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1.  Promoter variants in the MSMB gene associated with prostate cancer regulate MSMB/NCOA4 fusion transcripts 
Human genetics  2012;131(9):1453-1466.
Beta-microseminoprotein (MSP)/MSMB is an immunoglobulin superfamily protein synthesized by prostate epithelial cells and secreted into seminal plasma. Variants in the promoter of the MSMB gene have been associated with the risk of prostate cancer (PCa) in several independent genome-wide association studies. Both MSMB and an adjacent gene, NCOA4, are subjected to transcriptional control via androgen response elements. The gene product of NCOA4 interacts directly with the androgen receptor as a co-activator to enhance AR transcriptional activity. Here, we provide evidence for the expression of full-length MSMB-NCOA4 fusion transcripts regulated by the MSMB promoter. The predominant MSMB-NCOA4 transcript arises by fusion of the 5′UTR and exons 1–2 of the MSMB pre-mRNA, with exons 2–10 of the NCOA4 premRNA, producing a stable fusion protein, comprising the essential domains of NCOA4. Analysis of the splice sites of this transcript shows an unusually strong splice acceptor at NCOA4 exon 2 and the presence of Alu repeats flanking the exons potentially involved in the splicing event. Transfection experiments using deletion clones of the promoter coupled with luciferase reporter assays define a core MSMB promoter element located between –27 and –236 of the gene, and a negative regulatory element immediately upstream of the start codon. Computational network analysis reveals that the MSMB gene is functionally connected to NCOA4 and the androgen receptor signaling pathway. The data provide an example of how GWAS-associated variants may have multiple genetic and epigenetic effects.
doi:10.1007/s00439-012-1182-2
PMCID: PMC3956317  PMID: 22661295
2.  Structural Analogues of Smoothened Intracellular Loops as Potent Inhibitors of Hedgehog Pathway and Cancer Cell Growth 
Journal of medicinal chemistry  2007;50(18):4534-4538.
Smoothened is a critical component of the Hedgehog pathway that is essential for stem cell renewal and is dysregulated in many cancer types. We have found synthetic analogues of the second and third intracellular loops of smoothened to be potent inhibitors of the Hedgehog pathway. Palmitoylated peptides as short as 10 residues inhibited melanoma cells growth with IC50 in the low nanomolar range. The compounds are promising drug candidates and convenient tools for solving mechanisms of Hedgehog signaling.
doi:10.1021/jm0705657
PMCID: PMC3956439  PMID: 17685505
3.  Rationale, Timeline, Study Design, and Protocol Overview of the Therapeutic Hypothermia After Pediatric Cardiac Arrest Trials 
Objective
To describe the rationale, timeline, study design, and protocol overview of the Therapeutic Hypothermia after Pediatric Cardiac Arrest trials.
Design
Multicenter randomized controlled trials.
Setting
Pediatric intensive care and cardiac ICUs in the United States and Canada.
Patients
Children from 48 hours to 18 years old, who have return of circulation after cardiac arrest, who meet trial eligibility criteria, and whose guardians provide written consent.
Interventions
Therapeutic hypothermia or therapeutic normothermia.
Measurements and Main Results
From concept inception in 2002 until trial initiation in 2009, 7 years were required to plan and operationalize the Therapeutic Hypothermia after Pediatric Cardiac Arrest trials. Two National Institute of Child Health and Human Development clinical trial planning grants (R21 and R34) supported feasibility assessment and protocol development. Two clinical research networks, Pediatric Emergency Care Applied Research Network and Collaborative Pediatric Critical Care Research Network, provided infrastructure resources. Two National Heart Lung Blood Institute U01 awards provided funding to conduct separate trials of in-hospital and out-of-hospital cardiac arrest. A pilot vanguard phase that included half the clinical sites began on March 9, 2009, and this was followed by full trial funding through 2015.
Conclusions
Over a decade will have been required to plan, design, operationalize, and conduct the Therapeutic Hypothermia after Pediatric Cardiac Arrest trials. Details described in this report, such as participation of clinical research networks and clinical trial planning grants utilization, may be of utility for individuals who are planning investigator-initiated, federally supported clinical trials.
doi:10.1097/PCC.0b013e31828a863a
PMCID: PMC3947631  PMID: 23842585
cardiac arrest; in hospital; mortality; multicenter; outcome; out of hospital; pediatric; randomized controlled trial; targeted temperature control; therapeutic hypothermia; therapeutic normothermia
4.  Association between Amylin and Amyloid-β Peptides in Plasma in the Context of Apolipoprotein E4 Allele 
PLoS ONE  2014;9(2):e88063.
Amylin, a pancreatic peptide that readily crosses the blood brain barrier (BBB), and amyloid-beta peptide (Aβ), the main component of amyloid plaques and a major component of Alzheimer's disease (AD) pathology in the brain, share several features. These include having similar β-sheet secondary structures, binding to the same receptor, and being degraded by the same protease. Thus, amylin may be associated with Aβ, but the nature of their relationship remains unclear. In this study, we used human samples to study the relationship between plasma amylin and Aβ in the context of the apolipoprotein E alleles (ApoE). We found that concentrations of Aβ1-42 (P<0.0001) and Aβ1-40 (P<0.0001) increased with each quartile increase of amylin. Using multivariate regression analysis, the study sample showed that plasma amylin was associated with Aβ1-42 (β = +0.149, SE = 0.025, P<0.0001) and Aβ1-40 (β = +0.034, SE = 0.016, P = 0.04) as an outcome after adjusting for age, gender, ethnicity, ApoE4, BMI, diabetes, stroke, kidney function and lipid profile. This positive association between amylin and Aβ1-42 in plasma was found regardless of the ApoE genotype. In contrast, the relationship between amylin and Aβ1-40 in plasma seen in ApoE4 non-carriers disappeared in the presence of ApoE4. Using AD mouse models, our recent study demonstrates that intraperitoneal (i.p.) injection of synthetic amylin enhances the removal of Aβ from the brain into blood, thus resulting in increased blood levels of both amylin and Aβ. The positive association between amylin and Aβ, especially Aβ1-42, in human blood samples is probably relevant to the findings in the AD mouse models. The presence of ApoE4 may attenuate amylin's capacity to remove Aβ, especially Aβ1-40, from the AD brain.
doi:10.1371/journal.pone.0088063
PMCID: PMC3919737  PMID: 24520345
5.  Genetics and genomics of prostate cancer 
Asian Journal of Andrology  2013;15(3):309-313.
Prostate cancer (PCa) is one of the most common malignancies in the world with over 890 000 cases and over 258 000 deaths worldwide each year. Nearly all mortalities from PCa are due to metastatic disease, typically through tumors that evolve to be hormone-refractory or castrate-resistant. Despite intensive epidemiological study, there are few known environmental risk factors, and age and family history are the major determinants. However, there is extreme heterogeneity in PCa incidence worldwide, suggesting that major determining factors have not been described. Genome-wide association studies have been performed and a considerable number of significant, but low-risk loci have been identified. In addition, several groups have analyzed PCa by determination of genomic copy number, fusion gene generation and targeted resequencing of candidate genes, as well as exome and whole genome sequencing. These initial studies have examined both primary and metastatic tumors as well as murine xenografts and identified somatic alterations in TP53 and other potential driver genes, and the disturbance of androgen response and cell cycle pathways. It is hoped that continued characterization of risk factors as well as gene mutation and misregulation in tumors will aid in understanding, diagnosing and better treating PCa.
doi:10.1038/aja.2013.29
PMCID: PMC3739637  PMID: 23564043
androgen receptor; cancer progression; chromatin remodeling; metastasis; prostate cancer (PCa); risk factor; somatic mutation; tumor heterogeneity
6.  ARID5B Genetic Polymorphisms Contribute to Racial Disparities in the Incidence and Treatment Outcome of Childhood Acute Lymphoblastic Leukemia 
Journal of Clinical Oncology  2012;30(7):751-757.
Purpose
Recent genome-wide screens have identified genetic variations in ARID5B associated with susceptibility to childhood acute lymphoblastic leukemia (ALL). We sought to determine the contribution of ARID5B single nucleotide polymorphisms (SNPs) to racial disparities in ALL susceptibility and treatment outcome.
Patients and Methods
We compared the association between ARID5B SNP genotype and ALL susceptibility in whites (> 95% European genetic ancestry; 978 cases and 1,046 controls) versus in Hispanics (> 10% Native American ancestry; 330 cases and 541 controls). We determined the relationships between ARID5B SNP genotype and ALL relapse risk in 1,605 children treated on the Children's Oncology Group (COG) P9904/9905 clinical trials.
Results
Among 49 ARID5B SNPs interrogated, 10 were significantly associated with ALL susceptibility in both whites and Hispanics (P < .05), with risk alleles consistently more frequent in Hispanics than in whites. rs10821936 exhibited the most significant association in both races (P = 8.4 × 10−20 in whites; P = 1 × 10−6 in Hispanics), and genotype at this SNP was highly correlated with local Native American genetic ancestry (P = 1.8 × 10−8). Multivariate analyses in Hispanics identified an additional SNP associated with ALL susceptibility independent of rs10821936. Eight ARID5B SNPs were associated with both ALL susceptibility and relapse hazard; the alleles related to higher ALL incidence were always linked to poorer treatment outcome and were more frequent in Hispanics.
Conclusion
ARID5B polymorphisms are important determinants of childhood ALL susceptibility and treatment outcome, and they contribute to racial disparities in this disease.
doi:10.1200/JCO.2011.38.0345
PMCID: PMC3295551  PMID: 22291082
8.  Association Assessment of Copy Number Polymorphism and Risk of Age-Related Macular Degeneration 
Ophthalmology  2011;118(12):2442-2446.
Purpose
We previously identified a genetic copy number polymorphism (CNP147) that was statistically associated with age-related macular degeneration (AMD), and which resides downstream of the complement factor H (CFH) gene. Factor H protein is polymorphic at amino acid 402 in which the resulting histidine containing moiety has been established to impart significant risk of AMD. Here we present a method to precisely determine the exact copy number of CNP147 and examine in more detail the association with AMD.
Design
Case-control Study
Participants
421 AREDS (Age-related Eye Disease cohort Study) subjects of whom approximately 35% were diagnosed with neovascular disease, 19% with geographic atrophy, 16% with both, 30% with large drusen and 215 controls.
Methods
Using copy number assays available from Applied Biosystems Inc., we examined four loci spanning CNP147 and neighboring CNP148 in an AREDS matched case-control sample set. We analyzed these data by copy number while controlling for two high-risk CFH variants, rs1061170 (Y402H) and rs1410996. We phased the high risk CFH variants with CNP147 and analyzed haplotype frequencies in cases and controls. To further validate copy numbers, six Utah CEPH families (Centre D’etude du Polymorphism Humaine) were typed for CNP147 and the segregation assessed.
Main Outcome Measures
Increased or decreased risk of AMD from genetic loci.
Results
Having fewer than 2 copies of CNP147 is associated with an estimated 43% reduction in odds of having AMD in this sample set (adjusted odds ratio=0.57, P=0.006). CNP148 variation is rare in Caucasians and it was not statistically significant. Common haplotypes reveal that the risk alleles for rs1061170 and rs1410996 most frequently segregate with higher copy numbers for CNP147; but not exclusively, and that one haplotype that carried a deletion of CNP147 was highly protective (odds ratio=0.25 P=1.3×10−13) when compared to the reference.
Conclusions
In this matched subset of AREDS subjects, after adjusting for two known risk variants in CFH, CNP147 deletion statistically associates with diminished risk for AMD.
doi:10.1016/j.ophtha.2011.05.027
PMCID: PMC3223559  PMID: 21856016
Copy number polymorphism; age-related macular degeneration; HapMap 3; TaqMan Copy Number Assays; qPCR
9.  Detectable clonal mosaicism and its relationship to aging and cancer 
Jacobs, Kevin B | Yeager, Meredith | Zhou, Weiyin | Wacholder, Sholom | Wang, Zhaoming | Rodriguez-Santiago, Benjamin | Hutchinson, Amy | Deng, Xiang | Liu, Chenwei | Horner, Marie-Josephe | Cullen, Michael | Epstein, Caroline G | Burdett, Laurie | Dean, Michael C | Chatterjee, Nilanjan | Sampson, Joshua | Chung, Charles C | Kovaks, Joseph | Gapstur, Susan M | Stevens, Victoria L | Teras, Lauren T | Gaudet, Mia M | Albanes, Demetrius | Weinstein, Stephanie J | Virtamo, Jarmo | Taylor, Philip R | Freedman, Neal D | Abnet, Christian C | Goldstein, Alisa M | Hu, Nan | Yu, Kai | Yuan, Jian-Min | Liao, Linda | Ding, Ti | Qiao, You-Lin | Gao, Yu-Tang | Koh, Woon-Puay | Xiang, Yong-Bing | Tang, Ze-Zhong | Fan, Jin-Hu | Aldrich, Melinda C | Amos, Christopher | Blot, William J | Bock, Cathryn H | Gillanders, Elizabeth M | Harris, Curtis C | Haiman, Christopher A | Henderson, Brian E | Kolonel, Laurence N | Le Marchand, Loic | McNeill, Lorna H | Rybicki, Benjamin A | Schwartz, Ann G | Signorello, Lisa B | Spitz, Margaret R | Wiencke, John K | Wrensch, Margaret | Wu, Xifeng | Zanetti, Krista A | Ziegler, Regina G | Figueroa, Jonine D | Garcia-Closas, Montserrat | Malats, Nuria | Marenne, Gaelle | Prokunina-Olsson, Ludmila | Baris, Dalsu | Schwenn, Molly | Johnson, Alison | Landi, Maria Teresa | Goldin, Lynn | Consonni, Dario | Bertazzi, Pier Alberto | Rotunno, Melissa | Rajaraman, Preetha | Andersson, Ulrika | Freeman, Laura E Beane | Berg, Christine D | Buring, Julie E | Butler, Mary A | Carreon, Tania | Feychting, Maria | Ahlbom, Anders | Gaziano, J Michael | Giles, Graham G | Hallmans, Goran | Hankinson, Susan E | Hartge, Patricia | Henriksson, Roger | Inskip, Peter D | Johansen, Christoffer | Landgren, Annelie | McKean-Cowdin, Roberta | Michaud, Dominique S | Melin, Beatrice S | Peters, Ulrike | Ruder, Avima M | Sesso, Howard D | Severi, Gianluca | Shu, Xiao-Ou | Visvanathan, Kala | White, Emily | Wolk, Alicja | Zeleniuch-Jacquotte, Anne | Zheng, Wei | Silverman, Debra T | Kogevinas, Manolis | Gonzalez, Juan R | Villa, Olaya | Li, Donghui | Duell, Eric J | Risch, Harvey A | Olson, Sara H | Kooperberg, Charles | Wolpin, Brian M | Jiao, Li | Hassan, Manal | Wheeler, William | Arslan, Alan A | Bas Bueno-de-Mesquita, H | Fuchs, Charles S | Gallinger, Steven | Gross, Myron D | Holly, Elizabeth A | Klein, Alison P | LaCroix, Andrea | Mandelson, Margaret T | Petersen, Gloria | Boutron-Ruault, Marie-Christine | Bracci, Paige M | Canzian, Federico | Chang, Kenneth | Cotterchio, Michelle | Giovannucci, Edward L | Goggins, Michael | Bolton, Judith A Hoffman | Jenab, Mazda | Khaw, Kay-Tee | Krogh, Vittorio | Kurtz, Robert C | McWilliams, Robert R | Mendelsohn, Julie B | Rabe, Kari G | Riboli, Elio | Tjønneland, Anne | Tobias, Geoffrey S | Trichopoulos, Dimitrios | Elena, Joanne W | Yu, Herbert | Amundadottir, Laufey | Stolzenberg-Solomon, Rachael Z | Kraft, Peter | Schumacher, Fredrick | Stram, Daniel | Savage, Sharon A | Mirabello, Lisa | Andrulis, Irene L | Wunder, Jay S | García, Ana Patiño | Sierrasesúmaga, Luis | Barkauskas, Donald A | Gorlick, Richard G | Purdue, Mark | Chow, Wong-Ho | Moore, Lee E | Schwartz, Kendra L | Davis, Faith G | Hsing, Ann W | Berndt, Sonja I | Black, Amanda | Wentzensen, Nicolas | Brinton, Louise A | Lissowska, Jolanta | Peplonska, Beata | McGlynn, Katherine A | Cook, Michael B | Graubard, Barry I | Kratz, Christian P | Greene, Mark H | Erickson, Ralph L | Hunter, David J | Thomas, Gilles | Hoover, Robert N | Real, Francisco X | Fraumeni, Joseph F | Caporaso, Neil E | Tucker, Margaret | Rothman, Nathaniel | Pérez-Jurado, Luis A | Chanock, Stephen J
Nature genetics  2012;44(6):651-658.
In an analysis of 31,717 cancer cases and 26,136 cancer-free controls drawn from 13 genome-wide association studies (GWAS), we observed large chromosomal abnormalities in a subset of clones from DNA obtained from blood or buccal samples. Mosaic chromosomal abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of size >2 Mb were observed in autosomes of 517 individuals (0.89%) with abnormal cell proportions between 7% and 95%. In cancer-free individuals, the frequency increased with age; 0.23% under 50 and 1.91% between 75 and 79 (p=4.8×10−8). Mosaic abnormalities were more frequent in individuals with solid-tumors (0.97% versus 0.74% in cancer-free individuals, OR=1.25, p=0.016), with a stronger association for cases who had DNA collected prior to diagnosis or treatment (OR=1.45, p=0.0005). Detectable clonal mosaicism was common in individuals for whom DNA was collected at least one year prior to diagnosis of leukemia compared to cancer-free individuals (OR=35.4, p=3.8×10−11). These findings underscore the importance of the role and time-dependent nature of somatic events in the etiology of cancer and other late-onset diseases.
doi:10.1038/ng.2270
PMCID: PMC3372921  PMID: 22561519
10.  Evidence of association of APOE with age-related macular degeneration - a pooled analysis of 15 studies 
Human mutation  2011;32(12):1407-1416.
Age-related macular degeneration (AMD) is the most common cause of incurable visual impairment in high-income countries. Previous studies report inconsistent associations between AMD and apolipoprotein E (APOE), a lipid transport protein involved in low-density cholesterol modulation. Potential interaction between APOE and sex, and smoking status, has been reported. We present a pooled analysis (n=21,160) demonstrating associations between late AMD and APOε4 (OR=0.72 per haplotype; CI: 0.65–0.74; P=4.41×10−11) and APOε2 (OR=1.83 for homozygote carriers; CI: 1.04–3.23; P=0.04), following adjustment for age-group and sex within each study and smoking status. No evidence of interaction between APOE and sex or smoking was found. Ever smokers had significant increased risk relative to never smokers for both neovascular (OR=1.54; CI: 1.38–1.72; P=2.8×10−15) and atrophic (OR=1.38; CI: 1.18–1.61; P=3.37×10−5) AMD but not early AMD (OR=0.94; CI: 0.86–1.03; P=0.16), implicating smoking as a major contributing factor to disease progression from early signs to the visually disabling late forms. Extended haplotype analysis incorporating rs405509 did not identify additional risks beyondε2 and ε4 haplotypes. Our expanded analysis substantially improves our understanding of the association between the APOE locus and AMD. It further provides evidence supporting the role of cholesterol modulation, and low-density cholesterol specifically, in AMD disease etiology.
doi:10.1002/humu.21577
PMCID: PMC3217135  PMID: 21882290
age-related macular degeneration; AMD; apolipoprotein E; APOE; case-control association study
11.  Homeopathy for mental fatigue: lessons from a randomized, triple blind, placebo-controlled cross-over clinical trial 
Background
Difficulty in controlling attention can lead to mental fatigue in the healthy population. We identified one trial reporting a benefit in patients’ attention using a homeopathic formula preparation. One component of the preparation was potassium phosphate, widely available off the shelf as Kali phos 6x for cognitive problems. The aim of this exploratory trial was to assess the effectiveness of Kali phos 6x for attention problems associated with mental fatigue.
Methods
We recruited student and staff volunteers (University of York) with self-reported mental fatigue, excluding any using homeopathy or prescribed stimulants, or with a diagnosis of chronic fatigue syndrome. In a triple blind, cross-over, placebo-controlled clinical trial, 86 volunteers were randomized to receive Kali phos 6x or identical placebo 10 minutes before taking a psychological test of attention (Stroop Colour-Word Test). One week later they were crossed over and took the other preparation before repeating the test.
Results
We found no evidence of a treatment effect in a comparison of Kali phos 6x with placebo (Kali phos minus placebo = −1.1 (95% CI −3.0 to 0.9, P = 0.3) Stroop score units, Cohen effect size = −0.17) even when allowing for a weak period effect with accuracy scores in the second period being higher than those in the first (P = 0.05). We observed a ceiling effect in the Stroop test which undermined our ability to interpret this result.
Conclusions
Kali phos 6x was not found to be effective in reducing mental fatigue. A ceiling effect in our primary outcome measure meant that we could not rule out a type II error. Thorough piloting of an adequate outcome measure could have led to an unequivocal result.
Current Controlled Trials
ISRCTN16521161
doi:10.1186/1472-6882-12-167
PMCID: PMC3517425  PMID: 23025450
Crossover study design; Mental fatigue; Kali phos 6x; Stroop test
12.  A locally funded Puerto Rican parrot (Amazona vittata) genome sequencing project increases avian data and advances young researcher education 
GigaScience  2012;1:14.
Background
Amazona vittata is a critically endangered Puerto Rican endemic bird, the only surviving native parrot species in the United States territory, and the first parrot in the large Neotropical genus Amazona, to be studied on a genomic scale.
Findings
In a unique community-based funded project, DNA from an A. vittata female was sequenced using a HiSeq Illumina platform, resulting in a total of ~42.5 billion nucleotide bases. This provided approximately 26.89x average coverage depth at the completion of this funding phase. Filtering followed by assembly resulted in 259,423 contigs (N50 = 6,983 bp, longest = 75,003 bp), which was further scaffolded into 148,255 fragments (N50 = 19,470, longest = 206,462 bp). This provided ~76% coverage of the genome based on an estimated size of 1.58 Gb. The assembled scaffolds allowed basic genomic annotation and comparative analyses with other available avian whole-genome sequences.
Conclusions
The current data represents the first genomic information from and work carried out with a unique source of funding. This analysis further provides a means for directed training of young researchers in genetic and bioinformatics analyses and will facilitate progress towards a full assembly and annotation of the Puerto Rican parrot genome. It also adds extensive genomic data to a new branch of the avian tree, making it useful for comparative analyses with other avian species. Ultimately, the knowledge acquired from these data will contribute to an improved understanding of the overall population health of this species and aid in ongoing and future conservation efforts.
doi:10.1186/2047-217X-1-14
PMCID: PMC3626513  PMID: 23587420
Amazona vittata; Puerto rican parrot; Genome sequence; Annotation; Assembly; Local funding; Education
13.  Differential Gene and MicroRNA Expression between Etoposide Resistant and Etoposide Sensitive MCF7 Breast Cancer Cell Lines 
PLoS ONE  2012;7(9):e45268.
In order to develop targeted strategies for combating drug resistance it is essential to understand it’s basic molecular mechanisms. In an exploratory study we have found several possible indicators of etoposide resistance operating in MCF7VP cells, including up-regulation of ABC transporter genes, modulation of miRNA, and alteration in copy numbers of genes.
doi:10.1371/journal.pone.0045268
PMCID: PMC3445463  PMID: 23028896
14.  Single-cell sequencing analysis characterizes common and cell-lineage-specific mutations in a muscle-invasive bladder cancer 
GigaScience  2012;1:12.
Background
Cancers arise through an evolutionary process in which cell populations are subjected to selection; however, to date, the process of bladder cancer, which is one of the most common cancers in the world, remains unknown at a single-cell level.
Results
We carried out single-cell exome sequencing of 66 individual tumor cells from a muscle-invasive bladder transitional cell carcinoma (TCC). Analyses of the somatic mutant allele frequency spectrum and clonal structure revealed that the tumor cells were derived from a single ancestral cell, but that subsequent evolution occurred, leading to two distinct tumor cell subpopulations. By analyzing recurrently mutant genes in an additional cohort of 99 TCC tumors, we identified genes that might play roles in the maintenance of the ancestral clone and in the muscle-invasive capability of subclones of this bladder cancer, respectively.
Conclusions
This work provides a new approach of investigating the genetic details of bladder tumoral changes at the single-cell level and a new method for assessing bladder cancer evolution at a cell-population level.
doi:10.1186/2047-217X-1-12
PMCID: PMC3626503  PMID: 23587365
Single-cell exome sequencing; Bladder cancer; Tumor evolution; Population genetics
15.  Variations in Apolipoprotein E Frequency With Age in a Pooled Analysis of a Large Group of Older People 
American Journal of Epidemiology  2011;173(12):1357-1364.
Variation in the apolipoprotein E gene (APOE) has been reported to be associated with longevity in humans. The authors assessed the allelic distribution of APOE isoforms ε2, ε3, and ε4 among 10,623 participants from 15 case-control and cohort studies of age-related macular degeneration (AMD) in populations of European ancestry (study dates ranged from 1990 to 2009). The authors included only the 10,623 control subjects from these studies who were classified as having no evidence of AMD, since variation within the APOE gene has previously been associated with AMD. In an analysis stratified by study center, gender, and smoking status, there was a decreasing frequency of the APOE ε4 isoform with increasing age (χ2 for trend = 14.9 (1 df); P = 0.0001), with a concomitant increase in the ε3 isoform (χ2 for trend = 11.3 (1 df); P = 0.001). The association with age was strongest in ε4 homozygotes; the frequency of ε4 homozygosity decreased from 2.7% for participants aged 60 years or less to 0.8% for those over age 85 years, while the proportion of participants with the ε3/ε4 genotype decreased from 26.8% to 17.5% across the same age range. Gender had no significant effect on the isoform frequencies. This study provides strong support for an association of the APOE gene with human longevity.
doi:10.1093/aje/kwr015
PMCID: PMC3145394  PMID: 21498624
aged; apolipoprotein E2; apolipoprotein E3; apolipoprotein E4; apolipoproteins E; longevity; meta-analysis; multicenter study
16.  The abcc6a Gene is Required for Normal Zebrafish Development 
Pseudoxanthoma elasticum (PXE) is caused by mutations in the ABCC6 gene, which encodes a putative efflux pump, ABCC6. The zebrafish (Danio rerio) has two ABCC6-related sequences. To study the function of abcc6 during zebrafish development, the mRNA expression levels were measured using RT-PCR and in situ hybridization. The abcc6a showed a relatively high level of expression at 5 days post-fertilization (dpf) and the expression was specific to the Kupffer’s vesicles. The abcc6b expression was evident at 6 hpf and remained high up to 8 dpf, corresponding to embryonic kidney proximal tubules. Morpholinos were designed to both genes to block translation and to prevent pre-mRNA splicing. Injection of the abcc6a morpholinos into 1–4 cell zebrafish embryos decreased gene expression by 54 to 81%, and induced a phenotype, cardiac edema and curled tail associated with death at around 8 dpf. Microinjecting zebrafish embryos with full-length mouse Abcc6 mRNA together with the morpholino completely rescued this phenotype. No phenotypic changes were observed when the abcc6b gene morpholino was injected to embryos, with knock-down efficiency of 100%. These results suggest that abcc6a is an essential gene for normal zebrafish development and provide novel insight into the function of ABCC6, the gene mutated in PXE.
doi:10.1038/jid.2010.174
PMCID: PMC3357064  PMID: 20596085
Zebrafish model; Morpholino “knock-down”; Pseudoxanthoma elasticum
17.  Analysis of the ABCA4 Gene by Next-Generation Sequencing 
The authors conducted comprehensive analysis of an important and very variable eye disease gene, ABCA4, by next-generation sequencing in a large cohort of patients and follow-up analysis of identified mutations in both coding and noncoding regions of the ABCA4 locus.
Purpose.
To find all possible disease-associated variants in coding sequences of the ABCA4 gene in a large cohort of patients diagnosed with ABCA4-associated diseases.
Methods.
One hundred sixty-eight patients who had been clinically diagnosed with Stargardt disease, cone-rod dystrophy, and other ABCA4-associated phenotypes were prescreened for mutations in ABCA4 with the ABCA4 microarray, resulting in finding 1 of 2 expected mutations in 111 patients and 0 of 2 mutations in 57 patients. The next-generation sequencing (NGS) strategy was applied to these patients to sequence the entire coding region and the splice sites of the ABCA4 gene. Identified new variants were confirmed or rejected by Sanger sequencing and analyzed for possible pathogenicity by in silico programs and, where possible, by segregation analyses.
Results.
Sequencing was successful in 159 of 168 patients and identified the second disease-associated allele in 49 of 103 (∼48%) of patients with one previously identified mutation. Among those with no mutations, both disease-associated alleles were detected in 4 of 56 patients, and one mutation was detected in 10 of 56 patients. The authors detected a total of 57 previously unknown, possibly pathogenic, variants: 29 missense, 4 nonsense, 9 small deletions and 15 splice-site-altering variants. Of these, 55 variants were deemed pathogenic by a combination of predictive methods and segregation analyses.
Conclusions.
Many mutations in the coding sequences of the ABCA4 gene are still unknown, and many possibly reside in noncoding regions of the ABCA4 locus. Although the ABCA4 array remains a good first-pass screening option, the NGS platform is a time- and cost-efficient tool for screening large cohorts.
doi:10.1167/iovs.11-8182
PMCID: PMC3208189  PMID: 21911583
18.  Multicenter cohort association study of SLC2A1 single nucleotide polymorphisms and age-related macular degeneration 
Molecular Vision  2012;18:657-674.
Purpose
Age-related macular degeneration (AMD) is a major cause of blindness in older adults and has a genetically complex background. This study examines the potential association between single nucleotide polymorphisms (SNPs) in the glucose transporter 1 (SLC2A1) gene and AMD. SLC2A1 regulates the bioavailability of glucose in the retinal pigment epithelium (RPE), which might influence oxidative stress–mediated AMD pathology.
Methods
Twenty-two SNPs spanning the SLC2A1 gene were genotyped in 375 cases and 199 controls from an initial discovery cohort (the Amsterdam-Rotterdam-Netherlands study). Replication testing was performed in The Rotterdam Study (the Netherlands) and study populations from Würzburg (Germany), the Age Related Eye Disease Study (AREDS; United States), Columbia University (United States), and Iowa University (United States). Subsequently, a meta-analysis of SNP association was performed.
Results
In the discovery cohort, significant genotypic association between three SNPs (rs3754219, rs4660687, and rs841853) and AMD was found. Replication in five large independent (Caucasian) cohorts (4,860 cases and 4,004 controls) did not yield consistent association results. The genotype frequencies for these SNPs were significantly different for the controls and/or cases among the six individual populations. Meta-analysis revealed significant heterogeneity of effect between the studies.
Conclusions
No overall association between SLC2A1 SNPs and AMD was demonstrated. Since the genotype frequencies for the three SLC2A1 SNPs were significantly different for the controls and/or cases between the six cohorts, this study corroborates previous evidence that population dependent genetic risk heterogeneity in AMD exists.
PMCID: PMC3324365  PMID: 22509097
19.  Physical and Mental Health of the Homebound Elderly: An Overlooked Population 
There are currently more than 38.9 million people over the age of 65 in the United States. Up to 3.6 million of these people are considered housebound and in need of home-based care. Although homebound status is not defined specifically, with a broad range of disability levels, it is evident that people who are homebound suffer from a multitude of medical and psychiatric illnesses. This review examines the current literature to identify the specific physical and psychiatric factors most responsible for the elderly becoming and remaining housebound. The homebound elderly suffer from metabolic, cardiovascular, cerebrovascular, and musculoskeletal diseases, as well as from cognitive impairment, dementia and depression, at higher rates than the general elderly population. The information in this review will explain the specific types of care the homebound population need, and discuss the care that could help ease their suffering and delay their entry into a nursing home or hospital.
doi:10.1111/j.1532-5415.2010.03161.x
PMCID: PMC3044592  PMID: 21070195
homebound; psychiatric; medically
20.  ABCG2: A Perspective 
ABCG2, or Breast Cancer Resistance Protein (BCRP), is an ABC transporter that has been the subject of intense study since its discovery a decade ago. With high normal tissue expression in the brain endothelium, gastrointestinal tract, and placenta, ABCG2 is believed to be important in protection from xenobiotics, regulating oral bioavailability, forming part of the blood-brain barrier, the blood-testis barrier, and the maternal-fetal barrier. Notably, ABCG2 is often expressed in stem cell populations, where it likely plays a role in xenobiotic protection. However, clues to its epigenetic regulation in various cell populations are only beginning to emerge. While ABCG2 overexpression has been demonstrated in cancer cells after in vitro drug treatment, endogenous ABCG2 expression in certain cancers is likely a reflection of the differentiated phenotype of the cell of origin and likely contributes to intrinsic drug resistance. Notably, research into the transporter’s role in cancer drug resistance and its development as a therapeutic target in cancer has lagged. Substrates and inhibitors of the transporter have been described, among them chemotherapy drugs, tyrosine kinase inhibitors, antivirals, HMG-CoA reductase inhibitors, carcinogens, and flavonoids. This broad range of substrates complements the efficiency of ABCG2 as a transporter in laboratory studies and suggests that, while there are redundant mechanisms of xenobiotic protection, the protein is important in normal physiology. Indeed, emerging studies in pharmacology and toxicology assessing polymorphic variants in man, in combination with murine knockout models have confirmed its dynamic role. Work in pharmacology may eventually lead us to a greater understanding of the physiologic role of ABCG2.
doi:10.1016/j.addr.2008.11.003
PMCID: PMC3105088  PMID: 19135109
ABCG2; BCRP; drug-resistance; ABC transporter; chemotherapy; pharmacology
21.  Molecular Evolutionary Analysis of ABCB5: The Ancestral Gene Is a Full Transporter with Potentially Deleterious Single Nucleotide Polymorphisms 
PLoS ONE  2011;6(1):e16318.
Background
ABCB5 is a member of the ABC protein superfamily, which includes the transporters ABCB1, ABCC1 and ABCG2 responsible for causing drug resistance in cancer patients and also several other transporters that have been linked to human disease. The ABCB5 full transporter (ABCB5.ts) is expressed in human testis and its functional significance is presently unknown. Another variant of this transporter, ABCB5 beta posses a “half-transporter-like” structure and is expressed in melanoma stem cells, normal melanocytes, and other types of pigment cells. ABCB5 beta has important clinical implications, as it may be involved with multidrug resistance in melanoma stem cells, allowing these stem cells to survive chemotherapeutic regimes.
Methodology/Principal Findings
We constructed and examined in detail topological structures of the human ABCB5 protein and determined in-silico the cSNPs (coding single nucleotide polymorphisms) that may affect its function. Evolutionary analysis of ABCB5 indicated that ABCB5, ABCB1, ABCB4, and ABCB11 share a common ancestor, which began duplicating early in the evolutionary history of chordates. This suggests that ABCB5 has evolved as a full transporter throughout its evolutionary history.
Conclusions/Significance
From our in-silco analysis of cSNPs we found that a large number of non-synonymous cSNPs map to important functional regions of the protein suggesting that these SNPs if present in human populations may play a role in diseases associated with ABCB5. From phylogenetic analyses, we have shown that ABCB5 evolved as a full transporter throughout its evolutionary history with an absence of any major shifts in selection between the various lineages suggesting that the function of ABCB5 has been maintained during mammalian evolution. This finding would suggest that ABCB5 beta may have evolved to play a specific role in human pigment cells and/or melanoma cells where it is predominantly expressed.
doi:10.1371/journal.pone.0016318
PMCID: PMC3029322  PMID: 21298007
22.  Vata-L: Visual-Analogue Test Assessing Anosognosia for Language Impairment 
The Clinical Neuropsychologist  2010;24(8):1379-1399.
Lack of awareness (anosognosia) for one's own language impairments has rarely been investigated, despite hampering language rehabilitation. Assessment of anosognosia by means of self-report is particularly complex, as a patient's language difficulties may seriously prevent or bias the assessment. Other methods, such as measures of self-correction and error detection, have provided valuable information, although they are an indirect form of assessment of anosognosia and are not exempt from methodological criticisms. In this study we report on a new tool, the VATA-L (Visual-Analogue Test for Anosognosia for Language impairment), geared at assessing explicit anosognosia for aphasia. The VATA-L compares the patient's self-evaluation with caregivers’ evaluations of the patient's verbal communication abilities in a series of common situations. By means of non-verbal support and a system of check questions, this test minimizes some of the methodological limitations of existing diagnostic tools (e.g., structured interviews), enhancing reliability, and enabling assessment of patients with aphasia. Finally, normative data provided in the study allow a clearer interpretation of the patient's performance and facilitate assessment of anosognosia.
doi:10.1080/13854046.2010.524167
PMCID: PMC3026773  PMID: 21108150
Anosognosia; Unawareness; Aphasia; Brain damage; Assessment
23.  The ERCC6 Gene and Age-Related Macular Degeneration 
PLoS ONE  2010;5(11):e13786.
Background
Age-related macular degeneration (AMD) is the leading cause of irreversible visual loss in the developed countries and is caused by both environmental and genetic factors. A recent study (Tuo et al., PNAS) reported an association between AMD and a single nucleotide polymorphism (SNP) (rs3793784) in the ERCC6 (NM_000124) gene. The risk allele also increased ERCC6 expression. ERCC6 is involved in DNA repair and mutations in ERCC6 cause Cockayne syndrome (CS). Amongst others, photosensitivity and pigmentary retinopathy are hallmarks of CS.
Methodology/Principal Findings
Separate and combined data from three large AMD case-control studies and a prospective population-based study (The Rotterdam Study) were used to analyse the genetic association between ERCC6 and AMD (2682 AMD cases and 3152 controls). We also measured ERCC6 mRNA levels in retinal pigment epithelium (RPE) cells of healthy and early AMD affected human donor eyes. Rs3793784 conferred a small increase in risk for late AMD in the Dutch population (The Rotterdam and AMRO-NL study), but this was not replicated in two non-European studies (AREDS, Columbia University). In addition, the AMRO-NL study revealed no significant association for 9 other variants spanning ERCC6. Finally, we determined that ERCC6 expression in the human RPE did not depend on rs3793784 genotype, but, interestingly, on AMD status: Early AMD-affected donor eyes had a 50% lower ERCC6 expression than healthy donor eyes (P = 0.018).
Conclusions/Significance
Our meta-analysis of four Caucasian cohorts does not replicate the reported association between SNPs in ERCC6 and AMD. Nevertheless, our findings on ERCC6 expression in the RPE suggest that ERCC6 may be functionally involved in AMD. Combining our data with those of the literature, we hypothesize that the AMD-related reduced transcriptional activity of ERCC6 may be caused by diverse, small and heterogeneous genetic and/or environmental determinants.
doi:10.1371/journal.pone.0013786
PMCID: PMC2967476  PMID: 21072178
24.  Molecular Cloning and Characterization of the Human ErbB4 Gene: Identification of Novel Splice Isoforms in the Developing and Adult Brain 
PLoS ONE  2010;5(9):e12924.
ErbB4 is a growth factor receptor tyrosine kinase essential for neurodevelopment. Genetic variation in ErbB4 is associated with schizophrenia and risk-associated polymorphisms predict overexpression of ErbB4 CYT-1 isoforms in the brain in the disorder. The molecular mechanism of association is unclear because the polymorphisms flank exon 3 of the gene and reside 700 kb distal to the CYT-1 defining exon. We hypothesized that the polymorphisms are indirectly associated with ErbB4 CYT-1 via splicing of exon 3 on the CYT-1 background. We report via cloning and sequencing of adult and fetal human brain cDNA libraries the identification of novel splice isoforms of ErbB4, whereby exon 3 is skipped (del.3). ErbB4 del.3 transcripts exist as CYT-2 isoforms and are predicted to produce truncated proteins. Furthermore, our data refine the structure of the human ErbB4 gene, clarify that juxtamembrane (JM) splice variants of ErbB4, JM-a and JM-b respectively, are characterized by the replacement of a 75 nucleotide (nt) sequence with a 45-nt insertion, and demonstrate that there are four alternative exons in the gene. Our analyses reveal that novel splice variants of ErbB4 exist in the developing and adult human brain and, given the failure to identify ErbB4 del.3 CYT-1 transcripts, suggest that the association of risk polymorphisms in the ErbB4 gene with CYT-1 transcript levels is not mediated via an exon 3 splicing event.
doi:10.1371/journal.pone.0012924
PMCID: PMC2944867  PMID: 20886074
25.  Variation in factor B (BF) and complement component 2 (C2) genes is associated with age-related macular degeneration 
Nature genetics  2006;38(4):458-462.
Age-related macular degeneration (AMD) is the most common form of irreversible blindness in developed countries1,2. Variants in the factor H gene (CFH, also known as HF1), which encodes a major inhibitor of the alternative complement pathway, are associated with the risk for developing AMD3–8. Here we test the hypothesis that variation in genes encoding other regulatory proteins of the same pathway is associated with AMD. We screened factor B (BF) and complement component 2 (C2) genes, located in the major histo-compatibility complex class III region, for genetic variation in two independent cohorts comprising ~900 individuals with AMD and ~400 matched controls. Haplotype analyses identify a statistically significant common risk haplotype (H1) and two protective haplotypes. The L9H variant of BF and the E318D variant of C2 (H10), as well as a variant in intron 10 of C2 and the R32Q variant of BF (H7), confer a significantly reduced risk of AMD (odds ratio = 0.45 and 0.36, respectively). Combined analysis of the C2 and BF haplotypes and CFH variants shows that variation in the two loci can predict the clinical outcome in 74% of the affected individuals and 56% of the controls. These data expand and refine our understanding of the genetic risk for AMD.
doi:10.1038/ng1750
PMCID: PMC2921703  PMID: 16518403

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