[Changes of hypoxia-inducible factor in residual hepatocellular carcinoma following high-intensity focused ultrasound exposure in nude mice].

ABSTRACT

OBJECTIVE: To study the changes in hypoxia-inducible factor (HIF1α, HIF2α) in the residual tumor cells in nude mice bearing hepatocellular carcinoma (HCC) following treatment with high-intensity focused ultrasound (HIFU). METHODS: Thirty nude mice bearing human HCC received treatment with HIFU. At 1, 3, and 5 days and 1 and 2 weeks after the treatment, the mice were examined for pathological changes of the residual tumor with HE staining; SP immunohistochemistry, Western blotting and real-time quantitative PCR were used to detect the protein and mRNA expressions of HIF1α and HIF2α in the tumor. RESULTS: HE staining revealed the presence of residual tumor cells and large necrotic areas after the treatment. Immunohistochemistry showed a gradual increment of HIF1α protein and mRNA expressions after the treatment, reaching the peak level at 3 days (P<0.05) followed by progressive reduction at 5 days and 1 and 2 weeks. HIF2α expressions at either the protein or mRNA levels exhibited no significant changes within 3 days after the treatment (P>0.05) but increased significantly at 5 days and 1 and 2 weeks (P<0.05). CONCLUSION: The changes of HIF1α and HIF2α in the residual tumor after HIFU treatment in nude mice bearing HCC can be associated with tumor cell apoptosis and angiogenesis after the treatment.