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Sers C, Schäfer R. Silencing effects of mutant RAS signalling on transcriptomes. Adv Biol Regul 2023; 87:100936. [PMID: 36513579 DOI: 10.1016/j.jbior.2022.100936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Accepted: 11/23/2022] [Indexed: 11/30/2022]
Abstract
Mutated genes of the RAS family encoding small GTP-binding proteins drive numerous cancers, including pancreatic, colon and lung tumors. Besides the numerous effects of mutant RAS gene expression on aberrant proliferation, transformed phenotypes, metabolism, and therapy resistance, the most striking consequences of chronic RAS activation are changes of the genetic program. By performing systematic gene expression studies in cellular models that allow comparisons of pre-neoplastic with RAS-transformed cells, we and others have estimated that 7 percent or more of all transcripts are altered in conjunction with the expression of the oncogene. In this context, the number of up-regulated transcripts approximates that of down-regulated transcripts. While up-regulated transcription factors such as MYC, FOSL1, and HMGA2 have been identified and characterized as RAS-responsive drivers of the altered transcriptome, the suppressed factors have been less well studied as potential regulators of the genetic program and transformed phenotype in the breadth of their occurrence. We therefore have collected information on downregulated RAS-responsive factors and discuss their potential role as tumor suppressors that are likely to antagonize active cancer drivers. To better understand the active mechanisms that entail anti-RAS function and those that lead to loss of tumor suppressor activity, we focus on the tumor suppressor HREV107 (alias PLAAT3 [Phospholipase A and acyltransferase 3], PLA2G16 [Phospholipase A2, group XVI] and HRASLS3 [HRAS-like suppressor 3]). Inactivating HREV107 mutations in tumors are extremely rare, hence epigenetic causes modulated by the RAS pathway are likely to lead to down-regulation and loss of function.
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Affiliation(s)
- Christine Sers
- Laboratory of Molecular Tumor Pathology and systems Biology, Institute of Pathology, Charité Universitätstmedizin Berlin, Charitéplatz 1, D-10117 Berlin, Germany; German Cancer Consortium, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120, Heidelberg, Germany
| | - Reinhold Schäfer
- Comprehensive Cancer Center, Charité Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany; German Cancer Consortium, German Cancer Research Center, Im Neuenheimer Feld 280, D-69120, Heidelberg, Germany.
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2
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Kuhn N, Klinger B, Uhlitz F, Sieber A, Rivera M, Klotz-Noack K, Fichtner I, Hoffmann J, Blüthgen N, Falk C, Sers C, Schäfer R. Mutation-specific effects of NRAS oncogenes in colorectal cancer cells. Adv Biol Regul 2020; 79:100778. [PMID: 33431353 DOI: 10.1016/j.jbior.2020.100778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 12/21/2020] [Indexed: 11/16/2022]
Abstract
In colorectal cancer (CRC), the prevalence of NRAS mutations (5-9%) is inferior to that of KRAS mutations (40-50%). NRAS mutations feature lately during tumour progression and drive resistance to anti-EGFR therapy in KRAS wild-type tumours. To elucidate specific functions of NRAS mutations in CRC, we expressed doxycycline-inducible G12D and Q61K mutations in the CRC cell line Caco-2. A focused phospho-proteome analysis based on the Bio-Plex platform, which interrogated the activity of MAPK, PI3K, mTOR, STAT, p38, JNK and ATF2, did not reveal significant differences between Caco-2 cells expressing NRASG12D, NRASQ61K and KRASG12V. However, phenotypic read-outs were different. The NRAS Q61K mutation promoted anchorage-independent proliferation and tumorigenicity, similar to features driven by canonical KRAS mutations. In contrast, expression of NRASG12D resulted in reduced proliferation and apoptosis. At the transcriptome level, we saw upregulation of cytokines and chemokines. IL1A, IL11, CXCL8 (IL-8) and CCL20 exhibited enhanced secretion into the culture medium. In addition, RNA sequencing results indicated activation of the IL1-, JAK/STAT-, NFκB- and TNFα signalling pathways. These results form the basis for an NRASG12D-driven inflammatory phenotype in CRC.
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Affiliation(s)
- Natalia Kuhn
- Laboratory of Molecular Tumor Pathology and Cancer Systems Biology, Institute of Pathology, Charité Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany
| | - Bertram Klinger
- Laboratory of Molecular Tumor Pathology and Cancer Systems Biology, Institute of Pathology, Charité Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany; Integrative Research Institute Life Sciences, Humboldt University Berlin, Philippstraße 13, Building 18, D-10115, Berlin, Germany
| | - Florian Uhlitz
- Laboratory of Molecular Tumor Pathology and Cancer Systems Biology, Institute of Pathology, Charité Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany; Integrative Research Institute Life Sciences, Humboldt University Berlin, Philippstraße 13, Building 18, D-10115, Berlin, Germany
| | - Anja Sieber
- Laboratory of Molecular Tumor Pathology and Cancer Systems Biology, Institute of Pathology, Charité Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany; Integrative Research Institute Life Sciences, Humboldt University Berlin, Philippstraße 13, Building 18, D-10115, Berlin, Germany
| | - Maria Rivera
- Experimental Pharmacology and Oncology GmbH, Berlin-Buch, Robert-Rössle-Str. 10, D-13125, Berlin, Buch, Germany
| | - Kathleen Klotz-Noack
- Laboratory of Molecular Tumor Pathology and Cancer Systems Biology, Institute of Pathology, Charité Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany
| | - Iduna Fichtner
- Experimental Pharmacology and Oncology GmbH, Berlin-Buch, Robert-Rössle-Str. 10, D-13125, Berlin, Buch, Germany
| | - Jens Hoffmann
- Experimental Pharmacology and Oncology GmbH, Berlin-Buch, Robert-Rössle-Str. 10, D-13125, Berlin, Buch, Germany
| | - Nils Blüthgen
- Laboratory of Molecular Tumor Pathology and Cancer Systems Biology, Institute of Pathology, Charité Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany; Integrative Research Institute Life Sciences, Humboldt University Berlin, Philippstraße 13, Building 18, D-10115, Berlin, Germany
| | - Christine Falk
- Institute of Transplant Immunology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625, Hannover, Germany
| | - Christine Sers
- Laboratory of Molecular Tumor Pathology and Cancer Systems Biology, Institute of Pathology, Charité Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany; German Cancer Consortium (DKTK), German Cancer Research Center, Im Neuenheimer Feld 280, D-69120, Heidelberg, Germany.
| | - Reinhold Schäfer
- Laboratory of Molecular Tumor Pathology and Cancer Systems Biology, Institute of Pathology, Charité Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany; German Cancer Consortium (DKTK), German Cancer Research Center, Im Neuenheimer Feld 280, D-69120, Heidelberg, Germany; Comprehensive Cancer Center, Charité Universitätsmedizin Berlin, Charitéplatz 1, D-10117, Berlin, Germany.
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3
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Latorre E, Ostler EL, Faragher RGA, Harries LW. FOXO1 and ETV6 genes may represent novel regulators of splicing factor expression in cellular senescence. FASEB J 2019; 33:1086-1097. [PMID: 30088951 DOI: 10.1096/fj.201801154r] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Cellular plasticity is a key facet of cellular homeostasis requiring correct temporal and spatial patterns of alternative splicing. Splicing factors, which orchestrate this process, demonstrate age-related dysregulation of expression; they are emerging as potential influences on aging and longevity. The upstream drivers of these alterations are still unclear but may involve aberrant cellular signaling. We compared the phosphorylation status of proteins in multiple signaling pathways in early and late passage human primary fibroblasts. We then assessed the impact of chemical inhibition or targeted knockdown of direct downstream targets of the ERK and AKT pathways on splicing factor expression, cellular senescence, and proliferation kinetics in senescent primary human fibroblasts. Components of the ERK and AKT signaling pathways demonstrated altered activation during cellular aging. Inhibition of AKT and ERK pathways led to up-regulation of splicing factor expression, reduction in senescent cell load, and partial reversal of multiple cellular senescence phenotypes in a dose-dependent manner. Furthermore, targeted knockdown of the genes encoding the downstream targets FOXO1 or ETV6 was sufficient to mimic these observations. Our results suggest that age-associated dysregulation of splicing factor expression and cellular senescence may derive in part from altered activity of ERK and AKT signaling and may act in part through the ETV6 and FOXO1 transcription factors. Targeting the activity of downstream effectors of ERK and AKT may therefore represent promising targets for future therapeutic intervention.-Latorre, E., Ostler, E. L., Faragher, R. G. A., Harries, L. W. FOXO1 and ETV6 genes may represent novel regulators of splicing factor expression in cellular senescence.
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Affiliation(s)
- Eva Latorre
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Devon, United Kingdom; and
| | - Elizabeth L Ostler
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, United Kingdom
| | - Richard G A Faragher
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, United Kingdom
| | - Lorna W Harries
- Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, University of Exeter, Devon, United Kingdom; and
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Oláh G, Módis K, Törö G, Hellmich MR, Szczesny B, Szabo C. Role of endogenous and exogenous nitric oxide, carbon monoxide and hydrogen sulfide in HCT116 colon cancer cell proliferation. Biochem Pharmacol 2018; 149:186-204. [PMID: 29074106 PMCID: PMC5866187 DOI: 10.1016/j.bcp.2017.10.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 10/20/2017] [Indexed: 02/06/2023]
Abstract
The role of the three gasotransmitter systems - nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) - in cancer cells has not yet been studied simultaneously in the same experimental system. We measured the expression of NO and CO and H2S generating enzymes in primary colon cancer tissues and HCT116 colon cancer cells, and evaluated the effect of their pharmacological inhibition or pharmacological donation on cell proliferation. Increased expression of iNOS, nNOS, HO-1, CBS and 3-MST was detected in colon cancer. Inhibitors of NOS, HO-1/2, CBS/CSE and 3-MST, at lower concentrations, slightly stimulated HCT116 cell proliferation, but inhibited proliferation at higher concentrations. Donors of NO, CO or H2S inhibited HCT116 proliferation in a concentration-dependent manner. Inhibition of the cGMP/VASP pathway, Akt and p44/42 MAPK (Erk1/2) inhibited HCT116 cell proliferation. Endogenous NO and H2S biosynthesis were found to play a role in the maintenance of the activity of the cGMP/VASP pathway in HCT116 cells. We conclude that each of the three gasotransmitters play similar, bell-shaped roles in the control of HCT116 cell proliferation: endogenously produced NO, CO and H2S, at an optimal concentration, support HCT116 proliferation; inhibition of their production (which decreases gasotransmitter levels below optimal concentrations) as well as exogenous delivery of these gasotransmitters (which increases gasotransmitter levels above optimal concentrations) suppresses colon cancer cell proliferation. The current data give a mechanistic explanation for the paradoxical finding that both inhibitors and donors of NO, CO and H2S exert anticancer actions in cancer cells.
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Affiliation(s)
- Gabor Oláh
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Katalin Módis
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA; Department of Surgery, University of Texas Medical Branch, Galveston, TX, USA
| | - Gabor Törö
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Mark R Hellmich
- Department of Surgery, University of Texas Medical Branch, Galveston, TX, USA
| | - Bartosz Szczesny
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA
| | - Csaba Szabo
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, USA.
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Győrffy B, Stelniec-Klotz I, Sigler C, Kasack K, Redmer T, Qian Y, Schäfer R. Effects of RAL signal transduction in KRAS- and BRAF-mutated cells and prognostic potential of the RAL signature in colorectal cancer. Oncotarget 2016; 6:13334-46. [PMID: 26033452 PMCID: PMC4537018 DOI: 10.18632/oncotarget.3871] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 04/02/2015] [Indexed: 01/16/2023] Open
Abstract
Our understanding of oncogenic signaling pathways has strongly fostered current concepts for targeted therapies in metastatic colorectal cancer. The RALA pathway is novel candidate due to its independent role in controlling expression of genes downstream of RAS. We compared RALA GTPase activities in three colorectal cancer cell lines by GTPase pull-down assay and analyzed the transcriptional and phenotypic effects of transient RALA silencing. Knocking-down RALA expression strongly diminished the active GTP-bound form of the protein. Proliferation of KRAS mutated cell lines was significantly reduced, while BRAF mutated cells were mostly unaffected. By microarray analysis we identified common genes showing altered expression upon RALA silencing in all cell lines. None of these genes were affected when the RAF/MAPK or PI3K pathways were blocked. To investigate the potential clinical relevance of the RALA pathway and its associated transcriptome, we performed a meta-analysis interrogating progression-free survival of colorectal cancer patients of five independent data sets using Cox regression. In each dataset, the RALA-responsive signature correlated with worse outcome. In summary, we uncovered the impact of the RAL signal transduction on genetic program and growth control in KRAS- and BRAF-mutated colorectal cells and demonstrated prognostic potential of the pathway-responsive gene signature in cancer patients.
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Affiliation(s)
- Balázs Győrffy
- MTA TTK Lendület Cancer Biomarker Research Group, Budapest, Hungary.,Semmelweis University, 2nd Department of Pediatrics, Budapest, Hungary.,MTA-SE Pediatrics and Nephrology Research Group, Budapest, Hungary
| | - Iwona Stelniec-Klotz
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany
| | - Christian Sigler
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany
| | - Katharina Kasack
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany.,German Cancer Consortium (DKTK), German Cancer Research Center, Heidelberg, Germany
| | - Torben Redmer
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany.,German Cancer Consortium (DKTK), German Cancer Research Center, Heidelberg, Germany
| | - Yu Qian
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany
| | - Reinhold Schäfer
- Laboratories of Functional Genomics and Molecular Tumor Pathology, Charité Universitätsmedizin Berlin, Germany.,German Cancer Consortium (DKTK), German Cancer Research Center, Heidelberg, Germany
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Novel cancer chemotherapy hits by molecular topology: dual Akt and Beta-catenin inhibitors. PLoS One 2015; 10:e0124244. [PMID: 25910265 PMCID: PMC4409212 DOI: 10.1371/journal.pone.0124244] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 02/27/2015] [Indexed: 01/12/2023] Open
Abstract
Background and Purpose Colorectal and prostate cancers are two of the most common types and cause of a high rate of deaths worldwide. Therefore, any strategy to stop or at least slacken the development and progression of malignant cells is an important therapeutic choice. The aim of the present work is the identification of novel cancer chemotherapy agents. Nowadays, many different drug discovery approaches are available, but this paper focuses on Molecular Topology, which has already demonstrated its extraordinary efficacy in this field, particularly in the identification of new hit and lead compounds against cancer. This methodology uses the graph theoretical formalism to numerically characterize molecular structures through the so called topological indices. Once obtained a specific framework, it allows the construction of complex mathematical models that can be used to predict physical, chemical or biological properties of compounds. In addition, Molecular Topology is highly efficient in selecting and designing new hit and lead drugs. According to the aforementioned, Molecular Topology has been applied here for the construction of specific Akt/mTOR and β-catenin inhibition mathematical models in order to identify and select novel antitumor agents. Experimental Approach Based on the results obtained by the selected mathematical models, six novel potential inhibitors of the Akt/mTOR and β-catenin pathways were identified. These compounds were then tested in vitro to confirm their biological activity. Conclusion and Implications Five of the selected compounds, CAS n° 256378-54-8 (Inhibitor n°1), 663203-38-1 (Inhibitor n°2), 247079-73-8 (Inhibitor n°3), 689769-86-6 (Inhibitor n°4) and 431925-096 (Inhibitor n°6) gave positive responses and resulted to be active for Akt/mTOR and/or β-catenin inhibition. This study confirms once again the Molecular Topology’s reliability and efficacy to find out novel drugs in the field of cancer.
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7
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Zhang J, Wang Y, Li G, Yu H, Xie X. Down-regulation of nicotinamide N-methyltransferase induces apoptosis in human breast cancer cells via the mitochondria-mediated pathway. PLoS One 2014; 9:e89202. [PMID: 24558488 PMCID: PMC3928407 DOI: 10.1371/journal.pone.0089202] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 01/16/2014] [Indexed: 12/31/2022] Open
Abstract
Nicotinamide N-methyltransferase (NNMT) has been found involved in cell proliferation of several malignancies. However, the functional role of NNMT in breast cancer has not been elucidated. In the present study, we showed that NNMT was selectively expressed in some breast cancer cell lines, down-regulation of NNMT expression in Bcap-37 and MDA-MB-231 cell lines by NNMT shRNA significantly inhibited cell growth in vitro, decreased tumorigenicity in mice and induced apoptosis. The silencing reciprocal effect of NNMT was confirmed by over-expressing NNMT in the MCF-7 and SK-BR-3 breast cancer cell lines which lack constitutive expression of NNMT. In addition, down-regulation of NNMT expression resulted in reducing expression of Bcl-2 and Bcl-xL, up-regulation of Bax, Puma, cleaved caspase-9, cleaved caspase-3 and cleaved PARP, increasing reactive oxygen species production and release of cytochrome c from mitochondria, and decreasing the phosphorylation of Akt and ERK1/2. These data suggest that down-regulation of NNMT induces apoptosis via the mitochondria-mediated pathway in breast cancer cells.
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Affiliation(s)
- Jun Zhang
- Clinical Laboratory, Sir RunRun Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yanzhong Wang
- Clinical Laboratory, Sir RunRun Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Guiling Li
- Clinical Laboratory, Sir RunRun Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Haitao Yu
- Clinical Laboratory, Sir RunRun Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xinyou Xie
- Clinical Laboratory, Sir RunRun Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Key Laboratory of Biotherapy of Zhejiang Province, Hangzhou, China
- * E-mail:
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Everolimus in combination with letrozole inhibit human breast cancer MCF-7/Aro stem cells via PI3K/mTOR pathway: an experimental study. Tumour Biol 2013; 35:1275-86. [DOI: 10.1007/s13277-013-1170-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 08/29/2013] [Indexed: 01/08/2023] Open
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9
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Qu XA, Rajpal DK. Applications of Connectivity Map in drug discovery and development. Drug Discov Today 2012; 17:1289-98. [DOI: 10.1016/j.drudis.2012.07.017] [Citation(s) in RCA: 175] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 06/01/2012] [Accepted: 07/13/2012] [Indexed: 11/17/2022]
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10
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Zhang X, Zhang S, Liu Y, Liu J, Ma Y, Zhu Y, Zhang J. Effects of the combination of RAD001 and docetaxel on breast cancer stem cells. Eur J Cancer 2012; 48:1581-92. [DOI: 10.1016/j.ejca.2012.02.053] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2011] [Revised: 01/17/2012] [Accepted: 02/17/2012] [Indexed: 12/18/2022]
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Cooper KG, Winfree S, Malik-Kale P, Jolly C, Ireland R, Knodler LA, Steele-Mortimer O. Activation of Akt by the bacterial inositol phosphatase, SopB, is wortmannin insensitive. PLoS One 2011; 6:e22260. [PMID: 21779406 PMCID: PMC3136525 DOI: 10.1371/journal.pone.0022260] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Accepted: 06/22/2011] [Indexed: 01/25/2023] Open
Abstract
Salmonella enterica uses effector proteins translocated by a Type III Secretion System to invade epithelial cells. One of the invasion-associated effectors, SopB, is an inositol phosphatase that mediates sustained activation of the pro-survival kinase Akt in infected cells. Canonical activation of Akt involves membrane translocation and phosphorylation and is dependent on phosphatidyl inositide 3 kinase (PI3K). Here we have investigated these two distinct processes in Salmonella infected HeLa cells. Firstly, we found that SopB-dependent membrane translocation and phosphorylation of Akt are insensitive to the PI3K inhibitor wortmannin. Similarly, depletion of the PI3K regulatory subunits p85α and p85ß by RNAi had no inhibitory effect on SopB-dependent Akt phosphorylation. Nevertheless, SopB-dependent phosphorylation does depend on the Akt kinases, PDK1 and rictor-mTOR. Membrane translocation assays revealed a dependence on SopB for Akt recruitment to Salmonella ruffles and suggest that this is mediated by phosphoinositide (3,4) P(2) rather than phosphoinositide (3,4,5) P(3). Altogether these data demonstrate that Salmonella activates Akt via a wortmannin insensitive mechanism that is likely a class I PI3K-independent process that incorporates some essential elements of the canonical pathway.
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Affiliation(s)
- Kendal G. Cooper
- Laboratory of Intracellular Parasites, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Seth Winfree
- Laboratory of Intracellular Parasites, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Preeti Malik-Kale
- Laboratory of Intracellular Parasites, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Carrie Jolly
- Laboratory of Intracellular Parasites, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Robin Ireland
- Laboratory of Intracellular Parasites, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Leigh A. Knodler
- Laboratory of Intracellular Parasites, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
| | - Olivia Steele-Mortimer
- Laboratory of Intracellular Parasites, National Institutes of Allergy and Infectious Disease, National Institutes of Health, Rocky Mountain Laboratories, Hamilton, Montana, United States of America
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12
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Palchaudhuri R, Hergenrother PJ. Transcript profiling and RNA interference as tools to identify small molecule mechanisms and therapeutic potential. ACS Chem Biol 2011; 6:21-33. [PMID: 21105689 DOI: 10.1021/cb100310h] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The identification of the mechanism of action and therapeutic potential of bioactive small molecules remains a considerable challenge in the field of drug discovery and chemical biology. Apart from traditional target identification techniques, new tools have emerged that can significantly aid mechanism elucidation efforts. The development of pattern matching algorithms that compare transcription profile data to analogous data on compounds with known cellular targets allows for mechanistic insights without the need to synthesize chemically modified probes. In addition, such methods can be used to connect small molecules to particular disease states, thus aiding the rational identification of candidate therapeutics. Another method with considerable potential is whole-genome RNAi screening, a technique that can identify critical upstream proteins involved in a small molecule's mechanism of action. Several proof-of-concept studies using compounds with known cellular targets suggest this tool will enable mechanistic characterization of bioactive small molecules with unknown mechanisms. This Review highlights recent successes in using these pattern matching and chemical genetic tools, with the goal of uncovering small molecule mechanisms and identifying therapeutic candidates for disease treatment.
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Affiliation(s)
- Rahul Palchaudhuri
- Department of Chemistry, Roger Adams Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Paul J. Hergenrother
- Department of Chemistry, Roger Adams Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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