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He Y, Goyette MA, Chapelle J, Boufaied N, Al Rahbani J, Schonewolff M, Danek EI, Muller WJ, Labbé DP, Côté JF, Lamarche-Vane N. CdGAP is a talin-binding protein and a target of TGF-β signaling that promotes HER2-positive breast cancer growth and metastasis. Cell Rep 2023; 42:112936. [PMID: 37552602 DOI: 10.1016/j.celrep.2023.112936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 05/10/2023] [Accepted: 07/20/2023] [Indexed: 08/10/2023] Open
Abstract
Epithelial-to-mesenchymal transition (EMT) plays a crucial role in metastasis, which is the leading cause of death in breast cancer patients. Here, we show that Cdc42 GTPase-activating protein (CdGAP) promotes tumor formation and metastasis to lungs in the HER2-positive (HER2+) murine breast cancer model. CdGAP facilitates intravasation, extravasation, and growth at metastatic sites. CdGAP depletion in HER2+ murine primary tumors mediates crosstalk with a Dlc1-RhoA pathway and is associated with a transforming growth factor β (TGF-β)-induced EMT transcriptional signature. CdGAP is positively regulated by TGF-β signaling during EMT and interacts with the adaptor talin to modulate focal adhesion dynamics and integrin activation. Moreover, HER2+ breast cancer patients with high CdGAP mRNA expression combined with a high TGF-β-EMT signature are more likely to present lymph node invasion. Our results suggest CdGAP as a candidate therapeutic target for HER2+ metastatic breast cancer by inhibiting TGF-β and integrin/talin signaling pathways.
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Affiliation(s)
- Yi He
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada
| | - Marie-Anne Goyette
- Institut de Recherches Cliniques de Montréal, Université de Montréal, Montréal, QC H2W 1R7, Canada
| | - Jennifer Chapelle
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada
| | - Nadia Boufaied
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada
| | - Jalal Al Rahbani
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada
| | - Maribel Schonewolff
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada
| | - Eric I Danek
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada
| | - William J Muller
- Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montréal, QC H3A 1A3, Canada
| | - David P Labbé
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada; Division of Urology, Department of Surgery, McGill University, Montréal, QC H4A 3J1, Canada
| | - Jean-François Côté
- Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada; Institut de Recherches Cliniques de Montréal, Université de Montréal, Montréal, QC H2W 1R7, Canada
| | - Nathalie Lamarche-Vane
- Cancer Research Program, Research Institute of the McGill University Health Centre, Montréal, QC H4A 3J1, Canada; Department of Anatomy and Cell Biology, McGill University, Montréal, QC H3A 0C7, Canada.
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Gao K, Gao Z, Xia M, Li H, Di J. Role of plectin and its interacting molecules in cancer. Med Oncol 2023; 40:280. [PMID: 37632650 DOI: 10.1007/s12032-023-02132-4] [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: 04/24/2023] [Accepted: 07/20/2023] [Indexed: 08/28/2023]
Abstract
Plectin, as the cytolinker and scaffolding protein, are widely expressed and abundant in many tissues, and has involved in various cellular activities contributing to tumorigenesis, such as cell adhesion, migration, and signal transduction. Due to the specific expression and differential localization of plectin in cancer, most researchers focus on the role of plectin in cancer, and it has emerged as a potent driver of malignant hallmarks in many human cancers, which provides the possibility for plectin to be widely used as a biomarker and therapeutic target in the early diagnosis and targeted drug delivery of the disease. However, there is still a lack of systematic review on the interaction molecules and mechanism of plectin. Herein, we summarized the structure, expression and function of plectin, and mainly focused on recent studies on the functional and physical interactions between plectin and its interacting molecules, shedding light on the potential of targeting plectin for cancer therapy.
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Affiliation(s)
- Keyu Gao
- Department of Urology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221002, Jiangsu, China
| | - Zhimin Gao
- Department of Urology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221002, Jiangsu, China
| | - Mingyi Xia
- Cancer Institute, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China
- Center of Clinical Oncology, The Affiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, 221002, Jiangsu, China
- Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China
| | - Hailong Li
- Department of Urology, Affiliated Hospital of Xuzhou Medical University, Xuzhou, 221002, Jiangsu, China.
| | - Jiehui Di
- Cancer Institute, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China.
- Center of Clinical Oncology, The Affiliated Hospital of Xuzhou Medical University, 99 West Huaihai Road, Xuzhou, 221002, Jiangsu, China.
- Jiangsu Center for the Collaboration and Innovation of Cancer Biotherapy, Xuzhou Medical University, 209 Tongshan Road, Xuzhou, 221004, Jiangsu, China.
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Frey Y, Franz-Wachtel M, Macek B, Olayioye MA. Proteasomal turnover of the RhoGAP tumor suppressor DLC1 is regulated by HECTD1 and USP7. Sci Rep 2022; 12:5036. [PMID: 35322810 PMCID: PMC8943137 DOI: 10.1038/s41598-022-08844-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 03/09/2022] [Indexed: 11/16/2022] Open
Abstract
The Rho GTPase activating protein Deleted in Liver Cancer 1 (DLC1) is frequently downregulated through genetic and epigenetic mechanisms in various malignancies, leading to aberrant Rho GTPase signaling and thus facilitating cancer progression. Here we show that in breast cancer cells, dysregulation of DLC1 expression occurs at the protein level through rapid degradation via the ubiquitin–proteasome system. Using mass spectrometry, we identify two novel DLC1 interaction partners, the ubiquitin-ligase HECTD1 and the deubiquitinating enzyme ubiquitin-specific-processing protease 7 (USP7). While DLC1 protein expression was rapidly downregulated upon pharmacological inhibition of USP7, siRNA-mediated knockdown of HECTD1 increased DLC1 protein levels and impaired its degradation. Immunofluorescence microscopy analyses revealed that the modulation of HECTD1 levels and USP7 activity altered DLC1 abundance at focal adhesions, its primary site of action. Thus, we propose opposing regulatory mechanisms of DLC1 protein homeostasis by USP7 and HECTD1, which could open up strategies to counteract downregulation and restore DLC1 expression in cancer.
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Affiliation(s)
- Yannick Frey
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, 70569, Stuttgart, Germany
| | - Mirita Franz-Wachtel
- Proteome Center Tübingen, University of Tübingen, Auf der Morgenstelle 15, 72076, Tübingen, Germany
| | - Boris Macek
- Proteome Center Tübingen, University of Tübingen, Auf der Morgenstelle 15, 72076, Tübingen, Germany
| | - Monilola A Olayioye
- Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, 70569, Stuttgart, Germany. .,Stuttgart Research Center Systems Biology (SRCSB), University of Stuttgart, 70569, Stuttgart, Germany.
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Fixing the GAP: the role of RhoGAPs in cancer. Eur J Cell Biol 2022; 101:151209. [DOI: 10.1016/j.ejcb.2022.151209] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 01/29/2022] [Accepted: 02/08/2022] [Indexed: 12/12/2022] Open
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Abdellatef S, Fakhoury I, Al Haddad M, Jaafar L, Maalouf H, Hanna S, Khalil B, El Masri Z, Hodgson L, El-Sibai M. StarD13 negatively regulates invadopodia formation and invasion in high-grade serous (HGS) ovarian adenocarcinoma cells by inhibiting Cdc42. Eur J Cell Biol 2022; 101:151197. [PMID: 34958986 PMCID: PMC8756770 DOI: 10.1016/j.ejcb.2021.151197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 12/18/2021] [Accepted: 12/19/2021] [Indexed: 01/03/2023] Open
Abstract
Metastasis remains the main challenge to overcome for treating ovarian cancers. In this study, we investigate the potential role of the Cdc42 GAP StarD13 in the modulation of cell motility, invasion in ovarian cancer cells. StarD13 depletion does not affect the 2D motility of ovarian cancer cells. More importantly, StarD13 inhibits matrix degradation, invadopodia formation and cell invasion through the inhibition of Cdc42. StarD13 does not localize to mature TKS4-labeled invadopodia that possess matrix degradation ability, while a Cdc42 FRET biosensor, detects Cdc42 activation in these invadopodia. In fact, StarD13 localization and Cdc42 activation appear mutually exclusive in invadopodial structures. Finally, for the first time we uncover a potential role of Cdc42 in the direct recruitment of TKS4 to invadopodia. This study emphasizes the specific role of StarD13 as a narrow spatial regulator of Cdc42, inhibiting invasion, suggesting the suitability of StarD13 for targeted therapy.
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Affiliation(s)
- Sandra Abdellatef
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut, Lebanon
| | - Isabelle Fakhoury
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut, Lebanon
| | - Maria Al Haddad
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut, Lebanon
| | - Leila Jaafar
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut, Lebanon
| | - Hiba Maalouf
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut, Lebanon
| | - Samer Hanna
- Department of Pediatrics Hematology/Oncology division, Weill Cornell Medicine, Joan & Sanford I. Weill Medical College of Cornell University, Ithaca, NY, USA
| | - Bassem Khalil
- Department of Medicine, Icahn School of Medicine at Mount Sinai, Department of Biological Sciences, Fordham University, Bronx, NY, USA
| | - Zeinab El Masri
- Department of Biochemistry and Molecular Biology, University Park, Pennsylvania State University, State College, PA, USA
| | - Louis Hodgson
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY, USA,Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY, USA
| | - Mirvat El-Sibai
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Beirut, Lebanon,Correspondence to: Department of Natural Sciences, Lebanese American University, P.O. Box: 13-5053, Chouran 1102 2801, Beirut, Lebanon. (M. El-Sibai)
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Tumor suppressor gene DLC1: Its modifications, interactive molecules, and potential prospects for clinical cancer application. Int J Biol Macromol 2021; 182:264-275. [PMID: 33836193 DOI: 10.1016/j.ijbiomac.2021.04.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/02/2021] [Accepted: 04/04/2021] [Indexed: 12/12/2022]
Abstract
Deleted in liver cancer 1 (DLC1) is a recognized tumor suppressor gene that negatively regulates Rho family proteins by hydrolyzing the active GTP-bound state to its inactive GDP-bound state. Active Rho proteins play a positive role in tumorigenesis. Numerous in vitro and in vivo experiments have shown that DLC1 is downregulated or inactivated in various solid tumors, which may be due to the following five reasons: genomic deletion, epigenetic modification and ubiquitin-dependent proteasomal degradation may cause DLC1 underexpression; phosphorylation at the post-translation level may cause DLC1 inactivation; and failure to localize at focal adhesions (FAs) may prevent DLC1 from exerting full activity. All of the causes could be attributed to molecular binding. Experimental evidence suggests that direct or indirect targeting of DLC1 is feasible for cancer treatment. Therefore, elucidating the interaction of DLC1 with its binding partners might provide novel targeted therapies for cancer. In this review, we summarized the binding partners of DLC1 at both the gene and protein levels and expounded a variety of anticancer drugs targeting DLC1 to provide information about DLC1 as a cancer diagnostic indicator or therapeutic target.
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7
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Zhang Y, Li G. A tumor suppressor DLC1: The functions and signal pathways. J Cell Physiol 2019; 235:4999-5007. [DOI: 10.1002/jcp.29402] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 09/27/2019] [Indexed: 12/14/2022]
Affiliation(s)
- Yang Zhang
- Shandong Provincial Key Laboratory of Animal Resistant, School of Life SciencesShandong Normal UniversityJinan China
| | - Guorong Li
- Shandong Provincial Key Laboratory of Animal Resistant, School of Life SciencesShandong Normal UniversityJinan China
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Chen L, Hu W, Li G, Guo Y, Wan Z, Yu J. Inhibition of miR-9-5p suppresses prostate cancer progress by targeting StarD13. Cell Mol Biol Lett 2019; 24:20. [PMID: 30899277 PMCID: PMC6408831 DOI: 10.1186/s11658-019-0145-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 02/25/2019] [Indexed: 12/21/2022] Open
Abstract
Background This study aims to investigate the effects of inhibiting microRNA-9-5p (miR-9-5p) on the expression of StAR-related lipid transfer domain containing 13 (StarD13) and the progress of prostate cancer. Methods The mRNA expression levels of miR-9-5p and StarD13 were determined in several prostate cancer cell lines. We chose DU145 and PC-3 cells for further research. The CCK8 assay was used to measure the cell viability. The cell invasion and wound-healing assays were respectively applied to evaluate invasion and migration. The expression of E-cadherin (E-cad), N-cadherin (N-cad) and vimentin were measured via western blot. DU145 and PC-3 cells overexpressing StarD13 were generated to investigate the variation in proliferation, invasion and migration. A luciferase reporter assay was used to identify the target of miR-9-5p. Results Our results show that miR-9-5p was highly expressed and StarD13 was suppressed in prostate cancer cells. MiR-9-5p inhibition repressed the cells’ viability, invasion and migration. It also increased the expression of E-cad and decreased that of N-cad and vimentin. StarD13 overexpression gave the same results as silencing of miR-9-5p: suppression of cell proliferation, invasion and migration. The bioinformatics analysis predicted StarD13 as a target gene of miR-9-5p. Quantitative RT-PCR, western blot analysis and the dual-luciferase reporter assay were employed to confirm the prediction. Conclusion Our results show that miR-9-5p plays a powerful role in the growth, invasion, migration and epithelial–mesenchymal transition (EMT) of prostate cancer cells by regulating StarD13. A therapeutic agent inhibiting miR-9-5p could act as a tumor suppressor for prostate cancer.
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Affiliation(s)
- Lin Chen
- Department of Urology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, No. 26 Shengli Street, Jiang'an District, Wuhan, 430014 China
| | - Weifeng Hu
- Department of Urology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, No. 26 Shengli Street, Jiang'an District, Wuhan, 430014 China
| | - Guohao Li
- Department of Urology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, No. 26 Shengli Street, Jiang'an District, Wuhan, 430014 China
| | - Yonglian Guo
- Department of Urology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, No. 26 Shengli Street, Jiang'an District, Wuhan, 430014 China
| | - Zhihua Wan
- Department of Urology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, No. 26 Shengli Street, Jiang'an District, Wuhan, 430014 China
| | - Jiajun Yu
- Department of Urology, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, No. 26 Shengli Street, Jiang'an District, Wuhan, 430014 China
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Jensch A, Frey Y, Bitschar K, Weber P, Schmid S, Hausser A, Olayioye MA, Radde NE. The tumor suppressor protein DLC1 maintains protein kinase D activity and Golgi secretory function. J Biol Chem 2018; 293:14407-14416. [PMID: 30045871 DOI: 10.1074/jbc.ra118.003787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 07/05/2018] [Indexed: 12/12/2022] Open
Abstract
Many newly synthesized cellular proteins pass through the Golgi complex from where secretory transport carriers sort them to the plasma membrane and the extracellular environment. The formation of these secretory carriers at the trans-Golgi network is promoted by the protein kinase D (PKD) family of serine/threonine kinases. Here, using mathematical modeling and experimental validation of the PKD activation and substrate phosphorylation kinetics, we reveal that the expression level of the PKD substrate deleted in liver cancer 1 (DLC1), a Rho GTPase-activating protein that is inhibited by PKD-mediated phosphorylation, determines PKD activity at the Golgi membranes. RNAi-mediated depletion of DLC1 reduced PKD activity in a Rho-Rho-associated protein kinase (ROCK)-dependent manner, impaired the exocytosis of the cargo protein horseradish peroxidase, and was associated with the accumulation of the small GTPase RAB6 on Golgi membranes, indicating a protein-trafficking defect. In summary, our findings reveal that DLC1 maintains basal activation of PKD at the Golgi and Golgi secretory activity, in part by down-regulating Rho-ROCK signaling. We propose that PKD senses cytoskeletal changes downstream of DLC1 to coordinate Rho signaling with Golgi secretory function.
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Affiliation(s)
- Antje Jensch
- From the Institute for Systems Theory and Automatic Control and
| | - Yannick Frey
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany and
| | - Katharina Bitschar
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany and
| | - Patrick Weber
- From the Institute for Systems Theory and Automatic Control and
| | - Simone Schmid
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany and
| | - Angelika Hausser
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany and.,the Stuttgart Research Center Systems Biology (SRCSB), 70569 Stuttgart, Germany
| | - Monilola A Olayioye
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany and .,the Stuttgart Research Center Systems Biology (SRCSB), 70569 Stuttgart, Germany
| | - Nicole E Radde
- From the Institute for Systems Theory and Automatic Control and .,the Stuttgart Research Center Systems Biology (SRCSB), 70569 Stuttgart, Germany
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Basak P, Leslie H, Dillon RL, Muller WJ, Raouf A, Mowat MRA. In vivoevidence supporting a metastasis suppressor role forStard13(Dlc2) inErbB2(Neu) oncogene induced mouse mammary tumors. Genes Chromosomes Cancer 2017; 57:182-191. [DOI: 10.1002/gcc.22519] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 11/27/2017] [Accepted: 12/05/2017] [Indexed: 01/05/2023] Open
Affiliation(s)
- Pratima Basak
- Research Institute of Oncology & Hematology, CancerCare Manitoba; Winnipeg Manitoba R3E 0V9 Canada
- Department of Biochemistry & Medical Genetics; University of Manitoba; Winnipeg Manitoba R3E 0J9 Canada
- Department of Immunology; University of Manitoba; Winnipeg Manitoba R3E 0T5 Canada
| | - Heather Leslie
- Research Institute of Oncology & Hematology, CancerCare Manitoba; Winnipeg Manitoba R3E 0V9 Canada
| | - Rachelle L. Dillon
- Research Institute of Oncology & Hematology, CancerCare Manitoba; Winnipeg Manitoba R3E 0V9 Canada
| | - William J. Muller
- Department of Biochemistry; Rosalind and Morris Goodman Cancer Research Centre, McGill University; Montreal Quebec H3A 1A3 Canada
| | - Afshin Raouf
- Research Institute of Oncology & Hematology, CancerCare Manitoba; Winnipeg Manitoba R3E 0V9 Canada
- Department of Immunology; University of Manitoba; Winnipeg Manitoba R3E 0T5 Canada
| | - Michael R. A. Mowat
- Research Institute of Oncology & Hematology, CancerCare Manitoba; Winnipeg Manitoba R3E 0V9 Canada
- Department of Biochemistry & Medical Genetics; University of Manitoba; Winnipeg Manitoba R3E 0J9 Canada
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Abstract
Malignant carcinomas are often characterized by metastasis, the movement of carcinoma cells from a primary site to colonize distant organs. For metastasis to occur, carcinoma cells first must adopt a pro-migratory phenotype and move through the surrounding stroma towards a blood or lymphatic vessel. Currently, there are very limited possibilities to target these processes therapeutically. The family of Rho GTPases is an ubiquitously expressed division of GTP-binding proteins involved in the regulation of cytoskeletal dynamics and intracellular signaling. The best characterized members of the Rho family GTPases are RhoA, Rac1 and Cdc42. Abnormalities in Rho GTPase function have major consequences for cancer progression. Rho GTPase activation is driven by cell surface receptors that activate GTP exchange factors (GEFs) and GTPase-activating proteins (GAPs). In this review, we summarize our current knowledge on Rho GTPase function in the regulation of metastasis. We will focus on key discoveries in the regulation of epithelial-mesenchymal-transition (EMT), cell-cell junctions, formation of membrane protrusions, plasticity of cell migration and adaptation to a hypoxic environment. In addition, we will emphasize on crosstalk between Rho GTPase family members and other important oncogenic pathways, such as cyclic AMP-mediated signaling, canonical Wnt/β-catenin, Yes-associated protein (YAP) and hypoxia inducible factor 1α (Hif1α) and provide an overview of the advancements and challenges in developing pharmacological tools to target Rho GTPase and the aforementioned crosstalk in the context of cancer therapeutics.
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12
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Isolation and characterization of Streptomyces tauricus from Thajiwas glacier—a new source of actinomycin-D. Med Chem Res 2017. [DOI: 10.1007/s00044-017-1842-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Tensin4 is up-regulated by EGF-induced ERK1/2 activity and promotes cell proliferation and migration in hepatocellular carcinoma. Oncotarget 2016; 6:20964-76. [PMID: 26035355 PMCID: PMC4673243 DOI: 10.18632/oncotarget.4122] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 05/02/2015] [Indexed: 12/16/2022] Open
Abstract
The focal adhesion protein Tensin4, also known as cten (c-terminal tensin like), is structurally distinct from the three other members in the Tensin family. Its expression and potential functions in cancers including hepatocellular carcinoma (HCC) are not well understood. With immunohistochemistry, 43% (13/30) of our human HCC cases showed up-regulation of Tensin4 as compared with their corresponding non-tumorous livers. In HCC cells, treatment with epidermal growth factor (EGF) significantly induced Tensin4 transcript and protein expression, while treatment with pharmacological inhibitors against the MEK1/2 kinases abolished such induction, suggesting that Tensin4 expression was dependent on Ras/MAPK signaling. With immunofluorescence microscopy, the focal adhesion localization of Tensin4 was confirmed in HCC cells. Significantly, detailed examination using a panel of Tensin4 deletion constructs revealed that this specific focal adhesion localization required the N-terminal region together with the C-terminal SH2 domain. Up-regulation of ERK signaling by EGF in the HCC cells resulted in a change to a mesenchymal cell-like morphology through modulation of the actin cytoskeleton. Functionally, stable Tensin4 knockdown in SMMC-7721 HCC cells resulted in reduced cell proliferation and migration in vitro. Taken together, our data suggest that Tensin4 may play a pro-oncogenic role in HCC, possibly functioning as a downstream effector of Ras/MAPK signaling.
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Sabbir MG, Dillon R, Mowat MRA. Dlc1 interaction with non-muscle myosin heavy chain II-A (Myh9) and Rac1 activation. Biol Open 2016; 5:452-60. [PMID: 26977077 PMCID: PMC4890663 DOI: 10.1242/bio.015859] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 02/23/2016] [Indexed: 01/30/2023] Open
Abstract
The Deleted in liver cancer 1 (Dlc1) gene codes for a Rho GTPase-activating protein that also acts as a tumour suppressor gene. Several studies have consistently found that overexpression leads to excessive cell elongation, cytoskeleton changes and subsequent cell death. However, none of these studies have been able to satisfactorily explain the Dlc1-induced cell morphological phenotypes and the function of the different Dlc1 isoforms. Therefore, we have studied the interacting proteins associated with the three major Dlc1 transcriptional isoforms using a mass spectrometric approach in Dlc1 overexpressing cells. We have found and validated novel interacting partners in constitutive Dlc1-expressing cells. Our study has shown that Dlc1 interacts with non-muscle myosin heavy chain II-A (Myh9), plectin and spectrin proteins in different multiprotein complexes. Overexpression of Dlc1 led to increased phosphorylation of Myh9 protein and activation of Rac1 GTPase. These data support a role for Dlc1 in induced cell elongation morphology and provide some molecular targets for further analysis of this phenotype.
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Affiliation(s)
- Mohammad G Sabbir
- Research Institute of Oncology and Hematology, CancerCare Manitoba, Winnipeg, Manitoba R3E 0V9, Canada
| | - Rachelle Dillon
- Research Institute of Oncology and Hematology, CancerCare Manitoba, Winnipeg, Manitoba R3E 0V9, Canada
| | - Michael R A Mowat
- Research Institute of Oncology and Hematology, CancerCare Manitoba, Winnipeg, Manitoba R3E 0V9, Canada Department of Biochemistry and Medical Genetics, University of Manitoba, Winnipeg, Manitoba, R3E 0J9, Canada
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15
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Flavone inhibits migration through DLC1/RhoA pathway by decreasing ROS generation in breast cancer cells. In Vitro Cell Dev Biol Anim 2016; 52:589-97. [DOI: 10.1007/s11626-016-0010-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/11/2016] [Indexed: 12/14/2022]
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Song LJ, Liu Q, Meng XR, Li SL, Wang LX, Fan QX, Xuan XY. DLC-1 is an independent prognostic marker and potential therapeutic target in hepatocellular cancer. Diagn Pathol 2016; 11:19. [PMID: 26846339 PMCID: PMC4743322 DOI: 10.1186/s13000-016-0470-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/28/2016] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND The 5-year survival rate of patients with hepatocellular cancer (HCC) was very low because of invasion and metastasis in the early stage. Biomarkers might help predict early occurrence of invasion and metastasis. Accumulating evidence has shown that deleted in liver cancer-1 (DLC1) may be considered as a metastasis suppressor gene in numerous solid and hematological cancers. However, its prognostic role and mechanisms that regulate and coordinate these activities remain poorly understood. METHODS With the method of immunohistochemistry, the expression of DLC-1 as well as Rho A, ROCK2, moesin had been characterized in 80 HCC tissues and adjacent noncancerous tissues. The correlation between their expression and their relationships with clinicopathological characteristics of HCC were also investigated. In addition, the prognostic value of DLC1 expression within the tumor tissues was assessed by Cox regression and Kaplan-Meier analysis. RESULTS DLC1 expression was significantly lower in HCC tissues than in adjacent noncancerous tissues, and DLC-1 expression was found to be negatively correlated with tumor differentiation, TNM stage and lymph node metastasis. Furthermore, DLC-1 expression was found to inversely correlate with Rho A, ROCK2 and moesin which were all highly expressed in HCC tissues. Kaplan-Meier analysis showed that significantly longer 5-year survival rate was seen in HCC patients with higher DLC1 expression, compared to those with lower expression of DLC1. Multivariate Cox proportional hazard analyses revealed that DLC1 was an independent factor affecting the overall survival probability. CONCLUSION DLC1 could be served as a tumor suppressor gene in the progression especially in the invasion and metastasis of HCC. DLC1 perhaps played its role by regulating the expression of Rho A, ROCK2 and moesin. Evaluation of the expression of DLC-1 might be a good prognostic marker for patients with HCC.
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Affiliation(s)
- L J Song
- Department of Oncology, the first affiliated hospital of Zhengzhou University, Henan, 450000, China.
| | - Q Liu
- Department of Neurosurgery, the fifth affiliated hospital of Zhengzhou University, Henan, 450000, China.
| | - X R Meng
- Department of Oncology, the first affiliated hospital of Zhengzhou University, Henan, 450000, China.
| | - Sh L Li
- Department of Pathology, the first affiliated hospital of Zhengzhou University, Henan, 450000, China.
| | - L X Wang
- Department of Oncology, the first affiliated hospital of Zhengzhou University, Henan, 450000, China.
| | - Q X Fan
- Department of Oncology, the first affiliated hospital of Zhengzhou University, Henan, 450000, China.
| | - X Y Xuan
- Department of Microbiology and Immunology, Basic Medical School of Zhengzhou University, 100 Kexue Road, Zhengzhou, Henan, 450001, China.
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17
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Basak P, Dillon R, Leslie H, Raouf A, Mowat MRA. The Deleted in Liver Cancer 1 (Dlc1) tumor suppressor is haploinsufficient for mammary gland development and epithelial cell polarity. BMC Cancer 2015; 15:630. [PMID: 26353792 PMCID: PMC4565020 DOI: 10.1186/s12885-015-1642-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 09/01/2015] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Deleted in Liver Cancer 1 (Dlc1) is a tumor suppressor gene, which maps to human chromosome 8p21-22 and is found frequently deleted in many cancers including breast cancer. The promoter of the remaining allele is often found methylated. The Dlc1 gene encodes a RhoGAP protein that regulates cell proliferation, migration and inhibits cell growth and invasion when restored in Dlc1 deficient tumor cell lines. This study focuses on determining the role of Dlc1 in normal mammary gland development and epithelial cell polarity in a Dlc1 gene trapped (gt) mouse. METHODS Mammary gland whole mount preparations from 10-week virgin heterozygous Dlc1(gt/+) gene-trapped mice were compared with age-matched wild type (WT) controls. Hematoxylin-Eosin (H&E) and Masson's Trichrome staining of histological sections were carried out. Mammary glands from Dlc1(gt/+) mice and WT controls were enzymatically digested with collagenase and dispase and then cultured overnight to deplete hematopoietic and endothelial cells. The single cell suspensions were then cultured in Matrigel for 12 days. To knockdown Dlc1 expression, primary WT mammary epithelial cells were infected with short hairpin (sh) RNA expressing lentivirus or with a scrambled shRNA control. RESULTS Dlc1(gt/+) mice showed anomalies in the mammary gland that included increased ductal branching and deformities in terminal end buds and branch points. Compared to the WT controls, Masson's Trichrome staining showed a thickened stromal layer with increased collagen deposition in mammary glands from Dlc1(gt/+) mice. Dlc1(gt/+) primary mammary epithelial cells formed increased solid acinar spheres in contrast with WT and scrambled shRNA control cells, which mostly formed hollow acinar structures when plated in 3D Matrigel cultures. These solid acinar structures were similar to the acinar structures formed when Dlc1 gene expression was knocked down in WT mammary cells by shRNA lentiviral transduction. The solid acinar structures were not due to a defect in apoptosis as determined by a lack of detectible cleaved caspase 3 antibody staining. Primary mammary cells from Dlc1(gt/+) mice showed increased RhoA activity compared with WT cells. CONCLUSIONS The results illustrate that decreased Dlc1 expression can disrupt the normal cell polarization and mammary ductal branching. Altogether this study suggests that Dlc1 plays a role in maintaining normal mammary epithelial cell polarity and that Dlc1 is haploinsufficient.
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Affiliation(s)
- Pratima Basak
- Manitoba Institute of Cell Biology, CancerCare Manitoba, Winnipeg, MB, R3E 0V9, Canada.
- Department of Biochemistry & Medical Genetics, University of Manitoba, Winnipeg, MB, Canada.
- Department of Immunology, University of Manitoba, Winnipeg, MB, Canada.
- Regenerative Medicine Program, University of Manitoba, Winnipeg, MB, Canada.
| | - Rachelle Dillon
- Manitoba Institute of Cell Biology, CancerCare Manitoba, Winnipeg, MB, R3E 0V9, Canada.
| | - Heather Leslie
- Manitoba Institute of Cell Biology, CancerCare Manitoba, Winnipeg, MB, R3E 0V9, Canada.
| | - Afshin Raouf
- Manitoba Institute of Cell Biology, CancerCare Manitoba, Winnipeg, MB, R3E 0V9, Canada.
- Department of Immunology, University of Manitoba, Winnipeg, MB, Canada.
- Regenerative Medicine Program, University of Manitoba, Winnipeg, MB, Canada.
| | - Michael R A Mowat
- Manitoba Institute of Cell Biology, CancerCare Manitoba, Winnipeg, MB, R3E 0V9, Canada.
- Department of Biochemistry & Medical Genetics, University of Manitoba, Winnipeg, MB, Canada.
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Abstract
Metastases are responsible for most cancer-related deaths. One of the hallmarks of metastatic cells is increased motility and migration through extracellular matrixes. These processes rely on specific small GTPases, in particular those of the Rho family. Deleted in liver cancer-1 (DLC1) is a tumor suppressor that bears a RhoGAP activity. This protein is lost in most cancers, allowing malignant cells to proliferate and disseminate in a Rho-dependent manner. However, DLC1 is also a scaffold protein involved in alternative pathways leading to tumor and metastasis suppressor activities. Recently, substantial information has been gathered on these mechanisms and this review is aiming at describing the potential and known alternative GAP-independent mechanisms allowing DLC1 to impair migration, invasion, and metastasis formation.
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Braun AC, Olayioye MA. Rho regulation: DLC proteins in space and time. Cell Signal 2015; 27:1643-51. [PMID: 25889896 DOI: 10.1016/j.cellsig.2015.04.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 04/08/2015] [Indexed: 12/19/2022]
Abstract
Rho GTPases function as molecular switches that connect changes of the external environment to intracellular signaling pathways. They are active at various subcellular sites and require fast and tight regulation to fulfill their role as transducers of extracellular stimuli. New imaging technologies visualizing the active states of Rho proteins in living cells elucidated the necessity of precise spatiotemporal activation of the GTPases. The local regulation of Rho proteins is coordinated by the interaction with different guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) that turn on and off GTPase signaling to downstream effectors. GEFs and GAPs thus serve as critical signaling nodes that specify the amplitude and duration of a particular Rho signaling pathway. Despite their importance in Rho regulation, the molecular aspects underlying the spatiotemporal control of the regulators themselves are still largely elusive. In this review we will focus on the Deleted in Liver Cancer (DLC) family of RhoGAP proteins and summarize the evidence gathered over the past years revealing their different subcellular localizations that might account for isoform-specific functions. We will also highlight the importance of their tightly controlled expression in the context of neoplastic transformation.
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Affiliation(s)
- Anja C Braun
- University of Stuttgart, Institute of Cell Biology and Immunology, Allmandring 31, 70569 Stuttgart, Germany
| | - Monilola A Olayioye
- University of Stuttgart, Institute of Cell Biology and Immunology, Allmandring 31, 70569 Stuttgart, Germany.
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20
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Kaushik S, Ravi A, Hameed FM, Low BC. Concerted modulation of paxillin dynamics at focal adhesions by deleted in liver cancer-1 and focal adhesion kinase during early cell spreading. Cytoskeleton (Hoboken) 2015; 71:677-94. [DOI: 10.1002/cm.21201] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2014] [Accepted: 11/25/2014] [Indexed: 01/24/2023]
Affiliation(s)
- Shelly Kaushik
- Cell Signaling and Developmental Biology Laboratory; Department of Biological Sciences; National University of Singapore; Singapore
- Mechanobiology Institute, National University of Singapore; Singapore
| | - Archna Ravi
- Cell Signaling and Developmental Biology Laboratory; Department of Biological Sciences; National University of Singapore; Singapore
- Mechanobiology Institute, National University of Singapore; Singapore
| | - Feroz M. Hameed
- Mechanobiology Institute, National University of Singapore; Singapore
| | - Boon Chuan Low
- Cell Signaling and Developmental Biology Laboratory; Department of Biological Sciences; National University of Singapore; Singapore
- Mechanobiology Institute, National University of Singapore; Singapore
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21
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Barras D, Chevalier N, Zoete V, Dempsey R, Lapouge K, Olayioye MA, Michielin O, Widmann C. A WXW motif is required for the anticancer activity of the TAT-RasGAP317-326 peptide. J Biol Chem 2014; 289:23701-11. [PMID: 25008324 DOI: 10.1074/jbc.m114.576272] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
TAT-RasGAP317-326, a cell-permeable 10-amino acid-long peptide derived from the N2 fragment of p120 Ras GTPase-activating protein (RasGAP), sensitizes tumor cells to apoptosis induced by various anticancer therapies. This RasGAP-derived peptide, by targeting the deleted in liver cancer-1 (DLC1) tumor suppressor, also hampers cell migration and invasion by promoting cell adherence and by inhibiting cell movement. Here, we systematically investigated the role of each amino acid within the RasGAP317-326 sequence for the anticancer activities of TAT-RasGAP317-326. We report here that the first three amino acids of this sequence, tryptophan, methionine, and tryptophan (WMW), are necessary and sufficient to sensitize cancer cells to cisplatin-induced apoptosis and to reduce cell migration. The WMW motif was found to be critical for the binding of fragment N2 to DLC1. These results define the interaction mode between the active anticancer sequence of RasGAP and DLC1. This knowledge will facilitate the design of small molecules bearing the tumor-sensitizing and antimetastatic activities of TAT-RasGAP317-326.
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Affiliation(s)
- David Barras
- From the Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland
| | - Nadja Chevalier
- From the Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland
| | - Vincent Zoete
- the Molecular Modeling Group, Swiss Institute of Bioinformatics (SIB), Quartier Sorge, Bâtiment Génopode, 1015 Lausanne, Switzerland
| | - Rosemary Dempsey
- From the Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland
| | - Karine Lapouge
- the Department of Fundamental Microbiology, University of Lausanne, 1015 Lausanne, Switzerland, and
| | - Monilola A Olayioye
- the Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany
| | - Olivier Michielin
- the Molecular Modeling Group, Swiss Institute of Bioinformatics (SIB), Quartier Sorge, Bâtiment Génopode, 1015 Lausanne, Switzerland
| | - Christian Widmann
- From the Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland,
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22
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Jaiswal M, Dvorsky R, Amin E, Risse SL, Fansa EK, Zhang SC, Taha MS, Gauhar AR, Nakhaei-Rad S, Kordes C, Koessmeier KT, Cirstea IC, Olayioye MA, Häussinger D, Ahmadian MR. Functional cross-talk between ras and rho pathways: a Ras-specific GTPase-activating protein (p120RasGAP) competitively inhibits the RhoGAP activity of deleted in liver cancer (DLC) tumor suppressor by masking the catalytic arginine finger. J Biol Chem 2014; 289:6839-6849. [PMID: 24443565 DOI: 10.1074/jbc.m113.527655] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The three deleted in liver cancer genes (DLC1-3) encode Rho-specific GTPase-activating proteins (RhoGAPs). Their expression is frequently silenced in a variety of cancers. The RhoGAP activity, which is required for full DLC-dependent tumor suppressor activity, can be inhibited by the Src homology 3 (SH3) domain of a Ras-specific GAP (p120RasGAP). Here, we comprehensively investigated the molecular mechanism underlying cross-talk between two distinct regulators of small GTP-binding proteins using structural and biochemical methods. We demonstrate that only the SH3 domain of p120 selectively inhibits the RhoGAP activity of all three DLC isoforms as compared with a large set of other representative SH3 or RhoGAP proteins. Structural and mutational analyses provide new insights into a putative interaction mode of the p120 SH3 domain with the DLC1 RhoGAP domain that is atypical and does not follow the classical PXXP-directed interaction. Hence, p120 associates with the DLC1 RhoGAP domain by targeting the catalytic arginine finger and thus by competitively and very potently inhibiting RhoGAP activity. The novel findings of this study shed light on the molecular mechanisms underlying the DLC inhibitory effects of p120 and suggest a functional cross-talk between Ras and Rho proteins at the level of regulatory proteins.
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Affiliation(s)
- Mamta Jaiswal
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Radovan Dvorsky
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Ehsan Amin
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Sarah L Risse
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Eyad K Fansa
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Si-Cai Zhang
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Mohamed S Taha
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Aziz R Gauhar
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Saeideh Nakhaei-Rad
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Claus Kordes
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University, 40225 Düsseldorf
| | - Katja T Koessmeier
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf
| | - Ion C Cirstea
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf; Leibniz Institute for Age Research, 07745 Jena
| | - Monilola A Olayioye
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany
| | - Dieter Häussinger
- Clinic for Gastroenterology, Hepatology and Infectiology, Medical Faculty, Heinrich Heine University, 40225 Düsseldorf
| | - Mohammad R Ahmadian
- Institute of Biochemistry and Molecular Biology II, Heinrich Heine University, 40225 Düsseldorf.
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23
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24
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Vigil D, Kim TY, Plachco A, Garton AJ, Castaldo L, Pachter JA, Dong H, Chen X, Tokar B, Campbell SL, Der CJ. ROCK1 and ROCK2 are required for non-small cell lung cancer anchorage-independent growth and invasion. Cancer Res 2012. [PMID: 22942252 DOI: 10.1158/0008-5472.can-11-2373.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Evidence is emerging that the closely related ROCK1 and ROCK2 serine/threonine kinases support the invasive and metastatic growth of a spectrum of human cancer types. Therefore, inhibitors of ROCK are under preclinical development. However, a key step in their development involves the identification of genetic biomarkers that will predict ROCK inhibitor antitumor activity. One identified mechanism for ROCK activation in cancer involves the loss of function of the DLC1 tumor suppressor gene, which encodes a GTPase activating protein (RhoGAP) for the RhoA and RhoC small GTPases. DLC-1 loss may lead to hyperactivation of RhoA/C and its downstream effectors, the ROCK kinases. We therefore determined whether loss of DLC-1 protein expression identifies non-small cell lung carcinoma (NSCLC) cell lines whose growth and invasion phenotypes are sensitive to ROCK inhibition. We identified and characterized a novel small molecule pharmacologic inhibitor of ROCK and additionally applied genetic approaches to impair ROCK1 and/or ROCK2 activity, and we determined that although NSCLC anchorage-dependent growth was ROCK-independent, both anchorage-independent growth and Matrigel invasion were ROCK-dependent. However, loss of DLC-1 expression did not correlate with ROCK activation or with OXA-06 sensitivity. Unexpectedly, suppression of ROCK1 or ROCK2 expression alone was sufficient to impair anchorage-independent growth, supporting their nonoverlapping roles in oncogenesis. Mechanistically, the block in anchorage-independent growth was associated with accumulation of cells in the G(0)-G(1) phase of the cell cycle, but not increased anoikis. We conclude that ROCK may be a useful therapeutic target for NSCLC.
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Affiliation(s)
- Dominico Vigil
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7295, USA
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25
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Vigil D, Kim TY, Plachco A, Garton AJ, Castaldo L, Pachter JA, Dong H, Chen X, Tokar B, Campbell SL, Der CJ. ROCK1 and ROCK2 are required for non-small cell lung cancer anchorage-independent growth and invasion. Cancer Res 2012; 72:5338-47. [PMID: 22942252 DOI: 10.1158/0008-5472.can-11-2373] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Evidence is emerging that the closely related ROCK1 and ROCK2 serine/threonine kinases support the invasive and metastatic growth of a spectrum of human cancer types. Therefore, inhibitors of ROCK are under preclinical development. However, a key step in their development involves the identification of genetic biomarkers that will predict ROCK inhibitor antitumor activity. One identified mechanism for ROCK activation in cancer involves the loss of function of the DLC1 tumor suppressor gene, which encodes a GTPase activating protein (RhoGAP) for the RhoA and RhoC small GTPases. DLC-1 loss may lead to hyperactivation of RhoA/C and its downstream effectors, the ROCK kinases. We therefore determined whether loss of DLC-1 protein expression identifies non-small cell lung carcinoma (NSCLC) cell lines whose growth and invasion phenotypes are sensitive to ROCK inhibition. We identified and characterized a novel small molecule pharmacologic inhibitor of ROCK and additionally applied genetic approaches to impair ROCK1 and/or ROCK2 activity, and we determined that although NSCLC anchorage-dependent growth was ROCK-independent, both anchorage-independent growth and Matrigel invasion were ROCK-dependent. However, loss of DLC-1 expression did not correlate with ROCK activation or with OXA-06 sensitivity. Unexpectedly, suppression of ROCK1 or ROCK2 expression alone was sufficient to impair anchorage-independent growth, supporting their nonoverlapping roles in oncogenesis. Mechanistically, the block in anchorage-independent growth was associated with accumulation of cells in the G(0)-G(1) phase of the cell cycle, but not increased anoikis. We conclude that ROCK may be a useful therapeutic target for NSCLC.
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Affiliation(s)
- Dominico Vigil
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7295, USA
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26
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Kang Z, Xu F, Zhang QA, Lin J, Wu Z, Zhang X, Luo Y, Xu J, Guan M. Correlation of DLC1 gene methylation with oncogenic PIK3CA mutations in extramammary Paget's disease. Mod Pathol 2012; 25:1160-8. [PMID: 22522847 DOI: 10.1038/modpathol.2012.65] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Extramammary Paget's disease is a rare cutaneous malignant neoplasm. The genetic and epigenetic mechanisms underlying its pathology remain unknown. In this study, we investigated the expression levels, and mutation and methylation status of a common tumor suppressor gene, deleted in liver cancer 1 (DLC1), and an oncogene, PIK3CA, in tumor (n=132) and normal tissues (n=20) from unrelated patients. The presence of epigenetic and genetic lesions was then correlated to the patient pathology data to determine the potential role of these genes in extramammary Paget's disease etiology and progression. The DLC1 gene was found to be downregulated in 43 (33%) tumors, as compared with immunohistochemistry results from normal tissues. Methylation-sensitive, high-resolution melting analysis indicated that the DLC1 promoter was hypermethylated in 51 (39%) extramammary Paget's disease tumors. This hypermethylation was associated with significantly decreased DLC1 levels (P=0.011), and had a strong positive correlation with advanced age (P=0.002). PIK3CA mutations were detected by direct sequencing in 32 (24%) tumors, the majority of which were invasive. Furthermore, PIK3CA mutations significantly correlated with DLC1 hypermethylation. Thus, aberrant DLC1 methylation and PIK3CA mutations may have important roles in extramammary Paget's disease pathogenesis, and may represent potential molecular targets for therapy.
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Affiliation(s)
- Zhihua Kang
- Department of Laboratory Medicine, Huashan Hospital, Shanghai Medical School, Fudan University, Shanghai, The People's Republic of China
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27
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Effect of small interfering RNA transfection on FAK and DLC1 mRNA expression in OVCAR-3. Mol Biol Rep 2012; 39:9299-306. [PMID: 22760257 DOI: 10.1007/s11033-012-1724-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2012] [Accepted: 06/06/2012] [Indexed: 01/18/2023]
Abstract
RNA interference is an evolutionarily conserved cellular defense mechanism that protects cells from hostile genes and regulates the function of normal genes during growth and development. In this study, we established GFP-siFAK-DLC1 vector and transfect the vector into OVCAR-3 cells. RT-PCR and western blot analyses were performed for FAK, DLC1 mRNA, and protein expression in OVCAR-3 cells. ELISA method was used for caspase-3 and caspase-9 activities. These studies demonstrate that both recombinant pGFP-siFAK-DLC1 vector and pGFP-siCon-DLC1 vector may effectively promote DLC1 mRNA transcription and didn't affect siRNA effect. Recombinant vector (pGFP-siFAK-DLC1) may promote DLC1 gene expression, and effectively silence FAK gene expression. Silencing FAK mRNA expression and DLC1 mRNA expression may markedly enhance caspase-3 and caspase-9 activities in OVCAR-3 cells. These results showed that in ovarian cancer OVCAR-3 cell silencing FAK gene expression or / and increasing DLC-1 gene expression, could improve Caspase-3 and Caspase-9 protease activities. In the expression of DLC-1 and silence FAK expression group (double action group) effect was more significant as compared with the silence FAK gene group or expression of DLC-1 gene alone, difference was significant (p < 0.05).
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28
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Du X, Qian X, Papageorge A, Schetter AJ, Vass WC, Liu X, Braverman R, Robles AI, Lowy DR. Functional interaction of tumor suppressor DLC1 and caveolin-1 in cancer cells. Cancer Res 2012; 72:4405-16. [PMID: 22693251 DOI: 10.1158/0008-5472.can-12-0777] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Deleted in liver cancer 1 (DLC1), a tumor suppressor gene frequently inactivated in non-small cell lung cancer (NSCLC) and other malignancies, encodes a multidomain protein with a RhoGTPase-activating (RhoGAP) domain and a StAR-related lipid transfer (START) domain. However, no interacting macromolecule has been mapped to the DLC1 START domain. Caveolin-1 (CAV-1) functions as a tumor suppressor in most contexts and forms a complex with DLC1. Here, we have mapped the region of DLC1 required for interaction with CAV-1 to the DLC1 START domain. Mutation of the DLC1 START domain disrupted the interaction and colocalization with CAV-1. Moreover, DLC1 with a START domain mutation failed to suppress neoplastic growth, although it negatively regulated active Rho. CAV-1 and DLC1 expression levels were correlated in two public datasets of NSCLC lines and in two independent publicly available mRNA expression datasets of NSCLC tumors. Clinically, low DLC1 expression predicted a poor clinical outcome in patients with lung cancer. Together, our findings indicate that complex formation between the DLC1 START domain and CAV-1 contributes to DLC1 tumor suppression via a RhoGAP-independent mechanism, and suggest that DLC1 inactivation probably contributes to cancer progression.
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Affiliation(s)
- Xiaoli Du
- Laboratory of Cellular Oncology, Laboratory of Human Carcinogenesis, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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29
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Holeiter G, Bischoff A, Braun AC, Huck B, Erlmann P, Schmid S, Herr R, Brummer T, Olayioye MA. The RhoGAP protein Deleted in Liver Cancer 3 (DLC3) is essential for adherens junctions integrity. Oncogenesis 2012; 1:e13. [PMID: 23552697 PMCID: PMC3412646 DOI: 10.1038/oncsis.2012.13] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Epithelial cell-cell contacts are mediated by E-cadherin interactions, which are regulated by the balanced local activity of Rho GTPases. Despite the known function of Rho at adherens junctions (AJs), little is known about the spatial control of Rho activity at these sites. Here we provide evidence that in breast epithelial cells the Deleted in Liver Cancer 3 (DLC3) protein localizes to AJs and is essential for E-cadherin function. DLC3 is a still poorly characterized RhoA-specific GTPase-activating protein that is frequently downregulated in various types of cancer. We demonstrate that DLC3 depletion leads to mislocalization of E-cadherin and catenins, which was associated with impaired cell aggregation and increased migration. This is explained by aberrant local Rho signaling because ROCK inhibition restored cell-cell contacts in DLC3 knockdown cells. We thus identify DLC3 as a novel negative regulator of junctional Rho and propose that DLC3 loss contributes to carcinogenesis by compromising epithelial integrity.
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Affiliation(s)
- G Holeiter
- Institute of Cell Biology and Immunology, University of Stuttgart, Stuttgart, Germany
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30
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Grunda JM, Steg AD, He Q, Steciuk MR, Byan-Parker S, Johnson MR, Grizzle WE. Differential expression of breast cancer-associated genes between stage- and age-matched tumor specimens from African- and Caucasian-American Women diagnosed with breast cancer. BMC Res Notes 2012; 5:248. [PMID: 22616718 PMCID: PMC3476447 DOI: 10.1186/1756-0500-5-248] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 04/25/2012] [Indexed: 11/24/2022] Open
Abstract
Background Recent studies suggest that the poorer breast cancer outcome observed in African-American women (AAW) may, in part, result from underlying molecular factors. The purpose of this study was to investigate gene expression differences between Caucasian-American women (CAW) and AAW that may contribute to this poorer prognosis. Methods The expression of 84 genes involved in breast carcinoma prognosis, response to therapy, estrogen signaling, and tumor aggressiveness was assessed in age- and stage-matched CAW and AAW paraffin-embedded breast cancer specimens. The Wilcoxon–Mann–Whitney Test was used to identify genes with a significant difference in expression between CAW and AAW. To determine if the differentially expressed genes could segregate between the CAW and AAW, we performed semi-supervised principal component analysis (SSPCA). Results Twenty genes were differentially expressed between AAW and CAW. SSPCA incorporating these 20 genes segregated AAW and CAW into two distinct groups. AAW were significantly (p < 0.05) more likely to display aberrations in G1/S cell-cycle regulatory genes, decreased expression of cell-adhesion genes, and low to no expression of ESR1, PGR, ERBB2 and estrogen pathway targets. Conclusions The gene expression differences identified between AAW and CAW may contribute to more aggressive disease, resistance to therapy, enhanced metastatic potential and poor clinical outcome. These findings support the hypothesis that breast cancer specimens collected from AAW display distinct gene expression differences compared to similar tissues obtained from CAW. Additional population-based studies are necessary to determine if these gene expression variations contribute to the highly aggressive and treatment-resistant breast cancer phenotype frequently observed in AAW.
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Affiliation(s)
- Jessica M Grunda
- Department of Medicine, Division of Endocrinology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Zimonjic DB, Popescu NC. Role of DLC1 tumor suppressor gene and MYC oncogene in pathogenesis of human hepatocellular carcinoma: potential prospects for combined targeted therapeutics (review). Int J Oncol 2012; 41:393-406. [PMID: 22580498 PMCID: PMC3583004 DOI: 10.3892/ijo.2012.1474] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 02/17/2012] [Indexed: 02/07/2023] Open
Abstract
Hepatocellular carcinoma (HCC) is the third leading cause of cancer death, and its incidence is increasing worldwide in an alarming manner. The development of curative therapy for advanced and metastatic HCC is a high clinical priority. The HCC genome is complex and heterogeneous; therefore, the identification of recurrent genomic and related gene alterations is critical for developing clinical applications for diagnosis, prognosis and targeted therapy of the disease. This article focuses on recent research progress and our contribution in identifying and deciphering the role of defined genetic alterations in the pathogenesis of HCC. A significant number of genes that promote or suppress HCC cell growth have been identified at the sites of genomic reorganization. Notwithstanding the accumulation of multiple genetic alterations, highly recurrent changes on a single chromosome can alter the expression of oncogenes and tumor suppressor genes (TSGs) whose deregulation may be sufficient to drive the progression of normal hepatocytes to malignancy. A distinct and highly recurrent pattern of genomic imbalances in HCC includes the loss of DNA copy number (associated with loss of heterozygosity) of TSG-containing chromosome 8p and gain of DNA copy number or regional amplification of protooncogenes on chromosome 8q. Even though 8p is relatively small, it carries an unusually large number of TSGs, while, on the other side, several oncogenes are dispersed along 8q. Compelling evidence demonstrates that DLC1, a potent TSG on 8p, and MYC oncogene on 8q play a critical role in the pathogenesis of human HCC. Direct evidence for their role in the genesis of HCC has been obtained in a mosaic mouse model. Knockdown of DLC1 helps MYC in the induction of hepatoblast transformation in vitro, and in the development of HCC in vivo. Therapeutic interventions, which would simultaneously target signaling pathways governing both DLC1 and MYC functions in hepatocarcinogenesis, could result in progress in the treatment of liver cancer.
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Affiliation(s)
- Drazen B Zimonjic
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Tripathi SC, Kaur J, Matta A, Gao X, Sun B, Chauhan SS, Thakar A, Shukla NK, Duggal R, Choudhary AR, DattaGupta S, Sharma MC, Ralhan R, Siu KWM. Loss of DLC1 is an independent prognostic factor in patients with oral squamous cell carcinoma. Mod Pathol 2012; 25:14-25. [PMID: 22002576 DOI: 10.1038/modpathol.2011.145] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Deleted in liver cancer (DLC1), a Rho GTPase-activating protein, was observed to be differentially expressed in oral squamous cell carcinoma in comparison with normal tissues using tissue proteomics. In the current study, we investigated the clinical significance of loss of DLC1 expression in different stages of development of oral squamous cell carcinoma to determine its potential as a biomarker for oral dysplasia and prognosis of oral squamous cell carcinoma. Immunohistochemical analysis of DLC1 expression was carried out in oral squamous cell carcinoma patients (n=214), dysplasia (n=51), hyperplastic squamous mucosa (n=45), and histologically normal oral tissues (n=80), and correlated with clinicopathological parameters and disease prognosis over 91 months for oral squamous cell carcinomas. Loss of DLC1 expression was observed in oral squamous cell carcinoma (64%), oral dysplasia (31%), hyperplastic squamous mucosa (22%), and normal mucosa (16%). Significant loss of DLC1 expression was observed in oral squamous cell carcinomas as compared with dysplasia (P<0.001, odds ratio=3.8, 95% CI=2.0-7.3), suggesting it may be an important event involved in cancer progression. Among oral squamous cell carcinomas, the loss of DLC1 expression was significantly associated with poor prognosis (P=0.021, hazards ratio (HR)=1.8, 95% CI=1.1-2.9). Multivariate analysis revealed loss of DLC1 (P=0.023, HR=2.1, 95% CI=1.2-3.9) and histopathological grade (P=0.015, HR=1.7, 95% CI=1.1-2.7) to be independent predictors for disease-free survival in oral squamous cell carcinoma patients in comparison with known prognostic factors, viz. tumor stage, nodal status, and overall stage. Loss of DLC1 expression emerged as an important biomarker for predicting patients diagnosed with oral dysplasia at high risk of transformation upon future validation in longitudinal studies. Loss of DLC1 expression is a poor prognostic marker for oral squamous cell carcinoma patients.
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Shih YP, Takada Y, Lo SH. Silencing of DLC1 upregulates PAI-1 expression and reduces migration in normal prostate cells. Mol Cancer Res 2012; 10:34-9. [PMID: 22064653 PMCID: PMC3262057 DOI: 10.1158/1541-7786.mcr-11-0450] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Deleted in liver cancer 1 (DLC1) is a GTPase-activating protein (GAP) domain containing tumor suppressor that localizes to focal adhesions. In cancer cells, loss of DLC1 is known to enhance cancer cell migration. However, the role of DLC1 in normal cell migration has not been well studied. Here, we show that silencing of DLC1 (shDLC1) in normal prostate epithelial cells reduces cell migration in both Transwell and wound-healing assays. This migration defect is mainly due to upregulation of plasminogen activator inhibitor 1 (PAI-1). Silencing of PAI-1 rescues the shDLC1-reduced migration phenotype. Reexpression of DLC1 suppresses PAI-1 and restores the migration defect as well. In contrast, DLC1-K714E (GAP inactive) mutant neither decreases the PAI-1 level nor rescues the shDLC1 migration defect. Interestingly, DLC1-Y442F (tensin-binding and focal adhesion-localizing defective) mutant is able to suppress PAI-1 expression but does not restore the migration defect. Furthermore, PAI-1 upregulation in shDLC1 cells is EGFR-MEK pathway dependent and is able to promote in vitro angiogenesis. Together, our results show that at least the following two new mechanisms are involved in DLC1-mediated normal cell migration: (i) DLC1 modulates the expression of PAI-1, which is a negative regulator for cell migration, in a GAP domain and EGFR-MEK-dependent manner and (ii) Independent of PAI-1, the interaction of DLC1 with tensin members positively regulates cell migration.
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Affiliation(s)
- Yi-Ping Shih
- Center for Tissue Regeneration and Repair, University of California-Davis, Sacramento, CA 95817
- Department of Biochemistry and Molecular Medicine, University of California-Davis, Sacramento, CA 95817
| | - Yoshikazu Takada
- Department of Biochemistry and Molecular Medicine, University of California-Davis, Sacramento, CA 95817
- Department of Dermatology, University of California-Davis, Sacramento, CA 95817
| | - Su Hao Lo
- Center for Tissue Regeneration and Repair, University of California-Davis, Sacramento, CA 95817
- Department of Biochemistry and Molecular Medicine, University of California-Davis, Sacramento, CA 95817
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Makrodouli E, Oikonomou E, Koc M, Andera L, Sasazuki T, Shirasawa S, Pintzas A. BRAF and RAS oncogenes regulate Rho GTPase pathways to mediate migration and invasion properties in human colon cancer cells: a comparative study. Mol Cancer 2011; 10:118. [PMID: 21943101 PMCID: PMC3189908 DOI: 10.1186/1476-4598-10-118] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Accepted: 09/23/2011] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Colorectal cancer is a common disease that involves genetic alterations, such as inactivation of tumour suppressor genes and activation of oncogenes. Among them are RAS and BRAF mutations, which rarely coexist in the same tumour. Individual members of the Rho (Ras homology) GTPases contribute with distinct roles in tumour cell morphology, invasion and metastasis. The aim of this study is to dissect cell migration and invasion pathways that are utilised by BRAFV600E as compared to KRASG12V and HRASG12V oncoproteins. In particular, the role of RhoA (Ras homolog gene family, member A), Rac1 (Ras-related C3 botulinum toxin substrate 1) and Cdc42 (cell division cycle 42) in cancer progression induced by each of the three oncogenes is described. METHODS Colon adenocarcinoma cells with endogenous as well as ectopically expressed or silenced oncogenic mutations of BRAFV600E, KRASG12V and HRASG12V were employed. Signalling pathways and Rho GTPases were inhibited with specific kinase inhibitors and siRNAs. Cell motility and invasion properties were correlated with cytoskeletal properties and Rho GTPase activities. RESULTS Evidence presented here indicate that BRAFV600E significantly induces cell migration and invasion properties in vitro in colon cancer cells, at least in part through activation of RhoA GTPase. The relationship established between BRAFV600E and RhoA activation is mediated by the MEK-ERK pathway. In parallel, KRASG12V enhances the ability of colon adenocarcinoma cells Caco-2 to migrate and invade through filopodia formation and PI3K-dependent Cdc42 activation. Ultimately increased cell migration and invasion, mediated by Rac1, along with the mesenchymal morphology obtained through the Epithelial-Mesenchymal Transition (EMT) were the main characteristics rendered by HRASG12V in Caco-2 cells. Moreover, BRAF and KRAS oncogenes are shown to cooperate with the TGFβ-1 pathway to provide cells with additional transforming properties. CONCLUSION This study discriminates oncogene-specific cell migration and invasion pathways mediated by Rho GTPases in colon cancer cells and reveals potential new oncogene-specific characteristics for targeted therapeutics.
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Affiliation(s)
- Eleni Makrodouli
- Laboratory of Signal Mediated Gene Expression, Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, Vas, Constantinou Ave. 48, 11635, Athens, Greece
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Lukasik D, Wilczek E, Wasiutynski A, Gornicka B. Deleted in liver cancer protein family in human malignancies (Review). Oncol Lett 2011; 2:763-768. [PMID: 22866123 DOI: 10.3892/ol.2011.345] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 06/21/2011] [Indexed: 01/12/2023] Open
Abstract
The Deleted in Liver Cancer (DLC) protein family comprises proteins that exert their function mainly by the Rho GTPase-activating protein (GAP) domain and by regulation of the small GTPases. Since Rho GTPases are key factors in cell proliferation, polarity, cytoskeletal remodeling and migration, the aberrant function of their regulators may lead to cell transformation. One subgroup of these proteins is the DLC family. It was found that the first identified gene from this family, DLC1, is often lost in hepatocellular carcinoma and may be involved as a tumor suppressor in the liver. Subsequent studies evaluated the hypothesis that the DLC1 gene acts as a tumor suppressor, not only in liver cancer, but also in other types of cancer. Following DLC1, two other members of the DLC protein family, DLC2 and DLC3, were identified. However, limited published data are available concerning the role of these proteins in malignant transformation. This review focuses on the structure and the role of DLC1 and its relatives in physiological conditions and summarizes data published thus far regarding DLC function in the neoplastic process.
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Affiliation(s)
- D Lukasik
- Department of Pathology, Medical University of Warsaw, Warsaw 02-106, Poland
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Abstract
The invasion of cancer cells into the surrounding tissue is a prerequisite and initial step in metastasis, which is the leading cause of death from cancer. Invasive cell migration requires the formation of various structures, such as invadopodia and pseudopodia, which require actin assembly that is regulated by specialized actin nucleation factors. There is a large variety of different actin nucleators in human cells, such as formins, spire and Arp2/3-regulating proteins, and the list is likely to grow. Studies of the mechanisms of various actin nucleation factors that are involved in cancer cell function may ultimately provide new treatments for invasive and metastatic disease.
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Affiliation(s)
- Alexander Nürnberg
- Institute of Pharmacology, University of Marburg, Karl-von-Frisch-Str. 1, 35032 Marburg, Germany
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Luo HW, Luo QP, Yuan Y, Zhu XY, Huang SF, Peng Z, Li CL, Huang ZG, Feng WL. The intracellular stability of DLC1 is regulated by the 26S proteasome in human hepatocellular carcinoma cell line Hep3B. Biochem Biophys Res Commun 2010; 404:279-83. [PMID: 21130076 DOI: 10.1016/j.bbrc.2010.11.107] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 11/24/2010] [Indexed: 10/18/2022]
Abstract
Deleted in liver cancer 1 (DLC1), a tumor suppressor gene identified in a primary human hepatocellular carcinoma, encodes a Rho GTPase-activating protein (RhoGAP). Although DLC1 expression has been studied at the transcriptional level, little is known about its regulation at the protein level. Here we show that DLC1 is an unstable protein that is degraded by the 26S proteasome in human hepatocellular carcinoma Hep3B cells. In addition, five putative PEST motifs were identified in the N-terminus of DLC1. Unexpectedly, the N-terminus of DLC1 appeared to be stable. Furthermore, deletion of any one of the five PEST motifs except PEST2 decreased the stability of the N-terminus of DLC1, which suggests that the PEST motifs may play an unrevealed role in maintaining the stability of DLC1. These data indicated that the intracellular stability of DLC1 is regulated by the 26S proteasome via its PEST motifs.
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Affiliation(s)
- Hong-wei Luo
- Department of Clinical Hematology, Key Laboratory of Diagnostic Medicine Designated by the Ministry of Education, Chongqing Medical University, Chongqing 400016, PR China
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Ko FCF, Chan LK, Tung EKK, Lowe SW, Ng IOL, Yam JWP. Akt phosphorylation of deleted in liver cancer 1 abrogates its suppression of liver cancer tumorigenesis and metastasis. Gastroenterology 2010; 139:1397-407. [PMID: 20600027 DOI: 10.1053/j.gastro.2010.06.051] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 05/18/2010] [Accepted: 06/17/2010] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Deleted in liver cancer 1 (DLC1), which encodes a Rho GTPase activating protein, is a bona fide tumor suppressor in hepatocellular carcinoma. Underexpression of DLC1 in cancer has been attributed to genomic deletion and epigenetic silencing. However, the regulatory mechanism of the tumor suppressive activity of DLC1 remains elusive. In this study, we elucidated a novel post-translational modification by which the activity of DLC1 is functionally regulated. METHODS Molecular and biochemical approaches were employed to study Akt phosphorylation of DLC1. In vitro and in vivo functional assays were performed to elucidate the functional significance of Akt phosphorylation of DLC1. RESULTS Phosphorylation of ectopically expressed and endogenous DLC1 was enhanced upon insulin induction or with Akt expression in liver cancer cell lines. Conversely, addition of a phosphatidylinositol 3-kinase/Akt pathway inhibitor or silencing of Akt attenuated the phosphorylation level of DLC1. Site-directed mutagenesis was employed to replace the serine residue of the consensus Akt substrate motifs of DLC1 with alanine. S567 of DLC1 was identified as the only target of Akt phosphorylation. S567 is well conserved in all DLC family members. DLC2 was phosphorylated by Akt at the corresponding residue. Functional assays demonstrated that the S567D phosphomimetic DLC1 mutant lost its inhibitory activities in tumorigenesis and metastasis of oncogenically transformed hepatoblasts in a mouse model. CONCLUSIONS This study has revealed a novel post-translational modification that functionally deregulates the biologic activities of DLC1. Phosphorylation of DLC1 and DLC2 by Akt at the conserved residue points to a common regulatory mechanism of the DLC tumor suppressor family.
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Affiliation(s)
- Frankie Chi Fat Ko
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China
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DLC-1 as a modulator of proliferation, apoptosis and migration in Burkitt's lymphoma cells. Mol Biol Rep 2010; 38:1915-20. [PMID: 20882354 DOI: 10.1007/s11033-010-0311-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Accepted: 09/03/2010] [Indexed: 01/22/2023]
Abstract
Deleted in liver cancer-1(DLC-1) gene expression is frequently down-regulated or deleted in many types of human cancer. To evaluate whether DLC-1 could be a therapeutic target for non-Hodgkin lymphoma (NHL), we examined the expressions of DLC-1 in Burkitt's lymphoma (BL) cell lines and tested the effects of DLC-1 on cellular growth and migration in BL cells. DLC-1 expression was not detectable in two human BL cell lines, Raji and Daudi, by reverse transcription-PCR. The transfer of DLC-1 into Raji and Daudi cell lines caused a significant inhibition in cell proliferation. This inhibitory effect on cell proliferation in BL cell lines was accompanied by induction of apoptosis. Furthermore, restoration of DLC-1 expression in BL cells had a significant inhibitory effect on migration. Our findings suggest that DLC-1 may play an important role in lymphoma by acting as a bona fide new tumor suppressor gene.
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Hawthorn L, Luce J, Stein L, Rothschild J. Integration of transcript expression, copy number and LOH analysis of infiltrating ductal carcinoma of the breast. BMC Cancer 2010; 10:460. [PMID: 20799942 PMCID: PMC2939551 DOI: 10.1186/1471-2407-10-460] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 08/27/2010] [Indexed: 12/31/2022] Open
Abstract
Background A major challenge in the interpretation of genomic profiling data generated from breast cancer samples is the identification of driver genes as distinct from bystander genes which do not impact tumorigenesis. One way to assess the relative importance of alterations in the transcriptome profile is to combine parallel analyses that assess changes in the copy number alterations (CNAs). This integrated analysis permits the identification of genes with altered expression that map within specific chromosomal regions which demonstrate copy number alterations, providing a mechanistic approach to identify the 'driver genes'. Methods We have performed whole genome analysis of CNAs using the Affymetrix 250K Mapping array on 22 infiltrating ductal carcinoma samples (IDCs). Analysis of transcript expression alterations was performed using the Affymetrix U133 Plus2.0 array on 16 IDC samples. Fourteen IDC samples were analyzed using both platforms and the data integrated. We also incorporated data from loss of heterozygosity (LOH) analysis to identify genes showing altered expression in LOH regions. Results Common chromosome gains and amplifications were identified at 1q21.3, 6p21.3, 7p11.2-p12.1, 8q21.11 and 8q24.3. A novel amplicon was identified at 5p15.33. Frequent losses were found at 1p36.22, 8q23.3, 11p13, 11q23, and 22q13. Over 130 genes were identified with concurrent increases or decreases in expression that mapped to these regions of copy number alterations. LOH analysis revealed three tumors with whole chromosome or p arm allelic loss of chromosome 17. Genes were identified that mapped to copy neutral LOH regions. LOH with accompanying copy loss was detected on Xp24 and Xp25 and genes mapping to these regions with decreased expression were identified. Gene expression data highlighted the PPARα/RXRα Activation Pathway as down-regulated in the tumor samples. Conclusion We have demonstrated the utility of the application of integrated analysis using high resolution CGH and whole genome transcript analysis for detecting driver genes in IDC. The high resolution platform allowed a refined demarcation of CNAs and gene expression profiling provided a mechanism to detect genes directly impacted by the CNA. This is the first report of LOH integrated with gene expression in IDC using a high resolution platform.
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Affiliation(s)
- Lesleyann Hawthorn
- Medical College of Georgia Cancer Center, 1120 15th St, Augusta, GA 30912, USA.
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Sabbir MG, Wigle N, Loewen S, Gu Y, Buse C, Hicks GG, Mowat MRA. Identification and characterization of Dlc1 isoforms in the mouse and study of the biological function of a single gene trapped isoform. BMC Biol 2010; 8:17. [PMID: 20199662 PMCID: PMC2839985 DOI: 10.1186/1741-7007-8-17] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 03/03/2010] [Indexed: 01/01/2023] Open
Abstract
Background The Dlc1 (deleted in liver cancer 1) tumour suppressor gene codes for a RhoGTPase activating protein that is found inactivated in many tumour types. Several transcriptional isoforms have been described but the functional significance and tissue distribution of each form is presently poorly understood. Also, differences in the number of isoforms and splice variants reported still exist between different mammalian species. In order to better understand the number and function of the different variants of the Dlc1 gene in the mouse, we have carried out a detailed analysis. Extensive 3' RACE experiments were carried out in order to identify all possible Dlc1 isoforms and splice variants in the mouse. In addition, we have generated a gene trapped mouse that targets one of these isoforms in order to study its biological function. The effect of this gene trap insertion on the splicing of other isoforms has also been studied. Results In addition to the known 6.1 and 6.2 Kb transcripts of Dlc1, our study revealed the existence of a novel 7.6 Kb transcriptional isoform in the mouse, which corresponds to the human 7.4 Kb (KIAA1723) cDNA transcript. A gene trapped embryonic cell line, with an insertion between Exon 1 and 2 of the 6.1 Kb transcriptional isoform, was used to generate a transgenic mouse. This line showed a significant reduction in the expression of the trapped isoform. However, reduced expression of the other isoforms was not seen. Mice heterozygous for the gene trapped allele were phenotypically normal, but homozygous mutant embryos did not survive beyond 10.5 days post coitum. Dlc1gt/gt embryos showed defects in the brain, heart, and placental blood vessels. Cultured serum-free mouse embryo cells from Dlc1 deficient embryos had elevated RhoA activity and displayed alterations in the organization of actin filaments and focal adhesions. The Dlc1 deficient cells also exhibited increased wound closure in an in vitro scratch assay. Conclusions The mouse has three major transcriptional isoforms of the Dlc1 gene that are differentially expressed in various tissues. A mouse with exon 1 of the 6.1 Kb transcript gt resulted in hypomorphic expression of Dlc1 protein and an embryonic lethal phenotype in the homozygous condition, which indicates that this isoform plays a major role in mouse development. The Dlc1 deficient cells showed altered cytoskeleton structure, increased RhoA activity and cellular migration.
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Affiliation(s)
- Mohammad G Sabbir
- Manitoba Institute of Cell Biology, CancerCare Manitoba, 675 McDermot Avenue, Winnipeg, MB R3E 0V9, Canada
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Bennett LB, Taylor KH, Arthur GL, Rahmatpanah FB, Hooshmand SI, Caldwell CW. Epigenetic regulation of WNT signaling in chronic lymphocytic leukemia. Epigenomics 2010; 2:53-70. [PMID: 20473358 PMCID: PMC2869094 DOI: 10.2217/epi.09.43] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Certain WNT and WNT network target genes are expressed at higher or lower levels in chronic lymphocytic leukemia compared with normal B-cells. This includes upregulation of nuclear complex genes, as well as genes for cytoplasmic proteins and WNT ligands and their cognate receptors. In addition, epigenetic silencing of several negative regulators of the WNT pathway have been identified. The balance between epigenetic downregulation of negative effector genes and increased expression of positive effector genes demonstrate that the epigenetic downregulation of WNT antagonists is one mechanism, perhaps the main mechanism, that is permissive to active WNT signaling in chronic lymphocytic leukemia. Moreover, constitutive activation of the WNT network and target genes is likely to impact on additional interacting signaling pathways. Based on published studies, we propose a model of WNT signaling that involves mainly permissive expression, and sometimes overexpression, of positive effectors and downregulation of negative regulators in the network. In this model, DNA methylation, histone modifications and altered expression of microRNA molecules interact to allow continuous WNT signaling.
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Affiliation(s)
| | | | | | | | | | - Charles W Caldwell
- Author for correspondence: Department of Pathology & Anatomical Sciences, Ellis Fischel Cancer Center, University of Missouri, 115 Business Loop I-70 West, Columbia, MO 65203, USA, Tel.: +1 573 882 1234, Fax: +1 573 884 5206,
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Schönichen A, Geyer M. Fifteen formins for an actin filament: a molecular view on the regulation of human formins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2010; 1803:152-63. [PMID: 20102729 DOI: 10.1016/j.bbamcr.2010.01.014] [Citation(s) in RCA: 174] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2009] [Revised: 12/24/2009] [Accepted: 01/11/2010] [Indexed: 10/19/2022]
Abstract
The regulation of the actin cytoskeleton is a key process for the stability and motility of eukaryotic cells. Besides the Arp2/3 complex and its nucleation promoting factors, WH2 domain-containing proteins and a diverse family of formin proteins have recently been recognized as actin nucleators and potent polymerization factors of actin filaments. Formins are defined by the presence of a catalytic formin homology 2 (FH2) domain, yet, the modular domain architecture appears significantly different for the eight formin families identified in humans. A diverse picture of protein localization, interaction partners and cell specific regulation emerged, suggesting various functions of formins in the building and maintenance of actin filaments. This review focuses on the domain architecture of human formins, the regulation mechanisms of their activation and the diversity in formin cellular functions.
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Affiliation(s)
- André Schönichen
- Max-Planck-Institut für Molekulare Physiologie, Abteilung Physikalische Biochemie, Otto-Hahn-Str. 11, 44227 Dortmund, Germany
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Erlmann P, Schmid S, Horenkamp FA, Geyer M, Pomorski TG, Olayioye MA. DLC1 activation requires lipid interaction through a polybasic region preceding the RhoGAP domain. Mol Biol Cell 2009; 20:4400-11. [PMID: 19710422 DOI: 10.1091/mbc.e09-03-0247] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Deleted in Liver Cancer 1 (DLC1) is a GTPase-activating protein (GAP) with specificity for RhoA, RhoB, and RhoC that is frequently deleted in various tumor types. By inactivating these small GTPases, DLC1 controls actin cytoskeletal remodeling and biological processes such as cell migration and proliferation. Here we provide evidence that DLC1 binds to phosphatidylinositol-4,5-bisphosphate (PI(4,5)P(2)) through a previously unrecognized polybasic region (PBR) adjacent to its RhoGAP domain. Importantly, PI(4,5)P(2)-containing membranes are shown to stimulate DLC1 GAP activity in vitro. In living cells, a DLC1 mutant lacking an intact PBR inactivated Rho signaling less efficiently and was severely compromised in suppressing cell spreading, directed migration, and proliferation. We therefore propose that PI(4,5)P(2) is an important cofactor in DLC1 regulation in vivo and that the PBR is essential for the cellular functions of the protein.
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Affiliation(s)
- Patrik Erlmann
- Institute of Cell Biology and Immunology, University of Stuttgart, 70569 Stuttgart, Germany
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Peterburs P, Heering J, Link G, Pfizenmaier K, Olayioye MA, Hausser A. Protein Kinase D Regulates Cell Migration by Direct Phosphorylation of the Cofilin Phosphatase Slingshot 1 Like. Cancer Res 2009; 69:5634-8. [DOI: 10.1158/0008-5472.can-09-0718] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Heering J, Erlmann P, Olayioye MA. Simultaneous loss of the DLC1 and PTEN tumor suppressors enhances breast cancer cell migration. Exp Cell Res 2009; 315:2505-14. [PMID: 19482022 DOI: 10.1016/j.yexcr.2009.05.022] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2008] [Revised: 05/22/2009] [Accepted: 05/25/2009] [Indexed: 11/28/2022]
Abstract
The phosphatase and tensin homolog (PTEN) gene is a tumor suppressor frequently deleted or mutated in sporadic tumors of the breast, prostate, endometrium and brain. The protein acts as a dual specificity phosphatase for lipids and proteins. PTEN loss confers a growth advantage to cells, protects from apoptosis and favors cell migration. The deleted in liver cancer 1 (DLC1) gene has emerged as a novel tumor suppressor downregulated in a variety of tumor types including those of the breast. DLC1 contains a Rho GTPase activating domain that is involved in the inhibition of cell proliferation, migration and invasion. To investigate how simultaneous loss of PTEN and DLC1 contributes to cell transformation, we downregulated both proteins by RNA interference in the non-invasive MCF7 breast carcinoma cell line. Joint depletion of PTEN and DLC1 resulted in enhanced cell migration in wounding and chemotactic transwell assays. Interestingly, both proteins were found to colocalize at the plasma membrane and interacted physically in biochemical pulldowns and coimmunoprecipitations. We therefore postulate that the concerted local inactivation of signaling pathways downstream of PTEN and DLC1, respectively, is required for the tight control of cell migration.
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Affiliation(s)
- Johanna Heering
- University of Stuttgart, Institute of Cell Biology and Immunology, Allmandring 31, Stuttgart, Germany
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