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.