Colorectal cancer mouse metastasis model combining bioluminescent and micro-computed tomography imaging for monitoring the effects of 5-fluorouracil treatment

BACKGROUND: Colorectal cancer (CRC) is the fifth most fatal cancer with a low probability of surgery and limited treatment options, especially in metastatic CRC. In this study, we investigated whether a mouse model of metastatic CRC mimicked tumor progression and evaluated the effect of 5-fluorouracil (5-FU) treatment. METHODS: The CT26 mouse derived CRC cancer cell line was inoculated into mice, and the tumor bearing mice were divided into two groups: the experimental group and the control group. Micro-computed tomography (CT) and in vivo fluorescence were used to monitor the progression of metastatic CRC. A lung metastasis mouse model was employed to determine the effects of 5-FU on metastasis. RESULTS: Bioluminescence imaging (BLI) and computed tomography (CT), as non-invasive methods, can continuously monitor the growth of tumors in vivo. Thus, imaging techniques can be used to qualitatively and quantitatively evaluate tumor growth indicators. 5-FU injected intravenously reduced the viability of metastatic CRC cells and resulted in prolonged survival compared to the control group. Moreover, the 5-FU-treated group had significantly reduced fluorescence of the CT26 cells in the lung. The results observed by BLI and CT are consistent with the tissue morphology and structure presented in pathological examination. CONCLUSIONS: In summary, a successful mouse model of CRC metastasis for clinical application has been established.