Vitamin D binding protein genotype frequency in familial Mediterranean fever patients

Objective: Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent short episodes (1-3 days) of inflammation and fever. FMF is associated with MEFV gene mutations but some patients with FMF symptoms do not have a mutation in the coding region of the MEFV gene. Vitamin D binding protein (VDBP) has important functions, including transporting vitamin D and its metabolites to target cells. Circulating levels of vitamin D are decreased in several inflammatory conditions, including FMF. Thus, we hypothesize that VDBP may play a crucial role in FMF pathogenesis, in addition to the MEFV gene. Method: VDBP genotyping was performed by polymerase chain reaction (PCR)-restriction fragment length polymorphism in 107 FMF patients and 25 healthy individuals without FMF or family history. For this, after amplification of genomic DNA, PCR products were digested with restriction enzymes HaeIII and StyI and evaluated electrophoretically. Results: We observed a statistically significant difference in the frequency of the 1F-2 genotype. The frequency of allele 2 was significantly higher and allele 1S was significantly lower compared to the [MEFV(-)] group and healthy controls (p = 0.034, 0.001, and 0.012, respectively). We observed a significant association between the presence of allele 2 and amyloidosis (p = 0.026) and arthritis (p = 0.044) in the [MEFV(-)] group. Conclusion: Our results suggest that FMF symptoms in the absence of MEFV gene mutations may be due to the presence of VDBP allele 2. Therefore, VDBP genotype may explain the symptoms in FMF [MEFV(-)] patients.

Analysıs of gene copy number changes ın head and neck cancer

OBJECTIVE

Chromosomal alterations and copy number changes are frequent events in tumors, leading to amplification of focal regions containing several oncogenes. Gains and losses of several regions have been reported in head and neck cancer (HNC) but the copy number changes of the individual genes located in these regions have not been analyzed so far. In this study we aimed to analyze the copy number variations in patients with HNC.

DESIGN

Prospective study SETTING: University hospital PARTICIPANTS: 50 patients with squamous cell carcinoma of the head and neck METHODS: Copy number changes and amplifications of 22 genes in tumors and matched tissue were analyzed by MLPA which allows simultaneous analysis of gene copy numbers in multiple genetic regions.

RESULTS

Amplifications were observed in 52% and losses were detected in 20% of the samples. Chromosome 8 was found to harbor the most frequent copy number alterations. The most frequently amplified genes were CCND1 and the MED1 genes followed by the MTDH and MYC genes on the long arm and ZNF703 on the short arm of chromosome 8. Amplification of the ZNF703, PRDM14 and MYC genes were highly correlated suggesting that the genes displaying high copy number changes on chromosome 8 collaborate during carcinogenesis.

CONCLUSIONS

The alterations found in our study supports the contribution of gene amplifications and indicate cooperation between certain oncogenes in the pathogenesis of HNSCC. Correlations between amplification of less familiar genes and known oncogenes warrant further investigation. This article is protected by copyright. All rights reserved.

NPRL2 gene expression in the progression of colon tumors

Genetic and epigenetic factors affecting DNA methylation and gene expression are known to be involved in the development of colon cancer, but the full range of genetic alterations and many key genes involved in the pathogenesis of colon cancer remain to be identified. NPRL2 is a candidate tumor suppressor gene identified in the human chromosome 3p21.3 region. We evaluated the role of this gene in the pathogenesis of colorectal cancer by investigating NPRL2 mRNA expression in 55 matched normal and tumor colon tissue samples using quantitative RT-PCR analysis. There was significantly decreased NPRL2 expression in 45% of the patients. Lower NPRL2 expression was observed significantly more frequently in poorly differentiated tumor samples than in highly or moderately differentiated tumors. We conclude that expression of NPRL2 contributes to progression of colon cancer.

DNA Promoter Methylation in Breast Tumors Is Not Associated with Polymorphism in the GSTP1 Gene

The gluthathione S-transferases (GSTs) are a family of enzymes that play an important role in detoxification of a variety of potential carcinogenic, hydrophobic and electrophilic compounds. Glutathione-S-transferase P1 (GSTP1) is involved in thiol-mediated detoxification and breakdown of reactive oxygen species created by anticancer drug exposure. It is also an inhibitor of c-Jun N-terminal kinase 1 which is involved in stress response, apoptosis and cellular proliferation. It has been postulated that a decrease in GST enzyme activity could result in higher frequency and a specific pattern of mutations in cancer. Loss of GSTP1 expression is observed in approximately two thirds of breast cancer cases, which indicates its potential role in breast carcinogenesis. The GSTP1 gene exhibits deletion polymorphisms and homozygous deletion of the gene may result in lack of enzyme activity. The polymorphism in the GSTP1 gene results from a base substitution and leads to an amino acid change at codon 105. This amino acid resides at the substrate binding site of the enzyme and may modify the catalytic activity of the enzyme several-fold.DNA methylation is an important epigenetic modification of the genome. A specific methylation pattern has been observed in various types of cancers. Hypermethylation of the GSTP1 promoter has also been associated with gene silencing in different forms of cancer. In a previous study we have found that the GSTP1 gene was the second most frequently methylated gene in breast cancer. However, a possible relationship between the methylation status of the gene promoter and GSTP1 polymorphic variants has not been investigated.In this study we investigated the role of the different allelic variants in the methylation status of the GSTP1 gene in patients with breast cancer. A total of 48 patients with breast cancer and 32 healthy women were analyzed. The GSTP1 polymorphism was determined by PCR-RFLP. Methylation of the GSTP1 gene was evaluated by methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) using probes targeting the GSTP1 gene and metylation-sensitive enzyme digestion of the probe-DNA hybrids. The amplified products were analyzed by sequence-type capillary electrophoresis. Subsequent quantification of the methylation status was performed by comparing the relative signal peaks from the digested and undigested samples.The null allele was observed in % 56,2 of the patients and % 46.8 of the control group, respectively. No significant difference was observed between the distribution of the genotypes in the patients and the controls. The GSTP1 gene promoter was methylated in % 39.6 of the patients. However, the distribution of the genotypes and allele frequencies did not reveal any preferential methylation of a specific allele. The genotypes were not associated with increased likelihood of promoter methylation. Our data indicate that the deletion allele of the GSTP1 gene does affect the methylation status of the gene in breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1150.

Association between APOE polymorphisms and mesial temporal lobe epilepsy with hippocampal sclerosis

To evaluate the hypothetical link between apolipoprotein E (APOE) polymorphisms and mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) and whether presence of APOE epsilon4 allele shortens the latent period between febrile seizures and epilepsy. A further interest is whether presence of APOE epsilon4 allele has an impact on severity of the disease. Forty-seven patients with MTLE-HS were compared with 62 controls. APOE polymorphisms were determined from lymphocytes by standard methods. Eight patients (17%) and 10 controls (16.1%) were demonstrated to have one APOE epsilon4 allele. There was not any statistically significant difference in APOE epsilon4 frequency between patients and controls (P > 0.05). There was not any difference statistically according to onset age of epilepsy and the presence of APOE epsilon4 allele within patient group. APOE epsilon4 polymorphisms did not influence the severity of epilepsy. APOE epsilon4 polymorphisms had no impact on outcome after surgery. Patients with bilateral memory deficits, bilateral hippocampal atrophy and with bilateral epileptiform interictal EEG transients, were independently compared with patients having unilateral features and there were not any statistically significant differences. This study has found no association between APOE epsilon4 polymorphisms and presentation of MTLE-HS in a group of Turkish patients.

Polymorphism analysis in the COLIA1 gene of patients with thalassemia major and intermedia

beta-Thalassemia, an inherited blood disorder, mainly affects people from the Mediterranean region. This life-threatening anemia is so severe that regular blood transfusions and iron-chelating therapy is obligatory throughout life. Commonly occurring complications, especially in adult patients, are osteopenia and osteoporosis. Osteoporotic fractures are strongly associated with bone density, which is under polygenic control. Type I collagen, which is encoded by the COLIA1 and COLIA2 genes, is the major protein in the bone. A G-->T polymorphism in the regulatory region of the COLIA1 gene at a recognition site for transcription factor Sp1 has been strongly associated with osteoporotic fractures. In this study, the G-->T polymorphism is screened in 42 beta-thalassemia major and 10 beta-thalassemia intermedia patients. 64.3% of the beta-thalassemia patients were heterozygotes for G/T (Ss) polymorphism and 35.7% were homozygous for G/G (SS), 60% of the beta-thalassemia intermedia patients were heterozygous (Ss) and 40% were homozygous (ss). The number of heterozygotes in the beta-thalassemia major group was significantly higher, compared to the control group (F = 13.615, P = 0.001). The number of heterozygotes in beta-thalassemia intermedia group was also significantly higher, compared to the control group (F = 5.158, P = 0.029). Patients who are G/T heterozygotes (Ss) at the polymorphic Sp1 site have a lower bone mineral density than G/G homozygotes (SS) (P = 0.01).