Our research goals are to elucidate the mechanisms by which diet and nutrition affects drug metabolism, chemical toxicity, and carcinogenesis. The mechanistic studies in the lab are also being extended to field work on the nutritional prevention of human cancers.

Specific Research Projects

1. Molecular mechanisms by which tea plyphenols, isothiocyanates (from cruciferous vegetables), and allyl sulfide (from garlic) inhibit carcinogenesis and chemical toxicity. The contribution of oxidative cellular damage to the development of esophageal adenocarcinoma, especially under iron overload situations, in a surgically induced reflux model in rats; related mechanistic studies with human tissue samples. he roles of alterations of tumor suppressor gene p53, Rb, and p16 in esophageal carcinogenesis.
2. Collaborative human studies to determine whether tea consumption lowers the risk of esophageal, colon, stomach, and prostate cancers.

Chung, J.Y., Huang, C., Meng, X., Dong, Z., and Yang, C.S. (1999) Inhibition of activator protein 1 activity and cell growth by purified green tea and black tea polyphenols in H-ras-transformed cells: structure-activity relationship and mechanisms involved. Cancer Research 59:4610-4617.

Xing, E.P., Nie, Y., Song, Y., Yang, G-Y., Cai, Y.C., Wang, L-D., and Yang, C.S. (1999) Mechanisms of inactivation of p14ARF, p15INK4b and p16INK4a genes in human esophageal squamous cell carcinoma. Clinical Cancer Research 5:2704-2713.

Chen, X.X., Ding, Y.W., Yang, G-Y., Bondoc, F., Lee, M-J., and Yang, C.S. (2000) Oxidative damage in an esophageal adenocarcinoma model with rats. Carcinogenesis 21:257-263.

Yang, C.S., Chung, J.Y., Yang, G-Y., Chhabra, S.K., and Lee, M-J. (2000) Tea and tea polyphenols in cancer prevention. Journal of Nutrition 130:472S-478S.

Li, C., Lee, M-J., Sheng, S., Prabhu, S., Winnik, B., Huang, B., Meng, X., Chung, J.Y., Yan, S., Ho, C-T., and Yang, C.S. (2000) Structural identification and characterization of two metabolites of catechins in human urine and blood after tea ingestion. Chemical Research Toxicol. 13:177-184.

Lee, M-J., Prabhu, S., Meng, X., Li, C., and Yang, C.S. (2000) An improved method for the determination of green and black tea polyphenols in biomatrices by high performance liquid chromatography with coulometric array detection. Anal. Biochemistry 279:164-169.

Kim, S., Lee, M-J., Hong, J., Li, C., Smith, T.J., Yang, G-Y., Seril, D.N., and Yang, C.S. (2000) Plasma and tissue levels of tea catechins in rats and mice during chronic consumption of green tea polyphenols. Nutrition and Cancer 37:41-48.

Chen, X.X., Mikhail, S.S., Ding, Y.W., Yang, G-Y., Bondoc, F., and Yang, C.S. (2000) Effects of vitamin E and selenium supplementation on esophageal adenocarcinogenesis in a surgical model with rats. Carcinogenesis 21:1531-1536.

Yang, C.S., Landau, J.M., Huang, M-T., and Newmark, H.L. (2001) Inhibition of carcinogenesis by dietary polyphenolic compounds. Ann. Rev. Nutr. 21:381-406.

Chung, J.Y., Park, J.O., Phyu, H.P., Dong, Z., Yang, C.S. (2001) Mechanisms of inhibition of the ras-MAP kinase signaling pathway in 30.7b ras 12 cells by tea polyphenols (-)-epigallocatechin-3-gallate and theaflavin-3,3'-digallate. FASEB J. 15:2022-2024

Nomura, M., Kaji, A., He, Z., Ma, W-Y., Miyamoto, K-i., Yang, C.S., Dong, Z. (2001) Inhibitory Mechanisms of Tea Polyphenols on the Ultraviolet B-activated Phosphatidylinositol 3-Kinase-dependent Pathway. J. Biol. Chem., 276: 46624-46631.

Yang, C.S., Maliakal, P., and Meng, X. (2002) Inhibition of carcinogenesis by tea. Annu. Rev. Pharmacol. Toxicol., 42: 25-54.

Chen, X., Ding, Y.W., Liu, C-G. and Yang, C.S. Overexpression of grp94 (glucose-regulated protein 94) in esophageal adenocarcinomas in a surgical rat model and human patients. Carcinogenesis, 23: 123-130, 2002.

Meng, X., Lu, H., Lee, M-J., Zhu, N., Sheng, S., Ho, C-T., and Yang, C.S. (2002) Identification and characterization of methylated and ring-fission metabolites of tea catechins formed in humans, mice, and rats. Chemical Res. Toxicol. 15: 1042-1050.

Li, N., Chen, X., Liao, J., Yang, G-Y., Wang, S., Hosephson, Y., Han, C., Chen, J., Huang, M-T., and Yang, C.S. (2002) Inhibition of 7,12-dimethylbenz[a]anthracene (DMBA) -induced oral carcinogenesis in hamsters by tea and curcumin. Carcinogenesis, 23: 1307-1313.

Lee, M-J., Maliakal, P., Chen, L., Meng, X., Bondoc, F.Y., Prabhu, S., Lambert, J., Mohr, S., and Yang, C.S. (2002) Pharmacokinetics of tea catechins after ingestion of green tea and (-)-epigallocatechin-3-gallate by humans: formation of different metabolites and individual variability. Cancer Epidemiol. Biomark. Prev. 11: 1025-1032.

Seril, D.N., Liao, J., Ho, K-L.K., Yang, C.S., and Yang, G-Y. (2002) Inhibition of chronic ulcerative colitis-associated colorectal adenocarcinoma development in a murine model by N-acetylcysteine. Carcinogenesis, 23: 993-1001.

Seril, D.N., Liao, J., Ho, K-L., Warsi, A., Yang, C.S., and Yang, G-Y. (2002) Dietary iron supplementation enhances DSS-induced colitis and associated colorectal carcinoma development in mice. Dig. Dis. Sci., 47: 1266-1278.

Sun, C-L., Yuan, J-M., Lee, M-J., Yang, C.S., Gao, Y-T., Ross, R.K., and Yu, M.C. (2002) Urinary tea polyphenols in relation to gastric and esophageal cancers: a prospective study of men in Shanghai, China. Carcinogenesis, 23: 1497-1503.

Nie, Y., Liao, J., Zhao, X., Song, Y., Yang, G-Y., Wang, L-D., and Yang, C.S. (2002) Detection of multiple gene hypermethylation in the development of esophageal squamous cell carcinoma. Carcinogenesis, 23: 1713-1720.

Lu, Y-P., Lou, Y-R., Xie, J-G., Peng, Q-Y., Liao, J., Yang, C.S., Huang, M-T., and Conney, A.H. (2002) Topical applications of caffeine or (-)-epigallocatechin gallate (EGCG) inhibit carcinogenesis and selectively increase apoptosis in UVB-induced skin tumors in mice. Proc. Nat. Acad. Sci., 99: 12455-12460.