Green tea compound boosts protein’s tumour-suppressing activity

The study of the direct interaction between the anti-cancer protein p53 and the green tea compound, epigallocatechin gallate (EGCG), published in the journal Nature Communications, points to a new target for cancer drug discovery.

New York: Sipping green tea could be quite beneficial as researchers have found that a compound in the popular beverage may increase levels of a natural anti-cancer protein, known for its ability to repair DNA damage or destroy cancerous cells, says a new study.

The study of the direct interaction between the anti-cancer protein p53 and the green tea compound, epigallocatechin gallate (EGCG), published in the journal Nature Communications, points to a new target for cancer drug discovery.

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“Both p53 and EGCG molecules are extremely interesting. Mutations in p53 are found in over 50 per cent of human cancer, while EGCG is the major antioxidant in green tea, a popular beverage worldwide,” said corresponding author Chunyu Wang, Professor at Rensselaer Polytechnic Institute in Troy, New York.

“Now we find that there is a previously unknown, direct interaction between the two, which points to a new path for developing anti-cancer drugs. Our work helps to explain how EGCG is able to boost p53’s anti-cancer activity, opening the door to developing drugs with EGCG-like compounds.”

The protein p53 has several well-known anti-cancer functions, including halting cell growth to allow for DNA repair, activating DNA repair, and initiating programmed cell death — called apoptosis — if DNA damage cannot be repaired.

One end of the protein, known as the N-terminal domain, has a flexible shape, and therefore, can potentially serve several functions depending on its interaction with multiple molecules.

EGCG is a natural antioxidant, which means it helps to undo the near constant damage caused by using oxygen metabolism. Found in abundance in green tea, EGCG is also packaged as an herbal supplement.

The researchers found that the interaction between EGCG and p53 preserves the protein from degradation.

Typically, after being produced within the body, p53 is quickly degraded when the N-terminal domain interacts with a protein called MDM2.

This regular cycle of production and degradation holds p53 levels at a low constant.

“When EGCG binds with p53, the protein is not being degraded through MDM2, so the level of p53 will increase with the direct interaction with EGCG, and that means there is more p53 for anti-cancer function. This is a very important interaction,” said Wang.