Yunus Kasım Terzi

beta-Adrenoreceptor antagonists reduce cancer cell proliferation, invasion, and migration

Abstract Context: Propranolol, atenolol, and ICI118,551 are non-selective β-adrenergic receptor (AR), β1-AR, and β2-AR antagonists, respectively. Objective: We investigated the efficacy of propranolol, atenolol, and ICI118,551 on proliferation, migration, and invasion of non-stimulated breast (MCF7), colon (HT-29), and hepatocellular (HepG2) cancer cells. Materials and methods: β-AR expression profiling of cells was performed by real time PCR. Cell proliferation was determined by MTT. Boyden chamber and scratch assays were performed to evaluate invasion and migration. Results and discussion: All cell lines expressed β-ARs. ICI118,551 was the most cytotoxic, whereas atenolol was the least effective β-AR antagonist for 24, 48, and 72 h. Cell invasion was inhibited by ICI118,551 (45, 46, and 50% for MCF7, HT29, and HepG2, respectively) and propranolol (72, 65, and 90% for MCF7, HT29, and HepG2, respectively). Propranolol, atenolol, and ICI118,551 reduced migration of MCF7, HT-29, and HepG2 cells to varying extents depending on the application concentration and duration. Propranolol and atenolol reduced migration of MCF7 and HT-29 in a concentration-dependent manner, whereas migration of these cells decreased after 48 and 72 h of ICI118,551 applications. Conclusion: Beta2-AR antagonist seemed to be the most cytotoxic β-blocker on non-stimulated cancer cells. Propranolol and ICI118,551 were more effective than atenolol in inhibiting invasion and migration of non-stimulated MCF7 and HT-29 cells; ICI118,551 being the most potent. Concordantly, β2-selective blockage seemed to be more effective for non-stimulated cells. Effect of the selective β-AR antagonists showed variation depending on the concentration, incubation time, and histological origin of cells.

The Notch pathway is a critical regulator of angiogenesis in a skin model of ischemia

The Notch pathway is definitely required for normal vascular development. Although the contribution of Notch in postnatal angiogenesis is the focus of intense investigation, the implication of Notch in reparative neovascularization in the skin remains unexplored. In this study, we investigated Notch changes using a skin model of ischemia. Thirty Sprague-Dawley rats were divided into two groups. In the surgery group (n = 24), a caudally based dorsal skin flap was raised and sutured back into its initial position. In the control group, no surgical procedure was performed. Tissue biopsies were obtained at different time intervals. Tissue specimens were assessed for Delta-like ligand 4 (DLL4) and vascular endothelial growth factor (VEGF) gene expression by real-time polymerase chain reaction (PCR). Immunohistochemical staining was used for detection of DLL4 in tissue materials. Quantitative assessment of skin flap microvasculature was made. Compared with normoperfused tissue, VEGF and DLL4 expressions increased significantly (p < 0.01). Immunohistochemical analysis revealed weak and patchy expression of DLL4 in microvascular endothelial cells of normoperfused tissues. Conversely, DLL4 expression was upregulated in capillary endothelial cells after ischemia. In conclusion, in this study we have shown that the Notch ligand DLL4 is upregulated in skin tissue after ischemia. A deeper understanding of these fundamental principles will aid in the development of new avenues for the treatment of blood vessel-related skin pathologies.

Chronic tonsillitis is not associated with beta defensin 1 gene polymorphisms in Turkish population

BACKGROUND Defensins are antimicrobial peptides expressed on mucosal surfaces. They function as part of the innate immune system. Palatine tonsils play important roles in innate immune system. However, our knowledge on the pathophysiology of chronic tonsils is limited. OBJECTIVE The aim of this study was to investigate the association between beta defensin 1 gene single nucleotide polymorphisms and chronic tonsillitis. STUDY DESIGN Prospective, non-randomized, controlled clinical study. SETTING Tertiary referral center. SUBJECTS AND METHODS Eighty six patients with chronic tonsillitis and eighty controls without history of chronic tonsillitis were enrolled in this study. Genotypes were determined by restriction fragment length polymorphism analyses after polymerase chain reaction. RESULTS Genotype and allele frequencies of the -20G/A (rs11362), -44C/G (rs1800972) and -52G/A (rs1799946) single nucleotide polymorphisms were not statistically different between patients and control groups (p>0.05). CONCLUSION In this study, we found that DEFB1 gene -20G/A, -44C/G and -52G/A single nucleotide polymorphisms were not associated with chronic tonsillitis. Studies, which analyse other polymorphism of the beta defensin 1 gene in large case series, should be conducted to understand the role of DEFB1 gene on chronic tonsillitis.

Lack of association of matrix metalloproteinase-9 promoter gene polymorphism in obstructive sleep apnea syndrome

PURPOSE Obstructive sleep apnea syndrome (OSAS) is a public health problem. There is an effort to establish the genetic contributions to the development of OSAS. One is matrix metalloproteinases, extracellular matrix degrading enzymes related to systemic inflammation. However, the impact of matrix metalloproteinase-9 (MMP-9) genotypes on the development of OSAS is unknown. Our aim was to determine whether MMP-9 single nucleotide polymorphism (SNP) (MMP-9 -1562C > T) is related to susceptibility to OSAS. MATERIAL AND METHODS A total of 106 patients with a history of sleep apnea and 88 controls without a history of sleep apnea were enrolled in this study. Genotypes were determined by restriction fragment length polymorphism analyses after polymerase chain reaction. RESULTS Genotypes and allele frequencies of the MMP-9 -1562C > T SNP was not statistically different between the patient and control groups (p > 0.05). There was a statistical association between apnea-hypopnea index (AHI) and body mass index (BMI), and also between AHI and neck circumference (p < 0.001). There was no association among the genotypes and AHI, neck circumference, or BMI (p > 0.05). CONCLUSIONS We found no association between MMP-9 -1562C > T SNP and OSAS. Studies to investigate the role of other polymorphisms and expression of MMP-9 gene will provide more information.

The Notch Signaling System Is Involved in the Regulation of Reparative Angiogenesis in the Zone of Stasis.

The Notch pathway ligand Delta-like 4 (Dll4) functions as an antiangiogenic factor, inhibiting vascular endothelial growth factor (VEGF)–induced angiogenesis. This function is documented in tumor and embryonic vasculature. However, its implication in burn wounds remains unexplored. Our objective was to explore the involvement of the Notch in the healing of zone of stasis burns. We hypothesized that anti-Dll4 therapy would prevent progressive necrosis in the stasis zone by promoting angiogenesis. Burns were created in 21 rats using the comb burn model. The Notch inhibitor N-[N-(3,5-difluorophenacetyl)-1-alanyl]-S-phenylglycine-t-butyl-ester was administered in the treatment group. Controls were given the same amount of solvent. Seven days after the burn, skin samples were evaluated for VEGF and Dll4 gene expressions. Immunohistochemical analysis was used for the assessment of vascular density, endothelial Dll4 expression, and apoptosis count. Histologic grading of tissue damage was performed. Circulating levels of VEGF and Dll4 were determined. VEGF and Dll4 mRNA levels were found to be simultaneously induced after the burn. In the treatment group, a significant increase in the number of vessels was observed. However, gross evaluation documented an expansion of necrosis to the zone of stasis with marked activation of apoptosis. Histologic assessment showed that the resultant vascular overgrowth was accompanied by extensive edema and abundant infiltration of leukocytes. We provide evidence for the involvement of Notch in the regulation of angiogenesis in zone of stasis burns.

Effect of Hereditary Hemochromatosis Gene H63D and C282Y Mutations on Iron Overload in Sickle Cell Disease Patients.

Objective: Hemochromatosis is an autosomal recessive disease that is one of the most important reasons for iron overload. Sickle cell disease is a hemoglobinopathy that occurs as a result of a homozygous mutation in the hemoglobin gene. Erythrocyte transfusion is frequently used in the treatment of this disease. Iron overload as a result of transfusion is important in the mortality and morbidity of sickle cell anemia patients as well as in other hemoglobinopathies. In this study, the effect of hemochromatosis gene (HFE) p.H63D and p.C282Y mutations on transfusion-related cardiac and liver iron overload in sickle cell disease patients who carry homozygous hemoglobin S mutation has been investigated. Materials and Methods: This is a prospective single-center cross-sectional study in patients with homozygous hemoglobin S mutation between the years 2008 and 2013. The patients were divided into two groups. The first group (group A, n=31) was receiving chelation therapy and the second group (group B, n=13) was not. Direct and indirect iron loads were analyzed by magnetic resonance imaging and biochemically, respectively. HFE gene mutations were analyzed by polymerase chain reaction-restriction fragment length polymorphism method. Statistical analyses were performed by independent samples t-test. Results: p.H63D mutation was detected in 10 (32.3%) patients in group A and in only 1 patient (7.7%) in group B. When the 2 groups were compared for iron overload, iron deposition in the liver was significantly higher in group B (p=0.046). In addition, in group A, iron deposition was significantly higher in HFE mutation carriers compared to patients without the mutation (p=0.05). Conclusion: Results of this study showed that HFE gene mutations are important in iron deposition in the liver in patients with sickle cell disease.

Retrieving relevant experiments: The case of microRNA microarrays.

Content-based retrieval of biological experiments in large public repositories is a recent challenge in computational biology and bioinformatics. The task is, in general, to search in a database using a query-by-example without any experimental meta-data annotation. Here, we consider a more specific problem that seeks a solution for retrieving relevant microRNA experiments from microarray repositories. A computational framework is proposed with this objective. The framework adapts a normal-uniform mixture model for identifying differentially expressed microRNAs in microarray profiling experiments. A rank-based thresholding scheme is offered to binarize real-valued experiment fingerprints based on differential expression. An effective similarity metric is introduced to compare categorical fingerprints, which in turn infers the relevance between two experiments. Two different views of experimental relevance are evaluated, one for disease association and another for embryonic germ layer, to discern the retrieval ability of the proposed model. To the best of our knowledge, the experiment retrieval task is investigated for the first time in the context of microRNA microarrays.

Impact of MMP2, MMP9 and TIMP2 Gene Polymorphisms on Allograft Rejection in Pediatric Renal Transplant Recipients

Introduction Acute and chronic allograft rejection has been continuously an important obstacle in the follow up of renal transplant recipients. During the clinical management, several factors acting simultaneously result in acute rejection and chronic allograft nephropathy. Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are responsible for the organization of extracellular matrix. They play role in cell proliferation and cellular invasion. Changes in MMP expression levels have been reported to be associated with renal allograft rejection and interstitial fibrosis. In the current study, we aimed to investigate functional polymorphisms of MMP2, MMP9 and TIMP2 genes in pediatric renal transplant recipients. Materials and Methods A total of 68 kidney transplant recipients and 58 controls were enrolled in the current study. Kidney transplant recipient group was also divided into two subgroups: non-rejecters (n=47), and rejecters (n=21). The MMP2 -735C>T (rs2285053), MMP2 -1306C>T (rs243865), MMP2 -1575G>A (rs243866), MMP9 -1562C>T (rs3918242), TIMP2 -418G>A (rs8179090) and TIMP2 -303C>T (rs2277698) polymorphisms were analyzed by using polymerase chain reaction and restriction fragment length polymorphism methods. Allelic prevalence was compared with reference values of control group and Hardy-Weinberg equilibrium was tested. Results The mean age of the study group was 16.7±3.9 and the control group was 14.8±5.6 years. Mean follow-up time after transplantation was 37.7±7.9 months. We compared the allele frequencies in the two groups and calculated a statistically significant difference in rs2285053, rs243865, rs243866, rs3918242, rs8179090 and rs2277698 polymorphisms frequencies between the transplant recipients and controls. When the transplant recipient group was compared in itself regarding allograft rejection, all investigated polymorphisms but TIMP2 -418G>A (rs8179090) revealed a statistically significant difference between rejecters and non-rejecters (p<0.05). Discussion In our cohort, functional polymorphism of MMP2, MMP9 and TIMP2 genes revealed different allele frequencies in the pediatric renal transplant and control patients as well as in allograft rejection and non-rejection patients in the study group. Previously, expression profiles of these genes and proteins have been reported in transplant recipients. To our knowledge, this is the first study investigating functional MMP2, MMP9 and TIMP2 polymorphisms in pediatric kidney recipients. Conclusion MMPs and their tissue inhibitors could be important predictive biological markers for follow up of kidney transplant recipients.

Genomic Changes in Pediatric Renal Transplant Patients Detected by aCGH

Introduction Acute and chronic allograft rejection are major problems in kidney transplantation. Identifying differences among individuals at the genomic level might help us to understand the rationale of tissue and organ rejection. The aim of this study is to identify the copy losses and gains in the genomes of patients experienced rejection in acute and chronic terms. Materials and Methods This study was designed as a retrospective single center study. A total of 24 pediatric renal transplant patients (F/M:10/14) were enrolled in the study. Patients were divided into 3 groups which are 8 kidney transplantation patients without rejection, 8 patients with acute rejection and 8 patients with chronic rejection. Agilent SurePrint G3 Human CGH 60K arrays were used to identify genome wide copy number variations. Results Mean transplant age of the non-rejection group, acute rejection, and chronic rejections patients were 15.8±4.2, 13.2±2.7, 16.4±3.8 years respectively. Average rejection time for acute and chronic rejection patients was 16.9±9.7 and 26.4±6.7 months, respectively. Results of the aCGH analysis showed that copy number losses were detected on chromosomes 1q42.2-q42.3, 2q13, 4q31.1, 7q11.23, 11q13.2, 14q11.2, 20q13.32, and copy number gains were detected on chromosomes 1p36.13, 1p32.3, 2p24.1, 2p21, 3q23, 5p13.2, 11q13.2, 12q24.21, 13q12.12, 16p11.2, 18p11.31, 19q13.43, 20p13, 20q11.21, 21q22.12, 21q22.2. Copy number variations were detected in patients with acute and chronic kidney rejection group but not in the non-rejection group. Discussion The management of acute and chronic allograft transplantation rejection is one of the major concerns during the follow up of transplantation patients. Nevertheless standardized protocols and well tuned immunosuppressant therapies are used in transplant patients; interindividual differences can cause different responses to drugs. In this study, we identified several genomic loci that show differences in terms of copy number state among patient groups. 18p11.31 is one of the loci identified in this study. TGIF1 gene within this region was reported to be over-expressed previously in kidney transplantation patients who experienced chronic rejection, which supports our finding that overexpression could be due to gain detected. Conclusion In this study, we identified copy number differences among kidney transplantation patients which might be important for the short and long term graft survival. Each region and genes within these regions could be individual possible biomarker to predict graft health.

Vitamin D receptor gene TaqI single nucleotide polymorphism is not associated with lead levels in maternal and umbilical cord blood

Abstract Purpose: We aimed to investigate the association of vitamin D receptor (VDR) gene TaqI single nucleotide polymorphism (SNPs) with serum lead (Pb) levels in maternal and umbilical cord blood. Materials and methods: Eighty-one patients who lived in Konya, Turkey for the last 3 years and had delivery at Başkent University Konya Hospital in 2016 were included in this study. Venous blood samples were drawn from each volunteer immediately before giving birth to determine the maternal Pb levels and VDR SNPs. Additionally, umbilical cord blood samples were collected from the umbilical vein into tube with EDTA as an anticoagulant immediately after birth to determine Pb levels of the fetus. Results: The median level of Pb in the maternal blood was 29.00 (Interquartile Range (IQR) = 16.35) μg/L and the median Pb level in the cord blood was 22.50 (IQR = 9.75) μg/L. Blood Pb level of women living in the urban area was significantly higher than in those living in the rural area (Z = 2.118; p = .034). There was a very strong positive correlation between the Pb levels in the maternal blood and in the umbilical cord blood (ρ = 0.825, p < .001, respectively). Regarding VDR SNPs, “TT”, “TC”, and “CC” VDR TaqI genotypes were observed in 28 (34.6%), 45 (55.5%), and eight samples (9.9%), respectively. Pb levels in maternal and cord blood were higher in women with the “CC” VDR TaqI genotype; however, there was no statistically significant difference (p > .05). Conclusions: Although women with the “CC” VDR TaqI genotype had higher maternal and cord blood Pb levels, this was statistically insignificant and therefore, VDR TaqI SNPs did not significantly affect maternal and umbilical cord blood Pb levels.