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1.
Nucleic Acids Res ; 51(19): 10484-10505, 2023 10 27.
Article in English | MEDLINE | ID: mdl-37697435

ABSTRACT

Breast cancer linked with BRCA1/2 mutations commonly recur and resist current therapies, including PARP inhibitors. Given the lack of effective targeted therapies for BRCA1-mutant cancers, we sought to identify novel targets to selectively kill these cancers. Here, we report that loss of RNF8 significantly protects Brca1-mutant mice against mammary tumorigenesis. RNF8 deficiency in human BRCA1-mutant breast cancer cells was found to promote R-loop accumulation and replication fork instability, leading to increased DNA damage, senescence, and synthetic lethality. Mechanistically, RNF8 interacts with XRN2, which is crucial for transcription termination and R-loop resolution. We report that RNF8 ubiquitylates XRN2 to facilitate its recruitment to R-loop-prone genomic loci and that RNF8 deficiency in BRCA1-mutant breast cancer cells decreases XRN2 occupancy at R-loop-prone sites, thereby promoting R-loop accumulation, transcription-replication collisions, excessive genomic instability, and cancer cell death. Collectively, our work identifies a synthetic lethal interaction between RNF8 and BRCA1, which is mediated by a pathological accumulation of R-loops.


Subject(s)
BRCA1 Protein , Breast Neoplasms , Animals , Female , Humans , Mice , BRCA1 Protein/metabolism , BRCA2 Protein/genetics , Breast Neoplasms/genetics , DNA Damage , DNA-Binding Proteins/metabolism , Exoribonucleases/metabolism , Genomic Instability , Neoplasm Recurrence, Local , R-Loop Structures , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism , Ubiquitination
2.
Can Oncol Nurs J ; 34(2): 179-186, 2024.
Article in English | MEDLINE | ID: mdl-38706646

ABSTRACT

Background: Approximately 82% of children with childhood cancer survive more than five years after diagnosis. Living as a cancer survivor elicits a new reality that can include psychosocial impacts. These psychosocial impacts interact collectively, especially regarding reassimilation, and are rarely explored. Objective: To explore the psychosocial impacts of surviving childhood cancer and reassimilation back into society in young adult survivors of childhood cancer. Methodology: Individual in-depth semi-structured interviews were conducted with childhood cancer survivors and explored psychosocial aspects associated with returning to work, school, and social environments after remission. Interpretive phenomenological analysis was conducted once interviews were manually transcribed. A group interview with survivors was held to discuss the study's findings and interpretation. Results: Individual interviews and the group interview revealed three major themes: outlook on reassimilating, outlook on coping, and outlook on cancer. Conclusions: This work is a first step to understanding how survivors' personal outlook on coping and healthcare system barriers play influential roles in reassimilation following cancer treatment. Survivors expressed the need for reliable survivorship information and improved communication with healthcare providers regarding what to expect, so they could feel prepared for life post-cancer. These aspects need to be explored more deeply through other qualitative studies.

3.
J Gen Intern Med ; 34(10): 2062-2067, 2019 10.
Article in English | MEDLINE | ID: mdl-31388904

ABSTRACT

BACKGROUND: Venous thromboembolism includes deep vein thrombosis (DVT) and pulmonary embolism. Compression ultrasonography is the most common way to evaluate DVT and is typically performed by sonographers and interpreted by radiologists. Yet there is evidence that ultrasound examinations can be safely and accurately performed by clinicians at the bedside. OBJECTIVE: To measure the operating characteristics of hospital medicine providers performing point-of-care ultrasound (POCUS) for evaluation of DVT. DESIGN: This is a prospective cohort study enrolling a convenience sample of patients. Hospital medicine providers performed POCUS for DVT and the results were compared with the corresponding formal vascular study (FVS) interpreted by radiologists. PARTICIPANTS: Hospitalized non-ICU patients at four tertiary care hospitals for whom a DVT ultrasound was ordered. MAIN MEASURES: The primary outcomes were the sensitivity, specificity, and predictive values of the POCUS compression ultrasound compared with a FVS. The secondary outcome was the elapsed time between order and the POCUS study compared with the time the FVS was ordered to when the formal radiology report was finalized. KEY RESULTS: One hundred twenty-five limbs from 73 patients were scanned. The prevalence of DVT was 6.4% (8/125). The sensitivity of POCUS for DVT was 100% (95% CI 74-100%) and specificity was 95.8% (95% CI 91-98%) with a positive predictive value of 61.5% (95% CI 35-84%) and a negative predictive value of 100% (95% CI 98-100%). The median time from order to POCUS completion was 5.8 h versus 11.5 h median time from order until the radiology report was finalized (p = 0.001). CONCLUSION: Hospital medicine providers can perform compression-only POCUS for DVT on inpatients with accuracy similar to other specialties and settings, with results available sooner than radiology. The observed prevalence of DVT was lower than expected. POCUS may be reliable in excluding DVT but further study is required to determine how to incorporate a positive POCUS DVT result into clinical practice.


Subject(s)
Hospitalists/standards , Point-of-Care Testing/organization & administration , Ultrasonography/methods , Venous Thrombosis/diagnostic imaging , Adult , Aged , Aged, 80 and over , Case-Control Studies , Female , Humans , Male , Middle Aged , Prospective Studies , Sensitivity and Specificity , Time Factors
5.
Am J Transplant ; 18(10): 2534-2543, 2018 10.
Article in English | MEDLINE | ID: mdl-29498216

ABSTRACT

Incidence of postdonation hypertension, risk factors associated with its development, and impact of type of treatment received on renal outcomes were determined in 3700 kidney donors. Using Cox proportional hazard model, adjusted hazard ratios (HRs) for cardiovascular disease (CVD); estimated glomerular filtration rate (eGFR) <60, <45, <30 mL/min/1.73m2 ; end stage renal disease (ESRD); and death in hypertensive donors were determined. After a mean (standard deviation [SD]) of 16.6 (11.9) years of follow-up, 1126 (26.8%) donors developed hypertension and 894 with known antihypertensive medications. Hypertension developed in 4%, 10%, and 51% at 5, 10, and 40 years, respectively, and was associated with proteinuria, eGFR < 30, 45, and 60 mL/min/1.73m2 , CVD, and death. Blood pressure was <140/90 mm Hg at last follow-up in 75% of hypertensive donors. Use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (compared to other antihypertensive agents) was associated with a lower risk for eGFR <45 mL/min/1.73m², HR 0.64 (95% confidence interval [CI] 0.45-0.9), P = .01, and also less ESRD; HR 0.03 (95% CI 0.001-0.20), P = .004. In this predominantly Caucasian cohort, hypertension is common after donation, well controlled in most donors, and factors associated with its development are similar to those in the general population.


Subject(s)
Hypertension/epidemiology , Kidney/physiopathology , Living Donors/supply & distribution , Nephrectomy/adverse effects , Postoperative Complications , Tissue and Organ Harvesting/adverse effects , Adult , Female , Follow-Up Studies , Humans , Hypertension/etiology , Incidence , Kidney Transplantation , Longitudinal Studies , Male , Prognosis , Risk Factors , United States/epidemiology
6.
Clin Transplant ; 32(9): e13360, 2018 09.
Article in English | MEDLINE | ID: mdl-30053320

ABSTRACT

In the general population, obesity is associated with an increased risk of developing hypertension (HTN), type 2 diabetes mellitus (DM), and end-stage renal disease (ESRD). Therefore, most transplant centers have a body mass index (BMI) threshold for accepting living kidney donors. But there have been no studies of postdonation weight gain trends and any associated risks. We tracked serial BMIs in 940 donors for a median (IQ range) follow-up of 22.3 (15.4-35.8) years. We studied the impact of postdonation weight gain in a model adjusted for family history of HTN or DM. Donor characteristics included age, sex, smoking, fasting blood glucose, eGFR, systolic and diastolic BP, and BMI at time of donation and time postdonation. Postdonation weight gain was associated with a significant increase in the relative risk of developing HTN RR 1.93 (95% CI 1.51-2.46) (P < 0.001) and/or DM RR 4.18 (95% CI 2.05-8.5) (P < 0.0001), but not (to date) cardiovascular disease (CVD), reduced eGFR or death. Like the general population, donors gained weight as they aged; a higher BMI was associated with higher incidence of DM and HTN. Postdonation care should include ongoing counseling on the risks of substantial weight gain.


Subject(s)
Diabetes Mellitus, Type 2/etiology , Hypertension/etiology , Living Donors/supply & distribution , Nephrectomy/adverse effects , Obesity/etiology , Tissue and Organ Harvesting/adverse effects , Weight Gain , Adult , Body Mass Index , Female , Follow-Up Studies , Humans , Kidney Transplantation , Male , Middle Aged , Prognosis , Risk Factors
7.
Arterioscler Thromb Vasc Biol ; 37(12): 2370-2378, 2017 12.
Article in English | MEDLINE | ID: mdl-29025708

ABSTRACT

OBJECTIVE: Excess deposition of fat within and around vital organs and nonadipose tissues is hypothesized to contribute to cardiovascular disease (CVD) risk. We evaluated the association of abdominal intermuscular adipose tissue (IMAT) volume with coronary artery calcification in the CARDIA study (Coronary Artery Risk Development in Young Adults) participants. APPROACH AND RESULTS: We measured IMAT in the abdominal muscles, visceral adipose tissue and pericardial adipose tissue, and coronary artery calcification using computed tomography in 3051 CARDIA participants (56% women) at the CARDIA year 25 examination (2010-2011). Mean IMAT volume and mean IMAT/total muscle volume (IMAT normalized for muscle size) were calculated in a 10-mm block of slices centered at L3-L4. Multivariable analyses included potential confounders and traditional cardiovascular disease risk factors. Compared with the lowest quartile, the upper quartile of abdominal IMAT volume was associated with higher coronary artery calcification prevalence (odds ratio [95% confidence interval], 1.6 [1.2-2.1]) after adjusting for cardiovascular disease risk factors. Results were similar for highest versus lowest quartile of IMAT normalized to total muscle volume (odds ratio [95% confidence interval], 1.5 [1.1-2.0]). Significant associations of higher IMAT and normalized IMAT with coronary artery calcification prevalence persisted when body mass index, visceral adipose tissue, or pericardial adipose tissue were added to the models. CONCLUSIONS: In a large, community-based, cross-sectional study, we found that higher abdominal skeletal muscle adipose tissue volume was associated with subclinical atherosclerosis independent of traditional cardiovascular disease risk factors and other adipose depots.


Subject(s)
Abdominal Muscles/physiopathology , Adiposity , Coronary Artery Disease/epidemiology , Intra-Abdominal Fat/physiopathology , Vascular Calcification/epidemiology , Abdominal Muscles/diagnostic imaging , Adolescent , Adult , Age Factors , Asymptomatic Diseases , Computed Tomography Angiography , Coronary Angiography/methods , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/physiopathology , Cross-Sectional Studies , Female , Humans , Intra-Abdominal Fat/diagnostic imaging , Logistic Models , Male , Middle Aged , Multidetector Computed Tomography , Multivariate Analysis , Odds Ratio , Pericardium/diagnostic imaging , Pericardium/physiopathology , Prevalence , Risk Factors , United States/epidemiology , Vascular Calcification/diagnostic imaging , Vascular Calcification/physiopathology , Young Adult
8.
Clin Chem ; 63(7): 1237-1247, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28515098

ABSTRACT

BACKGROUND: Sustained remodeling of extracellular matrix can compromise organs and tissues. Procollagen type III N-terminal propeptide (PIIINP) and collagen type I carboxy-terminal telopeptide (ICTP) reflect collagen synthesis and degradation. We studied their predictive value for future death and disease. METHODS: A total of 3068 men and women in the Multi-Ethnic Study of Atherosclerosis who were free of cardiovascular disease (CVD) and in generally good health had a baseline blood sample taken for ICTP and PIIINP. Median follow-up was 13.0 years. Among 4 primary outcomes, CVD events (n = 697) were adjudicated, death (n = 571) was by death certificate, and chronic inflammatory-related severe hospitalization and death (ChrIRD, n = 726) and total cancer (n = 327) were classified using International Classification of Diseases codes. We used Poisson regression to study baseline ICTP and PIIINP relative to these outcomes. RESULTS: Mean (SD) PIIINP was 5.47 (1.95) µg/L and ICTP was 3.37 (1.70) µg/L. PIIINP and ICTP were highly correlated with each other and with estimated glomerular filtration rate (eGFR). Adjustment for age and eGFR attenuated relative risks, remaining 20%-30% per SD of both PIIINP and ICTP in prediction for total death and ChrIRD, and of PIIINP for cancer, with little additional attenuation by adjusting for risk factors and inflammatory biomarkers. CVD outcome was generally unrelated to PIIINP but became marginally inversely related to ICTP in the most adjusted model. CONCLUSIONS: The collagen biomarkers PIIINP and ICTP, in part through pathophysiologically parallel associations with renal function, predicted ChrIRD and total death. Moreover, PIIINP predicted future cancer. These collagen markers may help differentiate healthy from unhealthy aging.


Subject(s)
Atherosclerosis/diagnosis , Atherosclerosis/ethnology , Biomarkers/blood , Cardiovascular Diseases/diagnosis , Collagen/blood , Predictive Value of Tests , Atherosclerosis/blood , Cardiovascular Diseases/blood , Collagen/metabolism , Collagen Type I/blood , Ethnicity/statistics & numerical data , Female , Humans , Male , Middle Aged , Neoplasms/blood , Neoplasms/diagnosis , Peptide Fragments/blood , Peptides/blood , Procollagen/blood
9.
Clin Chem ; 62(7): 1020-31, 2016 Jul.
Article in English | MEDLINE | ID: mdl-27173011

ABSTRACT

BACKGROUND: GlycA is a biomarker that reflects integrated concentrations and glycosylation states of several acute-phase proteins. We studied the association of GlycA and inflammatory biomarkers with future death and disease. METHODS: A total of 6523 men and women in the Multi-Ethnic Study of Atherosclerosis who were free of overt cardiovascular disease (CVD) and in generally good health had a baseline blood sample taken. We assayed high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6), and d-dimer. A spectral deconvolution algorithm was used to quantify GlycA signal amplitudes from automated nuclear magnetic resonance (NMR) LipoProfile® test spectra. Median follow-up was 12.1 years. Among 4 primary outcomes, CVD events were adjudicated, death was by death certificate, and chronic inflammatory-related severe hospitalization and death (ChrIRD) and total cancer were classified using International Classification of Diseases (ICD) codes. We used Poisson regression to study baseline GlycA, hsCRP, IL-6, and d-dimer in relation to total death, CVD, ChrIRD, and total cancer. RESULTS: Relative risk per SD of GlycA, IL-6, and d-dimer for total death (n = 915); for total CVD (n = 922); and for ChrIRD (n = 1324) ranged from 1.05 to 1.20, independently of covariates. In contrast, prediction from hsCRP was statistically explained by adjustment for other inflammatory variables. Only GlycA was predictive for total cancer (n = 663). Women had 7% higher values of all inflammatory biomarkers than men and had a significantly lower GlycA prediction coefficient than men in predicting total cancer. CONCLUSIONS: The composite biomarker GlycA derived from NMR is associated with risk for total death, CVD, ChrIRD, and total cancer after adjustment for hsCRP, IL-6, and d-dimer. IL-6 and d-dimer contribute information independently of GlycA.


Subject(s)
Acute-Phase Proteins/analysis , Atherosclerosis/blood , Death Certificates , Inflammation/blood , Neoplasms/blood , Aged , Aged, 80 and over , Algorithms , Biomarkers/blood , Female , Humans , Male , Middle Aged , Predictive Value of Tests
10.
Cardiovasc Diabetol ; 15: 51, 2016 Mar 24.
Article in English | MEDLINE | ID: mdl-27013319

ABSTRACT

BACKGROUND: Oxidative stress, inflammation and endothelial dysfunction are interrelated factors in the etiology of cardiovascular disease, but their linkage to type 2 diabetes is less clear. We examined the association of these biomarkers with incident type 2 diabetes (T2D). METHODS: Analysis of 2339 participants in the community-based coronary artery risk development in young adults (CARDIA) study. Participants (age 40.1 ± 3.6 years, 44 % Black, 58 % women) were free of diabetes, and were followed 10 years. Cox regression was used to estimate hazard ratios (HRs) for incident T2D adjusting for the other biomarkers under study, demographic and lifestyle measures, dietary biomarkers, BMI (kg/m(2)) and metabolic syndrome components. RESULTS: F2-isoprostanes and oxidized LDL (oxidative stress) were positively associated with incident T2D, but the associations were attenuated by adjustment for BMI. C-reactive protein was positively associated with T2D even with full adjustment: HR (95 % CI) = 2.21 (1.26-3.88) for quartile 4 (Q4) v. quartile 1 (Q1). The HR (95 % CI) for T2D for biomarkers of endothelial dysfunction ICAM-1 and E-selectin for Q4 v. Q1 were 1.64 (0.96-2.81) and 1.68 (1.04-2.71) respectively, with full adjustment. Including these two markers in a common risk score incorporating BMI and clinical measures improved the prediction probability of T2D: relative risk for the average person classified up compared to the average person classified down: 1.09, (1.06-1.13), P < 0.0001. CONCLUSIONS: Biomarkers of inflammation and endothelial dysfunction were positively associated with incident T2D. ICAM-1 and E-selectin add to the prediction of T2D beyond a common risk score.


Subject(s)
Diabetes Mellitus, Type 2/epidemiology , Diabetes Mellitus, Type 2/metabolism , Endothelium/physiopathology , Oxidative Stress/physiology , Adult , Biomarkers/metabolism , Black People , C-Reactive Protein/metabolism , Diabetes Mellitus, Type 2/complications , Female , Follow-Up Studies , Humans , Incidence , Inflammation/complications , Inflammation/metabolism , Male , Middle Aged , Oxidative Stress/drug effects , Risk Factors
11.
PLoS Genet ; 9(1): e1003259, 2013.
Article in English | MEDLINE | ID: mdl-23382699

ABSTRACT

Rnf8 is an E3 ubiquitin ligase that plays a key role in the DNA damage response as well as in the maintenance of telomeres and chromatin remodeling. Rnf8(-/-) mice exhibit developmental defects and increased susceptibility to tumorigenesis. We observed that levels of p53, a central regulator of the cellular response to DNA damage, increased in Rnf8(-/-) mice in a tissue- and cell type-specific manner. To investigate the role of the p53-pathway inactivation on the phenotype observed in Rnf8(-/-) mice, we have generated Rnf8(-/-)p53(-/-) mice. Double-knockout mice showed similar growth retardation defects and impaired class switch recombination compared to Rnf8(-/-) mice. In contrast, loss of p53 fully rescued the increased apoptosis and reduced number of thymocytes and splenocytes in Rnf8(-/-) mice. Similarly, the senescence phenotype of Rnf8(-/-) mouse embryonic fibroblasts was rescued in p53 null background. Rnf8(-/-)p53(-/-) cells displayed defective cell cycle checkpoints and DNA double-strand break repair. In addition, Rnf8(-/-)p53(-/-) mice had increased levels of genomic instability and a remarkably elevated tumor incidence compared to either Rnf8(-/-) or p53(-/-) mice. Altogether, the data in this study highlight the importance of p53-pathway activation upon loss of Rnf8, suggesting that Rnf8 and p53 functionally interact to protect against genomic instability and tumorigenesis.


Subject(s)
Cell Transformation, Neoplastic/genetics , Neoplasms , Tumor Suppressor Protein p53 , Ubiquitin-Protein Ligases , Animals , Cell Transformation, Neoplastic/metabolism , Chromatin Assembly and Disassembly/genetics , DNA Breaks, Double-Stranded , DNA Damage , DNA Repair/genetics , Fibroblasts/cytology , Genomic Instability , Humans , Mice , Mice, Knockout , Neoplasms/genetics , Neoplasms/metabolism , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Ubiquitin-Protein Ligases/genetics , Ubiquitin-Protein Ligases/metabolism
12.
Am Heart J ; 170(6): 1170-83, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26678639

ABSTRACT

BACKGROUND: N-terminal-pro-B-type natriuretic peptide (NT-proBNP) and cardiac troponin T (TnT) predict cardiovascular disease (CVD) risk in a variety of populations. Whether their predictive value varies by ethnicity is unknown. We sought to determine whether NT-proBNP and TnT improve prediction of incident coronary heart disease (CHD) and CVD, independent of CVD risk factors, in a multiethnic population; whether NT-proBNP improves prediction compared with the Framingham Risk Score or the Pooled Cohort Risk Equation; and whether a second NT-proBNP further improves prediction. METHODS: Both NT-proBNP and TnT were measured in 5,592 MESA white, black, Hispanic, and Chinese participants (60% nonwhite; mean age 62.3 ± 10.3 years) in 2000 to 2002 and 2004 to 2005. We evaluated adjusted risk of incident CHD and CVD based on baseline and change in biomarker concentration. RESULTS: Participants were followed up through 2011 and incurred 370 CVD events (232 CHD). Concentrations of NT-proBNP and TnT varied by ethnicity. Both NT-proBNP and TnT were associated with an increased risk of events (adjusted hazard ratio [HR] for CHD [95% CI] for fifth quintile vs other 4 quintiles of NT-proBNP, 2.03 [1.50-2.76]; HR for CHD for detectable vs undetectable TnT, 3.95 [2.29-6.81]). N-terminal-pro-B-type natriuretic peptide improved risk prediction and classification compared with the Framingham Risk Score and the Pooled Cohort Risk Equation. Change in NT-proBNP was independently associated with events (HR for CHD per unit increase in ΔlogNT-proBNP, 1.95 [1.16-3.26]). None of the observed associations varied by ethnicity. CONCLUSIONS: Both NT-proBNP and TnT are predictors of incident CHD, independent of established risk factors and ethnicity, in a multiethnic population without known CVD. Change in NT-proBNP may add additional prognostic information.


Subject(s)
Atherosclerosis , Cardiovascular Diseases , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Troponin T/blood , Aged , Aged, 80 and over , Atherosclerosis/blood , Atherosclerosis/diagnosis , Atherosclerosis/ethnology , Biomarkers/blood , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/prevention & control , Ethnicity , Female , Humans , Male , Middle Aged , Predictive Value of Tests , Risk Assessment/methods , Risk Factors , United States/epidemiology
13.
Blood ; 119(15): 3495-502, 2012 Apr 12.
Article in English | MEDLINE | ID: mdl-22343728

ABSTRACT

In addition to its proapoptotic function, caspase-8 is also important for several other processes, including suppressing necroptosis, cell migration, and immune cell survival. In the present study, we report that the loss of caspase-8 in B lymphocytes leads to B-cell malignancies and that the risk for these tumors is further enhanced in the absence of p53. We also report that deficiency of caspase-8 results in impaired cytokinesis and that casp8(-/-) lymphomas display remarkably elevated levels of chromosomal aberrations. Our data support an important role for caspase-8 in the maintenance of genomic integrity and highlight its tumor-suppressive function.


Subject(s)
Caspase 8/physiology , Chromosomal Instability/genetics , Lymphoma, B-Cell/genetics , 3T3 Cells , Animals , Autoimmune Lymphoproliferative Syndrome/complications , Autoimmune Lymphoproliferative Syndrome/genetics , Autoimmune Lymphoproliferative Syndrome/immunology , Autoimmune Lymphoproliferative Syndrome/pathology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , B-Lymphocytes/physiology , Caspase 8/genetics , Cells, Cultured , Down-Regulation/genetics , Down-Regulation/immunology , Genes, p53/physiology , Genetic Predisposition to Disease , Lymphoma, B-Cell/etiology , Lymphoma, B-Cell/mortality , Lymphoma, B-Cell/pathology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Survival Analysis
14.
PLoS Genet ; 7(4): e1001381, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21552324

ABSTRACT

Eukaryotic cells have evolved to use complex pathways for DNA damage signaling and repair to maintain genomic integrity. RNF168 is a novel E3 ligase that functions downstream of ATM,γ-H2A.X, MDC1, and RNF8. It has been shown to ubiquitylate histone H2A and to facilitate the recruitment of other DNA damage response proteins, including 53BP1, to sites of DNA break. In addition, RNF168 mutations have been causally linked to the human RIDDLE syndrome. In this study, we report that Rnf168(-/-) mice are immunodeficient and exhibit increased radiosensitivity. Rnf168(-/-) males suffer from impaired spermatogenesis in an age-dependent manner. Interestingly, in contrast to H2a.x(-/-), Mdc1(-/-), and Rnf8(-/-) cells, transient recruitment of 53bp1 to DNA double-strand breaks was abolished in Rnf168(-/-) cells. Remarkably, similar to 53bp1 inactivation, but different from H2a.x deficiency, inactivation of Rnf168 impairs long-range V(D)J recombination in thymocytes and results in long insertions at the class-switch junctions of B-cells. Loss of Rnf168 increases genomic instability and synergizes with p53 inactivation in promoting tumorigenesis. Our data reveal the important physiological functions of Rnf168 and support its role in both γ-H2a.x-Mdc1-Rnf8-dependent and -independent signaling pathways of DNA double-strand breaks. These results highlight a central role for RNF168 in the hierarchical network of DNA break signaling that maintains genomic integrity and suppresses cancer development in mammals.


Subject(s)
DNA Breaks, Double-Stranded , Genomic Instability , Spermatogenesis/genetics , Ubiquitin-Protein Ligases/genetics , Age Factors , Animals , Chromosomal Proteins, Non-Histone/metabolism , DNA Repair , DNA-Binding Proteins/metabolism , Disease Models, Animal , Female , Immunoglobulin Class Switching/genetics , Male , Mice , Mice, Knockout , Mice, Mutant Strains , Neoplasms/genetics , Radiation Tolerance , Recombination, Genetic , Signal Transduction , Syndrome , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , Tumor Suppressor p53-Binding Protein 1 , Ubiquitin-Protein Ligases/metabolism
15.
PLoS Genet ; 7(11): e1002360, 2011 Nov.
Article in English | MEDLINE | ID: mdl-22125490

ABSTRACT

Ubiquitylation is fundamental for the regulation of the stability and function of p53 and c-Myc. The E3 ligase Pirh2 has been reported to polyubiquitylate p53 and to mediate its proteasomal degradation. Here, using Pirh2 deficient mice, we report that Pirh2 is important for the in vivo regulation of p53 stability in response to DNA damage. We also demonstrate that c-Myc is a novel interacting protein for Pirh2 and that Pirh2 mediates its polyubiquitylation and proteolysis. Pirh2 mutant mice display elevated levels of c-Myc and are predisposed for plasma cell hyperplasia and tumorigenesis. Consistent with the role p53 plays in suppressing c-Myc-induced oncogenesis, its deficiency exacerbates tumorigenesis of Pirh2(-/-) mice. We also report that low expression of human PIRH2 in lung, ovarian, and breast cancers correlates with decreased patients' survival. Collectively, our data reveal the in vivo roles of Pirh2 in the regulation of p53 and c-Myc stability and support its role as a tumor suppressor.


Subject(s)
Neoplasms/metabolism , Proto-Oncogene Proteins c-myc/metabolism , Tumor Suppressor Protein p53/metabolism , Ubiquitin-Protein Ligases/metabolism , Animals , Cell Transformation, Neoplastic , Gene Expression Regulation, Neoplastic , Genes, Tumor Suppressor , HEK293 Cells , Humans , Kaplan-Meier Estimate , Mice , Mice, Inbred C57BL , Neoplasms/genetics , Proteolysis , Proto-Oncogene Proteins c-myc/genetics , Radiation Tolerance , Tumor Suppressor Protein p53/genetics , Ubiquitin-Protein Ligases/genetics , Ubiquitination/genetics
16.
Nat Genet ; 36(9): 969-77, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15322543

ABSTRACT

Tumor-necrosis factor (TNF), a pleiotropic cytokine, triggers physiological and pathological responses in several organs. Here we show that deletion of the mouse gene Timp3 resulted in an increase in TNF-alpha converting enzyme activity, constitutive release of TNF and activation of TNF signaling in the liver. The increase in TNF in Timp3(-/-) mice culminated in hepatic lymphocyte infiltration and necrosis, features that are also seen in chronic active hepatitis in humans. This pathology was prevented when deletion of Timp3 was combined with Tnfrsf1a deficiency. In a liver regeneration model that requires TNF signaling, Timp3(-/-) mice succumbed to liver failure. Hepatocytes from Timp3(-/-) mice completed the cell cycle but then underwent cell death owing to sustained activation of TNF. This hepatocyte cell death was completely rescued by a neutralizing antibody to TNF. Dysregulation of TNF occurred specifically in Timp3(-/-), and not Timp1(-/-) mice. These data indicate that TIMP3 is a crucial innate negative regulator of TNF in both tissue homeostasis and tissue response to injury.


Subject(s)
Hepatitis, Chronic/genetics , Liver Regeneration/genetics , Proteins/genetics , Tumor Necrosis Factor-alpha/genetics , ADAM Proteins , ADAM17 Protein , Aging , Animals , Apoptosis , Cell Cycle/genetics , Hepatectomy , Liver/enzymology , Liver/pathology , Metalloendopeptidases/metabolism , Mice , Mice, Mutant Strains , Signal Transduction , Tissue Inhibitor of Metalloproteinases , Tumor Necrosis Factor-alpha/immunology , Tissue Inhibitor of Metalloproteinase-4
17.
Article in English | MEDLINE | ID: mdl-37623133

ABSTRACT

BACKGROUND: Uncorrected refractive error has been suggested to affect children's development, educational performance, and socialization. Sociodemographic and environmental differences among individuals may impact their accessibility to utilizing appropriate services, impacting their vision-dependent activities. METHODS: Guided by the population health framework, this retrospective study assessed the prevalence of self-reported vision correction needs and its determinants for a sample of adolescents (n = 6363) from the United Arab Emirates (UAE) aged 13 to 20 years between 2007 to 2009. RESULTS: The findings suggest a relatively high prevalence of self-reported vision correction needs (26.8%), with among 24.8% males and 31.7% among females. Factors that were significantly associated with vision correction needs included age, biological sex, location of residence (emirate), nationality, parental education and employment level, household financial status, screen time use, visiting an eye specialist in the past year, and daily functional capacity. CONCLUSION: Reporting the vision correction needs of the adolescent population and identifying its determinants may help identify and resolve modifiable barriers to accessing the appropriate vision care resources. Further research in assessing the type of refractive error, potential genetic and environmental factors, and vision care services in each emirate may help decision-makers set appropriate policies to improve the overall quality of eye health.


Subject(s)
Academic Performance , Refractive Errors , Child , Female , Male , Adolescent , Humans , Cross-Sectional Studies , United Arab Emirates/epidemiology , Retrospective Studies , Refractive Errors/epidemiology , Refractive Errors/therapy
18.
Nature ; 440(7084): 692-6, 2006 Mar 30.
Article in English | MEDLINE | ID: mdl-16572175

ABSTRACT

Bone metastases are a frequent complication of many cancers that result in severe disease burden and pain. Since the late nineteenth century, it has been thought that the microenvironment of the local host tissue actively participates in the propensity of certain cancers to metastasize to specific organs, and that bone provides an especially fertile 'soil'. In the case of breast cancers, the local chemokine milieu is now emerging as an explanation for why these tumours preferentially metastasize to certain organs. However, as the inhibition of chemokine receptors in vivo only partially blocks metastatic behaviour, other factors must exist that regulate the preferential metastasis of breast cancer cells. Here we show that the cytokine RANKL (receptor activator of NF-kappaB ligand) triggers migration of human epithelial cancer cells and melanoma cells that express the receptor RANK. RANK is expressed on cancer cell lines and breast cancer cells in patients. In a mouse model of melanoma metastasis, in vivo neutralization of RANKL by osteoprotegerin results in complete protection from paralysis and a marked reduction in tumour burden in bones but not in other organs. Our data show that local differentiation factors such as RANKL have an important role in cell migration and the tissue-specific metastatic behaviour of cancer cells.


Subject(s)
Bone Neoplasms/metabolism , Bone Neoplasms/secondary , Carrier Proteins/metabolism , Cell Movement , Membrane Glycoproteins/metabolism , Neoplasm Metastasis/pathology , Animals , Bone Neoplasms/pathology , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Carrier Proteins/genetics , Cell Death , Cell Differentiation , Cell Line, Tumor , Cell Proliferation , Epithelial Cells/pathology , Female , Humans , Melanoma/metabolism , Melanoma/pathology , Membrane Glycoproteins/genetics , Mice , Organ Specificity , Paralysis , RANK Ligand , Receptor Activator of Nuclear Factor-kappa B , Signal Transduction
19.
Discov Educ ; 1(1): 3, 2022.
Article in English | MEDLINE | ID: mdl-35795020

ABSTRACT

The rapid adoption of online technologies to deliver postsecondary education amid the COVID-19 pandemic has highlighted the potential for online learning, as well as important equity gaps to be addressed. For over ten years, McMaster University has delivered graduate global health education through a blended-learning approach. In partnership with universities in the Netherlands, India, Thailand, Norway, Colombia, and Sudan, experts from across the Consortium deliver lectures online to students around the world. In 2020, two courses were piloted with small groups of students from Canada and Colombia using machine translation supported by bilingual tutors. Students met weekly via video conferencing software, speaking in English and Spanish and relying on machine translation software to transcribe and translate for group members. Qualitative semi-structured interviews were conducted with students, tutors, and instructors to explore how artificial intelligence can be harnessed to integrate multilingual group work into course offerings, challenging the dominant use of English as the principal language of instruction in global health education. Findings highlight the potential for machine translation to bridge language divides, while also underscoring several key limitations of currently available technology. Further research is needed to investigate the potential for machine translation in facilitating multilingual online education as a pathway to more equitable and inclusive online learning environments.

20.
Biochemistry ; 50(27): 6102-12, 2011 Jul 12.
Article in English | MEDLINE | ID: mdl-21661747

ABSTRACT

Nonenzymatic modification of proteins in hyperglycemia is a major mechanism causing diabetic complications. These modifications can have pathogenic consequences when they target active site residues, thus affecting protein function. In the present study, we examined the role of glucose autoxidation in functional protein damage using lysozyme and RGD-α3NC1 domain of collagen IV as model proteins in vitro. We demonstrated that glucose autoxidation induced inhibition of lysozyme activity as well as NC1 domain binding to α(V)ß(3) integrin receptor via modification of critical arginine residues by reactive carbonyl species (RCS) glyoxal (GO) and methylglyoxal while nonoxidative glucose adduction to the protein did not affect protein function. The role of RCS in protein damage was confirmed using pyridoxamine which blocked glucose autoxidation and RCS production, thus protecting protein function, even in the presence of high concentrations of glucose. Glucose autoxidation may cause protein damage in vivo since increased levels of GO-derived modifications of arginine residues were detected within the assembly interface of collagen IV NC1 domains isolated from renal ECM of diabetic rats. Since arginine residues are frequently present within protein active sites, glucose autoxidation may be a common mechanism contributing to ECM protein functional damage in hyperglycemia and oxidative environment. Our data also point out the pitfalls in functional studies, particularly in cell culture experiments, that involve glucose treatment but do not take into account toxic effects of RCS derived from glucose autoxidation.


Subject(s)
Arginine/metabolism , Glucose/physiology , Proteins/antagonists & inhibitors , Proteins/physiology , Amino Acid Motifs , Animals , Collagen Type IV/antagonists & inhibitors , Collagen Type IV/chemistry , Collagen Type IV/metabolism , Diabetes Mellitus, Experimental/enzymology , Diabetes Mellitus, Experimental/metabolism , Glyoxal/adverse effects , Hyperglycemia/enzymology , Hyperglycemia/metabolism , Male , Micrococcus/enzymology , Muramidase/antagonists & inhibitors , Muramidase/metabolism , Protein Carbonylation , Protein Structure, Tertiary , Proteins/metabolism , Pyruvaldehyde/adverse effects , Random Allocation , Rats , Rats, Sprague-Dawley
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