Cell fusion corrects the 4-nitroquinoline 1-oxide sensitivity of Werner syndrome fibroblast cell lines

Prince, Polly R.; Ogburn, Charles E.; Moser, Michael J.; Emond, Mary J.; Martin, George M.; Monnat, Raymond J.

doi:10.1007/s004399900078

Cited by 28 publications

(5 citation statements)

References 48 publications

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“…g-induced regulation of common stress response genes was almost similar in old and WS cells (Figure 3a), which is in agreement with the observation that WS cells do not display significant g-irradiation hypersensitivity (Prince et al, 1999). g-Irradiation can affect all cellular components and induces several types of damage: AP sites, base modifications, DNA-DNA and DNAprotein crosslinks and strand breaks, with the most deleterious effect being DNA double-strand breaks.…”

Section: Discussionsupporting

confidence: 87%

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Gene expression responses to DNA damage are altered in human aging and in Werner Syndrome

et al. 2005

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The accumulation of DNA damage and mutations is considered a major cause of cancer and aging. While it is known that DNA damage can affect changes in gene expression, transcriptional regulation after DNA damage is poorly understood. We characterized the expression of 6912 genes in human primary fibroblasts after exposure to three different kinds of cellular stress that introduces DNA damage: 4-nitroquinoline-1-oxide (4NQO), c-irradiation, or UV-irradiation. Each type of stress elicited damage specific gene expression changes of up to 10-fold. A total of 85 genes had similar changes in expression of 3-40-fold after all three kinds of stress. We examined transcription in cells from young and old individuals and from patients with Werner syndrome (WS), a segmental progeroid condition with a high incidence of cancer, and found various age-associated transcriptional changes depending upon the type of cellular stress. Compared to young individuals, both WS and old individuals had similarly aberrant transcriptional responses to c-and UV-irradiation, suggesting a role for Werner protein in stress-induced gene expression. Our results suggest that aberrant DNA damage-induced gene regulation may contribute to the aging process and the premature aging in WS.

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Section: Discussionsupporting

confidence: 87%

“…WS cells have a selective survival sensitivity to 4NQO which is intriguing, as they are not sensitive to UV or most other DNA-damaging agents (Ogburn et al, 1997;Prince et al, 1999). The mechanism underlying the 4NQO sensitivity of WS cell lines is not known.…”

Section: Discussionmentioning

confidence: 99%

Gene expression responses to DNA damage are altered in human aging and in Werner Syndrome

et al. 2005

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“…We used complementary colony‐size distribution (CSD; Smith et al ., 1978), colony‐forming efficiency (CFE) and proliferative survival (Poot et al ., 2002b) assays to analyze the survival and proliferation of primary and SV40‐transformed fibroblasts that had been mutation typed and shown to lack WRN protein (Prince et al ., 1999; Moser et al ., 2000; Huang et al ., 2006; additional results not shown). Primary WS fibroblasts showed a marked reduction in median colony cell number in CSD assays as well as a reduced CFE in the absence of exogenous DNA damage.…”

Section: Resultsmentioning

confidence: 99%

“…The presence of chromosomal translocations, deletions and re-arrangements in primary WS fibroblast and lymphocyte cultures led to the suggestion that WS was a chromosomal instability syndrome (Hoehn et al ., 1975;Salk et al ., 1985), and that the cellular phenotype of WS might be an expression of constitutive genomic instability. Subsequent analyses revealed that the chromosomal instability of WS cells could be accentuated by DNA damage (Gebhart et al ., 1988), and that WRN-deficient cells were selectively sensitive to killing by 4-nitroquinoline 1-oxide (4-NQO ;Gebhart et al ., 1985;Ogburn et al ., 1997;Prince et al ., 1999;Hisama et al ., 2000); by camptothecin, a DNA topoisomerase I inhibitor (Okada et al ., 1998;Poot et al ., 1999); and most notably and strongly by DNA cross linking drugs such as cis -platinum ( cis -Pt), mitomycin-C, or 8-methoxypsoralen + UV light (8-MOP+UV; Poot et al ., 2001Poot et al ., , 2002a.…”

Section: Introductionmentioning

confidence: 99%

Functional role of the Werner syndrome RecQ helicase in human fibroblasts

Dhillon

Sidorova²,

Saintigny

et al. 2006

Aging Cell

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SummaryWerner syndrome is an autosomal recessive human genetic instability and cancer predisposition syndrome that also has features of premature aging. We focused on two questions related to Werner syndrome protein (WRN) function in human fibroblasts: Do WRN-deficient fibroblasts have a consistent cellular phenotype? What role does WRN play in the recovery from replication arrest? We identified consistent cell proliferation and DNA damage sensitivity defects in both primary and SV40-transformed fibroblasts from different Werner syndrome patients, and showed that these defects could be revealed by acute depletion of WRN protein. Mechanistic analysis of the role of WRN in recovery from replication arrest indicated that WRN acts to repair damage resulting from replication arrest, rather than to prevent the disruption or breakage of stalled replication forks. These results identify readily quantified cell phenotypes that result from WRN loss in human fibroblasts; delineate the impact of cell transformation on the expression of these phenotypes; and define a mechanistic role for WRN in the recovery from replication arrest.

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“…WRN Multimerization Domain Disrupts WRN Function in Vivo-Cells lacking functional WRN protein have a markedly increased sensitivity to the DNA-damaging drugs camptothecin and 4-nitroquinoline 1-oxide (33)(34)(35)(36)(37). To determine the influence of WRN(250 -366) expression on WRN function, we carried out toxicity assays using cells expressing FLAG-WRN(250 -366).…”

Section: Identification Of Wrn Exonuclease Domain Boundaries Andmentioning

confidence: 99%

Identification of a Coiled Coil in Werner Syndrome Protein That Facilitates Multimerization and Promotes Exonuclease Processivity

Perry

Asaithamby

Barnebey

et al. 2010

Journal of Biological Chemistry

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Werner syndrome (WS) is a rare progeroid disorder characterized by genomic instability, increased cancer incidence, and early onset of a variety of aging pathologies. WS is unique among early aging syndromes in that affected individuals are developmentally normal, and phenotypic onset is in early adulthood. The protein defective in WS (WRN) is a member of the large RecQ family of helicases but is unique among this family in having an exonuclease. RecQ helicases form multimers, but the mechanism and consequence of multimerization remain incompletely defined. Here, we identify a novel heptad repeat coiled coil region between the WRN nuclease and helicase domains that facilitates multimerization of WRN. We mapped a novel and unique DNA-dependent protein kinase phosphorylation site proximal to the WRN multimerization region. However, phosphorylation at this site affected neither exonuclease activity nor multimeric state. We found that WRN nuclease is stimulated by DNA-dependent protein kinase independently of kinase activity or WRN nuclease multimeric status. In addition, WRN nuclease multimerization significantly increased nuclease processivity. We found that the novel WRN coiled coil domain is necessary for multimerization of the nuclease domain and sufficient to multimerize with full-length WRN in human cells. Importantly, correct homomultimerization is required for WRN function in vivo as overexpression of this multimerization domain caused increased sensitivity to camptothecin and 4-nitroquinoline 1-oxide similar to that in cells lacking functional WRN protein.

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Cell fusion corrects the 4-nitroquinoline 1-oxide sensitivity of Werner syndrome fibroblast cell lines

Cited by 28 publications

References 48 publications

Gene expression responses to DNA damage are altered in human aging and in Werner Syndrome

Gene expression responses to DNA damage are altered in human aging and in Werner Syndrome

Functional role of the Werner syndrome RecQ helicase in human fibroblasts

Identification of a Coiled Coil in Werner Syndrome Protein That Facilitates Multimerization and Promotes Exonuclease Processivity

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