51
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Ruffini F, D'Atri S, Lacal PM. Neuropilin-1 expression promotes invasiveness of melanoma cells through vascular endothelial growth factor receptor-2-dependent and -independent mechanisms. Int J Oncol 2013; 43:297-306. [PMID: 23685409 DOI: 10.3892/ijo.2013.1948] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Accepted: 01/28/2013] [Indexed: 11/06/2022] Open
Abstract
The majority of human melanoma cell lines secretes vascular endothelial growth factor-A (VEGF-A) and expresses its receptors VEGFR-1, VEGFR-2 and neuropilin-1 (NRP‑1), a co-receptor for VEGF-A that amplifies the signalling through VEGFR-2. Since it is known that the VEGF-A/VEGFR-2 autocrine loop promotes melanoma cell invasiveness, the aim of the present study was to investigate the involvement of NPR-1 in melanoma progression. Syngeneic human melanoma cell lines expressing either VEGFR-2 or NRP-1, both or none of them, were analyzed for their in vitro ability to migrate, invade the extracellular matrix (ECM) and secrete active metalloproteinase-2 (MMP-2). The results indicate that NRP-1 cooperates with VEGFR-2 in melanoma cell migration induced by VEGF-A. Moreover, NRP-1 expression is sufficient to promote MMP-2 secretion and melanoma cell invasiveness, as demonstrated by the ability of cells expressing solely NRP-1 to spontaneously invade the ECM. This ability is specifically downregulated by anti-NRP-1 antibodies or by interfering with NRP-1 expression using an shRNA construct. Investigation of the signal transduction pathways triggered by NRP-1 in melanoma cells, indicated that NRP-1-dependent promotion of cell invasiveness involves Akt activation through its phosphorylation on T308. Overall, the results demonstrate that NRP-1 is involved in melanoma progression through VEGFR-2-dependent and -independent mechanisms and suggest NRP-1 as a target for the treatment of the metastatic disease.
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Affiliation(s)
- Federica Ruffini
- Laboratory of Molecular Oncology, Istituto Dermopatico dell'Immacolata-IRCCS, I-00167 Rome, Italy
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52
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Said NABM, Simpson KJ, Williams ED. Strategies and challenges for systematically mapping biologically significant molecular pathways regulating carcinoma epithelial-mesenchymal transition. Cells Tissues Organs 2013; 197:424-34. [PMID: 23774256 DOI: 10.1159/000351717] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/30/2013] [Indexed: 11/19/2022] Open
Abstract
Enormous progress has been made towards understanding the role of specific factors in the process of epithelial-mesenchymal transition (EMT); however, the complex underlying pathways and the transient nature of the transition continues to present significant challenges. Targeting tumour cell plasticity underpinning EMT is an attractive strategy to combat metastasis. Global gene expression profiling and high-content analyses are among the strategies employed to identify novel EMT regulators. In this review, we highlight several approaches to systematically interrogate key pathways involved in EMT, with particular emphasis on the features of multiparametric, high-content imaging screening strategies that lend themselves to the systematic discovery of highly significant modulators of tumour cell plasticity.
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53
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Serra V, Eichhorn PJA, García-García C, Ibrahim YH, Prudkin L, Sánchez G, Rodríguez O, Antón P, Parra JL, Marlow S, Scaltriti M, Pérez-Garcia J, Prat A, Arribas J, Hahn WC, Kim SY, Baselga J. RSK3/4 mediate resistance to PI3K pathway inhibitors in breast cancer. J Clin Invest 2013; 123:2551-63. [PMID: 23635776 DOI: 10.1172/jci66343] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 02/27/2013] [Indexed: 12/16/2022] Open
Abstract
The PI3K signaling pathway regulates diverse cellular processes, including proliferation, survival, and metabolism, and is aberrantly activated in human cancer. As such, numerous compounds targeting the PI3K pathway are currently being clinically evaluated for the treatment of cancer, and several have shown some early indications of efficacy in breast cancer. However, resistance against these agents, both de novo and acquired, may ultimately limit the efficacy of these compounds. Here, we have taken a systematic functional approach to uncovering potential mechanisms of resistance to PI3K inhibitors and have identified several genes whose expression promotes survival under conditions of PI3K/mammalian target of rapamycin (PI3K/mTOR) blockade, including the ribosomal S6 kinases RPS6KA2 (RSK3) and RPS6KA6 (RSK4). We demonstrate that overexpression of RSK3 or RSK4 supports proliferation upon PI3K inhibition both in vitro and in vivo, in part through the attenuation of the apoptotic response and upregulation of protein translation. Notably, the addition of MEK- or RSK-specific inhibitors can overcome these resistance phenotypes, both in breast cancer cell lines and patient-derived xenograft models with elevated levels of RSK activity. These observations provide a strong rationale for the combined use of RSK and PI3K pathway inhibitors to elicit favorable responses in breast cancer patients with activated RSK.
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Affiliation(s)
- Violeta Serra
- Experimental Therapeutics, Vall d'Hebron Institute of Oncology, Barcelona, Spain
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54
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Nechiporuk T, Klezovitch O, Nguyen L, Vasioukhin V. Dlg5 maintains apical aPKC and regulates progenitor differentiation during lung morphogenesis. Dev Biol 2013; 377:375-84. [PMID: 23466739 DOI: 10.1016/j.ydbio.2013.02.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 02/21/2013] [Accepted: 02/22/2013] [Indexed: 12/18/2022]
Abstract
Cell polarity plays an important role in tissue morphogenesis; however, the mechanisms of polarity and their role in mammalian development are still poorly understood. We show here that membrane-associated guanylate kinase protein Dlg5 is required for proper branching morphogenesis and progenitor differentiation in mammalian lung. We found that during lung development Dlg5 functions as an apical-basal polarity protein, which is necessary for the apical maintenance of atypical protein kinase C (aPKC). These results identify Dlg5 as a regulator of apical polarity complexes and uncover the critical function of Dlg5 in branching morphogenesis and differentiation of lung progenitor cells.
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Affiliation(s)
- Tamilla Nechiporuk
- Division of Human Biology, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, C3-168, Seattle, WA 98109, USA.
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55
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On the role of PDZ domain-encoding genes in Drosophila border cell migration. G3-GENES GENOMES GENETICS 2012; 2:1379-91. [PMID: 23173089 PMCID: PMC3484668 DOI: 10.1534/g3.112.004093] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Accepted: 09/10/2012] [Indexed: 12/31/2022]
Abstract
Cells often move as collective groups during normal embryonic development and wound healing, although the mechanisms governing this type of migration are poorly understood. The Drosophila melanogaster border cells migrate as a cluster during late oogenesis and serve as a powerful in vivo genetic model for collective cell migration. To discover new genes that participate in border cell migration, 64 out of 66 genes that encode PDZ domain-containing proteins were systematically targeted by in vivo RNAi knockdown. The PDZ domain is one of the largest families of protein-protein interaction domains found in eukaryotes. Proteins that contain PDZ domains participate in a variety of biological processes, including signal transduction and establishment of epithelial apical-basal polarity. Targeting PDZ proteins effectively assesses a larger number of genes via the protein complexes and pathways through which these proteins function. par-6, a known regulator of border cell migration, was a positive hit and thus validated the approach. Knockdown of 14 PDZ domain genes disrupted migration with multiple RNAi lines. The candidate genes have diverse predicted cellular functions and are anticipated to provide new insights into the mechanisms that control border cell movement. As a test of this concept, two genes that disrupted migration were characterized in more detail: big bang and the Dlg5 homolog CG6509. We present evidence that Big bang regulates JAK/STAT signaling, whereas Dlg5/CG6509 maintains cluster cohesion. Moreover, these results demonstrate that targeting a selected class of genes by RNAi can uncover novel regulators of collective cell migration.
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56
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Hance MW, Dole K, Gopal U, Bohonowych JE, Jezierska-Drutel A, Neumann CA, Liu H, Garraway IP, Isaacs JS. Secreted Hsp90 is a novel regulator of the epithelial to mesenchymal transition (EMT) in prostate cancer. J Biol Chem 2012; 287:37732-44. [PMID: 22989880 DOI: 10.1074/jbc.m112.389015] [Citation(s) in RCA: 111] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Prostate cancer (PCa) is the most frequently diagnosed malignancy in men, and the second highest contributor of male cancer related lethality. Disease mortality is due primarily to metastatic spread, highlighting the urgent need to identify factors involved in this progression. Activation of the genetic epithelial to mesenchymal transition (EMT) program is implicated as a major contributor of PCa progression. Initiation of EMT confers invasive and metastatic behavior in preclinical models and is correlated with poor clinical prognosis. Extracellular Hsp90 (eHsp90) promotes cell motility and invasion in cancer cells and metastasis in preclinical models, however, the mechanistic basis for its widespread tumorigenic function remains unclear. We have identified a novel and pivotal role for eHsp90 in driving EMT events in PCa. In support of this notion, more metastatic PCa lines exhibited increased eHsp90 expression relative to their lineage-related nonmetastatic counterparts. We demonstrate that eHsp90 promoted cell motility in an ERK and matrix metalloproteinase-2/9-dependent manner, and shifted cellular morphology toward a mesenchymal phenotype. Conversely, inhibition of eHsp90 attenuated pro-motility signaling, blocked PCa migration, and shifted cell morphology toward an epithelial phenotype. Last, we report that surface eHsp90 was found in primary PCa tumor specimens, and elevated eHsp90 expression was associated with increased levels of matrix metalloproteinase-2/9 transcripts. We conclude that eHsp90 serves as a driver of EMT events, providing a mechanistic basis for its ability to promote cancer progression and metastasis in preclinical models. Furthermore, its newly identified expression in PCa specimens, and potential regulation of pro-metastatic genes, supports a putative clinical role for eHsp90 in PCa progression.
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Affiliation(s)
- Michael W Hance
- Department of Cell, Medical University of South Carolina, Charleston, South Carolina 29425, USA
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57
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Optimized PCR conditions and increased shRNA fold representation improve reproducibility of pooled shRNA screens. PLoS One 2012; 7:e42341. [PMID: 22870320 PMCID: PMC3411659 DOI: 10.1371/journal.pone.0042341] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 07/03/2012] [Indexed: 12/22/2022] Open
Abstract
RNAi screening using pooled shRNA libraries is a valuable tool for identifying genetic regulators of biological processes. However, for a successful pooled shRNA screen, it is imperative to thoroughly optimize experimental conditions to obtain reproducible data. Here we performed viability screens with a library of ∼10,000 shRNAs at two different fold representations (100- and 500-fold at transduction) and report the reproducibility of shRNA abundance changes between screening replicates determined by microarray and next generation sequencing analyses. We show that the technical reproducibility between PCR replicates from a pooled screen can be drastically improved by ensuring that PCR amplification steps are kept within the exponential phase and by using an amount of genomic DNA input in the reaction that maintains the average template copies per shRNA used during library transduction. Using these optimized PCR conditions, we then show that higher reproducibility of biological replicates is obtained by both microarray and next generation sequencing when screening with higher average shRNA fold representation. shRNAs that change abundance reproducibly in biological replicates (primary hits) are identified from screens performed with both 100- and 500-fold shRNA representation, however a higher percentage of primary hit overlap between screening replicates is obtained from 500-fold shRNA representation screens. While strong hits with larger changes in relative abundance were generally identified in both screens, hits with smaller changes were identified only in the screens performed with the higher shRNA fold representation at transduction.
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58
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Loerke D, le Duc Q, Blonk I, Kerstens A, Spanjaard E, Machacek M, Danuser G, de Rooij J. Quantitative imaging of epithelial cell scattering identifies specific inhibitors of cell motility and cell-cell dissociation. Sci Signal 2012; 5:rs5. [PMID: 22763340 DOI: 10.1126/scisignal.2002677] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The scattering of cultured epithelial cells in response to hepatocyte growth factor (HGF) is a model system that recapitulates key features of metastatic cell behavior in vitro, including disruption of cell-cell adhesions and induction of cell migration. We have developed image analysis tools that do not require fluorescence tagging and that automatically track and characterize three aspects of scattering in live cells: increase in cell motility, loss of cell-cell adhesion, and spatial dispersion of cells (the redistribution of cells during scattering). We used these tools to screen a library of drugs, and we identified several efficient inhibitors of scattering, which we classified as selective inhibitors of either motility or loss of cell-cell adhesion, or as nonselective inhibitors. We validated the inhibitors and putative targets from this screen in two unrelated model cell lines. Using pharmacological treatments and RNA interference (RNAi), we found that nonsteroidal anti-inflammatory drugs inhibited cell-cell dissociation, that indirubins inhibited cell motility, and that cyclin-dependent kinase 1 and ribosomal S6 kinase were signaling intermediates in HGF-induced cell scattering. This assay is suitable for larger-scale screenings of chemical compounds or RNAi libraries.
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Affiliation(s)
- Dinah Loerke
- Department of Cell Biology, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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59
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Faure E, Garrouste F, Parat F, Monferran S, Leloup L, Pommier G, Kovacic H, Lehmann M. P2Y2 receptor inhibits EGF-induced MAPK pathway to stabilise keratinocyte hemidesmosomes. J Cell Sci 2012; 125:4264-77. [PMID: 22718344 DOI: 10.1242/jcs.097600] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
α6β4 integrin is the main component of hemidesmosomes (HD) that stably anchor the epithelium to the underlying basement membrane. Epithelial cell migration requires HD remodelling, which can be promoted by epidermal growth factor (EGF). We previously showed that extracellular nucleotides inhibit growth factor-induced keratinocyte migration. Here, we investigate the effect of extracellular nucleotides on α6β4 integrin localisation in HD during EGF-induced cell migration. Using a combination of pharmacological inhibition and gene silencing approaches, we found that UTP activates the P2Y2 purinergic receptor and Gαq protein to inhibit EGF/ERK1/2-induced cell migration in keratinocytes. Using a keratinocyte cell line expressing an inducible form of the Raf kinase, we show that UTP inhibits the EGF-induced ERK1/2 pathway activation downstream of Raf. Moreover, we established that ERK1/2 activation by EGF leads to the mobilisation of α6β4 integrin from HD. Importantly, activation of P2Y2R and Gαq by UTP promotes HD formation and protects these structures from EGF-triggered dissolution as revealed by confocal analysis of the distribution of α6β4 integrin, plectin, BPAG1, BPAG2 and CD151 in keratinocytes. Finally, we demonstrated that the activation of p90RSK, downstream of ERK1/2, is sufficient to promote EGF-mediated HD dismantling and that UTP does not stabilise HD in cells expressing an activated form of p90RSK. Our data underline an unexpected role of P2Y2R and Gαq in the inhibition of the ERK1/2 signalling pathway and in the modulation of hemidesmosome dynamics and keratinocyte migration.
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Affiliation(s)
- Emilie Faure
- Aix-Marseille Université, INSERM UMR 911, Centre de Recherche en Oncologie Biologique et en Oncopharmacologie, Marseille 13005, France
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60
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Sezaki T, Inada K, Sogabe T, Kakuda K, Tomiyama L, Matsuno Y, Ichikawa T, Matsuo M, Ueda K, Kioka N. Role of Dlg5/lp-dlg, a membrane-associated guanylate kinase family protein, in epithelial-mesenchymal transition in LLc-PK1 renal epithelial cells. PLoS One 2012; 7:e35519. [PMID: 22539977 PMCID: PMC3335148 DOI: 10.1371/journal.pone.0035519] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 03/17/2012] [Indexed: 01/10/2023] Open
Abstract
Discs large homolog 5 (Dlg5) is a member of the membrane-associated guanylate kinase adaptor family of proteins, some of which are involved in the regulation of epithelial-to-mesenchymal transition (EMT). Dlg5 has been described as a susceptibility gene for Crohn's disease; however, the physiological function of Dlg5 is unknown. We show here that transforming growth factor-β (TGF-β)-induced EMT suppresses Dlg5 expression in LLc-PK1 cells. Depletion of Dlg5 expression by knockdown promoted the expression of the mesenchymal marker proteins, fibronectin and α-smooth muscle actin, and suppressed the expression of E-cadherin. In addition, activation of JNK and p38, which are stimulated by TGF-β, was enhanced by Dlg5 depletion. Furthermore, inhibition of the TGF-β receptor suppressed the effects of Dlg5 depletion. These observations suggest that Dlg5 is involved in the regulation of TGF-βreceptor-dependent signals and EMT.
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Affiliation(s)
- Takuhito Sezaki
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Kohki Inada
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Takayuki Sogabe
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Kumiyo Kakuda
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Lucia Tomiyama
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Yohsuke Matsuno
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Takafumi Ichikawa
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Michinori Matsuo
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
| | - Kazumitsu Ueda
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Sakyo, Kyoto, Japan
| | - Noriyuki Kioka
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan
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61
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Reversible targeting of noncatalytic cysteines with chemically tuned electrophiles. Nat Chem Biol 2012; 8:471-6. [PMID: 22466421 PMCID: PMC3657615 DOI: 10.1038/nchembio.925] [Citation(s) in RCA: 362] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 02/02/2012] [Indexed: 01/29/2023]
Abstract
Targeting noncatalytic cysteine residues with irreversible acrylamide-based inhibitors is a powerful approach for enhancing pharmacological potency and selectivity. Nevertheless, concerns about off-target modification motivate the development of reversible cysteine-targeting strategies. Here we show that electron-deficient olefins, including acrylamides, can be tuned to react with cysteine thiols in a rapidly reversible manner. Installation of a nitrile group increased the olefins’ intrinsic reactivity, yet paradoxically eliminated the formation of irreversible adducts. Incorporation of these electrophiles into a noncovalent kinase recognition scaffold produced slowly dissociating, covalent inhibitors of the p90 ribosomal protein S6 kinase, RSK. A cocrystal structure revealed specific noncovalent interactions that stabilize the complex by positioning the electrophilic carbon near the targeted cysteine. Disruption of these interactions by protein unfolding or proteolysis promoted instantaneous cleavage of the covalent bond. Our results establish a chemistry-based framework for engineering sustained covalent inhibition without accumulating permanently modified proteins and peptides.
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62
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Hilinski MK, Mrozowski RM, Clark DE, Lannigan DA. Analogs of the RSK inhibitor SL0101: optimization of in vitro biological stability. Bioorg Med Chem Lett 2012; 22:3244-7. [PMID: 22464132 DOI: 10.1016/j.bmcl.2012.03.033] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Revised: 03/05/2012] [Accepted: 03/07/2012] [Indexed: 01/09/2023]
Abstract
The Ser/Thr protein kinase, RSK, is important in the etiology of tumor progression including invasion and motility. The natural product kaempferol-3-O-(3″,4″-di-O-acetyl-α-l-rhamnopyranoside), called SL0101, is a highly specific RSK inhibitor. Acylation of the rhamnose moiety is necessary for high affinity binding and selectivity. However, the acetyl groups can be cleaved by esterases, which accounts for the poor in vitro biological stability of SL0101. To address this problem a series of analogs containing acetyl group replacements were synthesized and their in vitro stability evaluated. Monosubstituted carbamate analogs of SL0101 showed improved in vitro biological stability while maintaining specificity for RSK. These results should facilitate the development of RSK inhibitors derived from SL0101 as anticancer agents.
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Affiliation(s)
- Michael K Hilinski
- Center for Cell Signaling, University of Virginia, Charlottesville, VA 22908, USA.
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63
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Abstract
The RSK (90 kDa ribosomal S6 kinase) family comprises a group of highly related serine/threonine kinases that regulate diverse cellular processes, including cell growth, proliferation, survival and motility. This family includes four vertebrate isoforms (RSK1, RSK2, RSK3 and RSK4), and single family member orthologues are also present in Drosophila and Caenorhabditis elegans. The RSK isoforms are downstream effectors of the Ras/ERK (extracellular-signal-regulated kinase) signalling pathway. Significant advances in the field of RSK signalling have occurred in the past few years, including several new functions ascribed to the RSK isoforms, the discovery of novel protein substrates and the implication of different RSK isoforms in cancer. Collectively, these new findings increase the diversity of biological functions regulated by RSK, and highlight potential new directions of research. In the present paper, we review the structure, expression and activation mechanisms of the RSK isoforms, and discuss their physiological roles on the basis of established substrates and recent discoveries.
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64
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Abstract
The discovery of RNA interference (RNAi) and the development of technologies exploiting its biology have enabled scientists to rapidly examine the consequences of depleting a particular gene product in a cell or an animal. The availability of genome-wide RNAi libraries targeting the mouse and human genomes has made it possible to carry out large scale, phenotype-based screens, which have yielded seminal information on diverse cellular processes ranging from virology to cancer biology. Today, several strategies are available to perform RNAi screens, each with their own technical and monetary considerations. Special care and budgeting must be taken into account during the design of these screens in order to obtain reliable results. In this review, we discuss a number of critical aspects to consider when planning an effective RNAi screening strategy, including selecting the right biological system, designing an appropriate selection scheme, optimizing technical aspects of the screen, and validating and verifying the hits. Similar to an artistic production, what happens behind the screen has a direct impact on its success.
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Affiliation(s)
- Eric Campeau
- Translational Biology Group, Calgary, AB, Canada.
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65
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Hu G, Luo J. A primer on using pooled shRNA libraries for functional genomic screens. Acta Biochim Biophys Sin (Shanghai) 2012; 44:103-12. [PMID: 22271906 DOI: 10.1093/abbs/gmr116] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The discovery of RNA interference (RNAi) has revolutionized genetic analysis in mammalian cells. Loss-of-function RNAi screens enable rapid, functional annotation of the genome. Of the various RNAi approaches, pooled shRNA libraries have received considerable attention because of their versatility. A number of genome-wide shRNA libraries have been constructed against the human and mouse genomes, and these libraries can be readily applied to a variety of screens to interrogate the function of human and mouse genes in an unbiased fashion. We provide an introduction to the technical aspects of using pooled shRNA libraries for genetic screens.
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Affiliation(s)
- Guang Hu
- Laboratory of Molecular Carcinogenesis, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709, USA.
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66
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Simpson KJ, Davis GM, Boag PR. Comparative high-throughput RNAi screening methodologies in C. elegans and mammalian cells. N Biotechnol 2012; 29:459-70. [PMID: 22306616 DOI: 10.1016/j.nbt.2012.01.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 01/16/2012] [Accepted: 01/18/2012] [Indexed: 01/05/2023]
Abstract
The discovery of RNAi in Caenorhabditis elegans has generated a paradigm shift in how research is performed. Targeted gene knockdown using high throughput screening approaches is becoming a routine feature of the scientific landscape, and researchers can now evaluate the function of each gene in the genome in a relatively short period of time. This review compares and contrasts high throughput screening methodologies in C. elegans and mammalian cells and highlights the breadth of applications of this technology.
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Affiliation(s)
- Kaylene J Simpson
- Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, Australia.
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67
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Jongsma M, Matas-Rico E, Rzadkowski A, Jalink K, Moolenaar WH. LPA is a chemorepellent for B16 melanoma cells: action through the cAMP-elevating LPA5 receptor. PLoS One 2011; 6:e29260. [PMID: 22195035 PMCID: PMC3237609 DOI: 10.1371/journal.pone.0029260] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 11/23/2011] [Indexed: 01/08/2023] Open
Abstract
Lysophosphatidic acid (LPA), a lipid mediator enriched in serum, stimulates cell migration, proliferation and other functions in many cell types. LPA acts on six known G protein-coupled receptors, termed LPA1–6, showing both overlapping and distinct signaling properties. Here we show that, unexpectedly, LPA and serum almost completely inhibit the transwell migration of B16 melanoma cells, with alkyl-LPA(18∶1) being 10-fold more potent than acyl-LPA(18∶1). The anti-migratory response to LPA is highly polarized and dependent on protein kinase A (PKA) but not Rho kinase activity; it is associated with a rapid increase in intracellular cAMP levels and PIP3 depletion from the plasma membrane. B16 cells express LPA2, LPA5 and LPA6 receptors. We show that LPA-induced chemorepulsion is mediated specifically by the alkyl-LPA-preferring LPA5 receptor (GPR92), which raises intracellular cAMP via a noncanonical pathway. Our results define LPA5 as an anti-migratory receptor and they implicate the cAMP-PKA pathway, along with reduced PIP3 signaling, as an effector of chemorepulsion in B16 melanoma cells.
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Affiliation(s)
- Maikel Jongsma
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Elisa Matas-Rico
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Adrian Rzadkowski
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Kees Jalink
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Wouter H. Moolenaar
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
- * E-mail:
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68
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Boehm JS, Hahn WC. Towards systematic functional characterization of cancer genomes. Nat Rev Genet 2011; 12:487-98. [PMID: 21681210 DOI: 10.1038/nrg3013] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Whole-genome approaches to identify genetic and epigenetic alterations in cancer genomes have begun to provide new insights into the range of molecular events that occurs in human tumours. Although in some cases this knowledge immediately illuminates a path towards diagnostic or therapeutic implementation, the bewildering lists of mutations in each tumour make it clear that systematic functional approaches are also necessary to obtain a comprehensive molecular understanding of cancer. Here we review the current range of methods, assays and approaches for genome-scale interrogation of gene function in cancer. We also discuss the integration of functional-genomics approaches with the outputs from cancer genome sequencing efforts.
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Affiliation(s)
- Jesse S Boehm
- Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, Massachusetts 02142, USA
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69
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Gallic acid indanone and mangiferin xanthone are strong determinants of immunosuppressive anti-tumour effects of Mangifera indica L. bark in MDA-MB231 breast cancer cells. Cancer Lett 2011; 305:21-31. [DOI: 10.1016/j.canlet.2011.02.011] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Revised: 02/12/2011] [Accepted: 02/15/2011] [Indexed: 11/18/2022]
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70
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Ma Q, Guin S, Padhye SS, Zhou YQ, Zhang RW, Wang MH. Ribosomal protein S6 kinase (RSK)-2 as a central effector molecule in RON receptor tyrosine kinase mediated epithelial to mesenchymal transition induced by macrophage-stimulating protein. Mol Cancer 2011; 10:66. [PMID: 21619683 PMCID: PMC3117816 DOI: 10.1186/1476-4598-10-66] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 05/28/2011] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Epithelial to mesenchymal transition (EMT) occurs during cancer cell invasion and malignant metastasis. Features of EMT include spindle-like cell morphology, loss of epithelial cellular markers and gain of mesenchymal phenotype. Activation of the RON receptor tyrosine kinase by macrophage-stimulating protein (MSP) has been implicated in cellular EMT program; however, the major signaling determinant(s) responsible for MSP-induced EMT is unknown. RESULTS The study presented here demonstrates that RSK2, a downstream signaling protein of the Ras-Erk1/2 pathway, is the principal molecule that links MSP-activated RON signaling to complete EMT. Using MDCK cells expressing RON as a model, a spindle-shape based screen was conducted, which identifies RSK2 among various intracellular proteins as a potential signaling molecule responsible for MSP-induced EMT. MSP stimulation dissociated RSK2 with Erk1/2 and promoted RSK2 nuclear translocation. MSP strongly induced RSK2 phosphorylation in a dose-dependent manner. These effects relied on RON and Erk1/2 phosphorylation, which is significantly potentiated by transforming growth factor (TGF)-β1, an EMT-inducing cytokine. Specific RSK inhibitor SL0101 completely prevented MSP-induced RSK phosphorylation, which results in inhibition of MSP-induced spindle-like morphology and suppression of cell migration associated with EMT. In HT-29 cancer cells that barely express RSK2, forced RSK2 expression results in EMT-like phenotype upon MSP stimulation. Moreover, specific siRNA-mediated silencing of RSK2 but not RSK1 in L3.6pl pancreatic cancer cells significantly inhibited MSP-induced EMT-like phenotype and cell migration. CONCLUSIONS MSP-induced RSK2 activation is a critical determinant linking RON signaling to cellular EMT program. Inhibition of RSK2 activity may provide a therapeutic opportunity for blocking RON-mediated cancer cell migration and subsequent invasion.
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Affiliation(s)
- Qi Ma
- Division of Cancer Biology at State Key Laboratory for Diagnosis & Treatment of Infectious Diseases, First Affiliated Hospital, Zhejiang University College of Medicine, Hangzhou 310003, China
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Dropulić B. Lentiviral vectors: their molecular design, safety, and use in laboratory and preclinical research. Hum Gene Ther 2011; 22:649-57. [PMID: 21486177 DOI: 10.1089/hum.2011.058] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Lentiviral vectors have been successfully used in the clinic and they are increasingly being used for nonclinical applications. They are capable of stably transducing a broad range of mammalian cell types, including nondividing cells, with high efficiency. This review summarizes the evolving molecular design of lentiviral vectors, describing how they have improved since their first description. Lentiviral vector safety and issues surrounding genotoxicity are discussed. Examples of successful application of lentiviral vectors in laboratory and preclinical research are described. These include functional genomics, target validation, protein manufacturing, in vivo imaging, transgenic animals, and stem cell research.
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Lu W, Liu X, Cao X, Xue M, Liu K, Zhao Z, Shen X, Jiang H, Xu Y, Huang J, Li H. SHAFTS: A Hybrid Approach for 3D Molecular Similarity Calculation. 2. Prospective Case Study in the Discovery of Diverse p90 Ribosomal S6 Protein Kinase 2 Inhibitors To Suppress Cell Migration. J Med Chem 2011; 54:3564-74. [DOI: 10.1021/jm200139j] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Weiqiang Lu
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Xiaofeng Liu
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Xianwen Cao
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Mengzhu Xue
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Kangdong Liu
- The Basic Medical College, Zhengzhou University, Zhengzhou 450001, China
| | - Zhenjiang Zhao
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Xu Shen
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Hualiang Jiang
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Yufang Xu
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Jin Huang
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
| | - Honglin Li
- State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology, Shanghai 200237, China
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