31 results on '"Wark L"'
Search Results
2. Telomeric aggregates and end-to-end chromosomal fusions require myc box II
- Author
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Caporali, A, Wark, L, Vermolen, B J, Garini, Y, and Mai, S
- Published
- 2007
- Full Text
- View/download PDF
3. Brief Report: Homozygous BUB1B Mutation and Susceptibility to Gastrointestinal Neoplasia
- Author
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Frio, T, Lavoie, J, Hamel, N, Geyer, F, Kushner, Y, Novak, D, Wark, L, Capelli, C, Reis-Filho, J, Mai, S, Pastinen, T, Tischkowitz, MD, Marcus, V, and Foulkes, W
- Published
- 2010
4. Three Dimensional Telomeric Profiles in Circulating Tumor Cells of High-Risk Prostate Cancer Patients Undergoing Androgen Deprivation and Radiation Therapy
- Author
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Wark, L., primary, Quon, H.C., additional, Ong, A., additional, Ahmed, S., additional, Koul, R., additional, Chowdhury, A., additional, and Mai, S., additional
- Published
- 2015
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5. Three-dimensional analysis tool for segmenting and measuring the structure of telomeres in mammalian nuclei
- Author
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Vermolen, B.J. (author), Young, I.T. (author), Chuang, A. (author), Wark, L. (author), Chuang, T. (author), Mai, S. (author), Garini, Y. (author), Vermolen, B.J. (author), Young, I.T. (author), Chuang, A. (author), Wark, L. (author), Chuang, T. (author), Mai, S. (author), and Garini, Y. (author)
- Abstract
Quantitative analysis in combination with fluorescence microscopy calls for innovative digital image measurement tools. We have developed a three-dimensional tool for segmenting and analyzing FISH stained telomeres in interphase nuclei. After deconvolution of the images, we segment the individual telomeres and measure a distribution parameter we call ?T . This parameter describes if the telomeres are distributed in a sphere-like volume (?T ? 1) or in a disk-like volume (?T » 1). Because of the statistical nature of this parameter, we have to correct for the fact that we do not have an infinite number of telomeres to calculate this parameter. In this study we show a way to do this correction. After sorting mouse lymphocytes and calculating ?T and using the correction introduced in this paper we show a significant difference between nuclei in G2 and nuclei in either G0/G1 or S phase. The mean values of ?T for G0/G1, S and G2 are 1.03, 1.02 and 13 respectively., Quantitative Imaging Group, Applied Sciences
- Published
- 2005
6. Pregnancy-specific reference ranges for haematological variables in a Scottish population
- Author
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Shields, R. C., primary, Caric, V., additional, Hair, M., additional, Jones, O., additional, Wark, L., additional, McColl, M. D., additional, and Ramsay, J. E., additional
- Published
- 2011
- Full Text
- View/download PDF
7. Outcomes following an initial unsuccessful colonoscopy: a 5-year complete audit of teaching hospital colonoscopy practice
- Author
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Sidhu, S., primary, Geraghty, J., additional, Karpha, I., additional, Wark, L., additional, Logan, C., additional, and Sarkar, S., additional
- Published
- 2011
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8. Defining a normal reference range for haematological variables during pregnancy in a Scottish population
- Author
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Shields, R., primary, Caric, V., additional, Jones, O., additional, Wark, L., additional, McColl, M., additional, Ramsay, J., additional, and Hair, M., additional
- Published
- 2010
- Full Text
- View/download PDF
9. Telomeric aggregates and end-to-end chromosomal fusions require myc box II
- Author
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Caporali, A, primary, Wark, L, additional, Vermolen, B J, additional, Garini, Y, additional, and Mai, S, additional
- Published
- 2006
- Full Text
- View/download PDF
10. Characterizing the three-dimensional organization of telomeres
- Author
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Vermolen, B. J., primary, Garini, Y., additional, Mai, S., additional, Mougey, V., additional, Fest, T., additional, Chuang, T. C.-Y., additional, Chuang, A. Y.-C., additional, Wark, L., additional, and Young, I. T., additional
- Published
- 2005
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11. Intervention interchange. Helping young children regulate their behavior: two fun interventions.
- Author
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Wark L and Nelson T
- Published
- 2009
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12. Internal family systems therapy for children in family therapy.
- Author
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Wark, Linda, Thomas, Melanie, Peterson, Shari, Wark, L, Thomas, M, and Peterson, S
- Subjects
SYSTEMIC family therapy ,FAMILY psychotherapy ,PSYCHOTHERAPY ,SCHOOL children ,FAMILIES ,FAMILIES & psychology ,CHILD psychology ,CHILD behavior ,PSYCHOLOGY of parents - Abstract
This article presents a developmentally supported implementation of Internal Family Systems Therapy for school-age children and their families. Relevant developmental characteristics of children are described. Suggestions for working with parents, child-oriented interventions, and a case example are presented. [ABSTRACT FROM AUTHOR]
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- 2001
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13. Premature aging is associated with higher levels of 8-oxoguanine and increased DNA damage in the Polg mutator mouse.
- Author
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Yu T, Slone J, Liu W, Barnes R, Opresko PL, Wark L, Mai S, Horvath S, and Huang T
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- Aging genetics, Animals, DNA Damage genetics, DNA Polymerase gamma genetics, DNA, Mitochondrial genetics, DNA-Directed DNA Polymerase genetics, Guanine analogs & derivatives, Mice, Mutation genetics, Aging, Premature genetics
- Abstract
Mitochondrial dysfunction plays an important role in the aging process. However, the mechanism by which this dysfunction causes aging is not fully understood. The accumulation of mutations in the mitochondrial genome (or "mtDNA") has been proposed as a contributor. One compelling piece of evidence in support of this hypothesis comes from the Polg
D257A/D257A mutator mouse (Polgmut/mut ). These mice express an error-prone mitochondrial DNA polymerase that results in the accumulation of mtDNA mutations, accelerated aging, and premature death. In this paper, we have used the Polgmut/mut model to investigate whether the age-related biological effects observed in these mice are triggered by oxidative damage to the DNA that compromises the integrity of the genome. Our results show that mutator mouse has significantly higher levels of 8-oxoguanine (8-oxoGua) that are correlated with increased nuclear DNA (nDNA) strand breakage and oxidative nDNA damage, shorter average telomere length, and reduced mtDNA integrity. Based on these results, we propose a model whereby the increased level of reactive oxygen species (ROS) associated with the accumulation of mtDNA mutations in Polgmut/mut mice results in higher levels of 8-oxoGua, which in turn lead to compromised DNA integrity and accelerated aging via increased DNA fragmentation and telomere shortening. These results suggest that mitochondrial play a central role in aging and may guide future research to develop potential therapeutics for mitigating aging process., (© 2022 The Authors. Aging Cell published by Anatomical Society and John Wiley & Sons Ltd.)- Published
- 2022
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14. Long-Term Dynamics of Three Dimensional Telomere Profiles in Circulating Tumor Cells in High-Risk Prostate Cancer Patients Undergoing Androgen-Deprivation and Radiation Therapy.
- Author
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Wark L, Quon H, Ong A, Drachenberg D, Rangel-Pozzo A, and Mai S
- Abstract
Patient-specific assessment, disease monitoring, and the development of an accurate early surrogate of the therapeutic efficacy of locally advanced prostate cancer still remain a clinical challenge. Contrary to prostate biopsies, circulating tumor cell (CTC) collection from blood is a less-invasive method and has potential as a real-time liquid biopsy and as a surrogate marker for treatment efficacy. In this study, we used size-based filtration to isolate CTCs from the blood of 100 prostate cancer patients with high-risk localized disease. CTCs from five time points: +0, +2, +6, +12 and +24 months were analyzed. Consenting treatment-naïve patients with cT3, Gleason 8-10, or prostate-specific antigen > 20 ng/mL and non-metastatic prostate cancer were included. For all time points, we performed 3D telomere-specific quantitative fluorescence in situ hybridization on a minimum of thirty isolated CTCs. The patients were divided into five groups based on the changes of number of telomeres vs telomere lengths over time and into three clusters based on all telomere parameters found on diagnosis. Group 2 was classified as non-respondent to treatment and the Cluster 3 presented more aggressive phenotype. Additionally, we compared our telomere results with the PSA levels for each patient at 6 months of ADT, at 6 months of completed RT, and at 36 months post-initial therapy. CTCs of patients with PSA levels above or equal to 0.1 ng/mL presented significant increases of nuclear volume, number of telomeres, and telomere aggregates. The 3D telomere analysis of CTCs identified disease heterogeneity among a clinically homogeneous group of patients, which suggests differences in therapeutic responses. Our finding suggests a new opportunity for better treatment monitoring of patients with localized high-risk prostate cancer.
- Published
- 2019
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15. Distinct 3D Structural Patterns of Lamin A/C Expression in Hodgkin and Reed-Sternberg Cells.
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Contu F, Rangel-Pozzo A, Trokajlo P, Wark L, Klewes L, Johnson NA, Petrogiannis-Haliotis T, Gartner JG, Garini Y, Vanni R, Knecht H, and Mai S
- Abstract
Classical Hodgkin's lymphoma (cHL) is a B-Cell lymphoma comprised of mononuclear Hodgkin cells (H) and bi- to multi-nucleated Reed-Sternberg (RS) cells. Previous studies revealed that H and RS cells express lamin A/C, a component of the lamina of the nuclear matrix. Since no information was available about the three-dimensional (3D) expression patterns of lamin A/C in H and RS cells, we analyzed the 3D spatial organization of lamin in such cells, using 3D fluorescent microscopy. H and RS cells from cHL derived cell lines stained positive for lamin A/C, in contrast to peripheral blood lymphocytes (PBLs), in which the lamin A/C protein was not detected or weak, although its presence could be transiently increased with lymphocyte activation by lipopolysaccharide (LPS). Most importantly, in H and RS cells, the regular homogeneous and spherically shaped lamin A/C pattern, identified in activated lymphocytes, was absent. Instead, in H and RS cells, lamin staining showed internal lamin A/C structures, subdividing the nuclei into two or more smaller compartments. Analysis of pre-treatment cHL patients' samples replicated the lamin patterns identified in cHL cell lines. We conclude that the investigation of lamin A/C protein could be a useful tool for understanding nuclear remodeling in cHL.
- Published
- 2018
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16. Dynamics of three-dimensional telomere profiles of circulating tumor cells in patients with high-risk prostate cancer who are undergoing androgen deprivation and radiation therapies.
- Author
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Wark L, Klonisch T, Awe J, LeClerc C, Dyck B, Quon H, and Mai S
- Subjects
- Aged, Androgen Antagonists therapeutic use, Cell Count methods, Cell Nucleus metabolism, Chemoradiotherapy methods, Female, Genomic Instability radiation effects, Healthy Volunteers, Humans, Imaging, Three-Dimensional methods, Immunohistochemistry, In Situ Hybridization, Fluorescence methods, Kallikreins blood, Male, Microscopy, Fluorescence, Middle Aged, Neoplastic Cells, Circulating metabolism, Neoplastic Cells, Circulating radiation effects, Prostate pathology, Prostate-Specific Antigen blood, Prostatic Neoplasms blood, Prostatic Neoplasms genetics, Prostatic Neoplasms pathology, Receptors, Androgen metabolism, Telomere metabolism, Telomere radiation effects, Telomere ultrastructure, Treatment Outcome, Antineoplastic Agents, Hormonal therapeutic use, Genomic Instability drug effects, Neoplastic Cells, Circulating drug effects, Prostatic Neoplasms therapy, Telomere drug effects
- Abstract
Introduction: Accurate assessment and monitoring of the therapeutic efficacy of locally advanced prostate cancer remains a major clinical challenge. Contrary to prostate biopsies, circulating tumor cells (CTCs) are a cellular source repeatedly obtainable by blood sampling and could serve as a surrogate marker for treatment efficacy. In this study, we used size-based filtration to isolate and enumerate CTCs from the blood of 20 patients with high-risk (any one of cT3, Gleason 8-10, or prostate-specific antigen>20ng/ml), nonmetastatic, and treatment-naive prostate cancer before and after androgen deprivation therapy (ADT) and radiation therapy (RT)., Materials and Methods: We performed 3D telomere-specific quantitative fluorescence in situ hybridization on isolated CTCs to determine 3D telomere profiles for each patient before and throughout the course of both ADT and RT., Results: Based on the distinct 3D telomere signatures of CTC before treatment, patients were divided into 3 groups. ADT and RT resulted in distinct changes in 3D telomere signatures of CTCs, which were unique for each of the 3 patient groups., Conclusion: The ability of 3D telomere analysis of CTCs to identify disease heterogeneity among a clinically homogeneous group of patients, which reveals differences in therapeutic responses, provides a new opportunity for better treatment monitoring and management of patients with high-risk prostate cancer., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2017
- Full Text
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17. High Mobility Group A2 protects cancer cells against telomere dysfunction.
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Natarajan S, Begum F, Gim J, Wark L, Henderson D, Davie JR, Hombach-Klonisch S, and Klonisch T
- Subjects
- Cell Line, Tumor, Humans, Protein Stability, Signal Transduction physiology, Telomere metabolism, HMGA2 Protein metabolism, Neoplasms metabolism, Neoplasms pathology, Telomere pathology, Telomeric Repeat Binding Protein 2 metabolism
- Abstract
The non-histone chromatin binding protein High Mobility Group AT-hook protein 2 (HMGA2) plays important roles in the repair and protection of genomic DNA in embryonic stem cells and cancer cells. Here we show that HMGA2 localizes to mammalian telomeres and enhances telomere stability in cancer cells. We present a novel interaction of HMGA2 with the key shelterin protein TRF2. We found that the linker (L1) region of HMGA2 contributes to this interaction but the ATI-L1-ATII molecular region of HMGA2 is required for strong interaction with TRF2. This interaction was independent of HMGA2 DNA-binding and did not require the TRF2 interacting partner RAP1 but involved the homodimerization and hinge regions of TRF2. HMGA2 retained TRF2 at telomeres and reduced telomere-dysfunction despite induced telomere stress. Silencing of HMGA2 resulted in (i) reduced binding of TRF2 to telomere DNA as observed by ChIP, (ii) increased telomere instability and (iii) the formation of telomere dysfunction-induced foci (TIF). This resulted in increased telomere aggregation, anaphase bridges and micronuclei. HMGA2 prevented ATM-dependent pTRF2T188 phosphorylation and attenuated signaling via the telomere specific ATM-CHK2-CDC25C DNA damage signaling axis. In summary, our data demonstrate a unique and novel role of HMGA2 in telomere protection and promoting telomere stability in cancer cells. This identifies HMGA2 as a new therapeutic target for the destabilization of telomeres in HMGA2+ cancer cells.
- Published
- 2016
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18. Wolfberries potentiate mitophagy and enhance mitochondrial biogenesis leading to prevention of hepatic steatosis in obese mice: the role of AMP-activated protein kinase α2 subunit.
- Author
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Lin D, He H, Ji H, Willis J, Willard L, Jiang Y, Medeiros DM, Wark L, Han J, Liu Y, and Lu B
- Subjects
- AMP-Activated Protein Kinases genetics, Animals, Autophagy-Related Protein-1 Homolog, Chaperonin 60 genetics, Chaperonin 60 metabolism, Diet, High-Fat, Dioxygenases genetics, Dioxygenases metabolism, Fatty Liver pathology, Fruit chemistry, Lipid Metabolism, Liver metabolism, Lutein blood, Mice, Mice, Inbred C57BL, Mice, Knockout, Mice, Obese, Mitochondria metabolism, Oxidative Stress, PPAR gamma genetics, PPAR gamma metabolism, Protein Serine-Threonine Kinases genetics, Protein Serine-Threonine Kinases metabolism, Reactive Oxygen Species metabolism, Real-Time Polymerase Chain Reaction, Xanthophylls blood, AMP-Activated Protein Kinases metabolism, Fatty Liver prevention & control, Lycium chemistry, Mitophagy physiology
- Abstract
Scope: The aim of this study is to investigate whether AMP-activated protein kinase α2 (AMPKα2) is essential for wolfberry's protective effects on mitochondrial dysfunction and subsequent hepatic steatosis in mice., Methods and Results: Six-week-old male AMPKα2 knockout mice and genetic background C57BL/6J (B6) mice were fed a control, high-fat diet (HD, 45% (kilocalorie) fat), and/or HD with 5% (kilocalarie) wolfberry diets for 18 wk. At termination, blood and liver tissues were sampled for analysis by ELISA, HPLC, microscopy, real-time PCR, and Western blot. HD lowered hepatic lutein and zeaxanthin contents, inhibited protein expression of β,β-carotene 9',10'-oxygenase 2 (BCO2) and heat shock protein 60 in mitochondria, increased reactive oxygen species level, and suppressed mitophagy and mitochondrial biogenesis as determined by accumulation of p62, inhibited phosphorylation of Unc-51-like kinase 1 on Ser555, and declined expression of peroxisome proliferator-activated receptor γ coactivator 1 α, resulting in hepatic steatosis in B6 and knockout mice. Dietary wolfberry elevated the xanthophyll concentrations and enhanced expression of BCO2 and heat shock protein 60, attenuated mitochondrial oxidative stress, activated AMPKα2, potentiated mitophagy and mitochondrial biogenesis, and enhanced lipid oxidation and secretion in the liver of B6 mice., Conclusion: Dietary wolfberry selectively activated AMPKα2, which resulted in enhanced mitochondrial biogenesis and potentiated mitophagy, leading to the prevention of hepatic steatosis in obese mice., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2014
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19. Three-dimensional telomere dynamics in follicular thyroid cancer.
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Wark L, Danescu A, Natarajan S, Zhu X, Cheng SY, Hombach-Klonisch S, Mai S, and Klonisch T
- Subjects
- Adenocarcinoma, Follicular pathology, Animals, Cell Proliferation, Female, In Situ Hybridization, Fluorescence, Male, Mice, Thyroid Gland cytology, Thyroid Gland pathology, Adenocarcinoma, Follicular genetics, Telomere chemistry, Thyroid Hormone Receptors beta genetics
- Abstract
Background: Over the last decade, annual incidence rates for thyroid cancer have been among the highest of all cancers in the Western world. However, the genomic mechanisms impacting thyroid carcinogenesis remain elusive., Methods: We employed an established mouse model of follicular thyroid cancer (FTC) with a homozygous proline to valine mutation (Thrb(PV/PV)) in the thyroid receptor β1 (TRβ1) and applied quantitative three-dimensional (3D) telomere analysis to determine 3D telomeric profiles in Thrb(PV)(/PV), Thrb(PV/)(+), and Thrb(+/+) mouse thyrocytes before and after histological presentation of FTC., Results: Using quantitative fluorescent in situ hybridization (Q-FISH) and TeloView™ image analysis, we found altered telomeric signatures specifically in mutant mouse thyrocytes. As early as 1 month of age, Thrb(PV/PV) mouse thyrocytes showed more telomeres than normal and heterozygous age-matched counterparts. Importantly, at the very early age of 1 month, 3D telomeric profiles of Thrb(PV/PV) thyrocyte nuclei reveal genetic heterogeneity with several nuclei populations exhibiting different telomere numbers, suggestive of various degrees of aneuploidy within the same animal. This was detected exclusively in Thrb(PV/PV) mice well before the presentation of histological signs of thyroid carcinoma., Conclusions: We identified quantitative 3D telomere analysis as a novel tool for early detection and monitoring of thyrocyte chromosomal (in)stability. This technique has the potential to identify human patients at risk for developing thyroid carcinoma.
- Published
- 2014
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20. Dietary wolfberry upregulates carotenoid metabolic genes and enhances mitochondrial biogenesis in the retina of db/db diabetic mice.
- Author
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Yu H, Wark L, Ji H, Willard L, Jaing Y, Han J, He H, Ortiz E, Zhang Y, Medeiros DM, and Lin D
- Subjects
- AMP-Activated Protein Kinases genetics, AMP-Activated Protein Kinases metabolism, Animals, DNA-Binding Proteins genetics, DNA-Binding Proteins metabolism, Diabetes Mellitus, Experimental, Dioxygenases genetics, Dioxygenases metabolism, Glutathione S-Transferase pi genetics, Glutathione S-Transferase pi metabolism, Liver drug effects, Liver metabolism, Lutein metabolism, Male, Mice, Mitochondria metabolism, Mitochondrial Proteins genetics, Mitochondrial Proteins metabolism, PPAR gamma genetics, PPAR gamma metabolism, Retina metabolism, Scavenger Receptors, Class B genetics, Scavenger Receptors, Class B metabolism, Transcription Factors genetics, Transcription Factors metabolism, Xanthophylls metabolism, Zeaxanthins, Carotenoids metabolism, Lycium chemistry, Mitochondria genetics, Retina drug effects, Up-Regulation
- Abstract
Scope: Our aim was to investigate whether dietary wolfberry altered carotenoid metabolic gene expression and enhanced mitochondrial biogenesis in the retina of diabetic mice., Methods and Results: Six-week-old male db/db and wild-type mice were fed the control or wolfberry diets for 8 weeks. At study termination, liver and retinal tissues were collected for analysis by transmission electron microscopy, real-time PCR, immunoprecipitation, Western blot, and HPLC. Wolfberry elevated zeaxanthin and lutein levels in the liver and retinal tissues and stimulated expression of retinal scavenger receptor class B type I, glutathione S-transferase Pi 1, and β,β-carotene 9',10'-oxygenase 2, and induced activation and nuclear enrichment of retinal AMP-activated protein kinase α2 (AMPK-α2). Furthermore, wolfberry attenuated hypoxia and mitochondrial stress as demonstrated by declined expression of hypoxia-inducible factor-1-α, vascular endothelial growth factor, and heat shock protein 60. Wolfberry enhanced retinal mitochondrial biogenesis in diabetic retinas as demonstrated by reversed mitochondrial dispersion in the retinal pigment epithelium, increased mitochondrial copy number, elevated citrate synthase activity, and upregulated expression of peroxisome proliferator-activated receptor γ co-activator 1α, nuclear respiratory factor 1, and mitochondrial transcription factor A., Conclusion: Consumption of dietary wolfberry could be beneficial to retinoprotection through reversal of mitochondrial function in diabetic mice., (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2013
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21. Heterozygous mutations in the PALB2 hereditary breast cancer predisposition gene impact on the three-dimensional nuclear organization of patient-derived cell lines.
- Author
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Wark L, Novak D, Sabbaghian N, Amrein L, Jangamreddy JR, Cheang M, Pouchet C, Aloyz R, Foulkes WD, Mai S, and Tischkowitz M
- Subjects
- Adolescent, Adult, Antineoplastic Agents pharmacology, Breast Neoplasms pathology, Carcinoma, Ductal, Breast pathology, Carcinoma, Intraductal, Noninfiltrating pathology, Case-Control Studies, Cell Survival drug effects, Centromere metabolism, Cisplatin pharmacology, Fanconi Anemia Complementation Group N Protein, Female, Genetic Association Studies, Genetic Predisposition to Disease, Hereditary Breast and Ovarian Cancer Syndrome pathology, Heterozygote, Humans, Karyotype, Male, Middle Aged, Mitomycin pharmacology, Telomere metabolism, Tumor Cells, Cultured, Breast Neoplasms genetics, Carcinoma, Ductal, Breast genetics, Carcinoma, Intraductal, Noninfiltrating genetics, Cell Nucleus metabolism, Hereditary Breast and Ovarian Cancer Syndrome genetics, Nuclear Proteins genetics, Tumor Suppressor Proteins genetics
- Abstract
PALB2/FANCN is a BRCA1- and BRCA2-interacting Fanconi Anemia (FA) protein crucial for key BRCA2 genome caretaker functions. Heterozygous germline mutations in PALB2 predispose to breast cancer and biallelic mutations cause FA. FA proteins play a critical role in the telomere maintenance pathway, with telomeric shortening observed in FA cells. Less is known about telomere maintenance in the heterozygous state. Here, we investigate the roles of PALB2 heterozygous mutations in genomic instability, an important carcinogenesis precursor. Patient-derived lymphoblastoid (LCL) and fibroblast (FCL) cell lines with monoallelic truncating PALB2 mutations were investigated using a combination of molecular imaging techniques including centromeric FISH, telomeric Q-FISH and spectral karyotyping (SKY). Mitomycin C and Cisplatin sensitivity was assayed via cellular metabolism of WST-1. The PALB2 c.229delT FCL showed increases in telomere counts associated with increased mean intensity compared with two wild-type FCLs generated from first-degree relatives (P =1.04E-10 and P =9.68E-15) and it showed evidence of chromosomal rearrangements. Significant differences in centromere distribution were observed in one of three PALB2 heterozygous FCLs analyzed when compared with PALB2 wild-type, BRCA1 and BRCA2 heterozygous FCLs. No significant consistently increased sensitivity to Mitomycin C or Cisplatin was observed in LCLs. Our results are suggestive of an altered centromere distribution profile and a telomere instability phenotype. Together, these may indicate critical nuclear organization defects associated with the predisposition to transformation and early stage development of PALB2-related cancers., (Copyright © 2013 Wiley Periodicals, Inc.)
- Published
- 2013
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22. Wolfberry Water Soluble Phytochemicals Down-Regulate ER Stress Biomarkers and Modulate Multiple Signaling Pathways Leading To Inhibition of Proliferation and Induction of Apoptosis in Jurkat Cells.
- Author
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Jiang Y, Zhang Y, Wark L, Ortiz E, Lim S, He H, Wang W, Medeiros D, and Lin D
- Abstract
Phytochemicals have received much recent attention in cancer prevention through simultaneous targeting multiple pathways in the disease progression. Here we determined that wolfberry phytochemicals was chemopreventive on the leukemic Jurkat cell. The water soluble wolfberry fractions (i.e., wolfberry phytochemicals) were enriched in carbohydrates (73.4 ± 4.5 % (w/w)), polyphenolics (1555 ± 112 mg quercetin equivalent/100 g freeze dry powder, including 213 mg rutin/100 g freeze dry powder), and had enhanced antioxidant activity (7771 ± 207 μM Trolox equivalent/100 g freeze dry powder). Wolfberry phytochemicals, but not purified wolfberry polysaccharide fractions, inhibited Jurkat cell proliferation, induced cycle arrest at the G2/M phase in a dose dependent manner starting at 1 mg/ml for 48 h. Wolfberry phytochemicals eliminated cellular reactive oxygen species, declined expression of endoplasmic reticulum (ER) stress biomarkers, including glucose regulated protein 78, inositol-requiring protein 1(IRE1), activating transcription factor 6 (ATF6), protein kinase RNA-like ER kinase (PERK), and c/EBP-homologous protein, and induced activation of AMP activated protein kinase, stabilization of β-catenin, and inhibition of NFκB, and AKT activity. Simultaneous siRNA knockdown of ATF6, IRE1 and PERK caused inhibition of cell proliferation and induction of apoptosis. Data suggested that ER stress and multiple survival/apoptosis signaling pathways were modulated by wolfberry phytochemicals during the apoptotic progression. Consumption of wolfberry could be an efficacious dietary strategy for preventing leukemia.
- Published
- 2011
23. Dietary wolfberry ameliorates retinal structure abnormalities in db/db mice at the early stage of diabetes.
- Author
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Tang L, Zhang Y, Jiang Y, Willard L, Ortiz E, Wark L, Medeiros D, and Lin D
- Subjects
- AMP-Activated Protein Kinases metabolism, Animals, Blood Glucose analysis, Burkitt Lymphoma, Diabetes Mellitus, Experimental complications, Diabetes Mellitus, Experimental drug therapy, Diabetes Mellitus, Experimental prevention & control, Diabetic Retinopathy pathology, Diet, Endoplasmic Reticulum drug effects, Gene Knockdown Techniques, Humans, Insulin blood, Male, Mice, Mice, Inbred C57BL, Reactive Oxygen Species analysis, Retina chemistry, Retina pathology, Diabetic Retinopathy prevention & control, Lycium, Phytotherapy, Retina drug effects
- Abstract
Hyperglycemia-linked oxidative stress and/or consequent endoplasmic reticulum (ER) stress are the causative factors of pathogenesis of diabetic retinopathy. Dietary bioactive components which mitigate oxidative stress may serve as potential chemopreventive agents to prevent or slow down the disease progression. Wolfberry is a traditional Asian fruit consumed for years to prevent aging eye diseases in Asian countries. Here we report that dietary wolfberry ameliorated mouse retinal abnormality at the early stage of type 2 diabetes in db/db mice. Male mice at six weeks of age were fed the control diet with or without 1% (kcal) wolfberry for eight weeks. Dietary wolfberry restored the thickness of the whole retina, in particular the inner nuclear layer and photoreceptor layer, and the integrity of the retinal pigment epithelia (RPE), and the ganglion cell number in db/db mice. Western blotting of whole retinal cell lysates revealed that addition of wolfberry lowered expression of ER stress biomarkers binding immunoglobulin protein (BiP), protein kinase RNA-like ER kinase (PERK), activating transcription factor 6 (ATF6) and caspase-12, and restored AMP-activated protein kinase (AMPK), thioredoxin, Mn superoxide dismutase (Mn SOD) and forkhead O transcription factor 3 α (FOXO3α) activities. To determine if our observations were due to the high contents of zeaxanthin and lutein in wolfberry, additional studies using these carotenoids were conducted. Using the human adult diploid RPE cell line ARPE-19, we demonstrated that both zeaxanthin and lutein could mimic the wolfberry preventive effect on activation of AMPK, thioredoxin, Mn SOD, FOXO3α activities, normalize cellular reactive oxygen species and attenuate ER stress in ARPE-19 cells exposed to a high glucose challenge. The zeaxanthin preventive effect was abolished by small interfering RNA knockdown of AMPKα. These results suggested that AMPK activation appeared to play a key role in upregulated expression of thioredoxin and Mn SOD, and mitigation of cellular oxidative stress and/or ER stress by wolfberry and zeaxanthin and/or lutein. Taken together, dietary wolfberry on retinal protection in diabetic mice is, at least partially, due to zeaxanthin and/or lutein.
- Published
- 2011
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24. Nuclear remodeling as a mechanism for genomic instability in cancer.
- Author
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Gadji M, Vallente R, Klewes L, Righolt C, Wark L, Kongruttanachok N, Knecht H, and Mai S
- Subjects
- Animals, Humans, Mice, Cell Nucleus genetics, Genomic Instability, Neoplasms genetics, Neoplasms pathology
- Abstract
This chapter focuses on the three-dimensional organization of the nucleus in normal, early genomically unstable, and tumor cells. A cause-consequence relationship is discussed between nuclear alterations and the resulting genomic rearrangements. Examples are presented from studies on conditional Myc deregulation, experimental tumorigenesis in mouse plasmacytoma, nuclear remodeling in Hodgkin's lymphoma, and in adult glioblastoma. A model of nuclear remodeling is proposed for cancer progression in multiple myeloma. Current models of nuclear remodeling are described, including our model of altered nuclear architecture and the onset of genomic instability., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
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25. Homozygous BUB1B mutation and susceptibility to gastrointestinal neoplasia.
- Author
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Rio Frio T, Lavoie J, Hamel N, Geyer FC, Kushner YB, Novak DJ, Wark L, Capelli C, Reis-Filho JS, Mai S, Pastinen T, Tischkowitz MD, Marcus VA, and Foulkes WD
- Subjects
- Adenocarcinoma genetics, Adenoma genetics, Adenomatous Polyposis Coli Protein genetics, Adenomatous Polyposis Coli Protein metabolism, Aged, Chromosome Disorders genetics, DNA Mutational Analysis, Female, Genomic Instability, Homozygote, Humans, Karyotyping, Male, Mosaicism, Oligonucleotide Array Sequence Analysis, Pedigree, Phenotype, Protein Serine-Threonine Kinases metabolism, Spindle Apparatus, Gastrointestinal Neoplasms genetics, Genetic Predisposition to Disease, Germ-Line Mutation, Protein Serine-Threonine Kinases genetics
- Abstract
A patient received a diagnosis of adenocarcinoma of the ampulla of Vater at 34 years of age. Two decades later, adenomatous polyps were found, followed by multiple primary invasive adenocarcinomas of both the colon and the stomach. Premature chromatid separation and mosaic variegated aneuploidy, combined with structural chromosomal abnormalities, were detected in his cells. We identified a germline homozygous intronic mutation, c.2386-11A→G, in the spindle-assembly checkpoint gene BUB1B, which creates a de novo splice site that is favored over the authentic (i.e., preferentially used) site. Our findings expand the phenotype associated with BUB1B mutations and the mosaic variegated aneuploidy syndrome to include common adult-onset cancers and provide evidence for the interdependency of the APC protein (encoded by the adenomatous polyposis coli gene) and the BUBR1 protein (encoded by BUB1B) in humans. (Funded by the Turner Family Cancer Research Fund and others.).
- Published
- 2010
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26. Nuclear imaging in three dimensions: a unique tool in cancer research.
- Author
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Klonisch T, Wark L, Hombach-Klonisch S, and Mai S
- Subjects
- Cell Nucleus genetics, Humans, In Situ Hybridization, Fluorescence, Microscopy, Fluorescence, Neoplasms genetics, Research, Cell Nucleus ultrastructure, Imaging, Three-Dimensional methods, Neoplasms ultrastructure, Telomere ultrastructure
- Abstract
Tumorigenesis includes alterations in the three-dimensional (3D) nuclear organization of the genome. The combination of sensitive quantitative fluorescent in situ hybridization (Q-FISH) and three-dimensional (3D) microscopy have evolved as powerful tools in studying the dynamic 3D organization of telomeres and chromosomes in the interphase nucleus of individual normal and tumor cells. Tumor-specific alterations in 3D telomere architecture, particularly the appearance of telomeric aggregates, are early events in tumorigenesis and have diagnostic and prognostic value. Novel tools in the 3D nuclear imaging arsenal now include high-throughput scanning capabilities and new 3D nano-resolution microscopy of tissues and cells. In this review, we summarize our current understanding of the biology of telomeres in the context of tumorigenesis and elucidate the important integrating function of advanced 3D imaging technologies in translating new discoveries in basic cancer research into new diagnostic tools for clinical oncologists to improve patient care., (Copyright © 2010 Elsevier GmbH. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
27. Nucleosomal response, immediate-early gene expression and cell transformation.
- Author
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Davie JR, Drobic B, Perez-Cadahia B, He S, Espino PS, Sun JM, Chen HY, Dunn KL, Wark L, Mai S, Khan DH, Davie SN, Lu S, Peltier CP, and Delcuve GP
- Subjects
- Animals, Gene Expression Regulation, Histones genetics, Histones metabolism, Humans, Mitogen-Activated Protein Kinases genetics, Mitogen-Activated Protein Kinases metabolism, Nucleosomes genetics, Ribosomal Protein S6 Kinases, 90-kDa genetics, Ribosomal Protein S6 Kinases, 90-kDa metabolism, ras Proteins genetics, ras Proteins metabolism, Cell Transformation, Neoplastic, Genes, Immediate-Early genetics, Nucleosomes metabolism, Signal Transduction physiology
- Published
- 2010
- Full Text
- View/download PDF
28. Increased genomic instability and altered chromosomal protein phosphorylation timing in HRAS-transformed mouse fibroblasts.
- Author
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Dunn KL, He S, Wark L, Delcuve GP, Sun JM, Yu Chen H, Mai S, and Davie JR
- Subjects
- Animals, Carcinogenicity Tests, Cell Line, Transformed, Chromatin Immunoprecipitation, Chromosome Aberrations, Data Interpretation, Statistical, Fibroblasts, Histones metabolism, Mice, Mitogen-Activated Protein Kinases genetics, Phorbol Esters pharmacology, Phosphorylation, Signal Transduction, Spectral Karyotyping, ras Proteins genetics, Gene Expression drug effects, Genomic Instability, HMGN1 Protein metabolism, Mitogen-Activated Protein Kinases metabolism, ras Proteins metabolism
- Abstract
The RAS-mitogen-activated protein kinase signaling pathway is often deregulated in cancer cells. In metastatic HRAS-transformed mouse fibroblasts (Ciras-3), the RAS-MAPK pathway is constitutively activated. We show here that Ciras-3 cells exhibit a higher incidence of chromosomal instability than 10T1/2 cells, including higher levels of clonal and nonclonal chromosomal aberrations. Stimulation of serum starved 10T1/2 and Ciras-3 cells with phorbol esters (TPA) results in the phosphorylation of histone H3 at serine 10 and serine 28. Regardless of the increased genomic instability in Ciras-3 cells, TPA-induced H3 phosphorylated at serine 10 and H3 phosphorylated at serine 28 partitioned into distinct nuclear subdomains as they did in the parental cells. However, the timing of the response of the H3 phosphorylation event to TPA induction was delayed in Ciras-3 cells. Further Ciras-3 cells, which have a more open chromatin structure, had increased steady state levels of phosphorylated H3 and HMGN1 relative to parental 10T1/2 cells. TPA-induced H3 phosphorylated at serine 10 and 28 were colocalized with the transcriptionally initiated form of RNA polymerase II in 10T1/2 and Ciras-3 cells. Chromatin immunoprecipitation assays demonstrated that TPA-induced H3 phosphorylation at serine 28 was associated with the immediate early JUN promoter, providing direct evidence that this histone post-translational modification is associated with transcriptionally active genes. Together our results demonstrate the increased genomic instability and alterations in the epigenetic program in HRAS-transformed cells., (Copyright 2009 Wiley-Liss,Inc.)
- Published
- 2009
- Full Text
- View/download PDF
29. Tip60 is a haplo-insufficient tumour suppressor required for an oncogene-induced DNA damage response.
- Author
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Gorrini C, Squatrito M, Luise C, Syed N, Perna D, Wark L, Martinato F, Sardella D, Verrecchia A, Bennett S, Confalonieri S, Cesaroni M, Marchesi F, Gasco M, Scanziani E, Capra M, Mai S, Nuciforo P, Crook T, Lough J, and Amati B
- Subjects
- Alleles, Animals, B-Lymphocytes metabolism, Carcinoma genetics, Carcinoma pathology, Cells, Cultured, Genes, Tumor Suppressor, Genes, myc genetics, Heterozygote, Histone Acetyltransferases genetics, Homeostasis, Humans, Lymphoma genetics, Lymphoma pathology, Lysine Acetyltransferase 5, Mice, Mice, Transgenic, Oncogene Protein p55(v-myc) genetics, Trans-Activators, Transcription, Genetic genetics, Tumor Suppressor Protein p53 genetics, Tumor Suppressor Protein p53 metabolism, Tumor Suppressor Proteins genetics, DNA Damage, Histone Acetyltransferases metabolism, Oncogene Protein p55(v-myc) metabolism, Oncogenes genetics, Tumor Suppressor Proteins metabolism
- Abstract
The acetyl-transferase Tip60 might influence tumorigenesis in multiple ways. First, Tip60 is a co-regulator of transcription factors that either promote or suppress tumorigenesis, such as Myc and p53. Second, Tip60 modulates DNA-damage response (DDR) signalling, and a DDR triggered by oncogenes can counteract tumour progression. Using E(mu)-myc transgenic mice that are heterozygous for a Tip60 gene (Htatip) knockout allele (hereafter denoted as Tip60+/- mice), we show that Tip60 counteracts Myc-induced lymphomagenesis in a haplo-insufficient manner and in a time window that is restricted to a pre- or early-tumoral stage. Tip60 heterozygosity severely impaired the Myc-induced DDR but caused no general DDR defect in B cells. Myc- and p53-dependent transcription were not affected, and neither were Myc-induced proliferation, activation of the ARF-p53 tumour suppressor pathway or the resulting apoptotic response. We found that the human TIP60 gene (HTATIP) is a frequent target for mono-allelic loss in human lymphomas and head-and-neck and mammary carcinomas, with concomitant reduction in mRNA levels. Immunohistochemical analysis also demonstrated loss of nuclear TIP60 staining in mammary carcinomas. These events correlated with disease grade and frequently concurred with mutation of p53. Thus, in both mouse and human, Tip60 has a haplo-insufficient tumour suppressor activity that is independent from-but not contradictory with-its role within the ARF-p53 pathway. We suggest that this is because critical levels of Tip60 are required for mounting an oncogene-induced DDR in incipient tumour cells, the failure of which might synergize with p53 mutation towards tumour progression.
- Published
- 2007
- Full Text
- View/download PDF
30. Eyewitness performance in cognitive and structured interviews.
- Author
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Memon A, Wark L, Holley A, Bull R, and Koehnken G
- Subjects
- Adolescent, Adult, Education, Continuing, Female, Forensic Psychiatry education, Humans, Male, Cognition, Forensic Psychiatry methods, Interviews as Topic methods, Mental Recall
- Abstract
This paper addresses two methodological and theoretical questions relating to the Cognitive Interview (CI), which previous research has found to increase witness recall in interviews. (1) What are the effects of the CI mnemonic techniques when communication techniques are held constant? (2) How do trained interviewers compare with untrained interviewers? In this study, witnesses (college students) viewed a short film clip of a shooting and were questioned by interviewers (research assistants) trained in conducting the CI or a Structured Interview (SI)--similar to the CI except for the "cognitive" components--or by untrained interviewers (UI). The CI and SI groups recalled significantly more correct information compared to the UI group. However they also reported more errors and confabulated details. Theoretical and practical implications of the results are discussed in terms of precisely identifying the CI facilitatory effects and consequent good practice in the forensic setting.
- Published
- 1997
- Full Text
- View/download PDF
31. Growth and development of the Lumi child in the Sepik district of New Guinea.
- Author
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Wark L and Malcolm LA
- Subjects
- Adolescent, Age Factors, Birth Weight, Black People, Body Height, Body Weight, Child, Child, Preschool, Deficiency Diseases, Dietary Proteins, Ethnicity, Female, Humans, Infant, Infant, Newborn, Male, Menstruation, New Guinea, Puberty, Sex Characteristics, Time Factors, Growth
- Published
- 1969
- Full Text
- View/download PDF
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