γ-tocopherol methyltransferase gene sequencing and SNP discovery associated with olive oil quality.

γ-tocophérol methyltransferase (GTMT), a key enzyme in the tocopherols biosynthesis pathway, is involved in the conversion of δ- and l'γ-tocophérol to ß- et l'α-tocophérol, respectively. In fact, it plays an important role in the α-tocopherol composition and the quality of olive oil. A total of 14 olive tree cultivars (Olea Europaea L.) were chosen and used in this study. They were sampled from different regions of Tunisia. Four cultivars from four Mediterranean regions (Greece, Algeria, Morocco, and Spain) were included for comparison. For each variety, DNA was extracted from young leaves. The Vte4 gene was PCR amplified from the 14 olive varieties and verified by electrophoresis on a 2% agarose gel for each variety. DNA sequencing of the olive cultivars revealed several single-nucleotide polymorphisms (SNPs). Statistical and bioinformatics analysis  draw attention to some associations between some of the SNPs, tocopherols contents and oleic acid content. In fact, two significant associations are obtained between SUBS24 and both Total-Tocopherols and Beta-Tocopherol. Moreover, dendrograms reveals that there is a correlation between genetic variability and chemical characteristics which make the Vte4 gene more interesting in terms of tocopherols levels.

Integration of Innovative Technologies in the Agri-Food Sector: The Fundamentals and Practical Case of DNA-Based Traceability of Olives from Fruit to Oil.

Several socio-economic problems have been hidden by the COVID-19 pandemic crisis. Particularly, the agricultural and food industrial sectors have been harshly affected by this devastating disease. Moreover, with the worldwide population increase and the agricultural production technologies being inefficient or obsolete, there is a great need to find new and successful ways to fulfill the increasing food demand. A new era of agriculture and food industry is forthcoming, with revolutionary concepts, processes and technologies, referred to as Agri-food 4.0, which enables the next level of agri-food production and trade. In addition, consumers are becoming more and more aware about the origin, traceability, healthy and high-quality of agri-food products. The integration of new process of production and data management is a mandatory step to meet consumer and market requirements. DNA traceability may provide strong approach to certify and authenticate healthy food products, particularly for olive oil. With this approach, the origin and authenticity of products are confirmed by the means of unique nucleic acid sequences. Selected tools, methods and technologies involved in and contributing to the advance of the agri-food sector are presented and discussed in this paper. Moreover, the application of DNA traceability as an innovative approach to authenticate olive products is reported in this paper as an application and promising case of smart agriculture.

SNP discovery and structural insights into OeFAD2 unravelling high oleic/linoleic ratio in olive oil.

Fatty Acid Desaturase 2 (FAD2), a key enzyme in the fatty acid biosynthesis pathway, is involved in the desaturation and conversion of oleic acid to linoleic acid. Therefore, it plays a crucial role in oleic/linoleic acid ratio and the quality of olive oil. DNA sequencing of 19 FAD2 genes from a set of olive oil varieties revealed several single-nucleotide polymorphisms (SNPs) and highlighted associations between some of the SNPs and saturated fatty acids contents. This was further confirmed by SNP-interaction and machine learning approach. Haplotype diversity analysis led to the discovery of three highly polymorphic SNPs and four haplotypes harboring differential oleic/linoleic acid ratios. Moreover, a combination of molecular modeling and docking experiments allowed a deeper and better understanding of the structure-function relationship of the FAD2 enzyme. Sequence patterns and variations involved in the regulation of the FAD2 activity were also identified. Furthermore, S82C and H213N substitutions in OeFAD2 make the Oueslati variety more interesting in terms of fatty acid profile and oleic acid level.

Immune checkpoint CD155 promoter methylation profiling reveals cancer-associated behaviors within breast neoplasia.

BACKGROUND: CD155 immune checkpoint has recently emerged as a compelling immunotherapeutic target. Epigenetic DNA methylation changes are recognized as key molecular mechanisms in cancer development. Hence, the identification of methylation markers that are sensitive and specific for breast cancer may improve early detection and predict prognosis. We speculate that CD155 promoter methylation can be a valuable epigenetic biomarker, based upon strong indications for its immunoregulatory functions. METHODS: Methylation analyses were conducted on 14 CpGs sites in the CD155 promoter region by bisulfite pyrosequencing. To elucidate the related gene expression changes, a transcriptional study using RT-qPCR was performed. Statistical analyses were performed to evaluate correlations of CD155 methylation profiles with mRNA expression together with clinical-pathological features, prognosis and immune infiltrate. RESULTS: CD155 promoter methylation profile was significantly associated with SBR grade, tumor size, molecular subgroups, HER2 and hormonal receptors expression status. Low CD155 methylation rates correlated with better prognosis in univariate cox proportional hazard analysis and appeared as an independent survival predictor in cox-regression multivariate analysis. Further, methylation changes at CD155 specific CpG sites were consistent with CD155 membranous mRNA isoform expression status. Statistical analyses also showed a significant association with immune Natural Killer cell infiltrate when looking at the CpG7, CpG8, CpG9 and CpG11 sites. CONCLUSION: Altogether, our results contribute to a better understanding of the impact of CD155 immune checkpoint modality expression in breast tumors, revealing for the first time that specific CpG sites from CD155 promoter may be a potential biomarker in breast cancer monitoring.

Can leukocytospermia predict prostate cancer via its effects on mitochondrial DNA?

Leukocytospermia was previously reported to affect sperm quality by the production of reactive oxygen species (ROS) leading to oxidative stress (OS). In turn, OS decreases sperm functional integrity, increases sperm DNA damage and ultimately alters fertility status. To elucidate the impact of leukocytospermia on sperm nuclear DNA integrity and mitochondrial DNA (mtDNA) structure, we conducted a study including 67 samples from infertile patients with low level of leucocytes (Group 1: n = 20) and with leukocytospermia (Group 2: n = 47). In addition to standard sperm parameters' assessment, we measured the levels of inflammation biomarkers [interleukin-6 (IL-6) and interleukin-8 (IL-8)] and evaluated the oxidative status [malondialdehyde (MDA) and enzymatic and non-enzymatic antioxidants]. In addition, we evaluated the level of sperm nuclear DNA fragmentation and analysed mitochondrial DNA (mtDNA) of sperm cells by sequencing of 5 genes [cytochrome oxidase I (COXI), cytochrome oxidase II (COXII), cytochrome oxidase III (COXIII), adenosine triphosphate synthase 6 (ATPase 6) and adenosine triphosphate synthase 8 (ATPase 8)]. As expected, patients with leukocytospermia had significantly higher MDA levels (32.56 ± 24.30 nmole/ml) than patients without leukocytospermia (17.59 ± 9.60 nmole/ml) (p < .018). Also, sperm DNA fragmentation index (DFI) was significantly higher in Group 2 (33.05 ± 18.14%) as compared to Group 1 (14.19 ± 9.50%) (p < .001). The sequencing of mtDNA revealed a high number of substitutions in Group 2 (n = 102) compared to Group 1 (n = 5). These substitutions were observed mainly in COXI. Among COXI substitutions found in Group 2, twelve changes were previously described in patients with prostate cancer and six of them were shown associated with this pathology. These findings suggest that leukocytospermia may predispose to the manifestation of prostate cancer through modification of mitochondrial DNA and this may be promoted by OS.

Immune checkpoint molecules B7-H6 and PD-L1 co-pattern the tumor inflammatory microenvironment in human breast cancer.

B7-H6 and PD-L1 belong to the B7 family co-stimulatory molecules fine-tuning the immune response. The present work investigates the clinical effect of B7-H6 protein expression with PD-L1 status and the infiltration of natural killer cells as potential biomarkers in breast tumor inflammatory microenvironment. The expression levels of B7-H6 protein by cancer cells and immune infiltrating cells in human breast cancer tissues and evaluate their associations with PD-L1 expression, NK cell status, clinical pathological features and prognosis were explored. The immunohistochemistry labeling method was used to assess B7-H6 and PD-L1 proteins expression by cancer and immune cells. The associations between immune checkpoint, major clinical pathological variables and survival rates were analyzed. B7-H6 protein was depicted in both breast and immune cells. Results showed that Tumor B7-H6 expression is highly associated with Her-2 over expression. B7-H6 + immune cells are highly related to the Scarff-Bloom-Richardson grade and associated with PD-L1 expression and NK cells status. Survival analysis revealed a better prognosis in patients with low expression of B7-H6 by cancer cells. Conversely, B7-H6 + immune cells were significantly associated with longer survival. Findings strongly suggest an interaction between B7 molecules that contributes to a particular design of the inflammatory microenvironment. This may influence the efficiency of therapies based on antibodies blocking the PD-L1/PD1 pathway and can explain the detection of clinical benefits only in a fraction of patients treated with immune checkpoint inhibitors.

The disordered charged biased proteins in the human diseasome.

Intrinsically disordered proteins (IDPs) are often involved in diseases and have been shown to be promising targets for drug development. Here, we focus on the human disordered charged biased proteins (HDCBPs). We have investigated the association of the HDCBPs with diseases by integrating various sources that cover public sources of gene-disease associations and intensive literature mining. The results indicate that 95% of HDCBPs are associated with multiple diseases, including mainly various cancers, nervous, endocrine, immune, hematological, and respiratory systems diseases. Our data show that the HDCBP-disease network constructed by integrating different levels of data together may improve our understanding of these complex diseases. Moreover, we present the top-ranked proteins that might be potential markers for diagnostic and drug targets.

Data mining analysis of human gut microbiota links Fusobacterium spp. with colorectal cancer onset.

Gut microbiota and their metabolites play a vital role in colon health and disease. Accumulating evidence suggests that the gut microbiota contributes to the risk of colorectal cancer (CRC). However, the role of a specific microbial community together with their metabolites contributing to the risk, initiation and progression of CRC is still unknown. Hence, we used a Bayesian Networks in combination with the IDA (Intervention calculus when the DAG is absent) to generate a graphical model that allows causal relationships to be inferred from observational data. Results from the analysis of publically available datasets showed that four species: Fusobacteium, Citrobacter, Microbacterium and Slaxkia have estimated non-null lower bounds of causal effects of CRC. These findings support the hypothesis that specific bacterial species (microbial markers) act in concert with locally modified microbiota to cause or influence CRC progression. Additional comprehensive studies are required to validate the potential use of F. nucleatum, Citrobacter as well as Slackia as microbial biomarkers in CRC for prevention, diagnosis, prognosis and/or therapeutics.

CD155 expression in human breast cancer: Clinical significance and relevance to natural killer cell infiltration.

AIMS: CD155 is a ligand of the NK activating receptor DNAM-1, it has been described in a variety of human malignancies, but its expression in breast cancer remains unclear and poorly studied. MAIN METHODS: CD155 expression and NK cells infiltration were investigated in 158 patients with breast cancer by immunohistochemistry (IHC). Statistical analyses were performed to evaluate correlations of CD155 expression with clinical-pathological features, prognosis and tumor immunity. KEY FINDINGS: Tumor cytoplasmic CD155 (cyt-CD155) was associated with lymphovascular invasion (p = 0.011), and membranous CD155 (m-CD155) was strongly correlated with the presence of Tumor Infiltrating natural killer cells (NK-TILs) (p = 0.0003). Survival analysis demonstrated that patients with high cyt-CD155 had a significantly worse overall survival (p < 0.001) and death free survival (p = 0.014) than those with low expression, while high levels of m-CD155 correlated with a better prognosis (p = 0.037). Furthermore, we found that patients with m-CD155Low/NKLow tumors had a significantly reduced overall survival (p = 0.012). Multivariate analysis showed that positive tumor m-CD155 status was a significant independent marker of good prognosis. Meanwhile, high cyt-CD155 expression was identified as an independent poor prognostic predictor, suggesting a key role in this malignancy. SIGNIFICANCE: Altogether, our results revealed that cyt-CD155 was associated with invasiveness and poorer prognosis, but the concomitant presence of m-CD155 and NK-TILs had an opposite prognostic relevance in breast cancer. These results raised the importance of CD155 IHC analysis to elucidate biomarker localization, leading to better understand and design therapeutic molecule targeting CD155 in breast tumors.

Tunisian Table Olive Oil Traceability and Quality Using SNP Genotyping and Bioinformatics Tools.

To enhance and highlight the authentication and traceability of table olive oil, we considered the analysis of 11 Tunisian table olive cultivars based on seven SNP molecular markers (SOD, CALC, FAD2.1, FAD2.3, PAL70, ANTHO3, and SAD.1) localized in six different genes. Accordingly, we assessed the potential genotype-phenotypes links between the seven SNPs, on the one hand, and the quantitative and qualitative parameters, on the other. The obtained genotypes were analyzed with computational biology tools based on bivariate analysis, multinomial logistic regression, and the Bayesian networks modeling. Obtained results showed that PAL70 SNP marker was negatively influenced by the phenol rate (r = -0.886; p <0.001), the oxidative stability (r = -0.884; p <0.001), traducing a direct effect of the PAL70 genotype deviations on the proportion of total phenol for each variety. Additionally, we revealed a significant association of SAD.1 marker with the content of the linolenic unsaturated fatty acids (C18:3; p=0.046). Moreover, SAD.1 was positively correlated with the saturated stearic acid C18:0 (r = 0.644; p = 0.032) based on multinomial logistic regression and Bayesian networks modeling, respectively. This research work provides better understanding and characterization of the quality of Tunisian table olive and supplies a significant knowledge and data information for table olive traceability and breeding.

First study of correlation between oleic acid content and SAD gene polymorphism in olive oil samples through statistical and bayesian modeling analyses.

BACKGROUND: Virgin olive oil is appreciated for its particular aroma and taste and is recognized worldwide for its nutritional value and health benefits. The olive oil contains a vast range of healthy compounds such as monounsaturated free fatty acids, especially, oleic acid. The SAD.1 polymorphism localized in the Stearoyl-acyl carrier protein desaturase gene (SAD) was genotyped and showed that it is associated with the oleic acid composition of olive oil samples. However, the effect of polymorphisms in fatty acid-related genes on olive oil monounsaturated and saturated fatty acids distribution in the Tunisian olive oil varieties is not understood. METHODS: Seventeen Tunisian olive-tree varieties were selected for fatty acid content analysis by gas chromatography. The association of SAD.1 genotypes with the fatty acids composition was studied by statistical and Bayesian modeling analyses. RESULTS: Fatty acid content analysis showed interestingly that some Tunisian virgin olive oil varieties could be classified as a functional food and nutraceuticals due to their particular richness in oleic acid. In fact, the TT-SAD.1 genotype was found to be associated with a higher proportion of mono-unsaturated fatty acids (MUFA), mainly oleic acid (C18:1) (r = - 0.79, p < 0.000) as well as lower proportion of palmitic acid (C16:0) (r = 0.51, p = 0.037), making varieties with this genotype (i.e. Zarrazi and Tounsi) producing more monounsaturated oleic acid (C18: 1) than saturated acid. These varieties could be thus used as nutraceuticals and functional food. CONCLUSION: The SAD.1 association with the oleic acid composition of olive oil was identified among the studied varieties. This correlation fluctuated between studied varieties, which might elucidate variability in lipidic composition among them and therefore reflecting genetic diversity through differences in gene expression and biochemical pathways. SAD locus would represent an excellent marker for identifying interesting amongst virgin olive oil lipidic composition.

Polymorphisms in XRCC1, ERCC2, and ERCC3 DNA repair genes, CYP1A1 xenobiotic metabolism gene, and tobacco are associated with bladder cancer susceptibility in Tunisian population.

Other than the established environmental risk factors associated with bladder cancer (BC), little is known about the genetic variations determining the individual susceptibility of this complex disease. This study aimed to investigate the relationship of BC with environmental agents and polymorphisms in XRCC1, ERCC2, and ERCC3 DNA repair genes and CYP1A1, CYP2D6, NAT1, and NAT2 xenobiotic metabolism genes through a hospital-based case-control study in Tunisia. The selection of the single nucleotide polymorphisms (SNPs) (rs25487, rs 13181, rs415407, rs446421, rs1058172, rs4921880, and rs1208) was performed using the dbSNP database. DNA genotyping was determined by PCR-RFLP after DNA extraction from whole blood. The risks of BC associated with every polymorphism as well as the studied environmental factors were estimated by multivariate-adjusted logistic regression using R software. In addition, gene-gene interactions were analyzed using generalized multifactor dimensionality reduction (GMDR) methods. Results showed that tobacco smoking and chewing parameters were significantly associated with BC risk. Single-gene variant analysis showed significant associations of the TT genotype of CYP1A1 and the rare GG genotype of ERCC2 with bladder cancer susceptibility (OR = 1.34, 95% CI 1.22-1.40, P < 0.0001). According to GMDR analysis, our findings indicated a significant association between BC and gene-gene interaction among the CYP1A1, ERCC3, and XRCC1. The present results suggest a potential role of XRCC1, ERCC2, ERCC3, and CYP1A1 besides tobacco intake in susceptibility to BC.

Identification and characterization of single nucleotide polymorphism markers in FADS2 gene associated with olive oil fatty acids composition.

BACKGROUND: Genotyping of the FAD2.1 and FAD2.3 polymorphisms in the fatty acid desaturase 2 gene (FADS2) shows that they are associated with the fatty acids composition of olive oil samples. However, these associations require further confirmation in the Tunisian olive oil cultivars, and little is known about the effect of polymorphisms in fatty acid-related genes on olive oil mono- and poly- unsaturated fatty acids distribution. METHODS: A set of olive oils from 12 Tunisian cultivars was chosen. The fatty acid composition of each olive oil sample was determined by gas chromatography. Statistical and modeling Bayesian analyses were used to assess whether the FAD2.1 and FAD2.3 genotypes were associated with fatty acids composition. RESULTS: The TT-FAD2.1 and the GG-FAD2.3 genotypes were found to be associated with a lower proportion of oleic acid (C18:1) (r = -0.778, p = 0.003; r = -0.781, p= 0.003) as well as higher proportion of linoleic (C18:2) (r = 0.693, p = 0.012; r = -0.759, p= 0.004) and palmitic acids (C16:0) (r = 0.643, p = 0.024; r = -0.503, p= 0.095), making varieties with this haplotype (i.e. Chemlali Sfax and Meski) producing more saturated (C16: 0) and polyunsaturated acids than oleic acid. The latter plays a major role in preventing several diseases. CONCLUSION: The two associations FADS2 FAD2.1 and FADS2 FAD2.3 with the fatty acid compositions of olive oil samples were identified among the studied olive cultivars. These associations differed between studied cultivars, which might explain variability in lipidic composition among them and consequently reflecting genetic diversity through differences in gene expression and biochemical pathways. FADS2 locus would constitute thus a good marker for detecting interesting lipidic chemotypes among commercial olive oils.

Putative Markers of Adulteration of Higher-Grade Olive Oil with Less Expensive Pomace Olive Oil Identified by Gas Chromatography Combined with Chemometrics.

This work has been performed to ascertain that extra-virgin olive oil (EVOO) is free of adulteration. For this purpose, refined pomace olive oils (RPOOs) are commonly used for extra-virgin olive oil adulteration and repassed olive oils (ROOs) are used for lampante olive oil (LOO) fraudulent operation. Indeed, fatty acid ethyl esters could be used as a parameter for the detection of EVOO fraud with 2% RPOO. The addition of >10% RPOO to EVOO would be detected by the amount of erythrodiol, uvaol, waxes, and aliphatic alcohols. Moreover, the use of stigmasta-3,5-diene content proved to be effective in EVOO adulteration even at a low level (with 1% RPOO). For the detection of adulteration of LOO with >5% ROO, the sum of erythrodiol, uvaol, and the waxes and esters can be considered as good markers of purity. Using linear discriminant analysis can identify the most discriminant variable that allows a faster and cheaper evaluation of extra-virgin olive oil adulteration by measuring only these variables.

Gene-environment interactions between ERCC2, ERCC3, XRCC1 and cadmium exposure in nasal polyposis disease.

Gene-environment interactions have long been known to play an important role in complex disease aetiology, such as nasal polyposis (NP). The present study supports the concept that DNA repair gene polymorphisms play critical roles in modifying individual susceptibility to environmental diseases. In fact, we investigated the role of polymorphisms in DNA repair genes and cadmium as risk factors for Tunisian patients with NP. To the best of our knowledge, this is the first report on the impact of combined effects of cadmium and ERCC3 7122 A>G (rs4150407), ERCC2 Lys751Gln (rs13181) and XRCC1 Arg399Gln (rs25487) genes in the susceptibility to NP disease. Significant associations between the risk of developing NP disease and ERCC2 [odds ratio (OR) = 2.0, 95 % confidence interval (CI) = 1.1-3.7, p = 0.023] and ERCC3 (OR = 2.2, 95 % CI = 1.2-4.1, p = 0.013) genotypes polymorphisms were observed. Blood concentrations of Cd in NP patients (2.2 µg/L) were significantly higher than those of controls (0.5 µg/L). A significant interaction between ERCC3 (7122 A>G) polymorphism and blood-Cd levels (for the median of blood-Cd levels: OR = 3.8, 95 % CI = 1.3-10.8, p = 0.014 and for the 75th percentiles of blood-Cd levels: OR = 2.7, 95 % CI = 1.1-7.2, p = 0.041) was found in association with the risk of NP disease. In addition, when we stratified ERCC2, ERCC3 and XRCC1 polymorphism genotypes by the median and 75th percentiles of blood-Cd levels, we found also significant interactions between ERCC2 (Lys751Gln) and ERCC3 (7122 A>G) genotypes polymorphism and this metal in association with NP disease. However, no interaction was found between XRCC1 (Arg399Gln) polymorphism genotypes and Cd in association with NP disease.

In silico characterization of functional SNP within the oestrogen receptor gene.

Single-nucleotide polymorphism (SNP) association studies have become crucial in uncovering the genetic correlations of genomic variants with complex diseases, quantitative traits and physiological responses to drugs. However, the identification of SNPs responsible for specific phenotypes is a difficult problem to solve, requiring multiple testing of hundreds or thousands of SNPs in candidate genes. In this study, we performed an analysis of the genetic variations that can alter the structure and function of oestrogen receptor α using different computational tools. Among the nonsynonymous SNPs, a total of four SNPs were found to be damaging by both a sequence homology-based tool (SIFT) and a structural homology-based method (polyphen-2, SNAP), as well as by the ESEfinder program, and one nonsense nsSNP was found. For noncoding SNPs, we found that one SNP in 5' UTR may potentially change protein expression level, nine SNPs were found to affect miRNA binding site and 28 SNPs might affect transcriptional regulation of the ESR1 gene. Reviewing the literature, 89 SNPs were found to be functional among which only four were located in exons.

OGDD (Olive Genetic Diversity Database): a microsatellite markers' genotypes database of worldwide olive trees for cultivar identification and virgin olive oil traceability.

Olive (Olea europaea), whose importance is mainly due to nutritional and health features, is one of the most economically significant oil-producing trees in the Mediterranean region. Unfortunately, the increasing market demand towards virgin olive oil could often result in its adulteration with less expensive oils, which is a serious problem for the public and quality control evaluators of virgin olive oil. Therefore, to avoid frauds, olive cultivar identification and virgin olive oil authentication have become a major issue for the producers and consumers of quality control in the olive chain. Presently, genetic traceability using SSR is the cost effective and powerful marker technique that can be employed to resolve such problems. However, to identify an unknown monovarietal virgin olive oil cultivar, a reference system has become necessary. Thus, an Olive Genetic Diversity Database (OGDD) (http://www.bioinfo-cbs.org/ogdd/) is presented in this work. It is a genetic, morphologic and chemical database of worldwide olive tree and oil having a double function. In fact, besides being a reference system generated for the identification of unkown olive or virgin olive oil cultivars based on their microsatellite allele size(s), it provides users additional morphological and chemical information for each identified cultivar. Currently, OGDD is designed to enable users to easily retrieve and visualize biologically important information (SSR markers, and olive tree and oil characteristics of about 200 cultivars worldwide) using a set of efficient query interfaces and analysis tools. It can be accessed through a web service from any modern programming language using a simple hypertext transfer protocol call. The web site is implemented in java, JavaScript, PHP, HTML and Apache with all major browsers supported. Database URL: http://www.bioinfo-cbs.org/ogdd/.

MnSOD and GPx1 polymorphism relationship with coronary heart disease risk and severity

BACKGROUND: Disturbance of the equilibrium between reactive oxygen species (ROS) and anti-oxidants (AOX) has been implicated in various diseases, including atherosclerosis, the most common pathologic process underlying coronary heart disease (CHD). Thus, the defense systems against ROS are critical protecting blood vessel walls against oxidative damage. In this study, we investigate whether Ala16Val MnSOD and Pro198Leu GPx polymorphisms are associated with CHD susceptibility and/or severity. METHODS: Both polymorphisms were genotyped in a sample of 203 controls and 164 patients. CHD risk and severity, antioxidant status (enzymatic and/or non enzymatic) and biochemical parameters were assessed and analysed by genotype. RESULTS: A significant association of MnSOD variant to CHD risk was revealed in males. Males harboring the Val/Val genotype were approximately at twofold increased risk of CHD compared to controls (Ala carriers vs Val/Val, adjusted OR 1.89; 95 % CI 1.18-3.42, p = 0.03). Significant decreases in SOD activity and total antioxidant status (TAS) were observed in Val carriers and by CHD status. Whereas, no association of GPx variant genotype (Leu/Leu) and activity to cardiopathy events was discerned. CHD severity, as demonstrated by the number of vessel stenosis, was associated with significantly higher frequency of Val allele and LDL levels in CHD subjects. CONCLUSIONS: Our results showed a lack of association of Pro198Leu GPx polymorphism to CHD risk and severity. However, they suggest that Ala16Val MnSOD polymorphism and decreased antioxidant defences are likely contributed to CHD risk in Tunisian men. Furthermore, the Val encoding MnSOD allele and decreased SOD activity were significantly correlated with CHD stenosis progression

Cytogenetic damage in the oral mucosa cells of bladder cancer patients exposed to tobacco in Southern Tunisia.

Bladder cancer was associated to exposure to several pollutants which can be absorbed, inhaled, or possibly ingested. We analyzed the frequency of micronuclei (MNC) and binucleated cells (BNC) in exfoliated cells of the oral mucosa of 24 bladder cancer (BC) patients and 48 controls residing in Southern Tunisia. An assessment was carried out on the incidence of MNC and BNC in 1,000 cells per individual. The data were analyzed with SPSS, using the chi-square and the Mann-Whitney U test, α = 0.05. The frequency of MN cells in BC cases was 2.5-fold higher, than in the control group (P < 0.001), while the difference for BNC between both groups was not significant. The smoking habits, age, and gender significantly influenced the MN but not the BNC alterations. The results of our study showed significantly increased frequencies of MN but not of BNC in exfoliated oral cells of BC patients associated with the smoking status, sex, and age. This study provides preliminary evidence that the frequency of MN in oral mucosa could be a predictive biomarker for cancers in parts of the body other than the upper aerodigestive tract, such as BC. Further scrupulous investigations are certainly warranted in order to implement this assay as a routine test in the planning and validation of cancer surveillance and prevention programs.

Inter-ethnic differences in genetic polymorphisms of xenobiotic-metabolizing enzymes (CYP1A1, CYP2D6, NAT1 and NAT2) in healthy populations: correlation with the functional in silico prediction.

Several studies have shown that many polymorphisms of the xenobiotic-metabolizing enzymes (XME) affect either enzymatic functions or are associated with various aspects of human health. Owing to the presence of these single nucleotide variants (SNVs), differences in detoxification capacity have been observed between many ethnicities. The aim of this investigation was to study the prevalence of four polymorphisms in XME among various ethnic groups. Attention was focused on polymorphisms of CYP2D6 (rs1058172, G>A, p.Arg365His), CYP1A1 (rs4646421, c.-26-728C>T), NAT1 (rs4921880, c.-85-1014T>A) and NAT2 (rs1208, A>G, p.Arg268Lys). These polymorphisms were analyzed in 261 healthy Tunisians individuals in comparison with different ethnic backgrounds from hapmap database. In addition, in silico functional prediction was also performed to determine the loss of function variants. Our results demonstrated that population's origins widely affect the genetic variability of XME enzymes and Tunisians show a characteristic pattern. In silico predictions showed a deleterious effect for p.Arg268Lys substitution on CYP2D6 function, findings confirmed its key role played in cancer susceptibility. These data show that detoxification genes structures depend on the studied population. This suggests that ethnic differences impact on disease risk or response to drugs and therefore should be taken into consideration in genetic association studies focusing on XME enzymes. Our results provide the first report on these SNV in Tunisian population and could be useful for further epidemiological investigations including targeted therapy.