Near-Infrared Photoimmunotherapy for Thoracic Cancers: A Translational Perspective

Photoinduced Actin Aggregation Involves Cell Death: A Mechanism of Cancer Cell Cytotoxicity after Near-Infrared Photoimmunotherapy

Near-infrared photoimmunotherapy (NIR-PIT) is a cancer treatment modality that uses antibody-photoabsorber (IR700) conjugates to destroy specific cells. The reaction between the antibody and photoabsorber is triggered by NIR-light, and this alters the shape and hydrophilicity of the conjugate. This photochemical reaction is responsible for NIR-PIT-induced cell death; however, the detailed mechanism underlying this effect remains unknown. In this study, we demonstrated that actin filaments underneath the cell membrane play an important role in NIR-PIT-induced cell death and that IR700 mediates the photochemical reaction of the conjugates, leading to actin filament aggregation upon NIR-light irradiation. The destruction of cortical actin beneath the cell plasma membrane allows water to flow into the cell based on osmotic conditions, resulting in cell rupture. This sequence of events may constitute the mechanism of NIR-PIT-induced cell death, making NIR-PIT a promising cancer treatment modality.

Near-infrared photoimmunotherapy in cancer treatment: a bibliometric and visual analysis

Background

Near-infrared photoimmunotherapy (NIR-PIT) is an emerging cancer treatment technology that combines the advantages of optical technology and immunotherapy to provide a highly effective, precise, and low side-effect treatment approach. The aim of this study is to visualize the scientific results and research trends of NIR-PIT based on bibliometric analysis methods.

Methods

The Web of Science Core Collection (WoSCC) database was searched in August 2024 for relevant publications in the field of NIR-PIT. Data were analyzed using mainly CiteSpace and R software for bibliometric and visual analysis of the country/region, authors, journals, references and keywords of the publications in the field.

Results

A total of 245 publications were retrieved, including articles (n = 173, 70.61%) and reviews (n = 72, 29.39%). The annual and cumulative number of publications increased every year. The highest number of publications was from the United States (149, 60.82%), followed by Japan (70, 28.57%) and China (33, 13.47%). The research institution with the highest number of publications was National Institutes of Health (NIH)-USA (114, 46.53%). Kobayashi H (109) was involved in the highest number of publications, Mitsunaga M (211) was the most frequently cited in total. CANCERS (17) was the most frequently published journal, and NAT MED (220) was the most frequently co-cited journal. The top 10 keywords include near-infrared photoimmunotherapy (166), photodynamic therapy (61), monoclonal antibody (58), in vivo (50), cancer (46), expression (31), breast cancer (27), enhanced permeability (24), antibody (23), growth factor receptor (16). Cluster analysis based on the co-occurrence of keywords resulted in 13 clusters, which identified the current research hotspots and future trends of NIR-PIT in cancer treatment.

Conclusion

This study systematically investigated the research hotspots and development trends of NIR-PIT in cancer treatment through bibliometric and visual analysis. As an emerging strategy, the research on the application of NIR-PIT in cancer treatment has significantly increased in recent years, mainly focusing on the targeting, immune activation mechanism, and treatment efficacy in solid tumors has received extensive attention. Future studies may focus on improving the efficacy and safety of NIR-PIT in cancer treatment, as well as developing novel photosensitizers and combination therapeutic regimens, and exploring the efficacy of its application in a wide range of solid tumors, which will provide an important reference and guidance for the application of NIR-PIT in clinical translation.

Lipid- and Polymer-Based Nanocarrier Platforms for Cancer Vaccine Delivery

Cancer immunotherapy has gained popularity in recent years in the search for effective treatment modalities for various malignancies, particularly those that are resistant to conventional chemo- and radiation therapy. Cancer vaccines target the cancer-immunity cycle by boosting the patient's own immune system to recognize and kill cancer cells, thus serving as both preventative and curative therapeutic tools. Among the different types of cancer vaccines, those based on nanotechnology have shown great promise in advancing the field of cancer immunotherapy. Lipid-based nanoparticles (NPs) have become the most advanced platforms for cancer vaccine delivery, but polymer-based NPs have also received considerable interest. This Review aims to provide an overview of the nanotechnology-enabled cancer vaccine landscape, focusing on recent advances in lipid- and polymer-based nanovaccines and their hybrid structures and discussing the challenges against the clinical translation of these important nanomedicines.

Contrast-enhanced ultrasound imaging for monitoring the efficacy of near-infrared photoimmunotherapy

BACKGROUND

Near-infrared photoimmunotherapy (NIR-PIT) is a promising cancer therapy combining NIR-light irradiation with an antibody and IR700DX, a light-sensitive substance, to destroy tumours. However, homogeneous irradiation is difficult because the light varies depending on the distance and tissue environment. Therefore, markers that indicate sufficient irradiation are necessary. Nanoparticles sized 10∼200 nm show enhanced permeation and retention within tumours, which is further enhanced via NIR-PIT (super enhanced permeability and retention, SUPR). We aimed to monitor the effectiveness of NIR-PIT by measuring SUPR.

METHODS

A xenograft mouse tumour model was established by inoculating human cancer cells in both buttocks of Balb/C-nu/nu mice, and NIR-PIT was performed on only one side. To evaluate SUPR, fluorescent signal examination was performed using QD800-fluorescent nanoparticles and NIR-fluorescent poly (d,l-lactide-co-glycolic acid) (NIR-PLGA) microparticles. Harmonic signals were evaluated using micro-bubbles of the contrast agent Sonazoid and contrast-enhanced ultrasound (CEUS) imaging. The correlation between SUPR immediately after treatment and NIR-PIT effectiveness on the day after treatment was evaluated.

FINDINGS

QD800 fluorescent signals persisted only in the treated tumours, and the intensity of remaining signals showed high positive correlation with the therapeutic effect. NIR-PLGA fluorescent signals and Sonazoid-derived harmonic signals remained for a longer time in the treated tumours than in the controls, and the kE value of the two-compartment model correlated with NIR-PIT effectiveness.

INTERPRETATION

SUPR measurement using Sonazoid and CEUS imaging could be easily adapted for clinical use as a therapeutic image-based biomarker for monitoring and confirming of NIR-PIT efficacy.

FUNDING

This research was supported by ARIM JAPAN of MEXT, the Program for Developing Next-generation Researchers (Japan Science and Technology Agency), KAKEN (18K15923, 21K07217) (JSPS), CREST (JPMJCR19H2, JST), and FOREST-Souhatsu (JST). Mochida Memorial Foundation for Medical and Pharmaceutical Research; Takeda Science Foundation; The Japan Health Foundation; and Princess Takamatsu Cancer Research Fund. Funders only provided financial support and had no role in the study design, data collection, data analysis, interpretation, and writing of the report.

Novel formats of antibody conjugates: recent advances in payload diversity, conjugation, and linker chemistry

INTRODUCTION

In the field of bioconjugates, the focus on antibody - drug conjugates (ADCs) with novel payloads beyond the traditional categories of potent cytotoxic agents is increasing. These innovative ADCs exhibit various molecular formats, ranging from small-molecule payloads, such as immune agonists and proteolytic agents, to macromolecular payloads, such as oligonucleotides and proteins.

AREAS COVERED

This review offers an in-depth exploration of unconventional strategies for designing conjugates with novel mechanisms of action and notable examples of approaches that show promising prospects. Representative examples of novel format payloads and their classification, attributes, and appropriate conjugation techniques are discussed in detail.

EXPERT OPINION

The existing basic technologies used to manufacture ADCs can be directly applied to synthesize novel formatted conjugates. However, a wide variety of new payloads require the creation of customized technologies adapted to the unique characteristics of these payloads. Consequently, fundamental technologies, such as conjugation methods aimed at achieving high drug - antibody ratios and developing stable crosslinkers, are likely to become increasingly important research areas in the future.

Immuno-photodynamic Therapy (IPDT): Organic Photosensitizers and Their Application in Cancer Ablation

Photosensitizer-based photodynamic therapy (PDT) has been considered as a promising modality for fighting diverse types of cancers. PDT directly inhibits local tumors by a minimally invasive strategy, but it seems to be incapable of achieving complete eradication and fails to prevent metastasis and recurrence. Recently, increasing events proved that PDT was associated with immunotherapy by triggering immunogenic cell death (ICD). Upon a specific wavelength of light irradiation, the photosensitizers will turn the surrounding oxygen molecules into cytotoxic reactive oxygen species (ROS) for killing the cancer cells. Simultaneously, the dying tumor cells release tumor-associated antigens, which could improve immunogenicity to activate immune cells. However, the progressively enhanced immunity is typically limited by the intrinsic immunosuppressive tumor microenvironment (TME). To overcome this obstacle, immuno-photodynamic therapy (IPDT) has come to be one of the most beneficial strategies, which takes advantage of PDT to stimulate the immune response and unite immunotherapy for inducing immune-OFF tumors to immune-ON ones, to achieve systemic immune response and prevent cancer recurrence. In this Perspective, we provide a review of recent advances in organic photosensitizer-based IPDT. The general process of immune responses triggered by photosensitizers (PSs) and how to enhance the antitumor immune pathway by modifying the chemical structure or conjugating with a targeting component was discussed. In addition, future perspectives and challenges associated with IPDT strategies are also discussed. We hope this Perspective could inspire more innovative ideas and provide executable strategies for future developments in the war against cancer.

Recent Advances in Localized Immunomodulation Technology: Application of NIR-PIT toward Clinical Control of the Local Immune System

Current immunotherapies aim to modulate the balance among different immune cell populations, thereby controlling immune reactions. However, they often cause immune overactivation or over-suppression, which makes them difficult to control. Thus, it would be ideal to manipulate immune cells at a local site without disturbing homeostasis elsewhere in the body. Recent technological developments have enabled the selective targeting of cells and tissues in the body. Photo-targeted specific cell therapy has recently emerged among these. Near-infrared photoimmunotherapy (NIR-PIT) has surfaced as a new modality for cancer treatment, which combines antibodies and a photoabsorber, IR700DX. NIR-PIT is in testing as an international phase III clinical trial for locoregional recurrent head and neck squamous cell carcinoma (HNSCC) patients (LUZERA-301, NCT03769506), with a fast-track designation by the United States Food and Drug Administration (US-FDA). In Japan, NIR-PIT for patients with recurrent head and neck cancer was conditionally approved in 2020. Although NIR-PIT is commonly used for cancer therapy, it could also be exploited to locally eliminate certain immune cells with antibodies for a specific immune cell marker. This strategy can be utilized for anti-allergic therapy. Herein, we discuss the recent technological advances in local immunomodulation technology. We introduce immunomodulation technology with NIR-PIT and demonstrate an example of the knockdown of regulatory T cells (Tregs) to enhance local anti-tumor immune reactions.

Chlorin e6-induced photodynamic effect facilitates immunogenic cell death of lung cancer as a result of oxidative endoplasmic reticulum stress and DNA damage

Suppression of the immune microenvironment is an important endogenous contributor to treatment failure in lung cancer. Photodynamic therapy (PDT) is widely used in the treatment of malignant tumors owing to its photo-selectivity and minimal side effects. Some studies have shown the ability of photodynamic action not only to cause photo-cytotoxicity to tumor cells but also to induce immunogenic cell death (ICD). However, the mechanism by which PDT enhances tumor immunogenicity is poorly understood. The present study aimed to explore the immunogenicity effect of PDT on lung cancer and to reveal the underlying mechanism. First, we searched for effective conditions for PDT-induced apoptosis in lung cancer cells. Just as expected, chlorin e6 (Ce6) PDT could enhance the immunogenicity of lung cancer cells alongside the induction of apoptosis, characterized by up-regulation of CRT, HSP90, HMGB1 and MHC-I. Further results showed the generation of ROS by Ce6 PDT under the above conditions, which is an oxidative damaging agent. Simultaneously, PDT induced endoplasmic reticulum (ER) stress in cells, as evidenced by enhanced Tht staining and up-regulated CHOP and GRP78 expression. Moreover, PDT led to DNA damage response (DDR) as well. However, the redox inhibitor NAC abolished the ER stress and DDR caused by PDT. More importantly, NAC also attenuated PDT-induced improvement of immunogenicity in lung cancer. On this basis, the PDT-induced CRT up-regulation was found to be attenuated in response to inhibition of ER stress. In addition, PDT-induced increase in HMGB1 and HSP90 release was blocked by inhibition of DDR. In summary, Ce6 PDT could produce ROS under certain conditions, which leads to ER stress that promotes CRT translocation to the cell membrane, and the resulting DNA damage causes the expression and release of nuclear HMGB1 and HSP90, thereby enhancing the immunogenicity of lung cancer. This current study elucidates the mechanism of PDT in ameliorating the immunogenicity of lung cancer, providing a rationale for PDT in regulating the immune microenvironment for the treatment of malignant tumors.

Photodynamic Therapy

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