Top PDF A critical role for FBXW8 and MAPK in cyclin D1 degradation and cancer cell proliferation.

A critical role for FBXW8 and MAPK in cyclin D1 degradation and cancer cell proliferation.

A critical role for FBXW8 and MAPK in cyclin D1 degradation and cancer cell proliferation.

This study has shown that the Ras/Raf/MEK/ERK MAPK signaling cascade promotes cyclin D1 phosphorylation at Thr286, resulting in ubiquitination and degradation of cyclin D1 (Fig. 5F). ERK/MAPK is a proline (Pro)-directed serine or threonine (Ser/ Thr) protein kinase [26]. Many proteins contain Ser/Thr-Pro sequences; however, most of them are not phosphorylated by ERK, suggesting that there is a strict relationship in ERK substrate specificity [28]. MAPK requires D-domains on the substrate to increase the efficiency of phosphorylation [27]. In this report, we identified a stringent D-domain at amino acids 179-193 of cyclin D1. Deleting this domain significantly reduced phosphorylation of cyclin D1 in cultured cells and dramatically inhibited ubiquitination of cyclin D1 in vitro (Figs. 2E and F), again demonstrating that ERK/MAPK plays a significant role in cyclin D1 regulation, as GSK3b, another proline-directed protein kinase responsible for cyclin D1 phosphorylation at Thr286, should not require the MAPK D-domain for phosphohrylation of its substrates. This possibility suggests that high levels of MAPK activity in cancer cells may make the requirement of GSK3b redundant for cyclin D1 phosphorylation at Thr286. We also found that similar D-domain sequences were conserved in cyclin D1s from mouse, rat, chicken, xenopus, and zebrafish. Alignment of cyclin D1 with other D-type cyclins has shown that Thr286 in cyclin D1 corresponds to Thr280 in cyclin D2 and Thr283 in cyclin D3 in their proximity to the carboxyl termini immediately followed by prolines [8,9]. In addition, we found very similar sequences of D-domains in the equivalent sites of cyclin D2 and cyclin D3. We therefore suggest that all D-type cyclins can be classified as ERK/MAPK substrates. In fact, cyclin D3 protein shows a very similar expression profile to cyclin D1 during cell cycle progression in colon cancer cells released from quiescence (Figs. S1 [H] and [I]).
Mostrar mais

12 Ler mais

Quercetin Suppresses Twist to Induce Apoptosis in MCF-7 Breast Cancer Cells.

Quercetin Suppresses Twist to Induce Apoptosis in MCF-7 Breast Cancer Cells.

Cyclin D1 expression was regulated by diverse signal transduction events including Wnt pathway, Akt pathway [35, 36]. More recently, few studies revealed the direct and indirect role of Twist in inhibition of a tumor suppressor E-Cadherin [3]. It is well known that inhibition of E-Cadherin will cause accumulation of β-catenin within cells leading to nuclear translocation. Entry of β-Catenin into nucleus activates expression of Cyclin D1 by binding to its promote [37, 38]. Twist is a basic helix-loop-helix (bHLH) transcription factor, which is a key transcrip- tion activator of epithelial to mesenchymal transition (EMT) and it is observed in various can- cer cell lines including breast cancer [3, 39, 40]. Increased twist levels in quercetin treated MDA-MB-231 cells promoted cell proliferation by increasing Cyclin D1. Decrease in levels of Twist by quercetin induced apoptosis in MCF-7 cells through cell cycle arrest by down regulat- ing Cyclin D1.
Mostrar mais

21 Ler mais

p14ARF post-transcriptional regulation of nuclear cyclin D1 in MCF-7 breast cancer cells: discrimination between a good and bad prognosis?

p14ARF post-transcriptional regulation of nuclear cyclin D1 in MCF-7 breast cancer cells: discrimination between a good and bad prognosis?

Understanding the signalling pathways that mediate the different states of cell cycle arrest is fundamental to our understanding of breast cancer development, prevention and better breast cancer treatment. The p14ARF-p53 pathway is well documented as an important defense against cancer by triggering apoptosis/quiescence or senescence [11]. In breast epithelial cancer cells, p14ARF and components of this pathway (p53 and p21) are frequently inactivated and impairs the cell’s ability to control its division and increases their susceptibility to oncogenic signals. In this report we describe the importance of the regulation and localisation of cyclin D1 mediated by p14ARF in both cell cycle inhibition and abnormal proliferation in MCF-7 senescent cells. Induction of p14ARF demonstrated rapid cell cycle arrest (within 6h of induction), and exhibited many of the hallmarks of a senescence phenotype conditional on expression of p14ARF and a functional p53/p21 pathway. We have shown that activation of the p14ARF-p53-p21 pathway both activates Rb through de- phosphorylation and inactivates it through degradation. These observations are consistent with its protective role in carcinogen- esis. Interestingly, p14ARF promotes accumulation of cyclin D1 at the protein level, but does not directly affect CCND1 mRNA transcription. Post-translational regulation of cyclin D1 was also confirmed by transcriptional and translational inhibitor treatment, strengthening the quantitative PCR results. In addition, by inhibiting protease activity through addition of MG132 we observe an increase in cyclin D1 protein expression suggesting that cyclin D1 expression was still modified by the ubiquitin- proteasome pathway post-p14ARF expression. These findings raise the question of the importance of cell cycle variations in
Mostrar mais

16 Ler mais

Water extract of Ashwagandha leaves has anticancer activity: identification of an active component and its mechanism of action.

Water extract of Ashwagandha leaves has anticancer activity: identification of an active component and its mechanism of action.

Cyclins are a highly conserved family of proteins that act as regulators of CDK kinases and show dramatic periodicity in their expression level during the cell cycle progression. Different cyclins exhibit distinct expression and degradation patterns that contribute to the temporal coordination of each mitotic event. It has been established that cyclin D1 forms a complex with CDK4 or CDK6 and is absolutely required for G1/S transition. Cyclin D1-CDK4/CDK6 complex forms an active kinase for the retinoblastoma protein (RB) resulting in RB-phosphorylation, release of E2F from RB-E2F complex and transcription of genes required for cell cycle progression. Cyclin D1 also plays a key role in linking the extracellular signaling to cell cycle progression. Its expression level increases during G2 phase, maintains through mitosis and G1 phase, and declines in S phase when DNA synthesis begins. During the cell cycle progression in response to pro proliferative signals, cyclin D1 level gets induced once again during G2 phase and decline on entry to S phase resulting commitment to continuing proliferation. Since ASH-WEX and TEG treatment resulted in G1 arrest in cancer cells, we examined the level of cyclins and CDKs as shown in Figure 6B. When normal and cancer cells were treated with TEG, cyclin D1 showed accumulation only in cancer cells. Furthermore, results from three independent experiments revealed that the level of cyclin B1 decreases in TEG and ASH-WEX treated cancer cells whereas it increases in normal cells. These data were reflective of the predominant growth arrest of cancer cells by ASH-WEX and TEG. To investigate it further, we examined the phosphorylation of RB using phosphor specific antibody. Whereas RB phosphorylation decreased in cancer cells, there was a moderate increase in normal cells (Figures 6B and 6C). Immunocytochemistry with anti-phospho RB antibody confirmed these results (Figure 6C), concluding that the ASH-WEX and TEG cause
Mostrar mais

11 Ler mais

Vanadate effects on bone metabolism: fish cell lines as an alternative to mammalian in vitro systems

Vanadate effects on bone metabolism: fish cell lines as an alternative to mammalian in vitro systems

VSa13 bone-derived cell line has been recently developed from the vertebra of Sparus aurata, a marine teleost fish, and fully characterized [51]. This cell line is capable of mineralizing its extracellular matrix under appropriate culture conditions and has been associated to the chondrocyte lineage as suggested by a relatively high expression of matrix gla protein (a calcification inhibitor normally produced by chondrocytes in cartilage), no expression of osteocalcin (an osteoblastic marker) and strong alcian blue staining (normally associated with cartilage extracellular matrix). The suitability of VSa13 cells to study in vitro vanadium insulin-like action on bone was confirmed by its responsiveness to insulin treatments (10 nM insulin was shown to decrease by 25% the degree of extracellular matrix (ECM) mineralization in VSa13 cell [52]). To date, only vanadate oligomeric solutions have been tested in VSa13 cells. Metavanadate (containing n-meric species with n = 1-5) and decavanadate (n = 1 or 10) effects on VSa13 cells viability, growth, accumulation and ECM mineralization have been investigated [52]. Vanadate oligomerization did not originate differences in toxicity levels after prolonged exposures (metavanadate and decavanadate solutions were shown to be non-toxic at concentrations below 10 µM during 15 days). However, decameric species exhibited higher toxicity after 2 h of treatment using 1 mM concentration (acute toxicity). Similarly, accumulation of vanadium in VSa13 cells was oligomerization-independent from 4 to 24 h but much slower for decavanadate within the first 2 h of treatment. These results were shown to be coherent with decameric species decomposition rate into monomeric species (half-life time of approximately 150 min), suggesting that decavanadate long-term effects resulted mainly from monomeric species. However, in short-term treatments in which decameric species were still present in solution, vanadate was shown to accumulate much slower in cells, and to induce higher toxicities. These results reinforced the hypothesis of the higher toxicity of species highly oligomerized, which are probably formed in specific cellular environments (e.g. in which the pH is low). Merged results of long-term treatments by monomeric and decameric vanadate indicate that cell proliferation was stimulated (Figure 2) in a dose-dependent manner. The observation that insulin did not stimulate VSa13 cell proliferation (inset of Figure 2) suggested that mitogenic pathways may not be controlled by this hormone in these cells. It also suggested that vanadate effects on cell proliferation were not mediated through insulin signalling pathways, and possibly involving other PTK.
Mostrar mais

14 Ler mais

A metal-based inhibitor of NEDD8-activating enzyme.

A metal-based inhibitor of NEDD8-activating enzyme.

[45–47], their activity against NEDD8-activating enzyme has not been explored. Inspired by the above findings as well as pioneering works from the Meggers’s group on the design of structurally rigid octahedral ruthenium(II) [48–53] and iridium(III) [53–55] com- plexes as shape-complementary inhibitors of protein kinases, we sought to investigate the biological effects of a series of cyclometallated rhodium(III) complexes on the NEDD8 pathway. Cyclometallated rhodium(III) complexes containing the dipyr- ido[3,2-a:29,39-c]phenazine dipyridophenazine (dppz) scaffold were chosen because of the following reasons: 1) the rhodium(III) complex adopts an octahedral geometry rather than a square planar or tetrahedral symmetry, thus allowing much larger structural complexity for potential use in drug design; 2) the octahedral geometry of the rhodium complex provides a globular and rigid scaffold with limited conformational freedoms of the co- ligands that may interact with the previously inaccessible regions of chemical space in NAE; 3) the synthetic route for 1 is modular and convenient, thus allowing structural modification without the need for lengthy synthetic protocols; and 4) the extended aromatic dppz ligand structurally resembles the planar nature of NAE inhibitor 6,6 99-biapigenin [44], potentially functioning as the recognition arm for NAE.
Mostrar mais

9 Ler mais

The differential expression of OCT4 isoforms in cervical carcinoma.

The differential expression of OCT4 isoforms in cervical carcinoma.

Several studies have investigated the function of OCT4 in carcinogenesis. OCT4A promoted tumorigenesis by inhibiting apoptosis through microRNA125b/BAK1 pathway [35]. Monsef et al. reported that cytoplasmic isoform 2 of OCT4 was present in prostate cancer and benign prostate hyperplasia [36]. OCT4B might represent a clinical prognostic biomarker for prostate cancer patients [30]. OCT4B-190 has been reported to inhibit cell apoptosis induced by heat shock [37], while OCT4B-265 promoted cell apoptosis under genotoxic conditions [38]. How- ever, few studies have explored the role of OCT4B in CC progression. In this study, by ectopic expression of OCT4B in SiHa cells we demonstrated that OCT4B promoted cervical cancer cell proliferation and xenograft growth, and inhibited cell apoptosis. To further confirm the onco- genic role of OCT4B in cervical carcinogenesis, we employed RNA interference to knockdown OCT4B in SiHa cells (S3 Fig.). Our results demonstrated that silencing of OCT4B in SiHa cells significantly inhibited cell growth and increased cell apoptosis. Taken together, these data cleraly suggest that OCT4B plays oncogenic role in cervical cancer due to its anti- apoptotic activity.
Mostrar mais

15 Ler mais

Chemokines in Homeostasis and Cancers

Chemokines in Homeostasis and Cancers

Rheumatoid arthritis (RA) is characterized by a mixed Th1-type inflammatory cell infiltration (Th1, neu- trophils, monocytes) in synovial space of the joints, in association with cartilage destruction and bone remod- eling. Chemokines produced in the inflamed joints at- tract leukocytes across the endothelial barrier to initiate and maintain active RA. Among CXC chemokines, high concentrations of CXCL8, CXCL5, and CXCL1 are de- tected in the sera, synovial fluids, and synovial tissues of RA patients. These chemokines attract neutrophils and promote angiogenesis. High production of CC chemok- ines CCL2, CCL3 and CCL5 which attract mainly mono- cytes is also found in RA (43, 44). CXCL12 expressed in the rheumatoid synovium, recruits CD4 memory T cells, which express increased levels of CXCR4, at the RA site. CXCL12 also blocks T cells from undergoing activation-induced apoptosis, thus further increasing the accumulation of T cells in the rheumatoid synovium. In- terestingly, CXCL12 may induce the migration of DCs from blood stream into the rheumatoid area, implying its potential role in amplifying a detrimental autoimmune response. (45)
Mostrar mais

12 Ler mais

PLK1 and β-TrCP-dependent ubiquitination and degradation of Rap1GAP controls cell proliferation.

PLK1 and β-TrCP-dependent ubiquitination and degradation of Rap1GAP controls cell proliferation.

Rap1GAP protein can be regulated at multiple post-transla- tional levels. Protein kinase A (PKA) phosphorylates Rap1GAP at Ser441 and Ser499 in response to activation of D1 dopamine receptors, which leads to its inhibition and subsequent activation of Rap1 [10]. Phosphorylation of Rap1GAP is likely to play an important role in regulating medium spiny neuron function through the ability of the dopamine/cAMP/PKA signaling pathway to regulate Rap1 activity [10]. Other kinases, such as CDK1, have also been reported to phosphorylate Rap1GAP at Ser484 during mitosis, but this phosphorylation does not affect the Rap1GAP stimulation of the GTPase activity of Rap1 by Rap1GAP [18]. Our results showed Ser484 phosphorylation was not essential for Rap1GAP degradation in mitosis. One possibility is that Ser484 phosphorylation might play a role in regulating the interaction of Rap1GAP with other proteins, but elucidation of the significance of CDK1-mediated Rap1GAP phosphorylation must await further studies. Furthermore, in unpublished work we have found that Rap1GAP phosphorylation might be reversed by dephosphorylation. The serine/threonine phosphatases, PPM1A and PPM1B, were two of the most abundant proteins co-purified from Rap1GAP complex by tandem affinity purification (TAP)- mass spectrometry. It is known that b-TrCP-dependent degrada- tion of the transcriptional factor Snail was triggered by GSK3b- mediated phosphorylation, and the small C-terminal domain phosphatase (SCP) is a specific phosphatase for Snail. By antagonizing GSK3b-mediated phosphorylation, SCP can stabi- lize Snail [21]. It will be interesting to test whether PPM1A or PPM1B-mediated Rap1GAP dephosphorylation antagonizes PLK1-mediated Rap1GAP phosphorylation. Future studies are needed to further explore the complex regulation of Rap1GAP proteins and whether dysregulation of Rap1GAP plays a role in tumorigenesis.
Mostrar mais

10 Ler mais

MicroRNAs in lung cancer

MicroRNAs in lung cancer

Additionally, ectopic expression or targeted ‘knockdown’ of miR-153 resulted in downregulation or increased expression of SNAI1 (Snail Family Zinc Finger 1) and ZEB2 (Zinc Finger E-Box Binding Homeobox 2) protein levels, respectively. These two transcription factors promote the repression of the adhesion molecule E-cadherin to regulate EMT during embryonic development. In fact, SNAI1 and ZEB2 are considered critical pro-metastatic factors for their EMT- inducing capabilities [26, 27]. These studies also defined SNAI1 and ZEB2, both of which serve as transcriptional repressors of E-cadherin through binding with E-box elements in the E-cadherin promoter, as direct targets of miR-153. Therefore, E-cadherin is a key factor in EMT since its expression is decreased in the cells that undergo EMT in the presence of miR-153 inhibitors. Thus, the downregulation of miR-153 is crucial for the acquisition or maintenance of mesenchymal cell morphology and contributes to the EMT-associated carcinoma cell invasion induced by TGF-β [26].
Mostrar mais

7 Ler mais

Amygdalin blocks bladder cancer cell growth in vitro by diminishing cyclin A and cdk2.

Amygdalin blocks bladder cancer cell growth in vitro by diminishing cyclin A and cdk2.

Amygdalin, a natural compound, has been used by many cancer patients as an alternative approach to treat their illness. However, whether or not this substance truly exerts an anti-tumor effect has never been settled. An in vitro study was initiated to investigate the influence of amygdalin (1.25–10 mg/ml) on the growth of a panel of bladder cancer cell lines (UMUC-3, RT112 and TCCSUP). Tumor growth, proliferation, clonal growth and cell cycle progression were investigated. The cell cycle regulating proteins cdk1, cdk2, cdk4, cyclin A, cyclin B, cyclin D1, p19, p27 as well as the mammalian target of rapamycin (mTOR) related signals phosphoAkt, phosphoRaptor and phosphoRictor were examined. Amygdalin dose- dependently reduced growth and proliferation in all three bladder cancer cell lines, reflected in a significant delay in cell cycle progression and G0/G1 arrest. Molecular evaluation revealed diminished phosphoAkt, phosphoRictor and loss of Cdk and cyclin components. Since the most outstanding effects of amygdalin were observed on the cdk2-cyclin A axis, siRNA knock down studies were carried out, revealing a positive correlation between cdk2/cyclin A expression level and tumor growth. Amygdalin, therefore, may block tumor growth by down-modulating cdk2 and cyclin A. In vivo investigation must follow to assess amygdalin’s practical value as an anti-tumor drug.
Mostrar mais

9 Ler mais

The loss of miR-26a-mediated post-transcriptional regulation of cyclin E2 in pancreatic cancer cell proliferation and decreased patient survival.

The loss of miR-26a-mediated post-transcriptional regulation of cyclin E2 in pancreatic cancer cell proliferation and decreased patient survival.

phase transition during the cell cycle. These cyclins are of particular interest in pancreatic cancer. Kota [11] and Zhou [27] reported that miR-26a directly upregulates the expression of cyclin D2 and cyclin E2 mRNA in HCC. Thus, both genes are possible targets of miR-26a in pancreatic cancer. On the other hand, EZH2 levels were increased in PDAC to promote cell proliferation and chemoresistance [20]. Therefore, we determined whether miR-26a could regulate the pancreatic cancer cell cycle through its target genes, cyclin D2 and cyclin E2. Cyclin D2 was not detected in the tumor cells and duct epithelial cells of ABPT, whereas cyclin E2 was positively correlated with miR-26a expression in pancre- atic cancer. Cyclin E2 decreased with miR-26a upregulation in Capan-2, SW-1990, and Panc-1 cells. The effects observed on cell proliferation and cyclin E2 expression were consistent with those observed for EZH2 in PDAC cells. These data suggest that miR- 26a downregulation led to the upregulation of cyclin E2 and EZH2, but not of cyclin D2, in PDAC tissues. Thus, the downregulated miR-26a contributed to the cell proliferation and poor survival in pancreatic cancer. These results are consistent with studies on other tumors, such as HCC, breast cancer, NPC, and lymphomas [12,27–30]. The altered expression of specific miRNAs in tumors is reportedly associated with cancer metastasis and poor prognosis [29–32]. Heinzelmann et al., [33] detected a miRNA signature that distinguishes between metastatic and nonmetastatic clear cell renal cell carcinomas. A group of 12 miRNAs, including the let-7 family, miR-30c, and miR-26a, were found to decrease in highly aggressive primary metastatic tumors. Furthermore, miR-26a expression in primary metastatic clear cell renal cell carcinoma was correlated with patient survival [33].
Mostrar mais

10 Ler mais

In vitro Anticancer Property of Yellow Pigment from Streptomyces griseoaurantiacus JUACT 01

In vitro Anticancer Property of Yellow Pigment from Streptomyces griseoaurantiacus JUACT 01

Soil samples for isolation of pigmented actinomycetes were collected from a variety of sources like rhizosphere of orchids, leaf litter soil, garden soil etc. Serial dilution and spread plate technique using Starch Casein Nitrate Agar (SCNA) media containing fluconazole (25 mg/L) and tetracycline (50 mg/L) were used for selective isolation of the actinomycetes. Preliminary identification was based on the microscopic and cultural observations as per the International Streptomyces Project (ISP) (Shirling and Gottlieb 1966). Molecular identification was performed by sequencing the conserved 16S ribosomal RNA gene encoding DNA fragment of 1500 bp, obtained after specific PCR amplification using the universal primers (Schwieger and Tebbe 1998). The sequence obtained was compared with similar sequences retrieved from the GenBank nucleotide sequences database (Altschul et al. 1990). The sequence was deposited in GenBank with the accession number KJ774106. A distance matrix tree was constructed using the neighbor- joining method (Saitou and Nei 1987), and the topology of the phylogenetic tree was built by bootstrap analysis (Felsenstein 1985) using MEGA6.2 (Tamura et al. 2011).
Mostrar mais

8 Ler mais

Development of microfluidic tools for cancer single cell encapsulation and proliferation in microdroplets

Development of microfluidic tools for cancer single cell encapsulation and proliferation in microdroplets

O papel da microfluidica no campo da biopsia líquida começa a ganhar cada vez mais atenção ao revelar-se como uma solução mais capaz na monitorização da progressão de cancro em doentes on- cológicos. O foco das dificuldades mais prementes na monitorização da doença encontra-se na desfa- sagem entre os métodos convencionais de crescimento celular in vitro e a representação actual da influência de microambientes celulares como um modelo 3D. Uma das áreas de especialidade do ramo da microfluidica consiste no uso de microdroplets como um meio de recriação de ambientes com- plexos que possam replicar os modelos actuais de crescimento celular em 3D. O objectivo principal desta tese consistiu em desenvolver estruturas de microfluidica que permitissem o encapsulamento, a proliferação e a monitorização de células cancerígenas individuais em microdroplets. Para tal, um conjunto de dispositivos de microfluidica à base de PDMS para formação e contenção de microdro- plets foram desenvolvidos recorrendo a técnicas de photolithography e softlithography, sendo posteri- ormente testados e optimizados para garantir o encapsulamento de células cancerígenas individu- ais. Depois da optimização dos parâmetros de formação de microdroplets relativos a tamanhos obtidos e estabilidade a longo prazo, o conjunto dos melhores parâmetros foi selecionado para experiências de crescimento celular. Diferentes densidades celulares de células MDA-MB-435S foram combinadas com diferentes percentagens de Matrigel® para acelerar o crescimento celular. Dentro dos resultados obti- dos na tese, foi possível monitorizar microdroplets até 20 dias após a sua formação e também se veri- ficaram sinais de agregação de células em microdroplets, reforçando o potencial destas técnicas em formar estruturas esferoides 3D a partir de células individuais.
Mostrar mais

84 Ler mais

Induction of Apoptosis and Reduction of Endogenous Glutathione Level by the Ethyl-Acetate Soluble Fraction of the Methanol Extract of the Roots of Potentilla fulgens in Cancer Cells.

Induction of Apoptosis and Reduction of Endogenous Glutathione Level by the Ethyl-Acetate Soluble Fraction of the Methanol Extract of the Roots of Potentilla fulgens in Cancer Cells.

All the collected cells were washed with PBS and proteins were extracted in cell lysis buffer (50mM Tris (pH 8.0), 150mM Nacl, 10% glycerol, 1% NP–40, 0.5% Sodium deoxycholate, 0.1% SDS and 0.42% NaF) containing protease inhibitor (1mM phenylmethylsulfonyl and 100 U/ml aprotinin). Protein concentrations were determined using the bicinchonic acid pro- tein assay and 40 μg protein lysates from each sample was loaded in Novex Tris-Glycine 4–20% gradiaent gels and electrophoresis was performed in NuPAGE electrophoresis system from (Invitrogen, USA). Proteins were transferred to PVDF membranes (Sigma) following the standard protocol. The membranes were probed with a 1:1000 dilution of a rabbit polyclonal antibody against PARP Ab-3 (Neo-Markers, USA) and mouse monoclonal antibody against β -actin (AC-15; ab6276; abcam, USA). The membranes were blocked in 5% non-fat dried milk, freshly made in TBST (10mM Tris-Cl, 150mM NaCl, 0.05% Tween 20) buffer. Alkaline-phos- phatase conjugated anti-mouse IgG (Abcam, USA) used as secondary antibody, and immuno- detection was obtained by treating the blot with the substrate solution of BCIP/NBT
Mostrar mais

16 Ler mais

Renata Nascimento Gomes, Felipe da Costa Souza, Alison Colquhoun

Renata Nascimento Gomes, Felipe da Costa Souza, Alison Colquhoun

While 13-HODE and 15-LOX-1 are generally believed to play an antitumorigenic role, data on 15-LOX-2 are less conclusive. Most research data available on 15-HETE refers to the 12/15-LOX rodent isoform, which can metabolize AA to form both 12-HETE and 15-HETE, making it more difficult to correlate the data with human 15-LOX-2 (149). Despite previous in vitro results reporting the overexpression of 15-LOX-2 in breast cancer cell lines (150), in breast tumor biopsy samples (n=120), 15-LOX-2 expression was decrea- sed in comparison with that in normal tissues (143). In lung cancer, a recent study treated NSCLC cell lines with both 13-HODE and 15-HETE and found a decrease in pro- liferation, induction of apoptosis and activation of peroxi- some proliferator-activated receptor g (PPARg) (151). While 15-LOX-1 is overexpressed and 13-HODE is present at higher concentrations in prostate cancer, 15-LOX-2 and 15-HETE are reportedly decreased in high-grade prostate neoplasia (152), suggesting opposing roles for 15-LOX-1 and 15-LOX-2 in pro- state cancer. The work of Hsi et al. (146) corroborated these opposite effects of 15-LOXs by showing that in the PC-3 prostate cell line, 13-HODE upregulated the activity of MAPK and increased the phosphorylation of PPARg, while 15-HETE downregulated MAPK and decreased PPARg phosphorylation. The role of eicosanoids and their degradation products in the development and progression of cancer has been a target of investigations for many years. Despite considerable study, many controversies still exist in the literature in relation to individual eicosanoids in specific tumor settings. As we have highlighted in this review, many eicosanoids are considered to be tumorigenic, some are believed to be antitumorigenic, and several have mixed properties dependent on the tumor type in question. Clearly, the complex interplay among the eicosanoid pathways, their products, their receptors and the subsequent intracellular signaling pathways that are acti- vated need to be better delineated and remain important subjects for future studies. An important goal in these studies will be to provide a better understanding of the complex role played by eicosanoids in both tumor cells and the tumor microenvironment. Such detailed information could provide new diagnostic and/or prognostic markers and identify new therapeutic strategies in cancer treatment.
Mostrar mais

10 Ler mais

urbe, Rev. Bras. Gest. Urbana  vol.6 número1

urbe, Rev. Bras. Gest. Urbana vol.6 número1

The ubiquitous presence of mobile telephony and proliferation of digital networks imply a critical role for these technologies in overcoming the constraints of space in fragmented cities. Academic literature draws from a range of disciplines but fails to address the signi icance of new technologies for African and South African cities. Debates on technologies and urban spaces re lect a Northern bias and case literature that dwells on the developmental aspects of )CT do not engage with the broader signi icance with regards to urban change in African cities. This research addresses these gaps by examining the local transformative qualities of mobile telephony in a South African city, Durban. )t focuses on the ways in which informal traders active in the city use technology. Actor-network theory was used in the analysis of the ield work, uncovering material and human actors, network stabilization processes and agency in determining the transformative potential of this form of digital networking at city and local scales. Findings indicate that appropriation of technology is informed by livelihood strategies. )nnovation is enabled when translation extends to appropriation. More in-depth research is needed on how technology is molded and appro- priated to suit livelihoods. Throughout the research the spatial dimensions of the relationship between mobile telephony and networks were considered. The network spaces that emerge from actor relations do not correspond with the physical spaces usually considered in policy.
Mostrar mais

15 Ler mais

Polymeric nanocapsules prevent oxidation of core-loaded molecules: evidence based on the effects of docosahexaenoic acid and neuroprostane on breast cancer cells proliferation

Polymeric nanocapsules prevent oxidation of core-loaded molecules: evidence based on the effects of docosahexaenoic acid and neuroprostane on breast cancer cells proliferation

NC samples were also analyzed by scanning-probe mi- croscopy in atomic force mode (AFM). Analyses were performed at atmospheric pressure, at room temperature, on Dimension 3000 atomic force microscope monitored by a Nanoscope IIIa controller (Digital Instruments, Santa Barbara, CA, USA). A droplet (5 μL) of each NC sample was deposited on mica, spread and dried with a stream of argon. The images were obtained in tapping mode, using commercial silicon probes, with a 228 μm-long cantilever, 75–98 kHz resonance frequencies, spring constants of 3.0–7.1 N/m and a nominal tip curvature radius of 5 nm. The scan rate was 1 Hz. Dimensional analyses were performed using the “section analyses” software of the equipment. In order to observe the influence of the probe on NC integrity, regions containing several NC were initially imaged with a large scan size (20 μm). In order to look for any oil leakage, zooming-in at smaller scale (1–2 μm) was then performed on some selected NC, which were then scanned three times. Images were then zoomed-out and these NC were compared, in size and occurrence of oil leakage, with their large- scale NC neighbors. NC were also imaged 24 h after the deposition on mica in order to get information on their integrity with time before fractionation.
Mostrar mais

12 Ler mais

The PICALM protein plays a key role in iron homeostasis and cell proliferation.

The PICALM protein plays a key role in iron homeostasis and cell proliferation.

A human PICALM cDNA lacking both exon 17a [NGMHFPQY] and a portion of exon 13 [DPFSATV] was subcloned into the GFPN1 vector (Stratagene, La Jolla, CA, USA), downstream of the GFP gene. Full length PICALM and all point mutants included a hemagglutinin (HA) carboxy-terminal tag followed by a stop codon. PICALM truncation mutants were generated by PCR using oligonucleotides to introduce a 3 9 TAA stop codon without a HA tag. All infections into MEFs for rescue assays were performed using human PICALM cDNA subcloned into the bicistronic MSCV-IRES-eGFP (MIE) retroviral vector [58]. Deletion PICALM constructs expressed in the MIE vector were generated by standard PCR protocols using oligonucleotides that hybridized to the appropriate regions of PICALM with flanking XhoI (59 end) or BamHI (39 end) restriction sites and a TAA stop codon at the 39 end immediately after the indicated amino acid. All point mutations within the PICALM gene were made using the Stratagene Site Directed Mutagenesis kit (Agilent Technologies, Santa Clara, CA). The NPF mutant changed the indicated codons to encode AAA (5 9-GCGGCCGCT-39), incor- porating a NotI site within the mutation site. NAAIRS mutagenesis [34,59] was performed by replacing consecutive stretches of six amino acids with sequence encoding the amino acids NAAIRS (5 9- AATGCAGCAATAAGATCT-3 9), as well as a BglII site to facilitate screening. Primary MEFs were immortalized with the SV40 DNA tumor virus early region T/t antigen in the pBABE vector (courtesy of Dr. Corinne Linardic, Duke University).
Mostrar mais

14 Ler mais

Centralization And Decentralization In Planning

Centralization And Decentralization In Planning

Thecases in which they frequentlyusedecentralizationare: *The desire toincrease the participation ofthe populationandbecause of itsgreat importancein achieving thedecisions and policiesbe realisticandsome of the propertiesthat helpin the success ofdevelopment policiesto reachtheir goals Messahaalarge size ofpopulationandthe stateso that it cannotaddressthe centralpolicies ofeachsprawlingspaceissueswhich forces theupperbodies of theplanningmake room fordecentralizedmanagement styleandtakethe brunt ofthe most important inthe process of preparingdevelopment plans Multiplicity ofnationalities andracesas it isin such circumstancesbeuniting of interestsis not possible orfar-fetchedprocess, which requires giving
Mostrar mais

3 Ler mais

Show all 10000 documents...

temas relacionados