title: Phenethyl isothiocyanate induces DNA damage-associated G2/M arrest and subsequent apoptosis in oral cancer cells with varying p53 mutations.
abstract: Phenethyl isothiocyanate (PEITC) is a naturally occurring cruciferous vegetable-derived compound that inhibits cell growth and induces apoptosis in oral cancer cells. However, the exact mechanism of PEITC action has not been fully elucidated. This study investigated the molecular mechanism and anticancer potential of PEITC in oral squamous cell carcinoma (OSCC) cells with various p53 statuses. PEITC inhibited the growth of OC2, SCC4, and SCC25 cells (functional p53 mutants) in a dose-dependent manner with low toxicity to normal cells. Treatment with PEITC induced reactive oxygen species production, nitric oxide generation, and GSH depletion and triggered DNA damage response as evidenced by flow cytometry, 8-OHdG formation, and comet assay. Furthermore, the subsequent activation of ATM, Chk2, and p53 as well as the increased expression of downstream proteins p21 and Bax resulted in a G2/M phase arrest by inhibiting Cdc25C, Cdc2, and cyclin B1. The PEITC-induced apoptotic cell death, following a diminished mitochondrial transmembrane potential, reduced the expression of Bcl-2 and Mcl-1, released mitochondrial cytochrome c, and activated caspase 3 and PARP cleavage. The p53 inhibitor pifithrin-α and the antioxidants N-acetylcysteine and glutathione (GSH) protected the cells from PEITC-mediated apoptosis. However, mito-TEMPO, catalase, apocynin, and L-NAME did not prevent PEITC-induced cell death, suggesting that PEITC induced G2/M phase arrest and apoptosis in oral cancer cells via a GSH redox stress and oxidative DNA damage-induced ATM-Chk2-p53-related pathway. These results provide new insights into the critical roles of both GSH redox stress and p53 in the regulation of PEITC-induced G2/M cell cycle arrest and apoptosis in OSCCs.
authors: Department of Medical Laboratory Sciences and Biotechnology, School of Medicine and Health Sciences, Fooyin University, Kaohsiung City 83102, Taiwan.
authors: Yao-Tsung
authors: YT
authors: Yeh
authors: Department of Medical Laboratory Sciences and Biotechnology, School of Medicine and Health Sciences, Fooyin University, Kaohsiung City 83102, Taiwan.
authors: Hua
authors: H
authors: Yeh
authors: Institute of Medical Sciences, College of Medicine, Tzu Chi University, Hualien, Taiwan.
authors: Shu-Hui
authors: SH
authors: Su
authors: Department of Medical Laboratory Sciences and Biotechnology, School of Medicine and Health Sciences, Fooyin University, Kaohsiung City 83102, Taiwan.
authors: Jian-Sheng
authors: JS
authors: Lin
authors: Department of Medical Laboratory Sciences and Biotechnology, School of Medicine and Health Sciences, Fooyin University, Kaohsiung City 83102, Taiwan.
authors: Kuo-Jui
authors: KJ
authors: Lee
authors: Department of Medical Laboratory Sciences and Biotechnology, School of Medicine and Health Sciences, Fooyin University, Kaohsiung City 83102, Taiwan.
authors: Huey-Wen
authors: HW
authors: Shyu
authors: Department of Medical Laboratory Sciences and Biotechnology, School of Medicine and Health Sciences, Fooyin University, Kaohsiung City 83102, Taiwan.
authors: Zi-Feng
authors: ZF
authors: Chen
authors: Department of Medical Laboratory Sciences and Biotechnology, School of Medicine and Health Sciences, Fooyin University, Kaohsiung City 83102, Taiwan.
authors: Sheng-Yun
authors: SY
authors: Huang
authors: Department of Medical Laboratory Sciences and Biotechnology, School of Medicine and Health Sciences, Fooyin University, Kaohsiung City 83102, Taiwan. Electronic address: sc096@fy.edu.tw.
authors: Shu-Jem
authors: SJ
authors: Su
mesh_terms: D016588:Anticarcinogenic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D064007:Ataxia Telangiectasia Mutated Proteins / Q000378:metabolism; D019607:Brassicaceae / Q000737:chemistry; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D064447:Checkpoint Kinase 2 / Q000378:metabolism; D004249:DNA Damage / Q000187:drug effects; D059565:G2 Phase Cell Cycle Checkpoints / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D005978:Glutathione / Q000378:metabolism; D006131:Growth Inhibitors / Q000494:pharmacology; D006801:Humans; D017879:Isothiocyanates / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects*; D009062:Mouth Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D009154:Mutation / Q000235:genetics; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000235:genetics
chemical_list: D016588:Anticarcinogenic Agents; D018797:Cell Cycle Proteins; D006131:Growth Inhibitors; D017879:Isothiocyanates; D017382:Reactive Oxygen Species; D016159:Tumor Suppressor Protein p53; D009569:Nitric Oxide; C058305:phenethyl isothiocyanate; D064447:Checkpoint Kinase 2; D064007:Ataxia Telangiectasia Mutated Proteins; D005978:Glutathione
keywords: Apoptosis; DNA damage; Free radicals; Glutathione; Oral squamous cell carcinoma; Phenethyl isothiocyanates; Reactive oxygen species; p53