[Proc Amer Assoc Cancer Res, Volume 47, 2006]
Prevention Research 4: Phytochemicals/Chemoprevention 1
Green tea and other natural products induced apoptosis in cervical cancer cells
Jean M. Feugang,
Sui Zhang and
University of Arizona, Dept of OB/GYN, Tucson, AZ, MD Anderson Cancer Center, Dept of Cardiovascular, Houston, TX, Arizona Cancer Ctr., University of Arizona, Tucson, AZ
Cervical cancer is the third most common gynecologic malignancy in the world, accounting for 15% of all cancers diagnosed in women. Cervical cancer has a well-characterized pre-malignant phase, cervical intraepithelial neoplasia (CIN). CIN is detectable using readily available well-established techniques including exfoliative cervical cytology (Pap smear), human papillomavirus (HPV) testing, and colposcopy. These facts make cervical cancer/CIN an ideal target for chemoprevention. Cancer chemoprevention is the administration of chemical agents to prevent or delay the development of cancer, in which chemical agents are used to prevent cancer in normal and/or high-risk populations. However, the number of currently available preventive agents is limited and the chemical agents are costly. Natural products, such as certain herbs have demonstrated anti-cancer effects. We investigated Arizona cactus extracts and green tea compounds (EGCG and polyphenol E) for their anti-cancer effects in cultured immortalized cervical epithelial cells and cervical cancer cells. Green tea compound and aqueous extracts of cactus pear were used to treat immortalized cervical epithelial cells and cervical cancer cells. The cactus mix and green tea compounds were used at six concentrations 0, 0.5, 1, 5, 10 or 25% and 0, 1, 5, 10, 25, 50 µg/ml, respectively. Growth inhibition, apoptosis induction, and cell cycle were analyzed in these cells. Cells exposed to these two natural products had a significant increase in apoptosis, especially cactus mix and tea-EGCG. Tea-poly E had a little effect on apoptosis induction at concentration of 50 µg/ml; however it increased G1 and decreased S phases. Natural products effectively inhibited immortalized cervical epithelial cells and cervical cancer cells growth, and induced apoptosis. The mechanism of the anti-cancer effects of natural products needs to be elucidated in future studies. Supported by the Womens Fund for Health, Education and Research, and the National Institutes of Health, National Cancer Institute (NIH/NCI), grant number NOI-CN-35158.
Copyright © 2006 by the American Association for Cancer Research.