1
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Zhou L, Tong Y, Ho BM, Li J, Chan HYE, Zhang T, Du L, He JN, Chen LJ, Tham CC, Yam JC, Pang CP, Chu WK. Etiology including epigenetic defects of retinoblastoma. Asia Pac J Ophthalmol (Phila) 2024:100072. [PMID: 38789041 DOI: 10.1016/j.apjo.2024.100072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 04/09/2024] [Accepted: 05/02/2024] [Indexed: 05/26/2024] Open
Abstract
Retinoblastoma (RB), originating from the developing retina, is an aggressive intraocular malignant neoplasm in childhood. Biallelic loss of RB1 is conventionally considered a prerequisite for initiating RB development in most RB cases. Additional genetic mutations arising from genome instability following RB1 mutations are proposed to be required to promote RB development. Recent advancements in high throughput sequencing technologies allow a deeper and more comprehensive understanding of the etiology of RB that additional genetic alterations following RB1 biallelic loss are rare, yet epigenetic changes driven by RB1 loss emerge as a critical contributor promoting RB tumorigenesis. Multiple epigenetic regulators have been found to be dysregulated and to contribute to RB development, including noncoding RNAs, DNA methylations, RNA modifications, chromatin conformations, and histone modifications. A full understanding of the roles of genetic and epigenetic alterations in RB formation is crucial in facilitating the translation of these findings into effective treatment strategies for RB. In this review, we summarize current knowledge concerning genetic defects and epigenetic dysregulations in RB, aiming to help understand their links and roles in RB tumorigenesis.
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Affiliation(s)
- Linbin Zhou
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Yan Tong
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Bo Man Ho
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Jiahui Li
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Hoi Ying Emily Chan
- Medicine Programme Global Physician-Leadership Stream, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Tian Zhang
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Lin Du
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Jing Na He
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Li Jia Chen
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Clement C Tham
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Jason C Yam
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Chi Pui Pang
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China.
| | - Wai Kit Chu
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China.
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2
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Ma M, Lv Y, Zhang K, Zhou L. RASFF1A inhibits the epithelial-mesenchymal transition of lens epithelial cells induced by TGFβ through regulating HDAC6. Tissue Cell 2024; 87:102325. [PMID: 38394972 DOI: 10.1016/j.tice.2024.102325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 01/16/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024]
Abstract
To explore the role of Ras-association domain family 1 A (RASSF1A) in TGFβ2-induced changes of lens epithelial cells (LECs) behavior. The human LEC line SRA01/04 cells were treated with TGFβ2 in the presence or absence of RASSF1A and histone deacetylase 6 (HDAC6). qRT-PCR and western blot were performed to analysis mRNA and proteins expression. Cell proliferation was evaluated using MTT assay and colony formation assay. Transwell and scratch-wound healing assays were conducted to detected cell migration ability. RASSF1A was downregulated in TGFβ2-induced SRA01/04 cells. RASSF1A overexpression inhibited the cell viability, colony formation and migration abilities of SRA01/04 cells induced by TGFβ2. Overexpression of RASSF1A suppressed TGFβ2-induced EMT of SRA01/04 cells, which was manifested as inhibition of EMT-related proteins α-SMA, Vimentin, Snail and Fn expression. Moreover, RASSF1A down-regulated the expression of HDAC6. Importantly, HDAC6 reversed the effects of RASSF1A on SRA01/04 cells. These findings indicate that RASSF1A prevented TGFβ2-induced proliferation, migration, and EMT of LECs by regulating HDAC6 expression, suggesting that RASSF1A holds promise as a potential target for cataracts treatment.
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Affiliation(s)
- Mingda Ma
- Department of Ophthalmology, Ningbo No.2 Hospital, Ningbo, Zhejiang 315010, China
| | - Yunkai Lv
- Department of Ophthalmology, Ningbo No.2 Hospital, Ningbo, Zhejiang 315010, China.
| | - Kun Zhang
- Department of Ophthalmology, Ningbo No.2 Hospital, Ningbo, Zhejiang 315010, China
| | - Lina Zhou
- Department of Ophthalmology, Yuyao Maternity And Child Health Care Hospital, Yuyao, Zhejiang 315400, China
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3
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Geissler F, Nesic K, Kondrashova O, Dobrovic A, Swisher EM, Scott CL, J. Wakefield M. The role of aberrant DNA methylation in cancer initiation and clinical impacts. Ther Adv Med Oncol 2024; 16:17588359231220511. [PMID: 38293277 PMCID: PMC10826407 DOI: 10.1177/17588359231220511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 11/21/2023] [Indexed: 02/01/2024] Open
Abstract
Epigenetic alterations, including aberrant DNA methylation, are now recognized as bone fide hallmarks of cancer, which can contribute to cancer initiation, progression, therapy responses and therapy resistance. Methylation of gene promoters can have a range of impacts on cancer risk, clinical stratification and therapeutic outcomes. We provide several important examples of genes, which can be silenced or activated by promoter methylation and highlight their clinical implications. These include the mismatch DNA repair genes MLH1 and MSH2, homologous recombination DNA repair genes BRCA1 and RAD51C, the TERT oncogene and genes within the P15/P16/RB1/E2F tumour suppressor axis. We also discuss how these methylation changes might occur in the first place - whether in the context of the CpG island methylator phenotype or constitutional DNA methylation. The choice of assay used to measure methylation can have a significant impact on interpretation of methylation states, and some examples where this can influence clinical decision-making are presented. Aberrant DNA methylation patterns in circulating tumour DNA (ctDNA) are also showing great promise in the context of non-invasive cancer detection and monitoring using liquid biopsies; however, caution must be taken in interpreting these results in cases where constitutional methylation may be present. Thus, this review aims to provide researchers and clinicians with a comprehensive summary of this broad, but important subject, illustrating the potentials and pitfalls of assessing aberrant DNA methylation in cancer.
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Affiliation(s)
- Franziska Geissler
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Ksenija Nesic
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Olga Kondrashova
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia
| | - Alexander Dobrovic
- University of Melbourne Department of Surgery, Austin Health, Heidelberg, VIC, Australia
| | | | - Clare L. Scott
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
- Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
- Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, VIC, Australia
- Peter MacCallum Cancer Centre and Sir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC, Australia
- Royal Women’s Hospital, Parkville, VIC, Australia
- Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Matthew J. Wakefield
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052Department of Obstetrics and Gynaecology, University of Melbourne, Parkville, VIC, Australia
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4
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Marković L, Bukovac A, Varošanec AM, Šlaus N, Pećina-Šlaus N. Genetics in ophthalmology: molecular blueprints of retinoblastoma. Hum Genomics 2023; 17:82. [PMID: 37658463 PMCID: PMC10474694 DOI: 10.1186/s40246-023-00529-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 08/25/2023] [Indexed: 09/03/2023] Open
Abstract
This review presents current knowledge on the molecular biology of retinoblastoma (RB). Retinoblastoma is an intraocular tumor with hereditary and sporadic forms. 8,000 new cases of this ocular malignancy of the developing retina are diagnosed each year worldwide. The major gene responsible for retinoblastoma is RB1, and it harbors a large spectrum of pathogenic variants. Tumorigenesis begins with mutations that cause RB1 biallelic inactivation preventing the production of functional pRB proteins. Depending on the type of mutation the penetrance of RB is different. However, in small percent of tumors additional genes may be required, such as MYCN, BCOR and CREBBP. Additionally, epigenetic changes contribute to the progression of retinoblastoma as well. Besides its role in the cell cycle, pRB plays many additional roles, it regulates the nucleosome structure, participates in apoptosis, DNA replication, cellular senescence, differentiation, DNA repair and angiogenesis. Notably, pRB has an important role as a modulator of chromatin remodeling. In recent years high-throughput techniques are becoming essential for credible biomarker identification and patient management improvement. In spite of remarkable advances in retinoblastoma therapy, primarily in high-income countries, our understanding of retinoblastoma and its specific genetics still needs further clarification in order to predict the course of this disease and improve therapy. One such approach is the tumor free DNA that can be obtained from the anterior segment of the eye and be useful in diagnostics and prognostics.
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Affiliation(s)
- Leon Marković
- Department of Ophthalmology, Reference Center of the Ministry of Health of the Republic of Croatia for Pediatric Ophthalmology and Strabismus, University Hospital "Sveti Duh", Zagreb, Croatia
- Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Anja Bukovac
- Department of Biology, School of Medicine, University of Zagreb, Šalata 3, 10000, Zagreb, Croatia
- Laboratory of Neurooncology, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10000, Zagreb, Croatia
| | - Ana Maria Varošanec
- Department of Ophthalmology, Reference Center of the Ministry of Health of the Republic of Croatia for Pediatric Ophthalmology and Strabismus, University Hospital "Sveti Duh", Zagreb, Croatia
- Faculty of Dental Medicine and Health Osijek, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Nika Šlaus
- Department of Biology, School of Medicine, University of Zagreb, Šalata 3, 10000, Zagreb, Croatia
| | - Nives Pećina-Šlaus
- Department of Biology, School of Medicine, University of Zagreb, Šalata 3, 10000, Zagreb, Croatia.
- Laboratory of Neurooncology, Croatian Institute for Brain Research, School of Medicine, University of Zagreb, Salata 12, 10000, Zagreb, Croatia.
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5
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Rathore S, Verma A, Ratna R, Marwa N, Ghiya Y, Honavar SG, Tiwari A, Das S, Varshney A. Retinoblastoma: A review of the molecular basis of tumor development and its clinical correlation in shaping future targeted treatment strategies. Indian J Ophthalmol 2023; 71:2662-2676. [PMID: 37417104 PMCID: PMC10491038 DOI: 10.4103/ijo.ijo_3172_22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2022] [Revised: 04/25/2023] [Accepted: 05/21/2023] [Indexed: 07/08/2023] Open
Abstract
Retinoblastoma is a retinal cancer that affects children and is the most prevalent intraocular tumor worldwide. Despite tremendous breakthroughs in our understanding of the fundamental mechanisms that regulate progression of retinoblastoma, the development of targeted therapeutics for retinoblastoma has lagged. Our review highlights the current developments in the genetic, epigenetic, transcriptomic, and proteomic landscapes of retinoblastoma. We also discuss their clinical relevance and potential implications for future therapeutic development, with the aim to create a frontline multimodal therapy for retinoblastoma.
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Affiliation(s)
- Shruti Rathore
- Ocular Oncology Services, Dr. Shroff’s Charity Eye Hospital, New Delhi, India
| | - Aman Verma
- Ocular Oncology Services, Dr. Shroff’s Charity Eye Hospital, New Delhi, India
| | - Ria Ratna
- Ocular Genetics Services, Dr. Shroff’s Charity Eye Hospital, New Delhi, India
| | - Navjot Marwa
- Ocular Oncology Services, Dr. Shroff’s Charity Eye Hospital, New Delhi, India
| | - Yagya Ghiya
- Ocular Oncology Services, Dr. Shroff’s Charity Eye Hospital, New Delhi, India
| | - Santosh G Honavar
- Ophthalmic Plastic Surgery, Orbit and Ocular Oncology, Centre for Sight, Hyderbad, Telangana, India
| | - Anil Tiwari
- Ocular Oncology Services, Dr. Shroff’s Charity Eye Hospital, New Delhi, India
| | - Sima Das
- Ocular Oncology Services, Dr. Shroff’s Charity Eye Hospital, New Delhi, India
| | - Akhil Varshney
- Ocular Oncology Services, Dr. Shroff’s Charity Eye Hospital, New Delhi, India
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6
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Retinoblastoma: From genes to patient care. Eur J Med Genet 2022; 66:104674. [PMID: 36470558 DOI: 10.1016/j.ejmg.2022.104674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 11/04/2022] [Accepted: 11/27/2022] [Indexed: 12/12/2022]
Abstract
Retinoblastoma is the most common paediatric neoplasm of the retina, and one of the earliest model of cancer genetics since the identification of the master tumour suppressor gene RB1. Tumorigenesis has been shown to be driven by pathogenic variants of the RB1 locus, but also genomic and epigenomic alterations outside the locus. The increasing knowledge on this "mutational landscape" is used in current practice for precise genetic testing and counselling. Novel methods provide access to pre-therapeutic tumour DNA, by isolating cell-free DNA from aqueous humour or plasma. This is expected to facilitate assessment of the constitutional status of RB1, to provide an early risk stratification using molecular prognostic markers, to follow the response to the treatment in longitudinal studies, and to predict the response to targeted therapies. The aim of this review is to show how molecular genetics of retinoblastoma drives diagnosis, treatment, monitoring of the disease and surveillance of the patients and relatives. We first recap the current knowledge on retinoblastoma genetics and its use in every-day practice. We then focus on retinoblastoma subgrouping at the era of molecular biology, and the expected input of cell-free DNA in the field.
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7
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Karmakar A, Ahamad Khan MM, Kumari N, Devarajan N, Ganesan SK. Identification of Epigenetically Modified Hub Genes and Altered Pathways Associated With Retinoblastoma. Front Cell Dev Biol 2022; 10:743224. [PMID: 35359459 PMCID: PMC8960645 DOI: 10.3389/fcell.2022.743224] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Accepted: 02/16/2022] [Indexed: 11/13/2022] Open
Abstract
Retinoblastoma (Rb) is the most common childhood malignancy initiated by biallelic mutation in RB1 gene and driven by various epigenetic events including DNA methylation and microRNA dysregulation. Hence, understanding the key genes that are critically modulated by epigenetic modifications in RB1−/− cells is very important to identify prominent biomarkers and therapeutic targets of Rb. In this study, we for the first time have integrated various Rb microarray NCBI-GEO datasets including DNA Methylation (GSE57362), miRNA (GSE7072) and mRNA (GSE110811) to comprehensively investigate the epigenetic consequences of RB loss in retinoblastoma tumors and identify genes with the potential to serve as early diagnostic markers and therapeutic targets for Rb. Interestingly, the GEO2R and co-expression network analysis have identified three genes namely E2F3, ESR1, and UNC5D that are significantly deregulated by modified DNA methylation, mRNA and microRNA expression in Rb tumors. Due to their recognition in all epigenetic, transcriptomic, and miRNA datasets, we have termed these genes as “common genes”. The results of our integrative bioinformatics analysis were validated in vitro by studying the gene and protein expression of these common genes in Y79, WERI-Rb-1, Rb cell lines and non-tumorigenic retinal pigment epithelial cell line (hTERT-RPE). The expression of E2F3 and UNC5D were up-regulated and that of ESR1 was down-regulated in Rb tumor cells when compared to that in non-tumorigenic hTERT-RPE cells. More importantly, UNC5D, a potent tumor suppressor gene in most cancers is significantly up-regulated in Y79 and Weri Rb1 cells, which, in turn, questions its anti-cancer properties. Together, our study shows that E2F3, ESR1, and UNC5D may be crucially involved in Rb tumorigenesis and possess the potential to act as early diagnostic biomarkers and therapeutic targets of Rb.
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Affiliation(s)
- Aditi Karmakar
- Department of Structural Biology and Bioinformatics, CSIR-Indian Institute of Chemical Biology, Kolkata, India
- CSIR-IICB Translational Research Unit of Excellence (TRUE), Kolkata, India
| | - Md. Maqsood Ahamad Khan
- Centre of Bioinformatics, Institute of Interdisciplinary Studies, University of Allahabad, Prayagraj, India
| | - Nidhi Kumari
- Department of Structural Biology and Bioinformatics, CSIR-Indian Institute of Chemical Biology, Kolkata, India
- CSIR-IICB Translational Research Unit of Excellence (TRUE), Kolkata, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Nalini Devarajan
- Central Research Laboratory, Meenakshi Academy of Higher Education and Research, Chennai, India
- *Correspondence: Nalini Devarajan, ; Senthil Kumar Ganesan,
| | - Senthil Kumar Ganesan
- Department of Structural Biology and Bioinformatics, CSIR-Indian Institute of Chemical Biology, Kolkata, India
- CSIR-IICB Translational Research Unit of Excellence (TRUE), Kolkata, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
- *Correspondence: Nalini Devarajan, ; Senthil Kumar Ganesan,
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Martínez-Sánchez M, Hernandez-Monge J, Rangel M, Olivares-Illana V. Retinoblastoma: from discovery to clinical management. FEBS J 2021; 289:4371-4382. [PMID: 34042282 DOI: 10.1111/febs.16035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/13/2021] [Accepted: 05/24/2021] [Indexed: 01/02/2023]
Abstract
The retinoblastoma gene (RB1) was the first tumour suppressor cloned; the role of its protein product (RB) as the principal driver of the G1 checkpoint in cell cycle control has been extensively studied. However, many other RB functions are continuously reported. Its role in senescence, DNA repair and apoptosis, among others, is indications of the significance of RB in a vast network of cellular interactions, explaining why RB loss or its malfunction is one of the leading causes of a large number of paediatric and adult cancers. RB was first reported in retinoblastoma, a common intraocular malignancy in the paediatric population worldwide. Currently, its diagnosis is clinical, and in nondeveloped countries, where the incidence is higher, it is performed in advanced stages of the disease, compromising the integrity of the eye and the patient's life. Even though new treatments are being continuously developed, enucleation is still a major choice due to the late disease stage diagnosis and treatments costs. Research into biomarkers is our best option to improve the chances of good results in the treatment and hopes of patients' good quality of life. Here, we recapitulated the history of the disease and the first treatments to put the advances in its clinical management into perspective. We also review the different functions of the protein and the progress in the search for biomarkers. It is clear that there is still a long way to go, but we should offer these children and their families a better way to deal with the disease with the community's effort.
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Affiliation(s)
- Mayra Martínez-Sánchez
- Laboratorio de Interacciones Biomoleculares y Cancer, Instituto de Física, Universidad Autónoma de San Luis Potosí, Mexico
| | - Jesús Hernandez-Monge
- Catedra CONACyT - Laboratorio de Biomarcadores Moleculares, Instituto de Física, Universidad Autónoma de San Luis Potosí, Mexico
| | - Martha Rangel
- Departamento de Oftalmología. Hospital Central "Ignacio Morones Prieto", San Luis Potosí, Mexico
| | - Vanesa Olivares-Illana
- Laboratorio de Interacciones Biomoleculares y Cancer, Instituto de Física, Universidad Autónoma de San Luis Potosí, Mexico
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9
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Lu J, Wilfred P, Korbie D, Trau M. Regulation of Canonical Oncogenic Signaling Pathways in Cancer via DNA Methylation. Cancers (Basel) 2020; 12:E3199. [PMID: 33143142 PMCID: PMC7692324 DOI: 10.3390/cancers12113199] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 10/24/2020] [Accepted: 10/28/2020] [Indexed: 02/07/2023] Open
Abstract
Disruption of signaling pathways that plays a role in the normal development and cellular homeostasis may lead to the dysregulation of cellular signaling and bring about the onset of different diseases, including cancer. In addition to genetic aberrations, DNA methylation also acts as an epigenetic modifier to drive the onset and progression of cancer by mediating the reversible transcription of related genes. Although the role of DNA methylation as an alternative driver of carcinogenesis has been well-established, the global effects of DNA methylation on oncogenic signaling pathways and the presentation of cancer is only emerging. In this article, we introduced a differential methylation parsing pipeline (MethylMine) which mined for epigenetic biomarkers based on feature selection. This pipeline was used to mine for biomarkers, which presented a substantial difference in methylation between the tumor and the matching normal tissue samples. Combined with the Data Integration Analysis for Biomarker discovery (DIABLO) framework for machine learning and multi-omic analysis, we revisited the TCGA DNA methylation and RNA-Seq datasets for breast, colorectal, lung, and prostate cancer, and identified differentially methylated genes within the NRF2-KEAP1/PI3K oncogenic pathway, which regulates the expression of cytoprotective genes, that serve as potential therapeutic targets to treat different cancers.
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Affiliation(s)
- Jennifer Lu
- Centre for Personalised Nanomedicine, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia; (J.L.); (P.W.)
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Premila Wilfred
- Centre for Personalised Nanomedicine, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia; (J.L.); (P.W.)
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Darren Korbie
- Centre for Personalised Nanomedicine, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia; (J.L.); (P.W.)
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Matt Trau
- Centre for Personalised Nanomedicine, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia; (J.L.); (P.W.)
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4072, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD 4072, Australia
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10
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Lee C, Kim JK. Chromatin regulators in retinoblastoma: Biological roles and therapeutic applications. J Cell Physiol 2020; 236:2318-2332. [PMID: 32840881 PMCID: PMC7891620 DOI: 10.1002/jcp.30022] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/13/2020] [Indexed: 12/17/2022]
Abstract
Retinoblastoma (RB) is a pediatric ocular tumor mostly occurring due to the biallelic loss of RB1 gene in the developing retina. Early studies of genomic aberrations in RB have provided a valuable insight into how RB can progress following the tumor-initiating RB1 mutations and have established a notion that inactivation of RB1 gene is critical to initiate RB but this causative genetic lesion alone is not sufficient for malignant progression. With the advent of high-throughput sequencing technologies, we now have access to the comprehensive genomic and epigenetic landscape of RB and have come to appreciate that RB tumorigenesis requires both genetic and epigenetic alterations that might be directly or indirectly driven by RB1 loss. This integrative perspective on RB tumorigenesis has inspired research efforts to better understand the types and functions of epigenetic mechanisms contributing to RB development, leading to the identification of multiple epigenetic regulators misregulated in RB in recent years. A complete understanding of the intricate network of genetic and epigenetic factors in modulation of gene expression during RB tumorigenesis remains a major challenge but would be crucial to translate these findings into therapeutic interventions. In this review, we will provide an overview of chromatin regulators identified to be misregulated in human RB among the numerous epigenetic factors implicated in RB development. For a subset of these chromatin regulators, recent findings on their functions in RB development and potential therapeutic applications are discussed.
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Affiliation(s)
- Chunsik Lee
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jong Kyong Kim
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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11
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Yazici H, Wu HC, Tigli H, Yilmaz EZ, Kebudi R, Santella RM. High levels of global genome methylation in patients with retinoblastoma. Oncol Lett 2020; 20:715-723. [PMID: 32565997 PMCID: PMC7286142 DOI: 10.3892/ol.2020.11613] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 09/26/2019] [Indexed: 02/07/2023] Open
Abstract
Retinoblastoma is a tumor of the embryonic neural retina in young children. The DNA methyltransferase 1 (DNMT1) gene has been demonstrated to be transcriptionally activated in cells lacking retinoblastoma 1 (RB1). Thus, there is a direct interaction between DNMT1 and RB1 in vivo. The present study hypothesized that uncontrolled DNMT1, DNMT2 and DNMT3 expression may lead to a high level of global genome methylation causing a second hit or where both alleles are altered, in RB1 and/or inactivation of other genes in retinal cells. To test this, the global genome methylation levels were analyzed in 69 patients with retinoblastoma, as well as 26 healthy siblings and 18 healthy unrelated children as the control groups. Peripheral blood and tumor tissue samples were obtained from 32 patients. The expression levels of DNMT genes were also determined in cell lines. Based on the median levels of global genome methylation in patients, higher genome-wide methylation levels in peripheral blood were associated with a 3.33-fold increased risk for retinoblastoma in patients compared with all healthy controls (95% confidence interval, 0.98–11.35; P<0.0001). The level of global genome methylation and the expression of DNMT genes were increased in the WERI-RB-1 cell line, which has a mutated RB1 gene, compared with a wild-type RB1-expressing cell line. These results supported the hypothesis that epigenetic alterations, as well as mutations in RB1, may be associated with the oncogenesis and inheritance of retinoblastoma. The repression of genes that interact with RB1, such as the DNMT gene family, may be important in patients with retinoblastoma with alterations in RB1, and may serve a role in the treatment and regression of retinoblastoma.
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Affiliation(s)
- Hülya Yazici
- Department of Environmental Health Sciences, Mailman School of Public Health of Columbia University, New York, NY 10032, USA.,Department of Basic Oncology, Division of Cancer Genetics, Oncology Institute, Istanbul University, Fatih, Istanbul 34093, Turkey
| | - Hui-Chen Wu
- Department of Environmental Health Sciences, Mailman School of Public Health of Columbia University, New York, NY 10032, USA
| | - Hulya Tigli
- Department of Basic Oncology, Division of Cancer Genetics, Oncology Institute, Istanbul University, Fatih, Istanbul 34093, Turkey.,Department of Molecular Biology, Gelişim University, Avcilar, Istanbul 34315, Turkey
| | - Elif Z Yilmaz
- Department of Basic Oncology, Division of Cancer Genetics, Oncology Institute, Istanbul University, Fatih, Istanbul 34093, Turkey.,Faculty of Medicine, Medipol University, Beykoz, Istanbul 34810, Turkey
| | - Rejin Kebudi
- Division of Pediatric Hematology-Oncology, Cerrahpaşa Medical Faculty, Istanbul University, Fatih, İstanbul 34098, Turkey.,Division of Pediatric Hematology-Oncology, Oncology Institute, Istanbul University, Fatih, Istanbul 34093, Turkey
| | - Regina M Santella
- Department of Environmental Health Sciences, Mailman School of Public Health of Columbia University, New York, NY 10032, USA
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12
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Sun J, Xi HY, Shao Q, Liu QH. Biomarkers in retinoblastoma. Int J Ophthalmol 2020; 13:325-341. [PMID: 32090044 DOI: 10.18240/ijo.2020.02.18] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 10/22/2019] [Indexed: 02/06/2023] Open
Abstract
Retinoblastoma (RB) is the most common intraocular malignancy of childhood caused by inactivation of the Rb genes. The prognosis of RB is better with an earlier diagnosis. Many diagnostic approaches and appropriate clinical treatments have been developed to improve clinical outcomes. However, limitations exist when utilizing current methods. Recently, many studies have identified identify new RB biomarkers which can be used in diagnosis, as prognostic indicators and may contribute to understanding the pathogenesis of RB and help determine specific treatment strategies. This review focuses on recent advances in the discovery of RB biomarkers and discusses their clinical utility and challenges from areas such as epigenetics, proteomics and radiogenomics.
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Affiliation(s)
- Jie Sun
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
| | - Hui-Yu Xi
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China.,Department of Ophthalmology, Xuzhou First People's Hospital of Xuzhou Medical University, Xuzhou Eye Research Institute, Xuzhou 221002, Jiangsu Province, China
| | - Qing Shao
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
| | - Qing-Huai Liu
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
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13
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Tomar S, Sethi R, Sundar G, Quah TC, Quah BL, Lai PS. Mutation spectrum of RB1 mutations in retinoblastoma cases from Singapore with implications for genetic management and counselling. PLoS One 2017; 12:e0178776. [PMID: 28575107 PMCID: PMC5456385 DOI: 10.1371/journal.pone.0178776] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 05/18/2017] [Indexed: 12/21/2022] Open
Abstract
Retinoblastoma (RB) is a rare childhood malignant disorder caused by the biallelic inactivation of RB1 gene. Early diagnosis and identification of carriers of heritable RB1 mutations can improve disease outcome and management. In this study, mutational analysis was conducted on fifty-nine matched tumor and peripheral blood samples from 18 bilateral and 41 unilateral unrelated RB cases by a combinatorial approach of Multiplex Ligation-dependent Probe Amplification (MLPA) assay, deletion screening, direct sequencing, copy number gene dosage analysis and methylation assays. Screening of both blood and tumor samples yielded a mutation detection rate of 94.9% (56/59) while only 42.4% (25/59) of mutations were detected if blood samples alone were analyzed. Biallelic mutations were observed in 43/59 (72.9%) of tumors screened. There were 3 cases (5.1%) in which no mutations could be detected and germline mutations were detected in 19.5% (8/41) of unilateral cases. A total of 61 point mutations were identified, of which 10 were novel. There was a high incidence of previously reported recurrent mutations, occurring at 38.98% (23/59) of all cases. Of interest were three cases of mosaic RB1 mutations detected in the blood from patients with unilateral retinoblastoma. Additionally, two germline mutations previously reported to be associated with low-penetrance phenotypes: missense-c.1981C>T and splice variant-c.607+1G>T, were observed in a bilateral and a unilateral proband, respectively. These findings have implications for genetic counselling and risk prediction for the affected families. This is the first published report on the spectrum of mutations in RB patients from Singapore and shows that further improved mutation screening strategies are required in order to provide a definitive molecular diagnosis for every case of RB. Our findings also underscore the importance of genetic testing in supporting individualized disease management plans for patients and asymptomatic family members carrying low-penetrance, germline mosaicism or heritable unilateral mutational phenotypes.
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Affiliation(s)
- Swati Tomar
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Raman Sethi
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Gangadhara Sundar
- Department of Ophthalmology, National University Hospital, Singapore, Singapore
| | - Thuan Chong Quah
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | | | - Poh San Lai
- Department of Paediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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14
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Li W, Liu J, Galvin JA. Epigenetics and Common Ophthalmic Diseases. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2016; 89:597-600. [PMID: 28018148 PMCID: PMC5168835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The study of ocular diseases and epigenetic dysregulation is an emerging area of research. The knowledge from the epigenetic mechanisms of DNA methylation, histone modifications, chromatin remodeling, and non-coding RNAs regarding the pathogenesis of ocular diseases will be helpful for improved treatment modalities for our patients. In particular, we focus upon the how epigenetic regulatory mechanisms impact five common ocular diseases: age related macular degeneration, age-related cataract, pterygium, retinoblastoma, and uveal melanoma. Hence, the foundation of this research paves the way for future specific therapeutic targets to treat and prevent vision loss.
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Affiliation(s)
| | | | - Jennifer A. Galvin
- To whom all correspondence should be addressed: Jennifer A. Galvin, MD, Assistant Professor, Department of Ophthalmology and Visual Science, Yale School of Medicine, 40 Temple Street, Suite 3B, New Haven, CT 06510, Tel: 203-785-2020, Fax: 203-785-5909,
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15
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Epigenetic regulation of human retinoblastoma. Tumour Biol 2016; 37:14427-14441. [PMID: 27639385 DOI: 10.1007/s13277-016-5308-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 09/05/2016] [Indexed: 01/05/2023] Open
Abstract
Retinoblastoma is a rare type of eye cancer of the retina that commonly occurs in early childhood and mostly affects the children before the age of 5. It occurs due to the mutations in the retinoblastoma gene (RB1) which inactivates both alleles of the RB1. RB1 was first identified as a tumor suppressor gene, which regulates cell cycle components and associated with retinoblastoma. Previously, genetic alteration was known as the major cause of its occurrence, but later, it is revealed that besides genetic changes, epigenetic changes also play a significant role in the disease. Initiation and progression of retinoblastoma could be due to independent or combined genetic and epigenetic events. Remarkable work has been done in understanding retinoblastoma pathogenesis in terms of genetic alterations, but not much in the context of epigenetic modification. Epigenetic modifications that silence tumor suppressor genes and activate oncogenes include DNA methylation, chromatin remodeling, histone modification and noncoding RNA-mediated gene silencing. Epigenetic changes can lead to altered gene function and transform normal cell into tumor cells. This review focuses on important epigenetic alteration which occurs in retinoblastoma and its current state of knowledge. The critical role of epigenetic regulation in retinoblastoma is now an emerging area, and better understanding of epigenetic changes in retinoblastoma will open the door for future therapy and diagnosis.
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Abstract
Epigenetics is currently one of the most promising areas of study in the field of biomedical research. Scientists have dedicated their efforts to studying epigenetic mechanisms in cancer for centuries. Additionally, the field has expanded from simply studying DNA methylation to other areas, such as histone modification, non-coding RNA, histone variation, nucleosome location, and chromosome remodeling. In ocular tumors, a large amount of epigenetic exploration has expanded from single genes to the genome-wide level. Most importantly, because epigenetic changes are reversible, several epigenetic drugs have been developed for the treatment of cancer. Herein, we review the current understanding of epigenetic mechanisms in ocular tumors, including but not limited to retinoblastoma and uveal melanoma. Furthermore, the development of new pharmacological strategies is summarized.
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Affiliation(s)
- Xuyang Wen
- Department of Ophthalmology, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
| | - Linna Lu
- Department of Ophthalmology, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
| | - Zhang He
- Department of Ophthalmology, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
| | - Xianqun Fan
- Department of Ophthalmology, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People’s Republic of China
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Benavente CA, Dyer MA. Genetics and epigenetics of human retinoblastoma. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2015; 10:547-62. [PMID: 25621664 DOI: 10.1146/annurev-pathol-012414-040259] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Retinoblastoma is a pediatric tumor of the developing retina from which the genetic basis for cancer development was first described. Inactivation of both copies of the RB1 gene is the predominant initiating genetic lesion in retinoblastoma and is rate limiting for tumorigenesis. Recent whole-genome sequencing of retinoblastoma uncovered a tumor that had no coding-region mutations or focal chromosomal lesions other than in the RB1 gene, shifting the paradigm in the field. The retinoblastoma genome can be very stable; therefore, epigenetic deregulation of tumor-promoting pathways is required for tumorigenesis. This review highlights the genetic and epigenetic changes in retinoblastoma that have been reported, with special emphasis on recent whole-genome sequencing and epigenetic analyses that have identified novel candidate genes as potential therapeutic targets.
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Affiliation(s)
- Claudia A Benavente
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105;
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18
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Yan B, Yao J, Tao ZF, Jiang Q. Epigenetics and ocular diseases: from basic biology to clinical study. J Cell Physiol 2014; 229:825-33. [PMID: 24318407 DOI: 10.1002/jcp.24522] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 12/02/2013] [Indexed: 12/23/2022]
Abstract
Epigenetics is an emerging field in ophthalmology and has opened a new avenue for understanding ocular development and ocular diseases related to aging and environment. Epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodeling, and deployment of non-coding RNAs, result in the heritable silencing of gene expression without any change in DNA sequence. Accumulating evidence suggests a potential link between gene expression, chromatin structure, non-coding RNAs, and cellular differentiation during ocular development. Disruption of the balance of epigenetic networks could become the etiology of several ocular diseases. Here, we summarized the current knowledge about epigenetic regulatory mechanisms in ocular development and diseases.
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Affiliation(s)
- Biao Yan
- Eye Hospital, Nanjing Medical University, Nanjing, China
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19
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Liu R, Zhang XH, Zhang K, Li W, Wang WJ, Luo DX, Gao L. 5-Aza-2''-deoxycytidine inhibits retinoblastoma cell by reactivating epigenetically silenced RASSF1A gene. Int J Ophthalmol 2014; 7:51-6. [PMID: 24634863 DOI: 10.3980/j.issn.2222-3959.2014.01.09] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 10/23/2013] [Indexed: 01/28/2023] Open
Abstract
AIM To investigate the effect of 5-Aza-2'-deoxycytidine (5-Aza-CdR), a DNA methyltransferase (DNMT) inhibitor, on the growth and survival of the Chinese retinoblastoma (RB) cell line HXO-RB44. METHODS The DNA methylation status of the Ras association domain family (RASSF1A) promoter in the presence of 5-Aza-CdR at different concentrations was analyzed by methylation-specific polymerase chain reaction (MSP). RASSF1A mRNA and protein levels were measured by semiquantitative RT-PCR and immunohistochemistry staining, respectively, when cells were treated with 5.0µmol/L of 5-Aza-CdR. The effect of 5.0µmol/L 5-Aza-CdR on the proliferation and viability of HXO-RB44 cells was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. RESULTS 5-Aza-CdR efficiently induced cell cycle arrest at G0/G1 and apoptotic death in HXO-RB44 cells. MSP analysis showed that unmethylated RASSF1A DNA increased and methylated RASSF1A decreased in a dose-dependent manner in a range of 0.5-5.0µmol/L 5-Aza-CdR. Accordingly, RASSF1A expression was reactivated at both mRNA and protein levels. Incubation time of 5-Aza-CdR treatment also functioned as a factor for the demethylation status of RASSF1A promoter DNA, with a plateau on day four. 5-Aza-CdR at 5.0µmol/L completely demethylated the RASSF1A promoter in HXO-RB44 cells on day four, and as a result, RASSF1A expression increased significantly from day 4 to day 7. CONCLUSION 5-Aza-CdR inhibits the growth of the HXO-RB44 RB cell line and induces apoptosis by demethylating the RASSF1A gene.
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Affiliation(s)
- Ru Liu
- Department of Ophthalmology, the Second Xiangya Hospital Central South University, Changsha 410011, Hunan Province, China ; Department of Ophthalmology, the First People's Hospital of Chenzhou City, Chenzhou 423000, Hunan Province, China ; Institute of Translational Medicine, the First People's Hospital of Chenzhou City, Chenzhou 423000, Hunan Province, China
| | - Xiao-Huan Zhang
- Department of Ophthalmology, the Second Xiangya Hospital Central South University, Changsha 410011, Hunan Province, China
| | - Kun Zhang
- Department of Ophthalmology, the Second Xiangya Hospital Central South University, Changsha 410011, Hunan Province, China
| | - Wei Li
- Department of Ophthalmology, the Second Xiangya Hospital Central South University, Changsha 410011, Hunan Province, China
| | - Wen-Jun Wang
- Department of Ophthalmology, the Second Xiangya Hospital Central South University, Changsha 410011, Hunan Province, China
| | - Di-Xian Luo
- Institute of Translational Medicine, the First People's Hospital of Chenzhou City, Chenzhou 423000, Hunan Province, China
| | - Ling Gao
- Department of Ophthalmology, the Second Xiangya Hospital Central South University, Changsha 410011, Hunan Province, China
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20
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Pentimalli F, Indovina P, Giordano A. Retinoblastoma beyondRB1: recent advances in genetic biomarkers. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/eop.10.75] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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21
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Thériault BL, Dimaras H, Gallie BL, Corson TW. The genomic landscape of retinoblastoma: a review. Clin Exp Ophthalmol 2013; 42:33-52. [PMID: 24433356 DOI: 10.1111/ceo.12132] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Accepted: 04/07/2013] [Indexed: 12/13/2022]
Abstract
Retinoblastoma is a paediatric ocular tumour that continues to reveal much about the genetic basis of cancer development. Study of genomic aberrations in retinoblastoma tumours has exposed important mechanisms of cancer development and identified oncogenes and tumour suppressors that offer potential points of therapeutic intervention. The recent development of next-generation genomic technologies has allowed further refinement of the genomic landscape of retinoblastoma at high resolution. In a relatively short period of time, a wealth of genetic and epigenetic data has emerged on a small number of tumour samples. These data highlight the inherent molecular complexity of this cancer despite the fact that most retinoblastomas are initiated by the inactivation of a single tumour suppressor gene. This review outlines the current understanding of the genomic, genetic and epigenetic changes in retinoblastoma, highlighting recent genome-wide analyses that have identified exciting candidate genes worthy of further validation as potential prognostic and therapeutic targets.
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Affiliation(s)
- Brigitte L Thériault
- Campbell Family Cancer Research Institute, Ontario Cancer Institute, Princess Margaret Cancer Centre, Toronto, Ontario, Canada
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22
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Ren R, Liu W, Huang L, Liu DTL, Choy KW, Shi J, Zhao J, Zhao B, Guan M, Shields CL, Pang CP, Li B, Yam GHF. Role of B lymphoma Mo-MLV insertion region 1 in the oncogenic behavior of retinoblastomas. Mol Vis 2013; 19:561-74. [PMID: 23559850 PMCID: PMC3611951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 03/13/2013] [Indexed: 10/31/2022] Open
Abstract
PURPOSE This study investigated the relationship between B lymphoma Mo-MLV insertion region 1 (BMI-1)--a polycomb protein for stem cell self-renewal and proliferation--and the clinicopathological parameters of human retinoblastomas, including differentiation status and retinal tissue invasion, as well as the effects of BMI-1 on retinoblastoma Y79 cells. METHODS Thirty-four archived human retinoblastoma samples were recruited for BMI-1 immunohistochemistry. The percentage of BMI-1-expressing cells was scored by independent pathologists and the data were correlated with the clinical features. Y79 cells were transfected to overexpress or specifically inhibit BMI-1 for cell proliferation, propidium iodide cell cycle and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) apoptosis analyses, multicellular sphere formation assay, and gene expression study. RESULTS BMI-1 was widely expressed in human retinoblastomas. Higher percentages of BMI-1-expressing cells were selectively limited to undifferentiated tumors and those tumors undergoing invasion to the optic nerve and choroid. However, there was no difference in BMI-1 expression in retinoblastoma retinas with or without tumor invasion. In Y79 cells, BMI-1 stimulated cell proliferation and suppressed apoptosis with reduced p14ARF and p16INK4 expression, along with upregulation of proliferating cell nuclear antigens cyclin D1 and D2. In contrast, silencing BMI-1 reversed these changes. It also upregulated CHX10 and Rx, but not other retinal development-related genes, including nestin and neurofilament M. CONCLUSIONS Our work indicates that BMI-1 might render important oncogenic property of retinoblastomas and it could be a therapeutic target for the cancer treatment.
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Affiliation(s)
- Ruojin Ren
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong,Beijing Institute of Ophthalmology, Beijing TongRen Hospital Eye Center, Capital Medical University, Beijing, China
| | - Weiwei Liu
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong,Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, P.R. China
| | - Li Huang
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - David Tai Li Liu
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Kwong Wai Choy
- Obstetrics & Gynaecology, The Chinese University of Hong Kong, Hong Kong
| | - Jitong Shi
- Beijing Institute of Ophthalmology, Beijing TongRen Hospital Eye Center, Capital Medical University, Beijing, China
| | - Junyang Zhao
- Beijing Institute of Ophthalmology, Beijing TongRen Hospital Eye Center, Capital Medical University, Beijing, China
| | - Bowen Zhao
- Beijing Institute of Ophthalmology, Beijing TongRen Hospital Eye Center, Capital Medical University, Beijing, China
| | - Ming Guan
- Department of Laboratory Medicine, Huashan Hospital, Fudan University, Shanghai, P.R. China
| | - Carol L. Shields
- Ocular Ocology Service, Wills Eye Institute, Thomas Jefferson University, PA
| | - Chi Pui Pang
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Bin Li
- Beijing Institute of Ophthalmology, Beijing TongRen Hospital Eye Center, Capital Medical University, Beijing, China
| | - Gary Hin Fai Yam
- Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Hong Kong,Tissue Engineering and Stem Cell Research Group, Singapore Eye Research Institute, 11 Third Hospital Avenue, Singapore, Singapore
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23
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Ramalho-Carvalho J, Pires M, Lisboa S, Graça I, Rocha P, Barros-Silva JD, Savva-Bordalo J, Maurício J, Resende M, Teixeira MR, Honavar M, Henrique R, Jerónimo C. Altered expression of MGMT in high-grade gliomas results from the combined effect of epigenetic and genetic aberrations. PLoS One 2013; 8:e58206. [PMID: 23505468 PMCID: PMC3594314 DOI: 10.1371/journal.pone.0058206] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2012] [Accepted: 01/31/2013] [Indexed: 01/06/2023] Open
Abstract
MGMT downregulation in high-grade gliomas (HGG) has been mostly attributed to aberrant promoter methylation and is associated with increased sensitivity to alkylating agent-based chemotherapy. However, HGG harboring 10q deletions also benefit from treatment with alkylating agents. Because the MGMT gene is mapped at 10q26, we hypothesized that both epigenetic and genetic alterations might affect its expression and predict response to chemotherapy. To test this hypothesis, promoter methylation and mRNA levels of MGMT were determined by quantitative methylation-specific PCR (qMSP) or methylation-specific multiplex ligation dependent probe amplification (MS-MLPA) and quantitative RT-PCR, respectively, in a retrospective series of 61 HGG. MGMT/chromosome 10 copy number variations were determined by FISH or MS-MLPA analysis. Molecular findings were correlated with clinical parameters to assess their predictive value. Overall, MGMT methylation ratios assessed by qMSP and MS-MLPA were inversely correlated with mRNA expression levels (best coefficient value obtained with MS-MLPA). By FISH analysis in 68.3% of the cases there was loss of 10q26.1 and in 15% of the cases polysomy was demonstrated; the latter displayed the highest levels of transcript. When genetic and epigenetic data were combined, cases with MGMT promoter methylation and MGMT loss depicted the lowest transcript levels, although an impact in response to alkylating agent chemotherapy was not apparent. Cooperation between epigenetic (promoter methylation) and genetic (monosomy, locus deletion) changes affecting MGMT in HGG is required for effective MGMT silencing. Hence, evaluation of copy number alterations might add relevant prognostic and predictive information concerning response to alkylating agent-based chemotherapy.
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Affiliation(s)
- João Ramalho-Carvalho
- Cancer Epigenetics Group, Research Center of the Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Malini Pires
- Cancer Epigenetics Group, Research Center of the Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Susana Lisboa
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Inês Graça
- Cancer Epigenetics Group, Research Center of the Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Patrícia Rocha
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
| | - João Diogo Barros-Silva
- Cancer Genetics Group, Research Center of the Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Joana Savva-Bordalo
- Cancer Epigenetics Group, Research Center of the Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Medical Oncology, Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Joaquina Maurício
- Department of Medical Oncology, Portuguese Oncology Institute-Porto, Porto, Portugal
| | - Mário Resende
- Department of Neurosurgery, Local Health Unit of Matosinhos - Hospital Pedro Hispano, Matosinhos, Portugal
| | - Manuel R. Teixeira
- Cancer Genetics Group, Research Center of the Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Mrinalini Honavar
- Department of Pathology, Local Health Unit of Matosinhos - Hospital Pedro Hispano, Matosinhos, Portugal
| | - Rui Henrique
- Cancer Epigenetics Group, Research Center of the Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Pathology, Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Carmen Jerónimo
- Cancer Epigenetics Group, Research Center of the Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Genetics, Portuguese Oncology Institute-Porto, Porto, Portugal
- Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- * E-mail:
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24
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Eyes on DNA methylation: current evidence for DNA methylation in ocular development and disease. J Ocul Biol Dis Infor 2012; 4:95-103. [PMID: 23538551 DOI: 10.1007/s12177-012-9078-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Accepted: 03/05/2012] [Indexed: 12/20/2022] Open
Abstract
Epigenetic modulation of chromatin states constitutes a vital component of the cellular repertoire of transcriptional regulatory mechanisms. The development of new technologies capable of generating genome-wide maps of chromatin modifications has re-energized the field. We are now poised to determine how species- and tissue-specific patterns of DNA methylation, in concert with other chromatin modifications, function to establish and maintain cell- and tissue-specific patterns of gene expression during normal development, cellular differentiation, and disease. This review addresses our current understanding of the major mechanisms and function of DNA methylation in vertebrates with a historical perspective and an emphasis on what is known about DNA methylation in eye development and disease.
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Livide G, Epistolato MC, Amenduni M, Disciglio V, Marozza A, Mencarelli MA, Toti P, Lazzi S, Hadjistilianou T, De Francesco S, D'Ambrosio A, Renieri A, Ariani F. Epigenetic and copy number variation analysis in retinoblastoma by MS-MLPA. Pathol Oncol Res 2012; 18:703-12. [PMID: 22278416 DOI: 10.1007/s12253-012-9498-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 01/03/2012] [Indexed: 12/31/2022]
Abstract
Retinoblastoma is the most common primary intraocular malignancy in children. Two step inactivation of RB1 (M1-M2) represents the key event in the pathogenesis of retinoblastoma but additional genetic and epigenetic events (M3-Mn) are required for tumor development. In the present study, we employed Methylation Specific Multiplex Ligation Probe Assay to investigate methylation status and copy number changes of 25 and 39 oncosuppressor genes, respectively. This technique was applied to analyse 12 retinoblastomas (5 bilateral and 7 unilateral) and results were compared to corresponding normal retina. We identified hypermethylation in seven new genes: MSH6 (50%), CD44 (42%), PAX5 (42%), GATA5 (25%), TP53 (8%), VHL (8%) and GSTP1 (8%) and we confirmed the previously reported hypermethylation of MGMT (58%), RB1 (17%) and CDKN2 (8%). These genes belong to key pathways including DNA repair, pRB and p53 signalling, transcriptional regulation, protein degradation, cell-cell interaction, cellular adhesion and migration. In the same group of retinoblastomas, a total of 29 copy number changes (19 duplications and 10 deletions) have been identified. Interestingly, we found deletions of the following oncosuppressor genes that might contribute to drive retinoblastoma tumorigenesis: TP53, CDH13, GATA5, CHFR, TP73 and IGSF4. The present data highlight the importance of epigenetic changes in retinoblastoma and indicate seven hypermethylated oncosuppressors never associated before to retinoblastoma pathogenesis. This study also confirms the presence of copy number variations in retinoblastoma, expecially in unilateral cases (mean 3 ± 1.3) where these changes were found more frequently respect to bilateral cases (mean 1.4 ± 1.1).
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Qu Y, Mu G, Wu Y, Dai X, Zhou F, Xu X, Wang Y, Wei F. Overexpression of DNA methyltransferases 1, 3a, and 3b significantly correlates with retinoblastoma tumorigenesis. Am J Clin Pathol 2010; 134:826-34. [PMID: 20959668 DOI: 10.1309/ajcphgq69fxdfwii] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
DNA methyltransferases (DNMTs) 1, 3a, and 3b affect DNA promoter methylation; studies have suggested that they have important roles in the development of cancers. In this study, we analyzed the expression of DNMTs 1, 3a, and 3b; the MIB-1 labeling index; and their clinical significance in 6 normal retinas and 62 retinoblastomas using immunohistochemical analysis. We found that DNMT proteins were not expressed in normal retinas, whereas they were frequently expressed in retinoblastomas (DNMT1, 100%; DNMT3a, 98%; and DNMT3b, 92%). Compared with well-differentiated retinoblastomas, the expression of DNMTs 1 and 3a significantly increased in poorly differentiated retinoblastomas (P = .002 and P = .003, respectively); in addition, the frequency of their increased expression was high. DNMT1 expression was significantly higher in invasive retinoblastoma. Furthermore, the expression of DNMTs was positively correlated with the MIB-1 labeling index in retinoblastoma. Our findings suggest that the overexpression of DNMTs 1, 3a, and 3b may be related to retinoblastoma tumorigenesis and progression and may represent a novel approach for retinoblastoma therapy.
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Affiliation(s)
- Yi Qu
- Department of Ophthalmology, Qilu Hospital of Shandong University, Jinan, China
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Indovina P, Acquaviva A, De Falco G, Rizzo V, Onnis A, Luzzi A, Giorgi F, Hadjistilianou T, Toti P, Tomei V, Pentimalli F, Carugi A, Giordano A. Downregulation and aberrant promoter methylation of p16INK4A: a possible novel heritable susceptibility marker to retinoblastoma. J Cell Physiol 2010; 223:143-50. [PMID: 20039270 DOI: 10.1002/jcp.22019] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
RB loss has long been recognized as the causative genetic alteration underlying retinoblastoma but it is increasingly evident that other alterations are required for the tumor to develop. Therefore, we set out to identify additional inheritable susceptibility markers and new potential preventive and therapeutic targets for retinoblastoma. We focused on the p16INK4A tumor suppressor gene because of its possible role in retinoblastoma pathogenesis and its involvement in predisposition to familial cancer. p16INK4A expression was analyzed in tumor samples from retinoblastoma patients by immunohistochemistry and in peripheral blood cells from both patients and their parents by real-time quantitative reverse transcription-PCR (qRT-PCR). Since promoter methylation is a common mechanism regulating p16INK4A expression, the methylation status of its promoter was also analyzed in blood samples from patients and their parents by methylation-specific PCR. A downregulation of p16INK4A was observed in 55% of retinoblastoma patients. Interestingly, in 56% of the cases showing p16INK4A downregulation at least one of the patients' parents bore the same alteration in blood cells. Analysis of p16INK4A promoter methylation showed hypermethylation in most patients with p16INK4A downregulation and in the parents with the same alteration in p16INK4A expression. The finding that p16INK4A was downregulated both in patients and their parents suggests that this alteration could be a novel inheritable susceptibility marker to retinoblastoma. The observation that p16INK4A downregulation seems to be due to its promoter hypermethylation opens the way for the development of new preventive and therapeutic strategies using demethylating agents.
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Affiliation(s)
- Paola Indovina
- Department of Human Pathology and Oncology, University of Siena, Siena, Italy
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Dalgard CL, Van Quill KR, O'Brien JM. Evaluation of the In vitro and In vivo Antitumor Activity of Histone Deacetylase Inhibitors for the Therapy of Retinoblastoma. Clin Cancer Res 2008; 14:3113-23. [DOI: 10.1158/1078-0432.ccr-07-4836] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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29
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Neoplasia: An Anniversary of Progress. Neoplasia 2007. [DOI: 10.1593/neo.07968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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30
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Cohen Y, Merhavi-Shoham E, Avraham RB, Frenkel S, Pe'er J, Goldenberg-Cohen N. Hypermethylation of CpG island loci of multiple tumor suppressor genes in retinoblastoma. Exp Eye Res 2007; 86:201-6. [PMID: 18068703 DOI: 10.1016/j.exer.2007.10.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2007] [Revised: 10/20/2007] [Accepted: 10/23/2007] [Indexed: 11/25/2022]
Abstract
Epigenetic silencing of tumor suppressor genes by methylation of discrete regions of the CpG islands is a major mechanism underlying tumorigenesis. Methylation of at least three of five specific genes may represent a distinct trait, termed the CpG island methylator phenotype (CIMP). Positive CIMP is associated with BRAF mutations. The present study sought to investigate the presence of BRAF mutations in human retinoblastoma and the role of epigenetic silencing of multiple tumor suppression genes in a search for methylation phenotype. Twenty-five archival retinoblastoma samples were analyzed for BRAF mutations with polymerase chain reaction, Mutector assay, and direct sequencing. Nineteen samples were also analyzed for the promoter methylation status of eight candidate cancer-related genes using real-time quantitative methylation-specific polymerase chain reaction after sodium bisulfite modification. The CIMP status was determined. No BRAF mutations were found. The frequencies of cancer-related gene methylation were as follows: 89% for RASSF1A, 52% for NEUROG1, 5% for DAP-kinase, RUNX3 and CACNA1G, and 0 for RAR-beta2, SOCS-1 and IGF-2. The lack of BRAF mutations in retinoblastoma is in accord with the negative CIMP status and the high hypermethylation rate for RASSF1A. The high methylation status for NEUROG1 may point to an alternative pathway in the development and progression of retinoblastoma, but further studies are needed.
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Affiliation(s)
- Yoram Cohen
- Department of Gynecology, Sheba Cancer Research Center, Sheba Medical Center, Tel Hashomer, Israel
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31
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Bowles E, Corson TW, Bayani J, Squire JA, Wong N, Lai PBS, Gallie BL. Profiling genomic copy number changes in retinoblastoma beyond loss of RB1. Genes Chromosomes Cancer 2007; 46:118-29. [PMID: 17099872 DOI: 10.1002/gcc.20383] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Loss of both RB1 alleles is rate limiting for development of retinoblastoma (RB), but genomic copy number gain or loss may impact oncogene(s) and tumor suppressor genes, facilitating tumor progression. We used quantitative multiplex polymerase chain reaction to profile "hot spot" genomic copy number changes for gain at 1q32.1, 6p22, and MYCN, and loss at 16q22 in 87 primary RB and 7 cell lines. Loss at 16q22 (48%) negatively associated with MYCN gain (18%) (Fisher's exact P = 0.031), gain at 1q32.1 (62%) positively associated with 6p "hot spot" gain (43%) (P = 0.033), and there was a trend for positive association between 1q and MYCN gain (P = 0.095). Cell lines had a higher frequency of MYCN amplification than primary tumors (29% versus 3%; P = 0.043). Novel high-level amplification of 1q32.1 in one primary tumor, confirmed by fluorescence in situ hybridization, strongly supports the presence of oncogene(s) in this region, possibly the mitotic kinesin, KIF14. Gene-specific quantitative multiplex polymerase chain reaction of candidate oncogenes at 1q32.1 (KIF14), 6p22 (E2F3 and DEK), and tumor suppressor genes at 16q22 (CDH11) and 17q21 (NGFR) showed the most common gene gains in RB to be KIF14 in cell lines (80%) and E2F3 in primary tumors (70%). The patterns of gain/loss were qualitatively different in 25 RB compared with 12 primary hepatocellular carcinoma and 12 breast cancer cell lines. Gene specific analysis of one bone marrow metastasis of RB, prechemotherapy and postchemotherapy, showed the typical genomic changes of RB pretreatment, which normalized after chemotherapy.
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Affiliation(s)
- Ella Bowles
- Division of Applied Molecular Oncology, Ontario Cancer Institute/Princess Margaret Hospital, University Health Network, Toronto, ON, Canada
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Corson TW, Gallie BL. One hit, two hits, three hits, more? Genomic changes in the development of retinoblastoma. Genes Chromosomes Cancer 2007; 46:617-34. [PMID: 17437278 DOI: 10.1002/gcc.20457] [Citation(s) in RCA: 179] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The childhood eye cancer retinoblastoma is initiated by the loss of both alleles of the prototypic tumor suppressor gene, RB1. However, a large number of cytogenetic and comparative genomic hybridization (CGH) studies have shown that these M1 and M2 mutational events--although necessary for initiation--are not the only genomic changes in retinoblastoma. Some of these subsequent changes, which we have termed M3 to Mn, are likely crucial for tumor progression not only in retinoblastoma but also in other cancers. Moreover, genes showing genomic change in cancer are more stable markers and, therefore, possible therapeutic targets than genes simply differentially expressed. In this review, we provide the first comprehensive summary of the genomic evidence implicating gain of 1q, 2p, 6p, and 13q, and loss of 16q in retinoblastoma oncogenesis, including karyotype, CGH, and microarray CGH data. We discuss the search for candidate oncogenes and tumor suppressor genes within these regions, including the candidates (KIF14, MDM4, MYCN, E2F3, DEK, CDH11, and others), plus associations between genomic changes and clinical parameters. We also review studies of other regions of the retinoblastoma genome, the epigenetic changes of aberrant methylation of MGMT, RASSF1A, CASP8, and MLH1, and the roles microRNAs might play in this cancer. Although many candidate genes have yet to be functionally validated in retinoblastoma, work in this field lays out a molecular cytogenetic pathway of retinoblastoma development. Candidate cancer genes carry diagnostic, prognostic, and therapeutic implications beyond retinoblastoma.
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Affiliation(s)
- Timothy W Corson
- Division of Applied Molecular Oncology, Ontario Cancer Institute/Princess Margaret Hospital, University Health Network, Toronto, ON, Canada
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Rehemtulla A, Ross BD. A review of the past, present, and future directions of neoplasia. Neoplasia 2006; 7:1039-46. [PMID: 16354585 PMCID: PMC1501177 DOI: 10.1593/neo.05793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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34
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Fan BJ, Tam POS, Choy KW, Wang DY, Lam DSC, Pang CP. Molecular diagnostics of genetic eye diseases. Clin Biochem 2006; 39:231-9. [PMID: 16412407 DOI: 10.1016/j.clinbiochem.2005.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Revised: 11/01/2005] [Accepted: 11/25/2005] [Indexed: 01/26/2023]
Abstract
Eye diseases can be simple or complex, and mostly of heterogeneous molecular genetics. Some eye diseases are caused by mutations in a single gene, but some diseases, such as primary open angle glaucoma, can be due to sequence variations in multiple genes. In some diseases, both genetic and epigenetic mechanisms are involved, as was recently revealed in the mechanism of retinoblastoma. Disease causative mutations and phenotypes may vary by ethnicity and geography. To date, more than a hundred candidate genes for eye diseases are known, although less than 20 have definite disease-causing mutations. The three common genetic eye diseases, primary open angle glaucoma, age-related macular degeneration, and retinitis pigmentosa, all have known gene mutations, but these account for only a portion of the patients. While the search for eye disease genes and mutations still goes on, known mutations have been utilized for diagnosis. Genetic markers for pre-symptomatic and pre-natal diagnosis are available for specific diseases such as primary open angle glaucoma and retinoblastoma. This paper reviews the molecular basis of common genetic eye diseases and the available genetic markers for clinical diagnosis. Difficulties and challenges in molecular investigation of some eye diseases are discussed. Establishment of ethnic-specific disease databases that contain both clinical and genetic information for identification of genetic markers with diagnostic, prognostic, or pharmacological value is strongly advocated.
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Affiliation(s)
- Bao Jian Fan
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong Eye Hospital, 147K Argyle Street, Kowloon, Hong Kong
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