Aim: To explore the use of cancer-testis antigen G antigen 1 (GAGE-1) in the diagnosis and potential therapeutic targeting of hepatocellular carcinoma (HCC), we measured the expression of GAGE-1 protein levels in HCC tissues and its serum immunoreactivity in HCC patients.
Materials and methods: We detected the expression of GAGE-1 protein in HCC by immunohistochemistry (IHC). We then analyzed the clinical significance of GAGE-1 expression in HCC with respect to clinicopathological parameters. We observed positive anti-GAGE-1 antibody reactivity in HCC patient serum, liver cirrhosis patients (LC), hepatitis B patients (HB), and normal human individuals (NHS) by enzyme-linked immunosorbent assay.
Results: The IHC results showed that the positive rates of GAGE-1 protein expression in cancer tissues and adjacent tissues were 43.3% (26/60) and 5% (3/60), respectively. The expression level of GAGE-1 protein in HCC tissues was significantly higher than that in tumor-adjacent tissues (P < 0.05). Positive GAGE-1 protein expression was not correlated with clinicopathological parameters (P > 0.05). Positive serum anti-GAGE-1 antibody reactivity in HCC patients, LC, HB, and NHS was 23.33% (14/59), 13.1% (8/61), 3.3% (2/60), and 3.4% (2/59), respectively. The frequency of anti-GAGE-1 antibody-positive sera in HCC patients and LC was significantly different than that in HB and NHS (P < 0.01), but no significant differences were found between HCC patients and LC (P = 0.485) or between HB and NHS (P = 0.410). Positive anti-GAGE-1 antibody reactivity was not correlated with clinicopathological parameters (P > 0.05).
Conclusion: These data illustrate that the GAGE-1 protein exhibits moderate cancer-restricted pattern of expression and immunogenicity, laying the foundation for the application of GAGE-1 in immunotherapy and for the diagnosis of HCC.
Keywords: Cancer-testis antigen; G antigen 1; immunohistochemistry; serology.