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Pei X, Mladenov E, Soni A, Li F, Stuschke M, Iliakis G. PTEN Loss Enhances Error-Prone DSB Processing and Tumor Cell Radiosensitivity by Suppressing RAD51 Expression and Homologous Recombination. Int J Mol Sci 2022; 23:12876. [PMID: 36361678 PMCID: PMC9658850 DOI: 10.3390/ijms232112876] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/19/2022] [Accepted: 10/19/2022] [Indexed: 09/29/2023] Open
Abstract
PTEN has been implicated in the repair of DNA double-strand breaks (DSBs), particularly through homologous recombination (HR). However, other data fail to demonstrate a direct role of PTEN in DSB repair. Therefore, here, we report experiments designed to further investigate the role of PTEN in DSB repair. We emphasize the consequences of PTEN loss in the engagement of the four DSB repair pathways-classical non-homologous end-joining (c-NHEJ), HR, alternative end-joining (alt-EJ) and single strand annealing (SSA)-and analyze the resulting dynamic changes in their utilization. We quantitate the effect of PTEN knockdown on cell radiosensitivity to killing, as well as checkpoint responses in normal and tumor cell lines. We find that disruption of PTEN sensitizes cells to ionizing radiation (IR). This radiosensitization is associated with a reduction in RAD51 expression that compromises HR and causes a marked increase in SSA engagement, an error-prone DSB repair pathway, while alt-EJ and c-NHEJ remain unchanged after PTEN knockdown. The G2-checkpoint is partially suppressed after PTEN knockdown, corroborating the associated HR suppression. Notably, PTEN deficiency radiosensitizes cells to PARP inhibitors, Olaparib and BMN673. The results show the crucial role of PTEN in DSB repair and show a molecular link between PTEN and HR through the regulation of RAD51 expression. The expected benefit from combination treatment with Olaparib or BMN673 and IR shows that PTEN status may also be useful for patient stratification in clinical treatment protocols combining IR with PARP inhibitors.
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Affiliation(s)
- Xile Pei
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Emil Mladenov
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Aashish Soni
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Fanghua Li
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
| | - Martin Stuschke
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- German Cancer Consortium (DKTK), Partner Site University Hospital Essen, 45147 Essen, Germany
| | - George Iliakis
- Division of Experimental Radiation Biology, Department of Radiation Therapy, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
- Institute of Medical Radiation Biology, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany
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Shin JW, Kim SH, Yoon JY. PTEN downregulation induces apoptosis and cell cycle arrest in uterine cervical cancer cells. Exp Ther Med 2021; 22:1100. [PMID: 34504554 PMCID: PMC8383748 DOI: 10.3892/etm.2021.10534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 06/18/2021] [Indexed: 11/06/2022] Open
Abstract
The tumor suppressors PTEN and p53 are often downregulated in various human cancer types, which has been associated with a poor prognosis. Recent evidence implies that PTEN downregulation may induce growth arrest of kidney cells and cancer cells. In the present study, the role of PTEN in the proliferation and survival of cervical cancer cells was investigated. It was found that PTEN silencing promoted apoptosis and cell-cycle arrest, accompanied by a significant decrease in the proportion of cells in the S1 phase of the cell cycle. Moreover, PTEN silencing in cervical cancer cells increased levels of p53, p27, p21, phospho-ERK and cleaved caspase-3, and decreased levels of cyclin A2 and cyclin D1. Furthermore, PTEN knockdown significantly impacted the viability of cervical cancer cells. P53 silencing did not affect the ability of PTEN knockdown to induce apoptosis in cervical cancer cells. Taken together, the present study results imply that PTEN silencing induces apoptosis and decreases proliferation in cervical cancer cells; hence, PTEN inhibition may represent a promising strategy for the treatment of cervical cancer.
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Affiliation(s)
- Jin Woo Shin
- Department of Obstetrics and Gynecology, Gil Medical Center, College of Medicine, Gachon University, Incheon 21565, Republic of Korea
| | - Se-Hee Kim
- Gachon Medical Research Institute, Gil Medical Center, Gachon University, Incheon 21565, Republic of Korea
| | - Jin Young Yoon
- Gachon Medical Research Institute, Gil Medical Center, Gachon University, Incheon 21565, Republic of Korea
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Dai X, Miao Y, Han P, Zhang X, Yang S, Lv Q, Hua D. PABPC1 Enables Cells with the Suspension Cultivation Feature. ACS Synth Biol 2021; 10:309-317. [PMID: 33502842 DOI: 10.1021/acssynbio.0c00440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cell-based vaccine manufacturing is an important strategy for viral disease prevention. Cultivating cells in suspension could maximize the utility of large bioreactors for cost-effective and scaled up vaccine production, where adapting adherent cells to suspension culture is the bottleneck and key. Through whole transcriptome sequencing of suspension and adherent strains of BHK-21 and CHO-K1 cells followed by the identification of differentially expressed genes, mutational analysis, gene ontology, and pathway enrichment analysis, we identified four candidate genes, PABPC1, LARS, GLUL, PFN1, feasible for genetically modulating anchorage-dependent cells toward cell suspension culture, and experimentally validated the functionality of PABPC1 in both BHK-21 and CHO-K1 cells. Our study unveiled a novel role of PABPC1 that could potentially aid in the establishment of a cost-effective vaccine manufacturing platform relying on cell cultivation in suspension.
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Affiliation(s)
- Xiaofeng Dai
- Wuxi School of Medicine, Jiangnan University, Wuxi, 214122, China
- Wuhan Ammunition Life-tech Company, Ltd., Wuhan, Hubei 430200, China
| | - Yujie Miao
- School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Peiyu Han
- Wuxi School of Medicine, Jiangnan University, Wuxi, 214122, China
| | - Xuanhao Zhang
- School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Siming Yang
- School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Qing Lv
- Affiliated Hospital of Jiangnan University, Wuxi, 214000, China
| | - Dong Hua
- Affiliated Hospital of Jiangnan University, Wuxi, 214000, China
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Kiesslich S, Kamen AA. Vero cell upstream bioprocess development for the production of viral vectors and vaccines. Biotechnol Adv 2020; 44:107608. [PMID: 32768520 PMCID: PMC7405825 DOI: 10.1016/j.biotechadv.2020.107608] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/28/2020] [Accepted: 07/30/2020] [Indexed: 12/13/2022]
Abstract
The Vero cell line is considered the most used continuous cell line for the production of viral vectors and vaccines. Historically, it is the first cell line that was approved by the WHO for the production of human vaccines. Comprehensive experimental data on the production of many viruses using the Vero cell line can be found in the literature. However, the vast majority of these processes is relying on the microcarrier technology. While this system is established for the large-scale manufacturing of viral vaccine, it is still quite complex and labor intensive. Moreover, scale-up remains difficult and is limited by the surface area given by the carriers. To overcome these and other drawbacks and to establish more efficient manufacturing processes, it is a priority to further develop the Vero cell platform by applying novel bioprocess technologies. Especially in times like the current COVID-19 pandemic, advanced and scalable platform technologies could provide more efficient and cost-effective solutions to meet the global vaccine demand. Herein, we review the prevailing literature on Vero cell bioprocess development for the production of viral vectors and vaccines with the aim to assess the recent advances in bioprocess development. We critically underline the need for further research activities and describe bottlenecks to improve the Vero cell platform by taking advantage of recent developments in the cell culture engineering field.
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Affiliation(s)
- Sascha Kiesslich
- Department of Bioengineering, McGill University, 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada
| | - Amine A Kamen
- Department of Bioengineering, McGill University, 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada.
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Physical Intimacy of Breast Cancer Cells with Mesenchymal Stem Cells Elicits Trastuzumab Resistance through Src Activation. Sci Rep 2015; 5:13744. [PMID: 26345302 PMCID: PMC4561910 DOI: 10.1038/srep13744] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 07/17/2015] [Indexed: 12/27/2022] Open
Abstract
The development of resistance to trastuzumab is a major obstacle for lasting effective treatment of patients with ErbB2-overexpressing tumors. Here, we demonstrate that the physical contact of breast cancer cells with mesenchymal stem cells (MSCs) is a potential modulator of trastuzumab response by activation of nonreceptor tyrosine kinase c-Src and down regulation of phosphatase and tensin homolog (PTEN). Using an in vitro patterned breast cancer/MSC co-culture model, we find that the presence of MSCs results in Src activation that is missing in cancer cells monoculture, transwell co-culture, and cells treated with MSCs conditioned media. Interestingly, the co-culture model also results in PTEN loss and activation of PI3K/AKT pathway that has been demonstrated as fundamental proliferative and survival pathways in clinical settings. To our knowledge, this is the first report that showed PTEN loss without the use of chemical inhibitors, matrix stiffness, or silencing RNAs. In addition, breast cancer cells in co-culture with MSCs conferred trastuzumab resistance in vitro as observed in the lack of inhibition of proliferative and migrative properties of the cancer cells. Our findings show that MSCs are potent mediators of resistance to trastuzumab and might reveal targets to enhance trastuzumab efficacy in patients.
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Kluge S, Benndorf D, Genzel Y, Scharfenberg K, Rapp E, Reichl U. Monitoring changes in proteome during stepwise adaptation of a MDCK cell line from adherence to growth in suspension. Vaccine 2015; 33:4269-80. [DOI: 10.1016/j.vaccine.2015.02.077] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 01/30/2015] [Accepted: 02/16/2015] [Indexed: 11/16/2022]
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Kala A, Jain PK, Friedman SH. Patterning of cells through patterning of biology. MOLECULAR BIOSYSTEMS 2015; 10:1689-92. [PMID: 24531692 DOI: 10.1039/c3mb70587k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
For the first time, cells have been patterned on surfaces through the spatial manipulation of native gene expression. By manipulating the inherent biology of the cell, as opposed to the chemical nature of the surfaces they are attached to, we have created a potentially more flexible way of creating patterns of cells that does not depend on the substrate. This was accomplished by bringing an siRNA that targets the expression of pten under the control of light, by modifying it with photocleavable groups. This pten-targeting siRNA has been previously demonstrated to induce dissociation of cells from surfaces. We modified this siRNA with dimethoxy nitro phenyl ethyl photocleavable groups (DMNPE) to allow the activity of the siRNA, and hence pten knockdown, to be toggled with light. Using this approach we demonstrated light dependent cell dissociation only with a DMNPE modified siRNA that targets pten and not with control siRNAs. In addition we demonstrated the ability to make simple patterns of cells through the application of masks during irradiation.
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Affiliation(s)
- A Kala
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri, 2464 Charlotte Street, Kansas City, MO 64108-2718, USA.
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8
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Differential SKIP expression in PTEN-deficient glioblastoma regulates cellular proliferation and migration. Oncogene 2014; 34:3711-27. [DOI: 10.1038/onc.2014.303] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 07/18/2014] [Accepted: 08/13/2014] [Indexed: 12/25/2022]
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Eskova A, Knapp B, Matelska D, Reusing S, Arjonen A, Lisauskas T, Pepperkok R, Russell R, Eils R, Ivaska J, Kaderali L, Erfle H, Starkuviene V. An RNAi screen identifies KIF15 as a novel regulator of the endocytic trafficking of integrin. J Cell Sci 2014; 127:2433-47. [PMID: 24659801 DOI: 10.1242/jcs.137281] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
α2β1 integrin is one of the most important collagen-binding receptors, and it has been implicated in numerous thrombotic and immune diseases. α2β1 integrin is a potent tumour suppressor, and its downregulation is associated with increased metastasis and poor prognosis in breast cancer. Currently, very little is known about the mechanism that regulates the cell-surface expression and trafficking of α2β1 integrin. Here, using a quantitative fluorescence-microscopy-based RNAi assay, we investigated the impact of 386 cytoskeleton-associated or -regulatory genes on α2 integrin endocytosis and found that 122 of these affected the intracellular accumulation of α2 integrin. Of these, 83 were found to be putative regulators of α2 integrin trafficking and/or expression, with no observed effect on the internalization of epidermal growth factor (EGF) or transferrin. Further interrogation and validation of the siRNA screen revealed a role for KIF15, a microtubule-based molecular motor, as a significant inhibitor of the endocytic trafficking of α2 integrin. Our data suggest a novel role for KIF15 in mediating plasma membrane localization of the alternative clathrin adaptor Dab2, thus impinging on pathways that regulate α2 integrin internalization.
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Affiliation(s)
| | - Bettina Knapp
- Medical Faculty, Institute for Medical Informatics and Biometry (IMB), Technische Universität Dresden, 01307 Dresden, Germany
| | - Dorota Matelska
- BioQuant, University of Heidelberg, 69120 Heidelberg, Germany
| | - Susanne Reusing
- BioQuant, University of Heidelberg, 69120 Heidelberg, Germany
| | - Antti Arjonen
- Centre for Biotechnology, University of Turku, 20520 Turku, Finland
| | | | | | - Robert Russell
- BioQuant, University of Heidelberg, 69120 Heidelberg, Germany
| | - Roland Eils
- BioQuant, University of Heidelberg, 69120 Heidelberg, Germany Integrative Bioinformatics and Systems Biology, DKFZ, BioQuant and Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Johanna Ivaska
- Centre for Biotechnology, University of Turku, 20520 Turku, Finland
| | - Lars Kaderali
- Medical Faculty, Institute for Medical Informatics and Biometry (IMB), Technische Universität Dresden, 01307 Dresden, Germany
| | - Holger Erfle
- BioQuant, University of Heidelberg, 69120 Heidelberg, Germany
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Memmel S, Sukhorukov VL, Höring M, Westerling K, Fiedler V, Katzer A, Krohne G, Flentje M, Djuzenova CS. Cell surface area and membrane folding in glioblastoma cell lines differing in PTEN and p53 status. PLoS One 2014; 9:e87052. [PMID: 24498019 PMCID: PMC3909012 DOI: 10.1371/journal.pone.0087052] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 12/17/2013] [Indexed: 01/22/2023] Open
Abstract
Glioblastoma multiforme (GBM) is characterized by rapid growth, invasion and resistance to chemo−/radiotherapy. The complex cell surface morphology with abundant membrane folds, microvilli, filopodia and other membrane extensions is believed to contribute to the highly invasive behavior and therapy resistance of GBM cells. The present study addresses the mechanisms leading to the excessive cell membrane area in five GBM lines differing in mutational status for PTEN and p53. In addition to scanning electron microscopy (SEM), the membrane area and folding were quantified by dielectric measurements of membrane capacitance using the single-cell electrorotation (ROT) technique. The osmotic stability and volume regulation of GBM cells were analyzed by video microscopy. The expression of PTEN, p53, mTOR and several other marker proteins involved in cell growth and membrane synthesis were examined by Western blotting. The combined SEM, ROT and osmotic data provided independent lines of evidence for a large variability in membrane area and folding among tested GBM lines. Thus, DK-MG cells (wild type p53 and wild type PTEN) exhibited the lowest degree of membrane folding, probed by the area-specific capacitance Cm = 1.9 µF/cm2. In contrast, cell lines carrying mutations in both p53 and PTEN (U373-MG and SNB19) showed the highest Cm values of 3.7–4.0 µF/cm2, which corroborate well with their heavily villated cell surface revealed by SEM. Since PTEN and p53 are well-known inhibitors of mTOR, the increased membrane area/folding in mutant GBM lines may be related to the enhanced protein and lipid synthesis due to a deregulation of the mTOR-dependent downstream signaling pathway. Given that membrane folds and extensions are implicated in tumor cell motility and metastasis, the dielectric approach presented here provides a rapid and simple tool for screening the biophysical cell properties in studies on targeting chemo- or radiotherapeutically the migration and invasion of GBM and other tumor types.
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Affiliation(s)
- Simon Memmel
- Lehrstuhl für Biotechnologie und Biophysik, Universität Würzburg, Am Hubland, Würzburg, Germany
| | - Vladimir L. Sukhorukov
- Lehrstuhl für Biotechnologie und Biophysik, Universität Würzburg, Am Hubland, Würzburg, Germany
- * E-mail: (VLS); (CSD)
| | - Marcus Höring
- Lehrstuhl für Biotechnologie und Biophysik, Universität Würzburg, Am Hubland, Würzburg, Germany
| | - Katherine Westerling
- Lehrstuhl für Biotechnologie und Biophysik, Universität Würzburg, Am Hubland, Würzburg, Germany
| | - Vanessa Fiedler
- Department of Radiation Oncology, University Hospital Würzburg, Würzburg, Germany
| | - Astrid Katzer
- Department of Radiation Oncology, University Hospital Würzburg, Würzburg, Germany
| | - Georg Krohne
- Elektronenmikroskopie, Biozentrum, Universität Würzburg, Am Hubland, Würzburg, Germany
| | - Michael Flentje
- Department of Radiation Oncology, University Hospital Würzburg, Würzburg, Germany
| | - Cholpon S. Djuzenova
- Department of Radiation Oncology, University Hospital Würzburg, Würzburg, Germany
- * E-mail: (VLS); (CSD)
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Reddy SDN, Pakala SB, Molli PR, Sahni N, Karanam NK, Mudvari P, Kumar R. Metastasis-associated protein 1/histone deacetylase 4-nucleosome remodeling and deacetylase complex regulates phosphatase and tensin homolog gene expression and function. J Biol Chem 2012; 287:27843-50. [PMID: 22700976 PMCID: PMC3431680 DOI: 10.1074/jbc.m112.348474] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 06/13/2012] [Indexed: 12/11/2022] Open
Abstract
Metastasis-associated protein 1 (MTA1) is widely overexpressed in human cancers and is associated with malignant phenotypic changes contributing to morbidity in the associated diseases. Here we discovered for the first time that MTA1, a master chromatin modifier, transcriptionally represses the expression of phosphatase and tensin homolog (PTEN), a tumor suppressor gene, by recruiting class II histone deacetylase 4 (HDAC4) along with the transcription factor Yin-Yang 1 (YY1) onto the PTEN promoter. We also found evidence of an inverse correlation between the expression levels of MTA1 and PTEN in physiologically relevant breast cancer microarray datasets. We found that MTA1 up-regulation leads to a decreased expression of PTEN protein and stimulation of PI3K as well as phosphorylation of its signaling targets. Accordingly, selective down-regulation of MTA1 in breast cancer cells increases PTEN expression and inhibits stimulation of the PI3K/AKT signaling. Collectively, these findings provide a mechanistic role for MTA1 in transcriptional repression of PTEN, leading to modulation of the resulting signaling pathways.
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Affiliation(s)
- Sirigiri Divijendra Natha Reddy
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Suresh B. Pakala
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Poonam R. Molli
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Neil Sahni
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Narasimha Kumar Karanam
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Prakriti Mudvari
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
| | - Rakesh Kumar
- From the Department of Biochemistry and Molecular Biology, School of Medicine and Health Sciences, The George Washington University, Washington, D. C. 20037
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Sadeq V, Isar N, Manoochehr T. Association of sporadic breast cancer with PTEN/MMAC1/TEP1 promoter hypermethylation. Med Oncol 2010; 28:420-3. [PMID: 20237868 DOI: 10.1007/s12032-010-9473-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Accepted: 02/25/2010] [Indexed: 10/19/2022]
Abstract
PTEN/MMAC1/TEP1 encodes a tumor suppressor protein, which regulates cell cycle progression, translation, and apoptosis by blocking the activation of Akt/PKB. The loss of PTEN function increases cell survival and induces tumor invasion. In this study, PTEN promoter status and its correlation with genetic and pathologic parameters were analyzed in genomic DNA from Iranian patients with breast cancer. DNA methylation patterns in the CpG islands were determined by a methylation-specific PCR (MSP) assay. PTEN promoter methylation was found to be present in 37 of 53(70%) tumor tissues and none in 20 normal counterparts. Moreover, promoter methylation was found in patients with heterozygote mutation in the PTEN gene. The pathological history of cancerous tissue sections showed that PTEN gene could be inactivated at the stages III and IV in sporadic breast cancer. These findings suggested that promoter hypermethylation of PTEN might contribute to the progression of sporadic breast cancer in human.
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Affiliation(s)
- Vallian Sadeq
- Division of Genetics, Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Islamic Republic of Iran.
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13
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Hays E, Schmidt J, Chandar N. Beta-catenin is not activated by downregulation of PTEN in osteoblasts. In Vitro Cell Dev Biol Anim 2009; 45:361-70. [DOI: 10.1007/s11626-009-9189-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 02/12/2009] [Indexed: 11/24/2022]
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14
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Mise-Omata S, Kuroda E, Sugiura T, Yamashita U, Obata Y, Doi TS. The NF-κB RelA Subunit Confers Resistance toLeishmania majorby Inducing Nitric Oxide Synthase 2 and Fas Expression but Not Th1 Differentiation. THE JOURNAL OF IMMUNOLOGY 2009; 182:4910-6. [DOI: 10.4049/jimmunol.0800967] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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15
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Cdc6 and cyclin E2 are PTEN-regulated genes associated with human prostate cancer metastasis. Neoplasia 2009; 11:66-76. [PMID: 19107233 DOI: 10.1593/neo.81048] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Revised: 09/30/2008] [Accepted: 10/06/2008] [Indexed: 11/18/2022]
Abstract
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is frequently inactivated in metastatic prostate cancer, yet the molecular consequences of this and their association with the metastatic phenotype are incompletely understood. We performed transcriptomic analysis and identified genes altered by conditional PTEN reexpression in C4-2, a human metastatic prostate cancer cell line with inactive PTEN. PTEN-regulated genes were disproportionately represented among genes altered in human prostate cancer progression and metastasis but not among those associated with tumorigenesis. From the former set, we identified two novel putative PTEN targets, cdc6 and cyclin E2, which were overexpressed in metastatic human prostate cancer and up-regulated as a function of PTEN depletion in poorly metastatic DU145 human prostate cancer cells harboring a wild type PTEN. Inhibition of cdc6 and cyclin E2 levels as a consequence of PTEN expression was associated with cell cycle G(1) arrest, whereas use of PTEN activity mutants revealed that regulation of these genes was dependent on PTEN lipid phosphatase activity. Computational and promoter-reporter evaluations implicated the E2F transcription factor in PTEN regulation of cdc6 and cyclin E2 expression. Our results suggest a hypothetical model whereby PTEN loss upregulates cell cycle genes such as cdc6 and cyclin E2 that in turn promote metastatic colonization at distant sites.
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Toyoshima F, Matsumura S, Morimoto H, Mitsushima M, Nishida E. PtdIns(3,4,5)P3 regulates spindle orientation in adherent cells. Dev Cell 2008; 13:796-811. [PMID: 18061563 DOI: 10.1016/j.devcel.2007.10.014] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 08/30/2007] [Accepted: 10/24/2007] [Indexed: 12/21/2022]
Abstract
Cultured adherent cells divide on the substratum, leading to formation of the cell monolayer. However, how the orientation of this anchorage-dependent cell division is regulated remains unknown. We have previously shown that integrin-dependent adhesion orients the spindle parallel to the substratum, which ensures this anchorage-dependent cell division. Here, we show that phosphatidylinositol-3,4,5-triphosphate (PtdIns(3,4,5)P3) is essential for this spindle orientation control. In metaphase, PtdIns(3,4,5)P3 is accumulated in the midcortex in an integrin-dependent manner. Inhibition of phosphatidylinositol-3-OH kinase (PI(3)K) reduces the accumulation of PtdIns(3,4,5)P3 and induces spindle misorientation. Introduction of PtdIns(3,4,5)P3 to these cells restores the midcortical accumulation of PtdIns(3,4,5)P3 and proper spindle orientation. PI(3)K inhibition causes dynein-dependent spindle rotations along the z-axis, resulting in spindle misorientation. Moreover, dynactin, a dynein-binding partner, is accumulated in the midcortex in a PtdIns(3,4,5)P3-dependent manner. We propose that PtdIns(3,4,5)P3 directs dynein/dynactin-dependent pulling forces on spindles to the midcortex, and thereby orients the spindle parallel to the substratum.
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Affiliation(s)
- Fumiko Toyoshima
- Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
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Wan W, Zou H, Sun R, Liu Y, Wang J, Ma D, Zhang N. Investigate the role of PTEN in chemotaxis of human breast cancer cells. Cell Signal 2007; 19:2227-36. [PMID: 17761400 DOI: 10.1016/j.cellsig.2007.06.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Accepted: 06/14/2007] [Indexed: 01/09/2023]
Abstract
Chemotaxis plays an important role in metastasis of cancer cells. In the current study, we investigated the role of PTEN, a tumor suppressor, in chemotaxis of human breast cancer cells. Over-expression of PTEN inhibited EGF-induced chemotaxis, probably due to an overall reduction of PIP(3) levels. Disruption of PTEN by siRNA caused a marked decrease in chemokinesis, cell adhesion, and membrane spreading, resulting in a severe defect in chemotaxis. In PTEN disrupted cells, PDK1, AKT, and PKCzeta exhibited elevated basal activities, which prevented EGF-induced further activation of these molecules. In the absence of EGF, active PDK1 was detected on multiple directions of the plasma membranes of PTEN disrupted cells, which competed against EGF-induced gradient sensing. To confirm the biological relevance of in vitro studies, both PTEN disrupted cells and its parental human breast cancer cells were injected into tail veins of SCID mice. Mice injected with PTEN disrupted cancer cells showed a marked decrease in lung metastasis. Taken together, our data show that PTEN plays a non-redundant role in EGF-induced chemotaxis of human breast cancer cells, and an optimal level of PTEN is required in these responses.
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Affiliation(s)
- Wuzhou Wan
- Beijing National Laboratory for Molecular Sciences (BNLMS), Department of Chemical Biology, and State Key Laboratory of Molecular Dynamic and Stable Structures, College of Chemistry, Peking University, Beijing, China
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Lackey J, Barnett J, Davidson L, Batty IH, Leslie NR, Downes CP. Loss of PTEN selectively desensitizes upstream IGF1 and insulin signaling. Oncogene 2007; 26:7132-42. [PMID: 17486056 PMCID: PMC2773499 DOI: 10.1038/sj.onc.1210520] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Many tumors have chronically elevated activity of PI 3-kinase-dependent signaling pathways, caused largely by oncogenic mutation of PI 3-kinase itself or loss of the opposing tumor suppressor lipid phosphatase, PTEN. Several PI 3-kinase-dependent feedback mechanisms have been identified that may affect the sensitivity of upstream receptor signaling, but the events required to initiate an inhibited state have not been addressed. We show that in a variety of cell types, loss of PTEN via experimental knockdown or in tumor cell lines correlates with a block in insulin-like growth factor 1 (IGF1)/insulin signaling, without affecting the sensitivity of platelet-derived growth factor or epidermal growth factor signaling. These effects on IGF/insulin signaling include a reduction of up to five- to tenfold in IGF-stimulated PI 3-kinase activation, a failure to activate the ERK kinases and, in some cells, reduced expression of insulin receptor substrate 1, and both IGF1 and insulin receptors. These data indicate that chronically elevated PI 3-kinase-dependent signaling to the degree seen in many tumors causes a selective loss of sensitivity in IGF1/insulin signaling that could significantly reduce the selective advantage of deregulated activation of IGF1/IGF1-R signaling in tumor development.
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Affiliation(s)
| | | | | | | | - Nick R. Leslie
- Author for correspondence, Nick Leslie, Tel: 44-1382-386263 Fax: 44-1382-385507
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Jaluria P, Betenbaugh M, Konstantopoulos K, Frank B, Shiloach J. Application of microarrays to identify and characterize genes involved in attachment dependence in HeLa cells. Metab Eng 2006; 9:241-51. [PMID: 17240181 PMCID: PMC2001267 DOI: 10.1016/j.ymben.2006.12.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2006] [Revised: 12/04/2006] [Accepted: 12/06/2006] [Indexed: 11/23/2022]
Abstract
The ability to modify cellular properties such as adhesion is of interest in the design and performance of biotechnology-related processes. The current study was undertaken in order to evaluate the effectiveness of modulating cellular adhesion in HeLa cells from a genomics perspective. Using DNA microarrays, differences in gene expression between two phenotypically distinct, anchorage-dependent and anchorage-independent, HeLa cell lines were identified. With the aid of several statistical methods and an extensive literature search, two genes were selected as potential targets for further study: siat7e and lama4. Subsequently, experiments were carried out to investigate the effects of siat7e and lama4 separately, on adhesion in HeLa cells by altering their expression in vivo. Decreasing the expression of siat7e, a type II membrane glycosylating sialyltransferase, in anchorage-independent HeLa cells using short interfering RNA (siRNA) resulted in greater aggregation (i.e. clumping) and morphological changes as compared to untreated anchorage-independent HeLa cells. Similar effects were seen in anchorage-independent HeLa cells when the expression of lama4 which encodes laminin alpha4, a member of the laminin family of glycoproteins, was enhanced as compared to untreated anchorage-independent HeLa cells. Using a shear flow chamber, an attachment assay was developed; illustrating either increased expression of siat7e or decreased expression of lama4 in anchorage-dependent HeLa cells reduced cellular adhesion. Collectively, the results of this study are consistent with the roles siat7e and lama4 play in adhesion processes in vivo and indicate modifying the expression of either gene can influence adhesion in HeLa cells. The strategy of applying bioinformatics techniques to characterize and manipulate phenotypic behaviors is a powerful tool for altering the properties of various cell lines for desired biotechnology objectives.
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Affiliation(s)
- Pratik Jaluria
- Department of Chemical and Biomolecular Engineering Johns Hopkins University Baltimore, MD 21218
- National Institute of Diabetes & Digestive & Kidney Diseases (NIDDK) National Institutes of Health (NIH) Bethesda, MD 20892
| | - Michael Betenbaugh
- Department of Chemical and Biomolecular Engineering Johns Hopkins University Baltimore, MD 21218
| | | | - Bryan Frank
- The Institute for Genomic Research (TIGR) Rockville, MD 20850
| | - Joseph Shiloach
- National Institute of Diabetes & Digestive & Kidney Diseases (NIDDK) National Institutes of Health (NIH) Bethesda, MD 20892
- Correspondences should be sent to: Joseph Shiloach, Biotechnology Core Laboratory, NIH/NIDDK, Bldg 14A Room 173, Bethesda, MD 20892, Ph: 301 496 9719, Fax: 301 451 5911, E. mail:
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Paternotte N, Zhang J, Vandenbroere I, Backers K, Blero D, Kioka N, Vanderwinden JM, Pirson I, Erneux C. SHIP2 interaction with the cytoskeletal protein Vinexin. FEBS J 2005; 272:6052-66. [PMID: 16302969 DOI: 10.1111/j.1742-4658.2005.04996.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The src homology 2 (SH2) domain-containing inositol 5-phosphatase 2 (SHIP2) catalyses the dephosphorylation of phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P3] to phosphatidylinositol 3,4-bisphosphate [PtdIns(3,4)P2]. We report the identification of the cytoskeletal protein Vinexin as a protein interacting with SHIP2. This was achieved by yeast two-hybrid screening using the C-terminal region of SHIP2 as bait. Vinexin has previously been identified as a vinculin-binding protein that plays a key role in cell spreading and cytoskeletal organization. The interaction between SHIP2 and Vinexin was confirmed in lysates of both COS-7 cells and mouse embryonic fibroblasts (MEF). The C-terminus was involved in the interaction, as shown by the transfection of a truncated C-terminus mutant of SHIP2. In addition, we showed the colocalization between Vinexin alpha and SHIP2 at the periphery of transfected COS-7 cells. When added in vitro to SHIP2, Vinexin did not affect the PtdIns(3,4,5)P3 5-phosphatase activity of SHIP2. Enhanced cell adhesion to collagen-I-coated dishes was shown upon transfection of either SHIP2 or Vinexin to COS-7 cells. This effect was no longer observed with either a catalytic mutant or the C-terminus mutant of SHIP2. It also appears SHIP2 specific; this was not seen with SHIP1. Adhesion to the same matrix was decreased in SHIP2-/- MEF cells compared with MEF+/+ cells. Our data suggest that SHIP2 interaction with Vinexin promotes the localization of SHIP2 at the periphery of the cells leaving its catalytic site intact. The complex formation between Vinexin and SHIP2 may increase cellular adhesion. The data reinforce the concept that SHIP2 is active both as a PtdIns(3,4,5)P3 5-phosphatase and as a modulator of focal contact formation.
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Affiliation(s)
- Nathalie Paternotte
- Interdisciplinary Research Institute (IRIBHM), Université Libre de Bruxelles, Brussels, Belgium
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