1,721,018 research outputs found
The plant-derived triterpenoid tingenin B is a potent anticancer agent due to its cytotoxic activity on cancer stem cells of breast cancer in vitro
No full textDespite the rapid advances in chemotherapy regimens, the outcome of patients with breast cancer is not satisfactory. One of the reasons of this dissatisfaction is that subsets of cells in tumors which referred as cancer stem cells (CSCs) show and/or gain resistance to therapies. Thus, compounds that target CSCs are urgently needed. Since some are already used in the clinic, natural products have great potential for further development as anti cancer drugs. The aim of this study is to investigate the cytotoxic activity of tingenin b (or 22β-hydroxytingenone) which is a quinone-methide triterpenoid structurally related to tingenone, against breast CSCs (stem-cell enriched population from MCF-7 cell line, MCF-7s). It has been found that tingenin b was cytotoxic against MCF-7s (IC50 value for 48 h was found to be 2.38 μM) by inducing apoptosis. It was evident by Annexin V staining positivity, decreased mitochondrial membrane potential and Bcl-2 dephosphorylation with a concomitant increase in Bax protein expression. In addition, endoplasmic reticulum stress was also found to be involved in tingenin b-induced cell death. In conclusion, the results warrant further studies aimed at elucidating and corroborating its possible use in the treatment of breast cancer
A promising therapeutic combination for metastatic prostate cancer: Chloroquine as autophagy inhibitor and palladium(II) barbiturate complex
No full textAutophagy is a catabolic process for cells that can provide energy sources and allows cancer cells to evade cell death. Therefore, studies on the combination of autophagy inhibitors with drugs are increasing as a new treatment modality in cancer. Previously, we reported the anti-tumor activity of a Palladium (Pd)(II) complex against different types of cancer in vitro and in vivo. Chloroquine (CQ), the worldwide used anti-malarial drug, has recently been focused as a chemosensitizer in cancer treatment. The aim of this study was to investigate the efficacy of a combined treatment of these agents that work through different mechanisms to provide an effective treatment modality for metastatic prostate cancer that is certainly fatal. Metastatic prostate cancer cell lines (PC-3 and LNCaP) were treated with Pd (II) complex, CQ, and their combination. The combination enhanced apoptosis by increasing phosphatidylserine translocation and pro-apoptotic proteins. Apoptosis was confirmed by the use of apoptosis inhibitor. The formation of acidic vesicular organelles (AVOs) was observed by acridine orange staining in fluorescence microscopy. The Pd (II) complex increased AVOs formation in prostate cancer cells and CQ-pretreatment has potentiated this effect. Importantly, treatment with CQ suppressed the pro-survival function of autophagy, which might have contributed to enhanced cytotoxicity. In addition, PI3K/AKT/mTOR-related protein expressions were altered after the combination of treatments. Our results suggest that combination treatment enhances apoptotic cell death possibly via the inhibition of autophagy, and may therefore be regarded as a novel and better approach for the treatment of metastatic prostate cancer
Is vitamin D 3 has any effect on the proliferation of colorectal cancer (HCT116) cells?
No full textBu çalışma, 04-09, Temmuz tarihlerinde Berlin[Almanya]’da düzenlenen 40. Congress of the Federation-of-European-Biochemical-Societies (FEBS) - The Biochemical Basis of Life Kongresi‘nde bildiri olarak sunulmuştur.Federat European Biochemical So
Investigation of cytotoxic/apoptotic effects of fenretinide and indole-3-carbinol combination on breast cancer cell lines
No full textGünümüzde meme kanseri hastalarının durumları, kliniğe yeni kemoterapi rejimleri girmesine rağmen halen tatmin edici değildir.Bu nedenle, meme kanseri hastalarında kullanılabilecek yeni yaklaşımlar gerekmektedir. Bu çalışmada, sentetik bir retinoid olan fenretinid (4-HPR) ile brokoli ve lahana gibi bitkilerde doğal bir bileşik olarak bulunan indol-3-karbinol'ün (I3C), MCF-7 (östrojen reseptör pozitif) ve MDA-MB-231 (östrojen reseptör negatif) hücre soyları üzerindeki sitotoksik aktiviteleri araştırılmıştır. MCF-7 ve MDA-MB-231 hücrelerinde, 4-HPR ve I3C kombinasyon tedavisinin apoptozisi indükleyerek, bileşiklerin yalnız başlarına kullanımına kıyasla daha güçlü bir sitotoksik aktiviteye neden olduğu bulunmuştur. Sonuç olarak, kombinasyon tedavisinin, insan meme kanseri tedavisinde kullanılabileceği öngörüsüyle in vivo deneylerin yapılması gerekmektedir.The outcome of patients with breast cancer is still not satisfactory to date although new chemotherapy regimens have been introduced into the clinics. Therefore, novel approaches are required for better management of breast cancer patients. In this study, cytotoxic activity of a new combination of fenretinide, a synthetic retinoid with indole-3 carbinol, a natural product present in vegetables such as broccoli and cabbage, is tested against MCF-7 (estrogen receptor positive) and MDA-MB-231 (estrogen receptor negative) cell lines.It has been found that the combination resulted in more powerful cytotoxic activity by inducing apoptosis, compared to their single use of each agent. In conclusion, this novel combination warrants in vivo experiments to elucidate its possible use in the treatment of breast cancer
Investigation of the relationship between pyruvate dehydrogenase enzyme complex and epithelial mesenchymal transition in vitro
No full textMitokondri son yıllarda, metastatik kanser araştırmalarında çok fazla ilgi çekmektedir. Metastaz kapasitesi yüksek olan kanser hücrelerinin, enerji üretimi için mitokondriyal solunuma kıyasla glikolizi tercih ettiğini gösteren pek çok çalışma bulunmaktadır. Bazı kanserlerde görülen bu değişimin sebebi olarak, mitokondri bekçisi olarak bilinen pirüvat dehidrojenaz enzim kompleksi (PDH) sorumlu tutulmaktadır. Epitelyal mezenkimal dönüşüm (EMD) süreci metastazın itici gücü olduğu ileri sürülmüştür. Bu tez çalışmasında, EMD ile kanser hücre metabolizması arasında bir bağlantının varlığı araştırılmıştır. Bu amaçla, PDH'yı baskılamak için, A-549 hücrelerinde farmakolojik inhibitör Cpi-613 ve RNAi kullanılmıştır. Cpi-613'in antiproliferatif etkisi, xCELLigence sistemi, SRB ve ATP canlılık testleri ile belirlendi. Antiproliferatif dozlar kullanılarak hücrelerde, yara iyileşmesi, invazyon ve ilaç dirençliliği test edildi. Hücrelerde EMD fenotipini göstermek için, EMD ilişkili proteinlerin ifadesi, western blot yöntemi ile analiz edildi. Cpi-613 uyarılmış EMD sürecinin TGF-β sinyal iletimine bağımlı olup olmadığını test etmek için SB-431542 (TGF-β reseptör inhibitörü) kullanıldı. Sonuç olarak, hem PDH'ın Cpi-613 tarafından inhibisyonu hem de PDHA1 ifadesinin baskılanması, EMD sürecine karakteristik morfolojik değişiklikleri uyardığı bulundu. Ayrıca, hızlı bir yara iyileşmesi, artmış invaziv potansiyel ve kemodirenç varlığı gösterildi. Bunun yanı sıra, SB-431542 uygulamasının, EMD sürecini tersine çevirdiği gözlendi. CD133+ (kanser kök hücre belirteci) hücre oranı shPDHA1 hücrelerinde shKontrol hücrelerine kıyasla daha yüksek bulundu. Özetle, PDH inhibisyonunun ve/veya PDHA1 ifadesinin baskılanmasının EMD fenotipini uyardığı ve daha da önemlisi kemoterapötik ilaçlara direnç gelişimi ile sonuçlandığı gösterildi. Bulgular doğrultusunda, Cpi-613 veya PDH inhibitörlerinin antikanser terapide kullanılmasının tartışmalı olduğu düşünüldü.Recently, mitochondria have attracted much attention in metastatic cancer research. There are several reports showing that highly metastatic cancer cells preferentially use glycolysis over mitochondrial respiration for energy production. Pyruvate dehydrogenase enzyme complex (PDH), the gatekeeper enzyme of mitochondria is shown to be responsible for this switch in some cancers. Epithelial mesenchymal transition (EMT), has been proposed to be a driving force of metastasis. In this study, the existence of a link between EMT and cancer cell metabolism has been investigated. To inhibit PDH activity, pharmacological (PDH inhibitor, Cpi-613) and RNAi (stable cell lines were established by lentivirus) were used in A-549 cells. The antiproliferative effect of Cpi-613 was investigated by xCELLigence System, SRB and ATP viability assays. Wound healing, invasion and drug sensitivity tests were applied at antiproliferative doses. To demonstrate the EMT phenotype in cells, the expression of EMT-related proteins were analyzed via western blotting. Furhermore, SB-431542 (TGF-β receptor inhibitor) was used to test whether Cpi-613 induced EMT depends on TGF-β signalling. As a result both the inhibition of PDH by Cpi-613 and the knockdown of PDHA1 induced morphological changes, which were characteristics of EMT. A more rapid wound healing, increased invasive potential and chemoresistance were also shown. SB-431542 treatment reversed the EMT phenotype. The proportion of CD133+ (a cancer stem cell marker) cells were also higher in shPDHA1 cells than those of shControl cells. In brief, knockdown of PDHA1 expression or inhibition of PDH activity induced the EMT phenotype and more importantly resulted in resistance to chemotherapeutic drugs. Therefore, the use of Cpi-613 or PDH blockers becomes debatable for use in anticancer therapy
Investigation of the relationship between pyruvate dehydrogenase enzyme complex and epithelial mesenchymal transition in vitro
No full textMitokondri son yıllarda, metastatik kanser araştırmalarında çok fazla ilgi çekmektedir. Metastaz kapasitesi yüksek olan kanser hücrelerinin, enerji üretimi için mitokondriyal solunuma kıyasla glikolizi tercih ettiğini gösteren pek çok çalışma bulunmaktadır. Bazı kanserlerde görülen bu değişimin sebebi olarak, mitokondri bekçisi olarak bilinen pirüvat dehidrojenaz enzim kompleksi (PDH) sorumlu tutulmaktadır. Epitelyal mezenkimal dönüşüm (EMD) süreci metastazın itici gücü olduğu ileri sürülmüştür. Bu tez çalışmasında, EMD ile kanser hücre metabolizması arasında bir bağlantının varlığı araştırılmıştır. Bu amaçla, PDH'yı baskılamak için, A-549 hücrelerinde farmakolojik inhibitör Cpi-613 ve RNAi kullanılmıştır. Cpi-613'in antiproliferatif etkisi, xCELLigence sistemi, SRB ve ATP canlılık testleri ile belirlendi. Antiproliferatif dozlar kullanılarak hücrelerde, yara iyileşmesi, invazyon ve ilaç dirençliliği test edildi. Hücrelerde EMD fenotipini göstermek için, EMD ilişkili proteinlerin ifadesi, western blot yöntemi ile analiz edildi. Cpi-613 uyarılmış EMD sürecinin TGF-β sinyal iletimine bağımlı olup olmadığını test etmek için SB-431542 (TGF-β reseptör inhibitörü) kullanıldı. Sonuç olarak, hem PDH'ın Cpi-613 tarafından inhibisyonu hem de PDHA1 ifadesinin baskılanması, EMD sürecine karakteristik morfolojik değişiklikleri uyardığı bulundu. Ayrıca, hızlı bir yara iyileşmesi, artmış invaziv potansiyel ve kemodirenç varlığı gösterildi. Bunun yanı sıra, SB-431542 uygulamasının, EMD sürecini tersine çevirdiği gözlendi. CD133+ (kanser kök hücre belirteci) hücre oranı shPDHA1 hücrelerinde shKontrol hücrelerine kıyasla daha yüksek bulundu. Özetle, PDH inhibisyonunun ve/veya PDHA1 ifadesinin baskılanmasının EMD fenotipini uyardığı ve daha da önemlisi kemoterapötik ilaçlara direnç gelişimi ile sonuçlandığı gösterildi. Bulgular doğrultusunda, Cpi-613 veya PDH inhibitörlerinin antikanser terapide kullanılmasının tartışmalı olduğu düşünüldü.Recently, mitochondria have attracted much attention in metastatic cancer research. There are several reports showing that highly metastatic cancer cells preferentially use glycolysis over mitochondrial respiration for energy production. Pyruvate dehydrogenase enzyme complex (PDH), the gatekeeper enzyme of mitochondria is shown to be responsible for this switch in some cancers. Epithelial mesenchymal transition (EMT), has been proposed to be a driving force of metastasis. In this study, the existence of a link between EMT and cancer cell metabolism has been investigated. To inhibit PDH activity, pharmacological (PDH inhibitor, Cpi-613) and RNAi (stable cell lines were established by lentivirus) were used in A-549 cells. The antiproliferative effect of Cpi-613 was investigated by xCELLigence System, SRB and ATP viability assays. Wound healing, invasion and drug sensitivity tests were applied at antiproliferative doses. To demonstrate the EMT phenotype in cells, the expression of EMT-related proteins were analyzed via western blotting. Furhermore, SB-431542 (TGF-β receptor inhibitor) was used to test whether Cpi-613 induced EMT depends on TGF-β signalling. As a result both the inhibition of PDH by Cpi-613 and the knockdown of PDHA1 induced morphological changes, which were characteristics of EMT. A more rapid wound healing, increased invasive potential and chemoresistance were also shown. SB-431542 treatment reversed the EMT phenotype. The proportion of CD133+ (a cancer stem cell marker) cells were also higher in shPDHA1 cells than those of shControl cells. In brief, knockdown of PDHA1 expression or inhibition of PDH activity induced the EMT phenotype and more importantly resulted in resistance to chemotherapeutic drugs. Therefore, the use of Cpi-613 or PDH blockers becomes debatable for use in anticancer therapy
The mechanism for anticancer and apoptosis-inducing properties of cu(ii) complex with quercetin and 1,10-phenanthroline
No full textThis article covers the anticancer activities and mechanisms of action of Cu(II) complexes of flavonoid-derived quercetin and 1,10-phenanthroline ligands. The antiproliferative activity of the complex and its ligands was evaluated by MTT, ATP, and SRB viability assays in human lung cancer cells (A549, H1299). Findings for apoptosis were determined by fluorescent staining, flow cytometry analysis, and the M30 antigen method. In addition, the mechanism of action of the complex was investigated by Annexin V staining, caspase 3/7 activity, ROS formation, and cell cycle analysis. The involvement of caspases, thus, apoptosis was confirmed by rescuing cell death by using a pan-caspase inhibitor (Z-VAD-FMK). Again, increased ROS levels in the cell showed that death may occur by apoptosis. For this reason, the accuracy of ROS-induced apoptosis in cells has been proven as a result of the application of N-acetylcysteine (NAC), which is a ROS inhibitor. The efficacy of the complex was compared with Cisplatin and ligands. The results showed that the Cu(II) flavonoid complex is cytotoxic on lung cancer cells and may have the potential to act as an effective metal-based anticancer drug with a lower IC50 over Cisplatin.Council of Higher Education (YoK) 100/2000 Ph.D. Scholarship Progra
Synthesis, biological characterization and evaluation of molecular mechanisms of novel copper complexes as anticancer agents
No full textBackground: To overcome the hurdles of cisplatin, majorly its toxicity and resistance, there has been extensive search for alternative anti-cancer metal-based compounds. Here, three Cu(II)-complexes, Cu(Sal-Gly)(phen), Cu(Sal-Gly)(pheamine), Cu(Sal-Gly)(phepoxy) are characterized for their interaction with DNA, cytotoxicity and mechanism of action. Methods: The binding ability of the complexes to Calf-Thymus DNA was evaluated by competition fluorescence studies with thiazole-orange, UV-Vis and circular dichroism spectroscopic titrations. Cytotoxicity was evaluated by MTT analysis. The DNA damage was analyzed through cleavage of supercoiled DNA via agarose gel-electrophoresis, and 8-oxo-guanidine and gamma H2AX staining in cells. Apoptosis was detected via DNA condensation/fragmentation, mitochondrial membrane potential, Annexin V staining and caspase 3/7 activity. Formation of reactive oxygen species was determined by DCFDA- and GSSG/GSH-analysis. Results: Binding constants to DNA were evaluated as 1.7 x 10(6) (Cu(Sal-Gly)(phen)), 2.5 x 10(6) (Cu(Sal-Gly)(pheamine)) and 3.2 x 10(5) (Cu(Sal-Gly)(phepoxy)). All compounds induced DNA damage. Apoptosis was the main form of cell death. There was an increase in ROS, which is most likely responsible for the observed DNA-damage. Although the compounds were cytotoxic to all tested cancer cell lines, only Cu(Sal-Gly)(pheamine) displayed significantly lower toxicity towards non-cancer cells, its associated phenotypes differing from the other two Cu-complexes. Thus, Cu(Sal-Gly)(pheamine) was further assayed for molecular changes in response to drug treatment using a custom designed RT-qPCR array. Results showed that Harakiri was significantly upregulated. Presence of p53 was not required for apoptosis in response to Cu-complexes. Conclusions and general significance: These Cu-complexes, namely Cu(Sal-Gly)(pheamine), may be considered promising anticancer agents with activity in cancer cells even with deficient p53 status.Portuguese Foundation for Science and Technology UID/QUI/00100/2013IST-UTL Center of the Portuguese Mass Spectrometry Networks REM2013 - RECI/QEQ-QIN/0189/201
Enhanced cytotoxic activity of doxorubicin through the inhibition of autophagy in triple negative breast cancer cell line
No full textBackground: The outcome of triple negative breast cancer is still poor and requires improvement with better therapy options. Autophagy has recently been shown to play a role in anticancer drug resistance. Therefore, we investigated if the effectiveness of doxorubicin was augmented by the inhibition of autophagy. Methods: MDA-MB-231 was used as a model cell line for triple negative breast cancer and 3-methyladenine was used as an inhibitor of autophagy. Cells were treated with 0.46-1.84 mu M doxorubicin and 2.5-10 mu M 3-methyladenine for 48 h. Cell death mode was examined with M30 and M65 ELISA assays. ROS level and LDH activity was examined and the cellular acidic compartment of cells was monitored by acridine orange staining. The expression of various autophagy and apoptosis related proteins/genes were evaluated with Western blotting and RT-qPCR respectively. Results: Synergism was observed between the compounds (CI value < 1.0). RT-qPCR analysis revealed that the combination resulted in a down-regulation of autophagy-related genes. Moreover, the combination resulted in a different cell death modality, upregulating necroptosis-related genes. This suggests that the mode of cell death may switch from apoptosis to necroptosis, which is a more severe form of cell death, when autophagy is inhibited. These results were further confirmed at protein level by Western blotting. Conclusion: Inhibition of autophagy seems to sensitize triple negative breast cancer cells to doxorubicin, warranting further in vivo studies for the proof of this concept. General significance: Autophagy has a key role in drug resistance in MDA-MB-231 cells. Therefore combinatorial approaches may effectively overcome resistance
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