Search

Background: Prostate Stem Cell Antigen (PSCA) is a small cell surface protein, overexpressed in 90% of prostate cancers. Determination of epitopes that elicit an appropriate response to the antibody generation is vital for diagnostic and immunotherapeutic purposes for prostate cancer treatment. Presently, bioinformatics B-cell prediction tools can predict the location of epitopes, which is uncomplicated, faster, and more cost-effective than experimental methods., Objective: We aimed to predict a novel linear peptide for Prostate Stem Cell Antigen (PSCA) protein in order to generate anti-PSCA-peptide (p) antibody and to investigate its effect on prostate cancer cells., Methods: In the current study, a novel linear peptide for PSCA was predicted using in silico methods that utilize a set of linear B-cell epitope prediction tools. Polyclonal antibody (anti-PSCA-p antibody "Patent No. 99318") against PSCA peptide was generated. The antibody reactivity was determined by the Enzyme-Linked Immunosorbent Assay (ELISA) and its specificity by immunocytochemistry (ICC), immunohistochemistry (IHC), and Western Blotting (WB) assays. The effect of the anti-PSCA-p antibody on PSCA-expressing prostate cancer cell line was assessed by Methylthiazolyldiphenyl- Tetrazolium bromide (MTT) assay., Results: New peptide-fragment of PSCA sequence as "N-CVDDSQDYYVGKKN-C" (PSCA-p) was selected and synthesized. The anti-PSCA-p antibody against the PSCA-p showed immunoreactivity with PSCA-p specifically bound to PC-3 cells. Also, the anti-PSCA-p antibody strongly stained the prostate cancer tissues as compared to Benign Prostatic Hyperplasia (BPH) and normal tissues (P < 0.001). As the degree of malignancy increased, the staining intensity was also elevated in prostate cancer tissue (P < 0.001). Interestingly, the anti-PSCA-p antibody showed anti-proliferative effects on PC-3 cells (31%) with no growth inhibition effect on PSCA-negative cells., Conclusion: In this study, we developed a new peptide sequence (PSCA-p) of PSCA. The PSCA-p targeting by anti-PSCA-p antibody inhibited the proliferation of prostate cancer cells, suggesting the potential of PSCA-p immunotherapy for future prostate cancer studies., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background: Prostate cancer is one of the leading causes of cancer deaths among men. New gene expressed in prostate (NGEP), is a prostate-specific gene expressed only in normal prostate and prostate cancer tissue. Because of its selective expression in prostate cancer cell surface, NGEP is a potential immunotherapeutic target. To target the NGEP in prostate cancer, it is essential to investigate its expression in prostate cancer cells. Methods: In the present study, we investigated NGEP expression in LNCaP and DU145 cells by real time and RT-PCR, flow cytometric and immunocytochemical analyses. Results: Real time and RT-PCR analyses of NGEP expression showed that NGEP was expressed in the LNCaP cells but not in DU145 cells. The detection of NGEP protein by flow cytometric and immunocytochemistry analyses indicated that NGEP protein was weakly expressed only in LNCaP cell membrane. Conclusion: Our results demonstrate that LNCaP cell line is more suitable than DU145 for NGEP expression studies; however, its low-level expression is a limiting issue. NGEP expression may be increased by androgen supplementation of LNCaP cell culture medium. [ABSTRACT FROM AUTHOR]