Emel Saglar

Assessment of ER Stress and Autophagy Induced by Ionizing Radiation in Both Radiotherapy Patients and Ex Vivo Irradiated Samples

Acute radiation leads to several toxic clinical states and triggers some molecular pathways. To shed light on molecular mechanisms triggered by ionizing radiation (IR), we examined the expression profiles of endoplasmic reticulum (ER) stress and autophagy‐related genes in individuals who were exposed to IR. Blood samples were collected from 50 cancer patients before radiotherapy and on the 5th, 15th, and 25th days of the treatment. Peripheral blood samples from 10 healthy volunteers were also obtained for ex vivo irradiation, divided into five and irradiated at a rate of 373 kGy/h to 0, 0.1, 0.5, 1, and 3Gy γ‐rays using a constant gamma source. GRP78, ATG5, LC3, ATF4, XBP1, and GADD153 genes were analyzed by quantitative real‐time polymerase chain reaction (QRT‐PCR) using beta 2 microglobulin (B2M) and glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) as references. In both groups, expressions of the selected genes have increased. It can be concluded that IR induces ER stress and related authophagy pathway in the peripheral lymphocyte cells proportionally by dose.

Mutations in the AVPR2, AVP-NPII, and AQP2 genes in Turkish patients with diabetes insipidus

The aim of this study was to identify mutations in three different genes, the arginine-vasopressin-neurophysin II (AVP-NPII) gene, the arginine-vasopressin receptor 2 (AVPR2) gene, and the vasopressin-sensitive water channel aquaporin-2 (AQP2) gene in Turkish patients affected by central diabetes insipidus or nephrogenic diabetes insipidus. This study included 15 patients from unrelated families. Prospective clinical data were collected for all patients including the patients underwent a water deprivation–desmopressin test. The coding regions of the AVPR2, AQP2, and AVP-NPII genes were amplified by polymerase chain reaction and submitted to direct sequence analysis. Of the 15 patients with diabetes insipidus referred to Gulhane Military Medical Academy, Department of Endocrinology and Metabolism, eight patients have AVPR2 mutations, five patients have AQP2 mutations and two patients have AVP-NPII mutations. Of the patients, which have AVPR2 mutations, one is compound heterozygous for AVPR2 gene. Seven of these mutations are novel. Comparison of the clinical outcomes of these mutations may facilitate in understanding the functions of AVP-NPII, AQP2, and AVPR2 genes in future studies.

Association of VNTR polymorphisms in DRD4, 5-HTT and DAT1 genes with obesity

Abstract Objective: To investigate the association between VNTR polymorphisms of DRD4, DAT1 and 5-HTT genes and obesity. Material and methods: Peripheral blood samples of 234 obese (BMI ≥ 30) and 148 healthy individuals (BMI ≤ 25) were objected to PCR to detect the VNTR of the 2nd intron of 5-HTT, 3rd exon of DRD4 and 3’UTR of DAT1 genes. Results: The association between obesity and genotype distributions of 5-HTT, DAT1 and DRD4 genes and between obesity and distributions of allele frequencies were tested by Chi Square (χ2) test and were not found statistically significant. BMI values for genotype of obese and morbidly obese (BMI > 40) individuals were analyzed by Kruskal-Wallis and not found statistically significant differences between BMI values for the most frequent genotypes of 5-HTT, DAT1 and DRD4 genes. Conclusions: As a conclusion, there was no association between 5-HTT, DAT1 and DRD4 genes VNTR polymorphisms and obesity.

Promoter hypermethylation of p16 and APC in gastrointestinal cancer patients.

BACKGROUND/AIMS Cancer is a consequence of the disruption of cellular regulation. Epigenetic is one of the reasons of this disruption. Epigenetic factors play a role in the carcinogenesis by affecting proto-oncogenes and tumor suppressor genes and it is one of the most popular research areas in recent years. DNA methylation, which is an epigenetic mechanism, occurs in the early stages of tumorigenesis. Promoter methylation which causes the silence of tumor suppressor genes have been studied extensively in various tumor types. The aim of this study was to investigate promoter methylation of certain tumor suppressor genes, Cyclin-dependent kinase inhibitor 2A (p16) and Adenomatous polyposis coli (APC), which take part in gastrointestinal tumorigenesis. MATERIALS AND METHODS To detect the promoter methylation of p16 and APC genes, tissue samples from 20 gastrointestinal cancer patients and peripheral blood samples from 15 healthy individuals were collected for Methylation-Specific Polymerase Chain Reaction (MSP) analysis. RESULTS According to the statistical analysis, in tumor tissue, positive methylation ratio of p16 and APC genes was found respectively 30% (6/20) and 50% (10/20). The difference of promoter methylation of these genes between tumor tissues and control group was significantly observed (p=0.02 and 0.001, respectively). An alteration of promoter methylation of APC gene according to tumor localization was found (p=0.007), but there was no significant difference observed in p16. CONCLUSION In our study, promoter methylation which was considered to be occurred as an early event in gastrointestinal carcinogenesis was observed in p16 and APC genes.

Investigation of P53, HIPK-2 and EIF2S1 Genes Expression Changes Induced by in Vitro Gamma Radiation

Bu çalışmada periferal insan lenfositlerinde düşük doz gama radyasyon maruziyeti sonrası P53, HIPK-2 ve EIF2S1 genlerinin indüksiyonunu araştırılmıştır. Gen ekspresyon değişiklikleri, B2M referans gen olarak kullanılarak kantitafif gerçek zamanlı polimeraz zincir reaksiyonu ile (KRT PZR) değerlendirilmiştir. Bu amaçla genç, sağlıklı ve sigara içmeyen on bireye ait kan örnekleri toplanmıştır. Her birey için beş tüpe bölünen örneklerden ilki kontrol olarak ayrılmış diğer dördü sabit gama kaynağında (Co60) 0,0327 kGy/sa doz hızına göre hesaplanmış 0,1 Gy, 0.5 Gy, 1 Gy ve 3 Gy gama radyasyonuna maruz bırakılmıştır. Sonuçlar eşik değerinin aşıldığı döngü değerlerine (CT) göre REST 2009 (Relative Expression Software Tool V. 2.0.13 ) programında değerlendirilmiş, hedef genin ve referans genin CT değerleri arasındaki farklılıklara göre hesaplanmıştır. P53, HIPK2 ve EIF2S1 genleri için linear bir doz-cevap ilişkisi bulunmuştur. KRT PZR sonuçları bu üç geninin maruz kalınan dozlarda up-regüle olduğunu göstermiştir. Elde edilen sonuçlar P53, HIPK2 ve EIF2S1 genlerinin radyasyon maruziyeti sonrasında indüklenen DNA hasarında ki gen ekspresyon değişikliklerinin değerlendirilmesinde kullanılabileceğini göstermiştir.