Effect of CD44 Aptamer on Snail Metastasis Factor and Aggressiveness of MDA-MB-231 Breast Cancer Cell Line

Background: The intracellular signaling pathways stimulated by CD44/hyaluronic acid (HA) interaction play a central role in the invasion and migration of cancer cells. Epithelial-mesenchyme transition (EMT) is an important factor in cancer metastasis and migration, which can be stimulated by the snail transcription factor. Previous studies showed cells that were subjected to snail-induced EMT, characterized by a CD44high/CD24low phenotype, expressed at their surface. Objectives: The aim of this study was to assess the inhibitory effect of CD44/HA interaction on the snail expression and invasive behavior of aggressive breast cancer cell line with a high CD44 expression in 2D and 3D culture. The cell surface binding capacity of the selected aptamer was evaluated via flow cytometry assay. Methods: To test our hypothesis, we disrupted the CD44/HA interaction by DNA aptamer, which specifically binds to the Hyaluronic Acid Binding Domain (HABD) of CD44. Then, expression level of snail mRNA was evaluated in MDA-MB 231 cells, cultured in 2D and 3D conditions by real-time PCR. Furthermore, invasive behavior was evaluated, using wound healing assay. Results: The results of this study showed that CD44 aptamer reduced snail expression and invasive behavior in MDA-MB 231 cell line. In addition, our result indicated that cells cultured in 3D were more sensitive to the aptamer in comparison to those cultured in the 2D model. Conclusions: The inhibition of CD44-HA interaction, using aptamer, negatively regulates the CD44 function in aggressive breast cancer cell line with the high level of CD44 expression.