Glioblastoma is one of the most aggressive forms of brain cancer. Rather than presenting as a well-defined tumor, glioblastoma will often infiltrate the surrounding brain tissue, making it extremely difficult to treat surgically or with chemotherapy or radiation. Likewise, several mouse models of glioblastoma have proven completely resistant to all treatment attempts.
To overcome this hurdle, Sanford-Burnham scientists and their collaborators at the Salk Institute developed a method to combine a tumor-homing peptide, a cell-killing peptide, and a nanoparticle that both enhances tumor cell death and allows the researchers to image the tumors. When used to treat mice with glioblastoma, this new nanosystem eradicates most tumors in one model and significantly delays tumor development in another. These findings were published the week of October 3 in the Proceedings of the National Academy of Sciences of the USA.
“This is a unique nanosystem for two reasons. First, linking the cell-killing peptide to nanoparticles made it possible for us to deliver it specifically to tumors, virtually eliminating the killer peptide’s toxicity to normal tissues. Second, ordinarily researchers and clinicians are happy if they are able to deliver more drugs to a tumor than to normal tissues. We not only accomplished that, but were able to design our nanoparticles to deliver the killer peptide right where it acts—the mitochondria, the cell’s energy-generating center,” says Dr. Erkki Ruoslahti, senior author of the study and distinguished professor in both Sanford-Burnham’s NCI-designated Cancer Center in La Jolla and the Center for Nanomedicine, a Sanford-Burnham collaboration with the University of California, Santa Barbara.