[Preliminary studies on the effects of tumor necrosis factor gene transfer on the growth of human hepatocellular carcinoma cells in nude mice].

An eukaryotic expression vector containing tumor necrosis factor alpha (TNF alpha) gene (psVK3-tnf) was transduced into hepatocellular carcinoma (HCC) cell line, SMMC7721, by calcium phosphate coprecipation method. The TNF-gene-transduced SMMC7721 cell began to secrete TNF after 24h (50 0/ml), reached peak level at 48-72h (90U/ml), and declined after 96h (40U/ml). Three weeks after the pSVK3-tnf DNA entrapped with calcium phosphate was introduced directly into subcutaneous nodules of human HCC in nude mice (treated mice), the growth of HCC was significantly delayed as compared to the pSVK3 group (control mice) (2.5 +/- 1.6 cm vs. 3.2 +/- 1.8 cm, n = 6, P < 0.05). There was a transient increase in TNF alpha level in peripheral blood in the treated but not in the control mice. The survival time of the treated mice was markedly prolonged as compared to the control (44.0 +/- 3.3d vs. 28.2 +/- 2.0d, n = 6, P < 0.01). The above results suggest that TNF alpha gene transfer might be a hopeful therapy for HCC.