【Animal Modeling】-Improved Animal Model of Orthotopic Hepatocellular Carcinoma Transplantation in Mice

  Objective To explore a technical method for establishing an efficient and stable animal model of liver orthotopic transplantation tumor.

  Methods Using a 10 μL microinjection needle, 5 μL of a solution containing 5×105 H22 cells was implanted in the left lobe of the liver of mice along the long axis of the liver lobe. In the key step of withdrawing the needle to avoid the leakage of H22 cells, cotton pressure was used respectively. The size, weight and pathological changes of liver tumors were detected on the 19th day after inoculation, and the differences in the effects of these two methods in the preparation of stable and homogeneous liver orthotopic transplantation tumors were compared.

  Results The liver tumor formation rate of both methods was 100%. There was no statistical difference in tumor size, weight and pathological manifestations between the two groups of mice, but compared with the cotton pressing group, the size of the liver transplanted tumor in the heat-sealing group was uniform, and the fluctuation of the tumor weight was small. In particular, at necropsy, high rates of ascites (36.4%) and abdominal aneurysm (36.4%) were found in the cotton-pressed group, but not in the heat-sealed group, with a statistically significant difference ( P<0.05). This indicated that the leakage of tumor cells from the injection hole in the cotton compression group was significantly increased, which was also the fundamental reason for the large fluctuation of the size of the liver transplant tumor in the cotton compression group. In addition, one mouse with ascites also developed multiple tumor nodules in the liver in the cotton pressure group, which may be the phenomenon of liver metastasis formed by ascites tumor cells through the vasculature.

  Conclusion This study successfully explored a set of technical methods and implementation points for the preparation of homogeneous and stable liver orthotopic transplantation tumors. It has the characteristics of short time, easy operation, and stable model, which provides a good reference for relevant researchers.