Pancreatic Cancer Can Run but Not Hide

A study published this week in Cancer Cell from the Perelman School of Medicine and the Abramson Cancer Center at the University of Pennsylvania describes how pancreatic cancer cells produce a protein that attracts immune cells and tricks them into helping cancer cells grow. Blocking the protein may also prove to be a new way to treat pancreatic cancer.

Pancreatic cancer is one of the most deadly types of cancer, mostly due to its aggressiveness and its ability to suppress the cancer-fighting properties of the immune system. Most pancreatic cancer cells contain a mutation in the KRAS gene. The Penn team looked to see how mutated KRAS proteins give pancreatic cancer its distinguishing properties. A group from New York University School of Medicine led by Dafna Bar-Sagi took a complementary approach and reported its findings in another manuscript also published this week in Cancer Cell.

"Both our group and the group from NYU have discovered a critical way in which pancreatic tumor cells cripple the immune system. From very early on, tumor cells produce a molecule that drives inflammatory cells to cloak the tumor and prevent other immune cells from killing the cancer," says Penn's senior author Robert Vonderheide, MD, DPhil, associate professor of Medicine and associate investigator in the Abramson Family Cancer Research Institute. "We found that simply disabling the ability of tumors to make this molecule leads to a house-of-cards effect that resulted in massive tumor death in experimental models."

Most notorious about tumors of the pancreas is the dense network surrounding the tumor that suppresses the immune system from killing the cancer. "We have long wondered: Why would pancreatic cancer cells go to such great lengths to suppress the immune system if the immune system did not hold the power to kill the cancer cells? Our findings demonstrate that if these suppression mechanisms are disabled, pancreatic cancer cells can be killed by the immune system," says Vonderheide.