Browsing by Author "Avci C.B."

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    Synergistic effect of ponatinib and epigallocatechin-3-gallate induces apoptosis in chronic myeloid leukemia cells through altering expressions of cell cycle regulatory genes
    (Zerbinis Publications, 2014) Goker B.; Caliskan C.; Caglar H.O.; Kayabasi C.; Balci T.; Tepedelen B.E.; Aygunes D.; Susluer S.Y.; Mutlu Z.; Gunell N.S.; Korkmaz M.; Saydam G.; Gunduz C.; Avci C.B.
    Purpose: Ponatinib (P) has been used for the treatment of chronic myeloid leukemia (CML) and it is known that inhibition of BCR-ABL fusion protein by ponatinib induces apoptosis of CML cells. Epigallocatechin-3-gallate (EGCG), which is a polyphenol in green tea, induces apoptosis in different types of cancer cells. The purpose of this study was to determine the cytotoxic and apoptotic effects of ponatinib and EGCG combination in K562 CML cell line. This study also aimed to detect alterations of the expression levels of cell cycle-regulation related genes after ponatinib and EGCG combination in K562 CML cell line. Methods: The cytotoxic effects of the compounds on K562 cells were determined in a time- and dose-dependent manner by using WST-1 analysis. The combination index (CI) isobologram was used to analyze the data. Apoptotic effects of P-EGCG were defined by flow cytometry and gene expressions were detected by RT-qPCR. Results: IC50 values of ponatinib and EGCG were 87.13 nM and 50μM, respectively. CI value of the P-EGCG was 0.658 and the combination showed synergistic effect (ED90 value: 28.39 nM ponatinib, 117.12 μg/ml EGCG). Ponatinib, EGCG and P-EGCG induced apoptosis compared to control cells. CyclinDl and CDC25A were downregulated by P-EGCG by 2.49 and 2.63-fold, respectively. TGF-β2 was upregulated by 4.57-fold. Conclusion: EGCG possesses cytotoxic and apoptotic properties and may cooperate with the growth inhibiting activity of ponatinib synergistically against CML cells. P-EGCG mediated apoptosis might be associated with upregulation of TGF-β2 gene and downregulation of cyclinDl and CDC25A genes.
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    Effect of Different Dentin Conditioning Agents on Growth Factor Release, Mesenchymal Stem Cell Attachment and Morphology
    (Elsevier Inc., 2020) Atesci A.A.; Avci C.B.; Tuglu M.I.; Ozates Ay N.P.; Eronat A.C.
    Introduction: EDTA has been considered the gold standard in regenerative endodontic treatments. The aim of this study was to evaluate the effects of different dentin conditioning agents other than EDTA on released growth factors, mesenchymal stem cell attachment, and morphology. Methods: Transforming growth factor beta 1, vascular endothelial growth factor, bone morphogenetic protein 2, and fibroblast growth factor 2 release from prepared dentin discs conditioned with 17% EDTA, 10% citric acid, 1% phytic acid (IP6), or 37% phosphoric acid were quantified using the enzyme-linked immunosorbent assay after final irrigation and after 3 days of adipose-derived mesenchymal stem cell (adMSC) seeding. Forty root fragments were prepared from extracted single-rooted teeth. The morphology and attachment of adMSCs on the conditioned root fragments were observed using a scanning electron microscope. Data for growth factor quantification were analyzed using 1-way analysis. Results: The highest transforming growth factor beta 1 release was observed after citric acid treatment followed by phosphoric acid; there was no significant difference between them, but compared with EDTA and 1% IP6, there were significant differences observed. The enzyme-linked immunosorbent assay detected a very minor exposure of vascular endothelial growth factor and fibroblast growth factor 2 after dentin conditioning, but there were no significant differences between the groups. The greatest bone morphogenetic protein 2 release was observed in the 1% IP6 group, but there were no significant differences between the groups. Three days of adMSC seeding after dentin conditioning has made a dramatic increase in all of the growth factors, and phosphoric acid appeared to be the most effective agent with significant differences compared with the remaining groups. Scanning electron microscopic observations showed that none of the conditioning solutions had an adverse effect on stem cell proliferation and attachment to root dentin. Different cell morphologies like round, oblong, flat, and well-attached cells with developed filopodia were observed in the dentin-conditioned groups. Conclusions: Phosphoric acid conditioning could be useful and may have beneficial effects in regenerative endodontic treatments. © 2019 American Association of Endodontists