Novel breast cancer susceptibility loci under linkage peaks identified in African ancestry consortia

BACKGROUND

Expansion of genome-wide association studies across population groups is needed to improve our understanding of shared and unique genetic contributions to breast cancer. We performed association and replication studies guided by a priori linkage findings from African ancestry (AA) relative pairs.

METHODS

We performed fixed-effect inverse-variance weighted meta-analysis under three significant AA breast cancer linkage peaks (3q26-27, 12q22-23, and 16q21-22) in 9241 AA cases and 10 193 AA controls. We examined associations with overall breast cancer as well as estrogen receptor (ER)-positive and negative subtypes (193,132 SNPs). We replicated associations in the African-ancestry Breast Cancer Genetic Consortium (AABCG).

RESULTS

In AA women, we identified two associations on chr12q for overall breast cancer (rs1420647, OR = 1.15, p = 2.50×10-6; rs12322371, OR = 1.14, p = 3.15×10-6), and one for ER-negative breast cancer (rs77006600, OR = 1.67, p = 3.51×10-6). On chr3, we identified two associations with ER-negative disease (rs184090918, OR = 3.70, p = 1.23×10-5; rs76959804, OR = 3.57, p = 1.77×10-5) and on chr16q we identified an association with ER-negative disease (rs34147411, OR = 1.62, p = 8.82×10-6). In the replication study, the chr3 associations were significant and effect sizes were larger (rs184090918, OR: 6.66, 95% CI: 1.43, 31.01; rs76959804, OR: 5.24, 95% CI: 1.70, 16.16).

CONCLUSION

The two chr3 SNPs are upstream to open chromatin ENSR00000710716, a regulatory feature that is actively regulated in mammary tissues, providing evidence that variants in this chr3 region may have a regulatory role in our target organ. Our study provides support for breast cancer variant discovery using prioritization based on linkage evidence.

Lifestyle factors, genetic susceptibility to obesity and their interactions on coronary artery disease risk: A cohort study in the UK Biobank

OBJECTIVE

We aimed to evaluate potential modifying effects of genetic susceptibility to obesity on the association of lifestyle factors with coronary artery disease (CAD) risk.

METHODS

A total of 328,606 participants (54% women) were included using data from the UK Biobank. We evaluated the risk of developing CAD associated with obesity-related polygenic scores (PGSs) and healthy lifestyle scores (HLSs). HLSs were constructed using six lifestyle factors. Obesity PGSs were created using genetic variants identified by genome-wide association studies, including 941 variants for body mass index (BMI) and 457 for waist-to-hip ratio (WHR). Both HLSs and PGSs were categorized into three groups.

RESULTS

During a 9-year median follow-up, 14,541 participants developed CAD. An unhealthy lifestyle was significantly associated with an increased CAD risk (hazard ratio [HR] = 2.24, 95% confidence interval [CI] = 2.09-2.40). High BMI and WHR PGSs were each significantly associated with an increased CAD risk (HRBMI = 1.23, 1.17-1.29; HRWHR = 1.15, 1.09-1.21). Lifestyle factors explained 41% (95% CI = 38%-45%) of CAD, while genetic variants for BMI explained only 10% (7%-14%). Risks of CAD were increased with poorer HLS independent of obesity-related PGSs. Individuals with the most unhealthy lifestyle and highest BMI PGS had the highest risk of CAD risk (HR = 2.59, 95% CI = 2.26-2.97), compared with participants with the healthiest lifestyle and lowest BMI PGS.

CONCLUSIONS

While the observational nature of the study precludes the establishment of causality, our study provides supports for a causal association between obesity and CAD risk and the importance of lifestyle modification in the prevention of CAD.

Evaluating interactions of polygenic risk scores and NAT2 genotypes with tobacco smoking in bladder cancer risk

Tobacco smoking is the most important risk factor for bladder cancer. Previous studies have identified the N-acetyltransferase (NAT2) gene in association with bladder cancer risk. The NAT2 gene encodes an enzyme that metabolizes aromatic amines, carcinogens commonly found in tobacco smoke. In our study, we evaluated potential interactions of tobacco smoking with NAT2 genotypes and polygenic risk score (PRS) for bladder cancer, using data from the UK Biobank, a large prospective cohort study. We used Cox proportional hazards models to measure the strength of the association. The PRS was derived using genetic risk variants identified by genome-wide association studies for bladder cancer. With an average of 10.1 years of follow-up of 390 678 eligible participants of European descent, 769 incident bladder cancer cases were identified. Current smokers with a PRS in the highest tertile had a higher risk of developing bladder cancer (HR: 6.45, 95% CI: 4.51-9.24) than current smokers with a PRS in the lowest tertile (HR: 2.41, 95% CI: 1.52-3.84; P for additive interaction = <.001). A similar interaction was found for genetically predicted metabolizing NAT2 phenotype and tobacco smoking where current smokers with the slow NAT2 phenotype had an increased risk of developing bladder cancer (HR: 5.70, 95% CI: 2.64-12.30) than current smokers with the fast NAT2 phenotype (HR: 3.61, 95% CI: 1.14-11.37; P for additive interaction = .100). Our study provides support for considering both genetic and lifestyle risk factors in developing prevention measures for bladder cancer.

Association of ESR1 germline variants with TP53 somatic variants in breast tumors in a genome-wide study

Background

In breast tumors, somatic mutation frequencies in TP53 and PIK3CA vary by tumor subtype and ancestry. HER2 positive and triple negative breast cancers (TNBC) have a higher frequency of TP53 somatic mutations than other subtypes. PIK3CA mutations are more frequently observed in hormone receptor positive tumors. Emerging data suggest tumor mutation status is associated with germline variants and genetic ancestry. We aimed to identify germline variants that are associated with somatic TP53 or PIK3CA mutation status in breast tumors.

Methods

A genome-wide association study was conducted using breast cancer mutation status of TP53 and PIK3CA and functional mutation categories including TP53 gain of function (GOF) and loss of function mutations and PIK3CA activating/hotspot mutations. The discovery analysis consisted of 2850 European ancestry women from three datasets. Germline variants showing evidence of association with somatic mutations were selected for validation analyses based on predicted function, allele frequency, and proximity to known cancer genes or risk loci. Candidate variants were assessed for association with mutation status in a multi-ancestry validation study, a Malaysian study, and a study of African American/Black women with TNBC.

Results

The discovery Germline x Mutation (GxM) association study found five variants associated with one or more TP53 phenotypes with P values <1×10-6, 33 variants associated with one or more TP53 phenotypes with P values <1×10-5, and 44 variants associated with one or more PIK3CA phenotypes with P values <1×10-5. In the multi-ancestry and Malaysian validation studies, germline ESR1 locus variant, rs9383938, was associated with the presence of TP53 mutations overall (P values 6.8×10-5 and 9.8×10-8, respectively) and TP53 GOF mutations (P value 8.4×10-6). Multiple variants showed suggestive evidence of association with PIK3CA mutation status in the validation studies, but none were significant after correction for multiple comparisons.

Conclusions

We found evidence that germline variants were associated with TP53 and PIK3CA mutation status in breast cancers. Variants near the estrogen receptor alpha gene, ESR1, were significantly associated with overall TP53 mutations and GOF mutations. Larger multi-ancestry studies are needed to confirm these findings and determine if these variants contribute to ancestry-specific differences in mutation frequency.

Large-scale alternative polyadenylation (APA)-wide association studies to identify putative susceptibility genes in human common cancers

Alternative polyadenylation (APA) modulates mRNA processing in the 3' untranslated regions (3'UTR), which affect mRNA stability and translation efficiency. Here, we build genetic models to predict APA levels in multiple tissues using sequencing data of 1,337 samples from the Genotype-Tissue Expression, and apply these models to assess associations between genetically predicted APA levels and cancer risk with data from large genome-wide association studies of six common cancers, including breast, ovary, prostate, colorectum, lung, and pancreas among European-ancestry populations. At a Bonferroni-corrected P □<□0.05, we identify 58 risk genes, including seven in newly identified loci. Using luciferase reporter assays, we demonstrate that risk alleles of 3'UTR variants, rs324015 ( STAT6 ), rs2280503 ( DIP2B ), rs1128450 ( FBXO38 ) and rs145220637 ( LDAH ), could significantly increase post-transcriptional activities of their target genes compared to reference alleles. Further gene knockdown experiments confirm their oncogenic roles. Our study provides additional insight into the genetic susceptibility of these common cancers.

Compound bioengineering protein supplementation improves intestinal health and growth performance of broilers

Currently, antimicrobial peptides (AMPs) are of growing interest as potential substitutes for antibiotic growth promoters in animal production. The present study was conducted to evaluate the effects of dietary supplementation of bioengineering artificial Parasin I protein (API) and artificial plectasin protein (APL) (named as compound bioengineering protein, CBP) on growth performance and intestinal health of broilers. A total of 450 one-day-old Arbor Acres male healthy broilers were randomly allotted to 5 dietary groups with 10 replicates of 9 individuals in each replicate and supplemented with 0, 250, 500, 750, and 1,000 mg/kg CBP for 6 wk. Dietary CBP supplementation increased (P < 0.01) body weight (6 wk), average daily gain (0-6 wk), and average daily feed intake (3-6 wk and 0-6 wk). CBP addition enhanced antioxidant capacity, which was accompanied by the higher (P < 0.05) activity of serum total antioxidant capacity (T-AOC) (750 mg/kg), jejunal glutathione peroxidase (750 mg/kg), and T-AOC (500 and 1,000 mg/kg). Dietary CBP addition improved intestinal health, reflecting by the increased (P < 0.05) villus height to crypt depth ratio in the duodenum, the upregulated (P < 0.01) mRNA levels of claudin-1 (500 and 750 mg/kg) in the ileum, the downregulated (P < 0.01) mRNA expression of occludin (500 mg/kg) in the duodenum and claudin-1 (500 mg/kg) and occludin (500 and 750 mg/kg) in the jejunum, and the upregulated mRNA expression of (P < 0.01) mucin2 (MUC2) (1,000 mg/kg) in the duodenum. In addition, CBP upregulated (P < 0.01) IL-10 (1,000 mg/kg) in duodenum and ileum, and downregulated (P < 0.05) the mRNA expression of IL-6 (750 and 1,000 mg/kg), interferon-γ (1,000 mg/kg) in the jejunum and TNF-α (250 mg/kg) in the ileum. Furthermore, dietary CBP increased (P < 0.01) the abundance of total bacteria and Lactobacillus (500 and 750 mg/kg), and reduced (P < 0.05) the abundance of Escherichia coli (750 mg/kg) in the cecum. In conclusion, CBP supplementation enhances the antioxidant capacity, intestinal health, immune function, and ameliorates the gut microflora population, thus improving the growth performance of broilers. Dietary supplementation of 750 mg/kg CBP exhibits a better beneficial effect.

Integrating genomics and proteomics data to identify candidate plasma biomarkers for lung cancer risk among European descendants

BACKGROUND

Plasma proteins are potential biomarkers for complex diseases. We aimed to identify plasma protein biomarkers for lung cancer.

METHODS

We investigated genetically predicted plasma levels of 1130 proteins in association with lung cancer risk among 29,266 cases and 56,450 controls of European descent. For proteins significantly associated with lung cancer risk, we evaluated associations of genetically predicted expression of their coding genes with the risk of lung cancer.

RESULTS

Nine proteins were identified with genetically predicted plasma levels significantly associated with overall lung cancer risk at a false discovery rate (FDR) of <0.05. Proteins C2, MICA, AIF1, and CTSH were associated with increased lung cancer risk, while proteins SFTPB, HLA-DQA2, MICB, NRP1, and GMFG were associated with decreased lung cancer risk. Stratified analyses by histological types revealed the cross-subtype consistency of these nine associations and identified an additional protein, ICAM5, significantly associated with lung adenocarcinoma risk (FDR < 0.05). Coding genes of NRP1 and ICAM5 proteins are located at two loci that have never been reported by previous GWAS. Genetically predicted blood levels of genes C2, AIF1, and CTSH were associated with lung cancer risk, in directions consistent with those shown in protein-level analyses.

CONCLUSION

Identification of novel plasma protein biomarkers provided new insights into the biology of lung cancer.

[Effects of titanium dioxide nanoparticles on circRNA expression profiles in human hepatocellular carcinoma cells HepG2]

OBJECTIVE

To investigate the effect of titanium dioxide nanoparticles (TiO₂ NPs) on the expression profile of circular ribonucleic acid (circRNA) in human hepatocytes through in vitro cell experiments, and to attempt to understand the potential mechanism of hepatotoxicity through bioinformatics analysis.

METHODS

TiO₂ NPs were characterized from the aspects of particle size, shape and agglomeration state. The cell counting kit-8 (CCK8) was used to detect the cytotoxicity of TiO₂ NPs against human hepatocellular carcinoma cells (HepG2) after exposure to 0, 1.56, 3.13, 6.25, 12.5, 25, 50, 100, and 200 mg/L TiO₂ NPs for 24 h or 48 h. The cells were treated at doses of 0 mg/L TiO₂ NPs (control group) and 100 mg/L TiO₂ NPs (treatment group), and collected after exposure for 48 h, and then RNA from the extracted cell samples was collected and sequenced. The differential circRNAs between the control and the TiO₂ NPs treatment groups were screened, and then the enrichment pathway of the differential circRNA target gene was analyzed by multivariate statistics. According to the sequencing results, significantly altered genes and important genes in the significant enrichment pathways were screened, and real-time reverse transcription-polymerase chain reaction (real-time RT-PCR) was performed to verify the results.

RESULTS

TiO₂ NPs were spherical anatase with a hydrated particle size of (323.50±85.44) nm and a Zeta potential of (-21.00±0.72) mV in a serum-free medium. The results of the CCK8 cytotoxicity assay showed that with the increase of TiO₂ NPs concentration, cell viability gradually decreased. A total of 11 478 circRNAs were found by RNA sequencing. Compared with the control groups, TiO₂ NPs treatment groups (100 mg/L) had a total of 89 differential circRNAs, of which 59 were up-regulated and 30 were down-regulated. Analysis of the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway showed that the targeted genes of differential circRNAs were mainly enriched in fatty acid degradation, Fanconi anemia pathway, and fatty acid metabolism. The expression levels of circRNA.6730, circRNA.3650 and circRNA.4321 were significantly different between the TiO₂ NPs treatment group and the control group, which were consistent with the sequencing results.

CONCLUSION

TiO₂ NPs can induce changes in circRNA expression profile, and epigenetics may play an important role in the mechanism of hepatotoxicity.

ASIC1a involves the acid-mediated activation of pancreatic stellate cells associated with autophagy induction

The acidic tumor microenvironment (TME) of pancreatic cancer affects the physiological function of pancreatic stellate cells (PSCs), which in turn promotes cancer progression. Acid-sensing ion channel 1a (ASIC1a) is responsible for acidosis-related physiopathological processes. In this study, we investigated the effect of acid exposure on the activation and autophagy of PSCs, and the role of ASIC1a in these events. The results showed that acidic medium upregulated the expression of ASIC1a, induced PSCs activation and autophagy, which can be suppressed by inhibiting ASIC1a using PcTx1 or ASIC1a knockdown, suggesting that ASIC1a involves these two processes. In addition, the acid-induced activation of PSCs was impaired after the application of autophagy inhibitor alone or in combination with ASIC1a siRNA, meaning a connection between autophagy and activation. Collectively, our study provides evidence for the involvement of ASIC1a in the acid-caused PSCs activation, which may be associated with autophagy induction.

Identification of target proteins for breast cancer genetic risk loci and blood risk biomarkers in a large study by integrating genomic and proteomic data

Genome-wide association studies (GWAS) have identified around 200 loci associated with breast cancer risk. However, protein targets for these loci remain largely unknown. Identifying protein targets and biomarkers can improve the understanding of cancer biology and etiology and identify high-risk individuals for cancer prevention. In this study, we investigated genetically predicted levels of 1142 circulating proteins with breast cancer risk in 133 384 cases and 113 789 controls of European ancestry included in the Breast Cancer Association Consortium (BCAC). We identified 22 blood protein biomarkers associated with the risk of overall breast cancer at a false discovery rate (FDR) <0.05, including nine proteins encoded by genes located at least 500 kb away from previously reported risk variants for breast cancer. Analyses focusing on 124 encoding genes located at GWAS-identified breast cancer risk loci found 20 proteins associated with overall breast cancer risk and one protein associated with triple-negative breast cancer risk at FDR <0.05. Adjustment for the GWAS-identified risk variants significantly attenuated the association for 13 of these proteins, suggesting that these proteins may be the targets of these GWAS-identified risk loci. The identified proteins are involved in various biological processes, including glutathione conjugation, STAT5 signaling and NF-κB signaling pathways. Our study identified novel protein targets and risk biomarkers for breast cancer risk.

Serum lipid profiles and cholesterol-lowering medication use in relation to subsequent risk of colorectal cancer in the UK Biobank cohort

BACKGROUND

Dyslipidemia is closely associated with metabolic syndrome, a known risk factor for colorectal cancer (CRC). However, the association of dyslipidemia with CRC risk is controversial. Most previous studies did not consider cholesterol-lowering medication use at the time of lipid measurements, which could bias findings.

METHODS

We analyzed data from 384,862 UK Biobank participants to disentangle the associations between blood lipids and CRC risk. Serum levels of total cholesterol, high- and low-density lipoprotein cholesterol (HDL-C, LDL-C), and triglyceride were measured at study baseline. Multivariable-adjusted Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During a median follow-up time of 8.2 years, 3,150 incident primary CRC cases were identified. Triglyceride levels were positively, while HDL-C levels were inversely associated with CRC risk (both Ptrend <0.005). No significant associations were found for total cholesterol and LDL-C. However, among non-users of cholesterol-lowering medications, a high total cholesterol level (>6.7 mmol/L, HR =1.11; 95% CI =1.00-1.24) and LDL-C level (>4.1 mmol/L, HR =1.11; 95% CI =0.99-1.23) was associated with an increased CRC risk compared with the referent group (5.2-6.2 mmol/L and 2.6-3.4 mmol/L for total and LDL cholesterol, respectively). Compared with non-users, cholesterol-lowering medication users had 15% increased CRC risk (HR =1.15; 95% CI =1.04-1.26).

CONCLUSIONS

Circulating total cholesterol, LDL-C, HDL-C and triglyceride were modestly associated with CRC risk.

IMPACT

Our findings call for careful consideration of cholesterol-lowering medication use in future studies of blood lipid-CRC associations.

Genome- and transcriptome-wide association studies of 386,000 Asian and European-ancestry women provide new insights into breast cancer genetics

By combining data from 160,500 individuals with breast cancer and 226,196 controls of Asian and European ancestry, we conducted genome- and transcriptome-wide association studies of breast cancer. We identified 222 genetic risk loci and 137 genes that were associated with breast cancer risk at a p < 5.0 × 10^-8 and a Bonferroni-corrected p < 4.6 × 10^-6, respectively. Of them, 32 loci and 15 genes showed a significantly different association between ER-positive and ER-negative breast cancer after Bonferroni correction. Significant ancestral differences in risk variant allele frequencies and their association strengths with breast cancer risk were identified. Of the significant associations identified in this study, 17 loci and 14 genes are located 1Mb away from any of the previously reported breast cancer risk variants. Pathways analyses including 221 putative risk genes identified multiple signaling pathways that may play a significant role in the development of breast cancer. Our study provides a comprehensive understanding of and new biological insights into the genetics of this common malignancy.

Degradation of oxalic acid produced by Botrytis elliptica infection in two ploidy levels of Lilium rosthornii Diels

Oxalic acid (OA) is a crucial pathogenic factor for Sclerotinia spp. fungi, which is closely related to Botrytis spp. fungi. Whether OA is a pathogenic factor for the causal agent of grey mould in lily, Botrytis elliptica, and the response of lily to OA are poorly understood. To address these questions, lesion tissues and deposition of calcium oxalate (CaOX) and callose were observed in diploid and tetraploid leaves of L. rosthornii after inoculation with B. elliptica. Oxalate oxidase (OXO) activity and the transcript levels of some genes related to OA degradation (LrGLP1, LrGLP2 and LrWRKY4), reactive oxygen species (ROS) production/scavenging systems (LrRBOHD, LrGST, LrPOD and LrAPX1) and pathogen-related protein (PR) synthesis (LrCHI, LrBGL and LrPR10) were compared. After diploid and tetraploid leaves inoculation, lesion tissue and callose and CaOX were separately observed around in guard cells and stomata rather than the epidermis in the infected area. OXO activity was triggered at 2 h post-inoculation (hpi) in both ploidy leaves, and it was higher in the latter from 12-48 hpi. Expression of LrGLP1, LrGLP2, LrRBOHD, LrGST, LrPOD, LrCHI, LrBGL and LrPR10 was higher in tetraploids than in diploids from 24(12)-36(48) hpi. In conclusion, for B. elliptica, OA mainly chelates Ca²⁺ from the stomata cell wall. The strong capability to degrade OA and higher expression levels of some genes related to ROS accumulation/scavenging and PR synthesis may partially explain the relatively higher grey mould resistance of tetraploid L. rosthornii.

[Study of the effects of long-term outcomes of autologous peripheral blood stem cell reinfusion in patients with decompensated cirrhosis]

Objective: Autologous peripheral blood stem cells (PBSC) derived from bone marrow can promote liver regeneration and improve the liver function of patients, but there are few studies on its effect on the long-term outcomes in patients with decompensated cirrhosis. Based on previous work, this study observed the clinical outcomes of PBSC treatment in patients with decompensated cirrhosis for 10 years, in order to provide more data support for the safety and efficacy of stem cells in clinical applications. Methods: Data of patients with decompensated liver cirrhosis who completed PBSC treatment in the Department of Gastroenterology of the First Affiliated Hospital of Air Force Military Medical University from August 2005 to February 2012 were included. The follow-up endpoint was death or liver transplantation, and patients who did not reach the follow-up endpoint were followed-up for at least 10 years. The patients with decompensated liver cirrhosis who met the conditions for PBSC treatment but did not receive PBSC treatment in our hospital during the same period were used as controls. Results: A total of 287 cases with decompensated liver cirrhosis had completed PBSC treatment, and 90 cases were lost to follow-up within 10 years after surgery. A total of 151 cases with complete survival follow-up data were included in the control group. There were no statistically significant differences in baseline information such as gender, age, etiological composition and liver function score between the two groups. The 10-year survival rate was higher in PBSC than control group (37.56% vs. 26.49%, P<0.05). Cholinesterase, albumin, international normalized ratio, Child-Turcotte-Pugh score, model for end-stage liver disease score, and other indicators were gradually recovered within 3 months to 1 year after PBSC treatment, and stabilized at a more desirable level in the long-term after follow-up for up to 10 years. There was no statistically significant difference in the incidence of liver cancer between the two groups (25.22% vs.31.85%, P=0.267). The age of onset of hepatocellular carcinoma was later in PBSC than control group [(56.66±7.21) years vs. (52.69±8.42) years, P<0.05]. Conclusions: This long-term observational follow-up study of more than ten years confirms that PBSC treatment can bring long-term benefits to patients with decompensated cirrhosis, with good long-term safety, thus providing more data support on the safety and efficacy of stem cells for clinical applications.

[Research progress of micronucleus visualization analysis and artificial intelligence detection strategy]

The micronucleomics test can comprehensively display a variety of harmful endpoints, such as DNA damage and repair, chromosome breakage or loss and cell growth inhibition, with fast, simple and economical feature. Micronucleomics is not only widely used in the comprehensive assessment of the types and modes of genetic action of exogenous chemicals (such as drugs, food additives, cosmetics, environmental pollutants, etc.), but also plays an important role in the screening and risk assessment of cancer population at high risk. However, the traditional micronucleomics image counting method has the characteristics of time-consuming, low accuracy, and high cost, which cannot meet the current analysis requirements of large-scale, multi-index, rapidity, high precision and visualization. In recent years, with the rapid development of the era of precision medicine based on big data, visualized analysis of new micronucleomics based on machine learning and detection strategies based on deep learning have shown a good application prospect. This review, based on the application value of micronucleomics, systematically compares the traditional and new artificial intelligence counting of micronucleus images, and discusses the future direction of micronucleus image detection.

Incorporating Polygenic Risk Scores and Nongenetic Risk Factors for Breast Cancer Risk Prediction Among Asian Women

IMPORTANCE

Polygenic risk scores (PRSs) have shown promise in breast cancer risk prediction; however, limited studies have been conducted among Asian women.

OBJECTIVE

To develop breast cancer risk prediction models for Asian women incorporating PRSs and nongenetic risk factors.

DESIGN, SETTING, AND PARTICIPANTS

This diagnostic study included women of Asian ancestry from the Asia Breast Cancer Consortium. PRSs were developed using data from genomewide association studies (GWASs) of breast cancer conducted among 123 041 women with Asian ancestry (including 18 650 women with breast cancer) using 3 approaches: (1) reported PRS for women with European ancestry; (2) breast cancer-associated single-nucleotide variations (SNVs) identified by fine-mapping of GWAS-identified risk loci; and (3) genomewide risk prediction algorithms. A nongenetic risk score (NGRS) was built, including 7 well-established nongenetic risk factors, using data of 416 case participants and 1558 control participants from a prospective cohort study. PRSs were initially validated in an independent data set including 1426 case participants and 1323 control participants and further evaluated, along with the NGRS, in the second data set including 368 case participants and 736 control participants nested within a prospective cohort study.

MAIN OUTCOMES AND MEASURES

Logistic regression was used to examine associations of risk scores with breast cancer risk to estimate odds ratios (ORs) with 95% CIs and area under the receiver operating characteristic curve (AUC).

RESULTS

A total of 126 894 women of Asian ancestry were included; 20 444 (16.1%) had breast cancer. The mean (SD) age ranged from 49.1 (10.8) to 54.4 (10.4) years for case participants and 50.6 (9.5) to 54.0 (7.4) years for control participants among studies that provided demographic characteristics. In the prospective cohort, a PRS with 111 SNVs developed using the fine-mapping approach (PRS111) showed a prediction performance comparable with a genomewide PRS that included more than 855 000 SNVs. The OR per SD increase of PRS111 score was 1.67 (95% CI, 1.46-1.92), with an AUC of 0.639 (95% CI, 0.604-0.674). The NGRS had a limited predictive ability (AUC, 0.565; 95% CI, 0.529-0.601). Compared with the average risk group (40th-60th percentile), women in the top 5% of PRS111 and NGRS were at a 3.84-fold (95% CI, 2.30-6.46) and 2.10-fold (95% CI, 1.22-3.62) higher risk of breast cancer, respectively. The prediction model including both PRS111 and NGRS achieved the highest prediction accuracy (AUC, 0.648; 95% CI, 0.613-0.682).

CONCLUSIONS AND RELEVANCE

In this study, PRSs derived using breast cancer risk-associated SNVs had similar predictive performance in Asian and European women. Including nongenetic risk factors in models further improved prediction accuracy. These findings support the utility of these models in developing personalized screening and prevention strategies.

Associations of genetic susceptibility to 16 cancers with risk of breast cancer overall and by intrinsic subtypes

Certain genetic variants are associated with risks of multiple cancers. We investigated breast cancer risk with overall genetic susceptibility to each of 16 other cancers. We constructed polygenic risk scores (PRS) for 16 cancers using risk variants identified by genome-wide association studies. We evaluated the associations of these PRSs with breast cancer risk (overall and by subtypes) using Breast Cancer Association Consortium data, including 106,278 cases and 91,477 controls of European ancestry. Odds ratios (OR) and 95% confidence intervals (CIs) were estimated to measure the association of each PRS with breast cancer risk. Data from the UK Biobank, including 4,337 cases and 209,983 non-cases, were used to replicate the findings. A 5%–8% significantly elevated risk of overall breast cancer was associated with per unit increase of the PRS for glioma and cancers of the corpus uteri, stomach, or colorectum. Analyses by subtype revealed that the PRS for corpus uteri cancer (OR = 1.09; 95% CI, 1.03–1.15) and stomach cancer (OR = 1.07; 95% CI, 1.03–1.12) were associated with estrogen receptor-positive breast cancer, while ovarian cancer PRS was associated with triple-negative breast cancer (OR = 1.25; 95% CI, 1.01–1.55). UK Biobank data supported the positive associations of overall breast cancer risk with PRS for melanoma and cancers of the stomach, colorectum, and ovary. Our study provides strong evidence for shared genetic susceptibility of breast cancer with several other cancers. Results from our study help uncover the genetic basis for breast and other cancers and identify individuals at high risk for multiple cancers.

[Research progress on the influence of nanoparticles on intestinal flora]

Nanoparticle is a kind of material with at least one dimension in Nanometer scale, which has unique physical and chemical properties and is widely used in the fields of food and engineering. Intestinal Flora is involved in the regulation of human circulation and metabolism. The disturbance of Intestinal Flora may cause inflammatory reaction and chronic metabolic diseases. Nano titanium dioxide, Nano silver, Nano zinc oxide, Nano carbon nanoparticles and other nanoparticles have been proven to have good antibacterial properties, and can affect the intestinal flora of experimental animals. In this paper, the effects and mechanisms of various nanoparticles on intestinal microflora are summarized, which is helpful to provide a new idea for the safety study of nanoparticles.

Discovery of structural deletions in breast cancer predisposition genes using whole genome sequencing data from > 2000 women of African-ancestry

Single germline nucleotide pathogenic variants have been identified in 12 breast cancer predisposition genes, but structural deletions in these genes remain poorly characterized. We conducted in-depth whole genome sequencing (WGS) in genomic DNA samples obtained from 1340 invasive breast cancer cases and 675 controls of African ancestry. We identified 25 deletions in the intragenic regions of ten established breast cancer predisposition genes based on a consensus call from six state-of-the-art SV callers. Overall, no significant case-control difference was found in the frequency of these deletions. However, 1.0% of cases and 0.3% of controls carried any of the eight putative protein-truncating rare deletions located in BRCA1, BRCA2, CDH1, TP53, NF1, RAD51D, RAD51C and CHEK2, resulting in an odds ratio (OR) of 3.29 (95% CI 0.74-30.16). We also identified a low-frequency deletion in NF1 associated with breast cancer risk (OR 1.93, 95% CI 1.14-3.42). In addition, we detected 56 deletions, including six putative protein-truncating deletions, in suspected breast predisposition genes. This is the first large study to systematically search for structural deletions in breast cancer predisposition genes. Many of the deletions, particularly those resulting in protein truncations, are likely to be pathogenic. Results from this study, if confirmed in future large-scale studies, could have significant implications for genetic testing for this common cancer.

Effect of supplementing hydroxy selenomethionine on meat quality of yellow feather broiler

This study was conducted to evaluate the effect of supplementing hydroxy selenomethionine (OH-SeMet) on performance, selenium (Se) deposition in the breast muscle, quality and oxidative stability, and expression of selenoprotein encoding genes of breast meat of the native slow-growing yellow-feathered broiler birds. A total of 375 one-day-old local yellow male birds were randomly assigned into 5 dietary treatments, supplemented with Se 0.0, 0.2, 0.4, 0.6, and 0.8 mg/kg in the form of OH-SeMet. Each treatment consisted of 5 replicates and each replicate had 15 birds, the birds were fed on basal diet containing corn and soybean meal, and the experiment lasted for 63 d. The results showed that dietary Se supplementation linearly increased (P < 0.001) Se contents in both serum and muscle, no significant changes (P > 0.05) were observed on growth performance, yield of breast, meat color, and intramuscular fat deposition of the breast muscle. Dietary Se addition improved water-holding capacity, the pH_24h value, and tenderness of breast muscle, evidenced by a linear decreases of shear force (P < 0.05), accompanied by lower thiobarbituric acid reactive substances and higher glutathione reductase activity. The mRNA abundance of selenoprotein encoding genes also responded to dietary Se levels. It is concluded that, dietary supplementation with OH-SeMet improved muscular Se deposition and meat quality of the native yellow birds, with enhanced antioxidant capability and regulation in selenogenome.

Large trans-ethnic meta-analysis identifies AKR1C4 as a novel gene associated with age at menarche

STUDY QUESTION

Does the expansion of genome-wide association studies (GWAS) to a broader range of ancestries improve the ability to identify and generalise variants associated with age at menarche (AAM) in European populations to a wider range of world populations?

SUMMARY ANSWER

By including women with diverse and predominantly non-European ancestry in a large-scale meta-analysis of AAM with half of the women being of African ancestry, we identified a new locus associated with AAM in African-ancestry participants, and generalised loci from GWAS of European ancestry individuals.

WHAT IS KNOWN ALREADY

AAM is a highly polygenic puberty trait associated with various diseases later in life. Both AAM and diseases associated with puberty timing vary by race or ethnicity. The majority of GWAS of AAM have been performed in European ancestry women.

STUDY DESIGN, SIZE, DURATION

We analysed a total of 38 546 women who did not have predominantly European ancestry backgrounds: 25 149 women from seven studies from the ReproGen Consortium and 13 397 women from the UK Biobank. In addition, we used an independent sample of 5148 African-ancestry women from the Southern Community Cohort Study (SCCS) for replication.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Each AAM GWAS was performed by study and ancestry or ethnic group using linear regression models adjusted for birth year and study-specific covariates. ReproGen and UK Biobank results were meta-analysed using an inverse variance-weighted average method. A trans-ethnic meta-analysis was also carried out to assess heterogeneity due to different ancestry.

MAIN RESULTS AND THE ROLE OF CHANCE

We observed consistent direction and effect sizes between our meta-analysis and the largest GWAS conducted in European or Asian ancestry women. We validated four AAM loci (1p31, 6q16, 6q22 and 9q31) with common genetic variants at P < 5 × 10-7. We detected one new association (10p15) at P < 5 × 10-8 with a low-frequency genetic variant lying in AKR1C4, which was replicated in an independent sample. This gene belongs to a family of enzymes that regulate the metabolism of steroid hormones and have been implicated in the pathophysiology of uterine diseases. The genetic variant in the new locus is more frequent in African-ancestry participants, and has a very low frequency in Asian or European-ancestry individuals.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Extreme AAM (<9 years or >18 years) were excluded from analysis. Women may not fully recall their AAM as most of the studies were conducted many years later. Further studies in women with diverse and predominantly non-European ancestry are needed to confirm and extend these findings, but the availability of such replication samples is limited.

WIDER IMPLICATIONS OF THE FINDINGS

Expanding association studies to a broader range of ancestries or ethnicities may improve the identification of new genetic variants associated with complex diseases or traits and the generalisation of variants from European-ancestry studies to a wider range of world populations.

STUDY FUNDING/COMPETING INTEREST(S)

Funding was provided by CHARGE Consortium grant R01HL105756-07: Gene Discovery For CVD and Aging Phenotypes and by the NIH grant U24AG051129 awarded by the National Institute on Aging (NIA). The authors have no conflict of interest to declare.

Effects of Screenings in Reducing Colorectal Cancer Incidence and Mortality Differ by Polygenic Risk Scores

INTRODUCTION

Colorectal cancer (CRC) screening reduces CRC incidence and mortality. However, it is unclear whether the reduction in CRC risk may differ by genetic susceptibility.

METHODS

We evaluated this question in a cohort of 304,740 participants of European descent aged 50 years and older. Genetic susceptibility was measured using a polygenic risk score (PRS) constructed with risk variants identified in genomewide association studies. Cox models were used to estimate hazard ratios and 95% confidence intervals of CRC risk.

RESULTS

Over a median follow-up of 7.0 years, 2,261 incident CRC cases and 528 CRC deaths were identified. CRC screening was associated with a significantly reduced CRC incidence among individuals with a high (hazard ratio, 0.80; 95% confidence interval, 0.71-0.92) and intermediate PRS (0.84, 0.71-0.98) but not among those with a low PRS (1.03, 0.86-1.25; Pinteraction, 0.005). A similar but more evident difference was observed for mortality (Pinteraction, 0.046), with more than 30% reduced mortality observed in the high PRS group (0.69, 0.52-0.91). Among the younger group (age 50-60 years), CRC screenings were associated with a slightly (but nonsignificantly) elevated incidence and mortality in the low PRS group but a reduced risk in the high PRS group (Pinteraction, 0.043 [incidence]; 0.092 [mortality]). No significant interaction was observed in the older group (age > 60 years).

DISCUSSION

Individuals with a higher genetic risk benefited more substantially from CRC screenings than those with a lower risk. Our findings suggest that PRS may be used to develop personalized CRC screening to maximize its effect on CRC prevention.

Healthy lifestyles, genetic modifiers, and colorectal cancer risk: a prospective cohort study in the UK Biobank

BACKGROUND

Both genetic and lifestyle factors play an etiologic role in colorectal cancer (CRC).

OBJECTIVES

We evaluated potential gene-environment interactions in CRC risk.

METHODS

We used data from 346,297 participants in the UK Biobank cohort. Healthy lifestyle scores (HLSs) were constructed using 8 lifestyle factors, primarily according to the American Cancer Society guidelines, and were categorized into unhealthy, intermediate, and healthy groups. A polygenic risk score (PRS) was created using 95 genetic risk variants identified by genome-wide association studies of CRC and was categorized by tertile. Cox models were used to estimate the HRs and 95% CIs of CRC risk associated with the HLS and PRS.

RESULTS

During a median follow-up of 5.8 y, 2066 incident cases of CRC were identified. Healthier HLSs were associated with reduced risk of CRC in a dose-response manner. The risk reduction was more apparent among those with high PRS (HRhealthy vs. unhealthy HLS1: 0.58; 95% CI: 0.43, 0.79 for men and 0.71; 0.58, 0.85 for men and women combined) than those with low PRS. Although no multiplicative interactions were identified, the HLS1 and PRS showed a significant additive interaction (P = 0.02 for all participants combined, 0.04 for men). In analyses including all participants, the adjusted CRC cumulative risk from age 40 to 75 y was 6.40% for those with high PRS/unhealthy HLS1, with a relative excess risk due to interaction of 0.58 (95% CI: 0.06, 1.10), compared with 2.09% among those with low PRS/healthy HLS1. This pattern was more apparent among those who reported not having received any bowel screening before baseline.

CONCLUSIONS

Although the observational nature of the study precludes proof of causality, our findings suggest that individuals with a high genetic susceptibility could benefit more substantially than those with a low genetic risk from lifestyle modification in reducing CRC risk.

Incorporating both genetic and tobacco smoking data to identify high-risk smokers for lung cancer screening

The US Preventive Services Task Force (USPSTF) recently proposed to widen the current lung cancer screening guideline to include less-heavy smokers. We sought to incorporate both genetic and tobacco smoking data to evaluate the proposed new guideline in white smokers. We constructed a polygenic risk score (PRS) using lung cancer risk variants. Using data from 308 490 participants of European descent in the UK Biobank, a population-based cohort study, we estimated hazard ratios of lung cancer associated with both tobacco smoking and PRS to identify individuals at a similar or higher risk than the group of heavy smokers who are recommended for screening under the USPSTF-2014 guideline (≥30 pack-years, either current or former smokers who quit within 15 years). During a median follow-up of 5.8 years, 1449 incident cases of lung cancer were identified. We found a similar lung cancer risk for current smokers with 20-29 pack-years [hazard ratio = 20.7, 95% confidence interval: 16.3-26.4] and the 'heavy smoker group' defined above (hazard ratio = 19.9, 95% confidence interval: 16.8-23.6) compared with never smokers. Current smokers with 20-29 pack-years did not reach a 6-year absolute risk of 0.0151, a suggested risk threshold for using low-dose computed tomography screening, until the age of 55 years. However, these smokers at high genetic risk (PRS ≥ 80%) reached this risk level at the age of 50. Our findings support the USPSTF proposal to lower the smoking pack-year eligibility to 20 pack-years for current smokers and suggest that PRS for lung cancer could be considered to identify high-risk smokers for screening.

Genetically predicted circulating protein biomarkers and ovarian cancer risk

OBJECTIVE

Most women with epithelial ovarian cancer (EOC) are diagnosed after the disease has metastasized and survival in this group remains poor. Circulating proteins associated with the risk of developing EOC have the potential to serve as biomarkers for early detection and diagnosis. We integrated large-scale genomic and proteomic data to identify novel plasma proteins associated with EOC risk.

METHODS

We used the germline genetic variants most strongly associated (P <1.5 × 10-11) with plasma levels of 1329 proteins in 3301 healthy individuals from the INTERVAL study to predict circulating levels of these proteins in 22,406 EOC cases and 40,941 controls from the Ovarian Cancer Association Consortium (OCAC). Association testing was performed by weighting the beta coefficients and standard errors for EOC risk from the OCAC study by the inverse of the beta coefficients from INTERVAL.

RESULTS

We identified 26 proteins whose genetically predicted circulating levels were associated with EOC risk at false discovery rate < 0.05. The 26 proteins included MFAP2, SEMG2, DLK1, and NTNG1 and a group of 22 proteins whose plasma levels were predicted by variants at chromosome 9q34.2. All 26 protein association signals identified were driven by association with the high-grade serous histotype that comprised 58% of the EOC cases in OCAC. Regional genomic plots confirmed overlap of the genetic association signal underlying both plasma protein level and EOC risk for the 26 proteins. Pathway analysis identified enrichment of seven biological pathways among the 26 proteins (Padjusted <0.05), highlighting roles for Focal Adhesion-PI3K-Akt-mTOR and Notch signaling.

CONCLUSION

The identified proteins further illuminate the etiology of EOC and represent promising new EOC biomarkers for targeted validation by studies involving direct measurement of plasma proteins in EOC patient cohorts.

Evaluating polygenic risk scores in assessing risk of nine solid and hematologic cancers in European descendants

Genome-wide association studies (GWAS) have identified many genetic risk variants for cancers. The utility of these variants in assessing risk of esophageal, gastric and endometrial cancers, as well as melanoma, glioma, diffuse large B-cell lymphoma, follicular lymphoma, chronic lymphoid leukemia and multiple myeloma, has not been adequately investigated. We constructed a site-specific polygenic risk score (PRS) for each of these nine cancers using their GWAS-identified risk variants. Using data from 400 807 participants of European descent in the UK Biobank, a population-based cohort study, we estimated the hazard ratios of each cancer associated with its PRS using Cox proportional hazard models. During a median follow-up of 5.8 years, 3905 incident cases of these nine cancers were identified in the cohort. The area under the receiver operating characteristic curve ranged from 0.53 to 0.69 for these cancers. Except for esophageal cancer, significant dose-response associations were observed between PRS and cancer risk. Compared to individuals in the middle quintile (40%-60%) at an average risk, those among the highest 5% of the PRS had a twofold elevated risk of melanoma, glioma, follicular lymphoma or multiple myeloma, and a fourfold elevated risk of chronic lymphoid leukemia. Using PRS, 63.0% of the participants could be classified as having an over twofold elevated risk for at least one cancer. The PRS derived using risk variants identified to date by GWAS showed the potential in identifying individuals at a significantly elevated risk of cancer for prevention.

Bio-detoxification of Jatropha curcas L. cake by a soil-borne Mucor circinelloides strain using a zebrafish survival model and solid-state fermentation

AIMS

The aims of the study were to (i) improve the evaluation criteria of detoxifying Jatropha curcas L. cake (JCC), (ii) isolate and characterize a JCC tolerant strain, (iii) explore its JCC detoxifying potential.

METHODS AND RESULTS

The zebrafish was employed as a survival model to screen the strains capable of detoxifying JCC. A strain identified as Mucor circinelloides SCYA25, which is highly capable of degrading all toxic components, was isolated from soil. Different solid-state fermentation parameters were optimized by response surface methodology. The optimal values for inoculation amount, moisture content, temperature, and time were found to be 18% (1·8 × 10⁶ spores g^-1 cake), 66%, 26, and 36 days, respectively, to achieve maximum detoxification of the JCC (92%). Under optimal fermentation conditions, the protein content of JCC was increased, while the concentrations of ether extract, crude fiber, toxins, and anti-nutritional substances were all degraded considerably (P < 0·05). Scanning electron microscopy and Fourier transform infrared spectrometer analysis revealed that the fermentation process could disrupt the surface structure and improve the ratio of α-helix to β-folding in the JCC protein, which may improve the digestibility when the detoxified JCC is used as a feedstuff.

CONCLUSIONS

Our results indicate that M. circinelloides SCYA25 is able to detoxify JCC and improve its nutritional profile, which is beneficial to the safe utilization of JCC as a protein feedstuff.

SIGNIFICANCE AND IMPACT OF THE STUDY

The newly identified M. circinelloides SCYA25 detoxified JCC in a safe manner to provide a potential alternative to soybean meal for the feed industry. These results also provide a new perspective and method for the toxicity evaluation and utilization of JCC and similar toxic agricultural by-products.

Abstract 28: Integrating genomic and transcriptomic data to identify genetic loci associated with breast cancer risk in women of African ancestry

Background: To date, most genome-wide association studies (GWAS) of breast cancer have been conducted only among women of Asian and European ancestry. It is difficult to generalize results from those studies to women of African ancestry (AA). We conducted a large genetic association study of breast cancer in women of AA by analyzing both genetic and transcriptomic data.

Methods: This collaborative study included 11,073 cases and 11,095 controls of AA who were participants in more than 15 studies conducted in the U.S. and Africa. Genotyping data were harmonized and imputed using the 1000 Genomes Project database as the reference. Imputed genotypes were used for GWAS to identify novel genetic risk loci for breast cancer. To search for susceptibility genes, we conducted a transcriptome-wide association study (TWAS), in which gene expression prediction models were built using genetic and tumor tissue RNA sequencing data from ~400 AA patients and used to impute expression levels of genes across the transcriptome for association analyses in all cases and controls included in the GWAS mentioned above.

Results: We identified five loci (5p15.33, 5q31.3, 10q26.13, 18q12.1, and 19p13.11) associated with breast cancer risk at P &lt; 5 × 10−8, including a novel locus at 5q31.3 (allelic odds ratio, OR = 1.18, 95% CI = 1.11-1.25, P = 4.65 × 10−8, nearby gene, ARHGAP26). This locus was also identified in association with estrogen receptor (ER) positive breast cancer at P &lt; 5 × 10−8. Analyses stratified by ER status replicated known loci associated specifically with ER-positive (10q26.13) or ER-negative (2q14.2, 2p11.2, 5p15.33) breast cancer at P &lt; 5 × 10−8. Of the 165 lead risk SNPs reported from previous breast cancer GWAS, 35 SNPs were replicated with the same association direction at P &lt; 0.05. We constructed a polygenic risk score using these 35 replicated SNPs and the lead risk SNP at the novel locus and estimated the AUC to be 0.575. Of the 7,592 genes tested in the TWAS, we identified one gene, AC091053.1, with an association at a Bonferroni-corrected threshold of 6.64 × 10−6 (0.05/7,592). AC091053.1 is a long non-coding RNA gene at locus 11p15.4, where no risk variants have been identified in any previous breast cancer GWAS. AC091053.1 is located in the region of protein coding gene DENND2B, which acts as a regulator of MAPK1/ERK2 kinase and reduces the tumorigenic phenotype in cells. The gene AC091053.1 was associated with ER-positive breast cancer with P = 4.11 × 10−5 and ER-negative breast cancer with P = 0.032.

Conclusions: Our study, the largest genetic study conducted to date in AA, identified novel breast cancer risk loci at 5q31.3 and 11p15.4 (AC091053.1) among women of AA and replicated &gt;30 associations reported in previous studies. Studies with a larger sample size are needed to further investigate genetic variants and genes associated with breast cancer risk in AA women.

Citation Format: Guochong Jia, Jie Ping, Yaohua Yang, Maureen Sanderson, Qiuyin Cai, Xingyi Guo, William J. Blot, Bingshan Li, Elisa V. Bandera, Manjeet K. Bolla, Montserrat García-Closas, Douglas F. Easton, Mary K. Fadden, Jian Gu, Dezheng Huo, Esther M. John, Kathryn L. Lunetta, Olufunmilayo I. Olopade, Xiang Shu, Melissa A. Troester, Song Yao, Breast Cancer Association Consortium, Andrew F. Olshan, Christine B. Ambrosone, Christopher A. Haiman, Jirong Long, Julie R. Palmer, Wei Zheng. Integrating genomic and transcriptomic data to identify genetic loci associated with breast cancer risk in women of African ancestry [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 28.

[Effects of titanium dioxide nanoparticles on fecal metabolome in rats after oral administration for 90 days]

OBJECTIVE

To explore the effects and related mechanisms of oral exposure titanium dioxide nanoparticles (TiO₂ NPs) for 90 days on the intestinal and the gut microbiota of rats, through fecal metabolomics.

METHODS

Twelve 4-week-old clean-grade Sprague Dawley (SD) rats were randomly de-vided into 2 groups by body weight, treated with TiO₂ NPs at dose of 0 or 50 mg/kg body weight everyday respectively for 90 days. The solution of each infection was freshly prepared and shocked fully by ultrasonic. Characterization of the particle size, crystal form, purity, and specific surface area of TiO₂ NPs was conducted. And the fresh feces of the rats were collected on the 90th day. After lyophilized and hydrophilic phase extraction, ultra performance liquid chromatography-Q-exactive orbitrap-high-resolution mass spectrometry system (UPLC-QEMS) was utilized for non-targeted determination of fecal meta-bolites. The metabolites were identified and labeled through Compound Discoverer 3.0 software, and used for subsequent metabolomics analysis. Bioinformatics analysis was carried out including unsupervised principal component analysis and supervised orthogonal projection to latent structure discriminant analysis for the differential metabolites between the two groups. The differential metabolites were followed-up for Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis.

RESULTS

Compared with the control group, the body weight of the rats was significantly reduced (P<0.05) in the treatment group. A total of 22 metabolites in fecal metabolomics showed significant changes. Among them, xanthine, 1-methyladenine, 3-hydroxypyridine, methionine sulfoxide, pyridoxine, 1,5-isoquinolinediol, N-acetylornithine, N-acetyl-D-galactosamine, L-citrulline, L-methionine, leucine, DL-tryptophan, L-ornithine, 4-methyl-5-thiazoleethanol, and L-glutamic acid totaled 15 metabolites increased significantly. N-acetylhistamine, D-pipecolinic acid, imidazolelactic acid, L-valine, 2,3,4,6-tetramethylpyrazine, caprolactam, and histamine totaled 7 metabolites decreased significantly. N-acetylhistamine, L-valine and methionine sulfoxide were changed more than 16 times. Analysis of KEGG pathway revealed that the two metabolic pathways arginine biosynthesis and aminoacyl-tRNA biosynthesis were significantly changed (false discover rate < 0.05, pathway impact > 0.1).

CONCLUSION

Oral exposure to TiO₂ NPs for 90 days could disrupt the metabolism of the intestine and gut microbiota, causing significant changes in metabolites and metabolic pathways which were related to inflammatory response, oxidative stress, glucose homeostasis, blood system and amino acid homeostasis in rat feces. It is suggested that the toxic effect of TiO₂ NPs on rats may be closely related to intestinal and gut microbiota metabolism.

[Effects of air pollution exposure on olfaction of rats in Beijing]

Objective: To evaluate the effects of exposure of fine particle matter (PM_2.5) and ozone (O₃) in Beijing as the main pollutants on olfaction of SD rats. Methods: In October 16, 2018, twenty 8-week-old SD rats were randomly divided into two groups, 10 rats in the exposure group and 10 rats in the control group. They were fed in air pollutant exposure system and clean experimental environment respectively, and the concentrations of PM_2.5 and O₃ in each system were measured. The degree of olfaction damage of SD rats at different feeding time was assessed by using the buried food test (BFT). The difference of BFT time between the two groups was analyzed by performing the repeated measures analysis of variance. Results: The results showed that the concentrations of PM_2.5 and O₃ in the exposure group were (22.65±11.47) μg/m³ and (12.36±5.87) μg/m³, respectively, while those in the control group were both 0 μg/m³. The repeated measures analysis of variance showed that the time of BFT in the exposure group was longer than that in the control group (F=6.49, P=0.031). With the increase of feeding time, the time of BFT was prolonged (F=61.69, P<0.001). Conclusion: Exposure to PM_2.5 and O₃ in the atmosphere might lead to olfaction damage in rats.

[Effect of subchronic combined oral exposure of titanium dioxide nanoparticles and glucose on levels of serum folate and vitamin B12 in young SD rats]

OBJECTIVE

To explore the effect of subchronic combined oral exposure of titanium dioxide nanoparticles and glucose on levels of serum folate and vitamin B₁₂ in young SD rats.

METHODS

At first, the physical and chemical properties of titanium dioxide nanoparticles, such as particle size, shape, crystal form and agglomeration degree in solution system, were characterized in detail. Eighty 4-week-old young SD rats were randomly divided into 8 groups (10 rats in each group, half male and half female). The rats were exposed to titanium dioxide nanoparticles through intragastric administration at 0, 2, 10 and 50 mg/kg body weight with or without 1.8 g/kg glucose daily for 90 days. At last, the concentrations of serum folate and vitamin B₁₂ were detected.

RESULTS

Titanium dioxide nanoparticles were anatase crystals, closely spherical shape, with an average particle size of (24±5) nm. In male young rats, compared with the control group, the serum folate concentration was significantly increased when exposed to titanium dioxide nanoparticles (10 mg/kg) and glucose. The difference was statistically significant (P<0.05). However, in female and male young rats, compared with glucose (1.8 g/kg) exposure group, titanium dioxide nanoparticles (50 mg/kg) and glucose significantly reduced the serum folate concentration. The difference was statistically significant (P<0.05). Through statistical analysis of factorial design and calculation of interaction, obvious antagonistic effect was observed between titanium dioxide nanoparticles and glucose on the serum folate concentration in the young female SD rats. The combined oral exposure of titanium dioxide nanoparticles and glucose had little effect on the concentration of serum vitamin B₁₂ in the young SD rats, with no significant interaction between the two substances. It was only found that titanium dioxide nanoparticles (2 mg/kg) and glucose significantly increased the serum vitamin B₁₂ concentration, compared with glucose (1.8 g/kg) exposure group. The difference was statistically significant (P<0.05).

CONCLUSION

Subchronic combined oral exposure of titanium dioxide nanoparticles and glucose had an obvious antagonistic effect on serum folate concentrations in young SD rats.

Evaluating the Utility of Polygenic Risk Scores in Identifying High-Risk Individuals for Eight Common Cancers

Background

Genome-wide association studies have identified common genetic risk variants in many loci associated with multiple cancers. We sought to systematically evaluate the utility of these risk variants in identifying high-risk individuals for eight common cancers.

Methods

We constructed polygenic risk scores (PRS) using genome-wide association studies–identified risk variants for each cancer. Using data from 400 812 participants of European descent in a population-based cohort study, UK Biobank, we estimated hazard ratios associated with PRS using Cox proportional hazard models and evaluated the performance of the PRS in cancer risk prediction and their ability to identify individuals at more than a twofold elevated risk, a risk level comparable to a moderate-penetrance mutation in known cancer predisposition genes.

Results

During a median follow-up of 5.8 years, 14 584 incident case patients of cancers were identified (ranging from 358 epithelial ovarian cancer case patients to 4430 prostate cancer case patients). Compared with those at an average risk, individuals among the highest 5% of the PRS had a two- to threefold elevated risk for cancer of the prostate, breast, pancreas, colorectal, or ovary, and an approximately 1.5-fold elevated risk of cancer of the lung, bladder, or kidney. The areas under the curve ranged from 0.567 to 0.662. Using PRS, 40.4% of the study participants can be classified as having more than a twofold elevated risk for at least one site-specific cancer.

Conclusions

A large proportion of the general population can be identified at an elevated cancer risk by PRS, supporting the potential clinical utility of PRS for personalized cancer risk prediction.

Association of Adult Weight Gain With Major Health Outcomes Among Middle-aged Chinese Persons With Low Body Weight in Early Adulthood

IMPORTANCE

The association of weight gain from early to middle adulthood with disease risk has not been adequately studied.

OBJECTIVE

To investigate the association of adult weight gain with major health outcomes in a Chinese population with low body weight in early adulthood.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study assessed data from 48 377 women and 35 989 men aged 40 to 59 years at recruitment in 2 prospective cohort studies in China. The Shanghai Women's Health Study recruited 74 941 women, aged 40 to 70 years, from January 1, 1996, to December 31, 2000, and the Shanghai Men's Health Study recruited 61 482 men, aged 40 to 74 years, from January 1, 2002, to December 31, 2006. This analysis was conducted from September 1, 2017, to April 30, 2018.

EXPOSURES

Weight gain from 20 years of age to 40 to 59 years of age.

MAIN OUTCOMES AND MEASURES

Mortality and incidence of cancers and other chronic diseases.

RESULTS

This analysis included 48 377 women (mean [SD] age, 47.8 [5.3] years) and 35 989 men (mean [SD] age, 49.6 [5.1] years). Per 5-kg weight gain from early to middle adulthood was associated with an approximately 10% (hazard ratio [HR], 1.09; 95% CI, 1.04-1.14 for men; HR, 1.14; 95% CI, 1.11-1.19 for women) elevated all-cause mortality and a greater than 20% (HR, 1.26; 95% CI, 1.16-1.38 for men; HR, 1.23; 95% CI, 1.14-1.33 for women) cardiovascular disease-related mortality in later life among individuals who reached a body mass index (BMI) of 23 or higher at middle adulthood. Body mass index at middle adulthood also modified the association of weight gain with risk of obesity-related cancers, with weight gain of 20 kg or more associated with increased risks both for men (HR, 1.34; 95% CI, 1.07-1.67) and for women (HR 1.45; 95% CI, 1.24-1.68). No similar associations were found for individuals with a BMI of 18.5 to 22.9. Regardless of BMI, weight gain was associated with elevated risks of type 2 diabetes, hypertension, fatty liver disease, stroke, gout, and gallstones, particularly for type 2 diabetes (HR, 7.87; 95% CI, 6.91-8.97 for women; HR, 4.95; 95% CI, 4.23-5.79 for men) and fatty liver disease (HR, 3.68; 95% CI, 3.42-3.95 for women; HR, 2.83, 95% CI, 2.56-3.13 for men) in individuals with weight gain of 20 kg or more compared with those with a healthy weight.

CONCLUSIONS AND RELEVANCE

This study found that weight gain from early to middle adulthood was associated with disease incidence and mortality in later life. The BMI at middle adulthood modified the association of weight gain with mortality and cancer incidence but not risk of other major chronic diseases.

Oral cancer-associated tertiary lymphoid structures: gene expression profile and prognostic value

Tertiary lymphoid structure (TLS) provides a local and critical microenvironment for both cellular and humoral immunity and supports effective antigen presentation and lymphocyte activation. However, the gene expression profile and prognostic significance of TLS in oral cancer remain largely unrevealed. In this study, we found the presence of both intratumoral and peritumoral TLSs in a series of 65 patients with oral cancer treated by surgical resection, with positive detection rates of 33.8 and 75.4%, respectively. The presence of intratumoral TLSs, but not peritumoral TLSs, was significantly associated with decreased P53 and Ki67 scores (P = 0·027 and 0·047, respectively). The survival analyses revealed that oral cancer patients with higher grades of TLSs was associated with improved disease-free survival (DFS) and overall survival (OS) (P = 0·037 and 0·031, respectively). Gene expression profiling analysis of the cytokines and chemokines responsible for lymph-node neogenesis identified a three-up-regulated-gene set, i.e. IL7, LTB and CXCL13, which was shown to be correlated with human oral cancer-associated TLSs. This study provides a framework for better understanding of oral cancer-associated TLSs and for delineating future innovative prognostic biomarkers and immune therapeutic strategies for oral cancer.

The oral microbiota - a mechanistic role for systemic diseases

Human oral microbiota is the ecological community of commensal, symbiotic, and pathogenic microorganisms found in the oral cavity. Oral microbiota generally exists in the form of a biofilm and plays a crucial role in maintaining oral homeostasis, protecting the oral cavity and preventing disease development. Human oral microbiota has recently become a new focus research for promoting the progress of disease diagnosis, assisting disease treatment, and developing personalised medicines. In this review, the scientific evidence supporting the association that endogenous and exogenous factors (diet, smoking, drinking, socioeconomic status, antibiotics use and pregnancy) modulate oral microbiota. It provides insights into the mechanistic role in which oral microbiota may influence systemic diseases, and summarises the challenges of clinical diagnosis and treatment based on the microbial community information. It provides information for noninvasive diagnosis and helps develop a new paradigm of personalised medicine. All these benefit human health in the post-metagenomics era.

Elliptically bent crystal x-ray spectrometer for time-resolved laser plasma experiments

Measuring time-resolved spectra is crucial in inertial confinement fusion and radiation source development experiments. An elliptically bent crystal spectrometer is designed to measure X-rays in the range of 2.5-11.0 keV, which was achieved using four different lattice spacings of 0.8512, 0.6687, 0.4246, and 0.2749 nm with spectral resolution E/δE of ∼500. The X-rays emitted from a source at one focus of the ellipse undergo Bragg reflection off a crystal and pass through the second focus of the ellipse to a streak camera slit with 18-mm length and 80-μm width to generate a time-resolved spectrum. An alignment method for the time-resolved spectrometer was developed with the straight line connecting the centers of the two small holes on the fabricated substrate being the axis of the ellipse, thus allowing the spacing between the source and the elliptical crystal to be tuned to couple with the streak camera. The time-resolved spectrometer's performance was experimentally tested at the Shenguang II laser facility. The results indicate that its performance is close to that predicted theoretically.

[Biomonitoring application in the exposome assessment]

Biomonitoring can be applied to assess internal exposure and environmental exposure by exposure markers with providing internal exposure to biological characterization and individual exposure information, which is a key tool to evaluate the risk exposure to disease by biological alternation information. With the development of high throughput, broad spectrum and high efficiency screening and detection technology, biomonitoring is defined as traditional biological monitoring (targeted monitoring) and non targeted monitoring analysis (exposomic approaches). An exposomic approach differs from traditional biomonitoring in that it can theoretically include all exposures of potential health significance, whether they are derived from exogenous sources. Both traditional and nontraditional biomonitoring methods should be used to understand the complexity of exposures faced throughout the lifespan. Through hybrid approaches, emerging techniques and the integration of bioinformatics, and developing the detection methods for low abundance chemicals, improving the differentiation ability between endogenous and exogenous chemical, the health outcomes and exposures can be widely recognized and characterized, which can finally contribute to improving the precise prevention and intervention for diseases under the new exposomic model.

[Analysis of related factors for primary hepatic carcinoma caused by chronic hepatitis B and hepatitis C]

Objective: To explore the related factors for primary hepatic carcinoma (PHC) caused by chronic hepatitis B (CHB) and hepatitis C (CHC). Methods: According to the principle of cross-sectional study, a cluster random sample method was used, a total of 366 chronic hepatitis patients in hospitals were recruited from three provincial tertiary hospitals in Shanxi, Henan and Jilin between July 2016 and October 2016, respectively. Using a self-designed unified questionnaire, face-to-face interviews was conducted on subjects, including sex, age, alcohol consumption, coffee consumption, green tea consumption, fish consumption, smoking, HBV/HCV diagnosis and treatment, diabetes mellitus, family history of PHC (whether PHC in first-degree relatives), etc. Multivariate unconditional logistic regression were performed to identify the related factors for PHC with CHB and CHC. According to the clinical diagnosis the patients were divided into a chronic hepatitis group (not developing to PHC) and a PHC group. Results: Among 366 cases patients, 287 (78.4%) cases were male, 79 cases were female (21.6%), average age was (52.7±9.3) years. 202 cases were chronic hepatitis group, 164 cases were PHC group. Multivariate unconditional logistics regression analysis indicated that alcohol consumption (odds ratio (OR)=2.11, 95%CI: 1.18-3.75), family history of PHC (OR=5.12, 95%CI: 2.60-10.08) were positively correlated with the development of PHC in chronic b, green tea consumption (OR=0.45, 95%CI: 0.23-0.88), antiviral treatment (OR=0.19, 95%CI: 0.11-0.32) were negatively correlated. Alcohol consumption (OR=3.98, 95%CI: 1.14-13.85) was positively correlated with the development of PHC in chronic c, antiviral treatment (OR=0.14, 95%CI: 0.04-0.50) was negatively correlated. Conclusion: Alcohol consumption, family history of PHC, green tea consumption and antiviral treatment were the related factors for the development of PHC in chronic hepatitis b. Alcohol consumption and antiviral treatment were the related factors for the development of PHC in chronic hepatitis c.

[Evaluation of health effect among occupational population exposed to nano-titanium dioxide: a cross-sectional study]

Objective: To characterize the health effects of nano-titanium dioxide exposure in an occupational cohort. Methods: Eighty-five male employees of a nano-titanium dioxide manufacturing enterprise in Shandong Province were evaluated in September 2014. Forty-four were exposed to nano-titanium dioxide (exposure group), and 41 were not exposed to nano-titanium dioxide (control group). We collected employees' basic information, smoking and drinking history, previous medical history, family history, and occupational history. Differences in blood pressure, hematological parameters, and blood biochemistry between the two groups were analyzed and compared. Multiple linear regression analysis was used to investigate the effect of nano-titanium dioxide exposure on blood pressure, hematological parameters, and blood biochemistry indices after controlling for age, smoking, drinking, and body mass index (BMI). Twenty-five employees from the exposure group and 25 employees from the control group were selected at random for measurement of genetic damage by cytokinesis-block micronucleus assay. Poisson regression analysis was used to investigate the effect of nano-titanium dioxide exposure on micronucleus frequency or micronucleus cell frequency after controlling for age, smoking, drinking, and BMI. Results: The median (P₂₅-P₇₅) surface area concentration of particles deposited in the tracheobronchial region, the surface area concentration of particles deposited in the alveolar region, and particle number concentration in the exposure group were 35.35(24.31-57.42) μ m²/cm³, 173.09(116.27-270.72) μ m²/cm³, and 40 244.00 (17 803.50-78 679.00) /cm³, respectively. These values were significantly higher than those in the control group 33.90 (27.44-43.29) μm²/cm³, 150.50(125.82-192.87)μm²/cm³, and 18 721.00 (12 721.00-51 898.50)/cm³, respectively. Z values were 15.47, 15.96, and 14.54, respectively (P<0.001 for all three values). Multiple linear regression analysis showed that exposure to nano-titanium dioxide contributed most to the alteration of mean corpuscular hemoglobin concentration, creatinine, and LDL-C, with standardized regression coefficients of 0.23, -0.51, and 0.30, respectively (P<0.05 for all three values), after adjusting for age, smoking, drinking, and BMI. There were no significant differences in micronucleus frequency and micronucleus cell frequency between the exposure group (3.00‰ (1.50‰-5.00‰) and 3.00‰ (2.00‰-4.00‰), respectively) and control group (2.00‰ (1.00‰-4.50‰) and 2.00‰ (1.00‰-4.00‰), respectively); P>0.05 for all comparisons. Poisson regression analysis showed that after adjusting for age, smoking, drinking, and BMI, there was still no statistically significant correlation between nano-titanium dioxide exposure and micronucleus frequency (OR=1.11, 95% CI: 0.81-1.54) or micronucleus cell frequency (OR=1.07, 95% CI: 0.75-1.51); P>0.05 for all comparisons. Conclusion: Nano-titanium dioxide particles exerted some health effects on the occupationally-exposed cohort, whose hematological parameters and blood biochemistry were influenced to some degree. However, a potential link between occupational exposure to nano-titanium dioxide and blood pressure or induction of genetic damage or was not found.

Abstract LB-160: Genetic variations in the AGEs/AGER pathway and risk of pancreatic cancer

Background: Chronic inflammation is implicated in pancreatic cancer carcinogenesis. Advanced glycation end-products (AGEs), which are rich in cooked red meat and cigarette smoke, can perpetuate inflammation by binding to the receptor for advanced glycation end products (AGER, also known as RAGE). We hypothesized that genetic variation of the AGEs/AGER pathway affects pancreatic cancer risk by modulating chronic inflammation.

Methods: We conducted a two-stage case-control study to examine the association between 96 single nucleotide polymorphisms (SNPs) in 21 genes (GLO1, MSR1, PINK1, KIF17, AGPAT1, AKR1B1, DDOST, CD36, SCARB1, AGER, APP, HMGB1, S100A8, S100B, S100P, S100A12, MMP9, ADAM10, PPARG, NOTCH4, and PDGF) of the AGEs/AGER pathway and risk of pancreatic cancer. The discovery study was conducted in 672 pancreatic cancer cases and 1361 controls ascertained from the Women’s Health Initiative (WHI) Study matched on age, race/ethnicity and study arm. The validation study was conducted in a PANC4 pooled hospital-based case-control study of 1,034 women cases and 989 women controls. A pooled analysis of 1706 cases and 2350 controls was also performed. SNP data were obtained or imputed from the previously performed GWASs. Pancreatic cancer risk was calculated as odds ratios (ORs) and 95% confidence intervals (Cis) using logistic regression models adjusting for age, race/ethnicity, body mass index (BMI), type 2 diabetes, and smoking using an additive genetic model. The potential interaction between individual SNP and red meat intake and cigarette smoking was examined. A false discovery rate (FDR) adjusted q value &lt; 0.20 was considered statistically significant in the pooled analyses. We also conducted logistic-Kernel machine (LKM) test to examine the association between sets of SNP and risk of pancreatic cancer in the pooled dataset.

Results: We identified 11 SNPs with raw P values &lt; 0.10 in the discovery stage in the WHI study. However, none of the SNPs was validated in the validation and pooled dataset. The LKM test showed that sets of SNPs in CD36 (P = 9.3E-10), GLO1(P =2.0E-7), and DDOST (P = 2.5E-4) were significantly associated with pancreatic cancer risk. We found an interaction effect between the GLO1 SNP rs6932648 and smoking status (never versus ever) in the WHI study (P for interaction = 0.01) and the pooled dataset (P for interaction = 0.049). In the pooled dataset, the variant T allele of rs6932648 (MAF = 0.12) was associated with increased risk of pancreatic cancer among ever smokers (additive OR = 1.26, 95% CI: 1.02-1.55), but not among never smokers (additive OR = 0.94, 95% CI: 0.78-1.14), compared with the C allele.

Summary and Conclusion: We did not observe significant association between any of 96 single SNP and pancreatic cancer risk. However, we found combined set of SNPs in the GLO1, DDOST, and CD36 genes were associated with risk of pancreatic cancer. GLO SNP rs6932648 may modify the association between smoking and risk of pancreatic cancer. GLO1, DDOST, and CD36 are involved in detoxification or clearance of AGEs compounds. Further investigation of AGEs and receptors systems in pancreatic cancer is warranted.

Citation Format: Guochong Jia, Kathryn Royse, Hongwei Tang, Donghui Li, Liang Chen, Lesley Tinker, Gloria Petersen, Alison Klein, Peter Richardson, Donna White, Haleh Sangi-Haghapeykar, Hashem B. El-Serag, Li Jiao. Genetic variations in the AGEs/AGER pathway and risk of pancreatic cancer [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 LB-160. doi:10.1158/1538-7445.AM2017-LB-160

MR Imaging Grading System for Skull Base Chordoma

BACKGROUND AND PURPOSE

Skull base chordoma has been widely studied in recent years, however, imaging characteristics of this tumor have not been well elaborated. The purpose of this study was to establish an MR imaging grading system for skull base chordoma.

MATERIALS AND METHODS

In this study, 156 patients with skull base chordomas were retrospectively assessed. Tumor-to-pons signal intensity ratios were calculated from pretreatment MR images R_T1 (ratio of tumor to pons signal intensity in T1 FLAIR sequence), R_T2 (ratio of tumor to pons signal intensity in T2 sequence) and R_EN (ratio of tumor to pons signal intensity in enhanced T1 FLAIR sequence), and significant ratios for overall survival and progression-free survival were selected to establish a grading system. Clinical variables among different MR imaging grades were then analyzed to evaluate the usefulness of the grading system.

RESULTS

R_T2 (P < .001) and R_EN (P = .04) were identified as significant variables affecting progression-free survival. After analysis, the classification criteria were set as follows: MR grade I, R_T2 > 2.49 and R_EN ≤ 0.77; MR grade II, R_T2 > 2.49 and R_EN > 0.77, or R_T2 ≤ 2.49 and R_EN ≤ 0.77; and MR grade III, R_T2 ≤ 2.49 and R_EN > 0.77. MR grade III tumors had a more abundant tumor blood supply than MR grade I tumors (P < .001), and the intraoperative blood loss of MR grade III tumors was higher than that of MR grade I tumors (P = .002). Additionally, skull base chordoma progression risk increased by 2.071 times for every single MR grade increase (P < .001).

CONCLUSIONS

A higher R_T2 value was a negative indicator of tumor progression, whereas a higher R_EN value was a positive risk factor of tumor progression. MR grade III tumors showed a more abundant blood supply than MR grade I tumors, and the risk of skull base chordoma progression increased with every single MR grade increase.

Influence of dietary rapeseed meal levels on growth performance, organ health and standardized ileal amino acid digestibility in meat ducks from 15 to 35 days of age

This study was conducted to investigate the effects of dietary rapeseed meal (RSM) inclusion levels on growth performance, organ health and standardized ileal amino acid digestibility (SIAAD) in meat ducks from 15 to 35 days of age. Six hundred and eighty 15-days-old ducks were randomly allotted to five treatments based on body weight. Five isonitrogenous and isoenergetic diets were formulated on a digestible amino acid basis by replacing 0% (the control), 25%, 50%, 75% and 100% (based on fresh) of protein from soya bean meal (SBM) with protein from RSM. The corresponding levels of RSM in experimental diets were 0%, 6.66%, 13.32%, 19.98% and 26.64% respectively. With increasing dietary RSM levels, body weight (BW) and average daily gain (ADG) linearly decreased (p < 0.001), whereas feed-to-gain ratio (F: G) linearly increased (p = 0.0078). Ducks fed the diets with 13.32% or more RSM had significantly lower (p < 0.05) BW, ADG and ADFI, or higher F: G than ducks fed the control diet. The maximum limit of dietary RSM supplementation was estimated to range from 4.27% to maximize ADG for 15 to 35 days to 11.69% to maintain feed intake for 15 to 35 days on the basis of a broken-line model. At day35, the 4th primary wing feather length and SIAAD (except for Met, Thr and Val) linearly decreased (p < 0.001), and the thyroid glands weight (% of BW) linearly increased (p < 0.05) with increasing dietary RSM levels. Ducks fed the RSM inclusion diets had significantly lower (p < 0.0001) serum aspartate aminotransferase (AST) and alanine transaminase (ALT) activities than ducks fed the control diet. These results suggested that the maximum limit of dietary RSM containing 7.57 μmol/g glucosinolates was estimated to be 4.27% to avoid growth reduction.

[Application of three control banding tools to occupational health risk assessment of titanium dioxide manufacturing factory]

Objective: To explore and validate suitable risk assessment methods for titanium dioxide though applying three risk assessment tools for nanomaterials based on the control banding (CB) approach. Methods: A factory manufacturing titanium dioxide in Jinan city, Shandong province, was assessed using a quantitative exposure method and qualitative risk assessment methods in September, 2014. A condensation particle counter equipment was used to monitor the number concentration of particles at packaging workshop and jet milling workshop. We employed three control banding tools, including CB nanotool, Stoffenmanager nano and the Guidance on working safely with nanomaterials and nanoproducts (GWSNN) to evaluate the two workshops, then compared the evaluation results. Results: The increases of particle concentrations were generated directly by packaging and jet milling processes, the number concentration from (3.52±1.46) ×10(4)/cm(3) to (14.70±8.86) ×10(4)/cm(3) at packaging workshop and from (0.97±0.25) ×10(4)/cm(3) to (1.26±0.35) ×10(4)/cm(3) at milling workshop (both P<0.05) . The number concentrations at packaging workshop were higher than those at jet milling workshop during both manufacturing and break times (both P<0.05) . The results of CB nanotool showed that the risk level of the packaging workshop was classified as high and the risk level of the jet milling workshop was classified asmedium. The results of Stoffenmanager nano showed that the risk level of the packaging workshop was classified as medium and the risk level of the jet milling workshop was classified as low. The results of GWSNN showed that the risk level of packaging workshop was classified as high and the risk level of jet milling workshop was classified as low. Conclusion: The results of evaluation based on the three control banding tools are related and aligned with the results of quantitative monitoring, so they are all suitable to perform occupational health risk assessment on industrial scale production of titanium dioxideto some extent.

[Hot research topics on cardiovascular diseases in occupational population: a bibliometric analysis]

Objective: To investigate the literature characteristics and research topics on cardiovascular diseases in the occupational population quantitatively via a bibliometric analysis, and to provide a reference for the selection of research directions. Methods: A search strategy was developed according to the words in Medical Subject Heading (MeSH) , and PubMed database was searched for articles on cardiovascular diseases in the occupational population published from 2006 to 2015. The information of published year, authors, journals, and MeSH words was extracted, frequently used MeSH words were screened out, and a cluster analysis was performed for frequently used MeSH words. Results: A total of 1 272 articles were found, and about 150 articles were published annually from 2011 to 2015. Most articles were published in Occupational and Environmental Medicine, and the author Tohr Nilsson had the highest number of published articles. The influencing factors mainly included occupational mental stress, smoking, and working system, and the health outcomes attracting the most attention were hypertension, hand-arm vibration, ischemic heart disease, and myocardial infarction. The articles were clustered into 5 types, and 5 hot topics were summarized. Conclusion: The bibliometric analysis of cardiovascular diseases in occupational population shows that hypertension and hand-arm vibration are hot research topics, which can provide a reference to researchers.