Glypican3 in genetically modified human monocyte-derived dendritic cells induced specific cytotoxity against glypican3 overexpressing human hepatocellular carcinoma cells in vitro.

Abstract

OBJECTIVES To transduce the new hepatocellular carcinoma (HCC) specific antigen gene glypican3 (GPC3) into dendritic cells (DCs) and to observe the in vitro cytotoxic effect induced by the genetically modified DCs against the hepatocellular carcinoma cell line (HepG2). METHODS This study was performed in China Medical University Shenyang, China from September 2007-February 2008. The design of the study was to modify DCs with GPC3 and to be used to activate human T cells and elicit a cell-mediated immune response against HepG2 in vitro. The GPC3 gene expression was identified by western blot and immunocytochemistry. The proliferation of responder cells and cytotoxicity against HepG2 were examined by water-soluble tetrazolium salt -1 and lactate dehydrogenase assay respectively. The interferon-y (IFN-y) secreted was detected by ELISA assay. RESULTS Both Western blot and immunocytochemical analysis assured the validity of GPC3 transfection. Glypican3 modified DCs were potent in inducing responder cells proliferation and IFN-y production. The cytotoxicity in the group of GPC3 transfected DCs were (38.90±0.95%) at the ratio of effector cells/target cells E/T:100:1, 30.83±1.24% at the ratio of E/T:50:1, and 23.84±0.65% at the ratio of E/T:10:1, respectively (which is significant compared with other groups, p<0.001). And the GPC3 modified DCs showed ability to induce high specific cytotoxicity against HepG2 in vitro. CONCLUSIONS The effector cells stimulated with DCs that were transfected with pEF-hGPC3 plasmid could effectively lyse GPC3 expressing HepG2 cells, which suggested that those genetically engineered DCs have the potential to serve as novel vaccine for HCC.