Aptamer-MiRNA Conjugates for Cancer Cell-Targeted Delivery

microRNAs (miRNAs) are short noncoding RNAs that effectively regulate the expression of a wide variety of genes. Increasing evidences have shown a fundamental role of miRNAs in cancer initiation and progression, thus indicating these molecules among the most promising for new approaches in cancer therapy. However, several hurdles limit the translation of miRNAs into the clinic. One of the most critical aspects is represented by the lack of a safe and reliable way to selectively target organs and tissues. Therefore, the development of cell-specific delivery means has become an essential step for the translation of miRNA-based therapeutics to clinic for cancer management. To this end aptamer-based approaches may provide efficient delivery tools for the selective accumulation of miRNA to target tumors, their intracellular uptake, processing, and functional silencing of target genes. In this chapter, we discuss the direct conjugation of miRNAs to aptamers against transmembrane receptors as innovative experimental approach for their selective delivery to cancer cells.