| Summary: | 碩士 === 中國醫藥學院 === 醫學研究所 === 90 === Apigenin, flavone and 17α-estradiol are belong to the phytoestrogens and they are present in our common fruits and vegetables such as tea leafs, clear, nuts etc. These compounds have been demonstrated to present cancer therapy and prevention such as colorectal, prostate, leukemia and skin cancers. The purpose of present study is to examine apigenin, flavone and 17α-estradiol whether or not could affect the growth, gene expression, cell cycle, cyclins and N-acetyltransferase (NAT) activity from human stomach cancer cell line (SC-M1). Cell viability, cell cycle and related enzymes (cyclins and cyclin dependent kinases) were examined and determined by flow cytometric assays (FACS). The effects of three compounds on the NAT activity were determined by high performance liquid chromatography (HPLC). The data from experiments indicated that apigenin, flavone and 17α-estradiol induced cytotoxicity, G2/M phase arrest of cell cycle on SC-M1 cells. The cyclins and cyclin dependent kinases examination were performed by FACS and RT-PCR both methods. The results demonstrated that 60 μM apigenin inhibit cyclin B1, CDK1, cyclin E and p53 protein and mRNA expression and this effects is dose dependent; 60 mM flavone inhibit cyclinA and CDK1 protein and cyclin B1, E and P21 mRNA expression but it did not affect CDK2 and P53 MRNA expression; 60 μM 17α-estradiol inhibit cyclin B1 and CDK1 protein expression, it not inhibit cyclin B1, D1 and CDK2 mRNA expression but it inhibit Cyclin E and p53 mRNA expression and promote p21 mRNE expression. The experiments also used differential display RT-PCR (DD RT-PCR) for determining apigenin, flavone and 17α-estradiol affect SC-M1 gene expression. The results demonstrated that 17α-estradiol promote gene expression of oncostatin M receptor from SC-M1 cells. It was also been confirmed by RT-PCR and FACS methods. The P38 MAPK is a down regulation factor for oncostatin M receptor that can regulate cell apoptosis and viability. The inhibitor (SB203580) of P38 MAPK was added to the cells for 3 hours then 60 μM 17α-estradiol was added to the cells the cell viability was increased about 6%. Therefore, 17α-estradiol is through the P38 MAPK pathway to induce cell apoptosis. The data also demonstrated that apigenin, flavone and 17α-estradiol affect NAT activity from SC-M1 cells which was based on the changes of the amounts of N-acetylation of 2-aminofluorene that was determined by HPLC.
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