STUDY: PARTIALLY REDUCING OR INACTIVATING THE GRP78 PROTEIN BY THERAPEUTIC AGENTS MAY BE A SECRET TO COMBATING PANCREATIC CANCER
May 22, 2017
Keck School of Medicine of the University of Southern California
Edited For Style and Length
Research by the Keck School of Medicine of the University of Southern California (USC) shows new promise in the fight against pancreatic cancer. Studies in mice with the KRAS mutation present in 90 percent of pancreatic cancer patients indicates that expressing only half the amount of the glucose-regulated protein GRP78 is enough to halt the earliest stage of pancreatic cancer development.
The study suggests that because the GRP78 protein is required for “switching” healthy pancreatic cells that produce enzymes to digest food into potentially cancerous cells, reducing the amount of this protein delays pancreatic cancer development and prolongs survival. The study, published online on May 16 in the Proceedings of the National Academy of Sciences of the United States of America, is the first to establish the pivotal role of the protein in pancreatic cancer.
“Cancer cells are addicted to high levels of GRP78 for cancer development and growth. Our hope is that partially reducing or inactivating the protein by therapeutic agents could one day be an effective complementary therapy for pancreatic cancer and other cancers, while sparing other healthy organs,” said Amy Lee, PhD, professor of biochemistry and molecular medicine at the Keck School and the Judy and Larry Freeman Chair in Basic Science Research at the USC Norris Comprehensive Cancer Center.
Lee, who was the first scientist to clone human GRP78, has since dedicated much of her research to investigating the protein’s role in cancer progression and treatment. For her scientific contributions, Lee was honored by a MERIT award from the National Cancer Institute and elected as Fellow of the American Association for the Advancement of Science.
“As developing drugs directly targeting the KRAS genetic mutation has been challenging, we are thrilled these findings indicate that we can attack KRAS-driven pancreatic cancer through an entirely new method,” Lee said.
GRP78 is a stress-inducible protein that folds newly synthesized proteins and performs quality control in the endoplasmic reticulum (an essential component of human cells). During stress, a fraction of GRP78 is shipped out to the cell surface to perform additional growth and survival functions. Cancer cells, particularly those that survive treatment, typically undergo more stress than healthy cells, resulting in increased levels of GRP78 to help the cancer cells survive, grow and develop therapeutic resistance.
Patients and physicians alike are eager for more effective treatments for pancreatic cancer, as it is among the deadliest forms of cancer. According to the American Cancer Society, more than 53,600 people will be diagnosed with pancreatic cancer this year, and more than 43,000 people will die from the disease. The average five-year survival rate for patients with pancreatic cancer is only about 7.7 % compared to about 89 percent for breast cancer per NIH Seer 2014 Statistics.
“Translating any basic science discovery into clinical practice is a long process that requires substantial resources,” Lee said. “But given the notorious difficulties of treating KRAS-mutation related cancers, particularly in a disease as devastating as pancreatic cancer, this research provides hope and a novel approach. I am excited to put our theories to test in the clinical setting.”
Related Keywords include Pancreatic Cancer, GRP78 Protein, KRAS Mutation, Halting Earliest Stage of Pancreatic Cancer.