Nanoparticles Loaded with Wnt and YAP/Mevalonate Inhibitors in Combination with Paclitaxel Stop the Growth of TNBC Patient‐Derived Xenografts and Diminish Tumorigenesis

Nanoparticle-Mediated mRNA Delivery to Triple-Negative Breast Cancer (TNBC) Patient-Derived Xenograft (PDX) Tumors

mRNA-based therapies can overcome several challenges faced by traditional therapies in treating a variety of diseases by selectively modulating genes and proteins without genomic integration. However, due to mRNA's poor stability and inherent limitations, nanoparticle (NP) platforms have been developed to deliver functional mRNA into cells. In cancer treatment, mRNA technology has multiple applications, such as restoration of tumor suppressors and activating antitumor immunity. Most of these applications have been evaluated using simple cell-line-based tumor models, which failed to represent the complexity, heterogeneity, and 3D architecture of patient tumors. This discrepancy has led to inconsistencies and failures in clinical translation. Compared to cell line models, patient-derived xenograft (PDX) models more accurately represent patient tumors and are better suitable for modeling. Therefore, for the first time, this study employed two different TNBC PDX tumors to examine the effects of the mRNA-NPs. mRNA-NPs are developed using EGFP-mRNA as a model and studied in TNBC cell lines, ex vivo TNBC PDX organotypic slice cultures, and in vivo TNBC PDX tumors. Our findings show that NPs can effectively accumulate in tumors after intravenous administration, protecting and delivering mRNA to PDX tumors with different genetic and chemosensitivity backgrounds. These studies offer more clinically relevant modeling systems for mRNA nanotherapies in cancer applications.

Nanoparticles Codelivering mRNA and SiRNA for Simultaneous Restoration and Silencing of Gene/Protein Expression In Vitro and In Vivo

RNA-based agents (siRNA, miRNA, and mRNA) can selectively manipulate gene expression/proteins and are set to revolutionize a variety of disease treatments. Nanoparticle (NP) platforms have been developed to deliver functional mRNA or siRNA inside cells to overcome their inherent limitations. Recent studies have focused on siRNA to knock down proteins causing drug resistance or mRNA technology to introduce tumor suppressors. However, cancer needs multitargeted approaches to selectively manipulate multiple gene expressions/proteins. In this proof-of-concept study, we developed NPs containing Luc-mRNA and siRNA-GFP as model agents ((M+S)-NPs) and showed that NPs can simultaneously deliver functional mRNA and siRNA and impact the expression of two genes/proteins in vitro. Additionally, after in vivo administration, (M+S)-NPs successfully knocked down GFP while introducing luciferase into a TNBC mouse model, indicating that our NPs have the potential to develop RNA-based anticancer therapeutics. These studies pave the way to develop RNA-based, multitargeted approaches for complex diseases like cancer.

Development of Pro-resolving and Pro-efferocytic Nanoparticles for Atherosclerosis Therapy

Atherosclerosis is a major contributor to cardiovascular diseases with a high global prevalence. It is characterized by the formation of lipid-laden plaques in the arteries, which eventually lead to plaque rupture and thrombosis. While the current lipid-lowering therapies are generally effective in lowering the risk of cardiovascular events, they do not address the underlying causes of disease. Defective resolution of inflammation and impaired efferocytosis are the main driving forces of atherosclerosis. Macrophages recognize cells for clearance by the expression of "eat me" and "do not eat me" signals, including the CD47-SIRPα axis. However, the "do not eat me" signal CD47 is overexpressed in atherosclerotic plaques, leading to compromised efferocytosis and secondary necrosis. In this context, prophagocytic antibodies have been explored to stimulate the clearance of apoptotic cells, but they are nonspecific and impact healthy tissues. In macrophages, downstream of signal regulatory protein α, lie protein tyrosine phosphatases, SHP 1/2, which can serve as effective targets for selectively phagocytosing apoptotic cells. While increasing the efferocytosis targets the end stages of lesion development, the underlying issue of inflammation still persists. Simultaneously increasing efferocytosis and reducing inflammation can be effective therapeutic strategies for managing atherosclerosis. For instance, IL-10 is a key anti-inflammatory mediator that enhances efferocytosis via phosphoSTAT3 (pSTAT3) activation. In this study, we developed a combination nanotherapy by encapsulating an SHP-1 inhibitor (NSC 87877) and IL-10 in a single nanoparticle platform [(S + IL)-NPs] to enhance efferocytosis and inflammation resolution. Our studies suggest that (S + IL)-NPs successfully encapsulated both agents, entered the macrophages, and delivered the agents into intracellular compartments. Additionally, (S + IL)-NPs decreased inflammation by suppressing pro-inflammatory markers and enhancing anti-inflammatory mediators. They also exhibited the potential for improved phagocytic activity via pSTAT3 activation. Our nanomedicine-mediated upregulation of the anti-inflammatory and efferocytic responses in macrophages shows promise for the treatment of atherosclerosis.

Clinically Translatable Approaches of Inhibiting TGF-β to Target Cancer Stem Cells in TNBC

Triple-negative breast cancer (TNBC) is a subtype of breast cancer that disproportionally accounts for the majority of breast cancer-related deaths due to the lack of specific targets for effective treatments. In this review, we highlight the complexity of the transforming growth factor-beta family (TGF-β) pathway and discuss how the dysregulation of the TGF-β pathway promotes oncogenic attributes in TNBC, which negatively affects patient prognosis. Moreover, we discuss recent findings highlighting TGF-β inhibition as a potent method to target mesenchymal (CD44⁺/CD24^-) and epithelial (ALDH^high) cancer stem cell (CSC) populations. CSCs are associated with tumorigenesis, metastasis, relapse, resistance, and diminished patient prognosis; however, due to differential signal pathway enrichment and plasticity, these populations remain difficult to target and persist as a major barrier barring successful therapy. This review highlights the importance of TGF-β as a driver of chemoresistance, radioresistance and reduced patient prognosis in breast cancer and highlights novel treatment strategies which modulate TGF-β, impede cancer progression and reduce the rate of resistance generation via targeting the CSC populations in TNBC and thus reducing tumorigenicity. Potential TGF-β inhibitors targeting based on clinical trials are summarized for further investigation, which may lead to the development of novel therapies to improve TNBC patient prognosis.