Optimal Light Dose for hEGFR-Targeted Near-Infrared Photoimmunotherapy

Tumor-associated genetic amplifications impact extracellular vesicle miRNA cargo and their recruitment of nerves in head and neck cancer

Cancer neuroscience is an emerging field of cancer biology focused on defining the interactions and relationships between the nervous system, developing malignancies, and their environments. Our previous work demonstrates that small extracellular vesicles (sEVs) released by head and neck squamous cell carcinomas (HNSCCs) recruit loco-regional nerves to the tumor. sEVs contain a diverse collection of biological cargo, including microRNAs (miRNAs). Here, we asked whether two genes commonly amplified in HNSCC, CCND1, and PIK3CA, impact the sEV miRNA cargo and, subsequently, sEV-mediated tumor innervation. To test this, we individually overexpressed these genes in a syngeneic murine HNSCC cell line, purified their sEVs, and tested their neurite outgrowth activity on dorsal root ganglia (DRG) neurons in vitro. sEVs purified from Ccnd1-overexpressing cells significantly increased neurite outgrowth of DRG compared to sEVs from parental or Pik3ca over-expressing cells. When implanted into C57BL/6 mice, Ccnd1 over-expressing tumor cells promoted significantly more tumor innervation in vivo. qPCR analysis of sEVs shows that increased expression of Ccnd1 altered the packaging of miRNAs (miR-15-5p, miR-17-5p, and miR-21-5p), many of which target transcripts important in regulating axonogenesis. These data indicate that genetic amplifications harbored by malignancies impose changes in sEV miRNA cargo, which can influence tumorc innervation.

Near-infrared photoimmunotherapy and anti-cancer immunity

The activation of the anti-cancer immune system is an important strategy to control cancer. A new form of cancer phototherapy, near-infrared photoimmunotherapy (NIR-PIT), was approved for clinical use in 2020 and uses IRDye® 700DX (IR700)-conjugated antibodies and NIR light. After irradiation with NIR light, the antibody-IR700 conjugate forms water-insoluble aggregations on the plasma membrane of target cells. This aggregation causes lethal damage to the plasma membrane, and effectively leads to immunogenic cell death (ICD). Subsequently, ICD activates anti-cancer immune cells such as dendritic cells and cytotoxic T cells. Combination therapy with immune-checkpoint blockade has synergistically improved the anti-cancer effects of NIR-PIT. Additionally, NIR-PIT can eliminate immunosuppressive immune cells in light-irradiated tumors by using specific antibodies against regulatory T cells and myeloid-derived suppressor cells. In addition to cancer-cell-targeted NIR-PIT, such immune-cell-targeted NIR-PIT has shown promising results by activating the anti-cancer immune system. Furthermore, NIR-PIT can be used to manipulate the tumor microenvironment by eliminating only targeted cells in the tumor, and thus it also can be used to gain insight into immunity in basic research.

Near Infrared Photoimmunotherapy: A Review of Recent Progress and Their Target Molecules for Cancer Therapy

Near infrared photoimmunotherapy (NIR-PIT) is a newly developed molecular targeted cancer treatment, which selectively kills cancer cells or immune-regulatory cells and induces therapeutic host immune responses by administrating a cancer targeting moiety conjugated with IRdye700. The local exposure to near-infrared (NIR) light causes a photo-induced ligand release reaction, which causes damage to the target cell, resulting in immunogenic cell death (ICD) with little or no side effect to the surrounding normal cells. Moreover, NIR-PIT can generate an immune response in distant metastases and inhibit further cancer attack by combing cancer cells targeting NIR-PIT and immune regulatory cells targeting NIR-PIT or other cancer treatment modalities. Several recent improvements in NIR-PIT have been explored such as catheter-driven NIR light delivery, real-time monitoring of cancer, and the development of new target molecule, leading to NIR-PIT being considered as a promising cancer therapy. In this review, we discuss the progress of NIR-PIT, their mechanism and design strategies for cancer treatment. Furthermore, the overall possible targeting molecules for NIR-PIT with their application for cancer treatment are briefly summarised.