Auto-antibodies in prostate cancer: Humoral immune response to antigenic determinants coded by the differentially expressed transcripts FLJ23438 and VAMP3

BACKGROUND Here we evaluate auto-antibody response against two potential antigenic determinants of genes highly expressed in low Gleason Score prostate cancer (PC) tumor samples, namely FLJ23438 and VAMP3. METHODS RT-PCR assays were used to analyze mRNA expression profiles of FLJ23438 and VAMP3 transcripts. The auto-antibody response against FLJ23438 and VAMP3 recombinant proteins was tested by immunoblot assays using PC, benign prostate hyperplasia (BPH), healthy donors (HD), and other human cancers plasma samples. RESULTS Our data showed that 37% (10/27) and 7.4% (2/27) of PC plasma samples presented auto-antibodies against FLJ23438 and VAMP3, respectively. Only 8.3% (1/12) of BPH plasma samples were reactive for both auto-antibodies, while none (0/12) of HD plasma samples tested were reactive. CONCLUSIONS The prevalence of 37% of positive PC plasma samples for anti-FLJ23438 antibodies suggests that humoral immune response against this antigenic determinant could be a potential serum marker for this cancer. Prostate 66: 1463–1473, 2006. © 2006 Wiley-Liss, Inc.