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author:("Li, jiang")
1.  Psychiatric disorders following fetal death: a population-based cohort study 
BMJ Open  2014;4(6):e005187.
Women have increased risks of severe mental disorders after childbirth and death of a child, but it remains unclear whether this association also applies to fetal loss and, if so, to which extent. We studied the risk of any inpatient or outpatient psychiatric treatment during the time period from 12 months before to 12 months after fetal death.
Cohort study using Danish population-based registers.
A total of 1 112 831 women born in Denmark from 1960 to 1995 were included. In total, 87 687cases of fetal death (International Classification of Disease-10 codes for spontaneous abortion or stillbirth) were recorded between 1996 and 2010.
Primary and secondary outcome measures
The main outcome measures were incidence rate ratios (risk of first psychiatric inpatient or outpatient treatment).
A total of 1379 women had at least one psychiatric episode during follow-up from the year before fetal death to the year after. Within the first few months after the loss, women had an increased risk of psychiatric contact, IRR: 1.51 (95% CI 1.15 to 1.99). In comparison, no increased risk of psychiatric contact was found for the period before fetal death. The risk of experiencing a psychiatric episode was highest for women with a loss occurring after 20 weeks of gestation (12 month probability: 1.95%, 95% CI 1.50 to 2.39).
Fetal death was associated with a transient increased risk of experiencing a first-time episode of a psychiatric disorder, primarily adjustment disorders. The risk of psychiatric episodes tended to increase with increasing gestational age at the time of the loss.
PMCID: PMC4054628  PMID: 24907247
Epidemiology; Obstetrics; Psychiatry
2.  The Transcriptomes of the Crucian Carp Complex (Carassius auratus) Provide Insights into the Distinction between Unisexual Triploids and Sexual Diploids 
Both sexual reproduction and unisexual reproduction are adaptive strategies for species survival and evolution. Unisexual animals have originated largely by hybridization, which tends to elevate their heterozygosity. However, the extent of genetic diversity resulting from hybridization and the genomic differences that determine the type of reproduction are poorly understood. In Carassius auratus, sexual diploids and unisexual triploids coexist. These two forms are similar morphologically but differ markedly in their modes of reproduction. Investigation of their genomic differences will be useful to study genome diversity and the development of reproductive mode. We generated transcriptomes for the unisexual and sexual populations. Genes were identified using homology searches and an ab initio method. Estimation of the synonymous substitution rate in the orthologous pairs indicated that the hybridization of gibel carp occurred 2.2 million years ago. Microsatellite genotyping in each individual from the gibel carp population indicated that most gibel carp genes were not tri-allelic. Molecular function and pathway comparisons suggested few gene expansions between them, except for the progesterone-mediated oocyte maturation pathway, which is enriched in gibel carp. Differential expression analysis identified highly expressed genes in gibel carp. The transcriptomes provide information on genetic diversity and genomic differences, which should assist future studies in functional genomics.
PMCID: PMC4100101  PMID: 24871367
crucian carp; gibel carp; RNA-seq; genetic diversity; unisexual reproduction
3.  Severe Maternal Stress Exposure Due to Bereavement before, during and after Pregnancy and Risk of Overweight and Obesity in Young Adult Men: A Danish National Cohort Study 
PLoS ONE  2014;9(5):e97490.
Perinatal stress may programme overweight and obesity. We examined whether maternal pre- and post-natal bereavement was associated with overweight and obesity in young men.
A cohort study was conducted including 119,908 men born from 1976 to 1993 and examined for military service between 2006 and 2011. Among them, 4,813 conscripts were born to mothers bereaved by death of a close relative from 12 months preconception to birth of the child (exposed group). Median body mass index (BMI) and prevalence of overweight and obesity were estimated. Odds ratio of overweight (BMI≥25 kg/m2) and obesity (BMI≥30 kg/m2) were estimated by logistic regression analysis adjusted for maternal educational level.
Median BMI was similar in the exposed and the unexposed group but the prevalence of overweight (33.3% versus 30.4%, p = 0.02) and obesity (9.8% versus 8.5%, p = 0.06) was higher in the exposed group. Conscripts exposed 6 to 0 months before conception and during pregnancy had a higher risk of overweight (odds ratio 1.15, 95% confidence interval (CI): 1.03; 1.27 and odds ratio 1.13, 95% CI: 1.03; 1.25, respectively). Conscripts born to mothers who experienced death of the child’s biological father before child birth had a two-fold risk of obesity (odds ratio 2.00, 95% CI: 0.93; 4.31). There was no elevated risk in those who experienced maternal bereavement postnatally.
Maternal bereavement during the prenatal period was associated with increased risk of overweight or obesity in a group of young male conscripts, and this may possibly be reflected to severe stress exposure early in life. However, not all associations were clear, and further studies are warranted.
PMCID: PMC4020839  PMID: 24828434
4.  Epigenetic Activation of AP-1 Promotes Squamous Cell Carcinoma Metastasis 
Science signaling  2013;6(273):ra28.1-15.
The transcription factor AP-1 (activator protein-1), a heterodimer of the JUN and FOS proteins, promotes the invasive growth and metastasis of various tumors such as squamous cell carcinoma (SCC), breast cancer and melanoma. AP-1 activity is transcriptionally induced through a positive-feedback loop. We identified the histone demethylase KDM4A (lysine-specific demethylase 4A) as a key epigenetic priming factor in this positive feedback loop. KDM4A contributed to the induction of genes encoding the AP-1 transcription factors and the invasive growth and metastasis of SCC. KDM4A knockdown decreased growth factor-induced mRNA expression and protein abundance of AP-1 family members, including JUN and FOSL1. Mechanistically, histone demethylation by KDM4A facilitated the binding of the AP-1 complex to the promoters of JUN and FOSL1, thereby promoting the positive feedback loop that maintains activation of AP-1. In a mouse model of SCC, KDM4A knockdown inhibited lymph node metastasis. Moreover, the abundance of KDM4A correlated with the abundance of JUN and FOSL1 in human SCC tissues and KDM4A expression was increased in human lymph node metastases. Our studies provide insights into the epigenetic control of AP-1 and tumor invasion, and suggest that KDM4A could be an important therapeutic target for inhibiting invasive SCC growth and metastasis.
PMCID: PMC3951265  PMID: 23633675
5.  Birth weight, gestational age, fetal growth and childhood asthma hospitalization 
Childhood asthma may have a fetal origin through fetal growth and development of the immunocompetence or respiratory organs.
We examined to which extent short gestational age, low birth weight and fetal growth restriction were associated with an increased risk of asthma hospitalization in childhood.
We undertook a cohort study based on several national registers in Denmark, Sweden and Finland. We included all live singleton born children in Denmark during 1979-2005 (N = 1,538,093), in Sweden during 1973-2004 (N = 3,067,670), and a 90% random sample of singleton children born in Finland during 1987-2004 (N = 1,050,744). The children were followed from three years of age to first hospitalization for asthma, emigration, death, their 18th birthday, or the end of study (the end of 2008 in Denmark, and the end of 2007 in Sweden or Finland), whichever came first. We computed the pseudo-values for each observation and used them in a generalized estimating equation to estimate relative risks (RR) for asthma hospitalization.
A total of 131,783 children were hospitalized for asthma during follow-up. The risk for asthma hospitalization consistently increased with lower birth weight and shorter gestational age. A 1000-g decrease in birth weight corresponded to a RR of 1.17 (95% confidence interval (CI) 1.15-1.18). A one-week decrease in gestational age corresponded to a RR of 1.05 (95% CI 1.04-1.06). Small for gestational age was associated with an increased risk of asthma hospitalization in term but not in preterm born children.
Fetal growth and gestational age may play a direct or indirect causal role in the development of childhood asthma.
PMCID: PMC3973844  PMID: 24602245
Asthma; Birth weight; Gestational age; Hospitalization; Small for gestational age
6.  In-Utero Exposure to Bereavement and Offspring IQ: A Danish National Cohort Study 
PLoS ONE  2014;9(2):e88477.
Intelligence is a life-long trait that has strong influences on lifestyle, adult morbidity and life expectancy. Hence, lower cognitive abilities are therefore of public health interest. Our primary aim was to examine if prenatal bereavement measured as exposure to death of a close family member is associated with the intelligence quotient (IQ) scores at 18-years of age of adult Danish males completing a military cognitive screening examination.
We extracted records for the Danish military screening test and found kinship links with biological parents, siblings, and maternal grandparents using the Danish Civil Registration System (N = 167,900). The prenatal exposure period was defined as 12 months before conception until birth of the child. We categorized children as exposed in utero to severe stress (bereavement) during prenatal life if their mothers lost an elder child, husband, parent or sibling during the prenatal period; the remaining children were included in the unexposed cohort. Mean score estimates were adjusted for maternal and paternal age at birth, residence, income, maternal education, gestational age at birth and birth weight.
When exposure was due to death of a father the offsprings' mean IQ scores were lower among men completing the military recruitment exam compared to their unexposed counterparts, adjusted difference of 6.5 standard IQ points (p-value = 0.01). We did not observe a clinically significant association between exposure to prenatal maternal bereavement caused by death of a sibling, maternal uncle/aunt or maternal grandparent even after stratifying deaths only due to traumatic events.
We found maternal bereavement to be adversely associated with IQ in male offspring, which could be related to prenatal stress exposure though more likely is due to changes in family conditions after death of the father. This finding supports other literature on maternal adversity during fetal life and cognitive development in the offspring.
PMCID: PMC3928249  PMID: 24558394
7.  Dual gene transfer of bFGF and PDGF in a single plasmid for the treatment of myocardial infarction 
Basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF) have been shown to be involved in a spectrum of cellular processes. In a previous study, we constructed a novel multigenic vector that contained two separate transcription units, each consisting of a strong promoter and an efficient polyadenylation signal. The two promoters were chosen for their ability to work simultaneously. Dual gene transfer of bFGF and PDGF in a single plasmid resulted in a significant increase in collateral blood vessel formation in a rabbit model of hind limb ischemia. The aim of the present study was to investigate the effect of this dual gene transfer strategy in a rat model of acute myocardial infarction (AMI). AMI was induced in rats by ligation of the left anterior descending coronary artery. The animals were randomly divided into four groups and treated with the following therapeutic strategies: Empty plasmid (control), plasmid encoding bFGF (PL-bFGF), plasmid encoding PDGF (PL-PDGF) or plasmid encoding bFGF and PDGF (PL-F-P). Echocardiography and histological examinations were performed 28 days subsequent to gene transfer. Dual gene therapy with bFGF and PDGF resulted in a significant angiogenic effect accompanied by vessel maturation, along with a significant reduction in infarct size and improvement in cardiac function. In a rat model of AMI, single plasmid-mediated dual gene therapy with bFGF and PDGF decreased infarct size and improved cardiac function due to the formation of functionally and morphologically mature vasculature. These results are relevant to the ongoing clinical trials involving the use of single plasmid-mediated angiogenic factors for the treatment of myocardial ischemic disease.
PMCID: PMC3919859  PMID: 24520269
acute myocardial infarction; basic fibroblast growth factor; platelet-derived growth factor
8.  Association between winter season and risk of death from cardiovascular diseases: a study in more than half a million inpatients in Beijing, China 
Seasonal associations of cardiovascular mortality have been noted in most populations of European origin years ago, but are not well evaluated in Asian populations recently.
Utilizing the electronic Hospitalization Summary Reports (HSRs) from 32 top-ranked hospitals in Beijing, China, we evaluated the association between winter season and the risk of cardiovascular death among hospitalized individuals. General additive models and logistic regression models were adjusted for confounding factors.
Older patients who were admitted to the hospital in the winter months (January, February, November and December) had a death risk that was increased by approximately 30% to 50% (P < 0.01) over those who were admitted in May. However, younger patients did not seem to experience the same seasonal variations in death risk. The excess winter deaths among older patients were associated with ischemic heart disease (RR = 1.22; 95% CI 1.13 to 1.31), pulmonary heart disease (RR = 1.42; 95% CI 1.10 to 1.83), cardiac arrhythmias (RR = 1.67; 95% CI 1.36 to 2.05), heart failure (RR = 1.30; 95% CI 1.09 to 1.54), ischemic stroke (RR = 1.30; 95% CI 1.17 to 1.43), and other cerebrovascular diseases (RR = 1.78; 95% CI 1.40 to 2.25). The risks of mortality were higher in winter months than in the month of May, regardless of the presence or absence of respiratory disease.
Winter season was associated with a substantially increased risk of cardiovascular death among older Chinese cardiovascular inpatients.
PMCID: PMC3840603  PMID: 24172216
Cardiovascular disease; Winter; Seasonality; Older adults; Mortality; Asian population
9.  Psychological Stress and Hospitalization for Childhood Asthma-a Nationwide Cohort Study in Two Nordic Countries 
PLoS ONE  2013;8(10):e78816.
Exposures to psychological stress in early life may contribute to the development or exacerbation of asthma. We undertook a cohort study based on data from several population-based registers in Denmark and Sweden to examine whether bereavement in childhood led to increased asthma hospitalization.
All singleton children born in Denmark during 1977-2008 and in Sweden during 1973-2006 were included in the study (N=5,202,576). The children were followed from birth to the date of first asthma hospitalization, emigration, death, their 18th birthday, or the end of study (31 December 2007 in Sweden and 31 December 2008 in Denmark), whichever came first. All the children were assigned to the non-bereaved group until they lost a close relative (mother, father or a sibling), from when they were included in the bereaved group. We evaluated the hazard ratio (HR) of first hospitalization for asthma in bereaved children using Cox proportional hazards regression models, compared to those who were in the non-bereaved group. We also did a sub-analysis on the association between bereavement and first asthma medication.
A total of 147,829 children were hospitalized for asthma. The overall adjusted HR of asthma hospitalization in bereaved children was 1.10 (95% confidence interval (CI): 1.04-1.16), compared to non-bereaved children. The risk of asthma hospitalization was increased in those who lost a close relative at age of 14-17 years (HR=1.54, 95% CI: 1.23-1.92), but not in younger age groups. The association between bereavement and asthma hospitalization did not change over time since bereavement. In the sub-analysis in singleton live births during 1996-2008 recorded in the DMBR, bereavement was associated with a lower use of asthma medication (HR=0.87, 95% CI: 0.80-0.95).
Our data suggests that psychological stress following bereavement in late adolescence is associated with an increased risk of asthma hospitalization or lowers the threshold for asthma hospitalization.
PMCID: PMC3808299  PMID: 24205324
10.  L_RNA_scaffolder: scaffolding genomes with transcripts 
BMC Genomics  2013;14:604.
Generation of large mate-pair libraries is necessary for de novo genome assembly but the procedure is complex and time-consuming. Furthermore, in some complex genomes, it is hard to increase the N50 length even with large mate-pair libraries, which leads to low transcript coverage. Thus, it is necessary to develop other simple scaffolding approaches, to at least solve the elongation of transcribed fragments.
We describe L_RNA_scaffolder, a novel genome scaffolding method that uses long transcriptome reads to order, orient and combine genomic fragments into larger sequences. To demonstrate the accuracy of the method, the zebrafish genome was scaffolded. With expanded human transcriptome data, the N50 of human genome was doubled and L_RNA_scaffolder out-performed most scaffolding results by existing scaffolders which employ mate-pair libraries. In these two examples, the transcript coverage was almost complete, especially for long transcripts. We applied L_RNA_scaffolder to the highly polymorphic pearl oyster draft genome and the gene model length significantly increased.
The simplicity and high-throughput of RNA-seq data makes this approach suitable for genome scaffolding. L_RNA_scaffolder is available at
PMCID: PMC3846640  PMID: 24010822
L_RNA_scaffolder; Scaffolding; Transcriptome; Genome
11.  Bidirectional regulation between WDR83 and its natural antisense transcript DHPS in gastric cancer 
Cell Research  2012;22(9):1374-1389.
Natural antisense transcripts (NATs) exist ubiquitously in mammalian genomes and play roles in the regulation of gene expression. However, both the existence of bidirectional antisense RNA regulation and the possibility of protein-coding genes that function as antisense RNAs remain speculative. Here, we found that the protein-coding gene, deoxyhypusine synthase (DHPS), as the NAT of WDR83, concordantly regulated the expression of WDR83 mRNA and protein. Conversely, WDR83 also regulated DHPS by antisense pairing in a concordant manner. WDR83 and DHPS were capable of forming an RNA duplex at overlapping 3′ untranslated regions and this duplex increased their mutual stability, which was required for the bidirectional regulation. As a pair of protein-coding cis-sense/antisense transcripts, WDR83 and DHPS were upregulated simultaneously and correlated positively in gastric cancer (GC), driving GC pathophysiology by promoting cell proliferation. Furthermore, the positive relationship between WDR83 and DHPS was also observed in other cancers. The bidirectional regulatory relationship between WDR83 and DHPS not only enriches our understanding of antisense regulation, but also provides a more complete understanding of their functions in tumor development.
PMCID: PMC3434345  PMID: 22491477
bidirectional regulation; natural antisense transcript; gastric cancer
12.  Correction: Prenatal Exposure to Bereavement and Type-2 Diabetes: A Danish Longitudinal Population Based Study 
PLoS ONE  2013;8(8):10.1371/annotation/dbd21894-4722-499c-afaf-b03015fae7d8.
PMCID: PMC3744642  PMID: 23976927
13.  Absorption of Hazardous Pollutants by a Medicinal Fern Blechnum orientale L. 
BioMed Research International  2013;2013:192986.
A Chinese medicinal fern Blechnum orientale (Linn) was separately collected from polluted and unpolluted sites to determine whether it could accumulate hazardous pollutants or not. Metal concentrations (Cu, Zn, Mn, Pb, Cd, Cr, As, and Hg) both in the fronds and roots and polycyclic aromatic hydrocarbons (PAHs) in the fronds of this fern were quantified. At both sites, roots of B. orientale had significantly higher heavy metals than the fronds. Concentrations of Pb, As, Hg, Cd, and Cu in the fronds at the polluted site were more than 2, 6, 7, 14, 5, and 13 times of those at the unpolluted site. Translocation factor and bioaccumulation factor implied that B. orientale did not have a good ability to transport heavy metals from the roots to the fronds. Total PAHs in the fronds at the polluted site were significantly higher than those at the unpolluted site, indicating the physiological PAHs absorption by B. orientale growing at polluted sites. Uptake of pollutants via stomata might be the main reason causing the significant accumulation of hazardous pollutants in the fronds of B. orientale. Large-scale systematical survey and intensive monitoring on pollutants in this medicinal fern should be necessarily strengthened.
PMCID: PMC3727117  PMID: 23936780
14.  Early life bereavement and childhood cancer: a nationwide follow-up study in two countries 
BMJ Open  2013;3(5):e002864.
Childhood cancer is a leading cause of child deaths in affluent countries, but little is known about its aetiology. Psychological stress has been suggested to be associated with cancer in adults; whether this is also seen in childhood cancer is largely unknown. We investigated the association between bereavement as an indicator of severe childhood stress exposure and childhood cancer, using data from Danish and Swedish national registers.
Population-based cohort study.
Denmark and Sweden.
All live-born children born in Denmark between 1968 and 2007 (n=2 729 308) and in Sweden between 1973 and 2006 (n=3 395 166) were included in this study. Exposure was bereavement by the death of a close relative before 15 years of age. Follow-up started from birth and ended at the first of the following: date of a cancer diagnosis, death, emigration, day before their 15th birthday or end of follow-up (2007 in Denmark, 2006 in Sweden).
Outcome measures
Rates and HRs for all childhood cancers and specific childhood cancers.
A total of 1 505 938 (24.5%) children experienced bereavement at some point during their childhood and 9823 were diagnosed with cancer before the age of 15 years. The exposed children had a small (10%) increased risk of childhood cancer (HR 1.10; 95% CI 1.04 to 1.17). For specific cancers, a significant association was seen only for central nervous system tumours (HR 1.14; 95% CI 1.02 to 1.28).
Our data suggest that psychological stress in early life is associated with a small increased risk of childhood cancer.
PMCID: PMC3664350  PMID: 23793702
Childhood cancer; bereavement; psychological stress; risk factor; follow up
16.  DNA Nanostructure-based Interfacial engineering for PCR-free ultrasensitive electrochemical analysis of microRNA 
Scientific Reports  2012;2:867.
MicroRNAs (miRNAs) have been identified as promising cancer biomarkers due to their stable presence in serum. As an alternative to PCR-based homogenous assays, surface-based electrochemical biosensors offer great opportunities for low-cost, point-of-care tests (POCTs) of disease-associated miRNAs. Nevertheless, the sensitivity of miRNA sensors is often limited by mass transport and crowding effects at the water-electrode interface. To address such challenges, we herein report a DNA nanostructure-based interfacial engineering approach to enhance binding recognition at the gold electrode surface and drastically improve the detection sensitivity. By employing this novel strategy, we can directly detect as few as attomolar (<1, 000 copies) miRNAs with high single-base discrimination ability. Given that this ultrasensitive electrochemical miRNA sensor (EMRS) is highly reproducible and essentially free of prior target labeling and PCR amplification, we also demonstrate its application by analyzing miRNA expression levels in clinical samples from esophageal squamous cell carcinoma (ESCC) patients.
PMCID: PMC3499757  PMID: 23162691
17.  Correction: Effects of Precipitation Increase on Soil Respiration: A Three-Year Field Experiment in Subtropical Forests in China 
PLoS ONE  2012;7(10):10.1371/annotation/1f49fc5e-e3f9-4b90-b555-97a54990ac3f.
PMCID: PMC3935814
18.  Prenatal Exposure to Bereavement and Type-2 Diabetes: A Danish Longitudinal Population Based Study 
PLoS ONE  2012;7(8):e43508.
The etiology of type-2 diabetes is only partly known, and a possible role of prenatal stress in programming offspring for insulin resistance has been suggested by animal models. Previously, we found an association between prenatal stress and type-1 diabetes. Here we examine the association between prenatal exposure to maternal bereavement during preconception and pregnancy and development of type-2 diabetes in the off-spring.
We utilized data from the Danish Civil Registration System to identify singleton births in Denmark born January 1st 1979 through December 31st 2008 (N = 1,878,246), and linked them to their parents, grandparents, and siblings. We categorized children as exposed to bereavement during prenatal life if their mothers lost an elder child, husband or parent during the period from one year before conception to the child’s birth. We identified 45,302 children exposed to maternal bereavement; the remaining children were included in the unexposed cohort. The outcome of interest was diagnosis of type-2 diabetes. We estimated incidence rate ratios (IRRs) from birth using log-linear poisson regression models and used person-years as the offset variable. All models were adjusted for maternal residence, income, education, marital status, sibling order, calendar year, sex, and parents’ history of diabetes at the time of pregnancy.
We found children exposed to bereavement during their prenatal life were more likely to have a type-2 diabetes diagnosis later in life (aIRR: 1.31, 1.01–1.69). These findings were most pronounced when bereavement was caused by death of an elder child (aIRR: 1.51, 0.94–2.44). Results also indicated the second trimester of pregnancy to be the most sensitive period of bereavement exposure (aIRR:2.08, 1.15–3.76).
Our data suggests that fetal exposure to maternal bereavement during preconception and the prenatal period may increase the risk for developing type-2 diabetes in childhood and young adulthood.
PMCID: PMC3429491  PMID: 22952698
19.  Identification of common carp (Cyprinus carpio) microRNAs and microRNA-related SNPs 
BMC Genomics  2012;13:413.
MicroRNAs (miRNAs) exist pervasively across viruses, plants and animals and play important roles in the post-transcriptional regulation of genes. In the common carp, miRNA targets have not been investigated. In model species, single-nucleotide polymorphisms (SNPs) have been reported to impair or enhance miRNA regulation as well as to alter miRNA biogenesis. SNPs are often associated with diseases or traits. To date, no studies into the effects of SNPs on miRNA biogenesis and regulation in the common carp have been reported.
Using homology-based prediction combined with small RNA sequencing, we have identified 113 common carp mature miRNAs, including 92 conserved miRNAs and 21 common carp specific miRNAs. The conserved miRNAs had significantly higher expression levels than the specific miRNAs. The miRNAs were clustered into three phylogenetic groups. Totally 394 potential miRNA binding sites in 206 target mRNAs were predicted for 83 miRNAs. We identified 13 SNPs in the miRNA precursors. Among them, nine SNPs had the potential to either increase or decrease the energy of the predicted secondary structures of the precursors. Further, two SNPs in the 3’ untranslated regions of target genes were predicted to either disturb or create miRNA-target interactions.
The common carp miRNAs and their target genes reported here will help further our understanding of the role of miRNAs in gene regulation. The analysis of the miRNA-related SNPs and their effects provided insights into the effects of SNPs on miRNA biogenesis and function. The resource data generated in this study will help advance the study of miRNA function and phenotype-associated miRNA identification.
PMCID: PMC3478155  PMID: 22908890
miRNAs; Targets; SNPs; miRNA biogenesis; Common carp
20.  Correction: NOXA-Induced Alterations in the Bax/Smac Axis Enhance Sensitivity of Ovarian Cancer Cells to Cisplatin 
PLoS ONE  2012;7(8):10.1371/annotation/a863b4b3-6d4c-447a-87e3-4d631ceb7a46.
PMCID: PMC3425604
21.  The 5-minute Apgar score as a predictor of childhood cancer: a population-based cohort study in five million children 
BMJ Open  2012;2(4):e001095.
The aetiology of childhood cancer remains largely unknown but recent research indicates that uterine environment plays an important role. We aimed to examine the association between the Apgar score at 5 min after birth and the risk of childhood cancer.
Nationwide population-based cohort study.
Nationwide register data in Denmark and Sweden.
Study population
All live-born singletons born in Denmark from 1978 to 2006 (N=1 771 615) and in Sweden from 1973 to 2006 (N=3 319 573). Children were followed up from birth to 14 years of age.
Main outcome measures
Rates and HRs for all childhood cancers and for specific childhood cancers.
A total of 8087 children received a cancer diagnosis (1.6 per 1000). Compared to children with a 5-min Apgar score of 9–10, children with a score of 0–5 had a 46% higher risk of cancer (adjusted HR 1.46, 95% CI 1.15 to 1.89). The potential effect of low Apgar score on overall cancer risk was mostly confined to children diagnosed before 6 months of age. Children with an Apgar score of 0–5 had higher risks for several specific childhood cancers including Wilms’ tumour (HR 4.33, 95% CI 2.42 to 7.73).
A low 5 min Apgar score was associated with a higher risk of childhood cancers diagnosed shortly after birth. Our data suggest that environmental factors operating before or during delivery may play a role on the development of several specific childhood cancers.
PMCID: PMC3425910  PMID: 22874628
Oncology; Epidemiology; Paediatric oncology; Preventive Medicine
22.  NOXA-Induced Alterations in the Bax/Smac Axis Enhance Sensitivity of Ovarian Cancer Cells to Cisplatin 
PLoS ONE  2012;7(5):e36722.
Ovarian cancer is the most common cause of death from gynecologic malignancy. Deregulation of p53 and/or p73-associated apoptotic pathways contribute to the platinum-based resistance in ovarian cancer. NOXA, a pro-apoptotic BH3-only protein, is identified as a transcription target of p53 and/or p73. In this study, we found that genetic variants of Bcl-2 proteins exist among cisplatin-sensitive and -resistant ovarian cancer cells, and the responses of NOXA and Bax to cisplatin are regulated mainly by p53. We further evaluated the effect of NOXA on cisplatin. NOXA induced apoptosis and sensitized A2780s and SKOV3 cells to cisplatin in vitro and in vivo. The effects were mediated by elevated Bax expression, enhanced caspase activation, release of Cyt C and Smac into the cytosol. Furthermore, gene silencing of Bax or Smac significantly attenuated NOXA and/or cisplatin-induced apoptosis in chemosensitive A2780s cells, whereas overexpression of Bax or addition of Smac-N7 peptide significantly increased NOXA and/or cisplatin-induced apoptosis in chemoresistant SKOV3 cells. To our knowledge, these data suggest a new mechanism by which NOXA chemosensitized ovarian cancer cells to cisplatin by inducing alterations in the Bax/Smac axis. Taken together, our findings show that NOXA is potentially useful as a chemosensitizer in ovarian cancer therapy.
PMCID: PMC3348888  PMID: 22590594
23.  Transcriptome analysis reveals the time of the fourth round of genome duplication in common carp (Cyprinus carpio) 
BMC Genomics  2012;13:96.
Common carp (Cyprinus carpio) is thought to have undergone one extra round of genome duplication compared to zebrafish. Transcriptome analysis has been used to study the existence and timing of genome duplication in species for which genome sequences are incomplete. Large-scale transcriptome data for the common carp genome should help reveal the timing of the additional duplication event.
We have sequenced the transcriptome of common carp using 454 pyrosequencing. After assembling the 454 contigs and the published common carp sequences together, we obtained 49,669 contigs and identified genes using homology searches and an ab initio method. We identified 4,651 orthologous pairs between common carp and zebrafish and found 129,984 paralogous pairs within the common carp. An estimation of the synonymous substitution rate in the orthologous pairs indicated that common carp and zebrafish diverged 120 million years ago (MYA). We identified one round of genome duplication in common carp and estimated that it had occurred 5.6 to 11.3 MYA. In zebrafish, no genome duplication event after speciation was observed, suggesting that, compared to zebrafish, common carp had undergone an additional genome duplication event. We annotated the common carp contigs with Gene Ontology terms and KEGG pathways. Compared with zebrafish gene annotations, we found that a set of biological processes and pathways were enriched in common carp.
The assembled contigs helped us to estimate the time of the fourth-round of genome duplication in common carp. The resource that we have built as part of this study will help advance functional genomics and genome annotation studies in the future.
PMCID: PMC3352309  PMID: 22424280
Sequence assembly; Genome duplication; Common carp; Substitution rate; Speciation
24.  The p53 Upregulated Modulator of Apoptosis (PUMA) Chemosensitizes Intrinsically Resistant Ovarian Cancer Cells to Cisplatin by Lowering the Threshold Set by Bcl-xL and Mcl-1 
Molecular Medicine  2011;17(11-12):1262-1274.
Ovarian cancer is the number one cause of death from gynecologic malignancy. A defective p53 pathway is a hallmark of ovarian carcinoma. The p53 mutation correlates significantly with resistance to platinum-based chemotherapy, early relapse and shortened overall survival in ovarian cancer patients. PUMA (p53 upregulated modulator of apoptosis), a BH3-only Bcl-2 family protein, was recently identified as a transcriptional target of p53 and a potent apoptosis inducer in various cancer cells. In this study, we showed that the induction of PUMA by cisplatin was abolished in p53-deficient SKOV3 cells. Elevated expression of PUMA-induced apoptosis and sensitized A2780s and SKOV3 ovarian cancer cells to cisplatin, and the combination of PUMA and low-dose cisplatin, significantly suppressed xenograft tumor growth in vivo through enhanced induction of apoptosis compared with treatment with PUMA or cisplatin alone. The effects of PUMA were mediated by enhanced caspase activation and release of cytochrome c and Smac (second mitochondria–derived activator of caspase) into the cytosol. Furthermore, PUMA chemosensitized intrinsically resistant SKOV3 cells to cisplatin through downregulation of B-cell lymphoma-extra large (Bcl-xL) and myeloid cell leukemia sequence 1 (Mcl-1). PUMA-mediated Bcl-xL downregulation mainly happened at the transcription level, whereas PUMA-induced Mcl-1 down-regulation was associated with caspase-dependent cleavage and proteasome-mediated degradation. To our knowledge, these data suggest a new mechanism by which overexpression of PUMA enhances sensitivity of SKOV3 cells to cisplatin by lowering the threshold set simultaneously by Bcl-xL and Mcl-1. Taken together, our findings indicate that PUMA is an important modulator of therapeutic responses of ovarian cancer cells and is potentially useful as a chemosensitizer in ovarian cancer therapy.
PMCID: PMC3321807  PMID: 21863213
25.  Label-free high-throughput microRNA expression profiling from total RNA 
Nucleic Acids Research  2011;39(22):e154.
MicroRNAs (miRNAs) are key biological regulators and promising disease markers whose detection technologies hold great potentials in advancing fundamental research and medical diagnostics. Currently, miRNAs in biological samples have to be labeled before being applied to most high-throughput assays. Although effective, these labeling-based approaches are usually labor-intensive, time-consuming and liable to bias. Besides, the cross-hybridization of co-existing miRNA precursors (pre-miRNAs) is not adequately addressed in most assays that use total RNA as input. Here, we present a hybridization-triggered fluorescence strategy for label-free, microarray-based high-throughput miRNA expression profiling. The total RNA is directly applied to the microarray with a short fluorophore-linked oligonucleotide Universal Tag which can be selectively captured by the target-bound probes via base-stacking effects. This Stacking-Hybridized Universal Tag (SHUT) assay has been successfully used to analyze as little as 100 ng total RNA from human tissues, and found to be highly specific to homogenous miRNAs. Superb discrimination toward single-base mismatch at the 5′ or 3′ end has been demonstrated. Importantly, the pre-miRNAs generated negligible signals, validating the direct use of total RNA.
PMCID: PMC3239174  PMID: 21976734

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