Browsing by Subject "Cell Proliferation"

Now showing 1 - 20 of 49
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    Cell division and cellular morphology of the chick retinal pigmented epithelial cells in culture. A time-lapse analysis
    (2005) Tuglu I.; Cezayirli E.; Vural K.; Gungor K.; Varol T.; Bekir N.
    Objective: To investigate the patterns of cell division, movement and shape during early stages of development of the chick embryo retinal pigmented epithelial (RPE) cells and to evaluate the morphology of dissociated embryonic cells with regard to their proliferation capacity. Methods: We conducted this study at the Department of Histology and Embryology, Celal Bayar University, Manisa, Turkey, between 2002 and 2003. We isolated the cells from chick embryos. We analyzed the images of the embryonic cells originated from neuroepithelia using a computer-based time-lapse acquisition system attached to a differential interference contrast microscope. Results: Retinal pigmented epithelial cells, despite being dissociated, depict a colony-type growth. Cells in the periphery of the colony and those outside the colony showed a tendency to proliferate and migrate and retained contact with the neighboring cells during division. Characteristics of cytokinesis were separation from the neighboring cell while retaining an attachment point, became rounded, moved up and started to shake and ascend to disseminate to the substrate to complete the division. The round-up stage was non-significantly shorter when the cell was closer to the center of the colony. Cells that were in the periphery of, or outside the colony had a round-up time of over one hour while cytokinesis-to-adhesion time was around 5 minutes. However, when we found the cells in the center of the colony, the times were half-an-hour and 1.5 hours for the daughter cells, a 2-fold difference between daughter cells with regard to the duration of attachment. Conclusion: Cell division, migration and proliferation are complex procedures influenced by growth factors, cell adhesion, matrix molecules underneath and the signal mechanisms and can be studied in detail using time-lapse microscopy, immunohistochemistry and confocal microscopy.
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    The effect of osteogenic medium on the adhesion of rat bone marrow stromal cell to the hydroxyapatite
    (2006) Deliloglu-Gurhan I.; Tuglu I.; Vatansever H.S.; Özdal-Kurt F.; Ekren H.; Taylan M.; Sen B.H.
    Objective: To investigate the adhesive properties of bone marrow stromal cell (BMSC) on the hydroxyapatite (HA) particles and analyze their behavior. Methods: The study took place in the Department of the Histology and Embryology, Celal Bayar University, Manisa and in the Department of Bioengineering, Ege University, Izmir, Turkey between 2004 and 2005. We cultured BMSC from the mature rat tibia and differentiated to the osteoblasts by osteogenic medium. The BMSCs were subcultured and were taken to the HA substrate. We measured their proliferation capacity and viability with MTT assay using the spectrophotometric method. Furthermore, we identified the osteoblast-like cells by inummohistochemical staining of osteonectin and osteocalcin and we analyzed the behavior of the cells on different sized HA particles by SEM at the end of 3 days incubation. Results: Osteogenic medium caused the proliferation capacity of BMSC to speed up and the effects appeared earlier. We confirmed the osteoblastic differentiation by staining of most cells with osteoblastic markers. Subcultured cells were similarly adhesive to the HA particles and the osteogenic medium did not alter this behavior. They spread on the substrate similarly. Most of the cells demonstrated the cytoplasmic protrusion. Morphology of the cells did not change much with or without osteogenic medium. Different sizes of HA particles did not affect the adhesive properties of these cells except HA gel. The spreading and attachment ratios of the cells on HA gel were more than the others. Conclusion: We found that there was heterogeneity in BMSC on differentiation capacity to the osteoblast, which was a sign of a subpopulation. Adhesive cells showed similar morphology and behavior under the effect of osteogenic medium. The only difference was the spreading capacity on the HA gel where cell used this substrate more effectively for adhesion.
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    Combined gossypol and zoledronic acid treatment results in synergistic induction of cell death and regulates angiogenic molecules in ovarian cancer cells
    (2009) Atmaca H.; Gorumlu G.; Karaca B.; Degirmenci M.; Tunali D.; Cirak Y.; Purcu D.U.; Uzunoglu S.; Karabulut B.; Sanli U.A.; Uslu R.
    In the present study, we aimed to evaluate the possible synergistic, cytotoxic effects of combination treatment of gossypol and zoledronic acid, in human ovarian cancer cell lines, OVCAR-3 and MDAH-2774, and to elucidate the role of this novel combination treatment on angiogenesis-related molecules in ovarian cancer. The XTT cell viability assay was used for showing cytotoxicity. Both DNA fragmentation by ELISA assay and caspase 3/7 activity measurement were used for demonstrating apoptosis. To elucidate the angiogenic molecules affected by combination treatment, mRNA levels of angiogenic molecules were measured using the Human Angiogenesis RT2 Profiler™ PCR Array (SuperArray, Frederick, MD) in ovarian cancer cell lines, OVCAR-3 and MDAH-2774.The combined treatment resulted in significant, synergistic cytotoxicity, and induced apoptosis. This effect was observed to happen in a dose- and time-dependent manner. Moreover, the combination treatment of 10 μM gossypol and 5 μM zoledronic acid resulted in significant down-regulation (≥ thee-fold) in mRNA levels of some pivotal angiogenic molecules in OVCAR-3 and MDAH-2774 cells as compared to the untreated control. However, this effect was different in the two ovarian cancer cell lines observed. Gossypol, in combination with zoledronic acid, may provide a rational treatment option for ovarian cancer, not only by direct inhibition of cell proliferation, but also inhibition of angiogenesis-related molecules.
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    Enhancement of taxane-induced cytotoxicity and apoptosis by gossypol in human breast cancer cell line MCF-7
    (2009) Karaca B.; Atmaca H.; Uzunoglu S.; Karabulut B.; Sanli U.A.; Uslu R.
    Purpose: Gossypol is a natural polyphenolic compound extracted from cotton plant (Gossypium species) which has shown potent inhibitory effect on cell growth of many types of cancers. In this study, we aimed to evaluate the interaction of gossypol with some conventional drugs known to be effective in the treatment of breast cancer, like taxanes, doxorubicin, gemcitabine, cisplatin and vinorelbine, in MCF-7 breast cancer cells. Materials and methods: The XTT viability assay was used to evaluate the cytotoxicity of various cytotoxic agents alone and in combination with gossypol in MCF-7 breast cancer cells. The combination effect analysis of Chou and Talalay was used to identify the most synergistic drug combinations. The possible synergistic effects of the combination of drugs on apoptosis were also evaluated by using two different apoptosis assays. Results: We identified strong synergistic cytotoxic and apoptotic activity of gossypol with taxanes among all other studied cytotoxic drugs. Conclusion: This study provides proof that gossypol combined with taxanes may have potential as a novel future treatment for breast cancer. © 2009 Zerbinis Medical Publications.
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    Radiosensitization of hormone-refractory prostate cancer cells by gossypol treatment
    (2010) Akagunduz O.; Karaca B.; Atmaca H.; Uzunoglu S.; Karabulut B.; Sanli U.A.; Haydaroglu A.; Uslu R.
    Purpose: Many drugs have been tested to increase the sensitivity of prostate cancer cells to radiotherapy. Gossypol, a natural polyphenols compound extracted from the cotton plant, is one of the agents the efficacy of which has been investigated in the treatment of prostate cancer for this purpose. The main aim of this study was to investigate the best gossypol application with irradiation, when gossypol was applied either sequentially (24 h before and after irradiation) or concurrently in PC-3 hormone-refractory and radioresistant prostate cancer cells. Methods: The XTT viability assay was used to evaluate the cytotoxicity of different concentrations of gossypol in PC-3 cells. Irradiation was applied to PC-3 cells via 6 MV photon linear accelerator and delivered 24 h before, 24 h after radiation or at the same time with gossypol administration. Results: Gossypol caused radiosensitization of PC-3 cells that are known to be radioresistant, with high Bcl-2 levels. Among different applications of gossypol and irradiation (before, after and concurrent) in prostate cancer cells, the best results were observed by the application of gossypol 24 h before irradiation. Conclusion: Our study suggests that gossypol represents a promising novel anticancer treatment for radiosensitization of human hormone-refractory prostate cancer cells. © 2010 Zerbinis Medical Publications.
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    Propolis from Turkey induces apoptosis through activating caspases in human breast carcinoma cell lines
    (2010) Seda Vatansever H.; Sorkun K.; Ismet Deliloĝlu Gurhan S.; Ozdal-Kurt F.; Turkoz E.; Gencay O.; Salih B.
    Propolis is a sticky substance that is collected from plants by honeybees that has anti-mutagenic and anti-carcinogenic properties with biological and therapeutic effects. The target of this study was to investigate the anti-apoptotic effect of propolis extracts (PE) on the caspase pathway in the human breast cell line MCF-7 in culture. Seven different propolis extracts, numbered PE 1-7, produced in their natural ecological environment, were collected from the Hacettepe University Beytepe Campus area in Ankara, Turkey. Individual extracts at 0.5, 0.25, 0.125 and 0.063 mg/ml were incubated with MCF-7 cells during 2 days culture. Cell growth and cytotoxicity were measured colorimetrically by MTT assay. Apoptotic cell death was determined by the TUNEL method (terminal deoxynucleotidyltransferase-biotin nick end-labelling) and caspase activity was investigated by immunocytochemistry using antibodies directed against caspase 6, caspase 8 and caspase 9. The results showed that the PE 5 and 6 extracts at 0.125 mg/ml dilution induced apoptosis in association with increased number of TUNEL positive cells. MTT results showed that cultures exposed to the same extracts and at the same dilution experienced better cell growth compared to those cultures exposed to the other extracts. Immunpositivity for all caspases was detected after treatment with all the extracts and at all dilutions, with stronger immunoreactivity for caspase 6 than caspases 8 and 9. Caspase 6 labelling was especially strong in PE 5 and PE 6. We conclude that propolis may have anti-tumour effects by increasing apoptosis through the caspase pathway. Such propolis extracts may be important economically and allow development of a relatively inexpensive cancer treatment. © 2009 Elsevier GmbH.
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    Comparison of XTT and Alamar blue assays in the assessment of the viability of various human cancer cell lines by AT-101 (-/- gossypol)
    (2010) Uzunoglu S.; Karaca B.; Atmaca H.; Kisim A.; Sezgin C.; Karabulut B.; Uslu R.
    This study compared the two different commercially available in vitro viability assays: XTT and Alamar blue (AB), to detect anti-proliferative effects of AT-101, a cotton plant extract, on six different human carcinoma cell lines including: prostate (PC-3 and DU-145), breast (MCF-7 and MDA-MB-231), and ovary (OVCAR-3 and MDAH 2774) in a time- and dose-dependent manner. Cells were exposed to AT-101 in the concentration range of 2.540 M for 24, 48, and 72h. The AB assay was slightly more sensitive than the XTT assay in the evaluation of AT-101 at 24h, suggesting that the AB assay might be used for detecting early changes in cell viability as compared to the XTT assay. Moreover, the AB assay showed less intra-assay variability as compared to the XTT. The non-toxic, non-radioactive AB metabolism assay allows rapid assessment of large numbers of samples, with simple equipment and at reduced cost for continuous monitoring of cancer cell viability, and, thus, should be accepted as a suitable alternative viability method. © 2010 Informa Healthcare USA, Inc.
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    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 cancer
    (2010) Karabulut B.; Karaca B.; Varol U.; Muslu U.; Cakar B.; Atmaca H.; Ksm A.; Uzunoglu S.; Uslu R.
    Background. 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® 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. © 2010 Karabulut et al; licensee BioMed Central Ltd.
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    Regulation of apoptosis-related molecules by synergistic combination of all-trans retinoic acid and zoledronic acid in hormone-refractory prostate cancer cell lines
    (2011) Karabulut B.; Karaca B.; Atmaca H.; Kisim A.; Uzunoglu S.; Sezgin C.; Uslu R.
    We report that all-trans retinoic acid (ATRA) in combination with zoledronic acid has strong synergistic cytotoxic and apoptotic effects against human hormone- and drug-refractory prostate cancer cells, PC-3 and DU-145, in a time- and dose-dependent manner. We further investigated the effect of the combination treatment on the apoptotic process by both oligoarray and protein array analysis in DU-145 cells, in which the drug combination shows much more strong synergistic effects, as compared to PC-3 cells. Moreover, we have also performed real time-PCR array analysis to validate oligoarray results. We demonstrated that the combination of ATRA and zoledronic acid is a strong inducer of apoptotic related cell death in human androgen-and drug refractory prostate cancer cells DU-145, at either transcriptional or translational levels. While expression of proapoptotic genes such as tumor necrosis factor receptor superfamily (TNFRSF), Bad, Bax, Fas, FADD are induced with the exposure of the combination, expression of antiapoptotic genes or proteins such as members of inhibitor apoptosis family (IAPs), MCL-1, LTBR, p53 and bcl-2 are reduced. Because this novel combination treatment has fewer side effects than is generally the case with conventional cytotoxic agents, this regimen may be a good option for treatment of elderly prostate cancer patients. © 2010 Springer Science+Business Media B.V.
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    Neurotoxic effect of statins on mouse neuroblastoma NB2a cell line
    (2011) Vural K.; Tuglu M.I.
    Objective: Evidences from cell culture experiments suggest a link between cholesterol and nervous system disease. Statins may have neurotoxic or neuroprotective effects, but these effects remain controversial. Therefore, the present study was aimed to investigate the possible toxicity of statins on a neurite outgrowth in mouse neuroblastoma NB2a cell line. Materials and Methods: We have utilized d-cAMP-induced terminally differentiated NB2a cells in culture as an experimental model to study the effects of statins. The cell survival and proliferation were studied by MTT. Measurement of neurite outgrowth was done by neurotoxicity screening test. NB2a cell differentiation was achieved by serum free medium plus 0.5 mM dibutyryl cAMP. Cells were incubated for 24 hours at 37°C. After this period, lovastatin, mevastatin and atorvastatin were added to wells at different concentrations (1, 3, 10, 100 μM). Approximately 100 cells were chosen for each sample and examined randomly 24 hours later, from 10 different fields. Total length of neurite was photographed microscopically and measured by image analyze software. Changes in neurite lengths were expressed as % inhibition compared to that of the control group. Results: Results showed that three statins at high concentrations induced neurite inhibition, inhibited proliferation and reduced the viability of differentiated neuroblastoma NB2a cells. Conclusions: Our results suggest that statins could act as a neurotoxic agent at high doses depending upon their concentrations. These results require further investigation at ultra structural and molecular levels to understand long term side effects for clinical safety of statins.
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    Effects of Thymus serpyllum extract on cell proliferation, apoptosis and epigenetic events in human breast cancer Cells
    (2012) Bozkurt E.; Atmaca H.; Kisim A.; Uzunoglu S.; Uslu R.; Karaca B.
    Thymus (T.) serpyllum (wild thyme) is an aromatic medicinal plant due to its several biological properties, including anticancer activity. Breast cancer is one of the most common malignancies and increasing evidence supports that it is not only a genetic but also an epigenetic disease. Epigenetics investigates changes in gene expression caused by mechanisms that do not involve alterations in DNA sequence. DNA methylation and histone acetylation are the most widely studied epigenetic changes in cancer cells. This study evaluated the effects of T. serpyllum on apoptosis and epigenetic events in breast cancer cells. XTT cell viability assay was used to determine cytotoxicity. DNA fragmentation and caspase 3/7 activity assays were used in the assesment of apoptosis. DNA methyltransferase (DNMT) and histone deacetylase (HDAC) activities were evaluated by ELISA and verified by qRT-PCR. T. serpyllum extract induced significant cytotoxicity in breast cancer cells (MCF-7 and MDAMB-231) but not in normal cells. It also induced apoptosis and inhibited the DNMT and HDAC activities in MDA-MB-231 cells. In the present study, the first preliminary data on the effects of the methanolic extract of T. serpyllum in normal and breast cancer cells were obtained and suggest that T. serpyllum may be a promising candidate in the development of novel therapeutic drugs for breast cancer treatment. Copyright © 2012, Taylor & Francis Group, LLC.
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    Zoledronic acid in combination with serine/threonine phosphatase inhibitors induces enhanced cytotoxicity and apoptosis in hormone-refractory prostate cancer cell lines by decreasing the activities of PP1 and PP2A
    (2012) Cirak Y.; Varol U.; Atmaca H.; Kisim A.; Sezgin C.; Karabulut B.; Uzunoglu S.; Uslu R.; Karaca B.
    OBJECTIVES • To investigate if the cytotoxic and apoptotic effect of zoledronic acid (ZA) can be enhanced by the addition of the serine/threonine protein phosphatase inhibitors calyculin A (CA) and okadaic acid (OA) in hormone and drug refractory prostate cancer cells, PC-3 and DU-145. • To discover the effect of these combination treatments on phosphatase 1 (PP1) and PP2A protein expression levels in prostate cancer cells. MATERIALS AND METHODS • An XTT cell viability assay was used to determine cytotoxicity. • Apoptosis was evaluated by enzymelinked immunosorbent assay (ELISA) using a Cell Death Detection ELISA Plus Kit and verifi ed by measuring caspase 3/7 enzyme activity. • The PP1 and PP2A enzyme activities were evaluated by serine/threonine phosphatase ELISA and expression levels of PP1 and PP2A proteins were then re-assessed by Western blot RESULTS • Combination of ZA with either CA or OA showed synergistic cytotoxicity and apoptosis compared with any agent alone in both PC-3 and DU-145 prostate cancer cells. • The combination of ZA with phosphatase inhibitors resulted in enhanced suppression of both PP1 and PP2A enzyme activity andprotein levels, which was more overt with the ZA/CA combination. CONCLUSION • Results from our study increase the translational potential of our in vitro fi ndings and offer the basic rationale for the design of new combinatory strategies with ZA and phosphatase inhibitors for the treatment of prostate cancer, which may become resistant to conventional therapy. © 2012 B J U I N T E R N A T I O N A L.
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    Investigation of therapeutic efficiency of bleomycin and bleomycin-glucuronide labeled with 131I on the cancer cell lines
    (Mary Ann Liebert Inc., 2013) Ediz M.; Avcibaşi U.; Ünak P.; Müftüler F.Z.B.; Medine E.I.; Yurt Kilçar A.; Demiroǧlu H.; Gümüşer F.G.; Sakarya S.
    The aim of this study is to determine the incorporations of radiolabeled bleomycin (131I-BLM) and bleomycin-glucuronide (131I- BLMGLU) on PC-3 (human prostate carcinoma cell line), Caco-2 (human colon adenocarcinoma cell line), Hutu-80 (Human Duodenum adenocarcinoma cell line), and A549 (Human lung adenocarcinoma epithelial cell line) cancerous cell lines. For this purpose, BLM and BLMGLU enyzmatically synthesized were labeled with 131I, quality control studies were done and the incorporation yields of 131I-BLM and 131I-BLMGLU on these cell lines were measured. Quality-control studies showed that the radiolabeling yields were obtained as 95% and 90% for 131I-BLM and 131I-BLMGLU, respectively. Also, as a result of the cell culture studies, it was found that 131I-BLM and 131I-BLMGLU had higher incorporation on PC-3 cells than that of other cell lines. In addition to this, it was reported that the incorporation yield of 131I-BLMGLU was higher than that 131I-BLM. At the end of the study, cytotoxicities of BLM and BLMGLU on PC-3 cancerous cell line were inspected and fluorescent images of BLM and BLMGLU were taken on PC-3 cells by using fluorescein isothiocyanate. In conclusion, cell culture studies demonstrated that the incorporation values of 131I-BLMGLU on the four cell lines were about five to six times higher than 131I-BLM. Radiolabeled glucuronide derivatives can be used in cancer therapy and tumor imaging, depending on the properties of radioiodine for the β-glucuronidase-rich tissues because glucuronidation leads to rapid and higher incorporation on adenocarcinoma cells. © Mary Ann Liebert, Inc.
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    Jak-Stat signaling pathway may play a role in the pathogenesis of cholesteatoma
    (2014) Eskiizmir G.; Seda Vatansever H.; Özgür E.; Aslan A.; Tanyeri G.; Gözüaçik D.; Kemal Özbilgin M.; Cingi C.
    Purpose Jak-Stat signaling pathway is one of the major signal transduction cascades which regulates most of the cellular events such as cell proliferation, differentiation, cell migration and apoptosis. This study aims to determine the activity of Jak-Stat signaling pathway in the pathogenesis of cholesteatoma. Materials and Methods Cholesteatoma and skin samples were obtained from 10 patients who underwent tympanomastoidectomy for chronic otitis media with cholesteatoma. Immunohistochemical analysis of cholesteatoma and skin was performed using anti-Jak1, anti-Jak2, anti-Jak3, anti-Stat1, anti-Stat2, anti-Stat3, anti-Stat4 and anti-Stat5 antibodies. The immunoreactivities in cholesteatoma and skin were quantified using H-score measurement and statistical comparison was performed. Results Jak1, Jak2, Jak3, Stat1 and Stat3 immunoreactivities were not detected in cholesteatoma; in contrast to the skin (129.8; 226.7; 33.0; 66.4;115.9). In addition, when H-score measurements of Stat2, Stat4 and Stat5 immunoreactivities were compared between cholesteatoma (172.8; 166.7; 120.0) and skin (400.0; 284.9; 292.0), statistically significant differences were found (p < 0.0001, p < 0.0001, p < 0.0001). Conclusions A remarkable deficiency in the family members of Jak-Stat signaling pathway was demonstrated in cholesteatoma. Therefore, perturbations in Jak-Stat signaling pathway may play a role in the pathogenesis of cholesteatoma. © 2014 Elsevier Inc.
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    The cytotoxic, neurotoxic, apoptotic and antiproliferative activities of extracts of some marine algae on the MCF-7 cell line
    (Informa Healthcare, 2014) Kurt O.; Özdal-Kurt F.; Tuʇlu M.I.; Akçora C.M.
    We investigated the cytotoxic, neurotoxic, apoptotic and antiproliferative effects of extracts from Petalonia fascia, Jania longifurca and Halimeda tuna on the MCF-7 breast cancer cell line. J. longifurca extracts were more toxic than those of P. fascia and H. tuna. The algal extracts showed significant toxic effects at different dilutions. The toxic effects were due to increased oxidative stress and resulted in apoptosis. Algal toxicity may exert negative effects through the food chain or by direct interaction. Algal toxicity also has potential for cancer therapy. The toxic effects that we observed may be especially important for therapy for breast tumors. © 2014 The Biological Stain Commission.
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    Enhanced cytotoxicity and apoptosis by thymoquinone in combination with zoledronic acid in hormone- and drugresistant prostate cancer cell lines
    (Zerbinis Publications, 2014) Dirican A.; Erten C.; Atmaca H.; Bozkurt E.; Kucukzeybek Y.; Varol U.; Tarhan M.O.; Karaca B.; Uslu R.
    Purpose: Thymoquinone (TQ), an active ingredient of black seed oil (Nigella Sativa), has been shown to possess cytotoxic activity against a variety of cancer cell lines. Our purpose was to investigate if the cytotoxic and apoptotic effect of zoledronic acid (ZA) can be enhanced by the addition of the TQ in hormone- and drug-refractory prostate cancer cells PC-3 and DU-145. Methods: XTT cell proliferation assay was used to assess cytotoxicity; DNA fragmentation and caspase 3/7 activity were also measured. Results: The combination of TQ and ZA resulted in a significant synergistic cytotoxic activity and DN A fragmentation when compared to any single agent alone, in a dose- and time-dependent manner. In addition, TQ and ZA combination increased the caspase 3/7 activity in PC-3 cell line, while this activity could not be demonstrated in DU-145 cell line. Conclusion: TQ and ZA had minimal hematological and non-hematological toxicity profile compared to cytotoxic agents. So, this combination may be an alternative approach for patients who are unable to be treated by conventional treatments because of poor performance status.
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    Disodium pentaborate decahydrate (DPD) induced apoptosis by decreasing hTERT enzyme activity and disrupting F-actin organization of prostate cancer cells
    (IOS Press BV, 2014) Korkmaz M.; Avcı C.B.; Gunduz C.; Aygunes D.; Erbaykent-Tepedelen B.
    Animal and cell culture studies have showed that boron and its derivativesmay be promising anticancer agents in prostate cancer treatment. Thus, DU145 cells were treated with disodium pentaborate decahydrate (DPD) for 24, 48, and 72 h in order to investigate the inhibitor effect and mechanisms of DPD. Then, cell proliferation, telomerase enzyme activity, actin polymerization, and apoptosis were detected by WST-1 assay, qRT-PCR, immunofluorescence labeling, and flow cytometry, respectively. We found that DPD inhibited the growth of human prostate cancer cell line DU145 at the concentration of 3.5 mM for 24 h. Our results demonstrated that 7 mM of DPD treatment prevented the telomerase enzyme activity at the rate of 38%. Furthermore, DPD has an apoptotic effect on DU145 cells which were examined by labeling DNA breaks. With 7 mM of DPD treatment, 8, 14, and 41% of apoptotic cells were detected for 24, 48, and 72 h, respectively. Additionally, immunofluorescence labeling showed that the normal organization of actin filaments was disrupted in DPD-exposed cells, which is accompanied by the alteration of cell shape and by apoptosis in targeted cells. Taken together, the results indicate that DPD may exert its cytotoxicity at least partly by interfering with the dynamic properties of actin polymerization and decreasing the telomerase activity. Eventually, for the first time, the results of this study showed that DPD suppressed the activity of telomerase in DU145 cells, and therefore, we suggested that DPD could be an important agent for its therapeutic potential in the treatment of prostate cancer. © International Society of Oncology and BioMarkers (ISOBM) 2013.
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    Capsaicin inhibits cell proliferation by cytochrome c release in gastric cancer cells
    (IOS Press BV, 2014) Meral O.; Alpay M.; Kismali G.; Kosova F.; Cakir D.U.; Pekcan M.; Yigit S.; Sel T.
    Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is the principal pungent component in hot peppers. The role of capsaicin in carcinogenesis is quite controversial. Although some investigators suspect that capsaicin is a carcinogen, co-carcinogen, or tumor promoter, others have reported that it has chemopreventive and chemotherapeutic effects. The present study aimed to evaluate the cytotoxicity and chemosensitizing activities of capsaicin alone and on 5-flourouracil (5-FU)-treated gastric cancer cells. In this study, the gastric cancer cell line HGC-27 was used and capsaicin used as a chemosensitizer and 5-flourouracil (5-FU) was used as chemotherapeutic. Cytotoxicity and chemosensitizing activities were analyzed with MTT assay; supernatant levels of LDH and glucose were detected as biochemical markers of cell viability; cytochrome c and AIF were evaluated with western blot; and additionally, wound-healing assays were employed. Results suggested that capsaicin had significant anticancer abilities; such capsaicin were capable of causing multifold decreases in the half maximal inhibitory concentration IC50 value of 5-FU. The continuing controversy surrounding consumption or topical application of capsaicin clearly suggests that more well-controlled epidemiologic studies are needed to evaluate the safety and efficacy of capsaicin use. In summary, the present study demonstrated that capsaicin has the potential to be used for treating gastric carcinoma with 5-FU in vitro. © 2014 International Society of Oncology and BioMarkers (ISOBM).
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    Zoledronic acid increases cytotoxicity by inducing apoptosis in hormone and docetaxel-resistant prostate cancer cell lines
    (Kluwer Academic Publishers, 2015) Varol U.; Degirmenci M.; Karaca B.; Atmaca H.; Kisim A.; Uzunoglu S.; Sezgin C.; Sanli U.A.; Uslu R.
    Our aim was to investigate the possible synergistic/additive cytotoxic and apoptotic effects of combination of docetaxel and zoledronic acid (ZA), in PC-3 hormone-refractory prostate cancer cells (HRPC), as well as their docetaxel-resistant sublines. We established a docetaxel-resistant cell line (PC-3R) from PC-3 prostate cancer cells, by intermittent exposure to increasing concentrations of docetaxel in vitro. We then examined the effect of ZA and docetaxel on cell proliferation in both PC-3 and PC-3R prostate cancer cells. XTT cell proliferation assay was used to assess the cytotoxicity, and DNA fragmentation and caspase 3/7 enzyme activity were measured to verify apoptosis. According to our results, docetaxel and ZA were found to be synergistically cytotoxic and apoptotic in both PC-3 and docetaxel-resistant PC-3R cells, in a dose- and time-dependent manner. Combined treatment with docetaxel and ZA synergistically inhibited PC-3 cell growth in vitro through an enhanced induction of cell death, compared with either agent alone; this result was also evident on PC-3R cells. Moreover, we have also demonstrated that apoptosis was induced in prostate cancer cells exposed to these drugs by a concentration-dependent increase in DNA fragmentation and caspase 3/7 enzyme activity. We concluded that ZA, either with docetaxel or not, might still exert some cytotoxicity even in docetaxel-resistant cells. From the clinical perspective, when the clinician decided to change the treatment in the post-docetaxel setting, continuing or combination with ZA may be an effective therapeutic approach for the treatment of HRPC patients. © 2014, International Society of Oncology and BioMarkers (ISOBM).
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    Novel combination of docetaxel and thymoquinone induces synergistic cytotoxicity and apoptosis in DU-145 human prostate cancer cells by modulating PI3K–AKT pathway
    (Springer-Verlag Italia s.r.l., 2015) Dirican A.; Atmaca H.; Bozkurt E.; Erten C.; Karaca B.; Uslu R.
    Background: The treatment of castrate-resistant prostate cancer (CRPC) still remains as an important challenge of daily oncology practice. Docetaxel significantly prolongs overall survival in men with CRPC. Thymoquinone (TQ), one of the flavonoid compounds isolated from Nigealla sativa, has been shown to possess cytotoxic activity against a variety of cancer cell lines. Materials and Methods: The aim of the study was to investigate the possible synergistic cytotoxic/apoptotic effects of a novel combination, docetaxel and TQ in DU-145 hormone- and drug-refractory prostate cancer cells and their effects on PI3K and ERK signaling pathways Results: We observed that the combination of docetaxel and TQ resulted in a significant synergistic cytotoxicy and apoptosis as compared to any single agent alone, in a dose-dependent manner. It was found that viability of the combination treated cells was not significantly changed in the presence of LY294002 as compared to inhibitor treated cells. However, in the presence of FR180204, viability of combination treated cells was significantly decreased as compared to inhibitor treated cells. In conclusion, cytotoxic effect of the docetaxel and TQ combination is correlated with the block of the PI3K/Akt signaling pathway in DU-145 cells. Conclusion: Therefore, this combination strategy may be an alternative approach for the challenging era of daily oncologic practice. Also, the combination of docetaxel and TQ might allow a reduction in docetaxel doses and diminish adverse effects of docetaxel while maintaining the therapeutic effect in patients with CRPC. © 2014, Federación de Sociedades Españolas de Oncología (FESEO).