title: Poly(ADP-ribosyl)ation enhances H-RAS protein stability and causes abnormal cell cycle progression in human TK6 lymphoblastoid cells treated with hydroquinone.
abstract: Hydroquinone (HQ), one of the most important benzene-derived metabolites, can induce aberrant cell cycle progression; however, the mechanism of this induction remains unclear. Poly(ADP-ribosyl)ation (PARylation), which is catalysed primarily by poly(ADP-ribose) polymerase-1 (PARP-1), participates in various biological processes, including cell cycle control. The results of the present study show an accumulation in G1 phase versus S phase of TK6 human lymphoblast cells treated with HQ for 48h compared with PBS-treated cells; after 72h of HQ treatment, the cells transitioned from G1 arrest to S phase arrest. We examined the expression of six genes related to the cell cycle or leukaemia to further explore the reason for this phenomenon. Among these genes, H-RAS was found to be associated with this phenomenon because its mRNA and protein expression decreased at 48h and increased at 72h. Experiments for PARP activity induction and inhibition revealed that the observed PARylation was positively associated with H-RAS expression. Moreover, in cells treated with HQ in conjunction with PARP-1 knockdown, expression of the H-RAS protein decreased and the number of cells in G1 phase increased. The degree of poly(ADP-ribosyl) modification of the H-RAS protein increased in cells treated with HQ for 72h, further supporting that changes in PARylation contributed to the rapid alteration of H-RAS protein expression, followed by abnormal progression of the cell cycle. Co-immunoprecipitation (co-IP) assays were employed to determine whether protein complexes were formed by PARP-1 and H-RAS proteins, and the direct interaction between these proteins indicated that PARylation regulated H-RAS expression. As detected by confocal microscopy, the H-RAS protein was found in the nucleus and cytoplasm. To our knowledge, this study is the first to reveal that H-RAS protein can be modified by PARylation.
authors.affiliation: Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, PR China; Department of Environmental and Occupational Health, Institute for Environment and Health, School of Public Health, Guangdong Medical College, Dongguan 523808, PR China.
authors.forename: Linhua
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Environmental and Occupational Health, Institute for Environment and Health, School of Public Health, Guangdong Medical College, Dongguan 523808, PR China.
authors.forename: Xiaoxuan
authors.initials: X
authors.lastname: Ling
authors.affiliation: Department of Environmental and Occupational Health, Institute for Environment and Health, School of Public Health, Guangdong Medical College, Dongguan 523808, PR China.
authors.forename: Huanwen
authors.initials: H
authors.lastname: Tang
authors.affiliation: Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, PR China; Department of Environmental and Occupational Health, Institute for Environment and Health, School of Public Health, Guangdong Medical College, Dongguan 523808, PR China.
authors.forename: Jialong
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, PR China; School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, PR China.
authors.forename: Qiaosheng
authors.initials: Q
authors.lastname: Wen
authors.affiliation: Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, PR China. Electronic address: zoufei616@163.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Zou
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D059447:Cell Cycle Checkpoints / Q000187:drug effects*; D045744:Cell Line, Tumor; D015536:Down-Regulation; D059585:G1 Phase Cell Cycle Checkpoints / Q000187:drug effects; D006801:Humans; D006873:Hydroquinones / Q000494:pharmacology*; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D055550:Protein Stability; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D059807:S Phase Cell Cycle Checkpoints / Q000187:drug effects; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D000970:Antineoplastic Agents; D006873:Hydroquinones; D000067856:Poly(ADP-ribose) Polymerase Inhibitors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011065:Poly(ADP-ribose) Polymerases; D018631:ras Proteins; C031927:hydroquinone
keywords: Cell cycle; H-RAS; Hydroquinone; PARP-1; PARylation