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1.
Cell ; 173(3): 595-610.e11, 2018 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-29656894

RESUMO

The evolutionary features of clear-cell renal cell carcinoma (ccRCC) have not been systematically studied to date. We analyzed 1,206 primary tumor regions from 101 patients recruited into the multi-center prospective study, TRACERx Renal. We observe up to 30 driver events per tumor and show that subclonal diversification is associated with known prognostic parameters. By resolving the patterns of driver event ordering, co-occurrence, and mutual exclusivity at clone level, we show the deterministic nature of clonal evolution. ccRCC can be grouped into seven evolutionary subtypes, ranging from tumors characterized by early fixation of multiple mutational and copy number drivers and rapid metastases to highly branched tumors with >10 subclonal drivers and extensive parallel evolution associated with attenuated progression. We identify genetic diversity and chromosomal complexity as determinants of patient outcome. Our insights reconcile the variable clinical behavior of ccRCC and suggest evolutionary potential as a biomarker for both intervention and surveillance.


Assuntos
Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Neoplasias Renais/genética , Neoplasias Renais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Biomarcadores Tumorais , Cromossomos , Evolução Clonal , Progressão da Doença , Evolução Molecular , Feminino , Heterogeneidade Genética , Variação Genética , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Mutação , Metástase Neoplásica , Fenótipo , Filogenia , Prognóstico , Estudos Prospectivos , Análise de Sequência de DNA
2.
Cell ; 173(3): 581-594.e12, 2018 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-29656895

RESUMO

Clear-cell renal cell carcinoma (ccRCC) exhibits a broad range of metastatic phenotypes that have not been systematically studied to date. Here, we analyzed 575 primary and 335 metastatic biopsies across 100 patients with metastatic ccRCC, including two cases sampledat post-mortem. Metastatic competence was afforded by chromosome complexity, and we identify 9p loss as a highly selected event driving metastasis and ccRCC-related mortality (p = 0.0014). Distinct patterns of metastatic dissemination were observed, including rapid progression to multiple tissue sites seeded by primary tumors of monoclonal structure. By contrast, we observed attenuated progression in cases characterized by high primary tumor heterogeneity, with metastatic competence acquired gradually and initial progression to solitary metastasis. Finally, we observed early divergence of primitive ancestral clones and protracted latency of up to two decades as a feature of pancreatic metastases.


Assuntos
Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Neoplasias Renais/genética , Neoplasias Renais/patologia , Mutação , Metástase Neoplásica , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Biópsia , Mapeamento Cromossômico , Cromossomos Humanos Par 14 , Cromossomos Humanos Par 9 , Progressão da Doença , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fenótipo , Estudos Prospectivos , Trombose , Resultado do Tratamento
3.
Mol Cell ; 81(4): 724-738.e9, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33476576

RESUMO

Micronuclei are aberrant nuclear compartments that can form as a result of chromosome mis-segregation. Frequent loss of micronuclear envelope integrity exposes DNA to the cytoplasm, leading to chromosome fragmentation and immune activation. Here, we use micronuclei purification to show that the endoplasmic reticulum (ER)-associated nuclease TREX1 inhibits cGAS activation at micronuclei by degrading micronuclear DNA upon micronuclear envelope rupture. We demonstrate that the ER accesses ruptured micronuclei and plays a critical role in enabling TREX1 nucleolytic attack. TREX1 mutations, previously implicated in immune disease, untether TREX1 from the ER, disrupt TREX1 localization to micronuclei, diminish micronuclear DNA damage, and enhance cGAS activation. These results establish ER-directed resection of micronuclear DNA by TREX1 as a critical regulator of cytosolic DNA sensing in chromosomally unstable cells and provide a mechanistic basis for the importance of TREX1 ER tethering in preventing autoimmunity.


Assuntos
Dano ao DNA , Retículo Endoplasmático/metabolismo , Exodesoxirribonucleases/metabolismo , Micronúcleos com Defeito Cromossômico , Mutação , Nucleotidiltransferases/metabolismo , Fosfoproteínas/metabolismo , Retículo Endoplasmático/genética , Ativação Enzimática/genética , Exodesoxirribonucleases/genética , Células HEK293 , Humanos , Nucleotidiltransferases/genética , Fosfoproteínas/genética , Transporte Proteico/genética
4.
Genes Dev ; 35(15-16): 1093-1108, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34266887

RESUMO

Abnormal numerical and structural chromosome content is frequently found in human cancer. To test the role of aneuploidy in tumor initiation and progression, we generated mice with random aneuploidies by transient induction of polo-like kinase 4 (Plk4), a master regulator of centrosome number. Short-term chromosome instability (CIN) from transient Plk4 induction resulted in formation of aggressive T-cell lymphomas in mice with heterozygous inactivation of one p53 allele and accelerated tumor development in the absence of p53. Transient CIN increased the frequency of lymphoma-initiating cells with a specific karyotype profile, including trisomy of chromosomes 4, 5, 14, and 15 occurring early in tumorigenesis. Tumor development in mice with chronic CIN induced by an independent mechanism (through inactivation of the spindle assembly checkpoint) gradually trended toward a similar karyotypic profile, as determined by single-cell whole-genome DNA sequencing. Overall, we show how transient CIN generates cells with random aneuploidies from which ones that acquire a karyotype with specific chromosome gains are sufficient to drive cancer formation, and that distinct CIN mechanisms can lead to similar karyotypic cancer-causing outcomes.


Assuntos
Aneuploidia , Instabilidade Cromossômica , Animais , Transformação Celular Neoplásica/genética , Centrossomo , Instabilidade Cromossômica/genética , Evolução Clonal , Instabilidade Genômica/genética , Camundongos
5.
Genes Dev ; 35(15-16): 1073-1075, 2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34341000

RESUMO

Chromosome instability (CIN) and aneuploidy are hallmarks of cancer cells, typically associated with aggressiveness and poor outcomes. Historically, the causative link between aneuploidy and cancer has been difficult to study due to its intrinsic complexity and the poor fitness of aneuploid cells. In this issue of Genes & Development, two companion papers (Trakala and colleagues [pp. 1079-1092] and Shoshani and colleagues [pp. 1093-1108]) exploited sophisticated mouse models to study the progression of aneuploidy from early phases to established tumors. Both groups observed that, while in the early nontumoral cells aneuploidy is characterized by random chromosomal gains, established tumors display a stereotypic karyotype with recurrent gains of only a few chromosomes. Thus, aneuploidy in tumors is not random but shows reproducible patterns of chromosomal changes induced by mechanisms that these two studies are beginning to unveil.


Assuntos
Aneuploidia , Neoplasias , Animais , Instabilidade Cromossômica/genética , Aberrações Cromossômicas , Cariótipo , Camundongos , Neoplasias/genética , Neoplasias/patologia
6.
Exp Cell Res ; 436(1): 113975, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38367657

RESUMO

Kinesin motors play a fundamental role in development by controlling intracellular transport, spindle assembly, and microtubule organization. In humans, patients carrying mutations in KIF11 suffer from an autosomal dominant inheritable disease called microcephaly with or without chorioretinopathy, lymphoedema, or mental retardation (MCLMR). While mitotic functions of KIF11 proteins have been well documented in centrosome separation and spindle assembly, cellular mechanisms underlying KIF11 dysfunction and MCLMR remain unclear. In this study, we generate KIF11-inhibition chick and zebrafish models and find that KIF11 inhibition results in microcephaly, chorioretinopathy, and severe developmental defects in vivo. Notably, loss-of-function of KIF11 causes the formation of monopolar spindle and chromosome misalignment, which finally contribute to cell cycle arrest, chromosome instability, and cell death. Our results demonstrate that KIF11 is crucial for spindle assembly, chromosome alignment, and cell cycle progression of progenitor stem cells, indicating a potential link between polyploidy and MCLMR. Our data have revealed that KIF11 inhibition cause microcephaly, chorioretinopathy, and development disorders through the formation of monopolar spindle, polyploid, and cell cycle arrest.


Assuntos
Fácies , Linfedema , Microcefalia , Doenças Retinianas , Displasia Retiniana , Animais , Pontos de Checagem do Ciclo Celular/genética , Instabilidade Cromossômica , Deficiências do Desenvolvimento , Cinesinas/genética , Cinesinas/metabolismo , Microcefalia/genética , Fenótipo , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
7.
Proc Natl Acad Sci U S A ; 119(40): e2204071119, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36179046

RESUMO

Many tumors express meiotic genes that could potentially drive somatic chromosome instability. While germline cohesin subunits SMC1B, STAG3, and REC8 are widely expressed in many cancers, messenger RNA and protein for RAD21L subunit are expressed at very low levels. To elucidate the potential of meiotic cohesins to contribute to genome instability, their expression was investigated in human cell lines, predominately in DLD-1. While the induction of the REC8 complex resulted in a mild mitotic phenotype, the expression of the RAD21L complex produced an arrested but viable cell pool, thus providing a source of DNA damage, mitotic chromosome missegregation, sporadic polyteny, and altered gene expression. We also found that genomic binding profiles of ectopically expressed meiotic cohesin complexes were reminiscent of their corresponding specific binding patterns in testis. Furthermore, meiotic cohesins were found to localize to the same sites as BORIS/CTCFL, rather than CTCF sites normally associated with the somatic cohesin complex. These findings highlight the existence of a germline epigenomic memory that is conserved in cells that normally do not express meiotic genes. Our results reveal a mechanism of action by unduly expressed meiotic cohesins that potentially links them to aneuploidy and chromosomal mutations in affected cells.


Assuntos
Expressão Ectópica do Gene , Neoplasias , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Instabilidade Cromossômica/genética , Proteínas Cromossômicas não Histona , Segregação de Cromossomos , Proteínas de Ligação a DNA/metabolismo , Humanos , Masculino , Meiose/genética , Neoplasias/genética , Proteínas Nucleares/metabolismo , Fosfoproteínas/metabolismo , RNA Mensageiro , Coesinas
8.
Proc Natl Acad Sci U S A ; 119(40): e2201738119, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36161943

RESUMO

Mismatch repair (MMR) is a replication-coupled DNA repair mechanism and plays multiple roles at the replication fork. The well-established MMR functions include correcting misincorporated nucleotides that have escaped the proofreading activity of DNA polymerases, recognizing nonmismatched DNA adducts, and triggering a DNA damage response. In an attempt to determine whether MMR regulates replication progression in cells expressing an ultramutable DNA polymerase ɛ (Polɛ), carrying a proline-to-arginine substitution at amino acid 286 (Polɛ-P286R), we identified an unusual MMR function in response to hydroxyurea (HU)-induced replication stress. Polɛ-P286R cells treated with hydroxyurea exhibit increased MRE11-catalyzed nascent strand degradation. This degradation by MRE11 depends on the mismatch recognition protein MutSα and its binding to stalled replication forks. Increased MutSα binding at replication forks is also associated with decreased loading of replication fork protection factors FANCD2 and BRCA1, suggesting blockage of these fork protection factors from loading to replication forks by MutSα. We find that the MutSα-dependent MRE11-catalyzed fork degradation induces DNA breaks and various chromosome abnormalities. Therefore, unlike the well-known MMR functions of ensuring replication fidelity, the newly identified MMR activity of promoting genome instability may also play a role in cancer avoidance by eliminating rogue cells.


Assuntos
Proteínas de Ligação a DNA , Hidroxiureia , Aminoácidos/genética , Arginina/genética , Adutos de DNA , Reparo de Erro de Pareamento de DNA , Replicação do DNA , Proteínas de Ligação a DNA/metabolismo , DNA Polimerase Dirigida por DNA/genética , DNA Polimerase Dirigida por DNA/metabolismo , Hidroxiureia/farmacologia , Proteína Homóloga a MRE11/genética , Proteína Homóloga a MRE11/metabolismo , Nucleotídeos/metabolismo , Prolina/genética
9.
J Cell Mol Med ; 28(7): e18182, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38498903

RESUMO

Chromosome instability (CIN) is a common contributor driving the formation and progression of anaplastic thyroid cancer (ATC), but its mechanism remains unclear. The BUB1 mitotic checkpoint serine/threonine kinase (BUB1) is responsible for the alignment of mitotic chromosomes, which has not been thoroughly studied in ATC. Our research demonstrated that BUB1 was remarkably upregulated and closely related to worse progression-free survival. Knockdown of BUB1 attenuated cell viability, invasion, migration and induced cell cycle arrests, whereas overexpression of BUB1 promoted the cell cycle progression of papillary thyroid cancer cells. BUB1 knockdown remarkably repressed tumour growth and tumour formation of nude mice with ATC xenografts and suppressed tumour metastasis in a zebrafish xenograft model. Inhibition of BUB1 by its inhibitor BAY-1816032 also exhibited considerable anti-tumour activity. Further studies showed that enforced expression of BUB1 evoked CIN in ATC cells. BUB1 induced CIN through phosphorylation of KIF14 at serine1292 (Ser1292 ). Overexpression of the KIF14ΔSer1292 mutant was unable to facilitate the aggressiveness of ATC cells when compared with that of the wild type. Collectively, these findings demonstrate that the BUB1/KIF14 complex drives the aggressiveness of ATC by inducing CIN.


Assuntos
Carcinoma Anaplásico da Tireoide , Neoplasias da Glândula Tireoide , Animais , Camundongos , Humanos , Carcinoma Anaplásico da Tireoide/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Camundongos Nus , Peixe-Zebra/metabolismo , Instabilidade Cromossômica , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/patologia , Linhagem Celular Tumoral , Proteínas Oncogênicas/genética , Cinesinas/genética
10.
Planta ; 260(1): 17, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38834908

RESUMO

MAIN CONCLUSION: Wheat lines harboring wild-relative chromosomes can be karyotypically unstable during long-term maintenance. Tissue culture exacerbates chromosomal instability but appears inefficient to induce somatic homoeologous exchange between alien and wheat chromosomes. We assessed if long-term refrigerator storage with regular renewal via self-fertilization, a widely used practice for crop germplasm maintenance, would ensure genetic fidelity of alien addition lines, and explored the possibility of inducing somatic homoeologues exchange by tissue culture. We cytogenetically characterized sampled stock seeds of originally confirmed 12 distinct wheat-Thinopyrum intermedium alien addition lines (dubbed TAI lines), and subjected immature embryos of the TAI lines to tissue culture. We find eight of the 12 TAI lines were karyotypically departed from their original identity as bona fide disomic alien addition lines due to extensive loss of whole-chromosomes of both Th. intermedium and wheat origins during the ca. 3-decade storage. Rampant numerical chromosome variations (NCVs) involving both alien and wheat chromosomes were detected in regenerated plants of all 12 studied TAI lines, but at variable rates among the wheat sub-genomes and chromosomes. Compared with NCVs, structural chromosome variations (SCVs) occurred at substantially lower rates, and no SCV involving the added alien chromosomes was observed. The NCVs manifested only moderate effects on phenotypes of the regenerated plants under field conditions.


Assuntos
Instabilidade Cromossômica , Cromossomos de Plantas , Técnicas de Cultura de Tecidos , Triticum , Triticum/genética , Triticum/crescimento & desenvolvimento , Cromossomos de Plantas/genética , Sementes/genética , Sementes/crescimento & desenvolvimento , Poaceae/genética , Poaceae/fisiologia , Cariótipo , Cariotipagem
11.
Chromosome Res ; 31(3): 21, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37592171

RESUMO

Chromosome instability (CIN) is a cancer hallmark that drives tumour heterogeneity, phenotypic adaptation, drug resistance and poor prognosis. High-grade serous ovarian cancer (HGSOC), one of the most chromosomally unstable tumour types, has a 5-year survival rate of only ~30% - largely due to late diagnosis and rapid development of drug resistance, e.g., via CIN-driven ABCB1 translocations. However, CIN is also a cell cycle vulnerability that can be exploited to specifically target tumour cells, illustrated by the success of PARP inhibitors to target homologous recombination deficiency (HRD). However, a lack of appropriate models with ongoing CIN has been a barrier to fully exploiting disease-specific CIN mechanisms. This barrier is now being overcome with the development of patient-derived cell cultures and organoids. In this review, we describe our progress building a Living Biobank of over 120 patient-derived ovarian cancer models (OCMs), predominantly from HGSOC. OCMs are highly purified tumour fractions with extensive proliferative potential that can be analysed at early passage. OCMs have diverse karyotypes, display intra- and inter-patient heterogeneity and mitotic abnormality rates far higher than established cell lines. OCMs encompass a broad-spectrum of HGSOC hallmarks, including a range of p53 alterations and BRCA1/2 mutations, and display drug resistance mechanisms seen in the clinic, e.g., ABCB1 translocations and BRCA2 reversion. OCMs are amenable to functional analysis, drug-sensitivity profiling, and multi-omics, including single-cell next-generation sequencing, and thus represent a platform for delineating HGSOC-specific CIN mechanisms. In turn, our vision is that this understanding will inform the design of new therapeutic strategies.


Assuntos
Transtornos Cromossômicos , Neoplasias Ovarianas , Humanos , Feminino , Proteína BRCA1/genética , Bancos de Espécimes Biológicos , Proteína BRCA2 , Neoplasias Ovarianas/genética , Translocação Genética , Instabilidade Cromossômica
12.
Chromosome Res ; 31(4): 32, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37910282

RESUMO

This review investigates the role of aneuploidy and chromosome instability (CIN) in the aging brain. Aneuploidy refers to an abnormal chromosomal count, deviating from the normal diploid set. It can manifest as either a deficiency or excess of chromosomes. CIN encompasses a broader range of chromosomal alterations, including aneuploidy as well as structural modifications in DNA. We provide an overview of the state-of-the-art methodologies utilized for studying aneuploidy and CIN in non-tumor somatic tissues devoid of clonally expanded populations of aneuploid cells.CIN and aneuploidy, well-established hallmarks of cancer cells, are also associated with the aging process. In non-transformed cells, aneuploidy can contribute to functional impairment and developmental disorders. Despite the importance of understanding the prevalence and specific consequences of aneuploidy and CIN in the aging brain, these aspects remain incompletely understood, emphasizing the need for further scientific investigations.This comprehensive review consolidates the present understanding, addresses discrepancies in the literature, and provides valuable insights for future research efforts.


Assuntos
Aneuploidia , Neoplasias , Animais , Humanos , Instabilidade Cromossômica , Aberrações Cromossômicas , Encéfalo , Cromossomos , Neoplasias/genética , Mamíferos/genética
13.
Drug Resist Updat ; 67: 100912, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36623445

RESUMO

Prostate cancer (PCa) is one of the most lethal causes of cancer-related death in male. It is characterized by chromosomal instability and disturbed signaling transduction. E3 ubiquitin ligases are well-recognized as mediators leading to genomic alterations and malignant phenotypes. There is a lack of systematic study on novel oncodrivers with genomic and clinical significance in PCa. In this study we used clustered regularly interspaced short palindromic repeats (CRISPR) system to screen 656 E3 ubiquitin ligases as oncodrivers or tumor repressors in PCa cells. We identified 51 significantly changed genes, and conducted genomic and clinical analysis on these genes. It was found that the Ring Finger Protein 19 A (RNF19A) was a novel oncodriver in PCa. RNF19A was frequently amplified and highly expressed in PCa and other cancer types. Clinically, higher RNF19A expression correlated with advanced Gleason Score and predicted castration resistance. Mechanistically, transcriptomics, quantitative and ubiquitination proteomic analysis showed that RNF19A ubiquitylated Thyroid Hormone Receptor Interactor 13 (TRIP13) and was transcriptionally activated by androgen receptor (AR) and Hypoxia Inducible Factor 1 Subunit Alpha (HIF1A). This study uncovers the genomic and clinical significance of a oncodriver RNF19A in PCa. The results of this study indicate that targeting AR/HIF1A-RNF19A-TRIP13 signaling axis could be an alternative option for PCa diagnosis and therapy.


Assuntos
Neoplasias de Próstata Resistentes à Castração , Ubiquitina-Proteína Ligases , Humanos , Masculino , ATPases Associadas a Diversas Atividades Celulares/genética , ATPases Associadas a Diversas Atividades Celulares/metabolismo , ATPases Associadas a Diversas Atividades Celulares/uso terapêutico , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Sistemas CRISPR-Cas , Detecção Precoce de Câncer , Ensaios de Triagem em Larga Escala , Gradação de Tumores , Neoplasias da Próstata/genética , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/genética , Neoplasias de Próstata Resistentes à Castração/patologia , Proteômica , Ubiquitina-Proteína Ligases/genética , Ubiquitinas/genética , Ubiquitinas/metabolismo , Ubiquitinas/uso terapêutico
14.
BMC Biol ; 21(1): 24, 2023 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-36747219

RESUMO

BACKGROUND: Studying genomic variation in rapidly evolving pathogens potentially enables identification of genes supporting their "core biology", being present, functional and expressed by all strains or "flexible biology", varying between strains. Genes supporting flexible biology may be considered to be "accessory", whilst the "core" gene set is likely to be important for common features of a pathogen species biology, including virulence on all host genotypes. The wheat-pathogenic fungus Zymoseptoria tritici represents one of the most rapidly evolving threats to global food security and was the focus of this study. RESULTS: We constructed a pangenome of 18 European field isolates, with 12 also subjected to RNAseq transcription profiling during infection. Combining this data, we predicted a "core" gene set comprising 9807 sequences which were (1) present in all isolates, (2) lacking inactivating polymorphisms and (3) expressed by all isolates. A large accessory genome, consisting of 45% of the total genes, was also defined. We classified genetic and genomic polymorphism at both chromosomal and individual gene scales. Proteins required for essential functions including virulence had lower-than average sequence variability amongst core genes. Both core and accessory genomes encoded many small, secreted candidate effector proteins that likely interact with plant immunity. Viral vector-mediated transient in planta overexpression of 88 candidates failed to identify any which induced leaf necrosis characteristic of disease. However, functional complementation of a non-pathogenic deletion mutant lacking five core genes demonstrated that full virulence was restored by re-introduction of the single gene exhibiting least sequence polymorphism and highest expression. CONCLUSIONS: These data support the combined use of pangenomics and transcriptomics for defining genes which represent core, and potentially exploitable, weaknesses in rapidly evolving pathogens.


Assuntos
Perfilação da Expressão Gênica , Transcriptoma , Virulência/genética , Genoma Fúngico , Genes Fúngicos , Doenças das Plantas/microbiologia
15.
J Cell Sci ; 134(15)2021 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-34342353

RESUMO

Centromere structure and function are defined by the epigenetic modification of histones at centromeric and pericentromeric chromatin. The constitutive heterochromatin found at pericentromeric regions is highly enriched for H3K9me3 and H4K20me3. Although mis-expression of the methyltransferase enzymes that regulate these marks, Suv39 and Suv420, is common in disease, the consequences of such changes are not well understood. Our data show that increased centromere localization of Suv39 and Suv420 suppresses centromere transcription and compromises localization of the mitotic kinase Aurora B, decreasing microtubule dynamics and compromising chromosome alignment and segregation. We find that inhibition of Suv420 methyltransferase activity partially restores Aurora B localization to centromeres and that restoration of the Aurora B-containing chromosomal passenger complex to the centromere is sufficient to suppress mitotic errors that result when Suv420 and H4K20me3 is enriched at centromeres. Consistent with a role for Suv39 and Suv420 in negatively regulating Aurora B, high expression of these enzymes corresponds with increased sensitivity to Aurora kinase inhibition in human cancer cells, suggesting that increased H3K9 and H4K20 methylation may be an underappreciated source of chromosome mis-segregation in cancer. This article has an associated First Person interview with the first author of the paper.


Assuntos
Centrômero , Cinetocoros , Aurora Quinase B/genética , Aurora Quinase B/metabolismo , Centrômero/metabolismo , Segregação de Cromossomos , Humanos , Cinetocoros/metabolismo , Mitose , Fosforilação , Transcrição Gênica
16.
Toxicol Appl Pharmacol ; 479: 116711, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37805091

RESUMO

Hexavalent chromium [Cr(VI)] is a human lung carcinogen with widespread exposure risks. Cr(VI) causes DNA double strand breaks that if unrepaired, progress into chromosomal instability (CIN), a key driving outcome in Cr(VI)-induced tumors. The ability of Cr(VI) to cause DNA breaks and inhibit repair is poorly understood in human lung epithelial cells, which are extremely relevant since pathology data show Cr(VI)-induced tumors originate from bronchial epithelial cells. In the present study, we considered immortalized and primary human bronchial epithelial cells. Cells were treated with zinc chromate at concentrations ranging 0.05 to 0.4µg/cm2 for acute (24 h) and prolonged (120 h) exposures. DNA double strand breaks (DSBs) were measured by neutral comet assay and the status of homologous recombination repair, the main pathway to fix Cr(VI)-induced DSBs, was measured by RAD51 foci formation with immunofluorescence, RAD51 localization with confocal microscopy and sister chromatid exchanges. We found acute and prolonged Cr(VI) exposure induced DSBs. Acute exposure induced homologous recombination repair, but prolonged exposure inhibited it resulting in chromosome instability in immortalized and primary human bronchial epithelial cells.


Assuntos
Cromo , Neoplasias , Humanos , Cromo/toxicidade , Cromo/metabolismo , Pulmão/metabolismo , Instabilidade Cromossômica , Células Epiteliais/metabolismo , Neoplasias/metabolismo , DNA/metabolismo , Rad51 Recombinase/genética , Rad51 Recombinase/metabolismo
17.
Mutagenesis ; 38(2): 100-108, 2023 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-36932659

RESUMO

Telomere length (TL), which is maintained by human telomerase reverse transcriptase (hTERT; component of telomerase) and/or TRF1/TRF2 (core components of shelterin) via different mechanisms, is essential for chromosomal stability and cell survival. Folates comprise a group of essential B9 vitamin that involve in DNA synthesis and methylation. This study aimed to evaluate the effects of folic acid (FA) and 5-methyltetrahydrofolate (5-MeTHF) on TL, chromosome stability, and cell survival of telomerase-negative BJ and telomerase-positive A375 cells in vitro. BJ and A375 cells were cultured in modified medium with FA or 5-MeTHF (22.6 or 2260 nM) for 28 days. TL and mRNA expression were determined by RT-qPCR. Chromosome instability (CIN) and cell death were measured by CBMN-Cyt assay. Results showed that abnormal TL elongation was observed in FA- and 5-MeTHF-deficient BJ cells. The TL of A375 cells showed no obvious alterations under the FA-deficient condition but was significantly elongated under the 5-MeTHF-deficient condition. In both BJ and A375 cells, FA and 5-MeTHF deficiency caused decreased TRF1, TRF2, and hTERT expression, increased CIN and cell death; while a high concentration of 5-MeTHF induced elongated TL, elevated CIN, increased TRF1 and TRF2 expression, and decreased hTERT expression, when compared with the FA counterpart. These findings concluded that folate deficiency induced TL instability in both telomerase-negative and -positive cells, and FA was more efficient in maintaining TL and chromosome stability compared with 5-MeTHF.


Assuntos
Melanoma , Telomerase , Humanos , Ácido Fólico/farmacologia , Telomerase/genética , Telomerase/metabolismo , Telômero/metabolismo , Instabilidade Cromossômica , Fibroblastos/metabolismo
18.
Mutagenesis ; 38(3): 160-168, 2023 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-36966355

RESUMO

Telomere length (TL), which is maintained by human telomerase reverse transcriptase (hTERT; component of telomerase) and/or TRF1/TRF2 (core components of shelterin) via different mechanisms, is essential for chromosomal stability and cell survival. Folates comprise a group of essential B9 vitamin that involve in DNA synthesis and methylation. This study aimed to evaluate the effects of folic acid (FA) and 5-methyltetrahydrofolate (5-MeTHF) on TL, chromosome stability, and cell survival of telomerase-negative BJ and telomerase-positive A375 cells in vitro. BJ and A375 cells were cultured in modified medium with FA or 5-MeTHF (22.6 or 2260 nM) for 28 days. TL and mRNA expression were determined by RT-qPCR. Chromosome instability (CIN) and cell death were measured by CBMN-Cyt assay. Results showed that abnormal TL elongation was observed in FA and 5-MeTHF deficient BJ cells. The TL of A375 cells showed no obvious alterations under the FA-deficient condition but was significantly elongated under the 5-MeTHF-deficient condition. In both BJ and A375 cells, FA and 5-MeTHF deficiency caused decreased TRF1, TRF2, and hTERT expression, increased CIN and cell death; while a high concentration of 5-MeTHF induced elongated TL, elevated CIN, increased TRF1 and TRF2 expression and decreased hTERT expression, when compared with the FA counterpart. These findings concluded that folate deficiency induced TL instability in both telomerase-negative and -positive cells, and FA was more efficient in maintaining TL and chromosome stability compared with 5-MeTHF.


Assuntos
Melanoma , Telomerase , Humanos , Ácido Fólico/farmacologia , Telomerase/genética , Telomerase/metabolismo , Telômero/metabolismo , Instabilidade Cromossômica , Fibroblastos/metabolismo
19.
Pathobiology ; 90(3): 166-175, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36202073

RESUMO

INTRODUCTION: Colorectal carcinoma (CRC) is among the most common carcinomas in women and men. In the advanced stage, patients are treated based on the RAS status. Recent studies indicate that in the future, in addition to KRAS and NRAS, alterations in other genes, such as PIK3CA or TP53, will be considered for therapy. Therefore, it is important to know the mutational landscape of routinely diagnosed CRC. METHOD: We report the molecular profile of 512 Swiss CRC patients analyzed by targeted next-generation sequencing as part of routine diagnostics at our institute. RESULTS: Pathogenic and likely pathogenic variants were found in 462 (90%) CRC patients. Variants were detected in TP53 (54.3%), KRAS (48.2%), PIK3CA (15.6%), BRAF (13.5%), SMAD4 (10.5%), FBXW7 (7.8%), NRAS (3.5%), PTEN (2.7%), ERBB2 (1.6%), AKT1 (1.5%), and CTNNB1 (0.9%). The remaining pathogenic alterations were found in the genes ATM(n= 1), MAP2K1(n= 1), and IDH2(n= 1). DISCUSSION/CONCLUSIONS: Our analysis revealed the prevalence of potential predictive markers in a large cohort of CRC patients obtained during routine diagnostic analysis. Furthermore, our study is the first of this size to uncover the molecular landscape of CRC in Switzerland.


Assuntos
Neoplasias Colorretais , Proteínas Proto-Oncogênicas p21(ras) , Masculino , Humanos , Feminino , Prevalência , Proteínas Proto-Oncogênicas p21(ras)/genética , Suíça/epidemiologia , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Mutação , Classe I de Fosfatidilinositol 3-Quinases/genética , Sequenciamento de Nucleotídeos em Larga Escala
20.
Arch Gynecol Obstet ; 307(4): 1115-1123, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36008642

RESUMO

BACKGROUND: High-risk HPV is clearly associated with cervical cancer. Integration of HPV DNA into the host genome is considered a key event in driving cervical carcinogenesis. However, the mechanism on how HR-HPV integration influences the host genome structure has remained enigmatic. METHODS: In our study, 25 DNA samples including 11 from fresh-frozen cervical carcinomas and 14 from fresh-frozen high-grade squamous intraepithelial lesion (HSILs) were detected using the method of HPV capture combined with next generation sequencing. RESULTS: We calculated the frequency in each viral gene or region and found that breakpoints were prone to occur in L1 and L2 instead of E2 in the cervical cancer (P = 0.0004 and P = 5.15 × 10-40) and HSIL group (P = 2.1 × 10-32 and P = 7.06 × 10-13). The results revealed that HPV16 showed a strong tendency toward intronic region (P = 5.02 × 10-64) but a subtle tendency toward intergenic region (P = 0.04). The most frequent integration site was in the MACROD2 gene (introns 2, 4, 5, 6, 8 and 9), which in MACROD2 functional domain. CONCLUSION: Our results revealed that MACROD2 is HPV hot spot integration site in cervical lesions, and its deficiency alter DNA repair and sensitivity to DNA damage thought impaired PARP1 activity resulting in chromosome instability.


Assuntos
Carcinoma de Células Escamosas , Infecções por Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/genética , Papillomavirus Humano , Infecções por Papillomavirus/genética , Carcinoma de Células Escamosas/genética , Colo do Útero/patologia , DNA Viral/genética , Displasia do Colo do Útero/patologia , Papillomaviridae/genética , Hidrolases , Enzimas Reparadoras do DNA
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