Identification of the antigens predominantly reacted with serum from patients with hepatocellular carcinoma

BACKGROUND. To identify antigens specifically recognized by the immune surveillance system in patients with hepatocellular carcinoma (HCC), the authors examined two complementary DNA (cDNA) libraries of moderately differentiated HCC by serologic analysis of recombinant cDNA expression libraries (SEREX). METHODS. The libraries were screened with autologous patients' sera, and sequences of the reacted clones were determined. To study the immunoreactivity of the antigens, sera from 20 patients with HCC, from 20 healthy volunteers, and from 16 patients with chronic viral hepatitis were examined. RESULTS. Twenty-seven antigens were identified. They included SART1, p57Kip2, ROCK-1, γ-catenin, and heat shock proteins, which are classified as tumor-associated genes. Three of 27 antigens - Tat-binding protein-1 (TBP-1), β4 integrin-binding protein (p27[BBP]), and ribosomal protein L30 (rpL30) - were reacted predominantly with sera from patients with HCC (55% of patients, 45% of patients, and 20% of patients, respectively). Patients in the control group had no antibodies against these three antigens. Seventy percent of patients with HCC had the antibody against at least one of these antigens. CONCLUSIONS. Disease specific humoral immune response against TBP-1, p27(BBP), and rpL30 was induced in patients with HCC, and the antibodies against these antigens also may be used as tumor markers.