WASHINGTON, April 21 — Pancreatic cancer cells can be reversed back into normal cells by introducing a protein called E47 that controls genes involved in growth and differentiation, a U.S. study suggested Monday.
The findings may lead to a potential new treatment for pancreatic cancer, one of the deadliest and most aggressive forms of cancer, which killed Apple co-founder Steve Jobs.
"For the first time, we have shown that overexpression of a single gene can reduce the tumor-promoting potential of pancreatic adenocarcinoma cells and reprogram them toward their original cell type," said Pamela Itkin-Ansari, adjunct professor at the Sanford- Burnham Medical Research Institute and lead author of the study published in the journal Pancreas.
"Thus, pancreatic cancer cells retain a genetic memory which we hope to exploit."
For the study, Itkin-Ansari and colleagues generated human pancreatic ductal adenocarcinoma cell lines to make higher than normal levels of E47, which caused cells to stall in the early growth phase, and differentiate back toward an acinar cell phenotype.
When the reprogrammed cancer cells were introduced into mice, their ability to form tumors was greatly diminished compared to untreated adenocarcinoma cells, the researchers found.
Currently, pancreatic adenocarcinoma, the most common form of pancreatic cancer, is treated with cytotoxic agents, yet the average survival for patients post-diagnosis is merely six months, and the improvements in therapies are measured in days, according to co-author Andrew Lowy, professor of surgery at the University of California San Diego.
"The finding that we can differentiate these cancer cells back to a non-threatening phenotype is encouraging," said Lowy, also co- chair of the U.S. National Cancer Institute's Pancreatic Cancer Task Force. "Indeed, there is a precedent for cell differentiation therapy in that the approach has been used to treat acute promyelocytic leukemia and some neuroblastomas successfully."
The researchers will next test patient-derived tumor tissue to determine if E47 can produce similar results and will screen for molecules that can induce overexpression of E47.
Pancreatic cancer is often called a "silent" cancer because it rarely shows early symptoms. It tends to be diagnosed at advanced stages when it causes weight loss, abdominal pain, and jaundice. In the United States, there are 49,000 new cases each year and 40, 000 people die of the disease, according to the American Cancer Society. (PNA/Xinhua)