Food Engineering / Gıda Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/12
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Article Citation - WoS: 3Citation - Scopus: 4Comparison of the Effects of Statins on A549 Nonsmall-Cell Lung Cancer Cell Line Lipids Using Fourier Transform Infrared Spectroscopy: Rosuvastatin Stands Out(Wiley, 2021) Aksoy, Hatice Nurdan; Ceylan, ÇağatayStatins are commonly prescribed antilipidemic and anticholesterol class of drugs. In addition to their major role, they have been found to have anticancer effects on in vitro, animal and clinical studies. The aim of this study was to investigate the effects of six different statins (rosuvastatin, pravastatin, simvastatin, lovastatin, fluvastatin, and atorvastatin) on A549 cancer cells lipids by Fourier transform infrared (FTIR) spectroscopy. Proliferation tests were carried out to detect the half-maximal inhibitory concentrations (IC50) of each statin on A549 cells. The IC50 values were 50 mu M for simvastatin, 150 mu M for atorvastatin and pravastatin, and 170 mu M for fluvastatin, 200 mu M for rosuvastatin and lovastatin on A549 cells. No correlation was found between the antiproliferative effects of the statins and lipid-lowering effect. The cells were treated with IC5, IC10, and IC50 values of each statins concentration and lipid extracts were compared using FTIR spectroscopy. The results indicated that different statins had different effects on the lipid content of A549 cells. The FTIR spectra of the lipid exctracts of statin-treated A549 cells indicated that the value of hydrocarbon chain length, unsaturation index, oxidative stress level, and phospholipid containing lipids increased except for rosuvastatin-treated A549 cells. In addition, rosuvastatin significantly lowered cholesterol ester levels. In conclusion, the contrasting effects of rosuvastatin should be further investigated.Article Citation - WoS: 6Citation - Scopus: 6A Molecular and Biophysical Comparison of Macromolecular Changes in Imatinib-Sensitive and Imatinib-Resistant K562 Cells Exposed To Ponatinib(SAGE Publications Inc., 2016) Kartal Yandım, Melis; Ceylan, Çağatay; Elmas, Efe; Baran, YusufChronic myeloid leukemia (CML) is a type of hematological malignancy that is characterized by the generation of Philadelphia chromosome encoding BCR/ABL oncoprotein. Tyrosine kinase inhibitors (TKIs), imatinib, nilotinib, and dasatinib, are used for the frontline therapy of CML. Development of resistance against these TKIs in the patients bearing T315I mutation is a major obstacle in CML therapy. Ponatinib, the third-generation TKI, is novel drug that is effective even in CML patients with T315I mutation. The exact mechanism of ponatinib in CML has been still unknown. In this study, we aimed to determine the potential mechanisms and structural metabolic changes activated by ponatinib treatment in imatinib-sensitive K562 human CML cell lines and 3 μM-imatinib-resistant K562/IMA3 CML cell lines generated at our lab. Apoptotic and antiproliferative effects of ponatinib on imatinib-sensitive and 3 μM-imatinib-resistant K562/IMA3 CML cells were determined by proliferation and apoptosis assays. Additionally, the effects of ponatinib on macromolecules and lipid profiles were also analyzed using Fourier transform infrared spectroscopy (FTIR). Our results revealed that ponatinib inhibited cell proliferation and induced apoptosis as determined by loss of mitochondrial membrane potential, increased caspase-3 enzyme activity, and transfer of phosphatidylserine to the plasma membrane in both K562 and K562/IMA-3 cells. Furthermore, cell cycle analyses revealed that ponatinib arrested K562 and K562/IMA-3 cells at G1 phase. Moreover, ponatinib treatment created a more ordered nucleic acid structure in the resistant cells. Although the lipid to protein ratio increased in imatinib-sensitive K562 cells with a little decrease in the K562/IMA-3 cells, ponatinib treatment indicated significant changes in the lipid composition such as a significant increase in the cellular cholesterol amounts much more in the K562/IMA-3 cells than the sensitive counterparts. Unsaturation in lipids was higher in the resistant cells; however, increases in lipids without phosphate and the number of acyl chains were much higher in the K562 cells. Taken together, all these results showed powerful antiproliferative and apoptotic effects of ponatinib in both imatinib-sensitive and imatinib-resistant CML cells in a dose-dependent manner, and hence, the use of ponatinib for the treatment of TKI-resistant CML patients may be an effective treatment approach in the clinic. More importantly, these results showed that FTIR spectroscopy can detect drug-induced physiological changes in cancer drug resistance.Article Citation - WoS: 11Citation - Scopus: 9Quantification of Staphylococcus Aureus in White Cheese by the Improved Dna Extraction Strategy Combined With Taqman and Lna Probe-Based Qpcr(Elsevier Ltd., 2014) Kadiroğlu, Pınar; Korel, Figen; Ceylan, ÇağatayFour different bacterial DNA extraction strategies and two different qPCR probe chemistries were studied for detection of Stapylococcus aureus from white cheeses. Method employing trypsin treatment followed by a commercial kit application and TaqMan probe-based qPCR was the most sensitive one detecting higher counts than standards in naturally contaminated samples.Article Citation - WoS: 13Citation - Scopus: 13Macromolecular Changes in Nilotinib Resistant K562 Cells; an in Vitro Study by Fourier Transform Infrared Spectroscopy(SAGE Publications Inc., 2012) Ceylan, Çağatay; Camgöz, Aylin; Baran, YusufNilotinib is a second generation tyrosine kinase inhibitor which is used in both first and second line treatment of chronic myeloid leukemia (CML). In the present work, the effects of nilotinib resistance on K562 cells were investigated at the molecular level using Fourier transform infrared (FT-IR) spectroscopy. Human K562 CML cells were exposed to step-wise increasing concentrations of nilotinib, and sub-clones of K562 cells resistant to 50 nM nilotinib were generated and referred to as K562/NIL-50 cells. Antiproliferative effects of nilotinib were determined by XTT cell proliferation assay. Changes in macromolecules in parental and resistant cells were studied by FT-IR spectroscopy. Nilotinib resistance caused significant changes which indicated increases in the level of glycogen and membrane/lipid order. The amount of unsaturated lipids increased in the nilotinib resistant cells indicating lipid peroxidation. The total amount of lipids did not change significantly but the relative proportion of cholesterol and triglycerides altered considerably. Moreover, the transcriptional status decreased but metabolic turn-over increased as revealed by the FT-IR spectra. In addition, changes in the proteome and structural changes in both proteins and the nucleus were observed in the K562/NIL-50 cells. Protein secondary structural analyses revealed that alpha helix structure and random coil structure decreased, however, anti-parallel beta sheet structure, beta sheet structure and turns structure increased. These results indicate that the FT-IR technique provides a method for analyzing drug resistance related structural changes in leukemia and other cancer types.Article Citation - WoS: 3Citation - Scopus: 3Evaluation of High Hydrostatic Pressure Effects on Bovine Red Blood Cells and Platelets(Taylor and Francis Ltd., 2009) Ceylan, Çağatay; Severcan, Mete; Bozoğlu, Faruk; Severcan, FerideThe objective of this study was to investigate the effects of high hydrostatic pressure (HHP) on the stability of red blood cells (RBCs) and platelets. Bovine blood cells (n=5) were treated with the pressure of 55, 110, 154 and 220MPa at 25°C for 5min. Light microscopy, atomic force microscopy and flow cytometry studies revealed that RBCs were morphologically stable up until the 220MPa pressure treatments, at which surface modifications were observed. The platelets were found to be less stable than RBCs. HHP application did not cause any significant change in the signal intensity, band area and frequency values of the infrared bands with the exception that a significant variation was observed in the area of the cholesterol band. No statistically significant variations were observed in the secondary structure elements due to HHP treatment according to the artificial neural network study based on the FTIR data.