New Research
Plant compound combats pancreatic cancer
Archived article from Sep 26, 2005
By Joseph Blumberg
In 2004, Rutgers researchers halted prostate cancer in laboratory animals using a compound derived from the seeds of the croton plant, an Asian shrub whose leaves produce a poison ivy-like skin rash. Now they have achieved the same kind of success with pancreatic cancer.
The pancreas is a multipurpose gland in the abdomen that produces enzymes to aid digestion, and hormones, such as insulin, that help balance sugar in the blood.
The cancer-fighting compound found in croton oil is 12-O-tetradecanoylphorbol-13-acetate or TPA.
“Pancreatic cancer has very limited treatment options and low survival rates,” said Allan H. Conney, director of the Susan Lehman Cullman Laboratory for Cancer Research at Rutgers’ Ernest Mario School of Pharmacy. “Each year, 32,000 Americans die from it.”
Conney and his team, encouraged by their progress with prostate cancer, initiated studies with the pancreas. In laboratory cultures, they applied TPA to human pancreatic cancer cells and found that the cell growth was inhibited by TPA when used in concentrations that are not toxic to people.
They also tested TPA in combination with all-trans retinoic acid (ATRA), a vitamin A derivative, and found that the TPA/ATRA combination in cell culture worked better than the individual compounds alone.
The researchers injected pancreatic cancer cells into mice to grow pancreatic tumors against which the compounds could be tested. Once the tumors were established, Conney and his team began treating the mice with TPA alone and in combination with ATRA. They observed inhibition of tumor growth and reduction in tumor size.
There was a substantial increase in apoptosis (programmed cell death) and a decrease in mitosis (cells reproducing) in the tumors. “We were simultaneously stopping the growth of new cancer cells and killing those already existing,” Conney said. “The impact on the tumors was most dramatic with the TPA/ATRA combination,” he added.
The increased efficacy of the potent combination would permit the use of even lower doses, Conney said. “It is this combination that we would very dearly like to see move to human clinical trials.”
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