Identification of a novel molecular probe for recognition of human osteosarcoma cell using the cell-SELEX method.

Osteosarcoma is the most common primary malignant bone tumor in adolescents and young adults. The lack of specific probes for human osteosarcoma hinders the early diagnosis and treatment of metastatic disease. In the present study, we have designed a novel aptamer using the cell-based Systematic Evolution of Ligands Exponential Enrichment (cell-SELEX) technique that specifically recognizes the U-2 OS human osteosarcoma cell line. Candidate aptamer families were identified through nine rounds of selection followed by sequence analysis and fluorescent labeling in addition to specific binding to U-2 OS cells. We identified one aptamer that showed high affinity and specificity to target cells, but did not recognize non-osteosarcoma negative control tumor cell lines. Moreover, we show that the selected aptamer can effectively be used as a molecular probe for specific recognition of clinical osteosarcoma samples. The generation of aptamer libraries can be used not only for the specific diagnosis of osteosarcoma, but also to build a platform for developing probe-carrier-antitumor drugs complexes and targeted therapies for osteosarcoma.