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Mouneimne G, Hansen SD, Selfors LM, Petrak L, Hickey MM, Gallegos LL, Simpson KJ, Lim J, Gertler FB, Hartwig JH, Mullins RD, Brugge JS. Differential remodeling of actin cytoskeleton architecture by profilin isoforms leads to distinct effects on cell migration and invasion. Cancer Cell 2012; 22:615-30. [PMID: 23153535 PMCID: PMC3500527 DOI: 10.1016/j.ccr.2012.09.027] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 09/06/2012] [Accepted: 09/28/2012] [Indexed: 01/17/2023]
Abstract
Dynamic actin cytoskeletal reorganization is integral to cell motility. Profilins are well-characterized regulators of actin polymerization; however, functional differences among coexpressed profilin isoforms are not well defined. Here, we demonstrate that profilin-1 and profilin-2 differentially regulate membrane protrusion, motility, and invasion; these processes are promoted by profilin-1 and suppressed by profilin-2. Compared to profilin-1, profilin-2 preferentially drives actin polymerization by the Ena/VASP protein, EVL. Profilin-2 and EVL suppress protrusive activity and cell motility by an actomyosin contractility-dependent mechanism. Importantly, EVL or profilin-2 downregulation enhances invasion in vitro and in vivo. In human breast cancer, lower EVL expression correlates with high invasiveness and poor patient outcome. We propose that profilin-2/EVL-mediated actin polymerization enhances actin bundling and suppresses breast cancer cell invasion.
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Affiliation(s)
- Ghassan Mouneimne
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Scott D. Hansen
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Laura M. Selfors
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Lara Petrak
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Michele M. Hickey
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Lisa L. Gallegos
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Kaylene J. Simpson
- Victorian Centre for Functional Genomics, Peter MacCallum Cancer Centre, East Melbourne, 3002
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, 3050
| | - James Lim
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Frank B. Gertler
- The Koch Institute for integrative Cancer Research at MIT, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - John H. Hartwig
- Division of Translational Medicine at Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115
| | - R. Dyche Mullins
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, CA 94158
| | - Joan S. Brugge
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
- Corresponding author: , Phone: 617 432 3974, Fax: 617 432 3969
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Bell K, Funke S, Pfeiffer N, Grus FH. Serum and antibodies of glaucoma patients lead to changes in the proteome, especially cell regulatory proteins, in retinal cells. PLoS One 2012; 7:e46910. [PMID: 23071659 PMCID: PMC3469602 DOI: 10.1371/journal.pone.0046910] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Accepted: 09/06/2012] [Indexed: 12/16/2022] Open
Abstract
Purpose Previous studies show significantly specifically changed autoantibody reactions against retinal antigens in the serum of glaucoma and ocular hypertension (OHT) patients in comparison to healthy people. As pathogenesis of glaucoma still is unknown the aim of this study was to analyze if the serum and antibodies of glaucoma patients interact with neuroretinal cells. Methods R28 cells were incubated with serum of patients suffering from primary open angle glaucoma (POAG), normal tension glaucoma (NTG) or OHT, POAG serum after antibody removal and serum from healthy people for 48 h under a normal or an elevated pressure of 15000 Pa (112 mmHg). RGC5 cells were additionally incubated with POAG antibodies under a normal pressure. Protein profiles of the R28 cells were measured with Seldi-Tof-MS, protein identification was performed with Maldi-TofTof-MS. Protein analysis of the RGC5 cells was performed with ESI-Orbitrap MS. Statistical analysis including multivariate statistics, variance component analysis as well as calculating Mahalanobis distances was performed. Results Highly significant changes of the complex protein profiles after incubation with glaucoma and OHT serum in comparison to healthy serum were detected, showing specific changes in the cells (e.g. Protein at 9192 Da (p<0.001)). The variance component analysis showed an effect of the serum of 59% on the cells. The pressure had an effect of 11% on the cells. Antibody removal led to significantly changed cell reactions (p<0.03). Furthermore, the incubation with POAG serum and its antibodies led to pro-apoptotic changes of proteins in the cells. Conclusions These studies show that the serum and the antibodies of glaucoma patients significantly change protein expressions involved in cell regulatory processes in neuroretinal cells. These could lead to a higher vulnerability of retinal cells towards stress factors such as an elevated IOP and eventually could lead to an increased apoptosis of the cells as in glaucoma.
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Affiliation(s)
- Katharina Bell
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Sebastian Funke
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Norbert Pfeiffer
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Franz H. Grus
- Experimental Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University, Mainz, Germany
- * E-mail:
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Zhou K, Gao Q, Zheng S, Pan S, Li P, Suo K, Simoncini T, Wang T, Fu X. 17β-estradiol induces vasorelaxation by stimulating endothelial hydrogen sulfide release. Mol Hum Reprod 2012; 19:169-76. [PMID: 23041593 DOI: 10.1093/molehr/gas044] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Estrogen exerts vascular protective effects, but the underlying mechanisms remain to be understood fully. In recent years, hydrogen sulfide (H(2)S) has increasingly been recognized as an important signaling molecule in the cardiovascular system. Vascular H(2)S is produced from L-cysteine, catalyzed by cystathionine γ-lyase (CSE). In our study, apolipoprotein E (ApoE)-deficient mice were ovariectomized and implanted with placebo (OVX mice) or 17β-estradiol (E(2)) pellets (OVX + E(2) mice). Compared with OVX mice, OVX + E(2) mice showed increased plasma H(2)S levels (P = 0.012) and decreased aortic lesion area (P = 0.028). These effects were largely reversed when supplementing with the irreversible CSE inhibitor DL-propargylglycine (PPG) in the OVX + E(2) + PPG mice. Meanwhile, the nitric oxide and prostacyclin-resistant responses to cumulative application of acetylcholine (ACh) were studied among all the three groups of femoral arteries. Compared with the arteries in the OVX group, the vasodilator sensitivity of arteries to ACh was increased in the OVX + E(2) group and attenuated in the OVX + E(2) + PPG group. E(2) and estrogen receptor (ER) α agonist 4',4″,4'″-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol rapidly increased H(2)S release in human endothelial cells, but not partially selective ERβ agonist 2,3-bis-(4-hydroxyphenyl)-propionitrile. These effects were inhibited by ER antagonist ICI 182780 or by protein kinase G (PKG) inhibitor KT5823. Furthermore, endothelial PKG activity was increased by E(2) (P = 0.003) and E(2)-induced vasodilation was inhibited by KT5823 (P = 0.009). In conclusion, the endothelial CSE/H(2)S pathway is activated by E(2) through PKG, which leads to vasodilation. These actions may be relevant to estrogen's anti-atherogenic effect.
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Affiliation(s)
- Kewen Zhou
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong Province, China
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Rust MB, Kullmann JA, Witke W. Role of the actin-binding protein profilin1 in radial migration and glial cell adhesion of granule neurons in the cerebellum. Cell Adh Migr 2012; 6:13-7. [PMID: 22647936 DOI: 10.4161/cam.19845] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Profilins are small G-actin-binding proteins essential for cytoskeletal dynamics. Of the four mammalian profilin isoforms, profilin1 shows a broad expression pattern, profilin2 is abundant in the brain, and profilin3 and profilin4 are restricted to the testis. In vitro studies on cancer and epithelial cell lines suggested a role for profilins in cell migration and cell-cell adhesion. Genetic studies in mice revealed the importance of profilin1 in neuronal migration, while profilin2 has apparently acquired a specific function in synaptic physiology. We recently reported a mouse mutant line lacking profilin1 in the brain; animals display morphological defects that are typical for impaired neuronal migration. We found that during cerebellar development, profilin1 is specifically required for radial migration and glial cell adhesion of granule neurons. Profilin1 mutants showed cerebellar hypoplasia and aberrant organization of cerebellar cortex layers, with ectopically arranged granule neurons. In this commentary, we briefly introduce the profilin family and summarize the current knowledge on profilin activity in cell migration and adhesion. Employing cerebellar granule cells as a model, we shed some light on the mechanisms by which profilin1 may control radial migration and glial cell adhesion. Finally, a potential implication of profilin1 in human developmental neuropathies is discussed.
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Affiliation(s)
- Marco B Rust
- Neurobiology/Neurophysiology Group, University of Kaiserslautern, Kaiserslautern, Germany.
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Ding Z, Bae YH, Roy P. Molecular insights on context-specific role of profilin-1 in cell migration. Cell Adh Migr 2012; 6:442-9. [PMID: 23076048 DOI: 10.4161/cam.21832] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Profilin-1 (Pfn1) is a ubiquitously expressed actin-monomer binding protein that has been linked to many cellular activities ranging from control of actin polymerization to gene transcription. Traditionally, Pfn1 has been considered to be an essential control element for actin polymerization and cell migration. Seemingly contrasting this view, a few recent studies have shown evidence of an inhibitory action of Pfn1 on motility of certain types of carcinoma cells. In this review, we summarize biochemistry and functional aspects of Pfn1 in normal cells and bring in newly emerged action of Pfn1 in cancer cells that may explain its context-specific role in cell migration.
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Affiliation(s)
- Zhijie Ding
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
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Protein phosphatase 1 dephosphorylates profilin-1 at Ser-137. PLoS One 2012; 7:e32802. [PMID: 22479341 PMCID: PMC3316545 DOI: 10.1371/journal.pone.0032802] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2011] [Accepted: 02/05/2012] [Indexed: 12/31/2022] Open
Abstract
Profilin-1 (PFN1) plays an important role in the control of actin dynamics, and could represent an important therapeutic target in several diseases. We previously identified PFN1 as a huntingtin aggregation inhibitor, and others have implicated it as a tumor-suppressor. Rho-associated kinase (ROCK) directly phosphorylates PFN1 at Ser-137 to prevent its binding to polyproline sequences. This negatively regulates its anti-aggregation activity. However, the phosphatase that dephosphorylates PFN1 at Ser-137, and thus activates it, is unknown. Using a phospho-specific antibody against Ser-137 of PFN1, we characterized PFN1 dephosphorylation in cultured cells based on immunocytochemistry and a quantitative plate reader-based assay. Both okadaic acid and endothall increased pS137-PFN1 levels at concentrations more consistent with their known IC50s for protein phosphatase 1 (PP1) than protein phosphatase 2A (PP2A). Knockdown of the catalytic subunit of PP1 (PP1Cα), but not PP2A (PP2ACα), increased pS137-PFN1 levels. PP1Cα binds PFN1 in cultured cells, and this interaction was increased by a phosphomimetic mutation of PFN1 at Ser-137 (S137D). Together, these data define PP1 as the principal phosphatase for Ser-137 of PFN1, and provide mechanistic insights into PFN1 regulation by phosphorylation.
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Menkhorst EM, Lane N, Winship AL, Li P, Yap J, Meehan K, Rainczuk A, Stephens A, Dimitriadis E. Decidual-secreted factors alter invasive trophoblast membrane and secreted proteins implying a role for decidual cell regulation of placentation. PLoS One 2012; 7:e31418. [PMID: 22359590 PMCID: PMC3281063 DOI: 10.1371/journal.pone.0031418] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 01/07/2012] [Indexed: 11/25/2022] Open
Abstract
Inadequate or inappropriate implantation and placentation during the establishment of human pregnancy is thought to lead to first trimester miscarriage, placental insufficiency and other obstetric complications. To create the placental blood supply, specialized cells, the ‘extravillous trophoblast’ (EVT) invade through the differentiated uterine endometrium (the decidua) to engraft and remodel uterine spiral arteries. We hypothesized that decidual factors would regulate EVT function by altering the production of EVT membrane and secreted factors. We used a proteomics approach to identify EVT membrane and secreted proteins regulated by decidual cell factors. Human endometrial stromal cells were decidualized in vitro by treatment with estradiol (10−8 M), medroxyprogesterone acetate (10−7 M) and cAMP (0.5 mM) for 14 days. Conditioned media (CM) was collected on day 2 (non-decidualized CM) and 14 (decidualized CM) of treatment. Isolated primary EVT cultured on Matrigel™ were treated with media control, non-decidualized or decidualized CM for 16 h. EVT CM was fractionated for proteins <30 kDa using size-exclusion affinity nanoparticles (SEAN) before trypsin digestion and HPLC-MS/MS. 43 proteins produced by EVT were identified; 14 not previously known to be expressed in the placenta and 12 which had previously been associated with diseases of pregnancy including preeclampsia. Profilin 1, lysosome associated membrane glycoprotein 1 (LAMP1), dipeptidyl peptidase 1 (DPP1/cathepsin C) and annexin A2 expression by interstitial EVT in vivo was validated by immunhistochemistry. Decidual CM regulation in vitro was validated by western blotting: decidualized CM upregulated profilin 1 in EVT CM and non-decidualized CM upregulated annexin A2 in EVT CM and pro-DPP1 in EVT cell lysate. Here, non-decidualized factors induced protease expression by EVT suggesting that non-decidualized factors may induce a pro-inflammatory cascade. Preeclampsia is a pro-inflammatory condition. Overall, we have demonstrated the potential of a proteomics approach to identify novel proteins expressed by EVT and to uncover the mechanisms leading to disease states.
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Affiliation(s)
| | - Natalie Lane
- Prince Henry's Institute, Clayton, Victoria, Australia
| | | | - Priscilla Li
- Prince Henry's Institute, Clayton, Victoria, Australia
| | - Joanne Yap
- Prince Henry's Institute, Clayton, Victoria, Australia
| | - Katie Meehan
- Prince Henry's Institute, Clayton, Victoria, Australia
| | - Adam Rainczuk
- Prince Henry's Institute, Clayton, Victoria, Australia
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SMN deficiency attenuates migration of U87MG astroglioma cells through the activation of RhoA. Mol Cell Neurosci 2011; 49:282-9. [PMID: 22197680 DOI: 10.1016/j.mcn.2011.12.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 11/23/2011] [Accepted: 12/05/2011] [Indexed: 12/13/2022] Open
Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disease that affects alpha motoneurons in the spinal cord caused by homozygous deletion or specific mutations in the survival motoneuron-1 (SMN1) gene. Cell migration is critical at many stages of nervous system development; to investigate the role of SMN in cell migration, U87MG astroglioma cells were transduced with shSMN lentivectors and about 60% reduction in SMN expression was achieved. In a monolayer wound-healing assay, U87MG SMN-depleted cells exhibit reduced cell migration. In these cells, RhoA was activated and phosphorylated levels of myosin regulatory light chain (MLC), a substrate of the Rho kinase (ROCK), were found increased. The decrease in cell motility was related to activation of RhoA/Rho kinase (ROCK) signaling pathway as treatment with the ROCK inhibitor Y-27632 abrogated both the motility defects and MLC phosphorylation in SMN-depleted cells. As cell migration is regulated by continuous remodeling of the actin cytoskeleton, the actin distribution was studied in SMN-depleted cells. A shift from filamentous to monomeric (globular) actin, involving the disappearance of stress fibers, was observed. In addition, profilin I, an actin-sequestering protein showed an increased expression in SMN-depleted cells. SMN is known to physically interact with profilin, reducing its actin-sequestering activity. The present results suggest that in SMN-depleted cells, the increase in profilin I expression and the reduction in SMN inhibitory action on profilin could lead to reduced filamentous actin polymerization, thus decreasing cell motility. We propose that the alterations reported here in migratory activity in SMN-depleted cells, related to abnormal activation of RhoA/ROCK pathway and increased profilin I expression could have a role in developing nervous system by impairing normal neuron and glial cell migration and thus contributing to disease pathogenesis in SMA.
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Zoidakis J, Makridakis M, Zerefos PG, Bitsika V, Esteban S, Frantzi M, Stravodimos K, Anagnou NP, Roubelakis MG, Sanchez-Carbayo M, Vlahou A. Profilin 1 is a potential biomarker for bladder cancer aggressiveness. Mol Cell Proteomics 2011; 11:M111.009449. [PMID: 22159600 DOI: 10.1074/mcp.m111.009449] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Of the most important clinical needs for bladder cancer (BC) management is the identification of biomarkers for disease aggressiveness. Urine is a "gold mine" for biomarker discovery, nevertheless, with multiple proteins being in low amounts, urine proteomics becomes challenging. In the present study we applied a fractionation strategy of urinary proteins based on the use of immobilized metal affinity chromatography for the discovery of biomarkers for aggressive BC. Urine samples from patients with non invasive (two pools) and invasive (two pools) BC were subjected to immobilized metal affinity chromatography fractionation and eluted proteins analyzed by 1D-SDS-PAGE, band excision and liquid chromatography tandem MS. Among the identified proteins, multiple corresponded to proteins with affinity for metals and/or reported to be phosphorylated and included proteins with demonstrated association with BC such as MMP9, fibrinogen forms, and clusterin. In agreement to the immobilized metal affinity chromatography results, aminopeptidase N, profilin 1, and myeloblastin were further found to be differentially expressed in urine from patients with invasive compared with non invasive BC and benign controls, by Western blot or Elisa analysis, nevertheless exhibiting high interindividual variability. By tissue microarray analysis, profilin 1 was found to have a marked decrease of expression in the epithelial cells of the invasive (T2+) versus high risk non invasive (T1G3) tumors with occasional expression in stroma; importantly, this pattern strongly correlated with poor prognosis and increased mortality. The functional relevance of profilin 1 was investigated in the T24 BC cells where blockage of the protein by the use of antibodies resulted in decreased cell motility with concomitant decrease in actin polymerization. Collectively, our study involves the application of a fractionation method of urinary proteins and as one main result of this analysis reveals the association of profilin 1 with BC paving the way for its further investigation in BC stratification.
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Affiliation(s)
- Jerome Zoidakis
- Biotechnology Division, Biomedical Research Foundation, Academy of Athens, Greece
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60
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Bioengineering embryonic stem cell microenvironments for the study of breast cancer. Int J Mol Sci 2011; 12:7662-91. [PMID: 22174624 PMCID: PMC3233430 DOI: 10.3390/ijms12117662] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 10/27/2011] [Accepted: 10/31/2011] [Indexed: 12/12/2022] Open
Abstract
Breast cancer is the most prevalent disease amongst women worldwide and metastasis is the main cause of death due to breast cancer. Metastatic breast cancer cells and embryonic stem (ES) cells display similar characteristics. However, unlike metastatic breast cancer cells, ES cells are nonmalignant. Furthermore, embryonic microenvironments have the potential to convert metastatic breast cancer cells into a less invasive phenotype. The creation of in vitro embryonic microenvironments will enable better understanding of ES cell-breast cancer cell interactions, help elucidate tumorigenesis, and lead to the restriction of breast cancer metastasis. In this article, we will present the characteristics of breast cancer cells and ES cells as well as their microenvironments, importance of embryonic microenvironments in inhibiting tumorigenesis, convergence of tumorigenic and embryonic signaling pathways, and state of the art in bioengineering embryonic microenvironments for breast cancer research. Additionally, the potential application of bioengineered embryonic microenvironments for the prevention and treatment of invasive breast cancer will be discussed.
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Fournier G, Cabaud O, Josselin E, Chaix A, Adélaïde J, Isnardon D, Restouin A, Castellano R, Dubreuil P, Chaffanet M, Birnbaum D, Lopez M. Loss of AF6/afadin, a marker of poor outcome in breast cancer, induces cell migration, invasiveness and tumor growth. Oncogene 2011; 30:3862-74. [DOI: 10.1038/onc.2011.106] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Profilin1 regulates PI(3,4)P2 and lamellipodin accumulation at the leading edge thus influencing motility of MDA-MB-231 cells. Proc Natl Acad Sci U S A 2010; 107:21547-52. [PMID: 21115820 DOI: 10.1073/pnas.1002309107] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Profilin1, a ubiquitously expressed actin-binding protein, plays a critical role in cell migration through actin cytoskeletal regulation. Given the traditional view of profilin1 as a promigratory molecule, it is difficult to reconcile observations that profilin1 is down-regulated in various invasive adenocarcinomas and that reduced profilin1 expression actually confers increased motility to certain adenocarcinoma cells. In this study, we show that profilin1 negatively regulates lamellipodin targeting to the leading edge in MDA-MB-231 breast cancer cells and normal cells; profilin1 depletion increases lamellipodin concentration at the lamellipodial tip (where it binds Ena/VASP), and this mediates the hypermotility. We report that the molecular mechanism underlying profilin1's modulation of lamellipodin localization relates to phosphoinositide control. Specifically, we show that phosphoinositide binding of profilin1 inhibits the motility of MDA-MB-231 cells by negatively regulating PI(3,4)P(2) at the membrane and thereby limiting recruitment of lamellipodin [a PI(3,4)P(2)-binding protein] and Ena/VASP to the leading edge. In summary, this study uncovers a unique biological consequence of profilin1-phosphoinositide interaction, thus providing direct evidence of profilin1's regulation of cell migration independent of its actin-related activity.
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Kanaan Z, Qadan M, Eichenberger MR, Galandiuk S. The actin-cytoskeleton pathway and its potential role in inflammatory bowel disease-associated human colorectal cancer. Genet Test Mol Biomarkers 2010; 14:347-53. [PMID: 20406101 DOI: 10.1089/gtmb.2009.0197] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
INTRODUCTION To improve our understanding of the various clinical phenotypes in inflammatory bowel disease (IBD)-associated colorectal cancer (CRC) and provide potential targets for early diagnosis and future therapy, we sought to identify new candidate genes and molecular pathways involved in the pathogenesis and progression of this disorder. Recent evidence has implicated the actin-cytoskeleton pathway in the development of metastatic sporadic CRC through cytoskeletal proteins such as fascin-1. We hereby propose that similar genetic polymorphisms and mutations among regulatory genes of the actin-cytoskeleton pathway may also be associated with increased dysplasia, carcinogenesis, and susceptibility for invasion and metastasis in IBD-associated CRC, as compared with sporadic CRC. MATERIALS AND METHODS To test this hypothesis, we identified three patients with IBD-associated CRC. We subsequently retrieved normal, dysplastic, and cancerous tissue from within the same surgical colonic specimen. Messenger RNA was subsequently isolated from fresh frozen tissue, and oligonucleotide arrays were carried out to identify genes that were differentially expressed between the three various tissue types (normal, dysplasia, and cancer). By utilizing the same specimen to obtain each of the three various tissue types, we excluded intersubject variability during the analysis. Finally, we performed bioinformatic interaction pathway analysis using the "Ingenuity Pathway Analysis" software. RESULTS Computerized pathway analysis revealed that the actin-cytoskeleton pathway was significantly dysregulated in the progression of normal cells, via dysplasia, to IBD-associated CRC (p < 0.05). Significantly up-regulated genes identified in the analysis included the fibroblast growth factor, Abelson interactor gene-2, profilin-2, and radixin genes. Conversely, the diaphanous homolog gene appeared to be significantly down-regulated. CONCLUSION Via the dysregulation of these five genes within the actin-cytoskeleton pathway, we propose that this molecular pathway provides a potential mechanism for the malignant transformation and progression of normal tissue, via dysplasia, to IBD-associated CRC.
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Affiliation(s)
- Ziad Kanaan
- Department of Surgery, Price Institute of Surgical Research, University of Louisville School of Medicine, Louisville, Kentucky 40292, USA
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Gau D, Ding Z, Baty C, Roy P. Fluorescence Resonance Energy Transfer (FRET)-based Detection of Profilin-VASP Interaction. Cell Mol Bioeng 2010; 4:1-8. [PMID: 21566724 DOI: 10.1007/s12195-010-0133-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Profilins belong to a family of small G-actin binding proteins which are thought to assist in F-actin elongation at the leading edge of migrating cells through their interactions with a host of actin-binding proteins including Ena (enabled)/VASP (vasodilator stimulated phosphoprotein). Profilin's interactions with the major actin regulators have been studied almost exclusively using biochemical methods. Therefore spatiotemporal features of these protein-protein interactions have not been resolved so far. In this paper, we for the first time demonstrate the feasibility of GFP-based fluorescence resonance energy transfer (FRET) technique to detect VASP's interaction with profilin-1, a ubiquitously expressed member of profilin family of genes. Specifically, we performed acceptor photobleaching FRET in MDA-MB-231 breast cancer cells to show prominent VASP-Pfn1 interaction at the membrane ruffles near the leading edge.
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Affiliation(s)
- Dave Gau
- Department of Bioengineering, University of Pittsburgh, 306 Center for Bioengineering, 300 Technology Drive, Pittsburgh, PA 15219, USA
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Richer SM, Stewart NK, Webb SA, Tomaszewski JW, Oakley MG. High affinity binding to profilin by a covalently constrained, soluble mimic of phosphatidylinositol-4,5-bisphosphate micelles. ACS Chem Biol 2009; 4:733-9. [PMID: 19639958 DOI: 10.1021/cb900121r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Phosphoinositide (PI) lipids are essential regulators of a wide variety of cellular functions. We present here the preparation of a multivalent analogue of a phosphatidylinositol-4,5-bisphosphate (PIP(2)) micelle containing only the polar headgroup portion of this lipid. We show that this dendrimer binds to the cytoskeletal protein profilin with an affinity indistinguishable from that of PIP(2), despite the fact that profilin discriminates between PIP(2) and its monomeric hydrolysis product inositol-1,4,5-triphosphate (IP(3)) under physiological conditions. These data demonstrate that the diacylglycerol (DAG) moiety of PIP(2) is not required for high-affinity binding and suggest that profilin uses multivalency as a key means to distinguish between the intact lipid and IP(3). The class of soluble membrane analogues described here is likely to have broad applicability in the study of protein.PI interactions.
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Affiliation(s)
- Sarah M. Richer
- Department of Chemistry, Indiana University, 212 South Hawthorne Drive, Bloomington, Indiana 47405
| | - Nichole K. Stewart
- Department of Chemistry, Indiana University, 212 South Hawthorne Drive, Bloomington, Indiana 47405
| | - Sarah A. Webb
- Department of Chemistry, Indiana University, 212 South Hawthorne Drive, Bloomington, Indiana 47405
| | - John W. Tomaszewski
- Department of Chemistry, Indiana University, 212 South Hawthorne Drive, Bloomington, Indiana 47405
| | - Martha G. Oakley
- Department of Chemistry, Indiana University, 212 South Hawthorne Drive, Bloomington, Indiana 47405
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Ding Z, Gau D, Deasy B, Wells A, Roy P. Both actin and polyproline interactions of profilin-1 are required for migration, invasion and capillary morphogenesis of vascular endothelial cells. Exp Cell Res 2009; 315:2963-73. [PMID: 19607826 DOI: 10.1016/j.yexcr.2009.07.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2009] [Revised: 07/07/2009] [Accepted: 07/07/2009] [Indexed: 11/15/2022]
Abstract
The objective of the present study was to evaluate how different ligand interactions of profilin-1 (Pfn1), an actin-binding protein that is upregulated during capillary morphogenesis of vascular endothelial cells (VEC), contribute to migration and capillary forming ability of VEC. We adopted a knockdown-knockin experimental system to stably express either fully functional form or mutants of Pfn1 that are impaired in binding to two of its major ligands, actin (H119E mutant) and proteins containing polyproline domains (H133S mutant), in a human dermal microvascular cell line (HmVEC) against near-null endogenous Pfn1 background. We found that silencing endogenous Pfn1 expression in HmVEC leads to slower random migration, reduced velocity of membrane protrusion and a significant impairment in matrigel-induced cord formation. Only re-expression of fully functional but not any of the two ligand-binding deficient mutants of Pfn1 rescues the above defects. We further show that loss of Pfn1 expression in VEC inhibits three-dimensional capillary morphogenesis, MMP2 secretion and ECM invasion. VEC invasion through ECM is also inhibited when actin and polyproline interactions of Pfn1 are disrupted. Together, these experimental data demonstrate that Pfn1 regulates VEC migration, invasion and capillary morphogenesis through its interaction with both actin and proline-rich ligands.
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Affiliation(s)
- Zhijie Ding
- Department of Bioengineering, University of Pittsburgh, PA, USA
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Krishnan K, Moens PDJ. Structure and functions of profilins. Biophys Rev 2009; 1:71-81. [PMID: 28509986 PMCID: PMC5425664 DOI: 10.1007/s12551-009-0010-y] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2009] [Revised: 05/07/2009] [Accepted: 05/13/2009] [Indexed: 10/20/2022] Open
Abstract
Profilins are small actin-binding proteins found in eukaryotes and certain viruses that are involved in cell development, cytokinesis, membrane trafficking, and cell motility. Originally identified as an actin sequestering/binding protein, profilin has been involved in actin polymerization dynamics. It catalyzes the exchange of ADP/ATP in actin and increases the rate of polymerization. Profilins also interact with polyphosphoinositides (PPI) and proline-rich domains containing proteins. Through its interaction with PPIs, profilin has been linked to signaling pathways between the cell membrane and the cytoskeleton, while its role in membrane trafficking has been associated with its interaction with proline-rich domain-containing proteins. Depending on the organism, profilin is present in a various number of isoforms. Four isoforms of profilin have been reported in higher organisms, while only one or two isoforms are expressed in single-cell organisms. The affinity of these isoforms for their ligands varies between isoforms and should therefore modulate their functions. However, the significance and the functions of the different isoforms are not yet fully understood. The structures of many profilin isoforms have been solved both in the presence and the absence of actin and poly-L-proline. These structural studies will greatly improve our understanding of the differences and similarities between the different profilins. Structural stability studies of different profilins are also shedding some light on our understanding of the profilin/ligand interactions. Profilin is a multifaceted protein for which a dramatic increase in potential functions has been found in recent years; as such, it has been implicated in a variety of physiological and pathological processes.
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Affiliation(s)
- Kannan Krishnan
- Centre for Bioactive Discovery in Health and Ageing, School of Science and Technology, University of New England, McClymont Bldg, Armidale, NSW, 2351, Australia
| | - Pierre D J Moens
- Centre for Bioactive Discovery in Health and Ageing, School of Science and Technology, University of New England, McClymont Bldg, Armidale, NSW, 2351, Australia.
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