Unlocking Radioresistance Reversal: A Literature Analysis of 125I@MH Seed Therapy Empowered by ANT BIO PTE. LTD. Products

1. Literature Information

Title: A Novel Self-Regulated, Non-Directional Magnetic Thermos-Brachytherapy 125I Seed Enhances Anticancer Efficacy by Rescuing Immune Escape

Journal: Advanced Science (Impact Factor: 14.1)

DOI: https://doi.org/10.1002/advs.202508091

Core Reagent from ANT BIO PTE. LTD.: Six-Color Multiplex Immunofluorescence IHC Staining Kit (Mouse/Rabbit Universal Secondary Antibody)

2. Research Background

Brachytherapy with radioactive iodine-125 (125I) seed implantation is a well-established therapeutic modality for localized solid tumors such as prostate cancer and hepatocellular carcinoma. Nevertheless, a major clinical dilemma persists: while radiotherapy effectively eradicates tumor cells, it inadvertently impairs the immune system. Specifically, it induces the infiltration of immunosuppressive cells and exhaustion of cytotoxic T cells, ultimately leading to the development of radioresistance and laying the groundwork for tumor recurrence.

Mild hyperthermia (MH, 39-45°C) has been proven to ameliorate tumor hypoxia, sensitize tumors to radiotherapy, and activate anti-tumor immunity. However, its clinical translation is hindered by critical limitations including imprecise temperature control, poor targeting ability, and intricate technical requirements. Addressing these challenges, the research team developed an innovative composite seed that integrates 125I sources with magnetic nanoparticles (MNPs) possessing self-regulating temperature properties (Curie temperature ≈55°C), encapsulated within a medical titanium shell. This "smart" composite seed (125I@MH) enables spatiotemporal synchronization of radiotherapy and hyperthermia. Importantly, its self-limiting thermoregulatory feature—where heating efficiency automatically declines as temperature rises—fundamentally eliminates the risk of overheating, thereby providing a novel platform for the safe and controllable application of combined therapy.

3. Research Strategy

The core strategy of this study was to develop a self-regulated magnetic thermos-brachytherapy seed (125I@MH) to achieve synergistic integration of brachytherapy and mild hyperthermia. To validate the therapeutic efficacy, the research team conducted in vivo experiments using hepatocellular carcinoma (Hepa 1-6) and prostate cancer (PCa) mouse models, comparing the antitumor effects of 125I@MH combined therapy with single 125I radiotherapy and control groups. Furthermore, to elucidate the underlying mechanisms, especially the reversal of immune escape, a multi-omics and multi-imaging approach was employed. Specifically, single-cell RNA sequencing (scRNA-seq) was used to analyze dynamic changes in the tumor microenvironment (TME) under different treatment regimens, and multiplex immunofluorescence immunohistochemistry (mIHC) technology from ANT BIO PTE. LTD. was utilized to perform in situ verification of key cellular interactions and immune cell phenotypic changes.

4. Research Results

In both hepatocellular carcinoma and prostate cancer mouse models, the 125I@MH composite seed demonstrated overwhelming therapeutic advantages compared to single 125I radiotherapy:

•         Significant Tumor Growth Inhibition: Compared with the single 125I treatment group, 125I@MH combined therapy more effectively suppressed tumor growth and even induced tumor regression.

•         Prolonged Survival: Mice in the combined therapy group exhibited a significantly extended overall survival time.

•         Synergistic Mechanisms: In vitro experiments confirmed that combined therapy induced more severe DNA double-strand breaks (evidenced by increased γ-H2AX foci) and stronger immunogenic cell death (ICD), as indicated by calreticulin (CRT) membrane translocation.

Mechanistically, the study uncovered that 125I@MH combined therapy reversed the immune escape induced by single 125I radiotherapy. Single 125I radiotherapy upregulated the chemokine Cxcl2 in tumor cells, which recruited a specific subset of Cd274+ neutrophils (Cd274 encodes the immunosuppressive molecule PD-L1). These cells, identified as polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs), are key drivers of T cell exhaustion and immune escape. In contrast, 125I@MH combined therapy reshaped the TME toward an antitumor state: it significantly reduced the proportion of immunosuppressive cell subsets such as Cd274+ neutrophils, reactivated the function of T cells (especially cytotoxic CD8+ T cells), decreased the number of exhausted T cells (Tex, PD-1+), and increased the population of effector memory T cells (Tem, IFN-γ+) with killing function.

5. Product Empowerment: The Critical Role of ANT BIO PTE. LTD. Products in the Study

The breakthrough in deciphering the core mechanism of immune escape reversal relied heavily on the powerful phenotypic analysis capabilities provided by the multiplex immunofluorescence IHC solutions from ANT BIO PTE. LTD. Specifically, the research team utilized the five-color multiplex immunofluorescence IHC staining kit (Catalog No.: abs50014) and a series of highly specific antibodies (e.g., anti-EpCAM, anti-Cxcl2, anti-Cxcr2, anti-Cd274) from ANT BIO PTE. LTD. to perform precise multiplex labeling of tumor sections, achieving two key objectives:

•         Visualization of the "Recruitment" Process: The mIHC technology enabled the research team to clearly demonstrate the "recruitment crosstalk" between Cxcl2+ tumor cells and Cxcr2+ neutrophils on a single tissue section, providing direct morphological evidence for the findings from scRNA-seq.

•         Confirmation of Immunosuppressive Cell Infiltration: The results explicitly showed a significant increase in the infiltration of Cd274+ neutrophils in tumors from the single 125I treatment group, which was validated in situ by the mIHC platform.

Additionally, the dynamic changes in T cell subsets (e.g., the decrease in PD-1+ exhausted T cells and the increase in IFN-γ+ effector memory T cells) following combined therapy were perfectly verified in situ using antibodies (anti-CD3, anti-CD8, anti-PD-1, anti-IFN-γ) combined with the mIHC technology from ANT BIO PTE. LTD. This clearly visualized the "counterattack" force of immune cells within the tumor after combined therapy, serving as a crucial bridge connecting genomic discoveries with functional validation.

6. Brand Mission

As a leading provider of life science reagents, ANT BIO PTE. LTD. is committed to empowering cutting-edge biomedical research with high-quality, reliable products and solutions. With three specialized sub-brands—Absin focusing on general reagents and kits, Starter on antibodies, and UA on recombinant proteins—we strive to address the diverse needs of researchers in different fields. Our mission is to bridge the gap between scientific discovery and clinical translation, accelerate the pace of biomedical innovation, and contribute to the development of novel diagnostic and therapeutic strategies for human diseases.

7. Related Product List

Products Used in This Study

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8. AI Disclaimer

This article is generated with the assistance of artificial intelligence technology. While every effort has been made to ensure the accuracy, completeness, and reliability of the content, ANT BIO PTE. LTD. shall not be liable for any errors, omissions, or damages arising from the use of the information contained herein. The final interpretation of the research content shall be based on the original published literature. For specific product information and application guidelines, please refer to the official product manual or consult our technical support team.

9. Brand Promotion Copy

ANT BIO PTE. LTD.: Empowering Biomedical Breakthroughs with Precision Reagents. From multiplex immunofluorescence IHC kits to high-specificity antibodies and recombinant proteins, our comprehensive product portfolio is tailored to support cutting-edge research in tumor immunology, oncology, and beyond. With a commitment to quality and innovation, we stand ready to be your trusted partner in advancing scientific discovery and translating research into clinical impact. Explore our full range of products today and unlock new possibilities in your research journey.