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Zhang L, Sheng M, Cao H, Zhang L, Shao W. Decoding the role of long non-coding RNAs in periodontitis: A comprehensive review. Biomed Pharmacother 2023; 166:115357. [PMID: 37619483 DOI: 10.1016/j.biopha.2023.115357] [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: 06/15/2023] [Revised: 08/13/2023] [Accepted: 08/21/2023] [Indexed: 08/26/2023] Open
Abstract
Periodontitis is an inflammatory disease characterized by the pathological loss of alveolar bone and the adjacent periodontal ligament. It is considered a disease that imposes a substantial health burden, with an incidence rate of 20-50%. The etiology of periodontitis is multifactorial, with genetic factors accounting for approximately half of severe cases. Studies have revealed that long non-coding RNAs (lncRNAs) play a pivotal role in periodontitis pathogenesis. Accumulating evidence suggests that lncRNAs have distinct regulatory mechanisms, enabling them to control numerous vital processes in periodontal cells, including osteogenic differentiation, inflammation, proliferation, apoptosis, and autophagy. In this review, we summarize the diverse roles of lncRNAs in the pathogenesis of periodontitis, shedding light on the underlying mechanisms of disease development. By highlighting the potential of lncRNAs as biomarkers and therapeutic targets, this review offers a new perspective on the diagnosis and treatment of periodontitis, paving the way for further investigation into the field of lncRNA-based therapeutics.
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Affiliation(s)
- Lizhi Zhang
- College & Hospital of Stomatology, Anhui Medical University, Key Lab. of Oral Diseases Research of Anhui Province, Hefei 230032, China; First Clinical Medical College, Anhui Medical University, Hefei, China
| | - Mengfei Sheng
- Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei 230032, Anhui, China
| | - Huake Cao
- First Clinical Medical College, Anhui Medical University, Hefei, China
| | - Lei Zhang
- College & Hospital of Stomatology, Anhui Medical University, Key Lab. of Oral Diseases Research of Anhui Province, Hefei 230032, China.
| | - Wei Shao
- College & Hospital of Stomatology, Anhui Medical University, Key Lab. of Oral Diseases Research of Anhui Province, Hefei 230032, China; Department of Microbiology and Parasitology, Anhui Provincial Laboratory of Pathogen Biology, School of Basic Medical Sciences, Anhui Medical University, Hefei 230032, Anhui, China.
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Miyai K, Ito K, Nakanishi K, Tsuda H. Seminoma component of mixed testicular germ cell tumor shows a higher incidence of loss of heterozygosity than pure-type seminoma. Hum Pathol 2018; 84:71-80. [PMID: 30266250 DOI: 10.1016/j.humpath.2018.09.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/07/2018] [Accepted: 09/13/2018] [Indexed: 12/21/2022]
Abstract
Using analysis of allelic loss (loss of heterozygosity [LOH]), we previously reported a putative progression pathway from germ cell neoplasia in situ (GCNIS) to seminoma and then to embryonal carcinoma in mixed-type testicular germ cell tumors. To identify the genetic backgrounds related to the progression of nonseminomatous germ cell tumor, patterns of LOH were studied in seminoma components in mixed tumors (18 cases), pure seminomas (20 cases), and coexisting GCNIS lesions. Each tumor was assessed for LOH at 22 polymorphic loci located on 12 chromosomal arms: 3q, 5q, 6p, 9p, 10q, 11p, 12p, 12q, 13q, 17p, 17q, and 18q. For all informative loci, the frequency of LOH in seminoma components in mixed tumors was significantly higher than that in pure seminomas (32% [96/302 loci] versus 19% [60/323 loci], P < .0001). The frequency of LOH in GCNIS lesions was not significantly different between the 2 tumor groups. The frequencies of LOH at chromosomes 6p and 10q were significantly higher in seminoma components in mixed tumors than in pure seminomas (P = .020 and P = .0041, respectively). Immunohistochemical analysis demonstrated a close association between the allelic status of the 10q23 locus and levels of phosphatase and tensin homolog deleted from chromosome 10 protein expression in seminoma (P = .00051). These data indicate that the seminoma, which has a potential to progress to nonseminomatous germ cell tumor, already exhibits several genetic changes including allelic losses of 6p and 10q, unlike pure seminoma.
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Affiliation(s)
- Kosuke Miyai
- Department of Basic Pathology, National Defense Medical College, Tokorozawa, Saitama 359-8513, Japan; Department of Laboratory Medicine, National Defense Medical College, Tokorozawa, Saitama 359-8513, Japan.
| | - Keiichi Ito
- Department of Urology, National Defense Medical College, Tokorozawa, Saitama 359-8513, Japan
| | - Kuniaki Nakanishi
- Department of Laboratory Medicine, National Defense Medical College, Tokorozawa, Saitama 359-8513, Japan
| | - Hitoshi Tsuda
- Department of Basic Pathology, National Defense Medical College, Tokorozawa, Saitama 359-8513, Japan
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Single nucleotide polymorphisms associated with colorectal cancer susceptibility and loss of heterozygosity in a Taiwanese population. PLoS One 2014; 9:e100060. [PMID: 24968322 PMCID: PMC4072675 DOI: 10.1371/journal.pone.0100060] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 05/22/2014] [Indexed: 01/01/2023] Open
Abstract
Given the significant racial and ethnic diversity in genetic variation, we are intrigued to find out whether the single nucleotide polymorphisms (SNPs) identified in genome-wide association studies of colorectal cancer (CRC) susceptibility in East Asian populations are also relevant to the population of Taiwan. Moreover, loss of heterozygosity (LOH) may provide insight into how variants alter CRC risk and how regulatory elements control gene expression. To investigate the racial and ethnic diversity of CRC-susceptibility genetic variants and their relevance to the Taiwanese population, we genotyped 705 CRC cases and 1,802 healthy controls (Taiwan Biobank) for fifteen previously reported East Asian CRC-susceptibility SNPs and four novel genetic variants identified by whole-exome sequencing. We found that rs10795668 in FLJ3802842 and rs4631962 in CCND2 were significantly associated with CRC risk in the Taiwanese population. The previously unreported rs1338565 was associated with a significant increased risk of CRC. In addition, we also genotyped tumor tissue and paired adjacent normal tissues of these 705 CRC cases to search for LOH, as well as risk-associated and protective alleles. LOH analysis revealed preferential retention of three SNPs, rs12657484, rs3802842, and rs4444235, in tumor tissues. rs4444235 has been recently reported to be a cis-acting regulator of BMP4 gene; in this study, the C allele was preferentially retained in tumor tissues (p = 0.0023). rs4631962 and rs10795668 contribute to CRC risk in the Taiwanese and East Asian populations, and the newly identified rs1338565 was specifically associated with CRC, supporting the ethnic diversity of CRC-susceptibility SNPs. LOH analysis suggested that the three CRC risk variants, rs12657484, rs3802842, and rs4444235, exhibited somatic allele-specific imbalance and might be critical during neoplastic progression.
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Veatch JR, McMurray MA, Nelson ZW, Gottschling DE. Mitochondrial dysfunction leads to nuclear genome instability via an iron-sulfur cluster defect. Cell 2009; 137:1247-58. [PMID: 19563757 DOI: 10.1016/j.cell.2009.04.014] [Citation(s) in RCA: 318] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2008] [Revised: 01/30/2009] [Accepted: 04/01/2009] [Indexed: 11/19/2022]
Abstract
Mutations and deletions in the mitochondrial genome (mtDNA), as well as instability of the nuclear genome, are involved in multiple human diseases. Here, we report that in Saccharomyces cerevisiae, loss of mtDNA leads to nuclear genome instability, through a process of cell-cycle arrest and selection we define as a cellular crisis. This crisis is not mediated by the absence of respiration, but instead correlates with a reduction in the mitochondrial membrane potential. Analysis of cells undergoing this crisis identified a defect in iron-sulfur cluster (ISC) biogenesis, which requires normal mitochondrial function. We found that downregulation of nonmitochondrial ISC protein biogenesis was sufficient to cause increased genomic instability in cells with intact mitochondrial function. These results suggest mitochondrial dysfunction stimulates nuclear genome instability by inhibiting the production of ISC-containing protein(s), which are required for maintenance of nuclear genome integrity. For a video summary of this article, see the PaperFlick file available with the online Supplemental Data.
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Affiliation(s)
- Joshua R Veatch
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA 98109, USA
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5
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Genome-wide analysis of genetic alterations in Barrett's adenocarcinoma using single nucleotide polymorphism arrays. J Transl Med 2009; 89:385-97. [PMID: 18663352 DOI: 10.1038/labinvest.2008.67] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We performed genome-wide analysis of copy-number changes and loss of heterozygosity (LOH) in Barrett's esophageal adenocarcinoma by single nucleotide polymorphism (SNP) microarrays to identify associated genomic alterations. DNA from 27 esophageal adenocarcinomas and 14 matching normal tissues was subjected to SNP microarrays. The data were analyzed using dChipSNP software. Copy-number changes occurring in at least 25% of the cases and LOH occurring in at least 19% were regarded as relevant changes. As a validation, fluorescence in situ hybridization (FISH) of 8q24.21 (CMYC) and 8p23.1 (SOX7) was performed. Previously described genomic alterations in esophageal adenocarcinomas could be confirmed by SNP microarrays, such as amplification on 8q (CMYC, confirmed by FISH) and 20q13 or deletion/LOH on 3p (FHIT) and 9p (CDKN2A). Moreover, frequent gains were detected on 2p23.3, 7q11.22, 13q31.1, 14q32.31, 17q23.2 and 20q13.2 harboring several novel candidate genes. The highest copy numbers were seen on 8p23.1, the location of SOX7, which could be demonstrated to be involved in amplification by FISH. A nuclear overexpression of the transcription factor SOX7 could be detected by immunohistochemistry in two amplified tumors. Copy-number losses were seen on 18q21.32 and 20p11.21, harboring interesting candidate genes, such as CDH20 and CST4. Finally, a novel LOH region could be identified on 6p in at least 19% of the cases. In conclusion, SNP microarrays are a valuable tool to detect DNA copy-number changes and LOH at a high resolution. Using this technique, we identified several novel genes and DNA regions associated with esophageal adenocarcinoma.
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Aberrant double-strand break repair resulting in half crossovers in mutants defective for Rad51 or the DNA polymerase delta complex. Mol Cell Biol 2009; 29:1432-41. [PMID: 19139272 DOI: 10.1128/mcb.01469-08] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Homologous recombination is an error-free mechanism for the repair of DNA double-strand breaks (DSBs). Most DSB repair events occur by gene conversion limiting loss of heterozygosity (LOH) for markers downstream of the site of repair and restricting deleterious chromosome rearrangements. DSBs with only one end available for repair undergo strand invasion into a homologous duplex DNA, followed by replication to the chromosome end (break-induced replication [BIR]), leading to LOH for all markers downstream of the site of strand invasion. Using a transformation-based assay system, we show that most of the apparent BIR events that arise in diploid Saccharomyces cerevisiae rad51Delta mutants are due to half crossovers instead of BIR. These events lead to extensive LOH because one arm of chromosome III is deleted. This outcome is also observed in pol32Delta and pol3-ct mutants, defective for components of the DNA polymerase delta (Pol delta) complex. The half crossovers formed in Pol delta complex mutants show evidence of limited homology-dependent DNA synthesis and are partially Mus81 dependent, suggesting that strand invasion occurs and the stalled intermediate is subsequently cleaved. In contrast to rad51Delta mutants, the Pol delta complex mutants are proficient for repair of a 238-bp gap by gene conversion. Thus, the BIR defect observed for rad51 mutants is due to strand invasion failure, whereas the Pol delta complex mutants are proficient for strand invasion but unable to complete extensive tracts of recombination-initiated DNA synthesis.
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Abstract
Loss of heterozygosity (LOH) can be a driving force in the evolution of mitotic/somatic diploid cells, and cellular changes that increase the rate of LOH have been proposed to facilitate this process. In the yeast Saccharomyces cerevisiae, spontaneous LOH occurs by a number of mechanisms including chromosome loss and reciprocal and nonreciprocal recombination. We performed a screen in diploid yeast to identify mutants with increased rates of LOH using the collection of homozygous deletion alleles of nonessential genes. Increased LOH was quantified at three loci (MET15, SAM2, and MAT) on three different chromosomes, and the LOH events were analyzed as to whether they were reciprocal or nonreciprocal in nature. Nonreciprocal LOH was further characterized as chromosome loss or truncation, a local mutational event (gene conversion or point mutation), or break-induced replication (BIR). The 61 mutants identified could be divided into several groups, including ones that had locus-specific effects. Mutations in genes involved in DNA replication and chromatin assembly led to LOH predominantly via reciprocal recombination. In contrast, nonreciprocal LOH events with increased chromosome loss largely resulted from mutations in genes implicated in kinetochore function, sister chromatid cohesion, or relatively late steps of DNA recombination. Mutants of genes normally involved in early steps of DNA damage repair and signaling produced nonreciprocal LOH without an increased proportion of chromosome loss. Altogether, this study defines a genetic landscape for the basis of increased LOH and the processes by which it occurs.
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Carr LL, Gottschling DE. Does age influence loss of heterozygosity? Exp Gerontol 2007; 43:123-9. [PMID: 18054191 DOI: 10.1016/j.exger.2007.10.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Revised: 10/09/2007] [Accepted: 10/17/2007] [Indexed: 10/22/2022]
Abstract
The striking correlation between advanced age and an increased incidence of cancer has led investigators to examine the influence of aging on genome maintenance. Because loss of heterozygosity (LOH) can lead to the inactivation of tumor suppressor genes, and thus carcinogenesis, understanding the affect of aging on this type of mutation event is particularly important. Several factors may affect the rate of LOH, including an increase in the amount of DNA damage, specifically double-strand breaks (DSBs), and the ability to efficiently repair this damage via pathways that minimize the loss of genetic information. Because of experimental constraints, there is only suggestive evidence for a change in the rate of DNA damage as humans age. However, recent studies in model organisms find that there are increased rates of LOH with age, and that repair of DNA damage occurs via a different pathway in old cells versus young cells. We speculate that the age-dependent change in DNA repair may explain why there is increased LOH, and that the findings from these model organisms may extend to humans.
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Affiliation(s)
- Laurie L Carr
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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Maeda G, Chiba T, Aoba T, Imai K. Epigenetic inactivation of E-cadherin by promoter hypermethylation in oral carcinoma cells. Odontology 2007; 95:24-9. [PMID: 17660978 DOI: 10.1007/s10266-007-0068-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2006] [Accepted: 12/24/2006] [Indexed: 12/31/2022]
Abstract
The loss of E-cadherin expression by epigenetic aberrations, including promoter hypermethylation and transcription repressor binding, plays a key role in the initiation of the epithelial-mesenchymal transition, which leads to the progression of oral squamous cell carcinomas. However, mutual actions and roles of the epigenetic pathways remain to be elucidated. In this study, we determined the methylation status of cytosine within CpG islands of the E-cadherin promoter region in relation to the expression level of SIP1, a major E-cadherin repressor in oral carcinoma cells. Methylation-specific polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism analyses showed that the expression of E-cadherin was downregulated in parallel with promoter hypermethylation. The use of a bisulfite-modified sequence further validated that methylation was observed in 22.6 +/- 38.7% (mean +/- 1 SD) of cytosines in carcinoma cells negligibly expressing E-cadherin, in contrast to 7.5 +/- 1.8% in E-cadherin-expressing cells. Treatment with a demethylating reagent, 5-azacytidine, induced upregulation of E-cadherin in some E-cadherin-expressing carcinoma cell lines but not in others. The finding that the unresponsive cell lines retained high expression of SIP1 supports the repressive effect of SIP1 on E-cadherin expression regardless of promoter hypermethylation. Collectively, the overall results suggest the dynamic but differential regulation of E-cadherin by epigenetic aberrations in the pathology of oral carcinomas.
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Affiliation(s)
- Genta Maeda
- Department of Biochemistry, The Nippon Dental University School of Life Dentistry at Tokyo, 1-9-20 Fujimi, Tokyo, Japan
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10
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Abstract
Neoplastic progression is generally characterized by the accumulation of multiple genetic alterations including loss of tumor suppression gene function. Loss of heterozygosity (LOH) has been used to identify genomic regions that harbor tumor suppressor genes and to characterize different tumor types, pathological stages and progression. LOH pattern has been detected by allelotyping using restriction fragment length polymorphism, and later by simple sequence length polymorphisms (SSLPs or microsatellite) for 10 years. This paper reviews the detection of LOH by recently developed single nucleotide polymorphism (SNP) arrays (all analyzed by Affymetrix array); furthermore, its advantage and disadvantage were analyzed in several kinds of cancer.
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Affiliation(s)
- Hai-Tao Zheng
- Department of General Surgery, Shanghai First People's Hospital, Shanghai Jiaotong University, Shanghai 200080, China
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11
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López M, Aguirre JM, Cuevas N, Anzola M, Videgain J, Aguirregaviria J, Castro A, de Pancorbo MM. Use of cytological specimens for p53 gene alteration detection in oral squamous cell carcinoma risk patients. Clin Oncol (R Coll Radiol) 2004; 16:366-70. [PMID: 15341441 DOI: 10.1016/j.clon.2004.03.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS Recurrence and multifocal nature are two important characteristics of oral squamous cell carcinoma. Leukoplakia is the most frequent pre-cancerous oral lesion and, in most cases, it is not possible to predict malignant capacity. The objective of this study is to identify p53 alterations in cells taken from the oral cavity of at-risk patients. MATERIALS AND METHODS The following samples were collected from 34 patients with oral leukoplakia with and without previous carcinoma: oral rinse, a brush swabbed over the lesions and hair roots. Mutational analysis of the p53 gene was performed by single-strand conformation polymorphisms and confirmed by DNA sequencing. RESULTS We detected 11 mutations in p53 gene in oral cytological specimens. These alterations were observed only in brush cytology samples in patients without previous carcinoma, and in both samples (rinse and brush) in patients with previous carcinoma. Three of these patients had disease recurrence. CONCLUSION This non-invasive technique may be useful in the follow-up of at-risk patients, and introduces new possibilities to analyse molecular markers before malignant lesions are clinically apparent.
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Affiliation(s)
- M López
- Buccal Medicine, Department of Stomatology, Faculty of Medicine and Odontology, University of the Basque Country EHU, Leioa, Spain
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Dumur CI, Dechsukhum C, Ware JL, Cofield SS, Best AM, Wilkinson DS, Garrett CT, Ferreira-Gonzalez A. Genome-wide detection of LOH in prostate cancer using human SNP microarray technology. Genomics 2003; 81:260-9. [PMID: 12659810 DOI: 10.1016/s0888-7543(03)00020-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Loss of heterozygosity (LOH) of chromosomal regions is crucial in tumor progression. In this study we assessed the potential of the Affymetrix GeneChip HuSNP mapping assay for detecting genome-wide LOH in prostate tumors. We analyzed two human prostate cell lines, P69SV40Tag (P69) and its tumorigenic subline, M12, and 11 prostate cancer cases. The M12 cells showed LOH in chromosomes 3p12.1-p22.1, 11q22.1-q24.2, 19p13.12, and 19q13.42. All of the prostate cases with informative single-nucleotide polymorphism (SNP) markers showed LOH in 1p31.2, 10q11.21, 12p13.1, 16q23.1-q23.2, 17p13.3, 17q21.31, and 21q21.2. Additionally, a high percentage of cases showed LOH at 6p25.1-p25.3 (75%), 8p22-p23.2, and 10q22.1 (70%). Several tumor suppressor genes (TSGs) have been mapped in these loci. These results demonstrate that the HuSNP mapping assay can serve as an alternative to comparative genomic hybridization for assessing genome-wide LOH and can identify chromosomal regions harboring candidate TSGs implicated in prostate cancer.
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Affiliation(s)
- Catherine I Dumur
- Department of Pathology, Virginia Commonwealth University, Richmond, VA23298-0248, USA
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Kakinuma S, Nishimura M, Sasanuma SI, Mita K, Suzuki G, Katsura Y, Sado T, Shimada Y. Spectrum of Znfn1a1 (Ikaros) inactivation and its association with loss of heterozygosity in radiogenic T-cell lymphomas in susceptible B6C3F1 mice. Radiat Res 2002; 157:331-40. [PMID: 11839096 DOI: 10.1667/0033-7587(2002)157[0331:soziia]2.0.co;2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Ikaros (now known as Znfn1a1), a Krüppel-type zinc-finger transcription factor that plays a critical role in both lineage commitment and differentiation of lymphoid cells, has recently been shown to function as a tumor suppressor gene. We have previously reported a high frequency of LOH (approximately 50%) at the Znfn1a1 locus in radiation-induced T-cell lymphoma in susceptible B6C3F1 mice. The aim of the present study was to delineate the types of Znfn1a1 inactivation, with special reference to the LOH status, and to determine the relative contribution of each type of Znfn1a1 inactivation in radiation-induced T-cell lymphomas in B6C3F1 mice. We demonstrated that Znfn1a1 was frequently altered (in approximately 50% of T-cell lymphomas), and that its inactivation was caused by a variety of mechanisms, which came under one of the following four categories: (1) null expression (14%); (2) expression of unusual dominant-negative isoforms (11%); (3) amino acid substitutions in the N-terminal zinc-finger domain for DNA binding caused by point mutations (22%); (4) lack of the Znfn1a1 isoform 1 due to the creation of a stop codon by insertion of a dinucleotide in exon 3 (3%). The null expression, amino acid substitutions, and dinucleotide insertion inactivation types were well correlated with LOH at the Znfn1a1 allele (86%) and were consistent with Knudson's two-hit theory. On the other hand, T-cell lymphomas expressing dominant-negative Znfn1a1 isoforms retained both alleles. These results indicate that Znfn1a1 inactivation takes place by a variety of mechanisms in radiation-induced murine T-cell lymphomas and is frequently associated with LOH, this association depending on the type of inactivation.
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Affiliation(s)
- Shizuko Kakinuma
- Division of Low Dose Radiation and Experimental Carcinogenesis, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
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Prasad KN, Hovland AR, Nahreini P, Cole WC, Hovland P, Kumar B, Prasad KC. Differentiation genes: are they primary targets for human carcinogenesis? Exp Biol Med (Maywood) 2001; 226:805-13. [PMID: 11568302 DOI: 10.1177/153537020122600901] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In spite of extensive research in molecular carcinogenesis, genes that can be considered primary targets in human carcinogenesis remain to be identified. Mutated oncogenes or cellular growth regulatory genes, when incorporated into normal human epithelial cells, failed to immortalize or transform these cells. Therefore, they may be secondary events in human carcinogenesis. Based on some experimental studies we have proposed that downregulation of a differentiation gene may be the primary event in human carcinogenesis. Such a gene could be referred to as a tumor-initiating gene. Downregulation of a differentiation gene can be accomplished by a mutation in the differentiation gene, by activation of differentiation suppressor genes, and by inactivation of tumor suppressor genes. Downregulation of a differentiation gene can lead to immortalization of normal cells. Mutations in cellular proto-oncogenes, growth regulatory genes, and tumor suppressor genes in immortalized cells can lead to transformation. Such genes could be called tumor-promoting genes. This hypothesis can be documented by experiments published on differentiation of neuroblastoma (NB) cells in culture. The fact that terminal differentiation can be induced in NB cells by adenosine 3',5'-cyclic monophosphate (cAMP) suggests that the differentiation gene in these cells is not mutated, and thus can be activated by an appropriate agent. The fact that cAMP-resistant cells exist in NB cell populations suggests that a differentiation gene is mutated in these cancer cells, or that differentiation regulatory genes have become unresponsive to cAMP. In addition to cAMP, several other differentiating agents have been identified. Our proposed hypothesis of carcinogenesis can also be applied to other human tumors such as melanoma, pheochromocytoma, medulloblastoma, glioma, sarcoma, and colon cancer.
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Affiliation(s)
- K N Prasad
- Center for Vitamins and Cancer Research, Department of Radiology, School of Medicine, University of Colorado Health Sciences Center, Denver, CO 80262, USA.
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15
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Cheng CW, Wu PE, Yu JC, Huang CS, Yue CT, Wu CW, Shen CY. Mechanisms of inactivation of E-cadherin in breast carcinoma: modification of the two-hit hypothesis of tumor suppressor gene. Oncogene 2001; 20:3814-23. [PMID: 11439345 DOI: 10.1038/sj.onc.1204505] [Citation(s) in RCA: 177] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2000] [Revised: 03/26/2001] [Accepted: 04/02/2001] [Indexed: 02/07/2023]
Abstract
Loss of heterozygosity (LOH) allows the expression of recessive mutation in tumor suppressor genes (TSG). Therefore, on the basis of Knudson's 'two-hit' hypothesis for TSG inactivation, the detection of a high LOH frequency in a chromosomal region is considered critical for TSG localization. One of these LOH regions in breast cancer is 16q22.1, which has been suggested to reflect the involvement of E-cadherin (E-cad), a cell-cell adhesion molecule. To confirm the tumorigenic role of E-cad, 81 sporadic invasive ductal carcinomas (IDCs) of the breast were tested for the 'two hits' required to inactivate this gene. A high frequency (37.3%) of LOH was detected in 67 informative tumors, but no mutation was found. To examine the possibility that transcriptional mechanisms serve as the second hit in tumors with LOH, specific pathways, including genetic variant and hypermethylation at the promoter region and abnormal expression of positive (WT1) and negative (Snail) transcription factors, were identified. Of these, promoter hypermethylation and increased expression of Snail were found to be common (>35%), and to be strongly associated with reduced/negative E-cad expression (P<0.05). However, unexpectedly, a significantly negative association was found between the existence of LOH and promoter hypermethylation (P<0.05), which contradicts the 'two-hit' model. Instead, since they coexisted in a high frequency of tumors, hypermethylation may work in concert with increased Snail to inactivate E-cad expression. Given that E-cad is involved in diverse mechanisms, loss of which is beneficial for tumors to invade but may also trigger apoptosis, this study suggests that maintaining a reversible mechanism, either by controlling the gene at the transcriptional level or by retaining an intact allele subsequent to LOH, might be important for E-cad in IDC and may also be common in TSGs possessing diverse functions. These findings provide clues to explain why certain TSGs identified by LOH cannot fulfil the two-hit hypothesis.
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Affiliation(s)
- C W Cheng
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 115, Taiwan
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16
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López M, Anzola M, Cuevas-Salazar N, Aguirre J, Martinez de Pancorbo M. p53, un gen supresor tumoral. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0304-4858(01)74350-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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17
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Toyooka S, Ouchida M, Jitsumori Y, Tsukuda K, Sakai A, Nakamura A, Shimizu N, Shimizu K. HD-PTP: A novel protein tyrosine phosphatase gene on human chromosome 3p21.3. Biochem Biophys Res Commun 2000; 278:671-8. [PMID: 11095967 DOI: 10.1006/bbrc.2000.3870] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A human cDNA encoding a novel protein tyrosine phosphatase has been isolated. The phosphatase has unique features in its domain structure: a "Zn-hand" domain containing several SH3-binding motifs, a tyrosine phosphatase domain, a C-terminal PEST motif, and an N-terminal domain similar to yeast BRO1, an apoptosis-related mammalian AIP1 and to a RHO-binding protein, Rhophilin. The gene is located at chromosome 3p21.3, an area frequently deleted in many types of cancer, especially within the functionally defined narrow region. The gene may be a human homolog of the rat PTP-TD14 gene reported by others, which can suppress H-ras-mediated transformation. We identified a hemizygous missense mutation in a lung cancer cell line. Thus, the phosphatase gene may be a candidate for one of the tumor suppressor genes located on 3p21.3.
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MESH Headings
- Amino Acid Sequence
- Animals
- Chromosome Mapping
- Chromosomes, Artificial, Yeast
- Chromosomes, Human, Pair 3
- DNA, Complementary
- Genetic Markers
- Humans
- Loss of Heterozygosity
- Models, Molecular
- Molecular Sequence Data
- Polymerase Chain Reaction
- Polymorphism, Single-Stranded Conformational
- Protein Structure, Secondary
- Protein Tyrosine Phosphatases/chemistry
- Protein Tyrosine Phosphatases/genetics
- Protein Tyrosine Phosphatases, Non-Receptor
- Rats
- Recombinant Proteins/chemistry
- Recombinant Proteins/metabolism
- Transfection
- Tumor Cells, Cultured
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Affiliation(s)
- S Toyooka
- Department of Surgery(II), Okayama University Medical School, Okayama, 700-8558, Japan
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18
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Mei R, Galipeau PC, Prass C, Berno A, Ghandour G, Patil N, Wolff RK, Chee MS, Reid BJ, Lockhart DJ. Genome-wide detection of allelic imbalance using human SNPs and high-density DNA arrays. Genome Res 2000; 10:1126-37. [PMID: 10958631 PMCID: PMC2235196 DOI: 10.1101/gr.10.8.1126] [Citation(s) in RCA: 175] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Most human cancers are characterized by genomic instability, the accumulation of multiple genetic alterations and allelic imbalance throughout the genome. Loss of heterozygosity (LOH) is a common form of allelic imbalance and the detection of LOH has been used to identify genomic regions that harbor tumor suppressor genes and to characterize tumor stages and progression. Here we describe the use of high-density oligonucleotide arrays for genome-wide scans for LOH and allelic imbalance in human tumors. The arrays contain redundant sets of probes for 600 genetic loci that are distributed across all human chromosomes. The arrays were used to detect allelic imbalance in two types of human tumors, and a subset of the results was confirmed using conventional gel-based methods. We also tested the ability to study heterogeneous cell populations and found that allelic imbalance can be detected in the presence of a substantial background of normal cells. The detection of LOH and other chromosomal changes using large numbers of single nucleotide polymorphism (SNP) markers should enable identification of patterns of allelic imbalance with potential prognostic and diagnostic utility.
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Affiliation(s)
- R Mei
- Affymetrix, Inc., Santa Clara, California 95051, USA.
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19
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McCann J, Kavet R, Rafferty CN. Assessing the potential carcinogenic activity of magnetic fields using animal models. ENVIRONMENTAL HEALTH PERSPECTIVES 2000; 108 Suppl 1:79-100. [PMID: 10698725 PMCID: PMC1637772 DOI: 10.1289/ehp.00108s179] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We update our 1997 publication by reviewing 29 new reports of tests of magnetic fields (MFs) in six different in vivo animal models of carcinogenesis: 2-year, lifetime, or multigeneration exposure studies in rats or mice; and promotion/progression models (rat mammary carcinoma, rat liver focus, mouse skin, several models of human leukemia/lymphoma in rats and mice, and brain cancer in rats). Individual experiments are evaluated using a set of data quality criteria, and summary judgments are made across multiple experiments by applying a criterion of rough reproducibility. The potential for carcinogenicity of MFs is discussed in light of the significant body of carcinogenesis data from animal bioassays that now exists. Excluding abstracts, approximately 80% of the 41 completed studies identified in this and our previous review roughly satisfy data quality criteria. Among these studies, the criterion for independent reproducibility is not satisfied for any positive results but is satisfied for negative results in chronic bioassays in rats and mice and for negative results in both promotion and co-promotion assays using the SENCAR mouse skin model. Results of independent replication studies using the rat mammary carcinoma model were conflicting. We conclude that long-term exposure to continuous 50- or 60-Hz MFs in the range of 0.002-5 mT is unlikely to result in carcinogenesis in rats or mice. Though results of most promotion/progression assays are negative, a weak promoting effect of MFs under certain exposure conditions cannot be ruled out based on available data.
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Affiliation(s)
- J McCann
- Electric Power Research Institute, Palo Alto, California, USA.
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20
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LaJeunesse DR, McCartney BM, Fehon RG. Structural analysis of Drosophila merlin reveals functional domains important for growth control and subcellular localization. J Cell Biol 1998; 141:1589-99. [PMID: 9647651 PMCID: PMC2133006 DOI: 10.1083/jcb.141.7.1589] [Citation(s) in RCA: 119] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/1998] [Revised: 05/14/1998] [Indexed: 02/08/2023] Open
Abstract
Merlin, the product of the Neurofibromatosis type 2 (NF2) tumor-suppressor gene, is a member of the protein 4.1 superfamily that is most closely related to ezrin, radixin, and moesin (ERM). NF2 is a dominantly inherited disease characterized by the formation of bilateral acoustic schwannomas and other benign tumors associated with the central nervous system. To understand its cellular functions, we are studying a Merlin homologue in Drosophila. As is the case for NF2 tumors, Drosophila cells lacking Merlin function overproliferate relative to their neighbors. Using in vitro mutagenesis, we define functional domains within Merlin required for proper subcellular localization and for genetic rescue of lethal Merlin alleles. Remarkably, the results of these experiments demonstrate that all essential genetic functions reside in the plasma membrane- associated NH2-terminal 350 amino acids of Merlin. Removal of a seven-amino acid conserved sequence within this domain results in a dominant-negative form of Merlin that is stably associated with the plasma membrane and causes overproliferation when expressed ectopically in the wing. In addition, we provide evidence that the COOH-terminal region of Merlin has a negative regulatory role, as has been shown for ERM proteins. These results provide insights into the functions and functional organization of a novel tumor suppressor gene.
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Affiliation(s)
- D R LaJeunesse
- Developmental, Cell and Molecular Biology Group, Department of Zoology, Duke University, Durham, North Carolina 27708-1000, USA
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21
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Albini A. Tumor and endothelial cell invasion of basement membranes. The matrigel chemoinvasion assay as a tool for dissecting molecular mechanisms. Pathol Oncol Res 1998; 4:230-41. [PMID: 9761943 DOI: 10.1007/bf02905254] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The spread of cancer cells from a primary tumor to distant organs is the major cause of death of cancer patients. Metastatic lesions are often resistent to cancer therapy because of the progressive phenotypic changes that they have undergone. Several genetic and epigenetic factors, both in the cell and in the host, contribute to the development of tumor progression towards metastases. In this review we will analyze the steps involved in tumor metastases, which can be potential targets for anti-metastatic therapy. One of the most critical events in cancer metastasis is the invasion of basement membranes. An assay which we developed over ten years ago, the matrigel "chemoinvasion" assay, has been a useful tool for studying the mechanisms involved in tumor and endothelial cell invasion of basement membranes and for the screening of anti-invasive agents. Here we will describe the assay and review some of the major results obtained with it.
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Affiliation(s)
- A Albini
- Advanced Biotechnology Center, National Institute for Research on Cancer, Genova, Italy.
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22
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Meng RD, El-Deiry WS. Tumor suppressor gene therapy for cancer: from the bench to the clinic. Drug Resist Updat 1998; 1:205-10. [PMID: 17092807 DOI: 10.1016/s1368-7646(98)80041-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/1998] [Revised: 04/06/1998] [Accepted: 04/06/1998] [Indexed: 11/16/2022]
Abstract
There is a growing list of possible tumor suppressors that can potentially be used to control cancer cell growth in the clinic. These include p53, Rb, p21, p16, p27, BRCAI and APC, some of which are already in clinical trials, p53 induces apoptosis and suppresses cancer cells containing multiple genetic alterations as well as multidrug-resistant cells, making it a promising and popular target. Other agents such as CDK-inhibitors are generally cytostatic with little evidence for apoptosis. The genetic make-up may help guide a rational therapy of particular tumors. Preclinical studies are exploring combinations of gene therapy and chemotherapy. Some early results are beginning to emerge from clinical trials including those using the E1b-deleted adenovirus that is unique in being a tumor-specific cytotoxic agent for the most common types of cancer.
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Affiliation(s)
- R D Meng
- Howard Hughes Medical Institute, Department of Medicine, Genetics, Cancer Center and The Institute for Human Gene Therapy, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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