An investigation of the relation between catalase C262T gene polymorphism and catalase enzyme activity in leukemia patients.

INTRODUCTION: Catalase (CAT), an antioxidant enzyme, catalyzes conversion of hydrogen peroxide to water and molecular oxygen, protecting cells against oxidative stress. The aim of this study was to investigate the possible association between CAT C262T polymorphism in the promoter region of the CAT gene and leukemia risk and to determine the relationship between CAT genotypes and CAT enzyme activities. MATERIAL AND METHODS: Genotypes of 102 cases and 112 healthy controls' genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism methods. Catalase activity was measured with the method of Aebi. RESULTS: The frequencies of the T allele among the cases and controls were 28.4% and 25.9%, respectively (p = 0.75). The frequencies of CC, CT, and TT among cases were 57.8%, 27.4%, and 14.7%, respectively, while in controls, the frequencies of CC, CT, and TT were 54.4%, 39.3%, and 6.3%, respectively, which were not significantly different. Although CAT enzyme activity was lower in leukemia patients with TT genotypes than in controls, this did not reach statistical significance (p = 0.37). CONCLUSIONS: This is the first report showing that CAT C262T polymorphism is not a genetic predisposing factor for the risk of leukemia in the Turkish population. However, additional research is needed to confirm these findings.

RhoA, ROCK-1, and ROCK-2 Gene Expression and Polymorphisms in Cholesteatoma Patients.

BACKGROUND: The aim of this study was to evaluate the gene polymorphism and expressions of Rho-A, ROCK-1, and ROCK-2 in cholesteatoma. METHODS: In this study, 120 healthy control group patients and 120 cholesteatoma patients were enrolled. Venous blood was taken from all of the cholesteatoma and control group patients. The genotyping of ROCK-1(G/T)rs35996865, ROCK-2(A/C)rs10178332, and Rho-A(A/T)rs2177268 polymorphisms was performed using predesigned TaqMan SNP Genotyping Assays. Assays-on-Demand SNP genotyping kit was used for the realtime polymerase chain reaction. The expression levels of Rho-A(Hs00357608_m1), ROCK-1(Hs01127699_m1), and ROCK-2(Hs00178154_m1) genes were determined. RESULTS: The expression of Rho-A, ROCK-1, and ROCK-2 was lower in cholesteatoma patients than in the control group. There was no difference in Rho-AAT/TT and ROCK-1GT/TT variation in cholesteatoma patients compared to the control. However, ROCK-2 AC/CC variance was lower in cholesteatoma patients. CONCLUSION: The expression of Rho-A, ROCK-1, and ROCK-2 genes may be decreased in cholesteatoma. Furthermore, since ROCK-2 AC/CC genotype is also lower in cholesteatoma, having C allele seems to decrease the risk of developing this disease.

The Correlation between IL-1ß-C31T Gene Polymorphism and Susceptibility to Breast Cancer.

PURPOSE: Interleukin-1 beta (IL-1ß), a pro-inflammatory cytokine, has been shown to influence breast cancer susceptibility. The relationship between its risk of breast cancer and IL-1ß-C31T polymorphism has been demonstrated, but the results remain controversial. Therefore, our study aimed to investigate the correlation between the IL-1ß-C31T gene polymorphism and susceptibility to breast cancer. METHODS: The genotype frequencies of IL-1ß-C31T polymorphism were compared between 204 breast cancer cases and 210 controls using polymerase chain reaction and restriction fragment length polymorphism techinques. Further multivariate binary logistic regression analyses were used to assess the association between IL-1ß-C31T polymorphism and breast cancer risk. RESULTS: The frequency of the T allele of IL-1ß-C31T polymorphism in breast cancer cases was significantly higher than that in the controls (56.1% vs. 47.9%). The frequencies of genotypes CC, CT, and TT in the cases were 22.1%, 43.6%, and 34.3%, respectively, while in the control group they were 24.3%, 55.7%, and 20.0%, respectively. There was a significant difference between the prevalence of TT genotype in the 2 groups (adjusted odds ratio [OR], 2.06; 95% confidence interval [CI], 1.16-3.66; p = 0.014). Breast cancer risk increased in women with TT genotype, body mass index (BMI) ≥ 25 kg/m2 (OR, 2.19; 95% CI, 1.09-4.36), late age at first birth (OR, 2.43; 95% CI, 1.29-4.56), postmenopausal status (OR, 3.15; 95% CI, 1.39-7.16), and negative smoking history (OR, 2.52; 95% CI, 1.32-4.82). Furthermore, increase in breast cancer risk among women diagnosed with invasive ductal carcinoma was associated with CT/TT genotypes (OR, 2.82; 95% CI, 1.38-5.76). CONCLUSION: The IL-1ß-C31T polymorphism affects breast cancer susceptibility, especially in women with late age at first birth, high BMI, postmenopausal status, negative smoking history, and invasive ductal carcinoma. Our study adds to the evidence about the importance of IL-1ß-C31T polymorphism in breast cancer susceptibility.

The influence of HER2 genotypes as molecular markers on breast cancer outcome.

Alterations of the human epidermal growth factor receptor 2 (HER2) protooncogene have been implicated in the carcinogenesis and prognosis of breast cancer. A polymorphism has been identified at codon 655 (ATC/isoleucine to GTC/valine [I655V]) in the transmembrane domain-coding region of this gene, which may be associated with the risk of breast cancer. In this study we aimed to determine whether the risk of breast cancer is associated with the I655V polymorphism of HER2 transmembrane domain-coding region at codon 655. The genomic DNA from breast cancer patients and control subjects underwent analysis by the polymerase chain reaction-fragment length polymorphism. We observed no overall association between HER2 genotype and breast cancer (p = 0.53). However, an elevated positive association was observed for Ile/Val+Val/Val versus Ile/Ile genotypes in women >age 60 years (p = 0.02). Further, other risk factors--namely, the body mass index and family history--were found to be risk factors for developing breast cancer (p = 0.006 and p = 0.00, respectively). In conclusion, results of this study suggest that polymorphisms of the HER2 gene may be important susceptibility biomarkers for breast cancer risk among older women.

Evaluation of sister chromatid exchange and chromosomal aberration frequencies in peripheral blood lymphocytes of gasoline station attendants.

Petroleum derivatives constitute a complex mixture of chemicals which contain well-known genotoxicants, such as benzene. Thus, chronic occupational exposure to such derivatives may be considered to possess genotoxic risk. In the present study, frequencies of sister chromatid exchange (SCE); aberrant cells, including numerical and structural chromosomal aberrations; and chromosome aberrations were investigated in peripheral blood lymphocytes from 30 exposed workers (15 smokers and 15 nonsmokers) and 30 controls (15 smokers and 15 nonsmokers). The exposed subjects were employed at 12 different petrol pumping stations in the city of Mersin, Turkey. Urinary phenol levels of exposed workers were found to be significantly higher than those of control subjects. Benzene exposure and cigarette smoking decrease the replication index and mitotic index. There is an interaction between benzene exposure and cigarette smoking for replication index and mitotic index. There is no interaction between cigarette smoking and benzene exposure for chromosomal aberrations. The results indicate that there are significant differences in SCE values in the exposed workers compared to the control individuals (P < 0.01), but there is no difference between smokers and nonsmokers for SCE frequency (P > 0.05). SCE frequency is higher in smokers than in nonsmokers.