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Fogarty EA, Buchert EM, Ma Y, Nicely AB, Buttitta LA. Transcriptional repression and enhancer decommissioning silence cell cycle genes in postmitotic tissues. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.06.592773. [PMID: 38766255 PMCID: PMC11100713 DOI: 10.1101/2024.05.06.592773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The mechanisms that maintain a non-cycling status in postmitotic tissues are not well understood. Many cell cycle genes have promoters and enhancers that remain accessible even when cells are terminally differentiated and in a non-cycling state, suggesting their repression must be maintained long term. In contrast, enhancer decommissioning has been observed for rate-limiting cell cycle genes in the Drosophila wing, a tissue where the cells die soon after eclosion, but it has been unclear if this also occurs in other contexts of terminal differentiation. In this study, we show that enhancer decommissioning also occurs at specific, rate-limiting cell cycle genes in the long-lived tissues of the Drosophila eye and brain, and we propose this loss of chromatin accessibility may help maintain a robust postmitotic state. We examined the decommissioned enhancers at specific rate-limiting cell cycle genes and show that they encode dynamic temporal and spatial expression patterns that include shared, as well as tissue-specific elements, resulting in broad gene expression with developmentally controlled temporal regulation. We extend our analysis to cell cycle gene expression and chromatin accessibility in the mammalian retina using a published dataset, and find that the principles of cell cycle gene regulation identified in terminally differentiating Drosophila tissues are conserved in the differentiating mammalian retina. We propose a robust, non-cycling status is maintained in long-lived postmitotic tissues through a combination of stable repression at most cell cycle gens, alongside enhancer decommissioning at specific rate-limiting cell cycle genes.
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Affiliation(s)
- Elizabeth A. Fogarty
- Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor 48109
| | - Elli M. Buchert
- Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor 48109
| | - Yiqin Ma
- Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor 48109
| | - Ava B. Nicely
- Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor 48109
| | - Laura A. Buttitta
- Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor 48109
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Jiang Y, Yu Y, Pan Z, Glandorff C, Sun M. Ferroptosis: a new hunter of hepatocellular carcinoma. Cell Death Discov 2024; 10:136. [PMID: 38480712 PMCID: PMC10937674 DOI: 10.1038/s41420-024-01863-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 02/06/2024] [Accepted: 02/12/2024] [Indexed: 03/17/2024] Open
Abstract
Ferroptosis is an iron ion-dependent, regulatory cell death modality driven by intracellular lipid peroxidation that plays a key role in the development of HCC. Studies have shown that various clinical agents (e.g., sorafenib) have ferroptosis inducer-like effects and can exert therapeutic effects by modulating different key factors in the ferroptosis pathway. This implies that targeting tumor cell ferroptosis may be a very promising strategy for tumor therapy. In this paper, we summarize the prerequisites and defense systems for the occurrence of ferroptosis and the regulatory targets of drug-mediated ferroptosis action in HCC, the differences and connections between ferroptosis and other programmed cell deaths. We aim to summarize the theoretical basis, classical inducers of ferroptosis and research progress of ferroptosis in HCC cells, clued to the treatment of HCC by regulating ferroptosis network. Further investigation of the specific mechanisms of ferroptosis and the development of hepatocellular carcinoma and interventions at different stages of hepatocellular carcinoma will help us to deepen our understanding of hepatocellular carcinoma, with a view to providing new and more precise preventive as well as therapeutic measures for patients.
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Affiliation(s)
- Yulang Jiang
- Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Key Laboratory of Liver and Kidney Diseases, Institute of Liver Diseases, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Yongxin Yu
- Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Key Laboratory of Liver and Kidney Diseases, Institute of Liver Diseases, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Ziyang Pan
- Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Key Laboratory of Liver and Kidney Diseases, Institute of Liver Diseases, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Christian Glandorff
- Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- Key Laboratory of Liver and Kidney Diseases, Institute of Liver Diseases, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
- University Clinic of Hamburg at the HanseMerkur Center of TCM, Hamburg, Germany
| | - Mingyu Sun
- Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
- Key Laboratory of Liver and Kidney Diseases, Institute of Liver Diseases, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
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Leite Rocha D, Ashton-Prolla P, Rosset C. Reviewing the occurrence of large genomic rearrangements in patients with inherited cancer predisposing syndromes: importance of a comprehensive molecular diagnosis. Expert Rev Mol Diagn 2022; 22:319-346. [PMID: 35234551 DOI: 10.1080/14737159.2022.2049247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Hereditary cancer predisposition syndromes are caused by germline pathogenic or likely pathogenic variants in cancer predisposition genes (CPG). The majority of pathogenic variants in CPGs are point mutations, but large gene rearrangements (LGRs) are present in several CPGs. LGRs can be much more difficult to characterize and perhaps they may have been neglected in molecular diagnoses. AREAS COVERED We aimed to evaluate the frequencies of germline LGRs in studies conducted in different populations worldwide through a qualitative systematic review based on an online literature research in PubMed. Two reviewers independently extracted data from published studies between 2009 and 2020. In total, 126 studies from 37 countries and 5 continents were included in the analysis. The number of studies in different continents ranged from 3 to 48 and for several countries there was an absolute lack of information. Asia and Europe represented most of the studies, and LGR frequencies varied from 3.04 to 15.06% in different continents. MLPA was one of the methods of choice in most studies (93%). EXPERT OPINION The LGR frequencies found in this review reinforce the need for comprehensive molecular testing regardless of the population of origin and should be considered by genetic counseling providers.
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Affiliation(s)
- Débora Leite Rocha
- Laboratório de Medicina Genômica, Serviço de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Rua Ramiro Barcelos, 2350, CEP: 90035-930, Porto Alegre, Rio Grande do Sul, Brazil
| | - Patrícia Ashton-Prolla
- Laboratório de Medicina Genômica, Serviço de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Rua Ramiro Barcelos, 2350, CEP: 90035-930, Porto Alegre, Rio Grande do Sul, Brazil.,Programa de Pós-Graduação em Genética e Biologia Molecular, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Rio Grande do Sul, Brazil. Av. Bento Gonçalves, 9500 - Prédio 43312 M, CEP: 91501-970, Caixa Postal 1505, Porto Alegre, Rio Grande do Sul, Brazil.,Serviço de Genética Médica, HCPA, Rio Grande do Sul, Brazil. Rua Ramiro Barcelos, 2350, CEP: 90035-930, Porto Alegre, Rio Grande do Sul, Brazil
| | - Clévia Rosset
- Laboratório de Medicina Genômica, Serviço de Pesquisa Experimental, Hospital de Clínicas de Porto Alegre (HCPA), Rua Ramiro Barcelos, 2350, CEP: 90035-930, Porto Alegre, Rio Grande do Sul, Brazil
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Structural changes of the macula and optic nerve head in the remaining eyes after enucleation for retinoblastoma: an optical coherence tomography study. BMC Ophthalmol 2017; 17:251. [PMID: 29246122 PMCID: PMC5732405 DOI: 10.1186/s12886-017-0650-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Accepted: 12/05/2017] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND To describe objectively the possible structural changes of the macula and optic nerve head in the free eyes of unilateral cured retinoblastoma patients and, also after enucleation using spectral domain optical coherence tomography. METHODS A cross sectional study involving 60 patients subdivided into three groups; 15 unilateral RB patients in whom enucleation was indicated as a sole treatment performed earlier in life [(study group (I)], 15 unilateral RB patients who had completely regressed disease with a preserved eye [(study group (II)] and 30 age and sex matched healthy controls. The remaining and free eyes in study groups and right eyes of control group had full ophthalmological examination, static automated perimetry and optical coherence tomography of the macula and optic nerve head. RESULTS In study group (II); a significant thinning of total macula, central fovea, ganglion cell layer (GCL), ganglion cell complex (GCC), and some sectors of outer nuclear layer (P- values ≤0.05) was found with no significant difference in peripapillary nerve fiber layer (pRNFL) thickness and optic nerve head parameters compared to the control group and the study group (I). A significantly thickened total macula, GCL, GCC, and pRNFL in study group (I) compared to study group (II). Thickened pRNFL was significantly correlated to standard automated perimetry pattern deviations. No significant difference was found between study group (I) and control group. CONCLUSION Retinoblastoma eyes characterized by thinning of central fovea, GCL, GCC compared to the control group. After unilateral enucleation, increased GCC and pRNFL thicknesses were detected compared to retinoblastoma group.
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Miles WO, Dyson NJ. Pumilio and nanos RNA-binding proteins counterbalance the transcriptional consequences of RB1 inactivation. Mol Cell Oncol 2014; 1:e968074. [PMID: 27308363 DOI: 10.4161/23723548.2014.968074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 08/20/2014] [Accepted: 08/20/2014] [Indexed: 11/19/2022]
Abstract
The ability of the retinoblastoma protein (RB) tumor suppressor to repress transcription stimulated by the E2 promoter binding factors (E2F) is integral to its biological functions. Our recent report described a conserved feedback mechanism mediated by the RNA-binding proteins Pumilio and Nanos that increases in importance following RB loss and helps cells to tolerate deregulated E2F.
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Affiliation(s)
- Wayne O Miles
- Massachusetts General Hospital Cancer Center and Harvard Medical School ; Charlestown, MA USA
| | - Nicholas J Dyson
- Massachusetts General Hospital Cancer Center and Harvard Medical School ; Charlestown, MA USA
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Miles WO, Korenjak M, Griffiths LM, Dyer MA, Provero P, Dyson NJ. Post-transcriptional gene expression control by NANOS is up-regulated and functionally important in pRb-deficient cells. EMBO J 2014; 33:2201-15. [PMID: 25100735 PMCID: PMC4282507 DOI: 10.15252/embj.201488057] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 07/11/2014] [Accepted: 07/15/2014] [Indexed: 11/09/2022] Open
Abstract
Inactivation of the retinoblastoma tumor suppressor (pRb) is a common oncogenic event that alters the expression of genes important for cell cycle progression, senescence, and apoptosis. However, in many contexts, the properties of pRb-deficient cells are similar to wild-type cells suggesting there may be processes that counterbalance the transcriptional changes associated with pRb inactivation. Therefore, we have looked for sets of evolutionary conserved, functionally related genes that are direct targets of pRb/E2F proteins. We show that the expression of NANOS, a key facilitator of the Pumilio (PUM) post-transcriptional repressor complex, is directly repressed by pRb/E2F in flies and humans. In both species, NANOS expression increases following inactivation of pRb/RBF1 and becomes important for tissue homeostasis. By analyzing datasets from normal retinal tissue and pRb-null retinoblastomas, we find a strong enrichment for putative PUM substrates among genes de-regulated in tumors. These include pro-apoptotic genes that are transcriptionally down-regulated upon pRb loss, and we characterize two such candidates, MAP2K3 and MAP3K1, as direct PUM substrates. Our data suggest that NANOS increases in importance in pRb-deficient cells and helps to maintain homeostasis by repressing the translation of transcripts containing PUM Regulatory Elements (PRE).
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Affiliation(s)
- Wayne O Miles
- Massachusetts General Hospital Cancer Center and Harvard Medical School Laboratory of Molecular Oncology, Charlestown, MA, USA
| | - Michael Korenjak
- Massachusetts General Hospital Cancer Center and Harvard Medical School Laboratory of Molecular Oncology, Charlestown, MA, USA
| | - Lyra M Griffiths
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Michael A Dyer
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Paolo Provero
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy Center for Translational Genomics and Bioinformatics, San Raffaele Scientific Institute, Milan, Italy
| | - Nicholas J Dyson
- Massachusetts General Hospital Cancer Center and Harvard Medical School Laboratory of Molecular Oncology, Charlestown, MA, USA
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7
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Abstract
The recent Company of Biologists workshop 'Growth, Division and Differentiation: Understanding Developmental Control', which was held in September 2011 at Wiston House, West Sussex, UK, brought together researchers aiming to understand cell proliferation and differentiation in various metazoans, ranging from flies to mice. Here, we review the common themes that emerged from the meeting, highlighting novel insights into the interplay between regulators of cell proliferation and differentiation during development.
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Affiliation(s)
- Philipp Kaldis
- Institute of Molecular and Cell Biology (IMCB), 61 Biopolis Drive, Proteos, Singapore 138673, Singapore.
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Madhavan J, Mallikarjuna K, Vikas K, George R, Bremner R, Kumaramanickavel G. CDKN1C (p57KIP2)mRNA expression in human retinoblastomas. Ophthalmic Genet 2010; 31:141-6. [DOI: 10.3109/13816810.2010.490544] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Das G, Choi Y, Sicinski P, Levine EM. Cyclin D1 fine-tunes the neurogenic output of embryonic retinal progenitor cells. Neural Dev 2009; 4:15. [PMID: 19416500 PMCID: PMC2694796 DOI: 10.1186/1749-8104-4-15] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2008] [Accepted: 05/05/2009] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Maintaining the correct balance of proliferation versus differentiation in retinal progenitor cells (RPCs) is essential for proper development of the retina. The cell cycle regulator cyclin D1 is expressed in RPCs, and mice with a targeted null allele at the cyclin D1 locus (Ccnd1-/-) have microphthalmia and hypocellular retinas, the latter phenotype attributed to reduced RPC proliferation and increased photoreceptor cell death during the postnatal period. How cyclin D1 influences RPC behavior, especially during the embryonic period, is unclear. RESULTS In this study, we show that embryonic RPCs lacking cyclin D1 progress through the cell cycle at a slower rate and exit the cell cycle at a faster rate. Consistent with enhanced cell cycle exit, the relative proportions of cell types born in the embryonic period, such as retinal ganglion cells and photoreceptor cells, are increased. Unexpectedly, cyclin D1 deficiency decreases the proportions of other early born retinal neurons, namely horizontal cells and specific amacrine cell types. We also found that the laminar positioning of horizontal cells and other cell types is altered in the absence of cyclin D1. Genetically replacing cyclin D1 with cyclin D2 is not efficient at correcting the phenotypes due to the cyclin D1 deficiency, which suggests the D-cyclins are not fully redundant. Replacement with cyclin E or inactivation of cyclin-dependent kinase inhibitor p27Kip1 restores the balance of RPCs and retinal cell types to more normal distributions, which suggests that regulation of the retinoblastoma pathway is an important function for cyclin D1 during embryonic retinal development. CONCLUSION Our findings show that cyclin D1 has important roles in RPC cell cycle regulation and retinal histogenesis. The reduction in the RPC population due to a longer cell cycle time and to an enhanced rate of cell cycle exit are likely to be the primary factors driving retinal hypocellularity and altered output of precursor populations in the embryonic Ccnd1-/- retina.
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Affiliation(s)
- Gaurav Das
- Department of Ophthalmology and Visual Sciences, John A Moran Eye Center, University of Utah, Salt Lake City, UT 84132, USA.
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Paderova J, Orlic-Milacic M, Yoshimoto M, da Cunha Santos G, Gallie B, Squire JA. Novel 6p rearrangements and recurrent translocation breakpoints in retinoblastoma cell lines identified by spectral karyotyping and mBAND analyses. ACTA ACUST UNITED AC 2008; 179:102-11. [PMID: 18036396 DOI: 10.1016/j.cancergencyto.2007.08.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Accepted: 08/28/2007] [Indexed: 01/09/2023]
Abstract
Gain of the short arm of chromosome 6, usually through isochromosome 6p formation, is present in approximately 50% of retinoblastoma tumors. The minimal region of gain maps to chromosome band 6p22. Two genes, DEK and E2F3, are implicated as candidate oncogenes. However, chromosomal translocations have been overlooked as a potential mechanism of activation of oncogenes at 6p22 in retinoblastoma. Here, we report combined spectral karyotyping), 4',6-diamidino-2-phenylindole banding, mBAND, and locus-specific fluorescence in situ hybridization analyses of four retinoblastoma cell lines, RB1021, RB247c, RB383, and Y79. In RB1021 and RB247c, 6p undergoes structural rearrangements involving a common translocation breakpoint at 6p22. These data imply that 6p translocations may represent another mechanism of activation of 6p oncogene(s) in a subset of retinoblastomas, besides the copy number increase. In addition to 6p22, other recurrent translocation breakpoints identified in this study are 4p16, 11p15, 17q21.3, and 20q13. Common regions of gain map to chromosomal arms 1q, 2p, 6p, 17q, and 21q.
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Affiliation(s)
- Jana Paderova
- Department of Applied Molecular Oncology, Ontario Cancer Institute, Princess Maragaret Hospital, 610 University Avenue, Toronto, Ontario, Canada M5G 2M9
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Taylor M, Dehainault C, Desjardins L, Doz F, Levy C, Sastre X, Couturier J, Stoppa-Lyonnet D, Houdayer C, Gauthier-Villars M. Genotype-phenotype correlations in hereditary familial retinoblastoma. Hum Mutat 2007; 28:284-93. [PMID: 17096365 DOI: 10.1002/humu.20443] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We studied 50 unrelated pedigrees with a family history of retinoblastoma (Rb) (165 carriers of a RB1 mutation) to delineate the spectrum of RB1 germline mutations in familial Rb and to identify genotype-phenotype correlations as well as putative modifiers. Patients were followed at Institut Curie and they were examined by an ophthalmologist, a pediatrician, and a geneticist. All cases of familial Rb were determined via genetic counseling. Clinical features included disease status, laterality, age at diagnosis, mutation type, follow-up, and disease-eye ratio (DER). To eliminate mosaic cases, first-generation carriers displaying low-penetrance (LP) Rb were excluded from the analysis. Complete penetrance was the rule for nonsense and frameshift mutations (25 families) and high penetrance was observed for large rearrangements (eight families). Promoter (two families) and missense (two families) mutations displayed heterogeneous phenotypes and LP. Variable penetrance was observed for splice abnormalities (13 families) and was explained by in/out of frame mutations or respect of functional domains. Surprisingly, two families with the LP g.45867G>T/IVS6+1G>T mutation presented data that conflicted with the data reported in previous publications, as unaffected carriers had paternally inherited mutant alleles. Moreover, RNA analyses suggested that the lack of penetrance in unaffected carriers could be explained by an increase in expression levels of the wild-type allele. This observation prompted us to define a new class "3" of LP alleles. We believe this is the first large-scale study of familial Rb with a high level of homogeneity in the clinical and genetic analysis of patients and their relatives, thereby allowing for reliable intrafamilial genotype-phenotype correlations. Our analysis suggests in some cases the influence of modifier factors probably involved in mRNA level regulation and/or pRB pathway regulation.
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Affiliation(s)
- Melissa Taylor
- Service d'Oncologie Pédiatrique, Institut Curie, Paris, France
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Kirienko NV, Fay DS. Transcriptome profiling of the C. elegans Rb ortholog reveals diverse developmental roles. Dev Biol 2007; 305:674-84. [PMID: 17368442 PMCID: PMC2680605 DOI: 10.1016/j.ydbio.2007.02.021] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2007] [Accepted: 02/14/2007] [Indexed: 11/25/2022]
Abstract
LIN-35 is the single C. elegans ortholog of the mammalian pocket protein family members, pRb, p107, and p130. To gain insight into the roles of pocket proteins during development, a microarray analysis was performed with lin-35 mutants. Stage-specific regulation patterns were revealed, indicating that LIN-35 plays diverse roles at distinct developmental stages. LIN-35 was found to repress the expression of many genes involved in cell proliferation in larvae, an activity that is carried out in conjunction with E2F. In addition, LIN-35 was found to regulate neuronal genes during embryogenesis and targets of the intestinal-specific GATA transcription factor, ELT-2, at multiple developmental stages. Additional findings suggest that LIN-35 functions in cell cycle regulation in embryos in a manner that is independent of E2F. A comparison of LIN-35-regulated genes with known fly and mammalian pocket protein targets revealed a high degree of overlap, indicating strong conservation of pocket protein functions in diverse phyla. Based on microarray results and our refinement of the C. elegans E2F consensus sequence, we were able to generate a comprehensive list of putative E2F-regulated genes in C. elegans. These results implicate a large number of genes previously unconnected to cell cycle control as having potential roles in this process.
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Affiliation(s)
| | - David S. Fay
- To whom correspondence should be addressed. David S. Fay, Telephone: (307) 766-4961, Fax: (307) 766-5098,
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Bender AM, Kirienko NV, Olson SK, Esko JD, Fay DS. lin-35/Rb and the CoREST ortholog spr-1 coordinately regulate vulval morphogenesis and gonad development in C. elegans. Dev Biol 2007; 302:448-62. [PMID: 17070797 PMCID: PMC1933485 DOI: 10.1016/j.ydbio.2006.09.051] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2006] [Revised: 08/28/2006] [Accepted: 09/30/2006] [Indexed: 11/21/2022]
Abstract
Using a genetic screen to identify genes that carry out redundant functions during development with lin-35/Rb, the C. elegans Retinoblastoma family ortholog, we have identified a mutation in spr-1. spr-1 encodes the C. elegans ortholog of human CoREST, a protein containing Myb-like SANT and ELM2 domains, which functions as part of a transcriptional regulatory complex. CoREST recruits mediators of transcriptional repression, including histone deacetylase, and demethylase, and interacts with the tumor suppression protein REST. spr-1/CoREST was previously shown in C. elegans to suppress defects associated with loss of the presenilin sel-12, which functions in the proteolytic processing of LIN-12/Notch. Here we show that lin-35 and spr-1 coordinately regulate several developmental processes in C. elegans including the ingression of vulval cells as well as germline proliferation. We also show that loss of lin-35 and spr-1 hypersensitizes animals to a reduction in LIN-12/Notch activity, leading to the generation of proximal germline tumors. This defect, which is observed in lin-35; spr-1; lin-12(RNAi) and lin-35; spr-1; hop-1(RNAi) triple mutants is likely due to a delay in the entry of germ cells into meiosis.
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Affiliation(s)
- Aaron M. Bender
- University of Wyoming, College of Agriculture, Department of Molecular Biology Dept 3944, 1000 E. University Avenue, Laramie, WY 82071
| | - Natalia V. Kirienko
- University of Wyoming, College of Agriculture, Department of Molecular Biology Dept 3944, 1000 E. University Avenue, Laramie, WY 82071
| | - Sara K. Olson
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, La Jolla CA 92093
| | - Jeffery D. Esko
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, La Jolla CA 92093
| | - David S Fay
- University of Wyoming, College of Agriculture, Department of Molecular Biology Dept 3944, 1000 E. University Avenue, Laramie, WY 82071
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Tell S, Yi H, Jockovich ME, Murray TG, Hackam AS. The Wnt signaling pathway has tumor suppressor properties in retinoblastoma. Biochem Biophys Res Commun 2006; 349:261-9. [PMID: 16930536 DOI: 10.1016/j.bbrc.2006.08.044] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2006] [Accepted: 08/08/2006] [Indexed: 12/29/2022]
Abstract
Retinoblastoma is a pediatric retinal tumor caused by mutational inactivation of the tumor suppressor pRb. Additional genetic changes, as yet unidentified, are believed to be required for tumor initiation. Mutations in the Wnt signaling pathway have been implicated in the pathogenesis of many cancers. Multiple Wnt pathway genes are expressed in the retina and the pRb and Wnt pathways interact biochemically, raising the possibility that alterations in the Wnt pathway contribute to retinoblastoma. Our studies showed that Wnt signaling activation significantly decreased the viability of retinoblastoma cell lines by inducing cell cycle arrest, which was associated with upregulated p53. Furthermore, immunolocalization of the Wnt signaling mediator beta-catenin in human and mouse retinoblastoma tissue indicated that canonical Wnt signaling is suppressed in tumors in vivo. These studies are consistent with the Wnt pathway acting as a tumor suppressor in retinoblastoma and suggest that loss of Wnt signaling is tumorigenic in the retina.
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Affiliation(s)
- Shoshana Tell
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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15
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Ruttum MS, Reis LM, Semina EV. Application of genetic approaches to ocular disease. Pediatr Clin North Am 2006; 53:751-65. [PMID: 16873003 DOI: 10.1016/j.pcl.2006.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The human eye is a complex organ whose development requires extraordinary coordination of developmental processes. Multiple genes responsible for the proper development and maintenance of the vertebrate eye have been identified and shown to be involved in a variety of debilitating ocular conditions. Genetic diseases involving the eye represent a leading cause of blindness in children and adults. This article summarizes current genetic approaches and their application to studies of ocular disease.
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Affiliation(s)
- Mark S Ruttum
- Medical College of Wisconsin, 925 North 87th Street, Milwaukee, WI 53226, USA.
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16
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Nájera C, Beneyto M. Retinoblastoma: implicaciones del estudio genético-molecular. Med Clin (Barc) 2006; 126:413-4. [PMID: 16595085 DOI: 10.1157/13086129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lv X, Wang N, Su L, Zhang S, Miao J. Inhibition of PC-PLC Blocked the Survival of Mouse Neural Cells by Up-Regulating the Expression of Integrin beta4 and Rb. Dev Neurosci 2006; 28:499-504. [PMID: 17028427 DOI: 10.1159/000095112] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2005] [Accepted: 11/19/2005] [Indexed: 12/21/2022] Open
Abstract
In order to understand the survival signals of neural cells during the development of the central nervous system (CNS), we explored the role of phosphatidylcholine-specific phospholipase C (PC-PLC) in the survival of primary culture mouse neural cells (MNCs). We found that when the activity of PC-PLC in the neural cells was suppressed by its specific inhibitor, D609 (tricyclodecan-9-yl-xanthogenate), the cell survival was blocked, the viability of the cells remarkably declined. At the same time, the expressions of integrin beta4 and Rb protein were evidently elevated. We also examined the intracellular ROS (reactive oxygen species) levels after the cells were treated with D609. The result showed that the ROS level in neural cells was reduced. Our data suggested that PC-PLC had an important role in regulating neural cell survival, and PC-PLC might perform its function by upregulating the expressions of integrin beta4 and Rb protein. The changes of intracellular ROS level induced by D609 indicated that a modest level of ROS might be indispensable to neural cell survival.
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Affiliation(s)
- Xin Lv
- Institute of Developmental Biology, School of Life Science, Shandong University, Jinan, China
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Li MH, Bouffet E, Hawkins CE, Squire JA, Huang A. Molecular genetics of supratentorial primitive neuroectodermal tumors and pineoblastoma. Neurosurg Focus 2005; 19:E3. [PMID: 16398467 DOI: 10.3171/foc.2005.19.5.4] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The supratentorial primitive neuroectodermal tumors (PNETs) are a group of highly malignant lesions primarily affecting young children. Although these tumors are histologically indistinguishable from infratentorial medulloblastoma, they often respond poorly to medulloblastoma-specific therapy. Indeed, existing molecular genetic studies indicate that supratentorial PNETs have transcriptional and cytogenetic profiles that are different from those of medullo-blastomas, thus pointing to unique biological derivation for the supratentorial PNET. Due to the rarity of these tumors and disagreement about their histopathological diagnoses, very little is known about the molecular characteristics of the supratentorial PNET. Clearly, future concerted efforts to characterize the molecular features of these rare tumors will be necessary for development of more effective supratentorial PNET treatment protocols and appropriate disease models. In this article the authors review existing molecular genetic data derived from human and mouse studies, with the aim of providing some insight into the putative histogenesis of these rare tumors and the underlying transforming pathways that drive their development. Studies of the related but distinct pineoblastoma PNET are also reviewed.
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Affiliation(s)
- Mei Hua Li
- Arthur and Sonia Labatt Brain Tumor Research Centre, Cancer Research Program, Division of Hematology and Oncology, Department of Pediatric Laboratory Medicine, Hospital for Sick Children, Toronto, Canada
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