OBJECTIVETo investigate the anti-tumor effect of intraportal administration of Adv-p53 in the treatment of the liver metastasis in mice.

METHODS2 x 10(5) of MCA-205 cells were injected into the mouse portal vein to establish a murine liver metastasis model. The spleen was transpositioned subcutaneously to enable the administration of Adv-p53 continually into the portal system. Different doses of Adv-p53 were injected intraportally, while HBSS and Adv-CMV were injected intraportaly in the control group. Tumors in the liver were examined on day 21 after Adv-p53 administration.

RESULTSThe liver weight in the Adv-p53 treated mice on day 0 group (1.20 +/- 0.34 g) was significantly less than that in the Adv-CMV group (2.59 +/- 0.48 g, P < 0.05). The number of metastatic nodules in the Adv-p53 treated mice on day 0 group (9.0 +/- 9.9) was significantly less than that in the Adv-CMV group (57.1 +/- 11.3, P < 0.05), indicating that intraportal administration of Adv-p53 inhibited the formation of liver metastasis. This anti-tumor effect was in a dose-dependent manner. After the liver metastasis was formed, Adv-p53 was administered intraportally. The liver weight in the Adv-p53 treated mice on day 5 group (1.22 +/- 0.09 g) was significantly less than that in the Adv-CMV group (3.98 +/- 1.01 g , P < 0.05). The number of metastatic nodules in the Adv-p53 treaed mice on day 5 group (5.5 +/- 3.5) was significantly less than that in the Adv-CMV group (113.2 +/- 5.8, P < 0.05). Repeatedly intraportal administration of Adv-p53 could enhance this anti-tumor effect.

CONCLUSIONLocal administration of Adv-p53 into the portal system would be a useful strategy for the liver metastasis treatment.