Selection of CD133-targeted DNA aptamers for the efficient and specific therapy of colorectal cancer

Tumor-targeted delivery of antitumor drugs is considered a promising strategy for improving the chemotherapeutic efficiency and reducing the incidence of side effects. The development of tumor-targeted aptamers to accommodate drugs has attracted great interest because of their convenience in biomedical applications. CD133 is a robust biomarker of colorectal cancer. In this study, Cs5, a novel specific aptamer with a dissociation constant in the nanomolar range, was developed using the cell-SELEX strategy from engineered CD133-expressing cells, and doxorubicin (Dox) was loaded into the Cs5 aptamer to form a chimera. The chimera showed an excellent targeting ability for CD133 through a selective killing effect in human colorectal cancer HCT116 cells expressing CD133. The in vitro and in vivo results demonstrated the highly efficient therapy and low toxicity of the chimera. Given the overexpression of CD133 in various tumors, our work provides a promising tool for specific cell identification and a wide range of applications in the field of targeted cancer therapy.