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Incrocci R, Monroy Del Toro R, Devitt G, Salimian M, Braich K, Swanson-Mungerson M. Epstein-Barr Virus Latent Membrane Protein 2A (LMP2A) Enhances ATP Production in B Cell Tumors through mTOR and HIF-1α. Int J Mol Sci 2024; 25:3944. [PMID: 38612754 PMCID: PMC11012313 DOI: 10.3390/ijms25073944] [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: 02/16/2024] [Revised: 03/26/2024] [Accepted: 03/30/2024] [Indexed: 04/14/2024] Open
Abstract
Epstein-Barr Virus (EBV) exists in a latent state in 90% of the world's population and is linked to numerous cancers, such as Burkitt's Lymphoma, Hodgkin's, and non-Hodgkin's Lymphoma. One EBV latency protein, latency membrane protein 2A (LMP2A), is expressed in multiple latency phenotypes. LMP2A signaling has been extensively studied and one target of LMP2A is the mammalian target of rapamycin (mTOR). Since mTOR has been linked to reprogramming tumor metabolism and increasing levels of hypoxia-inducible factor 1 α (HIF-1α), we hypothesized that LMP2A would increase HIF-1α levels to enhance ATP generation in B lymphoma cell lines. Our data indicate that LMP2A increases ATP generation in multiple Burkitt lymphoma cell lines that were dependent on HIF-1α. Subsequent studies indicate that the addition of the mTOR inhibitor, rapamycin, blocked the LMP2A-dependent increase in HIF-1α. Further studies demonstrate that LMP2A does not increase HIF-1α levels by increasing HIF-1α RNA or STAT3 activation. In contrast, LMP2A and mTOR-dependent increase in HIF-1α required mTOR-dependent phosphorylation of p70 S6 Kinase and 4E-BP1. These findings implicate the importance of LMP2A in promoting B cell lymphoma survival by increasing ATP generation and identifying potential pharmaceutical targets to treat EBV-associated tumors.
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Affiliation(s)
- Ryan Incrocci
- Department of Microbiology and Immunology, College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA
| | - Rosalinda Monroy Del Toro
- Department of Microbiology and Immunology, College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA
| | - Grace Devitt
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (G.D.); (M.S.)
| | - Melody Salimian
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (G.D.); (M.S.)
| | - Kamaljit Braich
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (G.D.); (M.S.)
| | - Michelle Swanson-Mungerson
- Department of Microbiology and Immunology, College of Graduate Studies, Midwestern University, Downers Grove, IL 60515, USA
- Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, IL 60515, USA; (G.D.); (M.S.)
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Yang T, You C, Meng S, Lai Z, Ai W, Zhang J. EBV Infection and Its Regulated Metabolic Reprogramming in Nasopharyngeal Tumorigenesis. Front Cell Infect Microbiol 2022; 12:935205. [PMID: 35846746 PMCID: PMC9283984 DOI: 10.3389/fcimb.2022.935205] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 05/31/2022] [Indexed: 01/05/2023] Open
Abstract
Viral oncogenes may drive cellular metabolic reprogramming to modulate the normal epithelia cell malignant transformation. Understanding the viral oncogene–mediated signaling transduction dysregulation that involves in metabolic reprogramming may provide new therapeutic targets for virus-associated cancer treatment. Latent EBV infection and expression of viral oncogenes, including latent membrane proteins 1 and 2 (LMP1/2), and EBV-encoded BamH I-A rightward transcripts (BART) microRNAs (miR-BARTs), have been demonstrated to play fundamental roles in altering host cell metabolism to support nasopharyngeal carcinoma (NPC) pathogenesis. Yet, how do EBV infection and its encoded oncogenes facilitated the metabolic shifting and their roles in NPC carcinogenesis remains unclear. In this review, we will focus on delineating how EBV infection and its encoded oncoproteins altered the metabolic reprograming of infected cells to support their malignances. Furthermore, based on the understanding of the host’s metabolic signaling alterations induced by EBV, we will provide a new perspective on the interplay between EBV infection and these metabolic pathways and offering a potential therapeutic intervention strategy in the treatment of EBV-associated malignant diseases.
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Affiliation(s)
- Tingting Yang
- Department of Pharmacy, Shenzhen University General Hospital, Shenzhen, China
| | - Chanping You
- Department of Pathology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Shuhui Meng
- Clinical Medical Research Center, Guangdong Provincial Engineering Research Center of Autoimmune Disease Precision Medicine, Shenzhen Engineering Research Center of Autoimmune Disease, Shenzhen People’s Hospital, Shenzhen, China
| | - Zhengquan Lai
- Department of Pharmacy, Shenzhen University General Hospital, Shenzhen, China
| | - Weipeng Ai
- Department of Pharmacy, Shenzhen University General Hospital, Shenzhen, China
- *Correspondence: Jun Zhang, ; Weipeng Ai,
| | - Jun Zhang
- Guangdong Key Laboratory of Genome Instability and Human Disease Prevention, Department of Biochemistry and Molecular Biology, Shenzhen University School of Medicine, Shenzhen, China
- *Correspondence: Jun Zhang, ; Weipeng Ai,
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Latent Membrane Proteins from EBV Differentially Target Cellular Pathways to Accelerate MYC-induced Lymphomagenesis. Blood Adv 2022; 6:4283-4296. [PMID: 35605249 PMCID: PMC9327557 DOI: 10.1182/bloodadvances.2022007695] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/12/2022] [Indexed: 11/20/2022] Open
Abstract
EBV LMP1 enhances MYC-mediated degradation of the p27kip1 tumor suppressor and accelerates MYC-induced lymphomagenesis. EBV LMP1 and LMP2A differentially use G1-specific cell cycle and BCR-mediated signaling to accelerate MYC-induced lymphomagenesis.
MYC translocations in association with Epstein-Barr virus (EBV) infection are often observed in B-cell lymphomas. A subset of Burkitt lymphoma (BL) expresses EBV latent membrane proteins 1 and 2A (LMP1 and LMP2A) in addition to the typical restricted EBV latent gene expression. EBV-associated diffuse large B-cell lymphoma (DLBCL) typically exhibits latency type II or III and expresses LMP1. Here, we investigate the role of LMP1 in MYC-driven lymphomagenesis in our murine model. λ-MYC mice develop tumors having a “starry sky” appearance and have abnormal p53 expression that is also observed in human BL. LMP2A/λ-MYC double-transgenic mice develop tumors significantly faster than mice only expressing MYC. Similar to LMP2A/λ-MYC mice, LMP1/λ-MYC mice also have accelerated MYC-driven lymphomagenesis. As observed in LMP2A/λ-MYC mice, p27kip1 was degraded in LMP1/λ-MYC pretumor and tumor B cells. Coexpression of LMP1 and LMP2A resulted in the enhancement of B cell proliferation. In contrast to LMP2A, the inhibition of Syk or cyclin-dependant kinase (CDK)4/6 activity did not effectively inhibit LMP1-mediated MYC lymphomagenesis. Also, in contrast to LMP2A, LMP1 did not lessen abnormal p53 expression in λ-MYC tumors. To investigate the significance of LMP1 expression in human BL development, we reanalyzed RNA sequencing (RNA-Seq) data of primary human BL from previous studies. Interestingly, p53 mutations were less observed in LMP1-expressing BL, although they were not significantly changed by EBV infection, indicating LMP1 may lessen p53 mutations in human primary BL. This suggests that LMP1 effects in EBV-associated human BL vary from what we observe in our murine model. Finally, our studies suggest a novel pathogenic role of LMP1 in lymphomagenesis.
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Dzobo K. The Role of Viruses in Carcinogenesis and Molecular Targeting: From Infection to Being a Component of the Tumor Microenvironment. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2021; 25:358-371. [PMID: 34037476 DOI: 10.1089/omi.2021.0052] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
About a tenth of all cancers are caused by viruses or associated with viral infection. Recent global events including the coronavirus disease-2019 (COVID-19) pandemic means that human encounter with viruses is increased. Cancer development in individuals with viral infection can take many years after infection, demonstrating that the involvement of viruses in cancer development is a long and complex process. This complexity emanates from individual genetic heterogeneity and the many steps involved in cancer development owing to viruses. The process of tumorigenesis is driven by the complex interaction between several viral factors and host factors leading to the creation of a tumor microenvironment (TME) that is ideal and promotes tumor formation. Viruses associated with human cancers ensure their survival and proliferation through activation of several cellular processes including inflammation, migration, and invasion, resistance to apoptosis and growth suppressors. In addition, most human oncoviruses evade immune detection and can activate signaling cascades including the PI3K-Akt-mTOR, Notch and Wnt pathways associated with enhanced proliferation and angiogenesis. This expert review examines and synthesizes the multiple biological factors related to oncoviruses, and the signaling cascades activated by these viruses contributing to viral oncogenesis. In particular, I examine and review the Epstein-Barr virus, human papillomaviruses, and Kaposi's sarcoma herpes virus in a context of cancer pathogenesis. I conclude with a future outlook on therapeutic targeting of the viruses and their associated oncogenic pathways within the TME. These anticancer strategies can be in the form of, but not limited to, antibodies and inhibitors.
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Affiliation(s)
- Kevin Dzobo
- International Centre for Genetic Engineering and Biotechnology (ICGEB), Cape Town Component, Cape Town, South Africa.,Division of Medical Biochemistry and Institute of Infectious Disease and Molecular Medicine, Department of Integrative Biomedical Sciences, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
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Hui KF, Yiu SPT, Tam KP, Chiang AKS. Viral-Targeted Strategies Against EBV-Associated Lymphoproliferative Diseases. Front Oncol 2019; 9:81. [PMID: 30873380 PMCID: PMC6400835 DOI: 10.3389/fonc.2019.00081] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 01/29/2019] [Indexed: 12/14/2022] Open
Abstract
Epstein-Barr virus (EBV) is strongly associated with a spectrum of EBV-associated lymphoproliferative diseases (EBV-LPDs) ranging from post-transplant lymphoproliferative disorder, B cell lymphomas (e.g., endemic Burkitt lymphoma, Hodgkin lymphoma, and diffuse large B cell lymphoma) to NK or T cell lymphoma (e.g., nasal NK/T-cell lymphoma). The virus expresses a number of latent viral proteins which are able to manipulate cell cycle and cell death processes to promote survival of the tumor cells. Several FDA-approved drugs or novel compounds have been shown to induce killing of some of the EBV-LPDs by inhibiting the function of latent viral proteins or activating the viral lytic cycle from latency. Here, we aim to provide an overview on the mechanisms by which EBV employs to drive the pathogenesis of various EBV-LPDs and to maintain the survival of the tumor cells followed by a discussion on the development of viral-targeted strategies based on the understanding of the patho-mechanisms.
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Affiliation(s)
- Kwai Fung Hui
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong
| | - Stephanie Pei Tung Yiu
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong
| | - Kam Pui Tam
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong
| | - Alan Kwok Shing Chiang
- Department of Paediatrics and Adolescent Medicine, Li Ka Shing Faculty of Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong, Hong Kong.,Center for Nasopharyngeal Carcinoma Research, The University of Hong Kong, Hong Kong, Hong Kong
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Choi DH, Yang J, Kim YS. Rapamycin suppresses postnatal muscle hypertrophy induced by myostatin-inhibition accompanied by transcriptional suppression of the Akt/mTOR pathway. Biochem Biophys Rep 2019; 17:182-190. [PMID: 30805561 PMCID: PMC6362869 DOI: 10.1016/j.bbrep.2018.12.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/26/2018] [Accepted: 12/20/2018] [Indexed: 01/16/2023] Open
Abstract
Myostatin (MSTN) is a well-known negative growth factor of muscle mass, and studies have shown that MSTN-inhibition would be a potential strategy to treat muscle atrophy seen in various clinical conditions. Recent studies suggest that MSTN-inhibition induces skeletal muscle hypertrophy through up-regulation of the anabolic Akt/mTOR pathway. Therefore, it was hypothesized that the muscle hypertrophy induced by MSTN-inhibition would be suppressed by the administration of rapamycin (RAP), a mTOR suppressor. A MSTN transgenic mouse strain (MSTN-pro), which is characterized by a postnatal hyper-muscularity due to MSTN inhibition through transgenic overexpression of MSTN propeptide, was used in producing experimental animals. Five-week-old male heterozygous MSTN-pro mice and wild-type littermates were administered with 0 or 3 mg/kg body weight of RAP intraperitoneally every other day for 4 weeks. The effects of RAP on muscle growth, mRNA abundance of signaling components of the Akt/mTOR pathway, and myogenic regulatory factors (MyoD, Myf5, MyoG, and Mrf4) were examined in comparison to wild-type mice. Body weight gain of MSTN-pro mice was significantly greater than that of wild-type mice. RAP suppressed body weight gain and muscle mass in both MSTN-pro and wild-type mice. The extent of both body weight and muscle mass suppression was significantly greater in MSTN-pro mice than in wild-type mice. Real-time qPCR analysis showed that mRNA abundance of the signaling molecules of the Akt/mTOR pathway, including Akt, p70S6K, and 4E-BP1, were significantly higher in MSTN-pro mice. RAP treatment decreased mRNA abundance of Akt, p70S6K and 4E-BP1 only in MSTN-pro mice. mRNA abundances of MyoD and MyoG were not affected by MSTN suppression or RAP treatment. mRNA abundance of Myf5 was decreased by RAP, but not affected by MSTN suppression. mRNA abundance of Mrf4 was decreased by MSTN suppression. RAP treatment decreased mRNA abundance of Mrf4 only in wild type mice. Results of this study indicate that transcriptional regulation of signaling components of the Akt/mTOR pathway and myogenic regulatory transcription factor Mrf4 is involved in the enhancement of skeletal muscle mass induced by MSTN suppression. Muscle mass increase induced by myostatin inhibition was suppressed by rapamycin administration. Myostatin suppression enhanced mRNA abundance of Akt, p70S6K and 4E-BP1 in mice. Rapamycin decreased the expression of Akt, p70S6K and 4E-BP1 in mice with myostatin suppression.
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Affiliation(s)
- Dong Hyuck Choi
- Department of Molecular Bioscience and Bioengineering, University of Hawaii, Honolulu, HI 96822, USA
| | - Jinzeng Yang
- Department of Human Nutrition, Food and Animal Sciences, University of Hawaii, Honolulu, HI 96822, USA
| | - Yong Soo Kim
- Department of Human Nutrition, Food and Animal Sciences, University of Hawaii, Honolulu, HI 96822, USA
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Spleen Tyrosine Kinase Inhibitor TAK-659 Prevents Splenomegaly and Tumor Development in a Murine Model of Epstein-Barr Virus-Associated Lymphoma. mSphere 2018; 3:3/4/e00378-18. [PMID: 30135222 PMCID: PMC6106053 DOI: 10.1128/mspheredirect.00378-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The novel SYK and FLT3 inhibitor TAK-659 prevents the enlargement of spleen and tumor development in a mouse model of EBV-associated lymphoma by counteracting the activation of cellular kinase SYK through the viral LMP2A gene by inducing cell death in tumor cells but not in nontumor cells. These findings indicate that TAK-659 may be a very effective nontoxic therapeutic molecule especially for EBV-positive hematologic malignancies. Epstein-Barr virus (EBV) is associated with several B and epithelial cell cancers. EBV-encoded latent membrane protein 2A (LMP2A) contributes to cellular transformation by mimicking B cell receptor signaling. LMP2A/MYC double transgenic mice develop splenomegaly and B cell lymphoma much faster than MYC transgenic mice do. In this study, we explored the potential therapeutic efficacy of a novel spleen tyrosine kinase (SYK) and FLT3 inhibitor TAK-659 for development of a treatment option for EBV-associated malignancies. In our transgenic model, TAK-659 treatment totally abrogated splenomegaly and tumor development in LMP2A/MYC mice in both pretumor and tumor cell transfer experiments. TAK-659 treatment killed tumor cells, but not host cells within the spleen and tumors. Furthermore, TAK-659 treatment abrogated metastasis of tumor cells into bone marrow. Our data also show that TAK-659 inhibits SYK phosphorylation and induces apoptosis in LMP2A/MYC tumor cells at low nanomolar concentrations. Therefore, TAK-659 may provide an effective therapeutic option for treatment of LMP2A-positive EBV-associated malignancies and should be explored further in clinical trials. IMPORTANCE The novel SYK and FLT3 inhibitor TAK-659 prevents the enlargement of spleen and tumor development in a mouse model of EBV-associated lymphoma by counteracting the activation of cellular kinase SYK through the viral LMP2A gene by inducing cell death in tumor cells but not in nontumor cells. These findings indicate that TAK-659 may be a very effective nontoxic therapeutic molecule especially for EBV-positive hematologic malignancies.
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8
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Zheng K, Fu C, Jiang C, Yue X, Ma S. Water extract of pilose antler can inhibit breast cancer progression of the mouse through modulating its immune system. FOOD AGR IMMUNOL 2018. [DOI: 10.1080/09540105.2018.1457012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Kexin Zheng
- College of Food Science and Technology, Shenyang Agricultural University, Shenyang, P.R. People’s Republic of China
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, P.R. People’s Republic of China
| | - Chenghao Fu
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, P.R. People’s Republic of China
| | - Chunying Jiang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, P.R. People’s Republic of China
| | - Xiqing Yue
- College of Food Science and Technology, Shenyang Agricultural University, Shenyang, P.R. People’s Republic of China
| | - Shiliang Ma
- College of Food Science and Technology, Shenyang Agricultural University, Shenyang, P.R. People’s Republic of China
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, P.R. People’s Republic of China
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9
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Yigit B, Halibozek PJ, Chen SS, O'Keeffe MS, Arnason J, Avigan D, Gattei V, Bhan A, Cen O, Longnecker R, Chiorazzi N, Wang N, Engel P, Terhorst C. A combination of an anti-SLAMF6 antibody and ibrutinib efficiently abrogates expansion of chronic lymphocytic leukemia cells. Oncotarget 2018; 7:26346-60. [PMID: 27029059 PMCID: PMC5041984 DOI: 10.18632/oncotarget.8378] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 03/07/2016] [Indexed: 11/25/2022] Open
Abstract
The signaling lymphocyte activation molecule family [SLAMF] of cell surface receptors partakes in both the development of several immunocyte lineages and innate and adaptive immune responses in humans and mice. For instance, the homophilic molecule SLAMF6 (CD352) is in part involved in natural killer T cell development, but also modulates T follicular helper cell and germinal B cell interactions. Here we report that upon transplantation of a well-defined aggressive murine B220+CD5+ Chronic Lymphocytic Leukemia (CLL) cell clone, TCL1-192, into SCID mice one injection of a monoclonal antibody directed against SLAMF6 (αSlamf6) abrogates tumor progression in the spleen, bone marrow and blood. Similarly, progression of a murine B cell lymphoma, LMP2A/λMyc, was also eliminated by αSlamf6. But, surprisingly, αSLAMF6 neither eliminated TCL1-192 nor LMP2A/λMyc cells, which resided in the peritoneal cavity or omentum. This appeared to be dependent upon the tumor environment, which affected the frequency of sub-populations of the TCL1-192 clone or the inability of peritoneal macrophages to induce Antibody Dependent Cellular Cytotoxicity (ADCC). However, co-administering αSlamf6 with the Bruton tyrosine kinase (Btk) inhibitor, ibrutinib, synergized to efficiently eliminate the tumor cells in the spleen, bone marrow, liver and the peritoneal cavity. Because an anti-human SLAMF6 mAb efficiently killed human CLL cells in vitro and in vivo, we propose that a combination of αSlamf6 with ibrutinib should be considered as a novel therapeutic approach for CLL and other B cell tumors.
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Affiliation(s)
- Burcu Yigit
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Peter J Halibozek
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Shih-Shih Chen
- Karches Center for Chronic Lymphocytic Leukemia Research, The Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Michael S O'Keeffe
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Jon Arnason
- Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - David Avigan
- Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Valter Gattei
- Clinical and Experimental Onco-Hematology Unit, Centro di Riferimento Oncologico, I.R.C.C.S., Aviano, Italy
| | - Atul Bhan
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Osman Cen
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Richard Longnecker
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Nicholas Chiorazzi
- Karches Center for Chronic Lymphocytic Leukemia Research, The Feinstein Institute for Medical Research, Manhasset, NY, USA
| | - Ninghai Wang
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Pablo Engel
- Immunology Unit, Department of Cell Biology, Immunology and Neurosciences, Medical School, University of Barcelona, Barcelona, Spain
| | - Cox Terhorst
- Division of Immunology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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10
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Sato Y. Challenges in Managing EBV-Associated T- and NK-Cell Lymphoproliferative Diseases. Front Pediatr 2018; 6:320. [PMID: 30460214 PMCID: PMC6232248 DOI: 10.3389/fped.2018.00320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 10/08/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Yoshitaka Sato
- Department of Virology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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11
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Mui UN, Haley CT, Tyring SK. Viral Oncology: Molecular Biology and Pathogenesis. J Clin Med 2017; 6:E111. [PMID: 29186062 PMCID: PMC5742800 DOI: 10.3390/jcm6120111] [Citation(s) in RCA: 101] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 11/17/2017] [Accepted: 11/22/2017] [Indexed: 02/06/2023] Open
Abstract
Oncoviruses are implicated in approximately 12% of all human cancers. A large number of the world's population harbors at least one of these oncoviruses, but only a small proportion of these individuals go on to develop cancer. The interplay between host and viral factors is a complex process that works together to create a microenvironment conducive to oncogenesis. In this review, the molecular biology and oncogenic pathways of established human oncoviruses will be discussed. Currently, there are seven recognized human oncoviruses, which include Epstein-Barr Virus (EBV), Human Papillomavirus (HPV), Hepatitis B and C viruses (HBV and HCV), Human T-cell lymphotropic virus-1 (HTLV-1), Human Herpesvirus-8 (HHV-8), and Merkel Cell Polyomavirus (MCPyV). Available and emerging therapies for these oncoviruses will be mentioned.
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Affiliation(s)
- Uyen Ngoc Mui
- Center for Clinical Studies, Houston, TX 77004, USA.
| | | | - Stephen K Tyring
- Center for Clinical Studies, Houston, TX 77004, USA.
- Department of Dermatology, University of Texas Health Science Center at Houston, Houston, TX 77004, USA.
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12
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EBV latent membrane protein 2A orchestrates p27 kip1 degradation via Cks1 to accelerate MYC-driven lymphoma in mice. Blood 2017; 130:2516-2526. [PMID: 29074502 DOI: 10.1182/blood-2017-07-796821] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/19/2017] [Indexed: 02/07/2023] Open
Abstract
Epstein-Barr virus (EBV) establishes lifelong infection in B lymphocytes of most human hosts and is associated with several B lymphomas. During latent infection, EBV encodes latent membrane protein 2A (LMP2A) to promote the survival of B cells by mimicking host B-cell receptor signaling. By studying the roles of LMP2A during lymphoma development in vivo, we found that LMP2A mediates rapid MYC-driven lymphoma onset by allowing B cells to bypass MYC-induced apoptosis mediated by the p53 pathway in our transgenic mouse model. However, the mechanisms used by LMP2A to facilitate transformation remain elusive. In this study, we demonstrate a key role of LMP2A in promoting hyperproliferation of B cells by enhancing MYC expression and MYC-dependent degradation of the p27kip1 tumor suppressor. Loss of the adaptor protein cyclin-dependent kinase regulatory subunit 1 (Cks1), a cofactor of the SCFSkp2 ubiquitin ligase complex and a downstream target of MYC, increases p27kip1 expression during a premalignant stage. In mice that express LMP2A, Cks1 deficiency reduces spleen weights, restores B-cell follicle formation, impedes cell cycle progression of pretumor B cells, and eventually prolongs MYC-driven tumor onset. This study demonstrates that LMP2A uses the role of MYC in the cell cycle, particularly in the p27kip1 degradation process, to accelerate lymphomagenesis in vivo. Thus, our results reveal a novel mechanism of EBV in diverting the functions of MYC in malignant transformation and provide a rationale for targeting EBV's roles in cell cycle modulation.
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Liu X, Cohen JI. The role of PI3K/Akt in human herpesvirus infection: From the bench to the bedside. Virology 2015; 479-480:568-77. [PMID: 25798530 PMCID: PMC4424147 DOI: 10.1016/j.virol.2015.02.040] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 12/25/2022]
Abstract
The phosphatidylinositol-3-kinase (PI3K)-Akt signaling pathway regulates several key cellular functions including protein synthesis, cell growth, glucose metabolism, and inflammation. Many viruses have evolved mechanisms to manipulate this signaling pathway to ensure successful virus replication. The human herpesviruses undergo both latent and lytic infection, but differ in cell tropism, growth kinetics, and disease manifestations. Herpesviruses express multiple proteins that target the PI3K/Akt cell signaling pathway during the course of their life cycle to facilitate viral infection, replication, latency, and reactivation. Rare human genetic disorders with mutations in either the catalytic or regulatory subunit of PI3K that result in constitutive activation of the protein predispose to severe herpesvirus infections as well as to virus-associated malignancies. Inhibiting the PI3K/Akt pathway or its downstream proteins using drugs already approved for other diseases can block herpesvirus lytic infection and may reduce malignancies associated with latent herpesvirus infections.
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Affiliation(s)
- XueQiao Liu
- Medical Virology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Jeffrey I Cohen
- Medical Virology Section, Laboratory of Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
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Chronic activation of mTOR complex 1 by branched chain amino acids and organ hypertrophy. Amino Acids 2015; 47:1167-82. [PMID: 25721400 DOI: 10.1007/s00726-015-1944-y] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 02/14/2015] [Indexed: 12/11/2022]
Abstract
The mitochondrial branched chain aminotransferase-deficient mouse model (BCATm KO), which exhibits elevated plasma and tissue branched chain amino acids (BCAAs), was used to study the effect of BCAAs on mammalian target of rapamycin complex 1 (mTORC1) regulation of organ size. BCATm is the first enzyme in the BCAA catabolic pathway. BCATm KO mouse exhibited hypertrophy of heart, kidneys, and spleen. On the other hand, the mass of the gastrocnemius was reduced relative to body mass. Feeding the mice with a diet supplemented with rapamycin prevented the enlargement of the heart and spleen, suggesting that mTORC1 is the mediator of these effects. Consistently, enlargement of these organs was accompanied by the activation of mTORC1 complex as evidenced by enhanced levels of S6 and 4E-BP1 phosphorylation. HSP20, HSP27 and GAPDH were also increased in the heart but not gastrocnemius, consistent with mTORC1 activation. Liver, however, displayed no weight difference between the KO and the wild-type mice despite the highest activation level of mTORC1 complex. These observations suggest that the anabolic effect of mTORC1 activation at the organ level by BCAAs and inhibition by rapamycin are complex phenomenon and tissue-specific. In addition, it suggests that rapamycin can be used to counter hypertrophy of the organs when activation of mTORC1 is the underlying cause.
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15
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Araújo NC, Sampaio Gonçalves de Lucena SB, da Silveira Rioja S. Effect of rapamycin on spleen size in longstanding renal transplant recipients. Transplant Proc 2015; 46:1319-23. [PMID: 24935295 DOI: 10.1016/j.transproceed.2014.03.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 03/14/2014] [Accepted: 03/27/2014] [Indexed: 10/25/2022]
Abstract
BACKGROUND Based on evidence available in the literature, rapamycin, a mammalian target of rapamycin (mTOR) inhibitor, but not calcineurin inhibitors (CNIs), has been shown to decrease spleen size. Small spleen, in some instances, is associated with hyposplenism, a condition recently reported in patients with longstanding renal transplant. Accordingly, the effect of immunosuppressive drugs on spleen size was evaluated. METHODS Renal transplant recipients (35 taking mTOR and 68 CNI) were included, in whom a standardized investigation of the kidney allograft and spleen with the use of color Doppler ultrasound was performed and a peripheral smear were reviewed for the presence of Howell-Jolly bodies (HJBs). RESULTS We enrolled 103 patients (64 men; 66 from a deceased donor). The mean age was 47.7 years (range, 23.0-74.0 y). Mean transplant duration was 1,899 days (range, 181-6,883 d). According to the presence of HJBs, the prevalence of hyposplenism was 47.6% for the entire cohort. The differences between the mTOR and CNI groups regarding sex and the presence of HJBs were not statistically significant (P > .05). Age, creatinine, hemoglobin, leukocytes, platelets, and Doppler parameters in spleen and kidney were similar in both groups (P > .05). mTOR patients had a decreased spleen length size (90.09 ± 13.02 mm vs 111.95 ± 18.66 mm; P < .001), a longer transplant duration (3,576 ± 1,594 d vs 1,036 ± 1,369 d; P < .001) and higher serum cholesterol (227.50 ± 38.75 mg/dL vs 182.67 ± 37.74 mg/dL; P < .001) and triglycerides (194.23 ± 79.88 mg/dL vs 148.70 ± 55.54 mg/dL; P = .003) levels compared with the CNI group. A multivariate analysis showed mTOR inhibitor to be the most important predictor of spleen size. In both the mTOR and CNI groups, the comparison between the subgroups of present and absent HJBs did not show any difference. CONCLUSIONS The findings of this study suggest that small spleens in transplant recipients may be linked to treatment with an mTOR inhibitor, although this apparently does not compromise splenic function.
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Affiliation(s)
- N C Araújo
- Division of Nephrology, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil.
| | | | - S da Silveira Rioja
- Division of Nephrology, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
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16
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Abstract
LMP2A is an EBV-encoded protein with three domains: (a) an N-terminal cytoplasmic domain, which has PY motifs that bind to WW domain-containing E3 ubiquitin ligases and an ITAM that binds to SH2 domain-containing proteins, (b) a transmembrane domain with 12 transmembrane segments that localizes LMP2A in cellular membranes, and (c) a 27-amino acid C-terminal domain which mediates homodimerization and heterodimerization of LMP2 protein isoforms. The most prominent two isoforms of the protein are LMP2A and LMP2B. The LMP2B isoform lacks the 19-amino acid N-terminal domain found in LMP2A, which modulates cellular signaling resulting in a baseline activation of B cells and degradation of cellular kinases leading to the downregulation of normal B cell signaling pathways. These two seemingly contradictory processes allow EBV to establish and maintain latency. LMP2 is expressed in many EBV-associated malignancies. While its antigenic properties may be useful in developing LMP2-specific immunity, the LMP2A N-terminal motifs also provide a basis to target LMP2A-modulated cellular kinases for the development of treatment strategies.
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Kawada JI, Ito Y, Iwata S, Suzuki M, Kawano Y, Kanazawa T, Siddiquey MNA, Kimura H. mTOR Inhibitors Induce Cell-Cycle Arrest and Inhibit Tumor Growth in Epstein–Barr Virus–Associated T and Natural Killer Cell Lymphoma Cells. Clin Cancer Res 2014; 20:5412-22. [DOI: 10.1158/1078-0432.ccr-13-3172] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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18
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Adamson AL, Le BT, Siedenburg BD. Inhibition of mTORC1 inhibits lytic replication of Epstein-Barr virus in a cell-type specific manner. Virol J 2014; 11:110. [PMID: 24917448 PMCID: PMC4059732 DOI: 10.1186/1743-422x-11-110] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 06/05/2014] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Epstein-Barr virus is a human herpesvirus that infects a majority of the human population. Primary infection of Epstein-Barr virus (EBV) causes the syndrome infectious mononucleosis. This virus is also associated with several cancers, including Burkitt's lymphoma, post-transplant lymphoproliferative disorder and nasopharyngeal carcinoma. As all herpesvirus family members, EBV initially replicates lytically to produce abundant virus particles, then enters a latent state to remain within the host indefinitely. METHODS Through a genetic screen in Drosophila, we determined that reduction of Drosophila Tor activity altered EBV immediate-early protein function. To further investigate this finding, we inhibited mTOR in EBV-positive cells and investigated subsequent changes to lytic replication via Western blotting, flow cytometry, and quantitative PCR. The student T-test was used to evaluate significance. RESULTS mTOR, the human homolog of Drosophila Tor, is an important protein at the center of a major signaling pathway that controls many aspects of cell biology. As the EBV immediate-early genes are responsible for EBV lytic replication, we examined the effect of inhibition of mTORC1 on EBV lytic replication in human EBV-positive cell lines. We determined that treatment of cells with rapamycin, which is an inhibitor of mTORC1 activity, led to a reduction in the ability of B cell lines to undergo lytic replication. In contrast, EBV-positive epithelial cell lines underwent higher levels of lytic replication when treated with rapamycin. CONCLUSIONS Overall, the responses of EBV-positive cell lines vary when treated with mTOR inhibitors, and this may be important when considering such inhibitors as anti-cancer therapeutic agents.
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Affiliation(s)
- Amy L Adamson
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina 27402, USA.
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19
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A novel strategy inducing autophagic cell death in Burkitt's lymphoma cells with anti-CD19-targeted liposomal rapamycin. Blood Cancer J 2014; 4:e180. [PMID: 24510029 PMCID: PMC3944660 DOI: 10.1038/bcj.2014.2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 11/20/2013] [Accepted: 12/31/2013] [Indexed: 11/18/2022] Open
Abstract
Relapsed or refractory Burkitt's lymphoma often has a poor prognosis in spite of intensive chemotherapy that induces apoptotic and/or necrotic death of lymphoma cells. Rapamycin (Rap) brings about autophagy, and could be another treatment. Further, anti-CD19-targeted liposomal delivery may enable Rap to kill lymphoma cells specifically. Rap was encapsulated by anionic liposome and conjugated with anti-CD19 antibody (CD19-GL-Rap) or anti-CD2 antibody (CD2-GL-Rap) as a control. A fluorescent probe Cy5.5 was also liposomized in the same way (CD19 or CD2-GL-Cy5.5) to examine the efficacy of anti-CD19-targeted liposomal delivery into CD19-positive Burkitt's lymphoma cell line, SKW6.4. CD19-GL-Cy5.5 was more effectively uptaken into SKW6.4 cells than CD2-GL-Cy5.5 in vitro. When the cells were inoculated subcutaneously into nonobese diabetic/severe combined immunodeficiency mice, intravenously administered CD19-GL-Cy5.5 made the subcutaneous tumor fluorescent, while CD2-GL-Cy5.5 did not. Further, CD19-GL-Rap had a greater cytocidal effect on not only SKW6.4 cells but also Burkitt's lymphoma cells derived from patients than CD2-GL-Rap in vitro. The specific toxicity of CD19-GL-Rap was cancelled by neutralizing anti-CD19 antibody. The survival period of mice treated with intravenous CD19-GL-Rap was significantly longer than that of mice treated with CD2-GL-Rap after intraperitoneal inoculation of SKW6.4 cells. Anti-CD19-targeted liposomal Rap could be a promising lymphoma cell-specific treatment inducing autophagic cell death.
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20
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Smets F, Sokal EM. Prevention and treatment for Epstein-Barr virus infection and related cancers. Recent Results Cancer Res 2014; 193:173-190. [PMID: 24008299 DOI: 10.1007/978-3-642-38965-8_10] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Epstein-Barr virus (EBV) was the first herpes virus described as being oncogenic in humans. EBV infection is implicated in post-transplant lymphoproliferative diseases (PTLD) and several other cancers in non-immunocompromised patients, with more than 200,000 new cases per year. While prevention of PTLD is improving, mainly based on EBV monitoring and preemptive tapering of immunosuppression, early diagnosis remains the best current option for the other malignancies. Significant progress has been achieved in treatment, with decreased mortality and morbidity, but some challenges are still to face, especially for the more aggressive diseases. Possible prevention by EBV vaccination would be a more global approach of this public health problem, but further active research is needed before this goal could be reached.
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Affiliation(s)
- Françoise Smets
- Université Catholique de Louvain, Cliniques Universitaires St-Luc, Avenue Hippocrate 10/1301, 1200, Brussels, Belgium,
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21
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Epstein-Barr virus latent membrane protein 2A enhances MYC-driven cell cycle progression in a mouse model of B lymphoma. Blood 2013; 123:530-40. [PMID: 24174629 DOI: 10.1182/blood-2013-07-517649] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Elevated expression of MYC is a shared property of many human cancers. Epstein-Barr virus (EBV) has been associated with lymphoid malignancies, yet collaborative roles between MYC and EBV in lymphomagenesis are unclear. EBV latent membrane protein 2A (LMP2A) functions as a B-cell receptor (BCR) mimic known to provide survival signals to infected B cells. Co-expression of human MYC and LMP2A in mice (LMP2A/λ-MYC) accelerates B lymphoma onset compared with mice expressing human MYC alone (λ-MYC mice). Here we show a novel role of LMP2A in potentiating MYC to promote G1-S transition and hyperproliferation by downregulating cyclin-dependent kinase inhibitor p27(kip1) in a proteasome-dependent manner. Expressing a gain-of-function S10A mutant of p27(kip1) has minor effect on tumor latency. However, pretumor B cells from λ-MYC mice expressing homozygous S10A mutant show a significant decrease in the percentage of S-phase cells. Interestingly, LMP2A is able to counteract the antiproliferative effect of the S10A mutant to promote S-phase entry. Finally, we show that LMP2A expression correlates with higher levels of MYC expression and suppression of p27(kip1) before lymphoma onset. Our study demonstrates a novel function of EBV LMP2A in maximizing MYC expression, resulting in hyperproliferation and cellular transformation into cancer cells in vivo.
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22
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Li R, Hayward SD. Potential of protein kinase inhibitors for treating herpesvirus-associated disease. Trends Microbiol 2013; 21:286-95. [PMID: 23608036 DOI: 10.1016/j.tim.2013.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2013] [Revised: 03/24/2013] [Accepted: 03/26/2013] [Indexed: 11/29/2022]
Abstract
Herpesviruses are ubiquitous human pathogens that establish lifelong persistent infections. Clinical manifestations range from mild self-limiting outbreaks such as childhood rashes and cold sores to the more severe and life-threatening outcomes of disseminated infection, encephalitis, and cancer. Nucleoside analog drugs that target viral DNA replication provide the primary means of treatment. However, extended use of these drugs can result in selection for drug-resistant strains, particularly in immunocompromised patients. In this review we will present recent observations about the participation of cellular protein kinases in herpesvirus biology and discuss the potential for targeting these protein kinases as well as the herpesvirus-encoded protein kinases as an anti-herpesvirus therapeutic strategy.
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Affiliation(s)
- Renfeng Li
- Viral Oncology Program, Department of Oncology, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA.
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23
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Walsh D, Mathews MB, Mohr I. Tinkering with translation: protein synthesis in virus-infected cells. Cold Spring Harb Perspect Biol 2013; 5:a012351. [PMID: 23209131 DOI: 10.1101/cshperspect.a012351] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Viruses are obligate intracellular parasites, and their replication requires host cell functions. Although the size, composition, complexity, and functions encoded by their genomes are remarkably diverse, all viruses rely absolutely on the protein synthesis machinery of their host cells. Lacking their own translational apparatus, they must recruit cellular ribosomes in order to translate viral mRNAs and produce the protein products required for their replication. In addition, there are other constraints on viral protein production. Crucially, host innate defenses and stress responses capable of inactivating the translation machinery must be effectively neutralized. Furthermore, the limited coding capacity of the viral genome needs to be used optimally. These demands have resulted in complex interactions between virus and host that exploit ostensibly virus-specific mechanisms and, at the same time, illuminate the functioning of the cellular protein synthesis apparatus.
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Affiliation(s)
- Derek Walsh
- Department of Microbiology, New York University School of Medicine, New York, NY 10016, USA.
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24
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Chen J. Roles of the PI3K/Akt pathway in Epstein-Barr virus-induced cancers and therapeutic implications. World J Virol 2012; 1:154-61. [PMID: 24175221 PMCID: PMC3782276 DOI: 10.5501/wjv.v1.i6.154] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 10/16/2012] [Accepted: 11/07/2012] [Indexed: 02/05/2023] Open
Abstract
Viruses have been shown to be responsible for 10%-15% of cancer cases. Epstein-Barr virus (EBV) is the first virus to be associated with human malignancies. EBV can cause many cancers, including Burkett's lymphoma, Hodgkin's lymphoma, post-transplant lymphoproliferative disorders, nasopharyngeal carcinoma and gastric cancer. Evidence shows that phosphoinositide 3-kinase/protein kinase B (PI3K/Akt) plays a key role in EBV-induced malignancies. The main EBV oncoproteins latent membrane proteins (LMP) 1 and LMP2A can activate the PI3K/Akt pathway, which, in turn, affects cell survival, apoptosis, proliferation and genomic instability via its downstream target proteins to cause cancer. It has also been demonstrated that the activation of the PI3K/Akt pathway can result in drug resistance to chemotherapy. Thus, the inhibition of this pathway can increase the therapeutic efficacy of EBV-associated cancers. For example, PI3K inhibitor Ly294002 has been shown to increase the effect of 5-fluorouracil in an EBV-associated gastric cancer cell line. At present, dual inhibitors of PI3K and its downstream target mammalian target of rapamycin have been used in clinical trials and may be included in treatment regimens for EBV-associated cancers.
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Affiliation(s)
- Jiezhong Chen
- Jiezhong Chen, Illawarra Health and Medical Research Institute, University of Wollongong, Northfields Avenue, NSW 2522, Australia
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25
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Abouelnasr A, Roy J, Cohen S, Kiss T, Lachance S. Defining the role of sirolimus in the management of graft-versus-host disease: from prophylaxis to treatment. Biol Blood Marrow Transplant 2012; 19:12-21. [PMID: 22771839 DOI: 10.1016/j.bbmt.2012.06.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Accepted: 06/28/2012] [Indexed: 11/16/2022]
Abstract
Graft-versus-host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Measures developed that have significantly reduced GVHD were also frequently associated with an increased risk of relapse. GVHD and graft-versus-tumor (GVT) effects are tightly linked, and balance between both reactions is difficult to achieve. To have an impact on the outcome and quality of life after HSCT, improvements in current strategies to prevent and treat GVHD while preserving the GVT effect are clearly needed. Sirolimus (rapamycin) is a lipophilic macrocytic lactone with immunosuppressive, antitumor, and antiviral properties. Because of its multiple modes of activities, it is being increasingly used in the management of GVHD. This review aims to summarize its mechanisms of action and potential advantages over other immunosuppressors and to analyze the most relevant studies investigating its role in both prevention and treatment of GVHD.
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Affiliation(s)
- Ahmed Abouelnasr
- Division of Haematology-Oncology, Stem Cell Transplant Program Hôpital Maisonneuve-Rosemont, Université de Montréal, Québec, Canada
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26
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Noch E, Khalili K. Oncogenic viruses and tumor glucose metabolism: like kids in a candy store. Mol Cancer Ther 2012; 11:14-23. [PMID: 22234809 DOI: 10.1158/1535-7163.mct-11-0517] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Oncogenic viruses represent a significant public health burden in light of the multitude of malignancies that result from chronic or spontaneous viral infection and transformation. Although many of the molecular signaling pathways that underlie virus-mediated cellular transformation are known, the impact of these viruses on metabolic signaling and phenotype within proliferating tumor cells is less well understood. Whether the interaction of oncogenic viruses with metabolic signaling pathways involves enhanced glucose uptake and glycolysis (both hallmark features of transformed cells) or dysregulation of molecular pathways that regulate oxidative stress, viruses are adept at facilitating tumor expansion. Through their effects on cell proliferation pathways, such as the PI3K and MAPK pathways, the cell cycle regulatory proteins p53 and ATM, and the cell stress response proteins HIF-1α and AMPK, viruses exert control over critical metabolic signaling cascades. Additionally, oncogenic viruses modulate the tumor metabolomic profile through direct and indirect interactions with glucose transporters, such as GLUT1, and specific glycolytic enzymes, including pyruvate kinase, glucose 6-phosphate dehydrogenase, and hexokinase. Through these pathways, oncogenic viruses alter the phenotypic characteristics and energy-use methods of transformed cells; therefore, it may be possible to develop novel antiglycolytic therapies to target these dysregulated pathways in virus-derived malignancies.
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Affiliation(s)
- Evan Noch
- Department of Neuroscience and Center for Neurovirology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140, USA
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27
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Modulation of autophagy-like processes by tumor viruses. Cells 2012; 1:204-47. [PMID: 24710474 PMCID: PMC3901111 DOI: 10.3390/cells1030204] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 06/13/2012] [Accepted: 06/14/2012] [Indexed: 02/07/2023] Open
Abstract
Autophagy is an intracellular degradation pathway for long-lived proteins and organelles. This process is activated above basal levels upon cell intrinsic or environmental stress and dysregulation of autophagy has been linked to various human diseases, including those caused by viral infection. Many viruses have evolved strategies to directly interfere with autophagy, presumably to facilitate their replication or to escape immune detection. However, in some cases, modulation of autophagy appears to be a consequence of the virus disturbing the cell’s metabolic signaling networks. Here, we summarize recent advances in research at the interface of autophagy and viral infection, paying special attention to strategies that human tumor viruses have evolved.
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Dargart JL, Fish K, Gordon LI, Longnecker R, Cen O. Dasatinib therapy results in decreased B cell proliferation, splenomegaly, and tumor growth in a murine model of lymphoma expressing Myc and Epstein-Barr virus LMP2A. Antiviral Res 2012; 95:49-56. [PMID: 22609829 DOI: 10.1016/j.antiviral.2012.05.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 05/03/2012] [Accepted: 05/07/2012] [Indexed: 11/16/2022]
Abstract
Epstein-Barr virus (EBV) infection and latency has been associated with malignant diseases including nasopharyngeal carcinoma, Hodgkin lymphoma, Burkitt lymphoma, and immune deficiency associated lymphoproliferative diseases. EBV-encoded latent membrane protein 2A (LMP2A) recruits Lyn and Syk kinases via its SH2-domain binding motifs, and modifies their signaling pathways. LMP2A transgenic mice develop hyperproliferative bone marrow B cells and immature peripheral B cells through modulation of Lyn kinase signaling. LMP2A/λ-MYC double transgenic mice develop splenomegaly and cervical lymphomas starting at 8 weeks of age. We reasoned that targeting Lyn in LMP2A-expressing B cells with dasatinib would provide a therapeutic option for EBV-associated malignancies. Here, we show that dasatinib inhibits B cell colony formation by LMP2A transgenic bone marrow cells, and reverses splenomegaly and tumor growth in both a pre-tumor and a syngeneic tumor transfer model of EBV-associated Burkitt lymphoma. Our data support the idea that dasatinib may prove to be an effective therapeutic molecule for the treatment of EBV-associated malignancies.
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Affiliation(s)
- Jamie L Dargart
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, 303 E. Chicago Avenue, Ward 6-245, Chicago, IL, USA
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29
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Dunn EF, Connor JH. HijAkt: The PI3K/Akt pathway in virus replication and pathogenesis. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 106:223-50. [PMID: 22340720 PMCID: PMC7149925 DOI: 10.1016/b978-0-12-396456-4.00002-x] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
As obligate parasites of cellular processes, viruses must take over cellular macromolecular machinery. It is also becoming clear that viruses routinely control intracellular signaling pathways through the direct or indirect control of kinases and phosphatases. This control of cellular phosphoproteins is important to promote a variety of viral processes, from control of entry to nuclear function to the stimulation of viral protein synthesis. This review focuses on the takeover of the cellular phosphatidylinositol-3-kinase (PI3K)/Akt signaling pathway by a variety of retroviruses, DNA viruses, and RNA viruses, highlighting the functions ascribed to virus activation of PI3K and Akt activity. This review also describes the role that the PI3K/Akt pathway plays in the host response, noting that it that can trigger anti- as well as proviral functions.
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Affiliation(s)
- Ewan F Dunn
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
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30
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A shared gene expression signature in mouse models of EBV-associated and non-EBV-associated Burkitt lymphoma. Blood 2011; 118:6849-59. [PMID: 22039254 DOI: 10.1182/blood-2011-02-338434] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The link between EBV infection and Burkitt lymphoma (BL) is strong, but the mechanism underlying that link has been elusive. We have developed a mouse model for EBV-associated BL in which LMP2A, an EBV latency protein, and MYC are expressed in B cells. Our model has demonstrated the ability of LMP2A to accelerate tumor onset, increase spleen size, and bypass p53 inactivation. Here we describe the results of total gene expression analysis of tumor and pretumor B cells from our transgenic mouse model. Although we see many phenotypic differences and changes in gene expression in pretumor B cells, the transcriptional profiles of tumor cells from LMP2A/λ-MYC and λ-MYC mice are strikingly similar, with fewer than 20 genes differentially expressed. We evaluated the functional significance of one of the most interesting differentially expressed genes, Egr1, and found that it was not required for acceleration of tumor onset by LMP2A. Our studies demonstrate the remarkable ability of LMP2A to affect the pretumor B-cell phenotype and tumorigenesis without substantially altering gene expression in tumor cells.
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31
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Roy D, Dittmer DP. Phosphatase and tensin homolog on chromosome 10 is phosphorylated in primary effusion lymphoma and Kaposi's sarcoma. THE AMERICAN JOURNAL OF PATHOLOGY 2011; 179:2108-19. [PMID: 21819957 DOI: 10.1016/j.ajpath.2011.06.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Revised: 06/18/2011] [Accepted: 06/28/2011] [Indexed: 12/23/2022]
Abstract
Primary effusion lymphoma (PEL) is a non-Hodgkin's B-cell lymphoma driven by Kaposi's sarcoma-associated herpesvirus. It is uniquely sensitive to mTOR, PI3K, and Akt inhibitors; however, the basis of this requirement for the mTOR pathway remains to be elucidated. The phosphatase and tensin homolog gene (PTEN) on chromosome 10 controls the first step in the phosphatidylinositol 3 kinase (PI3K)-Akt-mammalian target of rapamycin (mTOR) pathway and is genetically inactivated in many solid tumors. We find an absence of PTEN deletions, mutations, or protein mislocalization in PEL. However, we find consistent hyperphosphorylation at serine 380 of PTEN, which is an inactivating modification, in PEL cell lines and in tumor xenografts. We also evaluated a large tissue microarray of Kaposi's sarcoma biopsies and observed concordant high levels of phospho-PTEN, phospho-Akt, and phospho-S6 ribosomal protein. Reintroduction of PTEN into PEL inhibited colony formation in soft agar, verifying the functional dependence of PEL on PI3K signaling. This was also true for PEL cell lines that carried mutant p53 and for KS-like cell lines. Activating PTEN in these cancers may yield a new treatment strategy for PEL, KS, and similar PTEN wild-type lymphomas.
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Affiliation(s)
- Debasmita Roy
- Curriculum in Genetics and Molecular Biology, Lineberger Comprehensive Cancer Center, Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7290, USA
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32
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Hollander MC, Blumenthal GM, Dennis PA. PTEN loss in the continuum of common cancers, rare syndromes and mouse models. Nat Rev Cancer 2011; 11:289-301. [PMID: 21430697 PMCID: PMC6946181 DOI: 10.1038/nrc3037] [Citation(s) in RCA: 617] [Impact Index Per Article: 47.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PTEN is among the most frequently inactivated tumour suppressor genes in sporadic cancer. PTEN has dual protein and lipid phosphatase activity, and its tumour suppressor activity is dependent on its lipid phosphatase activity, which negatively regulates the PI3K-AKT-mTOR pathway. Germline mutations in PTEN have been described in a variety of rare syndromes that are collectively known as the PTEN hamartoma tumour syndromes (PHTS). Cowden syndrome is the best-described syndrome within PHTS, with approximately 80% of patients having germline PTEN mutations. Patients with Cowden syndrome have an increased incidence of cancers of the breast, thyroid and endometrium, which correspond to sporadic tumour types that commonly exhibit somatic PTEN inactivation. Pten deletion in mice leads to Cowden syndrome-like phenotypes, and tissue-specific Pten deletion has provided clues to the role of PTEN mutation and loss in specific tumour types. Studying PTEN in the continuum of rare syndromes, common cancers and mouse models provides insight into the role of PTEN in tumorigenesis and will inform targeted drug development.
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Affiliation(s)
- M Christine Hollander
- Medical Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892, USA
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