title: Prevention of carcinogenesis of mouse mammary epithelial cells RIII/MG by epigallocatechin gallate.
abstract: The chemopreventive effect of the polyphenols abundant in green tea on carcinogenesis has been attracting attention in recent years. Among tea polyphenols, epigallocatechin gallate (EGCG) has been studied as a preventive substance for carcinogenesis. We investigated the chemopreventive effect in a group treated with EGCG in vitro and in vivo using mouse mammary epithelial cells RIII/MG. In the in vitro experiment, crude catechin (catechin) containing 50% or more EGCG significantly inhibited the growth of RIII/MG cells, which were precancerous cultured cells. Many cells died, and a DNA ladder was observed. In the in vivo experiment, RIII/MG cells formed a tumor after 13 weeks in a group without catechin treatment, and the tumor formation rate in the 20th week was 40%. In a group treated with 0.1% catechin, a tumor began to grow in the 13th week, and the tumor formation rate in the 20th week was 20%. In a group treated with 1% catechin, no tumor was detected even in the 20th week. There was no significant difference in the change in body weight between the catechin treatment groups and the non-treatment group during the observation period. Tissue samples were stained by the nick-end-labeling method and apoptosis was observed in many cells. Based on the above findings, EGCG inhibited growth in the mouse viral mammary epithelial carcinogenesis model RIII/MG, and induced apoptosis, suggesting a clinical usefulness of EGCG as a chemopreventive substance.
authors.affiliation: Department of Surgery, School of Medicine, Kurume University, Asahimachi Kurume, Fukuoka 830-0011, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yanaga
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Fujii
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Koga
authors.forename: Ruriko
authors.initials: R
authors.lastname: Araki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shirouzu
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D001835:Body Weight; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology*; D053938:DNA Fragmentation; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects*; D005260:Female; D008321:Mammary Glands, Animal / Q000166:cytology*; D015674:Mammary Neoplasms, Animal / Q000517:prevention & control*; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D016588:Anticarcinogenic Agents; D002392:Catechin; C045651:epigallocatechin gallate