Hesperidin PLGA nanoparticles potentiate the efficacy of aPD-1 in treating triple negative breast cancer by regulating CCL2 and ADPN expression in cancer-associated adipocytes

Triple negative breast cancer (TNBC) represents a heterogeneous subtype of breast cancer characterized by an unfavorable prognosis due to its aggressive biology. Cancer-associated adipocytes (CAAs) play an active role in tumor development, invasion and metastasis, and response to treatment by secreting various cytokines. CAAs secrete CCL2 and ADPN which significantly affect the efficacy of aPD-1 in treating breast cancer. Our recent research has demonstrated that Hesperidin, a natural phenolic compound, significantly inhibits CCL2, elevates ADPN secreted by CAAs in vitro and in vivo, remodels the immune microenvironment, and potentiates the efficacy of aPD-1 in triple-negative breast cancer. We used Oil red staining, Bodipy 493/503 staining and quantitative real-time PCR to verify the formation of CAAs. ELISA was used to detect levels of CCL2, ADPN secreted by CAAs. Changes in the number of immune cells in mouse tumor tissues were detected using flow cytometry and immunofluorescence. Our data suggest that Hesperidin PLGA nanoparticles significantly reduced CCL2 and increased ADPN secreted by CAAs, which concurrently decreased the recruitment of M2 macrophages, Tregs and MDSCs while increased the infiltration of CD8