Establishment of a Non-Invasive Semi-Quantitative Bioluminescent Imaging Method for Monitoring of an Orthotopic Esophageal Cancer Mouse Model

Abstract

Orthotopic models of various types of tumors are widely used in anti-tumor therapeutic experiments in preclinical studies. However, there are few ways to appropriately monitor therapeutic effect in orthotopic tumor models, especially for tumors invisible from the outside. In this study we aimed to establish a non-invasive semi-quantitative bioluminescent imaging method of monitoring an orthotopic esophageal cancer mouse model. We confirmed that the TE8 esophageal cancer cell line implanted orthotopically into the abdominal esophagus of nu/nu mice (n = 5) developed not only a main tumor at the implanted site, but also local lymph node metastases and peritoneal disseminations within 6 weeks after inoculation. We established a TE8 cell line that stably expressed the firefly luciferase gene (TE8-Luc). We showed that TE8-Luc cells implanted subcutaneously into nu/nu mice (n = 5) grew over time until 5 weeks after inoculation. Tumor volume was strongly correlated with luminescent intensity emitted from the tumor, which was quantified using the IVIS imaging system. We then showed that TE8-Luc cells implanted orthotopically into the mouse abdominal esophagus (n = 8) also formed a tumor and that the luminescent intensity of such a tumor, as detected by IVIS, increased over time until 7 weeks after inoculation and was therefore likely to reflect tumor progression. We therefore propose that this orthotopic esophageal cancer model, monitored using the non-invasive semi-quantitative IVIS imaging system, will be useful for in vivo therapeutic experiments against esophageal cancer. This experimental setting is expected to contribute to the development of novel therapeutic technologies for esophageal cancer in preclinical studies.

Cancer‐associated fibroblasts (CAFs) promote the lymph node metastasis of esophageal squamous cell carcinoma

“…Furthermore, there are a few studies, which have reported orthotopic metastatic mouse models of esophageal cancer, however, of our knowledge, other orthotopic metastatic mouse models of cocultured EC with CAFs have not been reported . We have established and reported this esophageal orthotopic xenograft model, in which tumor volume and metastatic activity were evaluated by luciferase emission . In our study, we successfully transfected TE4 cells with luciferase and applied TE4‐luc cells to evaluate metastatic activity.…”

Selective inhibition of esophageal cancer cells by combination of HDAC inhibitors and Azacytidine

“…67,68 Orthotopic transplantation as alternative mouse model seems to be possible, but also showed some drawbacks before. [69][70][71][72] For example, Gros and colleagues 69 injected primary EAC cells into the submucosa of the abdominal esophagus by an invasive surgery technique, but only peritoneal carcinomatosis without formation of primary tumors was observed in this model. Still, our study provides a first comprehensive in vitro approach and insight to show cancer cell-selectivity for the entity of esophageal cancer by comparing non-neoplastic esophageal Het-1A cells to five esophageal and one GEJ cancer cell lines, providing a proof of principle concept.…”

The Synthetic β-Nitrostyrene Derivative CYT-Rx20 Inhibits Esophageal Tumor Growth and Metastasis via PI3K/AKT and STAT3 Pathways

“…The mice were housed 2~3 animals per cage in pathogen free conditions, under 12 h light/dark cycle, 22 ± 2°C room temperature, and 40–60% relative humidity with ad libitum food and drinking water. Orthotopic esophageal cancer model was performed according to a previous study [21]. A skin incision was made in the middle of the upper abdomen from the xiphoid process.…”