derived from SKBR3 and SKBR3-PR cells with or with si-NEAT1 transfection for comparison of IL-4-induced macrophage polarization by detecting the surface markers.LDH@si-NEAT1 nanocarriers were constructed,and their effects on MRP,MCRP and PD-L1 expressions and cell behaviors of the tumor cells were examined.THP-1 cells were treated with the CM from LDH@si-NEAT1-treated tumor cells,and the changes in their polarization were assessed.Results SKBR3-PR cells showered significantly upregulated NEAT1 and PD-L1 expressions and lowered miR-133b expression as compared with their parental cells.Transfection with si-NEAT1 and miR-133b mimics inhibited viability,promoted apoptosis and enhanced MRP and BCRP expressions in SKBR3-PR cells.NEAT1 knockdown obvious upregulated miR-133b and downregulated PD-L1,MRP and BCRP expressions.The CM from SKBR3-PR cells obviously promoted M2 polarization of THP-1 macrophages,which was significantly inhibited by CM from si-NEAT1-transfected cells.Treatment with LDH@si-NEAT1 effectively inhibited migration and invasion,promoted apoptosis,and reduced MRP,BCRP and PD-L1 expressions in the tumor cells.The CM from LDH@si-NEAT1-treated SKBR3-PR cells significantly downregulated Arg-1,CD163,IL-10,and PD-L1 and upregulated miR-133b expression in THP-1 macrophages.Conclusion LDH@si-NEAT1 reduces paclitaxel resistance of breast cancer cells and inhibits TAM polarization by targeting the miR-133b/PD-L1 axis.