Zdravka Medarova1, Mohanraja Kumar1, Anna Moore1
1Molecular Imaging Lab, Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, United States
Since their discovery in 1998, small interfering RNAs (siRNAs) have emerged as a powerful new tool for post-transcriptional gene silencing. Here, we describe the synthesis and testing of a tumor-targeted nanoparticle probe (MN-EPPT-siSurvivin) to specifically shuttle siRNA to tumor cells. The probe binds the tumor antigen uMUC-1, found on a range of adenocarcinomas, and useful as an imaging target. Human breast, pancreatic, and colorectal cancer cells took up high amounts of the probe. The uptake could be measured by MRI and resulted in significant knock-down of the target gene.