Green tea component upsets cancer cell metabolism
A new study reveals how an active component of green tea disrupts the metabolism of cancer cells in pancreatic cancer, offering an explanation for its effect on reducing risk of cancer and slowing its progression. The researchers believe the discovery signals a new approach to studying cancer prevention.
Reported in the journal Metabolomics, the study explores the effect of epigallocatechin gallate or "EGCG," an active biological agent of green tea. It shows that EGCG changes the metabolism of pancreatic cancer cells by suppressing the expression of lactate dehydrogenase A or LDHA, a critical enzyme in cancer metabolism.
Metabolism is all the chemical reactions that occur in cells - such as extracting and using energy - that keep them alive, growing and multiplying. These cells can be normal, and they can also be cancerous.
Numerous studies have previously suggested green tea and its extracts may provide suitable treatments for cancer, as well as other diseases.
For example, one published in 2012 suggested that drinking green tea may lower risk of digestive system cancers in women while another found EGCG delivered intravenously directly to tumors made two-thirds of them shrink or disappear within one month.
EGCG disrupts metabolism in cancer cells by suppressing LDHA
But, until this latest study, from Dr. Wai-Nang Lee of the Los Angeles Biomedical Research Institute (LA BioMed) and colleagues, it has not been clear how green tea and its extracts work to reduce the risk of cancer or slow growth of cancer cells.
The researchers found that EGCG - an active biological agent of green tea - disrupts metabolic flux in cancer cells in a similar way to oxamate, a known inhibitor of LDHA.
Using state-of-the-art metabolic profiling techniques, Dr. Lee and colleagues found EGCG disrupts the rate of turnover of molecules - known as "flux" - through a metabolic pathway in pancreatic cancer cells.
They found EGCG disrupts metabolic flux in cancer cells in a similar way to oxamate, a known inhibitor of LDHA.
They concluded that both EGCG and oxamate reduced the risk of cancer by suppressing the activity of LDHA, which in turn disrupts metabolic functions in cancer cells.
Entirely new way of looking at metabolism
The study is significant because there is a widely held belief among scientists that to treat cancer you have to use molecular mechanisms. Now there is a new possibility - change the metabolic system, as Dr. Lee comments:
"By explaining how green tea's active component could prevent cancer, this study will open the door to a whole new area of cancer research and help us understand how other foods can prevent cancer or slow the growth of cancerous cells."
He says the discovery also means we can look at metabolism in an entirely new way: "It is no longer a case of glucose goes in and energy comes out. Now we understand how cancer cell metabolism can be disrupted, and we can examine how we can use this knowledge to try to alter the course of cancer or prevent cancer."
In December 2013, Medical News Today also learned how researchers at the University of Cambridge in the UK are working on a combined treatment that spurs the of immune system to fight pancreatic cancer. The a drug that breaks down the protective barrier surrounding pancreatic cancer tumors allowing entry to cancer-fighting T cells. The effect is stronger when combined with an antibody that improves T-cell activity.
Written by Catharine Paddock PhD
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