The Genome Health Clinic and Genome Health Nutrigenomics concepts: diagnosis and nutritional treatment of genome and epigenome damage on an individual basis

Specific Genotypes Associated with Differences in Fasting Insulin Levels and Body Mass Index in Healthy Young Males: Implications for Gene-Nutrient Interactions-an Exploratory Study

Background

Genetic variation may significantly impact an individual's susceptibility to diseases, particularly when combined with specific nutrients. Additionally, genetic variations can lead to interindividual differences in metabolic responses.

Objective

The present study explores the association between gene variants and observed interindividual differences in metabolic responses.

Methods

The study included 30 healthy males (aged 20-34) who underwent a fasting period and subsequently consumed a standardized meal. Blood samples were collected both before and after the meal to assess metabolic changes. BMI served as an indirect measure for assessing physiological responses associated with body composition. Appetite changes were assessed using an online Visual Analog 100-point Scale. Buccal swabs were collected to analyze genetic variants in single nucleotide polymorphisms (SNPs).

Results

The data underwent multiple regression analysis, revealing significant associations with 3 SNPs and their metabolic status: the insulin-receptor substrate 1 (IRS1) gene variant rs2943641, genotypes CT and CC, with elevated fasting insulin levels (R2 = 0.639, P = < 0.0001); the mitochondrial uncoupling protein 1 (UCP1) gene variant rs1800592, genotypes GG and GA, with increased BMI (R2 = 0.261, P = 0.007); and the peroxisome proliferator-activated receptor γ2 (PPARγ2) gene variant rs1801282, genotypes GG and GC, with increased BMI (R2 = 0.200, P = 0.024).

Conclusions

Therefore, our study established significant associations between these 3 SNPs and differences in fasting insulin levels and BMI within our cohort.

Metabolomic and Lipidomic Characterization of Meningioma Grades Using LC-HRMS and Machine Learning

Meningiomas are among the most common brain tumors that arise from the leptomeningeal cover of the brain and spinal cord and account for around 37% of all central nervous system tumors. According to the World Health Organization, meningiomas are classified into three histological subtypes: benign, atypical, and anaplastic. Sometimes, meningiomas with a histological diagnosis of benign tumors show clinical characteristics and behavior of aggressive tumors. In this study, we examined the metabolomic and lipidomic profiles of meningioma tumors, focusing on comparing low-grade and high-grade tumors and identifying potential markers that can discriminate between benign and malignant tumors. High-resolution mass spectrometry coupled to liquid chromatography was used for untargeted metabolomics and lipidomics analyses of 85 tumor biopsy samples with different meningioma grades. We then applied feature selection and machine learning techniques to find the features with the highest information to aid in the diagnosis of meningioma grades. Three biomarkers were identified to differentiate low- and high-grade meningioma brain tumors. The use of mass-spectrometry-based metabolomics and lipidomics combined with machine learning analyses to prospect and characterize biomarkers associated with meningioma grades may pave the way for elucidating potential therapeutic and prognostic targets.

Drug-food Interactions in the Era of Molecular Big Data, Machine Intelligence, and Personalized Health

The drug-food interaction brings forth changes in the clinical effects of drugs. While favourable interactions bring positive clinical outcomes, unfavourable interactions may lead to toxicity. This article reviews the impact of food intake on drug-food interactions, the clinical effects of drugs, and the effect of drug-food in correlation with diet and precision medicine. Emerging areas in drug-food interactions are the food-genome interface (nutrigenomics) and nutrigenetics. Understanding the molecular basis of food ingredients, including genomic sequencing and pharmacological implications of food molecules, helps to reduce the impact of drug-food interactions. Various strategies are being leveraged to alleviate drug-food interactions; measures including patient engagement, digital health, approaches involving machine intelligence, and big data are a few of them. Furthermore, delineating the molecular communications across dietmicrobiome- drug-food-drug interactions in a pharmacomicrobiome framework may also play a vital role in personalized nutrition. Determining nutrient-gene interactions aids in making nutrition deeply personalized and helps mitigate unwanted drug-food interactions, chronic diseases, and adverse events from their onset. Translational bioinformatics approaches could play an essential role in the next generation of drug-food interaction research. In this landscape review, we discuss important tools, databases, and approaches along with key challenges and opportunities in drug-food interaction and its immediate impact on precision medicine.

LncRNA OGFRP1 acts as an oncogene in NSCLC via miR-4640-5p/eIF5A axis

BACKGROUND

Long noncoding RNAs (lncRNAs) OGFRP1 is up-regulated in endometrial cancer and cervical carcinoma, and OGFRP1 suppression inhibits the malignant behavior of cancer cells. Here, we evaluated the expression pattern, biological function and potential mechanism of OGFRP1 in non-small cell lung cancer (NSCLC).

METHODS

The expression of target genes in 25 pairs of clinically collected NSCLC and normal lung tissue samples was detected by qRT-PCR or western blot. We screened the siRNA (siOGFRP1) to down-regulate the expression of OGFRP1 in A549 and H1299 cells. The biological function of A549 and H1299 cells were examined by CCK8, wound healing and transwell assays. The molecular mechanism of OGFRP1 was further explored.

RESULTS

The expression of OGFRP1 in NSCLC tissues were higher than that in normal lung tissue. siOGFRP1 inhibited the proliferation, migration and invasion of A549 and H1299 cells. In addition, the expression of EMT-related and apoptosis-related proteins was changed by siOGFRP1 transfection. OGFRP1 can directly interact with miR-4640-5p, and siOGFRP1 increased the level of miR-4640-5p. Moreover, miR-4640-5p could directly bind to the 3' UTR region of eIF5A mRNA. eIF5A was highly expressed in NSCLC tissues, and predicted a poor prognosis. In addition, the expression of miR-4640-5p and eIF5A in NSCLC tissues were negatively correlated, while the expression of OGFRP1 and eIF5A were positively correlated. Knockdown of OGFRP1 inhibited the expression of eIF5A, while transfection of miR-4640-5p inhibitor up-regulated the expression of eIF5A.

CONCLUSIONS

Taken together, we demonstrated that down-regulation of OGFRP1 inhibited the progression of NSCLC through miR-4640-5p/eIF5A axis.

Dietary Pattern, Genomic Stability and Relative Cancer Risk in Asian Food Landscape

The incidence of cancer globally is increasing, partly due to lifestyle factors. Despite a better understanding of cancer biology and advancement in cancer management and therapies, current strategies in cancer treatment remain costly and cause socioeconomic burden especially in Asian countries. Hence, instead of putting more efforts in searches for new cancer cures, attention has now shifted to understanding how to mitigate cancer risk by modulating lifestyle factors. It has been established that carcinogenesis is multifactorial, and the important detrimental role of oxidative stress, chronic inflammation, and genomic instability is evident. To date, there is no study linking dietary pattern and genomic stability in cancer risk in the Asian food landscape. Thus, this present review article discusses recent literature on dietary pattern and genomic stability and its relationship with cancer risk in Asia.

Roadmap for translating results from the micronucleus assay into clinical practice: From observational studies to randomized controlled trials

According to the definition delivred by the WHO, a biomarker, independently from its role that may be indicative of exposure, response or effect, is inevitably linked to a clinical outcome or to a disease. The presence of a continuum from early biological events to therapy, and prognosis is the unifying mechanism that justifies this conclusion. Traditionally, the technical and inter-individual variability of the assays, together with the long duration between early pathogenetic events and the disease, prevented clinical applications to these biomarkers. These limitations became less important with the emerging of personalized preventive medicine because of the focus on disease prediction and prevention, and the recommended use of all data concerning measurable patient's features. Several papers have been published on the best validation procedures for translating biomarkers to real life. The history of cholesterol concentration is extensively discussed as a reliable example of a biomarker that - after a long and controversial validation process - is currently used in clinical practice. The frequency of micronucleated cells is a reliable biomarker for the pathogenesis of cancer and other non-communicable diseases, and the link with clinical outcomes is substantiated by epidemiological evidence and strong mechanistic basis. Available literature concerning the use of the micronucleus assay in clinical studies is discussed, and a suitable three-levels road-map driving this biomarker towards clinical practice is presented. Under the perspective of personalized medicine, the use of the micronucleus assays can play a decisive role in addressing preventive and therapeutic strategies of chronic diseases. In many cases the MN assay is either currently used in clinical practice or classified as adequate to consider translation into practice. The roadmap to clinical validation of the micronucleus assay finds inspiration from the history of biomarkers such as cholesterol, which clearly showed that the evidence from prospective studies or RCTs is critical to achieve the required level of trust from the healthcare profession. (307 words).

Diet as a Potential Moderator for Genome Stability and Immune Response in Pediatric Leukemia

Simple Summary

Pediatric acute lymphoblastic leukemia (ALL) is the most prevalent cancer affecting children in developed societies. Here, we review the role of diet in control of the incidence and progression of childhood ALL. Prenatally, ALL risk is associated with higher birthweights of newborns, suggesting that ALL begins to evolve in-utero. Indeed, maternal diet influences the fetal genome and immune development. Postnatally, breastfeeding associates with decreased risk of ALL development. Finally, for the ALL-affected child, certain dietary regimens that impact the hormonal environment may impede disease progression. Improved understanding of the dietary regulation of hormones and immunity may inform better approaches to predict, protect, and ultimately save children afflicted with pediatric leukemia.

Abstract

Pediatric leukemias are the most prevalent cancers affecting children in developed societies, with childhood acute lymphoblastic leukemia (ALL) being the most common subtype. As diet is a likely modulator of many diseases, this review focuses on the potential for diet to influence the incidence and progression of childhood ALL. In particular, the potential effect of diets on genome stability and immunity during the prenatal and postnatal stages of early childhood development are discussed. Maternal diet plays an integral role in shaping the bodily composition of the newborn, and thus may influence fetal genome stability and immune system development. Indeed, higher birth weights of newborns are associated with increased risk of ALL, which suggests in-utero biology may shape the evolution of preleukemic clones. Postnatally, the ingestion of maternal breastmilk both nourishes the infant, and provides essential components that strengthen and educate the developing immune system. Consistently, breast-feeding associates with decreased risk of ALL development. For children already suffering from ALL, certain dietary regimens have been proposed. These regimens, which have been validated in both animals and humans, alter the internal hormonal environment. Thus, hormonal regulation by diet may shape childhood metabolism and immunity in a manner that is detrimental to the evolution or expansion of preleukemic and leukemic ALL clones.

Correlation between genetic variation in thymine DNA glycosylase and smoking behavior

Cigarette smoking is a major lifestyle factor leading to different human diseases. The DNA repair gene, thymine DNA glycosylase, is important to cell survival because it stops cells from becoming cancerous protecting/preventing DNA. Exposure to CS may induce genetic changes such as single nucleotide polymorphisms in DNA repair genes. Therefore, the purpose of this study was to investigate the genotype and allele distributions of four TDG SNPs with only smoking behavior in normal patients. Four TDG SNPs-rs4135066 (C/T), rs3751209 (A/G), rs1866074 (C/T), and rs1882018 (C/T) were analyzed by genotyping 235 and 239 blood samples collected from cigarette smokers and non-smokers, among the Saudi population. The results showed that TDG rs4135066 has a significant susceptibility effect observed in long-term smokers (>5 years; OR = 4.53; P = 0.0347) but not in short-term smokers (≤5 years) in contrast with non-smokers. Also, in smokers aged less than 29 years, the "CT," "TT," and "CT + TT" alleles of rs1882018 increased the risk of developing all diseases related to smoking by approximately 6, 4, and 5 times, respectively, in contrast with the ancestral "CC" homozygous allele. A comparison of the allele distributions of TDG SNPs in a Saudi population with those in other populations represented in the HapMap project showed that the genetic makeup of the Saudi Arabian population appears to differ from that of other ethnicities. Exceptions include the Yoruba people in Ibadan, Nigeria; those of Mexican ancestry in Los Angeles, California; the Luhya population in Webuye, Kenya; Gujarati Indians in Houston, Texas; and the Tuscan population in Italy, which showed similar allelic frequencies for rs3751209 compared to our Saudi population. In this ethnic, we have found a high variation in the distribution of the alleles and genotype frequencies on TDG gene. This variation on TDG SNP's with smoking could lead to increase the susceptibility to many diseases related to smoking habits in this population.

The multifaceted role of vitamin B6 in cancer: Drosophila as a model system to investigate DNA damage

A perturbed uptake of micronutrients, such as minerals and vitamins, impacts on different human diseases, including cancer and neurological disorders. Several data converge towards a crucial role played by many micronutrients in genome integrity maintenance and in the establishment of a correct DNA methylation pattern. Failure in the proper accomplishment of these processes accelerates senescence and increases the risk of developing cancer, by promoting the formation of chromosome aberrations and deregulating the expression of oncogenes. Here, the main recent evidence regarding the impact of some B vitamins on DNA damage and cancer is summarized, providing an integrated and updated analysis, mainly centred on vitamin B₆. In many cases, it is difficult to finely predict the optimal vitamin rate that is able to protect against DNA damage, as this can be influenced by a given individual's genotype. For this purpose, a precious resort is represented by model organisms which allow limitations imposed by more complex systems to be overcome. In this review, we show that Drosophila can be a useful model to deeply understand mechanisms underlying the relationship between vitamin B₆ and genome integrity.

Oxidative Stress and Genomic Damage Induced In Vitro in Human Peripheral Blood by Two Preventive Treatments of Iron Deficiency Anemia

Iron deficiency is the most prevalent nutritional deficiency and the main cause of anemia worldwide. Since children aged 6-24 months are among the most vulnerable groups at risk, daily supplementation with ferrous sulfate is recommended by the Argentine Society of Pediatrics as preventive treatment of anemia. However, a single weekly dose would have fewer adverse side effects and has been therefore proposed as an alternative treatment. Ferrous sulfate is known by its pro-oxidative properties, which may lead to increased oxidative stress as well as lipid, protein, and DNA damage. We analyzed the effect of daily and weekly preventive treatment of iron deficiency anemia (IDA) on cell viability, oxidative stress, chromosome, and cytomolecular damage in peripheral blood cultured in vitro. The study protocol included the following: untreated negative control; bleomycin, hydrogen peroxide, or ethanol-treated positive control; daily 0.14 mg ferrous sulfate-supplemented group; and weekly 0.55 mg ferrous sulfate-supplemented group. We assessed cell viability (methyl-thiazolyl-tetrazolium and neutral red assays), lipid peroxidation (thiobarbituric acid reactive substances assay), antioxidant response (superoxide dismutase and catalase enzyme analysis), chromosome damage (cytokinesis-blocked micronucleus cytome assay), and cytomolecular damage (comet assay). Lipid peroxidation, antioxidant response, and chromosome and cytomolecular damage decreased after weekly ferrous sulfate supplementation (p < 0.05), suggesting less oxygen free radical production and decreased oxidative stress and genomic damage. Such a decrease in oxidative stress and genomic damage in vitro positions weekly supplementation as a better alternative for IDA treatment. Further studies in vivo would be necessary to corroborate whether weekly supplementation could improve IDA preventive treatment compliance in children.

Content of selected inorganic compounds in the eggs of hens kept in two different systems: organic and battery cage

Recent years have seen increased interest in the influence of bioactive dietary components on human genes and gene expression. A good source of many bioactive substances is the chicken egg. The egg is considered to be an excellent food provided by nature. It is a good source of nutrients such as vitamins A, B2, B6, B12, D, E and K, as well as elements including phosphorus, selenium, iron, zinc, magnesium and calcium. The research material use in this study consisted of eggs from hens kept in two different systems: organic and battery cages. The content of calcium (Ca), magnesium (Mg) and zinc (Zn) was determined in the egg contents - in the yolk and white respectively. The content of elements was determined by atomic absorption spectrometry (AAS) using an AA280 FS spectrometer with the automatic dilution of standards and samples. The eggs from the organically raised hens had a higher calcium, magnesium and zinc content. The greater variation in the Ca, Mg and Zn content in the organic eggs is due to the more individualized feeding system. The rearing system of the hens significantly affects the concentration of elements in the egg. The results of this research indicate that eggs from organic farming systems have a richer chemical composition in terms of the content of nutrients such as calcium, magnesium and zinc compared with eggs obtained from caged hens. Therefore, consumers purchasing eggs should consider the system in which the hens were reared, as eggs can be a valuable source of these elements in the diet.

The Role of the Status of Selected Micronutrients in Shaping the Immune Function

OBJECTIVE

This narrative review gives an overview on the essential role of adequate nutrition to an optimally functioning immune defence. Micronutrients act as regulators of the immune response, with the focus of this review on the immunomodulatory effects of the trace elements iron, zinc and selenium, and the vitamins A, D, E, C, B6 and B12 and folic acid.

RESULTS

Iron deficiency especially impairs the Th1 cell-borne cellular immunity. T lymphocytes are also most affected by a deficiency of zinc, needed for their maturation and the balance between the different T cell subpopulations and acting as a redox signal in the regulation of many enzymes. Selenium is also involved in redox reactions as the glutathione peroxidases and other redox enzymes are selenoproteins. Selenium status has shown special effects on cellular immunity and resistance to viral infections. Vitamin A in the form of retinoic acid induces a humoral Th2 cell response via antigen-presenting cells and is involved in maintaining intestinal immune defence and tolerance through its nuclear receptor RAR and via kinase signalling cascades. Immune tolerance is particularly promoted by vitamin D acting through dendritic cells to stimulate the differentiation of regulatory T cells. Vitamin E has antiinflammatory effects and stimulates naïve T cells especially in the elderly. Besides its antioxidative properties, vitamin C has effects on cell signalling and epigenetic regulation. The B vitamins are required for cytotoxic cellular immunity and modulate T cell responses.

CONCLUSION

A diverse diet and regular exposure to sunlight are the best sources for a balanced nutrient supply to maintain an optimal immune defence.

Mutagenic effects of spent potliner and derivatives on Allium cepa L. and Lactuca sativa L.: A molecular approach

Spent potliner (SPL) is a solid residue generated by the aluminum industry. Its composition is variable and complex, containing fluoride and cyanide salts as well as aluminum, which contributes to its toxicity. SPL is sometimes released directly into the soil, where it is prone to leaching and has the potential to cause alterations and damage to DNA. Considering that polymorphism analysis of simple sequence repeat (SSR) and inter-simple sequence repeat (ISSR) DNA markers is an interesting tool to determine the mutagenicity of an environmental pollutant, the present study adopted this approach to verify the mutagenic potential of SPL and its main toxic components (aluminum, fluoride, and cyanide) on root tip cells of Lactuca sativa and Allium cepa. Alterations in ISSR and SSR regions were identified by DNA fingerprinting (gain and loss of bands and changes in band intensity). The estimated dissimilarities indicated differences between treatments and the negative control. Furthermore, the relationship between the amplification profile of the markers and alterations in cell mitosis was discussed.

Impact of obesity and overweight on DNA stability: Few facts and many hypotheses

Health authorities are alarmed worldwide about the increase of obesity and overweight in the last decades which lead to adverse health effects including inflammation, cancer, accelerated aging and infertility. We evaluated the state of knowledge concerning the impact of elevated body mass on genomic instability. Results of investigations with humans (39 studies) in which DNA damage was monitored in lymphocytes and sperm cells, are conflicting and probably as a consequence of heterogeneous study designs and confounding factors (e.g. uncontrolled intake of vitamins and minerals and consumption of different food types). Results of animal studies with defined diets (23 studies) are more consistent and show that excess body fat causes DNA damage in multiple organs including brain, liver, colon and testes. Different molecular mechanisms may cause genetic instability in overweight/obese individuals. ROS formation and lipid peroxidation were found in several investigations and may be caused by increased insulin, fatty acid and glucose levels or indirectly via inflammation. Also reduced DNA repair and formation of advanced glycation end products may play a role but more data are required to draw firm conclusions. Reduction of telomere lengths and hormonal imbalances are characteristic for overweight/obesity but the former effects are delayed and moderate and hormonal effects were not investigated in regard to genomic instability in obese individuals. Increased BMI values affect also the activities of drug metabolizing enzymes which activate/detoxify genotoxic carcinogens, but no studies concerning the impact of these alterations of DNA damage in obese individuals are available. Overall, the knowledge concerning the impact of increased body weight and DNA damage is poor and further research is warranted to shed light on this important issue.

Proximate Composition and Heavy Metal Analysis of Three Aquatic Foods in Makoko River, Lagos, Nigeria

Three aquatic products, tilapia fish, lobster and crab, were collected from the landing site of fishermen in Makoko, a fishing suburb in Lagos State, Nigeria. They were analyzed for their proximate composition, and concentration of heavy metals (Cr, Cd, and Pb) was also measured in them. The nutrient values varied among the three organisms. The lobsters and crabs had higher protein values while tilapia was richer in lipid and moisture content. In most cases, these differences were not significant. The concentration of heavy metals also differed in the three organisms. All organisms had high concentrations of the three heavy metals analyzed. The heavy metal load as observed in this study is consistent with some previously reported values in literature. Plausible reasons for these differences were discussed in light of size, trophic level, choice of food of the organisms, and anthropogenic activities. It may be advisable that heavy metal concentrations are regularly monitored in edible aquatic food products so that human health is not at risk.

KLF15 Inhibits Cell Proliferation in Gastric Cancer Cells via Up-Regulating CDKN1A/p21 and CDKN1C/p57 Expression

BACKGROUND

Krüppel-like factors (KLFs) have been identified in multi-cancers and act as oncogenes or tumor suppressors. The function of KLF15, one member of KLFs, has not been well elucidated, especially in gastric cancer (GC).

AIMS

This study was designed to investigate the prognostic value and biological functions of KLF15 in GC.

METHODS

KLF15 protein expression in GC patients was evaluated by immunohistochemistry assays in 50 paired GC tissues and adjacent normal tissues, and correlations between KLF15 expression and clinicopathological characteristics and prognosis were analyzed. Then, we investigated the over-expression of KLF15 on cell proliferation and its mechanism in GC cells.

RESULTS

KLF15 expression levels were significantly down-regulated in GC tissues compared to adjacent normal tissues. And KLF15 expression was negatively correlated with clinical stage, lymphatic metastasis, and distant metastasis. Furthermore, KLF15 expression could predict prognosis in patients with GC. Moreover, over-expression of KLF15 could inhibit cell proliferation partly via regulating CDKN1A/p21 and CDKN1C/p57.

CONCLUSION

These findings demonstrate that KLF15 plays a significant role in GC progression and could be a therapeutic target for GC.

Genomic instability related to zinc deficiency and excess in an in vitro model: is the upper estimate of the physiological requirements recommended for children safe?

Micronutrients are important for the prevention of degenerative diseases due to their role in maintaining genomic stability. Therefore, there is international concern about the need to redefine the optimal mineral and vitamin requirements to prevent DNA damage. We analyzed the cytostatic, cytotoxic, and genotoxic effect of in vitro zinc supplementation to determine the effects of zinc deficiency and excess and whether the upper estimate of the physiological requirement recommended for children is safe. To achieve zinc deficiency, DMEM/Ham's F12 medium (HF12) was chelated (HF12Q). Lymphocytes were isolated from healthy female donors (age range, 5-10 yr) and cultured for 7 d as follows: negative control (HF12, 60 μg/dl ZnSO₄); deficient (HF12Q, 12 μg/dl ZnSO₄); lower level (HF12Q + 80 μg/dl ZnSO₄); average level (HF12Q + 180 μg/dl ZnSO₄); upper limit (HF12Q + 280 μg/dl ZnSO₄); and excess (HF12Q + 380 μg/dl ZnSO₄). The comet (quantitative analysis) and cytokinesis-block micronucleus cytome assays were used. Differences were evaluated with Kruskal-Wallis and ANOVA (p < 0.05). Olive tail moment, tail length, micronuclei frequency, and apoptotic and necrotic percentages were significantly higher in the deficient, upper limit, and excess cultures compared with the negative control, lower, and average limit ones. In vitro zinc supplementation at the lower and average limit (80 and 180 μg/dl ZnSO₄) of the physiological requirement recommended for children proved to be the most beneficial in avoiding genomic instability, whereas the deficient, upper limit, and excess (12, 280, and 380 μg/dl) cultures increased DNA and chromosomal damage and apoptotic and necrotic frequencies.

Role of Macronutrients and Micronutrients in DNA Damage: Results From a Food Frequency Questionnaire

The links between diet and genomic instability have been under investigation for several decades, and evidence suggests a significant causal or preventive role for various dietary factors. This study investigates the influence of macronutrients (calories, protein, and glucides) and micronutrients, such as vitamins and minerals, as assessed by a food frequency questionnaire, on genotoxicity biomarkers measured by cytokinesis-blocked micronucleus assay and comet assay. The results found significant positive and negative correlations. Micronucleus frequency tends to increase with higher intake of caffeine, calcium, magnesium, zinc, and protein (P < .05, Spearman correlation). Calorie and omega-6 intakes are negatively correlated with DNA damage measured by the comet assay. These results are somewhat controversial because some of the correlations found are contrary to dominant views in the literature; however, we suggest that unraveling the association between diet and genetic instability requires a much better understanding of the modulating role of macronutrients and micronutrients.

Upregulated long non-coding RNA AGAP2-AS1 represses LATS2 and KLF2 expression through interacting with EZH2 and LSD1 in non-small-cell lung cancer cells

Recently, long non-coding RNAs (lncRNAs) are identified as new crucial regulators of diverse cellular processes, including cell proliferation, differentiation and cancer cells metastasis. Accumulating evidence has revealed that aberrant lncRNA expression plays important roles in carcinogenesis and tumor progression. However, the expression pattern and biological function of lncRNAs in non-small-cell lung cancer (NSCLC) remain largely unknown. In this study, we performed comprehensive analysis of lncRNA expression in human NSCLC samples by using microarray data from Gene Expression Omnibus. After validation in a cohort of 80 pairs of NSCLC tissues, we identified a differentially expressed novel oncogenic lncRNA termed as AGAP2-AS1. The AGAP2-AS1 expression level was significantly upregulated in NSCLC tissues and negatively correlated with poor prognostic outcomes in patients. In vitro loss- and gain-of-function assays revealed that AGAP2-AS1 knockdown inhibited cell proliferation, migration and invasion, and induced cell apoptosis. In vivo assays also confirmed the ability of AGAP2-AS1 to promote tumor growth. Furthermore, mechanistic investigation showed that AGAP2-AS1 could bind with enhancer of zeste homolog 2 and lysine (K)-specific demethylase 1A, and recruit them to KLF2 and LATS2 promoter regions to repress their transcription. Taken together, our findings indicate that AGAP2-AS1 may act as an oncogene by repressing tumor-suppressor LATS2 and KLF2 transcription. By clarifying the AGAP2-AS1 mechanisms underlying NSCLC development and progression, these findings might promote the development of novel therapeutic strategies for this disease.

Discovery of nutritional biomarkers: future directions based on omics technologies

Understanding the interactions between food and human biology is of utmost importance to facilitate the development of more efficient nutritional interventions that might improve our wellness status and future health outcomes by reducing risk factors for non-transmittable chronic diseases, such as cardiovascular diseases, cancer, obesity and metabolic syndrome. Dissection of the molecular mechanisms that mediate the physiological effects of diets and bioactive compounds is one of the main goals of current nutritional investigation and the food industry as might lead to the discovery of novel biomarkers. It is widely recognized that the availability of robust nutritional biomarkers represents a bottleneck that delays the innovation process of the food industry. In this regard, omics sciences have opened up new avenues of research and opportunities in nutrition. Advances in mass spectrometry, nuclear magnetic resonance, next generation sequencing and microarray technologies allow massive genome, gene expression, proteomic and metabolomic profiling, obtaining a global and in-depth analysis of physiological/pathological scenarios. For this reason, omics platforms are most suitable for the discovery and characterization of novel nutritional markers that will define the nutritional status of both individuals and populations in the near future, and to identify the nutritional bioactive compounds responsible for the health outcomes.

Genotoxicity and cytotoxicity of chromium, copper, manganese and lead, and their mixture in WIL2-NS human B lymphoblastoid cells is enhanced by folate depletion

Heavy metal exposure or dietary deficiency is associated with increased genetic damage, cancer and age-related diseases. Folate (vitamin B9) required for DNA repair and synthesis may increase cellular susceptibility to metal induced genotoxicity. This study investigated the interactive effects of folic acid deficiency and sufficiency on genome instability and cytotoxicity induced by chromium (VI), copper (II), manganese (II), lead (IV), and their mixture (CCMP) in WIL2-NS human B lymphoblastoid cells. WIL2-NS cells were cultured in folic acid deficient (20 nM) and replete (2000 nM) RPMI 1640 medium treated with different concentrations (0.00-1000 μM) of the metals and CCMP for 48 h. Chromosomal damage and cytotoxicity were measured using the Cytokinesis-block Micronucleus Cytome assay. CCMP, Cr, Pb, Cu and Mn induced concentration dependent, increases in cells with chromosome damage (micronuclei, nucleoplasmic bridges, nuclear buds) and necrotic cells and decreased nuclear division index. The metals exhibited different cytotoxic and genotoxic potentials (CCMP>Cr>Pb>Cu>Mn) in both folate deficient and sufficient cells, with the cytogenotoxic effects being greater in folate deficient cells. Significant interaction between the metals and folic acid suggests that folic acid deficiency exacerbated cell proliferation inhibition and genome instability induced by metals. Folate deficiency, increasing metal concentration, and their interactions explained 3-11%, 74-92% and 4-12% of the variance of DNA damage biomarkers. In conclusion, exposure to the tested metals (0.01-1000 μM) increased chromosomal DNA damage in WIL2-NS cells and this was exacerbated by folate deficiency.

Downregulation of Kruppel-like factor 2 is associated with poor prognosis for nonsmall-cell lung cancer

Kruppel-like factor 2 (KLF2) expression is diminished in many malignancies. However, its expression and role in nonsmall-cell lung cancer (NSCLC) remain unknown. In this study, we found that KLF2 levels were decreased in NSCLC tissues compared with adjacent normal tissues. Its expression level was significantly correlated with TNM stages, tumor size, and lymph node metastasis. Moreover, patients with low levels of KLF2 expression had a relatively poor prognosis. Furthermore, knockdown of KLF2 expression by siRNA could promote cell proliferation, while ectopic expression of KLF2 inhibited cell proliferation and promoted apoptosis in NSCLC cells partly via regulating CDKN1A/p21 and CDKN2B/p15 protein expression. Our findings present that decreased KLF2 could be identified as a poor prognostic biomarker in NSCLC and regulate cell proliferation and apoptosis.

Developing suitable methods of nutritional status assessment: a continuous challenge

Reliable information about the nutritional status is essential to identify potential critical nutrients and the population groups at risk of deficiency, as well as to develop effective public health policies to counteract unfavorable nutrition patterns that contribute to morbidity and mortality. In this review, the important role of biomarkers in the assessment of nutritional status is outlined, major strengths and limitations of established and new biomarkers are described, and important criteria for biomarker selection and development are discussed. Indeed, biomarkers offer a more objective assessment tool than pure dietary approaches that suffer from inadequate data reporting in particular, although biomarkers are often only measured in subsamples because of the higher costs and proband burden they entail. However, biomarkers are subject to individual variability and influences from other factors besides the nutrient of interest. Rapid turnover or tight control of nutrient concentrations in blood (homeostasis) limits their sensitivity as biomarkers, as in the case of many trace elements. The existence of different forms of a micronutrient in the body adds additional complexity. Functional biomarkers, such as enzyme activities, mirror long-term status better but are subject to confounding factors, and some are influenced by several micronutrients, not specific for only 1, so using a combination of biomarkers is advisable. Additionally, the applicability of a biomarker also depends on the existence of adequate reference values and cutoff points for the target population. Therefore, a careful selection is warranted, especially when biomarkers are to be used in larger samples.

Mitigating the risk of radiation-induced cancers: limitations and paradigms in drug development

The United States radiation medical countermeasures (MCM) programme for radiological and nuclear incidents has been focusing on developing mitigators for the acute radiation syndrome (ARS) and delayed effects of acute radiation exposure (DEARE), and biodosimetry technologies to provide radiation dose assessments for guiding treatment. Because a nuclear accident or terrorist incident could potentially expose a large number of people to low to moderate doses of ionising radiation, and thus increase their excess lifetime cancer risk, there is an interest in developing mitigators for this purpose. This article discusses the current status, issues, and challenges regarding development of mitigators against radiation-induced cancers. The challenges of developing mitigators for ARS include: the long latency between exposure and cancer manifestation, limitations of animal models, potential side effects of the mitigator itself, potential need for long-term use, the complexity of human trials to demonstrate effectiveness, and statistical power constraints for measuring health risks (and reduction of health risks after mitigation) following relatively low radiation doses (<0.75 Gy). Nevertheless, progress in the understanding of the molecular mechanisms resulting in radiation injury, along with parallel progress in dose assessment technologies, make this an opportune, if not critical, time to invest in research strategies that result in the development of agents to lower the risk of radiation-induced cancers for populations that survive a significant radiation exposure incident.

Phenolic acid composition, antioxidant activity and phenolic content of tarhana supplemented with oat flour

In this study, oat flour (OF) was used to replace wheat flour in tarhana formulation at the levels of 10, 20, 30 and 40% (w/w). Control sample did not contain OF. The results showed that addition of OF caused increases in levels of phenolic acids within tarhana samples. The most abundant phenolic acids were vanillic and ferulic acids, and they were followed by gallic acid. Tarhana samples with OF also showed higher antioxidant activities than control sample did. Compared with the control sample, the total phenolic content level increased with the increase in the amount of OF. The results of sensory analysis showed that OF addition neither caused any undesirable taste nor an odor and panelists emphasised a sweet taste as the OF amounts were increased. Therefore, tarhana supplemented with OF can be claimed to be a good source of minerals, phenolics and antioxidants as compared to tarhana without OF.

Vitamin C intake reduces the cytotoxicity associated with hyperglycemia in prediabetes and type 2 diabetes

Hyperglycemia leads to the formation of free radicals and advanced glycation end-products (AGEs). Antioxidants can reduce the level of protein glycation and DNA damage. In this study, we compared the levels of vitamin C intake, which is among the most abundant antioxidants obtained from diet, with the levels of fasting plasma glucose (FPG), glycated hemoglobin (A1C), DNA damage, and cytotoxicity in prediabetic subjects and type 2 diabetic subjects. Our results indicated that there was no significant correlation between FPG or A1C and DNA damage parameters (micronuclei, nucleoplasmic bridges, and nuclear buds). FPG and A1C correlated with necrosis (r = 0.294; P = 0.013 and r = 0.401; P = 0.001, resp.). Vitamin C intake correlated negatively with necrosis and apoptosis (r = −0.246; P = 0.040, and r = −0.276; P = 0.021, resp.). The lack of a correlation between the FPG and A1C and DNA damage could be explained, at least in part, by the elimination of cells with DNA damage by either necrosis or apoptosis (cytotoxicity). Vitamin C appeared to improve cell survival by reducing cytotoxicity. Therefore, the present results indicate the need for clinical studies to evaluate the effect of low-dose vitamin C supplementation in type 2 diabetes.

A cytogenetic approach to the effects of low levels of ionizing radiation (IR) on the exposed Tunisian hospital workers

OBJECTIVES

The aim of this study is to assess chromosomal damage in Tunisian hospital workers occupationally exposed to low levels of ionizing radiation (IR).

MATERIALS AND METHODS

The cytokinesis-block micronucleus (CBMN) assay in the peripheral lymphocytes of 67 exposed workers compared to 43 controls matched for gender, age and smoking habits was used. The clastogenic/aneugenic effect of IR was evaluated using the CBMN assay in combination with fluorescence in situ hybridization with human pan-centromeric DNA in all the exposed subjects and controls.

RESULTS

The study showed a significant increase of the micronucleus (MN) frequency in the lymphocytes of the exposed workers compared to the control group (13.63 ± 4.9‰ vs. 6.52 ± 4.21‰, p < 0.05). The centromere analysis performed in our study showed that MNs in hospital staff were predominantly centromere negative (72%) and the mean negative labeled micronucleus (C-MN) frequency was significantly higher in the exposed subjects than in the controls (9.04 ± 4.57‰ vs. 1.17 ± 0.77‰). The multivariate regression analysis, taking into account all confounding factors, showed that only the time of exposure to IR had a significant effect on the level of MNs and C-MN.

CONCLUSION

The present study shows that chromosomal damage leading to the formation of micronucleated lymphocytes is more frequent in the hospital workers exposed to IR than in the controls, despite the low levels of exposure. The results of the study confirm the well-known clastogenic properties of ionizing radiation. In regards to health monitoring, detection of early genotoxic effects may allow for the adoption of preventive biological control measures, such as hygienic improvements in the workplace or reduction of hours of occupational exposure.

The influence of genetic polymorphisms in XRCC3 and ADH5 genes on the frequency of genotoxicity biomarkers in workers exposed to formaldehyde

The International Agency for Research on Cancer classified formaldehyde as carcinogenic to humans because there is "sufficient epidemiological evidence that it causes nasopharyngeal cancer in humans". Genes involved in DNA repair and maintenance of genome integrity are critically involved in protecting against mutations that lead to cancer and/or inherited genetic disease. Association studies have recently provided evidence for a link between DNA repair polymorphisms and micronucleus (MN) induction. We used the cytokinesis-block micronucleus (CBMN assay) in peripheral lymphocytes and MN test in buccal cells to investigate the effects of XRCC3 Thr241Met, ADH5 Val309Ile, and Asp353Glu polymorphisms on the frequency of genotoxicity biomarkers in individuals occupationally exposed to formaldehyde (n = 54) and unexposed workers (n = 82). XRCC3 participates in DNA double-strand break/recombination repair, while ADH5 is an important component of cellular metabolism for the elimination of formaldehyde. Exposed workers had significantly higher frequencies (P < 0.01) than controls for all genotoxicity biomarkers evaluated in this study. Moreover, there were significant associations between XRCC3 genotypes and nuclear buds, namely XRCC3 Met/Met (OR = 3.975, CI 1.053-14.998, P = 0.042) and XRCC3 Thr/Met (OR = 5.632, CI 1.673-18.961, P = 0.005) in comparison with XRCC3 Thr/Thr. ADH5 polymorphisms did not show significant effects. This study highlights the importance of integrating genotoxicity biomarkers and genetic polymorphisms in human biomonitoring studies.

DNA methylation patterns of imprinting centers for H19, SNRPN, and KCNQ1OT1 in single-cell clones of human amniotic fluid mesenchymal stem cell

OBJECTIVE

To test the hypothesis that human amniotic fluid mesenchymal stem cells contain a unique epigenetic signature in imprinting centers of H19, SNRPN, and KCNQ1OT1 during in vitro cell culture.

MATERIALS AND METHODS

By bisulfite genomic sequencing, we analyzed the imprinting centers of three imprinted genes (including H19, SNRPN, and KCNQ1OT/) in a total of six single-cell clones of human amniotic fluid mesenchymal stem cells at cell passages 7, 8, 9, and 10 during in vitro cell culture.

RESULTS

The imprinting centers of H19 and KCNQ1OT1 showed hypermethylation at passage 7 in all single-cell clones of human amniotic fluid mesenchymal stem cells, and there was no significant change in DNA methylation patterns during in vitro cell culture. The imprinting centers of SNRPN showed variable methylation patterns at passage 7 in six single-cell clones, and DNA methylation patterns varied during in vitro cell culture from passages 8 to 10.

CONCLUSION

In conclusion, human amniotic fluid mesenchymal stem cells contain a unique epigenetic signature during in vitro cell culture. H19 and KCNQ1OT1 possessed a substantial degree of hypermethylation status, and variable DNA methylation patterns of SNRPN was observed during in vitro cell culture of human amniotic fluid mesenchymal stem cells. Our results urge further understanding of epigenetic status of human amniotic fluid mesenchymal stem cells before it is applied in cell replacement therapy.

A combination of micronucleus assay and fluorescence in situ hybridization analysis to evaluate the genotoxicity of formaldehyde

A genotoxic effect of formaldehyde (FA), particularly micronucleus (MN) induction, has been shown in several previous studies. The aim of the present study was to assess the frequency of micronuclei and to identify the type of chromosomal damage in Tunisian staff members working in the Pathologic Anatomy Laboratory of Farhat Hached hospital (Sousse, Tunisia) who were exposed to FA. Assessment of chromosomal damage was performed in peripheral lymphocytes of 31 FA-exposed employees compared with 31 control employees working in the administrative department of the same hospital. The clastogenic/aneugenic effect of FA was evaluated using the standard MN assay in combination with fluorescence in situ hybridization (FISH) using pan-centromeric probes. The mean level of exposure to FA was 3.4 ppm. The results showed a significant increase of MN frequency in lymphocytes of exposed workers compared with the control group (25.35 ± 6.28 ‰ vs. 7.08  ± 4.62 ‰, p < 0.05). As assessed by FISH, the frequency of centromeric micronuclei (C+MN) was greater in exposed subjects than in controls (18.38 ± 5.94 ‰ vs. 5.03 ± 3.64 ‰). Among the C+MN, the frequency of MN containing one centromere (C1+MN) was significantly greater in pathologists and anatomists than in controls (15.35 ± 6.0 ‰ vs. 3.33 ± 2.74 ‰, p < 0.05). The results showed an effect of sex and time of FA exposure with significantly increased frequencies of all end points measuring aneuploidy (C+MN, C1+MN, and Cx+MN [more then one MN]). The increased frequency of C1+MN observed in the exposed group may suggest a slight aneugenic effect of FA exposure.

Expression and significance of Kruppel-like factor 6 gene in osteosarcoma

PURPOSE

Osteosarcoma is primary malignant tumour of bone. Kruppel-like factor 6 (KLF6) is a tumor suppressor gene frequently inactivated in a number of human cancers and a ubiquitously expressed zinc-finger transcription factor. The present study aimed to first explore the relationship between the expression level of the KLF6 gene in osteosarcoma and the occurrence of bone tumours.

METHODS

KLF6 mRNA and protein expression levels in osteosarcoma and normal bone tissue were assayed by real-time quantitative PCR and immunohistochemistry. KLF6 mRNA and protein expression levels in osteosarcoma cells and normal osteoblasts were detected by semi-quantitative reverse transcription PCR and Western blotting, respectively.

RESULTS

Both the expression of KLF6 mRNA and protein in osteosarcoma cells and tissues were significantly lower than that in normal cells and tumour-adjacent tissues.

CONCLUSIONS

KLF6 is a putative tumor suppressor gene involved in osteosarcoma which can be used as a new therapeutic target and an important marker for early diagnosis and postoperative monitoring.

The role of zinc in genomic stability

Zinc (Zn) is an essential trace element required for maintaining both optimal human health and genomic stability. Zn plays a critical role in the regulation of DNA repair mechanisms, cell proliferation, differentiation and apoptosis involving the action of various transcriptional factors and DNA or RNA polymerases. Zn is an essential cofactor or structural component for important antioxidant defence proteins and DNA repair enzymes such as Cu/Zn SOD, OGG1, APE and PARP and may also affect activities of enzymes such as BHMT and MTR involved in methylation reactions in the folate-methionine cycle. This review focuses on the role of Zn in the maintenance of genome integrity and the effects of deficiency or excess on genomic stability events and cell death.

Iron and genome stability: an update

Iron is an essential micronutrient which is required in a relatively narrow range for maintaining metabolic homeostasis and genome stability. Iron participates in oxygen transport and mitochondrial respiration as well as in antioxidant and nucleic acid metabolism. Iron deficiency impairs these biological pathways, leading to oxidative stress and possibly carcinogenesis. Iron overload has been linked to genome instability as well as to cancer risk increase, as seen in hereditary hemochromatosis. Iron is an extremely reactive transition metal that can interact with hydrogen peroxide to generate hydroxyl radicals that form the 8-hydroxy-guanine adduct, cause point mutations as well as DNA single and double strand breaks. Iron overload also induces DNA hypermethylation and can reduce telomere length. The current Recommended Dietary Allowances (RDA) for iron, according with Institute of Medicine Dietary Reference Intake (DRI), is based in the concept of preventing anemia, and ranges from 7mg/day to 18mg/day depending on life stage and gender. Pregnant women need 27mg/day. The maximum safety level for iron intake, the Upper Level (UL), is 40-45mg/day, based on the prevention of gastrointestinal distress associated to high iron intakes. Preliminary evidence indicates that 20mg/day iron, an intake slightly higher than the RDA, may reduce the risk of gastrointestinal cancer in the elderly as well as increasing genome stability in lymphocytes of children and adolescents. Current dietary recommendations do not consider the concept of genome stability which is of concern because damage to the genome has been linked to the origin and progression of many diseases and is the most fundamental pathology. Given the importance of iron for homeostasis and its potential influence over genome stability and cancer it is recommended to conduct further studies that conclusively define these relationships.

Hypomethylation of repeated DNA sequences in cancer

An important feature of cancer development and progression is the change in DNA methylation patterns, characterized by the hypermethylation of specific genes concurrently with an overall decrease in the level of 5-methylcytosine. Hypomethylation of the genome can affect both single-copy genes, repeat DNA sequences and transposable elements, and is highly variable among and within cancer types. Here, we review our current understanding of genome hypomethylation in cancer, with a particular focus on hypomethylation of the different classes and families of repeat sequences. The emerging data provide insights into the importance of methylation of different repeat families in the maintenance of chromosome structural integrity and the fidelity of normal transcriptional regulation. We also consider the events underlying cancer-associated hypomethylation and the potential for the clinical use of characteristic DNA methylation changes in diagnosis, prognosis or classification of tumors.

Does vitamin D protect against DNA damage?

Vitamin D is a secosteroid best known for its role in maintaining bone and muscle health. Adequate levels of vitamin D may also be beneficial in maintaining DNA integrity. This role of vitamin D can be divided into a primary function that prevents damage from DNA and a secondary function that regulates the growth rate of cells. The potential for vitamin D to reduce oxidative damage to DNA in a human has been suggested by clinical trial where vitamin D supplementation reduced 8-hydroxy-2'-deoxyguanosine, a marker of oxidative damage, in colorectal epithelial crypt cells. Studies in animal models and in different cell types have also shown marked reduction in oxidative stress damage and chromosomal aberrations, prevention of telomere shortening and inhibition of telomerase activity following treatment with vitamin D. The secondary function of vitamin D in preventing DNA damage includes regulation of the poly-ADP-ribose polymerase activity in the DNA damage response pathway involved in the detection of DNA lesions. It is also able to regulate the cell cycle to prevent the propagation of damaged DNA, and to regulate apoptosis to promote cell death. Vitamin D may contribute to prevention of human colorectal cancer, though there is little evidence to suggest that prevention of DNA damage mediates this effect, if real. Very limited human data mean that the intake of vitamin D required to minimise DNA damage remains uncertain.

Cytogenetic methods in human biomonitoring: principles and uses

Cellular phenotypes can be applied as biomarkers to differentiate normal from abnormal biological -conditions. Several cytogenetic methods have been developed and allow the accurate detection of such phenotypic changes.Based on their mechanisms of formation, cellular phenotypes may be used either as biomarkers of exposure or as biomarkers of effect. Therefore, it is important that cytogenetic methods implemented in human biomonitoring should be based on a good knowledge of these mechanisms.In this chapter, we aim to review the mechanistic basis, the methodology, and the use in human biomonitoring studies of four major cytogenetic endpoints: sister chromatid exchanges (SCEs), high frequency cells (HFCs), chromosomal aberrations (CAs), and micronuclei (MN). In addition, an overview of potential confounding factors on the induction of these cytogenetic makers is presented. Furthermore, the combination of cytogenetics with molecular methods, which allows chromosome and gene identification on metaphase as well as in interphase cells with high resolution, is discussed. Finally, practical recommendations for an efficient application of these cytogenetic assays and a correct interpretation of the results on the basis of cellular phenotype(s) assessment in human biomonitoring are highlighted.

Control of prostate cancer associated with withdrawal of a supplement containing folic acid, L-methyltetrahydrofolate and vitamin B12: a case report

Introduction

This is the first report of possible direct stimulation of hormone-resistant prostate cancer or interference of docetaxel cytotoxicity of prostate cancer in a patient with biochemical relapse of prostatic-specific antigen. This observation is of clinical and metabolic importance, especially at a time when more than 80 countries have fortified food supplies with folic acid and some contemplate further fortification with vitamin B₁₂.

Case presentation

Our patient is a 71-year-old Caucasian man who had been diagnosed in 1997 with prostate cancer, stage T1c, and Gleason score 3+4 = 7. His primary treatment included intermittent androgen deprivation therapy including leuprolide + bicalutamide + deutasteride, ketoconazole + hydrocortisone, nilandrone and flutamide to resistance defined as biochemical relapse of PSA. While undergoing docetaxel therapy to treat a continually increasing prostate-specific antigen level, withdrawal of 10 daily doses of a supplement containing 500 μg of vitamin B₁₂ as cyanocobalamin, as well as 400 μg of folic acid as pteroylglutamic acid and 400 μg of L-5-methyltetrahydrofolate for a combined total of 800 μg of mixed folates, was associated with a return to a normal serum prostatic-specific antigen level.

Conclusion

This case report illustrates the importance of the effects of supplements containing large amounts of folic acid, L-5-methyltetrahydrofolate, and cyanocobalamin on the metabolism of prostate cancer cells directly and/or B vitamin interference with docetaxel efficacy. Physicians caring for patients with prostate cancer undergoing watchful waiting, hormone therapy, and/or chemotherapy should consider the possible acceleration of tumor growth and/or metastasis and the development of drug resistance associated with supplement ingestion. We describe several pathways of metabolic and epigenetic interactions that could affect the observed changes in serum levels of prostate-specific antigen.

Evolutionary conservation of metabolism explains howDrosophila nutrigenomics can help us understand human nutrigenomics

While large populations in the third world are enduring famine, much of the developed world is undergoing an obesity epidemic. In addition to reflecting an unbalanced distribution of food, the "epidemic of overabundance" is ironically leading to a decrease in the health and longevity of the obese and improperly nourished in the first world. International consortia, such as the European Nutrigenomics Organization (NuGO), are increasing our knowledge of nutrientgene interactions and the effects of diet and obesity on human health. In this review, we summarize both previous and ongoing nutrigenomics studies in Drosophila and we explain how these studies can be used to provide insights into molecular mechanisms underlying nutrigenomics in humans. We will discuss how quantitative trait locus (QTL) experiments have identified genes that affect triglyceride levels in Drosophila, and how microarray analyses show that hundreds of genes have altered gene expression under different dietary conditions. Finally, we will discuss ongoing combined microarray-QTL studies, termed "genetical genomics," that promise to identify "master modulatory loci" that regulate global responses of potentially hundreds of genes under different dietary conditions. When "master modulatory loci" are identified in Drosophila, then experiments in mammalian models can be used to determine the relevance of these genes to human nutrition and health.

Nutrigenetics and nutrigenomics: viewpoints on the current status and applications in nutrition research and practice

Nutrigenetics and nutrigenomics hold much promise for providing better nutritional advice to the public generally, genetic subgroups and individuals. Because nutrigenetics and nutrigenomics require a deep understanding of nutrition, genetics and biochemistry and ever new 'omic' technologies, it is often difficult, even for educated professionals, to appreciate their relevance to the practice of preventive approaches for optimising health, delaying onset of disease and diminishing its severity. This review discusses (i) the basic concepts, technical terms and technology involved in nutrigenetics and nutrigenomics; (ii) how this emerging knowledge can be applied to optimise health, prevent and treat diseases; (iii) how to read, understand and interpret nutrigenetic and nutrigenomic research results, and (iv) how this knowledge may potentially transform nutrition and dietetic practice, and the implications of such a transformation. This is in effect an up-to-date overview of the various aspects of nutrigenetics and nutrigenomics relevant to health practitioners who are seeking a better understanding of this new frontier in nutrition research and its potential application to dietetic practice.

Diet composition modifies the toxicity of repeated soman exposure in rats

It was previously demonstrated that diet potently modulates the toxic effects of an acute lethal dose of the nerve agent soman. The current investigation was undertaken to examine the influence of diet on the cumulative toxicity of repeated soman administration. Rats were fed one of four distinct diets (standard, choline-enriched, glucose-enriched, or ketogenic) for four weeks prior to and throughout a repeated soman dosing and recovery regimen. Each diet group included animals exposed to an equivalent volume of saline that served as negative controls. In exposure Week 1, animals received three consecutive daily doses of 0.4 LD(50) soman. In exposure Week 2, animals received four consecutive daily doses of 0.5 LD(50) soman. In exposure Week 3, animals received five consecutive daily doses of 0.5 LD(50) soman. Week 4 constituted a post-exposure recovery evaluation. Throughout the experiment, behavioral function was assessed by a discriminated avoidance test that required intact sensory and motor function. Survival and body weight changes were recorded daily. Differences in toxicity as a function of diet composition became apparent during the first week. Specifically, rats fed the glucose-enriched diet showed pronounced intoxication during Week 1, resulting in imperfect survival, weight loss, and deteriorated avoidance performance relative to all other groups. All rats fed the glucose-enriched diet died by the end of exposure Week 2. In contrast, only 10% of animals fed the standard diet died by the end of Week 2. Also in Week 2, weight loss and disrupted avoidance performance were apparent for all groups except for those fed the ketogenic diet. This differential effect of diet composition became even more striking in Week 3 when survival in the standard and choline diet groups approximated 50%, whereas survival equaled 90% in the ketogenic diet group. Avoidance performance and weight loss measures corroborated the differential toxicity observed across diet groups. Upon cessation of soman exposure during the final week, recovery of weight and avoidance performance in survivors was comparable across diet groups. These results systematically replicate previous findings demonstrating that diet composition exacerbates or attenuates toxicity in rodents exposed acutely to organophosphorus compounds.

The in vitro MN assay in 2011: origin and fate, biological significance, protocols, high throughput methodologies and toxicological relevance

Micronuclei (MN) are small, extranuclear bodies that arise in dividing cells from acentric chromosome/chromatid fragments or whole chromosomes/chromatids lagging behind in anaphase and are not included in the daughter nuclei at telophase. The mechanisms of MN formation are well understood; their possible postmitotic fate is less evident. The MN assay allows detection of both aneugens and clastogens, shows simplicity of scoring, is widely applicable in different cell types, is internationally validated, has potential for automation and is predictive for cancer. The cytokinesis-block micronucleus assay (CBMN) allows assessment of nucleoplasmic bridges, nuclear buds, cell division inhibition, necrosis and apoptosis and in combination with FISH using centromeric probes, the mechanistic origin of the MN. Therefore, the CBMN test can be considered as a "cytome" assay covering chromosome instability, mitotic dysfunction, cell proliferation and cell death. The toxicological relevance of the MN test is strong: it covers several endpoints, its sensitivity is high, its predictivity for in vivo genotoxicity requires adequate selection of cell lines, its statistical power is increased by the recently available high throughput methodologies, it might become a possible candidate for replacing in vivo testing, it allows good extrapolation for potential limits of exposure or thresholds and it is traceable in experimental in vitro and in vivo systems. Implementation of in vitro MN assays in the test battery for hazard and risk assessment of potential mutagens/carcinogens is therefore fully justified.