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    Determination of plasma microRNA for early detection of gastric cancer
    (Springer, 2013) Gorur, Aysegul; Fidanci, Senay Balci; Unal, Nil Dogruer; Ayaz, Lokman; Akbayir, Serin; Yaroglu, Hatice Yildirim; Dirlik, Musa
    Gastric cancer is the fourth most prevalent malignancy worldwide and remains the second most common cause of cancer-related death globally. Understanding the molecular structure of gastric carcinogenesis might identify new diagnostic and therapeutic strategies for this disease. Thus, early detection of gastric cancer is a key measure to reduce the mortality and improve the prognosis of gastric cancer. There have recently been several reports that microRNAs (miRNAs) circulate in highly stable, cell-free forms in blood. Because serum and plasma miRNAs are relatively easy to access, circulating miRNAs also have great potential to serve as non-invasive biomarkers. Although a number of miRNAs associated with gastric cancer have been identified, the underlying mechanism of these miRNAs in tumorigenesis and tumor progression remains to be investigated. The purpose of this study is to identify the potential of serum miRNAs as biomarkers for early detection of gastric cancer patients. RNA was isolated using the High Pure miRNA Isolation Kit (Roche) following the manufacturer's protocol. cDNA and preamplification protocols were obtained from the isolated plasma miRNAs. The BioMark (TM) 96.96 Dynamic Array (Fluidigm Corporation) for real-time qPCR was used to simultaneously quantite the expression of 740 miRNAs. All statistical analyses were performed using the Biogazelle's qbase PLUS 2.0 software. In this study, among 740 miRNAs that we analyzed only miR-195-5p was significantly (p < 0.05, fold changes = 13, 3) down-regulated in gastric cancer patients compared with control. We demonstrated that miR-195-5p is a novel tumor suppressor miRNA and may contribute to gastric carcinogenesis. The miRNA expression profile described in this study should contribute to future studies on the role of miRNAs in gastric cancer.
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    Differential expression of microRNAs in plasma of patients with laryngeal squamous cell carcinoma: potential early-detection markers for laryngeal squamous cell carcinoma
    (Springer, 2013) Ayaz, Lokman; Gorur, Aysegul; Yaroglu, Hatice Yildirim; Ozcan, Cengiz; Tamer, Lulufer
    Altered microRNA (miRNA) expression has been found in many cancers, including lung, breast, prostate, bladder and colorectal cancer. Many recent studies have demonstrated that aberrant plasma miRNAs were also found in various types of cancers. However, the alteration in plasma miRNA expressions in laryngeal squamous cell carcinoma (LSCC) remains unclear. The present study aimed to investigate the alterations in plasma miRNAs in LSCC. In the present study, the expression profiles of 738 miRNAs in plasma from 20 patients and 44 healthy subjects were evaluated using high-throughput real-time quantitative polymerase chain reaction. Our results demonstrated that expression levels of 17 miRNAs were significantly upregulated in patients with LSCCs when compared to control group (p < 0.05). Expression levels of nine miRNAs were found significantly downregulated in LSCC patients (p < 0.05). In addition, 17 miRNAs were expressed only in LSCC group, and five of these miRNAs (miR-331-3p, 603, 1303, 660-5p and 212-3p) are LSCC specific and never seen before in plasma of any human subject. In conclusion, our study suggests that detecting these LSCC-specific miRNAs in plasma might serve as novel noninvasive biomarkers for LSCC.
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    Effects of Bevacizumab, Ranibizumab, and Aflibercept on MicroRNA Expression in a Retinal Pigment Epithelium Cell Culture Model of Oxidative Stress
    (Mary Ann Liebert, Inc, 2018) Dinc, Erdem; Ayaz, Lokman; Kurt, Akif Hakan
    Purpose: This study aimed to evaluate the effects of bevacizumab, ranibizumab, and aflibercept on the microRNA (miRNA) expression in human retinal pigment epithelium cell (ARPE-19) culture model of oxidative stress. Methods: Control cells were cultured in the hydrogen peroxide (H2O2)-free medium. In H2O2 group ARPE-19 cells were exposed to 600M H2O2 alone for 18h. In study groups, cells were preincubated with bevacizumab, ranibizumab, and aflibercept (1.25-2.5, 0.5 and 2.0mg/mL, respectively) for 3h before H2O2 exposure. Another group of ARPE-19 cells were incubated with drugs for 3h without H2O2 exposure. Cell viability and vascular endothelial growth factor (VEGF) levels were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and enzyme-linked immunosorbent assay. The expression levels of 1,152 miRNAs were determined by quantitative real-time PCR. Results: Incubation with 600M H2O2 alone for 18h decreased cell viability by approximate to 50%. Cell viability was greater in the anti-VEGF drug groups compared with the H2O2 group, but the differences were not significant (P>0.05). VEGF levels were significantly lower in the anti-VEGF drug groups compared with the H2O2 group (P<0.05 for all study groups), with no significant differences between the study groups (P>0.05). Incubation with anti-VEGF drugs alone had no effect on miRNA expression in ARPE-19 cells. However, preincubation with bevacizumab, ranibizumab, and aflibercept significantly altered the profile of H2O2-modulated miRNA expression. Conclusions: Preincubation with anti-VEGF drugs can alter the miRNA expression profile in response to H2O2-induced oxidative stress, and these drugs may have epigenetic effects.
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    Effects of Bone Marrow and Adipose-Derived Mesenchymal Stem Cells on microRNA Expressions in Acute Alkaline Corneal Burn
    (Mary Ann Liebert, Inc, 2021) Dinc, Erdem; Ayaz, Lokman; Kurt, A. Hakan; Dursun, Ozer; Yilmaz, Gulsen; Vatansever, Mustafa; Ozer, Omer
    Purpose: The aim of this study was to investigate the microRNA (miRNA) expressions of the corneal tissue after an alkaline burn and to compare the efficiency of adipose- and bone marrow-derived mesenchymal stem cells (MSCs) on expressions. Methods: Thirty-two rats were divided into 4 groups. No intervention was made in the control group. A chemical burn was created by applying 4 mu L NaOH soaked in 6 mm filter paper to the right eye of each animal in the other groups. Whereas only subconjunctival 0.1 mL phosphate-buffered saline (PBS) was injected to in the group 1, 2 x 10(6) adipose- or bone marrow-derived MSC in 0.1 mL PBS was injected subconjunctivally to the animals in the remaining groups (groups 2 and 3, respectively). Tissue samples were collected for miRNA analysis on the third day after the burn. Results: When group 1 was compared with the control group, the expression of 3 of 93 miRNAs increased significantly, whereas the expression of 50 miRNAs decreased significantly. Significant changes in miRNA expressions were observed when group 1 was compared with groups 2 and 3. Although a significant change was observed in the expression of 6 miRNAs in the adipose-derived MSC group, it was found that the expression of 65 miRNAs significantly changed in the bone marrow-derived MSC group. Conclusion: This study shows that there are significant changes in some miRNA expressions after corneal alkaline burn and these changes can be reversed with the subconjunctival injection of MSCs.
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    Effects of Mesenchymal Stem Cells on microRNA Expressions in Acute Alkaline Corneal Burn
    (Mary Ann Liebert, Inc, 2023) Dinc, Erdem; Ayaz, Lokman; Kurt, A. Hakan; Dursun, Ozer; Yilmaz, Gulsen; Vatansever, Mustafa; Ozer, Omer
    [Abstract Not Available]
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    The effects of sleep deprivation on insulin, resistin and visfatin levels in healthy humans
    (2023) Gürel, Elif Ezgi; Ayaz, Lokman; Öztürk, Levent
    Objective: Sleep deprivation is known to affect circulating insulin and glucose levels which in turn modulate glucose metabolism. However, the mechanism of alterations in glucose homeostasis during sleep deprivation is not known. In this study, we investigated circulating resistin and visfatin levels in response to 40 hours of sleep loss in order to shed light on the above-mentioned mechanism. Methods: This study included 12 healthy young adult subjects (aged between 18-32 years). All participants underwent polysomnographic evaluation and oral glucose tolerance test and then fasting venous blood samples were collected in morning hours. Then, subjects remained awake for 40 hours under actigraphic monitorization. At the end of sleep deprivation, blood samples were collected again. Serum insulin, resistin and visfatin levels were measured in all blood samples. Insulin was determined by chemical immune assay method, whereas resistin and visfatin levels were assayed by ELISA. Results: Compared to baseline, 40-hour total sleep deprivation resulted in a significant increase in serum insulin levels (10.75±7.75 vs 35.98±27.96 IU; p=0.002) and a significant decrease in resistin levels (21.94±7.65 vs 11.71±5.31 IU; p=0.002). Visfatin levels remained unchanged (6.29±3.31 vs 5.43±5.08 IU; p>0.05). Conclusion: These results suggested that short-term total sleep deprivation may lead to insulin resistance which was evidenced by a significant increase in insulin levels independent of resistin. This may contribute to pathophysiology of type 2 diabetes mellitus under conditions of chronic sleep deprivation.
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    Evaluation of Anti-Inflammatory and Antiapoptotic Effects of Bone Marrow and Adipose-Derived Mesenchymal Stem Cells in Acute Alkaline Corneal Burn
    (Mary Ann Liebert, Inc, 2021) Dinc, Erdem; Dursun, Ozer; Yilmaz, Gulsen; Kurt, A. Hakan; Ayaz, Lokman; Vatansever, Mustafa; Ozer, Omer
    Purpose: The aim of the present study is to comparatively evaluate the anti-inflammatory and antiapoptotic effects of bone marrow and adipose-derived mesenchymal stem cells (MSCs) applied subconjunctivally after alkaline corneal burn. Methods: Thirty-two rats were divided into 4 groups and included in the study (n = 8). While no intervention was made in the control group, a chemical burn was created by applying 4 mu L of NaOH soaked in 6 mm filter paper to the right eye of each subject in the other groups under general anesthesia. While only subconjunctival 0.1 mL phosphate-buffered saline (PBS) was injected to in the group 1, 2 x 10(6) adipose or bone marrow-derived MSC in 0.1 mL PBS was applied subconjunctivally to the subjects in the remaining groups (Group 2 and 3, respectively). Tissue samples were collected for histological analysis on the third day after the burn. Tissue samples were evaluated light microscopically and immunohistochemically stained for interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha), caspase-3 (Cas-3), and CD68. Results: The IL-1 beta and TNF-alpha staining scores and the number of CD68- and Cas-3-positive stained cells were significantly lower in the groups given bone marrow and adipose-derived MSC compared to the alkaline burn group (P < 0.0001, for all parameters). Epithelial IL-1 beta and TNF-alpha staining scores were significantly lower in the bone marrow-derived MSC group compared to the adipose-derived MSC group (P < 0.0001, for all parameters). Conclusions: The presented study shows that both bone-marrow and adipose-derived MSCs support wound healing in the corneal tissue and strongly suppress the inflammation occured in the tissue.
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    Evaluation of circulating miRNAs in wet age-related macular degeneration
    (Molecular Vision, 2014) Ertekin, Sevda; Yildirim, Ozlem; Dinc, Erdem; Ayaz, Lokman; Fidanci, Senay Balci; Tamer, Lulufer
    Purpose: In the present study, we aimed to investigate the changes in plasma miRNA in patients with wet age-related macular degeneration. Methods: The expression profiles of 384 miRNAs in plasma from 33 patients (22 male, 11 female) who were diagnosed with wet age-related macular degeneration with fundus examination, fundus fluorescein angiography, and optical coherence tomography and 31 controls (17 male, 14 female) were evaluated using high-throughput quantitative real-time PCR. Results: Our results demonstrated that the expression level of five miRNAs (miR-17-5p, miR-20a-5p, miR-24-3p, miR-106a-5p, and miR-223-3p) was significantly upregulated in patients with age-related macular degeneration when compared to the control group (p<0.05). The expression level of 11 miRNAs (miR-21-5p, miR-25-3p, miR-140-3p, miR-146b-5p, miR-192-5p, miR-335-5p, miR-342-3p, miR-374a-5p, miR-410, miR-574-3p, and miR-660-5p) was significantly downregulated in patients (p<0.05). In addition, ten miRNAs (miR-26b-5p, miR-27b-3p, miR-29a-3p, miR-139-3p, miR-212-3p, miR-324-3p, miR-324-5p, miR-532-3p, miR-744-5p, and miR-Let-7c) were expressed only in the patient group. Conclusions: Our results suggest that plasma miRNA levels may change in wet age-related macular degeneration. These molecules may have an important therapeutic target in patients who are unresponsive to antivascular endothelial growth factor therapy. However, further studies must be conducted for possible effects of miRNAs in vascular disorders of eye such as age-related macular degeneration.
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    Evaluation of microRNA responses in ARPE-19 cells against the oxidative stress
    (Taylor & Francis Ltd, 2018) Ayaz, Lokman; Dinc, Erdem
    Purpose: This study aimed to determine microRNA (miRNA) expression profile of human retinal pigment epithelium cell (ARPE-19) against the oxidative stress induced by hydrogen peroxide (H2O2).Methods: ARPE-19 cells were incubated with different concentrations of H2O2 (200, 600 and 800M) for 18h, and then cell viability, vascular endothelial growth factor levels and total oxidant status were evaluated. Expressions of 1152 miRNA were determined by quantitative real-time PCR in each group.Results: Expressions of 90 miRNA were significantly changed in the ARPE-19 cells incubated with H2O2 compared to control group. However, miR-143-3p was only found to be expressed in groups incubated with H2O2. While 24 miRNA (hsa-miR-200c-3p, miR-192-5p, miR-194-5p, miR-141-3p, miR-658, miR-18b-5p, miR-486-5p, miR-525-3p, miR-493-3p, miR-518d-3p, miR-29b-1-5p, miR-675-3p, miR-1238-3p, miR-195-3p, miR-1539, miR-490-5p, miR-3200-5p, miR-1273d, miR-130a-5p, miR-30b-5p, miR-1247-5p, miR-1910-5p, miR27a-5p and miR-200b-3p) upregulated due to the increased dose of H2O2, nine miRNA (hsa-miR-96-5p, miR-33a-5p, miR-345-5p, miR-106b-3p, miR-1285-3p, miR-23b-5p, miR-27b-5p, miR-103a-3p and miR-4289) were also found to be downregulated.Conclusion: This study suggests that oxidative stress may be an important factor on expression of miRNAs in ARPE-19 cells. These miRNAs may have a role in the pathogenesis of age-related macular degeneration related to oxidative stress. However, this relationship needs to be examined in new studies by evaluation of pathways and target genes.
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    Evaluation of miRNAs Related with Nuclear Factor Kappa B Pathway in Lipopolysaccharide Induced Acute Respiratory Distress Syndrome
    (Cellular & Molecular Biology Research Center, 2020) Azizoglu, Mustafa; Ayaz, Lokman; Bayrak, Gulsen; Yilmaz, Banu Coskun; Birbicer, Handan; Doruk, Nurcan
    This study aimed to determine the expression of nuclear factor kappa B (NF-kappa B) pathway related miRNAs in experimental acute respiratory distress syndrome (ARDS) induced by lipopolysaccharide (LPS) in rats, and to elucidate the underlying molecular mechanism. Twenty four sprague dawley rats were randomly divided into two groups; LPS (n = 12) and control (n = 12). Experimental ARDS was induced by intraperitoneal injection of E. coli LPS in LPS group. Intraperitoneal saline was administered in control group. Serum and lung samples were collected from both groups. Inununohistochemistry staining was performed for interleukin 1 beta (IL-beta), tumor necrosis factor alpha (TNF-alpha), CD 68, and caspase-3 in lung samples. Intensity of staining was scored as strong, moderate, weak, and no for evaluation of IL-1 beta and TNF-alpha. In addition, caspase-3 and CD68-positive stained cells were counted in sections. Expressions of 9 miRNAs were determined by quantitative real-time PCR in serum samples. IL-1 beta and TNF-alpha staining scores were significantly higher in the LPS group in comparison with the control group (P = 0.04 and P = 0.02, respectively). In addition, caspase-3 and CD68-positive stained cells were significantly higher in the LPS group (P = 0.02). Expressions of seven miRNAs were significantly changed in the LPS group in comparison with the control group. While six miRNAs (miR-7a-5p, miR-7b, miR9a-5p, miR-21-5p, miR-29a-3p, and miR-138-5p) were up regulated, only miR-124-3p was down regulated. This study suggests that these miRNAs may have a role in the pathogenesis of ARDS related to NF-kappa B. However, this relationship needs to be examined in new studies by evaluation of pathways and target genes.
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    Expression levels of maternal plasma microRNAs in preeclamptic pregnancies
    (Taylor & Francis Inc, 2021) Akgor, Utku; Ayaz, Lokman; Cayan, Filiz
    The present study aimed to identify the differential expression profiles of microRNAs in the plasma between patients with preeclampsia (PE) and healthy pregnancies using quantitative real-time PCR. The expression profiles of 32 miRNAs in maternal plasma from 31 patients with PE and 32 healthy pregnancies were evaluated. The expression levels of eight miRNAs including miR-210, miR-375, miR-197-3p, miR-132-3p, miR-29a-3p, miR-328, miR-24-3p, and miR-218-5p were significantly upregulated and the expression levels of three miRNAs, including miR-302b-3p, miR-191-5p, and miR-17-5p, were significantly downregulated in patients with preeclampsia when compared to healthy pregnant women. In conclusion, we identified 11 miRNAs that may be potential biomarkers for non-invasive diagnosis and a pivotal role in the prediction of PE. Considering the small cohort of patients, further studies with larger samples from different gestational stages are necessary to confirm our findings. IMPACT STATEMENT What is already known on this subject? The alterations in the release pattern of placenta-specific miRNAs detected in maternal serum have been found to be associated with pregnancy-related complications such as preeclampsia (PE). What do the results of this study add? In the present study, the release pattern of seven miRNAs had consistency and two of them had inconsistency with previous researches. Moreover, two novel miRNAs were also defined to demonstrate the interrelationship between PE and miRNAs. What are the implications of these findings for clinical practice and/or future research? The identification of 11 miRNAs that may be potential biomarkers for non-invasive diagnosis and a pivotal role in the prediction of PE. Considering the small cohort of patients, further studies with larger samples from different gestational stages are necessary to confirm our findings.
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    The G1057D polymorphism of insulin receptor substrate-2 associated with gestational diabetes mellitus
    (Taylor & Francis Ltd, 2014) Ayaz, Lokman; Celik, Sevim Karakas; Cayan, Filiz
    Objective: The Gly1057D polymorphism in the insulin receptor substrate-2 (IRS-2) gene has been reported to be associated with insulin resistance, obesity and type 2 diabetes; little is known about its possible association with gestational diabetes mellitus (GDM). To investigate this association we determined the distribution of its genotypes and frequency of alleles in GDM patients. Materials and methods: The study population consisted of 94 subjects; among them were 44 patients with GDM and 50 healthy controls without diabetes. Genomic DNA was extracted from the leukocyte by high pure polymerase chain reaction (PCR) template preparation kit. Genetic polymorphism of IRS-2 G1057D was detected by using PCR-based restriction fragment-length polymorphism (RFLP). Results: For IRS-2 G1057D polymorphism, there was no significant difference in genotype distribution between GDM patients and controls. The risk for GDM was 2.97 times higher (95% CI: 0.89-9.93, p = 0.076) in the individuals with the IRS-2 DD genotype compared to the GG genotype. Also individuals with the IRS-2 D allele had a significantly higher risk of GDM compared with individuals with the IRS-2 G allele, with a relative risk of 1.86 (95% CI: 1.02-3.37, p = 0.042) for cases compared with population controls. Conclusion: These results suggest that IRS-2 1057D allele may be associated with GDM.
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    Inhibition of Radiation-Induced Oxidative Damage in the Lung Tissue: May Acetylsalicylic Acid Have a Positive Role?
    (Springer/Plenum Publishers, 2016) Demirel, Can; Kilciksiz, Sevil Cagiran; Gurgul, Serkan; Erdal, Nurten; Yigit, Seyran; Tamer, Lulufer; Ayaz, Lokman
    The lung is relatively sensitive to irradiation. It is shown that acetylsalicylic acid (ASA) might reduce oxidative injury and that it has a place in protection from cancer. The aim of this study is to evaluate the potential radioprotective effects of ASA. Whole-body irradiation (6 Gy, single dose) was applied to the rats. Glutathione (GSH), malondialdehyde (MDA), myeloperoxidase (MPO), and nitric oxide (NO) levels in the lung tissue were measured. Control (C), Radiation (R), Radiation + ASA (R + ASA; received irradiation and 25 mg/kg of ASA intraperitoneally (i.p.)), and Radiation + Amifostine (R + WR-2721; received irradiation and 200 mg/kg of WR-2721 i.p.) groups were used. The MPO levels decreased statistically significantly in the group administered ASA. Histopathologically, a radioprotective effect of ASA was more evident in the R + ASA group. ASA is an agent which has not been used as a radioprotector in the clinic yet, and it is worth supporting with more advanced studies.
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    Intravitreal bevacizumab effects on VEGF levels in distant organs: an experimental study
    (Informa Healthcare, 2014) Dinc, Erdem; Yildirim, Ozlem; Yilmaz, S. Necat; Canacankatan, Necmiye; Ayaz, Lokman; Ozcan, Tuba; Temel, Gulhan O.
    Purpose: The aim of this study was to determine the effects of single-dose intravitreal bevacizumab on the levels of vascular endothelial growth factor (VEGF) in serum and distant organs. Methods: Adult New Zealand albino rabbits (n = 40) were divided into experimental and control groups. Experimental rabbits received a single 0.05 ml intravitreal injection of 1.25 mg bevacizumab (Avastin) into the right eye, and control rabbits (n = 8) received no injection. Following injection, group 1 rabbits (n = 8) were sacrificed on day 1, group 2 rabbits (n = 8) on day 7, group 3 rabbits (n = 8) on day 14, and group 4 rabbits (n = 8) on day 28; control rabbits were sacrificed on day 28. After sacrifice, samples of brain, heart, liver, kidney and blood were collected. Levels of VEGF in serum and tissue were measured using enzyme-linked immunosorbent assay. The presence of bevacizumab was evaluated by immunofluorescence staining in tissues. Results: Positive bevacizumab immunoreactivity was observed in brain, heart and kidney. Serum VEGF levels significantly decreased in groups 3 and 4 compared with controls (p < 0.05). Liver VEGF levels significantly decreased in group 3 compared with controls (p < 0.05). Conclusions: Intravitreal bevacizumab not only may escape from the blood-retinal barrier and enter the general circulation, but also may be disseminated to distant organs. Our study demonstrates that a single dose of intravitreally injected bevacizumab decreases VEGF levels in serum and liver.
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    MicroRNAs EXPRESSION PROFILES IN NON-SMALL CELL LUNG CANCER
    (Parlar Scientific Publications (P S P), 2021) Yaroglu, Hatice Yildirim; Akbayir, Serin; Gorur, Aysegul; Balci, Senay; Unal, Nil; Ayaz, Lokman; Ayan, Erhan
    MicroRNAs (miRNAs) are a new endogenous small non-coding RNA family that arranges expression of a few genes related in normal development as well as human diseases such as cancer. miRNAs are developing as potential diagnostic and therapeutic markers with deregulated expression in various cancers including lung cancer. In this study, we aimed to find out miRNA expression profiles and to show the relationship between non-small cell lung cancer and microRNAs levels, if there is. In the present study, the expression profiles of 740 miRNA in plasma from 31 patients and 64 healthy subjects were evaluated using high-throughput real-time quantitative polymerase chain reaction. All statistical analyses were performed using the BiogazelIe's qbase PLUS 2.0 software. Our results showed that expression levels of 7 microRNAs (miR-20b-5p, -30c, -146a, -192-5p, -206, -484, -574-3p) were significantly upregulated in patients when compared to control group (p<0.05). Expression levels of five miRNAs (miR-24-3p, -30a-5p, -106b-5p, -223-3p, -331-5p) were found significantly downregulated in lung cancer patients (p<0.05). Conclusion: In conclusion, our result showed that up -regulated and down-regulated miRNAs may be important role of early detection in non-small cell lung cancer.
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    Protective Effect of Combined Caffeic Acid Phenethyl Ester and Bevacizumab Against Hydrogen Peroxide-Induced Oxidative Stress in Human RPE Cells
    (Taylor & Francis Inc, 2017) Dinc, Erdem; Ayaz, Lokman; Kurt, Akif Hakan
    Purpose: This study aimed to evaluate the protective effects of caffeic acid phenethyl ester (CAPE) and combined CAPE-bevacizumab against oxidative stress induced by hydrogen peroxide (H2O2) in human retinal pigment epithelium. Methods: ARPE-19 cells were pretreated with 5, 10, and 30 mu M CAPE alone and in combination with bevacizumab for 3 h, then exposed to H2O2 for 16 h. Cell viability was evaluated with the 3-(4,5dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Vascular endothelial growth factor (VEGF) protein levels in the medium were measured using a human VEGF ELISA kit. Total antioxidant status (TAS) and total oxidant status (TOS) were measured in ARPE-19 cells using the test kit from Rel Assay. Expression levels of VEGF, Bax, Bcl-2, cytochrome c, apoptotic protease activating factor-1 (apaf-1), and caspase-3 were determined using reverse transcription polymerase chain reaction. Results: Pretreatment of ARPE-19 cells with 30 mu M CAPE and combined CAPE-bevacizumab reduced H2O2 mediated cell death. H2O2-induced oxidative stress increased TOS and VEGF production, which was significantly inhibited by CAPE and the CAPE-bevacizumab combination. VEGF, Bax, cytochrome c, apaf-1, and caspase-3 gene expressions were significantly decreased in cells pretreated with 5, 10, and 30 mu M CAPE and combined CAPE-bevacizumab compared to the H2O2 group. In addition, Bcl-2 expression was significantly increased in both the CAPE and CAPE-bevacizumab combination groups compared to the H2O2 group. Conclusions: CAPE has a protective effect on ARPE-19 cells against oxidative stress, and VEGF protein level and expression can be decreased by incubation with different concentrations of CAPE. These results demonstrate that CAPE suppresses the mitochondria-mediated apoptosis in ARPE-19 cells under oxidative stress. In addition, the use of CAPE in combination with bevacizumab has an additive effect.
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    A Review on the Design, Synthesis, and Structure-activity Relationships of Benzothiazole Derivatives against Hypoxic Tumors
    (Bentham Science Publ Ltd, 2022) Kurt, Akif Hakan; Ayaz, Lokman; Ayaz, Furkan; Seferoglu, Zeynel; Nural, Yahya
    There has been a growing body of studies on benzothiazoles and benzothiazole derivatives as strong and effective anti-tumor agents against lung, liver, pancreas, breast, and brain tumors. Due to the highly proliferative nature of the tumor cells, the oxygen levels get lower than that of normal tissues in the tumor microenvironment. This situation is called hypoxia and has been associated with increased ability for carcinogenesis. For the drug design and development strategies, the hypoxic nature of the tumor tissues has been exploited more aggressively. Hypoxia itself acts as a signal initiating system to activate the pathways that eventually lead to the spread of the tumor cells into the different tissues, increases the rate of DNA damage, and eventually ends up with more mutation levels that may increase the drug resistance. As one of the major mediators of hypoxic response, hypoxia-inducible factors (HIFs) have been shown to activate angiogenesis, metastasis, apoptosis resistance, and many other protumorigenic responses in cancer development. In the current review, we will be discussing the design, synthesis, and structure-activity relationships of benzothiazole derivatives against hypoxic tumors such as lung, liver, pancreas, breast, and brain as potential anti-cancer drug candidates. The focus points of the study will be the biology behind carcinogenesis and how hypoxia contributes to the process, recent studies on benzothiazole and its derivatives as anti-cancer agents against hypoxic cancers, conclusions, and future perspectives. We believe that this review will be useful for researchers in the field of drug design during their studies to generate novel benzothiazole-containing hybrids against hypoxic tumors with higher efficacies.
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    Soybean oil prevents peritoneal adhesions without impairing colonic anastomotic healing
    (Wiley, 2015) Dag, Ahmet; Colak, Tahsin; Koc, Okay; Ayaz, Lokman; Comelekoglu, Ulku; Serinsoz-Pfeiffer, Ebru
    Aim: Adhesion formation could potentially result in significant morbidity and mortality. In the present study, we investigated the role of soybean oil in the prevention of peritoneal adhesions and its effect on the anastomotic healing process. Patients and Methods: A total of 40 male Wistar Albino rats were randomly assigned to four groups: group A, adhesion induction method; group B, adhesion induction method with administration of soybean oil; group C, colonic anastomosis method; and group D, colonic anastomosis method with administration of soybean oil. Adhesions were scored on postoperative day 7. Anastomotic healing was assessed by determining anastomotic bursting pressure (ABP), tissue hydroxyproline content and the histopathological examination. The serum malondialdehyde (MDA), nitric oxide (NO) and myeloperoxidase (MPO) levels were determined to evaluate cellular response to injury. Results: The difference in mean values between saline-and soybean oil-treated groups, using both the adhesion method and colonic anastomosis method, were statistically significant (P = 0.0003, P = 0.009). Soybean oil administration resulted in no significant difference in terms of ABP and histopathological scores (P = 0.694 and P = 0.246, respectively). Tissue hydroxyproline content was increased significantly with soybean oil administration (P = 0.001). Mean MDA, NO and MPO levels were significantly decreased in the soybean-administered colonic anastomosis group (P = 0.001, P = 0.001, P = 0.002, and respectively). In the soybean-administered adhesion group, mean MDA, NO and MPO levels were lower than in the control group, but the differences were not significant (P = 0.113, P = 0.958, and P = 0.597, respectively). Conclusion: Soybean oil administration intraperitoneally has been shown to prevent adhesion formation effectively without impairing the colonic anastomotic healing process.