Objective To further investigate the expression of MAGE-1 gene in hepatocel
lular carcinoma (HCC).
Methods The tumors and adjacent liver tissue from 45 HCC patients and liver
tissue from 28 non-HCC patients (16 with liver cirrhosis and 12 with norma
l liver) were characterized by RT-PCR. A 421 bp PCR product from a cDNA fra
gment spanning exons 1, 2 and 3 was sequenced. The HLA type was assayed by
standard ELISA in 43 HCC patients.
Results Thirty-two of 45 tumor tissues from HCC patients expressed MAGE-1 m
RNA (71.1%). In contrast, MAGE-1 mRNA was not detected in adjacent tissues.
Three were found to have point mutations at 3 identical sites resulting in
the substitution of two amino acid residues. The most frequent HLA types i
n 43 HCC patients were: HLA-A2, 53.5%; A11, 25.6%; A24, 20.9%; A33, 20.9%;
HLA-B13, 28.3% and B35, 23.2%. Expression of HLA-A33 (20.9%) was higher in
HCC patients than that predicted in the normal Chinese population (8.8%). T
here was no discernable correlation between MAGE-1 expression and alpha -FP
level, tumor size and hepatitis B or C virus infection. The identification
of peptides which are restricted by haploptypes other than A1 should incre
ase the opportunity for peptide based immunotherapy.
Conclusions This study shows that MAGE-1 mRNA is highly expressed in HCC tu
mor tissue in Chinese patients. Previously unreported point mutations in th
e MAGE-1 gene are described and may also provide additional opportunities f
or immunotherapy.