251
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Chen L, Zhang R, Li P, Liu Y, Qin K, Fa ZQ, Liu YJ, Ke YQ, Jiang XD. P53-induced microRNA-107 inhibits proliferation of glioma cells and down-regulates the expression of CDK6 and Notch-2. Neurosci Lett 2012; 534:327-32. [PMID: 23220650 DOI: 10.1016/j.neulet.2012.11.047] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2012] [Revised: 11/22/2012] [Accepted: 11/28/2012] [Indexed: 11/18/2022]
Abstract
MicroRNAs (miRNAs) are small noncoding RNAs that function as tumor suppressors or oncogenes. MicroRNA-107 (miR-107), a transcriptional target of p53, is deregulated in many cancer cell lines. Here, we showed that miR-107 is down-regulated in glioma tissues and cell lines, in particular, p53-mutated U251 and A172. Transfection of wild-type p53 into these cells stimulated miR-107 expression. To investigate the role of miR-107 in tumorigenesis, we constructed a lentiviral vector overexpressing miR-107. Notably, miR-107 inhibited proliferation and arrested the cell cycle at the G0-G1 phase in glioma cells. Transduction of Lenti-GFP-miR-107 into glioma cells inhibited CDK6 and Notch-2 protein expression. Our findings collectively demonstrate that p53-induced miR-107 suppresses brain tumor cell growth and down-regulates CDK6 and Notch-2 expression, supporting its tumor suppressor role and utility as a target for glioma therapy.
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Affiliation(s)
- Lei Chen
- Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China
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252
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A microRNA component of the neoplastic microenvironment: microregulators with far-reaching impact. BIOMED RESEARCH INTERNATIONAL 2012; 2013:762183. [PMID: 23509776 PMCID: PMC3591172 DOI: 10.1155/2013/762183] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 07/27/2012] [Accepted: 08/11/2012] [Indexed: 02/08/2023]
Abstract
The interplay between tumor cells and their microenvironment plays a pivotal role in tumor development and progression. Although a growing body of evidence has established the importance of the tumor microenvironment, an understanding of the crosstalk between its components and cancer cells remains elusive. The pathways triggered by microenvironmental factors could modulate cancer-related gene transcription, also affecting small noncoding RNAs, microRNAs, which have emerged as key posttranscriptional regulators of gene expression, directly involved in human cancers. Although microRNAs regulate most biological mechanisms, their role in the tumor microenvironment has only recently become the focus of intense research. In this paper, we focus on the intertwined connection between the tumor microenvironment and aberrant expression of microRNAs involved in carcinogenesis. We also discuss the emerging roles of microRNAs in the tumor microenvironment as it relates to cancer progression. We conclude that microRNAs are critical for our understanding of the development of cancer, and that targeting microRNA signaling pathways in the microenvironment as well as in tumor cells opens new therapeutic avenues to the global control of cancer.
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253
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Sen CK, Roy S. OxymiRs in cutaneous development, wound repair and regeneration. Semin Cell Dev Biol 2012; 23:971-80. [PMID: 23063665 PMCID: PMC3762568 DOI: 10.1016/j.semcdb.2012.09.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 09/27/2012] [Indexed: 01/08/2023]
Abstract
The state of tissue oxygenation is widely recognized as a major microenvironmental cue that is known to regulate the expression of coding genes. Recent works have extended that knowledge to demonstrate that the state of tissue oxygenation may potently regulate the expression of microRNAs (miRs). Collectively, such miRs that are implicated in defining biological outcomes in response to a change in the state of tissue oxygenation may be referred to as oxymiRs. Broadly, oxymiRs may be categorized into three groups: (A) the existence (expression and/or turnover) of which is directly influenced by changes in the state of tissue oxygenation; (B) the existence of which is indirectly (e.g. oxygen-sensitive proteins, metabolites, pH, etc.) influenced by changes in the state of tissue oxygenation; and (C) those that modify biological outcomes to changes in the state of tissue oxygenation by targeting oxygen sensing pathways. This work represents the first review of how oxymiRs may regulate development, repair and regeneration. Currently known oxymiRs may affect the functioning of a large number of coding genes which have hitherto fore never been linked to oxygen sensing. Many of such target genes have been validated and that number is steadily growing. Taken together, our understanding of oxymiRs has vastly expanded the implications of changes in the state of tissue oxygenation. This emerging paradigm has major implications in untangling the complexities underlying diseases associated with ischemia and related hypoxic insult such as chronic wounds.
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Affiliation(s)
- Chandan K Sen
- Center for Regenerative Medicine and Cell-Based Therapies, Comprehensive Wound Center and Davis Heart and Lung Research Institute, The Ohio State University Medical Center, Columbus, OH 43210, USA.
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254
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Abstract
With the advent of next generation sequencing techniques a previously unknown world of non-coding RNA molecules have been discovered. Non-coding RNA transcripts likely outnumber the group of protein coding sequences and hold promise of many new discoveries and mechanistic explanations for essential biological phenomena and pathologies. The best characterized non-coding RNA family consists in humans of about 1400 microRNAs for which abundant evidence have demonstrated fundamental importance in normal development, differentiation, growth control and in human diseases such as cancer. In this review, we summarize the current knowledge and concepts concerning the involvement of microRNAs in cancer, which have emerged from the study of cell culture and animal model systems, including the regulation of key cancer-related pathways, such as cell cycle control and the DNA damage response. Importantly, microRNA molecules are already entering the clinic as diagnostic and prognostic biomarkers for patient stratification and also as therapeutic targets and agents.
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Affiliation(s)
- Martin D Jansson
- Biotech Research and Innovation Centre and Centre for Epigenetics, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
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255
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Bao B, Azmi AS, Ali S, Ahmad A, Li Y, Banerjee S, Kong D, Sarkar FH. The biological kinship of hypoxia with CSC and EMT and their relationship with deregulated expression of miRNAs and tumor aggressiveness. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1826:272-96. [PMID: 22579961 PMCID: PMC3788359 DOI: 10.1016/j.bbcan.2012.04.008] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 04/25/2012] [Accepted: 04/28/2012] [Indexed: 12/13/2022]
Abstract
Hypoxia is one of the fundamental biological phenomena that are intricately associated with the development and aggressiveness of a variety of solid tumors. Hypoxia-inducible factors (HIF) function as a master transcription factor, which regulates hypoxia responsive genes and has been recognized to play critical roles in tumor invasion, metastasis, and chemo-radiation resistance, and contributes to increased cell proliferation, survival, angiogenesis and metastasis. Therefore, tumor hypoxia with deregulated expression of HIF and its biological consequence lead to poor prognosis of patients diagnosed with solid tumors, resulting in higher mortality, suggesting that understanding of the molecular relationship of hypoxia with other cellular features of tumor aggressiveness would be invaluable for developing newer targeted therapy for solid tumors. It has been well recognized that cancer stem cells (CSCs) and epithelial-to-mesenchymal transition (EMT) phenotypic cells are associated with therapeutic resistance and contribute to aggressive tumor growth, invasion, metastasis and believed to be the cause of tumor recurrence. Interestingly, hypoxia and HIF signaling pathway are known to play an important role in the regulation and sustenance of CSCs and EMT phenotype. However, the molecular relationship between HIF signaling pathway with the biology of CSCs and EMT remains unclear although NF-κB, PI3K/Akt/mTOR, Notch, Wnt/β-catenin, and Hedgehog signaling pathways have been recognized as important regulators of CSCs and EMT. In this article, we will discuss the state of our knowledge on the role of HIF-hypoxia signaling pathway and its kinship with CSCs and EMT within the tumor microenvironment. We will also discuss the potential role of hypoxia-induced microRNAs (miRNAs) in tumor development and aggressiveness, and finally discuss the potential effects of nutraceuticals on the biology of CSCs and EMT in the context of tumor hypoxia.
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Affiliation(s)
- Bin Bao
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Asfar S. Azmi
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Shadan Ali
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Aamir Ahmad
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Yiwei Li
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Sanjeev Banerjee
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Dejuan Kong
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
| | - Fazlul H. Sarkar
- Department of Pathology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
- Department of Oncology, Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA
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256
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Chen L, Tweddle DA. p53, SKP2, and DKK3 as MYCN Target Genes and Their Potential Therapeutic Significance. Front Oncol 2012; 2:173. [PMID: 23226679 PMCID: PMC3508619 DOI: 10.3389/fonc.2012.00173] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 11/01/2012] [Indexed: 12/15/2022] Open
Abstract
Neuroblastoma is the most common extra-cranial solid tumor of childhood. Despite significant advances, it currently still remains one of the most difficult childhood cancers to cure, with less than 40% of patients with high-risk disease being long-term survivors. MYCN is a proto-oncogene implicated to be directly involved in neuroblastoma development. Amplification of MYCN is associated with rapid tumor progression and poor prognosis. Novel therapeutic strategies which can improve the survival rates whilst reducing the toxicity in these patients are therefore required. Here we discuss genes regulated by MYCN in neuroblastoma, with particular reference to p53, SKP2, and DKK3 and strategies that may be employed to target them.
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Affiliation(s)
- Lindi Chen
- Newcastle Cancer Centre, Northern Institute for Cancer Research, Newcastle University Newcastle, UK
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257
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Abstract
INTRODUCTION Angiogenesis, for its fundamental role in cancer growth and metastasis, has become an appealing target in cancer therapy. A number of angiogenesis-related microRNAs (miRNAs) are under investigation and they can affect the cancerous phenotype of malignant cells. AREAS COVERED The authors review the recent advances in angiogenesis-related miRNAs in human colon cancer. They also envisage future developments toward potential miRNA-based applications to cancer treatment. EXPERT OPINION Angiogenesis-related miRNAs may reasonably be considered as a valuable cancer therapeutic tool. More investigations should be performed to promote therapeutic-clinical research of miRNAs in patients with colon cancer.
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Affiliation(s)
- Liu Hong
- Fourth Military Medical University, Xijing Hospital of Digestive Diseases, State Key Laboratory of Cancer Biology, Shaanxi Province, China.
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258
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Huang YF, Yang CH, Huang CC, Hsu KS. Vascular endothelial growth factor-dependent spinogenesis underlies antidepressant-like effects of enriched environment. J Biol Chem 2012; 287:40938-55. [PMID: 23074224 DOI: 10.1074/jbc.m112.392076] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Current antidepressant treatments remain limited by poor efficacy and a slow onset of action. Increasing evidence demonstrates that enriched environment (EE) treatment can promote structural and behavioral plasticity in the brain and dampen stress-induced alterations of neuroplasticity. Here, we have examined whether short term exposure to EE is able to produce antidepressant-like effects. Our results show that housing adult mice in an EE cage for 7 days led to antidepressant-like behavioral profiles and a significant increase in the number of dendritic spines in hippocampal CA1 pyramidal neurons. These EE-induced antidepressant-like effects are primarily attributed to increased vascular endothelial growth factor (VEGF) expression through a hypoxia-inducible factor-1α (HIF-1α)-mediated transcriptional mechanism. Blockade of HIF-1α synthesis by lentiviral infection with HIF-1α small hairpin RNAs completely blocked the increase in expression of VEGF and the antidepressant-like effects induced by EE. Moreover, no significant antidepressant-like effects were observed with EE treatment in VEGF receptor 2 (Flk-1) knock-out mice. The increase in HIF-1α expression in the hippocampus induced by EE was associated with a decrease in endogenous levels of microRNA-107 (miR-107). Overexpression of miR-107 in the hippocampus completely blocked EE-induced HIF-1α expression and the antidepressant-like effects. These results support a model in which the down-regulation of miR-107, acting through HIF-1α, mediates VEGF-dependent spinogenesis to underlie the EE-induced antidepressant-like effects.
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Affiliation(s)
- Yu-Fei Huang
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan 701, Taiwan
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259
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Kim HW, Mallick F, Durrani S, Ashraf M, Jiang S, Haider KH. Concomitant activation of miR-107/PDCD10 and hypoxamir-210/Casp8ap2 and their role in cytoprotection during ischemic preconditioning of stem cells. Antioxid Redox Signal 2012; 17:1053-65. [PMID: 22482882 PMCID: PMC3423870 DOI: 10.1089/ars.2012.4518] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
AIMS To establish a functional link between microRNA-107 (miR-107) and stem cell survival during ischemic preconditioning (IPC) of stem cells with multiple cycles of brief anoxia/re-oxygenation (10 or 30 min, one to three cycles) and show that the cytoprotective effects were independent of hypoxamir-210. RESULTS We demonstrated the induction of miR-107 in response to the IPC-induced activation of Akt/hypoxia inducible factor-1α (HIF-1α) in preconditioned mesenchymal stem cells ((PC)MSC), which showed improved survival during subsequent exposure to 6 h of lethal anoxia (p<0.05 vs. non-preconditioned MSC[(non-PC)MSC]). In silico analysis and luciferase activity assay confirmed programmed cell death-10 (PDCD10) as a putative target of miR-107 in (PC)MSC, which was significantly reduced during IPC and inversely related to stem cell survival under 6 h of lethal anoxia. Loss-of-function studies with miR-107 antagomir showed a significantly reduced survival of (PC)MSC. A comparison of miR-107 and miR-210 showed that both miRs participated independently via their respective putative target genes Pdcd10 and Casp8ap2. The simultaneous abrogation of Pdcd10 and Casp8ap2 had a stronger effect on (PC)MSC survival under lethal anoxia. The transplantation of (PC)MSC in an acute model of myocardial infarction showed a significantly improved survival of transplanted (PC)MSC with concomitantly enhanced miR-107 expression in (PC)MSC-transplanted animal hearts. INNOVATION Cytoprotection afforded by IPC is regulated by miR-107 induction via Pdcd10 independent of miR-210/Casp8ap2 signaling, and the simultaneous abrogation miR-107/miR-210 has a stronger effect on the loss of (PC)MSC survival. CONCLUSION IPC enhances stem cell survival via the combined participation of hypoxia responsive miRs miR-107 and miR-210 via their respective putative target genes Pdcd10 and Casp8ap2.
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Affiliation(s)
- Ha Won Kim
- Department of Pathology, University of Cincinnati, Cincinnati, Ohio 45267, USA
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260
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Chan YC, Roy S, Huang Y, Khanna S, Sen CK. The microRNA miR-199a-5p down-regulation switches on wound angiogenesis by derepressing the v-ets erythroblastosis virus E26 oncogene homolog 1-matrix metalloproteinase-1 pathway. J Biol Chem 2012; 287:41032-43. [PMID: 23060436 DOI: 10.1074/jbc.m112.413294] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
miR-199a-5p plays a critical role in controlling cardiomyocyte survival. However, its significance in endothelial cell biology remains ambiguous. Here, we report the first evidence that miR-199a-5p negatively regulates angiogenic responses by directly targeting v-ets erythroblastosis virus E26 oncogene homolog 1 (Ets-1). Induction of miR-199a-5p in human dermal microvascular endothelial cells (HMECs) blocked angiogenic response in Matrigel® culture, whereas miR-199a-5p-deprived cells exhibited enhanced angiogenesis in vitro. Bioinformatics prediction and miR target reporter assay recognized Ets-1 as a novel direct target of miR-199a-5p. Delivery of miR-199a-5p blocked Ets-1 expression in HMECs, whereas knockdown endogenous miR-199a-5p induced Ets-1 expression. Matrix metalloproteinase 1 (MMP-1), one of the Ets-1 downstream mediators, was negatively regulated by miR-199a-5p. Overexpression of Ets-1 not only rescued miR-199a-5p-dependent anti-angiogenic effects but also reversed miR-199a-5p-induced loss of MMP-1 expression. Similarly, Ets-1 knockdown blunted angiogenic response and induction of MMP-1 in miR-199a-5p-deprived HMECs. Examination of cutaneous wound dermal tissue revealed a significant down-regulation of miR-199a-5p expression, which was associated with induction of Ets-1 and MMP-1. Mice carrying homozygous deletions in the Ets-1 gene exhibited blunted wound blood flow and reduced abundance of endothelial cells. Impaired wound angiogenesis was associated with compromised wound closure, insufficient granulation tissue formation, and blunted induction of MMP-1. Thus, down-regulation of miR-199a-5p is involved in the induction of wound angiogenesis through derepressing of the Ets-1-MMP1 pathway.
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Affiliation(s)
- Yuk Cheung Chan
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University Medical Center, Columbus, Ohio 43210, USA
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261
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Abstract
With the advent of next generation sequencing techniques a previously unknown world of non-coding RNA molecules have been discovered. Non-coding RNA transcripts likely outnumber the group of protein coding sequences and hold promise of many new discoveries and mechanistic explanations for essential biological phenomena and pathologies. The best characterized non-coding RNA family consists in humans of about 1400 microRNAs for which abundant evidence have demonstrated fundamental importance in normal development, differentiation, growth control and in human diseases such as cancer. In this review, we summarize the current knowledge and concepts concerning the involvement of microRNAs in cancer, which have emerged from the study of cell culture and animal model systems, including the regulation of key cancer-related pathways, such as cell cycle control and the DNA damage response. Importantly, microRNA molecules are already entering the clinic as diagnostic and prognostic biomarkers for patient stratification and also as therapeutic targets and agents.
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Affiliation(s)
- Martin D Jansson
- Biotech Research and Innovation Centre and Centre for Epigenetics, University of Copenhagen, Ole Maaløes Vej 5, DK-2200 Copenhagen, Denmark
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262
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De Lella Ezcurra AL, Bertolin AP, Melani M, Wappner P. Robustness of the hypoxic response: Another job for miRNAs? Dev Dyn 2012; 241:1842-8. [DOI: 10.1002/dvdy.23865] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2012] [Indexed: 12/22/2022] Open
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263
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Zheng J. Energy metabolism of cancer: Glycolysis versus oxidative phosphorylation (Review). Oncol Lett 2012; 4:1151-1157. [PMID: 23226794 DOI: 10.3892/ol.2012.928] [Citation(s) in RCA: 625] [Impact Index Per Article: 52.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 08/06/2012] [Indexed: 01/05/2023] Open
Abstract
Metabolic activities in normal cells rely primarily on mitochondrial oxidative phosphorylation (OXPHOS) to generate ATP for energy. Unlike in normal cells, glycolysis is enhanced and OXPHOS capacity is reduced in various cancer cells. It has long been believed that the glycolytic phenotype in cancer is due to a permanent impairment of mitochondrial OXPHOS, as proposed by Otto Warburg. This view is challenged by recent investigations which find that the function of mitochondrial OXPHOS in most cancers is intact. Aerobic glycolysis in many cancers is the combined result of various factors such as oncogenes, tumor suppressors, a hypoxic microenvironment, mtDNA mutations, genetic background and others. Understanding the features and complexity of the cancer energy metabolism will help to develop new approaches in early diagnosis and effectively target therapy of cancer.
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Affiliation(s)
- Jie Zheng
- Department of Pathology, School of Medicine, Southeast University, Nanjing, Jiangsu 210009, P.R. China
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264
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Trivellin G, Butz H, Delhove J, Igreja S, Chahal HS, Zivkovic V, McKay T, Patócs A, Grossman AB, Korbonits M. MicroRNA miR-107 is overexpressed in pituitary adenomas and inhibits the expression of aryl hydrocarbon receptor-interacting protein in vitro. Am J Physiol Endocrinol Metab 2012; 303:E708-19. [PMID: 22811466 DOI: 10.1152/ajpendo.00546.2011] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abnormal microRNA (miRNA) expression profiles have recently been associated with sporadic pituitary adenomas, suggesting that miRNAs can contribute to tumor formation; miRNAs are small noncoding RNAs that inhibit posttranscriptional expression of target mRNAs by binding to target sequences usually located in the 3'-UTR. In this study, we investigated the role played by miR-107, a miRNA associated with different human cancers, in sporadic pituitary adenomas and its interaction with the pituitary tumor suppressor gene aryl hydrocarbon receptor-interacting protein (AIP). miR-107 expression was evaluated in pituitary adenoma and normal pituitary samples using microRNA screen TLDA (TaqMan Low-Density Array) and RT-qPCR assays. We show that miR-107 expression was significantly upregulated in GH-secreting and nonfunctioning pituitary adenomas. We found that human AIP-3'-UTR is a target of miR-107 since miR-107 inhibited in vitro AIP expression to 53.9 ± 2% of the miRNA control in a luciferase assay and reduced endogenous AIP mRNA expression to 53 ± 22% of the miRNA control in human cells. However, we did not observe a negative correlation between AIP and miR-107 expression in the human tumor samples. Furthermore, we show that miR-107 overexpression inhibited cell proliferation in human neuroblastoma and rat pituitary adenoma cells. In conclusion, miR-107 is overexpressed in pituitary adenomas and may act as a tumor suppressor. We have identified and confirmed AIP as a miR-107 target gene. Expression data in human samples suggest that the expression of AIP and miR-107 could be influenced by a combination of tumorigenic factors as well as compensatory mechanisms stimulated by the tumorigenic process.
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Affiliation(s)
- Giampaolo Trivellin
- Dept. of Endocrinology, Barts & The London School of Medicine, Queen Mary University of London, London, UK EC1M 6BQ
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265
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Zhuang J, Ma W, Lago CU, Hwang PM. Metabolic regulation of oxygen and redox homeostasis by p53: lessons from evolutionary biology? Free Radic Biol Med 2012; 53:1279-85. [PMID: 22841759 PMCID: PMC3444283 DOI: 10.1016/j.freeradbiomed.2012.07.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2012] [Revised: 07/20/2012] [Accepted: 07/20/2012] [Indexed: 12/31/2022]
Abstract
The genetic links between p53 and metabolic processes such as oxidative phosphorylation are being studied with increasing interest given that cellular metabolism seems to play an important role in tumorigenesis. This review focuses on how p53 regulation of various metabolic genes may influence redox homeostasis, as the genome is constantly susceptible to oxidative damage, a consequence of living in an aerobic environment. Because p53-like genetic sequences are also found in life forms that may not necessarily benefit from tumor suppression, an evolutionary introduction is given in an attempt to understand why p53 might regulate a basic cellular activity such as metabolism. The presented epidemiologic and experimental data suggest that one reason may be for the homeostatic regulation of oxygen, the essential substrate for reactive oxygen species generation.
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Affiliation(s)
- Jie Zhuang
- Center for Molecular Medicine, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
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266
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Kasinski AL, Slack FJ. miRNA-34 prevents cancer initiation and progression in a therapeutically resistant K-ras and p53-induced mouse model of lung adenocarcinoma. Cancer Res 2012; 72:5576-87. [PMID: 22964582 DOI: 10.1158/0008-5472.can-12-2001] [Citation(s) in RCA: 201] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Lung cancer is the leading cause of cancer deaths worldwide, and current therapies fail to treat this disease in the vast majority of cases. The RAS and p53 pathways are two of the most frequently altered pathways in lung cancers, with such alterations resulting in loss of responsiveness to current therapies and decreased patient survival. The microRNA-34 (mir-34) gene family members are downstream transcriptional targets of p53, and miR-34 expression is reduced in p53 mutant tumors; thus, we hypothesized that treating mutant Kras;p53 tumors with miR-34 would represent a powerful new therapeutic to suppress lung tumorigenesis. To this end we examined the therapeutically resistant Kras(LSL-G12D)(/+);Trp53(LSL-R172H)(/+) mouse lung cancer model. We characterized tumor progression in these mice following lung-specific transgene activation and found tumors as early as 10 weeks postactivation, and severe lung inflammation by 22 weeks. Tumors harvested from these lungs have elevated levels of oncogenic miRNAs, miR-21 and miR-155; are deficient for p53-regulated miRNAs; and have heightened expression of miR-34 target genes, such as Met and Bcl-2. In the presence of exogenous miR-34, epithelial cells derived from these tumors show reduced proliferation and invasion. In vivo treatment with miR-34a prevented tumor formation and progression in Kras(LSL-G12D)(/+);Trp53(LSL-R172H)(/+) mice. Animals infected with mir-34a-expressing lentivirus at the same time as transgene activation had little to no evidence of tumorigenesis, and lentivirus-induced miR-34a also prevented further progression of preformed tumors. These data support the use of miR-34 as a lung tumor-preventative and tumor-static agent.
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Affiliation(s)
- Andrea L Kasinski
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA
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267
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Toffanin S, Sia D, Villanueva A. microRNAs: new ways to block tumor angiogenesis? J Hepatol 2012; 57:490-1. [PMID: 22691573 DOI: 10.1016/j.jhep.2012.06.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 06/04/2012] [Indexed: 12/04/2022]
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268
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Abstract
In recent years, microRNAs (miRNAs) have been identified as mediators of tumour suppression and stress responses exerted by the p53 tumour suppressor. p53-regulated miRNAs contribute to tumour suppression by controlling the expression of central components of multiple processes, including cell cycle progression, epithelial-mesenchymal transition, stemness, metabolism, cell survival and angiogenesis. The expression and activity of p53 itself is also under the control of miRNAs. Finally, genetic and epigenetic alterations identified in the p53-miRNA network indicate that these pathways are important for the initiation and progression of tumours. In the future, knowledge about the p53-miRNA network may be able to be exploited for diagnostic and therapeutic approaches in cancer prevention and treatment.
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Affiliation(s)
- Heiko Hermeking
- Experimental and Molecular Pathology, Institute of Pathology, Ludwig-Maximilians-Universität München, Thalkirchner Strasse 36, D-80337 Munich, Germany.
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269
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Ho JJD, Metcalf JL, Yan MS, Turgeon PJ, Wang JJ, Chalsev M, Petruzziello-Pellegrini TN, Tsui AKY, He JZ, Dhamko H, Man HSJ, Robb GB, Teh BT, Ohh M, Marsden PA. Functional importance of Dicer protein in the adaptive cellular response to hypoxia. J Biol Chem 2012; 287:29003-20. [PMID: 22745131 PMCID: PMC3436557 DOI: 10.1074/jbc.m112.373365] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 06/19/2012] [Indexed: 01/06/2023] Open
Abstract
The processes by which cells sense and respond to ambient oxygen concentration are fundamental to cell survival and function, and they commonly target gene regulatory events. To date, however, little is known about the link between the microRNA pathway and hypoxia signaling. Here, we show in vitro and in vivo that chronic hypoxia impairs Dicer (DICER1) expression and activity, resulting in global consequences on microRNA biogenesis. We show that von Hippel-Lindau-dependent down-regulation of Dicer is key to the expression and function of hypoxia-inducible factor α (HIF-α) subunits. Specifically, we show that EPAS1/HIF-2α is regulated by the Dicer-dependent microRNA miR-185, which is down-regulated by hypoxia. Full expression of hypoxia-responsive/HIF target genes in chronic hypoxia (e.g. VEGFA, FLT1/VEGFR1, KDR/VEGFR2, BNIP3L, and SLC2A1/GLUT1), the function of which is to regulate various adaptive responses to compromised oxygen availability, is also dependent on hypoxia-mediated down-regulation of Dicer function and changes in post-transcriptional gene regulation. Therefore, functional deficiency of Dicer in chronic hypoxia is relevant to both HIF-α isoforms and hypoxia-responsive/HIF target genes, especially in the vascular endothelium. These findings have relevance to emerging therapies given that we show that the efficacy of RNA interference under chronic hypoxia, but not normal oxygen availability, is Dicer-dependent. Collectively, these findings show that the down-regulation of Dicer under chronic hypoxia is an adaptive mechanism that serves to maintain the cellular hypoxic response through HIF-α- and microRNA-dependent mechanisms, thereby providing an essential mechanistic insight into the oxygen-dependent microRNA regulatory pathway.
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Affiliation(s)
- J. J. David Ho
- From the Departments of Medical Biophysics and
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Department of Medicine, University of Toronto, Toronto, Ontario M5B 1W8, Canada
| | | | - Matthew S. Yan
- From the Departments of Medical Biophysics and
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Department of Medicine, University of Toronto, Toronto, Ontario M5B 1W8, Canada
| | - Paul J. Turgeon
- Laboratory Medicine and Pathobiology and
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Department of Medicine, University of Toronto, Toronto, Ontario M5B 1W8, Canada
| | - Jenny Jing Wang
- Laboratory Medicine and Pathobiology and
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Department of Medicine, University of Toronto, Toronto, Ontario M5B 1W8, Canada
| | - Maria Chalsev
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Department of Medicine, University of Toronto, Toronto, Ontario M5B 1W8, Canada
| | - Tania N. Petruzziello-Pellegrini
- Laboratory Medicine and Pathobiology and
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Department of Medicine, University of Toronto, Toronto, Ontario M5B 1W8, Canada
| | - Albert K. Y. Tsui
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Department of Medicine, University of Toronto, Toronto, Ontario M5B 1W8, Canada
| | - Jeff Z. He
- Laboratory Medicine and Pathobiology and
| | - Helena Dhamko
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Department of Medicine, University of Toronto, Toronto, Ontario M5B 1W8, Canada
| | - H. S. Jeffrey Man
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Department of Medicine, University of Toronto, Toronto, Ontario M5B 1W8, Canada
| | - G. Brett Robb
- Division of RNA Biology, New England Biolabs, Ipswich, Massachusetts 01938-2723, and
| | - Bin T. Teh
- Van Andel Research Institute, Grand Rapids, Michigan 49503
| | | | - Philip A. Marsden
- From the Departments of Medical Biophysics and
- Laboratory Medicine and Pathobiology and
- Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Department of Medicine, University of Toronto, Toronto, Ontario M5B 1W8, Canada
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270
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miRNAs as potential therapeutic targets for age-related macular degeneration. Future Med Chem 2012; 4:277-87. [PMID: 22393936 DOI: 10.4155/fmc.11.176] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Since their recent discovery, miRNAs have been shown to play critical roles in a variety of pathophysiological processes. Such processes include pathological angiogenesis, the oxidative stress response, immune response and inflammation, all of which have been shown to have important and interdependent roles in the pathogenesis and progression of age-related macular degeneration (AMD). Here we present a brief review of the pathological processes involved in AMD and review miRNAs and other noncoding RNAs involved in regulating these processes. Specifically, we discuss several candidate miRNAs that show promise as AMD therapeutic targets due to their direct involvement in choroidal neovascularization or retinal pigment epithelium atrophy. We discuss potential miRNA-based therapeutics and delivery methods for AMD and provide future directions for the field of miRNA research with respect to AMD. We believe the future of miRNAs in AMD therapy is promising.
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271
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Meng S, Cao J, Wang L, Zhou Q, Li Y, Shen C, Zhang X, Wang C. MicroRNA 107 partly inhibits endothelial progenitor cells differentiation via HIF-1β. PLoS One 2012; 7:e40323. [PMID: 22792280 PMCID: PMC3391260 DOI: 10.1371/journal.pone.0040323] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 06/04/2012] [Indexed: 11/26/2022] Open
Abstract
Endothelial progenitor cells (EPCs) play an important role in tissue repair after ischemic heart disease. In particular, the recovery of endothelial function is reliant on the ability and rate of EPCs differentiate into mature endothelial cells. The present study evaluated the effect of microRNA 107 (miR-107) on the mechanism of EPCs differentiation. EPCs were isolated from rats' bone marrow and miR-107 expression of EPCs in hypoxic and normoxic conditions were measured by real-time qualitative PCR. CD31 was analyzed by flow cytometry and eNOS was examined by real-time qualitative PCR and western blotting and these were used as markers of EPC differentiation. In order to reveal the mechanism, we used miR107 inhibitor and lentiviral vector expressing a short hairpin RNA (shRNA) that targets miR-107 and hypoxia-inducible factor-1 β (HIF-1β) to alter miR107 and HIF-1β expression. MiR-107 expression were increased in EPCs under hypoxic conditions. Up-regulation of miR-107 partly suppressed the EPCs differentiation induced in hypoxia, while down-regulation of miR-107 promoted EPC differentiation. HIF-1β was the target. This study indicated that miR-107 was up-regulated in hypoxia to prevent EPCs differentiation via its target HIF-1β. The physiological mechanisms of miR-107 must be evaluated if it is to be used as a potential anti-ischemia therapeutic regime.
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Affiliation(s)
- Shu Meng
- Department of Cardiology, School of Medicine, Shanghai Jiao-tong University, Xin-hua Hospital, Shanghai, China
| | - JiaTian Cao
- Department of Cardiology, School of Medicine, Shanghai Jiao-tong University, No. 9 People's Hospital, Shanghai, China
| | - LianSheng Wang
- Department of Laboratory Medicine, School of Medicine, Shanghai Jiao-tong University, No.9 People's Hospital, Shanghai, China
| | - Qing Zhou
- Department of Cardiology, School of Medicine, Shanghai Jiao-tong University, Xin-hua Hospital, Shanghai, China
| | - YiGang Li
- Department of Cardiology, School of Medicine, Shanghai Jiao-tong University, Xin-hua Hospital, Shanghai, China
| | - ChengXing Shen
- Department of Cardiology, School of Medicine, Shanghai Jiao-tong University, Xin-hua Hospital, Shanghai, China
| | - XiaoPing Zhang
- Department of Nuclear Medicine, School of Medicine, Tongji University, Shanghai 10th People's Hospital, Shangha, China
| | - ChangQian Wang
- Department of Cardiology, School of Medicine, Shanghai Jiao-tong University, No. 9 People's Hospital, Shanghai, China
- * E-mail:
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272
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Lin CP, Choi YJ, Hicks GG, He L. The emerging functions of the p53-miRNA network in stem cell biology. Cell Cycle 2012; 11:2063-72. [PMID: 22580472 DOI: 10.4161/cc.20207] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The p53 pathway plays an essential role in tumor suppression, regulating multiple cellular processes coordinately to maintain genome integrity in both somatic cells and stem cells. Despite decades of research dedicated to p53 function in differentiated somatic cells, we are just starting to understand the complexity of the p53 pathway in the biology of pluripotent stem cells and tissue stem cells. Recent studies have demonstrated that p53 suppresses proliferation, promotes differentiation of embryonic stem (ES) cells and constitutes an important barrier to somatic reprogramming. In addition, emerging evidence reveals the role of the p53 network in the self-renewal, proliferation and genomic integrity of adult stem cells. Interestingly, non-coding RNAs, and microRNAs in particular, are integral components of the p53 network, regulating multiple p53-controlled biological processes to modulate the self-renewal and differentiation potential of a variety of stem cells. Thus, elucidation of the p53-miRNA axis in stem cell biology may generate profound insights into the mechanistic overlap between malignant transformation and stem cell biology.
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Affiliation(s)
- Chao-Po Lin
- Division of Cellular and Developmental Biology, Molecular and Cell Biology Department, University of California at Berkeley, Berkeley, CA, USA
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273
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Jones M, Lal A. MicroRNAs, wild-type and mutant p53: more questions than answers. RNA Biol 2012; 9:781-91. [PMID: 22664917 DOI: 10.4161/rna.20146] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The tumor suppressor p53 is a sequence-specific transcription factor that activates the expression of genes involved in apoptosis, cell cycle arrest and senescence. p53 can also inhibit gene expression and this effect is partly mediated by inducing several microRNAs (miRNAs). MiRNAs have emerged as a new class of regulators of the expression and function of eukaryotic genomes. Tumor suppressive or oncogenic functions have been attributed to some miRNAs. Recent studies have shown that p53 can alter the transcription of several miRNAs, and in some cases, it can also influence miRNA maturation. Conversely, miRNAs can also modulate the abundance and activity of p53 by direct or indirect mechanisms. Moreover, mutant p53 can actively repress the expression of some miRNAs that are activated by wild-type p53. In this review, we discuss recent evidences of this crosstalk between miRNAs and the p53 network and also highlight its implications in cancer.
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Affiliation(s)
- Matthew Jones
- Genetics Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
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274
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Zou C, Xu Q, Mao F, Li D, Bian C, Liu LZ, Jiang Y, Chen X, Qi Y, Zhang X, Wang X, Sun Q, Kung HF, Lin MC, Dress A, Wardle F, Jiang BH, Lai L. MiR-145 inhibits tumor angiogenesis and growth by N-RAS and VEGF. Cell Cycle 2012; 11:2137-45. [PMID: 22592534 DOI: 10.4161/cc.20598] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
MiR-145 is known as a tumor suppressor in numerous human cancers. However, its role in tumor angiogenesis remains poorly defined. In this study, we found that miR-145 was significantly downregulated in breast cancer tissues by using 106 cases of normal and cancer tissues as well as in breast cancer cells. MiR-145 exhibited inhibitory role in tumor angiogenesis, cell growth and invasion and tumor growth through the post-transcriptional regulation of the novel targets N-RAS and VEGF-A. In addition, we provide evidence that the expression levels of miR-145 correlate inversely with malignancy stages of breast tumors, although there is no association between miR-145 levels and hormone receptor levels in breast cancer. Taken together, these results demonstrate that miR-145 plays important inhibitory role in breast cancer malignancy by targeting N-RAS and VEGF-A, which may be potential therapeutic and diagnostic targets.
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Affiliation(s)
- Chao Zou
- Institute of Molecular and Chemical Biology, East China Normal University, Shanghai, China
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275
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Augustin R, Endres K, Reinhardt S, Kuhn PH, Lichtenthaler SF, Hansen J, Wurst W, Trümbach D. Computational identification and experimental validation of microRNAs binding to the Alzheimer-related gene ADAM10. BMC MEDICAL GENETICS 2012; 13:35. [PMID: 22594617 PMCID: PMC3459808 DOI: 10.1186/1471-2350-13-35] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 04/19/2012] [Indexed: 11/26/2022]
Abstract
Background MicroRNAs (miRNAs) are post-transcriptional regulators involved in numerous biological processes including the pathogenesis of Alzheimer’s disease (AD). A key gene of AD, ADAM10, controls the proteolytic processing of APP and the formation of the amyloid plaques and is known to be regulated by miRNA in hepatic cancer cell lines. To predict miRNAs regulating ADAM10 expression concerning AD, we developed a computational approach. Methods MiRNA binding sites in the human ADAM10 3' untranslated region were predicted using the RNA22, RNAhybrid and miRanda programs and ranked by specific selection criteria with respect to AD such as differential regulation in AD patients and tissue-specific expression. Furthermore, target genes of miR-103, miR-107 and miR-1306 were derived from six publicly available miRNA target site prediction databases. Only target genes predicted in at least four out of six databases in the case of miR-103 and miR-107 were compared to genes listed in the AlzGene database including genes possibly involved in AD. In addition, the target genes were used for Gene Ontology analysis and literature mining. Finally, we used a luciferase assay to verify the potential effect of these three miRNAs on ADAM10 3'UTR in SH-SY5Y cells. Results Eleven miRNAs were selected, which have evolutionary conserved binding sites. Three of them (miR-103, miR-107, miR-1306) were further analysed as they are linked to AD and most strictly conserved between different species. Predicted target genes of miR-103 (p-value = 0.0065) and miR-107 (p-value = 0.0009) showed significant overlap with the AlzGene database except for miR-1306. Interactions between miR-103 and miR-107 to genes were revealed playing a role in processes leading to AD. ADAM10 expression in the reporter assay was reduced by miR-1306 (28%), miR-103 (45%) and miR-107 (52%). Conclusions Our approach shows the requirement of incorporating specific, disease-associated selection criteria into the prediction process to reduce the amount of false positive predictions. In summary, our method identified three miRNAs strongly suggested to be involved in AD, which possibly regulate ADAM10 expression and hence offer possibilities for the development of therapeutic treatments of AD.
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Affiliation(s)
- Regina Augustin
- Helmholtz Centre Munich, German Research Centre for Environmental Health (GmbH) and Technical University Munich, Institute of Developmental Genetics, Ingolstädter Landstraße, 1, 85764, Munich-Neuherberg, Germany
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276
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Abstract
Advances in understanding the biology of tumour progression and metastasis have clearly highlighted the importance of aberrant tumour metabolism, which supports not only the energy requirements but also the enormous biosynthetic needs of tumour cells. Such metabolic alterations modulate glucose, amino acid and fatty-acid-dependent metabolite biosynthesis and energy production. Although much progress has been made in understanding the somatic mutations and expression genomics behind these alterations, the regulation of these processes by microRNAs (miRNAs) is only just beginning to be appreciated. This Review focuses on the miRNAs that are potential regulators of the expression of genes whose protein products either directly regulate metabolic machinery or serve as master regulators, indirectly modulating the expression of metabolic enzymes. We focus particularly on miRNAs in pancreatic cancer.
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277
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Lipid-based nanoparticle delivery of Pre-miR-107 inhibits the tumorigenicity of head and neck squamous cell carcinoma. Mol Ther 2012; 20:1261-9. [PMID: 22491216 DOI: 10.1038/mt.2012.67] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer worldwide with about 600,000 new cases diagnosed in the last year. Our laboratory showed that miR-107 expression is reduced and functions as a tumor suppressor gene in HNSCC suggesting the potential application of miR-107 as a novel anticancer therapeutic. In this study, we determined the efficiency and efficacy of cationic lipid nanoparticles to deliver pre-miR-107 (NP/pre-miR-107) in HNSCC cells in vitro and in vivo. NP/pre-miR-107 increased delivery of miR-107 into HNSCC cells by greater than 80,000-fold compared to free pre-miR-107. Levels of known miR-107 targets, protein kinase Cε (PKCε), cyclin-dependent kinase 6 (CDK6), and hypoxia-inducible factor 1-β (HIF1-β), decreased following NP/pre-miR-107 treatment. Clonogenic survival, cell invasion, and cell migration of HNSCC cells was inhibited with NP/pre-miR-107. Moreover, NP/pre-miR-107 reduced the cancer-initiating cell (CIC) population and dampened the expression of the core embryonic stem cell transcription factors, Nanog, Oct3/4, and Sox2. In a preclinical mouse model of HNSCC, systemic administration of NP/pre-miR-107 significantly retarded tumor growth by 45.2% compared to NP/pre-miR-control (P < 0.005, n = 7). Kaplan-Meier analysis showed a survival advantage for the NP/pre-miR-107 treatment group (P = 0.017). Our results demonstrate that cationic lipid nanoparticles are an effective carrier approach to deliver therapeutic miRs to HNSCC.
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278
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Collet G, Skrzypek K, Grillon C, Matejuk A, El Hafni-Rahbi B, Lamerant-Fayel N, Kieda C. Hypoxia control to normalize pathologic angiogenesis: potential role for endothelial precursor cells and miRNAs regulation. Vascul Pharmacol 2012; 56:252-61. [PMID: 22446152 DOI: 10.1016/j.vph.2012.03.001] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Revised: 02/18/2012] [Accepted: 03/02/2012] [Indexed: 01/12/2023]
Abstract
Tumor microenvironment is a complex and highly dynamic milieu that provides very important clues on tumor development and progression mechanisms. Tumor-associated endothelial cells play a key role in stroma organization. They achieve tumor angiogenesis, a formation of tumor-associated (angiogenic) vessels mainly through sprouting from locally preexisting vessels and/or recruitment of bone marrow-derived endothelial progenitor cells. This process participates to supply nutritional support and oxygen to the growing tumor. Endothelial cells constitute the interface between circulating blood cells, tumor cells and the extracellular matrix, thereby controlling leukocyte recruitment, tumor cell behavior and metastasis formation. Hypoxia, a critical parameter of the tumor microenvironment, controls endothelial/tumor cell interactions and is the key to tumor angiogenesis development. Under hypoxic stress, tumor cells produce factors that promote angiogenesis, vasculogenesis, tumor cell motility, metastasis and cancer stem cell selection. Targeting tumor vessels is a therapeutic strategy that has lately been fast evolving from antiangiogenesis to vessel normalization as discussed in this review. We shall focus on the pivotal role of endothelial cells within the tumor microenvironment, the specific features and the part played by circulating endothelial precursors cells. Attention is stressed on their recruitment to the tumor site and their role in tumor angiogenesis where they are submitted to miRNAs-mediated de/regulation. Here the compensation of the tumor deregulated angiogenic miRNAs - angiomiRs - is emphasized as a potential therapeutic approach. The strategy is to over express anti-angiomiRs in the tumor angiogenesis site upon selective delivery by precursor endothelial cells as miRs carriers.
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Affiliation(s)
- Guillaume Collet
- Centre de Biophysique Moléculaire, CNRS UPR 4301, rue Charles Sadron, 45071 Orleans, France
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279
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microRNA-125b inhibits tube formation of blood vessels through translational suppression of VE-cadherin. Oncogene 2012; 32:414-21. [PMID: 22391569 DOI: 10.1038/onc.2012.68] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Angiogenesis is controlled positively or negatively by extrinsic and intrinsic molecular cues in endothelial cells (ECs); in the tumor microenvironment, the action of positive regulators exceeds that of negative regulators. Thus, overinduction of negative regulators may inhibit tumor angiogenesis. MicroRNAs (miRNAs or miRs) are endogenous short noncoding RNAs regulating gene expression either through translational inhibition or destabilization of target mRNA. Here, we show that miR-125b expression is transiently induced in ECs on stimulation with vascular endothelial growth factor or by ischemia. miR-125b inhibits translation of vascular endothelial (VE)-cadherin mRNA and in vitro tube formation by ECs. Injection of miR-125b into the tumor inhibited VE-cadherin expression by ECs and induced nonfunctional blood vessel formation, resulting in inhibition of tumor growth. It has been suggested that pro-angiogenic signals in ECs also upregulate anti-angiogenic molecules simultaneously via negative feedback. Because miR-125b induction in ECs is transient after pro-angiogenic stimulation, prolonged overexpression of miR-125b could result in blood vessel regression. Thus, miR-125b may be useful in cancer therapy by causing the collapse of the lumen of ECs.
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280
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Oda Y, Nakajima M, Mohri T, Takamiya M, Aoki Y, Fukami T, Yokoi T. Aryl hydrocarbon receptor nuclear translocator in human liver is regulated by miR-24. Toxicol Appl Pharmacol 2012; 260:222-31. [PMID: 22387692 DOI: 10.1016/j.taap.2012.02.012] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Revised: 02/14/2012] [Accepted: 02/15/2012] [Indexed: 11/26/2022]
Abstract
Aryl hydrocarbon receptor nuclear translocator (ARNT) forms a heterodimer with aryl hydrocarbon receptor or hypoxia inducible factor 1α to mediate biological responses to xenobiotic exposure and hypoxia. Although the regulation mechanism of the ARNT expression is largely unknown, earlier studies reported that the human ARNT protein level was decreased by hydrogen peroxide or reactive oxygen species. These stimuli increase the miR-24 level in various human cell lines. In silico analysis predicts that some microRNAs including miR-16 and miR-23b may bind to ARNT mRNA. This background prompted us to investigate whether human ARNT is regulated by microRNAs. Overexpression of miR-24 into HuH-7 and HepG2 cells significantly decreased the ARNT protein level, but not the ARNT mRNA level, indicating translational repression. However, overexpression of miR-16 or miR-23b caused no change in the ARNT expression. The miR-24-dependent down-regulation of ARNT decreased the expression of its downstream genes such as CYP1A1 and carbonic anhydrase IX. Luciferase assay was performed to determine the element on the ARNT mRNA to which miR-24 binds. Finally, it was demonstrated that the miR-24 levels in a panel of 26 human livers were inversely correlated with the protein levels or the translational efficiency of ARNT. Taken together, we found that miR-24 negatively regulates ARNT expression in human liver, affecting the expression of its downstream genes. miR-24 would be one of the factors underlying the mechanisms by which ARNT protein is decreased by reactive oxygen species.
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Affiliation(s)
- Yuki Oda
- Drug Metabolism and Toxicology, Division of Pharmaceutical Sciences, Graduate School of Medical Science, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
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281
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Chuang CH, Yang D, Bai G, Freeland A, Pruitt SC, Schimenti JC. Post-transcriptional homeostasis and regulation of MCM2-7 in mammalian cells. Nucleic Acids Res 2012; 40:4914-24. [PMID: 22362746 PMCID: PMC3367205 DOI: 10.1093/nar/gks176] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The MiniChromosome Maintenance 2-7 (MCM2-7) complex provides essential replicative helicase function. Insufficient MCMs impair the cell cycle and cause genomic instability (GIN), leading to cancer and developmental defects in mice. Remarkably, depletion or mutation of one Mcm can decrease all Mcm levels. Here, we use mice and cells bearing a GIN-causing hypomophic allele of Mcm4 (Chaos3), in conjunction with disruption alleles of other Mcms, to reveal two new mechanisms that regulate MCM protein levels and pre-RC formation. First, the Mcm4Chaos3 allele, which disrupts MCM4:MCM6 interaction, triggers a Dicer1 and Drosha-dependent ∼40% reduction in Mcm2–7 mRNAs. The decreases in Mcm mRNAs coincide with up-regulation of the miR-34 family of microRNAs, which is known to be Trp53-regulated and target Mcms. Second, MCM3 acts as a negative regulator of the MCM2–7 helicase in vivo by complexing with MCM5 in a manner dependent upon a nuclear-export signal-like domain, blocking the recruitment of MCMs onto chromatin. Therefore, the stoichiometry of MCM components and their localization is controlled post-transcriptionally at both the mRNA and protein levels. Alterations to these pathways cause significant defects in cell growth reflected by disease phenotypes in mice.
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Affiliation(s)
- Chen-Hua Chuang
- Department of Biomedical Sciences and Center for Vertebrate Genomics, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
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282
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Loboda A, Jozkowicz A, Dulak J. HIF-1 versus HIF-2--is one more important than the other? Vascul Pharmacol 2012; 56:245-51. [PMID: 22366374 DOI: 10.1016/j.vph.2012.02.006] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Revised: 02/10/2012] [Accepted: 02/11/2012] [Indexed: 01/16/2023]
Abstract
Hypoxia is a state where oxygen availability/delivery is below the level necessary to maintain physiological oxygen tension for a particular tissue. It is well-established that when tissue demand exceeds its oxygen supply, a cascade of intracellular events is activated, with the elevation of the expression of hypoxia-inducible factors (HIFs). As a consequence, the extensive transcriptional response regulating angiogenesis, glucose metabolism, cell growth, metastasis and others processes is induced. The discovery of differences between HIF isoforms has provided new insights into HIFs biology. Importantly, the opposite effects can be exerted by HIF-1 and HIF-2 on the regulation of angiogenic response. Although both isoforms may upregulate the expression of pro-angiogenic vascular endothelial growth factor (VEGF), HIF-1 diminished the expression of interleukin-8 (IL-8) by inhibition of the Nrf2 transcription factor whereas HIF-2 augmented expression of IL-8 in an Nrf2-independent way but via upregulation of SP-1 activity. Moreover, the opposite regulation of c-Myc transcription factor by both HIF isoforms may influence IL-8 regulation. Complexity of effects exerted by both HIF isoforms resulting from the cooperation with other transcription factors should be subjected to intensive investigation especially in the context of pro-and anti-angiogenic therapies.
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Affiliation(s)
- Agnieszka Loboda
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland.
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283
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Abstract
The discovery of microRNAs (miRNAs) almost two decades ago established a new paradigm of gene regulation. During the past ten years these tiny non-coding RNAs have been linked to virtually all known physiological and pathological processes, including cancer. In the same way as certain key protein-coding genes, miRNAs can be deregulated in cancer, in which they can function as a group to mark differentiation states or individually as bona fide oncogenes or tumour suppressors. Importantly, miRNA biology can be harnessed experimentally to investigate cancer phenotypes or used therapeutically as a target for drugs or as the drug itself.
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284
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Abstract
The discovery of microRNAs (miRNAs) almost two decades ago established a new paradigm of gene regulation. During the past ten years these tiny non-coding RNAs have been linked to virtually all known physiological and pathological processes, including cancer. In the same way as certain key protein-coding genes, miRNAs can be deregulated in cancer, in which they can function as a group to mark differentiation states or individually as bona fide oncogenes or tumour suppressors. Importantly, miRNA biology can be harnessed experimentally to investigate cancer phenotypes or used therapeutically as a target for drugs or as the drug itself.
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Affiliation(s)
- Amaia Lujambio
- Cancer Biology and Genetics Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, New York 10065, USA
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285
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Rodríguez-Jiménez FJ, Moreno-Manzano V. Modulation of hypoxia-inducible factors (HIF) from an integrative pharmacological perspective. Cell Mol Life Sci 2012; 69:519-34. [PMID: 21984597 PMCID: PMC11115032 DOI: 10.1007/s00018-011-0813-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 08/17/2011] [Accepted: 09/01/2011] [Indexed: 12/11/2022]
Abstract
Oxygen homeostasis determines the activity and expression of a multitude of cellular proteins and the interplay of pathways that affect crucial cellular processes for development, physiology, and pathophysiology. Hypoxia-inducible factors (HIFs) are transcription factors that respond to changes in available oxygen in the cellular environment and drives cellular adaptation to such conditions. Selective gene expression under hypoxic conditions is the result of an exquisite regulation of HIF, from the pre-transcriptional stage of the HIF gene to the final transcriptional activity of HIF protein. We provide a dissected analysis of HIF modulation with special focus on hypoxic conditions and HIF pharmacological interventions that can guide the application of any future HIF-mediated therapy.
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286
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Kuschel A, Simon P, Tug S. Functional regulation of HIF-1α under normoxia--is there more than post-translational regulation? J Cell Physiol 2012; 227:514-24. [PMID: 21503885 DOI: 10.1002/jcp.22798] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The hypoxia-inducible factor-1 (HIF-1) is an oxygen-regulated transcriptional activator playing a pivotal role in mammalian physiology and disease pathogenesis, e.g., HIF-1 is indispensable in a broad range of developmental stages in different tumors. Its post-translational regulation via PHDs under the influence of hypoxia is widely investigated and accepted. Different non-hypoxic stimuli such as lipopolysaccharides (LPS), thrombin, and angiotensin II (Ang II), have been proven to enhance HIF-1 levels through activation of regulative mechanisms distinct from protein stabilization. Some of these stimuli specifically regulate HIF-1α at the transcriptional, post-transcriptional, or translational level, whereas others additionally influence post-translational modifications. Thus, it is difficult for the investigators to discern the impact of the different mechanisms leading to functional HIF-1 protein. Nevertheless, profound knowledge of additional regulatory networks appears to depict new therapeutic opportunities and thus is an interesting and important field for further investigations.
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Affiliation(s)
- A Kuschel
- Department of Sports Medicine, Rehabilitation and Disease Prevention, Johannes-Gutenberg-University Mainz, Germany
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287
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Li X, Zhang Y, Shi Y, Dong G, Liang J, Han Y, Wang X, Zhao Q, Ding J, Wu K, Fan D. MicroRNA-107, an oncogene microRNA that regulates tumour invasion and metastasis by targeting DICER1 in gastric cancer. J Cell Mol Med 2012; 15:1887-95. [PMID: 21029372 PMCID: PMC3918045 DOI: 10.1111/j.1582-4934.2010.01194.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
MicroRNAs are small non-coding RNA molecules that control expression of target genes. Previous studies showed that microRNA-107 (miR-107) is overexpressed in gastric cancer tissues compared with the matched normal tissues. However, it remains largely unclear as to how miR-107 exerts its function and modulates the malignant phenotypes of gastric cancer, because our understanding of miR-107 signalling pathways is limited. In this study, we demonstrate that miR-107 is frequently up-regulated in gastric cancers and its overexpression is significantly associated with gastric cancer metastasis. Furthermore, silencing the expression of miR-107 could inhibit gastric cancer cell migration and invasion in vitro and in vivo. Subsequent investigation characterized DICER1 as a direct target of miR-107. Up-regulation of DICER1 resulted in a dramatic reduction of in vitro migration, invasion, in vivo liver metastasis of nude mice, which is similar to that occurs with the silencing of miR-107, indicating that DICER1 functions as a metastasis suppressor in gastric cancer. Furthermore, the restoration of DICER1 can inhibit miR-107-induced gastric cancer cell invasion and metastasis. In conclusion, our results suggested that miR-107, an oncogene miRNA promoting gastric cancer metastasis through down-regulation of DICER1. Inhibition of miR-107 or restoration of DICER1 may represent a new potential therapeutic target for gastric cancer treatment.
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Affiliation(s)
- Xiaohua Li
- State Key Laboratory of Cancer Biology & Xijing Hospital of Digestive Diseases, The Fourth Military Medical University, Xi'an, China
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288
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microRNA-107 functions as a candidate tumor-suppressor gene in head and neck squamous cell carcinoma by downregulation of protein kinase Cɛ. Oncogene 2011; 31:4045-53. [PMID: 22158047 PMCID: PMC3307861 DOI: 10.1038/onc.2011.565] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer worldwide with about 600,000 new cases diagnosed each year. Understanding the molecular pathways that lead to HNSCC is crucial to identify new targets for anti-cancer drug development. Protein kinase Cε (PKCε) is elevated in HNSCC and regulates the activation of Akt, Stat3, and Rho GTPases. To date, the molecular mechanism of PKCε dysregulation in HNSCC remains to be elucidated. In silico analysis identified three putative microRNA-107 (miR-107) binding sites in the 3'-untranslated region (UTR) of PKCε. An inverse relationship was revealed between miR-107 and PKCε in HNSCC cell lines. Delivery of miR-107 reduced PKCε levels in SCC15, SCC25, and CAL27, three HNSCC cell lines with high PKCε and low miR-107. The activity of a luciferase reporter construct containing the 3'-UTR of PKCε was down-regulated by miR-107 and mutations in the three cognate miR-107 binding sites completely ablated the regulation by miR-107. Treatment with miR-107 significantly blocked cell proliferation, DNA replication, colony formation, and invasion in SCC25 and CAL27 cells. Ectopic expression of miR-resistant PKCε was sufficient to partially rescue the loss-of-function phenotype in miR-107-overexpressing SCC25 cells. Tumor growth in nude mice was retarded by 93 ± 7% in CAL27/miR-107 cells compared to CAL27/miR-control cells. Lastly, human primary HNSCC tumors with elevated PKCε had reduced miR-107 expression. Our results demonstrate that PKCε is directly regulated by miR-107 and moreover, suggest that miR-107 may be a potential anti-cancer therapeutic for HNSCC.
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289
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Barsotti AM, Beckerman R, Laptenko O, Huppi K, Caplen NJ, Prives C. p53-Dependent induction of PVT1 and miR-1204. J Biol Chem 2011; 287:2509-19. [PMID: 22110125 DOI: 10.1074/jbc.m111.322875] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
p53 is a tumor suppressor protein that acts as a transcription factor to regulate (either positively or negatively) a plethora of downstream target genes. Although its ability to induce protein coding genes is well documented, recent studies have implicated p53 in the regulation of non-coding RNAs, including both microRNAs (e.g. miR-34a) and long non-coding RNAs (e.g. lincRNA-p21). We have identified the non-protein coding locus PVT1 as a p53-inducible target gene. PVT1, a very large (>300 kb) locus located downstream of c-myc on chromosome 8q24, produces a wide variety of spliced non-coding RNAs as well as a cluster of six annotated microRNAs: miR-1204, miR-1205, miR-1206, miR-1207-5p, miR-1207-3p, and miR-1208. Chromatin immunoprecipitation (ChIP), electrophoretic mobility shift assay (EMSA), and luciferase assays reveal that p53 binds and activates a canonical response element within the vicinity of miR-1204. Consistently, we demonstrate the p53-dependent induction of endogenous PVT1 transcripts and consequent up-regulation of mature miR-1204. Finally, we have shown that ectopic expression of miR-1204 leads to increased p53 levels and causes cell death in a partially p53-dependent manner.
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Affiliation(s)
- Anthony M Barsotti
- Department of Biological Sciences, Columbia University, New York, New York 10027, USA
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290
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Weis SM, Cheresh DA. Tumor angiogenesis: molecular pathways and therapeutic targets. Nat Med 2011; 17:1359-70. [PMID: 22064426 DOI: 10.1038/nm.2537] [Citation(s) in RCA: 1269] [Impact Index Per Article: 97.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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291
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Caporali A, Emanueli C. MicroRNA regulation in angiogenesis. Vascul Pharmacol 2011; 55:79-86. [DOI: 10.1016/j.vph.2011.06.006] [Citation(s) in RCA: 134] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 06/25/2011] [Accepted: 06/30/2011] [Indexed: 12/21/2022]
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292
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Role of microRNAs in endothelial inflammation and senescence. Mol Biol Rep 2011; 39:4509-18. [PMID: 21952822 DOI: 10.1007/s11033-011-1241-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Accepted: 09/14/2011] [Indexed: 01/07/2023]
Abstract
The functionality of endothelial cells is fundamental for the homoeostasis of the vascular system. Increasing evidence shows that endothelial inflammation and senescence contribute greatly to multiple vascular diseases including atherosclerosis. However, little is known regarding the complex upstream regulators of gene expression and translation involved in these responses. MicroRNAs (miRNAs) have emerged as a novel class of endogenous, small, non-coding RNAs that negatively regulate over 30% of genes in a cell via degradation or translational inhibition of their target mRNAs. During the past few years, miRNAs have emerged as key regulators for endothelial biology and function. Endothelial inflammation is critically regulated by miRNAs such as miR-126 and miR-10a in vitro and in vivo. Endothelial aging is additionally controlled by miR-217 and miR-34a. In this review, we summarize the role of miRNAs and their target genes in endothelial inflammation and senescence, and discuss their applicability as drug targets.
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293
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MicroRNA-149*, a p53-responsive microRNA, functions as an oncogenic regulator in human melanoma. Proc Natl Acad Sci U S A 2011; 108:15840-5. [PMID: 21896753 DOI: 10.1073/pnas.1019312108] [Citation(s) in RCA: 141] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The tumor suppressor p53 is activated in response to cellular stress to prevent malignant transformation by activation of the DNA repair machinery to preserve the cell, or by induction of apoptosis to eliminate the cell should the damage prove irrevocable. The gene encoding p53 frequently undergoes inactivating mutations in many human cancers, but WT p53 is often expressed at high levels in melanoma, which, as judged from the malignant nature of the disease, fails to act as an effective tumor suppressor. Here we show that p53 directly up-regulates microRNA-149* (miR-149*) that in turn targets glycogen synthase kinase-3α, resulting in increased expression of Mcl-1 and resistance to apoptosis in melanoma cells. Although deficiency in miR-149* undermined survival of melanoma cells and inhibited melanoma growth in a mouse xenograft model, elevated expression of miR-149* was found in fresh human metastatic melanoma isolates, which was associated with decreased glycogen synthase kinase-3α and increased Mcl-1. These results reveal a p53-dependent, miR-149*-mediated pathway that contributes to survival of melanoma cells, provides a rational explanation for the ineffectiveness of p53 to suppress melanoma, and identifies the expression of miR-149* as a mechanism involved in the increased expression of Mcl-1 in melanoma cells.
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294
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Mestdagh P, Lefever S, Pattyn F, Ridzon D, Fredlund E, Fieuw A, Ongenaert M, Vermeulen J, De Paepe A, Wong L, Speleman F, Chen C, Vandesompele J. The microRNA body map: dissecting microRNA function through integrative genomics. Nucleic Acids Res 2011; 39:e136. [PMID: 21835775 PMCID: PMC3203610 DOI: 10.1093/nar/gkr646] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
While a growing body of evidence implicates regulatory miRNA modules in various aspects of human disease and development, insights into specific miRNA function remain limited. Here, we present an innovative approach to elucidate tissue-specific miRNA functions that goes beyond miRNA target prediction and expression correlation. This approach is based on a multi-level integration of corresponding miRNA and mRNA gene expression levels, miRNA target prediction, transcription factor target prediction and mechanistic models of gene network regulation. Predicted miRNA functions were either validated experimentally or compared to published data. The predicted miRNA functions are accessible in the miRNA bodymap, an interactive online compendium and mining tool of high-dimensional newly generated and published miRNA expression profiles. The miRNA bodymap enables prioritization of candidate miRNAs based on their expression pattern or functional annotation across tissue or disease subgroup. The miRNA bodymap project provides users with a single one-stop data-mining solution and has great potential to become a community resource.
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Affiliation(s)
- Pieter Mestdagh
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium and Life Technologies, Foster City, CA, USA.
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295
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MicroRNA-155 promotes resolution of hypoxia-inducible factor 1alpha activity during prolonged hypoxia. Mol Cell Biol 2011; 31:4087-96. [PMID: 21807897 DOI: 10.1128/mcb.01276-10] [Citation(s) in RCA: 226] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The hypoxia-inducible factor (HIF) is a key regulator of the transcriptional response to hypoxia. While the mechanism underpinning HIF activation is well understood, little is known about its resolution. Both the protein and the mRNA levels of HIF-1α (but not HIF-2α) were decreased in intestinal epithelial cells exposed to prolonged hypoxia. Coincident with this, microRNA (miRNA) array analysis revealed multiple hypoxia-inducible miRNAs. Among these was miRNA-155 (miR-155), which is predicted to target HIF-1α mRNA. We confirmed the hypoxic upregulation of miR-155 in cultured cells and intestinal tissue from mice exposed to hypoxia. Furthermore, a role for HIF-1α in the induction of miR-155 in hypoxia was suggested by the identification of hypoxia response elements in the miR-155 promoter and confirmed experimentally. Application of miR-155 decreased the HIF-1α mRNA, protein, and transcriptional activity in hypoxia, and neutralization of endogenous miR-155 reversed the resolution of HIF-1α stabilization and activity. Based on these data and a mathematical model of HIF-1α suppression by miR-155, we propose that miR-155 induction contributes to an isoform-specific negative-feedback loop for the resolution of HIF-1α activity in cells exposed to prolonged hypoxia, leading to oscillatory behavior of HIF-1α-dependent transcription.
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296
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Madathil SK, Nelson PT, Saatman KE, Wilfred BR. MicroRNAs in CNS injury: potential roles and therapeutic implications. Bioessays 2011; 33:21-6. [PMID: 21053309 DOI: 10.1002/bies.201000069] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Sindhu K Madathil
- Spinal Cord and Brain Injury Research Center, University of Kentucky Medical Center, University of Kentucky, Lexington, KY, USA
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297
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de Krijger I, Mekenkamp LJM, Punt CJA, Nagtegaal ID. MicroRNAs in colorectal cancer metastasis. J Pathol 2011; 224:438-47. [PMID: 21706478 DOI: 10.1002/path.2922] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 04/11/2011] [Accepted: 04/13/2011] [Indexed: 12/18/2022]
Abstract
Metastatic disease is the major cause of death in colorectal cancer (CRC) patients. The metastatic process is highly inefficient and comprises multiple sequential steps. While many genetic factors relevant in this process have already been identified, the epigenetic factors underlying each step still remain obscure. MicroRNAs (miRNAs) are key regulators in tumourigenesis, but their role in the development of cancer metastasis is poorly investigated. The majority of miRNAs involved in the metastatic process have been identified in breast cancer cell lines, and in CRC less data are available. We review the role of miRNAs in the metastatic pathway of CRC, including escape of apoptosis, epithelial-mesenchymal transition (EMT), angiogenesis, and invasion. Better understanding of the complex role of miRNAs in the development of CRC metastases may provide new insights that could be of therapeutic consequence.
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Affiliation(s)
- Inge de Krijger
- Department of Pathology, Radboud University Nijmegen Medical Centre, The Netherlands
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298
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Abstract
Tumor suppressor p53 plays a central role in tumor prevention. As a transcription factor, p53 mainly exerts its function through transcription regulation of its target genes to initiate various cellular responses. To maintain its proper function, p53 is tightly regulated by a wide variety of regulators in cells. Thus, p53, its regulators and regulated genes form a complex p53 network which is composed of hundreds of genes and their products. microRNAs (miRNAs) are a class of endogenously expressed, small non-coding RNA molecules which play a key role in regulation of gene expression at the post-transcriptional level. Recent studies have demonstrated that miRNAs interact with p53 and its network at multiple levels. p53 regulates the transcription expression and the maturation of a group of miRNAs. On the other hand, miRNAs can regulate the activity and function of p53 through direct repression of p53 or its regulators in cells. These findings have demonstrated that miRNAs are important components in the p53 network, and also added another layer of complexity to the p53 network.
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Affiliation(s)
- Zhaohui Feng
- Department of Radiation Oncology, Cancer Institute of New Jersey, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ 08903, USA.
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299
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Qiu J, Wang G, Hu J, Peng Q, Zheng Y. Id1-induced inhibition of p53 facilitates endothelial cell migration and tube formation by regulating the expression of beta1-integrin. Mol Cell Biochem 2011; 357:125-33. [DOI: 10.1007/s11010-011-0882-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 05/17/2011] [Indexed: 12/18/2022]
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300
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Hennessy EJ, Sheedy FJ, Santamaria D, Barbacid M, O'Neill LAJ. Toll-like receptor-4 (TLR4) down-regulates microRNA-107, increasing macrophage adhesion via cyclin-dependent kinase 6. J Biol Chem 2011; 286:25531-9. [PMID: 21628465 DOI: 10.1074/jbc.m111.256206] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Toll-like receptors (TLRs) modulate the expression of multiple microRNAs (miRNAs). Here, we report the down-regulation of miR-107 by TLR4 in multiple cell types. The miR-107 sequence occurs in an intron within the sequence encoding the gene for pantothenate kinase 1α (PanK1α), which is regulated by the transcription factor peroxisome proliferator-activating receptor α (PPAR-α). PanK1α is also decreased in response to lipopolysaccharide (LPS). The effect on both miR-107 and PanK1α is consistent with a decrease in PPAR-α expression. We have found that the putative miR-107 target cyclin-dependent kinase 6 (CDK6) expression is increased by TLR4 as a result of the decrease in miR-107. This effect is required for increased adhesion of macrophages in response to LPS, and CDK6-deficient mice are resistant to the lethal effect of LPS. We have therefore identified a mechanism for LPS signaling which involves a decrease in miR-107 leading to an increase in CDK6.
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Affiliation(s)
- Elizabeth J Hennessy
- School of Biochemistry and Immunology, Trinity College Dublin, Dublin 2, Ireland
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