TNF-alpha promoter polymorphisms in multiple sclerosis: no association with -308 and -238 alleles, but the -857 alleles in associated with the disease in Turkish patients.

Yazan: admin Tarih: Şub 25th, 2010 | Kategori:: Multiple sclerosis

Akcali A, Pehlivan S, Pehlivan M, Sever T, Akgul P, Neyal M.

Department of Neurology, Gaziantep University School of Medicine, Gaziantep, Turkey.

Summary Dysregulation in the expression of pro- and anti-inflammatory cytokines is one of the milestones in multiple sclerosis (MS) development and progression. Tumour necrosis factor (TNF-alpha), a proinflammatory cytokine is believed to play an important role in MS pathogenesis. The objective of this study is to investigate the association between TNF-alpha promoter region (TNF-alpha-238, -308 and -857) and susceptibility to MS and clinical course of the disease. Eighty-six relapsing remitting MS patients and 150 sex-, age- and ethnic-matched controls were enrolled in the study. Genotyping was performed by PCR-RFLP method. We observed a statistically significant increase in TNF-alpha 857 CC genotype in MS patients than controls (P < 0.001) while TNF-alpha 857 CT genotype showed a significant negative correlation with MS patients (P = 0.033). No differences in the distribution of the TNF-alpha-238 and -308 alleles were observed. None of the three polymorphisms (-238, -308 and -857) did not show relation with disease duration, Expanded Disability Status Scale or age of onset. On the other hand, significant difference of TNF -857 CC genotype was identified with the low disease index (P = 0.025). Although the study group is small, the results indicate that TNF-alpha 857 CC genotype may cause susceptibility to MS in the Turkish population.


The clinical significance of parathyroid tissue calcium sensing receptor gene polymorphisms and expression levels in end-stage renal disease patients.

Yazan: admin Tarih: Ağu 24th, 2009 | Kategori:: Gene polymorphisms, polymorphisms

Clin Nephrol. 2009 Aug;72(2):114-21.

Eren PA, Turan K, Berber I, Canbakan M, Kara M, Tellioglu G, Bugan U, Sevinç C, Turkmen F, Titiz MI.

1Departments of Molecular Genetics and 3Transplantation, Haydarpasa Numune Research and Training Hospital, and 2Department of Basic Sciences, Faculty of Pharmacy, Marmara University, Istanbul, Turkey.

Background: The calcium sending receptor (CaSR) allows parathyroid and kidney tubular cells to regulate PTH secretion and tubular calcium reabsorption. In the present report, we examined the relationship between CaSR gene polymorphisms and parathyroid CaSR expression and serum calcium/parathyroid hormone (PTH) levels and clinical progress in ESRD patients in the Turkish population. Methods: We genotyped the CaSR R990G and Q1011E variants in 192 end-stage renal disease (ESRD) patients by allele-specific PCR. CaSR expression in parathyroid tissues of operated 33 patients was quantified with quantitative reverse transcription-PCR. Results: Compared with other genotypes, the ratio of both codon 990-AA and 1011-CC polymorphisms was found higher in operated patients (p = 0.001). In the total patient group PTH levels were found higher in patients with CC1011 genotype than those with CG1011 (1015.15 +/- 925.41 pg/ml; 523.84 +/- 544.6 pg/ml, respectively, p = 0.002). There were statistically important higher Ca2+ levels in the AA990 allele carrying cases than AG990 positive ones (9.3 +/- 1.0 mg/dl vs. 8.8 +/- 0.9, p = 0.006). On the other hand, the expression of CaSR in parathyroid tissue was found inversely proportional with serum PTH level (r = -0.71). Conclusion: Present data suggest that co-presence of CaSR gene AA990 and CC1011 alleles is a possible risk factor for bad prognosis in secondary hyperparathyroidism. Patients carrying this genotype have tendency to require operation early in their medical therapy period and need postoperative close follow up for possible recurrences.


Identification of polymorphisms on the MDR1 gene among Turkish population and their effects on multidrug resistance in acute leukemia patients.

Yazan: admin Tarih: Ağu 6th, 2008 | Kategori:: Gene polymorphisms

Am J Hematol. 2005 Sep;80(1):26-34.  

Department of Biology, Middle East Technical University, Ankara, Turkey.

Multidrug-resistance (MDR) phenotype is a serious limitation to the effective chemotherapeutic treatment of many cancer types, including leukemia. One of the most important proteins, the over-expression of which is responsible for the multidrug-resistance phenotype in many cancer types, is P-glycoprotein. This protein is the product of the MDR1 gene. In previous studies, single-nucleotide polymorphisms (SNPs) C3435T, G2677T, and T-129C in the MDR1 gene were shown to be correlated with lower P-glycoprotein expression in normal tissues. It was suggested that this might have an advantage in cancer chemotherapy by resulting in a low drug-resistance phenotype. The frequencies of these SNPs were studied in 45 acute leukemia patients (25 of which were primary refractory and 20 of which were drug-sensitive) and 17 healthy individuals, forming a Turkish population of 62 individuals. In the first part of the study, these polymorphisms were compared with other populations. Marked differences were apparent between African and Turkish populations for the C3435T polymorphism. On the other hand, similarities were found between other Caucasian/Asian and Turkish populations (P < 0.001). However, for the G2677T polymorphism, the Turkish population is different than Japanese and German populations (P < 0.001). For the T-129C polymorphism, all individuals in the studied population were homozygous for the T/T genotype. In the second part of this study, drug-resistant and drug-sensitive acute leukemia patients were compared for these SNPs. These polymorphisms did not seem to have a significant effect on P-glycoprotein-mediated drug resistance in the patients studied.