Nude mice model of human hepatocellular carcinoma via orthotopic implantation of histologically intact tissue

AIM: To establish a nude mice model of human hepatocellular carcinoma (HCC) via orthotopic implantation of histologically intact tissue, in order to study biologic features of HCC in vivo and to direct clinical treatment respectively.METHODS: Histologically intact fresh specimens of HCC were orthotopically implanted in nude mice (BALB/c, nu/nu). Survival rate and growth curve were investigated with Bultrasound. Morphological characteristics of pathology and spontaneous metastatic rates were detected with microscopy. Expression of multidrug resistance genes studied with immunohistochemical method and RT-PCR, and other biologic features of implanted tumor were observed and compared with human HCC specimens. RESULTS: Out of the specimens from two patients with HCC, only one specimen survived in nude mice. The orthotopic implantation tumor survival rate, spontaneous intrahepatic metastatic rate, pulmonary metastatic rate and bone metastases rate were 100%, 75.0%, 37.5% and 37.5% respectively in the first passage. AFP was kept on secreting and increasing with the size of the tumor. The morphological characteristics and biologic features were similar to the donor's, the protein and mRNA of MDR1 and LRP were expressed in tumors of the model and the donor, and there was no significant difference between them (P>0.05). CONCLUTION: The model of nude mice with orthotopic implantation of histologically intact HCC tissue is an ideal model to study biologic features of HCC in vivo and to direct clinical treatment.

Nude mice multi-drug resistance model of orthotopic transplantation of liver neoplasm and Tc-99m MIBI SPECT on p-glycoprotein

AIM: To establish a model of drug-resistant neoplasms using a nude mice model, orthotopic transplantation of liver neoplasm and sporadic abdominal chemotherapy. METHODS: Hepatocellular carcinoma cells HepG2 were cultured and injected subdermally to form the tumor-supplying mice. The orthotopic drug-resistant tumors were formed by implanting the tumor bits under the envelope of the mice liver and induced by abdominal chemotherapy with Pharmorubicin. Physical examination, ultrasonography, spiral CT and visual inspection were used to examine tumor progression. RT-PCR and immunohistochemistry were used to detect expression of mdr1 mRNA and its encoded protein p-glycoprotein (p-gp). Tc-99m sestamibi scintigraphy was performed by obtaining planar abdominal images at 20 min after injection, and the liver/heart ratios were calculated. RESULTS: Post-implantation mortality was 0% (0/25), tumor implantation success was 90% (22/25), and the rate of implanting successfully for the second time was 100% (3/3). Tumor induction using Pharmorubicin was 80% (16/20). The mdrl mRNA expression of the induced group was 23 times higher than that of the control group, and p-gp protein expression was 13-fold higher compared to the control group. The liver/heart ratio (as assessed in vivo, using Tc-99m radiography) was decreased significantly in the induced group as compared to the control group. CONCLUSION: We have established an in vivo model of mdrl in nude mice by orthotopic transplantation of liver neoplasm coupled to chemotherapy. We propose that identification of drug resistance as characterized by decreased 99mTc-ppm radiography due to enhanced clearance by p-gp may be useful in detecting in vivo drug resistance, as well as a useful tool in designing more effective therapies.