G. Neta - Academia.edu (original) (raw)

Papers by G. Neta

Radiation Research, 2012

Childhood cancer five-year survival now exceeds 70-80%. Childhood exposure to radiation is a know... more Childhood cancer five-year survival now exceeds 70-80%. Childhood exposure to radiation is a known thyroid carcinogen; however, data are limited for the evaluation of radiation dose-response at high doses, modifiers of the dose-response relationship and joint effects of radiotherapy and chemotherapy. To address these issues, we pooled two cohort and two nested case-control studies of childhood cancer survivors including 16,757 patients, with 187 developing primary thyroid cancer. Relative risks (RR) with 95% confidence intervals (CI) for thyroid cancer by treatment with alkylating agents, anthracyclines or bleomycin were 3.25 (0.9-14.9), 4.5 (1.4-17.8) and 3.2 (0.8-10.4), respectively, in patients without radiotherapy, and declined with greater radiation dose (RR trends, P = 0.02, 0.12 and 0.01, respectively). Radiation dose-related RRs increased approximately linearly for <10 Gy, leveled off at 10-15-fold for 10-30 Gy and then declined, but remained elevated for doses >50 Gy. The fitted RR at 10 Gy was 13.7 (95% CI: 8.0-24.0). Doserelated excess RRs increased with decreasing age at exposure (P < 0.01), but did not vary with attained age or time-since-exposure, remaining elevated 25+ years after exposure. Gender and number of treatments did not modify radiation effects. Thyroid cancer risks remained elevated many decades following radiotherapy, highlighting the need for continued follow up of childhood cancer survivors.

Molecular medicine (Cambridge, Mass.), 2000

The epidermal growth factor receptor (EGFR) is expressed at different levels in many cell types a... more The epidermal growth factor receptor (EGFR) is expressed at different levels in many cell types and found overexpressed in many cancers. EGFR expression is increased or decreased in response to extracellular stimuli. We examined the effect of increased c-Jun expression on EGFR promoter activity. We used DNAse I foot-printing analysis to determine the binding of activator protein 1 (AP-1) to the promoter region. We also used cotransfection experiments and western blotting analysis to determine the effect of AP-1 family members on EGFR expression. AP-1 was able to bind to at least seven sites in the EGFR promoter region. Cotransfection of MCF-7 cells with a c-Jun expression vector and the EGFR promoter reporter resulted in a 7-fold increase in promoter activity. JunB, but not c-fos, also enhanced the EGFR promoter activity. An A-Fos-dominant negative shown to inhibit Jun-dependent transactivation was able to prevent c-Jun induction of the promoter activity, but only slightly decreased...

International Journal of Molecular Medicine, 2003

The epidermal growth factor receptor gene is highly regulated and responsive to extracellular sti... more The epidermal growth factor receptor gene is highly regulated and responsive to extracellular stimuli that control cell growth. We have identified five putative nuclear factor-kappaB (NF-kappaB) binding sites within the epidermal growth factor receptor (EGFR) promoter region by sequence analysis. We have analyzed the potential role of NF-kappaB family members in the regulation of the EGFR transcription. Electrophoretic mobility shift analysis demonstrated that the p50 and p49, subunit proteins of the NF-kappaB, bound to the EGFR promoter at four out of five of these sites. However, it was found that NF-kappaB could not transactivate the EGFR by cotransfection experiments with each NF-kappaB subunit, using p50, p65 and c-Rel and an EGFR promoter luciferase reporter. Treatment of cells with tumor necrosis factor (TNF)-alpha, which could degrade the I-kappaB and then result in translocation of NF-kappaB to nucleus, did not enhance EGFR promoter reporter gene transcription. Also, TNF-alpha did not induce EGFR expression at the protein level. These results indicate that even though purified NF-kappaB can bind to the putative sites, there is no evidence that NF-kappaB transactivates the EGFR promoter region.

Thyroid, 2012

Background: Hormonal differences are hypothesized to contribute to the approximately ‡ 2-fold hig... more Background: Hormonal differences are hypothesized to contribute to the approximately ‡ 2-fold higher thyroid cancer incidence rates among women compared with men worldwide. Although thyroid cancer cells express estrogen receptors and estrogen has a proliferative effect on papillary thyroid cancer (PTC) cells in vitro, epidemiologic studies have not found clear associations between thyroid cancer and female hormonal factors. We hypothesized that polymorphic variation in hormone pathway genes is associated with the risk of developing papillary thyroid cancer. Methods: We evaluated the association between PTC and 1151 tag single nucleotide polymorphisms (SNPs) in 58 candidate gene regions involved in sex hormone synthesis and metabolism, gonadotropins, and prolactin in a case-control study of 344 PTC cases and 452 controls, frequency matched on age and sex. Odds ratios and p-values for the linear trend for the association between each SNP genotype and PTC risk were estimated using unconditional logistic regression. SNPs in the same gene region or pathway were aggregated using adaptive rank-truncated product methods to obtain gene region-specific or pathway-specific p-values. To account for multiple comparisons, we applied the false discovery rate method. Results: Seven SNPs had p-values for linear trend < 0.01, including four in the CYP19A1 gene, but none of the SNPs remained significant after correction for multiple comparisons. Results were similar when restricting the dataset to women. p-values for examined gene regions and for all genes combined were ‡ 0.09. Conclusions: Based on these results, SNPs in selected hormone pathway genes do not appear to be strongly related to PTC risk. This observation is in accord with the lack of consistent associations between hormonal factors and PTC risk in epidemiologic studies.

Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 2014

Implementation science is a set of tools, principles, and methodologies that can be used to bring... more Implementation science is a set of tools, principles, and methodologies that can be used to bring scientific evidence into action, improve health care quality and delivery, and improve public health. As the burden of cancer increases in low- and middle-income countries, it is important to plan cancer control programs that are both evidence based and delivered in ways that are feasible, cost-effective, contextually appropriate, and sustainable. This review presents a framework for using implementation science for cancer control planning and implementation and discusses potential areas of focus for research and programs in low- and middle-income countries interested in integrating research into practice and policy.

American Journal of Public Health, 2015

A comprehensive guide that identifies critical evaluation and reporting elements necessary to mov... more A comprehensive guide that identifies critical evaluation and reporting elements necessary to move research into practice is needed. We propose a framework that highlights the domains required to enhance the value of dissemination and implementation research for end users. We emphasize the importance of transparent reporting on the planning phase of research in addition to delivery, evaluation, and long-term outcomes. We highlight key topics for which well-established reporting and assessment tools are underused (e.g., cost of intervention, implementation strategy, adoption) and where such tools are inadequate or lacking (e.g., context, sustainability, evolution) within the context of existing reporting guidelines. Consistent evaluation of and reporting on these issues with standardized approaches would enhance the value of research for practitioners and decision-makers. (Am J Public Health. Published online ahead of print November 13, 2014: e1-e9.

Ultrasound in Obstetrics & Gynecology, 2011

Objectives-Being small-for-gestational-age (SGA) is associated with an increased risk of morbidit... more Objectives-Being small-for-gestational-age (SGA) is associated with an increased risk of morbidity, but questions remain about how best to diagnose SGA, and thus, predict poor health consequences. The authors sought to compare an individualized reference for defining SGA with a simple ultrasound reference in predicting poor cognitive development at age five.

The Laryngoscope, 2012

Objectives/Hypothesis-Single nucleotide polymorphisms (SNPs) in the 8q24 chromosomal region ident... more Objectives/Hypothesis-Single nucleotide polymorphisms (SNPs) in the 8q24 chromosomal region identified from genome-wide scans have been associated with risk of several cancers including breast (rs1562430), prostate and colon (rs1447295 and rs6983267). A genome-wide scan in 26 families with papillary thyroid cancer (PTC) also found susceptibility loci in 8q24, supporting a closer evaluation of this chromosomal region in relation to risk of sporadic PTC.

PLoS ONE, 2013

Accumulating evidence suggests that alterations in immune function may be important in the etiolo... more Accumulating evidence suggests that alterations in immune function may be important in the etiology of papillary thyroid cancer (PTC). To identify genetic markers in immune-related pathways, we evaluated 3,985 tag single nucleotide polymorphisms (SNPs) in 230 candidate gene regions (adhesion-extravasation-migration, arachidonic acid metabolism/ eicosanoid signaling, complement and coagulation cascade, cytokine signaling, innate pathogen detection and antimicrobials, leukocyte signaling, TNF/NF-kB pathway or other) in a case-control study of 344 PTC cases and 452 controls. We used logistic regression models to estimate odds ratios (OR) and calculate one degree of freedom P values of linear trend (P SNP-trend ) for the association between genotype (common homozygous, heterozygous, variant homozygous) and risk of PTC. To correct for multiple comparisons, we applied the false discovery rate method (FDR). Gene region-and pathway-level associations (P Region and P Pathway ) were assessed by combining individual P SNP-trend values using the adaptive rank truncated product method. Two SNPs (rs6115, rs6112) in the SERPINA5 gene were significantly associated with risk of PTC (P SNP-FDR /P SNP-trend = 0.02/6610 26 and P SNP-FDR /P SNP-trend = 0.04/2610 25 , respectively). These associations were independent of a history of autoimmune thyroiditis (OR = 6.4; 95% confidence interval: 3.0-13.4). At the gene region level, SERPINA5 was suggestively associated with risk of PTC (P Region-FDR /P Region = 0.07/0.0003). Overall, the complement and coagulation cascade pathway was the most significant pathway (P Pathway = 0.02) associated with PTC risk largely due to the strong effect of SERPINA5. Our results require replication but suggest that the SERPINA5 gene, which codes for the protein C inhibitor involved in many biological processes including inflammation, may be a new susceptibility locus for PTC.

Occupational and Environmental Medicine, 2012

Chlorinated solvents are classified as probable or possible carcinogens. It is unknown whether ex... more Chlorinated solvents are classified as probable or possible carcinogens. It is unknown whether exposure to these agents increases the risk of malignant or benign brain tumours. Our objective was to evaluate associations of brain tumour risk with occupational exposure to six chlorinated solvents (i.e., dichloromethane, chloroform, carbon tetrachloride, 1,1,1-trichloroethane, trichloroethylene and perchloroethylene). 489 glioma cases, 197 meningioma cases and 799 controls were enrolled in a hospital-based case-control study conducted at three U.S.A. hospitals in Arizona, Massachusetts and Pennsylvania. Information about occupational history was obtained through a detailed inperson interview that included job-specific modules of questions such that the interview was tailored to each individual&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s particular work history. An industrial hygienist assessed potential solvent exposure based on this information and an exhaustive review of the relevant industrial hygiene literature. Unconditional logistic regression models were used to calculate OR and 95% CI for each solvent for ever/never, duration, cumulative, average weekly and highest exposure. Overall, we found no consistent evidence of an increased risk of glioma or meningioma related to occupational exposure to the six chlorinated solvents evaluated. There was some suggestion of an association between carbon tetrachloride and glioma in analyses restricted to exposed subjects, with average weekly exposure above the median associated with increased risk compared with below the median exposure (OR = 7.1, 95% CI 1.1 to 45.2). We found no consistent evidence for increased brain tumour risk related to chlorinated solvents.

Environmental Science & Technology, 2010

We characterized the distribution and determinants of fetal exposures to pesticide mixtures using... more We characterized the distribution and determinants of fetal exposures to pesticide mixtures using a cross-sectional study of 297 singletons delivered at Johns Hopkins Hospital in Baltimore, MD (2004MD ( -2005. Concentrations of nine persistent and twelve nonpersistent pesticides were measured in cord serum. Mixtures were identified using principal components analysis. Associations between mixtures and maternal and infant characteristics were evaluated using multivariate analysis. p,p′-DDE, p,p′-DDT, trans-nonachlor, oxychlordane, bendiocarb, propoxur, and trans-and cis-permethrin were detected in 100, 90, 93, 84, 73, 55, 52, and 41% of serum samples, respectively. There were four independent pesticide components: DDT (p,p′-DDT + p,p′-DDE), chlordane (trans-nonachlor + oxychlordane), permethrin (trans-and cis-permethrins + PBUT), and carbamate (bendiocarb + propoxur). DDT and chlordane were 6.1 (95%CI: 2.4, 15.5) and 2.1 (95%CI: 1.0, 4.2) times higher for infants of women >35, and 1.8 (95%CI: 1.2, 2.9) and 1.5 (95%CI: 1.1, 2.1) times higher in smoking mothers. DDT and carbamate were 15 (95%CI: 7, 30) and 2 (95%CI: 1, 4) times higher for infants of Asian compared with Caucasian mothers. No significant differences were observed for permethrin. Fetal exposures to pesticides are widespread, occur as mixtures, and differ by maternal race, age, and smoking status.

Environmental Science & Technology, 2011

We sought to characterize the relationships between cord serum concentrations of chlordane and pe... more We sought to characterize the relationships between cord serum concentrations of chlordane and permethrin pesticides, inflammatory cytokines, gestational age, and size at birth. Umbilical cord serum levels of trans-nonachlor, oxychlordane, cisand trans-permethrin, piperonyl butoxide, and cytokines (TNF-α, IFN-γ, IL-1β, IL-2, IL-6, IL-8, IL-10, IL-12p70, GMCSF), were quantified in 300 newborns at the Johns Hopkins Hospital in Baltimore, MD (2004MD ( -2005. Principal component analyses were used to quantitate chlordane and permethrin mixtures, and to identify independent cytokine components. Five cytokine components described 87% of the variance in cord serum cytokine levels; these (and predominant loadings) were: (1) all 9 cytokines; (2) acute phase (IL-1β, IL-6); (3) anti-inflammatory (IL-10) (4) TNF-α; and (5) IL-1β. Of these, the TNF-α component was significantly associated with a 2-day decrease in gestational age. Chlordane was associated with lower levels of the pro-inflammatory IL-1β [β: −0.11 (−0.20, −0.02)]. Permethrin was negatively associated with the anti-inflammatory cytokine IL-10 [β: −0.14 (−0.22, −0.05)]. Neither pesticides nor cytokines were significantly associated with birthweight, length or head circumference, and pesticides were not associated with gestational age. Our findings suggest that chlordane and permethrin concentrations in cord blood may be associated with levels of inflammatory cytokines in the fetus.

Endocrine Related Cancer, 2012

Relationships are unclear between polymorphisms in genes involved in metabolism and detoxificatio... more Relationships are unclear between polymorphisms in genes involved in metabolism and detoxification of various chemicals and papillary thyroid cancer (PTC) risk as well as their potential modification by alcohol or tobacco intake. We evaluated associations between 1647 tagging single nucleotide polymorphisms (SNPs) in 132 candidate genes/regions involved in metabolism of exogenous and endogenous compounds (Phase I/II, oxidative stress, and metal binding pathways) and PTC risk in 344 PTC cases and 452 controls. For 15 selected regions and their respective SNPs, we also assessed interaction with alcohol and tobacco use. Logistic regression models were used to evaluate the main effect of SNPs (P trend ) and interaction with alcohol/tobacco intake. Gene-and pathway-level associations and interactions (P gene interaction ) were evaluated by combining P trend values using the adaptive rank-truncated product method.

Cancer Epidemiology Biomarkers & Prevention, 2012

Background: Epidemiologic studies have shown consistent associations between obesity and increase... more Background: Epidemiologic studies have shown consistent associations between obesity and increased thyroid cancer risk, but, to date, no studies have investigated the relationship between thyroid cancer risk and obesity-related single-nucleotide polymorphisms (SNP).

Cancer Epidemiology Biomarkers & Prevention, 2010

The etiology of meningioma, the second-most common type of adult brain tumor in the United States... more The etiology of meningioma, the second-most common type of adult brain tumor in the United States, is largely unknown. Prior studies indicate that history of immune-related conditions may affect the risk of meningioma. To identify genetic markers for meningioma in genes involved with innate immunity, we conducted an exploratory association study of 101 meningioma cases and 330 frequency-matched controls of European ancestry using subjects from a hospital-based study conducted by the National Cancer Institute. We genotyped 1407 "tag" single nucleotide polymorphisms (SNPs) in 148 genetic regions chosen on the basis of an r 2 > 0.8 and minor allele frequency > 5% in Caucasians in HapMap1. Risk of meningioma was estimated by odds ratios and 95% confidence intervals. Seventeen SNPs distributed across twelve genetic regions (NFKB1 (3), FCER1G (3), CCR6 (2), VCAM1, CD14, TNFRSF18, RAC2, XDH, C1D, TLR1/TLR10/TLR6, NOS1, DEFA5) were associated with risk of meningioma with p<0.01. Although individual SNP tests were not significant after controlling for multiple comparisons, gene region-based tests were statistically significant (p<0.05) for TNFRSF18, NFKB1, FCER1G, CD14, C1D, CCR6, and VCAM1. Our results indicate that common genetic polymorphisms in innate immunity genes may be associated with risk of meningioma. Given the small sample size, replication of these results in a larger study of meningioma is needed.

Annals of Epidemiology, 2010