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1.
Plast Reconstr Surg ; 144(1): 12-20, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31246791

RESUMO

BACKGROUND: Pathogenic mutations have been identified in approximately 10 percent of patients who present with breast cancer. Notably, failure to identify deleterious genetic mutations has particular implications for patients undergoing abdominally based breast reconstruction, as the donor site can be used only once. The authors sought to determine: (1) how many patients underwent genetic testing before unilateral abdominally based free flap breast reconstruction; (2) how often deleterious mutations were detected after abdominally based free flap breast reconstruction; and (3) the cost-effectiveness of expanding genetic testing in this patient population. METHODS: The authors retrospectively identified all patients who underwent unilateral abdominally based free flap breast reconstruction at Brigham and Women's Hospital/Dana-Farber Cancer Institute between 2007 and 2016. Chart review was performed to collect relevant demographic and clinical data. Relevant hospital financial data were obtained. RESULTS: Of the 713 who underwent free flap breast reconstruction, 160 patients met inclusion criteria, and mean follow-up was 5.8 years. Three patients (1.9 percent of 160) underwent contralateral surgery after completing reconstruction, two of whom had BRCA2 and one with ATM mutation. One hundred eleven patients met National Comprehensive Cancer Network guidelines for genetic testing, but of those only 55.9 percent (62 patients) were tested. Financial data revealed that testing every patient in the cohort would result in a net savings of $262,000. CONCLUSIONS: During a relatively short follow-up period, a small percentage of patients were diagnosed with pathogenic mutations and underwent contralateral mastectomy and reconstruction. However, because of the costliness of surgery and the decreased cost of genetic testing, it is cost-effective to test every patient before unilateral abdominally based free flap breast reconstruction.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , Mutação/genética , Adulto , Idoso , Proteínas Mutadas de Ataxia Telangiectasia/genética , Proteína BRCA2/genética , Neoplasias da Mama/cirurgia , Quinase do Ponto de Checagem 2/genética , Assistência à Saúde , Proteínas de Grupos de Complementação da Anemia de Fanconi/genética , Feminino , Retalhos de Tecido Biológico/estatística & dados numéricos , Testes Genéticos , Humanos , Mamoplastia/métodos , Mastectomia/métodos , Pessoa de Meia-Idade , RNA Helicases/genética , Estudos Retrospectivos , Ubiquitina-Proteína Ligases/genética
2.
Med Oncol ; 36(8): 70, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31203460

RESUMO

Alterations in BRCA2, PALB2, CHEK2, and p53 genes have been identified for their association with male breast cancer in various studies. The incidence of male breast cancer in India is consistent with its global rate. The present study was carried out with an aim to evaluate the genetic alterations in male breast cancer patients from Malwa region of Punjab, India. Four male breast cancer patients belonging to different families were recruited from Guru Gobind Singh Medical College and Hospital, Faridkot, India. A total of 51 genes reported with implications in the pathogenesis of breast cancer were screened using next generation sequencing. Germline variations were found in BRCA1, BRCA2, PMS2, p53, and PALB2 genes, previously reported to be associated with MBC as well as FBC. In addition to these, 13 novel missense alterations were detected in eight genes including STK11, FZR1, PALB2, BRCA2, NF2, BAP1, BARD1, and CHEK2. Impact of these missense alterations on structure and function of protein was also analyzed through molecular dynamics simulation. Structural analysis of these single nucleotide polymorphisms (SNPs) revealed significant impact on the encoded protein functioning.


Assuntos
Neoplasias da Mama Masculina/genética , Idoso , Proteína BRCA2/genética , Neoplasias da Mama Masculina/epidemiologia , Quinase do Ponto de Checagem 2/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Simulação de Dinâmica Molecular , Mutação , Linhagem , Polimorfismo de Nucleotídeo Único , Proteínas Serina-Treonina Quinases/genética , Proteína Supressora de Tumor p53/genética , Ubiquitina-Proteína Ligases/genética
3.
J Sci Food Agric ; 99(13): 6097-6107, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31250448

RESUMO

BACKGROUND: Reactive oxygen species (ROS) can cause DNA damage. Rice protein (RP) inhibits ROS accumulation. However, a link between the reduction of ROS-derived DNA damage and the intake of RP is far from clear. The main objective of this study is to elucidate the effects of RPs on the reduction of DNA damage in growing and adult rats. RESULTS: An intake of RP for 2 weeks significantly reduced the hepatic accumulation of ROS and 8-hydroxydeoxyguanosine (8-OHdG) in growing and adult rats, whereas the hepatic p53 content was markedly increased by RPs. After 2 weeks' feeding, the mRNA levels and protein expressions of p53, ataxia-telangiectasia mutated (ATM), and Checkpoint kinase 2 (Chk2) were up-regulated by RPs, whereas Murine Double Minute 2 (MDM2) expressions were markedly inhibited by RPs, resulting in more p53 being translocated into the nucleus. Nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) was activated by RP by reducing Kelch-like ECH-associated protein 1 (Keap1), resulting in the up-regulation of antioxidant expressions of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) in RP groups. CONCLUSION: Rice protein can exert an endogenous antioxidant activity to reduce ROS-derived DNA damage by activating the Nrf2-Keap1 pathway. This study suggests that the activation of the ATM-Chk2-p53 pathway might be one of the mechanisms exerted by RP for reducing DNA damage in growing and adult rats. © 2019 Society of Chemical Industry.


Assuntos
Antioxidantes/metabolismo , Dano ao DNA , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Catalase/genética , Catalase/metabolismo , Quinase do Ponto de Checagem 2/genética , Quinase do Ponto de Checagem 2/metabolismo , Glutationa/metabolismo , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fígado/metabolismo , Masculino , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Proteína Supressora de Tumor p53/genética
4.
Molecules ; 24(4)2019 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-30769778

RESUMO

Theaflavin-3,3'-digallate (TF3) is a unique polyphenol in black tea. Epidemiological studies have proved that black tea consumption decreases the incidence rate of ovarian cancer. Our former research demonstrated that TF3 inhibited human ovarian cancer cells. Nevertheless, the roles of checkpoint kinase 2 (Chk2) and p27 kip1 (p27) in TF3-mediated inhibition of human ovarian cancer cells have not yet been investigated. In the current study, TF3 enhanced the phosphorylation of Chk2 to modulate the ratio of pro/anti-apoptotic Bcl-2 family proteins to initiate intrinsic apoptosis in a p53-independent manner and increased the expression of death receptors to activate extrinsic apoptosis in OVCAR-3 human ovarian carcinoma cells. In addition, TF3 up-regulated the expression of p27 to induce G0/G1 cell cycle arrest in OVCAR-3 cells. Our study indicated that Chk2 and p27 were vital anticancer targets of TF3 and provided more evidence that TF3 might be a potent agent to be applied as adjuvant treatment for ovarian cancer.


Assuntos
Biflavonoides/farmacologia , Carcinoma/tratamento farmacológico , Catequina/análogos & derivados , Quinase do Ponto de Checagem 2/genética , Inibidor de Quinase Dependente de Ciclina p27/genética , Neoplasias Ovarianas/tratamento farmacológico , Antioxidantes/química , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Biflavonoides/química , Camellia sinensis/química , Carcinoma/genética , Carcinoma/patologia , Catequina/química , Catequina/farmacologia , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Proteínas Proto-Oncogênicas c-bcl-2/genética , Transdução de Sinais/efeitos dos fármacos , Chá/química , Proteína Supressora de Tumor p53/genética
5.
Int J Cancer ; 145(2): 390-400, 2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-30613976

RESUMO

Breast cancer (BC) in men is rare and genetic predisposition is likely to play a relevant role in its etiology. Inherited mutations in BRCA1/2 account for about 13% of all cases and additional genes that may contribute to the missing heritability need to be investigated. In our study, a well-characterized series of 523 male BC (MBC) patients from the Italian multicenter study on MBC, enriched for non-BRCA1/2 MBC cases, was screened by a multigene custom panel of 50 cancer-associated genes. The main clinical-pathologic characteristics of MBC in pathogenic variant carriers and non-carriers were also compared. BRCA1/2 pathogenic variants were detected in twenty patients, thus, a total of 503 non-BRCA1/2 MBC patients were examined in our study. Twenty-seven of the non-BRCA1/2 MBC patients were carriers of germline pathogenic variants in other genes, including two APC p.Ile1307Lys variant carriers and one MUTYH biallelic variant carrier. PALB2 was the most frequently altered gene (1.2%) and PALB2 pathogenic variants were significantly associated with high risk of MBC. Non-BRCA1/2 pathogenic variant carriers were more likely to have personal (p = 0.0005) and family (p = 0.007) history of cancer. Results of our study support a central role of PALB2 in MBC susceptibility and show a low impact of CHEK2 on MBC predisposition in the Italian population. Overall, our data indicate that a multigene testing approach may benefit from appropriately selected patients with implications for clinical management and counseling of MBC patients and their family members.


Assuntos
Neoplasias da Mama Masculina/genética , Quinase do Ponto de Checagem 2/genética , Proteína do Grupo de Complementação N da Anemia de Fanconi/genética , Mutação , Análise de Sequência de DNA/métodos , Proteína da Polipose Adenomatosa do Colo/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , DNA Glicosilases/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Adulto Jovem
6.
Mol Cell ; 73(3): 562-573.e3, 2019 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-30595439

RESUMO

Across eukaryotes, disruption of DNA replication causes an S phase checkpoint response, which regulates multiple processes, including inhibition of replication initiation and fork stabilization. How these events are coordinated remains poorly understood. Here, we show that the replicative helicase component Cdc45 targets the checkpoint kinase Rad53 to distinct replication complexes in the budding yeast Saccharomyces cerevisiae. Rad53 binds to forkhead-associated (FHA) interaction motifs in an unstructured loop region of Cdc45, which is phosphorylated by Rad53 itself, and this interaction is necessary for the inhibition of origin firing through Sld3. Cdc45 also recruits Rad53 to stalled replication forks, which we demonstrate is important for the response to replication stress. Finally, we show that a Cdc45 mutation found in patients with Meier-Gorlin syndrome disrupts the functional interaction with Rad53 in yeast. Together, we present a single mechanism by which a checkpoint kinase targets replication initiation and elongation complexes, which may be relevant to human disease.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Quinase do Ponto de Checagem 2/metabolismo , Dano ao DNA , Reparo do DNA , Replicação do DNA , DNA Fúngico/biossíntese , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , Proteínas de Ciclo Celular/genética , Quinase do Ponto de Checagem 2/genética , Microtia Congênita/enzimologia , Microtia Congênita/genética , DNA Fúngico/genética , Proteínas de Ligação a DNA/genética , Transtornos do Crescimento/enzimologia , Transtornos do Crescimento/genética , Humanos , Micrognatismo/enzimologia , Micrognatismo/genética , Mutação , Proteínas Nucleares/genética , Patela/anormalidades , Patela/enzimologia , Fosforilação , Ligação Proteica , Pontos de Checagem da Fase S do Ciclo Celular , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genética
7.
J Hum Genet ; 64(4): 281-290, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30651582

RESUMO

Clinical criteria for genetic testing of genes other than BRCA1/2 in epithelial ovarian cancer (EOC) still do not exist. We assessed the frequency and predictors of deleterious mutations in 19 cancer predisposition genes in high-grade serous ovarian cancer (HGSOC) in Serbia. Next-generation sequencing was used to identify germline mutations in the whole coding regions of a gene panel. Patients' characteristics and sequencing data were summarized with descriptive statistics and compared using chi-square test. Among 131 HGSOC patients, 23 had BRCA1 (17.6%) while 5 had BRCA2 (3.8%) mutation. In addition, 9 (6.9%) pathogenic mutations were detected in other genes including BRIP1 (n = 2;1.5%), CHEK2 (n = 2;1.5%), NBN (n = 3;2.3%) and RAD51C (n = 2;1.5%). Factors that predicted for BRCA1/2 mutations were: breast and ovarian cancers in the same patient (p = 0.031), young age of EOC (p = 0.029), menstrual status (p = 0.004) and family history of cancer (p < 0.0001). However, these factors did not predict for mutations in other cancer susceptibility genes. Applying established referral criteria for genetic testing in Serbia will help identify BRCA1/2 mutation carriers but will not help identify mutations in other cancer susceptibility genes. Until better predictors emerge we should be performing wider genetic testing of EOC in order to identify all mutation carriers.


Assuntos
Proteína BRCA1/genética , Proteína BRCA2/genética , Predisposição Genética para Doença , Neoplasias Ovarianas/genética , Adulto , Idoso , Proteínas de Ciclo Celular/genética , Quinase do Ponto de Checagem 2/genética , Proteínas de Ligação a DNA/genética , Proteínas de Grupos de Complementação da Anemia de Fanconi/genética , Feminino , Testes Genéticos , Mutação em Linhagem Germinativa/genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Proteínas Nucleares/genética , Neoplasias Ovarianas/epidemiologia , Neoplasias Ovarianas/patologia , RNA Helicases/genética , Sérvia/epidemiologia
8.
Mol Omics ; 15(1): 59-66, 2019 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-30633282

RESUMO

The CHEK2 gene and its encoded protein Chk2 have a well-known role in cancers, especially those related to breast cancer mediated through the BRCA1 gene. Additionally Chk2 has a crucial role in DNA repair, apoptosis and the cell cycle, which is why classification of variants of uncertain significance (VUS) is an area highly sought for a better elucidation of the "genomic effect" that results. Because it can often take years before enough clinical data is accumulated, and the costly and expensive functional analysis for individual variants presents a significant hurdle, it is important to identify other tools to help aid in clarifying the impact of specific variants on a protein's function and eventually the patient's health outcome. Here we describe a newly identified CHEK2 variant and analyze with an integrated approach combining genomics (whole exome analysis), clinical study, radiographic imaging, and protein informatics to identify and predict the functional impact of the VUS on the protein's behavior and predicted impact on the related pathways. The observed and analyzed defects in the protein were consistent with the expected clinical effect. Here, we support the use of personalized protein modeling and informatics and further our goal of developing a large-scale protein deposition archive for all protein-level VUS.


Assuntos
Quinase do Ponto de Checagem 2/genética , Biologia Computacional/métodos , Genômica , Imagem Tridimensional , Adulto , Carcinogênese/genética , Carcinogênese/patologia , Quinase do Ponto de Checagem 2/química , Feminino , Humanos , Masculino , Modelos Moleculares , Neoplasias/genética , Linhagem , Fatores de Risco , Eletricidade Estática
9.
Genetics ; 211(2): 515-530, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30538107

RESUMO

The Mre11-Rad50-Xrs2 (MRX) complex acts together with the Sae2 protein to initiate resection of DNA double-strand breaks (DSBs) and to regulate a checkpoint response that couples cell cycle progression with DSB repair. Sae2 supports resistance to DNA damage and downregulates the signaling activities of MRX, Tel1, and Rad53 checkpoint proteins at the sites of damage. How these functions are connected to each other is not known. Here, we describe the separation-of-function sae2-ms mutant that, similar to SAE2 deletion, upregulates MRX and Tel1 signaling activities at DSBs by reducing Mre11 endonuclease activity. However, unlike SAE2 deletion, Sae2-ms causes neither DNA damage sensitivity nor enhanced Rad53 activation, indicating that DNA damage resistance depends mainly on Sae2-mediated Rad53 inhibition. The lack of Sae2, but not the presence of Sae2-ms, impairs long-range resection and increases both Rad9 accumulation at DSBs and Rad53-Rad9 interaction independently of Mre11 nuclease activity. Altogether, these data lead to a model whereby Sae2 plays distinct functions in limiting MRX-Tel1 and Rad9 abundance at DSBs, with the control on Rad9 association playing the major role in supporting DNA damage resistance and in regulating long-range resection and checkpoint activation.


Assuntos
Reparo do DNA , Endonucleases/genética , Proteínas de Saccharomyces cerevisiae/genética , Transdução de Sinais , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Quinase do Ponto de Checagem 2/genética , Quinase do Ponto de Checagem 2/metabolismo , Quebras de DNA de Cadeia Dupla , Regulação para Baixo , Endodesoxirribonucleases/genética , Endodesoxirribonucleases/metabolismo , Endonucleases/metabolismo , Exodesoxirribonucleases/genética , Exodesoxirribonucleases/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mutação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
10.
Breast Cancer ; 26(3): 397-405, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30535581

RESUMO

BACKGROUND: Few studies related to hereditary breast and ovarian cancer syndrome (HBOC) have been conducted in Brazil, and they are restricted to only small areas of the country. Here, we report the mutation profile of BRCA1/2, CHEK2 and TP53 genes in a cohort from Minas Gerais state. METHODS: These genes from 44 patients at high risk for HBOC were screened through high-resolution melting and/or sequencing. The pathogenicity of the alterations was checked using ClinVar database and bioinformatics programs. RESULTS: In BRCA genes we identified 46 variants, 38 without clinical significance and 8 pathogenic mutations including a new pathogenic mutation in BRCA1 gene (c.4688_4694delACCTGGAinsG). The most prevalent pathogenic mutation was c.4829_4830delTG, in the BRCA2 gene. This mutation was not described in the Brazilian population up to now and in this study, it was described with a prevalence of 6.8%. The p.R337H mutation in TP53 gene was found in one patient clinically diagnosed as HBOC and without clinical criteria for Li-Fraumeni syndrome. In CHEK2 gene, the undescribed variant c.485A > G was found and it presents as probably pathogenic through in silico analyses. Pathogenic mutations were found in 29.5% of the patients, 11.3% in BRCA1, 15.9% in BRCA2 and 2.3% in TP53 gene. CONCLUSIONS: Brazilian population is one of the most heterogeneous in the world and the mutational profile knowledge of genes related to HBOC from different regions can contribute to the definition of more cost-effective strategies for the prevention, identification and treatment of cancer.


Assuntos
Predisposição Genética para Doença/genética , Síndrome Hereditária de Câncer de Mama e Ovário/genética , Adulto , Idoso , Proteína BRCA1/genética , Proteína BRCA2/genética , Brasil , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Quinase do Ponto de Checagem 2/genética , Estudos de Coortes , Feminino , Síndrome Hereditária de Câncer de Mama e Ovário/patologia , Humanos , Pessoa de Meia-Idade , Mutação , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Proteína Supressora de Tumor p53/genética
11.
Biochem Biophys Res Commun ; 509(2): 379-383, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30594395

RESUMO

RecQL4 has been shown to be involved in DNA replication and repair, but its role in DNA damage checkpoint pathway has not been reported. Here, we show that RecQL4 plays an important role in the activation of ataxia telangiectasia mutated (ATM)-dependent checkpoint pathway in human cells. Cells depleted with RecQL4 or Rothmund-Thomson syndrome cells showed significant impairment in the activation of ATM and the downstream effector proteins such as checkpoint kinase 2 and p53 after DNA damage. This defect was recovered with the expression of wild type RecQL4 but not any mutant RecQL4 proteins with defective helicase activities. While RecQL4 failed to show any direct interaction with ATM, it stably interacted with the Mre11-Rad50-Nbs1 complex that is essential for the activation of ATM and was localized on the DNA damage foci. Thus, our results suggest that the helicase activity of RecQL4 plays an important role in the activation of ATM-dependent checkpoint pathway against DNA double strand breaks in human cells.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Reparo do DNA , DNA/genética , RecQ Helicases/genética , Síndrome de Rothmund-Thomson/genética , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Quinase do Ponto de Checagem 2/genética , Quinase do Ponto de Checagem 2/metabolismo , DNA/metabolismo , Quebras de DNA de Cadeia Dupla , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Replicação do DNA , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Teste de Complementação Genética , Humanos , Proteína Homóloga a MRE11/genética , Proteína Homóloga a MRE11/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Osteoblastos/citologia , Osteoblastos/metabolismo , Ligação Proteica , RecQ Helicases/deficiência , Síndrome de Rothmund-Thomson/metabolismo , Síndrome de Rothmund-Thomson/patologia , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
12.
Cancer Invest ; 36(6): 338-348, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30136875

RESUMO

Aneuploidy is a common feature of cancer cells and may contribute to cellular transformation and cancer development. In this study, we found that significant down-regulation of CDKN2A, CHEK2, CDCA8, TP53BP1, and CCNDBP1 led to chromosome imbalances in two diploid non-immortalized human cell lines; however, only CDKN2A inhibition enhanced cell proliferation and additionally up-regulated three cell cycle control genes: CDCA8, AURKA, and CCND. These results confirm that CDKN2A is a tumor suppressor gene driving human cancer development by inducing cell aneuploidy and cell cycle up-regulation.


Assuntos
Proliferação de Células/genética , Transformação Celular Neoplásica/genética , Inibidor de Quinase Dependente de Ciclina p18/genética , Genes Supressores de Tumor , Aneuploidia , Aurora Quinase A/genética , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Transformação Celular Neoplásica/patologia , Quinase do Ponto de Checagem 2/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética
13.
Genetics ; 209(4): 1197-1224, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29941619

RESUMO

A major event in germline development is the transition from stem/progenitor cells to entry into meiosis and gametogenesis. This transition requires downregulation of mitotic cell cycle activity and upregulation of processes associated with meiosis. We identify the Caenorhabditis elegans SCFPROM-1 E3 ubiquitin-ligase complex as functioning to downregulate mitotic cell cycle protein levels including cyclin E, WAPL-1, and KNL-2 at meiotic entry and, independently, promoting homologous chromosome pairing as a positive regulator of the CHK-2 kinase. SCFPROM-1 is thus a novel regulator of meiotic entry, coordinating downregulation of mitotic cell cycle proteins and promoting homolog pairing. We further show that SCFPROM-1 functions redundantly, in parallel to the previously described GLD-1 and GLD-2 meiotic entry pathways, downstream of and inhibited by GLP-1 Notch signaling, which specifies the stem cell fate. Accordingly, C. elegans employs three post-transcriptional pathways, SCFPROM-1-mediated protein degradation, GLD-1-mediated translational repression, and GLD-2-mediated translational activation, to control and coordinate the initiation of meiotic development.


Assuntos
Caenorhabditis elegans/fisiologia , Redes Reguladoras de Genes , Meiose , Transdução de Sinais , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ciclo Celular/genética , Quinase do Ponto de Checagem 2/genética , Proteínas de Drosophila/genética , Proteínas F-Box/genética , Gametogênese , Regulação da Expressão Gênica , Polinucleotídeo Adenililtransferase/genética , Biossíntese de Proteínas , Proteólise , Receptores Notch/genética
14.
Int J Sports Med ; 39(9): 704-711, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29945271

RESUMO

Telomere shortening is associated to sarcopenia leading to functional impairment during aging. There are mechanisms associated with telomere attrition, as well to its protection and repair. Physical training is a factor that attenuates telomere shortening, but little is known about the effects of different exercise intensities on telomere biology. Thus, we evaluated the effects of exercise intensity (moderate vs. high-intensity domain) on gene expression of senescence markers Checkpoint kinase 2 and tumor suppressor (Chk2 and p53, respectively), shelterin telomere repeat binding 1 and 2 (Trf1/Trf2), DNA repair (Xrcc5), telomerase reverse transcriptase (mTERT) and telomere length in middle aged mice. Three groups were studied: a control group (CTL) and two groups submitted to swimming at intensities below the lactate threshold (LI group) and above the lactate threshold (HI group) for 40 and 20 min respectively, for 12 weeks. After training, the HI group showed reduction in p53 expression in the muscle, and decreased shelterin complex expression when compared to LI group. No differences were observed between groups for mTERT expression and telomere length. Thus, exercise training in high-intensity domain was more effective on reducing markers of senescence and apoptosis. The higher intensity exercise training also diminished shelterin expression, with no differences in telomere length and mTERT expression. Such results possibly indicate a more effective DNA protection for the higher-intensity exercise training.


Assuntos
Limiar Anaeróbio/fisiologia , Quinase do Ponto de Checagem 2/genética , Expressão Gênica , Músculo Esquelético/metabolismo , Condicionamento Físico Animal/métodos , Encurtamento do Telômero/fisiologia , Proteína 2 de Ligação a Repetições Teloméricas/genética , Proteína Supressora de Tumor p53/genética , Envelhecimento/genética , Envelhecimento/metabolismo , Animais , Apoptose , Biomarcadores/metabolismo , Reparo do DNA , Ácido Láctico/sangue , Camundongos Endogâmicos C57BL , Natação/fisiologia , Telomerase/genética , Telomerase/metabolismo , Telômero/genética , Telômero/metabolismo
15.
Genome Res ; 28(8): 1179-1192, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29934426

RESUMO

Genome duplication is essential for cell proliferation, and the mechanisms regulating its execution are highly conserved. These processes give rise to a spatiotemporal organization of replication initiation across the genome, referred to as the replication program. Despite the identification of such programs in diverse eukaryotic organisms, their biological importance for cellular physiology remains largely unexplored. We address this fundamental question in the context of genome maintenance, taking advantage of the inappropriate origin firing that occurs when fission yeast cells lacking the Rad3/ATR checkpoint kinase are subjected to replication stress. Using this model, we demonstrate that the replication program quantitatively dictates the extent of origin de-regulation and the clustered localization of these events. Furthermore, our results uncover an accumulation of abnormal levels of single-stranded DNA (ssDNA) and the Rad52 repair protein at de-regulated origins. We show that these loci constitute a defining source of the overall ssDNA and Rad52 hotspots in the genome, generating a signature pattern of instability along the chromosomes. We then induce a genome-wide reprogramming of origin usage and evaluate its consequences in our experimental system. This leads to a complete redistribution of the sites of both inappropriate initiation and associated Rad52 recruitment. We therefore conclude that the organization of genome duplication governs the checkpoint control of origin-associated hotspots of instability and plays an integral role in shaping the landscape of genome maintenance.


Assuntos
Quinase do Ponto de Checagem 2/genética , Replicação do DNA/genética , Instabilidade Genômica/genética , Proteína Rad52 de Recombinação e Reparo de DNA/genética , Proteínas de Schizosaccharomyces pombe/genética , Proliferação de Células/genética , Reprogramação Celular/genética , DNA de Cadeia Simples/genética , Genoma Fúngico/genética , Origem de Replicação/genética , Fase S/genética , Schizosaccharomyces/genética
16.
Medicine (Baltimore) ; 97(23): e10894, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29879026

RESUMO

RATIONALE: Neurofibromatosis, including type 1 and type 2, is inherited dominant disease that causes serious consequences. The genetic mechanism of these diseases has been described, but germline mutation of checkpoint 2 kinase gene, together with other DNA repair related genes, has not been fully elucidated in the context of neurofibromatosis. PATIENT CONCERNS: In this article, we reported identical germline mutation of CHEK2 gene (p.R180C) in a 7-year-old Tibetan boy with NF1, and in a 12-year-old Chinese girl with NF2. DIAGNOSES: Neurofibromatosis 1 and 2 with CHECK2 gene germline mutation. INTERVENTIONS: Both patients underwent operation to obtain tumor tissue, and peripheral blood of their family was tested. OUTCOMES: Identical germline mutation of CHEK2 gene (p.R180C) was detected in both patients, and germline mutations of POLE, MUTYH and ATR were also detected. LESSONS: This is the first article to describe CHEK2 mutation in both NF1 and NF2. This article highlights a possible role of CHEK2, in association with other germline genetic mutations, in tumorigenesis of NF1 and NF2.


Assuntos
Quinase do Ponto de Checagem 2/genética , Mutação em Linhagem Germinativa/genética , Neurofibromatose 1/genética , Neurofibromatose 2/genética , Grupo com Ancestrais do Continente Asiático/genética , Criança , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino
17.
Med Sci Monit ; 24: 3176-3183, 2018 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-29761796

RESUMO

BACKGROUND This study aimed to investigate the mechanism of CHEK2 gene dysfunction in drug resistance of triple negative breast cancer (TNBC) cells. MATERIAL AND METHODS To perform our study, a stable CHEK2 wild type (CHEK2 WT) or CHEK2 Y390C mutation (CHEK2 Y390C) expressed MDA-MB-231 cell line was established. MTT assay, cell apoptosis assay and cell cycle assay were carried out to analyze the cell viability, apoptosis, and cell cycle respectively. Western blotting and qRT-PCR were applied for related protein and gene expression detection. RESULTS We found that the IC50 value of DDP (Cisplatin) to CHEK2 Y390C expressed MDA-MB-231 cells was significantly higher than that of the CHEK2 WT expressed cells and the control cells. After treatment with DDP for 48 h, cells expressing CHEK2 WT showed lower cell viability than that of the CHEK2 Y390C expressed cells and the control cells; compared with the CHEK2 Y390C expressed cells and the control cells, cells expressing CHEK2 WT showed significant G1/S arrest. Meanwhile, we found that compared with the CHEK2 Y390C expressed cells and the control cells, cell apoptosis was significantly increased in CHEK2 WT expressed cells. Moreover, our results suggested that cells expressing CHEK2 WT showed higher level of p-CDC25A, p-p53, p21, Bax, PUMA, and Noxa than that of the CHEK2 Y390C expressed cells and the control cells. CONCLUSIONS Our findings indicated that CHEK2 Y390C mutation induced the drug resistance of TNBC cells to chemotherapeutic drugs through administrating cell apoptosis and cell cycle arrest via regulating p53 activation and CHEK2-p53 apoptosis pathway.


Assuntos
Quinase do Ponto de Checagem 2/genética , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias de Mama Triplo Negativas/enzimologia , Neoplasias de Mama Triplo Negativas/genética , Apoptose/efeitos dos fármacos , Apoptose/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Quinase do Ponto de Checagem 2/metabolismo , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Dano ao DNA , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Técnicas de Silenciamento de Genes , Humanos , Mutação/genética , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Proteína Supressora de Tumor p53/metabolismo
18.
Molecules ; 23(5)2018 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-29734760

RESUMO

Kaempferol is a widely distributed dietary flavonoid. Epidemiological studies have demonstrated kaempferol consumption lowers the risk of ovarian cancer. Our previous research proved that kaempferol suppresses human ovarian cancer cells by inhibiting tumor angiogenesis. However, the effects of kaempferol on the cell cycle and extrinsic apoptosis of ovarian cancer cells have not yet been studied. In the present study, we demonstrated that kaempferol induced G2/M cell cycle arrest via the Chk2/Cdc25C/Cdc2 pathway and Chk2/p21/Cdc2 pathway in human ovarian cancer A2780/CP70 cells. Chk2 was not responsible for kaempferol-induced apoptosis and up-regulation of p53. Kaempferol stimulated extrinsic apoptosis via death receptors/FADD/Caspase-8 pathway. Our study suggested that Chk2 and death receptors played important roles in the anticancer activity of kaempferol in A2780/CP70 cells. These findings provide more evidence of the anti-ovarian cancer properties of kaempferol and suggest that kaempferol could be a potential candidate for ovarian cancer adjuvant therapy.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Quinase do Ponto de Checagem 2/genética , Células Epiteliais/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica , Quempferóis/farmacologia , Receptores de Morte Celular/genética , Apoptose/efeitos dos fármacos , Apoptose/genética , Proteína Quinase CDC2/genética , Proteína Quinase CDC2/metabolismo , Caspase 8/genética , Caspase 8/metabolismo , Linhagem Celular Tumoral , Quinase do Ponto de Checagem 2/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Proteína de Domínio de Morte Associada a Fas/genética , Proteína de Domínio de Morte Associada a Fas/metabolismo , Feminino , Pontos de Checagem da Fase G2 do Ciclo Celular/genética , Humanos , Ovário/efeitos dos fármacos , Ovário/metabolismo , Ovário/patologia , Receptores de Morte Celular/metabolismo , Transdução de Sinais , Fosfatases cdc25/genética , Fosfatases cdc25/metabolismo
19.
J Hum Genet ; 63(8): 877-886, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29785007

RESUMO

Germline CHEK2 mutations confer increased cancer risk, for breast and other types, which is variable depending on the specific mutation. Of these, Large Genomic Rearrangements (LGRs) have been rarely reported; to date only eight LGRs have been published with just the Czech founder mutation, the deletion of exons 9 and 10, being molecularly characterized and studied extensively. The present study aimed to molecularly define and determine the contribution of two rare, apparently novel CHEK2 LGRs, among Greek breast cancer patients. These specifically involve a ~6 kb in-frame deletion of exons 2 & 3 that removes CHEK2's FHA domain and a ~7.5 kb in-frame deletion of exon 6, which removes an α-helix of CHEK2's kinase domain. The latter was identified in 5 out of 2355 (0.22%) patients tested, while haplotype analysis revealed a common disease-associated haplotype, suggesting a single common ancestor and a Greek founder. Although in-frame, this LGR is predicted to be damaging by a yeast-based functional assay and structure-function predictions. The present study highlights the existence of rare, population-specific, genomic events in a known breast cancer predisposing gene, which can explain a proportion of hereditary breast cancer. Identification of such mutation carriers is rather important since appropriate clinical actionability will be inferred.


Assuntos
Neoplasias da Mama/genética , Quinase do Ponto de Checagem 2/genética , Deleção de Genes , Predisposição Genética para Doença , Adulto , Idoso , Neoplasias da Mama/patologia , Simulação por Computador , Análise Mutacional de DNA , Feminino , Rearranjo Gênico , Grécia , Haplótipos/genética , Humanos , Masculino , Repetições de Microssatélites/genética , Pessoa de Meia-Idade , Linhagem , Polimorfismo de Nucleotídeo Único/genética , Prevalência , Saccharomyces cerevisiae/metabolismo , Relação Estrutura-Atividade , Adulto Jovem
20.
Gynecol Oncol ; 150(1): 136-142, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29804637

RESUMO

OBJECTIVE: To analyze the expression and clinical role of CHK1 and CHK2 in metastatic high-grade serous carcinoma (HGSC). METHODS: HGSC effusions (n = 335; 280 peritoneal, 55 pleural) were analyzed for protein expression of total CHK1 and its phosphorylated forms p-ser317 and p-ser296, as well as total CHK2 and its phosphorylated form p-thr68 using immunohistochemistry. Expression was analyzed for association with clinicopathologic parameters, including chemotherapy response, and survival. RESULTS: Carcinoma cells stained positive, predominantly at the nuclei, in the majority of cases (range 83-100% for the five antibodies), while expression in reactive mesothelial cells and tumor-associated macrophages was more variable. Total CHK1 (p = 0.037), p-CHK1ser317 (p = 0.001), p-CHK1ser296 (p = 0.002) and p-CHK2thr68 (p < 0.001) expression was significantly higher in post-chemotherapy disease recurrence compared to pre-chemotherapy effusions obtained at diagnosis. CHK1, p-CHK1ser296, p-CHK2thr68 and p-CHK1ser317 nuclear expression was positively related to expression of the checkpoint regulator WEE1, previously studied in this cohort (p = 0.003, p = 0.013, p = 0.001 and p = 0.01, respectively). Higher total CHK1 (p = 0.007), p-CHK1ser317 (p = 0.004), CHK2 (p = 0.01) and p-CHK2thr68 (p = 0.048) expression was significantly related to shorter overall survival in univariate analysis, and CHK1ser317 was an independent prognostic marker in multivariate analysis (p = 0.025). Higher p-CHK1ser317 (p = 0.03) and CHK2 (p = 0.034) expression was additionally associated with poor progression-free survival. CONCLUSIONS: CHK1 and CHK2 and their activated forms are frequently expressed in HGSC effusions, with higher expression following exposure to chemotherapy, and their expression is related to survival.


Assuntos
Quinase 1 do Ponto de Checagem/metabolismo , Quinase do Ponto de Checagem 2/biossíntese , Quinase do Ponto de Checagem 2/metabolismo , Cistadenocarcinoma Seroso/enzimologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Quinase 1 do Ponto de Checagem/biossíntese , Quinase 1 do Ponto de Checagem/genética , Quinase do Ponto de Checagem 2/genética , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/patologia , Ativação Enzimática , Feminino , Humanos , Pessoa de Meia-Idade , Gradação de Tumores , Análise de Sobrevida , Adulto Jovem
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