101
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Cheung CCM, Chung GTY, Lun SWM, To KF, Choy KW, Lau KM, Siu SPK, Guan XY, Ngan RKC, Yip TTC, Busson P, Tsao SW, Lo KW. miR-31 is consistently inactivated in EBV-associated nasopharyngeal carcinoma and contributes to its tumorigenesis. Mol Cancer 2014; 13:184. [PMID: 25098679 PMCID: PMC4127521 DOI: 10.1186/1476-4598-13-184] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 07/27/2014] [Indexed: 01/08/2023] Open
Abstract
Background As a distinctive type of head and neck cancers, nasopharyngeal carcinoma (NPC) is genesis from the clonal Epstein-Barr virus (EBV)-infected nasopharyngeal epithelial cells accumulated with multiple genetic lesions. Among the recurrent genetic alterations defined, loss of 9p21.3 is the most frequent early event in the tumorigenesis of EBV-associated NPC. In addition to the reported CDKN2A/p16, herein, we elucidated the role of a miRNA, miR-31 within this 9p21.3 region as NPC-associated tumor suppressor. Methods The expression and promoter methylation of miR-31 were assessed in a panel of NPC tumor lines and primary tumors. Its in vitro and in vivo tumor suppression function was investigated through the ectopic expression of miR-31 in NPC cells. We also determined the miR-31 targeted genes and its involvement in the growth in NPC. Results Downregulation of miR-31 expression was detected in almost all NPC cell line, patient-derived xenografts (PDXs) and primary tumors. Both homozygous deletion and promoter hypermethylation were shown to be major mechanisms for miR-31 silencing in this cancer. Strikingly, loss of miR-31 was also obviously observed in the dysplastic lesions of nasopharynx. Restoration of miR-31 in C666-1 cells inhibited the cell proliferation, colony-forming and migratory capacities. Dramatic reduction of in vitro anchorage-independent growth and in vivo tumorigenic potential were demonstrated in the stable clones expressing miR-31. Furthermore, we proved that miR-31 suppressed the NPC cell growth via targeting FIH1 and MCM2. Conclusions The findings provide strong evidence to support miR-31 as a new NPC-associated tumor suppressor on 9p21.3 region. The inactivation of miR-31 may contribute to the early development of NPC.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Kwok-Wai Lo
- Department of Anatomical and Cellular Pathology, State Key Laboratory in Oncology in South China, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, People's Republic of China.
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102
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Rickinson AB. Co-infections, inflammation and oncogenesis: future directions for EBV research. Semin Cancer Biol 2014; 26:99-115. [PMID: 24751797 DOI: 10.1016/j.semcancer.2014.04.004] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Accepted: 04/04/2014] [Indexed: 12/24/2022]
Abstract
Epstein-Barr virus (EBV) is aetiologically linked to a wide range of human tumours. Some arise as accidents of the virus' lifestyle in its natural niche, the B lymphoid system; these include B-lymphoproliferative disease of the immunocompromised, Hodgkin Lymphoma, Burkitt Lymphoma and particular forms of diffuse large B cell lymphoma. Interestingly, HIV infection increases the incidence of each of these B cell malignancies, though by different degrees and for different reasons. Other EBV-associated tumours arise through rare viral entry into unnatural target tissues; these include all cases of nasal T/NK cell lymphoma and of undifferentiated nasopharyngeal carcinoma plus a small but significant subset of gastric carcinomas, a tumour type more generally associated with chronic Helicobacter pylori infection. Understanding EBV's involvement in the pathogenesis of these different malignancies is an important long-term goal. This article focuses on two overlapping, but relatively neglected, areas of research that could contribute to that goal. The first addresses the mechanisms whereby coincident infections with other pathogens increase the risk of EBV-positive malignancies, and takes as its paradigm the actions of holoendemic malaria and HIV infections as co-factors in Burkitt lymphomagenesis. The second widens the argument to include both infectious and non-infectious sources of chronic inflammation in the pathogenesis of EBV-positive tumours such as T/NK cell lymphoma, nasopharyngeal carcinoma and gastric carcinoma.
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Affiliation(s)
- A B Rickinson
- School of Cancer Sciences, University of Birmingham, Birmingham, UK.
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103
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Kenney SC, Mertz JE. Regulation of the latent-lytic switch in Epstein-Barr virus. Semin Cancer Biol 2014; 26:60-8. [PMID: 24457012 PMCID: PMC4048781 DOI: 10.1016/j.semcancer.2014.01.002] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 12/17/2013] [Accepted: 01/09/2014] [Indexed: 12/12/2022]
Abstract
Epstein-Barr virus (EBV) infection contributes to the development of several different types of human malignancy, including Burkitt lymphoma, Hodgkin lymphoma, and nasopharyngeal carcinoma. As a herpesvirus, EBV can establish latent or lytic infection in cells. EBV-positive tumors are composed almost exclusively of cells with latent EBV infection. Strategies for inducing the lytic form of EBV infection in tumor cells are being investigated as a potential therapy for EBV-positive tumors. In this article, we review how cellular and viral proteins regulate the latent-lytic EBV switch in infected B cells and epithelial cells, and discuss how harnessing lytic viral reactivation might be used therapeutically.
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Affiliation(s)
- Shannon C Kenney
- McArdle Laboratory for Cancer Research, 1400 University Avenue, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706-1599, USA; Department of Oncology, 1400 University Avenue, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706-1599, USA; Department of Medicine, 1400 University Avenue, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706-1599, USA.
| | - Janet E Mertz
- McArdle Laboratory for Cancer Research, 1400 University Avenue, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706-1599, USA; Department of Oncology, 1400 University Avenue, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706-1599, USA
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104
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Tsao SW, Yip YL, Tsang CM, Pang PS, Lau VMY, Zhang G, Lo KW. Etiological factors of nasopharyngeal carcinoma. Oral Oncol 2014; 50:330-8. [PMID: 24630258 DOI: 10.1016/j.oraloncology.2014.02.006] [Citation(s) in RCA: 160] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 01/29/2014] [Accepted: 02/07/2014] [Indexed: 12/18/2022]
Abstract
Nasopharyngeal carcinoma (NPC) is a common disease among southern Chinese. The major etiological factors proposed for NPC pathogenesis include genetic susceptibility, environment factors and EBV infection. In the high risk population, genetic susceptibility to NPC has been mapped to the HLA loci and adjacent genes in MHC region on chromosome 6p21. Consumption of preserved food including salted fish has been implicated in its etiology in earlier studies. Its contribution to pathogenesis of NPC remains to be determined. A decreasing trend of NPC incidence was observed in Hong Kong, Taiwan and Singapore in recent years which may be accounted by a change of dietary habits. A comprehensive epidemiological study will help to elucidate the relative importance of various risk factors in the pathogenesis of NPC. Despite the close association of EBV infection with NPC, the etiological role of EBV in NPC pathogenesis remains enigmatic. EBV infection in primary nasopharyngeal epithelial cells is uncommon and difficult to achieve. EBV does not transform primary nasopharyngeal epithelial cells into proliferative clones, which contrasts greatly with the well-documented ability of EBV to transform and immortalize primary B cells. Genetic alterations identified in premalignant nasopharyngeal epithelium may play crucial roles to support stable EBV infection. Subsequently, latent and lytic EBV gene products may drive clonal expansion and transformation of premalignant nasopharyngeal epithelial cells into cancer cells. Stromal inflammation in nasopharyngeal mucosa is believed to play an important role in modulating the growth and possibly drive the malignant transformation of EBV-infected nasopharyngeal epithelial cells. Furthermore, there are increasing evidences supporting a role of EBV infection to evade host immune surveillance. EBV-infected cells may have selective growth advantages in vivo by acquiring a stress-resistance phenotype. Understanding the etiological factors and pathogenesis of NPC will contribute effectively to the prevention and treatment of this disease.
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Affiliation(s)
- Sai Wah Tsao
- Department of Anatomy and Center for Cancer Research, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region.
| | - Yim Ling Yip
- Department of Anatomy and Center for Cancer Research, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Chi Man Tsang
- Department of Anatomy and Center for Cancer Research, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Pei Shin Pang
- Department of Anatomy and Center for Cancer Research, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Victoria Ming Yi Lau
- Department of Anatomy and Center for Cancer Research, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Guitao Zhang
- Department of Anatomy and Center for Cancer Research, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Kwok Wai Lo
- Department of Anatomical and Cellular Pathology and Li Ka Shing Institute of Health Science, The Chinese University of Hong Kong, Hong Kong Special Administrative Region.
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105
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Murata T, Sato Y, Kimura H. Modes of infection and oncogenesis by the Epstein-Barr virus. Rev Med Virol 2014; 24:242-53. [PMID: 24578255 DOI: 10.1002/rmv.1786] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 01/19/2014] [Accepted: 01/23/2014] [Indexed: 12/15/2022]
Abstract
The EBV is a human γ-herpesvirus associated with various neoplasms. It is responsible for causing cancers of B, T, and NK cells as well as cells of epithelial origin. Such diversity in target cells and the complicated steps of oncogenesis are perplexing when we speculate about the mechanisms of action of EBV-positive cancers. Here, we first note three common features that contribute to the development and maintenance of EBV-positive cancers: effects of EBV oncogenes, immunosuppression and evasion/exploitation of the immune system, and genetic and epigenetic predisposition/alteration of the host genome. Then, we demonstrate the mechanisms of oncogenesis and the means by which each EBV-positive cancer develops, with particular focus on the mode of EBV infection. The EBV has two alternative life cycles: lytic and latent. The latter is categorized into four programs (latency types 0-III) in which latent viral genes are expressed differentially depending on the tissue of origin and state of cells. The production of viral latent genes tends to decrease with an increase in time, and, in an approximate manner, the expression levels of viral genes are inversely correlated with the degree of abnormalities in the host genome. Occasional execution of the viral lytic cycle also contributes to oncogenesis. Understanding this life cycle of the EBV and its relevance in oncogenesis may provide valuable clues to the development of effective therapies for the associated cancers.
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Affiliation(s)
- Takayuki Murata
- Department of Virology, Nagoya University Graduate School of Medicine, Nagoya, Japan; Division of Virology, Aichi Cancer Center Research Institute, Nagoya, Japan
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106
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Poon RYC. DNA damage checkpoints in nasopharyngeal carcinoma. Oral Oncol 2014; 50:339-44. [PMID: 24503238 DOI: 10.1016/j.oraloncology.2014.01.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 01/16/2014] [Accepted: 01/18/2014] [Indexed: 10/25/2022]
Abstract
Nasopharyngeal carcinoma (NPC) is a highly invasive cancer with poor prognosis. One of the recurring themes of NPC biology and treatments is DNA damage. Epstein-Barr virus infection, which is generally accepted as a key etiological factor for NPC, triggers DNA damage responses. In normal cells, DNA damage checkpoints are able to prevent cell cycle progression following DNA damage and are critical for maintaining genome stability. Main features of the checkpoints include activation of ATM and ATR by sensors of DNA damage, which activates effector kinases CHK1 and CHK2; they in turn targets the CDC25/WEE1-cyclin B1-CDK1 axis to cause G(2) arrest, or the p53-p21(CIP1/WAF1) and pRb pathways to cause G(1) arrest. Significantly, these checkpoints are typically disrupted in NPC cells. While mutations are relatively rare, mechanisms including promoter modifications, miRNAs, and actions of Epstein-Barr virus-encoded proteins such as EBNA3C and LMP1 have been described. Paradoxically, radiation-mediated DNA damage remains the primary treatment of NPC. How dysregulation of the DNA damage checkpoints contribute to NPC tumorigenesis and responses to treatment remain poorly understood. In this review, the current understanding of the molecular mechanisms of the various DNA damage checkpoints and what is known about them in NPC are discussed.
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Affiliation(s)
- Randy Y C Poon
- Division of Life Science, Center for Cancer Research, and State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong.
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107
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Abstract
Epstein-Barr virus (EBV) is a member of gamma-herpesvirus, which can cause various types of tumor. Coexisting with the host for a long period of time, it has evolved unique and sophisticated strategy for survival by taking complicated, tactical modes of infection. Such modes include latent and lytic infections, and latent state is further categorized into four types. Differences and transitions in such lifestyles are significantly associated not only with virus amplification, but also with pathology and advancement of the disorders. I here review oncogenesis and pathogenesis of EBV-related disorders, especially focusing on our recent results on the modes of EBV infection.
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108
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Wei L, Qin G, Yang X, Hu M, Jiang F, Lai T. A new nasal cavity nursing methods application in patients with mechanical ventilation. Pak J Med Sci 2013; 29:977-81. [PMID: 24353671 PMCID: PMC3817784 DOI: 10.12669/pjms.294.3636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 06/13/2013] [Accepted: 06/18/2013] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To compare different nasal cavity nursing methods on mechanically ventilated patients. METHODS According to acute physiology and chronic health evaluation (APACHEII), 615 cases of mechanically ventilated patients were divided into group A, group B and group C by stratified random method. Traditional oral nursing plus aspirating secretions from oral cavity and nasal cavity q6h were done in group A. Based on methods in group A, normal saline was used for cleaning nasal cavity in group B. Besides the methods in group A, atomizing nasal cleansing a6h was also used in group C. Incidence rate of Ventilator-Associated Pneumonia (VAP) and APACHE II scores after administrating were compared. The correlation between APACHE II score and outcomes was analyzed by Spearman-rank correlation. RESULTS In group A, incidence of VAP was 36.76%, group B was 30.24%, group C was 20.38%, and the difference was statistically significant. APACHE II scores in group C were significantly lower compared with group A and B. APACHE II score was negatively correlated with clinical outcomes. CONCLUSIONS For mechanically ventilated patients, nasal nursing can't be ignored and the new atomizing nasal cleaning is an effective method for VAP prevention.
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Affiliation(s)
- Liuqing Wei
- Liuqing Wei, Department of Intensive Care Unit, Guangxi Hospital for Nationalities, Nanning, Guangxi, 530001, China.
| | - Gang Qin
- Gang Qin, Department of Intensive Care Unit, Guangxi Hospital for Nationalities, Nanning, Guangxi, 530001, China.
| | - Xining Yang
- Xining Yang, Department of Intensive Care Unit, Guangxi Hospital for Nationalities, Nanning, Guangxi, 530001, China.
| | - Meichun Hu
- Meichun Hu, Department of Intensive Care Unit, Guangxi Hospital for Nationalities, Nanning, Guangxi, 530001, China.
| | - Fufu Jiang
- Fufu Jiang, Department of Intensive Care Unit, Guangxi Hospital for Nationalities, Nanning, Guangxi, 530001, China.
| | - Tianwei Lai
- Tianwei Lai, Department of Intensive Care Unit, Guangxi Hospital for Nationalities, Nanning, Guangxi, 530001, China.
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109
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Efficient immortalization of primary nasopharyngeal epithelial cells for EBV infection study. PLoS One 2013; 8:e78395. [PMID: 24167620 PMCID: PMC3805559 DOI: 10.1371/journal.pone.0078395] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/09/2013] [Indexed: 12/15/2022] Open
Abstract
Nasopharyngeal carcinoma (NPC) is common among southern Chinese including the ethnic Cantonese population living in Hong Kong. Epstein-Barr virus (EBV) infection is detected in all undifferentiated type of NPC in this endemic region. Establishment of stable and latent EBV infection in premalignant nasopharyngeal epithelial cells is an early event in NPC development and may contribute to its pathogenesis. Immortalized primary nasopharyngeal epithelial cells represent an important tool for investigation of EBV infection and its tumorigenic potential in this special type of epithelial cells. However, the limited availability and small sizes of nasopharyngeal biopsies have seriously restricted the establishment of primary nasopharyngeal epithelial cells for immortalization. A reliable and effective method to immortalize primary nasopharyngeal epithelial cells will provide unrestricted materials for EBV infection studies. An earlier study has reported that Bmi-1 expression could immortalize primary nasopharyngeal epithelial cells. However, its efficiency and actions in immortalization have not been fully characterized. Our studies showed that Bmi-1 expression alone has limited ability to immortalize primary nasopharyngeal epithelial cells and additional events are often required for its immortalization action. We have identified some of the key events associated with the immortalization of primary nasopharyngeal epithelial cells. Efficient immortalization of nasopharyngeal epithelial cells could be reproducibly and efficiently achieved by the combined actions of Bmi-1 expression, activation of telomerase and silencing of p16 gene. Activation of MAPK signaling and gene expression downstream of Bmi-1 were detected in the immortalized nasopharyngeal epithelial cells and may play a role in immortalization. Furthermore, these newly immortalized nasopharyngeal epithelial cells are susceptible to EBV infection and supported a type II latent EBV infection program characteristic of EBV-infected nasopharyngeal carcinoma. The establishment of an efficient method to immortalize primary nasopharyngeal epithelial cells will facilitate the investigation into the role of EBV infection in pathogenesis of nasopharyngeal carcinoma.
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110
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Tsai MH, Raykova A, Klinke O, Bernhardt K, Gärtner K, Leung CS, Geletneky K, Sertel S, Münz C, Feederle R, Delecluse HJ. Spontaneous lytic replication and epitheliotropism define an Epstein-Barr virus strain found in carcinomas. Cell Rep 2013; 5:458-70. [PMID: 24120866 DOI: 10.1016/j.celrep.2013.09.012] [Citation(s) in RCA: 161] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Revised: 09/03/2013] [Accepted: 09/09/2013] [Indexed: 12/14/2022] Open
Abstract
The Epstein-Barr virus (EBV) is found in a variety of tumors whose incidence greatly varies around the world. A poorly explored hypothesis is that particular EBV strains account for this phenomenon. We report that M81, a virus isolated from a Chinese patient with nasopharyngeal carcinoma (NPC), shows remarkable similarity to other NPC viruses but is divergent from all other known strains. M81 exhibited a reversed tropism relative to common strains with a reduced ability to infect B cells and a high propensity to infect epithelial cells, which is in agreement with its isolation from carcinomas. M81 spontaneously replicated in B cells in vitro and in vivo at unusually high levels, in line with the enhanced viral replication observed in NPC patients. Spontaneous replication and epitheliotropism could be partly ascribed to polymorphisms within viral proteins. We suggest considering M81 and its closely related isolates as an EBV subtype with enhanced pathogenic potential.
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Affiliation(s)
- Ming-Han Tsai
- German Cancer Research Centre (DKFZ), Unit F100, 69120 Heidelberg, Germany; Inserm Unit U1074, DKFZ, 69120 Heidelberg, Germany
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111
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Downregulation of PAK5 inhibits glioma cell migration and invasion potentially through the PAK5-Egr1-MMP2 signaling pathway. Brain Tumor Pathol 2013; 31:234-41. [PMID: 24062079 DOI: 10.1007/s10014-013-0161-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 08/19/2013] [Indexed: 12/29/2022]
Abstract
PAK5 (p21 activated kinase 5) is upregulated in human colorectal carcinoma cells and is a known tumor promoter in carcinogenesis of the colon. Little is known regarding the mechanisms underlying the downstream targets of PAK5, and information concerning its biological significance in glioma is lacking. In this study, we investigated the effects of PAK5 on proliferation, migration, invasion, and apoptosis in human U87 and U251 glioma cells and examined the underlying molecular mechanism. We performed cell growth assays and cell cycle analysis to observe the cell proliferation. Flow cytometry analysis was performed to evaluate apoptosis, and in vitro scratch assays, cell migration assays, and gelatin zymography were performed to examine cell migration. Western blot analysis was performed to examine signal transduction in the cells. We demonstrated that suppression of PAK5 in glioma cells significantly inhibited cell migration and invasion. We also observed that suppression of PAK5 in human glioma cell lines inhibited cell growth because of G1 phase arrest. Additionally, flow cytometry and Western blot analysis indicated that PAK5 could inhibit cell apoptosis. These results suggest that the PAK5-Egr1-MMP2 signaling pathway is involved in tumor progression and may have a potential role in cancer prevention and treatment.
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112
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Wang XX, Cheng Q, Zhang SN, Qian HY, Wu JX, Tian H, Pei DS, Zheng JN. PAK5-Egr1-MMP2 signaling controls the migration and invasion in breast cancer cell. Tumour Biol 2013; 34:2721-9. [PMID: 23696025 DOI: 10.1007/s13277-013-0824-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 04/26/2013] [Indexed: 12/19/2022] Open
Abstract
p21-activated kinases (PAKs) are activated by various extracellular stimuli and, in turn, activate other kinases by phosphorylating them at specific serine/threonine residues or through protein-protein interaction. As a recently identified member of the group B PAK family, the role of PAK5 in cancer is poorly understood. In this study, we investigated the effect of PAK5 on the malignant phenotype, such as proliferation, cell cycle, apoptosis, migration, and invasion. Cell growth assay and cell cycle analysis consistently showed that knockdown of PAK5 could significantly inhibit the proliferation of breast cancer cells. Wound healing assay. migration assay, and invasion assay showed that PAK5 promoted cell migration. Furthermore, in order to elucidate the underlying mechanism of PAK5 on cellular growth and migration, we examined the protein expressions of cyclin D1, p21, early growth response protein 1 (Egr1), and matrix metalloproteinase 2 (MMP2). Our work further reveals the PAK5-Egr1-MMP2 signaling pathway to be a critical regulator of cell migration and invasion. These results suggest that PAK5 may be a potential therapeutic target for breast cancer.
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Affiliation(s)
- Xiao-Xia Wang
- Jiangsu Key Laboratory of Biological Cancer Therapy, Xuzhou Medical College, 84 West Huai-hai Road, Xuzhou, Jiangsu, 221002, China
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113
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Zhang G, Tsang CM, Deng W, Yip YL, Lui VWY, Wong SCC, Cheung ALM, Hau PM, Zeng M, Lung ML, Chen H, Lo KW, Takada K, Tsao SW. Enhanced IL-6/IL-6R signaling promotes growth and malignant properties in EBV-infected premalignant and cancerous nasopharyngeal epithelial cells. PLoS One 2013; 8:e62284. [PMID: 23658720 PMCID: PMC3641047 DOI: 10.1371/journal.pone.0062284] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 03/19/2013] [Indexed: 12/11/2022] Open
Abstract
Nasopharyngeal carcinoma (NPC) is etiologically associated with Epstein-Barr virus (EBV) infection. However, the exact role of EBV in NPC pathogenesis remains elusive. Activation of signal transducer and activator of transcription 3 (STAT3) is common in human cancers including NPC and plays an important role in the pathogenesis and progression of human cancers. Interleukin-6 (IL-6), a major inflammatory cytokine, is a potent activator of STAT3. In this study, we report that EBV-infected immortalized nasopharyngeal epithelial (NPE) cells often acquire an enhanced response to IL-6-induced STAT3 activation to promote their growth and invasive properties. Interestingly, this enhanced IL-6/STAT3 response was mediated by overexpression of IL-6 receptor (IL-6R). Furthermore, IL-6R overexpression enhanced IL-6-induced STAT3 activation in uninfected immortalized NPE cells in vitro, and promoted growth and tumorigenicity of EBV-positive NPC cell line (C666-1) in vivo. Moreover, it is shown for the first time that IL-6R was overexpressed in clinical specimens of NPC. IL-6 expression could also be strongly detected in the stromal cells of NPC and a higher circulating level of IL-6 was found in the sera of advance-staged NPC patients compared to the control subjects. Therefore, IL-6R overexpression, coupled with enhanced IL-6/STAT3 signaling may facilitate the malignant transformation of EBV-infected premalignant NPE cells into cancer cells, and enhance malignant properties of NPC cells.
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Affiliation(s)
- Guitao Zhang
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
- Department of Anatomy, Histology and Embryology, Capital Medical University, Beijing, China
| | - Chi Man Tsang
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
| | - Wen Deng
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
| | - Yim Ling Yip
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
| | - Vivian Wai-Yan Lui
- Department of Otoloaryngology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Sze Chuen Cesar Wong
- Department of Health Technology and Informatics, Hong Kong Polytechnic University, Hong Kong, SAR, China
| | - Annie Lai-Man Cheung
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
| | - Pok Man Hau
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
| | - Musheng Zeng
- State Key Laboratory of Oncology in Southern China, Cancer Institute, Sun Yat-sen University, Guangzhou, China
| | - Maria Li Lung
- Department of Clinical Oncology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
| | - Honglin Chen
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
| | - Kwok Wai Lo
- Department of Anatomical and Cellular Pathology, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Kenzo Takada
- Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
| | - Sai Wah Tsao
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, SAR, China
- * E-mail:
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