Impact of ABCB1 Gene Polymorphisms and Smoking on the Susceptibility Risk of Chronic Myeloid Leukemia and Cytogenetic Response

Background:IM, a strong and selective TKI, has been approved as the front line of treatment in CML patients. In spite of satisfactory results of imatinib in the treatment of patients with CML, patients with treatment failure or suboptimal response developed resistance that might be because of pharmacogenetic variants. This study attempted to evaluate the influence of ABCB1 gene polymorphisms and smoking on CML risk and resistance to imatinib. Methods: ABCB1 (c.1236C>T, c.3435C>T) polymorphisms were genotyped in 98 CML patients and 100 sex- and age-matched healthy subjects by PCR-RFLP method, followed by sequencing. The patients were evaluated for cytogenetic response by the standard chromosome banding analysis in regular intervals. Results:Our results showed that c.1236CC genotype was significantly associated with imatinib resistance (OR = 3.94; p = 0.038). Analysis of the joint of SNP-smoking combination showed that smokers with c.1236TT/CT and c.1236CC genotypes had the increased risk of CML (OR = 6.04; p = 0.00 and OR = 4.95, p = 0.005) and treatment failure (OR = 5.36, p = 0.001 and OR = 15.7, p = 0.002), respectively. Smokers with c.3435TT/CT and c.3435CC genotypes also displayed the elevated risk of CML development (OR = 6.01, p = 0 and OR = 4.36, p = 0.011) and IM resistance (OR = 5.61, p = 0.001 and OR = 13.58, p = 0.002), respectively. Conclusion:Our findings suggest that c.1236CC genotype has clinical importance in the prediction of treatment outcome with IM, and smoking could have a synergistic role in CML risk and IM resistance. Key Words: ATP binding cassette transporter subfamily B, Imatinib mesylate, Smoking     

Association between ABCB1-T1236C polymorphism and drug-resistant epilepsy in Iranian female patients

Background: One third of epileptic patients are resistant to several anti-epileptic drugs (AED). P-glycoprotein (P-gp) is an efflux transporter encoded by ATP-binding cassette subfamily B member 1 (ABCB1) gene that excludes drugs from the cells and plays a significant role in AEDs resistance. Over-expression of P-gp could be a result of polymorphisms in ABCB1 gene. We studied the association of T129C and T1236C single-nucleotide polymorphisms (SNP) of ABCB1 gene with drug-resistant epilepsy in Iranian epileptics. Methods: DNA samples were obtained from 200 healthy controls and 332 epileptic patients, of whom 200 were drug responsive and 132 drug resistant. The frequencies of the genotypes of the two SNP were determined by polymerase chain reaction followed by restriction fragment length polymorphism. Results: No significant association was found between T129C and T1236C genotypes and drug-resistant epilepsy neither in adults nor in children. However, the risk of drug resistance was higher in female patients with 1236CC (P = 0.02) or CT (P = 0.008) genotype than in those with TT genotype. The risk of drug resistance was also higher in patients with symptomatic epilepsies with 1236CC (P = 0.02) or CT (P = 0.004) genotype than in those with TT genotype. The risk of drug resistance was lower in patients with idiopathic epilepsies with 129TT genotype (P = 0.001) than in those with CT genotype. Conclusion: Our results indicate that T1236C polymorphism is associated with drug resistance in Iranian female epileptic patients. Replication studies with large sample sizes are needed to confirm our results. Key Words: ATP-binding cassette subfamily B member 1 (ABCB1), Drug-resistant epilepsy, Single nucleotide polymorphism     

Potential of Waxy gene microsatellite and single-nucleotide polymorphisms to develop japonica varieties with desired amylose levels in rice (Oryza sativa L.)

The Waxy (Wx) gene is responsible for the synthesis of amylose, a key determinant of the cooking and processing qualities of rice. Polymorphisms of CT-microsatellite and G–T single-nucleotide polymorphism (SNP) in the Wx gene and their relationship to amylose content (Ac) were explored using 178 non-waxy rice genotypes. Nine Wx microsatellite alleles, namely (CT)10 and 11, and (CT)14–20 were identified and 11 haplotypes were recognised by different combinations of CT-microsatellite and G–T SNP. Amylose content analysed in a random set of 39 genotypes was correlated with different microsatellite alleles/haplotypes. The highest Ac levels (>30%) correlated with (CT)10 and 16, high (26–30%) with (CT)11, 15 and 20, and intermediate (21–25%) with (CT)14, in all cases with G at the G–T SNP. The CT-classes (CT)17 and 18 (mean Ac value of 21%), could be subdivided into low amylose haplotypes (16–20%) for 17T and 18T and intermediate amylose haplotypes (21–25%) for 17G and 18G. The use of haplotypes proved to discriminate between intermediate and low amylose accessions within the same microsatellite class. Analyses of a segregating population of a cross between low and high Ac parents showed that CT-microsatellite may help to classify breeding lines and identify pollen contamination. We suggest that CT-microsatellite together with G–T SNP may be used as molecular marker by breeders to develop varieties with desired amylose levels.     

Effects of Ethanol Extracts from Grateloupia elliptica,a Red Seaweed,and Its Chlorophyll Derivative on 3T3-L1 Adipocytes: Suppression of Lipid Accumulation through Downregulation of Adipogenic Protein Expression

Grateloupia elliptica (G. elliptica) is a red seaweed with antioxidant, antidiabetic, anticancer, anti-inflammatory, and anticoagulant activities. However, the anti-obesity activity of G. elliptica has not been fully investigated. Therefore, the effect of G. elliptica ethanol extract on the suppression of intracellular lipid accumulation in 3T3-L1 cells by Oil Red O staining (ORO) was evaluated. Among the eight red seaweeds tested, G. elliptica 60% ethanol extract (GEE) exhibited the highest inhibition of lipid accumulation. GEE was the only extract to successfully suppress lipid accumulation among ethanol extracts from eight red seaweeds. In this study, we successfully isolated chlorophyll derivative (CD) from the ethyl acetate fraction (EA) of GEE by high-performance liquid chromatography and evaluated their inhibitory effect on intracellular lipid accumulation in 3T3-L1 adipocytes. CD significantly suppressed intracellular lipid accumulation. In addition, CD suppressed adipogenic protein expression such as sterol regulatory element-binding protein-1 (SREBP-1), peroxisome proliferator-activated receptor-γ (PPAR-γ), CCAAT/enhancer-binding protein-α (C/EBP-α), and fatty acid binding protein 4 (FABP4). Taken together, our results indicate that CD from GEE inhibits lipid accumulation by suppressing adipogenesis via the downregulation of adipogenic protein expressions in the differentiated adipocytes. Therefore, chlorophyll from G. elliptica has a beneficial effect on lipid metabolism and it could be utilized as a potential therapeutic agent for preventing obesity.     

Molecular Genetic Analysis of the Variable Number of Tandem-Repeat Alleles at the Phenylalanine Hydroxylase Gene in Iranian Azeri Turkish Population

Background:

The variable numbers of tandem-repeat (VNTR) alleles at the phenylalanine hydroxylase (PAH) gene have been used in carrier detection and prenatal diagnosis in phenylketonuria families. This study was carried out to analyze VNTR alleles at the PAH gene in Iranian Azeri Turkish population.

Methods:

In this study, 200 alleles from general population were studied by PCR.

Results:

The frequencies of VNTR alleles were 45%, 46%, 2%, 3%, 1%, and 3% in studied group regarding 3, 8, 9, 11, 12, and 13 repeat copies, respectively. Statistically significant differences were not found between expected and observed frequencies of VNTR genotypes (P > 0.05).

Conclusions:

VNTR alleles with three and eight repeats were frequent, and the VNTR alleles with 13 repeats showed 3% frequency in the tested group. This study is the first report on tested population genetic structure using VNTR alleles at the PAH gene. Key Words: Phenylalanine hydroxylase, Population genetics, Variable numbers of tandem-repeat     

Development of new markers to genotype the functional SNPs of SSIIa, a gene responsible for gelatinization temperature of rice starch

Gelatinization temperature (GT) is an important quality predictor that determines the cooking quality of rice. GT is genetically controlled by the starch synthase IIa (SSIIa) gene. Two functional single nucleotide polymorphisms (SNPs) inside the SSIIa have already been found to be responsible for the variation of GT. One of these, GC/TT SNP at 4329/4330 bp, could be genotyped by four primers in a single PCR ( Bao et al., 2006a), but another one, G/A SNP at 4198 bp, has not been detected by a PCR-based marker. Here, we developed cleaved amplified polymorphic sequence (CAPS) and derived cleaved amplified polymorphic sequence (dCAPS) markers to detect these SNPs. A dCAPS marker that the PCR products were cleaved by the BseR I restriction endonuclease was designed to detect GC/TT SNP. Both CAPS and dCAPS markers were designed to detect G/A SNP using the restriction endonuclease Nla III and Tsp45 I, respectively. All the markers developed were co-dominant. It was known that the A allele of G/A SNP was rare among rice germplasm, but it was still in use by rice breeders. 11 rice accessions including landrace and breeding lines with A allele of G/A SNP were detected. The F₂ individuals from two crosses were used to analyze the co-segregation between the SNP alleles and the GT. The segregation ratio of two SNPs did not conform to the expected Mendelian ratio of 1:2:1, but the SNPs were co-segregated with GT. The markers developed in the present study would be useful in molecular breeding for the improvement of the quality of rice grain.     

Prevalence of Class 1 Integrons and Extended Spectrum Beta Lactamases among Multi-Drug Resistant Escherichia coli Isolates from North of Iran

Background:

Extended spectrum beta lactamases (ESBLs) are an important cause of transferable multidrug resistance (MDR) in gram-negative bacteria. The most described ESBL genes are generally found within integron-like structures as mobile genetic elements. The aim of this study was to identify the accompanying of class 1 integrons and ESBLs in the MDR E. coli isolates.

Methods:

Susceptibility to antimicrobial agents was determined for 33 E. coli strains by the disk diffusion method. Double-disk synergy test was applied for screening ESBL. To identify the strains carrying integrons, the conserved regions of integron-encoded integrase gene intI1 were amplified. For detection of gene cassettes, 5′CS and 3′CS primers were used.

Results:

All E. coli isolates were identified as multi-drug resistant. More than 50% of the isolates were resistant to tetracycline, cephalothin, cefuroxime, amoxicillin-clavulanic acid, and third generation cephalosporines. Nearly all of the isolates displayed sensitivity to piperacillin. There was a significant correlation between production of ESBL and resistance to all antibiotics except for ciprofloxacin and piperacillin (P < 0.01). Thirty two MDR strains (97%) included class 1 integron, and some isolates that included integrons were similar in the size of gene cassettes. The isolates were different in the resistance profiles; however, some others had similar resistance profiles. Of eight ESBL positive isolates, seven (87.5%) carried class 1 integrons.

Conclusion:

Class 1 integrons were frequent in MDR and also ESBL-producing E. coli isolates. High prevalence of class 1 integrons confirms that integron-mediated antimicrobial gene cassettes are important in E. coli resistance profile. Key Words: Antibiotic, Integrons, Escherichia coli     

Gracilaria gracilis (Gracilariales,Rhodophyta) from Dakhla (Southern Moroccan Atlantic Coast) as Source of Agar: Content,Chemical Characteristics,and Gelling Properties

Agar is a sulfated polysaccharide extracted from certain marine red algae, and its gel properties depend on the seaweed source and extraction conditions. In the present study, the seaweed Gracilaria gracilis (Gracilariales, Rhodophyta) from Dakhla (Moroccan Atlantic Coast) was investigated for its agar content, structure, and gel properties. The agar yields of G. gracilis were 20.5% and 15.6% from alkaline pretreatment and native extraction, respectively. Agar with alkaline pretreatment showed a better gelling property supported by higher gel strength (377 g·cm⁻²), gelling (35.4 °C), and melting (82.1 °C) temperatures with a notable increase in 3,6-anhydro-galactose (11.85%) and decrease in sulphate (0.32%) contents. The sulfate falling subsequent to alkaline pretreatment was verified through FT-IR spectroscopy. The ¹³C NMR spectroscopy showed that alkaline-pretreated agar has a typical unsubstituted agar pattern. However, native agar had a partially methylated agarose structure. Overall, this study suggested the possibility of the exploitation of G. gracilis to produce a fine-quality agar. Yet, further investigation may need to determine the seasonal variability of this biopolymer according to the life cycle of G. gracilis.     

波兰小麦醇溶蛋白遗传差异及其与新疆稻麦的关系

利用酸性聚丙烯酰胺凝胶电泳（ＡＰＡＧＥ）对９份波兰小麦和２份新疆稻麦进行了醇溶蛋白分析。结果表明：⑴波兰小麦具有明显的醇溶蛋白多态性,９份材料具有７种醇溶蛋白带型,电泳分离出的２７条带中,２３条具有多态性;⑵供试波兰小麦间遗传距离在０－０．７５之间,平均值为０．４９,遗传变异较大。供试波兰小麦在遗传距离０．４９水平上聚为３类,其醇溶蛋白聚类与收集地关系不大;⑶新疆稻麦与波兰小麦的醇溶蛋白电泳图谱具     

Molecular and physico-chemical evaluation of enzymatic browning of whole meal and dough in a collection of tetraploid wheats

Many studies have demonstrated the role of polyphenol oxidase (PPO; E.C. 1.14.18.1) in darkening of wheat products. Even slight browning of pasta is a major hindrance to consumer acceptance. The aim of this research was to evaluate the variability of PPO activity, browning level, and protein content in a collection of more than 100 genotypes of tetraploid wheat, including cultivars and landraces. A molecular approach was followed to evaluate the efficiency of marker PPO18, discovered and used in common wheat, in detecting tetraploid wheat genotypes with low browning level. The data showed a significant genotype influence on the activity of the PPO enzyme, which was correlated with brown index of whole meal and dough, and with protein content. On the whole, the cultivars showed lower PPO activity, brown index, and protein content than landraces, but wide variability was present. Marker PPO18 detected four different alleles for Ppo-A1. The allele Ppo-A1f identified genotypes with high PPO activity and brown index, while the Ppo-A1b and null alleles were associated with the opposite characteristics. Hence, this marker can be used to select new tetraploid wheat cultivars with low browning level.     

Administration of Lupinus albus Gamma Conglutin (Cγ) to n5 STZ Rats Augmented Ins-1 Gene Expression and Pancreatic Insulin Content

Several studies support the health-promoting benefits of lupins, particularly lupin proteins. It has been demonstrated that Lupinus albus gamma conglutin (Cγ) protein lowered blood glucose levels; thus, Cγ showed promise as a new anti-diabetic compound for type 2 diabetes (T2D) treatment. The aim of this study was to evaluate the effect of Cγ on Ins-1 gene expression and on pancreatic insulin content in streptozotocin-mediated diabetic rats. Cγ was isolated from Lupinus albus seeds. Its identification was confirmed with polyacrylamide gel electrophoresis under native and denaturing conditions. We used streptozotocin (STZ) to induce T2D on the 5th day of life of newborn male Wistar rats (n5-STZ). After 20 weeks post-induction, these animals (glycemia?>?200 mg/dL) were randomly assigned to three groups that received the following one-week treatments: vehicle, 0.90 %?w/v NaCl (n5 STZ-Ctrl); glibenclamide, 10 mg/kg (n5 STZ-Glib); or Cγ, 120 mg/kg (n5 STZ-Cγ). Glucose and insulin levels were measured before and after treatment. Ins-1 gene expression was quantified using real time polymerase chain reaction and the pancreatic insulin content was evaluated with immunohistochemistry. Post-treatment, the n5 STZ-Cγ and n5 STZ-Glib groups showed reductions in glucose, increments in serum insulin, and increases in Ins-1 gene expression and beta cell insulin content compared to the n5 STZ-Ctrl group. The results showed that Cγ had beneficial effects on Ins-1 gene expression and pancreatic insulin content. These biological effects of Cγ strengthen its promising potential as a nutraceutical and/or new agent for controlling hyperglycemia.     

Discriminant analysis of selected yield components and fatty acid composition of chosen Triticum monococcum, Triticum dicoccum and Triticum spelta accessions

This study analyses the variability of key yield components, the content of protein and crude fat in grain and the fatty acid composition of 50 spring accessions of Triticum monococcum, Triticum dicoccum and Triticum spelta of various origins. The average protein content of the grain of T. monococcum was 20.8%, of T. dicoccum 19.7%, and of spelt 17.0%. The crude fat content of T. monococcum grain (2.7%) was significantly higher compared with T. spelta (2.4%) and T. dicoccum (2.3%). In crude fat, fatty acids C18:2, C18:1 and C16 predominated. T. spelta was characterised by the highest concentrations of C18:2 and C16 (55.89% and 18.77% respectively), while T. monococcum had the highest content of C18:1 (26.35%). The structure of analysed fatty acids proved to be highly desirable in this species. A discriminant analysis performed separately for five variables: protein and fat content and three biometrical characters and separately for fatty acid composition enabled three Triticum species to be distinguished. These species also differed significantly with respect to the C18:1/C16 ratio which was equal to 1.78, 1.06, 1.47 and 0.99 in T. monococcum, T. dicoccum, T. spelta and Triticum aestivum respectively.     

OGG1 DNA Repair Gene Polymorphism As a Biomarker of Oxidative and Genotoxic DNA Damage

Background:Single nucleotide polymorphisms in OGG1 gene modulates DNA repair capacity and functions as one of the first lines of protective mechanisms against 8-OHdG mutagenicity. OGG1-Cys326 gene polymorphism may decrease DNA repair function, causing oxidative stress due to higher oxidative DNA damage. The main purpose of this study was to examine the link of oxidative and genotoxic DNA damage with DNA repair OGG1 gene polymorphism, in charcoal workers exposed to polyaromatic hydrocarbons. Methods:Urinary 8-OHdG excretion (a biomarker of oxidative DNA damage) was determined in both exposed and control populations. Genotyping of OGG1 DNA repair gene in the blood samples of subjects was carried out by PCR-RFLP method. Results:The 8-OHdG urinary concentration was significantly higher (p < 0.05) in the exposed (geometric mean 12.33 ± 3.78) than in the unexposed (geometric mean 7.36 ± 2.29) population. DNA damage, as measured by 8-OHdG and TM content, was found to be significantly higher in OGG1 homozygous mutants (mt/mt; 18.81 ± 3.34; 6.04 ± 0.52) as compared to wild-type genotypes (wt/wt; 10.34 ± 2.25; 5.19 ± 2.50) and heterozygous (wt/mt) mutants (12.82 ± 2.81; 6.04 ± 0.93) in the exposed group. Conclusion:We found a significant association of OGG1 heterozygous (wt/mt) and homozygous (mt/mt) variants with oxidative and genotoxic damage, suggesting that these polymorphisms may modulate the effects of PAH exposure in occupational workers. Key Words: 8-hydroxy-2’-deoxyguanosine, 1-hydroxypyrene, Polycyclic aromatic hydrocarbons     

Identification of late blight, Colorado potato beetle, and blackleg resistance in three Mexican and two South American wild 2x (1EBN)Solanum species

Wild potatoes are important sources of genes for resistance to disease and insect pests. A collection of wild Mexican and South AmericanSolarium species from the US potato Genebank was evaluated under laboratory and/or field conditions for their reaction to late blight (Phytophthora infestans), Colorado potato beetle (CPB,Leptinotarsa decemlineata Say), and blackleg (Erwinia carotovora subsp.atroseptica (van Hall) Dye) in order to identify individual genotypes with multiple resistance genes. Late blight inoculations using aggressive isolates (US-8/A2 and US-11/A1 mating types) of P.infestans revealed a wide range of variation for resistance between and within the accessions of the wild species tested. For late blight, susceptible as well as moderately to highly resistant genotypes were observed in all the species tested. However, at least one accession from the three Mexican and one South American wild diploid species tested showed a relatively uniform high level of resistance toP. infestans. These includedS. bulbocastanum, S. pinnatisectum, S. cardiophyllum, andS. circaeifolium. Two accessions from South American speciesS. commersonii were highly susceptible to late blight. For the Colorado potato beetle test, only one species,S. pinnatisectum appeared uniformly resistant to CPB under field conditions. Results of screening for blackleg resistance showed that there were major differences between genotypes in the wild species. Accessions ofS. circaeifolium PI 498119 andS. bulbocastanum PI 243504 were identified as having significantly higher blackleg resistance than cultivated potato and the other wild species tested. However, genotypes from these two accessions were more susceptible to late blight and CPB. Characterization of theP. infestans isolate P1801C.16 used for late blight evaluation and multi-locus isolate tests using US-8/A2 and US-11/A1 races revealed that the resistance inS. pinnatisectum genotypes tested corresponded to a race-non-specific genetic system, which was different from any existing R genes.Solanum pin-natisectum genotypes with both high levels of late blight and CPB resistance as well as blackleg resistance genotypes identified in the present study represent a diverse gene pool that may be useful for development of new potato cultivars with multiple disease and insect resistance. The potential utilization of these valuable sources for improvement of cultivated potato is discussed.     

Genetic variability among cotton genotypes for cold tolerance

Even though planting cotton early in the season is advantageous, the cold sensitivity of cotton seedlings and low germination rates, especially in the areas experiencing low temperatures, are the main obstacle for the early seasonal planting. A total of 106 genotypes from three different species; Gossypium hirsutum L., G. barbadense L., and G. herbaceum L. were screened for cold tolerance using three different approaches. Furthermore, the best screening method to differentiate between the genotypes for cold tolerance, and to predict their field emergence rates was also determined. In detail, optimal germination percentages were measured at 30 °C with the results ranging from 61% to 99%. On the other hand, cold temperature germination rates and emergence percentages ranged from 8% to 82% in paper test and from 8% to 88% (the 7th day after planting) in sand test at 18 °C, and field emergence percentages ranged from 44% to 77% at 28 days after planting. A significant difference between cotton species in terms of their tolerance to cold was observed. That is, G. barbadense genotypes had higher germination rates than the other two species in the three methods used. There was no correlation between optimal germination rates and field emergence percentages. Among cold temperature germination methods, the 18 °C paper test was better in predicting of field emergence percentage, in differentiating between genotypes in terms of their cold tolerance and in determining seed vigor. G. hirsutum cultivars; 8106-2, AYDIN-110, CORINA, DP-388, DPL-50, DPL-5614, NAZILLI-342 and one G. barbadense cultivar, GIZA 70 were more cold tolerant among all the cotton cultivars screened in this study.     

Association Study of rs1333040 and rs1004638 Polymorphisms in the 9p21 Locus with Coronary Artery Disease in Southwest of Iran

Background:

Coronary artery disease (CAD) is a multifactorial and heterogenic disease. Recently, genome-wide association studies have reported that rs1333040 (C/T) and rs1004638 (A/T) single nucleotide polymorphisms (SNPs) in the 9p21 locus have very strong association with CAD. This study aimed to examine these associations in Southwest of Iran.

Methods:

Blood samples were collected from 200 CAD patients and 110 healthy individuals with no CAD. The association of two SNPs with CAD was evaluated by PCR and restriction fragment length polymorphism.

Results:

Chi-square test showed no association between rs1333040 SNP and CAD (X²: 4.66, df: 2, P=0.09). Also, there was no association between rs1004638 SNP and CAD (X²: 0.27, df: 2, P=0.88).

Conclusion:

No association was observed between rs1333040 and rs1004638 SNPs in the 9P21 region and CAD in Southwest of Iran. Key Words: Coronary artery disease, Single nucleotide polymorphisms, Genetic association study, Iran     

Defensive Responses of Rice Genotypes for Resistance Against Rice Leaffolder Cnaphalocrocis medinalis

The experiment was carried out to assess the reaction of different categories of rice genotypes viz., resistant, susceptible, hybrid, scented, popular and wild in response to the infestation by rice leaffolder (RLF), Cnaphalocrocis medinalis (Guenee) and to explore the possible use of these genotypes in developing RLF-resistant rice varieties. The changes of various biochemical constituents such as leaf soluble protein, phenol, ortho-dihydroxy phenol, tannin and enzymes viz., peroxidase, phenyl alanine ammonia lyase (PAL) were assessed spectrophotometrically in all the rice genotypes before and after RLF infestation. The protein profile was analyzed using sodium dodecyl sulphate-poly acrylamide gel electrophoresis (SDS-PAGE) method. A significant constituent of biochemical content such as tannin, phenol and ortho-dihydroxy phenol has been increased along with enzyme activities of peroxidase and PAL in the infested resistant (Ptb 33, TKM6 and LFR831311) and wild rice genotypes (Oryza minuta and O. rhizomatis). A decrease in leaf protein content was evident invariably in all the infested rice genotypes. It is also evident that the contents of biochemicals such as phenol, ortho-dihydroxy phenol and tannin were negatively correlated with leaffolder damage. However, leaf protein content was positively correlated with the damage by rice leaffolder. SDS-PAGE analysis for total protein profiling of healthy and C. medinalis-infested genotypes revealed the enhanced expression of a high molecular weight (> 97 kDa) protein in all the genotypes. Besides, there was also an increased induction of a 38 kDa protein in C. medinalis infested resistant genotypes, which was absent in uninfested plants. The present investigation proved that the elevated levels of biochemicals and enzymes may play a vital role in rice plants resistance to RLF.     

Impact of Methylenetetrahydrofolate Reductase C677T Polymorphism on the Risk of Gastric Cancer and Its Interaction with Helicobacter pylori Infection

Background

Attempts for early detection of gastric cancer have recently focused on host''s genetic susceptibility factors and gene-environment interactions. We have, herein, studied the association of MTHFR C677T single nucleotide polymorphism (SNP) and its interaction with Helicobacter pylori infection, smoking, age and gender on the risk of gastric cancer among an Iranian population.

Methods

Gastric cancer patients (n = 450) and cancer-free controls (n = 780) were studied for serum H. pylori-specific IgG antibodies by ELISA and MTHFR C677T polymorphism (SNP) by PCR-RFLP. Demographic and life style data were collected through patient interviews. Unconditional logistic regression model estimated odds ratio (OR) and the corresponding 95% confidence intervals (CI).

Results

The interactions of MTHFR genotype with H. pylori infection (P = 0.03), age (P = 0.049) and gender (P = 0.007) were statistically significant. Accordingly, MTHFR C677T carriers who were also positive for H. pylori infection exhibited 80% (OR = 1.8, 95% CI = 1.0-2.9) significant excess risk of non-cardia gastric cancer. Furthermore, subjects over the age of 50 or female subjects carrying MTHFR C677T SNP showed 40 (OR = 1.4, 95% CI = 1.0-2.0) and 100 (OR = 2.0, 95% CI = 1.2-3.2) percent increased risk of gastric cancer, respectively.

Conclusion

MTHFR C677T SNP seems to increase the risk of gastric cancer and the effect is significantly inflated by interactions with H. pylori infection, age and gender. Key Words: Helicobacter pylori, Smoking, Gender identity, Age group, Methylenetetrahydrofolate reductase     

The role of Ile3434Thr XRCC7 gene polymorphism in Differentiated Thyroid Cancer risk in an Iranian population

Background

The aim of this study was to understand any association between differentiated thyroid carcinoma (DTC) and Ile3434Thr XRCC7 gene polymorphism (GenBank accession number: rs7830743). DTC is the most prevalent thyroid neoplasm, which includes papillary and follicular cell carcinoma. XRCC7 gene encodes a protein that functions in non-homologous end joining DNA repair pathway. Non-synonymous polymorphisms in this gene may alter DNA repair capacity of the cell and change the risk of developing cancers.

Methods

DTC patients (n = 173) and cancer free individuals (n = 204) were enrolled in a case-control study. The Ile3434Thr polymorphic alleles were discriminated by using amplification refractory mutation system-PCR method. The frequencies of this single nucleotide polymorphism in case and control groups were compared. Also, risk ratio for developing DTC in dichotomized genotypes was estimated by multivariate logistic regression analysis.

Results

Dichotomized genotypes into those with and without the 3434Thr allele showed that this allele was associated with DTC (OR [odd ratio]: 1.89, 95% confidence interval (CI) = 1.29-2.79, P<0.001). Also, TC genotype was significantly associated with increased risk of DTC (OR: 2.42, 95% CI = 1.55-3.81, P = 0.0001) in individuals carrying this genotype.

Conclusion

Allele 3434Thr in XRCC7 gene might be associated with differentiated thyroid cancer risk. Further studies with larger samples are needed to verify these initial findings. Key Words: DNA repair enzymes, Thyroid neoplasms, Genetic polymorphism