Haplotype Analysis of Vitamin D Receptor (VDR) Gene in Breast Cancer Patients.

BACKGROUND: The aim of the study was to evaluate the role of well-characterized vitamin D receptor (VDR) gene polymorphisms, BsmI (rs 1544410), ApaI (rs 7975232), TaqI (rs 731236), and FokI (rs 10735810) and their haplotypes in the pathogenesis of breast cancer in Turkish women. METHODS: The subjects consisted of women including 331 breast cancer patients and 345 healthy controls. After conventional DNA isolation genotyping was done by a PCR-RFLP method, haplotype analysis was performed using Haploview 4.2. RESULTS: Haplotype analysis in different combinations revealed that frequencies of Fbt, fbt, bAt, and bt haplotypes are significantly higher in breast cancer patients than controls (χ2 = 6.862, p = 0.0088; χ2 = 4.176, p = 0.041; χ2 = 4.184, p = 0.0408; χ2 = 8.409, p = 0.0037 respectively). However, no statistically significant difference between genotypes of cases and controls were found when analyzed separately. CONCLUSIONS: All these data support the hypothesis that it is crucial to evaluate VDR gene polymorphism by haplotype analysis in order to understand how changes in VDR sequence influence the function of the VDR gene and how this variability affects the risk of breast cancer.

Evaluation of vitamin D receptor gene polymorphisms in patients with differentiated thyroid carcinomas and nodular goiter.

BACKGROUND: The role of vitamin D has previously been determined in autoimmune and malignant thyroid diseases. We aimed to identify the haplotype distribution of single nucleotide polymorphisms (SNPs) in the vitamin D receptor (VDR) gene, which has been suggested to play a role in the pathogenesis of differentiated thyroid cancers and benign thyroid diseases. METHODS: Two hundred and sixteen patients, 113 with benign and 103 with differentiated thyroid cancers, together with the same number of healthy controls, were included in the study. FokI, BsmI, ApaI, and TaqI SNPs in VDR were analyzed in all participants using the PCR-RFLP method. RESULTS: When the patients with differentiated thyroid cancers or the patients with nodular goiter and control cases were compared for BsmI, ApaI or TaqI polymorphisms, three genotype distributions (BB, Bb, bb; AA, Aa, aa; TT, Tt, tt) were found to not differ significantly. When the patients with differentiated thyroid cancers and control cases were compared for the FokI polymorphism in the VDR gene, the three genotype distributions (FF, Ff, ff) did not differ. However, in patients with nodular goiter, the FF genotype in the FokI polymorphism of the VDR gene was found to be statistically significantly higher (P=0.033). CONCLUSIONS: This is the first study in the literature evaluating the role of VDR gene SNPs in nodular goiter. We can suggest that SNP distribution in the VDR gene is not associated with malignancy but may cause some alterations in thyrocyte morphology and functions.

Association between BRAFV600E mutation and the clinicopathological features in incidental papillary thyroid microcarcinoma: A single-center study in Turkish patients.

OBJECTIVE: In this study, we evaluated the influences of BRAFV600E mutation on clinicopathological features in incidentally found papillary thyroid microcarcinomas (PTMCs). METHODS: This retrospective cohort study included 72 patients with PTMC who underwent surgery from 2008 to 2012. The mean follow-up of the whole cohort was three years. DNA was isolated using QIAamp DNA formalin-fixed, paraffin-embedded (FFPE) tissue kit. BRAF gene was amplified by the polymerase chain reaction-restriction fragment length (PCR-RFL) polymorphism method with the following primers. The clinicopathologic features (age, gender, histologic subtype, tumor size, presence of tumor capsule, bilaterality, multifocality, extrathyroidal extension (ETE), thyroid capsular invasion, presence of Hashimoto's thyroiditis, lymph node metastasis (LNM) and distant metastasis) were compared between the BRAF (+) and BRAF (-) patient groups. RESULTS: BRAFV600E mutation was detected in 30 of the 72 patients (41.6%). The presence of the mutation was statistically significantly associated with classic variant (p=0.046), invasion of thyroid capsule (p=0.002) and absence of tumor capsule (p=0.003). CONCLUSION: Although incidental PTMCs positive for the BRAFV600E mutation had more invasive behavior, the presence of the mutation was not associated with recurrences within three years of follow-up.

Association of Serum Paraoxonase 1 Activities, Polymorphisms and Oxidative Stress in Breast Cancer Patients with Type 2 Diabetes Mellitus.

BACKGROUND: The aim of the study was to investigate the association of paraoxonase 1 (PON1) polymorphism, PON1/arylesterase (ARE) activity and oxidative stress index (OSI) in breast cancer (BC) patients with type 2 diabetes (DM). METHODS: Our study group consisted of 30 healthy women (HV group) and 66 female BC patients. The BC patients were divided into two groups: those with (n=37) and without DM (n=29) (BDM and NBDM group). Genotyping of PON1 Q192R and L55M polymorphisms were done by polymerase chain reaction (PCR) - restriction fragment length polymorphism (RFLP) method. Serum PON1/ARE enzyme activities, total oxidant status (TOS) and total antioxidant status (TAS) were analysed by spectrophotometric method. The ratio of TOS to TAS was accepted as the oxidative stress index (OSI). RESULTS: PON1 Q192R genotype frequency distribution was significantly different in the BDM group compared to the NBDM group (p=0.021). When alleles distribution was examined, R and L alleles were significantly lower, Q and M alleles were significantly higher in the BDM group than in the NBDM group (p<0.001). TOS and OSI were statistically higher in BC patients than HV group (p<0.001). CONCLUSIONS: Our results suggest that PON1 gene Q and M alleles may be the risk factors predisposing formation of BC due to increased oxidant damage seen in DM. However, these statements require further confirmation with screening PON1 polymorphism in a greater number of patients with DM, and also wide range follow-up studies are necessary for the same purpose.

The Relationship Between Urothelial Type Bladder Cancer, Plasma 25-Hydroxyvitamin D Levels, and Vitamin D Receptor ApaI BsmI FokI, and TaqI Polymorphisms.

BACKGROUND: Bladder cancer is an important health problem which ranks 4th among most frequently seen cancer types in men. In our study we aimed to investigate the correlations among urothelial type bladder cancer polymorphisms, ApaI, BsmI, FokI, and TaqI, prevalently observed in the vitamin D receptor (VDR) gene and plasma vitamin D levels in a Turkish population. METHODS: Our study included 101 patients and 109 control subjects. Plasma 25(OH)D levels were determined using a HPLC method and VDR gene polymorphisms with PCR-RFLP method. RESULTS: A statistically significant intergroup difference was not observed with regard to age, gender, and BMIs of the patients. Median (min - max) 25(OH)D levels in the patient and the control groups were determined as 11.9 ng/dL (1.9 - 33.0 ng/dL) and 9.7 ng/dL (2.1 - 39.5 ng/dL), respectively. A statistically significant intergroup difference was not observed with regard to 25(OH)D levels (p = 0.402). A statistically significant intergroup differ-ence was not observed with regard to genotype distribution of ApaI, BsmI, and TaqI polymorphisms and allele frequencies. Control and urothelial type bladder cancer groups showed a statistically significant difference with respect to genotype distribution of FokI polymorphism (p = 0.048). However in a binary logistic regression model, when corrected OR values were estimated by including smoking history in the model, the correlation detected be-tween the presence of FF and increased risk of disease was not statistically significant (ORadj = 1.64, 95% CI = 0.89 - 3.02, p = 0.114). CONCLUSIONS: In the light of the data concerning Turkish population a statistically significant correlation could not be demonstrated between plasma vitamin D levels, ApaI, BsmI, FokI, and TaqI polymorphisms, and urothelial type bladder cancers. Since literature data are limited in number, further studies should be conducted in larger patient groups.

Association of the nibrin gene (NBN) variants with breast cancer.

Nibrin, encoded by the NBN gene, participates in DNA repair. Mutations in the NBN gene lead to Nijemen breakage syndrome, which may result in several types of diseases, particularly susceptibility to cancer, including breast cancer. Polymorphic variants and defective mutations occurring in the NBN gene increase the risk of breast cancer through the double-stranded break repair mechanism. The aim of the present study was to investigate a possible association between breast cancer and NBN genetic variants, NBN 924 T>C, 8360 G>C and 30537 G>C, in women with breast cancer. Locus-specific primers were designed to study 3 genetic variants in DNA samples isolated from peripheral blood samples of 101 women with breast cancer and 115 healthy controls. Subsequently, 3 polymerase chain reaction-restriction fragment length polymorphism methods were performed and the obtained results were statistically analysed. The NBN gene 924 T>C variant was found to be significantly associated with breast cancer (χ2=5.722, P=0.017). There were no statistically significant differences between cases and controls in the NBN gene 8360 G>C variant (χ2=1,125, P=0.570) or the NBN gene 30537 G>C variant (χ2=4.301, P=0.116). In conclusion, the NBN gene 924 T>C variant may be a genetic risk factor for breast cancer development in women with breast cancer.

The Relationship between Adiponectin and Breast Cancer.

OBJECTIVE: Breast cancer is the most common type of cancer in women worldwide. It is indicated that increased body mass index elevates the risk of developing breast cancer, worsens prognosis, and decreases survival. Several polymorphisms of adiponectin have been shown to affect serum levels of adiponectin and their association with breast cancer. The aim of this study was to investigate the relationship between the adiponectin 45T/G and 276 G/T gene polymorphism and breast cancer in the East Marmara region. MATERIALS AND METHODS: A case-control study was performed in 97 patients with breast cancer and 101 controls in East Marmara in order to evaluate the prevalence of adiponectin gene polymorphism at positions 45 and 276. Patients with familial breast cancer and those who had received chemotherapy or radiotherapy were excluded from the study. Adiponectin gene polymorphisms were investigated using polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP). RESULTS: Adiponectin 45T/G gene genotype frequencies of TT, TG, and GG were 61.9%, 37.1%, and 1% in patients with breast cancer, and 67.3%, 30.7%, and 2% in the control group, respectively. Adiponectin 276G/T gene genotype frequencies of GG, GT, and TT were 45.4%, 45.4%, and 9.3% in patients with breast cancer and 55.4%, 39.6%, and 5.0% in the control group, respectively. CONCLUSION: Our study showed that adiponectin 45T/G and 276 G/T gene polymorphism is not associated with breast cancer risk in patients from the East Marmara region.

Genotoxic effects of sulfur dioxide in human lymphocytes.

Sulfur dioxide (SO2), which is used as food preservative in apricot sulfurization and several fabricated foods, is a common air pollutant. The aim of this study was to reveal the possible genotoxic effects of SO2 using in vitro human lymphocytes. The different endpoints of genotoxicity: sister chromatid exchange (SCE), micronuclei (MN) tests and cell growth kinetics such as mitotic index (MI) and replication index (RI) were studied. The cells were treated with 0.1, 0.5 and 1.0 ppm concentrations of SO2. It was shown that SO2 caused significant increases in the frequency of SCE and MN in the middle and high dosage groups and also induced mitotic delays and decreased MI and RI. In conclusion, the results have confirmed that SO2 has potent mutagenicity and it can cause genetic damage leading to a malignancy.