1
|
Fordjour FK, Guo C, Ai Y, Daaboul GG, Gould SJ. A shared, stochastic pathway mediates exosome protein budding along plasma and endosome membranes. J Biol Chem 2022; 298:102394. [PMID: 35988652 PMCID: PMC9512851 DOI: 10.1016/j.jbc.2022.102394] [Citation(s) in RCA: 63] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 08/14/2022] [Accepted: 08/16/2022] [Indexed: 11/19/2022] Open
Abstract
Exosomes are small extracellular vesicles of ∼30 to 150 nm that are secreted by all cells, abundant in all biofluids, and play important roles in health and disease. However, details about the mechanism of exosome biogenesis are unclear. Here, we carried out a cargo-based analysis of exosome cargo protein biogenesis in which we identified the most highly enriched exosomal cargo proteins and then followed their biogenesis, trafficking, and exosomal secretion to test different hypotheses for how cells make exosomes. We show that exosome cargo proteins bud from cells (i) in exosome-sized vesicles regardless of whether they are localized to plasma or endosome membranes, (ii) ∼5-fold more efficiently when localized to the plasma membrane, (iii) ∼5-fold less efficiently when targeted to the endosome membrane, (iv) by a stochastic process that leads to ∼100-fold differences in their abundance from one exosome to another, and (v) independently of small GTPase Rab27a, the ESCRT complex–associated protein Alix, or the cargo protein CD63. Taken together, our results demonstrate that cells use a shared, stochastic mechanism to bud exosome cargoes along the spectrum of plasma and endosome membranes and far more efficiently from the plasma membrane than the endosome. Our observations also indicate that the pronounced variation in content between different exosome-sized vesicles is an inevitable consequence of a stochastic mechanism of small vesicle biogenesis, that the origin membrane of exosome-sized extracellular vesicles simply cannot be determined, and that most of what we currently know about exosomes has likely come from studies of plasma membrane-derived vesicles.
Collapse
Affiliation(s)
- Francis K Fordjour
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Chenxu Guo
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Yiwei Ai
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | | | - Stephen J Gould
- Department of Biological Chemistry, Johns Hopkins University, Baltimore, MD, USA.
| |
Collapse
|
2
|
Tagliatela AC, Hempstead SC, Hibshman PS, Hockenberry MA, Brighton HE, Pecot CV, Bear JE. Coronin 1C inhibits melanoma metastasis through regulation of MT1-MMP-containing extracellular vesicle secretion. Sci Rep 2020; 10:11958. [PMID: 32686704 PMCID: PMC7371684 DOI: 10.1038/s41598-020-67465-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 06/05/2020] [Indexed: 02/06/2023] Open
Abstract
Coronin 1C is overexpressed in multiple tumors, leading to the widely held view that this gene drives tumor progression, but this hypothesis has not been rigorously tested in melanoma. Here, we combined a conditional knockout of Coronin 1C with a genetically engineered mouse model of PTEN/BRAF-driven melanoma. Loss of Coronin 1C in this model increases both primary tumor growth rates and distant metastases. Coronin 1C-null cells isolated from this model are more invasive in vitro and produce more metastatic lesions in orthotopic transplants than Coronin 1C-reexpressing cells due to the shedding of extracellular vesicles (EVs) containing MT1-MMP. Interestingly, these vesicles contain melanosome markers suggesting a melanoma-specific mechanism of EV release, regulated by Coronin 1C, that contributes to the high rates of metastasis in melanoma.
Collapse
Affiliation(s)
- Alicia C Tagliatela
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Stephanie C Hempstead
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Priya S Hibshman
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Max A Hockenberry
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Hailey E Brighton
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Chad V Pecot
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Division of Hematology and Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - James E Bear
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
| |
Collapse
|
3
|
Chen H, Chen G, Li G, Zhang S, Chen H, Chen Y, Duggan D, Hu Z, Chen J, Zhao Y, Zhao Y, Huang H, Zheng SL, Trent JM, Yu L, Jiang D, Mo Z, Wang H, Mou Y, Jiang T, Mao Y, Xu J, Lu D. Two novel genetic variants in the STK38L and RAB27A genes are associated with glioma susceptibility. Int J Cancer 2019; 145:2372-2382. [PMID: 30714141 DOI: 10.1002/ijc.32179] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 01/07/2019] [Indexed: 11/09/2022]
Abstract
Glioma is the most common malignant primary brain tumors with poor prognosis. Genome wide association studies (GWAS) of glioma in populations with Western European ancestry were completed in the US and UK. However, our previous results strongly suggest the genetic heterogeneity could be important in glioma risk. To systematically investigate glioma risk-associated variants in Chinese population, we performed a multistage GWAS of glioma in the Han Chinese population, with a total of 3,097 glioma cases and 4,362 controls. In addition to confirming two associations reported in other ancestry groups, this study identified one new risk-associated locus for glioma on chromosome 12p11.23 (rs10842893, pmeta = 2.33x10-12, STK38L) as well as a promising association at 15q15-21.1 (rs4774756, pmeta = 6.12x10-8, RAB27A) in 3,097 glioma cases and 4,362 controls. Our findings demonstrate two novel association between the glioma risk region marked by variant rs10842893 and rs4774756) and glioma risk. These findings may advance the understanding of genetic susceptibility to glioma.
Collapse
Affiliation(s)
- Hongyan Chen
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital, Fudan University, and School of Life Sciences, Fudan University, Shanghai, China
| | - Gong Chen
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Gang Li
- Department of Neurosurgery, Tangdu hospital, the Fourth Military Medical University, Xi'an, China
| | - Shuo Zhang
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital, Fudan University, and School of Life Sciences, Fudan University, Shanghai, China
- Shanghai Ji Ai Genetics and IVF Institute, Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China
| | - Haitao Chen
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital, Fudan University, and School of Life Sciences, Fudan University, Shanghai, China
- State Key Laboratory of Organ Failure Research, Guangdong Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases and Hepatology Unit, Nanfang Hospital, Southern Medical University, GuangZhou, China
| | - Yuanyuan Chen
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital, Fudan University, and School of Life Sciences, Fudan University, Shanghai, China
| | - Dave Duggan
- Translational Genomics Research Institute (TGen), Phoenix, AZ
| | - Zhibin Hu
- Department of Epidemiology, Center for Global Health, Jiangsu Key Lab of Cancer Biomarkers, Prevention and Treatment, Collaborative Innovation Center For Cancer Personalized Medicine, School of Public Health, Nanjing Medical University, Nanjing, China
| | - Juxing Chen
- Department of Neurosurgery, Shanghai Institute of Neurosurgery, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Yingjie Zhao
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital, Fudan University, and School of Life Sciences, Fudan University, Shanghai, China
| | - Yao Zhao
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Huiling Huang
- Department of Neuroscience, Tianjin Huanhu Hospital, Tianjin, China
| | - S Lilly Zheng
- Program for Personalized Cancer Care, NorthShore University HealthSystem, Evanston, IL
| | - Jeffrey M Trent
- Translational Genomics Research Institute (TGen), Phoenix, AZ
| | - Long Yu
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital, Fudan University, and School of Life Sciences, Fudan University, Shanghai, China
| | - Deke Jiang
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital, Fudan University, and School of Life Sciences, Fudan University, Shanghai, China
- State Key Laboratory of Organ Failure Research, Guangdong Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases and Hepatology Unit, Nanfang Hospital, Southern Medical University, GuangZhou, China
| | - Zengnan Mo
- Center for Genomic and Personalized Medicine, Guangxi Medical University, Nanning, Guangxi, China
| | - Hongwei Wang
- Department of Medicine, The University of Chicago, Chicago, IL
| | - Yonggao Mou
- Department of Neurosurgery, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Tao Jiang
- Department of Molecular Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Ying Mao
- Department of Neurosurgery, Huashan Hospital, Fudan University, Shanghai, China
| | - Jianfeng Xu
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital, Fudan University, and School of Life Sciences, Fudan University, Shanghai, China
- Program for Personalized Cancer Care, NorthShore University HealthSystem, Evanston, IL
| | - Daru Lu
- State Key Laboratory of Genetic Engineering, Zhongshan Hospital, Fudan University, and School of Life Sciences, Fudan University, Shanghai, China
| |
Collapse
|
4
|
Tsukuba T, Sakai E, Nishishita K, Kadowaki T, Okamoto K. New functions of lysosomes in bone cells. J Oral Biosci 2017. [DOI: 10.1016/j.job.2017.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
5
|
Abstract
Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells target infected or transformed cells with perforin-containing cytotoxic granules through immune synapses, while platelets secrete several types of granules which contents are essential for thrombosis and hemostasis. Recent work has culminated in the notion that an exocytic SNARE complex, based on a very similar set of components, is primarily responsible for exocytosis of the diverse granules in these different cell types. Granule exocytosis is, in particular, uniquely dependent on the atypical Q-SNARE syntaxin 11, its interacting partners of the Sec/Munc (SM) family, and is regulated by Rab27a. Mutations in these exocytic components underlie disease manifestations of familial hemophagocytic lymphohistiocytosis (FHL) subtypes, characterized by hyperactivation of the immune system, as well as platelet granule secretion defects. Here we discuss the key discoveries that led to the converging notion of the syntaxin 11-based exocytosis machinery for cytotoxic granules and platelet-derived granules.
Collapse
Affiliation(s)
- Bor Luen Tang
- a Department of Biochemistry , Yong Loo Lin School of Medicine, National University of Singapore , Singapore and.,b NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore , Singapore
| |
Collapse
|
6
|
Jin SG, Xiong W, Wu X, Yang L, Pfeifer GP. The DNA methylation landscape of human melanoma. Genomics 2015; 106:322-30. [PMID: 26384656 DOI: 10.1016/j.ygeno.2015.09.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Revised: 09/10/2015] [Accepted: 09/11/2015] [Indexed: 11/17/2022]
Abstract
Using MIRA-seq, we have characterized the DNA methylome of metastatic melanoma and normal melanocytes. Individual tumors contained several thousand hypermethylated regions. We discovered 179 tumor-specific methylation peaks present in all (27/27) melanomas that may be effective disease biomarkers, and 3113 methylation peaks were seen in >40% of the tumors. We found that 150 of the approximately 1200 tumor-associated methylation peaks near transcription start sites (TSSs) were marked by H3K27me3 in melanocytes. DNA methylation in melanoma was specific for distinct H3K27me3 peaks rather than for broadly covered regions. However, numerous H3K27me3 peak-associated TSS regions remained devoid of DNA methylation in tumors. There was no relationship between BRAF mutations and the number of methylation peaks. Gene expression analysis showed upregulated immune response genes in melanomas presumably as a result of lymphocyte infiltration. Down-regulated genes were enriched for melanocyte differentiation factors; e.g., KIT, PAX3 and SOX10 became methylated and downregulated in melanoma.
Collapse
Affiliation(s)
- Seung-Gi Jin
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA; Department of Cancer Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - Wenying Xiong
- Department of Cancer Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - Xiwei Wu
- Department of Molecular and Cellular Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - Lu Yang
- Department of Molecular and Cellular Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
| | - Gerd P Pfeifer
- Center for Epigenetics, Van Andel Research Institute, Grand Rapids, MI 49503, USA; Department of Cancer Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA.
| |
Collapse
|
7
|
Shimada-Sugawara M, Sakai E, Okamoto K, Fukuda M, Izumi T, Yoshida N, Tsukuba T. Rab27A regulates transport of cell surface receptors modulating multinucleation and lysosome-related organelles in osteoclasts. Sci Rep 2015; 5:9620. [PMID: 25882854 PMCID: PMC5381753 DOI: 10.1038/srep09620] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 03/10/2015] [Indexed: 11/21/2022] Open
Abstract
Rab27A regulates transport of lysosome-related organelles (LROs) and release of secretory granules in various types of cells. Here, we identified up-regulation of Rab27A during differentiation of osteoclasts (OCLs) from bone-marrow macrophages (BMMs), by DNA microarray analysis. Rab27A deficiency in OCLs, using small interfering RNA (siRNA) knockdown in RAW-D cell line or BMMs derived from ashen mice, which display genetic defects in Rab27A expression, induced multinucleated and giant cells. Upon stimulation with macrophage-colony stimulating factor (M-CSF) and receptor activator of nuclear factor kappa-B ligand (RANKL), essential cytokines for OCL differentiation, phosphorylation levels of extracellular signal-regulated kinase (Erk), proto-oncogene tyrosine-protein kinase (Src), and p-38 were slightly enhanced in ashen BMMs than in wild-type BMMs. The cell surface level of c-fms, an M-CSF receptor, was slightly higher in ashen BMMs than in wild-type BMMs, and down-regulation of RANK, a RANKL receptor, was delayed. In addition to receptors, OCLs derived from ashen mice exhibited aberrant actin ring formation, abnormal subcellular localization of lysosome-associated membrane protein (LAMP2) and cathepsin K (CTSK), and marked reduction in resorbing activity. Thus, these findings suggest that Rab27A regulates normal transport of cell surface receptors modulating multinucleation and LROs in OCLs.
Collapse
Affiliation(s)
- Megumi Shimada-Sugawara
- 1] Division of Dental Pharmacology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8588, Japan [2] Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8588, Japan
| | - Eiko Sakai
- Division of Dental Pharmacology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8588, Japan
| | - Kuniaki Okamoto
- Division of Dental Pharmacology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8588, Japan
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences, Tohoku University, Aobayama, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Tetsuro Izumi
- Department of Molecular Medicine, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512, Japan
| | - Noriaki Yoshida
- Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8588, Japan
| | - Takayuki Tsukuba
- Division of Dental Pharmacology, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8588, Japan
| |
Collapse
|
8
|
Tang BL. The Cell Biology of Systemic Hyperinflammation Resulting from Failed Cytolytic Target Cell Killing. Cell 2015. [DOI: 10.4236/cellbio.2015.43005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
9
|
Booth AEG, Tarafder AK, Hume AN, Recchi C, Seabra MC. A role for Na+,K+-ATPase α1 in regulating Rab27a localisation on melanosomes. PLoS One 2014; 9:e102851. [PMID: 25051489 PMCID: PMC4106853 DOI: 10.1371/journal.pone.0102851] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 06/23/2014] [Indexed: 12/23/2022] Open
Abstract
The mechanism(s) by which Rab GTPases are specifically recruited to distinct intracellular membranes remains elusive. Here we used Rab27a localisation onto melanosomes as a model to investigate Rab targeting. We identified the α1 subunit of Na+,K+-ATPase (ATP1a1) as a novel Rab27a interacting protein in melanocytes and showed that this interaction is direct with the intracellular M4M5 loop of ATP1a1 and independent of nucleotide bound status of the Rab. Knockdown studies in melanocytes revealed that ATP1a1 plays an essential role in Rab27a-dependent melanosome transport. Specifically, expression of ATP1a1, like the Rab27a GDP/GTP exchange factor (Rab3GEP), is essential for targeting and activation of Rab27a to melanosomes. Finally, we showed that the ability of Rab27a mutants to target to melanosomes correlates with the efficiency of their interaction with ATP1a1. Altogether these studies point to a new role for ATP1a1 as a regulator of Rab27a targeting and activation.
Collapse
Affiliation(s)
- Antonia E. G. Booth
- Molecular Medicine, National Heart and Lung Institute, Sir Alexander Fleming Building, Imperial College London, London, United Kingdom
| | - Abul K. Tarafder
- Molecular Medicine, National Heart and Lung Institute, Sir Alexander Fleming Building, Imperial College London, London, United Kingdom
| | - Alistair N. Hume
- Molecular Medicine, National Heart and Lung Institute, Sir Alexander Fleming Building, Imperial College London, London, United Kingdom
- School of Biomedical Sciences, University of Nottingham, Medical School, Queens Medical Centre, Nottingham, United Kingdom
| | - Chiara Recchi
- Molecular Medicine, National Heart and Lung Institute, Sir Alexander Fleming Building, Imperial College London, London, United Kingdom
| | - Miguel C. Seabra
- Molecular Medicine, National Heart and Lung Institute, Sir Alexander Fleming Building, Imperial College London, London, United Kingdom
- CEDOC, Faculdade de Ciencias Medicas, FCM, Universidade Nova de Lisboa, Lisboa, Portugal
- * E-mail:
| |
Collapse
|
10
|
Lall P, Horgan CP, Oda S, Franklin E, Sultana A, Hanscom SR, McCaffrey MW, Khan AR. Structural and functional analysis of FIP2 binding to the endosome-localised Rab25 GTPase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2013; 1834:2679-90. [PMID: 24056041 DOI: 10.1016/j.bbapap.2013.09.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 09/08/2013] [Accepted: 09/12/2013] [Indexed: 11/30/2022]
Abstract
Rab small GTPases are the master regulators of intracellular trafficking in eukaryotes. They mediate spatial and temporal recruitment of effector proteins to distinct cellular compartments through GTP-induced changes in their conformation. Despite numerous structural studies, the molecular basis for Rab/effector specificity and subsequent biological activity remains poorly understood. Rab25, also known as Rab11c, which is epithelial-specific, has been heavily implicated in ovarian cancer development and independently appears to act as a tumour suppressor in the context of a distinct subset of carcinomas. Here, we show that Rab25 associates with FIP2 and can recruit this effector protein to endosomal membranes. We report the crystal structure of Rab25 in complex with the C-terminal region of FIP2, which consists of a central dimeric FIP2 coiled-coil that mediates a heterotetrameric Rab25-(FIP2)2-Rab25 complex. Thermodynamic analyses show that, despite a relatively conserved interface, FIP2 binds to Rab25 with an approximate 3-fold weaker affinity than to Rab11a. Reduced affinity is mainly associated with lower enthalpic gains for Rab25:FIP2 complex formation, and can be attributed to subtle differences in the conformations of switch 1 and switch 2. These cellular, structural and thermodynamic studies provide insight into the Rab11/Rab25 subfamily of small GTPases that regulate endosomal trafficking pathways in eukaryotes.
Collapse
Affiliation(s)
- Patrick Lall
- School of Biochemistry and Immunology, Trinity College, Dublin 2, Ireland
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Effects of Rab27a on proliferation, invasion, and anti-apoptosis in human glioma cell. Tumour Biol 2013; 34:2195-203. [PMID: 23553027 DOI: 10.1007/s13277-013-0756-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Accepted: 03/18/2013] [Indexed: 12/22/2022] Open
Abstract
This study aims to investigate the relationship between Rab27a and the characteristics of glioma cell U251 such as proliferation, apoptosis, and invasion and to provide an experimental basis for future therapy in human glioma. Recombinant plasmid of pcDNA3.1-Rab27a was constructed and transfected into U251 cells with the help of Lipofectamine™2000. The expression of Rab27a was detected by Western blot. Cell viability, cell cycle, cell apoptosis, and cell migration were analyzed, respectively, by (3-(4,5)-dimethylthi-azol-2-yl)-2,5-diphenytetrazolium bromide (MTT) assay, flow cytometry, and Transwell invasion chamber methods. Meanwhile, the effect of Rab27a on secretion of cathepsin D in U251 cells was also examined. With the help of luciferase reporter assay system, the relationship between miR-124 and gene Rab27a expression was explored. Western blot showed that the expression of Rab27a was significantly increased in pcDNA3.1-Rab27a transfection group (p < 0.01) and that was significantly decreased in Rab27a-shRNA transfection group (p < 0.01) compared with control group. MTT assay, flow cytometry, and Transwell invasion chamber experiment indicated that cell viability (p < 0.01), proliferation index (p < 0.05), and invasion ability (p < 0.01) were improved significantly in pcDNA3.1-Rab27a transfection group compared with control group and that cell viability (p < 0.01), proliferation index (p < 0.05), and invasion ability (p < 0.01) were reduced markedly in Rab27a-shRNA transfection group compared with control group. The apoptosis analysis by flow cytometry demonstrated that the ratio of apoptosis in pcDNA3.1-Rab27a transfection group was significantly lower than that in control group (p < 0.05) and the ratio was notably higher in Rab27a-shRNAtransfection group than that in the control group. Cathepsin D activity assay indicated that the release of cathepsin D was enhanced in pcDNA3.1-Rab27a transfection group compared to that in the control group (p < 0.05). Rab27a could increase the glioma cell ability, promote proliferation and invasion, and suppress cell apoptosis. The above-stated effects of Rab27a possibly were exerted by increasing the secretion of cathepsin D and regulated by miR-124. In addition, the inhibition of expression of Rab27a perhaps benefited the therapy for glioma patients.
Collapse
|