Aptamer-based therapy for targeting key mediators of cancer metastasis (Review)

Cancer-related deaths remain a challenging and devastating obstacle to defeat despite the tremendous advances in cancer treatment. Cancer metastasis is the major cause of these cancer-related deaths. Metastasis involves sequential steps during cancer cells' journey to a new site. These steps are coordinately regulated by specific intracellular regulators and cellular interactions between the cancer cells and the supporting microenvironment of the different organs. The development of aptamer-based therapeutics is a promising strategy to fight cancer metastasis as it holds potential advantages. Oligonucleotide and peptide aptamers are short sequences of single-stranded nucleic acids or amino acids, respectively, that target proteins, genetic materials, and cells. Antimetastatic aptamer-based therapeutics exert their pharmacological effect by direct interaction with the signaling pathways inside the cancer cells or the communications between cancer cells and the tumor microenvironment. In addition, aptamers have been utilized as a guiding ligand to deliver a therapeutic moiety to cancer cells or the supporting microenvironment. The selected aptamer possesses high specificity since it is designed to recognize and interact with its target. This review summarizes recent advances in the development of aptamer-based therapeutics targeting mediators of cancer metastasis. In addition, potential opportunities are discussed to inspire researchers in the field to develop novel aptamer-based antimetastatic treatments.