Sibel Oguzkan Balci

Association of endothelial nitric oxide synthase gene polymorphisms with endometrial carcinoma: a preliminary study

OBJECTIVE To investigate the relationship between specific endothelial nitric oxide synthase (eNOS) gene polymorphisms and endometrial cancer (ECa). MATERIAL AND METHODS The study group consisted of 89 patients histologically diagnosed with the endometrioid type of endometrial carcinoma. The control group consisted of 60 randomly selected individuals who had undergone total hysterectomy. Genomic DNA was isolated from paraffin-embedded endometrial tissues. We investigated the G894T polymorphisms (G894T) and variable number tandem repeats polymorphisms in intron 4 (VNTR intron 4) in the eNOS gene by using polymerase chain reaction (PCR) and/or restriction fragment length polymorphism (RFLP). The genotype distributions and allele frequencies of the two groups were compared. RESULTS Analysis of the VNTR intron 4 polymorphisms in eNOS gene revealed that the frequency of the AA genotype was significantly higher in the control group, whereas the frequency of the BB genotype was significantly higher in the ECa group. Analysis of the G894T polymorphisms in eNOS gene revealed a significantly higher frequency of the GG genotype in the control group but a significantly higher frequency of the TT genotype in the endometrial cancer group. CONCLUSION The G894T and VNTR intron 4 polymorphisms in eNOS gene could be an intriguing susceptibility factor that modulates an individuals risk of ECa in the Turkish population.

Childhood Obesity and the Role of Dopamine D2 Receptor and Cannabinoid Receptor-1 Gene Polymorphisms

AIMS The dopaminergic and endocannabinoid systems are involved in regulation of feeding behavior. The aim of the study is to examine the possible relation between polymorphisms of the dopamine D2 receptor (DRD2) and cannabinoid receptor-1 (CNR1) genes and childhood obesity. METHODS A hundred obese children and 100 healthy controls were analyzed for DRD2 Taq1A and Taq1B and CNR1 1359G/A polymorphisms. Genotyping was performed by polymerase chain reaction and restriction fragment length polymorphism. RESULTS There were no statistically significant differences in DRD2 Taq1A and DRD2 Taq1B genotypes or allelic frequencies between obese children and controls (p>0.05). In patients with Taq1B2 allele, morbid obesity was less frequent (p=0.010). The frequency of the A allele of CNR1 1359G/A polymorphism was significantly higher in obese children than in controls (21.0% vs. 13.0%, p=0.0166). The frequency of genotypes AG and GG of the CNR1 1359G/A SNP was different between obese children and control subjects (for AG: 34.0% vs. 22.0%, p=0.0294; for GG: 62.0% vs. 76.0%, p=0.0162, respectively). CONCLUSIONS No significant difference was found between genotypes and alleles of DRD2 Taq1A and DRD2 Taq1B polymorphism in patients and controls, while the CNR1 receptor 1359G/A polymorphism and the presence of the A allele may be one risk factor for susceptibility to obesity.

Relationship between the 1359 G/A polymorphism of the Central Cannabinoid Receptor 1 (CNR1) gene and susceptibility to cannabis addiction in a Turkish population

In this study, we investigate the existence of a possible genetic association between 1359 G/A polymorphism of the Central Cannabinoid Receptor 1 (CNR1) Gene CNR1 (p.Thr453Thr; rs1049353) single nucleotide polymorphism (SNP) and cannabis addiction. DNA samples used in this work are purified from venous leukocytes of 145 unrelated Turkish cannabis-dependent subjects and 140 Turkish control subjects. No significant difference is observed in genotype or allele frequencies of CNR1 1359 G/A polymorphism between these two groups. We also compared CNR1 1359 G/A polymorphism allele frequency distribution in our healthy Turkish population with other healthy populations. The comparison of healthy Turkish subjects with the healthy subjects from English-Irish, Chinese, European-American, African-American, Italian, German and Japanese populations revealed significant differences in allele frequencies. Data indicate that the 1359 G/A CNR1 polymorphism does not contribute to susceptibility to cannabinoid addiction in Turkish subjects. To the best of our knowledge, this is the first study on 1359 G/A CNR1 polymorphism in the Turkish population.

Genetic contributing factors to substance abuse: an association study between eNOS gene polymorphisms and cannabis addiction in a Turkish population

It is known to be largely related to behavioural changes and neuropsychiatric disorders, and studies demonstrating the influence of eNOS gene variants in the development of depressive, aggressive and suicidal behaviours exist in the literature. Here, we investigate two polymorphisms in the eNOS gene, namely, G894T (Glu298Asp) and intron 4 VNTR, as possible genetic contributing factors to cannabis addiction. DNA samples used in this work were purified from the peripheral blood of 94 unrelated Turkish cannabis-dependent subjects and 100 Turkish control subjects from the southeastern region of Turkey. The eNOS polymorphisms were characterised by the PCR and/or PCR-RFLP (Polymerase Chain Reaction-restriction fragment length polymorphism) method. The De-finetti programme, chi-square, Fisher’s exact test, odds ratio and 95% confidence intervals (CI) were used for statistical analysis. The incidence of aa and TT genotypes and the frequency of the alleles a and T were found to be significantly higher in the cannabis addicts group than in the control subjects (p < 0.05). The results indicate that G894T and intron 4 VNTR eNOS gene polymorphisms are statistically-significant contributing factors to susceptibility to cannabis addiction, while the same polymorphism alleles associated with high NO levels are a protective factor in Turkish subjects. To the best of our knowledge, this is the first study on eNOS gene polymorphisms involving the Turkish population.