title: Analysis of cell growth inhibitory effects of catechin through MAPK in human breast cancer cell line T47D.
abstract: We have investigated the cell growth inhibitory effects of crude catechin (catechin) containing approximately 53% of epigallocatechin-3-gallate (EGCG) on the human breast cancer cell line T47D, and the mechanism of its action, with emphasis on the cell cycle and mitogen-activated protein kinases (MAPK). A significant dose-dependent growth inhibition was observed after treatment with catechin. At 48 h after the addition of catechin, cells at the G2/M phase were increased by 8.3%, compared with the control. Analysis of the expression of cell cycle-related proteins after the addition of catechin showed that the cyclin-dependent kinase (cdk) 2 and the cdk4 proteins were decreased after administration, the expression of cyclin A protein was increased at 24 h after administration, however, the expression of the cyclin D1 and cyclin E proteins was unchanged. At 24 h after the administration of catechin, the phosphorylation of cell division cycle 2 (cdc2) was inhibited, and the expression of cyclin B1 protein was also decreased. Furthermore, the analysis of the MAPK expression showed that the phosphorylated JNK/SAPK protein began to increase at 3 h after catechin administration, and the expression persisted until 24 h after administration, then decreased. The phosphorylation of p38 protein was increased at 12 h, and began to decrease at 36 h after catechin administration. Based on these results, we speculate that, in the breast cancer cell line T47D, catechin phosphorylated JNK/SAPK and p38, and that the phosphorylated JNK/SAPK and p38 inhibited the phosphorylation of cdc2, and regulated the expression of cyclin A, cyclin B1, and cdk proteins, thereby causing G2 arrest. The results suggested that catechin (EGCG) may be an effective adjuvant therapy after breast cancer surgery.
authors.affiliation: Department of Surgery, Kurume University School of Medicine, Kurume 830-0011, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Deguchi
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Fujii
authors.forename: Shino
authors.initials: S
authors.lastname: Nakagawa
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Koga
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shirouzu
mesh_terms: D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology*; D042846:CDC2-CDC28 Kinases; D002352:Carrier Proteins / Q000378:metabolism; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D016213:Cyclins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020935:MAP Kinase Signaling System / Q000187:drug effects; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D014407:Tumor Cells, Cultured; D048051:p38 Mitogen-Activated Protein Kinases
chemical_list: D002352:Carrier Proteins; D016213:Cyclins; D011518:Proto-Oncogene Proteins; D002392:Catechin; C045651:epigallocatechin gallate; D017346:Protein Serine-Threonine Kinases; D042846:CDC2-CDC28 Kinases; C495894:CDK2 protein, human; C495900:CDK4 protein, human; D051357:Cyclin-Dependent Kinase 2; D051358:Cyclin-Dependent Kinase 4; D018844:Cyclin-Dependent Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048670:MAP Kinase Kinase 4; D020929:Mitogen-Activated Protein Kinase Kinases