1
|
Imoto K, Nadem C, Moriwaki SI, Nishigori C, Oh KS, Khan SG, Goldstein AM, Kraemer KH. Ancient origin of a Japanese xeroderma pigmentosum founder mutation. J Dermatol Sci 2012. [PMID: 23194742 DOI: 10.1016/j.jdermsci.2012.10.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
2
|
XPA Gene Mutations Resulting in Subtle Truncation of Protein in Xeroderma Pigmentosum Group A Patients with Mild Skin Symptoms. J Invest Dermatol 2010; 130:2481-8. [DOI: 10.1038/jid.2010.137] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
3
|
Messaoud O, Ben Rekaya M, Kefi R, Chebel S, Boughammoura-Bouatay A, Bel Hadj Ali H, Gouider-Khouja N, Zili J, Frih-Ayed M, Mokhtar I, Abdelhak S, Zghal M. Identification of a primarily neurological phenotypic expression of xeroderma pigmentosum complementation group A in a Tunisian family. Br J Dermatol 2010; 162:883-6. [DOI: 10.1111/j.1365-2133.2010.09646.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
4
|
Multiple shRNA expressions in a single plasmid vector improve RNAi against the XPA gene. Biochem Biophys Res Commun 2008; 370:301-5. [PMID: 18367095 DOI: 10.1016/j.bbrc.2008.03.078] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Accepted: 03/18/2008] [Indexed: 11/22/2022]
Abstract
To improve the efficiency of stable knockdown with short hairpin RNA (shRNA), we inserted multiple shRNA expression sequences into a single plasmid vector. In this study, the DNA repair factor XPA was selected as a target gene since it is not essential for cell viability and it is easy to check the functional knockdown of this gene. The efficiency of knockdown was compared among single and triple expression vectors. The single shRNA-expressing vector caused limited knockdown of the target protein in stable transfectants, however, the multiple expression vectors apparently increased the frequency of knockdown transfectants. There were correlations between the knockdown level and marker expression in multiple-expressing transfectants, whereas poorer correlations were observed in single vector transfectants. Multiple-transfectants exhibited reduced efficiency of repair of UV-induced DNA damage and an increased sensitivity to ultraviolet light-irradiation. We propose that multiple shRNA expression vectors might be a useful strategy for establishing knockdown cells.
Collapse
|
5
|
Hirai Y, Kodama Y, Moriwaki SI, Noda A, Cullings HM, Macphee DG, Kodama K, Mabuchi K, Kraemer KH, Land CE, Nakamura N. Heterozygous individuals bearing a founder mutation in the XPA DNA repair gene comprise nearly 1% of the Japanese population. Mutat Res 2006; 601:171-8. [PMID: 16905156 DOI: 10.1016/j.mrfmmm.2006.06.010] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2006] [Revised: 06/29/2006] [Accepted: 06/29/2006] [Indexed: 12/26/2022]
Abstract
Individuals who are homozygotes for mutations in DNA repair genes are at high risk for cancer. It is not well documented, however, if the heterozygous carriers of the mutation are also predisposed to cancer. To address the issue, xeroderma pigmentosum (XP) in Japan is an interesting candidate because of three major reasons: XP is an autosomal recessive disorder with an enormously elevated risk of skin cancer, the frequency of XP patients is higher in Japan than in other parts of the world, and more than half of Japanese XP patients are homozygous for the same founder mutation in the XPA gene. We screened archival blood samples from Japanese individuals who resided in Hiroshima or Nagasaki. A simple PCR-RFLP method was developed that is highly specific for detection of XPA heterozygotes carrying the founder mutation. We identified nine XPA heterozygotes among 1,020 individuals screened for a prevalence of 0.88%. This rate, if representative, implies that there are about 1 million carriers of the XPA founder mutation in the Japanese population. Thus, investigation of their cancer risk may be warranted.
Collapse
Affiliation(s)
- Yuko Hirai
- Department of Genetics, Radiation Effects Research Foundation, 5-2 Hijiyama Park, Hiroshima, Japan.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Arima Y, Nishigori C, Takeuchi T, Oka S, Morimoto K, Utani A, Miyachi Y. 4-Nitroquinoline 1-Oxide Forms 8-Hydroxydeoxyguanosine in Human Fibroblasts through Reactive Oxygen Species. Toxicol Sci 2006; 91:382-92. [PMID: 16547075 DOI: 10.1093/toxsci/kfj161] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
4-Nitroquinoline 1-oxide (4NQO) is thought to elicit its carcinogenicity by producing DNA adducts after being metabolized to 4-hydroxyaminoquinoline 1-oxide, which forms 8-hydroxydeoxyguanosine (8OHdG), oxidative damage. To determine whether reactive oxygen species (ROS) are involved in the generation of 8OHdG by 4NQO, we used high-performance liquid chromatography and immunohistochemistry to measure the levels of 8OHdG in normal human fibroblasts treated with 4NQO. The extent of ROS induced by 4NQO was determined by using fluorescent probes to detect ROS, electron paramagnetic resonance spectrometry using a cell-free system, and measurement of intracellular glutathione (GSH) levels. In fibroblasts, 4NQO dose dependently increased 8OHdG levels. Hydrogen peroxide (H2O2) and superoxide were detected in cells treated with 4NQO by using dichlorofluorescin diacetate and hydroethidine, respectively. The addition of catalase to culture medium reduced 8OHdG levels and the intensity of dichlorofluorescin fluorescence, while 4NQO generated hydroxyl radicals in the cell-free system. These findings suggest that 4NQO treatment leads to formation of superoxide, H2O2, and hydroxyl radicals, resulting in the production of a substantial amount of 8OHdG in DNA. Neither the level of 8OHdG nor that of GSH had returned to the basal level 24 h after removal of 4NQO even at a concentration as low as 1 microM. Our results suggest that generation of ROS and depletion of GSH in cells are also important factors for the generation of 8OHdG by 4NQO. This paper describes practical and sensitive ways to detect ROS and 8OHdG and discusses a new functional pathway to elicit genotoxicity.
Collapse
Affiliation(s)
- Yaeno Arima
- Department of Dermatology, Kyoto University Graduate School of Medicine, Sakyo-Ku, Kyoto 606-8507, Japan
| | | | | | | | | | | | | |
Collapse
|
7
|
Williams JR, Russell J, Dicello JF, Mabry MH. The genotype of the human cancer cell: implications for risk analysis. Mutat Res 1996; 365:17-42. [PMID: 8898987 DOI: 10.1016/s0165-1110(96)90010-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
An extremely large database describes genotypes associated with the human cancer phenotype and genotypes of human populations with genetic predisposition to cancer. Aspects of this database are examined from the perspective of risk analysis, and the following conclusions and hypotheses are proposed: (1) The genotypes of human cancer cells are characterized by multiple mutated genes. Each type of cancer is characterized by a set of mutated genes, a subset from a total of more than 80 genes, that varies between tissue types and between different tumors from the same tissue. No single cancer-associated gene nor carcinogenic pathway appears suitable as an overall indicator whose induction serves as a quantitative marker for risk analysis. (2) Genetic defects that predispose human populations to cancer are numerous and diverse, and provide a model for associating cancer rates with induced genetic changes. As these syndromes contribute significantly to the overall cancer rate, risk analysis should include an estimation of the effect of putative carcinogens on individuals with genetic predisposition. (3) Gene activation and inactivation events are observed in the cancer genotype at different frequencies, and the potency of carcinogens to induce these events varies significantly. There is a paradox between the observed frequency for induction of single mutational events in test systems and the frequency of multiple events in a single cancer cell, suggesting events are not independent. Quantitative prediction of cancer risk will depend on identifying rate-limiting events in carcinogenesis. Hyperproliferation and hypermutation may be such events. (4) Four sets of data suggest that hypermutation may be an important carcinogenic process. Current mechanisms of risk analysis do not properly evaluate the potency of putative carcinogens to induce the hypermutable state or to increase mutation in hypermutable cells. (5) High-dose exposure to carcinogens in model systems changes patterns of gene expression and may induce protective effects through delay in cell progression and other processes that affect mutagenesis and toxicity. Paradigms in risk analysis that require extrapolation over wide ranges of exposure levels may be flawed mechanistically and may underestimate carcinogenic effects of test agents at environmental levels. Characteristics of the human cancer genotype suggest that approaches to risk analysis must be broadened to consider the multiplicity of carcinogenic pathways and the relative roles of hyperproliferation and hypermutation. Further, estimation of risk to general human populations must consider effects on hypersusceptible individuals. The extrapolation of effects over wide exposure levels is an imprecise process.
Collapse
Affiliation(s)
- J R Williams
- Johns Hopkins Oncology Center, Baltimore MD 21287-5001, USA
| | | | | | | |
Collapse
|
8
|
Sato M, Nishigori C, Yagi T, Takebe H. Aberrant splicing and truncated-protein expression due to a newly identified XPA gene mutation. Mutat Res 1996; 362:199-208. [PMID: 8596539 DOI: 10.1016/0921-8777(95)00052-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A group A xeroderma pigmentosum (XPA) patient, XP2NI, is a compound heterozygote with a newly identified G to C transversion at the last nucleotide in exon 5 in one chromosome, and with the known splicing mutation in intron 3 in another chromosome in the XPA gene. XP2NI had mild skin symptoms and the cells were slightly less sensitive to UV radiation than the cells of typical severe XPA patients who have the splicing mutation in intron 3 homozygously. Reverse transcriptase (RT)-PCR and sequencing of the PCR products revealed that the mutation in exon 5 resulted in producing three types of aberrant mRNA, lacking 7 nucleotides at the end of exon 5, lacking entire exon 5, and lacking exons 3, 4 and 5. A significant amount of a truncated type of protein was produced in XP2NI cells, and the size of the protein indicated that it should have been translated from the mRNA, lacking the 7 nucleotides and retained one of the zinc-finger domains required for the DNA repair activity. The clinical mildness of XP2NI may be due to the residual DNA repair activity of the truncated XPA protein, while no XPA protein was detected in the XPA cells with the homozygous intron 3 splicing mutation.
Collapse
Affiliation(s)
- M Sato
- Department of Radiation Genetics, Faculty of Medicine, Kyoto University, Japan
| | | | | | | |
Collapse
|
9
|
Kondoh M, Ueda M, Ichihashi M. Correlation of the clinical manifestations and gene mutations of Japanese xeroderma pigmentosum group A patients. Br J Dermatol 1995; 133:579-85. [PMID: 7577588 DOI: 10.1111/j.1365-2133.1995.tb02709.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The gene responsible for xeroderma pigmentosum (XP) group A has recently been cloned and designated XPA gene. Previous studies have shown that most Japanese XPA patients have homozygous mutations for the splicing site of intron 3 of the XPA gene, which was recognized by restriction endonuclease (RE) AlwNI (AlwNI mutation). Other mutations found to date have been the nonsense mutation at codon 228 in exon 6, recognized by RE HphI (HphI mutation), and at codon 116 in exon 3, recognized by RE MseI (MseI mutation). Using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis, we examined the point mutations of the XPA gene in 16 XPA patients, their parents, and their four asymptomatic siblings. We found that eight patients were homozygous for the AlwNI mutation, two were compound heterozygotes for the AlwNI mutation and the HphI mutation, one was a compound heterozygote for the AlwNI mutation and the MseI mutation, three were compound heterozygotes for the AlwNI mutation and an unidentified mutation, and two were compound heterozygotes for the HphI mutation and an unidentified mutation. Investigation of their clinical features suggested that the four patients who were heterozygous for the HphI mutation and the AlwNI or an unidentified mutation had milder clinical manifestations such as later development of skin cancers and milder neurological deterioration, than those patients who were either homozygous for the AlwNI mutation or heterozygous for the AlwNI mutation and MseI mutation.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- M Kondoh
- Department of Dermatology, Kobe University School of Medicine, Japan
| | | | | |
Collapse
|
10
|
Matsumoto N, Saito N, Harada N, Tanaka K, Niikawa N. DNA-based prenatal carrier detection for group A xeroderma pigmentosum in a chorionic villus sample. Prenat Diagn 1995; 15:675-7. [PMID: 8532631 DOI: 10.1002/pd.1970150716] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
DNA-based prenatal carrier detection of group A xeroderma pigmentosum (XP-A) is reported. Chorionic villus sampling was done at the tenth gestational week in a pregnant woman whose first child suffers from XP-A. Genomic DNAs from the villi, proband, and parents were PCR (polymerase chain reaction)-amplified using three sets of primers, because the PCR and a subsequent enzyme digestion with HphI, AlwNI, or MseI may detect the three most frequent mutations of the XP-A complementing gene (XPAC) in Japanese XP-A patients. The results showed that the proband is a homozygote and that the parents and fetus are heterozygotes for a base substitution at the 3' acceptor site of intron 3 of XPAC, indicating that the fetus is a healthy carrier of XP-A. This is the first case of prenatal carrier detection of the disorder.
Collapse
Affiliation(s)
- N Matsumoto
- Department of Human Genetics, Nagasaki University School of Medicine, Japan
| | | | | | | | | |
Collapse
|
11
|
|
12
|
Kondoh M, Ueda M, Nakagawa K, Ichihashi M. Siblings with xeroderma pigmentosum complementation group A with different skin cancer development: importance of sun protection at an early age. J Am Acad Dermatol 1994; 31:993-6. [PMID: 7962783 DOI: 10.1016/s0190-9622(94)70270-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
BACKGROUND For patients with xeroderma pigmentosum (XP), strict protection from UV light exposure is the only way to prevent and retard skin cancer formation. OBJECTIVE Our purpose was to learn how the timing of sun protection influences the clinical findings in patients with XP. METHODS We studied two siblings with XP group A (XPA) who showed a significant difference in the age at onset of skin cancer development and in neurologic abnormalities. RESULTS The elder sister had had her first basal cell carcinoma (BCC) at 13 years of age and had had multiple BCCs by 25 years of age. Her younger sister had her first BCC at 23 years of age. Neurologic impairment of the younger sister was much milder. The elder sister started strict sun protection at 4 years of age, whereas the younger began at 2 years of age. Analysis of the XPA complementing gene revealed that both patients had the identical mutation. CONCLUSION In patients with XP the earlier sun protection begins the later skin cancer develops. Neurologic deterioration may also be reduced by earlier sun protection.
Collapse
Affiliation(s)
- M Kondoh
- Department of Dermatology, Kobe University School of Medicine, Japan
| | | | | | | |
Collapse
|
13
|
Cleaver JE, Volpe JP, Charles WC, Thomas GH. Prenatal diagnosis of xeroderma pigmentosum and Cockayne syndrome. Prenat Diagn 1994; 14:921-8. [PMID: 7534923 DOI: 10.1002/pd.1970141005] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In a study of fetal cells from a series of 12 pregnancies in ten families at risk for the ultraviolet light-sensitive, DNA repair-deficient diseases xeroderma pigmentosum (XP) and Cockayne syndrome (CS), we detected one XP and two CS homozygote fetuses. The diagnoses were confirmed by analysis of fetal skin fibroblasts or second amniotic samples after termination of the pregnancies. The measurement of ultraviolet light sensitivity and DNA repair depended on properties common to the seven excision repair-deficient XP complementation groups (A-G) and the two CS complementation groups (A, B). No XP variant families were included in the study, because the variant requires different testing techniques. Reliable and rapid diagnosis proved possible in all but one of the 12 pregnancies, supporting the use of these methods until the spectrum of mutations in the various XP and CS genes of the U.S. population is fully characterized and a DNA sequence-based diagnostic procedure becomes available.
Collapse
Affiliation(s)
- J E Cleaver
- Laboratory of Radiobiology and Environmental Health, University of California, San Francisco 94143-0750
| | | | | | | |
Collapse
|
14
|
Cleaver JE, McDowell M, Jones C, Wood R, Karentz D. Mutation and expression of the XPA gene in revertants and hybrids of a xeroderma pigmentosum cell line. SOMATIC CELL AND MOLECULAR GENETICS 1994; 20:327-37. [PMID: 7974007 DOI: 10.1007/bf02254721] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A series of ultraviolet (UV)-resistant cell lines have been generated from a UV-sensitive XP group A cell line homozygous for a stop codon (TGA) in the chromosome 9 XPA gene. Three lines generated by chemical mutagenesis acquired the ability to excise (6-4) photoproducts but not cyclobutane dimers from the whole genome; two lines generated by a fusion procedure with hamster cells acquired the ability to excise both (6-4) photoproducts and cyclobutane dimers from the whole genome. A central region of the hamster XPA gene was cloned and sequenced. With the use of species-specific primers in the polymerase chain reaction, we found that the hybrid cell lines do not contain a hamster XPA gene. Sequence analysis showed that all of the UV-resistant cell lines contain reversions of the human stop codon, resulting in missense mutations (glycine or leucine for arginine) or wild-type sequences. The concentration of XPA protein in revertant cell lines was about one-half that in normal cells, which would be expected from heterozygous cells; there was no evidence that the mutant proteins were less stable than the wild-type proteins. These results are consistent with the idea that the XPA protein initiates repair by binding to damaged sites with various affinities, depending on the photoproduct and the transcriptional state of the region. A concentration of XPA protein near 50% is needed before repair can proceed into nontranscribed regions of the genome. The revertant cell lines represent a class of missense mutations in the XPA gene that may have altered specificity and that can be used to understand some of the regulatory differences in repair of photoproducts in various regions of the genome.
Collapse
Affiliation(s)
- J E Cleaver
- Laboratory of Radiobiology and Environmental Health, University of California, San Francisco 94143-0750
| | | | | | | | | |
Collapse
|