Zuhal Eroglu

Methylenetetrahydrofolate reductase C677T and A1298C gene polymorphisms and therapy-related toxicity in children treated for acute lymphoblastic leukemia and non-Hodgkin lymphoma

This study aimed to investigate the association of the methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C polymorphisms with serum drug levels and toxicities after high-dose methotrexate (MTX) infusion. The study included 37 children with acute lymphoblastic leukemia or non-Hodgkin lymphoma. Serum MTX levels and toxicities of bone marrow, liver and kidney were analysed. Genotype analysis of the C677T and A1298C gene polymorphisms from genomic DNA of the subjects was performed by real-time PCR. Subjects with MTHFR polymorphism for C677T (CT, TT) had significantly higher MTX levels at 24 h (p = 0.009), and these genotypes did not seem to cause toxicity. Subjects with MTHFR polymorphism for A1298C (AC, CC) had significantly higher MTX levels at 48 h (p = 0.02), and had more grade III/IV anemia (p = 0.02), thrombocytopenia (p = 0.0001), elevated AST levels (p = 0.04) and frequent febrile neutropenic episodes (p = 0.004). The present study suggests that A1298C gene, but not C677T polymorphism is associated with MTX-related toxicity.

Association of the angiotensinogen M235T and angiotensin-converting enzyme insertion/deletion gene polymorphisms in Turkish type 2 diabetic patients with and without nephropathy

OBJECTIVE Recent studies have suggested an association between a deletion variant of the angiotensin-converting enzyme (ACE) gene and diabetic nephropathy. However, this finding has not been confirmed by all investigators. Furthermore, an M235T variant of the angiotensinogen (AGT) gene has been associated with hypertension, an important risk factor for the development and progression of diabetic nephropathy. RESEARCH DESIGN AND METHODS We investigated the relationship of the ACE insertion/deletion (I/D) and AGT M235T gene polymorphisms in Turkish patients with type 2 diabetes mellitus (DM) with and without diabetic nephropathy. A total of 102 individuals were screened for the presence of the ACE I/D and AGT M235T polymorphism: 46 individuals who had type 2 DM with diabetic nephropathy and, as controls, 56 individuals who had type 2 DM without diabetic nephropathy. Gene polymorphisms were determined by the specific melting temperature (T(m)) values of the resulting amplicons after real-time online polymerase chain reaction and melting curve analysis. RESULTS The frequencies of the ACE DD, ID, and II genotypes were 34.8%, 37.0%, and 28.3%, respectively, among type 2 diabetic patients with nephropathy, and 33.9%, 42.9%, 23.2%, respectively (P=.788), in the control subjects without diabetic nephropathy. On the other hand, the frequencies of the AGT MM, MT, and TT genotypes among the same groups were 26.1%, 52.2%, 21.7% and 26.8%, 57.1%, 16.1%, respectively (P=.758). CONCLUSIONS There were no differences in the frequencies of the AGT M235T and ACE I/D genotypes between Turkish patients with type 2 DM with and without nephropathy.

Cisplatin resistance induced by decreased apoptotic activity in non-small-cell lung cancer cell lines

We have investigated defective steps in apoptosis that might account for the development of resistance. For this purpose, A549 and Calu1 NSCLC (non‐small‐cell lung cancer) cell lines were treated with cisplatin to obtain resistant sub‐lines. Gene expression profiles and the phosphorylation status of the BAD (Bcl‐2/Bcl‐XL‐antagonist, causing cell death) protein were determined for each cell line. Cell death and cytochrome c release were analysed after treating cell lines with their appropriate cisplatin doses. Gene expression of BAD, Bid, caspases 4 and 6 were clearly decreased in the resistant cell lines, and the differential phosphorylation status of BAD also seemed to play a role in the development of cisplatin resistance. Since this is a new cisplatin‐resistant Calu1 cell line, it is noteworthy that DNA fragmentation, apoptotic cell ratio and cytochrome c levels were most decreased in the CR‐Calu1 cell line.

The relationship of the methylenetetrahydrofolate reductase C677T gene polymorphism in Turkish type 2 diabetic patients with and without nephropathy

Poor glycaemic control, hypertension and duration of diabetes are risk factors for the development of diabetic nephropathy, but there may be genetic factors. Recently, a common C to T mutation at nucleotide position 677 of the MTHFR gene (MTHFR677C > T) has been reported to be correlated with hyperhomocysteinemia and the severity of coronary artery disease as macroangiopathy. We aim to investigate Turkish type 2 diabetic patients with/without diabetic nephropathy and healthy group and examine the contribution of the MTHFR gene polymorphism to the development of diabetic nephropathy.

Role of mTOR in glioblastoma

Mammalian target of rapamycin (mTOR), which is a member of the serine/threonine protein kinase family, is a protein complex that has a central role of cell growth and proliferation. mTOR emerges as a critical cell growth checkpoint on phosphoinositide 3-kinase (PI3K) signaling pathway. In this case mTOR has become an important therapeutic target for glioblastoma (GBM) that is one of the most deadly types of cancer. Various combination treatments including inhibition of mTOR may provide more significant results in the treatment of GBM. In addition to new mTOR targets, which may have a plant origin form, more potent mTOR inhibitors by utilizing the computational methodology may emerge as a hope for GBM therapy. In the future, a better understanding of the functional properties of mTORC2 with its potent effective inhibitors may help design more efficiently GBM treatment modalities.

Effect Of G2706A and G1051A polymorphisms of the ABCA1 gene on the lipid, oxidative stress and homocystein levels in Turkish patients with polycystıc ovary syndrome

BackgroundObesity, insulin resistance and hyperandrogenism, crucial parameters of Polycystic ovary syndrome (PCOS) play significant pathophysiological roles in lipidemic aberrations associated within the syndrome. Parts of the metabolic syndrome (low HDL and insulin resistance) appeared to facilitate the association between PCOS and coronary artery disease, independently of obesity. ABCA1 gene polymorphism may be altered this components in PCOS patients.In this study, we studied 98 PCOS patients and 93 healthy controls. All subjects underwent venous blood drawing for complete hormonal assays, lipid profile, glucose, insulin, malondialdehyde, nitric oxide, disulfide levels and ABCA genetic study.ResultsIn PCOS group fasting glucose, DHEAS, 17-OHP, free testosterone, total-cholesterol, triglyceride, LDL-cholesterol and fibrinogen were significantly different compare to controls. The genotype ABCA G2706A distribution differed between the control group (GG 60.7%, GA 32.1%, AA 7.1%) and the PCOS patients (GG 8.7%, GA 8.7%, AA 76.8%). The frequency of the A allele (ABCAG2706A) was higher in PCOS patients than control group with 13,0% and 23,2%, respectively. In this study, the homocystein and insulin levels were significantly higher in PCOS patients with ABCA G1051A mutant genotype than those with heterozygote and wild genotypes.ConclusionsWe found higher percentage of AA genotype and A allele of ABCA G2706A in PCOS patients compare to controls. The fasting insulin and homocystein levels were significantly higher in PCOS patients with ABCA G1051A mutant genotype than those with heterozygote and wild genotypes.

miR-15a enhances the anticancer effects of cisplatin in the resistant non-small cell lung cancer cells

Platinum-based chemotherapies have long been used as a standard treatment in non-small cell lung cancer. However, cisplatin resistance is a major problem that restricts the use of cisplatin. Deregulated cell death mechanisms including apoptosis and autophagy could be responsible for the development of cisplatin resistance and miRNAs are the key regulators of these mechanisms. We aimed to analyse the effects of selected miRNAs in the development of cisplatin resistance and found that hsa-miR-15a-3p was one of the most significantly downregulated miRNAs conferring resistance to cisplatin in Calu1 epidermoid lung carcinoma cells. Only hsa-miR-15a-3p mimic transfection did not affect cell proliferation or cell death, though decreased cell viability was found when combined with cisplatin. We found that induced expression of hsa-miR-15a-3p via mimic transfection sensitised cisplatin-resistant cells to apoptosis and autophagy. Our results demonstrated that the apoptosis- and autophagy-inducing effects of hsa-miR-15a-3p might be due to suppression of BCL2, which exhibits a major connection with cell death mechanisms. This study provides new insights into the mechanism of cisplatin resistance due to silencing of the tumour suppressor hsa-miR-15a-3p and its possible contribution to apoptosis, autophagy and cisplatin resistance, which are the devil’s triangle in determining cancer cell fate.

The relationship of the apolipoprotein E gene polymorphism in Turkish Type 2 diabetic patients with and without nephropathy.

Objective: Apolipoprotein E (ApoE) genetic variation which is a major constituent of plasma lipoproteins causes diabetic nephropathy progress. Chronic kidney disease is associated with increased E2 allele and the decreased E4 allele risk. The aim of this study was to investigate the association between ApoE gene polymorphism in the development of diabetic nephropathy in Type 2 diabetes Turkish patients. Research design and methods: The objective of the study is to investigate the influence of ApoE gene polymorphism in the development of diabetic nephropathy in Turkish Type 2 diabetes. The ApoE genotypes were determined retrospectively in 46 patients with nephropathy and 56 without nephropathy and a control group of 35 healthy individuals. Genomic DNA was extracted from peripheral leukocytes of the subjects using the High Pure PCR Template Preparation Kit. For the detection of the presence of the three ApoE E alleles ε2, ε3, and ε4 (codon 112 and 158) were analyzed by the commercial LightCycler ApoE Mutation Detection Kit. Results: No differences in ApoE genotype or the allelic frequencies of ε2, ε3 or ε4 were found between the Type 2 diabetic patient group (with and without nephropathy) and a control group. Conclusions: We conclude that the ApoE gene polymorphism is not associated with the development of diabetic nephropathy in Turkish Type 2 diabetic patients. Lack of association between ApoE gene polymorphism and Type 2 diabetic nephropathy might be due to ethnic differences.

Apolipoprotein E gene polymorphism and polycystic ovary syndrome patients in Western Anatolia, Turkey

PurposeDyslipidemia, cardiovascular disease and hypertension are more frequently seen in patients with PCOS than in normal patients. We aimed at evaluating the distribution of Apo E alleles that can influence cardiovascular risk of the PCOS patients and control subjects.MethodsIn this study, 129 young women with PCOS and 91 healthy women were included. In all subjects we performed hormonal, biochemical and Apo E genetic analysis.ResultsThe Apo E3 allele was found at a significantly higher frequency in the PCOS patient group compared with the control group. The Apo E2 allele was found at a significantly higher frequency in the control group compared with the patient group with PCOS.ConclusionsAlthough there were genotype and allele differences between control and patient groups in this study, no statistically significant change was determined in lipid and other cardiovascular risk factors in connection with allele and genotype.

β1 and β2‐Adrenergic Receptor Polymorphisms and Idiopathic Ventricular Arrhythmias

Introduction: Idiopathic ventricular arrhythmias commonly refer to ventricular tachycardia (VT) and/or frequent/monomorphic premature ventricular contractions (PVC) in patients with structurally normal heart. Activation of sympathetic tone has been shown to play an important role in the provocation and maintenance of these arrhythmias. We investigated whether common single nucleotide polymorphisms in the β1 and β2‐adrenergic receptors are associated with idiopathic ventricular arrhythmias.