Study in Nature Medicine used an engineered common cold virus carrying a PET-imaging protein.
Scientists at the University of California, Los Angeles were able to deliver a genetic payload to prostate cancer cells that allowed them, using PET, to locate the diseased cells as they spread to the lymph nodes. The team reports that they used an engineered version of a common cold virus.
The investigators engineered a virus to travel to the lymph nodes using a prostate cancer-specific vector that dictates its payload to be expressed only in prostate cells. The payload in this case is a protein that can be imaged by PET scanning. This virus was then introduced into the tumor in the mouse.
The researchers report that they were able to detect PET signals only from the lymph nodes with cancer-cell involvement, indicating the virus reached and infected the prostate cancer cells and produced the imaging protein.
Lily Wu, M.D., Ph.D., a researcher at UCLA’s Jonsson Cancer Center and senior author of the study, also codeveloped TSTA, a two-step transcriptional amplification method. This increased genetic payload expression inside cancer cells in effect boosting the imaging signals.
The next step for Dr. Wu and her colleagues is linking this noninvasive imaging technique with a treatment component that activates a toxic agent in the genetic payload to kill the spreading cancer cells. Dr. Wu hopes one day to be able to find tiny prostate cancer metastases in patients and kill them at the same time, watching it all on a PET scanner.
“We now know we can reach these prostate cancer metastases at an earlier stage than before and we know we can deliver genes to those cancer cells that produce proteins that can be imaged by PET,” Dr. Wu comments. “Now we will find out how effective this genetic toxic payload is in preventing further spread of the cancer to other vital organs.”
The study is published in the July 11 advance online edition of Nature Medicine.