Effects of Tumor Microenvironment Heterogeneity on Nanoparticle Disposition and Efficacy in Breast Cancer Tumor Models
Menée à l'aide de modèles murins de cancer du sein, cette étude met en évidence le rôle joué par l'hétérogénéité du micro-environnement tumoral dans l'efficacité clinique de nanoparticules chargées en doxorubicine
Purpose: Tumor cells are surrounded by a complex microenvironment. The purpose of our study was to evaluate the role of heterogeneity of the tumor microenvironment in the variability of nanoparticle (NP) delivery and efficacy. Experimental Design: C3(1)-T-Antigen genetically engineered mouse model (C3-TAg) and T11/TP53Null orthotopic syngeneic murine transplant model (T11) representing human breast tumor subtypes basal-like and claudin-low, respectively, were evaluated. For the pharmacokinetic studies, non-liposomal doxorubicin (NL-doxo) or polyethylene glycol tagged (PEGylated) liposomal doxorubicin (PLD) was administered at 6 mg/kg intravenously (IV) x1. Area-under-the concentration versus time curve (AUC) of doxorubicin was calculated. Macrophages, collagen, and the amount of vasculature were assessed by immunohistochemistry. Chemokines and cytokines were measured by multiplex immunochemistry. NL-doxo or PLD was administered at 6 mg/kg IV weekly x6 in efficacy studies. Analyses of intermediary tumor response and overall survival were performed. Results: Plasma AUC of NL-doxo and PLD encapsulated and released doxorubicin were similar between two models. However, tumor sum total AUC of PLD was 2-fold greater in C3-TAg compared with T11 (P<0.05). T11 tumors showed significantly higher expression of CC chemokine ligand (CCL) 2 and vascular endothelial growth factor (VEGF)-a, greater vascular quantity, and decreased expression of VEGF-c compared to C3-TAg (P<0.05). PLD was more efficacious compared to NL-doxo in both models. Conclusions: The tumor microenvironment and/or tumor cell features of breast cancer affected NP tumor delivery and efficacy, but not the small molecule drug. Our findings reveal the role of the tumor microenvironment in variability of NP delivery and therapeutic outcomes.