Extract from Chinese herb god of thunder vine suppresses pancreatic cancer cells -
A diagnosis of pancreatic cancer, the fourth most common cause of cancer death in the US-can be devastating. Thanks in part to the aggressive cell replication and tumor growth, pancreas cancer progresses rapidly and has a survival rate five-year low (less than 5 percent).
GRP78, a protein that protects cells from dying, is more abundant in cancer cells and tissues than in normal organs and is thought to play a role in helping pancreatic cancer cells survive and prosper. University of Minnesota researchers have found triptolide, an extract of the Chinese herb thunder god vine ( Tirpterygium wilforii ), suppresses GRP78, possibly leading to death of pancreatic cancer cells.
For mammals to use proteins in the body, a process called protein folding must occur in the endoplasmic reticulum (ER) cells. If the proteins are folded rather quickly, the unfolded proteins and begin to build the cell becomes stressed. Stress activates extended RE a cellular process called the "unfolded protein response (UPR)." Initially, the UPR helps prime the ability of the protein-folding of the cell, enabling it to function properly again. But if the problem does not resolve, the UPR triggers cell death.
GRP78 helps cells survive long enough for the UPR to launch and correct protein folding problems. However, GRP78 is available higher amounts in cells of pancreatic cancer, which helps cancer cells to escape cell death, to live and multiply them.
Triptolide has previously been shown to have a negative effect on pancreatic cell viability cancer and growth of the block and the spread of these cells. in this study, led by Ashok Saluja, Ph.D., the researchers observed the effects of triptolide on cells of pancreatic cancer and tissue. They found that the UPR was successful in triptolide treated cells to allow cell death in cells defective.
"Our study shows that although increased expression of GRP78 confers a survival advantage to tumor cells, prolonged exposure to stress Triptolide induces chronic RE, which ultimately leads to cell death" the authors said. "In this context, inhibition of GRP78 by activation of the stress pathway RE by triptolide provides a new mechanism to inhibit the growth and survival of pancreatic cancer cells."
The article "Triptolide active response of the unfolded protein leading to chronic ER stress in cells of pancreatic cancer" is published in the American Journal of Physiology-Gastrointestinal and Liver Physiology. It is highlighted as one of the "best of the best" this month as part of APSselect program of the American Physiological Society.
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