US scientists have discovered that pancreatic cancer cells' growth and spread are fueled by an unusual metabolic pathway that someday might be blocked with targeted drugs to control the deadly cancer, according to a study published Wednesday in journal Nature.

Cancer cells are known to "rewire" their metabolic circuits differently from normal cells to provide energy for cancerous growth. The new study reveals that pancreatic tumor cells are dependent on an amino acid, glutamine, which they utilize via a molecular pathway that has no apparent backup system.

"Pancreatic cancer cells have painted themselves into a metabolic bottleneck," said Dana-Farber Cancer Institute's Alec Kimmelman, co-senior author of the study. "If you suppress any enzyme in that pathway, the cancer cells cannot effectively compensate and they can no longer grow."

Moreover, the investigators said, this novel glutamine pathway in pancreatic tumors does not appear to be important for normal cells, suggesting that inhibitor drugs could block cancer cells' growth without harming healthy tissues and organs.

If drugs can be developed to shut down the glutamine pathway, Kimmelman suggested, they might make pancreatic tumors more susceptible to standard treatments, such as radiation and chemotherapy, that cause free radicals to accumulate in cancer cells.

Pancreatic cancer is one of the most lethal and treatment- resistant of all cancers, with a dismal survival rate, and scientists have been searching for any vulnerability that could be exploited. One of the newer strategies in cancer research is studying the metabolic differences between cancer cells and normal cells with the goal of depriving tumors of their fuel.