Navigation Links
While on trail of dioxin, scientists pinpoint cancer target of green tea

Green tea appears to protect against cancer by affecting a "promiscuous" protein that pharmaceutical experts are already targeting in an effort to develop a new drug to stop the disease, scientists at the University of Rochester Medical Center have found. The research, which buttresses beliefs about the health benefits of green tea with solid scientific evidence, has been cited as part of the best doctoral thesis produced by a student at the university's School of Medicine and Dentistry this year.

The thesis by student Christine Palermo is part of a wider research project led by toxicologist Thomas A. Gasiewicz, Ph.D., whose decades-long studies of the harmful effects of dioxin ultimately led his group to explore the protective effects of green tea. While it's been reported that green tea protects people against some forms of cancer, such as breast and liver cancer, exactly how it does so has been difficult to pinpoint.

The latest results make more feasible the idea of harnessing green tea's protective power. Just as people with aches and pains no longer have to chew on willow bark to receive the benefits of the substance salicin ?they simply take an aspirin –the current research opens the door to extending the health benefits first discovered in green tea to people who never touch the beverage. Isolating the chemicals that protect against cancer would also sidestep questions such as how to take into account different types of teas and different brewing processes, or how much tea one needs to drink.

"It's important to find out the source of green tea's protective effects," says Gasiewicz, professor and chair of Environmental Medicine and director of Rochester's Environmental Health Science Center. "What is exciting here is that a completely new mechanism has been found that very well could be responsible for its protective effects, and that could help us find a compound that is much more potent."

Palermo, Gasiewicz, and current undergr aduate Claire Westlake discovered that a chaperone protein known as HSP90 is involved in conferring green tea's protective effects. Other researchers have shown that many cancer cells have an increase in the level of HSP90 compared to healthy cells, and that when HSP90 is blocked, levels of proteins that make cancer cells grow drop.

Drug makers are currently working on ways to block HSP90, which is known as a promiscuous chaperone protein because it binds to many different cells and receptors in the body. It turns out that those researchers are trying to duplicate what green tea does naturally. Gasiewicz says drug makers can learn from green tea, which might modulate HSP-90 in a way that researchers haven't seen before.

Gasiewicz is a world leader on dioxin, and it was by tracking the trail of dioxin's harmful effects on the body that his group made the green tea findings. His group has shown how dioxin and other substances like cigarette smoke manipulate a major cancer-causing molecule, the aryl hydrocarbon (AH) receptor, which frequently plays a role in turning on genes that are oftentimes harmful.

Two years ago the team discovered that AH activity is inhibited by a chemical found in white and green teas, epigallocatechingallate or EGCG, a cousin of flavonoids found in broccoli, cabbage, grapes and red wine that are known to help prevent cancer. The team had been working on other chemicals to try to stop AH activity.

"We initially hypothesized that EGCG would work in the same way as other AH antagonists, by binding directly to it. We were completely surprised that this isn't the case," says Gasiewicz, whose work was funded by the National Institute of Environmental Health Sciences and the American Institute for Cancer Research.

Instead, the team found that EGCG binds to HSP90, a protein that helps other proteins stay stable, serving the same role as a tail on a kite. When the two bind, HSP90 no longer turns on the AH recepto r, stopping the cascade of events that would lead to the activation of several harmful genes.

This weekend Palermo is receiving the Wallace Fenn Award, named after a long-time physiology professor at the University of Rochester School of Medicine and Dentistry. The award is given at graduation each year to a student who has produced an outstanding thesis. The research also has earned Palermo awards from the Society of Toxicology in each of the last three years; the current research was published in the April 5 issue of the journal Biochemistry. She is now a post-doctoral associate at Tulane, where she is looking into the causes of childhood leukemia.


'"/>

Source:University of Rochester Medical Center


Related biology news :

1. History-hunting geneticists can still follow familiar trail
2. Researchers hot on the trail of brain cell degeneration
3. Wisconsin scientists grow critical nerve cells
4. UCSB scientists probe sea floor venting to gain understanding of early life on Earth
5. UAB scientists discover the origin of a mysterious physical force
6. Fox Chase Cancer Center scientists identify immune-system mutation
7. Weizmann Institute scientists develop a new approach for directing treatment to metastasized prostate cancer in the bones.
8. U-M scientists find genes that control growth of common skin cancer
9. UCLA scientists transform HIV into cancer-seeking missile
10. RNA project to create language for scientists worldwide
11. Carnegie Mellon scientists develop tool that uses MRI to visualize gene expression in living animals
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:6/20/2016)... 20, 2016 Securus Technologies, a leading ... for public safety, investigation, corrections and monitoring announced ... it has secured the final acceptance by all ... Managed Access Systems (MAS) installed. Furthermore, Securus will ... be installed by October, 2016. MAS distinguishes between ...
(Date:6/9/2016)... , June 9, 2016 ... Police deploy Teleste,s video security solution to ensure the safety ... France during the major tournament Teleste, ... communications systems and services, announced today that its video security ... to back up public safety across the country. ...
(Date:6/2/2016)... --  The Weather Company , an IBM Business (NYSE: ... in which consumers will be able to interact with IBM ... voice or text and receive relevant information about the product ... have long sought an advertising solution that can create a ... and valuable; and can scale across millions of interactions and ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... Hill, N.C. (PRWEB) , ... June 27, 2016 ... ... U.S. commercial operations for Amgen, will join the faculty of the University ... serve as adjunct professor of strategy and entrepreneurship at UNC Kenan-Flagler, with a ...
(Date:6/24/2016)... Epic Sciences unveiled a liquid biopsy ... PARP inhibitors by targeting homologous recombination deficiency (HRD) ... test has already been incorporated into numerous clinical ... Over 230 clinical trials are investigating ... PARP, ATM, ATR, DNA-PK and WEE-1. Drugs targeting ...
(Date:6/23/2016)... ... June 23, 2016 , ... UAS LifeSciences, one of ... their brand, UP4™ Probiotics, into Target stores nationwide. The company, which has been ... Target to its list of well-respected retailers. This list includes such fine stores ...
(Date:6/23/2016)... Houston Methodist Willowbrook Hospital has signed ... to serve as their official health care provider. ... will provide sponsorship support, athletic training services, and ... volunteers, athletes and families. "We are ... and to bring Houston Methodist quality services and ...
Breaking Biology Technology: