Tumor-associated
antigens (TAAs) trigger a TAA-specific immune response, thus they are the crux of antitumor immunosurveillance. A major advance in
tumor immunology in the last 20 years was marked by the verification that CTL or
B-cell epitopes rather than integral TAAs induce immunoreactivity. Previous studies on the correlation between
heparanase (Hpa) expression and clinical or pathological features have generally used commercial
antibodies against full-length Hpa
protein rather than the functional
epitopes, and the
antigen determinants of such
antibodies have not yet been defined. In our investigation of Hpa
peptide expression in
gastric cancer tissues and its association with
tumor invasion,
metastasis and prognosis, we analyzed Hpa expression in the tissues of 132 patients with
gastric cancer using tissue microarray (TMA) technology and immunohistochemical staining. Three self-developed rabbit polyclonal
antibodies against Hpa multiple antigenic
peptides (MAP) and one commercial polyclonal rabbit antibody against the 50-8 kDa Hpa heterodimer were used. Clinical and pathological significance was evaluated using the Chi-square test and Kaplan-Meier survival curve analysis. The results demonstrated that the positivity rates using the antibody against MAP2 and the commercial antibody were 60.6% (80/132) and 65.2% (86/132), respectively. No expression of either MAP1 or MAP3 was noted in the
cancer tissues of the 132 cases. MAP2 behaved in a similar manner to the commercial antibody in that a higher Hpa expression was observed in the
cancer tissues with vessel invasion, serosal involvement, distant
metastasis, poor differentiation and TNM stages III and IV. Moreover, the patients with a positive Hpa expression had a far poorer prognosis, with lower one-year and five-year survival rates. Our results demonstrate that in a similar manner to full-length Hpa
proteins, MAP2 expression is closely associated with the invasion,
metastasis and prognosis of
gastric cancer. This finding may be of potential use in clinical
therapy and in estimating the prognosis of a
tumor.