Green Tea EGCG Suppresses Breast Cancer Cell Growth
Posted Mar 30 2011 10:14am
The nicotinic acetylcholine receptor (nAChR) has been shown to be involved in smoking-induced breast cancer formation. Studies have reported that activation of this receptor can stimulate the growth of breast cancer cells. Interestingly, estradiol, the main estrogen hormone, enhances the presence of these nAChR receptors in breast cancer tumors making them accessible to compounds like nicotine that can bind to them and stimulate breast cancer cell growth. This role of nicotine receptors in breast cancer development makes them an attractive target for breast cancer treatment.
A new research study explored the impact of the main green tea compound, EGCG, on the interactions between estradiol, nicotine, and breast cancer cell growth. For this study, the investigators cultured breast cancer cells and tested them using a variety of analytical techniques. The breast cancer researchers reported that
Both nicotine and estradiol approximately doubled the activity of the nAChR receptor pathway.
Breast cancer cell growth was stimulated by both nicotine and estradiol.
Treatment with green tea EGCG suppressed the presence of the nAChR nicotine receptors in breast cancer cells, resulting in the suppression of breast cancer cell growth.
Green tea EGCG also inhibited the binding of nicotine to the nicotine receptor.
These are fascinating and potentially important research findings. Previous studies have indicated that green tea consumption might decrease breast cancer risk and that EGCG can sensitize breast cancer cells to chemotherapy agents. Many of the effects of green tea and EGCG have been attributed to their anti-inflammatory, anti-oxidant, and immune-modulating properties. This new study suggests that EGCG can also block chemical pathways involved in breast cancer cell growth, specifically growth stimulated be estrogens and smoking. By blocking the function of this nicotine receptor, the study investigators suggest that EGCG might help block estrogen-induced and smoking-induced breast cancer development. If future animal and human studies confirm these cell culture results, green tea consumption might have an important role in breast cancer prevention.