Comparison of colorectal cancer in differentially established liver metastasis models

Background: Metastasis is one of the main reasons for colorectal cancer (CRC)-related deaths due to the lack of effective therapeutics mainly for liver metastasis. In the present study, we established an orthotopic colorectal cancer mouse model using different transplantation protocols to determine the optimal conditions for CRC liver metastasis. Materials and Methods: Luciferin-expressing HCT116 cells were used to induce liver metastasis models of colorectal cancer following both intra-splenic and cecal injections. Magnetic resonance imaging (MRI) and the In Vivo Imaging system were used to monitor internal growth of the primary tumor and metastasis. Results: The intra-splenic injection with high cell number (5×10⁶ cells/50 μL)-group achieved rapid tumor formation, and the highest metastatic rate. However, survival rates were shorter than those of the other groups. The time to develop primary tumors and liver metastases was slightly different between the two transplantation protocols followed and should be considered depending on the specific aim of each experiment. MRI and optical images correlated well with the pathological findings at necropsy with respect to both tumor growth and location. Conclusion: The model described herein will be effective in studying new therapeutic strategies against metastatic disease when used in conjunction with small animal MRI and optical imaging.