Apoptotic effect of bortezomib on pancreatic islet cells in STZ-induced diabetic rats

This study aimed to investigate the possible apoptotic role of bortezomib (BMZ) on pancreatic islets of streptozotocin (STZ)-induced diabetic rats.Methods: Sprague-Dawley rats were divided into groups that were administered BMZ alone or in combination with STZ. To evaluate the effect of BMZ on the development of diabetes, blood glucose levels were measured regularly in the animals. Islet cell viability was determined by staining the islets with fluorescein diacetate and propidium iodide. Expression of the Bcl-2 and bax genes was determined in islet cells by quantitative real-time polymerase chain reaction.Results: Administering STZ-induced hyperglycemia in the rats reduced the viability of islet cells and the bcl-2/bax ratio. In the group administered BMZ alone, the bcl-2/bax gene expression rate in islets increased significantly compared to the control group. BMZ co-administered with STZ significantly increased islet cell viability and the bcl-2/bax ratio compared to the diabetic group.Conclusions: This study demonstrates that BMZ may protect pancreatic islet cells from apoptosis by increasing islet viability and upregulating the bcl-2/bax gene expression ratio, even though it failed to protect against the destructive effect of STZ

Research of toll like reseptors in resistance mechanism against bortezomibe in Multiple Myeloma

Multiple myeloma (MM) kemik iliğindeki plazma hücrelerinin anormal proliferasyonu ve invazyonu ile karakterize edilen, tedavi edilemeyen hematolojik bir kanserdir. Günümüzde MM tedavisi için kullanılan en etkin tedavi yöntemlerinden birisi proteazom inhibitörü bortezomibin yer aldığı kemoterapötik rejimlerdir. Ancak bortezomibe karşı gelişen direnç mekanizması tedavinin başarısızlığına neden olmaktadır. Literatürde dirençlilik mekanizmasında rol aldığı bilinen birçok mekanizma çalışılmasına karşın, TLR'in ilaç dirençlilik mekanizmasındaki rolleri henüz aydınlatılmamıştır. Bu nedenle, bu tez çalışması ile MM hücre hatlarında bortezomibe karşı gelişen direnç mekanizmasında TLR'lerin rolünün araştırılması amaçlanmıştır. Bu amaç için, bortezomibe dirençli (KMS-20) ve hassas (KMS-28BM) MM hücre hatları kullanılmıştır. İlk olarak, bortezomibin doza ve zamana bağlı hücre canlılığına etkisi, MTT testi kullanılarak saptanmıştır. İkinci olarak, hücre hatları farklı bortezomib konsantrasyonları ile 12, 24 ve 48 saat muamele edildikten sonra total RNA izolasyonu ve ardından cDNA sentezi yapılmıştır. TLR 2, 3, 4, 7, 9 ve MyD88 genlerinin mRNA düzeyleri her gene özgü primer ve TaqMan problar kullanılarak real time RT-PCR yöntemi ile saptanmıştır. KMS-20 hücre hattında bortezomibin 12, 24 ve 48 saat için IC50 dozları sırasıyla 31.62nM; 15.85nM; 5.89nM olarak ve KMS-28BM hücre hattında ise 12, 24 ve 48 saat için IC50 dozları sırasıyla 11.84nM; 5.30nM; 3.66nM olarak saptanmıştır. KMS-20 için 12, 24 ve 48 saatlik dirençlik indeksleri (RI) sırasıyla 2.67; 2.99 ve 1.61 olarak hesaplanmıştır. Gen ifade düzeylerine bakıldığında, TLR2 ifade düzeyinin dirençli hücrede hassas hücreye göre doz ve zaman bağlı olarak çok anlamlı azalış gösterdiği bulunmuştur. TLR3 ve TLR4 gen ifadesi hassas hücrede doz ve zamana bağlı azalış gösterirken, dirençli hücrelerde tamamen baskılanmıştır. TLR7 ifadesi hassas hücrede doza ve zaman bağlı azalış gösterirken, dirençli hücrede anlamlı bir artışa neden olmuştur. TLR9 hassas hücrede doz ve zamana bağlı anlamlı azalış gösterirken, dirençli hücrede sadece yüksek konsantrasyonlarda anlamlı azalma göstermiştir. MyD88 dirençli hücrede sadece 48 saatte anlamlı artış, hassasta özellikle 24 ve 48 saatte doza ve zamana bağlı azalma göstermiştir. Sonuçta, dirençli ve hassas hücrelerdeki tüm gen ifade düzeyleri karşılaştırıldığında, dirençli hücrelerde TLR2, TLR3 ve TLR4 mRNA düzeylerindeki azalmanın ya da tamamen baskılanmanın, buna karşın TLR7 ve MyD88 mRNA düzeylerindeki artışın bortezomibe karşı gelişen direnç mekanizmasında rol alabileceği görülmüştür.Multiple myeloma (MM) is a hematologic malignancy that is characterized as an abnormal proliferation and invasion of plasma cells into the bone marrow. The most effective treatment method currently available for MM therapy is chemotherapeutic regimens in which the proteasome inhibitor bortezomibin is involved. However, resistance mechanism against bortezomib causes failure of treatment. Despite the study of many mechanisms known to play a role in the resistance mechanism in the literature, the role of TLR in drug resistance has not yet been elucidated. Therefore, this thesis study aimed to investigate the role of TLRs in the resistance mechanism against bortezomib in MM cell lines. For this purpose, bortezomib-resistant (KMS-20) and sensitive (KMS-28BM) MM cell lines were used. Firstly, it was determined the dose and time dependent effects of bortezomib for two cell lines on cell viability by using MTT test. Secondly, cell lines were treated with different concentrations of bortezomib for 12, 24 and 48 hours, followed by total RNA isolation followed by cDNA synthesis. mRNA levels of TLR 2, 3, 4, 7, 9 and MyD88 genes were determined by real-time RT-PCR using primers specific for each gene and TaqMan probes. IC50 doses in the 12, 24 and 48 hours for KMS-20 cell line were, respectively; 31.62 nM; 15.85nM; 5.89 nM and IC50 doses in the 12, 24 and 48 hours for KMS-28BM cell line were, respectively; 11.84 nM; 5.30nM; 3.66 nM. The resistance index (RI) of KMS-20 cell line for 12, 24 and 48 hours were 2.67; 2.99 and 1.61 respectively. When gene expression levels were examined, TLR2 expression levels were found to be significantly decreased in resistant cells compared to sensitive cells, depending on dose and time. While TLR3 and TLR4 gene expression showed dose and time dependent decrease in sensitive cells, they were completely suppressed in resistant cells. While the TLR7 expression showed a dose-dependent and time-dependent decrease in the sensitive cell, it was shown a significantly increase in the resistant cell. TLR9 showed a significant decrease in dose and time in sensitive cells, while a significant decrease in only high concentrations in resistant cells. A significant increase in only 48 hours in the MyD88 resistant cell showed, while a significantly decrease showed at 24 and 48 hours in sensitive cells. Finally, when all gene expression levels in resistant and sensitive cells are compared, the decrease or complete suppression of TLR2, TLR3 and TLR4 mRNA levels, but the increase of TLR7 and MyD88 mRNA levels in resistant cells may play a role in the resistance mechanism against bortezomib

The relationship between public expenditure and foreing debt in Turkey; an econometric analysis

The main aspect of this study is to analyse the relationship between public expenditures and foreign debt in Turkey considering the period after 2002 during political stability. In this respect, as first theoretical framework of this relationship between two variables is generated. Thereafter literature review on this aspect is followed by an econometric analysis of the relationship. The study is composed of two sections. First section introduced theoretical framework. Second section put forward the econometric analysis of public expenditure – foreign debt relationship by some estimation methods and tests. Respectly historical developments of public expenditure and foreign debt in Turkey are suggested. Econometric model followed the historical framework through estimation methods. Granger Casuality Analysis and Johansen Cointegration Analysis were used to test the relationship between variables The findings through econometric modelling suggested positive relationship between public expenditure and foreign debt during the period after the year 2002. The results are consistent with theoretical framework and literatüre. Accordingly, increase in public expenditure during the period of political stability after 2002 could bring about increase in foreign debtBu çalışmanın temel amacı Türkiye'de kamu harcamaları ve dış borçlanma ilişkisini 2002 sonrası dönemini dikkate alarak araştırmaktır. Bu bağlamda ilk olarak kamu harcamaları ve dış borçlanmaya yönelik teorik çerçeveye yer verilmiş, ardından literatür taraması yapılarak kamu harcamaları ve dış borçlanma arasındaki ilişki ekonometrik olarak incelenmiştir. Çalışma iki bölümden oluşmaktadır. Birinci bölümde kamu harcamaları ve dış borçlanmaya yönelik teorik bilgiler sunulmuş, ikinci bölümde ise Türkiye'de kamu harcamaları ve dış borçlanma ilişkisinin ekonometrik analizi gerçekleştirilerek, Türkiye'de kamu harcamalarının tarihsel gelişimi, kamu harcamaları ve dış borçlanma ilişkisine yönelik literatür taraması ve değişkenler arasındaki ilişkinin test edilmesine yer verilmiştir. Değişkenler arasında ilişkinin test edilmesi amacıyla Granger Nedensellik Analizi ve Johansen Eşbütünleşme Analizi kullanılmıştır. Bu analizlerden elde edilen sonuçlara göre ise Türkiye'de 2002 sonrası dönemde kamu harcamaları ile dış borçlanma arasında bir ilişkinin olduğu ve bu ilişkinin yönünün pozitif olduğu tespit edilmiştir. Teorik beklentiyle uyumlu olan bu sonuç aynı zamanda 2002 sonrası dönemde kamu harcamalarında meydana gelen artışların dış borç stokunda da artışlar yaratacağı bulgusunu sunmaktadı

İnsan lösemi hücre hatlarında s-allil-l-sistein’in apoptoz ve otofaji üzerine olası etkilerinin araştırılması

S-Allyl-L-cysteine (SAC) is a biological active organosulfur component of garlic and has various pharmacological effects. SAC has displayed anti-cancer activity but the mechanism is unresolved. This study has focused on investigating the possible apoptotic and autophagic effects of SAC on two human leukemia cell lines: acute promyelocytic leukemia (HL-60) and chronic myeloid leukemia (K562).MATERIAL AND METHODS: Cell cytotoxicity was evaluated via MTT test. Bax, Bcl-2, caspase 3, mTOR, AKT, and PI3K gene expression amounts were identified via Real time quantitative reverse transcription polymerase chain reaction (qRT-PCR). HL-60 and K562 cells were incubated with SAC at three diverse doses (5 mM, 10 mM, and 20 mM) (3,75 mM, 7,5 mM, and 15 mM), respectively.RESULTS: SAC caused a cytotoxic effect on HL-60 and K562 cells with IC50 values of approximately 11.525 mM and 10.025 mM, respectively. In HL-60 cells, an increase in Bax expression levels was detected at doses of 5 mM and 10 mM SAC (p=0.027, p=0.000). Treatment with 10 mM SAC increased the expression level of caspase 3 in HL-60 cells as compared with the control and 5 mM SAC treated cells (p=0.000, p=0.020). In K562 cells, SAC induced a significant decrease in mTOR, AKT, and PI3K expression levels in at all doses (p=0.000, p=0.000, p=0.000).CONCLUSIONS: In conclusion, our data indicates that SAC induces autophagy in K562 cells by downregulating the PI3K/AKT/mTOR signaling pathway. Furthermore, increased Bax and caspase 3 gene expression levels suggest that SAC may be an effective active ingredient with which to induce apoptosis in HL-60 cells.: S-Allil-L-sistein (SAC), sarımsağın biyolojik olarak aktif bir organosülfür bileşenidir ve çeşitli farmakolojik etkilere sahiptir. SAC anti-kanser aktivite göstermektedir, ancak mekanizması belirlenememiştir. Bu çalışma, SAC'nin iki insan lösemi hücre dizisi üzerindeki olası apoptotik ve otofajik etkilerini araştırmaya odaklanmıştır: akut promiyelositik lösemi (HL-60) ve kronik miyeloid lösemi (K562

Cytotoxic and apoptotic activities of novel Pd(II) complexes against human leukemia cell lines in vitro

WOS: 000399809000001In the investigation for alternative chemotherapeutic strategies against leukemia, Pd(II) complexes were synthesized and investigated for cytotoxic and apoptotic properties on two human leukemia cell lines (HL-60 and K562). Pd(II) complexes (Pd-5a and Pd-6a) with 5a and 6a as ligands were synthesized and characterized by H-1-NMR and F-TIR. The cytotoxicity of the compounds was quantified using MTT method. Bax, Bcl-2, and caspase 3 gene expression levels were estimated using RT-qPCR. Here we show that Pd(II) complexes have important cytotoxic activity on human leukemia cell lines. RT-qPCR indicated that Bax and caspase 3 gene expression levels were increased after 24h treatment with Pd-5a and Pd-6a complexes in both HL-60 and K562 cells at some selected dose. Furthermore, Bcl-2 gene expression level decreased after 24h treatment with Pd-5a and Pd-6a complexes in K562 cells at all selected dose. In HL-60 cells, only one selected Pd-5a dose (25 mu M) decreased the gene expression level of Bcl-2. The results obtained in the present investigation indicate that these two newly synthesized Pd(II) complexes have apoptotic effects at appropriate doses through caspase 3 and Bax genes and might represent a novel potentially active agents for the management of human leukemia cell lines.Aksaray University Scientific Research Fund [2014-009]This study was supported by Aksaray University Scientific Research Fund, grant number 2014-009

Antitumor and apoptotic effects of new-generation platinum compounds on human leukemia cell lines HL-60 and K562

The goal of this investigation is to report the fabrication, characterization, cytotoxicity, and apoptotic assessment of new platinum based compounds on K562 and HL-60 human leukemia cells. Two new platinum (II) compounds, Pt-5a and Pt-6a, were prepared and characterized by fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy ((HNMR)-H-1), environmental scanning electron microscopy (ESEM) and energy dispersive spectrometer (EDS) techniques. The cytotoxic activities of the compounds were evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) test. Caspase-3, B-cell lymphoma 2 (Bcl-2), and B-cell lymphoma 2 associated X protein (Bax) gene expressions were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) to illuminate the mechanism of apoptosis. The results present that the applied compounds exhibited dose-dependent cytotoxic effects in-vitro. Pt-5a and Pt-6a compounds caused a rise in Bax in HL-60 cells while a reduction in Bcl-2 was recorded in all applied doses. In HL-60 cells, an increase in caspase-3 was detected at doses of 25 mu M and 50 mu M of Pt-5a and 30 mu M of Pt-6a. The treatment with 40 mu M of Pt-5a increased caspase-3 and Bax in K562 cells compared with control cells. Bcl-2 was found to be low in 20 mu M of Pt-5a treatment in K562 cells. Pt-6a caused a significant increase in caspase-3 at the dose of 30 mu M in the same cells. It is proposed that the newly synthesized platinum compounds may prove to be significant in the development of anticancer-effective drugs as they trigger apoptosis in a dose-dependent manner

Antitumor activities on HL-60 human leukemia cell line, molecular docking, and quantum-chemical calculations of some sulfonamide-benzoxazoles

WOS: 000413975300017PubMed: 27829297We previously synthesized some novel benzoxazole derivatives-containing sulfonamide. In this study, the compounds were investigated for their antitumor activities against the HL-60 human leukemia cells, using the MTT assay. Moreover, quantum chemical calculations using the DFT methods were applied for understanding the difference in antitumor activity. Additionally, molecular docking into active site of the DNA Topo II enzyme was performed on 3QX3. PDB file in order to find out possible mechanism of antitumor effect. According to all obtained results showed that compounds 1b, 1c, and 1d could be potential drug candidates as new antitumor agents, and are promising for cancer therapy.Scientific Research Project of Aksaray University [2014-022]; Scientific Research Project of Ankara University [16H0237002]This study was supported by the Scientific Research Project of Aksaray University [grant number: 2014-022] and the Scientific Research Project of Ankara University [grant number: 16H0237002]

Influence of sulfurization temperature on Cu2ZnSnS4 absorber layer on flexible titanium substrates for thin film solar cells

In this study, the effect of sulfurization temperature on the morphology, composition and structure of Cu2ZnSnS4 (CZTS) thin films grown on titanium (Ti) substrates has been investigated. Since Ti foils are flexible, they were preferred as a substrate. As a result of their flexibility, they allow large area manufacturing and roll-to-roll processes. To understand the effects of sulfurization temperature on the CZTS formation on Ti foils, CZTS films fabricated with various sulfurization temperatures were investigated with several analyses including x-ray diffraction (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy and Raman scattering. XRD measurements showed a sharp and intense peak coming from the (112) planes of the kesterite type lattice structure (KS), which is strong evidence for good crystallinity. The surface morphologies of our thin films were investigated using SEM. Electron dispersive spectroscopy was also used for the compositional analysis of the thin films. According to these analysis, it is observed that Ti foils were suitable as substrates for the growth of CZTS thin films with desired properties and the sulfurization temperature plays a crucial role for producing good quality CZTS thin films on Ti foil substrates.TUBITAK (114F341