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The XPB Subunit of the TFIIH Complex Plays a Critical Role in HIV-1 Transcription and XPB Inhibition by Spironolactone Prevents HIV-1 Reactivation from Latency. J Virol 2021; 95:JVI.01247-20. [PMID: 33239456 PMCID: PMC7851559 DOI: 10.1128/jvi.01247-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
HIV transcription requires assembly of cellular transcription factors at the HIV-1promoter. The TFIIH general transcription factor facilitates transcription initiation by opening the DNA strands around the transcription start site and phosphorylating the C-terminal domain for RNA polymerase II (RNAPII) for activation. Spironolactone (SP), an FDA approved aldosterone antagonist, triggers the proteasomal degradation of the XPB subunit of TFIIH, and concurrently suppresses acute HIV infection in vitro Here we investigated SP as a possible block-and-lock agent for a functional cure aimed at the transcriptional silencing of the viral reservoir. The long-term activity of SP was investigated in primary and cell line models of HIV-1 latency and reactivation. We show that SP rapidly inhibits HIV-1 transcription by reducing RNAPII recruitment to the HIV-1 genome. shRNA knockdown of XPB confirmed XPB degradation as the mechanism of action. Unfortunately, long-term pre-treatment with SP does not result in epigenetic suppression of HIV upon SP treatment interruption, since virus rapidly rebounds when XPB reemerges; however, SP alone without ART maintains the transcriptional suppression. Importantly, SP inhibits HIV reactivation from latency in both cell line models and resting CD4+T cells isolated from aviremic infected individuals upon cell stimulation with latency reversing agents. Furthermore, long-term treatment with concentrations of SP that potently degrade XPB does not lead to global dysregulation of cellular mRNA expression. Overall, these results suggest that XPB plays a key role in HIV transcriptional regulation and XPB degradation by SP strengthens the potential of HIV transcriptional inhibitors in block-and-lock HIV cure approaches.IMPORTANCE Antiretroviral therapy (ART) effectively reduces an individual's HIV loads to below the detection limit, nevertheless rapid viral rebound immediately ensues upon treatment interruption. Furthermore, virally suppressed individuals experience chronic immune activation from ongoing low-level virus expression. Thus, the importance of identifying novel therapeutics to explore in block-and-lock HIV functional cure approaches, aimed at the transcriptional and epigenetic silencing of the viral reservoir to block reactivation from latency. We investigated the potential of repurposing the FDA-approved spironolactone (SP), as one such drug. SP treatment rapidly degrades a host transcription factor subunit, XPB, inhibiting HIV transcription and blocking reactivation from latency. Long-term SP treatment does not affect cellular viability, cell cycle progression or global cellular transcription. SP alone blocks HIV transcription in the absence of ART but does not delay rebound upon drug removal as XPB rapidly reemerges. This study highlights XPB as a novel drug target in block-and-lock therapeutic approaches.
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Xu Y, Wu Z, Liu L, Liu J, Wang Y. Rat Model of Cockayne Syndrome Neurological Disease. Cell Rep 2020; 29:800-809.e5. [PMID: 31644904 DOI: 10.1016/j.celrep.2019.09.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 08/26/2019] [Accepted: 09/11/2019] [Indexed: 12/14/2022] Open
Abstract
Cockayne syndrome (CS) is a rare genetic neurodevelopmental disorder, characterized by a deficiency in transcription-coupled subpathway of nucleotide excision DNA repair (TC-NER). Mutation of the Cockayne syndrome B (CSB) gene affects basal transcription, which is considered a major cause of CS neurologic dysfunction. Here, we generate a rat model by mimicking a nonsense mutation in the CSB gene. In contrast to that of the Csb-/- mouse models, the brains of the CSB-deficient rats are more profoundly affected. The cerebellar cortex shows significant atrophy and dysmyelination. Aberrant foliation of the cerebellum and deformed hippocampus are visible. The white matter displays high glial fibrillary acidic protein (GFAP) staining indicative of reactive astrogliosis. RNA sequencing (RNA-seq) analysis reveals that CSB deficiency affects the expression of hundreds of genes, many of which are neuronal genes, suggesting that transcription dysregulation could contribute to the neurologic disease seen in the CSB rat models.
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Affiliation(s)
- Yingying Xu
- Key Laboratory of Neurological Function and Health, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China
| | - Zhenzhen Wu
- Key Laboratory of Neurological Function and Health, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China
| | - Lingyun Liu
- School of Basic Medical Science, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Jiena Liu
- Key Laboratory of Neurological Function and Health, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China
| | - Yuming Wang
- Key Laboratory of Neurological Function and Health, School of Basic Medical Science, Guangzhou Medical University, Guangzhou 511436, China.
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Lawania S, Singh A, Sharma S, Singh N, Behera D. The multi-faceted high order polymorphic synergistic interactions among nucleotide excision repair genes increase the risk of lung cancer in North Indians. Mutat Res 2019; 816-818:111673. [PMID: 31195348 DOI: 10.1016/j.mrfmmm.2019.111673] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 05/08/2019] [Accepted: 06/04/2019] [Indexed: 11/25/2022]
Abstract
It is evident that gene-gene interactions are pervasive in the determination of the susceptibility of human diseases. Polymorphisms in nucleotide excision repair pathway (NER) genes can cause variations in the repair capacity and therefore, might lead to increase in susceptibility towards lung cancer through complex gene-gene and gene-smoking interactions. Logistic regression analysis, along with high order genetic interaction were analyzed using data mining tools such as multifactor dimensionality reduction (MDR) and classification and regression tree analysis (CART). Overall, a protective effect was reported when a combinatorial effect of SNPs were studied by applying logistic regression analysis. Multifactor dimensionality reduction (MDR) analysis, revealed that the four factor model i.e. XPC K939Q, XPA 5'UTR, XPG F670W and XPG D1104H had the best ability to predict lung cancer risk (CVC = 100, p < 0.0001). While a two factor model, including smoking and XPG F670W suggested smoking was associated with the risk of developing lung cancer (CVC = 100, p < 0.0001). Individually XPG F670W was identified as the primary risk factor. In classification and regression tree analysis (CART), we observed a 6-fold risk for SCLC patients carrying XPA 5'UTR (M), XPD K751Q (W) (OR: 6.20; 95%CI: 2.40-16.01, p = 0.0001).Polymorphic NER genes might jointly modulate lung cancer risk through gene-gene and gene-smoking interaction.
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Affiliation(s)
- Shweta Lawania
- Department of Biotechnology, Thapar University, Punjab, 147002, India
| | - Amrita Singh
- Department of Biotechnology, Thapar University, Punjab, 147002, India
| | - Siddharth Sharma
- Department of Biotechnology, Thapar University, Punjab, 147002, India.
| | - Navneet Singh
- Department of Pulmonary Medicine, Post Graduate Institute of Medical Education & Research (PGIMER), Sector 14, Chandigarh, India
| | - Digamber Behera
- Department of Pulmonary Medicine, Post Graduate Institute of Medical Education & Research (PGIMER), Sector 14, Chandigarh, India
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Smyth E, Zhang S, Cunningham D, Wotherspoon A, Soong R, Peckitt C, Valeri N, Fassan M, Rugge M, Okines A, Allum W, Stenning S, Nankivell M, Langley R, Tan P. Pharmacogenetic Analysis of the UK MRC (Medical Research Council) MAGIC Trial: Association of Polymorphisms with Toxicity and Survival in Patients Treated with Perioperative Epirubicin, Cisplatin, and 5-fluorouracil (ECF) Chemotherapy. Clin Cancer Res 2017; 23:7543-7549. [PMID: 28972045 PMCID: PMC6175041 DOI: 10.1158/1078-0432.ccr-16-3142] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 04/21/2017] [Accepted: 09/26/2017] [Indexed: 11/16/2022]
Abstract
Purpose: Germline polymorphisms may affect chemotherapy efficacy and toxicity. We examined the effect of polymorphisms in drug metabolism and DNA repair genes on pathologic response rates, survival, and toxicity for patients randomized to surgery alone or perioperative ECF chemotherapy in the MRC MAGIC trial.Experimental Design: DNA was extracted from nontumor resection formalin-fixed paraffin-embedded (FFPE) blocks. ERCC1, ERCC2, XRCC1, DYPD, and OPRT SNPs were evaluated using Sequenom, GSTP1, GSTT1 deletion, and TYMS (TS) 5' 2R/3R using multiplex PCR. Post PCR amplification, TS 2R/3R and GSTT1 samples underwent gel electrophoresis.Results: Polymorphism data were available for 289 of 456 (63.4%) operated patients. No polymorphism was statistically significantly associated with pathologic response to chemotherapy. Median overall survival (OS) for patients treated with surgery alone with any TS genotype was not different (1.76 years 2R/2R, 1.68 years 2R/3R, 2.09 years 3R/3R). Median OS for patients with a TS 2R/2R genotype treated with chemotherapy was not reached, whereas median OS for 2R/3R and 3R/3R patients were 1.44 and 1.60 years, respectively (log rank P value = 0.0053). The P value for the interaction between treatment arm and genotype (3R/3R and 3R/2R vs. 2R/2R) was 0.029. No polymorphism was statistically significantly associated with chemotherapy toxicity.Conclusions: In MAGIC, patients with a TS 2R/2R genotype appeared to derive a larger benefit from perioperative ECF chemotherapy than patients with 3R containing genotypes. Further exploration of this potential predictive biomarker in this patient population is warranted. Clin Cancer Res; 23(24); 7543-9. ©2017 AACR.
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Affiliation(s)
- Elizabeth Smyth
- Department of Gastrointestinal Oncology and Lymphoma, Royal Marsden Hospital, London & Sutton, United Kingdom
| | - Shenli Zhang
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore, Singapore
| | - David Cunningham
- Department of Gastrointestinal Oncology and Lymphoma, Royal Marsden Hospital, London & Sutton, United Kingdom.
| | - Andrew Wotherspoon
- Department of Pathology, Royal Marsden Hospital, London & Sutton, United Kingdom
| | - Richie Soong
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
| | - Clare Peckitt
- Department of Clinical Research and Development, Royal Marsden Hospital, London & Sutton, United Kingdom
| | - Nicola Valeri
- Department of Gastrointestinal Oncology and Lymphoma, Royal Marsden Hospital, London & Sutton, United Kingdom
- Department of Molecular Pathology, The Institute of Cancer Research London & Sutton, United Kingdom
| | - Matteo Fassan
- Department of Medicine, Surgical Pathology & Cytopathology Unit, University of Padua, Padua, Italy
| | - Massimo Rugge
- Department of Medicine, Surgical Pathology & Cytopathology Unit, University of Padua, Padua, Italy
| | - Alicia Okines
- Department of Gastrointestinal Oncology and Lymphoma, Royal Marsden Hospital, London & Sutton, United Kingdom
| | - William Allum
- Department of Medicine, Surgical Pathology & Cytopathology Unit, University of Padua, Padua, Italy
| | - Sally Stenning
- Department of Surgery, Royal Marsden Hospital, London & Sutton, United Kingdom
| | - Matthew Nankivell
- Department of Surgery, Royal Marsden Hospital, London & Sutton, United Kingdom
| | - Ruth Langley
- Medical Research Council Clinical Trials Unit at UCL, London, United Kingdom
| | - Patrick Tan
- Cancer and Stem Cell Biology Program, Duke-NUS Medical School, Singapore, Singapore
- Cancer Science Institute of Singapore, National University of Singapore, Singapore, Singapore
- Department of Cellular and Molecular Research, National Cancer Centre, Singapore, Singapore
- Cancer Therapeutics and Stratified Oncology Group, Genome Institute of Singapore, Singapore, Singapore
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Ahmed T, Nawaz S, Noreen R, Bangash KS, Rauf A, Younis M, Anwar K, Khawaja MA, Azam M, Qureshi AA, Akhter S, Kiemeney LA, Qamar R, Ali SHB. A 3' untranslated region polymorphism rs2304277 in the DNA repair pathway gene OGG1 is a novel risk modulator for urothelial bladder carcinoma. Ann Hum Genet 2017; 82:74-87. [PMID: 29139108 DOI: 10.1111/ahg.12225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 08/30/2017] [Accepted: 09/16/2017] [Indexed: 12/14/2022]
Abstract
Altered DNA repair capacity may affect an individual's susceptibility to cancers due to compromised genomic integrity. This study was designed to elucidate the association of selected polymorphisms in DNA repair genes with urothelial bladder carcinoma (UBC). OGG1 rs1052133 and rs2304277, XRCC1 rs1799782 and rs25487, XRCC3 rs861539, XPC rs2228001, and XPD rs13181 were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 200 UBC cases and 200 controls. We found association of OGG1 rs2304277 [odds ratio (OR)GG = 3.55, 95% confidence interval (CI) = 1.79-7.06] and XPC rs2228001 (ORAC = 2.38, 95% CI = 1.43-3.94) with UBC. In stratified analysis with respect to smoking status, OGG1 rs2304277 and XPC rs2228001 exhibited increased risk in smokers [(rs2304277 ORGG = 4.96, 95% CI = 1.51-16.30) (rs2228001 ORAC = 2.19, 95% CI = 1.02-4.72)] as well as nonsmokers [(rs2304277 ORGG = 2.95, 95% CI = 1.26-6.90) (rs2228001 ORAC = 2.57, 95% CI = 1.31-5.04)]. These polymorphisms were also associated with both low-grade [(rs2304277 ORGG = 3.73, 95% CI = 1.72-8.09) (rs2228001 ORAC = 2.18, 95% CI = 1.21-3.92)] and high-grade tumors [(rs2304277 ORGG = 3.45, 95% CI = 1.52-7.80) (rs2228001 ORAC = 2.81, 95% CI = 1.48-5.33)] as well as with non-muscle-invasive bladder cancer [(rs2304277 ORGG = 4.03, 95% CI = 1.87-8.67) (rs2228001 ORAC = 2.14, 95% CI = 1.20-3.81)] and muscle-invasive bladder cancer [(rs2304277 ORGG = 3.06, 95%CI = 1.31-7.13) (rs2228001 ORAC = 2.95, 95%CI = 1.51-5.75)]. This is the first study on DNA repair gene polymorphisms and UBC in the Pakistani population. It identifies OGG1 rs2304277 and replicates XPC rs2228001 as significant modulators of UBC susceptibility.
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Affiliation(s)
- Tayyaba Ahmed
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Saira Nawaz
- Bahauddin Zakariya University, Multan, Pakistan
| | | | | | - Abdur Rauf
- Nishtar Medical College & Hospital, Multan, Pakistan
| | | | - Khursheed Anwar
- Pakistan Atomic Energy Commission General Hospital, Islamabad, Pakistan
| | | | - Maleeha Azam
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan
| | - Abid Ali Qureshi
- Department of Radiology, The Children's Hospital & The Institute of Child Health, Lahore, Pakistan
| | - Saeed Akhter
- Department of Urology, Shifa International Hospital, Islamabad, Pakistan
| | - Lambertus A Kiemeney
- Radboud university medical center, Radboud Institute for Health Sciences, Nijmegen, Rhe Netherlands
| | - Raheel Qamar
- Department of Biosciences, COMSATS Institute of Information Technology, Islamabad, Pakistan.,Pakistan Academy of Sciences, Islamabad, Pakistan
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Lawania S, Singh N, Behera D, Sharma S. Xeroderma pigmentosum complementation group D polymorphism toward lung cancer susceptibility survival and response in patients treated with platinum chemotherapy. Future Oncol 2017; 13:2645-2665. [PMID: 29035087 DOI: 10.2217/fon-2017-0211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM The study investigated role of xeroderma pigmentosum complementation group D (XPD) single nucleotide polymorphisms in modulating lung cancer risk and its association with overall survival and clinical outcomes. METHODS XPD polymorphisms were detected using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). RESULTS CC genotype of A751C polymorphism was associated with an increased lung cancer risk (p = 0.01). Classification and Regression Tree (CART) analysis depicted C156A as the major contributing factor. Patients having CC, treated with irinotecan-cisplatin/carboplatin regimen showed a better survival (median survival time = 25.2) whereas a poor survival was for XPD G312A. Similarly, patients treated with pemetrexed and carrying heterozygous genotype of G312A polymorphism had a poor survival (p = 0.01). CONCLUSION A751C and G312A act as a predictive marker in lung cancer patients treated with platinum chemotherapy. These findings might facilitate therapeutic decisions for individualized therapy in lung cancer patient. [Formula: see text].
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Affiliation(s)
- Shweta Lawania
- Department of Biotechnology, Thapar University, Patiala, Punjab 147002, India
| | - Navneet Singh
- Department of Pulmonary Medicine, Post Graduate Institute of Medical Education & Research (PGIMER), Sector 14, Chandigarh, India
| | - Digamber Behera
- Department of Pulmonary Medicine, Post Graduate Institute of Medical Education & Research (PGIMER), Sector 14, Chandigarh, India
| | - Siddharth Sharma
- Department of Biotechnology, Thapar University, Patiala, Punjab 147002, India
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Brooks PJ. Blinded by the UV light: how the focus on transcription-coupled NER has distracted from understanding the mechanisms of Cockayne syndrome neurologic disease. DNA Repair (Amst) 2013; 12:656-71. [PMID: 23683874 PMCID: PMC4240003 DOI: 10.1016/j.dnarep.2013.04.018] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cockayne syndrome (CS) is a devastating neurodevelopmental disorder, with growth abnormalities, progeriod features, and sun sensitivity. CS is typically considered to be a DNA repair disorder, since cells from CS patients have a defect in transcription-coupled nucleotide excision repair (TC-NER). However, cells from UV-sensitive syndrome patients also lack TC-NER, but these patients do not suffer from the neurologic and other abnormalities that CS patients do. Also, the neurologic abnormalities that affect CS patients (CS neurologic disease) are qualitatively different from those seen in NER-deficient XP patients. Therefore, the TC-NER defect explains the sun sensitive phenotype common to both CS and UVsS, but cannot explain CS neurologic disease. However, as CS neurologic disease is of much greater clinical significance than the sun sensitivity, there is a pressing need to understand its molecular basis. While there is evidence for defective repair of oxidative DNA damage and mitochondrial abnormalities in CS cells, here I propose that the defects in transcription by both RNA polymerases I and II that have been documented in CS cells provide a better explanation for many of the severe growth and neurodevelopmental defects in CS patients than defective DNA repair. The implications of these ideas for interpreting results from mouse models of CS, and for the development of treatments and therapies for CS patients are discussed.
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Affiliation(s)
- P J Brooks
- Laboratory of Neurogenetics, National Institute on Alcohol Abuse and Alcoholism, NIH, 5625 Fishers Lane, 3S-32, Bethesda, MD 20892, USA.
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Gan Y, Li XR, Chen DJ, Wu JH. Association between polymorphisms of XRCC1 Arg399Gln and XPD Lys751Gln genes and prognosis of colorectal cancer in a Chinese population. Asian Pac J Cancer Prev 2013; 13:5721-4. [PMID: 23317245 DOI: 10.7314/apjcp.2012.13.11.5721] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We conducted this study to detect associations between XRCC1 Arg399Gln and XPD Lys751Gln genotypes and survival of colorectal cancer patients treated with 5-FU/oxalipatin chemotherapy. We included 289 Chinese patients with advanced colorectal cancer, who had received 5-FU/oxalipatin chemotherapy as first-line treatment from January 2005 to January 2007. All patients were followed up till Nov. 2011. Genotyping for XRCC1 Arg399Gln and XPD Lys751Gln polymorphisms was based upon duplex polymerase-chain-reaction with the PCR-RFLP method. In our study, we found the XRCC1 399 Gln/Gln genotype to confer significantly higher rates of response to chemotherapy when compared to the Arg/Arg genotype [OR (95% CI)=2.56(1.57-2.55)]. patients with the XPD 751 Gln/Gln genotype had significantly higher rates of response to chemotherapy [OR (95% CI)=1.54(0.87-2.65)] and those with the XRCC1 399 Gln/Gln genotype had a longer average survival time and significantly lower risk of death than did those with the Arg/Arg genotype [HR (95% CI)=0.66(0.36-0.95)]. Similarly, those carrying the XPD 751Gln/Gln genotype had 0.51-fold the risk of death of those with XPD 751Lys/Lys [HR (95% CI)=0.51(0.33-0.94)]. In conclusion, it is suggested that the XRCC1 Arg399Gln and XPD Lys751Gln polymorphisms should be routinely assessed to determine colorectal patients who are more likely to benefit from 5-FU/oxalipatin chemotherapy.
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Affiliation(s)
- Yi Gan
- Department of General Surgery, 3rd Xiang-Ya Hospital of Central South University, Changsha, China
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Diderich KEM, Nicolaije C, Priemel M, Waarsing JH, Day JS, Brandt RMC, Schilling AF, Botter SM, Weinans H, van der Horst GTJ, Hoeijmakers JHJ, van Leeuwen JPTM. Bone fragility and decline in stem cells in prematurely aging DNA repair deficient trichothiodystrophy mice. AGE (DORDRECHT, NETHERLANDS) 2012; 34:845-861. [PMID: 21814739 PMCID: PMC3682057 DOI: 10.1007/s11357-011-9291-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2010] [Accepted: 06/14/2011] [Indexed: 05/31/2023]
Abstract
Trichothiodystrophy (TTD) is a rare, autosomal recessive nucleotide excision repair (NER) disorder caused by mutations in components of the dual functional NER/basal transcription factor TFIIH. TTD mice, carrying a patient-based point mutation in the Xpd gene, strikingly resemble many features of the human syndrome and exhibit signs of premature aging. To examine to which extent TTD mice resemble the normal process of aging, we thoroughly investigated the bone phenotype. Here, we show that female TTD mice exhibit accelerated bone aging from 39 weeks onwards as well as lack of periosteal apposition leading to reduced bone strength. Before 39 weeks have passed, bones of wild-type and TTD mice are identical excluding a developmental defect. Albeit that bone formation is decreased, osteoblasts in TTD mice retain bone-forming capacity as in vivo PTH treatment leads to increased cortical thickness. In vitro bone marrow cell cultures showed that TTD osteoprogenitors retain the capacity to differentiate into osteoblasts. However, after 13 weeks of age TTD females show decreased bone nodule formation. No increase in bone resorption or the number of osteoclasts was detected. In conclusion, TTD mice show premature bone aging, which is preceded by a decrease in mesenchymal stem cells/osteoprogenitors and a change in systemic factors, identifying DNA damage and repair as key determinants for bone fragility by influencing osteogenesis and bone metabolism.
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Affiliation(s)
- Karin E. M. Diderich
- MGC Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Claudia Nicolaije
- Department of Internal Medicine, Erasmus MC, Room Ee585, P.O Box 2040, CA Rotterdam, The Netherlands
| | - Matthias Priemel
- Center of Biomechanics and Skeletal Biology, Department of Trauma Surgery, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany
| | - Jan H. Waarsing
- Department of Orthopaedics, Erasmus MC, 3000 DR Rotterdam, The Netherlands
| | - Judd S. Day
- Department of Orthopaedics, Erasmus MC, 3000 DR Rotterdam, The Netherlands
| | - Renata M. C. Brandt
- MGC Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Arndt F. Schilling
- Center of Biomechanics and Skeletal Biology, Department of Trauma Surgery, University Medical Center Hamburg Eppendorf, 20246 Hamburg, Germany
- Biomechanics Section, Hamburg University of Technology, 21073 Hamburg, Germany
| | - Sander M. Botter
- MGC Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, Rotterdam, The Netherlands
- Department of Internal Medicine, Erasmus MC, Room Ee585, P.O Box 2040, CA Rotterdam, The Netherlands
| | - Harrie Weinans
- Department of Orthopaedics, Erasmus MC, 3000 DR Rotterdam, The Netherlands
| | | | - Jan H. J. Hoeijmakers
- MGC Department of Cell Biology and Genetics, Center for Biomedical Genetics, Erasmus MC, Rotterdam, The Netherlands
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Savolainen L, Cassel T, Helleday T. The XPD subunit of TFIIH is required for transcription-associated but not DNA double-strand break-induced recombination in mammalian cells. Mutagenesis 2010; 25:623-9. [PMID: 20833695 DOI: 10.1093/mutage/geq054] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Mutations in the XPD gene can give rise to three phenotypically distinct disorders: xeroderma pigmentosum (XP), trichothiodystrophy (TTD) or combined XP and Cockayne syndrome (CS) (XP/CS). The role of Xeroderma Pigmentosum group D protein (XPD) in nucleotide excision repair explains the increased risk of skin cancer in XP patients but not all the clinical phenotypes found in XP/CS or TTD patients. Here, we describe that the XPD-defective UV5 cell line is impaired in transcription-associated recombination (TAR), which can be reverted by the introduction of the wild-type XPD gene expressed from a vector. UV5 cells are defective in TAR, despite having intact transcription and homologous recombination (HR) repair of DNA double-strand breaks (DSBs). Interestingly, we find reduced spontaneous HR in XPD-defective cells, suggesting that transcription underlies a portion of spontaneous HR events. We also report that transcription-coupled repair (TCR)-defective cells, mutated in the Cockayne syndrome B (CSB) protein, have a defect in TAR, but not in DSB-induced HR. However, the TAR defect may be associated with a general transcription defect in CSB-deficient cells. In conclusion, we show a novel role for the XPD protein in TAR, linking TAR with TCR.
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Affiliation(s)
- Linda Savolainen
- Department of Genetics, Microbiology and Toxicology, Arrhenius Laboratory, Stockholm University, S-106 91 Stockholm, Sweden
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Wang A, Alimova IN, Luo P, Jong A, Triche TJ, Wu L. Loss of CAK phosphorylation of RAR{alpha} mediates transcriptional control of retinoid-induced cancer cell differentiation. FASEB J 2009; 24:833-43. [PMID: 19917671 DOI: 10.1096/fj.09-142976] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Although the role of the classic retinoic acid (RA)-induced genomic pathway in cancer cell differentiation is well recognized, the underlying mechanisms remain to be dissected. Retinoic acid receptor alpha (RARalpha) is a transcription factor activated by RA, and its serine 77 (RARalphaS77) is the main residue phosphorylated by the cyclin-dependent kinase (CDK)-activating kinase (CAK) complex. We report here that in both human myeloid leukemia and mouse embryonic teratocarcinoma stem cells, either RA-suppressed CAK phosphorylation of RARalpha or mutation of RARalphaS77 to alanine (RARalphaS77A) coordinates CAK-dependent G(1) arrest with cancer cell differentiation by transactivating RA-target genes. Both hypophosphorylated RARalpha and RARalphaS77A reduce binding to retinoic acid-responsive elements (RARE) in the promoters of RA-target genes while stimulating gene transcription. The enhanced transactivation and reduced RARalpha-chromatin interaction are accompanied by RARalpha dissociation from the transcriptional repressor N-CoR and are association with the coactivator NCoA-3. Such effects of decreased CAK phosphorylation of RARalphaS77 on mediating RA-dependent transcriptional control of cancer cell differentiation are examined correspondingly in both RA-resistant myeloid leukemia and embryonic teratocarcinoma stem RARalpha(-/-) cells. These studies demonstrate, for the first time, that RA couples G(1) arrest to transcriptional control of cancer cell differentiation by suppressing CAK phosphorylation of RARalpha to release transcriptional repression.-Wang, A., Alimova, I. N., Luo, P. Jong, A., Triche, T. J., Wu, L. Loss of CAK phosphorylation of RARalpha mediates transcriptional control of retinoid-induced cancer cell differentiation.
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Affiliation(s)
- Anxun Wang
- Department of Pathology, MS# 103, Childrens Hospital Los Angeles, University of Southern California Keck School of Medicine, 4650 Sunset Blvd, Los Angeles, CA 90027, USA
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Giglia-Mari G, Theil AF, Mari PO, Mourgues S, Nonnekens J, Andrieux LO, de Wit J, Miquel C, Wijgers N, Maas A, Fousteri M, Hoeijmakers JHJ, Vermeulen W. Differentiation driven changes in the dynamic organization of Basal transcription initiation. PLoS Biol 2009; 7:e1000220. [PMID: 19841728 PMCID: PMC2754661 DOI: 10.1371/journal.pbio.1000220] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2008] [Accepted: 09/07/2009] [Indexed: 01/01/2023] Open
Abstract
A novel mouse model reveals that the dynamic behavior of transcription factors can vary considerably between different cells of an organism. Studies based on cell-free systems and on in vitro–cultured living cells support the concept that many cellular processes, such as transcription initiation, are highly dynamic: individual proteins stochastically bind to their substrates and disassemble after reaction completion. This dynamic nature allows quick adaptation of transcription to changing conditions. However, it is unknown to what extent this dynamic transcription organization holds for postmitotic cells embedded in mammalian tissue. To allow analysis of transcription initiation dynamics directly into living mammalian tissues, we created a knock-in mouse model expressing fluorescently tagged TFIIH. Surprisingly and in contrast to what has been observed in cultured and proliferating cells, postmitotic murine cells embedded in their tissue exhibit a strong and long-lasting transcription-dependent immobilization of TFIIH. This immobilization is both differentiation driven and development dependent. Furthermore, although very statically bound, TFIIH can be remobilized to respond to new transcriptional needs. This divergent spatiotemporal transcriptional organization in different cells of the soma revisits the generally accepted highly dynamic concept of the kinetic framework of transcription and shows how basic processes, such as transcription, can be organized in a fundamentally different fashion in intact organisms as previously deduced from in vitro studies. The accepted model of eukaryotic mRNA production is that transcription factors spend most of their time diffusing throughout the cell nucleus, encountering gene promoters (their substrate) in a random fashion and binding to them for a very short time. A similar modus operandi has been accepted as a paradigm for interactions within most of the chromatin-associated enzymatic processes (transcription, replication, DNA damage response). However, it is not known whether such behavior is indeed a common characteristic for all cells in the organism. To answer this question, we generated a knock-in mouse that expresses in all cells a fluorescently tagged transcription factor (TFIIH) that functions in both transcription initiation and DNA repair. This new tool, when combined with quantitative imaging techniques, allowed us to monitor the mobility of this transcription factor in virtually all living tissues. In this study, we show that, in contrast to the aforementioned paradigm, in highly differentiated postmitotic cells such as neurons, hepatocytes, and cardiac myocytes, TFIIH is effectively immobilized on the chromatin during transcription, whereas in proliferative cells, TFIIH has the same dynamic behavior as in cultured cells. Our study also points out that results obtained from in vitro or cultured cell systems cannot always be directly extrapolated to the whole organism. More importantly, this raises a question for researchers in the transcription field: why do some cells opt for a dynamic framework for transcription, whereas others exhibit a static one?
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Affiliation(s)
- Giuseppina Giglia-Mari
- Department of Genetics, Erasmus MC, Rotterdam, The Netherlands
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
- * E-mail: (GG-M); (WV)
| | - Arjan F. Theil
- Department of Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Pierre-Olivier Mari
- Department of Genetics, Erasmus MC, Rotterdam, The Netherlands
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Sophie Mourgues
- CNRS, IPBS (Institut de Pharmacologie et de Biologie Structurale), Toulouse, France
- Université de Toulouse, UPS, IPBS, Toulouse, France
| | - Julie Nonnekens
- Department of Genetics, Erasmus MC, Rotterdam, The Netherlands
| | | | - Jan de Wit
- Department of Genetics, Erasmus MC, Rotterdam, The Netherlands
| | | | - Nils Wijgers
- Department of Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Alex Maas
- Department of Genetics, Erasmus MC, Rotterdam, The Netherlands
| | - Maria Fousteri
- Department of Toxicogenetics, LUMC, Leiden, The Netherlands
| | | | - Wim Vermeulen
- Department of Genetics, Erasmus MC, Rotterdam, The Netherlands
- * E-mail: (GG-M); (WV)
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Lai JI, Tzeng CH, Chen PM, Lin JK, Lin TC, Chen WS, Jiang JK, Wang HS, Wang WS. Very low prevalence of XPD K751Q polymorphism and its association with XPD expression and outcomes of FOLFOX-4 treatment in Asian patients with colorectal carcinoma. Cancer Sci 2009; 100:1261-6. [PMID: 19432884 PMCID: PMC11159978 DOI: 10.1111/j.1349-7006.2009.01186.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2009] [Revised: 03/21/2009] [Accepted: 03/29/2009] [Indexed: 01/21/2023] Open
Abstract
Xeroderma pigmentosum group D (XPD) participates in DNA unwinding during nucleotide excision repair, which may alter the efficacy of platinum-based chemotherapy. We analyzed the influence of codon 751 Lys-->Gln polymorphism of XPD on its protein expression levels, clinico-pathological features, and outcome of 188 Chinese patients with metastatic colorectal carcinoma (CRC) that had been treated with first-line Oxaliplatin + Leucovorin + 5-Fluorouracil (FOLFOX-4) chemotherapy. The results showed that in comparison with Caucasian populations, a remarkably lower prevalence of Lys/Gln genotype was noted (16%, n = 30). No between-group difference in XPD protein expression of patients with or without this polymorphism was noted (56.5%vs 59.7%; P = 0.783). Patients with Gln751 allele have a significantly lower response to FOLFOX-4 treatment (36.7%vs 58.2%, P = 0.03), and shorter progression-free (7 vs 11 months; P < 0.01) and overall (14 vs 22 months; P < 0.01) survivals. The incidence of grade 3/4 oxaliplatin-neuropathies was very similar in both groups (13.3%vs 16.5%; P = 0.67). By adjusted analysis, this polymorphism was further identified as an independent prognostic factor (P = 0.03). These data suggest that Asian populations have a significantly lower prevalence of codon 751 Lys/Gln polymorphism in XPD, which could be a key determinant for good response to oxaliplatin-based treatment and favorable outcomes.
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Affiliation(s)
- Jiun-I Lai
- National Yang-Ming University School of Medicine, Taipei, Taiwan
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14
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Wu Y, Brosh RM. FANCJ helicase operates in the Fanconi Anemia DNA repair pathway and the response to replicational stress. Curr Mol Med 2009; 9:470-82. [PMID: 19519404 PMCID: PMC2763586 DOI: 10.2174/156652409788167159] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Fanconi anemia (FA) is an autosomal recessive disorder characterized by multiple congenital anomalies, progressive bone marrow failure, and high cancer risk. Cells from FA patients exhibit spontaneous chromosomal instability and hypersensitivity to DNA interstrand cross-linking (ICL) agents. Although the precise mechanistic details of the FA/BRCA pathway of ICL-repair are not well understood, progress has been made in the identification of the FA proteins that are required for the pathway. Among the 13 FA complementation groups from which all the FA genes have been cloned, only a few of the FA proteins are predicted to have direct roles in DNA metabolism. One of the more recently identified FA proteins, shown to be responsible for complementation of the FA complementation group J, is the BRCA1 Associated C-terminal Helicase (BACH1, designated FANCJ), originally identified as a protein associated with breast cancer. FANCJ has been proposed to function downstream of FANCD2 monoubiquitination, a critical event in the FA pathway. Evidence supports a role for FANCJ in a homologous recombination (HR) pathway of double strand break (DSB) repair. In this review, we will summarize the current knowledge in terms of FANCJ functions through its enzymatic activities and protein interactions. The molecular roles of FANCJ in DNA repair and the response to replicational stress will be discussed.
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Affiliation(s)
- Yuliang Wu
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
| | - Robert M. Brosh
- Laboratory of Molecular Gerontology, National Institute on Aging, NIH, 5600 Nathan Shock Drive, Baltimore, MD 21224, USA
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15
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Wu Y, Suhasini AN, Brosh RM. Welcome the family of FANCJ-like helicases to the block of genome stability maintenance proteins. Cell Mol Life Sci 2009; 66:1209-22. [PMID: 19099189 PMCID: PMC2663010 DOI: 10.1007/s00018-008-8580-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The FANCJ family of DNA helicases is emerging as an important group of proteins for the prevention of human disease, cancer, and chromosomal instability. FANCJ was identified by its association with breast cancer, and is implicated in Fanconi Anemia. Proteins with sequence similarity to FANCJ are important for maintenance of genomic stability. Mutations in genes encoding proteins related to FANCJ, designated ChlR1 in human and Chl1p in yeast, result in sister chromatid cohesion defects. Nematodes mutated in dog-1 show germline as well as somatic deletions in genes containing guanine-rich DNA. Rtel knockout mice are embryonic lethal, and embryonic stem cells show telomere loss and chromosomal instability. FANCJ also shares sequence similarity with human XPD and yeast RAD3 helicases required for nucleotide excision repair. The recently solved structure of XPD has provided new insight to the helicase core and accessory domains of sequence related Superfamily 2 helicases. The functions and roles of members of the FANCJ-like helicase family will be discussed.
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Affiliation(s)
- Y. Wu
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, 251 Bayview Blvd, Baltimore, MD 21224 USA
| | - A. N. Suhasini
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, 251 Bayview Blvd, Baltimore, MD 21224 USA
| | - R. M. Brosh
- Laboratory of Molecular Gerontology, National Institute on Aging, National Institutes of Health, NIH Biomedical Research Center, 251 Bayview Blvd, Baltimore, MD 21224 USA
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16
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Gao R, Price DK, Sissung T, Reed E, Figg WD. Ethnic disparities in Americans of European descent versus Americans of African descent related to polymorphic ERCC1, ERCC2, XRCC1, and PARP1. Mol Cancer Ther 2008; 7:1246-50. [PMID: 18483312 PMCID: PMC3571703 DOI: 10.1158/1535-7163.mct-07-2206] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Nucleotide excision repair (NER) and base excision repair (BER) pathways are DNA repair pathways that are important in carcinogenesis and in response to DNA-damaging chemotherapy. ERCC1 and ERCC2 are important molecular markers for NER; XRCC1 and PARP1 are important molecular markers for BER. Functional polymorphisms have been described that are associated with altered expression levels of these genes and with altered DNA repair capability. We assayed genomic DNA from 156 Americans of European descent and 164 Americans of African descent for the allelic frequencies of specific polymorphisms of ERCC1 N118N (500C>T), ERCC1 C8092A, ERCC2 K751Q (2282A>C), XRCC1 R399Q (1301G>A), XRCC1 R194W (685C>T), and PARP1 V762A (2446T>C). Differences were observed between Americans of European descent and Americans of African descent in the allelic frequencies of the ERCC1 N118N polymorphism (P < 0.000001). Differences were also observed between these two ethnic groups for ERCC2 K751Q (P = < 0.006675), XRCC1 R399Q (P < 0.000001), and PARP1 V762A (P = 0.000001). The ERCC1 N118N polymorphic variant that is seen most commonly in Americans of European descent is associated with a measurable reduction in NER function. ERCC1-mediated reduction in NER functionality affects the repair of cisplatin-DNA lesions.
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Affiliation(s)
- Rui Gao
- Molecular Pharmacology Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
- University of Maryland, College Park, MD
| | - Douglas K. Price
- Molecular Pharmacology Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Tristan Sissung
- Clinical Pharmacology Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Eddie Reed
- Centers for Disease Control and Prevention, Atlanta, GA
| | - William D. Figg
- Molecular Pharmacology Section, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
- Clinical Pharmacology Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
- Medical Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
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17
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Prognostic importance of DNA repair gene polymorphisms of XRCC1 Arg399Gln and XPD Lys751Gln in lung cancer patients from India. J Cancer Res Clin Oncol 2007; 134:645-52. [PMID: 17952468 DOI: 10.1007/s00432-007-0328-4] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2007] [Accepted: 09/28/2007] [Indexed: 10/22/2022]
Abstract
PURPOSE Inter individual variation in lung cancer susceptibility may be modulated in part through genetic polymorphisms in the DNA repair genes, especially the genes involved in the Base Excision Repair (BER) and nucleotide excision repair (NER) pathway. Two of the genetic polymorphisms, XRCC1Arg399Gln and XPD Lys751Gln have been extensively studied in the association with lung cancer risk, although published studies have been inconclusive. METHODS In order to verify the role of the common variant alleles in the XPD gene, we have genotyped 211 lung cancer patients and 211 healthy controls using PCR-RFLP assays in a hospital based, case-control study in an Indian population. Logistic regression models were fit to examine the relationship between the log odds of lung cancer and each covariate. Overall Survival in relation to various genotypes and clinicopathological factors were analyzed using Kaplan Meier estimates and hazard ratios were calculated using Cox Regression analysis. RESULTS The carriers of XRCC1 399 AA genotypes were at higher risk of lung cancer (OR = 2.1, 95% CI:1.224-3.669, P = 0.007) than carriers of GG genotype. Subjects carrying 751 AC genotype were at an increased risk of carcinoma of the lung (OR = 1.8; 95% CI:1.233-2.807, P = 0.003) than subjects with AA genotypes. Compared to the XRCC1 399 GG/ XPD 751 AA reference genotype, the combined variants, XRCC1 399 GG/ XPD 751 AC+CC (OR = 1.9, 95% CI: 1.037-3.481), P = 0.03), XRCC1 399 GA+AA/ XPD 751 AA (OR = 1.7, 95% CI: 1.020-2.833, P = 0.04), XRCC1 399 GA+AA/XPD 751 AC+CC (OR = 2.7, 95% CI: 1.582-4.864, P = 0.01), had significantly higher odds ratios. Increasing numbers of either XPD or XRCC1 variant alleles were associated with shorter overall survival, the risk being significant for the XRCC1 gene polymorphism (P = 0.01 by log-rank test). The hazard of dying was significant for the XRCC1 399 AA genotype (HR = 3.04, 95%CI: 1.393-6.670, P = 0.005). Higher tumour stage also came out as significant predictors of patient death. CONCLUSIONS These findings suggest that genetic polymorphisms in the DNA repair genes may modulate overall lung cancer susceptibility and that pathological stage and XRCC1 Arg399Gln independently predicted overall survival among Indian lung cancer patients.
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Wang JG, Barsky LW, Davicioni E, Weinberg KI, Triche TJ, Zhang XK, Wu L. Retinoic acid induces leukemia cell G1arrest and transition into differentiation by inhibiting cyclin‐dependent kinase‐activating kinase binding and phosphorylation of PML/RAR. FASEB J 2006; 20:2142-4. [PMID: 16935935 DOI: 10.1096/fj.06-5900fje] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Acute promyelocytic leukemia (APL) cells express promyelocytic leukemia/retinoic acid receptor alpha (PML/RARalpha) fusion protein, which leads to the blocking of APL cell differentiation. Treatment of APL with all-trans-retinoic acid (ATRA) induces disease remission by in vivo differentiation of APL cells. Differentiation requires cell cycle exit; yet how ATRA couples cell cycle exit to differentiation of APL remains largely unknown. We previously found that ATRA-induced cell differentiation accompanies ubiquitination-proteolysis of ménage à trois 1 (MAT1), an assembly factor and targeting subunit of cyclin-dependent kinase (CDK)-activating kinase (CAK) that regulates G1 exit. We report here that CAK binds to and phosphorylates PML/RARalpha in actively proliferating APL cells. In response to ATRA, PML/RARalpha is dissociated from CAK, leading to MAT1 degradation, G1 arrest, and decreased CAK phosphorylation of PML/RARalpha. CAK phosphorylation of PML/RARalpha is inhibited when MAT1 levels are reduced. Both MAT1 degradation and PML/RARalpha hypophosphorylation occur in ATRA-induced G1-arresting cells undergoing differentiation but not in the synchronized G1 cells that do not differentiate. These findings reveal a novel ATRA signaling on APL cell differentiation, in which ATRA coordinates G1 arrest and transition into differentiation by inducing MAT1 degradation and PML/RARalpha hypophosphorylation through disrupting PML/RARalpha binding and phosphorylation by CAK.
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Affiliation(s)
- Jian-guang Wang
- Department of Pathology, Childrens Hospital Los Angeles Saban Research Institute, Los Angeles, California 90027, USA
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García-Campelo R, Alonso-Curbera G, Antón Aparicio LM, Rosell R. Pharmacogenomics in lung cancer: an analysis of DNA repair gene expression in patients treated with platinum-based chemotherapy. Expert Opin Pharmacother 2006; 6:2015-26. [PMID: 16197356 DOI: 10.1517/14656566.6.12.2015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Lung cancer is a worldwide epidemic and despite platinum-based chemotherapy being the cornerstone of non-small cell lung cancer treatment, patient response rates to these regimens remain very low. Although resistance to cisplatin is multifactorial, DNA repair plays a critical role in cisplatin resistance. One of the most important goals in translational research is to investigate the clinical use of DNA repair pathways that may influence cisplatin chemosensitivity. Trying to understand the role of genes involved in DNA repair and response to treatment has become one of the main objectives of individualised chemotherapy. It is well known that chemosensitivity is individually predetermined, and the upregulation of mRNA transcripts has been linked to differential response to cytotoxic drugs. In this article, the authors try to highlight the more relevant aspects regarding these issues, primarily focused on the potential role of ERCC1, RRM1, XPD and BRCA1 expression profiling as predictors of anticancer drug efficacy.
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Affiliation(s)
- Rosario García-Campelo
- Medical Oncology Service, Hospital Juan Canalejo, As Xubias, 84, 15006, A Coruña, Spain.
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20
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Du YC, Gu S, Zhou J, Wang T, Cai H, Macinnes MA, Bradbury EM, Chen X. The dynamic alterations of H2AX complex during DNA repair detected by a proteomic approach reveal the critical roles of Ca(2+)/calmodulin in the ionizing radiation-induced cell cycle arrest. Mol Cell Proteomics 2006; 5:1033-44. [PMID: 16522924 DOI: 10.1074/mcp.m500327-mcp200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
By using DNA nuclease digestion and a quantitative "dual tagging" proteomic approach that integrated mass spectrometry, stable isotope labeling, and affinity purification, we studied the histone H2AX-associating protein complex in chromatin in mammalian cells in response to ionizing radiation (IR). In the non-irradiated control cells, calmodulin (CaM) and the transcription elongation factor facilitates chromatin transcription (FACT) were associated with H2AX. Thirty minutes after exposing cells to IR the CaM and FACT complexes dissociated, whereas two DNA repair proteins, poly(ADP-ribose) polymerase-1 and DEAH box polypeptide 30 isoform 1, interacted with H2AX. Two hours and 30 min after exposure, none of the above proteins were in the complex. H2B, nucleophosmin/B23, and calreticulin were associated with H2AX in both non-irradiated and irradiated cells. The results suggest that the H2AX complex undergoes dynamic changes upon induction of DNA damage and during DNA repair. The genuine interactions between H2AX and H2B, nucleophosmin/B23, calreticulin, poly(ADP-ribose) polymerase-1, and CaM under each condition were validated by immunoprecipitation/Western blotting and mammalian two-hybrid assays. Because multiple Ca(2+)-binding proteins were found in the H2AX complex, the roles of Ca(2+) were examined. The results indicate that Ca(2+)/CaM plays important roles in regulating IR-induced cell cycle arrest, possibly through mediating chromatin structure. The dataset presented here demonstrates that sensitive profiling of the dynamics of functional cellular protein-protein interactions can successfully lead to the dissection of important metabolic or signaling pathways.
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Affiliation(s)
- Yu-Chun Du
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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21
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Gal TJ, Huang WY, Chen C, Hayes RB, Schwartz SM. DNA repair gene polymorphisms and risk of second primary neoplasms and mortality in oral cancer patients. Laryngoscope 2006; 115:2221-31. [PMID: 16369171 DOI: 10.1097/01.mlg.0000183736.96004.f7] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES/HYPOTHESIS We tested the hypothesis that polymorphisms in genes involved in DNA repair pathways are associated with the development of second primary neoplasms of the upper aerodigestive tract (UADT), as well as mortality, in patients previously diagnosed with oral squamous cell cancer (OSCC). METHODS DNA specimens from 279 OSCC patients who had participated in two previous population-based case-control studies were assayed for the following polymorphisms: X-ray repair cross-complementing (XRCC) 1 Arg399Gln, XRCC3 Thr241Met, xeroderma pigmentosum complementing group D (XPD) Lys751Gln, and O-methylguanine- DNA methyltransferase (MGMT) Leu84Phe and Val143Ile. Baseline demographic information was obtained from personal interviews and tumor characteristics and treatment were obtained from cancer registry files. Cox proportional hazards models were used to calculate hazards ratio (HR) estimates for each polymorphism in relation to the risk of developing second primary neoplasms at any site, UADT, and head and neck. HRs were also determined for associations with all-cause mortality and oral cancer specific mortality. RESULTS A significant increased risk of second neoplasms (all sites combined, as well as for UADT sites and for head and neck squamous cell cancers) was observed among XRCC3 241Met allele homozygotes (HR 2.65-3.44, P < .02). No significant association with the development of second neoplasms was observed for the XRCC1 399Gln, XPD 751Gln, or MGMT 84Phe or 143Ile alleles. Although no associations with oral cancer-specific mortality were observed, we found a significant inverse association between all-cause mortality and possessing at least one copy of the XRCC1 399Gln allele (HR 0.68, 95% confidence interval [CI] 0.47-0.97, P = .03), as well as a suggestion of a direct association between all-cause mortality and having one copy of the XRCC3 241Met allele (HR 1.39, 95% CI 0.95-2.03, P = .09). CONCLUSIONS Polymorphisms in the DNA repair enzyme gene XRCC3 241Met was associated with an increased risk of second neoplasms, and polymorphisms of the XRCC1 399Gln gene were associated with a decreased risk of all-cause mortality in patients with primary OSCC. These findings require confirmation in other populations before the clinical implications can be considered.
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Affiliation(s)
- Thomas J Gal
- Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of Washington, Seattle, Washington 98195, USA.
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22
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Mehta PA, Alonzo TA, Gerbing RB, Elliott JS, Wilke TA, Kennedy RJ, Ross JA, Perentesis JP, Lange BJ, Davies SM. XPD Lys751Gln polymorphism in the etiology and outcome of childhood acute myeloid leukemia: a Children's Oncology Group report. Blood 2006; 107:39-45. [PMID: 16150943 DOI: 10.1182/blood-2005-06-2305] [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: 11/20/2022] Open
Abstract
AbstractGenetic polymorphisms result in interindividual variation in DNA repair capacity and may, in part, account for susceptibility of a cell to genotoxic agents and to malignancy. Polymorphisms in XPD, a member of the nucleotide excision repair pathway, have been associated with development of treatment-related acute myeloid leukemia (AML) and with poor outcome of AML in elderly patients. We hypothesized that XPD Lys751Gln polymorphism may play a role in causation of AML in children and, as shown in adults, may affect the outcome of childhood AML therapy. Genotyping of 456 children treated for de novo AML was performed at XPD exon 23. Genotype frequencies in patients were compared with healthy control subject frequencies, and patient outcomes were analyzed according to genotype. Gene frequencies in AML patients and healthy controls were similar. There were no significant differences in overall survival (P = .82), event-free survival (P = .78), treatment-related mortality (P = .43), or relapse rate (RR) (P = .92) between patients with XPD751AA versus 751AC versus 751CC genotypes, in contrast to reports in adult AML. These data, representing the only data in pediatric AML, suggest that XPD genotype does not affect the etiology or outcome of childhood AML.
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Affiliation(s)
- Parinda A Mehta
- Cincinnati Children's Hospital and Medical Center, 3333 Burnet Ave, Cincinnati, OH 45229, USA.
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23
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Abstract
Myc regulates to some degree every major process in the cell. Proliferation, growth, differentiation, apoptosis, and metabolism are all under myc control. In turn, these processes feed back to adjust the level of c-myc expression. Although Myc is regulated at every level from RNA synthesis to protein degradation, c-myc transcription is particularly responsive to multiple diverse physiological and pathological signals. These signals are delivered to the c-myc promoter by a wide variety of transcription factors and chromatin remodeling complexes. How these diverse and sometimes disparate signals are processed to manage the output of the c-myc promoter involves chromatin, recruitment of the transcription machinery, post-initiation transcriptional regulation, and mechanisms to provide dynamic feedback. Understanding these mechanisms promises to add new dimensions to models of transcriptional control and to reveal new strategies to manipulate Myc levels.
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Affiliation(s)
- J Liu
- Gene Regulation Section, Laboratory of Pathology, NCI, DCS, Bldg. 10, Rm 2N106, Bethesda, MD 20892-1500, USA
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24
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Scicchitano DA. Transcription past DNA adducts derived from polycyclic aromatic hydrocarbons. Mutat Res 2005; 577:146-54. [PMID: 15922365 DOI: 10.1016/j.mrfmmm.2005.03.015] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2005] [Revised: 03/22/2005] [Accepted: 03/22/2005] [Indexed: 12/20/2022]
Abstract
The ability of a DNA lesion to block transcription is a function of many variables: (1) the ability of the RNA polymerase active site to accommodate the damaged base; (2) the size and shape of the adduct, which includes the specific modified base; (3) the stereochemistry of the adduct; (4) the base incorporated into the growing transcript; (5) and the local DNA sequence. Each of these parameters, either alone or in combination, can influence how a particular lesion in the genome will affect transcription elongation, resulting in potential clearance of the lesion via transcription-coupled DNA repair or in the formation of truncated or full-length transcripts that might encode defective proteins.
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Affiliation(s)
- David A Scicchitano
- Department of Biology, 1009 Silver Center, 100 Washington Square East, New York University, New York, NY 10003, USA.
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25
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Yu HP, Wang XL, Sun X, Su YH, Wang YJ, Lu B, Shi LY, Xiong CL, Li YY, Li F, Xu SQ. Polymorphisms in the DNA repair gene XPD and susceptibility to esophageal squamous cell carcinoma. ACTA ACUST UNITED AC 2004; 154:10-5. [PMID: 15381366 DOI: 10.1016/j.cancergencyto.2004.01.027] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2003] [Revised: 01/20/2004] [Accepted: 01/27/2004] [Indexed: 12/15/2022]
Abstract
Polymorphisms of the nucleotide excision repair gene XPD are candidates for influencing cancer susceptibility. To determine the effect of XPD genetic polymorphisms on the risk of esophageal squamous cell carcinoma (ESCC) and its interaction with carcinogen exposure, XPD polymorphisms at codon 312 (Asp-->Asn) and codon 751 (Lys-->Gln) were determined in 135 ESCC patients and 152 normal controls. Polymorphism at codon 312 made no contribution to genetic risk for ESCC. Our results showed that there was a significant difference between frequencies for XPD 751 Gln/Gln genotype in ESCC patients (8.9%) and normal cases (1.3%), and that Gln/Gln genotype was associated with an increased risk of ESCC (odds ratio [OR] = 6.71; 95% confidence interval [CI]: 1.90-23.73). The results of the logistic regression model showed that XPD 751 Gln/Gln genotype and drinking were candidates for influencing the risk of ESCC. Among smokers, the risk of ESCC in XPD 751 Gln/Gln genotype increased 8-fold than that XPD 751 Lys/Lys genotype (OR = 8.42, 95% CI: 1.02-69.58). The results indicated that XPD 751 Gln/Gln genotype may be contributing factors in the risk of ESCC and may modify risk attributable to environmental exposures.
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Affiliation(s)
- Hong-Ping Yu
- Institute of Environmental Medicine, Tongji Medical College of Huazhong University of Science and Technology, 13 Hangkong Road, Wuhan 430030, China
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He Q, Peng H, Collins SJ, Triche TJ, Wu L. Retinoid‐modulated MAT1 ubiquitination and CAK activity. FASEB J 2004; 18:1734-6. [PMID: 15345685 DOI: 10.1096/fj.04-2182fje] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Human cyclin-dependent kinase (CDK)-activating kinase (CAK) has a dual function in cross-regulation of cell cycle and differentiation, whereas menage a trois 1 (MAT1) assembles CAK and determines CAK's substrate specificity. Although the dynamic state of MAT1 protein levels is found to modulate CAK activity, how intracellular regulation of MAT1 controls CAK activity is unknown. Recent studies demonstrate that retinoic acid (RA)-induced human HL60 cell proliferation/differentiation (P/D) transition is accompanied by MAT1 degradation and decreased CAK phosphorylation of retinoic acid receptor alpha (RARa). Thus, we investigated the biochemical pathway of MAT1 degradation and its relationship with CAK phosphorylation of RARa. We find that RA induces ubiquitination-proteolysis of MAT1 and that ubiquitin-proteasome targets CAK-free MAT1 only. RA-induced MAT1 ubiquitination reduces CAK abundance and decreases CAK phosphorylation of RARalpha, whereas inhibition of MAT1 ubiquitination resists this RA-effect. These findings reveal that RA induces MAT1 ubiquitination to decrease CAK phosphorylation of RARalpha, suggesting a novel mechanism of RA-mediated P/D transition in which MAT1 ubiquitination may act as an integral part of RA-effect to decrease CAK activity in the switch from proliferation to differentiation.
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Affiliation(s)
- Qiaojun He
- Department of Pathology, University of Southern California Keck School of Medicine, Los Angeles, California 90027, USA
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XPD Polymorphism and Risk of Subsequent Cancer in Individuals with Nonmelanoma Skin Cancer. Cancer Epidemiol Biomarkers Prev 2004. [DOI: 10.1158/1055-9965.1271.13.8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Abstract
Background: Individuals with nonmelanoma skin cancer (NMSC) are at increased risk of developing subsequent cancers. Genetic predisposition to reduced DNA repair capacity may be an underlying susceptibility factor explaining the excess risk of malignancies. To test this hypothesis, a cohort study was conducted to examine the association between XPD Lys751Gln polymorphism and risk of a second primary cancer in individuals with NMSC. Methods: A subgroup of 481 individuals with a history of NMSC who participated in the CLUE II community-based cohort was followed for the development of a second primary cancer. Blood specimens donated in 1989 were genotyped for the XPD Lys751Gln polymorphism using the 5′ nuclease assay. Cox proportional regression with delayed entry was used to calculate the incidence rate ratio (IRR) and 95% confidence interval (95% CI) for risk of developing a second primary cancer according to XPD genotype. All statistical tests were two sided. Results: Eighty individuals developed a second primary cancer. The most frequent occurring cancers were of the prostate (18%), lung (15%), and breast (15%). Persons with at least one Gln allele had an increased risk of a second primary cancer compared with the reference Lys/Lys genotype (adjusted IRR 2.22, 95% CI 1.30-3.76). When the reference category was limited to never smokers with the Lys/Lys genotype, the risk of developing a second primary cancer associated with having at least one Gln allele was increased >3-fold in both never smokers (IRR 3.93, 95% CI 1.36-11.36) and ever smokers (IRR 6.14, 95% CI 2.17-17.37). Conclusion: These findings suggest that individuals with NMSC who have the variant XPD Gln allele are at increased risk of developing a second primary cancer.
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Yahagi S, Shibuya K, Obayashi I, Masaki H, Kurata Y, Kudoh J, Shimizu N. Identification of two novel clusters of ultrahigh-sulfur keratin-associated protein genes on human chromosome 11. Biochem Biophys Res Commun 2004; 318:655-64. [PMID: 15144888 DOI: 10.1016/j.bbrc.2004.04.074] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Indexed: 11/23/2022]
Abstract
We analyzed two novel clusters of keratin-associated protein (KAP) genes on human chromosome 11 (11p15.5 and 11q13.5) in which we identified two known human KRTAP5 genes, KerA (=KRN1) and KerB, and nine novel KRTAP5 family genes. RT-PCR analysis of these KAP genes showed preferential expression in human hair root, suggesting these gene products are required for hair formation. Based on the deduced amino acid sequences, all these KAP proteins were classified into an ultrahigh-sulfur (UHS) type KAP with high cysteine content (> 30 mol%). These KAPs also showed high glycine and serine contents (average 24.30 and 21.13 mol%, respectively), distinguishing from other UHS/HS KAP families located on human chromosomes 17 and 21. Dot-matrix analysis revealed a significant similarity between these two KAP gene clusters. We postulated a mechanism by which these two KAP gene clusters are generated via genomic duplication of a primordial gene cluster followed by genetic modification during evolution.
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Affiliation(s)
- Shoichi Yahagi
- Department of Molecular Biology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
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Zhang S, He Q, Peng H, Tedeschi-Blok N, Triche TJ, Wu L. MAT1-modulated cyclin-dependent kinase-activating kinase activity cross-regulates neuroblastoma cell G1 arrest and neurite outgrowth. Cancer Res 2004; 64:2977-83. [PMID: 15126328 DOI: 10.1158/0008-5472.can-03-4018] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cyclin-dependent kinase-activating kinase (CAK) regulates cell cycle G1 exit, where cells commonly commit either to proliferate or to differentiate. CAK activity in G1 regulation is determined by its assembly factor and targeting subunit, ménage à trois 1 (MAT1). The precise mechanism of how proliferation/differentiation transition is induced from cancer cell G1 arrest remains unknown. We present evidence that in neuroblastoma CHP126 cells, CAK interacts with and phosphorylates retinoblastoma tumor suppressor protein (pRb) and retinoid X receptor alpha (RXRalpha). Retinoic acid (RA)-induced neuroblastoma cell proliferation/differentiation transition is associated with decreased CAK activity, as evidenced by a switch from CAK hyperphosphorylation of pRb and RXRalpha to hypophosphorylation of pRb and RXRalpha. Manipulation of MAT1 abundance shows that MAT1 reduction mimics RA-induced hypophosphorylation of pRb/RXRalpha, proliferation inhibition, and neurite outgrowth, whereas MAT1 overexpression resists these RA actions. Thus, these findings reveal an important mechanism by which MAT1-modulated CAK activity is crucial in the switch from proliferation to differentiation in neuroblastoma cells.
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Affiliation(s)
- Shineng Zhang
- Department of Pathology, University of Southern California Keck School of Medicine, Los Angeles, California 90027, USA
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Kramata P, Zajc B, Sayer JM, Jerina DM, Wei CSJ. A single site-specific trans-opened 7,8,9,10-tetrahydrobenzo[a]pyrene 7,8-diol 9,10-epoxide N2-deoxyguanosine adduct induces mutations at multiple sites in DNA. J Biol Chem 2003; 278:14940-8. [PMID: 12595542 DOI: 10.1074/jbc.m211557200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Site-specific mutagenicity of trans-opened adducts at the exocyclic N(2)-amino group of guanine by the (+)-(7R,8S,9S,10R)- and (-)-(7S,8R,9R,10S)-enantiomers of a benzo[a]pyrene 7,8-diol 9,10-epoxide (7-hydroxyl and epoxide oxygen are trans, BPDE-2) has been determined in Chinese hamster V79 cells and their repair-deficient counterpart, V-H1 cells. Four vectors containing single 10S-BPDE-dG or 10R-BPDE-dG adducts positioned at G(0) or G(-1) in the analyzed 5'-ACTG(0)G(-1)GA sequence of the non-transcribed strand were separately transfected into the cells. Mutations at each of the seven nucleotides were analyzed by a novel primer extension assay using a mixture of one dNTP complementary to the mutated nucleotide and three other ddNTPs and were optimized to quantify levels of a mutation as low as 1%. Only G --> T mutations were detected at the adducted sites; the 10S adduct derived from the highly carcinogenic (+)-diol epoxide was 40-50 and 75-140% more mutagenic than the 10R adduct in V79 and V-H1 cells, respectively. Importantly, the 10S adducts, but not the 10R adducts, induced separate non-targeted mutations at sites 5' to the G(-1) and G(0) lesions (G(0) --> T and C --> T, respectively) in both cell lines. Neither the T 5' to G(0) nor sites 3' to the lesions showed mutations. Non-targeted mutations may enhance overall mutagenicity of the 10S-BPDE-dG lesion and contribute to the much higher carcinogenicity and mutagenicity of (+)-BPDE-2 compared with its (-)-enantiomer. Our study reports a definitive demonstration of mutations distal to a site-specific polycyclic aromatic hydrocarbon adduct.
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Affiliation(s)
- Pavel Kramata
- Susan Lehman Cullman Laboratory for Cancer Research, Department of Chemical Biology, College of Pharmacy, Rutgers, State University of New Jersey, Piscataway, New Jersey 08854-8020, USA.
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Gurubhagavatula S, Liu G, Park S, Zhou W, Su L, Wain JC, Lynch TJ, Neuberg DS, Christiani DC. Pharmacogenomic strategies for developing customized chemotherapy in non-small cell lung cancer. Pharmacogenomics 2003; 22:2594-601. [PMID: 15173214 DOI: 10.1200/jco.2004.08.067] [Citation(s) in RCA: 231] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In this review, we deal with six groups of cytotoxic drugs commonly used in the treatment of non-small cell lung cancer (NSCLC). Although there are many reviews of thymidylate synthase (TS) and antifolate inhibitors, in this article, we have tried to highlight aspects that are more important for medical oncologists to consider when treating NSCLC patients. There is compelling evidence that TS gene transcripts and TS polymorphisms could be used to decide which patients can best benefit from adjuvant chemotherapy approaches, especially in colorectal cancer, and not less importantly, to tailor chemotherapy in metastatic NSCLC when using drugs akin to fluorouracil, such as pemetrexed. Secondly, cisplatin is central to chemotherapy combinations and evidence indicates that DNA repair capacity influences response to cisplatin-based regimens. ERCC1 gene transcript stands out as a predictive marker of cisplatin sensitivity. Thirdly, preliminary studies indicate that upregulation of beta-tubulin III correlates with response to paclitaxel and vinorelbine. Fourthly, overexpression of ribonucleotide reductase can influence response to gemcitabine. Fifthly, we describe mechanisms of resistance to topoisomerase I inhibitors, although this subject has not yet been completely elucidated. Finally, to understand the mechanisms of resistance to EGF-R inhibitors, which have been shown to be useful in many different types of cancer, the Src-STAT signaling pathways are described here in detail. Hopefully, the assessment of Src and of STAT-3 can be implemented as predictive markers.
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32
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Tang D, Cho S, Rundle A, Chen S, Phillips D, Zhou J, Hsu Y, Schnabel F, Estabrook A, Perera FP. Polymorphisms in the DNA repair enzyme XPD are associated with increased levels of PAH-DNA adducts in a case-control study of breast cancer. Breast Cancer Res Treat 2003; 75:159-66. [PMID: 12243508 DOI: 10.1023/a:1019693504183] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We present findings on the associations between DNA adduct levels in breast tissue, risk of breast cancer, and polymorphisms in the DNA repair enzyme XPD. Breast cancer cases, benign breast disease (BBD) controls, and healthy controls were enrolled. Polycyclic aromatic hydrocarbons (PAH)-DNA adduct levels were measured by immunohistochemistry in breast tissue samples from cases and BBD controls. XPD polymorphisms at codons 312 and 751 was determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analysis using white blood cell DNA. Neither of the polymorphisms were associated with case-control status, both in comparisons of cases and BBD controls, and cases and healthy controls. XPD polymorphisms at codons 312 and 751 were associated with higher levels of PAH-DNA in tumor tissue from breast cancer cases. Subjects with an Asp/Asn or Asn/Asn polymorphic genotype in codon 312 of XPD had elevated levels of PAH-DNA adducts compared to subjects with the Asp/Asp genotype (0.55 optical density (OD) v.s. 0.33 OD, p < 0.01). PAH-DNA adducts were associated with increasing copy number of the Gln allele for the codon 751 polymorphism (p for trend <0.01). Among subjects with the Asp/Asn or Asn/Asn genotype at codon 312, adduct levels were higher in tumor tissue compared to tissue from BBD controls (0.55 OD v.s. 0.36 OD, p = 0.003). Among subjects with the Gln/Gln genotype at codon 751 adduct levels were higher in tumor tissue compared to tissue from BBD controls (0.68 OD v.s. 0.40 OD, p = 0.01). The trend of increasing PAH-DNA adduct levels with either the Asn/Asn or Gln/Gln genotype was greater in tumor tissue than the trend in BBD control tissue.
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Affiliation(s)
- Deliang Tang
- Department of Environmental Health Sciences, Joseph L. Mailman School of Public Health, Columbia University, New York, NY 10032, USA
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Herouy Y, Krutmann J, Norgauer J, Schöpf E. Xeroderma Pigmentosum: Mondscheinkinder. Xeroderma Pigmentosum: Children of the Moon. J Dtsch Dermatol Ges 2003; 1:191-8. [PMID: 16285494 DOI: 10.1046/j.1610-0387.2003.02032.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Xeroderma pigmentosum is based on a genetic defect in the DNA repair system, which is diagnosed in early childhood. Xeroderma pigmentosum is a rare disorder, which is transmitted in an autosomal recessive manner. Children with xeroderma pigmentosum display hypersensitivity to ultraviolet (UV) radiation. These patients experience serious sunburns with minimal exposure and then develop poikiloderma in the sun-exposed areas. Squamous cell carcinomas, basal cell carcinomas and malignant melanomas all appear during childhood. The majority of patients do not reach adult, but die from metastatic cutaneous malignancies. Genetically, xeroderma pigmentosum is differentiated into 7 complementation groups (XP-A to XP-G) and the xeroderma pigmentosum variants (XP-V). The assignment to the specific complementation group is made by fusing of xeroderma pigmentosum fibroblasts. Xeroderma pigmentosum must be distinguished from other so-called DNA repair deficiency syndromes, including Cockayne syndrome and trichothiodystrophy. A topical DNA repair enzyme appears to be helpful. A recombinant liposomal encapsulated T4 endonuclease V repairs UV-induced cyclobutane-pyrimidine dimers. Direct curative treatment of xeroderma pigmentosum could be achieved with gene therapy in future. Transfection of an intact repair gene which specifically codes for the missing repair protein could open new possibilities in the therapy of xeroderma pigmentosum.
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Affiliation(s)
- Yared Herouy
- Universitäts-Hautklinik, Albert-Ludwigs-Universität, Freiburg.
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34
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Affiliation(s)
- Frédéric Coin
- Institut de Genetique et de Biologie Moleculaire et Cellulaire, Dept. of Transcription, CNRS/INSERM/ULP, B.P. 162, 67404 Illkirch, C.U. de Strasbourg, France
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Dollfus H, Porto F, Caussade P, Speeg-Schatz C, Sahel J, Grosshans E, Flament J, Sarasin A. Ocular manifestations in the inherited DNA repair disorders. Surv Ophthalmol 2003; 48:107-22. [PMID: 12559331 DOI: 10.1016/s0039-6257(02)00400-9] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Deoxyribonucleic acid (DNA) repair is a fundamental process designed to keep the integrity of genomic DNA that is continuously challenged by intrinsic or environmental induced alterations. Numerous genes involved in DNA repair have been cloned and are involved in different DNA repair pathways: base excision repair, nucleotide excision repair, mismatch repair, DNA recombination. Inherited conditions due to mutations in DNA repair genes include mainly: xeroderma pigmentosum, Cockayne syndrome, Trichothiodystrophy, Bloom syndrome, Rothmund-Thomson syndrome, and Werner syndrome. Minor to major ocular manifestations occur in these syndromes. For example, eyelid skin cancers in xeroderma pigmentosum and retinal dystrophy in Cockayne syndrome are major features of these syndromes. This review focuses on the DNA repair pathways, the general and ocular features of the related syndromes, the laboratory tests useful for diagnosis, and the general processes implied with DNA repair (ultraviolet sensitivity, carcinogenesis, apoptosis, oxydative stress, and premature aging).
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Affiliation(s)
- Hélène Dollfus
- Fédération de Génétique Médicale, Clinique Ophtalmologique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
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Fujinaga K, Irwin D, Geyer M, Peterlin BM. Optimized chimeras between kinase-inactive mutant Cdk9 and truncated cyclin T1 proteins efficiently inhibit Tat transactivation and human immunodeficiency virus gene expression. J Virol 2002; 76:10873-81. [PMID: 12368330 PMCID: PMC136629 DOI: 10.1128/jvi.76.21.10873-10881.2002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The human cyclin T1 (hCycT1) protein from the positive transcription elongation factor b (P-TEFb) binds the transactivator Tat and the transactivation response (TAR) RNA stem loop from human immunodeficiency virus type 1 (HIV). This complex activates the elongation of viral transcription. To create effective inhibitors of Tat and thus HIV replication, we constructed mutant hCycT1 proteins that are defective in binding its kinase partner, Cdk9, or TAR. Although these mutant hCycT1 proteins did not increase Tat transactivation in murine cells, their dominant-negative effects were small in human cells. Higher inhibitory effects were obtained when hCycT1 was fused with the mutant Cdk9 protein. Since the autophosphorylation of the C terminus of Cdk9 is required for the formation of the stable complex between P-TEFb, Tat, and TAR, these serines and threonines were changed to glutamate in a kinase-inactive Cdk9 protein. This chimera inhibited Tat transactivation and HIV gene expression in human cells. Therefore, this dominant-negative kinase-inactive mutant Cdk9.hCycT1 chimera could be used for antiviral gene therapy.
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Affiliation(s)
- Koh Fujinaga
- Department of Medicine, University of California at San Francisco, San Francisco, California 94143-0703, USA
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37
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Abstract
Trichothiodystrophy (TTD) is a complex disorder caused by mutations in the XPD gene which affect both DNA repair and transcription. A mouse with a TTD mutation has now been found to display remarkable signs of premature ageing.
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Affiliation(s)
- Alan Lehmann
- Genome Damage and Stability Centre, University of Sussex, Falmer, BN1 9RQ, Brighton, UK.
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Conney AH, Chang RL, Cui XX, Schiltz M, Yagi H, Jerina DM, Wei SJ. Dose-dependent differences in the profile of mutations induced by carcinogenic (R,S,S,R) bay- and fjord-region diol epoxides of polycyclic aromatic hydrocarbons. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2002; 500:697-707. [PMID: 11765016 DOI: 10.1007/978-1-4615-0667-6_102] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Chinese hamster V79 cells were exposed to a high or low concentration of the highly carcinogenic (R,S,S,R) or the less active (S,R,R,S) bay- or fjord-region diol epoxides of benzo[a]pyrene, benzo[c]phenanthrene or dibenz[c,h]acridine. Independent 8-azaguanine-resistant clones were isolated, and base substitutions at the hypoxanthine (guanine) phosphoribosyltransferase (hprt) locus were determined. For the three (R,S,S,R) diol epoxides studied, the proportion of mutations at AT base pairs increased as the concentration of diol epoxide decreased. Concentration-dependent differences in the mutational profile were not observed, however, for the three (S,R,R,S) diol epoxides. In studies, with V-H1 cells (a DNA repair deficient variant of V79 cells), a concentration-dependent difference in the profile of mutations for the (R,S,S,R) diol epoxide of benzo[a]pyrene was not observed. These results suggest that concentration-dependent differences in the mutational profile are dependent on an intact DNA repair system. In additional studies, we initiated mouse skin with a high or low dose of benzo[a]pyrene and promoted the mice for 26 weeks with 12-O-tetradecanoylphorbol-13-acetate. Papillomas were examined for mutations in the c-Ha-ras proto-oncogene. Dose-dependent differences in the profile of c-Ha-ras mutations in the tumors were observed. In summary, (i) dose-dependent differences in mutational profiles at the hprt locus were observed in Chinese hamster V79 cells treated with several highly mutagenic and carcinogenic (R,S,S,R) bay- or fjord-region diol epoxides but not with their less active (S,R,R,S) diol epoxide enantiomers, (ii) a dose-dependent difference in the mutational profile was not observed for the (R,S,S,R) diol epoxide of benzo[a]pyrene in a DNA-repair defective V79 cell line, and (iii) a dose-dependent difference in the mutational profile in the c-Ha-ras proto-oncogene was observed in tumors from mice treated with a high or low dose of benzo[a]pyrene.
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Affiliation(s)
- A H Conney
- Department of Chemical Biology, College of Pharmacy, Rutgers, the State University of New Jersey, Piscataway 08854-8020, USA
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Jawhari A, Uhring M, Crucifix C, Fribourg S, Schultz P, Poterszman A, Egly JM, Moras D. Expression of FLAG fusion proteins in insect cells: application to the multi-subunit transcription/DNA repair factor TFIIH. Protein Expr Purif 2002; 24:513-23. [PMID: 11922769 DOI: 10.1006/prep.2001.1597] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The multi-subunit transcription/DNA repair factor TFIIH was used as a model system to show that the expression of FLAG fusion proteins in insect cells constitutes a versatile tool for both structural and functional investigations. In the present study, we have constructed recombinant baculoviruses expressing the four core TFIIH subunits fused at their N-terminus to the FLAG peptide. Using these recombinant viruses we have established protocols based on anti-FLAG immunoaffinity chromatography that allow the systematic analysis of pairwise interaction within multiprotein complexes and have developed a double tag strategy (FLAG and hexahistidine tags) for the identification and purification of stable TFIIH subcomplexes. A simple purification procedure was developed that leads to the isolation of recombinant TFIIH containing the full set of subunits. The purified recombinant TFIIH was shown to be active in a transcription assay and to be structurally homologous to the endogenous complex by electron microscopy and image analysis.
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Affiliation(s)
- Anass Jawhari
- Institut de Génétique et de Biologie Cellulaire et Moléculaire, 67404 Illkirch Cedex, C.U. de Strasbourg, France
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Zhou M, Nekhai S, Bharucha DC, Kumar A, Ge H, Price DH, Egly JM, Brady JN. TFIIH inhibits CDK9 phosphorylation during human immunodeficiency virus type 1 transcription. J Biol Chem 2001; 276:44633-40. [PMID: 11572868 DOI: 10.1074/jbc.m107466200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tat stimulates human immunodeficiency virus, type 1 (HIV-1), transcription elongation by recruitment of the human transcription elongation factor P-TEFb, consisting of CDK9 and cyclin T1, to the TAR RNA structure. It has been demonstrated further that CDK9 phosphorylation is required for high affinity binding of Tat/P-TEFb to the TAR RNA structure and that the state of P-TEFb phosphorylation may regulate Tat transactivation. We now demonstrate that CDK9 phosphorylation is uniquely regulated in the HIV-1 preinitiation and elongation complexes. The presence of TFIIH in the HIV-1 preinitiation complex inhibits CDK9 phosphorylation. As TFIIH is released from the elongation complex between +14 and +36, CDK9 phosphorylation is observed. In contrast to the activity in the "soluble" complex, phosphorylation of CDK9 is increased by the presence of Tat in the transcription complexes. Consistent with these observations, we have demonstrated that purified TFIIH directly inhibits CDK9 autophosphorylation. By using recombinant TFIIH subcomplexes, our results suggest that the XPB subunit of TFIIH is responsible for this inhibition of CDK9 phosphorylation. Interestingly, our results further suggest that the phosphorylated form of CDK9 is the active kinase for RNA polymerase II carboxyl-terminal domain phosphorylation.
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Affiliation(s)
- M Zhou
- Virus Tumor Biology Section, Basic Research Laboratory, Division of Basic Sciences, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA
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Moné MJ, Volker M, Nikaido O, Mullenders LH, van Zeeland AA, Verschure PJ, Manders EM, van Driel R. Local UV-induced DNA damage in cell nuclei results in local transcription inhibition. EMBO Rep 2001; 2:1013-7. [PMID: 11713193 PMCID: PMC1084123 DOI: 10.1093/embo-reports/kve224] [Citation(s) in RCA: 155] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
UV-induced DNA damage causes cells to repress RNA synthesis and to initiate nucleotide excision repair (NER). NER and transcription are intimately linked processes. Evidence has been presented that, in addition to damaged genes, undamaged loci are transcriptionally inhibited. We investigated whether RNA synthesis from undamaged genes is affected by the presence of UV damage elsewhere in the same nucleus, using a novel technique to UV irradiate only part of a nucleus. We show that the basal transcription/repair factor TFIIH is recruited to the damaged nuclear area, partially depleting the undamaged nuclear area. Remarkably, this sequestration has no effect on RNA synthesis. This result was obtained for cells that are able to carry out NER and for cells deficient in NER. We conclude that cross talk between NER and transcription occurs only over short distances in nuclei of living cells.
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Affiliation(s)
- M J Moné
- Swammerdam Institute for Life Sciences, BioCentrum Amsterdam, University of Amsterdam, Plantage Muidergracht 12, 1018 TV Amsterdam, The Netherlands
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42
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Murai M, Enokido Y, Inamura N, Yoshino M, Nakatsu Y, van der Horst GT, Hoeijmakers JH, Tanaka K, Hatanaka H. Early postnatal ataxia and abnormal cerebellar development in mice lacking Xeroderma pigmentosum Group A and Cockayne syndrome Group B DNA repair genes. Proc Natl Acad Sci U S A 2001; 98:13379-84. [PMID: 11687625 PMCID: PMC60879 DOI: 10.1073/pnas.231329598] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Xeroderma pigmentosum (XP) and Cockayne syndrome (CS) are rare autosomal recessive disorders associated with a defect in the nucleotide excision repair (NER) pathway required for the removal of DNA damage induced by UV light and distorting chemical adducts. Although progressive neurological dysfunction is one of the hallmarks of CS and of some groups of XP patients, the causative mechanisms are largely unknown. Here we show that mice lacking both the XPA (XP-group A) and CSB (CS-group B) genes in contrast to the single mutants display severe growth retardation, ataxia, and motor dysfunction during early postnatal development. Their cerebella are hypoplastic and showed impaired foliation and stunted Purkinje cell dendrites. Reduced neurogenesis and increased apoptotic cell death occur in the cerebellar external granular layer. These findings suggest that XPA and CSB have additive roles in the mouse nervous system and support a crucial role for these genes in normal brain development.
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Affiliation(s)
- M Murai
- Division of Protein Biosynthesis, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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43
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Maru Y, Bergmann E, Coin F, Egly JM, Shibuya M. TFIIH functions are altered by the P210BCR-ABL oncoprotein produced on the Philadelphia chromosome. Mutat Res 2001; 483:83-8. [PMID: 11600136 DOI: 10.1016/s0027-5107(01)00229-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
P210BCR-ABL counteracted against the complementary effect of XPB on DNA repair when ultraviolet (UV)-sensitive 27-1 cells were treated with UV or cisplatin but not with hydrogen peroxide. Wortmannin, an inhibitor of PI3 kinase did not affect its anti-repair effect. Enhanced recruitment of p44 with TFIIH after cisplatin treatment is inhibited by the expression of P210BCR-ABL in a kinase activity-dependent manner. Although purified TFIIH from P210BCR-ABL expressor and non-expressor showed almost no difference in molar ratio of each component, the in vitro activity of TFIIH was decreased by 5-10% in repair assay but was increased by more than two-fold in transcription assay.
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Affiliation(s)
- Y Maru
- Department of Genetics, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, 108-0071, Tokyo, Japan.
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44
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George JW, Salazar EP, Vreeswijk MP, Lamerdin JE, Reardon JT, Zdzienicka MZ, Sancar A, Kadkhodayan S, Tebbs RS, Mullenders LH, Thompson LH. Restoration of nucleotide excision repair in a helicase-deficient XPD mutant from intragenic suppression by a trichothiodystrophy mutation. Mol Cell Biol 2001; 21:7355-65. [PMID: 11585917 PMCID: PMC99909 DOI: 10.1128/mcb.21.21.7355-7365.2001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The UV-sensitive V-H1 cell line has a T46I substitution mutation in the Walker A box in both alleles of XPD and lacks DNA helicase activity. We characterized three partial revertants that curiously display intermediate UV cytotoxicity (2- to 2.5-fold) but normal levels of UV-induced hprt mutations. In revertant RH1-26, the efficient removal of pyrimidine (6-4) pyrimidone photoproducts from both strands of hprt suggests that global-genomic nucleotide excision repair is normal, but the pattern of cyclobutane pyrimidine dimer removal suggests that transcription-coupled repair (TCR) is impaired. To explain the intermediate UV survival and lack of RNA synthesis recovery in RH1-26 after 10 J of UV/m(2), we propose a defect in repair-transcription coupling, i.e., the inability of the cells to resume or reinitiate transcription after the first TCR event within a transcript. All three revertants carry an R658H suppressor mutation, in one allele of revertants RH1-26 and RH1-53 and in both alleles of revertant RH1-3. Remarkably, the R658H mutation produces the clinical phenotype of trichothiodystrophy (TTD) in several patients who display intermediate UV sensitivity. The XPD(R658H) TTD protein, like XPD(T46I/R658H), is codominant when overexpressed in V-H1 cells and partially complements their UV sensitivity. Thus, the suppressing R658H substitution must restore helicase activity to the inactive XPD(T46I) protein. Based on current knowledge of helicase structure, the intragenic reversion mutation may partially compensate for the T46I mutation by perturbing the XPD structure in a way that counteracts the effect of this mutation. These findings have implications for understanding the differences between xeroderma pigmentosum and TTD and illustrate the value of suppressor genetics for studying helicase structure-function relationships.
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Affiliation(s)
- J W George
- Biology and Biotechnology Research Program, Lawrence Livermore National Laboratory, Livermore, California 94551-0808, USA
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45
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Sandrock B, Egly JM. A yeast four-hybrid system identifies Cdk-activating kinase as a regulator of the XPD helicase, a subunit of transcription factor IIH. J Biol Chem 2001; 276:35328-33. [PMID: 11445587 DOI: 10.1074/jbc.m105570200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To understand the role of the various components of TFIIH, a DNA repair/transcription factor, a yeast four-hybrid system was designed. When the ternary Cdk-activating kinase (CAK) complex composed of Cdk7, cyclin H, and MAT1 was used as bait, the xeroderma pigmentosum (XP) D helicase of transcription factor IIH (TFIIH), among other proteins, was identified as an interacting partner. Deletion mutant analyses demonstrated that the coiled-coil and the hydrophobic domains of MAT1 interlink the CAK complex directly with the N-terminal domain of XPD. Using immunoprecipitates from cells coinfected with baculoviruses, we further validated the bridging function of XPD, which anchors CAK to the core TFIIH. In addition we show that upon interaction with MAT1, CAK inhibits the helicase activity of XPD. This inhibition is overcome upon binding to p44, a subunit of the core TFIIH. It is not surprising that under these conditions some XPD mutations affect interactions not only with p44, but also with MAT1, thus preventing either the CAK inhibitory function within CAK.XPD and/or the role of CAK within TFIIH and, consequently, explaining the variety of the XP phenotypes.
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Affiliation(s)
- B Sandrock
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/Université Louis Pasteur, B. P. 163, 67404 Illkirch Cedex, France
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46
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Jaiswal AS, Narayan S. p53-dependent transcriptional regulation of the APC promoter in colon cancer cells treated with DNA alkylating agents. J Biol Chem 2001; 276:18193-9. [PMID: 11279192 DOI: 10.1074/jbc.m101298200] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The APC (adenomatous polyposis coli) gene product is involved in cell cycle arrest and in apoptosis. The loss of APC function is associated with the development of colorectal carcinogenesis. In previous studies, we have shown that the APC gene is inducible and that the DNA damage-induced level of APC mRNA requires p53. In the present study, we examined the role of p53 in the transcriptional regulation of APC promoter and characterized two p53-binding sites on the cloned APC promoter (pAPCP). Results of electrophoretic mobility shift assay showed specific interactions of p53 protein with p53-binding site oligonucleotides. The DNA-protein complex formed in electrophoretic mobility shift assay was competed with unlabeled excess of p53-binding site oligonucleotide, unaffected with p53-binding site mutant or Sp1-binding site oligonucleotides, and supershifted with anti-p53 antibodies. In a transient transfection assay, the pAPCP promoter activity was lower in HCT-116(p53(+/+)) cells versus HCT-116(p53(-/-)) cells. p53-dependent down-regulation was further confirmed after co-transfection of pAPCP plasmid with pCMV-p53 into HCT-116(p53(-/-)) and SAOS-2 (p53-negative) cells. However, the treatment of cells with DNA alkylating agents methylmethane sulfonate and N-methyl-N'-nitro-N-nitrosoguanidine, which cause phosphorylation of p53 at Ser(15) and Ser(392), induced pAPCP promoter activity in HCT-116(p53(+/+)) cells. Other than p53-binding sites, using deletion mutation constructs, we have shown that N-methyl-N'-nitro-N-nitrosoguanidine-induced transcriptional activation of the pAPCP promoter in HCT-116(p53(+/+)) cells depended upon the Sp1-binding site and the E-box B site. From these results, we conclude that unphosphorylated p53 can down-regulate and phosphorylated p53 can up-regulate the pAPCP promoter activity involving the p53, Sp1, or E-box B elements. These studies are important to understanding the role of p53 and APC in DNA damage-induced cell cycle arrest and/or apoptosis of cancer cells.
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Affiliation(s)
- A S Jaiswal
- Department of Anatomy and Cell Biology and the Shands Cancer Center, College of Medicine, The University of Florida, Gainesville, Florida 32610, USA
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47
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Jaitovich-Groisman I, Benlimame N, Slagle BL, Perez MH, Alpert L, Song DJ, Fotouhi-Ardakani N, Galipeau J, Alaoui-Jamali MA. Transcriptional regulation of the TFIIH transcription repair components XPB and XPD by the hepatitis B virus x protein in liver cells and transgenic liver tissue. J Biol Chem 2001; 276:14124-32. [PMID: 11278765 DOI: 10.1074/jbc.m010852200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Human hepatitis B virus is a risk factor for the development of hepatocellular carcinoma. The hepatitis B virus x protein (HBx) has been shown to inactivate the p53 tumor suppressor protein and impair DNA repair, cell cycle, and apoptosis mechanisms. Herein we report that HBx represses two components of the transcription-repair factor TFIIH, XPB (p89), and XPD (p80), both in p53-proficient and p53-deficient liver cells. This inhibition is observed while HBx maintains its transactivation function. Expression of HBx in liver cells results in down-regulation of endogenous XPB and XPD mRNAs and proteins; this inhibition is not observed with other TFIIH subunits, XPA or PCNA. In liver tissue from HBx transgenics, XPB and XPD proteins are down-regulated in comparison to matched normal liver tissue. HBx has been shown to interact with Sp1 transcription factor and affects its DNA binding activity. Sp1 is essential for the basal promoter activity of XPB in liver cells and Drosophila SL2 cells. In the Sp1-deficient SL2 cells, HBx-induced XPB and XPD inhibition is Sp1-dependent. In summary, our results provide evidence that HBx represses the expression of key TFIIH proteins at least in part through Sp1 elements; this repression may impair TFIIH function in DNA repair mechanisms.
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MESH Headings
- Animals
- Animals, Genetically Modified
- Apoptosis
- Blotting, Western
- Cell Line
- Chloramphenicol O-Acetyltransferase/metabolism
- DNA Helicases
- DNA Repair/genetics
- DNA-Binding Proteins/metabolism
- Down-Regulation
- Drosophila
- Drosophila Proteins
- Female
- Flow Cytometry
- Gene Expression Regulation, Viral
- Humans
- Immunohistochemistry
- Liver/metabolism
- Male
- Mice
- Mice, Transgenic
- Models, Genetic
- Plasmids/metabolism
- Promoter Regions, Genetic
- Proteins/metabolism
- RNA, Messenger/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Sp1 Transcription Factor/metabolism
- TATA-Binding Protein Associated Factors
- Trans-Activators/genetics
- Trans-Activators/metabolism
- Transcription Factor TFIID
- Transcription Factor TFIIH
- Transcription Factors/genetics
- Transcription Factors, TFII
- Transcription, Genetic
- Transcriptional Activation
- Transfection
- Tumor Cells, Cultured
- Viral Regulatory and Accessory Proteins
- Xeroderma Pigmentosum Group D Protein
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Affiliation(s)
- I Jaitovich-Groisman
- Lady Davis Institute of the Sir Mortimer B. Davis Jewish General Hospital, Departments of Medicine, Pharmacology and Therapeutics, Pathology, and Oncology, Faculty of Medicine, McGill University, Montreal H3T 1E2, Canada
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48
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Cantor SB, Bell DW, Ganesan S, Kass EM, Drapkin R, Grossman S, Wahrer DC, Sgroi DC, Lane WS, Haber DA, Livingston DM. BACH1, a novel helicase-like protein, interacts directly with BRCA1 and contributes to its DNA repair function. Cell 2001; 105:149-60. [PMID: 11301010 DOI: 10.1016/s0092-8674(01)00304-x] [Citation(s) in RCA: 510] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BRCA1 interacts in vivo with a novel protein, BACH1, a member of the DEAH helicase family. BACH1 binds directly to the BRCT repeats of BRCA1. A BACH1 derivative, bearing a mutation in a residue that was essential for catalytic function in other helicases, interfered with normal double-strand break repair in a manner that was dependent on its BRCA1 binding function. Thus, BACH1/BRCA1 complex formation contributes to a key BRCA1 activity. In addition, germline BACH1 mutations affecting the helicase domain were detected in two early-onset breast cancer patients and not in 200 matched controls. Thus, it is conceivable that, like BRCA1, BACH1 is a target of germline cancer-inducing mutations.
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Affiliation(s)
- S B Cantor
- The Dana-Farber Cancer Institute and the Harvard, Medical School, Boston, MA 02115, USA
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49
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Abstract
Multistep carcinogenesis is exemplified by chronic myeloid leukemia with clinical manifestation consisting of a chronic phase and blast crisis. Pathological generation of BCR-ABL (breakpoint cluster region-Abelson) results in growth promotion, differentiation, resistance to apoptosis, and defect in DNA repair in targeted blood cells. Domains in BCR and ABL sequences work in concert to elicit a variety of leukemogenic signals including Ras, STAT5 (signal transducer and activator of transcription-5), Myc, cyclin D1, P13 (phosphatidylinositol 3-kinase), RIN1 (Ras interaction/interference), and activation of actin cytoskeleton. However, the mechanism of differentiation of transformed cells is poorly understood. A mutator phenotype of BCR-ABL could explain the transformation to blast crisis. The aim of this review is to integrate molecular and biological information on BCR, ABL, and BCR-ABL and to focus on how signaling from those molecules mirrors the biological phenotypes of chronic myeloid leukemia.
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MESH Headings
- Animals
- Blast Crisis/genetics
- Cell Differentiation
- Cell Transformation, Neoplastic/genetics
- Disease Progression
- Fusion Proteins, bcr-abl/chemistry
- Fusion Proteins, bcr-abl/genetics
- Fusion Proteins, bcr-abl/physiology
- Gene Expression Regulation, Leukemic
- Genes, abl
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/enzymology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Leukemia, Myeloid, Accelerated Phase/genetics
- Leukemia, Myeloid, Chronic-Phase/genetics
- Mice
- Mice, Knockout
- Models, Biological
- Neoplasm Proteins/physiology
- Neoplastic Stem Cells/enzymology
- Neoplastic Stem Cells/pathology
- Oncogene Proteins/chemistry
- Oncogene Proteins/genetics
- Oncogene Proteins/physiology
- Phenotype
- Philadelphia Chromosome
- Phosphorylation
- Protein Processing, Post-Translational
- Protein Structure, Tertiary
- Protein-Tyrosine Kinases
- Proto-Oncogene Proteins
- Proto-Oncogene Proteins c-abl/chemistry
- Proto-Oncogene Proteins c-abl/genetics
- Proto-Oncogene Proteins c-abl/physiology
- Proto-Oncogene Proteins c-bcr
- Rats
- Signal Transduction
- Structure-Activity Relationship
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Affiliation(s)
- Y Maru
- Department of Genetics, Institute of Medical Science, University of Tokyo, Japan.
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50
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Kadkhodayan S, Coin F, Salazar EP, George JW, Egly JM, Thompson LH. Codominance associated with overexpression of certain XPD mutations. Mutat Res 2001; 485:153-68. [PMID: 11182546 DOI: 10.1016/s0921-8777(00)00077-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mutations in the XPD gene are associated with three complex clinical phenotypes, namely xeroderma pigmentosum (XP), XP in combination with Cockayne syndrome (XP-CS), and trichothiodystrophy (TTD). XP is caused by a deficiency in nucleotide excision repair (NER) that results in a high risk of skin cancer. TTD is characterized by severe developmental and neurological defects, with hallmark features of brittle hair and scaly skin, and sometimes has defective NER. We used CHO cells as a system to study how specific mutations alter the dominant/recessive behavior of XPD protein. Previously we identified the T46I and R75W mutations in two highly UV-sensitive hamster cell lines that were reported to have paradoxically high levels of unscheduled DNA synthesis. Here we report that these mutants have greatly reduced XPD helicase activity and fully defective NER in a cell-extract excision assay. We conclude that the unscheduled DNA synthesis seen in these mutants is caused by abortive "repair" that does not contribute to cell survival. These mutations, as well as the K48R canonical helicase-domain mutation, each produced codominant negative phenotypes when overexpressed in wild-type CHO cells. The common XP-specific R683W mutation also behaved in a codominant manner when overexpressed, which is consistent with the idea that this mutation may affect primarily the enzymatic activity of the protein rather than impairing protein interactions, which may underlie TTD. A C-terminal mutation uniquely found in TTD (R722W) was overexpressed but not to levels sufficiently high to rigorously test for a codominant phenotype. Overexpression of mutant XPD alleles may provide a simple means of producing NER deficiency in other cell lines.
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Affiliation(s)
- S Kadkhodayan
- Biology and Biotechnology Research Program, L441, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551-0808, USA
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