Coexpression of MAGE-A peptides and HLA class I molecules in hepatocellular carcinoma.

Melanoma antigen (MAGE)-A derived peptides are tumour-specific and induce a strong in vitro T-cell response, if presented with human leukocyte antigen (HLA) molecules, which are involved in T-cell-mediated immune surveillance. MAGE-A-derived peptides are recognised by autologous cytotoxic T lymphocytes. The MAGE-A expression profile of hepatocellular carcinomas (HCC) was analysed by PCR assay covering MAGE-A transcripts in 13 patients. MAGE-A peptide expression was determined using a reverse transcription-PCR method. Cryostat sections were stained with monoclonal antibodies directed against HLA class I molecules. Twelve (92.3%) out of thirteen tumours expressed one MAGE-A gene. In at least 90% of the tumours, one MAGE-A peptide was expressed. Determination of the HLA status of the tumours showed a significant loss in approximately 40% of the tumours. The tumour-specific expression of MAGE genes and antigens encoded by a MAGE-family gene may represent useful targets for tumour-specific immunotherapy in HCC patients, in addition to established treatment options.