Creation of a murine orthotopic hepatoma model with intraabdominal metastasis

Aim: To create an orthotopic hepatoma model with local metastasis monitored with ultrasound could be created as a platform for testing new treatments. Background: Hepatoma accounts for 25% of liver tumors in children with poor overall survival. Intraabdominal metastasis are present in 35% of patients at time of diagnosis. We hypothesized that an orthotopic tumor model with local metastasis could be created as a platform for testing treatment modalities and could be monitored with ultrasound. Patients and methods: One million human hepatoma cells (Hep3B) were injected into the left lobe of the liver of immunocompromised mice. Tumor volume was monitored with high frequency-ultrasound until it reached 1,000mm3. At that time animals were sacrificed and examined for gross metastatic disease. Tumor sections were analyzed with hematoxylin and eosin (H&E) staining. Results: Tumor formed in 8/15 mice. The tumor was detected as small as 19.59mm3 on ultrasound. Of the forming tumors, tumor size was 145±177.93mm3 at 60 days post-injection, 665±650.39mm3 at 67 days, and reached >1000mm3 by 76.6±9.9 days. At necropsy, four mice (50%) had tumor only within the liver, four (50%) had additional tumors in omentum, pelvis and peritoneum. H&E showed tumor within the normal liver parenchyma, with multiple mitotic figures, small areas of necrosis, and hemorrhage within the tumor. Conclusion: We have successfully established an orthotopic hepatoma murine model, with a local metastatic rate of 50%. Non-invasive tumor monitoring is feasible via ultrasound.