title: Quantitative phosphoproteomic analysis reveals γ-bisabolene inducing p53-mediated apoptosis of human oral squamous cell carcinoma via HDAC2 inhibition and ERK1/2 activation.
abstract: γ-Bisabolene, one of main components in cardamom, showed potent in vitro and in vivo anti-proliferative activities against human oral squamous cell carcinoma (OSCC). γ-Bisabolene activated caspases-3/9 and decreased mitochondrial memebrane potential, leading to apoptosis of OSCC cell lines (Ca9-22 and SAS), but not normal oral fibroblast cells. Phosphoproteome profiling of OSCC cells treated with γ-bisabolene was identified using TiO2-PDMS plate and LC-MS/MS, then confirmed using Western blotting and real-time RT-PCR assays. Phosphoproteome profiling revealed that γ-bisabolene increased the phosphorylation of ERK1/2, protein phosphatases 1 (PP1), and p53, as well as decreased the phosphorylation of histone deacetylase 2 (HDAC2) in the process of apoptosis induction. Protein-protein interaction network analysis proposed the involvement of PP1-HDAC2-p53 and ERK1/2-p53 pathways in γ-bisabolene-induced apoptosis. Subsequent assays indicated γ-bisabolene eliciting p53 acetylation that enhanced the expression of p53-regulated apoptotic genes. PP1 inhibitor-2 restored the status of HDAC2 phosphorylation, reducing p53 acetylation and PUMA mRNA expression in γ-bisabolene-treated Ca9-22 and SAS cells. Meanwhile, MEK and ERK inhibitors significantly decreased γ-bisabolene-induced PUMA expression in both cancer cell lines. Notably, the results ascertained the involvement of PP1-HDAC2-p53 and ERK1/2-p53 pathways in mitochondria-mediated apoptosis of γ-bisabolene-treated cells. This study demonstrated γ-bisabolene displaying potent anti-proliferative and apoptosis-inducing activities against OSCC in vitro and in vivo, elucidating molecular mechanisms of γ-bisabolene-induced apoptosis. The novel insight could be useful for developing anti-cancer drugs.
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan.|Department of biochemistry, College of life sciences, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Yu-Jen
authors.initials: YJ
authors.lastname: Jou
authors.affiliation: Graduate Institute of Integrated Medicine, China Medical University, Taichung, Taiwan.|Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chao-Jung
authors.initials: CJ
authors.lastname: Chen
authors.affiliation: Proteomics Core Laboratory, Department of Medical Research, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Yu-Ching
authors.initials: YC
authors.lastname: Liu
authors.affiliation: Department of Biological Science and Technology, China Medical University, Taichung, Taiwan.
authors.forename: Tzong-Der
authors.initials: TD
authors.lastname: Way
authors.affiliation: Department of Microbiology, School of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Chih-Ho
authors.initials: CH
authors.lastname: Lai
authors.affiliation: Department of Otolaryngology, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chun-Hung
authors.initials: CH
authors.lastname: Hua
authors.affiliation: School of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, China Medical University, Taichung, Taiwan.
authors.forename: Ching-Ying
authors.initials: CY
authors.lastname: Wang
authors.affiliation: Department of Biotechnology, College of Health Science, Asia University, Wufeng, Taichung, Taiwan.
authors.forename: Su-Hua
authors.initials: SH
authors.lastname: Huang
authors.affiliation: Department of biochemistry, College of life sciences, National Chung Hsing University, Taichung, Taiwan.
authors.forename: Jung-Yie
authors.initials: JY
authors.lastname: Kao
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, China Medical University, Taichung, Taiwan.|Department of Biotechnology, College of Health Science, Asia University, Wufeng, Taichung, Taiwan.
authors.forename: Cheng-Wen
authors.initials: CW
authors.lastname: Lin
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism*; D056464:Histone Deacetylase 2 / Q000037:antagonists & inhibitors*; D006801:Humans; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009062:Mouth Neoplasms / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism*; D010750:Phosphoproteins / Q000032:analysis; D040901:Proteomics; D012717:Sesquiterpenes / Q000494:pharmacology* / Q000627:therapeutic use; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D010750:Phosphoproteins; D012717:Sesquiterpenes; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; C511058:gamma-bisabolene; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C533423:HDAC2 protein, human; D056464:Histone Deacetylase 2
keywords: Cell biology; Histone deacetylase; Oral squamous cell carcinoma; P53 acetylation; Phosphoproteomics; γ-Bisabolene