Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Serpil Oguztuzun is active.

Publication


Featured researches published by Serpil Oguztuzun.


Apmis | 2011

Prognostic significance of micropapillary pattern in lung adenocarcinoma and expression of apoptosis-related markers: caspase-3, bcl-2, and p53

Ebru Cakir; Aydin Yilmaz; Funda Demirag; Serpil Oguztuzun; Sezgi Sahin; Ülkü Yazıcı; Mehtap Aydin

Cakir E, Yilmaz A, Demirag F, Oguztuzun S, Sahin S, Yazici UE, Aydin M. Prognostic significance of micropapillary pattern in lung adenocarcinoma and expression of apoptosis related markers: caspase‐3, bcl‐2, and p53. APMIS 2011;


Oncotarget | 2017

MicroRNA 603 acts as a tumor suppressor and inhibits triple-negative breast cancer tumorigenesis by targeting elongation factor 2 kinase

Recep Bayraktar; Martin Pichler; Pinar Kanlikilicer; Cristina Ivan; Emine Bayraktar; Nermin Kahraman; Serpil Oguztuzun; Mustafa Ulasli; Ahmet Arslan; George A. Calin; Gabriel Lopez-Berestein; Bulent Ozpolat

Triple negative breast cancer (TNBC) is an aggressive type of breast cancer characterized by the absence of defined molecular targets, including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and is associated with high rates of relapse and distant metastasis despite surgery and adjuvant chemotherapy. The lack of effective targeted therapies for TNBC represents an unmet therapeutic challenge. Eukaryotic elongation factor 2 kinase (eEF2K) is an atypical calcium/calmodulin-dependent serine/threonine kinase that promotes TNBC tumorigenesis, progression, and drug resistance, representing a potential novel molecular target. However, the mechanisms regulating eEF2K expression are unknown. Here, we report that eEF2K protein expression is highly up-regulated in TNBC cells and patient tumors and it is associated with poor patient survival and clinical outcome. We found that loss/reduced expression of miR-603 leads to eEF2K overexpression in TNBC cell lines. Its expression results in inhibition of eEF2K by directly targeting the 3-UTR and the inhibition of tumor cell growth, migration and invasion in TNBC. In vivo therapeutic gene delivery of miR-603 into TNBC xenograft mouse models by systemic administration of miR-603-nanoparticles led to a significant inhibition of eEF2K expression and tumor growth, which was associated with decreased activity of the downstream targets of eEF2K, including Src, Akt, cyclin D1 and c-myc. Our findings suggest that miR-603 functions as a tumor suppressor and loss of miR-603 expression leads to increase in eEF2K expression and contributes to the growth, invasion, and progression of TNBC. Taken together, our data suggest that miR-603-based gene therapy is a potential strategy against TNBC.


Phosphorus Sulfur and Silicon and The Related Elements | 2016

Synthesis, structural characterization, and cytotoxic activity of new spirocyclic octachlorocyclotetraphosphazenes

Muhammet Işıklan; Levent Sayın; Ömer Sonkaya; Tuncer Hökelek; Mustafa Türk; Serpil Oguztuzun

GRAPHICAL ABSTRACT ABSTRACT Octachlorocyclotetraphosphazene, N4P4Cl8, (1) was reacted with N, N′-dibenzylethylenediamine to synthesize partially substituted monospiro- (2), dispiro- (5) and tetraspirocyclotetraphosphazene (8) derivatives. The reactions of 2 and 5 with excess pyrrolidine and morpholine produced fully substituted pyrrolidino (3 and 6) and morpholino (4 and 7) spirocyclotetraphosphazenes. The structures of the compounds were determined with 1D (1H, 13C, 31P, and DEPT) NMR, 2D (HSQC) NMR, ESI-MS, FTIR, and elemental analysis. The solid-state structures of 6 and 7 were examined by X-ray crystallography. In 7, intramolecular C-H…O hydrogen bonds link the molecules into centrosymmetric dimmers. The cytotoxic activity of all the compounds against human cervix carcinoma cell lines (HeLa) was investigated. The study showed that these compounds exert limited cytotoxic, apoptotic and necrotic effects on HeLa cancer cell lines.


Cutaneous and Ocular Toxicology | 2016

Comparison of TLR-2, TLR-4, and antimicrobial peptide levels in different lesions of acne vulgaris.

Emin Ozlu; Ayse Serap Karadag; Seyma Ozkanli; Serpil Oguztuzun; Murat Kilic; Ebru Zemheri; Ozge Akbulak; Necmettin Akdeniz

Abstract Context: Recent studies have shown that tolls like receptors (TLRs) and antimicrobial peptides (hBD-1, cathelicidin) play an important role in the pathogenesis of acne vulgaris (AV). Objective: To evaluate and report the expression of TLR-2, TLR-4, hBD-1 and cathelicidin in different regions of skin in AV. Participants: This study was performed in 80 patients with AV and a control group of 20 healthy individuals. Material and methods: Skin biopsies were performed from 20 papular, 20 pustular, 20 comedonal and 20 nodular lesions of patients and 20 healthy volunteers. Expression levels of TLR-2, TLR-4, hBD-1 and cathelicidin in four separate areas (epidermis, dermis, inflammation region and skin appendages) were evaluated by immunohistochemical method. Further, these parameters were compared between different skin lesions. Results: A significant difference was found between the levels of staining of TLR-2, TLR-4 and hBD-1 from the epidermis, inflammation region, dermis and skin appendages (p < 0.05). Levels of cathelicidin were different in only the inflammation region (p < 0.05). The level of TLR-2 in the epidermis with nodules was lower than the papules and comedones (p < 0.05). Levels of TLR-2 in the inflammation and dermis of the cases with papules were significantly higher when compared to pustules (p < 0.05). The levels of staining of TLR-4 in the dermis with comedones were significantly lower compared to the cases with papules (p < 005). The level of hBD-1 in the epidermis region of comedones was significantly higher compared to nodules (p < 0.05). The expression of cathelicidin in the inflammation region of comedones was significantly low (p < 0.05). Conclusion: It is thought that TLR-2, TLR-4, hBD-1 and cathelicidin play an important role in the pathogenesis of AV and in the development of different acne types. We think that, better results could be obtained in treatment of AV with different treatment options targeted in regulation of TLR-2, TLR-4, hBD-1 and cathelicidin release.


Cornea | 2016

Investigation of Glutathione S-Transferase Isoenzyme Protein Expression in Patients With Pterygium.

Remzi Karadag; Nurettin Bayram; Serpil Oguztuzun; Busra Bozer; Huseyin Bayramlar; Gulcin Simsek; Christopher J. Rapuano

Purpose: We investigated glutathione S-transferase (GST) enzymes in terms of their potential effects on the pathogenesis of pterygium. Methods: Twenty-six pterygium specimens and 15 normal conjunctival specimens of 15 control subjects were investigated. Expressions of GST (alpha, mu, pi, and theta) enzymes were assessed by immunohistochemical staining. A brown color in the cytoplasm and/or nuclei of epithelial cells was evaluated as positive staining for GST enzymes. For each antibody, the intensity of the reaction [negative (−), weak (1+), moderate (2+), or strong (3+)] was determined to describe the immunoreactions. Results: The median age was 52 years in the both groups. There was no significant difference between the groups in terms of age, sex, and intraocular pressure measurements (P > 0.05 for all). Of the 26 pterygium specimens, 15 (57.7%) (8 weak, 4 moderate, and 3 strong staining) were identified with GST pi-1 (GSTP1) expression and 20 (76.9%) (12 weak, 7 moderate, and 1 strong staining) with GST theta-1 (GSTT1) expression. Of the 15 control specimens, 4 (26.7%) (4 weak staining) were identified with the GSTP1 expression, and 1 (6.7%) with GSTT1 expression. GSTP1 and GSTT1 expressions were significantly higher in the pterygium specimens than in the controls (P = 0.043, P < 0.001; respectively). None of tissue specimens had positive staining for GST mu-1 or GST alpha-1 in both groups (both; P = 1.00). Conclusions: The significant increase of GSTP1 and GSTT1 expressions in pterygium may be because of the increased activation of GST in response to excessive free radical formation from ultraviolet exposure to maintain antioxidant capacity in pterygium.


European Journal of Obstetrics & Gynecology and Reproductive Biology | 2015

Is montelukast effective in regression of endometrial implants in an experimentally induced endometriosis model in rats

Sadiman Kiykac Altinbas; Omer Lutfi Tapisiz; Sabri Cavkaytar; Gulcin Simsek; Serpil Oguztuzun; Umit Goktolga

OBJECTIVE Montelukast, a selective antagonist of Type 1 cysteinyl leukotriene receptors (CysLT1Rs), antagonizes the proinflammatory and proasthmatic activities of CysLT1Rs. We investigated the effect of montelukast on a surgically induced endometriosis rat model. STUDY DESIGN Thirty-two sexually mature, cycling, female Wistar-Albino rats, in which endometriotic implants were surgically induced, were randomly divided into three groups. Group I [Montelukast (M), 10 rats)] was given 1.6 mg/kg/day of oral montelukast sodium. Group II [Leuprolide acetate (L), 11 rats] was given 1 mg/kg single dose of s.c.leuprolide acetate. Group III [Control (C), 11 rats] received saline solution through an orogastric tube and served as controls. After a 3-weeks medication, the rats were sacrificed to investigate the endometriotic implants for size and morphological and histological characteristics, including immunoreactivity of MMP-2 and VEGF. RESULTS The mean area of implants decreased from 48.2 ± 24.7 to 29.3 ± 15.8mm(2) in Group I (M) (P = 0.008) and from 62 ± 32.1 to 39.9 ± 18.1mm(2) in Group II (L) (P=0.003). In Group III (C), the mean area increased from 41.1 ± 31.1 to 60.4 ± 37.1mm(2) (P = 0.025). Histopathological analysis showed statistically significant lower scores in rats treated with montelukast compared to leuprolide and controls. MMP H scores were not different between the groups in both epithelial and stromal MMP-2 immunostaining. VEGF H scores were statistically lower in Group 1 (M) in epithelial VEGF immunostaining when compared to Group II (L) and Group III (C) (P=0.006). CONCLUSION(S) Montelukast may effectively cause a significant decrease in the area of endometriotic implants.


Clinical and Experimental Dermatology | 2011

Expression of GSTM4 and GSTT1 in patients with Tinea versicolor, Tinea inguinalis and Tinea pedis infections: a preliminary study

M. Kilic; Serpil Oguztuzun; A. S. Karadag; E. Cakir; M. Aydin; L. Ozturk

Background.  Several skin diseases are believed to be associated with oxidative stress. Defence against reactive oxygen species in the skin involves a variety of antioxidant enzymes, including glutathione‐S‐transferases (GSTs) catalysing the reaction between reduced glutathione, and a variety of exogenously and endogenously derived electrophilic compounds. The mammalian soluble GSTs are divided into five main classes: alpha (A), mu (M), pi (P), theta (T) and zeta (Z).


International Journal of Dermatology | 2017

An investigation of cytochrome p450 (CYP) and glutathione S‐transferase (GST) isoenzyme protein expression and related interactions with phototherapy in patients with psoriasis vulgaris

Ayse Serap Karadag; Tugba Kevser Uzuncakmak; Seyma Ozkanli; Serpil Oguztuzun; Busra Moran; Ozge Akbulak; Emin Ozlu; Itır Ebru Zemheri; Serap Gunes Bilgili; Necmettin Akdeniz

Oxidative stress may play an important role in the pathogenesis of psoriasis. Glutathione S‐transferases (GSTs) make up a group of antioxidant enzymes. Cytochrome p450 (CYP) enzymes can influence oxidation and reduction reactions. We investigated the potential effects of GST and CYP enzymes in the pathogenesis of psoriasis. The study included 32 psoriasis patients and 22 healthy subjects. Psoriasis patients were administered 20 sessions of narrowband ultraviolet B phototherapy. Expressions of GST and CYP enzymes were assessed by immunohistochemical staining. Expression levels of GSTK1, GSTM1, and GSTT1 were significantly higher in psoriasis than in control tissues (P = 0.022, P = 0.001, and P = 0.006, respectively). Pre‐ and post‐treatment expression was similar. Expression of CYP1A1 and CYP2E1 was significantly higher in pre‐ (P = 0.003 and P = 0.001, respectively) and post‐treatment (P = 0.003 and P = 0.001, respectively) psoriatic tissues than in control tissues. No significant differences in CYP1B1 levels between the study and control groups were detected before treatment (P > 0.05). However, CYP1B1 levels were higher in post‐treatment psoriatic tissue than in control tissue (P = 0.045). The significant increases in expression of GSTK1, GSTM1, and GSTT1 in psoriasis may reflect the increased activation of GST in response to excessive free radical formation from activated neutrophils or ultraviolet exposure to maintain antioxidant capacity in psoriasis. Furthermore, expressions of CYP1A1 and CYP2E1 represent important enzymatic systems in psoriasis. These findings suggest that psoriasis is an oxidative stress condition, although phototherapy does not affect these enzymatic systems. Further investigation is required.


Cutaneous and Ocular Toxicology | 2017

The investigation of antimicrobial peptides expression and its related interaction with methotrexate treatment in patients with psoriasis vulgaris

Emin Ozlu; Ayse Serap Karadag; Seyma Ozkanli; Serpil Oguztuzun; Ozge Akbulak; Tugba Kevser Uzuncakmak; Serkan Demirkan; Necmettin Akdeniz

Abstract Background: Psoriasis is a chronic, inflammatory and immune-mediated disease. Recently, the role of antimicrobial peptides (AMPs) such as human beta defensins (hBDs) in the pathogenesis of psoriasis has been investigated. We aimed to evaluate the expression profiles of hBD-1 and hBD-2 in psoriatic skin before and after methotrexate (MTX) therapy and to compare healthy controls. Methods: Immunohistochemical expressions of hBD-1 and hBD-2 were assessed in 16 patients with psoriasis vulgaris and 20 normal skin biopsies from healthy controls. The patients were administered a 12 week of MTX and skin biopsy samples were obtained from the lesional skin of the patients pre-/posttreatment and normal body of the healthy controls. Results: The median (range) Psoriasis Area and Severity Index (PASI) value was 21.6 (8.2–27.7) before the treatment whereas; 3.05 (1–23.4) after the treatment. hBD-1 expression in psoriasis patients was significantly higher as compared to the healthy controls before treatment (p < 0.01). No significant difference was observed between psoriasis patients and healthy controls in terms of hBD-2 expression before treatment (p > 0.05). No significant difference was observed between before–after MTX treatment in terms of hBD-1 and hBD-2 expression levels in psoriasis patients (p > 0.05). Conclusions: These findings suggest a role for hBD-1 in psoriasis pathogenesis. But MTX treatment does not affect on hBD-1 and hBD-2 expressions. Further studies are needed to assess the roles of these AMPs in psoriasis etiopathogenesis.


Medical Principles and Practice | 2018

Glutathione S-Transferases and Cytochrome P450 enzyme expression in patients with Intracranial Tumors: Preliminary Report of 55 Patients

Cahit Kural; Arzu Kaya Kocdogan; Guler Gulcin Simsek; Serpil Oguztuzun; Pınar Kaygın; Irmak Yılmaz; Tugbag Bayram; Yusuf Izci

Objective: Intracranial tumors are one of the most frightening and difficult-to-treat tumor types. In addition to surgery, protocols such as chemotherapy and radiotherapy also take place in the treatment. Glutathione S-transferase (GST) and cytochrome P450 (CYP) enzymes are prominent drug-metabolizing enzymes in the human body. The aim of this study is to show the expression of GSTP1, GSTM1, CYP1A1, and CYP1B1 in different types of brain tumors and compare our results with those in the literature. Subjects and Methods: The expression of GSTP1, GSTM1, CYP1A1, and CYP1B1 was analyzed using immunostaining in 55 patients with intracranial tumors in 2016–2017. For GST and CYP expression in normal brain tissue, samples of a portion of surrounding normal brain tissue as well as a matched far neighbor of tumor tissue were used. The demographic features of the patients were documented and the expression results compared. Results: The mean age of the patients was 46.72 years; 29 patients were female and 26 were male. Fifty-seven specimens were obtained from 55 patients. Among them, meningioma was diagnosed in 12, metastases in 12, glioblastoma in 9, and pituitary adenoma in 5. The highest GSTP1, GSTM1, and CYP1A1 expressions were observed in pituitary adenomas. The lowest GSTP1 expression was detected in glioblastomas and the lowest CYP1B1 expression in pituitary adenomas. Conclusion: GSTP1 and CYP expression is increased in intracranial tumors. These results should be confirmed with a larger series and different enzyme subtypes.

Collaboration


Dive into the Serpil Oguztuzun's collaboration.

Top Co-Authors

Avatar

Ayse Serap Karadag

Istanbul Medeniyet University

View shared research outputs
Top Co-Authors

Avatar

Emin Ozlu

Istanbul Medeniyet University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Necmettin Akdeniz

Istanbul Medeniyet University

View shared research outputs
Top Co-Authors

Avatar

Ozge Akbulak

Istanbul Medeniyet University

View shared research outputs
Top Co-Authors

Avatar

Seyma Ozkanli

Istanbul Medeniyet University

View shared research outputs
Top Co-Authors

Avatar

Busra Moran

Kırıkkale University

View shared research outputs
Top Co-Authors

Avatar

Ebru Zemheri

Istanbul Medeniyet University

View shared research outputs
Top Co-Authors

Avatar

Gülten Kahraman

Turkish Atomic Energy Authority

View shared research outputs
Researchain Logo
Decentralizing Knowledge