Expression and immunogenicity of NY-ESO-1 in colorectal cancer.

Serum assays of NY-ESO-1 antibodies provide a guide to discriminate between patients who suffer from different types of cancer. In the present study, the expression of NY-ESO-1 was detected with the aim to identify a novel tumor antigen in colorectal cancer (CRC). Sera were obtained from 89 healthy individuals and 236 patients with CRC with stage I, II, III and IV tumors. The NY-ESO-1 autoantibody levels were determined using an enzyme-linked immunosorbent assay. The mRNA and protein expression levels of NY-ESO-1 were detected using reverse transcription-polymerase chain reaction and immunohistochemistry, respectively, in 60 CRC and paired adjacent non-tumor tissues. NY-ESO-1 antibody was detected in 40 of the 236 (16.9%) patients with CRC. The NY-ESO-1 antibody combined with carcinoembryonic antigen enhanced the sensitivity, from 52.1 to 62.7%, of the diagnosis of CRC. The frequency of antibody positivity increased with the TNM cancer stage (8.8 vs. 28.3% in stages I+II and III+IV, respectively). The mRNA and protein expression levels of NY-ESO-1 were significantly higher in CRC tissue than in adjacent non-tumor tissue. In conclusion, NY-ESO-1 is frequently expressed in CRC with the capacity of inducing a humoral immune response in CRC patients, exhibiting the potential to be a promising biomarker for CRC.