Mannosylated engineered trichosanthin-legumain protein vaccine hydrogel for breast cancer immunotherapy

Promising future of breast cancer vaccine asking for multidisciplinary collaboration: a literature review

Despite improved efficacy of breast cancer vaccine (BCV) made by multidisciplinary collaboration from fields such as materials science and computer science, clinical translation is still far from satisfactory. Herein, we reviewed the evolution trajectory of BCV and summarized the frontier topics and challenges for achieving successful clinical translation. Our analysis suggests that multi-omics and immunoinformatics are increasingly being used to expand target repertoires, and dedicated vaccine platforms are facilitating precise spatiotemporal co-delivery of epitopes and immune modulators. BCV has evolved towards precise delivery, strong immune properties, and combined therapy. Clinical translation requires the joint efforts of experts in clinical oncology, immunology, pharmacology, materials, and computer science.

Enzyme/pH-sensitive nanoparticles based on poly(β-L-malic acid) for drug delivery with enhanced endocytosis

Nanoparticles (NPs) derived from branched copolymers of poly (β-L-malic acid) (PMLA) have been extensively investigated for drug delivery due to their high density of pendant carboxyl groups. This abundant functional group availability enhances their potential as effective drug delivery systems; however, the strong negative charge of PMLA poses a challenge in its uptake by cancer cells due to electrostatic repulsion. In this study, we developed novel enzyme- and pH-sensitive nanoparticles (EP-NPs) based on PMLA, demonstrating tumor-specific behavior and selective activation within tumor tissues. To enhance the cellular internalization of the nanoparticles, we incorporated transactivator of transcription (TAT). In summary, long-chain polyethylene glycol (PEG) was conjugated to PMLA to confer specificity to the TAT peptide. This was achieved using a tetrapeptide linker: alanine-alanine-asparagine-leucine (AANL), which serves as a substrate for legumain. Legumain is a highly conserved cysteine protease primarily found in lysosomes and blood vessels, initially discovered in legumes. It is markedly overexpressed in numerous solid tumors, as well as in endothelial cells and tumor-associated macrophages. The release of doxorubicin in tumor cells was sustained due to the low pH (5.0-5.5) and degradation of PMLA. The PEG modification optimized the particle size and shielded the nanoparticles from plasma proteins and detection by the reticuloendothelial system, thereby prolonging their long circulation time. Once the nanoparticles reached the tumor microenvironment, the AANL was cleaved by legumain, exposing the TAT peptide on the surface, which enhances cellular internalization. Both in vitro and in vivo efficacy studies demonstrated that these EP-NPs significantly inhibited tumor growth while exhibiting negligible systemic toxicity, thereby suggesting that the developed enzyme/pH-sensitive PMLA-based nanoparticle holds great promise as an anti-tumor drug delivery system.

Trichosanthin elicits antitumor activity via MICU3 mediated mitochondria calcium influx

INTRODUCTION

Trichosanthin (TK) is a glycoprotein extracted from the Chinese medicinal herb Trichosanthes kirilowi, which has anti-virus and anti-tumor activity. However, the target and detailed mechanism of TK remains elusive.

OBJECTIVES

We aimed to identify novel antitumor targets of TK in lung adenocarcinoma and study its anti-tumor mechanism.

METHODS

We utilized a Lewis lung carcinoma mouse model to evaluate the inhibition of TK on tumor growth. CCK8 assay was utilized to calculate IC50 of trichosanthin on A549 and H1299. In-vitro cellular assays and in-vivo xenograft mice studies were used to investigate MICU3 overexpression and TK treatment on tumor growth. Fluo-4 dye and JC-1 staining was used to measure the mitochondrial calcium levels and membrane potential. H&E and immunohistochemistry staining were applied the asses the effect of TK on tumor and microenvironment. RNA sequencing was applied to analyze transcriptome changes in TK-treated and MICU3-overexpressed tumor cells. The influence of trichosanthin on DNMT3B expression and MICU3 methylation were detected by qPCR and Western blotting. Transcriptional activity of the MICU3 gene was measured by ChIP-PCR and luciferase assays.

RESULTS

Trichosanthin ihibited the tumor growth in vivo, resulting cancer cell growth inhibition and cell death, with almost no effect on normal cells. IC50 of trichosanthin in A549 and H1299 cells were 62.8 μg/ml and 39.7 μg/ml, respectively. Mitochondrial Calcium Uptake Family complex MICU3 was shown to associated with favorable prognosis and was upregulated upon trichosanthin treatment, along with reduces tumor cell growth and migration, and increased cell death both in vitro and in vivo. Increased mitochondrial calcium level was observed in MICU3 overexpression cells. Pathway analysis of RNA-seq data revealed that cytokine and receptor pathways were enriched in MICU3-overexpressing cells. Trichosanthin decreased DNMT3B expression and altered MICU3 methylation while increased FOSL2 expression and reduced methylation that correlated with increased transcription of the MICU3 gene.

CONCLUSION

Trichosanthin elicits antitumor activity in lung adenocarcinoma via repressing DNMT3B and increasing FOSL2, which in turn induces MICU3-mediated mitochondrial calcium influx and tumor cell death.

Aggregable gold nanoparticles for cancer photothermal therapy

Photothermal therapy (PTT) is an important non-invasive cancer treatment method. Enhancing the photothermal conversion efficiency (PCE) of photothermal agents (PTAs) and prolonging their tumor accumulation and retention are effective strategies to enhance the efficiency of cancer PTT. Recently, tremendous progress has been made in developing stimuli-responsive aggregable gold nanoparticles as effective PTAs for PTT. In this review, we discuss the chemical principles underlying gold nanoparticle aggregation and highlight the progress in gold nanoparticle aggregation triggered by different stimuli, especially tumor microenvironment-related factors, for cancer PTT. Covalent condensation reactions, click cycloaddition reactions, chelation reactions, and Au-S bonding, as well as non-covalent electrostatic interactions, hydrophobic interactions, hydrogen bonding, and van der Waals forces play key roles in the aggregation of gold nanoparticles. Enzymes, pH, reactive oxygen species, small molecules, salts, and light drive the occurrence of gold nanoparticle aggregation. Targeted aggregation of gold nanoparticles prolongs tumor accumulation and retention of PTAs and improves PCE, resulting in enhanced tumor PTT. Moreover, the major challenges of aggregable gold nanoparticles as PTAs are pointed out and the promising applications are also prospected at the end. With the deepening of research, we expect aggregable gold nanoparticles to become essential PTAs for tumor therapy.

Recent advancements of hydrogels in immunotherapy: Breast cancer treatment

Breast cancer is the most prevalent cancer among women and the leading cause of cancer-related deaths in this population. Recent advances in Immunotherapy, or combined immunotherapy, offering a more targeted and less toxic approach, expand the survival rate of patients more than conventional treatment. Notably, hydrogels, a versatile platform provided promising avenues to combat breast cancer in preclinical studies and extended to clinical practices. With advantages such as the alternation of tumor microenvironment, immunomodulation, targeted delivery of therapeutic agents, and their sustained release at specific sites of interest, hydrogels can potentially be used for the treatment of breast cancer. This review highlights the advantages, mechanisms of action, stimuli-responsiveness properties, and recent advancements of hydrogels for treating breast cancer immunotherapy. Moreover, post-treatment and its clinical translations are discussed in this review. The integration of hydrogels in immunotherapy strategies may pave the way for more effective, personalized, and patient-friendly approaches to combat breast cancer, ultimately contributing to a brighter future for breast cancer patients.

Engineering customized nanovaccines for enhanced cancer immunotherapy

Nanovaccines have gathered significant attention for their potential to elicit tumor-specific immunological responses. Despite notable progress in tumor immunotherapy, nanovaccines still encounter considerable challenges such as low delivery efficiency, limited targeting ability, and suboptimal efficacy. With an aim of addressing these issues, engineering customized nanovaccines through modification or functionalization has emerged as a promising approach. These tailored nanovaccines not only enhance antigen presentation, but also effectively modulate immunosuppression within the tumor microenvironment. Specifically, they are distinguished by their diverse sizes, shapes, charges, structures, and unique physicochemical properties, along with targeting ligands. These features of nanovaccines facilitate lymph node accumulation and activation/regulation of immune cells. This overview of bespoke nanovaccines underscores their potential in both prophylactic and therapeutic applications, offering insights into their future development and role in cancer immunotherapy.

Neoantigens and cancer-testis antigens as promising vaccine candidates for triple-negative breast cancer: Delivery strategies and clinical trials

Immunotherapy is gaining prominence as a promising strategy for treating triple-negative breast cancer (TNBC). Neoantigens (neoAgs) and cancer-testis antigens (CTAs) are tumor-specific targets originating from somatic mutations and epigenetic changes in cancer cells. These antigens hold great promise for personalized cancer vaccines, as supported by preclinical and early clinical evidence in TNBC. This review delves into the potential of neoAgs and CTAs as vaccine candidates, emphasizing diverse strategies and delivery approaches. It also highlights the current status of vaccination modalities undergoing clinical trials in TNBC therapy. A comprehensive understanding of neoAgs, CTAs, vaccination strategies, and innovative delivery methods is crucial for optimizing neoAg-based immunotherapies in clinical practice.

Tumor-Associated Macrophage Targeting of Nanomedicines in Cancer Therapy

The tumor microenvironment (TME) is pivotal in tumor growth and metastasis, aligning with the "Seed and Soil" theory. Within the TME, tumor-associated macrophages (TAMs) play a central role, profoundly influencing tumor progression. Strategies targeting TAMs have surfaced as potential therapeutic avenues, encompassing interventions to block TAM recruitment, eliminate TAMs, reprogram M2 TAMs, or bolster their phagocytic capabilities via specific pathways. Nanomaterials including inorganic materials, organic materials for small molecules and large molecules stand at the forefront, presenting significant opportunities for precise targeting and modulation of TAMs to enhance therapeutic efficacy in cancer treatment. This review provides an overview of the progress in designing nanoparticles for interacting with and influencing the TAMs as a significant strategy in cancer therapy. This comprehensive review presents the role of TAMs in the TME and various targeting strategies as a promising frontier in the ever-evolving field of cancer therapy. The current trends and challenges associated with TAM-based therapy in cancer are presented.

Advances in Cancer Vaccine Research

The use of cancer vaccines is considered a promising therapeutic strategy in clinical oncology, which is achieved by stimulating antitumor immunity with tumor antigens delivered in the form of cells, peptides, viruses, and nucleic acids. The ideal cancer vaccine has many advantages, including low toxicity, specificity, and induction of persistent immune memory to overcome tumor heterogeneity and reverse the immunosuppressive microenvironment. Many therapeutic vaccines have entered clinical trials for a variety of cancers, including melanoma, breast cancer, lung cancer, and others. However, many challenges, including single antigen targeting, weak immunogenicity, off-target effects, and impaired immune response, have hindered their broad clinical translation. In this review, we introduce the principle of action, components (including antigens and adjuvants), and classification (according to applicable objects and preparation methods) of cancer vaccines, summarize the delivery methods of cancer vaccines, and review the clinical and theoretical research progress of cancer vaccines. We also present new insights into cancer vaccine technologies, platforms, and applications as well as an understanding of potential next-generation preventive and therapeutic vaccine technologies, providing a broader perspective for future vaccine design.

The role of dysregulated mRNA translation machinery in cancer pathogenesis and therapeutic value of ribosome-inactivating proteins

Dysregulated protein synthesis is a hallmark of tumors. mRNA translation reprogramming contributes to tumorigenesis, which is fueled by abnormalities in ribosome formation, tRNA abundance and modification, and translation factors. Not only malignant cells but also stromal cells within tumor microenvironment can undergo transformation toward tumorigenic phenotypes during translational reprogramming. Ribosome-inactivating proteins (RIPs) have garnered interests for their ability to selectively inhibit protein synthesis and suppress tumor growth. This review summarizes the role of dysregulated translation machinery in tumor development and explores the potential of RIPs in cancer treatment.

Biological function, regulatory mechanism, and clinical application of mannose in cancer

Studies examining the regulatory roles and clinical applications of monosaccharides other than glucose in cancer have been neglected. Mannose, a common type of monosaccharide found in human body fluids and tissues, primarily functions in protein glycosylation rather than carbohydrate metabolism. Recent research has demonstrated direct anticancer effects of mannose in vitro and in vivo. Simply supplementing cell culture medium or drinking water with mannose achieved these effects. Moreover, mannose enhances the effectiveness of current cancer treatments including chemotherapy, radiotherapy, targeted therapy, and immune therapy. Besides the advancements in basic research on the anticancer effects of mannose, recent studies have reported its application as a biomarker for cancer or in the delivery of anticancer drugs using mannose-modified drug delivery systems. This review discusses the progress made in understanding the regulatory roles of mannose in cancer progression, the mechanisms underlying its anticancer effects, and its current application in cancer diagnosis and treatment.

Self-assembling and pH-responsive protein nanoparticle as potential platform for targeted tumor therapy

Frequent injections at high concentrations are often required for many therapeutic proteins due to their short in vivo half-life, which usually leads to unsatisfactory therapeutic outcomes, adverse side effects, high cost, and poor patient compliance. Herein we report a supramolecular strategy, self-assembling and pH regulated fusion protein to extend the in vivo half-life and tumor targeting ability of a therapeutically important protein trichosanthin (TCS). TCS was genetically fused to the N-terminus of a self-assembling protein, Sup35p prion domain (Sup35), to form a fusion protein of TCS-Sup35 that self-assembled into uniform spherical TCS-Sup35 nanoparticles (TCS-Sup35 NP) rather than classic nanofibrils. Importantly, due to the pH response ability, TCS-Sup35 NP well retained the bioactivity of TCS and possessed a 21.5-fold longer in vivo half-life than native TCS in a mouse model. As a result, in a tumor-bearing mouse model, TCS-Sup35 NP exhibited significantly improved tumor accumulation and antitumor activity without detectable systemic toxicity as compared with native TCS. These findings suggest that self-assembling and pH responding protein fusion may provide a new, simple, general, and effective solution to remarkably improve the pharmacological performance of therapeutic proteins with short circulation half-lives.