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1.
Proc Natl Acad Sci U S A ; 121(29): e2404551121, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-38990945

RESUMO

Confined cell migration hampers genome integrity and activates the ATR and ATM mechano-transduction pathways. We investigated whether the mechanical stress generated by metastatic interstitial migration contributes to the enhanced chromosomal instability observed in metastatic tumor cells. We employed live cell imaging, micro-fluidic approaches, and scRNA-seq to follow the fate of tumor cells experiencing confined migration. We found that, despite functional ATR, ATM, and spindle assembly checkpoint (SAC) pathways, tumor cells dividing across constriction frequently exhibited altered spindle pole organization, chromosome mis-segregations, micronuclei formation, chromosome fragility, high gene copy number variation, and transcriptional de-regulation and up-regulation of c-MYC oncogenic transcriptional signature via c-MYC locus amplifications. In vivo tumor settings showed that malignant cells populating metastatic foci or infiltrating the interstitial stroma gave rise to cells expressing high levels of c-MYC. Altogether, our data suggest that mechanical stress during metastatic migration contributes to override the checkpoint controls and boosts genotoxic and oncogenic events. Our findings may explain why cancer aneuploidy often does not correlate with mutations in SAC genes and why c-MYC amplification is strongly linked to metastatic tumors.


Assuntos
Movimento Celular , Amplificação de Genes , Proteínas Proto-Oncogênicas c-myc , Estresse Mecânico , Humanos , Movimento Celular/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Linhagem Celular Tumoral , Camundongos , Mitose/genética , Instabilidade Cromossômica , Regulação Neoplásica da Expressão Gênica , Neoplasias/genética , Neoplasias/patologia , Neoplasias/metabolismo
3.
J Biomed Sci ; 31(1): 74, 2024 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-39014450

RESUMO

BACKGROUND: Prostate cancer (PrCa) is the most frequently diagnosed cancer in men. Variants in known moderate- to high-penetrance genes explain less than 5% of the cases arising at early-onset (< 56 years) and/or with familial aggregation of the disease. Considering that BubR1 is an essential component of the mitotic spindle assembly checkpoint, we hypothesized that monoallelic BUB1B variants could be sufficient to fuel chromosomal instability (CIN), potentially triggering (prostate) carcinogenesis. METHODS: To unveil BUB1B as a new PrCa predisposing gene, we performed targeted next-generation sequencing in germline DNA from 462 early-onset/familial PrCa patients and 1,416 cancer patients fulfilling criteria for genetic testing for other hereditary cancer syndromes. To explore the pan-cancer role of BUB1B, we used in silico BubR1 molecular modeling, in vitro gene-editing, and ex vivo patients' tumors and peripheral blood lymphocytes. RESULTS: Rare BUB1B variants were found in ~ 1.9% of the early-onset/familial PrCa cases and in ~ 0.6% of other cancer patients fulfilling criteria for hereditary disease. We further show that BUB1B variants lead to decreased BubR1 expression and/or stability, which promotes increased premature chromatid separation and, consequently, triggers CIN, driving resistance to Taxol-based therapies. CONCLUSIONS: Our study shows that different BUB1B variants may uncover a trigger for CIN-driven carcinogenesis, supporting the role of BUB1B as a (pan)-cancer predisposing gene with potential impact on genetic counseling and treatment decision-making.


Assuntos
Instabilidade Cromossômica , Predisposição Genética para Doença , Neoplasias da Próstata , Proteínas Serina-Treonina Quinases , Humanos , Masculino , Neoplasias da Próstata/genética , Proteínas Serina-Treonina Quinases/genética , Pessoa de Meia-Idade , Mutação em Linhagem Germinativa , Adulto , Proteínas de Ciclo Celular
4.
Methods Mol Biol ; 2825: 67-78, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38913303

RESUMO

Somatic chromosomal mosaicism, chromosome instability, and cancer are intimately linked together. Addressing the role of somatic genome variations (encompassing chromosomal mosaicism and instability) in cancer yields paradoxical results. Firstly, somatic mosaicism for specific chromosomal rearrangement causes cancer per se. Secondly, chromosomal mosaicism and instability are associated with a variety of diseases (chromosomal disorders demonstrating less severe phenotypes, complex diseases), which exhibit cancer predisposition. Chromosome instability syndromes may be considered the best examples of these diseases. Thirdly, chromosomal mosaicism and instability are able to result not only in cancerous diseases but also in non-cancerous disorders (brain diseases, autoimmune diseases, etc.). Currently, the molecular basis for these three outcomes of somatic chromosomal mosaicism and chromosome instability remains incompletely understood. Here, we address possible mechanisms for the aforementioned scenarios using a system analysis model. A number of theoretical models based on studies dedicated to chromosomal mosaicism and chromosome instability seem to be valuable for disentangling and understanding molecular pathways to cancer-causing genome chaos. In addition, technological aspects of uncovering causes and consequences of somatic chromosomal mosaicism and chromosome instability are discussed. In total, molecular cytogenetics, cytogenomics, and system analysis are likely to form a powerful technological alliance for successful research against cancer.


Assuntos
Instabilidade Cromossômica , Mosaicismo , Neoplasias , Humanos , Neoplasias/genética , Aberrações Cromossômicas
5.
Methods Mol Biol ; 2825: 79-111, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38913304

RESUMO

Cytogenetic analysis has traditionally focused on the clonal chromosome aberrations, or CCAs, and considered the large number of diverse non-clonal chromosome aberrations, or NCCAs, as insignificant noise. Our decade-long karyotype evolutionary studies have unexpectedly demonstrated otherwise. Not only the baseline of NCCAs is associated with fuzzy inheritance, but the frequencies of NCCAs can also be used to reliably measure genome or chromosome instability (CIN). According to the Genome Architecture Theory, CIN is the common driver of cancer evolution that can unify diverse molecular mechanisms, and genome chaos, including chromothripsis, chromoanagenesis, and polypoidal giant nuclear and micronuclear clusters, and various sizes of chromosome fragmentations, including extrachromosomal DNA, represent some extreme forms of NCCAs that play a key role in the macroevolutionary transition. In this chapter, the rationale, definition, brief history, and current status of NCCA research in cancer are discussed in the context of two-phased cancer evolution and karyotype-coded system information. Finally, after briefly describing various types of NCCAs, we call for more research on NCCAs in future cytogenetics.


Assuntos
Aberrações Cromossômicas , Neoplasias , Humanos , Neoplasias/genética , Instabilidade Cromossômica , Análise Citogenética/métodos , Cariotipagem/métodos
6.
Methods Mol Biol ; 2825: 247-262, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38913314

RESUMO

Hodgkin lymphoma (HL) is one of the most common lymphomas, with an incidence of 3 per 100,000 persons. Current treatment uses a cocktail of genotoxic agents, including adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD), along with or without radiotherapy. This treatment regimen has proved to be efficient in killing cancer cells, resulting in HL patients having a survival rate of >90% cancer-free survival at five years. However, this therapy does not have a specific cell target, and it can induce damage in the genome of non-cancerous cells. Previous studies have shown that HL survivors often exhibit karyotypes characterized by complex chromosomal abnormalities that are difficult to analyze by conventional banding. Multicolor fluorescence in situ hybridization (M-FISH) is a powerful tool to analyze complex karyotypes; we used M-FISH to investigate the presence of chromosomal damage in peripheral blood lymphocytes from five healthy individuals and five HL patients before, during, and one year after anti-cancer treatment. Our results show that this anti-cancer treatment-induced genomic chaos that persists in the hematopoietic stem cells from HL patients one year after finishing therapy. This chromosomal instability may play a role in the occurrence of second primary cancers that are observed in 10% of HL survivors. This chapter will describe a protocol for utilizing M-FISH to study treatment-induced genome chaos in Hodgkin's lymphoma (HL) patients, following a brief discussion.


Assuntos
Doença de Hodgkin , Hibridização in Situ Fluorescente , Doença de Hodgkin/genética , Doença de Hodgkin/terapia , Humanos , Hibridização in Situ Fluorescente/métodos , Aberrações Cromossômicas/efeitos da radiação , Doxorrubicina/uso terapêutico , Genoma Humano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Instabilidade Cromossômica , Linfócitos/efeitos da radiação , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , Bleomicina/uso terapêutico
7.
Methods Mol Biol ; 2825: 309-331, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38913318

RESUMO

Across eukaryotes, genome stability is essential for normal cell function, physiology, and species survival. Aberrant expression of key genes or exposure to genotoxic agents can have detrimental effects on genome stability and contribute to the development of various diseases, including cancer. Chromosome instability (CIN), or ongoing changes in chromosome complements, is a frequent form of genome instability observed in cancer and is a driver of genetic and cell-to-cell heterogeneity that can be rapidly detected and quantitatively assessed using surrogate markers of CIN. For example, single cell quantitative imaging microscopy (QuantIM) can be used to simultaneously identify changes in nuclear areas and micronucleus formation. While changes in nuclear areas are often associated with large-scale changes in chromosome complements (i.e., ploidy), micronuclei are small extra-nuclear bodies found outside the primary nucleus that have previously been employed as a measure of genotoxicity of test compounds. Here, we present a facile QuantIM approach that allows for the rapid assessment and quantification of CIN associated phenotypes and genotoxicity. First, we provide protocols to optimize and execute CIN and genotoxicity assays. Secondly, we present the critical imaging settings, optimization steps, downstream statistical analyses, and data visualization strategies employed to obtain high quality and robust data. These approaches can be easily applied to assess the prevalence of CIN associated phenotypes and genotoxic stress for a myriad of experimental and clinical contexts ranging from direct tests to large-scale screens of various genetic contexts (i.e., aberrant gene expression) or chemical compounds. In summary, this QuantIM approach facilitates the identification of novel CIN genes and/or genotoxic agents that will provide greater insight into the aberrant genes and pathways underlying CIN and genotoxicity.


Assuntos
Instabilidade Cromossômica , Dano ao DNA , Análise de Célula Única , Análise de Célula Única/métodos , Humanos , Microscopia/métodos , Testes de Mutagenicidade/métodos , Núcleo Celular/metabolismo , Núcleo Celular/efeitos dos fármacos , Mutagênicos/toxicidade , Testes para Micronúcleos/métodos
8.
Methods Mol Biol ; 2825: 345-360, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38913320

RESUMO

Many cancers display whole chromosome instability (W-CIN) and structural chromosomal instability (S-CIN), referring to increased rates of acquiring numerically and structurally abnormal chromosome changes. This protocol provides detailed steps to analyze the W-CIN and S-CIN across cancer types, intending to leverage large-scale bulk sequencing and SNP array data complemented with the computational models to gain a better understanding of W-CIN and S-CIN.


Assuntos
Instabilidade Cromossômica , Neoplasias , Polimorfismo de Nucleotídeo Único , Humanos , Neoplasias/genética , Aberrações Cromossômicas , Biologia Computacional/métodos
9.
Nat Commun ; 15(1): 4871, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38871738

RESUMO

The phenomenon of mixed/heterogenous treatment responses to cancer therapies within an individual patient presents a challenging clinical scenario. Furthermore, the molecular basis of mixed intra-patient tumor responses remains unclear. Here, we show that patients with metastatic lung adenocarcinoma harbouring co-mutations of EGFR and TP53, are more likely to have mixed intra-patient tumor responses to EGFR tyrosine kinase inhibition (TKI), compared to those with an EGFR mutation alone. The combined presence of whole genome doubling (WGD) and TP53 co-mutations leads to increased genome instability and genomic copy number aberrations in genes implicated in EGFR TKI resistance. Using mouse models and an in vitro isogenic p53-mutant model system, we provide evidence that WGD provides diverse routes to drug resistance by increasing the probability of acquiring copy-number gains or losses relative to non-WGD cells. These data provide a molecular basis for mixed tumor responses to targeted therapy, within an individual patient, with implications for therapeutic strategies.


Assuntos
Instabilidade Cromossômica , Receptores ErbB , Neoplasias Pulmonares , Mutação , Proteína Supressora de Tumor p53 , Humanos , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Animais , Camundongos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Receptores ErbB/genética , Receptores ErbB/metabolismo , Receptores ErbB/antagonistas & inibidores , Resistencia a Medicamentos Antineoplásicos/genética , Linhagem Celular Tumoral , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/tratamento farmacológico , Adenocarcinoma de Pulmão/patologia , Terapia de Alvo Molecular/métodos , Feminino , Variações do Número de Cópias de DNA , Masculino
10.
PLoS One ; 19(6): e0300434, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38905307

RESUMO

Homologous recombination is a key process that governs the stability of eukaryotic genomes during DNA replication and repair. Multiple auxiliary factors regulate the choice of homologous recombination pathway in response to different types of replication stress. Using Schizosaccharomyces pombe we have previously suggested the role of DNA translocases Rrp1 and Rrp2, together with Srs2 helicase, in the common synthesis-dependent strand annealing sub-pathway of homologous recombination. Here we show that all three proteins are important for completion of replication after hydroxyurea exposure and provide data comparing the effect of overproduction of Srs2 with Rrp1 and Rrp2. We demonstrate that Srs2 localises to rDNA region and is required for proper replication of rDNA arrays. Upregulation of Srs2 protein levels leads to enhanced replication stress, chromosome instability and viability loss, as previously reported for Rrp1 and Rrp2. Interestingly, our data suggests that dysregulation of Srs2, Rrp1 and Rrp2 protein levels differentially affects checkpoint response: overproduction of Srs2 activates simultaneously DNA damage and replication stress response checkpoints, while cells overproducing Rrp1 mainly launch DNA damage checkpoint. On the other hand, upregulation of Rrp2 primarily leads to replication stress response checkpoint activation. Overall, we propose that Srs2, Rrp1 and Rrp2 have important and at least partially independent functions in the maintenance of distinct difficult to replicate regions of the genome.


Assuntos
Dano ao DNA , DNA Helicases , Replicação do DNA , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Instabilidade Cromossômica , DNA Helicases/metabolismo , DNA Helicases/genética , DNA Ribossômico/genética , DNA Ribossômico/metabolismo , Hidroxiureia/farmacologia , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Estresse Fisiológico
11.
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
13.
BMC Plant Biol ; 24(1): 391, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38735929

RESUMO

BACKGROUND: Unreduced gamete formation during meiosis plays a critical role in natural polyploidization. However, the unreduced gamete formation mechanisms in Triticum turgidum-Aegilops umbellulata triploid F1 hybrid crosses and the chromsome numbers and compostions in T. turgidum-Ae. umbellulata F2 still not known. RESULTS: In this study, 11 T.turgidum-Ae. umbellulata triploid F1 hybrid crosses were produced by distant hybridization. All of the triploid F1 hybrids had 21 chromosomes and two basic pathways of meiotic restitution, namely first-division restitution (FDR) and single-division meiosis (SDM). Only FDR was found in six of the 11 crosses, while both FDR and SDM occurred in the remaining five crosses. The chromosome numbers in the 127 selfed F2 seeds from the triploid F1 hybrid plants of 10 crosses (no F2 seeds for STU 16) varied from 35 to 43, and the proportions of euploid and aneuploid F2 plants were 49.61% and 50.39%, respectively. In the aneuploid F2 plants, the frequency of chromosome loss/gain varied among genomes. The chromosome loss of the U genome was the highest (26.77%) among the three genomes, followed by that of the B (22.83%) and A (11.81%) genomes, and the chromosome gain for the A, B, and U genomes was 3.94%, 3.94%, and 1.57%, respectively. Of the 21 chromosomes, 7U (16.54%), 5 A (3.94%), and 1B (9.45%) had the highest loss frequency among the U, A, and B genomes. In addition to chromosome loss, seven chromosomes, namely 1 A, 3 A, 5 A, 6 A, 1B, 1U, and 6U, were gained in the aneuploids. CONCLUSION: In the aneuploid F2 plants, the frequency of chromosome loss/gain varied among genomes, chromsomes, and crosses. In addition to variations in chromosome numbers, three types of chromosome translocations including 3UL·2AS, 6UL·1AL, and 4US·6AL were identified in the F2 plants. Furthermore, polymorphic fluorescence in situ hybridization karyotypes for all the U chromosomes were also identified in the F2 plants when compared with the Ae. umbellulata parents. These results provide useful information for our understanding the naturally occurred T. turgidum-Ae. umbellulata amphidiploids.


Assuntos
Aegilops , Instabilidade Cromossômica , Cromossomos de Plantas , Hibridização Genética , Triticum , Triticum/genética , Cromossomos de Plantas/genética , Aegilops/genética , Meiose/genética , Triploidia , Poliploidia , Genoma de Planta
14.
Int J Mol Sci ; 25(10)2024 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-38791575

RESUMO

Chromosomal instability is a hallmark of colorectal carcinogenesis and produces an accumulation of different forms of aneuploidies or broad copy number aberrations. Colorectal cancer is characterized by gain-type broad copy number aberrations, specifically in Chr20, Chr8q, Chr13 and Chr7, but their roles and mechanisms in cancer progression are not fully understood. It has been suggested that broad copy number gains might contribute to tumor development through the so-called caricature transcriptomic effect. We intend to investigate the impact of broad copy number gains on long non-coding RNAs' expression in colorectal cancer, given their well-known role in oncogenesis. The influence of such chromosomal aberrations on lncRNAs' transcriptome profile was investigated by SNP and transcriptome arrays in our series of colorectal cancer samples and cell lines. The correlation between aneuploidies and transcriptomic profiles led us to obtain a class of Over-UpT lncRNAs, which are transcripts upregulated in CRC and further overexpressed in colon tumors bearing specific chromosomal aberrations. The identified lncRNAs can contribute to a wide interaction network to establish the cancer driving effect of gain-type aneuploidies.


Assuntos
Aneuploidia , Neoplasias Colorretais , Regulação Neoplásica da Expressão Gênica , RNA Longo não Codificante , Humanos , RNA Longo não Codificante/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Variações do Número de Cópias de DNA , Transcriptoma , Feminino , Linhagem Celular Tumoral , Perfilação da Expressão Gênica , Masculino , Instabilidade Cromossômica , Pessoa de Meia-Idade , Aberrações Cromossômicas , Polimorfismo de Nucleotídeo Único
15.
Elife ; 122024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38805560

RESUMO

Solid tumors generally exhibit chromosome copy number variation, which is typically caused by chromosomal instability (CIN) in mitosis. The resulting aneuploidy can drive evolution and associates with poor prognosis in various cancer types as well as poor response to T-cell checkpoint blockade in melanoma. Macrophages and the SIRPα-CD47 checkpoint are understudied in such contexts. Here, CIN is induced in poorly immunogenic B16F10 mouse melanoma cells using spindle assembly checkpoint MPS1 inhibitors that generate persistent micronuclei and diverse aneuploidy while skewing macrophages toward a tumoricidal 'M1-like' phenotype based on markers and short-term anti-tumor studies. Mice bearing CIN-afflicted tumors with wild-type CD47 levels succumb similar to controls, but long-term survival is maximized by SIRPα blockade on adoptively transferred myeloid cells plus anti-tumor monoclonal IgG. Such cells are the initiating effector cells, and survivors make de novo anti-cancer IgG that not only promote phagocytosis of CD47-null cells but also suppress tumor growth. CIN does not affect the IgG response, but pairing CIN with maximal macrophage anti-cancer activity increases durable cures that possess a vaccination-like response against recurrence.


Assuntos
Instabilidade Cromossômica , Imunoglobulina G , Macrófagos , Animais , Camundongos , Macrófagos/imunologia , Antígeno CD47/metabolismo , Antígeno CD47/genética , Antígeno CD47/imunologia , Camundongos Endogâmicos C57BL , Melanoma Experimental/imunologia , Melanoma Experimental/terapia , Melanoma Experimental/genética , Linhagem Celular Tumoral , Feminino
16.
Cell Signal ; 120: 111222, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38729327

RESUMO

BACKGROUND: Bone development involves the rapid proliferation and differentiation of osteogenic lineage cells, which makes accurate chromosomal segregation crucial for ensuring cell proliferation and maintaining chromosomal stability. However, the mechanism underlying the maintenance of chromosome stability during the rapid proliferation and differentiation of Prx1-expressing limb bud mesenchymal cells into osteoblastic precursor cells remains unexplored. METHODS: A transgenic mouse model of RanGAP1 knockout of limb and head mesenchymal progenitor cells was constructed to explore the impact of RanGAP1 deletion on bone development by histomorphology and immunostaining. Subsequently, G-banding karyotyping analysis and immunofluorescence staining were used to examine the effects of RanGAP1 deficiency on chromosome instability. Finally, the effects of RanGAP1 deficiency on chromothripsis and bone development signaling pathways were elucidated by whole-genome sequencing, RNA-sequencing, and qPCR. RESULTS: The ablation of RanGAP1 in limb and head mesenchymal progenitor cells expressing Prx1 in mice resulted in embryonic lethality, severe cartilage and bone dysplasia, and complete loss of cranial vault formation. Moreover, RanGAP1 loss inhibited chondrogenic or osteogenic differentiation of mesenchymal stem cells (MSCs). Most importantly, we found that RanGAP1 loss in limb bud mesenchymal cells triggered missegregation of chromosomes, resulting in chromothripsis of chromosomes 1q and 14q, further inhibiting the expression of key genes involved in multiple bone development signaling pathways such as WNT, Hedgehog, TGF-ß/BMP, and PI3K/AKT in the chromothripsis regions, ultimately disrupting skeletal development. CONCLUSIONS: Our results establish RanGAP1 as a critical regulator of bone development, as it supports this process by preserving chromosome stability in Prx1-expressing limb bud mesenchymal cells.


Assuntos
Diferenciação Celular , Instabilidade Cromossômica , Botões de Extremidades , Células-Tronco Mesenquimais , Animais , Camundongos , Desenvolvimento Ósseo , Condrogênese/genética , Proteínas de Homeodomínio/metabolismo , Proteínas de Homeodomínio/genética , Botões de Extremidades/metabolismo , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/citologia , Camundongos Knockout , Osteogênese/genética , Transdução de Sinais
17.
Histopathology ; 85(2): 327-337, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38715404

RESUMO

BACKGROUND AND AIMS: Gastric cancers (GC) are divided into subtypes based on molecular profile: Epstein-Barr virus (EBV)-positive, microsatellite instability (MSI), chromosomal instability (CIN) and genomically stable (GS) tumours. The prognostic impact of this classification is unclear. The aim was to evaluate whether the molecular subtypes determined using in-situ hybridisation (ISH) and immunohistochemistry (IHC) are associated with clinicopathological parameters and prognosis. METHODS AND RESULTS: The study included 503 GC patients. Based on ISH (EBV) and IHC (MSI and TP53), tumours were divided into EBV-positive, MSI, CIN (EBVneg/MSS/TP53aberrant) and GS (EBVneg/MSS/TP53wild-type) subgroups. Survival analyses with intestinal- and diffuse-type tumours were examined separately. EBV-positive tumours associated with male sex. Both EBV-positive and MSI tumours associated with intestinal type. CIN tumours associated with intestinal-type and positive lymph node status. GS tumours associated with diffuse-type and negative lymph node status. In the total cohort, no significant differences in the 5-year survival were observed. In intestinal tumours, the 5-year survival was better in EBV-positive tumours compared with GS tumours [hazard ratio (HR) = 0.57, 95% confidence interval (CI) = 0.33-0.99]. In diffuse tumours, the 5-year survival was worse in CIN tumours compared with GS tumours (HR = 1.57, 95% CI = 1.14-2.18). In radically resected diffuse tumours, the 5-year survival was worse in MSI tumours compared with GS tumours (HR = 3.26, 95% CI = 1.20-8.82). CONCLUSIONS: The molecular classification is associated with histological type but not prognosis in GC. As the prognostic effects of molecular subtypes in intestinal- and diffuse-type cancers may differ, combining histological and molecular information is recommended for future studies.


Assuntos
Imuno-Histoquímica , Hibridização In Situ , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/patologia , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/classificação , Neoplasias Gástricas/virologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Prognóstico , Instabilidade de Microssatélites , Adulto , Idoso de 80 Anos ou mais , Infecções por Vírus Epstein-Barr/complicações , Biomarcadores Tumorais/análise , Instabilidade Cromossômica
18.
Int J Mol Sci ; 25(8)2024 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-38674062

RESUMO

Chromosomal instability (CIN), defined by variations in the number or structure of chromosomes from cell to cell, is recognized as a distinctive characteristic of cancer associated with the ability of tumors to adapt to challenging environments. CIN has been recognized as a source of genetic variation that leads to clonal heterogeneity (CH). Recent findings suggest a potential association between CIN and CH with the prognosis of BC patients, particularly in tumors expressing the epidermal growth factor receptor 2 (HER2+). In fact, information on the role of CIN in other BC subtypes, including luminal B BC, is limited. Additionally, it remains unknown whether CIN in luminal B BC tumors, above a specific threshold, could have a detrimental effect on the growth of human tumors or whether low or intermediate CIN levels could be linked to a more favorable BC patient prognosis when contrasted with elevated levels. Clarifying these relationships could have a substantial impact on risk stratification and the development of future therapeutic strategies aimed at targeting CIN in BC. This study aimed to assess CIN and CH in tumor tissue samples from ten patients with luminal B BC and compare them with established clinicopathological parameters. The results of this study reveal that luminal B BC patients exhibit intermediate CIN and stable aneuploidy, both of which correlate with lymphovascular invasion. Our results also provide valuable preliminary data that could contribute to the understanding of the implications of CIN and CH in risk stratification and the development of future therapeutic strategies in BC.


Assuntos
Neoplasias da Mama , Instabilidade Cromossômica , Humanos , Feminino , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Neoplasias da Mama/metabolismo , Projetos Piloto , Pessoa de Meia-Idade , Idoso , Adulto , Receptor ErbB-2/metabolismo , Receptor ErbB-2/genética , Prognóstico , Aneuploidia , Heterogeneidade Genética
19.
Cancer Immunol Immunother ; 73(5): 95, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38607586

RESUMO

BACKGROUND: Homologous recombination deficiency (HRD), though largely uncharacterized in clear cell renal cell carcinoma (ccRCC), was found associated with RAD51 loss of expression. PBRM1 is the second most common mutated genes in ccRCC. Here, we introduce a HRD function-based PBRM1-RAD51 ccRCC classification endowed with diverse immune checkpoint blockade (ICB) responses. METHODS: Totally 1542 patients from four independent cohorts were enrolled, including our localized Zhongshan hospital (ZSHS) cohort and Zhongshan hospital metastatic RCC (ZSHS-mRCC) cohort, The Cancer Genome Atlas (TCGA) cohort and CheckMate cohort. The genomic profile and immune microenvironment were depicted by genomic, transcriptome data and immunohistochemistry. RESULTS: We observed that PBRM1-loss ccRCC harbored enriched HRD-associated mutational signature 3 and loss of RAD51. Dual-loss of PBRM1 and RAD51 identified patients hyper-sensitive to immunotherapy. This dual-loss subtype was featured by M1 macrophage infiltration. Dual-loss was, albeit homologous recombination defective, with high chromosomal stability. CONCLUSIONS: PBRM1 and RAD51 dual-loss ccRCC indicates superior responses to immunotherapy. Dual-loss ccRCC harbors an immune-desert microenvironment but enriched with M1 macrophages. Dual-loss ccRCC is susceptible to defective homologous recombination but possesses high chromosomal stability.


Assuntos
Carcinoma de Células Renais , Carcinoma , Neoplasias Renais , Humanos , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/terapia , Imunoterapia , Neoplasias Renais/genética , Neoplasias Renais/terapia , Instabilidade Cromossômica , Microambiente Tumoral , Rad51 Recombinase , Proteínas de Ligação a DNA/genética , Fatores de Transcrição/genética
20.
Proc Natl Acad Sci U S A ; 121(16): e2309621121, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38588415

RESUMO

Chromosomal instability (CIN) is the persistent reshuffling of cancer karyotypes via chromosome mis-segregation during cell division. In cancer, CIN exists at varying levels that have differential effects on tumor progression. However, mis-segregation rates remain challenging to assess in human cancer despite an array of available measures. We evaluated measures of CIN by comparing quantitative methods using specific, inducible phenotypic CIN models of chromosome bridges, pseudobipolar spindles, multipolar spindles, and polar chromosomes. For each, we measured CIN fixed and timelapse fluorescence microscopy, chromosome spreads, six-centromere FISH, bulk transcriptomics, and single-cell DNA sequencing (scDNAseq). As expected, microscopy of tumor cells in live and fixed samples significantly correlated (R = 0.72; P < 0.001) and sensitively detect CIN. Cytogenetics approaches include chromosome spreads and 6-centromere FISH, which also significantly correlate (R = 0.76; P < 0.001) but had limited sensitivity for lower rates of CIN. Bulk genomic DNA signatures and bulk transcriptomic scores, CIN70 and HET70, did not detect CIN. By contrast, scDNAseq detects CIN with high sensitivity, and significantly correlates with imaging methods (R = 0.82; P < 0.001). In summary, single-cell methods such as imaging, cytogenetics, and scDNAseq can measure CIN, with the latter being the most comprehensive method accessible to clinical samples. To facilitate the comparison of CIN rates between phenotypes and methods, we propose a standardized unit of CIN: Mis-segregations per Diploid Division. This systematic analysis of common CIN measures highlights the superiority of single-cell methods and provides guidance for measuring CIN in the clinical setting.


Assuntos
Instabilidade Cromossômica , Neoplasias , Humanos , Linhagem Celular Tumoral , Instabilidade Cromossômica/genética , Centrômero , Cariotipagem , Perfilação da Expressão Gênica , Segregação de Cromossomos , Aneuploidia
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