title: Gypenosides causes DNA damage and inhibits expression of DNA repair genes of human oral cancer SAS cells.
abstract: Gypenosides (Gyp) are the major components of Gynostemma pentaphyllum Makino, a Chinese medical plant. Recently, Gyp has been shown to induce cell cycle arrest and apoptosis in many human cancer cell lines. However, there is no available information to address the effects of Gyp on DNA damage and DNA repair-associated gene expression in human oral cancer cells. Therefore, we investigated whether Gyp induced DNA damage and DNA repair gene expression in human oral cancer SAS cells. The results from flow cytometric assay indicated that Gyp-induced cytotoxic effects led to a decrease in the percentage of viable SAS cells. The results from comet assay revealed that the incubation of SAS cells with Gyp led to a longer DNA migration smear (comet tail) when compared with control and this effect was dose-dependent. The results from real-time PCR analysis indicated that treatment of SAS cells with 180 mug/ml of Gyp for 24 h led to a decrease in 14-3-3sigma, DNA-dependent serine/threonine protein kinase (DNAPK), p53, ataxia telangiectasia mutated (ATM), ataxia-telangiectasia and Rad3-related (ATR) and breast cancer gene 1 (BRCA1) mRNA expression. These observations may explain the cell death caused by Gyp in SAS cells. Taken together, Gyp induced DNA damage and inhibited DNA repair-associated gene expressions in human oral cancer SAS cells in vitro.
authors.affiliation: School of Chinese Medicine, China Medical University, No 91, Hsueh-Shih Road, Taichung 40402, Taiwan, R.O.C.
authors.forename: Kung-Wen
authors.initials: KW
authors.lastname: Lu
authors.forename: Jung-Chou
authors.initials: JC
authors.lastname: Chen
authors.forename: Tung-Yuan
authors.initials: TY
authors.lastname: Lai
authors.forename: Jai-Sing
authors.initials: JS
authors.lastname: Yang
authors.forename: Shu-Wen
authors.initials: SW
authors.lastname: Weng
authors.forename: Yi-Shih
authors.initials: YS
authors.lastname: Ma
authors.forename: Nou-Ying
authors.initials: NY
authors.lastname: Tang
authors.forename: Pei-Jung
authors.initials: PJ
authors.lastname: Lu
authors.forename: Jing-Ru
authors.initials: JR
authors.lastname: Weng
authors.forename: Jing-Gung
authors.initials: JG
authors.lastname: Chung
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D020552:Comet Assay; D004249:DNA Damage; D004260:DNA Repair / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D029774:Gynostemma; D006801:Humans; D066298:In Vitro Techniques; D008516:Medicine, Chinese Traditional / Q000379:methods; D009062:Mouth Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology; D010936:Plant Extracts / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D010936:Plant Extracts; C474918:gypenoside