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.