The nanoparticle system, described in the Aug. 15 online edition of Science Translational Medicine, could relieve a significant bottleneck in cancer-drug development. Among those potential targets are many considered to be “undruggable,” meaning that the proteins don’t have any pockets where a traditional drug could bind to them.
The new nanoparticles, which deliver short strands of RNA that can shut off a particular gene, may help scientists go after those undruggable proteins.
Within the nanoparticles, strands of RNA are mixed with a protein that further helps them along their journey: When the particles enter a cell, they are encapsulated in membranes known as endosomes. The protein-RNA mixture can cross the endosomal membrane, allowing the particles to get into the cell’s main compartment and start breaking down mRNA.
In a study of mice with ovarian tumors, the researchers found that treatment with the RNAi nanoparticles eliminated most of the tumors.The researchers are now using the particles to test other potential targets for ovarian cancer as well as other types of cancer, including pancreatic cancer.