Establishment of and Comparison between Orthotopic Xenograft and Subcutaneous Xenograft Models of Gallbladder Carcinoma

Background: Gallbladder carcinoma (GBC) is the most common carcinoma of the biliary system. Among itsresearch models, orthotopic xenograft models, important research tools, have been rarely reported in the literaturehowever. Aim: To explore establishment of an orthotopic xenograft model and to evaluate the advantage anddisadvantage as compared with other models. Materials and
Methods: Subcutaneous xenograft and orthotopicxenograft models of gallbladder carcinoma in nude mice were established and compared with human gallbladdercarcinomas.
Results: For the orthotopic xenograft model and clinical gallbladder carcinomas, the lymph nodemetastatic rates were 69.2% and 53.3% (p>0.05); ascites generation rates, 38.5% and 11.7%(p<0.05); liverinvasive rates, 100% and 61.7%(p<0.05); and lymphatic vessel densities (LVD), 10.4±3.02 and 8.77±2.92 (p>0.05),respectively. In the subcutaneous xenograft model, no evidence of ascites generation, lymph node metastasisand liver metastasis were found, and its LVD was lower (4.56±1.53, p<0.05).
Conclusions: Compared with thesubcutaneous xenograft model, the orthotopic xenograft model better simulates clinical gallbladder carcinomain terms of metastasis and invasion, which may be attributed to the difference in microenvironment and LVD.