Blood DNA methylation and liver cancer in American Indians: evidence from the Strong Heart Study

PURPOSE

Liver cancer incidence among American Indians/Alaska Natives has risen over the past 20 years. Peripheral blood DNA methylation may be associated with liver cancer and could be used as a biomarker for cancer risk. We evaluated the association of blood DNA methylation with risk of liver cancer.

METHODS

We conducted a prospective cohort study in 2324 American Indians, between age 45 and 75 years, from Arizona, Oklahoma, North Dakota and South Dakota who participated in the Strong Heart Study between 1989 and 1991. Liver cancer deaths (n = 21) were ascertained using death certificates obtained through 2017. The mean follow-up duration (SD) for non-cases was 25.1 (5.6) years and for cases, 11.0 (8.8) years. DNA methylation was assessed from blood samples collected at baseline using MethylationEPIC BeadChip 850 K arrays. We used Cox regression models adjusted for age, sex, center, body mass index, low-density lipoprotein cholesterol, smoking, alcohol consumption, and immune cell proportions to examine the associations.

RESULTS

We identified 9 CpG sites associated with liver cancer. cg16057201 annotated to MRFAP1) was hypermethylated among cases vs. non-cases (hazard ratio (HR) for one standard deviation increase in methylation was 1.25 (95% CI 1.14, 1.37). The other eight CpGs were hypomethylated and the corresponding HRs (95% CI) ranged from 0.58 (0.44, 0.75) for cg04967787 (annotated to PPRC1) to 0.77 (0.67, 0.88) for cg08550308. We also assessed 7 differentially methylated CpG sites associated with liver cancer in previous studies. The adjusted HR for cg15079934 (annotated to LPS1) was 1.93 (95% CI 1.10, 3.39).

CONCLUSIONS

Blood DNA methylation may be associated with liver cancer mortality and may be altered during the development of liver cancer.

Edge State, Band Topology, and Time Boundary Effect in the Fine-Grained Categorization of Chern Insulators

We predict novel topological phases with broken time-reversal symmetry supporting the coexistence of opposite chiral edge states, which are fundamentally different from the photonic spin-Hall, valley-Hall, and higher-order topological phases. We find a fine-grained categorization of Chern insulators, their band topologies characterized by identical Chern numbers are completely different. Furthermore, we prove that different topologies cause zeros in their Bloch wave function overlaps, which imprint the band gap closing and appear at the degenerate points of topological phase transition. The Bloch wave function overlaps predict the reflection and refraction at a topological time boundary, and the overlap zeros ensure the existence of vanishing revival amplitude at critical times even though different topologies before and after the time boundary have identical Chern numbers. Our findings create new opportunities for topological metamaterials, uncover the topological feature hidden in the time boundary effect as a probe of topology, and open a venue for the exploration of the rich physics originating from the long-range couplings.

Genome-wide association study identifies high-impact susceptibility loci for HCC in North America

BACKGROUND AND AIMS

Despite the substantial impact of environmental factors, individuals with a family history of liver cancer have an increased risk for HCC. However, genetic factors have not been studied systematically by genome-wide approaches in large numbers of individuals from European descent populations (EDP).

APPROACH AND RESULTS

We conducted a 2-stage genome-wide association study (GWAS) on HCC not affected by HBV infections. A total of 1872 HCC cases and 2907 controls were included in the discovery stage, and 1200 HCC cases and 1832 controls in the validation. We analyzed the discovery and validation samples separately and then conducted a meta-analysis. All analyses were conducted in the presence and absence of HCV. The liability-scale heritability was 24.4% for overall HCC. Five regions with significant ORs (95% CI) were identified for nonviral HCC: 3p22.1, MOBP , rs9842969, (0.51, [0.40-0.65]); 5p15.33, TERT , rs2242652, (0.70, (0.62-0.79]); 19q13.11, TM6SF2 , rs58542926, (1.49, [1.29-1.72]); 19p13.11 MAU2 , rs58489806, (1.53, (1.33-1.75]); and 22q13.31, PNPLA3 , rs738409, (1.66, [1.51-1.83]). One region was identified for HCV-induced HCC: 6p21.31, human leukocyte antigen DQ beta 1, rs9275224, (0.79, [0.74-0.84]). A combination of homozygous variants of PNPLA3 and TERT showing a 6.5-fold higher risk for nonviral-related HCC compared to individuals lacking these genotypes. This observation suggests that gene-gene interactions may identify individuals at elevated risk for developing HCC.

CONCLUSIONS

Our GWAS highlights novel genetic susceptibility of nonviral HCC among European descent populations from North America with substantial heritability. Selected genetic influences were observed for HCV-positive HCC. Our findings indicate the importance of genetic susceptibility to HCC development.

MDF-Net: A Multi-Scale Dynamic Fusion Network for Breast Tumor Segmentation of Ultrasound Images

Breast tumor segmentation of ultrasound images provides valuable information of tumors for early detection and diagnosis. Accurate segmentation is challenging due to low image contrast between areas of interest; speckle noises, and large inter-subject variations in tumor shape and size. This paper proposes a novel Multi-scale Dynamic Fusion Network (MDF-Net) for breast ultrasound tumor segmentation. It employs a two-stage end-to-end architecture with a trunk sub-network for multiscale feature selection and a structurally optimized refinement sub-network for mitigating impairments such as noise and inter-subject variation via better feature exploration and fusion. The trunk network is extended from UNet++ with a simplified skip pathway structure to connect the features between adjacent scales. Moreover, deep supervision at all scales, instead of at the finest scale in UNet++, is proposed to extract more discriminative features and mitigate errors from speckle noise via a hybrid loss function. Unlike previous works, the first stage is linked to a loss function of the second stage so that both the preliminary segmentations and refinement subnetworks can be refined together at training. The refinement sub-network utilizes a structurally optimized MDF mechanism to integrate preliminary segmentation information (capturing general tumor shape and size) at coarse scales and explores inter-subject variation information at finer scales. Experimental results from two public datasets show that the proposed method achieves better Dice and other scores over state-of-the-art methods. Qualitative analysis also indicates that our proposed network is more robust to tumor size/shapes, speckle noise and heavy posterior shadows along tumor boundaries. An optional post-processing step is also proposed to facilitate users in mitigating segmentation artifacts. The efficiency of the proposed network is also illustrated on the "Electron Microscopy neural structures segmentation dataset". It outperforms a state-of-the-art algorithm based on UNet-2022 with simpler settings. This indicates the advantages of our MDF-Nets in other challenging image segmentation tasks with small to medium data sizes.

Early T-cell precursor lymphoblastic leukaemia with monocytic morphology negative for CD3 by flow cytometry: A diagnostic challenge solved by immunohistochemistry

No abstract available.

High-throughput measurement of double strand break global repair phenotype in peripheral blood mononuclear cells after long-term cryopreservation

Peripheral blood mononuclear cells (PBMCs) are a useful model for biochemical assays, particularly for etiological studies. We describe here a method for measuring DNA repair capacity (DRC) in archival cryogenically preserved PBMCs. To model DRC, we measured γ-H2AX repair kinetics in thawed PBMCs after irradiation with 3 Gy gamma rays. Time-dependent fluorescently labeled γ-H2AX levels were measured at five time points from 1 to 20 h, yielding an estimate of global DRC repair kinetics as well as a measure of unrepaired double strand breaks at 20 h. While γ-H2AX levels are traditionally measured by either microscopy or flow-cytometry, we developed a protocol for imaging flow cytometry (IFC) that combines the detailed information of microscopy with the statistical power of flow methods. The visual imaging component of the IFC allows for monitoring aspects such as cellular health and apoptosis as well as fluorescence localization of the γ-H2AX signal, which ensures the power and significance of this technique. Application of a machine-learning based image classification improved flow cytometry fluorescent measurements by identifying apoptotic cells unable to undergo DNA repair. We present here DRC repair parameters from 18 frozen archival PBMCs and 28 fresh blood samples collected from a demographically diverse cohort of women measured in a high-throughput IFC format. This thaw method and assay can be used alone or in conjunction with other assays to measure etiological phenotypes in cryogenic biobanks of PBMCs.

Improved prediction of breast cancer risk based on phenotypic DNA damage repair capacity in peripheral blood B cells

Background

Standard Breast Cancer (BC) risk prediction models based only on epidemiologic factors generally have quite poor performance, and there have been a number of risk scores proposed to improve them, such as AI-based mammographic information, polygenic risk scores and pathogenic variants. Even with these additions BC risk prediction performance is still at best moderate. In that decreased DNA repair capacity (DRC) is a major risk factor for development of cancer, we investigated the potential to improve BC risk prediction models by including a measured phenotypic DRC assay.

Methods

Using blood samples from the Breast Cancer Family Registry we assessed the performance of phenotypic markers of DRC in 46 matched pairs of individuals, one from each pair with BC (with blood drawn before BC diagnosis) and the other from controls matched by age and time since blood draw. We assessed DRC in thawed cryopreserved peripheral blood mononuclear cells (PBMCs) by measuring γ-H2AX yields (a marker for DNA double-strand breaks) at multiple times from 1 to 20 hrs after a radiation challenge. The studies were performed using surface markers to discriminate between different PBMC subtypes.

Results

The parameter F res , the residual damage signal in PBMC B cells at 20 hrs post challenge, was the strongest predictor of breast cancer with an AUC (Area Under receiver-operator Curve) of 0.89 [95% Confidence Interval: 0.84-0.93] and a BC status prediction accuracy of 0.80. To illustrate the combined use of a phenotypic predictor with standard BC predictors, we combined F res in B cells with age at blood draw, and found that the combination resulted in significantly greater BC predictive power (AUC of 0.97 [95% CI: 0.94-0.99]), an increase of 13 percentage points over age alone.

Conclusions

If replicated in larger studies, these results suggest that inclusion of a fingerstick-based phenotypic DRC blood test has the potential to markedly improve BC risk prediction.

[Factors influencing bilirubin elevation and its correlation with UGT1A1 gene polymorphism in the early postoperative period of transjugular intrahepatic portosystemic shunt]

Objective: To investigate the factors influencing total bilirubin elevation and its correlation with UGT1A1 gene polymorphism in the early postoperative period of transjugular intrahepatic portosystemic shunt (TIPS). Methods: 104 cases with portal hypertension and esophageal variceal hemorrhage (EVB) treated with elective TIPS treatment were selected as the study subjects and were divided into a bilirubin-elevated group and a normal bilirubin group according to the total bilirubin elevation level during the early postoperative period. Univariate analysis and logistic regression were used to analyze the factors influencing total bilirubin elevation in the early postoperative period. PCR amplification and first-generation sequencing technology were used to detect the polymorphic loci of the UGT1A1 gene promoter TATA box, enhancer c.-3279 T > G, c.211G > A, and c.686C > A. Logistic regression was used to analyze the correlation of four locus alleles and genotypes with elevated total bilirubin in the early postoperative period. Results: Among the 104 cases, 47 patients were in the bilirubin elevated group, including 35 males (74.5%) and 12 females (25.5%), aged (50.72 ± 12.56) years. There were 57 cases in the normal bilirubin group, including 42 males (73.7%) and 15 females (26.3%), aged (51.63 ± 11.10) years. There was no statistically significant difference in age (t = -0.391, P = 0.697) and gender (χ(2) = 0.008, P = 0.928) between the two groups of patients. Univariate analysis revealed that preoperative alanine transaminase (ALT) level (χ(2) = 5.954, P = 0.015), total bilirubin level (χ(2) = 16.638, P < 0.001), MELD score (χ(2) = 10.054, P = 0.018), Child-Pugh score (χ(2) = 6.844, P = 0.022), and postoperative portal vein branch development (χ(2) = 6.738, P = 0.034) were statistically significantly different between the two groups. Logistic regression analysis showed that preoperative ALT level, total bilirubin level, and portal vein branch development after TIPS were correlated with the elevated total bilirubin in the early postoperative period. The polymorphism of the c.211G > A locus of the UGT1A1 gene correlation had elevated total bilirubin in the early postoperative period of TIPS. The risk of elevated total bilirubin was increased in the population carrying allele A (P = 0.001, OR = 4.049) in the early postoperative period. Allelic polymorphisms in the TATA box promoter region and enhancer c.-3279 T > G and c.686C > A had no statistically significant difference between the bilirubin-elevated group and the normal bilirubin group. Conclusion: The preoperative ALT level, total bilirubin level, and portal vein branch development are correlated with the elevated total bilirubin in early postoperative patients. The polymorphisms of the UGT1A1 gene and enhancer c.211G > A are correlated with the occurrence of elevated total bilirubin in the early postoperative period of TIPS. Allele A carrier may have a higher risk of elevated total bilirubin in the early postoperative period.

Metabolomic Evaluation of Air Pollution-related Bone Damage and Potential Mediation

Ambient air pollution has been associated with bone damage. However, no studies have evaluated the metabolomic response to air pollutants and its potential influence on bone health in postmenopausal women. We analyzed data from WHI participants with plasma samples. Whole-body, total hip, femoral neck, and spine BMD at enrollment and follow-up (Y1, Y3, Y6). Daily particulate matter NO, NO2, PM10 and SO2 were averaged over 1-, 3-, and 5-year periods before metabolomic assessments. Statistical analyses included multivariable-adjusted linear mixed models, pathways analyses, and mediation modeling. NO, NO2, and SO2, but not PM10, were associated with taurine, inosine, and C38:4 phosphatidylethanolamine (PE), at all averaging periods. We found a partial mediation of C38:4 PE in the association between 1-year average NO and lumbar spine BMD (p-value: 0.032). This is the first study suggesting that a PE may partially mediate air pollution-related bone damage in postmenopausal women.

Abstract P4-03-26: Blood DNA Methylation and Breast Cancer: a Prospective Case-Control Analysis in the Breast Cancer Prospective Family Study Cohort

Breast cancer has increased dramatically in young women &lt; 50 years in the US over the past decade. DNA methylation is a type of epigenetic change that plays an important role in cancer etiology by silencing tumor suppressor genes or DNA repair-related genes through hypermethylation or activating oncogenes through hypomethylation. Previous genome-wide association studies have suggested DNA methylation in blood is a potential epigenetic markers of breast cancer risk. In this study, we applied targeted methyl-seq to examine the DNA methylation profile in regulatory sequences of 57 known DNA repair pathway genes, together with 123 other genes, located in immune-related loci and genome-wide association peaks for breast cancer. We used a nested case-control design within the Breast Cancer Prospective Family Study Cohort (FroF-SC) and examined DNA methylation profile in DNA from the blood of breast cancer cases (N=293) and age-matched controls (N=327). In the preliminary data analysis, we observed that the methylation levels in 5 genes were statistically significantly different between cases and controls using Wilcoxon Rank Sum Test (Table 1). Some candidate loci show methylation values spanning a wide range (Std Dev) in both cases and controls, suggesting the presence of genotype-dependent allele-specific methylation (ASM). We then conducted generalized estimating equations (GEE model) adjusting for age at blood draw and calculated the odds ratios (ORs) and 95%CI for the association between methylation levels in the 90th and 10th percentiles of differentially methylated genes (90% vs 10% methylation) and breast cancer risk. The ORs (95% CI) from the GEE models were 1.26 (0.97, 1.63, p=0.08) for CD6, 1.27 (0.85, 1.91, p=0.24) for SDCCAG3, 1.12 (0.85, 1.48, p=0.40) for DCLRE1B, 1.29 (0.88, 1.90, p=0.20) for IP09, and 1.63 (1.08, 2.45, p=0.02) for GNPDA1 (Table 2). The associations were not different by age group. Our preliminary results suggest that DNA methylation measured in blood may be a biomarker of breast cancer susceptibility.

Citation Format: HuiChen Wu, Angelica Castano, Yuyan Liao, Regina Santella, David Brenner, Mary Beth Terry, Benjamin Tycko. Blood DNA Methylation and Breast Cancer: a Prospective Case-Control Analysis in the Breast Cancer Prospective Family Study Cohort [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P4-03-26.

Association of blood manganese, selenium with steatosis, fibrosis in the National Health and Nutrition Examination Survey, 2017-18

BACKGROUND & AIMS

Chronic liver disease is a growing health burden worldwide. Chronic metal exposures may be associated with non-alcoholic fatty liver disease (NAFLD). We aimed to evaluate the association of blood cadmium (Cd), mercury (Hg), lead (Pb), manganese (Mn), and selenium (Se) with two hallmark features of NAFLD: liver steatosis and fibrosis in the general U.S.

METHODS

We analyzed transient liver elastography data from participants of the National Health and Nutrition Examination Survey (NHANES) 2017-18, using ordinal logistic regression analyses to evaluate the cross-sectional association between blood metal concentrations and clinical stages of steatosis and fibrosis. We applied survey weights, strata, and primary sampling units and analyses were conducted using the R survey package.

RESULTS

4,154 participants were included. Median (IQR) for blood Mn and blood Se were 9.28 (7.48-11.39) and 191.08 (176.55-207.16) μg/L, respectively. Per interquartile range increase of natural log transformed blood Mn, the adjusted odds ratio (OR) (95% CI) was 1.59 (1.13-2.23) for a higher grade of steatosis and 1.16 (0.67-2.00) for liver fibrosis. The corresponding OR for steatosis was 2.00 (1.24-3.24) and 2.14 (1.04-4.42) in Black and Mexican American participants, respectively. The corresponding OR for liver fibrosis was 2.96 (1.42-6.17) for females. Per interquartile range increase of natural log transformed blood Se, the adjusted OR was 2.25 (1.30-3.89) for steatosis but 0.31 (0.13-0.72) for liver fibrosis. The inverse association of blood Se with liver fibrosis was also observed in males and White participants. Blood Cd, Hg, and Pb were not associated with liver steatosis and fibrosis in fully-adjusted models overall.

CONCLUSIONS

In NHANES 2017-18, higher blood Mn was positively associated with liver steatosis, and higher Se was positively associated with liver steatosis but negatively associated with liver fibrosis. Longitudinal studies are needed to examine the association of Mn and Se with fibrosis progression.

DNA repair phenotype and cancer risk: a systematic review and meta-analysis of 55 case-control studies

DNA repair phenotype can be measured in blood and may be a potential biomarker of cancer risk. We conducted a systematic review and meta-analysis of epidemiological studies of DNA repair phenotype and cancer through March 2021. We used random-effects models to calculate pooled odds ratios (ORs) of cancer risk for those with the lowest DNA repair capacity compared with those with the highest capacity. We included 55 case–control studies that evaluated 12 different cancers using 10 different DNA repair assays. The pooled OR of cancer risk (all cancer types combined) was 2.92 (95% Confidence Interval (CI) 2.49, 3.43) for the lowest DNA repair. Lower DNA repair was associated with all studied cancer types, and pooled ORs (95% CI) ranged from 2.02 (1.43, 2.85) for skin cancer to 7.60 (3.26, 17.72) for liver cancer. All assays, except the homologous recombination repair assay, showed statistically significant associations with cancer. The effect size ranged from 1.90 (1.00, 3.60) for the etoposide-induced double-strand break assay to 5.06 (3.67, 6.99) for the γ-H2AX assay. The consistency and strength of the associations support the use of these phenotypic biomarkers; however large-scale prospective studies will be important for understanding their use related to age and screening initiation.

Improvement on recovery and reproducibility for quantifying urinary mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs)

Efficient and reproducible measurements of multiple polycyclic aromatic hydrocarbon (PAH) metabolites in urinary samples are required to evaluate the complex health effects of PAH exposure. Here, we demonstrate a highly practical, automated off-line solid-phase extraction (SPE) of deconjugated hydroxylated PAHs followed by LC-MS/MS to simultaneously measure eight mono-hydroxylated PAH compounds: 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 2&3-hydroxyphenanthrene, 4-hydroxyphenanthrene and 1-hydroxypyrene. Initially, we observed low recovery rates (e.g., 16% for 1-hydroxypyrene) when using previously published methods. We optimized the procedure by choosing polymeric absorbent-based cartridges, automating the sample loading step by diluting samples with 15% methanol/sodium acetate, and most importantly, replacing acetonitrile with methanol as the eluting solvent. Optimized sample preparation has improved the recovery rates to more than 69% for analytes of interest. This improvement led to higher method sensitivity and detection frequency, especially for 1-hydroxypyrene, in all of 100 urine samples collected in the New York City site of the Legacy Girls Study. The limits of detection ranged from 7.6 pg/mL to 20.3 pg/mL using 1 mL of urine, compared to the 2 mL required in CDC, method 09-OD. The average coefficients of variance of quality control samples (n = 60) ranged between 7 and 21%; variance of repeated measurements (n = 45) was less than 10%. This efficient and reliable method for measuring PAH metabolites will greatly benefit epidemiology studies and biomonitoring programs.

Guard Cell-Specific Pectin METHYLESTERASE53 Is Required for Abscisic Acid-Mediated Stomatal Function and Heat Response in Arabidopsis

Pectin is a major component of the plant cell wall, forming a network that contributes to cell wall integrity and flexibility. Pectin methylesterase (PME) catalyzes the removal of methylester groups from the homogalacturonan backbone, the most abundant pectic polymer, and contributes to intercellular adhesion during plant development and different environmental stimuli stress. In this study, we identified and characterized an Arabidopsis type-II PME, PME53, which encodes a cell wall deposited protein and may be involved in the stomatal lineage pathway and stomatal functions. We demonstrated that PME53 is expressed explicitly in guard cells as an abscisic acid (ABA)-regulated gene required for stomatal movement and thermotolerance. The expression of PME53 is significantly affected by the stomatal differentiation factors SCRM and MUTE. The null mutation in PME53 results in a significant increase in stomatal number and susceptibility to ABA-induced stomatal closure. During heat stress, the pme53 mutant highly altered the activity of PME and significantly lowered the expression level of the calmodulin AtCaM3, indicating that PME53 may be involved in Ca²⁺-pectate reconstitution to render plant thermotolerance. Here, we present evidence that the PME53-mediated de-methylesterification status of pectin is directed toward stomatal development, movement, and regulation of the flexibility of the guard cell wall required for the heat response.

Incidence of hepatocellular carcinoma in a community-based Taiwanese population without chronic HBV/HCV infection

Background & Aims

In addition to HBV/HCV causing hepatocellular carcinoma (HCC), other risk factors including obesity and alcohol drinking also increase risk. We describe the cumulative risk of HCC and mortality from liver-related disease by selected modifiable risk factors among a non-hepatitis virus-infected population.

Methods

For a community-based cohort, residents aged 30–65 years living in 7 townships in Taiwan were recruited, and have been followed up since 1991. A total of 18,541 individuals were seronegative for markers of chronic infection of HBV/HCV and with no history of HCC at baseline. New non-HBV/HCV HCC cases and liver-related deaths were ascertained through data linkage to the National Cancer Registry and Death Certification System from 1 January 1991 through 31 December 2017.

Results

There were 207 HCC cases and 215 liver-related deaths identified. The incidence rate of non-HBV/HCV HCC was 47.2 per 100,000 person-years. The mortality rate of liver-related death was 49.0 per 100,000 person-years. Baseline information on alcohol consumption, heart disease, diabetes, elevated aspartate aminotransferase, and alanine aminotransferase predicted higher risks of HCC, with hazard ratios (HRs) (95% CIs) of 1.7 (1.1–2.5), 2.2 (1.1–4.1), 1.9 (1.0–3.5), 1.7 (1.1–2.4), and 1.6 (1.0–2.4), respectively. The HRs (95% CIs) of liver-related death were 2.3 (1.6–3.2) for alcohol consumption, 1.4 (1.1–1.9) for BMI ≥25 kg/m², 2.2 (1.4–3.3) for elevated aspartate aminotransferase, and 1.5 (1.0–2.4) for elevated alanine aminotransferase. The HR (95% CI) was 8.1 (3.6–18.5) for those with diabetes and elevated aspartate aminotransferase.

Conclusions

Individuals with elevated liver enzymes are at high risk of liver disease. Prevention and treatment of diabetes and heart disease are critical for non-hepatitis B, non-hepatitis C (NonB/C)-HCC.

Lay summary

We followed up individuals with no chronic HBV or HCV infection and described the risk of hepatocellular carcinoma (HCC, the most common form of primary liver cancer) and mortality from liver-related disease by modifiable risk factors. This study estimated the incidence rate of HCC by selected lifestyle risk factors and chronic diseases conditions. Alcohol consumption, heart disease, diabetes, and abnormal blood liver function tests showed a strong association with HCC risk and mortality.

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Alcohol drinking increases risks of NonB/C-HCC and liver-related death.

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Both heart disease and diabetes are associated with the risk of NonB/C-HCC.

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Elevated AST and ALT are major risk factors for NonB/C-HCC and liver-related death.

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Prevention and treatment of diabetes and heart disease are critical for NonB/C-HCC.

Effect of heat stress on oxidative damage and antioxidant defense system in white clover (Trifolium repens L.)

This study leads to advances in the field of heat tolerance among different plant species. We concluded that a coordinated, increased antioxidant defense system enabled white clover to reduce heat-induced oxidative damage. The rise in global ambient temperature has a wide range of effects on plant growth, and, therefore, on the activation of various molecular defenses before the appearance of heat damage. Elevated temperatures result in accelerated generation of reactive oxygen species (ROS), causing an imbalance between ROS production and the ability of scavenging systems to detoxify and remove the reactive intermediates. The aim of this study was to determine the role of antioxidant defense systems in the alleviation of heat stress (HS) consequences in white clover (Trifolium repens L.), which is cultivated worldwide. We evaluated how temperature and time parameters contribute to the thermotolerance of white clover at different growth stages. We revealed HS protection in white clover from 37 to 40 °C, with 40 °C providing the greatest protection of 3-day-old seedlings and 28-day-old adult plants. Heat-provoked oxidative stress in white clover was confirmed by substantial changes in electrolyte leakage, malondialdehyde (MDA), and chlorophyll content, as well as superoxide anion (O₂^·-) and hydrogen peroxide (H₂O₂) production. Furthermore, superoxide dismutase (SOD) and ascorbate peroxidase (APX) as well as a high level of GSH non-enzymatic antioxidant were the most responsive, and were associated with acquired thermotolerance through the regulation of ROS generation. We demonstrated, by studying protoplast transient gene expression, direct genetic evidence of endogenous antioxidant-related genes that confer HS tolerance in white clover. Our present study clearly establishes that oxidative stress ensues from HS, which triggers the induction of antioxidant defense systems for ROS scavenging in white clover.

Reproductive and environmental exposures and the breast cancer risk in Taiwanese women

Breast cancer (BC) incidence is increasing around the globe, including in Taiwan, though the cause of the increasing incidence is less clear. We followed up 11,296 Taiwanese females who did not have BC at baseline, and ascertained new invasive BC (N = 351) through data linkage to the National Cancer Registry from 1991 to 2018 to examine whether reproductive, lifestyle and environmental risk factors including polycyclic aromatic hydrocarbons (PAH) were associated with BC risk. We conducted a nested case–control study using baseline blood available from a total of 305 women with BC and 598 women without BC matched on time in cohort. We examined the association of PAH-albumin adducts and BC risk using conditional logistic regression models. Age at menarche (HR 0.6 (95% CI 0.5–0.9) for ≥ 15 vs. < 13 years) and multiparity were associated with BC risk (HR 2.0 (95% CI 1.4–2.8), 2.8 (1.9–4.2), and 2.4 (1.0–5.0) for 3–4, 1–2 and 0 live birth, compared with women ≥ 5 births). PAH-albumin adducts were not associated with BC risk. Given the increasing BC incidence in Taiwan, there is a need to identify environmental factors that are important to this population.

Circulating growth factor concentrations and breast cancer risk: a nested case-control study of IGF-1, IGFBP-3, and breast cancer in a family-based cohort

Background

Insulin-like growth factor 1 (IGF-1) and binding protein 3 (IGFBP-3) are associated with breast cancer in women at average risk of cancer. Less is known whether these biomarkers also predict risk in women with breast cancer family history.

Methods

We conducted a nested case-control study within the New York site of the Breast Cancer Family Registry (BCFR, n = 80 cases, 156 controls), a cohort enriched for breast cancer family history. Using conditional logistic regression, we estimated the association between IGF-1 and IGFBP-3 levels and breast cancer risk and examined whether this risk differed by predicted absolute breast cancer risk based on pedigree models.

Results

The overall association between IGF-1 or IGFBP-3 elevation (≥ median in controls) and breast cancer risk was elevated, but not statistically significant (IGF-1 OR = 1.37, 95% CI = 0.66–2.85; IGFBP-3 OR = 1.62, 95% CI = 0.81–3.24). Women with elevated predicted absolute 10-year risk ≥ 3.4% and elevated IGFBP-3 (≥ median) had more than a 3-fold increased risk compared to women with lower predicted absolute 10-year risk (< 3.4%) and low IGFBP-3 (OR = 3.47 95% CI = 1.04–11.6).

Conclusions

These data offer some support that the overall magnitude of the associations between IGF-1 and IGFBP3 seen in average risk cohorts may be similar in women enriched with a strong breast cancer family history.

[Using text mining to identify gap in acquired immunodeficiency syndrome related information dissemination between the official channel delivery and the needs of adolescents]

Objective: The study intends to identify gap in HIV/AIDS awareness dissemination between the official channel delivery and the needs of adolescents. Methods: We crawled all the HIV/AIDS queries from "Baidu zhidao" till June 11st, 2018. "Baidu zhidao" inquiry and information form official public service announcement (abbreviated for "official delivery" hereafter) were the data source for comparative analysis. We categorized the text data into four kinds, "prevention", "testing and treatment", "symptoms and infection" and "legalization and policies" according to official categorization. Word segmentation was used for text mining and word frequency statistics, as well word cloud was used for word frequency visualization (all based on a comparison after removing the useless words). Results: Of the official delivery, the proportion of prevention category accounted for 32.3% (n=162) (ranks 1^st), and the proportion of legalization and policies category was 14.1% (n=71). While among the "Baidu zhidao" inquiry information, the proportion of testing and treatment category accounted for 51.7% (n=51 264), and the proportion of prevention category accounted for 11.4% (n=11 272). The frequencies of same terms/ repeated terms of two channels accounted for 60% (59.3%-63.9%) of each category among the official delivery, of which, the proportion of interest terms comparatively less and more diverse in "Baidu zhidao" inquiries. The proportion of the terms frequency of each category was about 45% in "prevention, testing and treatment", 34.3% (n=14 781) in "symptoms and infection" and 17.0% (n=5 744) in "legalization and policies", respectively. Conclusion: A big gap was identified between the available official source and inquiries' term, especially word frequency discrepancy between "legalization and policies" and "prevention" categories. It underscore the necessity for the official channel to address the needs and interests of adolescents in the future.

Frequent loss of CD10 expression in follicular lymphoma with leukaemic presentation

INTRODUCTION

Follicular lymphoma (FL) is usually a nodal lymphoma expressing CD10, rarely with leukaemic presentation (FL-LP).

MATERIALS AND METHODS

We searched for FL-LP in our institution from 2000 to 2018 and characterised the neoplastic cells by flow cytometry, immunohistochemistry and fluorescence in situ hybridization. Thirteen (6.1%) of 212 FL cases were FL-LP, all de novo neoplasms. The leukaemic cells were small in 12 cases and large in one. All had concurrent FL, mostly (92%; 12/13) low-grade. The single case with large leukaemic cells had a concurrent primary splenic low-grade FL and a double-hit large B-cell lymphoma in the marrow.

RESULTS

CD10 was expressed in the leukaemic cells in 38% (5/13) cases by flow cytometry and in 77% (10/13) cases in tumours (p= 0.0471). IGH/BCL2 reciprocal translocation was identified in 85% (11/13) cases. Most patients were treated with chemotherapy. In a median follow-up time of 36 months, nine patients were in complete remission. The 2- and 5-year survival rates were at 100% and 83%, respectively. In this study, we characterised a series of de novo FL-LP in Taiwan. All patients had concurrent nodal and/or tissue tumours, which might suggest that these patients seek medical help too late.

CONCLUSION

The lower CD10 expression rate by flow cytometry than by immunohistochemistry might be due to different epitopes for these assays. Alternatively, loss of CD10 expression might play a role in the pathogenesis of leukaemic change. The clinical course of FL-LP could be aggressive, but a significant proportion of the patients obtained complete remission with chemotherapy.

Influence of pubertal development on urinary oxidative stress biomarkers in adolescent girls in the New York LEGACY cohort

Puberty is a time of intense growth and differentiation of breast tissue and a window of susceptibility (WOS) for breast cancer. Although oxidative stress markers have been associated with breast cancer risk, it is unclear whether oxidative stress levels are different during the pubertal WOS, and if so, whether these differences are related to breast cancer susceptibility. We measured urinary biomarkers of whole body oxidative stress (urinary F2-Isoprostanes and 8-oxodeoxyguanosine (8-oxodG)) in 158 girls (ages 6-13 years), 71 with and 87 without a breast cancer family history (BCFH) from a cohort of adolescent girls from the New York site of the LEGACY cohort (Lessons in Epidemiology and Genetics in Adults Cancer from Youth). We compared levels of urinary oxidative stress biomarkers (F2-Isoprostanes and 8-oxodG) across the pubertal window, defined by Tanner Stage (TS) of breast development, both cross-sectionally and longitudinally within girls over an 18-month follow up period. Urinary oxidative stress biomarkers were unrelated to pubertal stages in cross-sectional analyses after considering adjustments for body mass index (BMI) and BCFH. In our longitudinal analysis, we found that urinary 8-oxodG levels, but not F2-Isoprostane levels, increased with age in BCFH + girls (β = 6.12, 95% CI = 0.08-12.16) compared to BCFH-girls. Higher BMI was associated with higher level of F2-Isoprostane in both cross-sectional (β = 0.02, 95% CI = 0.0004-0.05) and longitudinal analysis (β = 0.02, 95% CI = 0.0002-0.05). These findings support that higher BMI increases oxidative stress biomarkers over the pubertal window and that there are changes in 8-oxodG oxidative stress biomarkers in girls with a BCFH compared to girls without a BCFH.

Abstract C082: Prenatal exposure to polycyclic aromatic hydrocarbons and altered DNA methylation in breast cancer-related genes

Background/Purpose: Minority populations, particularly young African American women, bear a disproportionate burden of more aggressive breast cancer subtypes. These racial/ethnic disparities can be partially explained by the distribution of risk factors, including urban environmental exposures. Polycyclic aromatic hydrocarbons (PAH) are widespread carcinogenic and hormonally active environmental contaminants with disproportionately high exposure in urban low income and/or communities of racial and ethnic minorities. In our Columbia's Children Center for Environmental Health (CCCEH) birth cohort, prenatal PAH exposure has been associated with lower global DNA methylation in umbilical cord white blood cells (WBC). We extend this work to examine whether prenatal PAH exposure is associated with altered WBC DNA methylation in genes associated with breast cancer risk, including DNA repair, growth, and age at menarche.

Methods: CCCEH enrolled nonsmoking African-American and Dominican pregnant women in New York City between 1998 and 2006 and followed their children through 9 years of age. We examined measures of PAH exposure through two primary sources: 1) prospective maternal personal air monitoring in the third trimester of pregnancy, and 2) PAH-DNA adducts measured in maternal blood at delivery and umbilical cord blood. We examined differences in WBC DNA methylation in 21 candidate genes in 223 girls (ages 7 or 9 years) by prenatal PAH exposure using targeted massively parallel bisulfite sequencing. For each amplicon, we used multivariable linear regression models to assess the association of DNA methylation and the three measures of prenatal PAH exposure. We adjusted all models for girls' age and race/ethnicity and tested for confounding by socioeconomic and reproductive variables and having a smoker in the house prenatally and at year 7 or 9. The sum levels of eight airborne PAH were analyzed as a log-transformed continuous variable (n=223). PAH-DNA adducts in maternal (n=185) and cord blood (n=115) were categorized as below the limit of detection (reference), and above and below the median in those with detectible adducts.

Results: We found significantly different methylation levels by ethnicity in five candidate genes; we did not observe varied methylation by girls' age or BMI at the time of blood collection. We observed evidence of decreased methylation in DNA repair gene BRCA1 (Δ = -2.3, p-value 0.06) with increasing airborne PAH levels. For cord blood PAH-DNA adducts, compared to those with non-detectable adducts, we observed decreased methylation in an imprinted gene associated with breast cancer and body weight regulation, H19 (Δ = -6.5, p-value 0.001) in girls with the highest level of detectable adducts (above the median in those with detectable adducts).

Conclusions: Preliminary findings from this urban cohort suggest that measures of prenatal exposure to PAH may result in altered methylation in genes related to breast cancer risk and body weight in young girls.

Citation Format: Nur Zeinomar, Hui-Chen Wu, Xinran Ma, Julie B. Herbstman, Frederica P. Perera, Rachel L. Miller, Mary Beth Terry. Prenatal exposure to polycyclic aromatic hydrocarbons and altered DNA methylation in breast cancer-related genes [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr C082.

High levels of global genome methylation in patients with retinoblastoma

Retinoblastoma is a tumor of the embryonic neural retina in young children. The DNA methyltransferase 1 (DNMT1) gene has been demonstrated to be transcriptionally activated in cells lacking retinoblastoma 1 (RB1). Thus, there is a direct interaction between DNMT1 and RB1 in vivo. The present study hypothesized that uncontrolled DNMT1, DNMT2 and DNMT3 expression may lead to a high level of global genome methylation causing a second hit or where both alleles are altered, in RB1 and/or inactivation of other genes in retinal cells. To test this, the global genome methylation levels were analyzed in 69 patients with retinoblastoma, as well as 26 healthy siblings and 18 healthy unrelated children as the control groups. Peripheral blood and tumor tissue samples were obtained from 32 patients. The expression levels of DNMT genes were also determined in cell lines. Based on the median levels of global genome methylation in patients, higher genome-wide methylation levels in peripheral blood were associated with a 3.33-fold increased risk for retinoblastoma in patients compared with all healthy controls (95% confidence interval, 0.98–11.35; P<0.0001). The level of global genome methylation and the expression of DNMT genes were increased in the WERI-RB-1 cell line, which has a mutated RB1 gene, compared with a wild-type RB1-expressing cell line. These results supported the hypothesis that epigenetic alterations, as well as mutations in RB1, may be associated with the oncogenesis and inheritance of retinoblastoma. The repression of genes that interact with RB1, such as the DNMT gene family, may be important in patients with retinoblastoma with alterations in RB1, and may serve a role in the treatment and regression of retinoblastoma.

DDT exposure during pregnancy and DNA methylation alterations in female offspring in the Child Health and Development Study

Studies measuring dichlorodiphenyltrichloroethane (DDT) exposure during key windows of susceptibility including the intrauterine period suggest that DDT exposure is associated with breast cancer risk. We hypothesized that prenatal DDT exposure is associated with DNA methylation. Using prospective data from 316 daughters in the Child Health and Development Study, we examined the association between prenatal exposure to DDTs and DNA methylation in blood collected in midlife (mean age: 49 years). To identify differentially methylated regions (DMRs) associated with markers of DDTs (p,p'-DDT and the primary metabolite of p,p'-DDT, p,p'-DDE, and o,p'-DDT, the primary constituents of technical DDT), we measured methylation in 30 genes important to breast cancer. We observed DDT DMRs in three genes, CCDC85A, CYP1A1 and ZFPM2, each of which has been previously implicated in pubertal development and breast cancer susceptibility. These findings suggest prenatal DDT exposure may have life-long consequence through alteration in genes relevant to breast cancer.

The plastidial Arabidopsis thaliana NFU1 protein binds and delivers [4Fe-4S] clusters to specific client proteins

Proteins incorporating iron-sulfur (Fe-S) co-factors are required for a plethora of metabolic processes. Their maturation depends on three Fe-S cluster assembly machineries in plants, located in the cytosol, mitochondria, and chloroplasts. After de novo formation on scaffold proteins, transfer proteins load Fe-S clusters onto client proteins. Among the plastidial representatives of these transfer proteins, NFU2 and NFU3 are required for the maturation of the [4Fe-4S] clusters present in photosystem I subunits, acting upstream of the high-chlorophyll fluorescence 101 (HCF101) protein. NFU2 is also required for the maturation of the [2Fe-2S]-containing dihydroxyacid dehydratase, important for branched-chain amino acid synthesis. Here, we report that recombinant Arabidopsis thaliana NFU1 assembles one [4Fe-4S] cluster per homodimer. Performing co-immunoprecipitation experiments and assessing physical interactions of NFU1 with many [4Fe-4S]-containing plastidial proteins in binary yeast two-hybrid assays, we also gained insights into the specificity of NFU1 for the maturation of chloroplastic Fe-S proteins. Using bimolecular fluorescence complementation and in vitro Fe-S cluster transfer experiments, we confirmed interactions with two proteins involved in isoprenoid and thiamine biosynthesis, 1-hydroxy-2-methyl-2-(E)-butenyl-4-diphosphate synthase and 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate synthase, respectively. An additional interaction detected with the scaffold protein SUFD enabled us to build a model in which NFU1 receives its Fe-S cluster from the SUFBC2D scaffold complex and serves in the maturation of specific [4Fe-4S] client proteins. The identification of the NFU1 partner proteins reported here more clearly defines the role of NFU1 in Fe-S client protein maturation in Arabidopsis chloroplasts among other SUF components.

P1569The Impact of Multidisciplinary Cardio-Oncology Program on the Cardiovascular Outcomes in Breast Cancer Patients

Background

Chemo- and target therapies may induce myocardial dysfunction and lead to poor prognoses. Early detection of minor myocardial dysfunction is important for the prevention of subsequent cardiotoxicity. Cardio-oncology is a multidisciplinary field focusing on managing and preventing cardiovascular complications in cancer patients. However, whether Cardio-oncology program truly makes difference in cardiovascular outcomes remains unknown. Herein, we are sharing our experiences in our Medical Center.

Methods

Since 2014 till 2017, we recruited 154 patients with newly diagnosed breast cancer preparing for Epirubicin therapy. Echocardiography, biomarkers, six minute walking distance and cardiovascular adverse events including new onset of hypertension, stroke, myocardial infarction (MI) and mortality were recorded at baseline, three months, six months and one year. Any functional decline was reported to oncologists for the consideration of changing regimens. Otherwise, cardiologists would be consulted for cardiovascular educations and therapies. The echocardiographic and clinical records of 450 breast patients receiving Epirubicin therapy during 2010 to 2013 were also collected as comparison.

Results

Compared with the ratio of 20% patients receiving echocardiography prior to 2014, the ratio increased to 100% since Cardio-Oncology program started. Also, the drop of left ventricular ejection fraction (LVEF) from 25% attenuated to 5%. Before Cardio-Oncology Program, there were 1.7% of new onset hypertension, 0.8% of MI, 0.8% of stroke and 16.8% of mortality. Conversely, after the program, there were only 0.6% of new onset hypertension while no other cardiovascular complications were reported. Furthermore, compared with previous reports of the effectiveness of Cardio-Oncology Program, our result also displayed a superior impact on the cardiovascular outcomes.

Conclusions

Collectively, through a comprehensive monitoring and an early intervention of myocardial dysfunction post chemotherapies, Cardio-Oncology Program truly decreased the cardiovascular complications in breast cancer patients.

Acknowledgement/Funding

Chi-Mei Medical Center

Coordination of ABA and Chaperone Signaling in Plant Stress Responses

The abscisic acid (ABA) and chaperone signaling pathways are the central regulators of plant stress defense. Despite their significance and potential overlap, these systems have been described separately. In this review, we summarize information about mechanisms by which the ABA and chaperone signaling pathways might be coregulated. The central factors that join the ABA and chaperone signaling systems are the SWI/SNF chromatin-remodeling proteins, which are involved in stress memory. A benefit from coordination is that the signals sensed through both the ABA and chaperone signaling systems are perceived and stored via chromatin-remodeling factors. For improving plant stress resistance, we propose new bioengineering strategies, which we term 'bioengineering memory'.

Iron-sulfur protein NFU2 is required for branched-chain amino acid synthesis in Arabidopsis roots

Numerous proteins require a metallic co-factor for their function. In plastids, the maturation of iron-sulfur (Fe-S) proteins necessitates a complex assembly machinery. In this study, we focused on Arabidopsis thaliana NFU1, NFU2, and NFU3, which participate in the final steps of the maturation process. According to the strong photosynthetic defects observed in high chlorophyll fluorescence 101 (hcf101), nfu2, and nfu3 plants, we determined that NFU2 and NFU3, but not NFU1, act immediately upstream of HCF101 for the maturation of [Fe4S4]-containing photosystem I subunits. An additional function of NFU2 in the maturation of the [Fe2S2] cluster of a dihydroxyacid dehydratase was obvious from the accumulation of precursors of the branched-chain amino acid synthesis pathway in roots of nfu2 plants and from the rescue of the primary root growth defect by supplying branched-chain amino acids. The absence of NFU3 in roots precluded any compensation. Overall, unlike their eukaryotic and prokaryotic counterparts, which are specific to [Fe4S4] proteins, NFU2 and NFU3 contribute to the maturation of both [Fe2S2] and [Fe4S4] proteins, either as a relay in conjunction with other proteins such as HCF101 or by directly delivering Fe-S clusters to client proteins. Considering the low number of Fe-S cluster transfer proteins relative to final acceptors, additional targets probably await identification.

Pectin Methylesterases: Cell Wall Remodeling Proteins Are Required for Plant Response to Heat Stress

Heat stress (HS) is expected to be of increasing worldwide concern in the near future, especially with regard to crop yield and quality as a consequence of rising or varying temperatures as a result of global climate change. HS response (HSR) is a highly conserved mechanism among different organisms but shows remarkable complexity and unique features in plants. The transcriptional regulation of HSR is controlled by HS transcription factors (HSFs) which allow the activation of HS-responsive genes, among which HS proteins (HSPs) are best characterized. Cell wall remodeling constitutes an important component of plant responses to HS to maintain overall function and growth; however, little is known about the connection between cell wall remodeling and HSR. Pectin controls cell wall porosity and has been shown to exhibit structural variation during plant growth and in response to HS. Pectin methylesterases (PMEs) are present in multigene families and encode isoforms with different action patterns by removal of methyl esters to influencing the properties of cell wall. We aimed to elucidate how plant cell walls respond to certain environmental cues through cell wall-modifying proteins in connection with modifications in cell wall machinery. An overview of recent findings shed light on PMEs contribute to a change in cell-wall composition/structure. The fine-scale modulation of apoplastic calcium ions (Ca2+) content could be mediated by PMEs in response to abiotic stress for both the assembly and disassembly of the pectic network. In particular, this modulation is prevalent in guard cell walls for regulating cell wall plasticity as well as stromal aperture size, which comprise critical determinants of plant adaptation to HS. These insights provide a foundation for further research to reveal details of the cell wall machinery and stress-responsive factors to provide targets and strategies to facilitate plant adaptation.

Breast cancer family history and allele-specific DNA methylation in the legacy girls study

Family history, a well-established risk factor for breast cancer, can have both genetic and environmental contributions. Shared environment in families as well as epigenetic changes that also may be influenced by shared genetics and environment may also explain familial clustering of cancers. Epigenetic regulation, such as DNA methylation, can change the activity of a DNA segment without a change in the sequence; environmental exposures experienced across the life course can induce such changes. However, genetic-epigenetic interactions, detected as methylation quantitative trait loci (mQTLs; a.k.a. meQTLs) and haplotype-dependent allele-specific methylation (hap-ASM), can also contribute to inter-individual differences in DNA methylation patterns. To identify differentially methylated regions (DMRs) associated with breast cancer susceptibility, we examined differences in white blood cell DNA methylation in 29 candidate genes in 426 girls (ages 6-13 years) from the LEGACY Girls Study, 239 with and 187 without a breast cancer family history (BCFH). We measured methylation by targeted massively parallel bisulfite sequencing (bis-seq) and observed BCFH DMRs in two genes: ESR1 (Δ4.9%, P = 0.003) and SEC16B (Δ3.6%, P = 0.026), each of which has been previously implicated in breast cancer susceptibility and pubertal development. These DMRs showed high inter-individual variability in methylation, suggesting the presence of mQTLs/hap-ASM. Using single nucleotide polymorphisms data in the bis-seq amplicon, we found strong hap-ASM in SEC16B (with allele specific-differences ranging from 42% to 74%). These findings suggest that differential methylation in genes relevant to breast cancer susceptibility may be present early in life, and that inherited genetic factors underlie some of these epigenetic differences.

Aflatoxin B1 exposure increases the risk of hepatocellular carcinoma associated with hepatitis C virus infection or alcohol consumption

BACKGROUND

Hepatocarcinogenicity of aflatoxin B₁ (AFB₁) has rarely been studied in populations with hepatitis C virus (HCV) infection and those without hepatitis B virus (HBV) and HCV infection (non-B-non-C). This case-control study nested in a community-based cohort aimed to investigate the HCC risk associated with AFB₁ in HCV-infected and non-B-non-C participants.

METHODS

Baseline serum AFB₁-albumin adduct levels were measured in 100 HCC cases and 1767 controls seronegative for anti-HCV and HBsAg (non-B-non-C), and another 103 HCC cases and 176 controls who were anti-HCV-seropositive and HBsAg-seronegative. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated using logistic regression.

RESULTS

In 20 years of follow-up, the follow-up time to newly developed HCC was significantly shorter in participants with higher serum AFB₁-albumin adduct levels in non-B-non-C (p = 0.0162) and HCV-infected participants (p < 0.0001). Within 8 years of follow-up, HCV infection and AFB₁ exposure were independent risk factors for HCC. Elevated serum AFB₁-albumin adduct levels were significantly associated with an increased risk of HCC newly developed within 8 years of follow-up in non-B-non-C participants with habitual alcohol consumption [crude OR (95% CI) for high vs. low/undetectable levels, 4.22 (1.16-15.37)] and HCV-infected participants [3.39 (1.31-8.77)], but not in non-B-non-C participants without alcohol drinking habit. AFB₁ exposure remained an independent risk predictor for HCV-related HCC after adjustment for other HCC predictors (multivariate-adjusted OR [95% CI], 3.65 [1.32-10.10]).

CONCLUSIONS

AFB₁ exposure contributes to the development of HCC in participants with significant risk factors for cirrhosis including alcohol and HCV infection.

Maternal cigarette smoking during pregnancy and offspring DNA methylation in midlife

Maternal smoking in pregnancy (MSP) has been associated with DNA methylation in specific CpG sites (CpGs) in infants and children. We investigated whether MSP, independent of own personal active smoking, was associated with midlife DNA methylation in CpGs that were previously identified in studies of MSP-DNA methylation in children. We used data on MSP collected from pregnant mothers of 89 adult women born in 1959-1964 and measured DNA methylation in blood (granulocytes) collected in 2001-2007 (mean age: 43 years). Seventeen CpGs were differentially methylated by MSP, with multiple CpGs mapping to CYP1A1, MYO1G, AHRR, and GFI1. These associations were consistent in direction with prior studies (e.g., MSP associated with more and less methylation in AHRR and CYP1A1, respectively) and, with the exception of AHRR CpGs, were not substantially altered by adjustment for active smoking. These preliminary results confirm prior prospective reports that MSP influences the offspring DNA methylation, and extends the timeframe to midlife, and suggest that these effects may persist into adulthood, independently of active smoking.

Plasma DNA methylation marker and hepatocellular carcinoma risk prediction model for the general population

Metastases in the later stages of hepatocellular carcinoma (HCC) cause the majority of deaths associated with the disease, making early detection crucial to patient survival. Risk models assessing HCC risk in the general population can be used for risk stratification for further HCC surveillance, however, none have been validated externally. Methylation of circulating DNA shows potential for non-invasive diagnosis of HCC. We conducted a prospective case-control study nested within a community-based cohort. We measured methylation levels in six genes (CDKN2A, RASSF1A, STEAP4, TBX2, VIM and ZNF154) which were identified in our previous work, using pre-diagnostic plasma DNA from 237 HCC cases and 257 matched controls. We found TBX2 hypermethylation was associated with increased HCC risk, with ORs (95% CI) of 3.2 (1.8-6.0). The associations were mainly among high-risk subjects; among subjects infected with HBV/HCV, the OR (95% CI) of TBX2 methylation was 5.3 (2.2-12.7). Among subjects with high risk scores, the ORs (95% CIs) were 7.8 (1.5-38.6) for Wen-HCC model ≥16, 5.8 (2.2-15.5) for Hung-HCC ≥15 and 7.5 (2.2-26.0) for Michikawa-HCC ≥8. Adding TBX2 methylation improved the accuracy of risk models for a high-risk population, with the area under the curve (AUC) of 76% for Wen-HCC score with TBX2 methylation compared with 69% with Wen-HCC alone. The AUCs were 63% for Hung-HCC score plus TBX2 methylation, and 53% for Hung-HCC alone, 65% for Michikawa-HCC score plus TBX2 methylation and 58% for Michikawa-HCC alone. Our findings suggest the potential increase in risk assessment discrimination and accuracy from incorporation of DNA methylation.

Using Silicon Polymer Impression Technique and Scanning Electron Microscopy to Measure Stomatal Aperture, Morphology, and Density

The number of stomata on leaves can be affected by intrinsic development programming and various environmental factors, in addition the control of stomatal apertures is extremely important for the plant stress response. In response to elevated temperatures, transpiration occurs through the stomatal apertures, allowing the leaf to cool through water evaporation. As such, monitoring of stomata behavior to elevated temperatures remains as an important area of research. The protocol allows analysis of stomatal aperture, morphology, and density through a non-destructive imprint of Arabidopsis thaliana leaf surface. Stomatal counts were performed and observed under a scanning electron microscope.

[Spatial analysis and prediction of severe fever with thrombocytopenia syndrome in Zhejiang province, 2011-2015]

Objective: To understand the distribution of the severe fever with thrombocytopenia syndrome (SFTS) in Zhejiang province, and predict the incidence and the probability of SFTS outbreak. Methods: Based on the cases of SFTS from 2011-2015, software ArcGIS 10.0 was used to analyze the spatial distribution, Moran's I and Getis-Ord Gi were used to analyze the spatial autocorrelation. The incidence trend was explored by trend surface analysis, and the prediction was made by Kriging interpolation. Results: The incidence of SFTS increased and the distribution expanded in Zhejiang from 2011 to 2015, the seasonal and the demographic characteristics of SFTS were similar to the previous research; there were regional clustering of the cases (P<0.001); a downward trend was observed from northeast to southwest in terms of incidence of SFTS; the second-order disjunctive Kriging interpolation based on circular model and the indicator Kriging interpolation based on exponential model had higher prediction accuracy, the probabilities of outbreak in Anji, Daishan and Tiantai were high, the prediction deviation of inland was less than that of edge area. Conclusion: The prediction of SFTS by Kriging interpolation had high accuracy, the incidence of SFTS was higher and the distribution of SFTS was larger than the results of surveillance, the risk areas for epidemic were Anji, Daishan, Ninghai,Tiantai, Sanmen and Linhai.

Abstract 2747: Plasma DNA methylation marker and hepatocellular carcinoma risk prediction model for the general population

Metastases in the later stages of hepatocellular carcinoma (HCC) cause the majority of deaths associated with the disease, making early detection crucial to patient survival. Risk models that assess HCC risk in the general population can be used for risk stratification for further HCC surveillance, however, none have been validated externally. Methylation of circulating DNA shows potential for noninvasive and early diagnosis of HCC. Most evidence, however, comes from cross-sectional studies raising concerns about temporality. We conducted a prospective case-control study nested within a community-based cohort. We measured methylation levels in of 6 genes (CDKN2A, RASSF1A, STEAP4, TBX2, VIM, and ZNF154) using pre-diagnostic plasma DNA from 237 HCC cases and 257 matched controls. We found TBX2 hypermethylation was associated with increased HCC risk, with ORs (95%CI) of 3.7 (1.9-7.2). The associations were mainly among high-risk subjects; among subjects infected with HBV/HCV, the OR (95%CI) of TBX2 methylation was 5.3 (2.2-12.7). Among subjects with high risk, the ORs (95%CIs) were 8.9 (1.0-73.9) for Wen-HCC score ≥16, 5.6 (2.1-14.6) for Hung-HCC score ≥15, and 7.2 (2.1-24.4) for Michikawa-HCC ≥8. Adding information on TBX2 methylation improved the accuracy of risk models for a high risk population, with the area under the curve (AUC) of 74% for TBX2 methylation and Wen-HCC score compared with 64% with Wen-HCC score alone. The AUCs were 63% for Hung-HCC score and TBX2 methylation, 53% for Hung-HCC score alone, 65% for Michikawa-HCC score and TBX2 methylation and 59% for Michikawa-HCC risk alone. Our findings suggest the potential increase in risk assessment discrimination and accuracy from incorporation of DNA methylation.

Citation Format: Hui-Chen Wu, Hwai-I Yang, Qiao Wang, Chien-Jen Chen, Regina M. Santella. Plasma DNA methylation marker and hepatocellular carcinoma risk prediction model for the general population [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2747. doi:10.1158/1538-7445.AM2017-2747

Global Level of Plasma DNA Methylation is Associated with Overall Survival in Patients with Hepatocellular Carcinoma

BACKGROUND

The impact of folate deficiency on global DNA methylation is uncertain. It also is unclear whether global DNA methylation is associated with outcome in HCC. LINE-1 methylation levels, as a surrogate marker of global methylation, may be influenced by folate deficiency. However, the interaction between LINE-1 methylation and folate level on overall survival (OS) in hepatocellular carcinoma (HCC) patients is unknown. We evaluated whether LINE-1 hypomethylation and folate deficiency are associated with HCC prognosis.

METHODS

We prospectively recruited 172 HCC patients between 2008 and 2012. LINE-1 methylation levels in plasma and white blood cells (WBC) were measured by pyrosequencing, and plasma folate levels by a radioprotein-binding assay.

RESULTS

Patients with plasma LINE-1 methylation <70.0% (hypomethylation) had significantly worse OS compared with those with ≥70.0% methylation (hypermethylation) [hazard ratio (HR) = 1.77; 95% confidence interval (CI) 1.12-2.79; P = 0.015]. HCC patients with lower plasma folate levels also had worse survival (<27.7 vs. ≥27.7 nmol/L; HR = 1.96; 95% CI, 1.24-3.09; P = 0.004). Furthermore, survival was poor in patients in whom both plasma LINE-1 methylation and folate levels were low compared with those patients in whom both levels were high (HR = 3.36; 95%CI, 1.77-6.40; P < 0.001). This interaction neared statistical significance (P = 0.057). No significant association was found between WBC LINE-1 methylation levels and survival.

CONCLUSIONS

These findings suggest that both lower plasma levels of LINE-1 methylation and folate are associated with worse survival in HCC patients.

Pectin methylesterase is required for guard cell function in response to heat

Pectin is an important cell wall polysaccharide required for cellular adhesion, extension, and plant growth. The pectic methylesterification status of guard cell walls influences the movement of stomata in response to different stimuli. Pectin methylesterase (PME) has a profound effect on cell wall modification, especially on the degree of pectic methylesterification during heat response. The Arabidopsis thaliana PME34 gene is highly expressed in guard cells and in response to the phytohormone abscisic acid. The genetic data highlighted the significant role of PME34 in heat tolerance through the regulation of stomatal movement. Thus, the opening and closure of stomata is mediated by changes in response to a given stimulus, could require a specific cell wall modifying enzyme to function properly.

PECTIN METHYLESTERASE34 Contributes to Heat Tolerance through Its Role in Promoting Stomatal Movement

Pectin, a major component of the primary cell wall, is synthesized in the Golgi apparatus and exported to the cell wall in a highly methylesterified form, then is partially demethylesterified by pectin methylesterases (PMEs; EC 3.1.1.11). PME activity on the status of pectin methylesterification profoundly affects the properties of pectin and, thereby, is critical for plant development and the plant defense response, although the roles of PMEs under heat stress (HS) are poorly understood. Functional genome annotation predicts that at least 66 potential PME genes are contained in Arabidopsis (Arabidopsis thaliana). Thermotolerance assays of PME gene T-DNA insertion lines revealed two null mutant alleles of PME34 (At3g49220) that both consistently showed reduced thermotolerance. Nevertheless, their impairment was independently associated with the expression of HS-responsive genes. It was also observed that PME34 transcription was induced by abscisic acid and highly expressed in guard cells. We showed that the PME34 mutation has a defect in the control of stomatal movement and greatly altered PME and polygalacturonase (EC 3.2.1.15) activity, resulting in a heat-sensitive phenotype. PME34 has a role in the regulation of transpiration through the control of the stomatal aperture due to its cell wall-modifying enzyme activity during the HS response. Hence, PME34 is required for regulating guard cell wall flexibility to mediate the heat response in Arabidopsis.

Aflatoxin B1 exposure increases the risk of cirrhosis and hepatocellular carcinoma in chronic hepatitis B virus carriers

The relation between aflatoxin B₁ (AFB₁ ) and cirrhosis in chronic carriers of hepatitis B virus (HBV) remains inconclusive. This case-control study nested in a large community-based cohort aimed to assess the effect of AFB₁ exposure on cirrhosis and HCC in chronic HBV carriers. Serum AFB₁ -albumin adduct levels at study entry were measured in 232 cirrhosis cases, 262 HCC cases and 577 controls. Multivariate-adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were estimated using logistic regression. Among all chronic HBV carriers, the time intervals between study entry and diagnosis of HCC, cirrhosis, cirrhotic HCC, and non-cirrhotic HCC were all significantly (p < 0.0001) shorter in participants with high serum levels of AFB₁ -albumin adducts than those with low/undetectable levels. There were significant dose-response relations with serum AFB₁ -albumin adduct level at study entry for cirrhosis (p-trend = 0.0001) and cirrhotic HCC (p-trend < 0.0001) newly diagnosed within 9 years after entry as well as non-cirrhotic HCC (p-trend = 0.021) newly diagnosed within 4 years after entry. The aORs (95% CIs) for high versus undetectable serum AFB₁ -albumin adduct levels were 2.45 (1.51-3.98) for cirrhosis (p = 0.0003), 5.47 (2.20-13.63) for cirrhotic HCC (p = 0.0003), and 5.39 (1.11-26.18) for non-cirrhotic (p = 0.0368) HCC, respectively. There remained a significant dose-response relation between serum AFB₁ -albumin adduct level and HCC risk (p-trend = 0.0291) in cirrhosis patients, showing an aOR (95% CI) of 3.04 (1.11-8.30) for high versus undetectable serum levels (p = 0.0299). It is concluded that AFB₁ exposure may increase the risk of cirrhosis and HCC in a dose-response manner among chronic HBV carriers.

DNA Methylation in Breast Tumor from High-risk Women in the Breast Cancer Family Registry

To examine DNA methylation profiles in breast tumors of women with a strong breast cancer family history, we measured methylation by bisulfite sequencing in 40 genes in 40 breast tumor tissues from women in the Breast Cancer Family Registry. We selected candidate genes from analysis of the Cancer Genome Atlas project (TCGA) breast data. Compared to TCGA breast cancer, BCFR cases are younger and more likely to be ER-negative. Overall, we found that many of the methylation differences between BCFR tumor and normal adjacent tissues were smaller than that in TCGA samples. We found only 32% of tested genes were hypermethylated in BCFR; the largest difference was 36.1% for SEPW1, and the smallest difference was 10% for RYR2. These data suggest the importance of examining breast cancer cases including familial cases enriched with early-onset cancers to identify methylation markers that can be examined in blood as biomarkers for early detection.

Telomere Length and Risk of Hepatocellular Carcinoma: A Nested Case-control Study in Taiwan Cancer Screening Program Cohort

BACKGROUND

Telomere length (TL) measured in peripheral blood leucocytes (PBL) might be a useful biomarker to identify elevated cancer risk.

PATIENTS AND METHODS

A case-control study which included 268 newly-diagnosed HCC cases and 536 matched controls, was conducted. Absolute TL in PBL was analyzed by quantitative real-time PCR.

RESULTS

The overall median length of TL was not statistically shorter in HCC cases compared to healthy controls. However, we found a significant synergistic effect of longer TL and HCV infection to increase HCC risk with a relative excess risk of 6.86 (95% CI: 2.14-11.58). Among HCC cases, significant shorter TLs were observed for <5 years (OR=3.93, 95% CI: 2.00-7.72); 5-10 years (OR=2.16, 95% CI: 1.10-4.24) compared to >10 years prior to diagnosis.

CONCLUSION

Shorter PBL TL alone was not significantly associated with increased HCC risk. Among HCC cases, significant shorter TLs were observed for <5 years prior to diagnosis.

Terahertz generation from laser-driven ultrafast current propagation along a wire target

Generation of intense coherent THz radiation by obliquely incidenting an intense laser pulse on a wire target is studied using particle-in-cell simulation. The laser-accelerated fast electrons are confined and guided along the surface of the wire, which then acts like a current-carrying line antenna and under appropriate conditions can emit electromagnetic radiation in the THz regime. For a driving laser intensity ∼3×10^{18}W/cm^{2} and pulse duration ∼10 fs, a transient current above 10 KA is produced on the wire surface. The emission-cone angle of the resulting ∼0.15 mJ (∼58 GV/m peak electric field) THz radiation is ∼30^{∘}. The conversion efficiency of laser-to-THz energy is ∼0.75%. A simple analytical model that well reproduces the simulated result is presented.

Abstract 4439: Relationship between DNA methylation of TET genes and levels of 5-methyl-cytosine and 5-hydroxymethyl-cytosine in hepatocellular carcinoma

Long-term survival after hepatocellular carcinoma (HCC) diagnosis has clearly improved as a result of treatment by means of a liver transplant. However, a large number of cases do not meet the transplant criteria and undergo resection. In these patients, loss of global DNA hydroxymethylation has been linked to worse prognosis, but no association has been found in transplant patients. Differential epigenetic processing is a possible reason for this, and has not been previously explored. The process of DNA demethylation is mediated by the family of ten-eleven translocation (TET) proteins, that catalyze the conversion of 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC). There are three different TET protein variants: TET1, TET2 and TET3. Studies have shown that expression of at least TET1 is epigenetically regulated. In this study we investigated the association between DNA methylation of TET genes and global DNA methylation and hydroxymethylation in 66 tumor (T) and non-tumor (NT) paired samples of individuals treated at Columbia Presbyterian Medical Center in New York. Levels of 5mC and 5hmC were determined by UPLC/MS/MS, and DNA methylation of the TET promoters was obtained from Illumina Infinium 450k CpG array data. Mean levels of 5mC (T = 3.15±0.49% vs. NT = 3.80±0.12% (p&lt;0.0001) and 5hmC (T = 0.11±0.04% vs. NT = 0.23±0.07%, p&lt;0.0001) in tumor tissues were statistically significantly lower than in non-tumor tissues. In contrast, average DNA methylation levels of TET1 (T = 0.40±0.06% vs. NT = 0.35±0.02%, p&lt;0.0001) were statistically significantly lower in non-tumor tissues than in tumor tissues. However, this was not the case for TET2 or TET3. TET1 DNA methylation levels negatively correlate with global DNA 5mC levels in tumor and non-tumor tissue (Spearman correlation coefficient: T = -0.47 (p = 0.002) and NT = -0.60 (p&lt;0.0001)). In contrast, associations between gene DNA methylation and 5hmC DNA levels were different for the tumor and non-tumor tissue samples. 5hmC levels positively and statistically significantly correlated with TET1 and TET2 DNA methylation (Spearman corr. coef TET1 NT = 0.57 (p&lt;0.0001), and TET2 NT = 0.56 (p&lt;0.0001)) in non-tumor tissue while there was a statistically significant negative correlation with TET3 (Spearman corr. coef. TET3 T = -0.37 (p = 0.005)). No other associations were found between 5mC and 5hmC levels and TET gene DNA methylation levels. These findings suggest higher expression of TET1 correlates with a hypomethylated state and that the accumulation of 5hmC possibly results from a downregulation of TET1 and TET2 in non-tumor tissue. HCC carcinogenesis alters this process, and while further studies need to be conducted, TET3 seems to play a larger role in tumor cells. Our sample size was limited, but these results suggest that future research of 5hmC might help elucidate HCC underlying molecular events and aid in the design of prognostic markers.

Citation Format: Lissette Delgado-Cruzata, Hui-Chen Wu, Jin Shen, Tiffany Thomas, Abby B. Siegel, Yu-Jing Zhang, Abhishek Goyal, Christine C. Hsu, Helen E. Remotti, Regina M. Santella. Relationship between DNA methylation of TET genes and levels of 5-methyl-cytosine and 5-hydroxymethyl-cytosine in hepatocellular carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4439.

Abstract 2555: Promoter DNA methylation patterns in breast tumor and matched adjacent non-tumor tissues in the breast cancer family registry

Alterations in DNA methylation occur frequently in breast carcinogenesis, but little is known about the DNA methylation changes in familial breast tumors. To examine whether the DNA methylation profiles in breast cancer tissues from high risk women from breast cancer families are similar to breast tumor tissues from The Cancer Genome Atlas project (TCGA), we measured DNA methylation by next generation sequencing in 48 genes identified in TCGA in 40 formalin-fixed, paraffin-embedded tumor tissues, and the corresponding adjacent non-tumor tissues from women with invasive breast cancer at the New York site of the Breast Cancer Family Registry (BCFR). We observed differences in DNA methylation patterns between tumor and normal adjacent tissue for five of the selected genes (RYR2, C1orf14, SLC7A14, SEPW1, and RPTOR). The methylation levels in tumor and adjacent tissues, respectively were 24% and 14% for RYR2, (p = 0.01), 55% and 29% for C1orf14 (p = 0.01), 32% and 21% for SLC7A14 (p = 0.002), 53% and 28% for RPTOR (p = 0.01) and 74% and 38% SEPW1 (p&lt;0.0001). We only confirmed 5 of the 48 loci identified in TCGA in our sample of high risk women, suggesting genes identified from TCGA may be different than those in high-risk women. As tissue-specific methylation may prove to have strong prognostic significance, this suggests a critical need to engage in large-scale studies examining genome-wide DNA methylation profiles in high risk women in order to understand the etiology of familial breast cancer.

Citation Format: Hui-Chen Wu, Hanina Hibshoosh, Regina Santella, Mary Beth Terry. Promoter DNA methylation patterns in breast tumor and matched adjacent non-tumor tissues in the breast cancer family registry. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2555.

Antisite disorder driven spontaneous exchange bias effect in La(2-x)Sr(x) CoMnO₆ (0 ⩽ x ⩽ 1)

Doping at the rare-earth site by divalent alkaline-earth ions in perovskite lattice has witnessed a variety of magnetic and electronic orders with spatially correlated charge, spin and orbital degrees of freedom. Here, we report an antisite disorder driven spontaneous exchange bias effect as a result of hole carrier (Sr(2+)) doping in La(2-x)Sr(x)CoMnO6 (0  <  x  <  1) double perovskites. X-ray diffraction and Raman spectroscopy have evidenced an increase in disorder with the increase of Sr content up to x  =  0.5 and thereby a decrease from x  =  0.5 to 1. X-ray absorption spectroscopy has revealed that only Co is present in the mixed valence of Co(2+) and Co(3+) states with Sr doping to compensate the charge neutrality. Magnetotransport is strongly correlated with the increase of antisite disorder. The antisite disorder at the B-site interrupts the long-range ferromagnetic order by introducing various magnetic interactions and instigates reentrant glassy dynamics, phase separation and canted type antiferromagnetic behavior with the decrease of temperature. This leads to a novel magnetic microstructure with unidirectional anisotropy that causes a spontaneous exchange bias effect that can be tuned with the amount of antisite disorder.

Blood DNA methylation markers in prospectively identified hepatocellular carcinoma cases and controls from Taiwan

AIM: To determine if gene-specific DNA methylation in prospectively collected blood samples is associated with later development of hepatocellular carcinoma (HCC).

METHODS: Comparing genome-wide DNA methylation profiles using Illumina Human methylation 450K arrays, we previously identified a list of loci that were differentially methylated between tumor and adjacent nontumor tissues. To examine if dysregulation of DNA methylation patterns observed in tumor tissues can be detected in white blood cell (WBC) DNA, we conducted a prospective case-control study nested within a community-based cancer screening cohort in Taiwan with 16 years of follow up. We measured methylation levels in ninety-six loci that were aberrant in DNA methylation in HCC tumor tissues compared to adjacent tissues. Baseline WBC DNA from 159 HCC cases and 312 matched controls were bisulfite treated and assayed by Illumina BeadArray. We used the χ² test for categorical variables and student’s t-test for continuous variables to assess the difference in selected characteristics between cases and controls. To estimate associations with HCC risk, we used conditional logistic regression models stratified on the matching factors to calculate odds ratios (OR) and 95%CI.

RESULTS: We found that high methylation level in cg10272601 in WNK2 was associated with increased risk of HCC, with an OR of 1.91 (95%CI: 1.27-2.86). High methylation levels in both cg12680131 in TPO and cg22511877 in MYT1L, however, were associated with decreased risk. The ORs (95%CI) were 0.59 (0.39-0.87) and 0.50 (0.33-0.77), respectively, for those with methylation levels of cg12680131 and cg22511877 above the median compared with those with levels below the median. These associations were still statistically significant in multivariable conditional logistic regression models after adjusting for hepatitis B virus infection and alcohol consumption.

CONCLUSION: These findings support the measurement of methylation markers in WBC DNA as biomarkers of HCC susceptibility but should be replicated in additional prospective studies.

Abstract 3835: DNA methylation levels in mononuclear DNA in breast cancer from the New York site of the BCFR

Alterations in DNA methylation both at specific loci and overall, have been associated with breast cancer. These alterations have primarily been observed at the tissue level, although emerging studies are evaluating white blood cell (WBC) DNA methylation.

To examine whether DNA methylation change measured prospectively in a family-based cohort are associated with breast cancer risk, we measured methylation levels of two repetitive elements (LINE-1, and Sat2) and three genes in mononuclear cell DNA (BLNK, CUEDC1, and IBSP) previously identified as differentially methylated in breast cancer in a genome-wide association study. After an average of 8 years of followup, we observed 81 invasive incident breast cancers and compared their methylation levels measured with baseline bloods with the remaining 1,508 women not affected with breast cancer in the New York site of the Breast Cancer Family Registry (BCFR). We found that the overall percent methylation in CUEDC1 was statistically significantly higher in breast cancer cases than in controls (78.0% versus 76.8%, respectively, p = 0.02). In a multivariable Cox Proportional Hazards model adjusting for age at blood draw, with each 1 unit increase in CUEDC1 methylation level, the OR for breast cancer increased by 1.07 (95% Confidence Interval (CI) = 1.00-1.14). We did not find the other methylation markers to be related to risk. The area under the curve was 67.6% (95% CI = 61.4% to 73.8%) for the 5 methylation markers and Gail risk score, compared with 63.3% for the Gail score only.

Our finding for CUEDC1 replicates the finding from the Sisters Study supporting that selected markers selected markers of epigenetic changes measured in WBC may be potential biomarkers of breast cancer risk.

Citation Format: Hui-Chen Wu, Qiao Wang, Regina M. Santella, Mary B. Terry. DNA methylation levels in mononuclear DNA in breast cancer from the New York site of the BCFR. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3835. doi:10.1158/1538-7445.AM2015-3835