IGF-I triple helix strategy in hepatoma treatment

Background/Aims: To investigate the effect of gene therapy for hepatocellul ar carcinoma based on inhibition of cellular IGF-I expression, the techniqu e of IGF-I triple helix was investigated in mice developing programmed hepa toma. Methodology: mhAT1F1 mouse hepatoma cell Line was transfected in vitro with IGF-I triple helix expression vector (pMT-AG-TH) or with IGF-I antisense e xpression vector (pMT-Anti-IGF-I). 10x10(6) transfected cells of either tri ple helix or antisense type were inoculated intraperitonealy into transgeni c ATIIITB6 mice developing genetically programmed hepatoma (mice die betwee n the age of 6 and 7 months). In parallel, human cell cultures established from surgically removed hepatomas were investigated. Results: mhAT1F1 and human primary cell cultures, transfected with pMT-AG-T H or pMIT-Anti-IGF-I Vectors resulted in total inhibition of IGF-I demonstr ated by immunocytochemical and Northern blot techniques. Transfected cells changed their phenotype and recovered major histocompatibility complex I ex pression showed by fluorescence-activated cell sorting analysis and Western blot. Moreover, two phenomena were observed in IGF-I "antisense" or "tripl e helix" transfected cells: 1) the apoptosis, demonstrated by TUNEL techniq ue; 2) the presence of IL-6 simultaneously with disappearance of tumor necr osis factor-alpha and IL-10, investigated by reverse transcriptase-polymera se chain reaction technique. In in vivo experiments, injection of murine tr ansfected cells into mice in terminal-phase prolonged their survival 3-4 mo nths in 100% of cases, as well in "antisense" group (8/8) as in '"triple he lix" group (10/10). Conclusions: Injection of hepatoma cells transfected with IGF-I triple heli x expression vector, and showing immunogenic and apoptotic characteristics, can constitute an effective cellular therapy against hepatocellular carcin oma.