[Possibilities of glypican-3-specific immunotherapy for hepatocellular carcinoma]

The patients with hepatitis B or C based liver cirrhosis are at high risk for developing Hepatocellular carcinoma (HCC), and HCC patients treated surgically or by other therapies are also at high risk for recurrence. As a result, the prognosis of HCC remains poor, and new therapies for the prevention of cancer development and recurrence are urgently needed. We previously reported that glypican 3 (GPC3) was over expressed specifically in HCC. In this report, we found the HLA-A2 or HLA-A24 restricted GPC3 epitope peptide, and investigated whether these peptides could induce GPC3 reactive CTLs from the peripheral blood mononuclear cells (PBMCs) of HLA-A2+ or HLA-A24+ HCC patients. We used HLA-A2.1 (HHD) transgenic mice (Tgm) to identify the HLA-A2-restricted GPC3 epitopes. We found that these epitope peptides could induce peptide-reactive CTLs in about 50% of HLA A2+ or HLA-A24+, and GPC3+ HCC patients. Our study raises the possibility that these GPC3 peptides may therefore be applicable to cancer immunotherapy for prevention of cancer development and recurrence of HCC.