Identification of new aptamer BC-3 targeting RPS7 from rapid screening for bladder carcinoma

Aptamers,short single DNA or RNA oligonucleotides,have shown immense application potential as molecular probes for the early diagnosis and therapy of cancer.However,conventional cell-SELEX technologies for aptamer discovery are time-consuming and laborious.Here we discovered a new aptamer BC-3 by using an improved rapid X-Aptamer selection process for human bladder carcinoma,for which there is no specific molecular probe yet.We show that BC-3 exhibited excellent affinity in bladder cancer cells but not normal cells.We demonstrate that BC-3 displayed high selectivity for tumor cells over their normal counterparts in vitro,in mice,and in patient tumor tissue specimens.Further endocytosis pathway analysis revealed that BC-3 internalized into bladder cancer cells via clathrin-mediated endocytosis.Importantly,we identified ribosomal protein S7(RPS7)as the binding target of BC-3 via an integrated methodology(mass spectrometry,colocalization assay,and immunoblotting).Together,we report that a novel aptamer BC-3 is discovered for bladder cancer and its properties in the disease are unearthed.Our findings will facilitate the discovery of novel diagnostic and therapeutic strategies for bladder cancer.