Micellar paclitaxel boosts ICD and chemo-immunotherapy of metastatic triple negative breast cancer
Triple negative breast cancer (TNBC) with easy metastasis, “cold” tumor immune microenvironment, and lack of targeted therapy remains poorly prognosed. Chemo-immunotherapy deemed as a potential treatment for TNBC is however confronted by low TNBC selectivity, pronounced systemic toxicity, and limited immunogenic cell death (ICD) induction. Here, employing clinically validated ATN peptide as a ligand and reduction-sensitive biodegradable micelles as a vehicle we constructed α5β1 integrin-targeted micellar paclitaxel (ATN-MPTX) to elicit strong and selective ICD and chemo-immunotherapy of TNBC. ATN-MPTX exhibited evident targetability and prominent uptake in α5β1 integrin-positive 4 T1 cells and induced significantly stronger ICD than free PTX and non-targeted MPTX. The therapeutic studies in 4 T1 TNBC model demonstrated that ATN-MPTX caused superior tumor accumulation and treatment efficacy to all controls. Of note, ATN-MPTX plus nano-STING agonist further augmented the immunotherapeutic effects by increasing secretion of proinflammatory cytokines and CD4+ and CD8+ T cells in the tumor and spleen while reducing Treg, leading to significantly improved inhibition of 4 T1 primary tumor and more interestingly mitigated lung metastases. This strong and selective ICD induction of ATNMPTX renders it an interesting tool to enhance chemo-immunotherapy of TNBC.
X.Y. Qiu, Y. Qu, B.B. Guo, H. Zheng, F.H. Meng*, and Z.Y. Zhong*, Micellar paclitaxel boosts ICD and chemo-immunotherapy of metastatic triple negative breast cancer, J. Control. Release 2022, 341, 498-510.