M1 Macrophage-Derived Exosomes Loaded with Gemcitabine and Deferasirox against Chemoresistant Pancreatic Cancer

Fucoidan, as an immunostimulator promotes M1 macrophage differentiation and enhances the chemotherapeutic sensitivity of capecitabine in colon cancer

Chemotherapy resistance is one of the most critical challenges in colorectal cancer (CRC) treatment. The occurrence and development of chemotherapy resistance closely related to the tumor immune microenvironment (TIME). As the most important immunosuppressive immune cells infiltrating into the TIME, macrophages are essential for chemotherapy resistance in CRC treatment. In this study, we found that a kind of fucoidan (FPS1M) induced macrophages differentiation to the M1 phenotype, and this transformation promoted cancer cells apoptosis both in vitro and in vivo. TNFα is a key mediator of FPS1M-induced tumorcidal activity of macrophages. Mechanistically, as a stimulator of TLR4, FPS1M enhanced macrophages glycolysis and regulated macrophages differentiation to the M1 phenotype by the activation of TLR4 mediated PI3K/AKT/mTOR signaling axis. In addition, FPS1M improved the immunosuppressed tumor microenvironment by increasing the infiltration of M1 macrophages in tumor tissue, which was conducive to improving the sensitivity of tumor to chemotherapy. Collectively, our findings demonstrated that FPS1M has the great potential to be used in tumor immunotherapy. The results also suggested that the combination of FPS1M with capecitabine is an alternative therapy method for colon cancer.

Recent nanotechnology advancements to treat multidrug-resistance pancreatic cancer: Pre-clinical and clinical overview

Pancreatic cancer (PC) remains one of the most lethal and incurable forms of cancer and has a poor prognosis. One of the significant therapeutic challenges in PC is multidrug resistance (MDR), a phenomenon in which cancer cells develop resistance toward administered therapy. Development of novel therapeutic platforms that could overcome MDR in PC is crucial for improving therapeutic outcomes. Nanotechnology is emerging as a promising tool to enhance drug efficacy and minimize off-target responses via passive and/or active targeting mechanisms. Over the past decade, tremendous efforts have been made to utilize nanocarriers capable of targeting PC cells while minimizing off-target effects. In this review article, we first give an overview of PC and the major molecular mechanisms of MDR, and then we discuss recent advancements in the development of nanocarriers used to overcome PC drug resistance. In doing so, we explore the developmental stages of this research in both pre-clinical and clinical settings. Lastly, we discuss current challenges and gaps in the literature as well as potential future directions in the field.

Mannose-decorated ginsenoside Rb1 albumin nanoparticles for targeted anti-inflammatory therapy

Ginsenoside Rb1 is a potential anti-inflammatory natural molecule, but its therapeutic efficacy was tremendously hampered by the low solubility and non-targeted delivery. In this study, we innovatively developed a mannose (Man)-modified albumin bovine serum albumin carrier (Man-BSA) to overcome the previously mentioned dilemmas of Rb1. The constructed Man-BSA@Rb1 NPs could improve the solubility and increase the cellular uptake of Rb1, finally leading to the enhanced anti-inflammatory effects. The robust therapeutics of Man-BSA@Rb1 NPs were measured in terms of nitrite, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels, which might be achieved by potently inhibiting nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways in lipopolysaccharide (LPS)-induced Raw264.7 cells. Moreover, the therapeutic efficacy of Man-BSA@Rb1 NPs was further confirmed in the d-Gal/LPS-induced liver injury model. The results indicated that Man-BSA may offer a promising system to improve the anti-inflammatory therapy of Rb1.

Docetaxel-loaded M1 macrophage-derived exosomes for a safe and efficient chemoimmunotherapy of breast cancer

The conversion of tumor-promoting M2 macrophage phenotype to tumor-suppressing M1 macrophages is a promising therapeutic approach for cancer treatment. However, the tumor normally provides an abundance of M2 macrophage stimuli, which creates an M2 macrophage-dominant immunosuppressive microenvironment. In our study, docetaxel (DTX) as chemotherapeutic modularity was loaded into M1 macrophage-derived exosomes (M1-Exo) with M1 proinflammatory nature to establish DTX-M1-Exo drug delivery system. We found that DTX-M1-Exo induced naïve M0 macrophages to polarize to M1 phenotype, while failed to repolarize to M2 macrophages upon Interleukin 4 restimulation due to impaired mitochondrial function. This suggests that DTX-M1-Exo can achieve long-term robust M1 activation in immunosuppressive tumor microenvironment. The in vivo results further confirmed that DTX-M1-Exo has a beneficial effect on macrophage infiltration and activation in the tumor tissues. Thus, DTX-M1-Exo is a novel macrophage polarization strategy via combined chemotherapy and immunotherapy to achieve great antitumor therapeutic efficacy.

Immune-Cell-Derived Exosomes for Cancer Therapy

Exosomes are a type of extracellular vesicles secreted by cells in normal or pathological conditions for cell-cell communication. With immunomodulatory characteristics and potential therapeutic properties, immune-cell-derived exosomes play an important role in cancer therapy. They express various antigens on their surface, which can be employed for antigen presentation, immunological activation, and metabolic regulation, leading to the killing of cancerous cells. In addition, immune-cell-derived exosomes have received extensive attention as a drug delivery platform in effective antitumor therapy due to their excellent biocompatibility, low immunogenicity, and high loading capacity. In this review, the biological and therapeutic characteristics of immune-cell-derived exosomes are comprehensively outlined. The antitumor mechanism of exosomes secreted by immune cells, including macrophages, dendritic cells, T cells, B cells, and natural killer cells, are systematically summarized. Moreover, the applications of immune-cell-derived exosomes as nanocarriers to transport antitumor agents (chemotherapeutic drugs, genes, proteins, etc.) are discussed. More importantly, the existing challenges of immune-cell-derived exosomes are pointed out, and their antitumor potentials are also discussed.

Macrophage-Derived Small Extracellular Vesicles in Multiple Diseases: Biogenesis, Function, and Therapeutic Applications

Macrophages (Mφs), as immune cells, play a pivotal role against pathogens and many diseases, such as cancer, inflammation, cardiovascular diseases, orthopedic diseases, and metabolic disorders. In recent years, an increasing number of studies have shown that small extracellular vesicles (sEVs) derived from Mφs (M-sEVs) play important roles in these diseases, suggesting that Mφs carry out their physiological functions through sEVs. This paper reviews the mechanisms underlying M-sEVs production via different forms of polarization and their biological functions in multiple diseases. In addition, the prospects of M-sEVs in disease diagnosis and treatment are described.

Silver nanoclusters show advantages in macrophage tracing in vivo and modulation of anti-tumor immuno-microenvironment

Macrophage-based nanomedicine represents an emerging powerful strategy for cancer therapy. Unfortunately, some obstacles and challenges limit the translational applications of macrophage-mediated nanodrug delivery system. For instance, tracking and effective cell delivery for targeted tumor sites remain to be overcome, and controlling the states of macrophages is still rather difficult due to their plastic nature in response to external stimuli. To address these critical issues, here, we reported a novel type of silver nanoclusters (AgNCs) with excellent fluorescent intensity, especially long-lasting cell labeling stability after endocytosis by macrophages, indicating promising applications in tracking macrophage-based nanomedicine delivery. Our mechanistic investigations uncovered that these merits originate from the escape of AgNCs from lysosomal degradation within macrophages. In addition, the AgNCs would prime the M1-like polarization of macrophages (at least in part) through the toll-like receptor 4 signaling pathway. The engineered macrophages laden with AgNCs could be employed for lung metastasis breast cancer treatment, showing the effective targeting propensity to metastatic tumors, remarkable regulation of tumor immune microenvironment and inhibition of tumor growth. Collectively, AgNC-trained macrophages appear to be a promising strategy for tumor immune-microenvironment regulation, which might be generalized to a wider spectrum of cancer therapeutics.

Macrophage-Derived Extracellular Vesicles: A Promising Tool for Personalized Cancer Therapy

The incidence of cancer is increasing dramatically, affecting all ages of the population and reaching an ever higher worldwide mortality rate. The lack of therapies' efficacy is due to several factors such as a delay in diagnosis, tumor regrowth after surgical resection and the occurrence of multidrug resistance (MDR). Tumor-associated immune cells and the tumor microenvironment (TME) deeply affect the tumor's progression, leading to several physicochemical changes compared to physiological conditions. In this scenario, macrophages play a crucial role, participating both in tumor suppression or progression based on the polarization of onco-suppressive M1 or pro-oncogenic M2 phenotypes. Moreover, much evidence supports the pivotal role of macrophage-derived extracellular vesicles (EVs) as mediators in TME, because of their ability to shuttle the cell-cell and organ-cell communications, by delivering nucleic acids and proteins. EVs are lipid-based nanosystems with a broad size range distribution, which reflect a similar composition of native parent cells, thus providing a natural selectivity towards target sites. In this review, we discuss the impact of macrophage-derived EVs in the cancer's fate as well as their potential implications for the development of personalized anticancer nanomedicine.

Ribonucleotide reductase M2 subunit silencing suppresses tumorigenesis in pancreatic cancer via inactivation of PI3K/AKT/mTOR pathway

BACKGROUND/OBJECTIVES

Ribonucleotide Reductase M2 subunit (RRM2) is elevated in pancreatic cancer and involved in DNA synthesis and cell proliferation. But its specific mechanism including genetic differences and upstream regulatory pathways remains unclear.

METHODS

We analyzed RRM2 expression of 178 pancreatic cancer patients in Gene Expression Profiling Interactive Analysis (GEPIA) database. Besides, more pancreatic cancer specimens were collected and detected RRM2 expression by immunohistochemistry. RRM2 knockdown by shRNA was applied for functional and mechanism analysis in vitro. Xenograft tumor growth was significantly slower by RRM2 silencing in vivo.

RESULTS

It showed that high RRM2 expression had a poorer overall survival and disease free survival. RRM2 expression was higher in tumor grade 2 and 3 than grade 1. Immunohistochemistry data validated that high RRM2 expression predicted worse survival. RRM2 knockdown significantly reduced cell proliferation, inhibited colony formation and suppressed cell cycle progress. Further mechanism assay showed silencing RRM2 lead to inactivation of PI3K/AKT/mTOR pathway and inhibition of mutant p53, which induce S phase arrest and/or apoptosis. In panc-1 cells, S-phase arrest mediated by mutant p53 inhibition, p21 increase and cell cycle related proteins change. While in miapaca-2 cells, induction of apoptosis and S-phase arrest mediated by CDK1 played a coordinated role.

CONCLUSION

Taken together, high RRM2 expression was associated with worse prognosis. Importantly, RRM2 knockdown deactivated PI3K/AKT/mTOR pathway, resulting in cell cycle arrest and/or apoptosis. This study shed light on the molecular mechanism of RRM2 in pancreatic tumor progression and is expected to provide a new theoretical basis for pancreatic cancer treatment.

Tumor-Derived Extracellular Vesicles Regulate Cancer Progression in the Tumor Microenvironment

Extracellular vesicles (EVs) are nanosized particles released by numerous kinds of cells, which are now increasingly considered as essential vehicles of cell-to-cell communication and biomarkers in disease diagnosis and treatment. They contain a variety of biomolecular components, including lipids, proteins and nucleic acids. These functional molecules can be transmitted between tumor cells and other stromal cells such as endothelial cells, fibroblasts and immune cells utilizing EVs. As a result, tumor-derived EVs can deliver molecules to remodel the tumor microenvironment, thereby influencing cancer progression. On the one hand, tumor-derived EVs reprogram functions of endothelial cells, promote cancer-associated fibroblasts transformation, induce resistance to therapy and inhibit the immune response to form a pro-tumorigenic environment. On the other hand, tumor-derived EVs stimulate the immune response to create an anti-tumoral environment. This article focuses on presenting a comprehensive and critical overview of the potential role of tumor-derived EVs-mediated communication in the tumor microenvironment.

Nanocarriers for pancreatic cancer imaging, treatments, and immunotherapies

Pancreatic tumors are highly desmoplastic and immunosuppressive. Delivery and distribution of drugs within pancreatic tumors are compromised due to intrinsic physical and biochemical stresses that lead to increased interstitial fluid pressure, vascular compression, and hypoxia. Immunotherapy-based approaches, including therapeutic vaccines, immune checkpoint inhibition, CAR-T cell therapy, and adoptive T cell therapies, are challenged by an immunosuppressive tumor microenvironment. Together, extensive fibrosis and immunosuppression present major challenges to developing treatments for pancreatic cancer. In this context, nanoparticles have been extensively studied as delivery platforms and adjuvants for cancer and other disease therapies. Recent advances in nanotechnology have led to the development of multiple nanocarrier-based formulations that not only improve drug delivery but also enhance immunotherapy-based approaches for pancreatic cancer. This review discusses and critically analyzes the novel nanoscale strategies that have been used for drug delivery and immunomodulation to improve treatment efficacy, including newly emerging immunotherapy-based approaches. This review also presents important perspectives on future research directions that will guide the rational design of novel and robust nanoscale platforms to treat pancreatic tumors, particularly with respect to targeted therapies and immunotherapies. These insights will inform the next generation of clinical treatments to help patients manage this debilitating disease and enhance survival rates.

Targeting Cancer Cell Tight Junctions Enhances PLGA-Based Photothermal Sensitizers' Performance In Vitro and In Vivo

The development of non-invasive photothermal therapy (PTT) methods utilizing nanoparticles as sensitizers is one of the most promising directions in modern oncology. Nanoparticles loaded with photothermal dyes are capable of delivering a sufficient amount of a therapeutic substance and releasing it with the desired kinetics in vivo. However, the effectiveness of oncotherapy methods, including PTT, is often limited due to poor penetration of sensitizers into the tumor, especially into solid tumors of epithelial origin characterized by tight cellular junctions. In this work, we synthesized 200 nm nanoparticles from the biocompatible copolymer of lactic and glycolic acid, PLGA, loaded with magnesium phthalocyanine, PLGA/Pht-Mg. The PLGA/Pht-Mg particles under the irradiation with NIR light (808 nm), heat the surrounding solution by 40 °C. The effectiveness of using such particles for cancer cells elimination was demonstrated in 2D culture in vitro and in our original 3D model with multicellular spheroids possessing tight cell contacts. It was shown that the mean inhibitory concentration of such nanoparticles upon light irradiation for 15 min worsens by more than an order of magnitude: IC50 increases from 3 µg/mL for 2D culture vs. 117 µg/mL for 3D culture. However, when using the JO-4 intercellular junction opener protein, which causes a short epithelial–mesenchymal transition and transiently opens intercellular junctions in epithelial cells, the efficiency of nanoparticles in 3D culture was comparable or even outperforming that for 2D (IC50 = 1.9 µg/mL with JO-4). Synergy in the co-administration of PTT nanosensitizers and JO-4 protein was found to retain in vivo using orthotopic tumors of BALB/c mice: we demonstrated that the efficiency in the delivery of such nanoparticles to the tumor is 2.5 times increased when PLGA/Pht-Mg nanoparticles are administered together with JO-4. Thus the targeting the tumor cell junctions can significantly increase the performance of PTT nanosensitizers.