Effects of green tea extracts on gene expression in HepG2 and Cal-27 cells.
Green tea extract is known to contain compounds that are able to produce antioxidant effects in many types of living cells. Treatment of cultured human hepatoma (HepG2) cells with green tea extract resulted in dramatically increased expression of at least 15 genes that are present on a commercial human drug metabolism gene array. RT-PCR was used to confirm the microarray results, and analysis of the 5'-flanking region of each of these genes revealed potential electrophile/antioxidant response elements. Members of the acetyl transferase, epoxide hydrolase, sulfotransferase and glutathione transferase gene families were strongly induced. In addition, the human tongue carcinoma cell line Cal-27 did not respond to green tea extract in the same way, as none of the induced genes in the HepG2 cells were induced in the Cal-27 cells. The lack of induction of detoxification enzymes in the Cal-27 cell line may help to explain the previously observed increased cytotoxicity of green tea catechins on this cell line.
Yang
Shin-Pei
SP
Department of Chemistry and Biochemistry, The University of North Carolina at Greensboro, 414 Science Building, Greensboro, NC 27402-6170, USA.
Wilson
Kimberly
K
Kawa
Abdul
A
Raner
Gregory M
GM
D024506:5' Flanking Region / Q000187:drug effects / Q000235:genetics; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D045744:Cell Line, Tumor; D004273:DNA, Neoplasm / Q000096:biosynthesis; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D020411:Oligonucleotide Array Sequence Analysis; D016877:Oxidants / Q000633:toxicity; D010936:Plant Extracts / Q000494:pharmacology; D012334:RNA, Neoplasm / Q000096:biosynthesis; D020218:Response Elements; D013662:Tea / Q000737:chemistry*
D000972:Antineoplastic Agents, Phytogenic; D004273:DNA, Neoplasm; D009363:Neoplasm Proteins; D016877:Oxidants; D010936:Plant Extracts; D012334:RNA, Neoplasm; D013662:Tea