P90 ribosomal S6 kinases : A bona fide target for novel targeted anticancer therapies?

The 90 kDa ribosomal S6 kinase (RSK) family of proteins is a group of highly conserved Ser/Thr kinases. They are downstream effectors of the Ras/ERK/MAPK signaling cascade. ERK1/2 activation directly results in the phosphorylation of RSKs, which further, through interaction with a variety of different downstream substrates, activate various signaling events. In this context, they have been shown to mediate diverse cellular processes like cell survival, growth, proliferation, EMT, invasion, and metastasis. Interestingly, increased expression of RSKs has also been demonstrated in various cancers, such as breast, prostate, and lung cancer. This review aims to present the most recent advances in the field of RSK signaling that have occurred, such as biological insights, function, and mechanisms associated with carcinogenesis. We additionally present and discuss the recent advances but also the limitations in the development of pharmacological inhibitors of RSKs, in the context of the use of these kinases as putative, more efficient targets for novel anticancer therapeutic approaches

Palladium (II) complex and thalidomide intercept angiogenic signaling via targeting FAK/Src and Erk/Akt/PLC gamma dependent autophagy pathways in human umbilical vein endothelial cells

The current study assessed the effects of the thalidomide and palladium (II) saccharinate complex of terpyridine on the suppression of angiogenesis-mediated cell proliferation. The viability was assessed after treatment with palladium (II) complex (1.56-100 mu M) and thalidomide (0.1-400 mu M) alone by using ATP assay for 48 h. Palladium (II) complex was found to inhibit growth statistically significant in a dose-dependent manner in HUVECs and promoted PARP-1 cleavage through the production of ROS. On the other hand, thalidomide did not cause any significant change in cell viability. Moreover, cell death was observed to be manifested as late apoptosis due to Annexin V/SYTOX staining after palladium (II) complex treatment however, thalidomide did not demonstrate similar results. Thalidomide and palladium (II) complex also suppressed HUVEC migration and capillary-like structure tube formation in vitro in a time-dependent manner. Palladium (II) complex (5 mg/ml) treatment showed a strong antiangiogenic effect similar to positive control thalidomide (5 mg/ml) and suc-cessfully disrupted the vasculature and reduced the thickness of the vessels compared to control (agar). Furthermore, suppression of autophagy enhanced the cell death and anti-angiogenic effect of thalidomide and palladium (II) complex. We also showed that being treated with thalidomide and palladium (II) complex inhibited phosphorylation of the signaling regulators downstream of the VEGFR2. These results provide evidence for the regulation of endothelial cell functions that are relevant to angiogenesis through the suppression of the FAK/Src/Akt/ERK1/2 signaling pathway. Our results also indicate that PLC-gamma 1 phosphorylation leads to acti-vation of p-Akt and p-Erk1/2 which cause stimulation on cell proliferation at lower doses. Hence, we demon-strated that palladium (II) and thalidomide can induce cell death via the Erk/Akt/PLC gamma signaling pathway and that this pathway might be a novel mechanism

Kedi Oositlerinin In Vitro Olgunlaştırılması ve Kumulus Hücrelerinin Apoptoz Oranları Üzerine, Ovaryum Taşıma ve Saklama Sıcaklığının Etkisi

Çalışmanın amacı, ovaryumların iki farklı sıcaklıkta (37°C ve 4°C) taşınma ve soğukta 24 saat bekletilmenin kumulus hücrelerindeki apoptoza ve kedi oositlerinin in vitro olgunlaşma oranları (IVM) üzerine etkilerini incelemektir. Kısırlaştırılmış 15 kediden ovaryumlar alındı ve yarısı 37°C, diğer yarısı da 4°C’de olmak üzere, fosfat tampon tuzlu solüsyonunda (PBS) laboratuara taşındı. Soğukta bekletmenin etkilerini belirlemek içinse, 4°C ‘de taşınan ovaryumların yarısı, aynı sıcaklıkta olmak üzere 24 saat bekletildi. Seçilen kumulus oosit kompleksleri (COCs), %100’e yakın nemin sağlandığı %5 CO2’li inkübatörde mineral yağ altındaki 500 μL modifiye Sentetik Ovidukt Medyumu (mSOF) içeren dört gözlü petrilerde olmak üzere 38°C’de 48 saat süreyle olgunlaştırıldı. Apoptozun etkileri, hem iki farklı taşıma grubunda, hem de soğukta 24 saat bekletilen grupta olmak üzere in vitro olgunlaşmanın hemen öncesinde kumulus hücrelerinde test edildi. Apoptosis derecesi, deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) test ile ölçüldü. Oositlerin in vitro olgunlaşma düzeyleri Hoechst (33342) boyama ile belirlendi. Apoptotik hücre oranları, 37°C ve 4°C taşıma gruplarında sırasıyla; %19.40 ve %21.55 olarak belirlendi (P>0.001). Aynı değer, 24 saatlik soğukta bekletilen grupta ise daha yoğun olarak (%34.80) görüldü (P<0.001). IVM bulguları da sırasıyla 37°C ve 4 °C taşıma gruplarında %49.77, %44.55 (P>0.05) iken, 24 saat soğukta bekletme grubunda ise %18.90 olarak bulundu (P<0.05). Çalışma sonuçları, (I) kedi ovaryumlarının sıcak veya soğukta taşıma sırasında kumulus hücrelerinin, apoptoza kısmen maruz kaldıklarını, (II) ovaryumların 4°C’de 24 saat bekletilmesinin kumulus hücrelerinin apoptozunu önemli derecede artırdığını ve (III) 4°C’de 24 saat bekletmenin, oositlerin IVM oranlarını olumsuz etkilediğini göstermiştir

Effects of Ovary Transport and Storage Temperature on In Vitro Maturation and Cumulus Cell Apoptosis Rates in Cat Oocytes

Çalışmanın amacı, ovaryumların iki farklı sıcaklıkta (37°C ve 4°C) taşınma ve soğukta 24 saat bekletilmenin kumulus hücrelerindeki apoptoza ve kedi oositlerinin in vitro olgunlaşma oranları (IVM) üzerine etkilerini incelemektir. Kısırlaştırılmış 15 kediden ovaryumlar alındı ve yarısı 37°C, diğer yarısı da 4°C’de olmak üzere, fosfat tampon tuzlu solüsyonunda (PBS) laboratuara taşındı. Soğukta bekletmenin etkilerini belirlemek içinse, 4°C ‘de taşınan ovaryumların yarısı, aynı sıcaklıkta olmak üzere 24 saat bekletildi. Seçilen kumulus oosit kompleksleri (COCs), %100’e yakın nemin sağlandığı %5 CO2’li inkübatörde mineral yağ altındaki 500 μL modifiye Sentetik Ovidukt Medyumu (mSOF) içeren dört gözlü petrilerde olmak üzere 38°C’de 48 saat süreyle olgunlaştırıldı. Apoptozun etkileri, hem iki farklı taşıma grubunda, hem de soğukta 24 saat bekletilen grupta olmak üzere in vitro olgunlaşmanın hemen öncesinde kumulus hücrelerinde test edildi. Apoptosis derecesi, deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) test ile ölçüldü. Oositlerin in vitro olgunlaşma düzeyleri Hoechst (33342) boyama ile belirlendi. Apoptotik hücre oranları, 37°C ve 4°C taşıma gruplarında sırasıyla; %19.40 ve %21.55 olarak belirlendi (P>0.001). Aynı değer, 24 saatlik soğukta bekletilen grupta ise daha yoğun olarak (%34.80) görüldü (P<0.001). IVM bulguları da sırasıyla 37°C ve 4 °C taşıma gruplarında %49.77, %44.55 (P>0.05) iken, 24 saat soğukta bekletme grubunda ise %18.90 olarak bulundu (P<0.05). Çalışma sonuçları, (I) kedi ovaryumlarının sıcak veya soğukta taşıma sırasında kumulus hücrelerinin, apoptoza kısmen maruz kaldıklarını, (II) ovaryumların 4°C’de 24 saat bekletilmesinin kumulus hücrelerinin apoptozunu önemli derecede artırdığını ve (III) 4°C’de 24 saat bekletmenin, oositlerin IVM oranlarını olumsuz etkilediğini göstermiştir

Effects of combined administration of doxorubicin and chloroquine on lung pathology in mice with solid Ehrlich ascites carcinoma

Combined use of a chemotherapeutic agent and an autophagy inhibitor is a novel cancer treatment strategy. We investigated the effects of chloroquine (CQ) on lung pathology caused by both solid Ehrlich ascites carcinoma (EAC) and doxorubicin (DXR). A control group and eight experimental groups of adult female mice were inoculated subcutaneously with 2.5 x 10(6) EAC cells. DXR (1.5 mg/kg and 3 mg/kg) and CQ (25 mg/kg and 50 mg/kg) alone or in combination were injected intraperitoneally on days 2, 7 and 12 following inoculation with EAC cells. Lung tissue samples were examined using immunohistochemistry (IHC) for endothelial (eNOS), inducible nitric oxide synthase (iNOS) and neutrophil gelatinase-associated lipocalin (NGAL). Serum catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) and malondialdehyde (MDA) levels were measured using ELISA. We found decreased levels of iNOS and eNOS in the groups that received 1.5 mg/kg DXR alone and in combination with 25 mg/kg and 50 mg/kg CQ. Combined administration of DXR and CQ partially prevented disruption of alveolar structure. Levels of antioxidant enzymes and MDA were lower in all treated groups; the greatest reduction was observed in mice that received the combination of 25 mg/kg CQ + 1.5 mg/kg DXR. Levels of NGAL were elevated in all treated groups. We found that CQ ameliorated both EAC and DOX induced lung pathology in female mice with solid EAC by reducing oxidative stress

A promising natural product, pristimerin, results in cytotoxicity against breast cancer stem cells in vitro and xenografts in vivo through apoptosis and an incomplete autopaghy in breast cancer

Several natural products have been suggested as effective agents for the treatment of cancer. Given the important role of CSCs (Cancer Stem Cells) in cancer, which is a trendy hypothesis, it is worth investigating the effects of pristimerin on CSCs as well as on the other malignant cells (MCF-7 and MDA-MB-231) of breast cancer. The anti-growth activity of pristimerin against MCF-7 and MCF-7s (cancer stem cell enriched population) cells was investigated by real time viability monitorization (xCELLigence System (R)) and ATP assay, respectively. Mode of cell death was evaluated using electron and fluorescence microscopies, western blotting (autophagy, apoptosis and ER-stress related markers) and flow cytometry (annexin-V staining, caspase 3/7 activity, BCL-2 and PI3K expressions). Pristimerin showed an anti-growth effect on cancer cells and cancer stem cells with IC50 values ranging at 0.38-1.75 mu M. It inhibited sphere formation at relatively lower doses (<1.56 mu M). Apoptosis was induced in MCF-7 and MCF-7s cells. In addition, extensive cytoplasmic vacuolation was observed, implying an incompleted autophagy as evidenced by the increase of autophagy-related proteins (p62 and LC3-II) with an unfolded protein response (UPR). Pristimerin inhibited the growth of MCF-7 and MDA-MB-231-originated xenografts in NOD.CB17-Prkdc(scid)/J mice. In mice, apoptosis was further confirmed by cleavage of PARP, activation of caspase 3 and/or 7 and TUNEL staining. Taken together, pristimerin shows cytotoxic activity on breast cancer both in vitro and in vivo. It seems to represent a robust promising agent for the treatment of breast cancer. Pristimerin's itself or synthetic novel derivatives should be taken into consideration for novel potent anticancer agent(s). (C) 2017 Elsevier Ltd. All rights reserved