Portal de Periódicos da CAPES

Novel HER2 Aptamer Selectively Delivers Cytotoxic Drug to HER2-positive Breast Cancer Cells in Vitro

2012; BioMed Central; Volume: 10; Issue: 1 Linguagem: Inglês

10.1186/1479-5876-10-148

1479-5876

Zhe Liu, Jinhong Duan, Yongmei Song, Jie Ma, Fengdan Wang, Xin Lu, Xian‐Da Yang,

Advanced Biosensing Techniques and Applications

Abstract Background Aptamer-based tumor targeted drug delivery system is a promising approach that may increase the efficacy of chemotherapy and reduce the related toxicity. HER2 protein is an attractive target for tumor-specific drug delivery because of its overexpression in multiple malignancies, including breast, gastric, ovarian, and lung cancers. Methods In this paper, we developed a new HER2 aptamer (HB5) by using systematic evolution of ligands by exponential enrichment technology (SELEX) and exploited its role as a targeting ligand for delivering doxorubicin (Dox) to breast cancer cells in vitro . Results The selected aptamer was an 86-nucleotide DNA molecule that bound to an epitope peptide of HER2 with a K d of 18.9 nM. The aptamer also bound to the extracellular domain (ECD) of HER2 protein with a K d of 316 nM , and had minimal cross reactivity to albumin or trypsin. In addition, the aptamer was found to preferentially bind to HER2-positive but not HER2-negative breast cancer cells. An aptamer-doxorubicin complex (Apt-Dox) was formulated by intercalating Dox into the DNA structure of HB5. The Apt-Dox complex could selectively deliver Dox to HER2-positive breast cancer cells while reducing the drug intake by HER2-negative cells in vitro . Moreover, Apt-Dox retained the cytotoxicity of Dox against HER2-positive breast cancer cells, but reduced the cytotoxicity to HER2-negative cells. Conclusions The results suggest that the selected HER2 aptamer may have application potentials in targeted therapy against HER2-positive breast cancer cells .