Limiting Protein Activity Shows Promise Treating Prostate Cancer

A potential new treatment has been found for prostate cancer, the leading cause of cancer death among men.

PAK-1 proteins play a role in the development of prostate cancer cells. Researchers looked to create a way to both package and administer IPA-3, a small molecule that limits the activity of PAK-1 proteins.

“PAK-1 is kind of like an on/off switch,” said study co-author Somanath Shenoy, an associate professor in UGA's College of Pharmacy. “When it turns on, it makes cancerous cells turn into metastatic cells that spread throughout the body.”

Researchers used a bubble-like structure called liposome to wrap around the IPA-3 molecule and injected it intravenously. This shell helps ensure that IPA-3 is not metabolized by the body too quickly, and allows for the inhibitor to have enough time to disrupt the PAK-1 protein.

The results of the study published in Nanomedicine: Nanotechnology, Biology and Medicine found the molecule was able to significantly slow cancer progression in mice, while also causing the cancer cells to undergo apoptosis.

“When we first began these experiments, we injected IPA-3 directly into the bloodstream, but it was absorbed so quickly that we had to administer the treatment 7 days a week for it to be effective,” Shenoy said. “But the liposome that (researcher Brian Cummings, an associate professor in UGA's College of Pharmacy) created makes the IPA-3 much more stable, and it reduced the treatment regimen to only twice a week.”

Although the results showed potential in the treatment of prostate cancer, more research needs to be done before it’s used in human clinical trials.

“The results of our experiments are promising, and we hope to move toward clinical trials soon,” Shenoy said. “But we must figure out what side effects this treatment may have before we can think about using it in humans.”