Zinc finger protein 671 has a cancer-inhibiting function in colorectal carcinoma via the deactivation of Notch signaling.

Zinc finger protein 671 (ZNF671) has been described as a vital cancer inhibitor in multiple neoplasms, yet the functional roles of ZNF671 in colorectal carcinoma (CRC) remain unresolved. This project examined the possible link between ZNF671 and CRC. Lower levels of ZNF671 were observed in CRC tissue compared with noncancerous tissue, which were related to a worse survival rate in CRC patients. High methylation levels at the ZNF671 gene promoter region were shown in CRC tissue, which were inversely correlated with ZNF671 expression. Treatment with demethylation agents restored ZNF671 levels in CRC cell lines. Up-regulation of ZNF671 resulted in suppressive effects on the proliferative ability and metastatic potency of CRC cells. Moreover, the up-regulation of ZNF671 reinforced the chemosensitivity of CRC cells. A mechanism study determined ZNF671 to be a vital mediator of Notch signaling. The up-regulation of ZNF671 decreased the expression of Notch1 and lowered the levels of NICD, HES1, and HEY1. The overexpression of NICD1 diminished ZNF671-mediated antitumor effects. ZNF671 depletion reinforced Notch signaling, and Notch suppression reversed ZNF671-depletion-elicited protumor effects. Moreover, the overexpression of ZNF671 weakened the tumorigenicity of CRC cells in a xenograft model in vivo. In summary, ZNF671 exerts a cancer-inhibiting function in CRC via the deactivation of Notch signaling. Low ZNF671 levels caused by gene promoter hypermethylation contribute to the malignant transformation of CRC. This work underlines the interest of ZNF671 as a target candidate for exploiting novel anti-CRC therapies.

FIGLA, LHX8 and SOHLH1 transcription factor networks regulate mouse oocyte growth and differentiation.

Germ-cell transcription factors control gene networks that regulate oocyte differentiation and primordial follicle formation during early, postnatal mouse oogenesis. Taking advantage of gene-edited mice lacking transcription factors expressed in female germ cells, we analyzed global gene expression profiles in perinatal ovaries from wildtype, FiglaNull, Lhx8Null and Sohlh1Null mice. Figla deficiency dysregulates expression of meiosis-related genes (e.g. Sycp3, Rad51, Ybx2) and a variety of genes (e.g. Nobox, Lhx8, Taf4b, Sohlh1, Sohlh2, Gdf9) associated with oocyte growth and differentiation. The absence of FIGLA significantly impedes meiotic progression, causes DNA damage and results in oocyte apoptosis. Moreover, we find that FIGLA and other transcriptional regulator proteins (e.g. NOBOX, LHX8, SOHLH1, SOHLH2) are co-expressed in the same subset of germ cells in perinatal ovaries and Figla ablation dramatically disrupts KIT, NOBOX, LHX8, SOHLH1 and SOHLH2 abundance. In addition, not only do FIGLA, LHX8 and SOHLH1 cross-regulate each other, they also cooperate by direct interaction with each during early oocyte development and share downstream gene targets. Thus, our findings substantiate a major role for FIGLA, LHX8 and SOHLH1 as multifunctional regulators of networks necessary for oocyte maintenance and differentiation during early folliculogenesis.

Specific Amino Acid Substitutions in OXA-51-Type ß-Lactamase Enhance Catalytic Activity to a Level Comparable to Carbapenemase OXA-23 and OXA-24/40.

The chromosomal blaOXA-51-type gene encodes carbapenem-hydrolyzing class D ß-lactamases (CHDLs), specific variants shown to mediate carbapenem resistance in the Gram-negative bacterial pathogen Acinetobacter baumannii. This study aims to characterize the effect of key amino acid substitutions in OXA-51 variants of carbapenem-hydrolyzing class D ß-lactamases (CHDLs) on substrate catalysis. Mutational and structural analyses indicated that each of the L167V, W222G, or I129L substitutions contributed to an increase in catalytic activity. The I129L mutation exhibited the most substantial effect. The combination of W222G and I129L substitutions exhibited an extremely strong catalytic enhancement effect in OXA-66, resulting in higher activity than OXA-23 and OXA-24/40 against carbapenems. These findings suggested that specific arrangement of residues in these three important positions in the intrinsic OXA-51 type of enzyme can generate variants that are even more active than known CHDLs. Likewise, mutation leading to the W222M change also causes a significant increase in the catalytic activity of OXA-51. blaOXA-51 gene in A. baumannii may likely continue to evolve, generating mutant genes that encode carbapenemase with extremely strong catalytic activity.

Association of Ambient Fine Particulate Matter (PM2.5) with Elevated Fecal Hemoglobin Concentration and Colorectal Carcinogenesis: A Population-Based Retrospective Cohort Study.

The roles of ambient fine particulate matter (PM2.5) in the prevention of colorectal cancer (CRC) have been scarcely highlighted as there is short of empirical evidence regarding the influences of PM2.5 on multistep carcinogenic processes of CRC. A retrospective cohort design with multistate outcomes was envisaged by linking monthly average PM2.5 concentrations at 22 city/county level with large-scale cohorts of cancer-screened population to study the influences of PM2.5 on short-term inflammatory process and multistep carcinogenic processes of CRC. Our study included a nationwide CRC screening cohort of 4,628,995 aged 50-69 years who attended first screen between 2004 and 2009 and continued periodical screens until 2016. We aimed to illustrate the carcinogenesis of PM2.5 related to CRC by applying both hierarchical logistical and multistate Markov regression models to estimate the effects of air pollution on fecal immunochemical test (FIT) positive (a proxy of inflammatory marker) and pre-clinical and clinical states of CRC in the nationwide cohort. We found a significant association of high PM2.5 exposure and FIT-positive by an increased risk of 11% [95% confidence interval (CI), 10-12]. PM2.5 enhanced the risk of being preclinical state by 14% (95% CI, 10-18) and that of subsequent progression from pre-clinical to clinical state by 21% (95% CI, 14-28). Furthermore, the elevated risks for CRC carcinogenesis were significantly higher for people living in high PM2.5 pollution areas in terms of yearly averages and the number days above 35 µg/m3 than those living in low PM2.5 pollution areas. We concluded that both short-term and long-term PM2.5 exposure were associated with multistep progression of CRC, which were useful to design precision primary and secondary prevention strategies of CRC for people who are exposed to high PM2.5 pollution.

Children's environmental health based on birth cohort studies of Asia (2) - air pollution, pesticides, and heavy metals.

The life style and child raising environment in Asia are quite different compared with Western countries. Besides, the children's environmental threats and difficulties in conducting studies could be different. To address children's environmental health in Asia area, the Birth Cohort Consortium of Asia (BiCCA) was co-established in 2011. We reviewed the mercury, polychlorinated biphenyls, perfluoroalkyl substances, phthalates, and environmental tobacco smoke in pervious based on birth cohort studies in Asia. The aim of this study was to summarize the traditional environmental pollution and the target subjects were also based on the birth cohort in Asia area. Environmental pollutants included air pollutants, pesticides focusing on organochlorine pesticides, diakylphosphates, and pyrethroid, and heavy metals including lead, arsenic, cadmium, manganese, vanadium, and thallium. Fetal growth and pregnancy outcomes, childhood growth and obesity, neurodevelopment and behavioral problems, and allergic disease and immune function were classified to elucidate the children's health effects. In total, 106 studies were selected in this study. The evidences showed air pollution or pesticides may affect growth during infancy or childhood, and associated with neurodevelopmental or behavioral problems. Prenatal exposure to lead or manganese was associated with neurodevelopmental or behavioral problems, while exposure to arsenic or cadmium may influence fetal growth. In addition to the harmonization and international collaboration of birth cohorts in Asia; however, understand the whole picture of exposure scenario and consider more discipline in the research are necessary.

Right hemicolectomy and multivisceral resection of right colon cancer: A report of 21 cases.

The long- and short-term outcomes in 21 patients with right colon cancer after right hemicolectomy and multivisceral resection surgery were investigated. Short-term therapeutic effects and long-term survival rate were retrospectively analyzed in patients with right colon cancer. These individuals underwent right hemicolectomy in combination with multivisceral resections including pancreatic head, duodenum, kidney, liver, gallbladder, and abdominal wall at the Department of General Surgery in the Henan Tumor Hospital between January 2003 and August 2014. The patients had an average age of 58.9 years (range: 39-78). Three patients had metastatic invasion only to the duodenum; meanwhile 18 patients had invasion to the duodenum and other adjacent organs. The median survival time was 41 months (95% CI: 6.972-75.028) with one death in the perioperative period. No patients lost follow-up. One-, 3-, and 5-year survival rate was 75%, 56%, and 43%, respectively. It was concluded that indications for surgery should be tightly controlled. Favorable clinical outcomes of right hemicolectomy and multivisceral resection surgery were demonstrated for patients with right colon cancer at the T4 stage.

Exposure to ambient temperature and heat index in relation to DNA methylation age: A population-based study in Taiwan.

BACKGROUND: Climate change caused an increase in ambient temperature in the past decades. Exposure to high ambient temperature could result in biological aging, but relevant studies in a warm environment were lacking. We aimed to study the exposure effects of ambient temperature and heat index (HI) in relation to age acceleration in Taiwan, a subtropical island in Asia. METHODS: The study included 2,084 participants from Taiwan Biobank. Daily temperature and relative humidity data were collected from weather monitoring stations. Individual residential exposure was estimated by ordinary kriging. Moving averages of ambient temperature and HI from 1 to 180 days prior to enrollment were calculated to estimate the exposure effects in multiple time periods. Age acceleration was defined as the difference between DNA methylation age and chronological age. DNA methylation age was calculated by the Horvath's, Hannum's, Weidner's, ELOVL2, FHL2, phenotypic (Pheno), Skin & blood, and GrimAge2 (Grim2) DNA methylation age algorithms. Multivariable linear regression models, generalized additive models (GAMs), and distributed lag non-linear models (DLNMs) were conducted to estimate the effects of ambient temperature and HI exposures in relation to age acceleration. RESULTS: Exposure to high ambient temperature and HI were associated with increased age acceleration, and the associations were stronger in prolonged exposure. The heat stress days with maximum HI in caution (80-90°F), extreme caution (90-103°F), danger (103-124°F), and extreme danger (>124°F) were also associated with increased age acceleration, especially in the extreme danger days. Each extreme danger day was associated with 571.38 (95 % CI: 42.63-1100.13), 528.02 (95 % CI: 36.16-1019.87), 43.9 (95 % CI: 0.28-87.52), 16.82 (95 % CI: 2.36-31.28) and 15.52 (95 % CI: 2.17-28.88) days increase in the Horvath's, Hannum's, Weidner's, Pheno, and Skin & blood age acceleration, respectively. CONCLUSION: High ambient temperature and HI may accelerate biological aging.

Development of a Novel Endometrial Signature Based on Endometrial microRNA for Determining the Optimal Timing for Embryo Transfer.

Though tremendous advances have been made in the field of in vitro fertilization (IVF), a portion of patients are still affected by embryo implantation failure issues. One of the most significant factors contributing to implantation failure is a uterine condition called displaced window of implantation (WOI), which refers to an unsynchronized endometrium and embryo transfer time for IVF patients. Previous studies have shown that microRNAs (miRNAs) can be important biomarkers in the reproductive process. In this study, we aim to develop a miRNA-based classifier to identify the WOI for optimal time for embryo transfer. A reproductive-related PanelChip® was used to obtain the miRNA expression profiles from the 200 patients who underwent IVF treatment. In total, 143 out of the 167 miRNAs with amplification signals across 90% of the expression profiles were utilized to build a miRNA-based classifier. The microRNA-based classifier identified the optimal timing for embryo transfer with an accuracy of 93.9%, a sensitivity of 85.3%, and a specificity of 92.4% in the training set, and an accuracy of 88.5% in the testing set, showing high promise in accurately identifying the WOI for the optimal timing for embryo transfer.

Letter to editor 'Non-invasive model for predicting high-risk esophageal varices based on liver and spleen stiffness'.

This letter to the editor relates to the study entitled "Non-invasive model for predicting high-risk esophageal varices based on liver and spleen stiffness". Acute bleeding caused by esophageal varices is a life-threatening complication in patients with liver cirrhosis. Due to the discomfort, contraindications, and associated complications of upper gastrointestinal endoscopy screening, it is crucial to identify an imaging-based non-invasive model for predicting high-risk esophageal varices in patients with cirrhosis.

Non-invasive model for predicting high-risk esophageal varices based on liver and spleen stiffness.

BACKGROUND: Acute bleeding due to esophageal varices (EVs) is a life-threatening complication in patients with cirrhosis. The diagnosis of EVs is mainly through upper gastrointestinal endoscopy, but the discomfort, contraindications and complications of gastrointestinal endoscopic screening reduce patient compliance. According to the bleeding risk of EVs, the Baveno VI consensus divides varices into high bleeding risk EVs (HEVs) and low bleeding risk EVs (LEVs). We sought to identify a non-invasive prediction model based on spleen stiffness measurement (SSM) and liver stiffness measurement (LSM) as an alternative to EVs screening. AIM: To develop a safe, simple and non-invasive model to predict HEVs in patients with viral cirrhosis and identify patients who can be exempted from upper gastrointestinal endoscopy. METHODS: Data from 200 patients with viral cirrhosis were included in this study, with 140 patients as the modelling group and 60 patients as the external validation group, and the EVs types of patients were determined by upper gastrointestinal endoscopy and the Baveno VI consensus. Those patients were divided into the HEVs group (66 patients) and the LEVs group (74 patients). The effect of each parameter on HEVs was analyzed by univariate and multivariate analyses, and a non-invasive prediction model was established. Finally, the discrimination ability, calibration ability and clinical efficacy of the new model were verified in the modelling group and the external validation group. RESULTS: Univariate and multivariate analyses showed that SSM and LSM were associated with the occurrence of HEVs in patients with viral cirrhosis. On this basis, logistic regression analysis was used to construct a prediction model: Ln [P/(1-P)] = -8.184 -0.228 × SSM + 0.642 × LSM. The area under the curve of the new model was 0.965. When the cut-off value was 0.27, the sensitivity, specificity, positive predictive value and negative predictive value of the model for predicting HEVs were 100.00%, 82.43%, 83.52%, and 100%, respectively. Compared with the four prediction models of liver stiffness-spleen diameter to platelet ratio score, variceal risk index, aspartate aminotransferase to alanine aminotransferase ratio, and Baveno VI, the established model can better predict HEVs in patients with viral cirrhosis. CONCLUSION: Based on the SSM and LSM measured by transient elastography, we established a non-invasive prediction model for HEVs. The new model is reliable in predicting HEVs and can be used as an alternative to routine upper gastrointestinal endoscopy screening, which is helpful for clinical decision making.

A single-nucleotide polymorphism in the methylene tetrahydrofolate reductase (MTHFR) gene is associated with risk of radiation pneumonitis in lung cancer patients treated with thoracic radiation therapy.

BACKGROUND: This study examined the association between functional single-nucleotide polymorphisms in candidate genes from oxidative stress pathways and risk of radiation pneumonitis (RP) in patients treated with thoracic radiation therapy for locally advanced lung cancer. METHODS: A review was conducted of 136 patients treated with radiation therapy for lung cancer between 2001 and 2007, and who had prior genotyping of functional single-nucleotide polymorphisms in oxidative stress genes including superoxide dismutase 2 (SOD2; rs4880) and methylene tetrahydrofolate reductase (MTHFR; rs1801131, rs1801133). RP events were retrospectively scored using the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. Cox proportional hazard regression was performed to identify clinical variables and genotypes associated with risk of RP of grades ≥2 and ≥3 on univariate and multivariate analysis, respectively. P values were corrected for multiple hypothesis esting. RESULTS: With a median follow-up of 21.4 months, the incidence of grade ≥2 RP was 29% and grade ≥3 RP was 14%. On multivariate analysis, after adjusting for clinical factors such as concurrent chemotherapy and consolidation docetaxel, and lung dosimetric parameters such as volume receiving greater than 20 Gy and mean lung dose, MTHFR genotype (rs1801131; AA versus AC/CC) was significantly associated with risk of grade ≥2 RP (hazard ratio: 0.37; 95% confidence interval: 0.18-0.76; P = .006, corrected P = .018) and grade ≥3 RP (hazard ratio: 0.21; 95% confidence interval: 0.06-0.70; P = .01; corrected P = .03). SOD2 genotype was not associated with RP. CONCLUSIONS: This study showed an association between MTHFR genotype and risk of clinically significant RP. Further study of MTHFR-related pathways may provide insight into the mechanisms behind RP.

Design and analysis issues in gene and environment studies.

Both nurture (environmental) and nature (genetic factors) play an important role in human disease etiology. Traditionally, these effects have been thought of as independent. This perspective is ill informed for non-mendelian complex disorders which result as an interaction between genetics and environment. To understand health and disease we must study how nature and nurture interact. Recent advances in human genomics and high-throughput biotechnology make it possible to study large numbers of genetic markers and gene products simultaneously to explore their interactions with environment. The purpose of this review is to discuss design and analytic issues for gene-environment interaction studies in the "-omics" era, with a focus on environmental and genetic epidemiological studies. We present an expanded environmental genomic disease paradigm. We discuss several study design issues for gene-environmental interaction studies, including confounding and selection bias, measurement of exposures and genotypes. We discuss statistical issues in studying gene-environment interactions in different study designs, such as choices of statistical models, assumptions regarding biological factors, and power and sample size considerations, especially in genome-wide gene-environment studies. Future research directions are also discussed.

[The current situation of children neglect and its influencing factors for rural children aged 0 - 6 years in Chongqing].

OBJECTIVE: To learn the current situation of children neglect and its influencing factors among children aged from 0 - 6 years in rural Chongqing. METHODS: Scales and evaluation methods in the "Chinese rural child neglected evaluation model" were used in this study. The investigation was conducted by using multistage stratified cluster sampling method in December 2010, and 822 rural children aged 0 to 6 years of three districts in Chongqing were randomly select for the survey, with neglect rate and the neglect degree to describe their neglect status, using logistic regression analysis to analyze factors affecting children neglect. RESULTS: The total neglect rate and the neglect degree in the rural children were 35.64% (293/822) and 49.69 ± 6.45, respectively. The neglect degree in boys was higher than that of girls (boys: 50.23 ± 6.40 vs girls: 49.09 ± 6.47, P < 0.05). Further, Our data demonstrated both the neglect rate and the neglect degrees in children whose parents away from home were higher than that of the children whose parents stayed with them (neglect rate: 40.48% (202/499) vs 28.17% (91/323), P < 0.05; neglect degree: 50.64 ± 6.29 vs 48.23 ± 6.44, P < 0.05). Based on multivariate unconditional logistic regression analysis, the determinants of children neglect were: parents were away from home (OR = 1.61, 95%CI: 1.17 - 2.21), single mother and remarried family (OR = 1.39, 95%CI: 1.10 - 1.76), maternal occupation(OR = 0.81, 95%CI: 0.73 - 0.90), estrangement relationship between children and their mothers (OR = 1.42, 95%CI: 1.02 - 1.97). CONCLUSION: The neglect situation of rural children is serious in Chongqing, and the main factors are parents away from home, single mother and remarried family, maternal occupation, and estrangement relationship between children and their mothers.

[The situation of children neglect between left-behind children and living-with-parents children in rural areas of two western provinces of China].

OBJECTIVE: To understand the children neglect situation of left-behind children (children who do not grow up with their parents) and non-left-behind children in China's western rural and its influencing factors. METHODS: Scales and evaluation methods in the "Chinese rural child neglected evaluation model" were used in this study. The investigation was conducted by using multistage stratified cluster sampling method; three countries were sampled randomly in Shanxi and Chongqing in November 2010, respectively. And, in every county, children from rural area aged from zero to six were randomly selected, with neglect rate and degree to describe their neglected status, using logistic regression analysis to analyze factors affecting the neglect rate. RESULTS: Among 1568 subjects (859 left-behind and 709 living-with-parents), the total neglect rates were 29.78% (467/1568), and the total neglect degrees were 48.51 ± 6.49; the neglect rates for left-behind ones and living-with parents ones were 34.34% (295/859) and 24.26% (172/709) (P < 0.05); the neglect degree were 49.59 ± 6.54 and 47.19 ± 6.18 (P < 0.05). The neglect degree among left-behind ones and living-with parents ones between 0 to 2 years old were 48.59 ± 6.33 and 45.78 ± 5.94 (P < 0.05); in 3 to 6 years old group, which were 50.43 ± 6.60 and 48.25 ± 6.16(P < 0.05). The degrees in boy's group of these two kinds of children were 49.83 ± 6.67, 47.36 ± 6.28(P < 0.05) and girl's were 49.32 ± 6.38, 47.01 ± 6.08 (P < 0.05). On the other side, the neglect rate of left-behind and non-left-behind children between 0 to 2 years old were 39.33% (153/389) and 18.54% (56/302) (P < 0.05). The rates of boy's group were 34.91% (162/464) and 25.13% (94/374) (P < 0.05), and girl's were 33.67% (133/395) and 23.28% (78/335) (P < 0.05). Results showed that if the left-behind child's father was with lower education background, and the child and his mother feel stranger to each other, which led to the conclusion there was more chance for them to be neglected (OR values were 1.29 and 1.55, P < 0.05). If the non-neglected child's father was farmer or migrant worker and the relationship between the mother and father was poor, then there was more chance for them to be neglected (OR values were 0.85 and 1.92, P < 0.05). CONCLUSION: The situation of children neglect in the western rural regions in China is serious. Both the neglect rate and degree among left-behind children are higher than those living-with-parents children. The influencing factors of neglect rate are different in the two groups.

Precise delivery of multi-stimulus-responsive nanocarriers based on interchangeable visual guidance.

Cancer treatment is imminent, and controlled drug carriers are an important development direction for future clinical chemotherapy. Visual guidance is a feasible means to achieve precise treatment, reduce toxicity and increase drug efficacy. However, the existing visual control methods are limited by imaging time-consuming, sensitivity and side effects. In addition, the ability of the carrier to respond to environmental stimuli in vivo is another difficulty that limits its application. Here, we propose a highly stimulus-responsive GC liposome with precise tracing and sensitive feedback capabilities. It combines magnetic resonance imaging and fluorescence imaging, and addresses the need for precise visualization by alternating imaging modalities. More importantly, GC liposomes are a carrier that can accumulate stimuli. In this paper, by tracking the fragmentation process of empty GC and drug-loaded D-GC liposomes, we confirm the synergistic effect between multiple stimuli, which can result in a more efficient drug release performance. Finally, in mice models we examined the GC liposome imaging approach and the D-GC + UV group guided by this visualization exhibited the highest tumor inhibition efficiency (6.85-fold). This study highlights the advantages of alternate visualization-guided and co-stimulation treatment strategies, and provides design ideas and potential materials for efficient and less toxic cancer treatments.

Associations between prenatal exposure to perfluoroalkyl substances, hypomethylation of MEST imprinted gene and birth outcomes.

Prenatal perfluoroalkyl substance (PFAS) exposure has been linked to adverse birth outcomes, but the underlying mechanism has yet to be elucidated. DNA methylation changes in mesoderm-specific transcript (MEST) imprinted gene may be a mechanism of the prenatal exposure effects of PFASs on fetal growth. The aim was to investigate the prenatal PFASs exposure effects on DNA methylation changes in MEST imprinted gene involved in fetal growth. Among 486 mother-infant pairs from the Taiwan Birth Panel Study, PFASs and DNA methylation levels at 5 CpG sites of MEST promoter region were measured in cord blood. Univariable and multivariable linear regressions were performed to estimate the associations between prenatal PFAS exposure, MEST DNA methylation levels, and child birth outcomes. Mediation analysis was performed to examine the potential pathway of MEST methylation between PFASs and birth outcomes. We found that higher prenatal perfluorooctyl sulfonate (PFOS) exposure was significantly associated with lower methylation levels at 5 CpG sites of MEST promoter region (an adjusted ß range: -1.56, -2.22). Significant negative associations were also found between MEST methylation levels and child birth weight. Furthermore, the associations between PFOS and perfluorooctanoic acid (PFOA) exposure and MEST methylation levels were more profound in girls than in boys. The mediated effect of average MEST methylation level between PFOS exposure and birth weight was 18.3 (95% CI = 2.1, 40.2; p = 0.014). The direct effect of PFOS exposure to birth weight independent to average MEST methylation level was -93.2 (95% CI = -170.5, -17.8; p = 0.018). In conclusion, our results suggest that prenatal PFAS exposure, especially PFOS, is associated with lower methylation levels at MEST promoter region, which not only leverages the role of imprinted gene in ensuring the integrity of fetal growth but also provides a potential mechanism for evaluating the prenatal exposure effect.

The developmentally timed decay of an essential microRNA family is seed-sequence dependent.

MicroRNA (miRNA) abundance is tightly controlled by regulation of biogenesis and decay. Here, we show that the mir-35 miRNA family undergoes selective decay at the transition from embryonic to larval development in C. elegans. The seed sequence of the miRNA is necessary and largely sufficient for this regulation. Sequences outside the seed (3' end) regulate mir-35 abundance in the embryo but are not necessary for sharp decay at the transition to larval development. Enzymatic modifications of the miRNA 3' end are neither prevalent nor correlated with changes in decay, suggesting that miRNA 3' end display is not a core feature of this mechanism and further supporting a seed-driven decay model. Our findings demonstrate that seed-sequence-specific decay can selectively and coherently regulate all redundant members of a miRNA seed family, a class of mechanism that has great biological and therapeutic potential for dynamic regulation of a miRNA family's target repertoire.

Interaction strengths between the ribosome and tRNA at various steps of translocation.

Transfer RNA (tRNA) translocates inside the ribosome during translation. We studied the interaction strengths between the ribosome and tRNA at various stages of translocation. We utilized an optical trap to measure the mechanical force to rupture tRNA from the ribosome. We measured the rupture forces of aminoacyl tRNA or peptidyl tRNA mimic from the ribosome in a prepeptidyl transfer state, the pretranslocational state, and the posttranslocational state. In addition, we measured the interaction strength between the ribosome and aminoacyl-tRNA in presence of viomycin. Based on the interaction strengths between the ribosome and tRNA under these conditions, 1), we concluded that tRNA interaction with the 30S subunit is far more important than the interaction with the 50S subunit in the mechanism of translocation; and 2), we propose a mechanism of translocation where the ribosomal ratchet motion, with the aid of EF-G, drives tRNA translocation.

Interactions between genetic polymorphisms in the apoptotic pathway and environmental factors on esophageal adenocarcinoma risk.

How genetic variations in apoptosis pathway interact with environmental factors to contribute to esophageal adenocarcinoma (EA) risk has not been comprehensively investigated. We conducted a case-only analysis in 335 Caucasian EA patients that were genotyped for 242 single nucleotide polymorphisms (SNPs) in 43 apoptotic genes. Gene-environment interactions were assessed using a two-step approach. First, random forest algorithm was used to screen for the potential interacting markers. Next, we used case-only logistic regression model to estimate the effects of gene-environment interactions on EA risk. Four SNPs (PERP rs648802; PIK3CA rs4855094, rs7644468 and TNFRSF1A rs4149579) had significant interaction with gastroesophageal reflux disease (GERD). The presence of variant alleles in TP53BP1 rs560191, CASP7 rs7907519 or BCL2 rs12454712 enhanced the risk of smoking by 2.08-2.58 times [interaction odds ratio (ORi)=2.08-2.58, adjusted P-value (Padj)=0.02-0.04]. Compared with patients carrying ≤1 risk genotype, the risk of GERD on EA was increased in persons with two (ORi=1.89, Padj=0.016) or ≥3 (ORi=4.30, Padj<0.0001) risk genotypes. Compared with cases with ≤1 risk genotype, smoking-associated EA risk increased by 3.15 times when ≥2 risk genotypes were present (ORi=3.15, Padj<0.0001). In conclusion, interactions among apoptotic SNPs and GERD or smoking play an important role in EA development.

Genetic associations with sporadic neuroendocrine tumor risk.

Genetic risk factors for sporadic neuroendocrine tumors (NET) are poorly understood. We tested risk associations in patients with sporadic NET and non-cancer controls, using a custom array containing 1536 single-nucleotide polymorphisms (SNPs) in 355 candidate genes. We identified 18 SNPs associated with NET risk at a P-value <0.01 in a discovery set of 261 cases and 319 controls. Two of these SNPs were found to be significantly associated with NET risk in an independent replication set of 235 cases and 113 controls, at a P value ≤0.05. An SNP in interleukin 12A (IL12A rs2243123), a gene implicated in inflammatory response, replicated with an adjusted odds ratio (95% confidence interval) (aOR) = 1.47 (1.03, 2.11) P-trend = 0.04. A second SNP in defender against cell death, (DAD1 rs8005354), a gene that modulates apoptosis, replicated at aOR = 1.43 (1.02, 2.02) P-trend = 0.04. Consistent with our observations, a pathway analysis, performed in the discovery set, suggested that genetic variation in inflammatory pathways or apoptosis pathways is associated with NET risk. Our findings support further investigation of the potential role of IL12A and DAD1 in the etiology of NET.