Ultrasound microbubble contrast agent-mediated suicide gene transfection in the treatment of hepatic cancer.

The aim of this study was to investigate the role of ultrasound microbubble contrast agent-mediated suicide gene transfection in the treatment of hepatic cancer. We intratumorally injected KDR-TK, AFP-TK and microbubble contrast agent into nude mice prior to ultrasound treatment and administration of prodrugs (GCV and 5-FC). The tumor volume, tumor inhibition rate, survival time and apoptosis of tumor cells was determined. The sizes of subcutaneous hepatic cancers in mice receiving treatment were comparable to those in the control group, and the survival time was similar between the two groups (P>0.05). However, the tumor inhibition rate and the number of apoptotic cells in the treatment group was markedly higher compared with that in the control group (P<0.05). Evident tumor necrosis was absent in both groups, except at the needle tract. Ultrasound therapy following injection of suicide genes and microbubble contrast agents is able to inhibit cancer growth in vivo. This may be attributed to the induction of cancer cell apoptosis.