Browsing by Author "Cakar, B"
Now showing 1 - 8 of 8
Results Per Page
Sort Options
Item COMPARISON OF A NOVEL, LABEL-FREE, AND REAL-TIME CELL BASED SYSTEM (XCELLIGENCE) WITH A CONVENTIONAL VIABILITY ASSAY (XTT) TO DETERMINE THE ANTI-PROLIFERATIVE EFFECT OF AT-101 IN HUMAN BREAST CANCER CELLSKaraca, B; Atmaca, H; Asli, K; Bozkurt, E; Cakar, B; Surmeli, ZG; Gursoy, P; Karabulut, B; Uzunoglu, S; Sezgin, CItem Paclitaxel in combination with AT-101 induces apoptosis via supressing Bcl-2, bcl-XL, mcl-1 proteins in human breast cancer cells.Cakar, B; Gursoy, P; Atmaca, H; Kisim, A; Bozkurt, E; Uzunoglu, S; Sezgin, C; Sanli, UA; Karabulut, B; Uslu, R; Karaca, BItem FIBROBLAST GROWTH FACTOR RECEPTOR 2 (FGFR2) POLYMORPHISM STATUS OF TURKISH BREAST CANCER PATIENTSUslu, R; Karaca, B; Atmaca, H; Kisim, A; Cakar, B; Karabulut, B; Sezgin, C; Uzunoglu, SItem Trabectedin to induce mitochondrial membrane potential dissipation and reactive oxygen species generation in breast cancer cells.Atmaca, H; Bozkurt, E; Cakar, B; Surmeli, ZG; Uzunoglu, S; Uslu, R; Karaca, BItem Enhancing cytotoxic and apoptotic effect in OVCAR-3 and MDAH-2774 cells with all-trans retinoic acid and zoledronic acid: a paradigm of synergistic molecular targeting treatment for ovarian cancerKarabulut, B; Karaca, B; Varol, U; Muslu, U; Cakar, B; Atmaca, H; Kisim, A; Uzunoglu, S; Uslu, RBackground: Ovarian cancer is the most fatal gynecologic malignancies in the world. Although, platinum based treatments are widely used, the disease becomes treatment refractory within two years, and novel treatment options should be searched. All-trans retinoic acid (ATRA) induces growth arrest, differentiation and cell death in some types of cancer cells and its combination with various anticancer agents results in enhanced cytotoxicity. Zoledronic acid is a common bisphosphonate known for its anticancer effects beyond its current use in the treatment of cancer-induced bone disease. We aimed to investigate the possible additive/synergistic effect of both agents in OVCAR-3 and MDAH-2774 ovarian cancer cell lines, since both agents show superiority to conventional cytotoxics in terms of adverse events. Methods: XTT cell proliferation assay was used for showing cytotoxicity. For verifying apoptosis, both DNA Fragmentation by ELISA assay and caspase 3/7 activity measurement were used. OligoGeArray (R) which consists of 112 apoptosis related genes was used to elucidate the genetic changes within cancer cells. To validate our oligoarray results, quantitative real-time PCR was performed on four selected genes that were maximally effected by the combination treatment: lymphotoxin beta receptor (LTBR), myeloid cell leukemia-1 (MCL-1), tumor necrosis factor receptor superfamily, member 1A (TNFRSF1A), TNFRSF1A-associated death domain protein (TRADD). Results: We demonstrated that a novel combination of ATRA and zoledronic acid is a strong inducer of apoptotic related cell death in both ovarian cancer cells. While the combination therapy significantly induced proapoptotic genes such as tumor necrosis factor receptor superfamily (TNFRSF), TRADD and caspase 4, some of the antiapoptotic genes such as members of MCL-1, LTBR, BAG3 and Bcl-2 family members were inhibited. Conclusions: These are the preliminary molecular results of a novel combination treatment of ATRA and zoledronic acid, with fewer side effects as compared to conventional cytotoxic agents. With additional experimental analysis, it may serve as a good option for the treatment of refractory and elderly ovarian cancer patients, for whom there exists very limited choice of treatment.Item Pretreatment with AT-101 enhances tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis of breast cancer cells by inducing death receptors 4 and 5 protein levelsKisim, A; Atmaca, H; Cakar, B; Karabulut, B; Sezgin, C; Uzunoglu, S; Uslu, R; Karaca, BTumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily and has been shown to induce extrinsic pathway of apoptosis in many types of cancer cells. AT-101, an (-)-enantiomer of gossypol, is a potent anticancer agent that is shown to be an inhibitor of Bcl-2/Bcl-XL. In this study, we searched whether pretreatment with either of these drugs would result in the enhancement of apoptosis through induction of death receptors and activation of mitochondrial pathways within breast cancer cells. Human breast cancer (MCF-7 and MDA-MB-231) and normal breast cells (MCF-10A) were treated with drugs alone/in combination/sequentially. XTT cell viability assay was used to evaluate cytotoxicity. For showing apoptosis, both DNA Fragmentation and caspase 3/7 activity measurements were done. ELISA and Western blot analysis were done to assess DR4 and DR5 protein levels. The expression levels of apoptotic proteins were assessed by human apoptosis antibody array. The sequential treatment of AT-101 followed by TRAIL resulted in significant synergistic cytotoxicity and apoptosis. Moreover, pretreatment of breast cancer cells with AT-101 and then with TRAIL caused enhancement of the expression levels of DR4 and DR5 in both cancer cell lines, suggesting that these cells were under strong apoptotic stimuli. These findings all together, strongly suggest that pretreatment with AT-101 enhances TRAIL-induced death-inducing signaling complex resulting in the engagement of the mitochondrial pathway to apoptosis in breast cancer cells. These promising, preliminary results make AT-101 and TRAIL a novel combination treatment candidate for breast cancer.Item Synergistic cytotoxic/apoptotic effects of AT-101, a phytochemical with BIB-mimetic property, in combination with paclitaxel in human breast cancer cellsKaraca, SB; Muslu, U; Cakar, B; Kisim, A; Atmaca, H; Purcu, DU; Uzunoglu, S; Uslu, RItem OCTREOTIDE IN COMBINATION WITH DOCETAXEL TRIGGERS APOPTOSIS BY INDUCING SSTR2 AND SSTR5 LEVELS IN HUMAN BREAST CANCER CELLS, MCF-7 AND MDA-MB-231Karaca, B; Muslu, U; Surmeli, ZG; Cakar, B; Atmaca, H; Asli, K; Sezgin, C; Uzunoglu, S; Karabulut, B; Uslu, R