Pancreatic cancer is the deadliest form of cancer with a five-year survival rate of just five percent, well behind that of many common cancer types. Scientists working to improve the odds have made an exciting breakthrough, finding that a peptide taken from the foot-and-mouth-disease virus naturally zeroes in on the majority of pancreatic cancer cells, providing them with a new vehicle for drug delivery that proved capable of completely killing off tumors in early experiments.
The research was carried out by scientists at Queen Mary University of London, who were studying a peptide in the foot-and-mouth disease virus that naturally targets a protein called alpha-v-beta-6 (avβ6). This protein occurs in abundance on the surface of most pancreatic cancer cells, so the scientists set out to see if it could help guide drugs to that destination.
“Foot-and-mouth-disease virus uses avβ6 as a route to infect cattle, as the virus binds to this protein on a cow’s tongue,” says lead researcher Professor John Marshall. “By testing pieces of the protein in the virus that attaches to avβ6, we’ve developed a route to deliver a drug specifically to pancreatic cancers. Our previous research had shown that 84 per cent of pancreatic cancer patients have high levels of avβ6 on their cancers.”
The team’s experiments first involved human cancer cells in the lab, some genetically engineered to feature avβ6 on the surface and some not. The scientists then combined the peptide with a powerful cancer drug called tesirine and exposed both groups of cells to their new combination therapy. The cells featuring avβ6 proved much more vulnerable, while those without avβ6 needed far higher doses of the drug to die off.
In the next round of experiments, mice with tumors bearing avβ6 proteins were given just a small dose of the peptide-drug combination three times a week, which caused the tumors to stop growing. The team then upped the dosage but reduced the frequency to just twice a week, and found that this time around the tumors were completely killed off.
“These very exciting results, that are the result of many years of laboratory testing, offer a completely new way of treating pancreatic cancer.” says Marshall. “One advantage of targeting avβ6 is that it is very specific to the cancer, because most normal human tissues have little or none of this protein. So we’re hopeful that, if we can develop this into an effective treatment for pancreatic cancer, it would have limited side effects.”
From here, the team hopes to conduct further experiments using more complicated mice models as a way of exploring the therapy’s ability to prevent metastases, or secondary tumors.
The research was published in the journal Theranostics.
Source: Pancreatic Cancer Research Fund