A Novel Color-Coded Liver Metastasis Mouse Model to Distinguish Tumor and Adjacent Liver Segment

Theranostics applications of quantum dots in regenerative medicine, cancer medicine, and infectious diseases

Quantum dots (QDs) have attracted attention for their application and commercialization in all industrial fields, including communications, displays, and solar cells, due to their excellent optical properties based on the quantum size effect. In recent years, the development of QDs that do not contain cadmium which is toxic to cells and living organisms, has progressed, and they have attracted considerable attention in the bio-imaging field for targeting molecules and cells. Furthermore, recently, the need for diagnostics and treatment at the single molecule and single cell level in the medical field has been increasing, and the application of QDs in the medical field is also accelerating. Therefore, this paper outlines the frontiers of diagnostic and therapeutic applications (theranostics) of QDs, especially in advanced medical fields such as regenerative medicine, oncology, and infectious diseases.

Proof of Principle of Combining Fluorescence-Guided Surgery with Photoimmunotherapy to Improve the Outcome of Pancreatic Cancer Therapy in an Orthotopic Mouse Model

BACKGROUND

Pancreatic cancer is a recalcitrant disease in which R0 resection is often not achieved owing to difficulty in visualization of the tumor margins and proximity of adjacent vessels. To improve outcomes, we have developed fluorescence-guided surgery (FGS) and photoimmunotherapy (PIT) using a fluorescent tumor-specific antibody.

METHODS

Nude mice received surgical orthotopic implantation (SOI) of the human pancreatic cancer cell line BxPC-3 expressing green fluorescent protein. An anti-carcinoembryonic antigen-related cell adhesion molecule (CEACAM) monoclonal antibody (6G5j) was conjugated to the 700-nm fluorescent dye IR700DyeDX (6G5j-IR700DX). Three weeks after SOI, 16 mice received 50 μg 6G5j-IR700DX via the tail vein 24 h before surgery and were randomized to two groups: FGS-only (n = 8) and FGS + PIT (n = 8). All tumors were imaged with the Pearl Trilogy imaging system and resected under the guidance of the FLARE imaging system. The FGS + PIT group received PIT of the post-surgical bed at an intensity of 150 mW/cm² for 30 min. Mice were sacrificed 4 weeks after initial surgery, and tumors were imaged with a Dino-Lite digital microscope, excised, and weighed.

RESULTS

The 6G5j-IR700DX dye illuminated the orthotopic pancreatic tumors for FGS and PIT. The metastatic recurrence rate was 100.0% for FGS-only and 25.0% for FGS + PIT (p = 0.007). The average total recurrent tumor weight was 2370.3 ± 1907.8 mg for FGS-only and 705.5 ± 1200.0 mg for FGS + PIT (p = 0.039).

CONCLUSIONS

FGS and adjuvant PIT can be combined by using a single antibody-fluorophore conjugate to significantly reduce the frequency of pancreatic cancer recurrence.

Indocyanine green (ICG) fluorescence guide for the use and indications in general surgery: recommendations based on the descriptive review of the literature and the analysis of experience

Indocyanine Green is a fluorescent substance visible in near-infrared light. It is useful for the identification of anatomical structures (biliary tract, ureters, parathyroid, thoracic duct), the tissues vascularization (anastomosis in colorectal, esophageal, gastric, bariatric surgery, for plasties and flaps in abdominal wall surgery, liver resection, in strangulated hernias and in intestinal ischemia), for tumor identification (liver, pancreas, adrenal glands, implants of peritoneal carcinomatosis, retroperitoneal tumors and lymphomas) and sentinel node identification and lymphatic mapping in malignant tumors (stomach, breast, colon, rectum, esophagus and skin cancer). The evidence is very encouraging, although standardization of its use and randomized studies with higher number of patients are required to obtain definitive conclusions on its use in general surgery. The aim of this literature review is to provide a guide for the use of ICG fluorescence in general surgery procedures.

Proof of concept of improved fluorescence-guided surgery of colon cancer liver metastasis using color-coded imaging of a tumor-labeling fluorescent antibody and indocyanine green restricted to the adjacent liver segment

BACKGROUND

Indocyanine green has been used for fluorescence-guided surgery of liver metastasis and labeling of liver segments. However, indocyanine green is nonspecific, and indocyanine green labeling does not always clearly outline tumor margins. In addition, it is difficult to distinguish between a tumor and its adjacent liver segment colored with indocyanine green alone. In the present study, we performed fluorescence-guided surgery in an orthotopic colon-cancer liver metastasis mouse model by labeling the metastatic liver tumor with an anti-carcinoembryonic antigen fluorescent antibody and with indocyanine green restricted to the adjacent liver segment.

METHODS

A liver metastasis model was established with human LS174T colon cancer tumor fragments. To label the tumor, mice received SGM-101, an anti-carcinoembryonic antigen antibody conjugated to a near-infrared fluorophore (700 nm), currently in clinical trials, 3 days before surgery. Indocyanine green (800 nm) was injected after ligation of the tumor-bearing Glissonean pedicle with fluorescence labeling restricted to the liver segment adjacent to the tumor. Bright-light surgery and fluorescence-guided surgery were performed to resect the liver metastasis. To assess recurrence, mice underwent necropsy 3 weeks after surgery and the tumor was weighed.

RESULTS

Fluorescence-guided anatomic left lateral lobectomy and fluorescence-guided partial liver resection were both performed with color-coded double labeled imaging. Tumor weight 3 weeks after surgery was significantly lower with fluorescence-guided surgery compared to bright-light surgery (38 ± 57 mg vs 836 ± 668 mg, P = .011) for partial liver resection.

CONCLUSION

The present study provides a proof-of-concept that color-coded and double labeling of the tumor and adjacent liver segment has the potential to improve liver metastasectomy.

The Effect and Related Mechanism of Action of Astragalus Compatible with Curcumin against Colon Cancer Metastasis in Mice

Colon cancer (CC) is the third most common tumor worldwide. Colon carcinogenesis is strongly linked to inflammation. The initiation and progression of colon cancer may be influenced by epigenetic processes. Cancer metastasis is a multistep process involving several genes and their products. During tumor metastasis, cancer cells first enhance their proliferative capacity by lowering autophagy and apoptosis, and then, their capacity is stimulated by boosting tumors' ability to take nutrients from the outside via angiogenesis. Traditional treatment focuses on eliminating tumor cells by triggering cell death or activating the immune system, which often results in side effects or chemoresistance recurrence. On the contrary, Chinese medicine theory considers the patient's entire inner system and aids in tumor shrinkage while also taking into account the mouse' general health. Because many Chinese herbal medicines (CHM) are consumed as food, using edible CHMs as a diet resource therapy for colon cancer treatment is a viable option. Two traditional Chinese herbs, Astragalus membranaceus and Curcuma zedoaria, are commonly utilized jointly in colon cancer preventive therapy. As a result, the anticancer effect of astragalus and curcumin (AC) on colon cancer suppression in an 18-week AOM-DSS colon cancer mouse model is investigated in this research. These findings may offer a scientific foundation for investigating colon cancer diagnostic biomarkers and therapeutic application of AC in colon cancer treatment. These studies also highlighted the potential effect and mechanism of AC in the treatment of colon cancer, as well as providing insight into how to effectively use it.

Fluorescence Molecular Targeting of Colon Cancer to Visualize the Invisible

Colorectal cancer (CRC) is a common cause of cancer and cancer-related death. Surgery is the only curative modality. Fluorescence-enhanced visualization of CRC with targeted fluorescent probes that can delineate boundaries and target tumor-specific biomarkers can increase rates of curative resection. Approaches to enhancing visualization of the tumor-to-normal tissue interface are active areas of investigation. Nonspecific dyes are the most-used approach, but tumor-specific targeting agents are progressing in clinical trials. The present narrative review describes the principles of fluorescence targeting of CRC for diagnosis and fluorescence-guided surgery with molecular biomarkers for preclinical or clinical evaluation.