Cascade Downregulation of the HER Family by a Dual-Targeted Recombinant Protein-Drug Conjugate to Inhibit Tumor Growth and Metastasis

A Multifunctional Bimetallic Nanoplatform for Synergic Local Hyperthermia and Chemotherapy Targeting HER2-Positive Breast Cancer

Anti-HER2 (human epidermal growth factor receptor 2) therapies significantly increase the overall survival of patients with HER2-positive breast cancer. Unfortunately, a large fraction of patients may develop primary or acquired resistance. Further, a multidrug combination used to prevent this in the clinic places a significant burden on patients. To address this issue, this work develops a nanotherapeutic platform that incorporates bimetallic gold-silver hollow nanoshells (AuAg HNSs) with exceptional near-infrared (NIR) absorption capability, the small-molecule tyrosine kinase inhibitor pyrotinib (PYR), and Herceptin (HCT). This platform realizes targeted delivery of multiple therapeutic effects, including chemo-and photothermal activities, oxidative stress, and immune response. In vitro assays reveal that the HCT-modified nanoparticles exhibit specific recognition ability and effective internalization by cells. The released PYR inhibit cell proliferation by downregulating HER2 and its associated pathways. NIR laser application induces a photothermal effect and tumor cell apoptosis, whereas an intracellular reactive oxygen species burst amplifies oxidative stress and triggers cancer cell ferroptosis. Importantly, this multimodal therapy also promotes the upregulation of genes related to TNF and NF-κB signaling pathways, enhancing immune activation and immunogenic cell death. In vivo studies confirm a significant reduction in tumor volume after treatment, substantiating the potential effectiveness of these nanocarriers.

OX40L-expressing M1-like macrophage exosomes for cancer immunotherapy

With only limited clinical patient benefit, focusing on new immune checkpoint pathways could be an important complement to current immune checkpoint drugs. In addition, not only does T cell-mediated adaptive immunity play an important role, but also macrophage-mediated innate immunity, due to its abundant presence in solid tumors. Here, we developed an engineered M1-like macrophage exosome, OX40L M1-exos. OX40L M1-exos can activate the adaptive immunity by activating the OX40/OX40L pathway and can reprogram M2-like tumor-associated macrophages into M1-like macrophages, thereby restoring and enhancing macrophage-mediated innate immunity. Our OX40L M1-exos achieved an effective synergistic effect of innate and adaptive immunity and achieved a potent therapeutic effect in a mouse breast cancer model, effectively inhibiting tumor growth and metastasis. These results suggest that OX40L M1-exos are an attractive therapeutic strategy and may be an important complement to current cancer immunotherapies.

Extracellular Vesicles Facilitate the Transportation of Nanoparticles within and between Cells for Enhanced Tumor Therapy

The interaction between nanoparticles and cells is closely associated with the therapeutic effects of nanomedicine. Nanoparticles could be transported among cells, but the process-related mechanism remains to be further explored. In this study, it was found that endocytosed cationic polymer nanoparticles (cNPs) could be excreted in an extracellular vesicle (EV)-coated form (cNP@EVs). It was deduced that cNPs may pass through early endosomes, multivesicular bodies (MVBs), and autophagic MVBs within cells. Moreover, a high level of autophagy facilitated the exocytosis process. Since EVs were the effective vehicles for conveying biological information and substances, cNP@EVs were proved to be efficient forms for the intercellular transportation of nanoparticles and have the potential as efficient biomimetic drug delivery systems. These properties endowed cNP@EVs with deep penetration and enhanced antitumor activity. Our findings provided a proof-of-concept for understanding the transfer process of nanoparticles among cells and may help us to further utilize EV-mediated transportation of nanoparticles, therefore, expanding its clinical application.

Preclinical and Basic Research Strategies for Overcoming Resistance to Targeted Therapies in HER2-Positive Breast Cancer

The amplification of epidermal growth factor receptor 2 (HER2) is associated with a poor prognosis and HER2 gene is overexpressed in approximately 15-30% of breast cancers. In HER2-positive breast cancer patients, HER2-targeted therapies improved clinical outcomes and survival rates. However, drug resistance to anti-HER2 drugs is almost unavoidable, leaving some patients with an unmet need for better prognoses. Therefore, exploring strategies to delay or revert drug resistance is urgent. In recent years, new targets and regimens have emerged continuously. This review discusses the fundamental mechanisms of drug resistance in the targeted therapies of HER2-positive breast cancer and summarizes recent research progress in this field, including preclinical and basic research studies.

Self-intensified synergy of a versatile biomimetic nanozyme and doxorubicin on electrospun fibers to inhibit postsurgical tumor recurrence and metastasis

Tumor-positive resection margins after surgery can result in tumor recurrence and metastasis. Although adjuvant postoperative radiotherapy and chemotherapy have been adopted in clinical practice, they lack efficacy and result in unavoidable side effects. Herein, a self-intensified in-situ therapy approach using electrospun fibers loaded with a biomimetic nanozyme and doxorubicin (DOX) is developed. The fabricated PEG-coated zeolite imidazole framework-67 (PZIF67) is demonstrated as a versatile nanozyme triggering reactions in cancer cells based on endogenous H₂O₂ and •O₂^-. The PZIF67-generated •OH induces reactive oxygen species (ROS) overload, implementing chemodynamic therapy (CDT). The O₂ produced by PZIF67 inhibits the expression of hypoxia-up-regulated proteins, thereby suppressing tumor progression. PZIF67 also catalyzes the degradation of glutathione, further disturbing the intracellular redox homeostasis and enhancing CDT. Furthermore, the introduced DOX not only kills cancer cells individually, but also replenishes the continuously consumed substrates for PZIF67-catalyzed reactions. The PZIF67-weakened drug resistance strengthens the cytotoxicity of DOX. The combined application of PZIF67 and DOX also suppresses metastasis-associated genes. Both in vitro and in vivo results demonstrate that the self-intensified synergy of PZIF67 and DOX on electrospun fibers efficiently prevents postsurgical tumor recurrence and metastasis, offering a feasible therapeutic regimen for operable malignant tumors.

Protein-Caged Nanoparticles: A Promising Nanomedicine Against Cancer

Cancer is a severe threat to human wellness. A broad range of nanoparticles (NPs) have been developed to treat cancer. Given their safety profile, natural biomolecules such as protein-based NPs (PNPs) are promising substitutes for synthetic NPs that are currently used in drug delivery systems. In particular, PNPs have diverse characteristics and are monodisperse, chemically and genetically changeable, biodegradable, and biocompatible. To promote their application in clinical settings, PNPs must be precisely fabricated to fully exploit their advantages. This review highlights the different types of proteins that can be used to produce PNPs. Additionally, the recent applications of these nanomedicines and their therapeutic benefits against cancer are explored. Several future research directions that can facilitate the clinical application of PNPs are suggested.