title: The repressive effect of green tea ingredients on amyloid precursor protein (APP) expression in oral carcinoma cells in vitro and in vivo.
abstract: In a hamster model of N-methyl-N-benzylnitrosamine (MBN)-induced oral carcinogenesis, the incidence of buccal pouch (HBP) carcinomas in MBN-treated hamsters (17.8+/-7.5) was significantly higher than MBN-treated hamsters given tea (10.8+/-3.9) (P<0.05). Amyloid precursor protein (APP) expression was also significantly increased in MBN-induced HBP carcinomas but was significantly reduced by tea intake (P<0.0001). Furthermore, APP expression and secretion by OECM-1 oral squamous cell carcinoma cells was inhibited by a major polyphenolic ingredient of green tea, (-)-epigallocatechin gallate, in a dose-dependent manner. Thus, APP might promote oral carcinogenesis, whereas green tea ingredients might diminish it by down-regulating APP.
authors.affiliation: Department of Medical Research and Education, Veterans General Hospital-Taipei, Taipei, Taiwan, ROC.
authors.forename: Shun-Yao
authors.initials: SY
authors.lastname: Ko
authors.forename: Kuo-Wei
authors.initials: KW
authors.lastname: Chang
authors.forename: Shu-Chun
authors.initials: SC
authors.lastname: Lin
authors.forename: Hui-Chuan
authors.initials: HC
authors.lastname: Hsu
authors.forename: Tsung-Yun
authors.initials: TY
authors.lastname: Liu
mesh_terms: D016564:Amyloid beta-Protein Precursor / Q000032:analysis / Q000235:genetics*; D000818:Animals; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D002392:Catechin / Q000031:analogs & derivatives / Q000494:pharmacology; D045744:Cell Line, Tumor; D006224:Cricetinae; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008647:Mesocricetus; D009061:Mouth Mucosa / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D009062:Mouth Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D008517:Phytotherapy; D028321:Plant Preparations / Q000737:chemistry / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013662:Tea / Q000737:chemistry*
chemical_list: D016564:Amyloid beta-Protein Precursor; D028321:Plant Preparations; D012333:RNA, Messenger; D013662:Tea; D002392:Catechin; C045651:epigallocatechin gallate