The establishment of rabbit VX2 HCC model with tumor lump frozen in liquid nitrogen: Study on its modeling effect

Objective To discuss the establishment of rabbit VX2 hepatocellular carcinoma (HCC) model by using tumor lump which is frozen in liquid nitrogen and has good activity after resuscitation, and to compare the modeling effect with that by using conventional method. Methods The VX2 tumor blocks with good growth state were selected, the necrotic tissues were remove and the tissues in good condition were wrapped with tinfoil and frozen in liquid nitrogen for three months. Twenty Japanese white rabbits were randomly divided into two groups: Group A(control group, n=10) and group B (experiment group, n=10). In group A, rabbit liver cancer model was established by liver transplantation of fresh tumor lump with in situ planting method. In group B, the fresh liver tumor lumps were frozen in liquid nitrogen for three months first, then, the resuscitated tumor tissues were implanted into the liver with in situ planting method. Two weeks later, enhanced CT scan and DSA angiography were performed to check the tumor-modeling effect and tumor blood supply. After tumor-loaded rabbits were sacrificed, the gross specimens were removed and sent for pathological examinations. HE staining was adopted, and immunofluorescence staining of vascular endothelial growth factor (VEGF) and CD31 was used to calculate the microvessel density (MVD). Results In both group A and group B, the success rate of modeling was 100%. No significant differences in tumor growth rate and the expression levels of VEGF and MVD existed between the two groups. Conclusion The imaging manifestations on CT and DSA and the histologic characteristics of rabbit VX2 HCC model, which is established with tumor lump frozen in liquid nitrogen, are no obviously different from those of rabbit VX2 HCC model, which is established with conventional modeling methods. The freezing method of whole tumor lump can well preserve the tumor strain activity, thereby saving the manpower and material resources in the preparation of VX2 HCC model.