Establishment of an orthotopic transplantation tumor model of hepatocellular carcinoma in mice

Abstract

Aim: To improve the outcome of orthotopic transplantation in a mouse model, we used an absorbable gelatin sponge (AGS) in nude mice to establish an orthotopic implantation tumor model.

Methods: MHCC-97L hepatocellular carcinoma (HCC) cells stably expressing the luciferase gene were injected into the subcutaneous region of nude mice. One week later, the ectopic tumors were harvested and transplanted into the left liver lobe of nude mice. The AGS was used to establish the nude mouse orthotopic implantation tumor model. The tumor suppressor gene, paired box gene 5 (PAX5), which is a tumor suppressor in HCC, was transfected into HCC cells to validate the model. Tumor growth was measured by bioluminescence imaging technology. Semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and histopathology were used to confirm the tumorigenicity of the implanted tumor from the MHCC-97L cell line.

Results: We successfully developed an orthotopic transplantation tumor model in nude mice with the use of an AGS. The success rate of tumor transplantation was improved from 60% in the control group to 100% in the experimental group using AGS. The detection of fluorescent signals showed that tumors grew in all live nude mice. The mice were divided into 3 groups: AGS-, AGS+/PAX5- and AGS+/PAX5+. Tumor size was significantly smaller in PAX5 transfected nude mice compared to control mice (P < 0.0001). These fluorescent signal results were consistent with observations made during surgery. Pathologic examination further confirmed that the tissues from the ectopic tumor were HCC. Results from RT-PCR proved that the HCC originated from MHCC-97L cells.

Conclusion: Using an AGS is a convenient and efficient way of establishing an indirect orthotopic liver transplantation tumor model with a high success rate.

Keywords: Absorbable gelatin sponge; Bioluminescence imaging; Hepatocellular carcinoma; Nude mice; Orthotopic transplantation tumor model.

Figure 1

Representative images of fluorescence signals in nude mice detected by the International Veterinary Information Service system. The fluorescence signal intensity shows xenograft tumor size.

Figure 2

Harvesting orthotopic liver transplantation tumors. Tumors were harvested from the mice in groups II and III. Tumor size and weight in the paired box gene 5 (PAX5) group were smaller than those in the control group (P < 0.0001).

Figure 3

Tumor growth curve determined by the International Veterinary Information Service system. The P value was calculated using repeated measures analysis of variance. PAX5: Paired box gene 5.

Figure 4

Liver tissues from nude mice were detected by hematoxylin and eosin staining. A: Liver tumor, × 200; B: Normal liver, × 200.

Figure 5

Gene expression of paired box gene 5 in liver tumor tissues of mice in situ which was detected by reverse transcription-polymerase chain reaction. The expression of β-actin which acted as the internal control was determined. PAX5: Paired box gene 5.