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Zebian A, El-Dor M, Shaito A, Mazurier F, Rezvani HR, Zibara K. XPC multifaceted roles beyond DNA damage repair: p53-dependent and p53-independent functions of XPC in cell fate decisions. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2022; 789:108400. [PMID: 35690409 DOI: 10.1016/j.mrrev.2021.108400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Revised: 11/19/2021] [Accepted: 11/19/2021] [Indexed: 06/15/2023]
Abstract
Xeroderma pigmentosum group C protein (XPC) acts as a DNA damage recognition factor for bulky adducts and as an initiator of global genome nucleotide excision repair (GG-NER). Novel insights have shown that the role of XPC is not limited to NER, but is also implicated in DNA damage response (DDR), as well as in cell fate decisions upon stress. Moreover, XPC has a proteolytic role through its interaction with p53 and casp-2S. XPC is also able to determine cellular outcomes through its interaction with downstream proteins, such as p21, ARF, and p16. XPC interactions with effector proteins may drive cells to various fates such as apoptosis, senescence, or tumorigenesis. In this review, we explore XPC's involvement in different molecular pathways in the cell and suggest that XPC can be considered not only as a genomic caretaker and gatekeeper but also as a tumor suppressor and cellular-fate decision maker. These findings envisage that resistance to cell death, induced by DNA-damaging therapeutics, in highly prevalent P53-deficent tumors might be overcome through new therapeutic approaches that aim to activate XPC in these tumors. Moreover, this review encourages care providers to consider XPC status in cancer patients before chemotherapy in order to improve the chances of successful treatment and enhance patients' survival.
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Affiliation(s)
- Abir Zebian
- University of Bordeaux, INSERM U1035, BMGIC, Bordeaux, France; PRASE, Lebanese University, Beirut, Lebanon
| | | | - Abdullah Shaito
- Biomedical Research Center, Qatar University, P.O. Box 2713, Doha, Qatar
| | | | | | - Kazem Zibara
- PRASE, Lebanese University, Beirut, Lebanon; Biology Department, Faculty of Sciences - I, Lebanese University, Beirut, Lebanon.
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2
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Borský P, Andrýs C, Krejsek J, Hamáková K, Kremláček J, Málková A, Bartošová L, Fiala Z, Palička V, Borská L. Serum Level of Antibodies (IgG, IgM) Against Benzo[a]pyrene-7,8-diol-9,10-epoxide-DNA Adducts in Children Dermatologically Exposed to Coal Tar. ACTA MEDICA (HRADEC KRÁLOVÉ) 2017; 60:27-31. [PMID: 28467299 DOI: 10.14712/18059694.2017.46] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Crude coal tar (CCT) contains polycyclic aromatic hydrocarbons (PAHs). Benzo[a]pyrene (BaP) is metabolized into a highly reactive metabolite benzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE) that is able to bind to DNA and creates BPDE-DNA adducts. Adducted DNA becomes immunogenic and induces immune response by production of antibodies against BPDE-DNA adducts (Ab-BPDE-DNA). Circulating Ab-BPDE-DNA was proposed as potential biomarker of genotoxic exposure to BaP (PAHs). Goeckerman therapy (GT) of psoriasis uses dermal application of CCT ointment (PAHs). In presented study (children with psoriasis treated by GT; n = 19) the therapy significantly increased the level of Ab-BPDE-DNA (EI = 0.29/0.19-0.34 vs. 0.31/0.25-0.40; median/lower-upper quartile; p < 0.01). The results support the idea of Ab-BPDE-DNA level as a possible tentative indicator of exposure, effects and susceptibility of the organism to the exposure of BaP (PAHs).
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Affiliation(s)
- Pavel Borský
- Institute of Hygiene and Preventive Medicine, Charles University, Faculty of Medicine, Hradec Králové, Czech Republic
| | - Ctirad Andrýs
- Institute of Clinical Immunology and Allergology, Charles University, Faculty of Medicine, Hradec Králové, Czech Republic
| | - Jan Krejsek
- Institute of Clinical Immunology and Allergology, Charles University, Faculty of Medicine, Hradec Králové, Czech Republic
| | - Květoslava Hamáková
- Clinic of Dermal and Venereal Diseases, Charles University Hospital, Hradec Králové, Czech Republic
| | - Jan Kremláček
- Institute of Pathological Physiology, Charles University, Faculty of Medicine, Hradec Králové, Czech Republic
| | - Andrea Málková
- Institute of Hygiene and Preventive Medicine, Charles University, Faculty of Medicine, Hradec Králové, Czech Republic
| | - Lenka Bartošová
- Institute of Hygiene and Preventive Medicine, Charles University, Faculty of Medicine, Hradec Králové, Czech Republic
| | - Zdeněk Fiala
- Institute of Hygiene and Preventive Medicine, Charles University, Faculty of Medicine, Hradec Králové, Czech Republic
| | - Vladimír Palička
- Institute of Clinical Biochemistry and Diagnostics, Charles University Hospital and Faculty of Medicine, Hradec Králové, Czech Republic
| | - Lenka Borská
- Institute of Pathological Physiology, Charles University, Faculty of Medicine, Hradec Králové, Czech Republic.
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3
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Abstract
The cells in the human body are continuously challenged by a variety of genotoxic attacks. Erroneous repair of the DNA can lead to mutations and chromosomal aberrations that can alter the functions of tumor suppressor genes or oncogenes, thus causing cancer development. As a central tumor suppressor, p53 guards the genome by orchestrating a variety of DNA-damage-response (DDR) mechanisms. Already early in metazoan evolution, p53 started controlling the apoptotic demise of genomically compromised cells. p53 plays a prominent role as a facilitator of DNA repair by halting the cell cycle to allow time for the repair machineries to restore genome stability. In addition, p53 took on diverse roles to also directly impact the activity of various DNA-repair systems. It thus appears as if p53 is multitasking in providing protection from cancer development by maintaining genome stability.
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Affiliation(s)
- Ashley B Williams
- Medical Faculty, Institute for Genome Stability in Ageing and Disease, University of Cologne, 50931 Cologne, Germany Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC) and Systems Biology of Ageing Cologne, University of Cologne, 50931 Cologne, Germany
| | - Björn Schumacher
- Medical Faculty, Institute for Genome Stability in Ageing and Disease, University of Cologne, 50931 Cologne, Germany Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), Center for Molecular Medicine Cologne (CMMC) and Systems Biology of Ageing Cologne, University of Cologne, 50931 Cologne, Germany
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4
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Piberger AL, Köberle B, Hartwig A. The broccoli-born isothiocyanate sulforaphane impairs nucleotide excision repair: XPA as one potential target. Arch Toxicol 2013; 88:647-58. [PMID: 24352536 DOI: 10.1007/s00204-013-1178-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 11/26/2013] [Indexed: 11/28/2022]
Abstract
The isothiocyanate sulforaphane (SFN), the major hydrolysis product of glucosinolates present in broccoli, has frequently been proposed to exert anticarcinogenic properties, mainly due to the induction of the nrf2/Keap1/ARE-signaling pathway. As potential underlying mechanism, a SFN-dependent zinc release from Keap1, the negative regulator of nrf2, has been described. This raises the question whether SFN is able to interfere with other zinc binding structures as well, for example those essential for DNA repair. Within this study, a SFN-induced deliberation of zinc from a synthesized peptide resembling the zinc binding domain of the xeroderma pigmentosum A (XPA) protein was observed starting at 50 μM SFN. Since XPA is absolutely required for nucleotide excision repair, the impact of SFN on the repair of (+)-anti-benzo[a]pyrene 7,8-diol-9,10-epoxide ((+)-anti-BPDE)-induced DNA adducts in HCT 116 cells was investigated. While preincubation with SFN did not affect initial lesion levels, a dose-dependent repair inhibition of (+)-anti-BPDE-induced DNA damage during the first 12 h after lesion induction was observed, starting at 1 μM SFN. In contrast, the later phase of DNA repair was not impaired by SFN. In support of an inactivation of XPA also in cells, SFN increased the (+)-anti-BPDE-induced cytotoxicity XPA dependently in XP12RO cells. Comparison of p53-proficient and p53-deficient cells revealed no difference in SFN-induced DNA repair inhibition, indicating that p53 is no cellular target of SFN. Since DNA repair processes are required to maintain DNA integrity, the presented data suggest a potential impairment of genomic stability by SFN.
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Affiliation(s)
- Ann Liza Piberger
- Department of Food Chemistry and Toxicology, Institute of Applied Bioscience, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, 76131, Karlsruhe, Germany
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5
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Bowden NA, Ashton KA, Avery-Kiejda KA, Zhang XD, Hersey P, Scott RJ. Nucleotide excision repair gene expression after Cisplatin treatment in melanoma. Cancer Res 2010; 70:7918-26. [PMID: 20807809 DOI: 10.1158/0008-5472.can-10-0161] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Two of the hallmark features of melanoma are its development as a result of chronic UV radiation exposure and the limited efficacy of cisplatin in the disease treatment. Both of these DNA-damaging agents result in large helix-distorting DNA damage that is recognized and repaired by nucleotide excision repair (NER). The aim of this study was to examine the expression of NER gene transcripts, p53, and p21 in melanoma cell lines treated with cisplatin compared with melanocytes. Basal expression of all genes was greater in the melanoma cell lines compared with melanocytes. Global genome repair (GGR) transcripts showed significantly decreased relative expression (RE) in melanoma cell lines 24 hours after cisplatin treatment. The basal RE of p53 was significantly higher in the melanoma cell lines compared with the melanocytes. However, induction of p53 was only significant in the melanocytes at 6 and 24 hours after cisplatin treatment. Inhibition of p53 expression significantly decreased the expression of all the GGR transcripts in melanocytes at 6 and 24 hours after cisplatin treatment. Although the RE levels were lower with p53 inhibition, the induction of the GGR genes was very similar to that in the control melanocytes and increased significantly across the time points. The findings from this study revealed reduced GGR transcript levels in melanoma cells 24 hours after cisplatin treatment. Our findings suggest a possible mechanistic explanation for the limited efficacy of cisplatin treatment and the possible role of UV light in melanoma.
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Affiliation(s)
- Nikola A Bowden
- Centre for Information Based Medicine, University of Newcastle, Newcastle, New South Wales, Australia.
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Sigounas G, Hairr JW, Cooke CD, Owen JR, Asch AS, Weidner DA, Wiley JE. Role of benzo[alpha]pyrene in generation of clustered DNA damage in human breast tissue. Free Radic Biol Med 2010; 49:77-87. [PMID: 20347033 DOI: 10.1016/j.freeradbiomed.2010.03.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Revised: 03/06/2010] [Accepted: 03/18/2010] [Indexed: 12/23/2022]
Abstract
Complex DNA damage may manifest in double-strand breaks (DSBs) and non-DSB, bistranded, oxidatively induced clustered DNA lesions (OCDLs). Although the carcinogen benzo[alpha]pyrene (B[alpha]P) has been shown to induce chromosomal aberrations and transformation of mammary cells, it is not known whether this compound engenders clustered DNA damage. Normal primary breast tissue-derived cells were treated with B[alpha]P, and the levels of DNA lesions, chromosomal aberrations, total antioxidant capacity (TAC), and reactive oxygen species (ROS) were determined. DNA from cells treated with 2 and 8 microM B[alpha]P exhibited increases of 3- and 4-fold in APE1 (p<0.001), 11- and 19-fold in Endo III (p<0.001), and 8- and 15-fold in hOGG1 (p<0.001) OCDLs, respectively, compared to the 0 microM B[alpha]P-treated (control) group. Mammary cells treated with 8 microM B[alpha]P produced 0.12 aberrations per cell (p<0.05) and there was a strong positive correlation (r=0.91) between the levels of OCDLs and those of chromosomal aberrations. Finally, TAC was decreased by 25% (p<0.02), whereas ROS production increased by 2-fold (p<0.02) in cells treated with 8 microM B[alpha]P compared to the control group. In conclusion, oxidatively induced clustered DNA damage mediated through differential expression of APE1, reduced TAC, and increased ROS may play a significant role in the chemically induced transformation of normal primary mammary cells.
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Affiliation(s)
- George Sigounas
- Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA.
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7
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Georgakilas AG, Mosley WG, Georgakila S, Ziech D, Panayiotidis MI. Viral-induced human carcinogenesis: an oxidative stress perspective. MOLECULAR BIOSYSTEMS 2010; 6:1162-72. [DOI: 10.1039/b923958h] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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8
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Ohno K, Ishihata K, Tanaka-Azuma Y, Yamada T. A genotoxicity test system based on p53R2 gene expression in human cells: Assessment of its reactivity to various classes of genotoxic chemicals. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2008; 656:27-35. [DOI: 10.1016/j.mrgentox.2008.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Revised: 05/31/2008] [Accepted: 07/05/2008] [Indexed: 01/26/2023]
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9
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Shen W, liu H, Yu Y. Translation initiation proteins, ubiquitin-proteasome system related proteins, and 14-3-3 proteins as response proteins in FL cells exposed to anti-benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide. Proteomics 2008; 8:3450-68. [DOI: 10.1002/pmic.200800085] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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10
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Shen S, Lee J, Weinfeld M, Le XC. Attenuation of DNA damage-induced p53 expression by arsenic: a possible mechanism for arsenic co-carcinogenesis. Mol Carcinog 2008; 47:508-18. [PMID: 18085531 DOI: 10.1002/mc.20406] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Inhibition of DNA repair processes has been suggested as one predominant mechanism in arsenic co-genotoxicity. However, the underlying mode of action responsible for DNA repair inhibition by arsenic remains elusive. To further elucidate the mechanism of repair inhibition by arsenic, we examined the effect of trivalent inorganic and methylated arsenic metabolites on the repair of benzo(a)pyrene diol epoxide (BPDE)-DNA adducts in normal human primary fibroblasts and their effect on repair-related protein expression. We observed that monomethylarsonous acid (MMA(III)) was the most potent inhibitor of the DNA repair. MMA(III) did not change the expression levels of some key repair proteins involved upstream of the dual incision in the global nucleotide excision repair (NER) pathway, including p48, XPC, xeroderma pigmentosum complementation group A (XPA), and p62-TFIIH. However, it led to a marked impairment of p53 induction in response to BPDE treatment. The abrogated p53 expression translated into reduced p53 DNA-binding activity, suggesting a possibility of downregulating downstream repair genes by p53. A p53-null cell line failed to exhibit the inhibitory effect of MMA(III) on NER, implicating a role for p53 in the NER inhibition by MMA(III). Further investigation revealed that MMA(III) dramatically inhibited p53 phosphorylation at serine 15, implying that MMA(III) destabilized p53 by inhibiting its phosphorylation. Because p53 is required for proficient global NER, our data suggest that arsenic inhibits NER through suppressing p53 induction in response to DNA damage in cells with normal p53 gene expression.
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Affiliation(s)
- Shengwen Shen
- Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, Alberta, Canada
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11
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Schavinsky-Khrapunsky Y, Priel E, Aboud M. Dose-dependent dual effect of HTLV-1 tax oncoprotein on p53-dependent nucleotide excision repair in human T-cells. Int J Cancer 2008; 122:305-16. [PMID: 17918160 DOI: 10.1002/ijc.23091] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In this study we investigated the effect of Tax on nucleotide excision repair (NER) in human T-cell lines by using the host cell repair analysis of UVC-irradiated reporter plasmid. This analysis revealed a p53-dependent NER activity in wild type (w.t.) p53-containing T-cells and p53-independent NER in w.t. p53-lacking T-cells. Notably, in the w.t. p53-containing cells Tax exerted a dose-dependent dual effect on NER. While low Tax doses markedly stimulated this repair, high Tax doses strongly reduced it. Further experiments demonstrated that the low Tax doses enhanced, in these cells, the level and the transcriptional function of their w.t. p53 protein. On the other hand, although the high Tax doses further increased the level of p53, they functionally inactivated its accumulating molecules. Both of these Tax effects on p53 proved to be mediated by Tax-induced NF-kappaB-related mechanisms. Together, these data suggest that by NF-kappaB activation Tax elevates the level of the cellular w.t. p53. However, while at low Tax doses the elevating w.t. p53 molecules are functionally active and capable of stimulating NER, intensifying further the NF-kappaB activation by the high Tax doses concomitantly evokes certain mechanism(s) which functionally inactivates the accumulating p53 protein. In contrast to this dual effect on the p53-dependent NER, Tax displayed only an inhibitory effect on the p53-independent NER by its high doses, whereas its low doses had no effect on this repair. The mechanisms of the NF-kappaB-associated effects on the level and function of the cellular w.t.p53 and of the p53-independent NER noted in our experimental systems are further investigated in our laboratory.
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Affiliation(s)
- Yana Schavinsky-Khrapunsky
- The Shraga Segal Department of Microbiology and Immunology, Faculty of Health Sciences and Cancer Research Center, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
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12
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Shen W, Liu H, Yu Y. Proteomic Analysis of Cellular Responses to Different Concentrations of anti-Benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide in Human Amniotic Epithelial FL Cells. J Proteome Res 2007; 6:4737-48. [DOI: 10.1021/pr070406b] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Wenyan Shen
- Department of Pathophysiology, Zhejiang University, School of Medicine, Hangzhou 310058, China
| | - Hui Liu
- Department of Pathophysiology, Zhejiang University, School of Medicine, Hangzhou 310058, China
| | - Yingnian Yu
- Department of Pathophysiology, Zhejiang University, School of Medicine, Hangzhou 310058, China
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13
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Kundu CN, Balusu R, Jaiswal AS, Gairola CG, Narayan S. Cigarette smoke condensate-induced level of adenomatous polyposis coli blocks long-patch base excision repair in breast epithelial cells. Oncogene 2007; 26:1428-38. [PMID: 16924228 DOI: 10.1038/sj.onc.1209925] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 07/11/2006] [Accepted: 07/11/2006] [Indexed: 11/09/2022]
Abstract
Our previous studies have shown that treatment with cigarette smoke condensate (CSC) transforms normal breast epithelial cell line, MCF-10A. In the present study, the mechanism of CSC-induced transformation of breast epithelial cells was examined. We first determined whether benzo[a]pyrene (B[a]P)- and CSC-induced levels of APC are capable of inhibiting long-patch base excision repair (LP-BER) since our earlier studies had shown that an interaction of APC with DNA polymerase beta (pol-beta) blocks strand-displacement synthesis. With the use of a novel in vivo LP-BER assay, it was demonstrated that increased and decreased APC levels in different breast cancer cell lines were associated with a decrease or increase in LP-BER activity, respectively. The effect of APC on LP-BER in malignant and pre-malignant breast epithelial cell lines was produced by either overexpression or knockdown of APC. Furthermore, it was shown that the decreased LP-BER in B[a]P- or CSC-treated pre-malignant breast epithelial cells is associated with an increased level of APC and decreased cell growth. Our results suggest that the decreased growth allows cells to repair the damaged DNA before mitosis, and failure to repair damaged DNA has the potential to transform pre-malignant breast epithelial cells.
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Affiliation(s)
- C N Kundu
- Department of Anatomy and Cell Biology, UF Shands Cancer Center, University of Florida, Gainesville, FL 32610, USA
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14
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Oh DH, Yeh K. Differentiating human keratinocytes are deficient in p53 but retain global nucleotide excision repair following ultraviolet radiation. DNA Repair (Amst) 2006; 4:1149-59. [PMID: 16043423 DOI: 10.1016/j.dnarep.2005.06.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Revised: 05/03/2005] [Accepted: 06/08/2005] [Indexed: 11/20/2022]
Abstract
Terminally differentiating keratinocytes constitute the predominant cell type within the skin epidermis and play an important role in the overall photobiology of human skin following ultraviolet radiation. However, the DNA repair capacity of differentiating keratinocytes is unclear, and little is known regarding how such repair activity is regulated in these cells. We systematically compared the global genomic nucleotide excision repair response of cultured undifferentiated human keratinocytes to those that were allowed to differentiate in 1.2 mM Ca(2+), in some cases supplemented with phorbol ester or Vitamin C. Differentiated cells ceased replication and expressed typical markers of differentiation. Following ultraviolet radiation, keratinocytes that were differentiated up to 12 days removed cyclobutane pyrimidine dimers and pyrimidine(6,4)pyrimidone photoproducts from the global genome as efficiently as undifferentiated cells. However, following the onset of calcium-induced differentiation, basal levels of p53 were nearly undetectable by 12 days of differentiation when global repair activity was unaffected. Following ultraviolet radiation, induction of p53 following ultraviolet radiation was abrogated by 6 days of calcium-induced differentiation. Basal levels of mRNA encoding the DNA damage recognition proteins, XPC and DDB2, were relatively insensitive to differentiation and p53 levels. However, following ultraviolet radiation, inductions of mRNA encoding the DNA damage recognition proteins, DDB2 and XPC, were differentially affected by differentiation. Rapid loss of DDB2 mRNA induction was associated with differentiation, while XPC mRNA induction diminished more slowly with differentiation. These results indicate that human keratinocytes preserve global nucleotide excision repair as well as expression of genes encoding key DNA damage recognition proteins well into the terminal differentiation process, perhaps using mechanisms other than p53.
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Affiliation(s)
- Dennis H Oh
- Department of Dermatology, University of California, San Francisco, CA, USA.
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15
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Porter PC, Clark DR, McDaniel LD, McGregor WG, States JC. Telomerase-immortalized human fibroblasts retain UV-induced mutagenesis and p53-mediated DNA damage responses. DNA Repair (Amst) 2006; 5:61-70. [PMID: 16140041 DOI: 10.1016/j.dnarep.2005.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2004] [Revised: 07/20/2005] [Accepted: 07/21/2005] [Indexed: 12/23/2022]
Abstract
Immortalized cells frequently have disruptions of p53 activity and lack p53-dependent nucleotide excision repair (NER). We hypothesized that telomerase immortalization would not alter p53-mediated ultraviolet light (UV)-induced DNA damage responses. DNA repair proficient primary diploid human fibroblasts (GM00024) were immortalized by transduction with a telomerase expressing retrovirus. Empty retrovirus transduced cells senesced after a few doublings. Telomerase transduced GM00024 cells (tGM24) were cultured continuously for 6 months (>60 doublings). Colony forming ability after UV irradiation was dose-dependent between 0 and 20J/m2 UVC (LD50=5.6J/m2). p53 accumulation was UV dose- and time-dependent as was induction of p48(XPE/DDB2), p21(CIP1/WAF1), and phosphorylation on p53-S15. UV dose-dependent apoptosis was measured by nuclear condensation. UV exposure induced UV-damaged DNA binding as monitored by electrophoretic mobility shift assays using UV irradiated radiolabeled DNA probe was inhibited by p53-specific siRNA transfection. p53-Specific siRNA transfection also prevented UV induction of p48 and improved UV survival measured by colony forming ability. Strand-specific NER of cyclobutane pyrimidine dimers (CPD) within DHFR was identical in tGM24 and GM00024 cells. CPD removal from the transcribed strand was nearly complete in 6h and from the non-transcribed strand was 73% complete in 24h. UV-induced HPRT mutagenesis in tGM24 was indistinguishable from primary human fibroblasts. These wide-ranging findings indicate that the UV-induced DNA damage response remains intact in telomerase-immortalized cells. Furthermore, telomerase immortalization provides permanent cell lines for testing the immediate impact on NER and mutagenesis of selective genetic manipulation without propagation to establish mutant lines.
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Affiliation(s)
- Paul C Porter
- Department of Pharmacology & Toxicology, University of Louisville, 570 South Preston Street, Rm221, Louisville, KY 40202, USA
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16
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Ferguson BE, Oh DH. Proficient global nucleotide excision repair in human keratinocytes but not in fibroblasts deficient in p53. Cancer Res 2005; 65:8723-9. [PMID: 16204041 DOI: 10.1158/0008-5472.can-05-1457] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The p53 tumor suppressor protein is important for many cellular responses to DNA damage in mammalian cells, but its role in regulating DNA repair in human keratinocytes is undefined. We compared the nucleotide excision repair (NER) response of human fibroblasts and keratinocytes deficient in p53. Fibroblasts expressing human papillomavirus 16 E6 oncoprotein had impaired repair of UV radiation-induced cyclobutane pyrimidine dimers in association with reduced levels of p53 and XPC, which is involved in DNA damage recognition. In contrast, keratinocytes expressing E6 alone or concurrently with the E7 oncoprotein, while possessing reduced levels of p53 but normal levels of XPC, continued to repair pyrimidine dimers as efficiently as control cells with normal p53 levels. Despite preservation of DNA repair, E6 and E6/E7 keratinocytes were hypersensitive to UV radiation. E6 fibroblasts exhibited markedly reduced basal and induced levels of mRNA encoding DDB2, another protein implicated in early events in global NER. In contrast, E6 or E6/E7 keratinocytes possessed basal DDB2 mRNA levels that were not significantly altered relative to control cells, although little induction occurred following UV radiation. Intact global NER was also confirmed in SCC25 cells possessing inactivating mutations in p53 as well as in cells treated with pifithrin-alpha, a chemical inhibitor of p53 that decreased sensitivity of cells to UV radiation. Collectively, these results indicate that human keratinocytes, unlike fibroblasts, do not require p53 to maintain basal global NER activity, but p53 may still be important in mediating inducible responses following DNA damage.
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Affiliation(s)
- Bridget E Ferguson
- Department of Dermatology, University of California-San Francisco, San Francisco VA Medical Center, San Francisco, California 94121, USA
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17
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Ford JM. Regulation of DNA damage recognition and nucleotide excision repair: another role for p53. Mutat Res 2005; 577:195-202. [PMID: 15927209 DOI: 10.1016/j.mrfmmm.2005.04.005] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 04/06/2005] [Accepted: 04/06/2005] [Indexed: 10/25/2022]
Abstract
In response to DNA damage, the p53 tumor suppressor gene product is activated leading to the induction of several downstream cellular processes including cell cycle checkpoints, DNA repair or apoptosis. Experiments first performed in the Hanawalt laboratory identified a p53-dependent pathway affecting global genomic nucleotide excision repair. The mechanisms involved in this process include both transcriptional and post-translational regulation by p53 of the DDB2 and XPC gene products, two critical DNA damage recognition proteins required for GGR. A historical review of this work is presented.
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Affiliation(s)
- James M Ford
- Department of Medicine (Oncology), Stanford University School of Medicine, 1115 CCSR Bldg., 269 Campus Drive Stanford, CA 94305, USA.
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Porter PC, Mellon I, States JC. XP-A cells complemented with Arg228Gln and Val234Leu polymorphic XPA alleles repair BPDE-induced DNA damage better than cells complemented with the wild type allele. DNA Repair (Amst) 2005; 4:341-9. [PMID: 15661657 DOI: 10.1016/j.dnarep.2004.10.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2004] [Accepted: 10/18/2004] [Indexed: 11/25/2022]
Abstract
Functional effects of Arg228Gln and Val2343Leu XPA polymorphisms on benzo[a]pyrene-r-7,t-8-dihydrodiol-t-9,10-epoxide-(+/-)-anti (BPDE) survival and repair were investigated in SV40 immortalized XP12RO cells complemented with wild type and polymorphic XPA cDNAs in an inducible cDNA expression system. In contrast to previous studies showing little impact of XPA polymorphisms on UV survival and repair, cells complemented with polymorphic XPAs displayed improved BPDE survival and repair as compared to wild type XPA-complemented cells. Survival after BPDE treatment was measured using AlamarBlue reduction and colony forming ability. Cells expressing low levels of either polymorphic XPA had equivalent or improved survival compared to wild type XPA-complemented cells (XPAwt cells). XPA induction improved BPDE survival in Arg228Gln (R228Q cells) and Val234Leu (V234L cells) complemented cells, but not XPAwt cells. BPDE-induced DNA damage repair was measured both by reactivation after transfection of a luciferase reporter plasmid reacted with BPDE in vitro, and by removal of adducts from genomic DNA of BPDE-treated cells. BPDE-induced DNA damage repair in R228Q and V234L cells expressing XPA at very low levels was similar to repair in XPAwt cells expressing XPA at normal levels. XPA induction improved repair in R228Q and V234L cells but not in XPAwt cells. Our findings suggest that both Arg228Gln and Val234Leu XPAs function better than wild type XPA for BPDE adduct removal. These observations differ from UV repair results suggesting that the differences are lesion specific. The location of the polymorphisms within the putative poly(ADP-ribose) binding domain suggests that poly(ADP-ribose) interaction is important in repair.
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Affiliation(s)
- Paul C Porter
- Department of Pharmacology and Toxicology, Center for Genetics and Molecular Medicine, James Graham Brown Cancer Center, and Center for Environmental and Occupational Health Sciences, University of Louisville, Louisville, KY 40202, USA
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Gatza ML, Chandhasin C, Ducu RI, Marriott SJ. Impact of transforming viruses on cellular mutagenesis, genome stability, and cellular transformation. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2005; 45:304-325. [PMID: 15645440 DOI: 10.1002/em.20088] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
It is estimated that 15% of all cancers are etiologically linked to viral infection. Specific cancers including adult T-cell leukemia, hepatocellular carcinoma, and uterine cervical cancer are associated with infection by human T-cell leukemia virus type I, hepatitis B virus, and high-risk human papilloma virus, respectively. In these cancers, genomic instability, a hallmark of multistep cancers, has been explicitly linked to the expression of oncoproteins encoded by these viruses. This review discusses mechanisms utilized by these viral oncoproteins, Tax, HBx, and E6/E7, to mediate genomic instability and cellular transformation.
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Affiliation(s)
- Michael L Gatza
- Interdepartmental Program in Cell and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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Azran I, Schavinsky-Khrapunsky Y, Aboud M. Role of Tax protein in human T-cell leukemia virus type-I leukemogenicity. Retrovirology 2004; 1:20. [PMID: 15310405 PMCID: PMC514576 DOI: 10.1186/1742-4690-1-20] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2004] [Accepted: 08/13/2004] [Indexed: 11/17/2022] Open
Abstract
HTLV-1 is the etiological agent of adult T-cell leukemia (ATL), the neurological syndrome TSP/HAM and certain other clinical disorders. The viral Tax protein is considered to play a central role in the process leading to ATL. Tax modulates the expression of many viral and cellular genes through the CREB/ATF-, SRF- and NF-κB-associated pathways. In addition, Tax employs the CBP/p300 and p/CAF co-activators for implementing the full transcriptional activation competence of each of these pathways. Tax also affects the function of various other regulatory proteins by direct protein-protein interaction. Through these activities Tax sets the infected T-cells into continuous uncontrolled replication and destabilizes their genome by interfering with the function of telomerase and topoisomerase-I and by inhibiting DNA repair. Furthermore, Tax prevents cell cycle arrest and apoptosis that would otherwise be induced by the unrepaired DNA damage and enables, thereby, accumulation of mutations that can contribute to the leukemogenic process. Together, these capacities render Tax highly oncogenic as reflected by its ability to transform rodent fibroblasts and primary human T-cells and to induce tumors in transgenic mice. In this article we discuss these effects of Tax and their apparent contribution to the HTLV-1 associated leukemogenic process. Notably, however, shortly after infection the virus enters into a latent state, in which viral gene expression is low in most of the HTLV-1 carriers' infected T-cells and so is the level of Tax protein, although rare infected cells may still display high viral RNA. This low Tax level is evidently insufficient for exerting its multiple oncogenic effects. Therefore, we propose that the latent virus must be activated, at least temporarily, in order to elevate Tax to its effective level and that during this transient activation state the infected cells may acquire some oncogenic mutations which can enable them to further progress towards ATL even if the activated virus is re-suppressed after a while. We conclude this review by outlining an hypothetical flow of events from the initial virus infection up to the ultimate ATL development and comment on the risk factors leading to ATL development in some people and to TSP/HAM in others.
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Affiliation(s)
- Inbal Azran
- Department of Microbiology and Immunology and Cancer Research Center, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Yana Schavinsky-Khrapunsky
- Department of Microbiology and Immunology and Cancer Research Center, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Mordechai Aboud
- Department of Microbiology and Immunology and Cancer Research Center, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva 84105, Israel
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