Avicenna J Med Biotech arij002 Avicenna Journal of Medical Biotechnology 2008-2835 2008-4625 Avicenna Research Institute ajmb242 Development of a Single Stranded DNA Aptamer as a Molecular Probe for LNCap Cells Using Cell-SELEX AlmasiFaezehImmunology Research Center, Tabriz University of Medical Sciences, Tabriz, IranMousavi GargariSeyed LatifImmunology Research Center, Tabriz University of Medical Sciences, Tabriz, IranDepartment of Immunology, School of Medicine, Tabriz University of Medical Sciences, Tabriz, IranBitarafFatemehDivision of Neonatal-Perinatal Medicine, Wayne State University , Detroit, MI, , United States of AmericaRasoulinejadSamanehDivision of Neonatal-Perinatal Medicine, Wayne State University, Detroit, MI, United States of America 8 3 104 111 18 12 2015 15 2 2016

<p>Background: Nowadays, highly specific aptamers generated by cell SELEX technology (systematic evolution of ligands by exponential enrichment) are being applied for early detection of cancer cells. Prostate Specific Membrane Antigen (PSMA), over expressed in prostate cancer, is a highly specific marker and therefore can be used for diagnosis of the prostate cancer cells. The aim of the present study was to select single-stranded DNA aptamers against LNCap cells highly expressing PSMA, using cell&ndash;SELEX method which can be used as a diagnostic tool for the detection of prostate cancer cells.<br /> Methods: After 10 rounds of cell-SELEX, DNA aptamers were isolated against PSMA using LNCaP cells as a target and PC-3 cell lines for counter SELEX. Five DNA aptamers with more than 70% affinity were selected up on flow cytometry analysis of positive clones.<br /> Results: Dissociation constants of two selected sequences (A12-B1) were estimated in the range of 33.78&plusmn;3.77 and 57.49&plusmn;2.214 <em>pmol</em>, respectively. Conserved secondary structures of A12 and B1 sequences suggest the necessity of these structures for binding with high affinity to native PSMA. Comparison of the secondary structures of our isolated aptamers and aptamer A10 obtained by protein SELEX showed similar stem-loop structures which could be responsible for the recognition of PSMA on LNCap cell surface.<br /> Conclusion: Our results indicated that selected aptamers may turn out to be ideal candidates for the development of a detection tool and also can be used in targeted drug delivery for future smart drugs.</p>