Ben Jemaa et al. Journal of Experimental & Clinical Cancer Research 2010, 29:171 http://www.jeccr.com/content/29/1/171 Page 2 of 9 described, including the cytosolic variants PSMA’, PSM- C, PSM-D [10] and PSMA-E. These variants are thought to be the consequence of alternative splicing of the PSMA gene [11]. Concerning prostate tumorigenesis, the membrane form of PSMA is predominantly expressed. However, in normal prostate the dominating form of this protein is the one that appears in the cytoplasm [12,13]. If acting as a transmembrane receptor, PSMA can be internalized from the plasma membrane and trafficking through the endocytic system [13]. Although the PSMA have been noted in a subset of non prostatic tissues (small intestine, proximal renal tubule), the level of expression of PSMA in these tissues is less than in pros- tate tissue [14]. PSMA functions as folate hydrolase and neuropeptidase [15,16] with expression at low levels in benign prostatic epithelium and upregulated several fold in the majority of advanced prostatic malignancies [17]. In these tumors, PSMA immunoexpression has been shown to correlate with aggressiveness of the PC, with highest levels expressed in an androgen-deprived state and metastatic disease [18]. Unlike PSMA, PSA is a 33 kDa glycoprotein of the kallikrein family of proteases [19]. It is found in normal, hyperplastic and malignant prostate tissue, and is not specific biomarker for PC [20]. It is secreted into the lumen of prostatic duct to liquefy the seminal coagulum [21]. In invasive adenocarcinomas, disruption of the nor- mal glandular architecture and loss of the polarity of prostatic cells appear to allow PSA increased direct leak- age into peripheral circulation [22]. PSA is the most widely used serum marker for the diagnosis and follow- up of PC [23]. Unlike serum PSA, there are drawbacks to use tissue PSA, like for example, the loss of expres- sion of tissue PSA associated with advanced disease and the development of androgen-independent prostate can- cer (AIPC) [20,24]. Angiogenesis, the establishment of new blood vessels from preexisting blood, is thought to be required for process of tumorigenesis and metastasis and may prove to be a useful prognostic marker for prostate cancer [25]. A notable finding is that PSMA, an angiogenic endothelial cell which is like one of several peptidases that play a role in angiogenesis. PSMA expression was specifically detected on the neovasculature of many other prostates not related tumors, suggesting the possi- bility that PSMA may also functionally contribute to angiogenesis of primary and metastatic cancers [26,27]. Therefore, it has been suggested that PSMA may be uti- lized both as a marker and as a therapeutic target [26,6]. In prostate cancer, a significant correlation between PSMA expression and angiogenesis has been shown [26,28]. However, the biological role of both angiogenesis [29] and PSMA expression in PC is still unclear for there are, indeed, studies in which the presence of these mole- cules is deprived of any prognostic significance [30]. Interestingly, in vitro and in vivo investigation, it was revealed that PSA suppresses angiogenesis and, there- fore, tumor growth and PC invasiveness by activating the angiostatin-like fragments [31,32]. The present study was undertaken to relate the co- expression of prostate-associated antigens, PSMA and PSA, with the degree of vascularization in normal and pathologic (hyperplasia and cancer) prostate tissues to elucidate their possible role in tumor progression. On the basis of the heterogeneity in PSMA and PSA expres- sion along prostatic tumor progression, we suggested the presence of various profiles of these prostate-asso- ciated antigens in each prostatic group (NP, BPH and PC). This led us to better investigate the association between the two markers in each prostatic group. The ultimate question was which, if any, of these factors could provide additional information regarding the biol- ogy of prostate tumorigenesis. Materials and methods Prostates were obtained from: (i) transurethral resec- tions from 44 men (aged from 61 to 85 years) diagnosed clinically and histopathologically with Benign Prostate Hyperplasia (BPH); (ii) radical prostatectomy from 39 men (aged from 57 to 90 years) diagnosed with prostate cancer (PC) (dominant Gleason grade ≥7); and (iii) his- tologically normal prostates (NP) obtained at autopsy (8-10 hours after death) from 6 men (aged from 21 to 40 years) without histories or reproductive, endocrine or related diseases. All pathological, clinical and personal data were anon- ymized and separated from any personal identifiers. This study was made with the consent of the patients’ relatives or their family in autopsy cases. All the proce- dures followed were examined and approved by the Hospital of La Rabta of Tunis, the Hospital of Charles Nicolle of Tunis and the Military Hospital of Tunis (HMPIT) (Tunisia). The primary antibodies used were: mouse anti-human PSMA (3E6), mouse anti-human PSA (ER-PR8) and mouse anti-human CD34 (QBend10) (Dako, Glostrup, Denmark). CD34 antibody was used to label vessels in the prostate tissues. For hematoxylin-eosin staining and immunohisto- chemistry analysis, tissues were fixed for 24 hours at room temperature in 0.1 M phosphate-buffered 10% for- maldehyde, dehydrated and embedded in paraffin. Sec- tions (3 mm thick) were processed following the NovoLink™Polymer Detection Systems (Novocastra Laboratories Ltd, Newcastle, UK) method. Sections were deparaffinized, rehydrated through graded alcohols and