A synthetic derivative of vitamin D was found by Salk Institute researchers to collapse the barrier of cells shielding pancreatic tumors, making this seemingly impenetrable cancer much more susceptible to therapeutic drugs. The discovery has led to human trials for pancreatic cancer, even in advance of its publication today in the journal Cell. By attacking a wound repair mechanism called fibrosis, the findings may also have implications for other tough-to-treat tumors, such as lung, kidney and liver cancer.

"While the success of this drug in humans with pancreatic cancer is still unclear, the findings in animal studies were strong, raising hope that ongoing clinical trials will give people with this terrible disease hope for a truly new type of therapy," says Ronald Evans, director of Salk's Gene Expression Laboratory and senior author of the new paper.

Pancreatic cancer is one of the deadliest forms of cancer, a fact highlighted in recent years by the deaths of well-known figures such as Steve Jobs and Patrick Swayze. About 46,000 people are diagnosed in the United States each year and about 40,000 people die from the disease, according to the National Institutes of Health.

"For pancreatic cancer, the five-year survival rate is the lowest of all cancers," says Evans, holder of Salk's March of Dimes Chair and a Howard Hughes Medical Institute investigator. "Part of the problem is that the science of pancreatic cancer and its renowned resistance to therapy has not been understood and that's why the work that we're doing is so important."