Preventive Effect of 6-shogaol on D-galactosamine Induced Hepatotoxicity Through NF-?B/MAPK Signaling Pathway in Rats

This analysis aims to see whether 6-shogaol could protect rats against D-galactosamine (D-GalN)-induced Hepatotoxicity. The Wistar rats were divided into four groups (n=6). Group 1 received a standard diet, Group 2 received an oral administration of 6-shogaol (20 mg/kg b.wt), Group 3 received an intraperitoneal injection of D-GalN (400 mg/kg b.wt) on 21st day, and Group 4 received an oral administration of 6-shogaol (20mg/kg b.wt) for 21 days and D-GalN (400 mg/kg b.wt) injection only on 21st day. The hepatic marker enzymes activity, lipid peroxidative markers level increased significantly and antioxidant activity/level significantly reduced in D-GalN-induced rats. 6-shogaol Pretreatment effectively improves the above changes in D-GalN-induced rats. Further, inflammatory marker expression and MAPK signaling molecules were downregulated by 6-shogaol. These findings showed that 6-shogaol exerts hepatoprotective effects via the enhanced antioxidant system and attenuated the inflammation and MAPK signaling pathway in D-GalN-induced rats.

Association between Intrinsic Capacity and Sarcopenia in Hospitalized Older Patients

OBJECTIVES

This study aimed to clarify the association between intrinsic capacity (IC) and sarcopenia in hospitalized older patients.

DESIGN

A cross-sectional study.

SETTING

Hospital-based.

PARTICIPANTS

This study included 381 inpatients aged ≥ 60 years (225 men and 156 women).

MEASUREMENTS

IC was evaluated in five domains defined by the World Health Organization: cognition (Mini-Mental State Examination), locomotion (Short Physical Performance Battery test), vitality (Short-Form Mini Nutritional Assessment), sensory (self-reported hearing and vision) and psychological (5-item Geriatric Depression Scale) capacities. IC composite score (0-5) was calculated based on five domains, with lower scores representing greater IC. Sarcopenia was defined in accordance with the criteria recommended by the Asian Working Group for Sarcopenia (AWGS) 2019. Multiple linear and logistic regressions were performed to explore the associations between IC composite score and IC domains with sarcopenia and its defining components.

RESULTS

The mean age of 381 patients included was 81.95±8.42 years. Of them, 128 (33.6%) patients had sarcopenia. The median IC composite score was 1 (1, 2). Cognition, locomotion, vitality, sensory and psychological capacities were impaired in 22.6%, 63.5%, 18.9%, 27.3% and 11.3% of patients. Multiple linear regression analyses showed that favorable IC domain scores in cognition, locomotion and vitality were associated with a stronger handgrip strength. A higher vitality score was associated with a greater appendicular skeletal muscle mass index (ASMI), and a higher locomotion score was associated with a greater gait speed. The multiple logistic regression analysis showed that only vitality impairment was associated with sarcopenia. A higher IC composite score was associated with higher risks of sarcopenia, as well as low ASMI, handgrip strength and gait speed.

CONCLUSION

This study indicated that a more serious impairment of IC was associated with a greater risk of sarcopenia. Vitality was the domain most strongly associated with sarcopenia. IC may be employed to detect and manage sarcopenia.

Characterization of serum adiponectin and leptin in healthy perinatal dairy cows or cows with ketosis, and their effectson ketosis involved indices

We investigated changes in concentrations of ADP (adiponectin), LEP (leptin), BHBA (beta-hydroxybutyric acid), NEFA (non-esterified fatty acid), Glucose (Glu) and INS (insulin) in serum of healthy perinatal dairy cows and cows with ketosis. Twenty-one healthy cows and seventeen cows with ketosis from a herd of a total 60 Holstein cows (near dry period i.e. 56 days antepartum) were selected. Blood was collected through the tail vein every 7 days, from 56 day antepartum to 56 day postpartum. Serum ADP, LEP, BHBA, NEFA, Glu, and INS concentrations were determined, and ketosis was diagnosed through serum BHBA (≥1.2 mmol/L). We showed the concentration of serum adipokines and energy balancing indices were stable during antepar- tum period. However, ADP concentration increased while LEP decreased, and there were a significant increase in cows with ketosis compared to that of in healthy cows. Serum BHBA and NEFA concentrations increased significantly at first, and then gradually decreased in both healthy cows and cows with ketosis. However, cows with ketosis showed higher concentrations of BHBA and NEFA which restored later. The serum concentration of Glu in both healthy dairy cows and cows with ketosis showed a decreasing trend. INS concentration in healthy cows was decreased while it was increased in cows with ketosis. The results reflect the extent of hypo- glycemia and lipid mobilization postpartum, suggest IR exists in cows with ketosis while serum ADP and LEP might play roles in the development of ketosis.

Chicory fibre improves reproductive performance of pregnant rats involving in altering intestinal microbiota composition

AIM

Chicory fibre (CF) is rich in fructan, which always functions as a quality dietary fibre source during mammalian pregnancy; however, its effect on reproductive performance remains unclear.

METHODS AND RESULTS

40 pregnant SD rats were randomly allotted to receive one of four diets: basal diet (control group), basal diet + 5% CF, basal diet + 10% CF, and basal diet + 15% CF, respectively. We found that CF significantly increased the number born alive and total litter birth weight (P < 0·05), increased the expression of intestinal tight junction proteins, mucins and antimicrobial peptides, accompanied by the increase of villi height and the decrease of crypts depth of pregnant SD rats (P < 0·05). We also observed that CF markedly increased the acetic acid, propanoic acid, butyric acid and total SCFAs concentrations in caecum contents and promoted the expression of SCFAs-related receptors (P < 0·05). Notably, rats fed CF increased the relative abundance of Bacteroidetes (P < 0·001), decreased the relative abundance of Firmicutes and Proteobacteria, while markedly lowered the Firmicutes/ Bacteroidetes ratio (F/B ratio) (P < 0·05). Intriguingly, the number born alive and total litter birth weight were positively correlated with some probiotics and negatively correlated with other harmful bacteria by Pearson correlation analysis.

CONCLUSION

Collectively, CF can enhance intestinal barrier function and maintain intestinal health, and may improve reproductive performance by altering intestinal microbiota composition.

SIGNIFICANCE AND IMPACT OF THE STUDY

Adding suitable dietary fibre to the diet can improve the reproductive performance of sows. Indeed, there exist various problems in the application of traditional dietary fibres, including high insoluble fibre content and anti-nutritional factor level, and mycotoxin contamination. This study demonstrates that dietary CF supplementation improves reproductive performance and intestinal health. Thus, CF can be applied in pregnancy animals as a new dietary fibre additive in animal husbandry.

Relationship of adiponectin, leptin, visfatin and IGF-1 in cow's venous blood and venous cord blood with calf birth weight

The Intrauterine fetal development process is complicated and affected by many regulating factors such as maternal nutritional status, transcription factors and adipokines. Adipokines are kinds of active substances secreted by adipose tissue, including more than 50 kinds of molecules. To explore the correlation between calf birth weights and adipokines including adiponectin, leptin, visfatin, and IGF-1 in cows venous and venous cord blood. Fifty-four healthy multiparous Chinese Holstein cows were used; in which, cows with a calf weight less than 40 kg were included in group A (n=9); those with a calf weight between 40 kg~45 kg were included in group B (n=25) and ≥45 kg were included in group C (n=20), venous blood and cord venous blood was collected. An ELISA kit was used to evaluate the concentration of adiponectin, leptin, visfatin, and IGF-1, correlations between index-index and index-calf birth weight were analysed. In both cows venous and cord venous blood, adiponectin, leptin, visfatin, and IGF-1 levels were significantly correlated with each other (p⟨0.01), and levels of these adipokines in venous blood were significantly higher than cord venous blood (p⟨0.01). Adiponectin, leptin, visfatin, and IGF-1 in venous cord blood were positively correlated with calf birth weights, and significantly correlated with calf birth weights respectively (p⟨0.01). Our study showed that adiponectin, leptin, and IGF-1 were found in venous blood and cord venous blood, and adiponectin, leptin, and IGF-1 in venous and cord venous blood potentially inter-regulated each other; adiponectin, leptin, and IGF-1 in venous blood were not significantly correlated with calf birth weights, while adiponectin, leptin, visfatin, and IGF-1 in venous cord blood were significantly correlated with calf birth weights, respectively.

Effect of butein and glucose on oxidative stress and p38 activation marker in non-small cell lung cancer cell

INTRODUCTION

Tumor microenvironment is known to alter the anticancer drug efficiency. One of the factors that get altered in cancer microenvironment is glucose concentration. Butein, an active principle from plant, known to have anticancer effect against different types of tumor. The objective of the study is to determine the effect of butein on glucose exposed non-small cell lung cancer cells (NSCLCCs).

METHODS

The current study deals with the effect of butein (6.25-50μM) on NSCLCCs treated with different concentrations (0-40 mM) of glucose.

RESULTS AND DISCUSSION

Glucose concentration, 0 mM and 40 mM, was found to be lethal at 72 h. Viable cell numbers were statistically increased in 5-mM, 10-mM, and 20-mM glucose-treated cells. Butein at 12.5 µM inhibits (p < 0.05) glucose-induced cell proliferation. Butein inhibits glucose-induced proliferation through DNA damage and oxidative stress. Mitochondrial reactive oxygen species (ROS) level was elevated in 20-mM glucose-treated cells when compared to 5-mM glucose-treated cells, whereas butein treatment further increases glucose-induced mitochondrial ROS. Pharmacological inhibitor of glycolysis, such as 2-deoxy glucose (2-DG), was found to inhibit (p < 0.05) glucose-induced cells proliferation. Furthermore, 2-DG and butein showed synergistic anticancer effect. Butein treatment increases p38 phosphorylation. Inhibition of p38 phosphorylation and antioxidant pretreatment partially revert the glucose-induced cell proliferation. However, inhibition of p38 phosphorylation combined with antioxidant pretreatment completely reverts the anticancer effect of butein. The present study concludes through the evidence that butein could serve as a potential anticancer compound in tumor microenvironment.

Mendelian Randomization and mediation analysis of leukocyte telomere length and risk of lung and head and neck cancers

BACKGROUND

Evidence from observational studies of telomere length (TL) has been conflicting regarding its direction of association with cancer risk. We investigated the causal relevance of TL for lung and head and neck cancers using Mendelian Randomization (MR) and mediation analyses.

METHODS

We developed a novel genetic instrument for TL in chromosome 5p15.33, using variants identified through deep-sequencing, that were genotyped in 2051 cancer-free subjects. Next, we conducted an MR analysis of lung (16 396 cases, 13 013 controls) and head and neck cancer (4415 cases, 5013 controls) using eight genetic instruments for TL. Lastly, the 5p15.33 instrument and distinct 5p15.33 lung cancer risk loci were evaluated using two-sample mediation analysis, to quantify their direct and indirect, telomere-mediated, effects.

RESULTS

The multi-allelic 5p15.33 instrument explained 1.49-2.00% of TL variation in our data (p = 2.6 × 10-9). The MR analysis estimated that a 1000 base-pair increase in TL increases risk of lung cancer [odds ratio (OR) = 1.41, 95% confidence interval (CI): 1.20-1.65] and lung adenocarcinoma (OR = 1.92, 95% CI: 1.51-2.22), but not squamous lung carcinoma (OR = 1.04, 95% CI: 0.83-1.29) or head and neck cancers (OR = 0.90, 95% CI: 0.70-1.05). Mediation analysis of the 5p15.33 instrument indicated an absence of direct effects on lung cancer risk (OR = 1.00, 95% CI: 0.95-1.04). Analysis of distinct 5p15.33 susceptibility variants estimated that TL mediates up to 40% of the observed associations with lung cancer risk.

CONCLUSIONS

Our findings support a causal role for long telomeres in lung cancer aetiology, particularly for adenocarcinoma, and demonstrate that telomere maintenance partially mediates the lung cancer susceptibility conferred by 5p15.33 loci.

Fine mapping of MHC region in lung cancer highlights independent susceptibility loci by ethnicity

The basis for associations between lung cancer and major histocompatibility complex genes is not completely understood. Here the authors further consider genetic variation within the MHC region in lung cancer patients and identify independent associations within HLA genes that explain MHC lung cancer associations in Europeans and Asian populations.

Lung cancer has several genetic associations identified within the major histocompatibility complex (MHC); although the basis for these associations remains elusive. Here, we analyze MHC genetic variation among 26,044 lung cancer patients and 20,836 controls densely genotyped across the MHC, using the Illumina Illumina OncoArray or Illumina 660W SNP microarray. We impute sequence variation in classical HLA genes, fine-map MHC associations for lung cancer risk with major histologies and compare results between ethnicities. Independent and novel associations within HLA genes are identified in Europeans including amino acids in the HLA-B*0801 peptide binding groove and an independent HLA-DQB1*06 loci group. In Asians, associations are driven by two independent HLA allele sets that both increase risk in HLA-DQB1*0401 and HLA-DRB1*0701; the latter better represented by the amino acid Ala-104. These results implicate several HLA–tumor peptide interactions as the major MHC factor modulating lung cancer susceptibility.

Identification of susceptibility pathways for the role of chromosome 15q25.1 in modifying lung cancer risk

Genome-wide association studies (GWAS) identified the chromosome 15q25.1 locus as a leading susceptibility region for lung cancer. However, the pathogenic pathways, through which susceptibility SNPs within chromosome 15q25.1 affects lung cancer risk, have not been explored. We analyzed three cohorts with GWAS data consisting 42,901 individuals and lung expression quantitative trait loci (eQTL) data on 409 individuals to identify and validate the underlying pathways and to investigate the combined effect of genes from the identified susceptibility pathways. The KEGG neuroactive ligand receptor interaction pathway, two Reactome pathways, and 22 Gene Ontology terms were identified and replicated to be significantly associated with lung cancer risk, with P values less than 0.05 and FDR less than 0.1. Functional annotation of eQTL analysis results showed that the neuroactive ligand receptor interaction pathway and gated channel activity were involved in lung cancer risk. These pathways provide important insights for the etiology of lung cancer.

Common TDP1 Polymorphisms in Relation to Survival among Small Cell Lung Cancer Patients: A Multicenter Study from the International Lung Cancer Consortium

Purpose: DNA topoisomerase inhibitors are commonly used for treating small-cell lung cancer (SCLC). Tyrosyl-DNA phosphodiesterase (TDP1) repairs DNA damage caused by this class of drugs and may therefore influence treatment outcome. In this study, we investigated whether common TDP1 single-nucleotide polymorphisms (SNP) are associated with overall survival among SCLC patients.Experimental Design: Two TDP1 SNPs (rs942190 and rs2401863) were analyzed in 890 patients from 10 studies in the International Lung Cancer Consortium (ILCCO). The Kaplan-Meier method and Cox regression analyses were used to evaluate genotype associations with overall mortality at 36 months postdiagnosis, adjusting for age, sex, race, and tumor stage.Results: Patients homozygous for the minor allele (GG) of rs942190 had poorer survival compared with those carrying AA alleles, with a HR of 1.36 [95% confidence interval (CI): 1.08-1.72, P = 0.01), but no association with survival was observed for patients carrying the AG genotype (HR = 1.04, 95% CI, 0.84-1.29, P = 0.72). For rs2401863, patients homozygous for the minor allele (CC) tended to have better survival than patients carrying AA alleles (HR = 0.79; 95% CI, 0.61-1.02, P = 0.07). Results from the Genotype Tissue Expression (GTEx) Project, the Encyclopedia of DNA Elements (ENCODE), and the ePOSSUM web application support the potential function of rs942190.Conclusions: We found the rs942190 GG genotype to be associated with relatively poor survival among SCLC patients. Further investigation is needed to confirm the result and to determine whether this genotype may be a predictive marker for treatment efficacy of DNA topoisomerase inhibitors. Clin Cancer Res; 23(24); 7550-7. ©2017 AACR.

Pleiotropy of genetic variants on obesity and smoking phenotypes: Results from the Oncoarray Project of The International Lung Cancer Consortium

Obesity and cigarette smoking are correlated through complex relationships. Common genetic causes may contribute to these correlations. In this study, we selected 241 loci potentially associated with body mass index (BMI) based on the Genetic Investigation of ANthropometric Traits (GIANT) consortium data and calculated a BMI genetic risk score (BMI-GRS) for 17,037 individuals of European descent from the Oncoarray Project of the International Lung Cancer Consortium (ILCCO). Smokers had a significantly higher BMI-GRS than never-smokers (p = 0.016 and 0.010 before and after adjustment for BMI, respectively). The BMI-GRS was also positively correlated with pack-years of smoking (p<0.001) in smokers. Based on causal network inference analyses, seven and five of 241 SNPs were classified to pleiotropic models for BMI/smoking status and BMI/pack-years, respectively. Among them, three and four SNPs associated with smoking status and pack-years (p<0.05), respectively, were followed up in the ever-smoking data of the Tobacco, Alcohol and Genetics (TAG) consortium. Among these seven candidate SNPs, one SNP (rs11030104, BDNF) achieved statistical significance after Bonferroni correction for multiple testing, and three suggestive SNPs (rs13021737, TMEM18; rs11583200, ELAVL4; and rs6990042, SGCZ) achieved a nominal statistical significance. Our results suggest that there is a common genetic component between BMI and smoking, and pleiotropy analysis can be useful to identify novel genetic loci of complex phenotypes.

Second malignant neoplasms after childhood non-central nervous system embryonal tumours in North America: A population-based study

BACKGROUND

Few studies in North America have quantified the risks of second malignant neoplasms (SMNs) among survivors of childhood non-central nervous system (non-CNS) embryonal tumours due to their rarity. We aimed to investigate these risks by combining population-based data from the United States of America and Canada.

METHODS

We evaluated patients with childhood non-CNS embryonal tumours reported to the Surveillance Epidemiology and End Results program and eight Canadian cancer registries from 1969 to 2010. Standardised incidence ratio (SIR) and cumulative incidence of SMNs were calculated. Subgroup analyses were conducted by the type of first primary cancer, age at first primary diagnosis and follow-up duration.

FINDINGS

Of the 13,107 survivors, 190 SMNs were reported over 134,548 person-years of follow-up. The SIR for all SMNs combined was 6.4 (95% confidence interval [CI]: 5.5-7.4). Most site-specific SIRs were significantly increased, ranging from 36 (95% CI: 26-49) for bone and joint cancer to 3.1 (95% CI: 1.5-5.2) for brain tumour. The risk for second malignancies declined as the time elapsed from the first primary diagnosis and was less prominent for patients first diagnosed at age 1-4 years. Notably, rhabdomyosarcoma survivors had a higher risk for SMNs than those with other first primaries. The overall cumulative incidence of SMNs was 1.0% at 10 years, increasing to 2.2% at 20 years and 4.1% at 30 years.

INTERPRETATION

Survivors with childhood non-CNS embryonal tumours faced an increased risk for SMNs compared to the general population. The risk variations observed in different patient categories may help target prevention strategies in high-risk subgroups.

Abstract 2248: Common TDP1 polymorphisms in relation to survival among small cell lung cancer patients in a multicenter study from the International Lung Cancer Consortium

Introduction: DNA topoisomerase inhibitors (e.g. etoposide, irinotecan, teniposide, topotecan) are commonly used for treating small cell lung cancer (SCLC). Tyrosyl-DNA phosphodiesterase (TDP1) plays a role in repairing DNA damage caused by DNA topoisomerase inhibitors and it is believed to be responsible for resistance to this class of drugs. The purpose of this study was to determine whether common TDP1 polymorphisms are associated with overall survival among SCLC patients.

Method: Two common TDP1 SNPs (rs942190 and rs2401863, r2(European)=0.63 and r2(East Asian)=0.26) were analyzed in 898 patients from 10 studies in the International Lung Cancer Consortium, conducted in the U.S., Canada, Japan, Italy, Spain and the United Kingdom. Genotype data were obtained from either the OncoArray Consortium or other existing genome-wide association studies. Cox proportional hazard regression models with robust standard error were used to evaluate genotype associations for overall survival at 36 months post-diagnosis, adjusting for age, sex, race and tumor stage.

Results: Patients homozygous for the minor allele (GG) of TDP1 SNP rs942190 were associated with poorer survival compared to those carrying both major alleles (AA), with a hazard ratio (HR) of 1.36 (95% confidence interval (CI): 1.07-1.72, p-value=0.01), but there was no association with survival for patients with the heterozygous genotype (HR=1.02, 95% CI: 0.83-1.27, p-value=0.83). For rs2401863, patients carrying both minor alleles (CC) tended to have better survival than patients carrying AA alleles, but this was within the limits of chance given no significant association (HR=0.79, 95% CI: 0.61-1.02, p-value=0.07). In addition, multi-tissue expression quantitative trait loci (eQTL) analyses from the Genotype-Tissue Expression Project indicated a potential effect of rs942190 on lung tissue, with higher TDP1 gene expression for the GG than AG or AA genotypes.

Conclusion: We found that among SCLC patients the TDP1 rs942190 GG genotype was associated with poor overall survival. Further study could determine if this genotype can serve as a predictive marker for the treatment efficacy of DNA topoisomerase inhibitors in SCLC.

Citation Format: Pawadee Lohavanichbutr, Lori C. Sakoda, Christopher I. Amos, Susanne M. Arnold, David C. Christiani, Michael P. Davies, John K. Field, Eric B. Haura, Rayjean J. Hung, Takashi Kohno, Maria Teresa Landi, Geoffrey Liu, Yi Liu, Michael W. Marcus, Grainne M. O'Kane, Matthew B. Schabath, Kouya Shiraishi, Stacey A. Slone, Adonina Tardón, Ping Yang, Kazushi Yoshida, Ruyang Zhang, Xuchen Zong, Noel S. Weiss, Chu Chen. Common TDP1 polymorphisms in relation to survival among small cell lung cancer patients in a multicenter study from the International Lung Cancer Consortium [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 2248. doi:10.1158/1538-7445.AM2017-2248

Large-scale association analysis identifies new lung cancer susceptibility loci and heterogeneity in genetic susceptibility across histological subtypes

Although several lung cancer susceptibility loci have been identified, much of the heritability for lung cancer remains unexplained. Here 14,803 cases and 12,262 controls of European descent were genotyped on the OncoArray and combined with existing data for an aggregated genome-wide association study (GWAS) analysis of lung cancer in 29,266 cases and 56,450 controls. We identified 18 susceptibility loci achieving genome-wide significance, including 10 new loci. The new loci highlight the striking heterogeneity in genetic susceptibility across the histological subtypes of lung cancer, with four loci associated with lung cancer overall and six loci associated with lung adenocarcinoma. Gene expression quantitative trait locus (eQTL) analysis in 1,425 normal lung tissue samples highlights RNASET2, SECISBP2L and NRG1 as candidate genes. Other loci include genes such as a cholinergic nicotinic receptor, CHRNA2, and the telomere-related genes OFBC1 and RTEL1. Further exploration of the target genes will continue to provide new insights into the etiology of lung cancer.

Risperidone-induced topological alterations of anatomical brain network in first-episode drug-naive schizophrenia patients: a longitudinal diffusion tensor imaging study

BACKGROUND

It remains unclear whether the topological deficits of the white matter network documented in cross-sectional studies of chronic schizophrenia patients are due to chronic illness or to other factors such as antipsychotic treatment effects. To answer this question, we evaluated the white matter network in medication-naive first-episode schizophrenia patients (FESP) before and after a course of treatment.

METHOD

We performed a longitudinal diffusion tensor imaging study in 42 drug-naive FESP at baseline and then after 8 weeks of risperidone monotherapy, and compared them with 38 healthy volunteers. Graph theory was utilized to calculate the topological characteristics of brain anatomical network. Patients' clinical state was evaluated using the Positive and Negative Syndrome Scale (PANSS) before and after treatment.

RESULTS

Pretreatment, patients had relatively intact overall topological organizations, and deficient nodal topological properties primarily in prefrontal gyrus and limbic system components such as the bilateral anterior and posterior cingulate. Treatment with risperidone normalized topological parameters in the limbic system, and the enhancement positively correlated with the reduction in PANSS-positive symptoms. Prefrontal topological impairments persisted following treatment and negative symptoms did not improve.

CONCLUSIONS

During the early phase of antipsychotic medication treatment there are region-specific alterations in white matter topological measures. Limbic white matter topological dysfunction improves with positive symptom reduction. Prefrontal deficits and negative symptoms are unresponsive to medication intervention, and prefrontal deficits are potential trait biomarkers and targets for negative symptom treatment development.

Abstract 2569: A genome wide association study of lung cancer identifies 11 novel susceptibility loci

Background

Genome wide association studies (GWAS) of lung cancer have identified susceptibility loci at 15q25, 5p15, 6p21, 13q13 and 22q12 that contain relevant candidate genes such as CHRNA3/5, TERT, HLA, BRCA2 and CHEK2, respectively. Many of these alleles appear more relevant to a particularly histological type of lung cancer.

With the aim of identifying novel lung cancer susceptibility loci, The Transdisciplinary Research in Cancer of the Lung (TRICL), the International Lung Cancer Consortium (ILCCO) and Lung Cancer Cohort Consortium (LC3) have undertaken a very large collaborative GWAS across 29 lung cancer studies, including analysis of the predominant lung cancer histological subtypes.

Methods

In collaboration with the Center for Disease Research (CIDR), TRICL, ILCCO and LC3 have genotyped 18,000 case-control pairs on the GAME-On Oncoarray. SNP imputation was undertaken using the 1,000 Genomes v3 reference panel, followed by logistic regression of each genetic variant with lung cancer and considering ancestry inferred by genetic profile to correct for cryptic population structure. The OncoArray and our previous GWAS results were combined using meta-analysis. This allowed for a GWAS of 10,155,682 SNPs for 25,655 lung cancer cases and 52,451 controls, as well as histology specific analysis of 6,629 squamous cell and 9,817 adenocarcinomas. Alternate genotyping techniques (Affymetrix, Taqman) were used to confirm the fidelity of the genotyping for variants of interest.

Results

We have identified common genetic variants exceeding genome wide significance (p&lt;5×10-8) at eleven novel susceptibility loci. This included two associated with overall lung cancer (1p31, 19q13), eight with lung adenocarcinomas (3q28, 6p25, 8p12, 9p21, 10q25, 11q23, 15q21, 20q13) and one with squamous-cell lung carcinomas (10q24). These genetic variants are located near several intriguing candidate genes, such as telomere function genes (OBFC1, RTEL1), nicotine metabolism genes (CYP2A6), genes somatically mutated in lung cancer (NRG1) and genetic susceptibility loci linked to other cancers (IRF4, CDNK2A). In additional, we noted several borderline (p&lt;10-6) associations with common variants located near nicotine addiction genes (CHRNB2, CHRNA2, CHRNA4, DBH) and other genes somatically translocated in lung cancer (ROS1). Integration of eQTL databases suggests that many of the associated genetic variants influence gene expression levels of these candidate genes.

Conclusion

We have identified eleven novel lung cancer susceptibility loci, doubling the number implicated by GWAS. These genetic variants were common (MAF 0.05-0.49) with modest to small genetic effects (OR's 1.10-1.17). Further expansion of GWAS efforts, particularly within histological subtypes of lung cancer, is likely to identify additional susceptibility loci and further increase our understanding of lung cancer aetiology.

Citation Format: James Dowling Mckay, Yafang Li, Younghun Han, Xiangjun Xioa, John Field, Xuchen Zong, Heike Bickeböller, David C. Christiani, Paul Brennan, Maria-Teresa Landi, Rayjean Hung, Christopher I. Amos, on behalf of the OncoArray Lung Cancer Group. A genome wide association study of lung cancer identifies 11 novel susceptibility loci. [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 2569.

Fine mapping of chromosome 5p15.33 based on a targeted deep sequencing and high density genotyping identifies novel lung cancer susceptibility loci

Chromosome 5p15.33 has been identified as a lung cancer susceptibility locus, however the underlying causal mechanisms were not fully elucidated. Previous fine-mapping studies of this locus have relied on imputation or investigated a small number of known, common variants. This study represents a significant advance over previous research by investigating a large number of novel, rare variants, as well as their underlying mechanisms through telomere length. Variants for this fine-mapping study were identified through a targeted deep sequencing (average depth of coverage greater than 4000×) of 576 individuals. Subsequently, 4652 SNPs, including 1108 novel SNPs, were genotyped in 5164 cases and 5716 controls of European ancestry. After adjusting for known risk loci, rs2736100 and rs401681, we identified a new, independent lung cancer susceptibility variant in LPCAT1: rs139852726 (OR = 0.46, P = 4.73×10(-9)), and three new adenocarcinoma risk variants in TERT: rs61748181 (OR = 0.53, P = 2.64×10(-6)), rs112290073 (OR = 1.85, P = 1.27×10(-5)), rs138895564 (OR = 2.16, P = 2.06×10(-5); among young cases, OR = 3.77, P = 8.41×10(-4)). In addition, we found that rs139852726 (P = 1.44×10(-3)) was associated with telomere length in a sample of 922 healthy individuals. The gene-based SKAT-O analysis implicated TERT as the most relevant gene in the 5p15.33 region for adenocarcinoma (P = 7.84×10(-7)) and lung cancer (P = 2.37×10(-5)) risk. In this largest fine-mapping study to investigate a large number of rare and novel variants within 5p15.33, we identified novel lung and adenocarcinoma susceptibility loci with large effects and provided support for the role of telomere length as the potential underlying mechanism.

Factors Impacting Transgender Patients' Discomfort with Their Family Physicians: A Respondent-Driven Sampling Survey

Background

Representing approximately 0.5% of the population, transgender (trans) persons in Canada depend on family physicians for both general and transition-related care. However, physicians receive little to no training on this patient population, and trans patients are often profoundly uncomfortable and may avoid health care. This study examined factors associated with patient discomfort discussing trans health issues with a family physician in Ontario, Canada.

Methods

433 trans people age 16 and over were surveyed using respondent-driven sampling for the Trans PULSE Project; 356 had a family physician. Weighted logistic regression models were fit to produce prevalence risk ratios (PRRs) via average marginal predictions, for transmasculine (n = 184) and transfeminine (n = 172) trans persons.

Results

Among the 83.1% (95% CI = 77.4, 88.9) of trans Ontarians who had a family physician, approximately half reported discomfort discussing trans health issues. 37.2% of transmasculine and 38.1% of transfeminine persons reported at least one trans-specific negative experience. In unadjusted analysis, sociodemographics did not predict discomfort, but those who planned to medically transition sex, but had not begun, were more likely to report discomfort (transmasculine: PRR = 2.62 (95% CI = 1.44, 4.77); transfeminine: PRR = 1.85 (95% CI = 1.08, 3.15)). Adjusted for other factors, greater perceived physician knowledge about trans issues was associated with reduced likelihood of discomfort, and previous trans-specific negative experiences with a family physician with increased discomfort. Transfeminine persons who reported three or more types of negative experiences were 2.26 times as likely, and transmasculine persons 1.61 times as likely, to report discomfort. In adjusted analyses, sociodemographic associations differed by gender, with being previously married or having higher education associated with increased risk of discomfort among transfeminine persons, but decreased risk among transmasculine persons.

Conclusions

Within this transgender population, discomfort in discussing trans health issues with a family physician was common, presenting a barrier to accessing primary care despite having a regular family physician and “universal” health insurance.

Identification of lung cancer histology-specific variants applying Bayesian framework variant prioritization approaches within the TRICL and ILCCO consortia

Large-scale genome-wide association studies (GWAS) have likely uncovered all common variants at the GWAS significance level. Additional variants within the suggestive range (0.0001> P > 5×10(-8)) are, however, still of interest for identifying causal associations. This analysis aimed to apply novel variant prioritization approaches to identify additional lung cancer variants that may not reach the GWAS level. Effects were combined across studies with a total of 33456 controls and 6756 adenocarcinoma (AC; 13 studies), 5061 squamous cell carcinoma (SCC; 12 studies) and 2216 small cell lung cancer cases (9 studies). Based on prior information such as variant physical properties and functional significance, we applied stratified false discovery rates, hierarchical modeling and Bayesian false discovery probabilities for variant prioritization. We conducted a fine mapping analysis as validation of our methods by examining top-ranking novel variants in six independent populations with a total of 3128 cases and 2966 controls. Three novel loci in the suggestive range were identified based on our Bayesian framework analyses: KCNIP4 at 4p15.2 (rs6448050, P = 4.6×10(-7)) and MTMR2 at 11q21 (rs10501831, P = 3.1×10(-6)) with SCC, as well as GAREM at 18q12.1 (rs11662168, P = 3.4×10(-7)) with AC. Use of our prioritization methods validated two of the top three loci associated with SCC (P = 1.05×10(-4) for KCNIP4, represented by rs9799795) and AC (P = 2.16×10(-4) for GAREM, represented by rs3786309) in the independent fine mapping populations. This study highlights the utility of using prior functional data for sequence variants in prioritization analyses to search for robust signals in the suggestive range.

Abstract 3713: Second malignant neoplasms after non-CNS embryonal tumors in North America

Background: Childhood cancer survivors are known to face an increased risk of adverse medical conditions related to the initial disease or cancer treatment; however, few studies have quantified the risk of second malignant neoplasms (SMNs) among survivors of childhood non-CNS embryonal cancer due to its rarity. In this study, we combined data from the U.S. and Canada to investigate the risk of SMNs.

Methods: Data from 13,107 survivors of childhood non-CNS embryonal tumors reported to the Surveillance Epidemiology and End Results (SEER) program in the U.S. and 8 population-based cancer registries in Canada (between 1973 to 2010) were analyzed. We calculated standardized incidence ratios (SIRs) for all types of second primaries by type of first primary, age at first cancer diagnosis, and follow-up duration. Expected numbers of SMNs were obtained by applying age-, sex-, calendar year-, and registry-specific cancer incidence rates to person-years contributed by these cancer survivors.

Results: One hundred and ninety SMNs were reported over 134,548 person-years of follow-up, with bone and joint cancer and leukemia being the most common SMNs (19% and 16% respectively). The SIR for all SMNs combined was 6.4 (95% CI: 5.53-7.35). Most site-specific SIRs were significantly increased, ranging from 36.4 (95% CI: 25.5-49.2) for bone and joint cancer, to 3.1 (95% CI: 1.54-5.2) for brain tumor. Among all the survivors, those who survived rhabdomyosarcoma carried the greatest risk of SMN development with SIR of 11.5 (95% CI: 8.7-14.6). Bone and joint tumors were mostly seen among retinoblastoma survivors, reflecting a markedly risk of 139.3 (95% CI: 85-207). When stratified by follow-up period, we observed that the risk patterns varied by SMN site. For example, the risk for a second malignancy in the thyroid remained significantly increased even after 20 years of follow-up, whereas the elevated risk of secondary leukemia persisted for 10 years but decreased rapidly afterwards. Details of stratified analyses by first primary tumor site, age at first diagnosis, and follow-up duration will be presented.

Conclusion: Survivors of childhood non-CNS embryonal tumors have increased risks of developing SMNs compared to the general population. Increased surveillance may explain the elevated risks within the first few years of the initial diagnosis, but treatment effects and shared etiology most likely account for the excess risk later in life.

Citation Format: Xuchen Zong, Jason D. Pole, Paul Grundy, Salaheddin M. Mahmud, Louise Parker, Rayjean J. Hung. Second malignant neoplasms after non-CNS embryonal tumors in North America. [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 3713. doi:10.1158/1538-7445.AM2015-3713

Informed genome-wide association analysis with family history as a secondary phenotype identifies novel loci of lung cancer

Lung cancer is the leading cause of cancer death worldwide. Although several genetic variants associated with lung cancer have been identified in the past, stringent selection criteria of genome-wide association studies (GWAS) can lead to missed variants. The objective of this study was to uncover missed variants by using the known association between lung cancer and first-degree family history of lung cancer to enrich the variant prioritization for lung cancer susceptibility regions. In this two-stage GWAS study, we first selected a list of variants associated with both lung cancer and family history of lung cancer in four GWAS (3,953 cases, 4,730 controls), then replicated our findings for 30 variants in a meta-analysis of four additional studies (7,510 cases, 7,476 controls). The top ranked genetic variant rs12415204 in chr10q23.33 encoding FFAR4 in the Discovery set was validated in the Replication set with an overall OR of 1.09 (95% CI=1.04, 1.14, P=1.63×10(-4)). When combining the two stages of the study, the strongest association was found in rs1158970 at Ch4p15.2 encoding KCNIP4 with an OR of 0.89 (95% CI=0.85, 0.94, P=9.64×10(-6)). We performed a stratified analysis of rs12415204 and rs1158970 across all eight studies by age, gender, smoking status, and histology, and found consistent results across strata. Four of the 30 replicated variants act as expression quantitative trait loci (eQTL) sites in 1,111 nontumor lung tissues and meet the genome-wide 10% FDR threshold.

An electric-field assisted growth control methodology for integrating ZnO nanorods with microstructures

The growth control of ZnO nanorods bridging over two microelectrodes in a three-electrode structure (the top cathode and anode, and the bottom gate) was realized using a wet chemical method with the assistance of an electric field generated by applying AC sine wave power on the top electrodes and a DC voltage on the bottom gate. A numerical control model for controlling the growth position, direction and density of ZnO nanorods on the microstructure was established based on the simulation of the electric-field distribution around the microstructures. The three input parameters in the numerical control model were defined as the peak-to-peak voltage of the AC sine wave (x1), the frequency of the AC sine wave (x2) and gate voltage (x3). Moreover, five output parameters (y1, y2, y3, y4, y5) in the model were defined as the electric field intensities at specific points on the electrodes to characterize the growth rate, direction, position and morphology of the ZnO nanorods integrated with the microelectrodes. The relationship between the defined outputs and inputs were established using 3(rd) polynomial fitting, which served as the numerical control model for the prediction of nanorod growth. The experimental results validated that growth control methodology provides us with an effective approach to integrate ZnO nanorods into devices.

Measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the reaction (3)He(↑)(e,e')X

We report the first measurement of the target-normal single-spin asymmetry in deep-inelastic scattering from the inclusive reaction 3)He(↑)(e,e')X on a polarized (3)He gas target. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation but can be nonzero if two-photon-exchange contributions are included. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of 1.7<W<2.9  GeV, 1.0<Q(2)<4.0  GeV(2) and 0.16<x<0.65. Neutron asymmetries were extracted using the effective nucleon polarization and measured proton-to-(3)He cross-section ratios. The measured neutron asymmetries are negative with an average value of (-1.09±0.38)×10(-2) for invariant mass W>2  GeV, which is nonzero at the 2.89σ level. Our measured asymmetry agrees both in sign and magnitude with a two-photon-exchange model prediction that uses input from the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering.

Rare variants of large effect in BRCA2 and CHEK2 affect risk of lung cancer

We conducted imputation to the 1000 Genomes Project of four genome-wide association studies of lung cancer in populations of European ancestry (11,348 cases and 15,861 controls) and genotyped an additional 10,246 cases and 38,295 controls for follow-up. We identified large-effect genome-wide associations for squamous lung cancer with the rare variants BRCA2 p.Lys3326X (rs11571833, odds ratio (OR) = 2.47, P = 4.74 × 10(-20)) and CHEK2 p.Ile157Thr (rs17879961, OR = 0.38, P = 1.27 × 10(-13)). We also showed an association between common variation at 3q28 (TP63, rs13314271, OR = 1.13, P = 7.22 × 10(-10)) and lung adenocarcinoma that had been previously reported only in Asians. These findings provide further evidence for inherited genetic susceptibility to lung cancer and its biological basis. Additionally, our analysis demonstrates that imputation can identify rare disease-causing variants with substantive effects on cancer risk from preexisting genome-wide association study data.

Beam-target double-spin asymmetry A{LT} in charged pion production from deep inelastic scattering on a transversely polarized {3}He target at 1.4<Q{2}<2.7 GeV{2}

We report the first measurement of the double-spin asymmetry A{LT} for charged pion electroproduction in semi-inclusive deep-inelastic electron scattering on a transversely polarized {3}He target. The kinematics focused on the valence quark region, 0.16<x<0.35 with 1.4<Q{2}<2.7  GeV{2}. The corresponding neutron A{LT} asymmetries were extracted from the measured {3}He asymmetries and proton over {3}He cross section ratios using the effective polarization approximation. These new data probe the transverse momentum dependent parton distribution function g{1T}{q} and therefore provide access to quark spin-orbit correlations. Our results indicate a positive azimuthal asymmetry for π{-} production on {3}He and the neutron, while our π{+} asymmetries are consistent with zero.

Single spin asymmetries in charged pion production from semi-inclusive deep inelastic scattering on a transversely polarized 3He Target at Q2 = 1.4-2.7 GeV2

We report the first measurement of target single spin asymmetries in the semi-inclusive (3)He(e,e'π(±))X reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.16 < x < 0.35 with 1.4 < Q(2) < 2.7 GeV(2). The Collins and Sivers moments were extracted from the azimuthal angular dependence of the measured asymmetries. The π(±) Collins moments for (3)He are consistent with zero, except for the π(+) moment at x = 0.35, which deviates from zero by 2.3σ. While the π(-) Sivers moments are consistent with zero, the π(+) Sivers moments favor negative values. The neutron results were extracted using the nucleon effective polarization and measured cross section ratios of proton to (3)He, and are largely consistent with the predictions of phenomenological fits and quark model calculations.

System size and energy dependence of jet-induced hadron pair correlation shapes in Cu+Cu and Au+Au collisions at square root sNN=200 and 62.4 GeV

We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from dijets in Cu+Cu and Au+Au collisions at square root sNN=62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from Delta phi=pi in central and semicentral collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.

Measurement of direct photon production in p+p collisions at sqrt[s] = 200 GeV

Cross sections for midrapidity production of direct photons in p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are reported for transverse momenta of 3 < pT < 16 GeV/c. Next-to-leading order perturbative QCD (pQCD) describes the data well for pT >5 GeV/c, where the uncertainties of the measurement and theory are comparable. We also report on the effect of requiring the photons to be isolated from parton jet energy. The observed fraction of isolated photons is well described by pQCD for pT >7 GeV/c.

Azimuthal angle correlations for rapidity separated Hadron pairs in d+Au collisions at square root of sNN=200 GeV

Deuteron-gold (d+Au) collisions at the Relativistic Heavy Ion Collider provide ideal platforms for testing QCD theories in dense nuclear matter at high energy. In particular, models suggesting strong saturation effects for partons carrying small nucleon momentum fraction (x) predict modifications to jet production at forward rapidity (deuteron-going direction) in d+Au collisions. We report on two-particle azimuthal angle correlations between charged hadrons at forward/backward (deuteron/gold going direction) rapidity and charged hadrons at midrapidity in d+Au and p+p collisions at square root of sNN=200 GeV. Jet structures observed in the correlations are quantified in terms of the conditional yield and angular width of away-side partners. The kinematic region studied here samples partons in the gold nucleus with x~0.1 to ~0.01. Within this range, we find no x dependence of the jet structure in d+Au collisions.

J/psi production and nuclear effects for d + Au and p + p collisions at square root of S(NN) = 200 GeV

J/psi production in d + Au and p + p collisions at square root of S(NN) = 200 GeV has been measured by the PHENIX experiment at rapidities -2.2 < y < +2.4. The cross sections and nuclear dependence of J/psi production versus rapidity, transverse momentum, and centrality are obtained and compared to lower energy p + A results and to theoretical models. The observed nuclear dependence in d + Au collisions is found to be modest, suggesting that the absorption in the final state is weak and the shadowing of the gluon distributions is small and consistent with Dokshitzer-Gribov-Lipatov-Altarelli-Parisi-based parametrizations that fit deep-inelastic scattering and Drell-Yan data at lower energies.

Dynamics of magnetic defects in heavy fermion LiV2O4 from stretched exponential 7Li NMR relaxation

7Li NMR measurements on LiV2O4 from 0.5 to 4.2 K are reported. A small concentration of magnetic defects within the structure drastically changes the nuclear magnetization relaxation versus time from a pure exponential as in pure LiV2O4 to a stretched exponential, indicating glassy behavior of the magnetic defects. The stretched exponential function is described as arising from a distribution of 7Li nuclear spin-lattice relaxation rates and we present a model for the distribution in terms of the dynamics of the magnetic defects. Our results explain the origin of recent puzzling 7Li NMR literature data on LiV2O4 and our model is likely applicable to other glassy systems.

Nuclear modification factors for hadrons at forward and backward rapidities in deuteron-gold collisions at sqrt[s(NN)]=200 GeV

We report on charged hadron production in deuteron-gold reactions at sqrt[s(NN)]=200 GeV. Our measurements in the deuteron direction cover 1.4<eta<2.2, referred to as forward rapidity, and in the gold direction -2.0<eta<-1.4, referred to as backward rapidity, and a transverse momentum range p(T)=0.5-4.0 GeV/c. We compare the relative yields for different deuteron-gold collision centrality classes. We observe a suppression relative to binary collision scaling at forward rapidity, sensitive to low momentum fraction (x) partons in the gold nucleus, and an enhancement at backward rapidity, sensitive to high momentum fraction partons in the gold nucleus.

Double helicity asymmetry in inclusive midrapidity pi0 production for polarized p+p collisions at square root s = 200 GeV

We present a measurement of the double longitudinal spin asymmetry in inclusive pi(0) production in polarized proton-proton collisions at sqrt[s]=200 GeV. The data were taken at the Relativistic Heavy Ion Collider with average beam polarizations of 0.27. The measurements are the first in a program to study the longitudinal spin structure of the proton, using strongly interacting probes, at collider energies. The asymmetry is presented for transverse momenta 1-5 GeV/c at midrapidity, where next-to-leading-order perturbative quantum chromodynamic (NLO pQCD) calculations well describe the unpolarized cross section. The observed asymmetry is small and is compared to a NLO pQCD calculation with a range of polarized gluon distributions.

Absence of suppression in particle production at large transverse momentum in sqrt[s(NN)]=200 GeV d+Au collisions

Transverse momentum spectra of charged hadrons with p(T)<8 GeV/c and neutral pions with p(T)<10 GeV/c have been measured at midrapidity by the PHENIX experiment at BNL RHIC in d+Au collisions at sqrt[s(NN)]=200 GeV. The measured yields are compared to those in p+p collisions at the same sqrt[s(NN)] scaled up by the number of underlying nucleon-nucleon collisions in d+Au. The yield ratio does not show the suppression observed in central Au+Au collisions at RHIC. Instead, there is a small enhancement in the yield of high momentum particles.

Design of a logarithmic k-space spiral trajectory

Spiral acquisitions are used in fast cardiac imaging because they traverse k-space efficiently and minimize flow artifacts. A variable pitch logarithmic spiral trajectory is designed to critically sample the low-frequency region in k-space and gradually undersample the high-frequency region. An approximate analytical expression for the trajectory provides a fast means to calculate the gradient waveforms and the sampled data points. A numerical method is introduced based on the trajectory curvature and the rate of change in the gradient magnitude with time for the composite Archimedean-logarithmic trajectory. The pulse sequence is implemented and images are acquired on phantoms and human hearts. The images show improved image resolution and some improvement in image quality as a result of increased extent in k-space and reduction in aliasing artifacts, respectively.

A single histidine residue determines the pH sensitivity of the pacemaker channel HCN2

Hyperpolarization-activated cyclic nucleotide-gated (HCN) cation channels control the rhythmic activity of heart and neuronal networks. The activation of these channels is regulated in a complex manner by hormones and neurotransmitters. In addition it was suggested that the channels may be controlled by the pH of the cytosol. Here we demonstrate that HCN2, a member of the HCN channel family, is directly modulated by the intracellular pH in the physiological range. Protons inhibit HCN2 channels by shifting the voltage dependence of channel activation to more negative voltages. By using site-directed mutagenesis, we have identified a single histidine residue (His-321) localized at the boundary between the voltage-sensing S4 helix and the cytoplasmic S4-S5 linker of the channel that is a major determinant of pH sensitivity. Replacement of His-321 by either arginine, glutamine, or glutamate results in channels that are no longer sensitive to shifts in intracellular pH. In contrast, cAMP-mediated modulation is completely intact in mutant channels indicating that His-321 is not involved in the molecular mechanism that controls modulation of HCN channel activity by cyclic nucleotides. Because His-321 is conserved in all four HCN channels known so far, regulation by intracellular pH is likely to constitute a general feature of both cardiac and neuronal pacemaker channels.

Cellular expression and functional characterization of four hyperpolarization-activated pacemaker channels in cardiac and neuronal tissues

Hyperpolarization-activated cation currents (I(h)) have been identified in cardiac pacemaker cells and a variety of central and peripheral neurons. Four members of a gene family encoding hyperpolarization-activated, cyclic nucleotide-gated cation channels (HCN1--4) have been cloned recently. Native I(h) currents recorded from different cell types exhibit distinct activation kinetics. To determine if this diversity of I(h) currents may be caused by differential expression of HCN channel isoforms, we investigated the cellular distribution of the transcripts of HCN1--4 in the murine sinoatrial node, retina and dorsal root ganglion (DRG) by in situ hybridization. In the sinoatrial node, the most prominently expressed HCN channel is HCN4, whereas HCN2 and HCN1 are detected there at moderate and low levels, respectively. Retinal photoreceptors express high levels of HCN1, whereas HCN2, 3 and 4 were not found in these cells. In DRG neurons, the dominant HCN transcript is HCN1, followed by HCN2. We next determined the functional properties of recombinant HCN1--4 channels expressed in HEK293 cells. All four channel types gave rise to I(h) currents but displayed marked differences in their activation kinetics. Our results suggest that the heterogeneity of native I(h) currents is generated, at least in part, by the tissue-specific expression of HCN channel genes.

Evaluating the evidence of effectiveness for preventive interventions: using a registry system to influence policy through science

In order to deal with the serious problems of drug use, delinquency, and mental health problems in this country, policy makers, communities, practitioners, and advocates need to identify prevention programs that have empirical support and at the same time meet their own community needs regarding acceptability, cost, and training, and supervision. An "evidence-based" approach to prevention, one that identifies the scientific knowledge about what prevention programs work, for whom, and under what circumstances, should play a critical part in this process. The premise of this evidence-based approach is that the wide adoption of prevention programs that have been found to be successful in rigorous evaluations, will lead to successful population-based prevention strategies. A web-based registry, or database that describes the available scientific information on individual preventive trials, would be of high potential use to policy makers engaged in prevention planning for their communities. This presentation describes a model registry based on descriptions of 167 preventive trials aimed at children aged 0-6. Empirical findings are presented regarding two critical components of the registry, the measurement of the quality of the trial and the strength of evidence for a beneficial effect produced by each intervention. Implications for the use of such a registry are also discussed.

Mutations in the S4 domain of a pacemaker channel alter its voltage dependence

In an attempt to study the functional role of the positively charged amino acids present in the S4 segment of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels, we have introduced single and sequential amino acid replacements throughout this domain in the mouse type 2 HCN channel (mHCN2). Sequential neutralization of the first three positively charged amino acids resulted in cumulative shifts of the midpoint voltage activation constant towards more hyperpolarizing potentials. The contribution of each amino acid substitution was approximately -20 mV. Amino acid replacements to neutralize either the first (K291Q) or fourth (R300Q) positively charged amino acid resulted in the same shift (about 20 mV) towards more hyperpolarized potentials. Replacing the first positively charged amino acid with the negatively charged glutamic acid (K291E) produced a shift of approximately -50 mV in the same direction. None of the above amino acid substitutions had any measurable effect on the time course of channel activation. This suggests that the S4 domain of HCN channels critically controls the voltage dependence of channel opening but is not involved in regulating activation kinetics. No channel activity was detected in mutants with neutralization of the last six positively charged amino acids from the S4 domain, suggesting that these amino acids cannot be altered without impairing channel function.

Structure and function of cardiac pacemaker channels

Cardiac pacemaking is controlled by a mixed Na(+)/K(+) current named I(f), which is activated by hyperpolarized membrane potentials. Recently, a family of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels has been cloned. The members of this family exhibit the general features of I(f) channels. This review describes the molecular diversity of the HCN channel family and the structural determinants of channel function including activation by voltage, modulation by cyclic nucleotides and ion permeation. The relationships between cloned HCN channel types and native cardiac I(f) currents are explored.

Regulation of intracellular calcium by a signalling complex of IRAG, IP3 receptor and cGMP kinase Ibeta

Calcium release from the endoplasmic reticulum controls a number of cellular processes, including proliferation and contraction of smooth muscle and other cells. Calcium release from inositol 1,4,5-trisphosphate (IP3)-sensitive stores is negatively regulated by binding of calmodulin to the IP3 receptor (IP3R) and the NO/cGMP/cGMP kinase I (cGKI) signalling pathway. Activation of cGKI decreases IP3-stimulated elevations in intracellular calcium, induces smooth muscle relaxation and contributes to the antiproliferative and pro-apoptotic effects of NO/cGMP. Here we show that, in microsomal smooth muscle membranes, cGKIbeta phosphorylated the IP3R and cGKIbeta, and a protein of relative molecular mass 125,000 which we now identify as the IP3R-associated cGMP kinase substrate (IRAG). These proteins were co-immunoprecipitated by antibodies directed against cGKI, IP3R or IRAG. IRAG was found in many tissues including aorta, trachea and uterus, and was localized perinuclearly after heterologous expression in COS-7 cells. Bradykinin-stimulated calcium release was not affected by the expression of either IRAG or cGKIbeta, which we tested in the absence and presence of cGMP. However, calcium release was inhibited after co-expression of IRAG and cGKIbeta in the presence of cGMP. These results identify IRAG as an essential NO/cGKI-dependent regulator of IP3-induced calcium release.

Molecular cloning and functional characterization of a new modulatory cyclic nucleotide-gated channel subunit from mouse retina

Cyclic nucleotide-gated (CNG) channels play a key role in olfactory and visual transduction. Native CNG channels are heteromeric complexes consisting of the principal alpha subunits (CNG1-3), which can form functional channels by themselves, and the modulatory beta subunits (CNG4-5). The individual alpha and beta subunits that combine to form the CNG channels in rod photoreceptors (CNG1 + CNG4) and olfactory neurons (CNG2 + CNG4 + CNG5) have been characterized. In contrast, only an alpha subunit (CNG3) has been identified so far in cone photoreceptors. Here we report the molecular cloning of a new CNG channel subunit (CNG6) from mouse retina. The cDNA of CNG6 encodes a peptide of 694 amino acids with a predicted molecular weight of 80 kDa. Among the CNG channel subunits, CNG6 has the highest overall similarity to the CNG4 beta subunit (47% sequence identity). CNG6 transcripts are present in a small subset of retinal photoreceptor cells and also in testis. Heterologous expression of CNG6 in human embryonic kidney 293 cells did not lead to detectable currents. However, when coexpressed with the cone photoreceptor alpha subunit, CNG6 induced a flickering channel gating, weakened the outward rectification in the presence of extracellular Ca(2+), increased the sensitivity for L-cis diltiazem, and enhanced the cAMP efficacy of the channel. Taken together, the data indicate that CNG6 represents a new CNG channel beta subunit that may associate with the CNG3 alpha subunit to form the native cone channel.

Oxidative folding of reduced and denatured huwentoxin-I

Huwentoxin-I, a neurotoxic peptide with 33 amino acid residues and three disulfide bonds, was used to investigate the pathway of reduction/denaturation and of oxidative folding in small proteins with multiple disulfide bonds. Titration of thiol groups, reversed-phase HPLC, 1D NMR spectroscopy, and biological activity assays were used to monitor the extent of reduction/ denaturation and renaturation of the toxin. The reduction and denaturation of huwentoxin-I resulted in a 100% loss of bioactivity as measured in a mouse phrenic nerve-diaphragm preparation. About 90% of full biological activity could be restored under optimized conditions of oxidative refolding of the reduced peptide. Several reaction conditions employing air oxidation, oxidized and reduced glutathione (GSSG and GSH), and cystine/cysteine were investigated in order to find optimal conditions for renaturation of huwentoxin-I. The best renaturation yield was achieved in 0.1 mM GSSG and 1 mM GSH at pH 8.5 and 4 degrees C over 24 hr. High concentrations of glutathione and high temperatures reduced renaturation yields. Oxidative refolding of huwentoxin-I in air requires about 6 days for maximal yields and is inhibited by EDTA.

Two pacemaker channels from human heart with profoundly different activation kinetics

Cardiac pacemaking is produced by the slow diastolic depolarization phase of the action potential. The hyperpolarization-activated cation current (If) forms an important part of the pacemaker depolarization and consists of two kinetic components (fast and slow). Recently, three full-length cDNAs encoding hyperpolarization-activated and cyclic nucleotide-gated cation channels (HCN1-3) have been cloned from mouse brain. To elucidate the molecular identity of cardiac pacemaker channels, we screened a human heart cDNA library using a highly conserved neuronal HCN channel segment and identified two cDNAs encoding HCN channels. The hHCN2 cDNA codes for a protein of 889 amino acids. The HCN2 gene is localized on human chromosome 19p13.3 and contains eight exons spanning approximately 27 kb. The second cDNA, designated hHCN4, codes for a protein of 1203 amino acids. Northern blot and PCR analyses showed that both hHCN2 and hHCN4 are expressed in heart ventricle and atrium. When expressed in HEK 293 cells, either cDNA gives rise to hyperpolarization-activated cation currents with the hallmark features of native If. hHCN2 and hHCN4 currents differ profoundly from each other in their activation kinetics, being fast and slow, respectively. We thus conclude that hHCN2 and hHCN4 may underlie the fast and slow component of cardiac If, respectively.