A novel aptamer developed for breast cancer cell internalization.

Breast cancer affects one in eight women in the United States, with a mortality rate that is second only to lung cancer. Although chemotherapy is widely used in breast cancer treatment, its side effects remain a challenge. One way to address this problem is through drug delivery by the internalization of cell-type-specific probes. Although nucleic acid aptamers are excellent probes for molecular recognition, only a few studies have demonstrated that aptamers can be internalized into living cells. Therefore, herein we report the development of a cancer-cell-specific DNA aptamer probe, KMF2-1a. By using the cell-SELEX method, this aptamer was selected against breast cancer cell line MCF-10AT1. Our results show that KMF2-1a is internalized efficiently and specifically to the endosome of target breast cancer cells. These results indicate that KMF2-1a is a promising agent for cell-type-specific intracellular delivery with both diagnostic and therapeutic implications.