1
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Quan B, Li Z, Yang H, Li S, Yan X, Wang Y. The splicing factor YBX1 promotes the progression of osteosarcoma by upregulating VEGF 165 and downregulating VEGF 165b. Heliyon 2023; 9:e18706. [PMID: 37554848 PMCID: PMC10405001 DOI: 10.1016/j.heliyon.2023.e18706] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 07/23/2023] [Accepted: 07/25/2023] [Indexed: 08/10/2023] Open
Abstract
VEGF165 and its isoform VEGF165b have the same length but opposite functions in cancer. Some studies have indicated the important role of VEGF165 in osteosarcoma (OS); however, VEGF165b has not been taken into consideration. This study aims to clarify the roles of the two isoforms in OS and the mechanism controlling their formation from an alternative splicing perspective. By in vivo and in vitro experiments, we assessed the expression and function of VEGF165 and VEGF165b, screened the underlying splicing factors, and verified the regulatory function of splicing factor YBX1 on the two isoforms and its role in OS. The results showed that in OS, VEGF165 was upregulated but VEGF165b was downregulated. VEGF165 promoted the proliferation, migration and invasion of OS cells and induced angiogenesis in OS tumours; however, VEGF165b showed the opposite function. Of the four screened splicing factors, YBX1 was upregulated in OS tissues. It was positively correlated with VEGF165 but negatively correlated with VEGF165b. Further study indicated that YBX1 could upregulate VEGF165 but downregulate VEGF165b. Moreover, YBX1 promoted the proliferation, migration and invasion of OS cells and induced angiogenesis in OS tumours. OS patients with higher YBX1 had a poor prognosis within five years, but this difference disappeared in a longer follow-up. In conclusion, VEGF165b was antineoplastic and downregulated in OS, in contrast to VEGF165. YBX1 was found to be an important splicing factor that increased VEGF165 but decreased VEGF165b. Targeting YBX1 could endogenously alter the levels of VEGF165 and VEGF165b simultaneously.
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Affiliation(s)
- Bingxuan Quan
- The Fifth Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
- The Fifth Department of Orthopedics, Affiliated Hospital of Chifeng University, Chifeng, China
| | - Zhigang Li
- The Fifth Department of Orthopedics, Affiliated Hospital of Chifeng University, Chifeng, China
| | - Hongbo Yang
- The Second Department of Orthopedics, Affiliated Hospital of Chifeng University, Chifeng, China
| | - Shuo Li
- The Second Department of Orthopedics, The First Hospital of Qiqihar, Qiqihar, Heilongjiang Province, China
| | - Xiuchun Yan
- Department of Gastroenterological Surgery, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang Province, China
| | - Yansong Wang
- The Fifth Department of Orthopedics, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China
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2
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Abstract
Dysregulated RNA splicing is a molecular feature that characterizes almost all tumour types. Cancer-associated splicing alterations arise from both recurrent mutations and altered expression of trans-acting factors governing splicing catalysis and regulation. Cancer-associated splicing dysregulation can promote tumorigenesis via diverse mechanisms, contributing to increased cell proliferation, decreased apoptosis, enhanced migration and metastatic potential, resistance to chemotherapy and evasion of immune surveillance. Recent studies have identified specific cancer-associated isoforms that play critical roles in cancer cell transformation and growth and demonstrated the therapeutic benefits of correcting or otherwise antagonizing such cancer-associated mRNA isoforms. Clinical-grade small molecules that modulate or inhibit RNA splicing have similarly been developed as promising anticancer therapeutics. Here, we review splicing alterations characteristic of cancer cell transcriptomes, dysregulated splicing's contributions to tumour initiation and progression, and existing and emerging approaches for targeting splicing for cancer therapy. Finally, we discuss the outstanding questions and challenges that must be addressed to translate these findings into the clinic.
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Affiliation(s)
- Robert K Bradley
- Computational Biology Program, Public Health Sciences Division and Basic Sciences Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
| | - Olga Anczuków
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA.
- Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA.
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3
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The VEGF/VEGFR Axis Revisited: Implications for Cancer Therapy. Int J Mol Sci 2022; 23:ijms232415585. [PMID: 36555234 PMCID: PMC9779738 DOI: 10.3390/ijms232415585] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Revised: 12/04/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
The vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor (VEGFR) axis is indispensable in the process of angiogenesis and has been implicated as a key driver of tumor vascularization. Consequently, several strategies that target VEGF and its cognate receptors, VEGFR-1 and VEGFR-2, have been designed to treat cancer. While therapies targeting full-length VEGF have resulted in an improvement in both overall survival and progression-free survival in various cancers, these benefits have been modest. In addition, the inhibition of VEGFRs is associated with undesirable off-target effects. Moreover, VEGF splice variants that modulate sprouting and non-sprouting angiogenesis have been identified in recent years. Cues within the tumor microenvironment determine the expression patterns of these variants. Noteworthy is that the mechanisms of action of these variants challenge the established norm of VEGF signaling. Furthermore, the aberrant expression of some of these variants has been observed in several cancers. Herein, developments in the understanding of the VEGF/VEGFR axis and the splice products of these molecules, as well as the environmental cues that regulate these variants are reviewed. Furthermore, strategies that incorporate the targeting of VEGF variants to enhance the effectiveness of antiangiogenic therapies in the clinical setting are discussed.
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4
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Wan L, Deng M, Zhang H. SR Splicing Factors Promote Cancer via Multiple Regulatory Mechanisms. Genes (Basel) 2022; 13:1659. [PMID: 36140826 PMCID: PMC9498594 DOI: 10.3390/genes13091659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/09/2022] [Accepted: 09/14/2022] [Indexed: 11/17/2022] Open
Abstract
Substantial emerging evidence supports that dysregulated RNA metabolism is associated with tumor initiation and development. Serine/Arginine-Rich proteins (SR) are a number of ultraconserved and structurally related proteins that contain a characteristic RS domain rich in arginine and serine residues. SR proteins perform a critical role in spliceosome assembling and conformational transformation, contributing to precise alternative RNA splicing. Moreover, SR proteins have been reported to participate in multiple other RNA-processing-related mechanisms than RNA splicing, such as genome stability, RNA export, and translation. The dysregulation of SR proteins has been reported to contribute to tumorigenesis through multiple mechanisms. Here we reviewed the different biological roles of SR proteins and strategies for functional rectification of SR proteins that may serve as potential therapeutic approaches for cancer.
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Affiliation(s)
- Ledong Wan
- Department of Pathology, Research Unit of Intelligence Classification of Tumor Pathology and Precision Therapy of Chinese Academy of Medical Sciences (2019RU042), Zhejiang University School of Medicine, Hangzhou 310058, China
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Min Deng
- Department of Pathology, First Peoples Hospital Fuyang, Hangzhou 311400, China
| | - Honghe Zhang
- Department of Pathology, Research Unit of Intelligence Classification of Tumor Pathology and Precision Therapy of Chinese Academy of Medical Sciences (2019RU042), Zhejiang University School of Medicine, Hangzhou 310058, China
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5
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Al Kawas H, Saaid I, Jank P, Westhoff CC, Denkert C, Pross T, Weiler KBS, Karsten MM. How VEGF-A and its splice variants affect breast cancer development - clinical implications. Cell Oncol (Dordr) 2022; 45:227-239. [PMID: 35303290 PMCID: PMC9050780 DOI: 10.1007/s13402-022-00665-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2022] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Altered expression levels and structural variations in the vascular endothelial growth factor (VEGF) have been found to play important roles in cancer development and to be associated with the overall survival and therapy response of cancer patients. Particularly VEGF-A and its splice variants have been found to affect physiological and pathological angiogenic processes, including tumor angiogenesis, correlating with tumor progression, mostly caused by overexpression. This review focuses on the expression and impact of VEGF-A splice variants under physiologic conditions and in tumors and, in particular, the distribution and role of isoform VEGF165b in breast cancer. CONCLUSIONS AND PERSPECTIVES Many publications already highlighted the importance of VEGF-A and its splice variants in tumor therapy, especially in breast cancer, which are summarized in this review. Furthermore, we were able to demonstrate that cytoplasmatic VEGFA/165b expression is higher in invasive breast cancer tumor cells than in normal tissues or stroma. These examples show that the detection of VEGF splice variants can be performed also on the protein level in formalin fixed tissues. Although no quantitative conclusions can be drawn, these results may be the starting point for further studies at a quantitative level, which can be a major step towards the design of targeted antibody-based (breast) cancer therapies.
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Affiliation(s)
- Hivin Al Kawas
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Inas Saaid
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | - Paul Jank
- Institute of Pathology, Philipps-Universität Marburg, 35043, Marburg, Germany
| | | | - Carsten Denkert
- Institute of Pathology, Philipps-Universität Marburg, 35043, Marburg, Germany
| | - Therese Pross
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany
| | | | - Maria Margarete Karsten
- Department of Gynecology with Breast Center, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Charitéplatz 1, 10117, Berlin, Germany.
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6
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Pan XW, Xu D, Chen WJ, Chen JX, Chen WJ, Ye JQ, Gan SS, Zhou W, Song X, Shi L, Cui XG. USP39 promotes malignant proliferation and angiogenesis of renal cell carcinoma by inhibiting VEGF-A 165b alternative splicing via regulating SRSF1 and SRPK1. Cancer Cell Int 2021; 21:486. [PMID: 34544400 PMCID: PMC8454004 DOI: 10.1186/s12935-021-02161-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 08/18/2021] [Indexed: 01/01/2023] Open
Abstract
Background The benefit of targeted therapy for renal cell carcinoma (RCC) is largely crippled by drug resistance. Rapid disease progression and poor prognosis occur in patients with drug resistance. New treatments demand prompt exploration for clinical therapies. Ubiquitin-specific peptidase 39 (USP39) serves as the pro-tumor factor in several previous studies of other malignant tumors. To investigate the function and mechanism of USP39 in promoting malignant proliferation and angiogenesis of RCC. Methods We applied ONCOMINE database to analyze the correlation between USP39 expression level and the clinical characteristics of RCC. USP39 knockdown or overexpression plasmids were transfected into 786-O and ACHN cells. The HUVEC received cell supernatants of 786-O and ACHN cells with knockdown or overexpression USP39.The effect of USP39 on RCC was evaluated by MTT assay, cell cycle analysis, colony formation assay and tubule formation assay. The interaction between USP39 and VEGF-A alternative splicing was assessed by affinity purification and mass spectrometry, co-immunoprecipitation and Western blot assays. Results The mRNA expression level of USP39 in RCC was significantly higher than that in normal renal tissue (P < 0.001), and negatively correlated with the survival rate of RCC patients (P < 0.01). Silencing of USP39 in 786-O and ACHN cells inhibited cell proliferation and colony formation, and induced S phase arrest. USP39 overexpression significantly increased the number of tubules (P < 0.05) and branches (P < 0.01) formed by HUVEC cells, and USP39 knockdown produced an opposite effect (P < 0.05). The USP39 (101–565) fragment directly mediated its binding to SRSF1 and SRPK1, and promoted the phosphorylation of SRSF1 to regulate VEGF-A alternative splicing. USP39 knockdown upregulated the expression of VEGF-A165b, and USP39 overexpression downregulated the expression of VEGF-A165b significantly (both P < 0.05). Conclusion USP39 acted as a pro-tumor factor by motivating the malignant biological processes of RCC, probably through inhibiting VEGF-A165b alternative splicing and regulating SRSF1 and SRPK1. USP39 may prove to be a potential therapeutic target for RCC. Graphic abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12935-021-02161-x.
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Affiliation(s)
- Xiu-Wu Pan
- Department of Urology, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, 1665 Kongjiang Road, Shanghai, 200092, China.,Depanrtment of Urology, Third Affiliated Hospital of the Second Military Medical University, Shanghai, 201805, China
| | - Da Xu
- Depanrtment of Urology, Third Affiliated Hospital of the Second Military Medical University, Shanghai, 201805, China
| | - Wen-Jin Chen
- Depanrtment of Urology, Third Affiliated Hospital of the Second Military Medical University, Shanghai, 201805, China
| | - Jia-Xin Chen
- Depanrtment of Urology, Third Affiliated Hospital of the Second Military Medical University, Shanghai, 201805, China
| | - Wei-Jie Chen
- Depanrtment of Urology, Third Affiliated Hospital of the Second Military Medical University, Shanghai, 201805, China
| | - Jian-Qing Ye
- Depanrtment of Urology, Third Affiliated Hospital of the Second Military Medical University, Shanghai, 201805, China
| | - Si-Shun Gan
- Depanrtment of Urology, Third Affiliated Hospital of the Second Military Medical University, Shanghai, 201805, China
| | - Wang Zhou
- Depanrtment of Urology, Third Affiliated Hospital of the Second Military Medical University, Shanghai, 201805, China.
| | - Xu Song
- Department of Urology, Shanghai Seventh People's Hospital, Shandong, 200137, China.
| | - Lei Shi
- Department of Urology, Yantai Yuhuangding Hospital of Qingdao University Medical College, Shandong, 264000, China.
| | - Xin-Gang Cui
- Department of Urology, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, 1665 Kongjiang Road, Shanghai, 200092, China.
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7
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Li Q, Zeng C, Liu H, Yung KWY, Chen C, Xie Q, Zhang Y, Wan SWC, Mak BSW, Xia J, Xiong S, Ngo JCK. Protein-Protein Interaction Inhibitor of SRPKs Alters the Splicing Isoforms of VEGF and Inhibits Angiogenesis. iScience 2021; 24:102423. [PMID: 33997701 PMCID: PMC8102418 DOI: 10.1016/j.isci.2021.102423] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 03/13/2021] [Accepted: 04/09/2021] [Indexed: 12/14/2022] Open
Abstract
Serine-arginine (SR) protein kinases (SRPKs) regulate the functions of the SR-rich splicing factors by phosphorylating multiple serines within their C-terminal arginine-serine-rich domains. Dysregulation of these phosphorylation events has been implicated in many diseases, suggesting SRPKs are potential therapeutic targets. In particular, aberrant SRPK1 expression alters the balances of proangiogenic (VEGF165) and antiangiogenic (VEGF165b) splicing isoforms of the key angiogenesis factor, vascular endothelial growth factor (VEGF), through the phosphorylation of prototypic SR protein SRSF1. Here, we report a protein-protein interaction (PPI) inhibitor of SRPKs, docking blocker of SRPK1 (DBS1), that specifically blocks a conserved substrate docking groove unique to SRPKs. DBS1 is a cell-permeable inhibitor that effectively inhibits the binding and phosphorylation of SRSF1 and subsequently switches VEGF splicing from the proangiogenic to the antiangiogenic isoform. Our findings thus provide a new direction for the development of SRPK inhibitors through targeting a unique PPI site to combat angiogenic diseases.
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Affiliation(s)
- Qingyun Li
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
- Hong Kong Branch of National Engineering Research Center of Genetic Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Chuyue Zeng
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Haizhen Liu
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Kristen Wing Yu Yung
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Chun Chen
- Department of Cellular Biology, Jinan University, Guangzhou, China
| | - Qiuling Xie
- Department of Cellular Biology, Jinan University, Guangzhou, China
| | - Yu Zhang
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Stephanie Winn Chee Wan
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Bertha Sze Wing Mak
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Jiang Xia
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Sheng Xiong
- Department of Cellular Biology, Jinan University, Guangzhou, China
- Hong Kong Branch of National Engineering Research Center of Genetic Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
| | - Jacky Chi Ki Ngo
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
- Hong Kong Branch of National Engineering Research Center of Genetic Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
- Center for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China
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8
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Natua S, Ashok C, Shukla S. Hypoxia-induced alternative splicing in human diseases: the pledge, the turn, and the prestige. Cell Mol Life Sci 2021; 78:2729-2747. [PMID: 33386889 PMCID: PMC11072330 DOI: 10.1007/s00018-020-03727-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 11/24/2020] [Accepted: 11/28/2020] [Indexed: 12/30/2022]
Abstract
Maintenance of oxygen homeostasis is an indispensable criterion for the existence of multicellular life-forms. Disruption of this homeostasis due to inadequate oxygenation of the respiring tissues leads to pathological hypoxia, which acts as a significant stressor in several pathophysiological conditions including cancer, cardiovascular defects, bacterial infections, and neurological disorders. Consequently, the hypoxic tissues develop necessary adaptations both at the tissue and cellular level. The cellular adaptations involve a dramatic alteration in gene expression, post-transcriptional and post-translational modification of gene products, bioenergetics, and metabolism. Among the key responses to oxygen-deprivation is the skewing of cellular alternative splicing program. Herein, we discuss the current concepts of oxygen tension-dependent alternative splicing relevant to various pathophysiological conditions. Following a brief description of cellular response to hypoxia and the pre-mRNA splicing mechanism, we outline the impressive number of hypoxia-elicited alternative splicing events associated with maladies like cancer, cardiovascular diseases, and neurological disorders. Furthermore, we discuss how manipulation of hypoxia-induced alternative splicing may pose promising strategies for novel translational diagnosis and therapeutic interventions.
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Affiliation(s)
- Subhashis Natua
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, 462066, Madhya Pradesh, India
| | - Cheemala Ashok
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, 462066, Madhya Pradesh, India
| | - Sanjeev Shukla
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhopal, 462066, Madhya Pradesh, India.
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9
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Bessa C, Matos P, Jordan P, Gonçalves V. Alternative Splicing: Expanding the Landscape of Cancer Biomarkers and Therapeutics. Int J Mol Sci 2020; 21:ijms21239032. [PMID: 33261131 PMCID: PMC7729450 DOI: 10.3390/ijms21239032] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 11/24/2020] [Accepted: 11/25/2020] [Indexed: 02/07/2023] Open
Abstract
Alternative splicing (AS) is a critical post-transcriptional regulatory mechanism used by more than 95% of transcribed human genes and responsible for structural transcript variation and proteome diversity. In the past decade, genome-wide transcriptome sequencing has revealed that AS is tightly regulated in a tissue- and developmental stage-specific manner, and also frequently dysregulated in multiple human cancer types. It is currently recognized that splicing defects, including genetic alterations in the spliced gene, altered expression of both core components or regulators of the precursor messenger RNA (pre-mRNA) splicing machinery, or both, are major drivers of tumorigenesis. Hence, in this review we provide an overview of our current understanding of splicing alterations in cancer, and emphasize the need to further explore the cancer-specific splicing programs in order to obtain new insights in oncology. Furthermore, we also discuss the recent advances in the identification of dysregulated splicing signatures on a genome-wide scale and their potential use as biomarkers. Finally, we highlight the therapeutic opportunities arising from dysregulated splicing and summarize the current approaches to therapeutically target AS in cancer.
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Affiliation(s)
- Cláudia Bessa
- Department of Human Genetics, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Paulo Matos
- Department of Human Genetics, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
| | - Peter Jordan
- Department of Human Genetics, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
- Correspondence: (P.J.); (V.G.); Tel.: +351-217-519-380 (P.J.)
| | - Vânia Gonçalves
- Department of Human Genetics, National Health Institute Dr. Ricardo Jorge, 1649-016 Lisbon, Portugal; (C.B.); (P.M.)
- BioISI—Biosystems & Integrative Sciences Institute, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon, Portugal
- Correspondence: (P.J.); (V.G.); Tel.: +351-217-519-380 (P.J.)
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10
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Dardente H, English WR, Valluru MK, Kanthou C, Simpson D. Debunking the Myth of the Endogenous Antiangiogenic Vegfaxxxb Transcripts. Trends Endocrinol Metab 2020; 31:398-409. [PMID: 32396842 DOI: 10.1016/j.tem.2020.01.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/28/2019] [Accepted: 01/14/2020] [Indexed: 12/19/2022]
Abstract
In this opinion article we critically assess evidence for the existence of a family of antiangiogenic vascular endothelial growth factor (Vegfaxxxb) transcripts, arising from the use of a phylogenetically conserved alternative distal splice site within exon 8 of the VEGFA gene. We explain that prior evidence for Vegfaxxxb transcripts in tissues rests heavily upon flawed RT-PCR methodologies, with the extensive use of 5'-tailing in primer design being the main issue. Furthermore, our analysis of large RNA-seq data sets (human and ovine) fails to identify a single Vegfaxxxb transcript. Therefore, we challenge the very existence of Vegfaxxxb transcripts, which further questions the physiological relevance of studies based on the use of 'anti-VEGFAxxxb' antibodies. Our analysis has implications for the proposed therapeutic use of isoform-specific anti-VEGFA strategies for treating cancer and retinopathies.
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Affiliation(s)
- Hugues Dardente
- PRC, INRA, CNRS, IFCE, Université de Tours, 37380 Nouzilly, France.
| | - William R English
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Manoj K Valluru
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Chryso Kanthou
- Department of Oncology and Metabolism, Tumour Microcirculation Group, University of Sheffield, School of Medicine, Beech Hill Road, Sheffield, S10 2RX, UK
| | - David Simpson
- Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, BT7 1NN, UK
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11
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Karsten MM, Beck MH, Rademacher A, Knabl J, Blohmer JU, Jückstock J, Radosa JC, Jank P, Rack B, Janni W. VEGF-A165b levels are reduced in breast cancer patients at primary diagnosis but increase after completion of cancer treatment. Sci Rep 2020; 10:3635. [PMID: 32108136 PMCID: PMC7046696 DOI: 10.1038/s41598-020-59823-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 01/30/2020] [Indexed: 01/26/2023] Open
Abstract
The antiangiogenic splice variant VEGF-A165b is downregulated in a variety of cancer entities, but little is known so far about circulating plasma levels. The present analysis addresses this question and examines circulating VEGF-A/VEGF-A165b levels in a collective of female high-risk breast cancer patients over the course of treatment. Within the SUCCES-A trial 205 patients were recruited after having received primary breast surgery. Using ELISA VEGF-A/VEGF-A165b concentrations were determined and correlated to clinical characteristics (1) before adjuvant chemotherapy, (2) four weeks and (3) two years after therapy and compared to healthy controls (n = 107). VEGF165b levels were significantly elevated after completion of chemotherapy. Within the breast cancer cohort, VEGF-A165b levels increased two years after completion of chemotherapy. VEGF-A plasma concentrations were significantly elevated in the breast cancer cohort at all examined time points and decreased after treatment. VEGF-A levels two years after chemotherapy correlated with increased cancer related mortality, no such correlation could be found between VEGF-A165b and the examined clinical characteristics. Compared to controls, VEGF-A/VEGF-A165b ratios were decreased in patients before and after chemotherapy. Our data suggests that circulating VEGF-A165b is significantly reduced in women with primary breast cancer at time of diagnosis; furthermore, levels change during adjuvant treatment.
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Affiliation(s)
- Maria Margarete Karsten
- Department of Gynecology and Breast Care Center, University Hospital, Charité Universitätsmedizin Berlin, Berlin, Germany.
| | - Maximilian Heinz Beck
- Department of Gynecology and Breast Care Center, University Hospital, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Angela Rademacher
- Department of Obstetrics and Gynecology, University Hospital, LMU Munich, Munich, Germany.,Department of Orthopedics, Schön Clinic, Munich, Harlaching, Germany
| | - Julia Knabl
- Department of Obstetrics and Gynecology, University Hospital, LMU Munich, Munich, Germany
| | - Jens-Uwe Blohmer
- Department of Gynecology and Breast Care Center, University Hospital, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Julia Jückstock
- Department of Obstetrics and Gynecology, University Hospital, LMU Munich, Munich, Germany
| | - Julia Caroline Radosa
- Department of Gynecology and Obstetrics, Saarland University Hospital, Homburg, Germany
| | - Paul Jank
- Department of Pathology, Philipps-University Marburg, Marburg, Germany
| | - Brigitte Rack
- Department of Obstetrics and Gynecology, University Hospital, LMU Munich, Munich, Germany.,Department of Gynecology and Obstetrics, University Hospital Ulm, Ulm, Germany
| | - Wolfgang Janni
- Department of Gynecology and Obstetrics, University Hospital Ulm, Ulm, Germany
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12
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Ji Y, Mishra RK, Davuluri RV. In silico analysis of alternative splicing on drug-target gene interactions. Sci Rep 2020; 10:134. [PMID: 31924844 PMCID: PMC6954184 DOI: 10.1038/s41598-019-56894-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 12/18/2019] [Indexed: 12/24/2022] Open
Abstract
Identifying and evaluating the right target are the most important factors in early drug discovery phase. Most studies focus on one protein ignoring the multiple splice-variant or protein-isoforms, which might contribute to unexpected therapeutic activity or adverse side effects. Here, we present computational analysis of cancer drug-target interactions affected by alternative splicing. By integrating information from publicly available databases, we curated 883 FDA approved or investigational stage small molecule cancer drugs that target 1,434 different genes, with an average of 5.22 protein isoforms per gene. Of these, 618 genes have ≥5 annotated protein-isoforms. By analyzing the interactions with binding pocket information, we found that 76% of drugs either miss a potential target isoform or target other isoforms with varied expression in multiple normal tissues. We present sequence and structure level alignments at isoform-level and make this information publicly available for all the curated drugs. Structure-level analysis showed ligand binding pocket architectures differences in size, shape and electrostatic parameters between isoforms. Our results emphasize how potentially important isoform-level interactions could be missed by solely focusing on the canonical isoform, and suggest that on- and off-target effects at isoform-level should be investigated to enhance the productivity of drug-discovery research.
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Affiliation(s)
- Yanrong Ji
- Division of Health and Biomedical Informatics, Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Rama K Mishra
- The Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, IL, USA.,Department of Biochemistry and Molecular Genetics, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.,Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Ramana V Davuluri
- Division of Health and Biomedical Informatics, Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
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13
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An Intricate Connection between Alternative Splicing and Phenotypic Plasticity in Development and Cancer. Cells 2019; 9:cells9010034. [PMID: 31877720 PMCID: PMC7016785 DOI: 10.3390/cells9010034] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 12/10/2019] [Accepted: 12/18/2019] [Indexed: 12/12/2022] Open
Abstract
During tumor progression, hypoxia, nutrient deprivation or changes in the extracellular environment (i.e., induced by anti-cancer drugs) elicit adaptive responses in cancer cells. Cellular plasticity increases the chance that tumor cells may survive in a challenging microenvironment, acquire new mechanisms of resistance to conventional drugs, and spread to distant sites. Re-activation of stem pathways appears as a significant cause of cellular plasticity because it promotes the acquisition of stem-like properties through a profound phenotypic reprogramming of cancer cells. In addition, it is a major contributor to tumor heterogeneity, depending on the coexistence of phenotypically distinct subpopulations in the same tumor bulk. Several cellular mechanisms may drive this fundamental change, in particular, high-throughput sequencing technologies revealed a key role for alternative splicing (AS). Effectively, AS is one of the most important pre-mRNA processes that increases the diversity of transcriptome and proteome in a tissue- and development-dependent manner. Moreover, defective AS has been associated with several human diseases. However, its role in cancer cell plasticity and tumor heterogeneity remains unclear. Therefore, unravelling the intricate relationship between AS and the maintenance of a stem-like phenotype may explain molecular mechanisms underlying cancer cell plasticity and improve cancer diagnosis and treatment.
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14
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Cho WC, Jour G, Aung PP. Role of angiogenesis in melanoma progression: Update on key angiogenic mechanisms and other associated components. Semin Cancer Biol 2019; 59:175-186. [PMID: 31255774 DOI: 10.1016/j.semcancer.2019.06.015] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 06/05/2019] [Accepted: 06/26/2019] [Indexed: 01/09/2023]
Abstract
Angiogenesis, the formation of new blood vessels from existing blood vessels, is a complex and highly regulated process that plays a role in a wide variety of physiological and pathological processes. In malignancy, angiogenesis is essential for neoplastic cells to acquire the nutrients and oxygen critical for their continued proliferation. Angiogenesis requires a sequence of well-coordinated events mediated by a number of tightly regulated interactions between pro-angiogenic factors and their corresponding receptors expressed on various vascular components (e.g., endothelial cells and pericytes) and stromal components forming the extracellular matrix. In this review, we discuss the functional roles of key growth factors and cytokines known to promote angiogenesis in cutaneous melanoma and key factors implicated in the extracellular matrix remodeling that acts synergistically with angiogenesis to promote tumor progression in melanoma, incorporating some of the most up-to-date basic science knowledge from recently published in vivo and in vitro experimental studies.
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Affiliation(s)
- Woo Cheal Cho
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - George Jour
- Department of Pathology and Dermatology, NYU Langone Medical Center, New York, NY, USA
| | - Phyu P Aung
- Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
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15
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Peach CJ, Kilpatrick LE, Woolard J, Hill SJ. Comparison of the ligand-binding properties of fluorescent VEGF-A isoforms to VEGF receptor 2 in living cells and membrane preparations using NanoBRET. Br J Pharmacol 2019; 176:3220-3235. [PMID: 31162634 PMCID: PMC6692582 DOI: 10.1111/bph.14755] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Revised: 05/01/2019] [Accepted: 05/21/2019] [Indexed: 11/28/2022] Open
Abstract
Background and Purpose Vascular endothelial growth factor A (VEGF‐A) is a key mediator of angiogenesis. A striking feature of the binding of a fluorescent analogue of VEGF165a to nanoluciferase‐tagged VEGF receptor 2 (VEGFR2) in living cells is that the BRET signal is not sustained and declines over time. This may be secondary to receptor internalisation. Here, we have compared the binding of three fluorescent VEGF‐A isoforms to VEGFR2 in cells and isolated membrane preparations. Experimental Approach Ligand‐binding kinetics were monitored in both intact HEK293T cells and membranes (expressing nanoluciferase‐tagged VEGFR2) using BRET between tagged receptor and fluorescent analogues of VEGF165a, VEGF165b, and VEGF121a. VEGFR2 endocytosis in intact cells expressing VEGFR2 was monitored by following the appearance of fluorescent ligand‐associated receptors in intracellular endosomes using automated quantitative imaging. Key Results Quantitative analysis of the effect of fluorescent VEGF‐A isoforms on VEGFR2 endocytosis in cells demonstrated that they produce a rapid and potent translocation of ligand‐bound VEGFR2 into intracellular endosomes. NanoBRET can be used to monitor the kinetics of the binding of fluorescent VEGF‐A isoforms to VEGFR2. In isolated membrane preparations, ligand‐binding association curves were maintained for the duration of the 90‐min experiment. Measurement of the koff at pH 6.0 in membrane preparations indicated shorter ligand residence times than those obtained at pH 7.4. Conclusions and Implications These studies suggest that rapid VEGF‐A isoform‐induced receptor endocytosis shortens agonist residence times on the receptor (1/koff) as VEGFR2 moves from the plasma membrane to the intracellular endosomes.
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Affiliation(s)
- Chloe J Peach
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Laura E Kilpatrick
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham, UK.,Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, The Midlands, UK
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16
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Nakayama K, Kataoka N. Regulation of Gene Expression under Hypoxic Conditions. Int J Mol Sci 2019; 20:ijms20133278. [PMID: 31277312 PMCID: PMC6651685 DOI: 10.3390/ijms20133278] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/28/2019] [Accepted: 07/02/2019] [Indexed: 02/07/2023] Open
Abstract
Eukaryotes are often subjected to different kinds of stress. In order to adjust to such circumstances, eukaryotes activate stress–response pathways and regulate gene expression. Eukaryotic gene expression consists of many different steps, including transcription, RNA processing, RNA transport, and translation. In this review article, we focus on both transcriptional and post-transcriptional regulations of gene expression under hypoxic conditions. In the first part of the review, transcriptional regulations mediated by various transcription factors including Hypoxia-Inducible Factors (HIFs) are described. In the second part, we present RNA splicing regulations under hypoxic conditions, which are mediated by splicing factors and their kinases. This work summarizes and discusses the emerging studies of those two gene expression machineries under hypoxic conditions.
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Affiliation(s)
- Koh Nakayama
- Oxygen Biology Laboratory, Medical Research Institute, Tokyo Medical and Dental University (TMDU), Tokyo 113-8510, Japan.
| | - Naoyuki Kataoka
- Laboratory of Cell Regulation, Departments of Applied Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan.
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17
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Boudria A, Abou Faycal C, Jia T, Gout S, Keramidas M, Didier C, Lemaître N, Manet S, Coll JL, Toffart AC, Moro-Sibilot D, Albiges-Rizo C, Josserand V, Faurobert E, Brambilla C, Brambilla E, Gazzeri S, Eymin B. VEGF 165b, a splice variant of VEGF-A, promotes lung tumor progression and escape from anti-angiogenic therapies through a β1 integrin/VEGFR autocrine loop. Oncogene 2018; 38:1050-1066. [PMID: 30194450 DOI: 10.1038/s41388-018-0486-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 06/25/2018] [Accepted: 07/29/2018] [Indexed: 12/21/2022]
Abstract
Vascular endothelial growth factor-A (VEGF-A) is highly subjected to alternative pre-mRNA splicing that generates several splice variants. The VEGFxxx and VEGFxxxb families encode splice variants of VEGF-A that differ only at the level of six amino acids in their C-terminal part. The expression level of VEGFxxx splice variants and their function as pro-angiogenic factors during tumor neo-angiogenesis have been well-described. The role of VEGFxxxb isoforms is less well known, but they have been shown to inhibit VEGFxxx-mediated angiogenesis, while being partial or weak activators of VEGFR receptors in endothelial cells. On the opposite, their role on tumor cells expressing VEGFRs at their surface remains largely unknown. In this study, we find elevated levels of VEGF165b, the main VEGFxxxb isoform, in 36% of non-small cell lung carcinoma (NSCLC), mainly lung adenocarcinoma (46%), and show that a high VEGF165b/VEGF165 ratio correlates with the presence of lymph node metastases. At the molecular level, we demonstrate that VEGF165b stimulates proliferation and invasiveness of two lung tumor cell lines through a VEGFR/β1 integrin loop. We further provide evidence that the isoform-specific knockdown of VEGF165b reduces tumor growth, demonstrating a tumor-promoting autocrine role for VEGF165b in lung cancer cells. Importantly, we show that bevacizumab, an anti-angiogenic compound used for the treatment of lung adenocarcinoma patients, increases the expression of VEGF165b and activates the invasive VEGFR/β1 integrin loop. Overall, these data highlight an unexpected role of the VEGF165b splice variant in the progression of lung tumors and their response to anti-angiogenic therapies.
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Affiliation(s)
- Asma Boudria
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France.,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France
| | - Cherine Abou Faycal
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France.,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France
| | - Tao Jia
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France.,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France
| | - Stephanie Gout
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France.,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France
| | - Michelle Keramidas
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM, U1209, UMR CNRS 5309, Team Cancer Targets and Experimental Therapeutics, Grenoble, 38042, France
| | - Chloé Didier
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM, U1209, UMR CNRS 5309, Team Cancer Targets and Experimental Therapeutics, Grenoble, 38042, France
| | - Nicolas Lemaître
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Tumor Molecular Pathology and Biomarkers, Grenoble, 38042, France
| | - Sandra Manet
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Cell Adhesion Dynamics and Differentiation, Grenoble, 38042, France
| | - Jean-Luc Coll
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM, U1209, UMR CNRS 5309, Team Cancer Targets and Experimental Therapeutics, Grenoble, 38042, France
| | - Anne-Claire Toffart
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Tumor Molecular Pathology and Biomarkers, Grenoble, 38042, France
| | - Denis Moro-Sibilot
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Tumor Molecular Pathology and Biomarkers, Grenoble, 38042, France
| | - Corinne Albiges-Rizo
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Cell Adhesion Dynamics and Differentiation, Grenoble, 38042, France
| | - Véronique Josserand
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM, U1209, UMR CNRS 5309, Team Cancer Targets and Experimental Therapeutics, Grenoble, 38042, France
| | - Eva Faurobert
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Cell Adhesion Dynamics and Differentiation, Grenoble, 38042, France
| | - Christian Brambilla
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Tumor Molecular Pathology and Biomarkers, Grenoble, 38042, France
| | - Elisabeth Brambilla
- Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.,INSERM U1209, UMR CNRS 5309, Team Tumor Molecular Pathology and Biomarkers, Grenoble, 38042, France
| | - Sylvie Gazzeri
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France.,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France
| | - Beatrice Eymin
- INSERM U1209, UMR CNRS 5309, Team RNA splicing, Cell Signaling and Response to Therapies, Grenoble, 38042, France. .,Université Grenoble Alpes, Institut Pour l'Avancée des Biosciences, Grenoble, 38041, France.
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18
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El Marabti E, Younis I. The Cancer Spliceome: Reprograming of Alternative Splicing in Cancer. Front Mol Biosci 2018; 5:80. [PMID: 30246013 PMCID: PMC6137424 DOI: 10.3389/fmolb.2018.00080] [Citation(s) in RCA: 151] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/09/2018] [Indexed: 12/15/2022] Open
Abstract
Alternative splicing allows for the expression of multiple RNA and protein isoforms from one gene, making it a major contributor to transcriptome and proteome diversification in eukaryotes. Advances in next generation sequencing technologies and genome-wide analyses have recently underscored the fact that the vast majority of multi-exon genes under normal physiology engage in alternative splicing in tissue-specific and developmental-specific manner. On the other hand, cancer cells exhibit remarkable transcriptome alterations partly by adopting cancer-specific splicing isoforms. These isoforms and their encoded proteins are not insignificant byproducts of the abnormal physiology of cancer cells, but either drivers of cancer progression or small but significant contributors to specific cancer hallmarks. Thus, it is paramount that the pathways that regulate alternative splicing in cancer, including the splicing factors that bind to pre-mRNAs and modulate spliceosome recruitment. In this review, we present a few distinct cases of alternative splicing in cancer, with an emphasis on their regulation as well as their contribution to cancer cell phenotype. Several categories of splicing aberrations are highlighted, including alterations in cancer-related genes that directly affect their pre-mRNA splicing, mutations in genes encoding splicing factors or core spliceosomal subunits, and the seemingly mutation-free disruptions in the balance of the expression of RNA-binding proteins, including components of both the major (U2-dependent) and minor (U12-dependent) spliceosomes. Given that the latter two classes cause global alterations in splicing that affect a wide range of genes, it remains a challenge to identify the ones that contribute to cancer progression. These challenges necessitate a systematic approach to decipher these aberrations and their impact on cancer. Ultimately, a sufficient understanding of splicing deregulation in cancer is predicted to pave the way for novel and innovative RNA-based therapies.
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Affiliation(s)
- Ettaib El Marabti
- Biological Sciences Program, Carnegie Mellon University in Qatar, Doha, Qatar
| | - Ihab Younis
- Biological Sciences Program, Carnegie Mellon University in Qatar, Doha, Qatar
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19
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Ved N, Da Vitoria Lobo ME, Bestall SM, L Vidueira C, Beazley-Long N, Ballmer-Hofer K, Hirashima M, Bates DO, Donaldson LF, Hulse RP. Diabetes-induced microvascular complications at the level of the spinal cord: a contributing factor in diabetic neuropathic pain. J Physiol 2018; 596:3675-3693. [PMID: 29774557 PMCID: PMC6092307 DOI: 10.1113/jp275067] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 05/08/2018] [Indexed: 02/06/2023] Open
Abstract
KEY POINTS Diabetes is thought to induce neuropathic pain through activation of dorsal horn sensory neurons in the spinal cord. Here we explore the impact of hyperglycaemia on the blood supply supporting the spinal cord and chronic pain development. In streptozotocin-induced diabetic rats, neuropathic pain is accompanied by a decline in microvascular integrity in the dorsal horn. Hyperglycaemia-induced degeneration of the endothelium in the dorsal horn was associated with a loss in vascular endothelial growth factor (VEGF)-A165 b expression. VEGF-A165 b treatment prevented diabetic neuropathic pain and degeneration of the endothelium in the spinal cord. Using an endothelial-specific VEGFR2 knockout transgenic mouse model, the loss of endothelial VEGFR2 signalling led to a decline in vascular integrity in the dorsal horn and the development of hyperalgesia in VEGFR2 knockout mice. This highlights that vascular degeneration in the spinal cord could be a previously unidentified factor in the development of diabetic neuropathic pain. ABSTRACT Abnormalities of neurovascular interactions within the CNS of diabetic patients is associated with the onset of many neurological disease states. However, to date, the link between the neurovascular network within the spinal cord and regulation of nociception has not been investigated despite neuropathic pain being common in diabetes. We hypothesised that hyperglycaemia-induced endothelial degeneration in the spinal cord, due to suppression of vascular endothelial growth factor (VEGF)-A/VEGFR2 signalling, induces diabetic neuropathic pain. Nociceptive pain behaviour was investigated in a chemically induced model of type 1 diabetes (streptozotocin induced, insulin supplemented; either vehicle or VEGF-A165 b treated) and an inducible endothelial knockdown of VEGFR2 (tamoxifen induced). Diabetic animals developed mechanical allodynia and heat hyperalgesia. This was associated with a reduction in the number of blood vessels and reduction in Evans blue extravasation in the lumbar spinal cord of diabetic animals versus age-matched controls. Endothelial markers occludin, CD31 and VE-cadherin were downregulated in the spinal cord of the diabetic group versus controls, and there was a concurrent reduction of VEGF-A165 b expression. In diabetic animals, VEGF-A165 b treatment (biweekly i.p., 20 ng g-1 ) restored normal Evans blue extravasation and prevented vascular degeneration, diabetes-induced central neuron activation and neuropathic pain. Inducible knockdown of VEGFR2 (tamoxifen treated Tie2CreERT2 -vegfr2flfl mice) led to a reduction in blood vessel network volume in the lumbar spinal cord and development of heat hyperalgesia. These findings indicate that hyperglycaemia leads to a reduction in the VEGF-A/VEGFR2 signalling cascade, resulting in endothelial dysfunction in the spinal cord, which could be an undiscovered contributing factor to diabetic neuropathic pain.
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Affiliation(s)
- N Ved
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine University of Nottingham, Nottingham, NG7 2UH, UK.,Institute of Ophthalmology, 11-43 Bath St, London, EC1V 9EL, UK.,Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | - M E Da Vitoria Lobo
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine University of Nottingham, Nottingham, NG7 2UH, UK
| | - S M Bestall
- Arthritis Research UK Pain Centre and School of Life Sciences, The Medical School QMC, University of Nottingham, Nottingham, NG7 2UH, UK
| | - C L Vidueira
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine University of Nottingham, Nottingham, NG7 2UH, UK
| | - N Beazley-Long
- Arthritis Research UK Pain Centre and School of Life Sciences, The Medical School QMC, University of Nottingham, Nottingham, NG7 2UH, UK
| | | | - M Hirashima
- Division of Vascular Biology, Kobe University, Japan
| | - D O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine University of Nottingham, Nottingham, NG7 2UH, UK.,Centre of Membrane and Protein and Receptors (COMPARE), University of Birmingham, Birmingham and University of Nottingham, Nottingham, UK
| | - L F Donaldson
- Institute of Ophthalmology, 11-43 Bath St, London, EC1V 9EL, UK
| | - R P Hulse
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine University of Nottingham, Nottingham, NG7 2UH, UK.,School of Science and Technology, Nottingham Trent University, Nottingham, NG11 8NS, UK
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20
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Urbanski L, Leclair N, Anczuków O. Alternative-splicing defects in cancer: Splicing regulators and their downstream targets, guiding the way to novel cancer therapeutics. WILEY INTERDISCIPLINARY REVIEWS. RNA 2018; 9:e1476. [PMID: 29693319 PMCID: PMC6002934 DOI: 10.1002/wrna.1476] [Citation(s) in RCA: 221] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 02/27/2018] [Accepted: 03/01/2018] [Indexed: 12/14/2022]
Abstract
Defects in alternative splicing are frequently found in human tumors and result either from mutations in splicing-regulatory elements of specific cancer genes or from changes in the regulatory splicing machinery. RNA splicing regulators have emerged as a new class of oncoproteins and tumor suppressors, and contribute to disease progression by modulating RNA isoforms involved in the hallmark cancer pathways. Thus, dysregulation of alternative RNA splicing is fundamental to cancer and provides a potentially rich source of novel therapeutic targets. Here, we review the alterations in splicing regulatory factors detected in human tumors, as well as the resulting alternatively spliced isoforms that impact cancer hallmarks, and discuss how they contribute to disease pathogenesis. RNA splicing is a highly regulated process and, as such, the regulators are themselves tightly regulated. Differential transcriptional and posttranscriptional regulation of splicing factors modulates their levels and activities in tumor cells. Furthermore, the composition of the tumor microenvironment can also influence which isoforms are expressed in a given cell type and impact drug responses. Finally, we summarize current efforts in targeting alternative splicing, including global splicing inhibition using small molecules blocking the spliceosome or splicing-factor-modifying enzymes, as well as splice-switching RNA-based therapeutics to modulate cancer-specific splicing isoforms. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Splicing Regulation/Alternative Splicing.
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21
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Peach CJ, Mignone VW, Arruda MA, Alcobia DC, Hill SJ, Kilpatrick LE, Woolard J. Molecular Pharmacology of VEGF-A Isoforms: Binding and Signalling at VEGFR2. Int J Mol Sci 2018; 19:E1264. [PMID: 29690653 PMCID: PMC5979509 DOI: 10.3390/ijms19041264] [Citation(s) in RCA: 259] [Impact Index Per Article: 43.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 04/14/2018] [Accepted: 04/16/2018] [Indexed: 02/07/2023] Open
Abstract
Vascular endothelial growth factor-A (VEGF-A) is a key mediator of angiogenesis, signalling via the class IV tyrosine kinase receptor family of VEGF Receptors (VEGFRs). Although VEGF-A ligands bind to both VEGFR1 and VEGFR2, they primarily signal via VEGFR2 leading to endothelial cell proliferation, survival, migration and vascular permeability. Distinct VEGF-A isoforms result from alternative splicing of the Vegfa gene at exon 8, resulting in VEGFxxxa or VEGFxxxb isoforms. Alternative splicing events at exons 5⁻7, in addition to recently identified posttranslational read-through events, produce VEGF-A isoforms that differ in their bioavailability and interaction with the co-receptor Neuropilin-1. This review explores the molecular pharmacology of VEGF-A isoforms at VEGFR2 in respect to ligand binding and downstream signalling. To understand how VEGF-A isoforms have distinct signalling despite similar affinities for VEGFR2, this review re-evaluates the typical classification of these isoforms relative to the prototypical, “pro-angiogenic” VEGF165a. We also examine the molecular mechanisms underpinning the regulation of VEGF-A isoform signalling and the importance of interactions with other membrane and extracellular matrix proteins. As approved therapeutics targeting the VEGF-A/VEGFR signalling axis largely lack long-term efficacy, understanding these isoform-specific mechanisms could aid future drug discovery efforts targeting VEGF receptor pharmacology.
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Affiliation(s)
- Chloe J Peach
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
| | - Viviane W Mignone
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
- CAPES-University of Nottingham Programme in Drug Discovery, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Maria Augusta Arruda
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
- CAPES-University of Nottingham Programme in Drug Discovery, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
| | - Diana C Alcobia
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
| | - Laura E Kilpatrick
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
- Centre of Membrane Proteins and Receptors (COMPARE), University of Birmingham and University of Nottingham, Midlands NG7 2UH, UK.
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22
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Chen Y, Mathy NW, Lu H. The role of VEGF in the diagnosis and treatment of malignant pleural effusion in patients with non‑small cell lung cancer (Review). Mol Med Rep 2018; 17:8019-8030. [PMID: 29693703 PMCID: PMC5983970 DOI: 10.3892/mmr.2018.8922] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 02/15/2018] [Indexed: 12/21/2022] Open
Abstract
Malignant pleural effusion (MPE) is a severe medical condition, which can result in breathlessness, pain, cachexia and reduced physical activity. It can occur in almost all types of malignant tumors; however, lung cancer is the most common cause of MPE, accounting for ~1/3 of clinical cases. Although there are numerous therapeutic approaches currently available for the treatment of MPE, none are fully effective and the majority can only alleviate the symptoms of the patients. Vascular endothelial growth factor (VEGF) has now been recognized as one of the most important regulatory factors in tumor angiogenesis, which participates in the entire process of tumor growth through its function to stimulate tumor angiogenesis, activate host vascular endothelial cells and promote malignant proliferation. Novel drugs targeting VEGF, including endostar and bevacizumab, have been developed and approved for the treatment of various tumors. Data from recent clinical studies have demonstrated that drugs targeting VEGF are effective and safe for the clinical management of MPE. Therefore, VEGF‑targeting represents a promising novel strategy for the diagnosis and treatment of MPE. The present review summarized recent advances in the role of VEGF in the pathogenesis, diagnosis and clinical management of MPE in patients with non‑small cell lung cancer.
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Affiliation(s)
- Yao Chen
- Department of Oncology, Jianghan University School of Medicine, Wuhan, Hubei 430056, P.R. China
| | | | - Hongda Lu
- Department of Oncology, Wuhan Central Hospital, Wuhan, Hubei 430014, P.R. China
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23
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Clegg LE, Mac Gabhann F. A computational analysis of pro-angiogenic therapies for peripheral artery disease. Integr Biol (Camb) 2018; 10:18-33. [PMID: 29327758 PMCID: PMC7017937 DOI: 10.1039/c7ib00218a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Inducing therapeutic angiogenesis to effectively form hierarchical, non-leaky networks of perfused vessels in tissue engineering applications and ischemic disease remains an unmet challenge, despite extensive research and multiple clinical trials. Here, we use a previously-developed, multi-scale, computational systems pharmacology model of human peripheral artery disease to screen a diverse array of promising pro-angiogenic strategies, including gene therapy, biomaterials, and antibodies. Our previously-validated model explicitly accounts for VEGF immobilization, Neuropilin-1 binding, and weak activation of VEGF receptor 2 (VEGFR2) by the "VEGFxxxb" isoforms. First, we examine biomaterial-based delivery of VEGF engineered for increased affinity to the extracellular matrix. We show that these constructs maintain VEGF close to physiological levels and extend the duration of VEGFR2 activation. We demonstrate the importance of sub-saturating VEGF dosing to prevent angioma formation. Second, we examine the potential of ligand- or receptor-based gene therapy to normalize VEGF receptor signaling. Third, we explore the potential for antibody-based pro-angiogenic therapy. Our model supports recent observations that improvement in perfusion following treatment with anti-VEGF165b in mice is mediated by VEGF-receptor 1, not VEGFR2. Surprisingly, the model predicts that the approved anti-VEGF cancer drug, bevacizumab, may actually improve signaling of both VEGFR1 and VEGFR2 via a novel 'antibody swapping' effect that we demonstrate here. Altogether, this model provides insight into the mechanisms of action of several classes of pro-angiogenic strategies within the context of the complex molecular and physiological processes occurring in vivo. We identify molecular signaling similarities between promising approaches and key differences between promising and ineffective strategies.
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Affiliation(s)
- Lindsay E Clegg
- Institute for Computational Medicine, Institute for NanoBioTechnology, and Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA.
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24
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Jun JC, Rathore A, Younas H, Gilkes D, Polotsky VY. Hypoxia-Inducible Factors and Cancer. CURRENT SLEEP MEDICINE REPORTS 2017. [PMID: 28944164 DOI: 10.1007/s40675-017-0062-7.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
PURPOSE OF REVIEW Hypoxia inducible factors (HIFs) mediate the transcription of hundreds of genes that allow cells to adapt to hypoxic environments. In this review, we summarize the current state of knowledge about mechanisms of HIF activation in cancer, as well as downstream cancer-promoting consequences such as altered substrate metabolism, angiogenesis, and cell differentiation. In addition, we examine the proposed relationship between respiratory-related hypoxia, HIFs, and cancer. RECENT FINDINGS HIFs are increased in many forms of cancer, and portend a poor prognosis and response to therapy. CONCLUSION HIFs play a critical role in various stages of carcinogenesis. HIF and its transcription targets may be useful as biomarkers of disease and therapeutic targets for cancer.
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Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Aman Rathore
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Haris Younas
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Daniele Gilkes
- Division of Breast Cancer, Department of Oncology, Johns Hopkins University, Baltimore, MD
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
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25
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Dynamics and implications of circulating anti-angiogenic VEGF-A 165b isoform in patients with ST-elevation myocardial infarction. Sci Rep 2017; 7:9962. [PMID: 28855597 PMCID: PMC5577291 DOI: 10.1038/s41598-017-10505-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 08/09/2017] [Indexed: 12/22/2022] Open
Abstract
Angiogenesis is crucial to restore microvascular perfusion in the jeopardized myocardium in the weeks following reperfused ST-segment elevation myocardial infarction (STEMI). (VEGF)-A165b, an anti-angiogenic factor, has been identified as a regulator of vascularization; however, it has not been previously implicated in acute myocardial infarction. We sought to investigate the dynamics of circulating VEGF-A165b and its association with cardiac magnetic resonance-derived infarct size and left ventricular ejection fraction (LVEF). 50 STEMI patients and 23 controls were included. Compared with control individuals, serum VEGF-A165b was elevated in STEMI patients prior to primary percutaneous coronary intervention (PCI). Following PCI, serum VEGF-A165b increased further, reaching a maximum level at 24 h and decreased one month after reperfusion. VEGF-A165b levels at 24 h were associated with a large infarct size and inversely related to LVEF. VEGF-A165b expression was increased in myocardial infarct areas from patients with previous history of AMI. An ex vivo assay using serum from STEMI patients showed that neutralization of VEGF-A165b increased tubulogenesis. Overall, the study suggests that VEGF-A165b might play a deleterious role after AMI as an inhibitor of angiogenesis in the myocardium. Accordingly, neutralization of VEGF-A165b could represent a novel pro-angiogenic therapy for reperfusion of myocardium in STEMI.
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26
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Paine SK, Mondal LK, Borah PK, Bhattacharya CK, Mahanta J. Pro- and antiangiogenic VEGF and its receptor status for the severity of diabetic retinopathy. Mol Vis 2017; 23:356-363. [PMID: 28680264 PMCID: PMC5482372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 06/20/2017] [Indexed: 11/23/2022] Open
Abstract
PURPOSE Alteration of pro- and antiangiogenic homeostasis of vascular endothelial growth factor (VEGF) isoforms in patients with hyperglycemia seems crucial but substantially unexplored at least quantitatively for diabetic retinopathy (DR). Therefore, in the present study we aimed to estimate the difference between the pro- (VEGF165a) and antiangiogenic (VEGF165b) VEGF isoforms and its soluble receptors for severity of DR. METHODS The study included 123 participants (diabetic retinopathy: 81, diabetic control: 20, non-diabetic control: 22) from the Regional Institute of Ophthalmology, Kolkata. The protein levels of VEGF165a (proangiogenic), VEGF165b (antiangiogenic), VEGF receptor 1 (VEGFR1), VEGFR2, and VEGFR3 in plasma were determined with enzyme-linked immunosorbent assay (ELISA). RESULTS An imbalance in VEGF homeostasis, a statistically significant concomitant increase (p<0.0001) in the level of VEGF165a and a decrease in the level of VEGF165b, was observed with the severity of the disease. Increased differences between VEGF165a and VEGF165b i.e. VEGF165a-b concomitantly increased statistically significantly with the severity of the disease (p<0.0001), patients with diffuse diabetic macular edema (DME) with proliferative DR (PDR) had the highest imbalance. The plasma soluble form of VEGFR2 concentration consistently increased statistically significantly with the severity of the disease (p<0.0001). CONCLUSIONS The increased difference or imbalance between the pro- (VEGF165a) and antiangiogenic (VEGF165b) homeostasis of the VEGF isoforms, seems crucial for an adverse prognosis of DR and may be a better explanatory marker compared with either VEGF isoform.
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Affiliation(s)
- Suman K. Paine
- Regional Medical Research Centre-NE Region (Indian Council of Medical Research), Assam, India
| | | | - Prasanta K. Borah
- Regional Medical Research Centre-NE Region (Indian Council of Medical Research), Assam, India
| | - Chandra K. Bhattacharya
- Regional Medical Research Centre-NE Region (Indian Council of Medical Research), Assam, India
| | - Jagadish Mahanta
- Regional Medical Research Centre-NE Region (Indian Council of Medical Research), Assam, India
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27
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Bates DO, Morris JC, Oltean S, Donaldson LF. Pharmacology of Modulators of Alternative Splicing. Pharmacol Rev 2017; 69:63-79. [PMID: 28034912 PMCID: PMC5226212 DOI: 10.1124/pr.115.011239] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
More than 95% of genes in the human genome are alternatively spliced to form multiple transcripts, often encoding proteins with differing or opposing function. The control of alternative splicing is now being elucidated, and with this comes the opportunity to develop modulators of alternative splicing that can control cellular function. A number of approaches have been taken to develop compounds that can experimentally, and sometimes clinically, affect splicing control, resulting in potential novel therapeutics. Here we develop the concepts that targeting alternative splicing can result in relatively specific pathway inhibitors/activators that result in dampening down of physiologic or pathologic processes, from changes in muscle physiology to altering angiogenesis or pain. The targets and pharmacology of some of the current inhibitors/activators of alternative splicing are demonstrated and future directions discussed.
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Affiliation(s)
- David O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (D.O.B.); School of Chemistry, UNSW Australia, Sydney, Australia (J.C.M.); School of Physiology, Pharmacology and Neurosciences, School of Clinical Sciences/Bristol Renal, University of Bristol, Bristol, United Kingdom (S.O.); and School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (L.F.D.)
| | - Jonathan C Morris
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (D.O.B.); School of Chemistry, UNSW Australia, Sydney, Australia (J.C.M.); School of Physiology, Pharmacology and Neurosciences, School of Clinical Sciences/Bristol Renal, University of Bristol, Bristol, United Kingdom (S.O.); and School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (L.F.D.)
| | - Sebastian Oltean
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (D.O.B.); School of Chemistry, UNSW Australia, Sydney, Australia (J.C.M.); School of Physiology, Pharmacology and Neurosciences, School of Clinical Sciences/Bristol Renal, University of Bristol, Bristol, United Kingdom (S.O.); and School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (L.F.D.)
| | - Lucy F Donaldson
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (D.O.B.); School of Chemistry, UNSW Australia, Sydney, Australia (J.C.M.); School of Physiology, Pharmacology and Neurosciences, School of Clinical Sciences/Bristol Renal, University of Bristol, Bristol, United Kingdom (S.O.); and School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, United Kingdom (L.F.D.)
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28
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Jun JC, Rathore A, Younas H, Gilkes D, Polotsky VY. Hypoxia-Inducible Factors and Cancer. CURRENT SLEEP MEDICINE REPORTS 2017; 3:1-10. [PMID: 28944164 DOI: 10.1007/s40675-017-0062-7] [Citation(s) in RCA: 147] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE OF REVIEW Hypoxia inducible factors (HIFs) mediate the transcription of hundreds of genes that allow cells to adapt to hypoxic environments. In this review, we summarize the current state of knowledge about mechanisms of HIF activation in cancer, as well as downstream cancer-promoting consequences such as altered substrate metabolism, angiogenesis, and cell differentiation. In addition, we examine the proposed relationship between respiratory-related hypoxia, HIFs, and cancer. RECENT FINDINGS HIFs are increased in many forms of cancer, and portend a poor prognosis and response to therapy. CONCLUSION HIFs play a critical role in various stages of carcinogenesis. HIF and its transcription targets may be useful as biomarkers of disease and therapeutic targets for cancer.
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Affiliation(s)
- Jonathan C Jun
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Aman Rathore
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Haris Younas
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
| | - Daniele Gilkes
- Division of Breast Cancer, Department of Oncology, Johns Hopkins University, Baltimore, MD
| | - Vsevolod Y Polotsky
- Division of Pulmonary and Critical Care, Department of Medicine, Johns Hopkins University, Baltimore, MD
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29
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Huang C, Dong H, Zou M, Luo L, Hu Y, Xie Z, Le Y, Liu L, Zou F, Cai S. Bevacizumab reduced auto-phosphorylation of VEGFR2 to protect HDM-induced asthma mice. Biochem Biophys Res Commun 2016; 478:181-186. [PMID: 27453339 DOI: 10.1016/j.bbrc.2016.07.072] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 07/18/2016] [Indexed: 01/29/2023]
Abstract
Vascular endothelial growth factor (VEFG) is a major angiogenic factor involved in both normal physiological processes, such as embryonic development and wound healing, and in diseases, like cancer. Recent studies have revealed the functions of VEGF in inflammation and immunoregulation. Asthma is a chronic inflammation of the airways characterized by airway epithelial barrier dysfunction and imbalance in T-helper (Th) 1/Th2 during immunoregulation. We hypothesized that VEGF plays an important role in asthma. Utilizing a house dust mite extract (HDM)-induced murine model of asthma, we investigated whether bevacizumab, a humanized anti-VEGF monoclonal antibody, could protect the epithelial barrier in murine airways. We found that bevacizumab reduced airway hyper-responsiveness (AHR) and airway inflammation induced by HDM. In addition, HDM exposure promoted expression of VEGF, and caused AHR, disruptions of the epithelial barrier, and airway inflammation. Bevacizumab ameliorated AHR and the release of Th2 cytokines, thereby protecting the epithelial barrier. Our data suggest that bevacizumab may be a new therapeutic strategy for asthma.
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Affiliation(s)
- Chaowen Huang
- Chronic Airways Diseases Laboratory, Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Hangming Dong
- Chronic Airways Diseases Laboratory, Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Mengchen Zou
- Chronic Airways Diseases Laboratory, Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Lishan Luo
- Chronic Airways Diseases Laboratory, Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Yahui Hu
- Chronic Airways Diseases Laboratory, Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Zhefan Xie
- Chronic Airways Diseases Laboratory, Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Yanqing Le
- Chronic Airways Diseases Laboratory, Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Laiyu Liu
- Chronic Airways Diseases Laboratory, Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Fei Zou
- School of Public Health and Tropical Medicine, Southern Medical University, Guangzhou 510515, China
| | - Shaoxi Cai
- Chronic Airways Diseases Laboratory, Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
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30
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Dai B, Zhang P, Zhang Y, Pan C, Meng G, Xiao X, Wu Z, Jia W, Zhang J, Zhang L. RNaseH2A is involved in human gliomagenesis through the regulation of cell proliferation and apoptosis. Oncol Rep 2016; 36:173-80. [PMID: 27176716 DOI: 10.3892/or.2016.4802] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 02/06/2016] [Indexed: 11/06/2022] Open
Abstract
Mutations in the RNaseH2A gene are involved in Aicardi‑Goutieres syndrome, an autosomal recessive neurological dysfunction; however, studies assessing RNaseH2A in relation to glioma are scarce. This study aimed to assess the role of RNaseH2A in glioma and to unveil the underlying mechanisms. RNaseH2A was silenced in glioblastoma cell lines U87 and U251. Gene expression was assessed in the cells transfected with RNaseH2A shRNA or scramble shRNA by microarrays, validated by quantitative real time PCR. Protein expression was evaluated by western blot analysis. Cell proliferation was assessed by the MTT assay; cell cycle distribution and apoptosis were analyzed by flow cytometry. Finally, the effects of RNaseH2A on colony formation and tumorigenicity were assessed in vitro and in a mouse xenograft model, respectively. RNaseH2A was successively knocked down in U87 and U251 cells. Notably, RNaseH2A silencing resulted in impaired cell proliferation, with 70.7 and 57.8% reduction in the U87 and U251 cells, respectively, with the cell cycle being blocked in the G0/G1 phase in vitro. Meanwhile, clone formation was significantly reduced by RNaseH2A knockdown, which also increased cell apoptosis by approximately 4.5-fold. In nude mice, tumor size was significantly decreased after RNaseH2A knockdown: 219.29±246.43 vs. 1160.26±222.61 mm3 for the control group; similar findings were obtained for tumor weight (0.261±0.245 and 1.127±0.232 g) in the shRNA and control groups, respectively). In the microarray data, RNaseH2A was shown to modulate several signaling pathways responsible for cell proliferation and apoptosis, such as IL-6 and FAS pathways. RNaseH2A may be involved in human gliomagenesis, likely by regulating signaling pathways responsible for cell proliferation and apoptosis.
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Affiliation(s)
- Bin Dai
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100050, P.R. China
| | - Peng Zhang
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100050, P.R. China
| | - Yisong Zhang
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100050, P.R. China
| | - Changcun Pan
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100050, P.R. China
| | - Guolu Meng
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100050, P.R. China
| | - Xinru Xiao
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100050, P.R. China
| | - Zhen Wu
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100050, P.R. China
| | - Wang Jia
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100050, P.R. China
| | - Junting Zhang
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100050, P.R. China
| | - Liwei Zhang
- Department of Neurosurgery, Beijing Tian Tan Hospital, Capital Medical University, China National Clinical Research Center for Neurological Diseases, Beijing 100050, P.R. China
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31
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EphB4 inhibitor overcome the acquired resistance to cisplatin in melanomas xenograft model. J Pharmacol Sci 2015; 129:65-71. [DOI: 10.1016/j.jphs.2015.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2015] [Revised: 08/08/2015] [Accepted: 08/24/2015] [Indexed: 11/22/2022] Open
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32
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Splicing Regulators and Their Roles in Cancer Biology and Therapy. BIOMED RESEARCH INTERNATIONAL 2015; 2015:150514. [PMID: 26273588 PMCID: PMC4529883 DOI: 10.1155/2015/150514] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 03/10/2015] [Accepted: 04/01/2015] [Indexed: 12/17/2022]
Abstract
Alternative splicing allows cells to expand the encoding potential of their genomes. In this elegant mechanism, a single gene can yield protein isoforms with even antagonistic functions depending on the cellular physiological context. Alterations in splicing regulatory factors activity in cancer cells, however, can generate an abnormal protein expression pattern that promotes growth, survival, and other processes, which are relevant to tumor biology. In this review, we discuss dysregulated alternative splicing events and regulatory factors that impact pathways related to cancer. The SR proteins and their regulatory kinases SRPKs and CLKs have been frequently found altered in tumors and are examined in more detail. Finally, perspectives that support splicing machinery as target for the development of novel anticancer therapies are discussed.
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Zhao YJ, Han HZ, Liang Y, Shi CZ, Zhu QC, Yang J. Alternative splicing of VEGFA, APP and NUMB genes in colorectal cancer. World J Gastroenterol 2015; 21:6550-60. [PMID: 26074693 PMCID: PMC4458765 DOI: 10.3748/wjg.v21.i21.6550] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2014] [Revised: 02/10/2015] [Accepted: 03/12/2015] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate alternative splicing in vascular endothelial growth factor A (VEGFA), amyloid beta precursor protein (APP), and Numb homolog (NUMB) in colorectal cancer (CRC). METHODS Real-time quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and PCR-restriction fragment length polymorphism analyses were performed to detect the expression of VEGFA, APP, and NUMB mRNA in 20 CRC tissues and matched adjacent normal tissues, as well as their alternative splicing variants. RESULTS qRT-PCR analysis revealed that the expression of APP, NUMB, and VEGFA165b mRNA were significantly downregulated, while VEGFA mRNA was upregulated, in CRC tissues (all P < 0.05). PCR-restriction fragment length polymorphism analysis revealed that the expression of VEGFA165a/b in CRC tissues was significantly higher than in adjacent normal tissues (P < 0.05). Compared with adjacent normal tissues, the expression of NUMB-PRR(S) in CRC tissues was significantly decreased (P < 0.05), and the expression of NUMB-PRR(L) was increased (P < 0.05). CONCLUSION Alternative splicing of VEGFA, APP, and NUMB may regulate the development of CRC, and represent new targets for its diagnosis, prognosis, and treatment.
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Wilkie MD, Emmett MS, Santosh S, Lightbody KA, Lane S, Goodyear PW, Sheard JD, Boyd MT, Pritchard-Jones RO, Jones TM. Relative expression of vascular endothelial growth factor isoforms in squamous cell carcinoma of the head and neck. Head Neck 2015; 38:775-81. [DOI: 10.1002/hed.23959] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 10/02/2014] [Accepted: 12/12/2014] [Indexed: 11/06/2022] Open
Affiliation(s)
- Mark D. Wilkie
- Department of Molecular and Clinical Cancer Medicine; Liverpool Cancer Research Centre, University of Liverpool; Liverpool United Kingdom
- Department of Otorhinolaryngology - Head and Neck Surgery; University Hospital Aintree; Liverpool United Kingdom
| | - Maxine S. Emmett
- Department of Molecular and Clinical Cancer Medicine; Liverpool Cancer Research Centre, University of Liverpool; Liverpool United Kingdom
| | - Shilpa Santosh
- Department of Pathology; University Hospital Aintree; Liverpool United Kingdom
| | - Kathryn A. Lightbody
- Department of Otorhinolaryngology - Head and Neck Surgery; University Hospital Aintree; Liverpool United Kingdom
| | - Steven Lane
- Department of Biostatistics; University of Liverpool; Liverpool United Kingdom
| | - Paul W. Goodyear
- Department of Otorhinolaryngology - Head and Neck Surgery; University Hospital Aintree; Liverpool United Kingdom
| | - Jon D. Sheard
- Department of Pathology; University Hospital Aintree; Liverpool United Kingdom
| | - Mark T. Boyd
- Department of Molecular and Clinical Cancer Medicine; Liverpool Cancer Research Centre, University of Liverpool; Liverpool United Kingdom
| | - Rowan O. Pritchard-Jones
- Department of Molecular and Clinical Cancer Medicine; Liverpool Cancer Research Centre, University of Liverpool; Liverpool United Kingdom
| | - Terence M. Jones
- Department of Molecular and Clinical Cancer Medicine; Liverpool Cancer Research Centre, University of Liverpool; Liverpool United Kingdom
- Department of Otorhinolaryngology - Head and Neck Surgery; University Hospital Aintree; Liverpool United Kingdom
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Bunni J, Shelley-Fraser G, Stevenson K, Oltean S, Salmon A, Harper SJ, Carter JG, Bates DO. Circulating levels of anti-angiogenic VEGF-A isoform (VEGF-Axxxb) in colorectal cancer patients predicts tumour VEGF-A ratios. Am J Cancer Res 2015; 5:2083-2089. [PMID: 26269767 PMCID: PMC4529627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/10/2015] [Indexed: 06/04/2023] Open
Abstract
PURPOSE Bevacizumab as an adjunct to chemotherapy improves survival for some patients with metastatic colorectal cancer. Immunohistochemical staining of samples from the registration ECOG E3200 trial of bevacizumab with FOLFOX demonstrated that only patients with carcinomas expressing low levels of VEGF-A165b, an anti-angiogenic splice variant of the Vascular Endothelial Growth Factor family of proteins, benefited from bevacizumab treatment. To identify a more useful biomarker of response we tested the hypothesis that circulating VEGF-A165b levels correlate with immunohistochemical staining. EXPERIMENTAL DESIGN 17 patients with biopsy proven colorectal adenocarcinoma had pre-operative blood samples drawn. They underwent resection and had post-resection blood drawn. The plasma was analysed for levels of VEGF-Axxxb using enzyme-linked immunosorbent assay (ELISA) and the tumour blocks stained for VEGF-Axxxb and pan-VEGF-A. The normalised ratio of VEGF-Axxxb expression to that of panVEGF-A expression scored by IHC was calculated and correlated with plasma VEGF-A165b levels. RESULTS Plasma levels of VEGF-Axxxb significantly correlated with the VEGF-Axxxb:panVEGF-A ratio (r=0.594, P<0.02) in colorectal cancers. Median plasma VEGF-Axxxb levels were 151 pg/ml. The mean (1.5±0.17) and median, IQR (1.8, 1-2) IHC scores of the patients with greater than median plasma VEGF-Axxxb were significantly greater than those with less than median plasma VEGF-Axxxb levels (mean ± SEM=0.85±10.12, median, IQR=1, 0.54-1). CONCLUSION These results suggest that plasma VEGF-Axxxb levels could be an effective biomarker of response to Bevacizumab. These results indicate that a prospective trial is warranted to explore the use of plasma VEGF-Axxxb levels to stratify patients for colorectal cancer treatment by bevacizumab.
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Affiliation(s)
- John Bunni
- Department of Physiology and Pharmacology, Microvascular Research Laboratories, University of Bristol Bristol, United Kingdom
| | | | - Kirsty Stevenson
- Department of Pathology, Bristol Royal Infirmary Bristol, United Kingdom
| | - Sebastian Oltean
- Department of Physiology and Pharmacology, Microvascular Research Laboratories, University of Bristol Bristol, United Kingdom
| | - Andy Salmon
- Department of Physiology and Pharmacology, Microvascular Research Laboratories, University of Bristol Bristol, United Kingdom
| | - Steven J Harper
- Department of Physiology and Pharmacology, Microvascular Research Laboratories, University of Bristol Bristol, United Kingdom
| | - James G Carter
- Department of Physiology and Pharmacology, Microvascular Research Laboratories, University of Bristol Bristol, United Kingdom
| | - David O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Bristol, United Kingdom
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Hamdollah Zadeh MA, Amin EM, Hoareau-Aveilla C, Domingo E, Symonds KE, Ye X, Heesom KJ, Salmon A, D'Silva O, Betteridge KB, Williams AC, Kerr DJ, Salmon AHJ, Oltean S, Midgley RS, Ladomery MR, Harper SJ, Varey AHR, Bates DO. Alternative splicing of TIA-1 in human colon cancer regulates VEGF isoform expression, angiogenesis, tumour growth and bevacizumab resistance. Mol Oncol 2015; 9:167-78. [PMID: 25224594 PMCID: PMC4286123 DOI: 10.1016/j.molonc.2014.07.017] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/23/2014] [Accepted: 07/24/2014] [Indexed: 02/06/2023] Open
Abstract
The angiogenic capability of colorectal carcinomas (CRC), and their susceptibility to anti-angiogenic therapy, is determined by expression of vascular endothelial growth factor (VEGF) isoforms. The intracellular protein T-cell Intracellular Antigen (TIA-1) alters post-transcriptional RNA processing and binds VEGF-A mRNA. We therefore tested the hypothesis that TIA-1 could regulate VEGF-A isoform expression in colorectal cancers. TIA-1 and VEGF-A isoform expression was measured in colorectal cancers and cell lines. We discovered that an endogenous splice variant of TIA-1 encoding a truncated protein, short TIA-1 (sTIA-1) was expressed in CRC tissues and invasive K-Ras mutant colon cancer cells and tissues but not in adenoma cell lines. sTIA-1 was more highly expressed in CRC than in normal tissues and increased with tumour stage. Knockdown of sTIA-1 or over-expression of full length TIA-1 (flTIA-1) induced expression of the anti-angiogenic VEGF isoform VEGF-A165b. Whereas flTIA-1 selectively bound VEGF-A165 mRNA and increased translation of VEGF-A165b, sTIA-1 prevented this binding. In nude mice, xenografted colon cancer cells over-expressing flTIA-1 formed smaller, less vascular tumours than those expressing sTIA-1, but flTIA-1 expression inhibited the effect of anti-VEGF antibodies. These results indicate that alternative splicing of an RNA binding protein can regulate isoform specific expression of VEGF providing an added layer of complexity to the angiogenic profile of colorectal cancer and their resistance to anti-angiogenic therapy.
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Affiliation(s)
- Maryam A Hamdollah Zadeh
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Elianna M Amin
- Centre for Research in Biomedicine, Faculty of Health and Life Sciences, University of the West of England, Bristol BS16 1QY, UK
| | - Coralie Hoareau-Aveilla
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Enric Domingo
- Molecular and Population Genetics, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Kirsty E Symonds
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Xi Ye
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Katherine J Heesom
- Proteomics Facility, Faculty of Veterinary and Medical Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Andrew Salmon
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Olivia D'Silva
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Kai B Betteridge
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Ann C Williams
- School of Cellular and Molecular Medicine, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - David J Kerr
- Nuffield Dept Clinical and Laboratory Sciences, University of Oxford, UK
| | - Andrew H J Salmon
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Sebastian Oltean
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Rachel S Midgley
- Molecular and Population Genetics, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, UK
| | - Michael R Ladomery
- Centre for Research in Biomedicine, Faculty of Health and Life Sciences, University of the West of England, Bristol BS16 1QY, UK
| | - Steven J Harper
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - Alexander H R Varey
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - David O Bates
- Microvascular Research Laboratories, Veterinary Sciences Building, School of Physiology and Pharmacology, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK; Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, NG7 2UH, UK.
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Guyot M, Pagès G. VEGF Splicing and the Role of VEGF Splice Variants: From Physiological-Pathological Conditions to Specific Pre-mRNA Splicing. Methods Mol Biol 2015; 1332:3-23. [PMID: 26285742 DOI: 10.1007/978-1-4939-2917-7_1] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
During this past decade, the vascular endothelial growth factor (VEGF) pathway has been extensively studied. VEGF is a paradigm of molecular regulation since its expression is controlled at all possible steps including transcription, mRNA stability, translation, and pre-mRNA splicing. The latter form of molecular regulation is probably the least studied. This field has been neglected; yet different forms of VEGF with different sizes and different physiological properties issued from alternative splicing have been described a long time ago. Recently a new level of complexity was added to the field of splicing of VEGF pre-mRNA. Whereas thousands of publications have described VEGF as a pro-angiogenic factor, an alternative splicing event generates specific anti-angiogenic forms of VEGF that only differ from the others by a modification in the last six amino acids of the protein. According to the scientists who discovered these isoforms, which are indistinguishable from the pro-angiogenic ones with pan VEGF antibodies, some of the literature on VEGF is at least inexact if not completely false. Moreover, the presence of anti-angiogenic forms of VEGF may explain the disappointing efficacy of anti-VEGF therapies on the overall survival of patients with different forms of cancers and with wet age-related macular degeneration. This review focuses on the existence of the different alternative splice variants of VEGF and the molecular mechanisms associated with their expression and function.
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Affiliation(s)
- Mélanie Guyot
- Institute for Research on Cancer and Aging of Nice (IRCAN), University of Nice Sophia Antipolis, Centre Antoine Lacassagne 33 Avenue de Valombrose, UMR CNRS 7284/INSERM U 1081, Nice, 06189, France
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Beazley-Long N, Gaston K, Harper SJ, Orlando A, Bates DO. Novel mechanisms of resistance to vemurafenib in melanoma - V600E B-Raf reversion and switching VEGF-A splice isoform expression. Am J Cancer Res 2014; 5:433-441. [PMID: 25628951 PMCID: PMC4300704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 11/28/2014] [Indexed: 06/04/2023] Open
Abstract
Targeting activating mutations in the proto-oncogene B-Raf, in melanoma, has led to increases in progression free survival. Treatment with vemurafenib, which inhibits the most common activating-mutated form of B-Raf (B-Raf(V600E)), eventually results in resistance to therapy. VEGF-A is the principal driver of angiogenesis in primary and metastatic lesions. The bioactivity of VEGF-A is dependent upon alternative RNA splicing and pro-angiogenic isoforms of VEGF-A are upregulated in many disease states dependent upon angiogenesis, including cancers. Using techniques including RT-PCR, Western blotting, ELISA and luciferase reporter assays, the effect of vemurafenib on proliferation, ERK1/2 phosphorylation and the levels of pro- and anti-angiogenic VEGF-A isoforms was investigated in melanoma cell types expressing either wild-type B-Raf or B-Raf(V600E), including a primary melanoma culture derived from a highly vascularised and active nodule taken from a patient with a V600E mutant melanoma. The primary melanoma culture was characterised and found to have reverted to wild-type B-Raf. In B-Raf(V600E) A375 cells ERK1/2 phosphorylation, pro-angiogenic VEGF-A mRNA, total VEGF-A protein expression and VEGF-A 3'UTR activity were all decreased in a concentration-dependent manner by vemurafenib. Conversely vemurafenib treatment of wild-type B-Raf cells significantly increased ERK1/2 phosphorylation, pro-angiogenic VEGF-A mRNA and total VEGF-A expression in a concentration-dependent manner. A switch to pro-angiogenic VEGF-A isoforms, with a concomitant upregulation of expression by increasing VEGF-A mRNA stability, may be an additional oncogenic and pathological mechanism in B-Raf(V600E) melanomas, which promotes tumor-associated angiogenesis and melanoma-genesis. We have also identified the genetic reversal of B-Raf(V600E) to wild-type in an active melanoma nodule taken from a V600E-positive patient and continued vemurafenib treatment for this patient is likely to have had a detrimental effect by promoting B-Raf(WT) activity.
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Affiliation(s)
- Nicholas Beazley-Long
- Microvascular Research Laboratories, University of Bristol Bristol, UK, BS2 8EJ ; School of Life Sciences, University of Nottingham, Queen's Medical School Nottingham, UK, NG7 2UH
| | - Kevin Gaston
- School of Biochemistry, University of Bristol Bristol, UK, BS8 1TD
| | - Steven J Harper
- Microvascular Research Laboratories, University of Bristol Bristol, UK, BS2 8EJ
| | - Antonio Orlando
- Department of Plastic Surgery, Southmead Hospital Brunel Building, North Bristol Trust, UK, BS10 5NB
| | - David O Bates
- Microvascular Research Laboratories, University of Bristol Bristol, UK, BS2 8EJ ; Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre Nottingham, UK, NG7 2UH
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Carter JG, Gammons MVR, Damodaran G, Churchill AJ, Harper SJ, Bates DO. The carboxyl terminus of VEGF-A is a potential target for anti-angiogenic therapy. Angiogenesis 2014; 18:23-30. [PMID: 25274272 PMCID: PMC4280485 DOI: 10.1007/s10456-014-9444-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Accepted: 09/10/2014] [Indexed: 11/25/2022]
Abstract
Anti-VEGF-A therapy has become a mainstay of treatment for ocular neovascularisation and in cancer; however, their effectiveness is not universal, in some cases only benefiting a minority of patients. Anti-VEGF-A therapies bind and block both pro-angiogenic VEGF-Axxx and the partial agonist VEGF-Axxxb isoforms, but their anti-angiogenic benefit only comes about from targeting the pro-angiogenic isoforms. Therefore, antibodies that exclusively target the pro-angiogenic isoforms may be more effective. To determine whether C-terminal-targeted antibodies could inhibit angiogenesis, we generated a polyclonal antibody to the last nine amino acids of VEGF-A165 and tested it in vitro and in vivo. The exon8a polyclonal antibody (Exon8apab) did not bind VEGF-A165b even at greater than 100-fold excess concentration, and dose dependently inhibited VEGF-A165 induced endothelial migration in vitro at concentrations similar to the VEGF-A antibody fragment ranibizumab. Exon8apab can inhibit tumour growth of LS174t cells implanted in vivo and blood vessel growth in the eye in models of age-related macular degeneration, with equal efficacy to non-selective anti-VEGF-A antibodies. It also showed that it was the VEGF-Axxx levels specifically that were upregulated in plasma from patients with proliferative diabetic retinopathy. These results suggest that VEGF-A165-specific antibodies can be therapeutically useful.
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Affiliation(s)
- James G. Carter
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
- Cancer Biology, Queens Medical Centre, University of Nottingham, D Floor West Block, Nottingham, NG7 2UH UK
| | - Melissa V. R. Gammons
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
| | - Gopinath Damodaran
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
| | - Amanda J. Churchill
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
| | - Steven J. Harper
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
| | - David O. Bates
- Microvascular Research Laboratories, School of Physiology and Pharmacology, University of Bristol, Preclinical Veterinary Sciences Building, Southwell Street, Bristol, BS2 8EJ UK
- Cancer Biology, Queens Medical Centre, University of Nottingham, D Floor West Block, Nottingham, NG7 2UH UK
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40
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Chen DB, Zheng J. Regulation of placental angiogenesis. Microcirculation 2014; 21:15-25. [PMID: 23981199 DOI: 10.1111/micc.12093] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 08/21/2013] [Indexed: 12/13/2022]
Abstract
Ample interest has been evoked in using placental angiogenesis as a target for the development of diagnosis tools and potential therapeutics for pregnancy complications based on the knowledge of placental angiogenesis in normal and aberrant pregnancies. Although these goals are still far from reach, one would expect that two complementary processes should be balanced for therapeutic angiogenesis to be successful in restoring a mature and functional vascular network in the placenta in any pregnancy complication: (i) pro-angiogenic stimulation of new vessel growth and (ii) anti-angiogenic inhibition of vessel overgrowth. As the best model of physiological angiogenesis, investigations of placental angiogenesis provide critical insights not only for better understanding of normal placental endothelial biology but also for the development of diagnosis tools for pregnancy complications. Such investigations will potentially identify novel pro-angiogenic factors for therapeutic intervention for tissue damage in various obstetric complications or heart failure or anti-angiogenic factors to target on cancer or vision loss in which circulation needs to be constrained. This review summarizes the genetic and molecular aspects of normal placental angiogenesis as well as the signaling mechanisms by which the dominant angiogenic factor vascular endothelial growth factor regulates placental angiogenesis with a focus on placental endothelial cells.
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Affiliation(s)
- Dong-Bao Chen
- Department of Obstetrics & Gynecology, University of California, Irvine, California, USA
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Hulse RP, Beazley-Long N, Hua J, Kennedy H, Prager J, Bevan H, Qiu Y, Fernandes ES, Gammons MV, Ballmer-Hofer K, Gittenberger de Groot AC, Churchill AJ, Harper SJ, Brain SD, Bates DO, Donaldson LF. Regulation of alternative VEGF-A mRNA splicing is a therapeutic target for analgesia. Neurobiol Dis 2014; 71:245-59. [PMID: 25151644 PMCID: PMC4194316 DOI: 10.1016/j.nbd.2014.08.012] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 07/29/2014] [Accepted: 08/06/2014] [Indexed: 12/02/2022] Open
Abstract
Vascular endothelial growth factor-A (VEGF-A) is best known as a key regulator of the formation of new blood vessels. Neutralization of VEGF-A with anti-VEGF therapy e.g. bevacizumab, can be painful, and this is hypothesized to result from a loss of VEGF-A-mediated neuroprotection. The multiple vegf-a gene products consist of two alternatively spliced families, typified by VEGF-A165a and VEGF-A165b (both contain 165 amino acids), both of which are neuroprotective. Under pathological conditions, such as in inflammation and cancer, the pro-angiogenic VEGF-A165a is upregulated and predominates over the VEGF-A165b isoform. We show here that in rats and mice VEGF-A165a and VEGF-A165b have opposing effects on pain, and that blocking the proximal splicing event – leading to the preferential expression of VEGF-A165b over VEGF165a – prevents pain in vivo. VEGF-A165a sensitizes peripheral nociceptive neurons through actions on VEGFR2 and a TRPV1-dependent mechanism, thus enhancing nociceptive signaling. VEGF-A165b blocks the effect of VEGF-A165a. After nerve injury, the endogenous balance of VEGF-A isoforms switches to greater expression of VEGF-Axxxa compared to VEGF-Axxxb, through an SRPK1-dependent pre-mRNA splicing mechanism. Pharmacological inhibition of SRPK1 after traumatic nerve injury selectively reduced VEGF-Axxxa expression and reversed associated neuropathic pain. Exogenous VEGF-A165b also ameliorated neuropathic pain. We conclude that the relative levels of alternatively spliced VEGF-A isoforms are critical for pain modulation under both normal conditions and in sensory neuropathy. Altering VEGF-Axxxa/VEGF-Axxxb balance by targeting alternative RNA splicing may be a new analgesic strategy. The different vegf-a splice variants, VEGF-A165a and VEGF-A165b have pro- and anti-nociceptive actions respectively. Pro-nociceptive actions of VEGF-A165a are dependent on TRPV1. Alternative pre-mRNA splicing underpins peripheral sensitization by VEGF-A isoforms in normal and neuropathic animals.
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Affiliation(s)
- R P Hulse
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK; Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK
| | - N Beazley-Long
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK; School of Life Sciences, The Medical School, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK
| | - J Hua
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - H Kennedy
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - J Prager
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - H Bevan
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - Y Qiu
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | | | - M V Gammons
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | | | | | - A J Churchill
- Clinical Sciences, University of Bristol, Bristol BS1 2LX, UK
| | - S J Harper
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK
| | - S D Brain
- King's College London, London SE1 9NH, UK
| | - D O Bates
- Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK.
| | - L F Donaldson
- Physiology and Pharmacology, University of Bristol, Bristol BS8 1TD, UK; School of Life Sciences, The Medical School, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK.
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42
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Ngo DTM, Farb MG, Kikuchi R, Karki S, Tiwari S, Bigornia SJ, Bates DO, LaValley MP, Hamburg NM, Vita JA, Hess DT, Walsh K, Gokce N. Antiangiogenic actions of vascular endothelial growth factor-A165b, an inhibitory isoform of vascular endothelial growth factor-A, in human obesity. Circulation 2014; 130:1072-80. [PMID: 25116954 DOI: 10.1161/circulationaha.113.008171] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
BACKGROUND Experimental studies suggest that visceral adiposity and adipose tissue dysfunction play a central role in obesity-related cardiometabolic complications. Impaired angiogenesis in fat has been implicated in the development of adipose tissue hypoxia, capillary rarefaction, inflammation, and metabolic dysregulation, but pathophysiological mechanisms remain unknown. In this study, we examined the role of a novel antiangiogenic isoform of vascular endothelial growth factor-A (VEGF-A), VEGF-A165b, in human obesity. METHODS AND RESULTS We biopsied paired subcutaneous and visceral adipose tissue in 40 obese subjects (body mass index, 45±8 kg/m(2); age, 45±11 years) during bariatric surgery and characterized depot-specific adipose tissue angiogenic capacity using an established ex vivo assay. Visceral adipose tissue exhibited significantly blunted angiogenic growth compared with subcutaneous fat (P<0.001) that was associated with marked tissue upregulation of VEGF-A165b (P=0.004). The extent of VEGF-A165b expression correlated negatively with angiogenic growth (r=-0.6, P=0.006). Although recombinant VEGF-A165b significantly impaired angiogenesis, targeted inhibition of VEGF-A165b with neutralizing antibody stimulated fat pad neovascularization and restored VEGF receptor activation. Blood levels of VEGF-A165b were significantly higher in obese subjects compared with lean control subjects (P=0.02), and surgical weight loss induced a marked decline in serumVEGF-A165b (P=0.003). CONCLUSIONS We demonstrate that impaired adipose tissue angiogenesis is associated with overexpression of a novel antiangiogenic factor, VEGF-A165b, that may play a pathogenic role in human adiposopathy. Moreover, systemic upregulation of VEGF-A165b in circulating blood may have wider-ranging implications beyond the adipose milieu. VEGF-A165b may represent a novel area of investigation to gain further understanding of mechanisms that modulate the cardiometabolic consequences of obesity.
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Affiliation(s)
- Doan T M Ngo
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Melissa G Farb
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Ryosuke Kikuchi
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Shakun Karki
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Stephanie Tiwari
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Sherman J Bigornia
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - David O Bates
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Michael P LaValley
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Naomi M Hamburg
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Joseph A Vita
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Donald T Hess
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Kenneth Walsh
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.)
| | - Noyan Gokce
- From the Evans Department of Medicine and Whitaker Cardiovascular Institute (D.T.M.N., M.G.F., R.K., S.K., S.T., S.J.B., N.M.H., J.A.V., K.W., N.G.) and Department of General Surgery (D.T.H.), Boston University School of Medicine, Boston, MA; Microvascular Research Laboratories, School of Physiology and Pharmacology, Bristol Heart Institute, School of Veterinary Science, University of Bristol, Bristol, UK (D.O.B.); and Department of Biostatistics, Boston University School of Public Health, Boston, MA (M.P.L.).
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Gammons MV, Lucas R, Dean R, Coupland SE, Oltean S, Bates DO. Targeting SRPK1 to control VEGF-mediated tumour angiogenesis in metastatic melanoma. Br J Cancer 2014; 111:477-85. [PMID: 25010863 PMCID: PMC4119992 DOI: 10.1038/bjc.2014.342] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 04/23/2014] [Accepted: 05/01/2014] [Indexed: 01/06/2023] Open
Abstract
Background: Current therapies for metastatic melanoma are targeted either at cancer mutations driving growth (e.g., vemurafenib) or immune-based therapies (e.g., ipilimumab). Tumour progression also requires angiogenesis, which is regulated by VEGF-A, itself alternatively spliced to form two families of isoforms, pro- and anti-angiogenic. Metastatic melanoma is associated with a splicing switch to pro-angiogenic VEGF-A, previously shown to be regulated by SRSF1 phosphorylation by SRPK1. Here, we show a novel approach to preventing angiogenesis—targeting splicing factor kinases that are highly expressed in melanomas. Methods: We used RT–PCR, western blotting and immunohistochemistry to investigate SRPK1, SRSF1 and VEGF expression in tumour cells, and in vivo xenograft assays to investigate SRPK1 knockdown and inhibition in vivo. Results: In both uveal and cutaneous melanoma cell lines, SRPK1 was highly expressed, and inhibition of SRPK1 by knockdown or with pharmacological inhibitors reduced pro-angiogenic VEGF expression maintaining the production of anti-angiogenic VEGF isoforms. Both pharmacological SRPK1 inhibitors and SRPK1 knockdown reduced growth of human melanomas in vivo, but neither affected cell proliferation in vitro. Conclusions: These results suggest that selective blocking of pro-angiogenic isoforms by inhibiting splice-site selection with SRPK1 inhibitors reduces melanoma growth. SRPK1 inhibitors may be used as therapeutic agents.
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Affiliation(s)
- M V Gammons
- Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - R Lucas
- Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - R Dean
- Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - S E Coupland
- Department of Molecular and Clinical Cancer Medicine, University of Liverpool, Liverpool, UK
| | - S Oltean
- Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK
| | - D O Bates
- 1] Microvascular Research Laboratories, School of Physiology and Pharmacology, Preclinical Veterinary Sciences Building, University of Bristol, Southwell Street, Bristol BS2 8EJ, UK [2] Cancer Biology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham, Queen's Medical Centre, Nottingham NG2 7UH, UK
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Abstract
Vascular endothelial growth factor (VEGF)-VEGF receptor (VEGFR) system has been shown to play central roles not only in physiological angiogenesis, but also in pathological angiogenesis in diseases such as cancer. Based on these findings, a variety of anti-angiogenic drugs, including anti-VEGF antibodies and VEGFR/multi-receptor kinase inhibitors have been developed and approved for the clinical use. While the clinical efficacy of these drugs has been clearly demonstrated in cancer patients, they have not been shown to be effective in curing cancer, suggesting that further improvement in their design is necessary. Abnormal expression of an endogenous VEGF-inhibitor sFlt-1 has been shown to be involved in a variety of diseases, such as preeclampsia and aged macular degeneration. In addition, various factors modulating angiogenic processes have been recently isolated. Given this complexity then, extensive studies on the interrelationship between VEGF signals and other angiogenesis-regulatory systems will be important for developing future strategies to suppress diseases with an angiogenic component.
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Affiliation(s)
- Masabumi Shibuya
- Jobu University, Director, Institute of Physiology and Medicine, Gunma 372-8588 ; Tokyo Medical and Dental University, Department of Molecular Oncology, Tokyo 113-8519 ; University of Tokyo, Tokyo 108-8639, Japan
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Wu HR, Guan YY, Wu XP, Zhu JF. Effect of recombinant human VEGF 165b protein and bevacizumab on expression of CD34 and cell apoptosis in human gastric carcinoma xenografts in nude mice. Shijie Huaren Xiaohua Zazhi 2014; 22:1058-1063. [DOI: 10.11569/wcjd.v22.i8.1058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the effect of recombinant human VEGF165b protein (rhVEGF165b) and bevacizumab on expression of CD34 and cell apoptosis in human gastric carcinoma xenografts in nude mice.
METHODS: Thirty male nude mice were used to establish the human gastric carcinoma xenograft model. The mice were randomly divided into three groups: a rhVEGF165b group (intraperitoneal injection, 10 μg/kg), a bevacizumab group (intraperitoneal injection, 5 mg/kg) and a control group. Tumor growth was detected by measuring tumor volume and weight. The expression of CD34 and apoptosis of tumor cells were detected by immunohistochemistry and TdT-mediated dUTP nick end labeling (TUNEL) assay at weeks 1, 2 and 3, respectively.
RESULTS: Tumor volume and weight at weeks 1 and 2 in the rhVEGF165b group (week 1: 0.546 ± 0.132 vs 0.637 ± 0.084, 1.894 ± 0.599 vs 0.46 ± 0.093; week 2: 1.894 ± 0.599 vs 2.238 ± 0.29, 1.537 ± 0.568 vs 2.013 ± 0.833; P < 0.05 for all) and at weeks 1, 2 and 3 in the bevacizumab group (week 1: 0.453 ± 0.119 vs 0.637 ± 0.084, 0.320 ± 0.097 vs 0.460 ± 0.093; week 2: 1.691 ± 0.381 vs 2.238 ± 0.290, 1.168 ± 0.524 vs 2.013 ± 0.833; week 3: 1.709 ± 0.474 vs 4.872 ± 0.594, 1.747 ± 0.557 vs 3.463 ± 0.986, P < 0.05 for all) were significantly smaller than those in the control group. At week 3, tumor volume and weight were significantly larger in the rhVEGF165b group than in the bevacizumab group (3.843 ± 1.339 vs 1.709 ± 0.474, 3.066 ± 1.281 vs 1.747 ± 0.557, P < 0.05 for both). Microvascular density (MVD) and apoptosis index (AI) at weeks 1, 2 and 3 in the rhVEGF165b group and bevacizumab group were significantly different from those in the control group. MVD and AI also differed significantly between the rhVEGF165b group and bevacizumab group.
CONCLUSION: Both rhVEGF165b and bevacizumab can inhibit the growth of human gastric carcinoma cells possibly by inhibiting angiogenesis and inducing apoptosis, with rhVEGF165b having a more significant effect in early stage.
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Association of VEGF-A splice variant mRNA expression with outcome in bevacizumab-treated patients with metastatic breast cancer. Clin Breast Cancer 2014; 14:330-8. [PMID: 24703319 DOI: 10.1016/j.clbc.2014.02.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 02/19/2014] [Accepted: 02/24/2014] [Indexed: 12/31/2022]
Abstract
BACKGROUND The prognostic utility of vascular endothelial growth factor A (VEGF-A) splice variants in patients with advanced breast cancer treated with bevacizumab has not been studied. PATIENTS AND METHODS A total of 111 patients with metastatic breast cancer treated with weekly docetaxel or ixabepilone without bevacizumab (cohort A) and 100 treated with weekly paclitaxel and bevacizumab (cohort B) were studied. Formalin-fixed tumors were macrodissected for reverse transcription quantitative polymerase chain reaction relative quantification of VEGF-A165, -189, and -206 isoforms spliced at exon 8 proximal splice site (VEGF-Axxxa) and at exon 8 distal splice site (VEGF-Axxxb). RESULTS For high VEGF-Axxxa, the hazard ratios (HRs) for progression were 1.08 (P = .71) in non-bevacizumab-treated patients (cohort A) and 0.66 (P = .22) in bevacizumab-treated patients (cohort B), and the HRs for death were 1.45 (P = .13) and 0.50 (P = .049), respectively. The interaction of VEGF-Axxxa with bevacizumab administration was significant (P = .011) for overall survival (OS). High tissue VEGF-Axxxb was not prognostic in cohort A but was predictive for bevacizumab benefit in cohort B (HR for progression, 0.57 [P = .04]; HR for death, 0.51 [P = .02]). Exploratory analyses done only in cohort B suggested that abundance of VEGFR1 messenger RNA (mRNA) in peripheral blood and low VEGFR2 mRNA in tissue correlated with poor outcome. In multivariate analysis, high tissue mRNA of angiogenic VEGF-Axxxa in the presence of bevacizumab therapy predicted for favorable progression-free survival (HR for progression, 0.39; P = .0227) and OS (HR for death, 0.32; P = .0140). CONCLUSION Tissue mRNA expression of angiogenic VEGF-Axxxa isoforms was retrospectively associated with adverse prognosis in the absence of bevacizumab and with favorable outcome when bevacizumab was administered in patients with advanced breast cancer.
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Ramakrishnan S, Anand V, Roy S. Vascular endothelial growth factor signaling in hypoxia and inflammation. J Neuroimmune Pharmacol 2014; 9:142-60. [PMID: 24610033 PMCID: PMC4048289 DOI: 10.1007/s11481-014-9531-7] [Citation(s) in RCA: 231] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 02/11/2014] [Indexed: 12/22/2022]
Abstract
Infection, cancer and cardiovascular diseases are the major causes for morbidity and mortality in the United States according to the Center for Disease Control. The underlying etiology that contributes to the severity of these diseases is either hypoxia induced inflammation or inflammation resulting in hypoxia. Therefore, molecular mechanisms that regulate hypoxia-induced adaptive responses in cells are important areas of investigation. Oxygen availability is sensed by molecular switches which regulate synthesis and secretion of growth factors and inflammatory mediators. As a consequence, tissue microenvironment is altered by re-programming metabolic pathways, angiogenesis, vascular permeability, pH homeostasis to facilitate tissue remodeling. Hypoxia inducible factor (HIF) is the central mediator of hypoxic response. HIF regulates several hundred genes and vascular endothelial growth factor (VEGF) is one of the primary target genes. Understanding the regulation of HIF and its influence on inflammatory response offers unique opportunities for drug development to modulate inflammation and ischemia in pathological conditions.
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Affiliation(s)
- S Ramakrishnan
- Department of Pharmacology, University of Minnesota, Minneapolis, MN, 55455, USA,
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Chung HJ, Mahalingam M. Angiogenesis, vasculogenic mimicry and vascular invasion in cutaneous malignant melanoma – implications for therapeutic strategies and targeted therapies. Expert Rev Anticancer Ther 2014; 14:621-39. [DOI: 10.1586/14737140.2014.883281] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Zbytek B, Carlson JA, Granese J, Ross J, Mihm MC, Slominski A. Current concepts of metastasis in melanoma. ACTA ACUST UNITED AC 2014; 3:569-585. [PMID: 19649148 DOI: 10.1586/17469872.3.5.569] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The main cause of death in melanoma patients is widespread metastases. Staging of melanoma is based on the primary tumor thickness, ulceration, lymph node and distant metastases. Metastases develop in regional lymph nodes, as satellite or in-transit lesions, or in distant organs. Lymph flow and chemotaxis is responsible for the homing of melanoma cells to different sites. Standard pathologic evaluation of sentinel lymph nodes fails to find occult melanoma in a significant proportion of cases. Detection of small numbers of malignant melanoma cells in these and other sites, such as adjacent to the primary site, bone marrow or the systemic circulation, may be enhanced by immunohistochemistry, reverse transcription PCR, evaluation of lymphatic vessel invasion and proteomics. In the organs to which melanoma cells metastasize, extravasation of melanoma cells is regulated by adhesion molecules, matrix metalloproteases, chemokines and growth factors. Melanoma cells may travel along external vessel lattices. After settling in the metastatic sites, melanoma cells develop mechanisms that protect them against the attack of the immune system. It is thought that one of the reasons why melanoma cells are especially resistant to killing is the fact that melanocytes (cells from which melanoma cells derive) are resistant to such noxious factors as ultraviolet light and reactive oxygen species. Targeted melanoma therapies are, so far, largely unsuccessful, and new ones, such as adjuvant inhibition of melanogenesis, are under development.
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Affiliation(s)
- Blazej Zbytek
- Department of Pathology and Laboratory Medicine, University of Tennessee Health Science Center, 930 Madison Avenue, Memphis, TN 38163, USA, Tel.: +1 901 448 6300, ,
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Oltean S, Bates DO. Hallmarks of alternative splicing in cancer. Oncogene 2013; 33:5311-8. [PMID: 24336324 DOI: 10.1038/onc.2013.533] [Citation(s) in RCA: 451] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Revised: 11/04/2013] [Accepted: 11/04/2013] [Indexed: 12/17/2022]
Abstract
The immense majority of genes are alternatively spliced and there are many isoforms specifically associated with cancer progression and metastasis. The splicing pattern of specific isoforms of numerous genes is altered as cells move through the oncogenic process of gaining proliferative capacity, acquiring angiogenic, invasive, antiapoptotic and survival properties, becoming free from growth factor dependence and growth suppression, altering their metabolism to cope with hypoxia, enabling them to acquire mechanisms of immune escape, and as they move through the epithelial-mesenchymal and mesenchymal-epithelial transitions and metastasis. Each of the 'hallmarks of cancer' is associated with a switch in splicing, towards a more aggressive invasive cancer phenotype. The choice of isoforms is regulated by several factors (signaling molecules, kinases, splicing factors) currently being identified systematically by a number of high-throughput, independent and unbiased methodologies. Splicing factors are de-regulated in cancer, and in some cases are themselves oncogenes or pseudo-oncogenes and can contribute to positive feedback loops driving cancer progression. Tumour progression may therefore be associated with a coordinated splicing control, meaning that there is the potential for a relatively small number of splice factors or their regulators to drive multiple oncogenic processes. The understanding of how splicing contributes to the various phenotypic traits acquired by tumours as they progress and metastasise, and in particular how alternative splicing is coordinated, can and is leading to the development of a new class of anticancer therapeutics-the alternative-splicing inhibitors.
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Affiliation(s)
- S Oltean
- School of Physiology and Pharmacology, University of Bristol, Bristol, UK
| | - D O Bates
- Division of Pre-clinical Oncology, School of Clinical Sciences, University of Nottingham, Queen's Medical Center, Nottingham, UK
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