Cancer Cell Membrane-Coated Gambogic Acid Nanoparticles for Effective Anticancer Vaccination by Activating Dendritic Cells

Endoplasmic reticulum-targeted biomimetic nanoparticles induce apoptosis and ferroptosis by regulating endoplasmic reticulum function in colon cancer

Colorectal cancer (CRC) is a major threat to human health, as it is one of the most common malignancies with a high incidence and mortality rate. The cancer cell membrane (CCM) has significant potential in targeted tumor drug delivery due to its membrane antigen-mediated homologous targeting ability. The endoplasmic reticulum (ER) in cancer cells plays a crucial role in apoptosis and ferroptosis. In this study, we developed an ER-targeted peptide-modified CCM-biomimetic nanoparticle-delivered lovastatin (LOV) nanomedicine delivery system (EMPP-LOV) for cancer treatment. Both in vitro and in vivo experiments demonstrated that EMPP could effectively target cancer cells and localize within the ER. EMPP-LOV modulated ER function to promote apoptosis and ferroptosis in tumor cells. Furthermore, synergistic antitumor efficacy was observed in both in vitro and in vivo models. EMPP-LOV induced apoptosis in CRC cells by over-activating endoplasmic reticulum stress and promoted ferroptosis by inhibiting the mevalonate pathway, leading to synergistic tumor growth inhibition with minimal toxicity to major organs. Overall, the EMPP-LOV delivery system, with its subcellular targeting capability within tumor cells, presents a promising therapeutic platform for CRC treatment.

Neogambogic acid enhances anti-PD-1 immunotherapy efficacy by attenuating suppressive function of MDSCs in pancreatic cancer

BACKGROUND

Anti-PD-1-based immunotherapy has limited benefits in patients with pancreatic cancer. Accumulating data indicate that natural products exert antitumor activity by remodeling the tumor immune microenvironment. It has been reported that neogambogic acid (NGA), an active natural monomer extracted from Garcinia, has anti-inflammatory and antitumor effects. Nevertheless, there are few systematic studies on the antitumor efficacy and immunomodulatory effects of NGA in pancreatic cancer.

METHODS

An orthotopic mouse model of pancreatic cancer was established and were treated with different doses of NGA. Tumor growth and ascites were observed. Flow cytometry and immunohistochemistry (IHC) were used to investigate the tumor immune microenvironment. CD11b+ MDSCs were infused back into mice with pancreatic cancer to observe tumor progression after NGA treatment. Bone marrow cells were induced to differentiate into MDSCs, and the effects of NGA on MDSCs were analyzed and the underlying mechanism was explored. The effects of NGA combined with an anti-PD-1 antibody on pancreatic cancer were further tested.

RESULTS

NGA significantly inhibited the tumor growth and improve ascites character in pancreatic cancer model mice. Flow cytometry and IHC analysis revealed that NGA decreased the MDSCs proportion and infiltration in the tumor microenvironment. Moreover, adoptive MDSCs largely attenuated the inhibitory effect of NGA on the progression of pancreatic cancer. In addition, we showed that NGA significantly promoted apoptosis and inhibited the differentiation, migration and immunosuppressive function of MDSCs and decreased level of STAT3 and p-STAT3. Furthermore, we demonstrated that NGA synergistically enhanced the efficacy of anti-PD-1 antibodies against pancreatic cancer.

CONCLUSION

NGA inhibited the progression of pancreatic cancer by inhibiting MDSCs in the tumor microenvironment, and enhanced the efficacy of anti-PD-1 therapy in the treatment of pancreatic cancer.

Novel Strategies for Tumor Treatment: Harnessing ROS-Inducing Active Ingredients from Traditional Chinese Medicine Through Multifunctional Nanoformulations

Reactive oxygen species (ROS) encompass a diverse group of chemically reactive molecules or ions distinguished by their substantial oxidative potential. Empirical studies have shown that the targeted administration of high toxic concentrations of ROS can effectively induce tumor cell death in various types. Numerous bioactive ingredients derived from traditional Chinese medicine (TCM), recognized for their ROS-inducing properties, have demonstrated significant anti-tumor activity. Nonetheless, their clinical application has been hindered by challenges such as low solubility, limited bioavailability, and poor selectivity. Multifunctional nanoformulations possess the potential to overcome these challenges and enhance the anticancer efficacy of ROS-inducing active compounds. Through extensive searches of various academic databases and a thorough review and screening of relevant literature, this study aims to systematically summarize and generalize multiple active ingredients in TCM that induce ROS generation, along with their multifunctional nanoformulations, from various perspectives. The objective is to provide new insights and references for fundamental cancer research and clinical treatments. Furthermore, we acknowledge that although numerous active ingredients and their nanoformulations in TCM have demonstrated ROS-inducing and anti-tumor potentials, potentially offering novel strategies for tumor therapy, the underlying mechanisms require further comprehensive investigation.

Robust anti-tumor immunity through the integration of targeted lipid nanoparticle-based mRNA nanovaccines with PD-1/PD-L1 blockade

Tumor mRNA vaccines present a personalized approach in cancer immunotherapy, encoding distinct tumor antigens to evoke robust immune responses and offering the potential against emerging tumor variants. Despite this, the clinical advancement of tumor mRNA vaccines has been hampered by their limited delivery capacity and inefficient activation of antigen-presenting cells (APCs). Herein, we employed microfluidics technology to engineer mannose-modified lipid-based nanovaccines for specifically targeting APCs. The encapsulation process efficiently entrapped the cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) agonist along with mRNA encoding antigens. The targeted nanovaccines (TNVs) exhibited a narrow particle size distribution, ensuring consistent and efficient delivery. These TNVs significantly enhanced gene expression of mRNA, facilitating antigen presentation and immune activation. When compared to non-targeted nanovaccines, TNVs outperformed in terms of antigen presentation and immune activation. Furthermore, the combination of anti-PD-L1 antibodies with TNVs elicited a synergistic anti-tumor effect. This was attributed to the anti-PD-L1 antibodies' ability to overcome the immune suppression of tumor cells. Our findings suggest that the combination treatment elicited the most robust anti-tumor immune activation and immune memory effect. These results indicate that integrating tumor mRNA vaccines with immune checkpoint inhibitors or other immunostimulatory agents may be crucial for enhancing the immune response.

Engineered Cell Membrane-Coated Nanoparticles: New Strategies in Glioma Targeted Therapy and Immune Modulation

Gliomas, the most prevalent primary brain tumors, pose considerable challenges due to their heterogeneity, intricate tumor microenvironment (TME), and blood-brain barrier (BBB), which restrict the effectiveness of traditional treatments like surgery and chemotherapy. This review provides an overview of engineered cell membrane technologies in glioma therapy, with a specific emphasis on targeted drug delivery and modulation of the immune microenvironment. This study investigates the progress in engineered cell membranes, encompassing physical, chemical, and genetic alterations, to improve drug delivery across the BBB and effectively target gliomas. The examination focuses on the interaction of engineered cell membrane-coated nanoparticles (ECM-NPs) with the TME in gliomas, emphasizing their potential to modulate glioma cell behavior and TME to enhance therapeutic efficacy. The review further explores the involvement of ECM-NPs in immunomodulation techniques, highlighting their impact on immune reactions. While facing obstacles related to membrane stability and manufacturing scalability, the review outlines forthcoming research directions focused on enhancing membrane performance. This review underscores the promise of ECM-NPs in surpassing conventional therapeutic constraints, proposing novel approaches for efficacious glioma treatment.

Progress in the Regulation of Immune Cells in the Tumor Microenvironment by Bioactive Compounds of Traditional Chinese Medicine

The tumor microenvironment (TME) can aid tumor cells in evading surveillance and clearance by immune cells, creating an internal environment conducive to tumor cell growth. Consequently, there is a growing focus on researching anti-tumor immunity through the regulation of immune cells within the TME. Various bioactive compounds in traditional Chinese medicine (TCM) are known to alter the immune balance by modulating the activity of immune cells in the TME. In turn, this enhances the body's immune response, thus promoting the effective elimination of tumor cells. This study aims to consolidate recent findings on the regulatory effects of bioactive compounds from TCM on immune cells within the TME. The bioactive compounds of TCM regulate the TME by modulating macrophages, dendritic cells, natural killer cells and T lymphocytes and their immune checkpoints. TCM has a long history of having been used in clinical practice in China. Chinese medicine contains various chemical constituents, including alkaloids, polysaccharides, saponins and flavonoids. These components activate various immune cells, thereby improving systemic functions and maintaining overall health. In this review, recent progress in relation to bioactive compounds derived from TCM will be covered, including TCM alkaloids, polysaccharides, saponins and flavonoids. This study provides a basis for further in-depth research and development in the field of anti-tumor immunomodulation using bioactive compounds from TCM.

Cell membrane coated nanoparticles as a biomimetic drug delivery platform for enhancing cancer immunotherapy

Cancer immunotherapy, a burgeoning modality for cancer treatment, operates by activating the autoimmune system to impede the growth of malignant cells. Although numerous immunotherapy strategies have been employed in clinical cancer therapy, the resistance of cancer cells to immunotherapeutic medications and other apprehensions impede the attainment of sustained advantages for most patients. Recent advancements in nanotechnology for drug delivery hold promise in augmenting the efficacy of immunotherapy. However, the efficacy is currently constrained by the inadequate specificity of delivery, low rate of response, and the intricate immunosuppressive tumor microenvironment. In this context, the investigation of cell membrane coated nanoparticles (CMNPs) has revealed their ability to perform targeted delivery, immune evasion, controlled release, and immunomodulation. By combining the advantageous features of natural cell membranes and nanoparticles, CMNPs have demonstrated their unique potential in the realm of cancer immunotherapy. This review aims to emphasize recent research progress and elucidate the underlying mechanisms of CMNPs as an innovative drug delivery platform for enhancing cancer immunotherapy. Additionally, it provides a comprehensive overview of the current immunotherapeutic strategies involving different cell membrane types of CMNPs, with the intention of further exploration and optimization.

Mammalian Cell Membrane Hybrid Polymersomes for mRNA Delivery

Cell membranes are structures essential to the cell function and adaptation. Recent studies have targeted cell membranes to identify their protective and interactive properties. Leveraging these attributes of cellular membranes and their application to vaccine delivery is gaining increasing prominence. This study aimed to fuse synthetic polymeric nanoparticles with cell membranes to develop cell membrane hybrid polymersomes (HyPSomes) for enhanced vaccine delivery. We designed a platform to hybridize cell membranes with methoxy-poly(ethylene glycol)-block-polylactic acid nanoparticles by using the properties of both components. The formed HyPSomes were optimized by using dynamic light scattering, transmission electron microscopy, and Förster resonance energy transfer, and their stability was confirmed. The synthesized HyPSomes replicated the antigenic surface of the source cells and possessed the stability and efficacy of synthetic nanoparticles. These HyPSomes demonstrated enhanced cellular uptake and translation efficiency and facilitated endosome escape. HyPSomes showed outstanding capabilities for the delivery of foreign mRNAs to antigen-presenting cells. HyPSomes may serve as vaccine delivery systems by bridging the gap between synthetic and natural systems. These systems could be used in other contexts, e.g., diagnostics and drug delivery.

The future of cancer vaccines against colorectal cancer

INTRODUCTION

Colorectal cancer (CRC) is the second most lethal malignancy worldwide. Immune checkpoint inhibitors (ICIs) benefit only 15% of patients with mismatch repair-deficient/microsatellite instability (dMMR/MSI) CRC. The majority of patients are not suitable due to insufficient immune infiltration. Cancer vaccines are a potential approach for inducing tumor-specific immunity within the solid tumor microenvironment.

AREA COVERED

In this review, we have provided an overview of the current progress in CRC vaccines over the past three years and briefly depict promising directions for further exploration.

EXPERT OPINION

Cancer vaccines are certainly a promising field for the antitumor treatment against CRC. Compared to monotherapy, cancer vaccines are more appropriate as adjuvants to standard treatment, especially in combination with ICI blockade, for microsatellite stable patients. Improved vaccine construction requires neoantigens with sufficient immunogenicity, satisfactory HLA-binding affinity, and an ideal delivery platform with perfect lymph node retention and minimal off-target effects. Prophylactic vaccines that potentially prevent CRC carcinogenesis are also worth investigating. The exploration of appropriate biomarkers for cancer vaccines may benefit prognostic prediction analysis and therapeutic response prediction in patients with CRC. Although many challenges remain, CRC vaccines represent an exciting area of research that may become an effective addition to current guidelines.

Nanomaterial Delivery Vehicles for the Development of Neoantigen Tumor Vaccines for Personalized Treatment

Tumor vaccines have been considered a promising therapeutic approach for treating cancer in recent years. With the development of sequencing technologies, tumor vaccines based on neoantigens or genomes specifically expressed in tumor cells, mainly in the form of peptides, nucleic acids, and dendritic cells, are beginning to receive widespread attention. Therefore, in this review, we have introduced different forms of neoantigen vaccines and discussed the development of these vaccines in treating cancer. Furthermore, neoantigen vaccines are influenced by factors such as antigen stability, weak immunogenicity, and biosafety in addition to sequencing technology. Hence, the biological nanomaterials, polymeric nanomaterials, inorganic nanomaterials, etc., used as vaccine carriers are principally summarized here, which may contribute to the design of neoantigen vaccines for improved stability and better efficacy.

The role of dendritic cells in cancer immunity and therapeutic strategies

Dendritic cells (DCs) are asserted as the most potent antigen-presenting cells (APCs) that orchestrate both innate and adaptive immunity, being extremely effective in the induction of robust anti-cancer T cell responses. Hence, the modulation of DCs function represents an attractive target for improving cancer immunotherapy efficacy. A better understanding of the immunobiology of DCs, the interaction among DCs, immune effector cells and tumor cells in tumor microenvironment (TME) and the latest advances in biomedical engineering technology would be required for the design of optimal DC-based immunotherapy. In this review, we focus on elaborating the immunobiology of DCs in healthy and cancer environments, the recent advances in the development of enhancing endogenous DCs immunocompetence via immunomodulators as well as DC-based vaccines. The rapidly developing field of applying nanotechnology to improve DC-based immunotherapy is also highlighted.

Emerging tendencies for the nano-delivery of gambogic acid: a promising approach in oncotherapy

Despite the advancements in cancer therapies during the past few years, chemo/photo resistance, severe toxic effects, recurrence of metastatic tumors, and non-selective targeting remain incomprehensible. Thus, much effort has been spent exploring natural anticancer compounds endowed with biosafety and high effectiveness in cancer prevention and therapy. Gambogic acid (GA) is a promising natural compound in cancer therapy. It is the major xanthone component of the dry resin extracted from the Garcinia hanburyi Hook. f. tree. GA has significant antiproliferative effects on different types of cancer, and it exerts its anticancer activities through various pathways. Nonetheless, the clinical translation of GA has been hampered, partly due to its water insolubility, low bioavailability, poor pharmacokinetics, rapid plasma clearance, early degradation in blood circulation, and detrimental vascular irritation. Lately, procedures have been invented demonstrating the ability of nanoparticles to overcome the challenges associated with the clinical use of natural compounds both in vitro and in vivo. This review sheds light on the recent emerging trends for the nanodelivery of GA to cancer cells. To the best of our knowledge, no similar recent review described the different nanoformulations designed to improve the anticancer therapeutic activity and targeting ability of GA.

Autophagy/ferroptosis in colorectal cancer: Carcinogenic view and nanoparticle-mediated cell death regulation

The cell death mechanisms have a long history of being evaluated in diseases and pathological events. The ability of triggering cell death is considered to be a promising strategy in cancer therapy, but some mechanisms have dual functions in cancer, requiring more elucidation of underlying factors. Colorectal cancer (CRC) is a disease and malignant condition of colon and rectal that causes high mortality and morbidity. The autophagy targeting in CRC is therapeutic importance and this cell death mechanism can interact with apoptosis in inhibiting or increasing apoptosis. Autophagy has interaction with ferroptosis as another cell death pathway in CRC and can accelerate ferroptosis in suppressing growth and invasion. The dysregulation of autophagy affects the drug resistance in CRC and pro-survival autophagy can induce drug resistance. Therefore, inhibition of protective autophagy enhances chemosensitivity in CRC cells. Moreover, autophagy displays interaction with metastasis and EMT as a potent regulator of invasion in CRC cells. The same is true for ferroptosis, but the difference is that function of ferroptosis is determined and it can reduce viability. The lack of ferroptosis can cause development of chemoresistance in CRC cells and this cell death mechanism is regulated by various pathways and mechanisms that autophagy is among them. Therefore, current review paper provides a state-of-art analysis of autophagy, ferroptosis and their crosstalk in CRC. The nanoparticle-mediated regulation of cell death mechanisms in CRC causes changes in progression. The stimulation of ferroptosis and control of autophagy (induction or inhibition) by nanoparticles can impair CRC progression. The engineering part of nanoparticle synthesis to control autophagy and ferroptosis in CRC still requires more attention.