EDB-FN targeted probes for the surgical navigation, radionuclide imaging, and therapy of thyroid cancer

Exploring the mechanism of fibronectin extra domain B in the tumor microenvironment and implications for targeted immunotherapy and diagnostics (Review)

Fibronectin extra domain B (FN‑EDB) is a unique domain of FN), whose expression is significantly upregulated in the tumor microenvironment (TME). FN‑EDB plays a key role in tumor cell adhesion, angiogenesis and invasion, and is closely related to tumor malignancy and poor prognosis. Moreover, the high expression of FN‑EDB in multiple cancer types makes it a potential therapeutic target. However, comprehensive studies of the mechanism of FN‑EDB in different cancer types and its potential as therapeutic targets are lacking. The present study aimed to explore the general role of FN‑EDB in multiple types of cancer and to integrate the knowledge of cell biology, molecular biology and immunology, so as to give a comprehensive understanding of the role of FN‑EDB in TME. Furthermore, by focusing on the use of FN‑EDB in clinical diagnosis and treatment, the potential of targeting FN‑EDB as a diagnostic and therapeutic target was evaluated and the progress in clinical trials of these drugs was discussed. By searching web sites such as PubMed and web of science, various high‑quality studies including RNA sequencing, drug experiments, cell experiments, animal models, clinical randomized controlled experiments and large‑scale cohort studies were collected, with sufficient evidence to support a comprehensive evaluation of the function and potential application of FN‑EDB. The present study revealed the general role of FN‑EDB in multiple types of cancer and evaluated its potential as a diagnostic and therapeutic target. It also provided a basis for future development of more effective and precise cancer therapies.

Recent advancements in new tracers from first-in-human studies

Recent advancements in the development of positron emission tomography (PET) tracers have significantly enhanced our ability to image neuroinflammatory processes and neurotransmitter systems, which are vital for understanding and treating neurodegenerative and psychiatric disorders. Similarly, innovative tracers in oncology provide detailed images of the metabolic and molecular characteristics of tumors, which are crucial for tailoring targeted therapies and monitoring responses, including radiotherapy. Notable advancements include programmed death ligand 1 (PD-L1)-targeting agents for lung cancer, prostate-specific membrane antigen-based tracers for prostate cancer, chemokine receptor-targeting agents for hematological malignancies, human epidermal growth factor receptor 2 (HER2)-targeting tracers for various cancers, Claudin 18 based tracers for epithelial tumors, glutamine tracers for colorectal cancer, and ascorbic acid analogs for assessing cancer metabolism and therapy efficacy. Additionally, novel tracers have been developed for non-neurological and non-oncological applications, including adrenal imaging, amyloidosis, and human immunodeficiency virus (HIV) infection. This overview focuses on the newly developed tracers, particularly those used in neurology and oncology.

EDB-FN-targeted probes for near infrared fluorescent imaging and positron emission tomography imaging of breast cancer in mice

The extra domain B splice variant of fibronectin (EDB-FN), which is overexpressed in several cancers, is an approved diagnostic and therapeutic target of cancers. The aim of this study was to evaluate the EDB-FN-targeting peptide EDBp as a noninvasive imaging modality for molecular imaging of breast cancer in mice. Western blot, flow cytometry and immunofluorescence were used to assess the expression level of EDB-FN and its binding to EDRp in MCF7, SKBR3, 4T1, EMT6, MDA-MB-231 and MDA-MB-453 cells. Establishment MDA-MB-231-luc cells-based subcutaneous tumor model mice or pulmonary metastasis model mice. The EDRp molecular probes to perform fluorescent probes for near-infrared fluorescence (NIRF)·and PET imaging of model mice. Our results demonstrate that EDBp-Cy5 had a strong binding ability to the MDA-MB-231 cells and exhibited specific tumor accumulation in MDA-MB-231 subcutaneous and pulmonary metastasis model mice. Importantly, the EDBp peptide-based radiotracer [18F]-AlF-NOTA-EDBp provided excellent diagnostic value for positron emission tomography (PET) imaging of breast cancer, especially in subcutaneous model mice. The uptake of [18F]-AlF-NOTA-EDBp in subcutaneous tumors (6.53 ± 0.89%, ID/g) was unexpectedly higher than that in the kidney (4.96 ± 0.20, %ID/g). The high tumor uptake of these probes in mice suggests their potential for application in imaging of EDB-FN-positive breast cancer for disease staging of regional and distant metastases.

Radiolabeled multi-layered coated gold nanoparticles as potential biocompatible PET/SPECT tracers

The demand for tailored, disease-adapted, and easily accessible radiopharmaceuticals is one of the most persistent challenges in nuclear imaging precision medicine. The aim of this work was to develop two multimodal radiotracers applicable for both SPECT and PET techniques, which consist of a gold nanoparticle core, a shell involved in radioisotope entrapment, peripherally placed targeting molecules, and biocompatibilizing polymeric sequences. Shell decoration with glucosamine units located in sterically hindered molecular environments is expected to result in nanoparticle accumulation in high-glucose-consuming areas. Gold cores were synthesized using the Turkevich method, followed by citrate substitution with linear PEG α,ω-functionalized with thiol and amine groups. The free amine groups facilitated the binding of branched polyethyleneimine through an epoxy ring-opening reaction by using PEG α,ω-diglycidyl ether as a linker. Afterwards, the glucose-PEG-epoxy prepolymer has been grafted onto the surface of AuPEG-PEI conjugates. Finally, the AuPEG-PEI-GA conjugates were radiolabeled with 99mTc or 68Ga. Instant thin-layer chromatography was used to evaluate the radiolabeling yield. The biocompatibility of non-labeled and 99mTc or 68Ga labeled nanoparticles was assessed on normal fibroblasts. The 99mTc complexes remained stable for over 22 hours, while the 68Ga containing ones revealed a slight decrease in stability after 1 hour.