March 21 (UPI) -- A combination therapy that uses two drugs could help in the fight pancreatic cancer, a new study says.
The first drug blocks the process called lysosome, which enables cancer cells to reuse key nutrients for survival, and the second drug shut down the pathway used to fix up DNA, according to research published Wednesday in PNAS.
The researchers combined chloroquine, which is used to treat malaria, with more than 500 different inhibitors to see if it could create a response to fight off the disease. They discovered a complementary inhibitor known as a replication stress response inhibitor that then took the next step.
During a second data set, the researchers measured small molecules called metabolites in pancreatic tumor cells that were only treated with chloroquine. This revealed that chloroquine helped decrease the amino acid aspartate, which helps create nucleotides that are necessary for DNA replication and repair.
The researchers were encouraged to see how well this therapy worked on pancreatic cancer cells after testing the therapy on lab mice, they said in a press release.
This new work is important because pancreatic cancer is the third leading cause of cancer death in the U.S., according to the Hirshberg Foundation for Pancreatic Cancer Research.
The American Cancer Society estimates that more than 56,000 people will be diagnosed with pancreatic cancer this year. The disease has an 8.5 percent survival rate, according to the National Cancer Institute.
Pancreatic cancer is extremely resistant to most treatments, which accounts for the low survival rate.
"The study provides evidence that using chloroquine in combination with an inhibitor of the replication stress response pathway could be a new treatment to reduce tumor growth in pancreatic cancer patients and help improve the prognosis for people with the disease," the researchers said. "The findings also stress the importance of learning how existing drugs work to repurpose them for potential use in treating other diseases."