Ben Jemaa et al. Journal of Experimental & Clinical Cancer Research 2010, 29:171 http://www.jeccr.com/content/29/1/171 Page 8 of 9 invasiveness [31]. The vascular suppressive action of PSA could explain the low proliferation rate of tumor prostate growth and the low of angiogenesis process in malignant prostate [32]. In the study of Papadopoulous et al, it was found that high PSA expression is accompa- nied by low intratumoral angiogenesis in cancerous prostate epithelial cells [32]. The association between high PSA expression and low intratumoral angiogenesis seems to be consistent with our finding that prostate cancer expresses significantly less of tissue PSA than benign prostate tissue. The fundamental agent of angio- genesis, bFGF, promotes the proliferation and the migration of prostatic cancer cells by activation of MAPKs pathway and this effect of bFGF shows to be modulated by SOCS-3 (Suppressor of cytokine signal- ling-3) [28,45]. Interestingly, treatment with bFGF sti- mulates the expression of PSMA in LNCaP (androgen- dependent) cell line and restores the expression of this protein in disseminated form of prostate cancer, PC3 and DU145, (androgen-independent cells) [28]. Recently, Colombatti M et al, reporting for the first time a poten- tial interaction of PSMA with signaling molecules by activating the NFkB transcription factor and MAPK pathways in prostate cancer LNCaP cell line. The authors suggested a possible cross talk between PSMA, IL-6 and RANTES chemokine and its implication in cell proliferation and cell survival in prostate cancer cells [37]. Conclusion In conclusion, these data provide further evidence that PSMA is an important factor in prostate cancer biology. Moreover, PSMA and PSA seem to be inversely regu- lated in prostate cells, especially in prostate cancer cells. Little information exists concerning the role of signaling pathway in regulating cell apoptosis and survival/angio- genesis in prostate cancer cells in context to PSMA and PSA co-expression, formed the basis of our future study. More understanding of their regulation within signaling cascade in our prostatic subgroups could be interesting. List of abbreviations 1, 25-VD: 1α, 25-dihydroxyvitamin D3; BPH: Benign prostate hyperplasia; NP: Normal prostate; O.D: Optical density; PC: Prostate cancer; PSA: Prostate specific antigen; PSMA: Prostate Specific Membrane Antigen; PZ: Peripheral zone; TZ: Transition zone. Acknowledgements Grants support: Ministry of Higher Education and Scientific Research in Tunisia. Author details 1Unit of Immunology and Microbiology Environmental and Carcinogenesis (IMEC), Faculty of Sciences of Bizerte, 7021, Zarzouna, University of 7-November at Carthage, Tunisia. 2Department of Urology, Hospital of La Rabta Tunis, Tunisia. 3Department of Legal Medicine, Hospital of Charles Nicolle Tunis, Tunisia. 4Department of Urology, Military Hospital of Tunis, Tunisia. 5Department of Anathomopathology, Hospital of Menzel Bourguiba, Tunisia. Authors’ contributions RO contributed to the conception and design of the study; RO and ABJ contributed to data analysis, interpretation and to manuscript writing; ABJ, YB, SS, AB, NBR, LO, YN and AH contributed to collection and assembly of data. All authors read and approved the final manuscript. Competing interests The authors declare that they have no competing interests. Received: 28 September 2010 Accepted: 28 December 2010 Published: 28 December 2010 References 1. 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