Direct Validation of Aptamers as Powerful Tools to Image Solid Tumor

Visualization of cancer cells requires distinguishing malignant from normal cells by objective criteria with high specificity. For several years, tumor markers expressed on the surface of cancer cells have been characterized as cancer signatures, and their labeling with specific imaging probes has revolutionized cancer diagnosis. This specific labeling is also an important tool in surgery tumor ablation. The present study considers the tumor labeling potential of an aptamer that specifically recognizes the epithelial cancer biomarker mucin1 (MUC1). This anti-MUC1 aptamer was investigated in vitro in a three-dimensional (3D) environment and compared to an anti-MUC1 antibody for its capacity to visualize cancer cells. Multicellular spheroids of breast cancer MCF-7 cells were used as tumor models and anti-MUC1 fluorescent aptamer and antibody were visualized by fluorescence imaging. Results showed that the antibodies interacted only with cells located on the surface of the spheroid, whereas the anti-MUC1 apt...