Abstract
The Wilms tumor 1 gene, WT1, is overexpressed in various types of cancer, including gastric cancer. The product of WT1 is highly immunogenic and is a promising target molecule for cancer immunotherapy. The current study aimed to examine the production of WT1-specific IgG and IgM autoantibodies to identify biomarkers of diagnostic value in patients with gastric cancer. IgG antibodies that bind to WT1-derived peptides were obtained, the serum levels of which correlate with those of IgG antibodies against the WT1 protein in patients with intestinal malignancies. The serum levels of IgG and IgM antibodies against the WT1-271 peptide (271-288 amino acids) were examined in 39 healthy individuals and 97 patients with gastric cancer. The positivity cutoff value was determined according to the receiver operating characteristic curve. The association between WT1-271 IgM and the clinicopathological factors and prognosis of patients was additionally analyzed. The results revealed that serum WT1-271 IgM antibody levels in patients with gastric cancer were significantly higher than those in healthy individuals. The sensitivity and specificity of this antibody for gastric cancer were 67.0 and 71.8%, respectively; this sensitivity was improved when compared with conventional tumor markers (P<0.001). There was no statistical difference in WT1-271 IgG antibody levels between patients with gastric cancer and healthy individuals. Serum WT1-271 IgM antibody levels were not significantly associated with clinicopathological factors but were associated with unfavorable prognosis. Serum WT1-271 IgM antibody levels could serve as a diagnostic biomarker in patients with gastric cancer.