1
|
Ghalavand MA, Asghari A, Farhadi M, Taghizadeh-Hesary F, Garshasbi M, Falah M. The genetic landscape and possible therapeutics of neurofibromatosis type 2. Cancer Cell Int 2023; 23:99. [PMID: 37217995 DOI: 10.1186/s12935-023-02940-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 05/07/2023] [Indexed: 05/24/2023] Open
Abstract
Neurofibromatosis type 2 (NF2) is a genetic condition marked by the development of multiple benign tumors in the nervous system. The most common tumors associated with NF2 are bilateral vestibular schwannoma, meningioma, and ependymoma. The clinical manifestations of NF2 depend on the site of involvement. Vestibular schwannoma can present with hearing loss, dizziness, and tinnitus, while spinal tumor leads to debilitating pain, muscle weakness, or paresthesias. Clinical diagnosis of NF2 is based on the Manchester criteria, which have been updated in the last decade. NF2 is caused by loss-of-function mutations in the NF2 gene on chromosome 22, leading the merlin protein to malfunction. Over half of NF2 patients have de novo mutations, and half of this group are mosaic. NF2 can be managed by surgery, stereotactic radiosurgery, monoclonal antibody bevacizumab, and close observation. However, the nature of multiple tumors and the necessity of multiple surgeries over the lifetime, inoperable tumors like meningiomatosis with infiltration of the sinus or in the area of the lower cranial nerves, the complications caused by the operation, the malignancies induced by radiotherapy, and inefficiency of cytotoxic chemotherapy due to the benign nature of NF-related tumors have led a march toward exploring targeted therapies. Recent advances in genetics and molecular biology have allowed identifying and targeting of underlying pathways in the pathogenesis of NF2. In this review, we explain the clinicopathological characteristics of NF2, its genetic and molecular background, and the current knowledge and challenges of implementing genetics to develop efficient therapies.
Collapse
Affiliation(s)
- Mohammad Amin Ghalavand
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Alimohamad Asghari
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Skull Base Research Center, The Five Senses Health Institute, Hazrat Rasoul Akram Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Farhadi
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Farzad Taghizadeh-Hesary
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
- Radiation Oncology Department, Iran University of Medical Sciences, Tehran, Iran
| | - Masoud Garshasbi
- Department of Medical Genetics, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Masoumeh Falah
- ENT and Head and Neck Research Center and Department, The Five Senses Health Institute, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
2
|
Abstract
OBJECTIVES In this review, we discuss current knowledge about the genetics and epigenetics of vestibular schwannoma (VS) in relation to hearing loss. A multistep and sequential genetic algorithm suitable for the identification of Neurofibromatosis Type 2 (NF2) constitutional and somatic mutations is discussed. DATA SOURCES, STUDY SELECTION A review was performed of the English literature from 1990 to 2019 using PubMed regarding genetics and epigenetics of vestibular schwannoma and NF2. CONCLUSION NF2 is a genetic disorder characterized by NF2 mutations that affect the function of a tumor suppressor called merlin. In particular, individuals with NF2 develop bilateral VS that can lead to hearing loss and even deafness. Recent advances in genetic and epigenetic studies have improved our understanding of the genotype-phenotype relationships that affect hearing in NF2 patients. Specific constitutional NF2 mutations including particular truncating, deletion, and missense mutations have been associated with poorer hearing outcomes and more severe clinical manifestations. Epigenetic events, such as DNA methylation and histone modifications, also contribute to the development and progression of hearing loss in NF2 patients. Furthermore, the accumulation of multiple NF2 and non-NF2 genetic and epigenetic abnormalities at the level of the tumor may contribute to worse hearing outcomes. Understanding genetic and epigenetic signatures in individual NF2 patients and particularly in each VS will allow us to develop novel gene therapies and precision medicine algorithms to preserve hearing in NF2 individuals.
Collapse
|
3
|
Torres-Martín M, Lassaletta L, de Campos JM, Isla A, Pinto GR, Burbano RR, Melendez B, Castresana JS, Rey JA. Genome-wide methylation analysis in vestibular schwannomas shows putative mechanisms of gene expression modulation and global hypomethylation at the HOX gene cluster. Genes Chromosomes Cancer 2014; 54:197-209. [PMID: 25533176 DOI: 10.1002/gcc.22232] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Revised: 11/09/2014] [Accepted: 11/25/2014] [Indexed: 12/17/2022] Open
Abstract
Schwannomas are tumors that develop from Schwann cells in the peripheral nerves and commonly arise from the vestibular nerve. Vestibular schwannomas can present unilaterally and sporadically or bilaterally when the tumor is associated with neurofibromatosis Type 2 (NF2) syndrome. The molecular hallmark of the disease is biallelic inactivation of the NF2 gene. The epigenetic signature of schwannomas remains poorly understood and is mostly limited to DNA methylation of the NF2 gene, whose altered expression due to epigenetic factors in this tumor is controversial. In this study, we tested the genomewide DNA methylation pattern of schwannomas to shed light on this epigenetic alteration in these particular tumors. The methodology used includes Infinium Human Methylation 450K BeadChip microarrays in a series of 36 vestibular schwannomas, 4 nonvestibular schwannomas, and 5 healthy nerves. Our results show a trend toward hypomethylation in schwannomas. Furthermore, homeobox (HOX) genes, located at four clusters in the genome, displayed hypomethylation in several CpG sites in the vestibular schwannomas but not in the nonvestibular schwannomas. Several microRNA (miRNA) and protein-coding genes were also found to be hypomethylated at promoter regions and were confirmed as upregulated by expression analysis; including miRNA-21, Met Proto-Oncogene (MET), and PMEPA1. We also detected methylation patterns that might be involved in alternative transcripts of several genes such as NRXN1 or MBP, which would increase the complexity of the methylation and expression patterns. Overall, our results show specific epigenetic signatures in several coding genes and miRNAs that could potentially be used as therapeutic targets.
Collapse
Affiliation(s)
- Miguel Torres-Martín
- Molecular Neuro-oncogenetics Laboratory, Research Unit, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain
| | | | | | | | | | | | | | | | | |
Collapse
|
4
|
TORRES-MARTIN MIGUEL, LASSALETTA LUIS, ISLA ALBERTO, DE CAMPOS JOSEM, PINTO GIOVANNYR, BURBANO ROMMELR, CASTRESANA JAVIERS, MELENDEZ BARBARA, REY JUANA. Global expression profile in low grade meningiomas and schwannomas shows upregulation of PDGFD, CDH1 and SLIT2 compared to their healthy tissue. Oncol Rep 2014; 32:2327-34. [PMID: 25333347 PMCID: PMC4240498 DOI: 10.3892/or.2014.3526] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 08/26/2014] [Indexed: 12/20/2022] Open
Abstract
Schwannomas and grade I meningiomas are non‑metastatic neoplasms that share the common mutation of gene NF2. They usually appear in neurofibromatosis type 2 patients. Currently, there is no drug treatment available for both tumors, thus the use of wide expression technologies is crucial to identify therapeutic targets. Affymetrix Human Gene 1.0 ST was used to test global gene expression in 22 meningiomas, 31 schwannomas and, as non-tumoral controls, 3 healthy meningeal tissues, 8 non-tumoral nerves and 1 primary Schwann cell culture. A non-stringent P-value cut-off and fold change were used to establish deregulated genes. We identified a subset of genes that were upregulated in meningiomas and schwannomas when compared to their respectively healthy tissues, including PDGFD, CDH1 and SLIT2. Thus, these genes should be thoroughly studied as targets in a possible combined treatment.
Collapse
Affiliation(s)
- MIGUEL TORRES-MARTIN
- Molecular Neuro-Oncogenetics Laboratory, Research Unit, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain
| | - LUIS LASSALETTA
- Department of Otolaryngology, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain
| | - ALBERTO ISLA
- Department of Neurosurgery, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain
| | | | - GIOVANNY R. PINTO
- Genetics and Molecular Biology Laboratory, Federal University of Piau, Parnaiba, Brazil
| | - ROMMEL R. BURBANO
- Human Cytogenetics Laboratory, Institute of Biological Sciences, Federal University of Para, Belem, Brazil
| | - JAVIER S. CASTRESANA
- Department of Biochemistry and Genetics, University of Navarra School of Sciences, Pamplona, Spain
| | - BARBARA MELENDEZ
- Molecular Pathology Research Unit, Virgen de la Salud Hospital, Toledo, Spain
| | - JUAN A. REY
- Molecular Neuro-Oncogenetics Laboratory, Research Unit, Hospital Universitario La Paz, IdiPAZ, Madrid, Spain
| |
Collapse
|
5
|
|
6
|
Torres-Martin M, Lassaletta L, de Campos JM, Isla A, Gavilan J, Pinto GR, Burbano RR, Latif F, Melendez B, Castresana JS, Rey JA. Global profiling in vestibular schwannomas shows critical deregulation of microRNAs and upregulation in those included in chromosomal region 14q32. PLoS One 2013; 8:e65868. [PMID: 23776562 PMCID: PMC3679163 DOI: 10.1371/journal.pone.0065868] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 04/29/2013] [Indexed: 12/21/2022] Open
Abstract
Background Vestibular schwannomas are benign tumors that arise from Schwann cells in the VIII cranial pair and usually present NF2 gene mutations and/or loss of heterozygosity on chromosome 22q. Deregulation has also been found in several genes, such as ERBB2 and NRG1. MicroRNAs are non-coding RNAs approximately 21 to 23 nucleotides in length that regulate mRNAs, usually by degradation at the post-transcriptional level. Methods We used microarray technology to test the deregulation of miRNAs and other non-coding RNAs present in GeneChip miRNA 1.0 (Affymetrix) over 16 vestibular schwannomas and 3 control-nerves, validating 10 of them by qRT-PCR. Findings Our results showed the deregulation of 174 miRNAs, including miR-10b, miR-206, miR-183 and miR-204, and the upregulation of miR-431, miR-221, miR-21 and miR-720, among others. The results also showed an aberrant expression of other non-coding RNAs. We also found a general upregulation of the miRNA cluster located at chromosome 14q32. Conclusion Our results suggest that several miRNAs are involved in tumor formation and/or maintenance and that global upregulation of the 14q32 chromosomal site contains miRNAs that may represent a therapeutic target for this neoplasm.
Collapse
Affiliation(s)
- Miguel Torres-Martin
- Neuro-Oncology Laboratory, Research Unit, La Paz University Hospital, IdiPAZ, Madrid, Spain.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Torres-Martin M, Lassaletta L, San-Roman-Montero J, De Campos JM, Isla A, Gavilan J, Melendez B, Pinto GR, Burbano RR, Castresana JS, Rey JA. Microarray analysis of gene expression in vestibular schwannomas reveals SPP1/MET signaling pathway and androgen receptor deregulation. Int J Oncol 2013; 42:848-62. [PMID: 23354516 PMCID: PMC3597452 DOI: 10.3892/ijo.2013.1798] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2012] [Accepted: 01/04/2013] [Indexed: 11/06/2022] Open
Abstract
Vestibular schwannomas are benign neoplasms that arise from the vestibular nerve. The hallmark of these tumors is the biallelic inactivation of neurofibromin 2 (NF2). Transcriptomic alterations, such as the neuregulin 1 (NRG1)/ErbB2 pathway, have been described in schwannomas. In this study, we performed a whole transcriptome analysis in 31 vestibular schwannomas and 9 control nerves in the Affymetrix Gene 1.0 ST platform, validated by quantitative real-time PCR (qRT-PCR) using TaqMan Low Density arrays. We performed a mutational analysis of NF2 by PCR/denaturing high-performance liquid chromatography (dHPLC) and multiplex ligation-dependent probe amplification (MLPA), as well as a microsatellite marker analysis of the loss of heterozygosity (LOH) of chromosome 22q. The microarray analysis demonstrated that 1,516 genes were deregulated and 48 of the genes were validated by qRT-PCR. At least 2 genetic hits (allelic loss and/or gene mutation) in NF2 were found in 16 tumors, seven cases showed 1 hit and 8 tumors showed no NF2 alteration. MET and associated genes, such as integrin, alpha 4 (ITGA4)/B6, PLEXNB3/SEMA5 and caveolin-1 (CAV1) showed a clear deregulation in vestibular schwannomas. In addition, androgen receptor (AR) downregulation may denote a hormonal effect or cause in this tumor. Furthermore, the osteopontin gene (SPP1), which is involved in merlin protein degradation, was upregulated, which suggests that this mechanism may also exert a pivotal role in schwannoma merlin depletion. Finally, no major differences were observed among tumors of different size, histological type or NF2 status, which suggests that, at the mRNA level, all schwannomas, regardless of their molecular and clinical characteristics, may share common features that can be used in their treatment.
Collapse
Affiliation(s)
- Miguel Torres-Martin
- Research Unit, La Paz University Hospital, Hospital La Paz Institute for Health Research (IdiPAZ), 28046 Madrid, Spain.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Abstract
DNA copy gains are a common event in tumor growth. This study determines the gene dosage/amplification of seven tumor-related genes in patients undergoing vestibular schwannoma (VS) surgery and analyzes its clinical implications. Thirty-three patients undergoing surgery for VS were studied. Seven genes (EGFR, ERBB2, ERBB3, ERBB4, MDM2, MDM4, and NMYC) were analyzed by Quantitative real-time PCR. Copy gains were correlated with demographic, clinical and radiological data. Of the 33 samples, 48 % were positive for copy gains in at least one gene. There were no positive samples for gene amplification. A clinical correlation between tumor size and copy gains of ERBB2 was found. Patients with copy gains of this gene had larger tumors measured by diameter (p = 0.027) and volume (p = 0.005). Copy gains of EGFR, ERBB2, ERBB4, and MDM4 were associated with preoperative tinnitus. Contrary to other tumors of the central nervous system, development of VS does not appear to involve gene amplification. However, copy gains of certain tumor-related genes may play a role in the biological behavior of these neoplasms. Our findings support the role of ERBB2 in VS development and growth.
Collapse
|
9
|
Torres-Martín M, Martinez-Glez V, Peña-Granero C, Lassaletta L, Isla A, de Campos JM, Pinto GR, Burbano RR, Meléndez B, Castresana JS, Rey JA. Expression analysis of tumor-related genes involved in critical regulatory pathways in schwannomas. Clin Transl Oncol 2012; 15:409-11. [PMID: 23054753 DOI: 10.1007/s12094-012-0937-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 08/30/2012] [Indexed: 11/26/2022]
Abstract
PURPOSE Gene expression array analysis is providing key data on the potential candidate genes and biological pathways involved in schwannoma origin and development. In this way we performed expression array studies on tumor-related genes in schwannomas. METHODS The GE Array Q Series HS-006 (SuperArray, Bethesda, MD, USA) was used to determine the expression levels of 96 genes corresponding to 6 primary biological regulatory pathways in a series of 23 schwannomas. RESULTS We identified 15 genes down-regulated, primarily corresponding to signal transduction functions, and 26 genes up-regulated, most frequently involving cell adhesion functions. CONCLUSIONS In addition to the NF2 inactivation (considered as an early step), variations of other biological regulatory pathways might play a key role in schwannoma.
Collapse
Affiliation(s)
- Miguel Torres-Martín
- Unidad de Investigación, IdiPAz, Hospital Universitario La Paz, Paseo de la Castellana 261, 28046, Madrid, Spain.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Celis-Aguilar E, Lassaletta L, Torres-Martín M, Rodrigues FY, Nistal M, Castresana JS, Gavilan J, Rey JA. The molecular biology of vestibular schwannomas and its association with hearing loss: a review. GENETICS RESEARCH INTERNATIONAL 2012; 2012:856157. [PMID: 22567403 PMCID: PMC3335540 DOI: 10.1155/2012/856157] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 10/08/2011] [Accepted: 11/03/2011] [Indexed: 01/16/2023]
Abstract
Hearing loss is the most common symptom in patients with vestibular schwannoma (VS). In the past, compressive mechanisms caused by the tumoral mass and its growth have been regarded as the most likely causes of the hearing loss associated with VS. Interestingly, new evidence proposes molecular mechanisms as an explanation for such hearing loss. Among the molecular mechanisms proposed are methylation of TP73, negative expression of cyclin D1, expression of B7-H1, increased expression of the platelet-derived growth factor A, underexpression of PEX5L, RAD54B, and PSMAL, and overexpression of CEA. Many molecular mechanisms are involved in vestibular schwannoma development; we review some of these mechanisms with special emphasis on hearing loss associated with vestibular schwannoma.
Collapse
Affiliation(s)
- Erika Celis-Aguilar
- Instituto Nacional de Neurología y Neurocirugía Manuel Velasco Suarez, 14269 Ciudad de México, DF, Mexico
| | - Luis Lassaletta
- Department of Otolaryngology, “La Paz” University Hospital, 28046 Madrid, Spain
| | - Miguel Torres-Martín
- Unidad de Investigación, Laboratorio Oncogenetica Molecular, “La Paz” University Hospital, 28046 Madrid, Spain
| | - F. Yuri Rodrigues
- Department of Pathology, “La Paz” University Hospital, 28046 Madrid, Spain
| | - Manuel Nistal
- Department of Pathology, “La Paz” University Hospital, 28046 Madrid, Spain
| | - Javier S. Castresana
- Brain Tumor Biology Unit, CIFA, University of Navarra School of Sciences, 31009 Pamplona, Spain
| | - Javier Gavilan
- Department of Otolaryngology, “La Paz” University Hospital, 28046 Madrid, Spain
| | - Juan A. Rey
- Department of Pathology, “La Paz” University Hospital, 28046 Madrid, Spain
| |
Collapse
|
11
|
Martínez-Glez V, Alvarez L, Franco-Hernández C, Torres-Martin M, de Campos JM, Isla A, Vaquero J, Lassaletta L, Castresana JS, Casartelli C, Rey JA. Genomic deletions at 1p and 14q are associated with an abnormal cDNA microarray gene expression pattern in meningiomas but not in schwannomas. ACTA ACUST UNITED AC 2009; 196:1-6. [PMID: 19963129 DOI: 10.1016/j.cancergencyto.2009.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 07/01/2009] [Accepted: 08/02/2009] [Indexed: 11/19/2022]
Abstract
The molecular pathology of meningiomas and shwannomas involve the inactivation of the NF2 gene to generate grade I tumors. Genomic losses at 1p and 14q are observed in both neoplasms, although more frequently in meningiomas. The inactivation of unidentified genes located in these regions appears associated with tumor progression in meningiomas, but no clues to its molecular/clinical meaning are available in schwannomas. Recent microarray gene expression studies have demonstrated the existence of molecular subgroups in both entities. In the present study, we correlated the presence of genomic deletions at 1p, 14q, and 22q with the expression patterns of 96 tumor-related genes obtained by cDNA low-density microarrays in a series of 65 tumors including 42 meningiomas and 23 schwannomas. Two expression pattern groups were identified by cDNA mycroarray analysis when compared to the expression pattern in normal control RNA in both meningiomas and schwannomas, each one with patterns similar and different from the normal control. Meningioma and schwannoma subgroups differed in the expression of 38 and 16 genes, respectively. Using MLPA and microsatellites, we identified genomic losses at 1p, 14q, and 22q at nonrandom frequencies (12.5-69%) in meningiomas and schwannomas. Losses at 22q were almost equally frequent in both molecular expression subgroups in both neoplasms. However, deletions at 1p and 14q accumulated in meningiomas with a gene expression pattern different from the normal pattern, whereas the inverse situation occurred in schwannomas. Those anomalies characterized the schwannomas with expression pattern similar to the normal control. These findings suggest that deletions at 1p and 14q enhance the development of an abnormal tumor-related gene expression pattern in meningiomas, but this fact is not corroborated in schwannomas.
Collapse
Affiliation(s)
- Victor Martínez-Glez
- Research Unit-Unidad de Investigación, Hospital Universiatrio La Paz, Paseo Castellana 261, 28046 Madrid, Spain
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Lassaletta L, Martínez-Glez V, Torres-Martín M, Rey JA, Gavilán J. cDNA microarray expression profile in vestibular schwannoma: correlation with clinical and radiological features. CANCER GENETICS AND CYTOGENETICS 2009; 194:125-7. [PMID: 19781445 DOI: 10.1016/j.cancergencyto.2009.06.016] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2009] [Revised: 06/15/2009] [Accepted: 06/15/2009] [Indexed: 10/20/2022]
|
13
|
Nagarajan RP, Costello JF. Molecular epigenetics and genetics in neuro-oncology. Neurotherapeutics 2009; 6:436-46. [PMID: 19560734 PMCID: PMC3981537 DOI: 10.1016/j.nurt.2009.04.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2009] [Revised: 03/26/2009] [Accepted: 04/09/2009] [Indexed: 01/25/2023] Open
Abstract
Gliomas arise through genetic and epigenetic alterations of normal brain cells, although the exact cell of origin for each glioma subtype is unknown. The alteration-induced changes in gene expression and protein function allow uncontrolled cell division, tumor expansion, and infiltration into surrounding normal brain parenchyma. The genetic and epigenetic alterations are tumor subtype and tumor-grade specific. Particular alterations predict tumor aggressiveness, tumor response to therapy, and patient survival. Genetic alterations include deletion, gain, amplification, mutation, and translocation, which result in oncogene activation and tumor suppressor gene inactivation, or in some instances the alterations may simply be a consequence of tumorigenesis. Epigenetic alterations in brain tumors include CpG island hypermethylation associated with tumor suppressor gene silencing, gene-specific hypomethylation associated with aberrant gene activation, and genome-wide hypomethylation potentially leading to loss of imprinting, chromosomal instability, and cellular hyperproliferation. Other epigenetic alterations, such as changes in the position of histone variants and changes in histone modifications are also likely to be important in the molecular pathology of brain tumors. Given that histone deacetylases are targets for drugs that are already in clinical trial, surprisingly little is known about histone acetylation in primary brain tumors. Although a majority of epigenetic alterations are independent of genetic alterations, there is interaction on specific genes, signaling pathways and within chromosomal domains. Next-generation sequencing technology is now the method of choice for genomic and epigenome profiling, allowing more comprehensive understanding of genetic and epigenetic contributions to tumorigenesis in the brain.
Collapse
Affiliation(s)
- Raman P. Nagarajan
- grid.266102.10000000122976811Brain Tumor Research Center, Department of Neurosurgery, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, 94143 San Francisco, California
| | - Joseph F. Costello
- grid.266102.10000000122976811Brain Tumor Research Center, Department of Neurosurgery, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, 94143 San Francisco, California
| |
Collapse
|
14
|
Nagarajan RP, Costello JF. Epigenetic mechanisms in glioblastoma multiforme. Semin Cancer Biol 2009; 19:188-97. [PMID: 19429483 DOI: 10.1016/j.semcancer.2009.02.005] [Citation(s) in RCA: 131] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Accepted: 02/11/2009] [Indexed: 11/26/2022]
Abstract
Glioblastoma multiforme (GBM) is an aggressive and lethal cancer, accounting for the majority of primary brain tumors in adults. GBMs are characterized by genetic alterations large and small, affecting genes that control cell growth, apoptosis, angiogenesis, and invasion. Epigenetic alterations also affect the expression of cancer genes alone, or in combination with genetic mechanisms. For example, in each GBM, hundreds of genes are subject to DNA hypermethylation at their CpG island promoters. A subset of GBMs is also characterized by locus-specific and genome-wide decrease in DNA methylation, or DNA hypomethylation. Other epigenetic alterations, such as changes in the position of histone variants and changes in histone modifications are also likely important in the molecular pathology of GBM, but somewhat surprisingly there are very limited data about these in GBM. Alterations in histone modifications are especially important to understand, given that histone deacetylases are targets for drugs that are in clinical trial for GBMs. The technological wave of next-generation sequencing will accelerate GBM epigenome profiling, allowing the direct integration of DNA methylation, histone modification and gene expression profiles. Ultimately, genomic and epigenomic data should provide new predictive markers of response and lead to more effective therapies for GBM.
Collapse
Affiliation(s)
- Raman P Nagarajan
- Brain Tumor Research Center, Department of Neurosurgery, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA 94143, USA
| | | |
Collapse
|
15
|
Lassaletta L, Patrón M, González T, Martinez-Glez V, Rey JA, Gavilan J. RASSF1A methylation and cyclin D1 expression in vestibular schwannomas. Acta Neuropathol 2007; 114:431-3. [PMID: 17668224 DOI: 10.1007/s00401-007-0272-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Revised: 07/09/2007] [Accepted: 07/19/2007] [Indexed: 01/28/2023]
|