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1.
Anticancer Res ; 39(9): 4743-4748, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31519574

RESUMO

BACKGROUND/AIM: Overexpression of human telomerase reverse transcriptase (hTERT) allows disordered proliferation and immortality of malignant cells, which has been of interest for the development of targeted therapies. The present study aimed to characterize hTERT gene expression in a series of cancer cell lines. MATERIALS AND METHODS: Leukemia cell lines K-562, its vincristine-resistant derivative K-562-Lucena1 and daunorubicin-resistant derivative FEPS; gastric adenocarcinoma lines AGP01, ACP02 and ACP03; melanoma SK-Mel-103 cells; and MN01 and MRC5, two non-neoplastic cell lines were analyzed by real-time polymerase chain reaction in order to evaluate hTERT gene expression. RESULTS: In leukemia cells, hTERT gene expression was significantly increased only in K-562 (p<0.05) and K-562-Lucena1 (p<0.001) when compared to the calibrator MRC5. For solid tumor types, only ACP03 presented a significant hTERT gene expression when compared to ACP02 (p<0.05). hTERT gene expression in K-562 and K-562-L ucena was significantly increased (p<0.05 to p<0.001) compared to all other cell lines except ACP03. CONCLUSION: In leukemia cell lines, hTERT gene overexpression was shown to be a potential target for pharmacological assays for drugs aiming to inhibit telomerase activity and control cell proliferation in oncohematological diseases.


Assuntos
Regulação Neoplásica da Expressão Gênica , Telomerase/genética , Biomarcadores Tumorais , Linhagem Celular Tumoral , Neoplasias Hematológicas/genética , Humanos , Neoplasias/genética , Especificidade de Órgãos/genética
2.
Nucleic Acids Res ; 47(18): 9950-9966, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31504744

RESUMO

HMGB1 is a ubiquitous non-histone protein, which biological effects depend on its expression and subcellular location. Inside the nucleus, HMGB1 is engaged in many DNA events such as DNA repair, transcription and telomere maintenance. HMGB1 has been reported to bind preferentially to bent DNA as well as to noncanonical DNA structures like 4-way junctions and, more recently, to G-quadruplexes. These are four-stranded conformations of nucleic acids involved in important cellular processes, including telomere maintenance. In this frame, G-quadruplex recognition by specific proteins represents a key event to modulate physiological or pathological pathways. Herein, to get insights into the telomeric G-quadruplex DNA recognition by HMGB1, we performed detailed biophysical studies complemented with biological analyses. The obtained results provided information about the molecular determinants for the interaction and showed that the structural variability of human telomeric G-quadruplex DNA may have significant implications in HMGB1 recognition. The biological data identified HMGB1 as a telomere-associated protein in both telomerase-positive and -negative tumor cells and showed that HMGB1 gene silencing in such cells induces telomere DNA damage foci. Altogether, these findings provide a deeper understanding of telomeric G-quadruplex recognition by HMGB1 and suggest that this protein could actually represent a new target for cancer therapy.


Assuntos
Quadruplex G , Proteína HMGB1/genética , Conformação de Ácido Nucleico , Telômero/genética , DNA/química , DNA/genética , Escherichia coli/genética , Proteína HMGB1/química , Humanos , Telomerase/química , Telomerase/genética , Telômero/química
3.
Nucleic Acids Res ; 47(18): 9842-9856, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31392988

RESUMO

To elucidate the molecular nature of evolutionary changes of telomeres in the plant order Asparagales, we aimed to characterize telomerase RNA subunits (TRs) in these plants. The unusually long telomere repeat unit in Allium plants (12 nt) allowed us to identify TRs in transcriptomic data of representative species of the Allium genus. Orthologous TRs were then identified in Asparagales plants harbouring telomere DNA composed of TTAGGG (human type) or TTTAGGG (Arabidopsis-type) repeats. Further, we identified TRs across the land plant phylogeny, including common model plants, crop plants, and plants with unusual telomeres. Several lines of functional testing demonstrate the templating telomerase function of the identified TRs and disprove a functionality of the only previously reported plant telomerase RNA in Arabidopsis thaliana. Importantly, our results change the existing paradigm in plant telomere biology which has been based on the existence of a relatively conserved telomerase reverse transcriptase subunit (TERT) associating with highly divergent TRs even between closely related plant taxa. The finding of a monophyletic origin of genuine TRs across land plants opens the possibility to identify TRs directly in transcriptomic or genomic data and/or predict telomere sequences synthesized according to the respective TR template region.


Assuntos
Evolução Molecular , Filogenia , RNA/genética , Telomerase/genética , Telômero/genética , Allium/genética , Arabidopsis/genética , Asparagales/genética , Embriófitas/genética , Genoma de Planta/genética , Humanos
4.
DNA Cell Biol ; 38(9): 915-921, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31429604

RESUMO

Pharynx-larynx cancer is a complex malignant tumor with the sixth-highest morbidity and mortality rate worldwide. The telomerase reverse transcriptase TERT-CLPTM1L gene, located on chromosome 5p15.33, plays a key role in the occurrence and progression of various cancer. The purpose of this hospital-based case-control study of patients in northern China was to explore the association between two single-nucleotide polymorphisms (SNPs) rs401681 in TERT and rs2736100 in CLPTM1L and the risk of head and neck cancer. We collected samples and relative characteristics and then analyzed the relationship between SNPs and pharynx-larynx cancer susceptibility by logistic regression analysis. The results suggested that the male patients carrying CT and CT+CC genotype model of rs401681 was associated with reduced risk of pharynx-larynx cancer compared with the CC genotype (adjusted odds ratios were 0.701 and 0.704, and 95% confidence intervals were 0.495-0.992 and 0.506-0.980; p-values were 0.045 and 0.038, respectively). In addition, we found that subjects with allele-C showed a relatively low risk of pharyngeal cancer when smoking exposure history was obtained. But the limitation is that in the future we need to further investigate about the exact functional effect of these two variant genes and a larger scale sample. Overall, in this research, our results show that the TERT-CLPTM1L gene could be a meaningful biomarker for pharynx-larynx cancer susceptibility.


Assuntos
Neoplasias Laríngeas/genética , Proteínas de Membrana/genética , Proteínas de Neoplasias/genética , Neoplasias Faríngeas/genética , Polimorfismo de Nucleotídeo Único , Telomerase/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
5.
Zhonghua Yi Xue Za Zhi ; 99(25): 1959-1962, 2019 Jul 02.
Artigo em Chinês | MEDLINE | ID: mdl-31269600

RESUMO

Objective: To investigate the prognostic values of IDH, TERT and 1p/19q in patients with anaplastic oligodendroglioma. Methods: In the study, 66 patients with pathological diagnosis of anaplastic oligodendroglioma were enrolled (The First Affiliated Hospital of Zhengzhou University 2011 to 2016 years). Kaplan-Meier method was used to calculate the survival rates. Log-rank was used to calculate the differences in group. Chi-square testwas used tocalculate the differences in common factor group. Cox regression model was used to conduct multivariate analysis. Results: The median survival time of IDH-wt and IDH-mt subgroups were 16.10 and 42.00 months with statistical significance (P=0.001). The median survival time of 1p/19q codeleted and 1p/19q noncodeleted subgroups were 42.00 and 22.40 months with statistical significance (P=0.012). IDH-mt and 1p/19q codeleted predicted better survivals compared with IDH-wt and 1p/19q noncodeleted (P=0.001). And IDH-mt and 1p/19q noncodeleted predicted better survivals compared with IDH-wt and 1p/19q noncodeleted (P=0.041), too. Multivariate survival analysis demonstrated that Molecular groups was an independent factor to evaluate the prognosis of anaplastic oligodendroglioma (P=0.008). Conclusion: IDH-mtand (or) 1p/19q codeletedpredicted better survivals in patients with anaplastic oligodendroglioma. IDH and 1p/19q deleted might be a biomarker for predicting prognosis of patients with anaplastic oligodendroglioma.


Assuntos
Neoplasias Encefálicas , Isocitrato Desidrogenase/genética , Oligodendroglioma , Telomerase/genética , Adulto , Neoplasias Encefálicas/genética , Cromossomos Humanos Par 1 , Cromossomos Humanos Par 19 , Humanos , Mutação , Oligodendroglioma/genética , Prognóstico
6.
Biosci Rep ; 39(7)2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31296788

RESUMO

Glioblastoma is the most common malignant brain tumor in adults. Unfortunately, it has a very poor prognosis and no cure. In a recent paper by Yuan et al. (Bioscience Reports (2019), DOI:10.1042/BSR20190045) RNAscope was used to detect insulin-like growth factor binding protein 2 (IGFBP2) mRNA in glioblastoma biopsies. The study revealed that patients with high levels of IGFBP2 mRNA had shorter survival and that IGFBP2 transcript level was an independent prognostic factor. It is also of value to determine the prognostic effect of IGFBP2 on established biomarkers such as isocitrate dehydrogenase (IDH1) mutations or telomerase reverse transcriptase (TERT) promoter mutation. In the present study, the combination of having a TERT promoter mutation, and at the same time a high level of IGFBP2 mRNA, was associated with very poor survival rates. It was concluded that IGFBP2 predicts the survival of the patients with TERT promoter mutation. This finding may have important implications for glioblastoma prognosis. IGFBP2 re-emerges as a candidate biomarker and potential therapeutic target in glioma. Further research into its functional roles during glioma progression may provide additional insights into this deadly disease.


Assuntos
Neoplasias Encefálicas , Glioblastoma , Telomerase/genética , Adulto , Humanos , Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina , Isocitrato Desidrogenase , Mutação , Prognóstico , RNA Mensageiro
7.
Endocrinology ; 160(10): 2328-2338, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31305897

RESUMO

In this study, we examined the relationship between coexisting BRAF V600E and TERT promoter mutations in papillary thyroid cancer (PTC) and response to therapy. PTC cases (n = 568) with known BRAF and TERT status, diagnosed from 2000 to 2012 and actively monitored at one institution, were reviewed retrospectively. Associations between BRAF V600E and TERT promoter mutations and clinicopathological features, Tumor-Node-Metastasis stage, initial risk, response to therapy, follow-up, and final disease outcome were assessed according to American Thyroid Association 2015 criteria and the American Joint Committee on Cancer/Tumor-Node-Metastasis (8th edition) staging system. Median follow-up was 120 months. TERT promoter mutations (any type) were detected in 13.5% (77/568) of PTC cases with known BRAF status. The C228T and C250T TERT hotspot mutations were found in 54 (9.5%) and 23 (4%) patients, respectively, and 22 other TERT promoter alterations were identified. Coexisting BRAF V600E and TERT hotspot promoter mutations were detected in 9.5% (54/568) of patients, and significantly associated with older patient age (P = 0.001), gross extrathyroidal extension (P = 0.003), tumor stage pT3-4 (P = 0.005), stage II to IV (P = 0.019), intermediate or high initial risk (P = 0.003), worse than excellent response to primary therapy (P = 0.045), recurrence (P = 0.015), and final outcome of no remission (P = 0.014). We conclude that coexisting BRAF V600E and TERT mutations in patients with PTC are associated with poor initial prognostic factors and clinical course and may be useful for predicting a worse response to therapy, recurrence, and poorer outcome than in patients without the above mutations.


Assuntos
Antineoplásicos/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/metabolismo , Telomerase/metabolismo , Câncer Papilífero da Tireoide/metabolismo , Neoplasias da Glândula Tireoide/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Regiões Promotoras Genéticas , Proteínas Proto-Oncogênicas B-raf/genética , Estudos Retrospectivos , Telomerase/genética , Câncer Papilífero da Tireoide/tratamento farmacológico , Câncer Papilífero da Tireoide/genética , Neoplasias da Glândula Tireoide/tratamento farmacológico , Neoplasias da Glândula Tireoide/genética , Adulto Jovem
8.
Dokl Biochem Biophys ; 485(1): 150-152, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31201638

RESUMO

A hybrid 6XRE-hTERT promoter consisting of the hTERT tumor-specific promoter and six copies of the XRE element from the CYP1A1 human gene promoter was created. Using a human lung cancer cells as a model, we showed that XRE elements in the hybrid promoter greatly increase the activity of the hTERT promoter and ensure the reporter gene transcriptional activation in response to the treatment of the cells with the AhR ligand benzo(a)pyrene. However, similar effects were also observed in normal human bronchial epithelial cells HBEpC, which indicates the loss of the tumor-specific activity by the 6XRE-hTERT hybrid promoter. XRE elements can be used for nonspecific transcription enhancement but are unsuitable for the creation of tumor-specific promoters with enhanced activity.


Assuntos
Citocromo P-450 CYP1A1 , Elementos de Resposta , Telomerase , Ativação Transcricional/efeitos dos fármacos , Células A549 , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Benzo(a)pireno/toxicidade , Brônquios/metabolismo , Brônquios/patologia , Citocromo P-450 CYP1A1/biossíntese , Citocromo P-450 CYP1A1/genética , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Humanos , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo , Mucosa Respiratória/metabolismo , Mucosa Respiratória/patologia , Telomerase/biossíntese , Telomerase/genética
9.
Int J Mol Sci ; 20(11)2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31146388

RESUMO

Stem cells undergo senescence both in vivo, contributing to the progressive decline in self-healing mechanisms, and in vitro during prolonged expansion. Here, we show that an early developmental zebrafish embryo extract (ZF1) could act as a modulator of senescence in human mesenchymal stem cells (hMSCs) isolated from both adult tissues, including adipose tissue (hASCs), bone marrow (hBM-MSCs), dental pulp (hDP-MSCs), and a perinatal tissue such as the Wharton's Jelly (hWJ-MSCs). In all the investigated hMSCs, ZF1 decreased senescence-associated ß-galactosidase (SA ß-gal) activity and enhanced the transcription of TERT, encoding the catalytic telomerase core. In addition, it was associated, only in hASCs, with a transcriptional induction of BMI1, a pleiotropic repressor of senescence. In hBM-MSCs, hDP-MSCs, and hWJ-MSCs, TERT over-expression was concomitant with a down-regulation of two repressors of TERT, TP53 (p53), and CDKN1A (p21). Furthermore, ZF1 increased the natural ability of hASCs to perform adipogenesis. These results indicate the chance of using ZF1 to modulate stem cell senescence in a source-related manner, to be potentially used as a tool to affect stem cell senescence in vitro. In addition, its anti-senescence action could also set the basis for future in vivo approaches promoting tissue rejuvenation bypassing stem cell transplantation.


Assuntos
Senescência Celular , Embrião não Mamífero/química , Células-Tronco Mesenquimais/efeitos dos fármacos , Extratos de Tecidos/farmacologia , Animais , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Telomerase/genética , Telomerase/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Peixe-Zebra
10.
Anal Chim Acta ; 1075: 137-143, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31196419

RESUMO

Nucleic acid probes are very useful tools in biological and medical science. However, the essential sensing mechanism of nucleic acid probes was prone to the interference of surrounding sequences. Especially when the target sequences formed secondary structures such as hairpin or quadruplex, the nucleic acid probes were hindered from hybridizing with target strands, greatly disabled the function of probes. Herein, we have established an Open strand based strategy for eliminating the influence of secondary structures on the performance of nucleic acid probes. The strategy was general toward different lengths, secondary structures and sequences of the targeting strand, and we found that the improvement was higher when the secondary structure of the targeting strand was more complicated. Experiments on synthetic single stranded DNA and real clinical genomic DNA samples were conducted for low abundance mutation detection, and the limit of detection for TERT-C228T and BRCA2 rs80359065 mutations could be 0.02% and 0.05% respectively, demonstrating the clinical practicability of our proposed strategy in low abundance mutation detection.


Assuntos
Sondas de DNA/química , DNA de Cadeia Simples/análise , Proteína BRCA2/genética , Sondas de DNA/genética , DNA de Cadeia Simples/genética , Desoxirribonuclease IV (Fago T4-Induzido)/química , Feminino , Corantes Fluorescentes/química , Humanos , Limite de Detecção , Medições Luminescentes/métodos , Conformação de Ácido Nucleico , Hibridização de Ácido Nucleico , Neoplasias Ovarianas/genética , Mutação Puntual , Telomerase/genética
11.
Chem Pharm Bull (Tokyo) ; 67(6): 505-518, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31155555

RESUMO

Nucleic acid therapeutics such as antisense and small interfering RNA (siRNA) have attracted increasing attention as innovative medicines that interfere with and/or modify gene expression systems. We have developed new functional oligonucleotides that can target DNA and RNA with high efficiency and selectivity. This review summarizes our achievements, including (1) the formation of non-natural triplex DNA for sequence-specific inhibition of transcription; (2) artificial receptor molecules for 8-oxidized-guanosine nucleosides; and (3) reactive oligonucleotides with a cross-linking agent or a functionality-transfer nucleoside for RNA pinpoint modification.


Assuntos
DNA/química , RNA/química , Reagentes para Ligações Cruzadas/química , DNA/metabolismo , DNA/farmacologia , Humanos , Nucleosídeos/análogos & derivados , Nucleosídeos/farmacologia , Oligonucleotídeos/química , Oligonucleotídeos/metabolismo , Polietilenoglicóis/química , RNA/metabolismo , Telomerase/genética , Telomerase/metabolismo , Transcrição Genética/efeitos dos fármacos
12.
Int J Mol Sci ; 20(12)2019 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-31200515

RESUMO

Telomere and telomerase regulation contributes to the onset and evolution of several tumors, including highly aggressive thyroid cancers (TCs). TCs are the most common endocrine malignancies and are generally characterized by a high rate of curability. However, a small but significant percentage develops distant metastasis or progresses into undifferentiated forms associated with bad prognosis and for which poor therapeutic options are available. Mutations in telomerase reverse transcriptase (TERT) promoter are among the most credited prognostic marker of aggressiveness in TCs. Indeed, their frequency progressively increases passing from indolent lesions to aggressive and anaplastic forms. TERT promoter mutations create binding sites for transcription factors, increasing TERT expression and telomerase activity. Furthermore, aggressiveness of TCs is associated with TERT locus amplification. These data encourage investigating telomerase regulating pathways as relevant drivers of TC development and progression to foster the identification of new therapeutics targets. Here, we summarize the current knowledge about telomere regulation and TCs, exploring both canonical and less conventional pathways. We discuss the possible role of telomere homeostasis in mediating response to cancer therapies and the possibility of using epigenetic drugs to re-evaluate the use of telomerase inhibitors. Combined treatments could be of support to currently used therapies still presenting weaknesses.


Assuntos
Biomarcadores Tumorais/genética , Telomerase/genética , Homeostase do Telômero , Neoplasias da Glândula Tireoide/genética , Animais , Humanos , Mutação , Telomerase/metabolismo , Neoplasias da Glândula Tireoide/patologia
13.
Nat Rev Gastroenterol Hepatol ; 16(9): 544-558, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31253940

RESUMO

Telomerase is a key enzyme for cell survival that prevents telomere shortening and the subsequent cellular senescence that is observed after many rounds of cell division. In contrast, inactivation of telomerase is observed in most cells of the adult liver. Absence of telomerase activity and shortening of telomeres has been implicated in hepatocyte senescence and the development of cirrhosis, a chronic liver disease that can lead to hepatocellular carcinoma (HCC) development. During hepatocarcinogenesis, telomerase reactivation is required to enable the uncontrolled cell proliferation that leads to malignant transformation and HCC development. Part of the telomerase complex, telomerase reverse transcriptase, is encoded by TERT, and several mechanisms of telomerase reactivation have been described in HCC that include somatic TERT promoter mutations, TERT amplification, TERT translocation and viral insertion into the TERT gene. An understanding of the role of telomeres and telomerase in HCC development is important to develop future targeted therapies and improve survival of this disease. In this Review, the roles of telomeres and telomerase in liver carcinogenesis are discussed, in addition to their potential translation to clinical practice as biomarkers and therapeutic targets.


Assuntos
Carcinoma Hepatocelular/metabolismo , Cirrose Hepática/metabolismo , Neoplasias Hepáticas/metabolismo , Telomerase/metabolismo , Telômero/metabolismo , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma Hepatocelular/genética , Divisão Celular/fisiologia , Sobrevivência Celular/fisiologia , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Modelos Animais de Doenças , Humanos , Fígado/metabolismo , Cirrose Hepática/genética , Neoplasias Hepáticas/genética , Camundongos , Mutação , Telomerase/genética , Telômero/genética
14.
PLoS Genet ; 15(6): e1008188, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31237867

RESUMO

Telomerase, particularly its main subunit, the reverse transcriptase, TERT, prevents DNA erosion during eukaryotic chromosomal replication, but also has poorly understood non-canonical functions. Here, in the model social amoeba Dictyostelium discoideum, we show that the protein encoded by tert has telomerase-like motifs, and regulates, non-canonically, important developmental processes. Expression levels of wild-type (WT) tert were biphasic, peaking at 8 and 12 h post-starvation, aligning with developmental events, such as the initiation of streaming (~7 h) and mound formation (~10 h). In tert KO mutants, however, aggregation was delayed until 16 h. Large, irregular streams formed, then broke up, forming small mounds. The mound-size defect was not induced when a KO mutant of countin (a master size-regulating gene) was treated with TERT inhibitors, but anti-countin antibodies did rescue size in the tert KO. Although, conditioned medium (CM) from countin mutants failed to rescue size in the tert KO, tert KO CM rescued the countin KO phenotype. These and additional observations indicate that TERT acts upstream of smlA/countin: (i) the observed expression levels of smlA and countin, being respectively lower and higher (than WT) in the tert KO; (ii) the levels of known size-regulation intermediates, glucose (low) and adenosine (high), in the tert mutant, and the size defect's rescue by supplemented glucose or the adenosine-antagonist, caffeine; (iii) the induction of the size defect in the WT by tert KO CM and TERT inhibitors. The tert KO's other defects (delayed aggregation, irregular streaming) were associated with changes to cAMP-regulated processes (e.g. chemotaxis, cAMP pulsing) and their regulatory factors (e.g. cAMP; acaA, carA expression). Overexpression of WT tert in the tert KO rescued these defects (and size), and restored a single cAMP signaling centre. Our results indicate that TERT acts in novel, non-canonical and upstream ways, regulating key developmental events in Dictyostelium.


Assuntos
Agregação Celular/genética , Dictyostelium/genética , Morfogênese/genética , Telomerase/genética , Adenosina/genética , Animais , Agregação Celular/efeitos dos fármacos , Quimiotaxia/genética , AMP Cíclico/genética , Dictyostelium/crescimento & desenvolvimento , Inibidores Enzimáticos/farmacologia , Técnicas de Inativação de Genes , Glucose/genética , Transdução de Sinais/genética , Telomerase/antagonistas & inibidores
15.
Int J Mol Sci ; 20(11)2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151281

RESUMO

Human telomeres were one of the first discovered and characterized sequences forming quadruplex structures. Association of these structures with oncogenic and tumor suppressor proteins suggests their important role in cancer development and therapy efficacy. Since cationic porphyrin TMPyP4 is known as G-quadruplex stabilizer and telomerase inhibitor, the aim of the study was to analyze the anticancer properties of this compound in two different human breast-cancer MCF7 and MDA-MB-231 cell lines. The cytotoxicity of TMPyP4 alone or in combination with doxorubicin was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromid) and clonogenic assays, and the cell-cycle alterations were analyzed by flow cytometry. Telomerase expression and activity were evaluated using qPCR and telomeric repeat amplification protocol (TRAP) assays, respectively. The contribution of G-quadruplex inhibitor to protein pathways engaged in cell survival, DNA repair, adhesion, and migration was performed using immunodetection. Scratch assay and functional assessment of migration and cell adhesion were also performed. Consequently, it was revealed that in the short term, TMPyP4 neither revealed cytotoxic effect nor sensitized MCF7 and MDA-MB-231 to doxorubicin, but altered breast-cancer cell adhesion and migration. It suggests that TMPyP4 might substantially contribute to a significant decrease in cancer cell dissemination and, consequently, cancer cell survival reduction. Importantly, this effect might not be associated with telomeres or telomerase.


Assuntos
Adesão Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Porfirinas/farmacologia , Telomerase/antagonistas & inibidores , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA , Reparo do DNA , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Transdução de Sinais , Telomerase/genética , Telomerase/metabolismo
16.
Eur J Endocrinol ; 181(1): 1-11, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31042674

RESUMO

Objective: Follicular-derived thyroid cancers generally have a good prognosis, but in a minority of cases, they have an aggressive behavior and develop distant metastases, with an increase in the associated mortality. None of the prognostic markers currently available prior to surgery can identify such cases. Methods: TERT promoter and BRAF gene mutations were examined in a series of 436 consecutive TIR-4 and TIR-5 nodes referred for surgery. Follow-up (median: 59 months, range: 7-293 months) was available for 384/423 patients with malignant nodes. Results: TERT promoter and BRAF mutations were detected in 20/436 (4.6%) and 257/434 thyroid nodules (59.2%), respectively. At the end of the follow-up, 318/384 patients (82.8%) had an excellent outcome, 48/384 (12.5%) had indeterminate response or biochemical persistence, 18/384 (4.7%) had a structural persistence or died from thyroid cancer. TERT promoter mutations correlated with older age (P < 0.0001), larger tumor size (P = 0.0002), oxyntic and aggressive PTC variants (P = 0.01), higher tumor stages (P < 0.0001), distant metastases (<0.0001) and disease outcome (P < 0.0001). At multivariate analysis, TERT promoter mutation was not an independent predictor of disease outcome. TERT promoter mutation- (OR: 40.58; 95% CI: 3.06-539.04), and N1b lymph node metastases (OR: 40.16, 95% CI: 3.48-463.04) were independent predictors of distant metastases. BRAF mutation did not predict the outcome, and it correlated with a lower incidence of distant metastases (P = 0.0201). Conclusions: TERT promoter mutation proved an independent predictor of distant metastases, giving clinicians the chance to identify many of the patients who warranted more aggressive initial treatment and closer follow-up.


Assuntos
Carcinoma Papilar, Variante Folicular/genética , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas B-raf/genética , Telomerase/genética , Câncer Papilífero da Tireoide/genética , Neoplasias da Glândula Tireoide/genética , Adenocarcinoma Folicular/genética , Adenocarcinoma Folicular/patologia , Adulto , Fatores Etários , Carcinoma Papilar, Variante Folicular/patologia , Feminino , Humanos , Linfonodos/patologia , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Mutação , Invasividade Neoplásica , Metástase Neoplásica , Estadiamento de Neoplasias , Prognóstico , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Carga Tumoral
17.
Cancer Sci ; 110(7): 2247-2257, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31099446

RESUMO

Glioblastoma is one of the most devastating human malignancies for which a novel efficient treatment is urgently required. This pre-clinical study shows that eribulin, a specific inhibitor of telomerase reverse transcriptase (TERT)-RNA-dependent RNA polymerase, is an effective anticancer agent against glioblastoma. Eribulin inhibited the growth of 4 TERT promoter mutation-harboring glioblastoma cell lines in vitro at subnanomolar concentrations. In addition, it suppressed the growth of glioblastoma cells transplanted subcutaneously or intracerebrally into mice, and significantly prolonged the survival of mice harboring brain tumors at a clinically equivalent dose. A pharmacokinetics study showed that eribulin quickly penetrated brain tumors and remained at a high concentration even when it was washed away from plasma, kidney or liver 24 hours after intravenous injection. Moreover, a matrix-assisted laser desorption/ionization mass spectrometry imaging analysis revealed that intraperitoneally injected eribulin penetrated the brain tumor and was distributed evenly within the tumor mass at 1 hour after the injection whereas only very low levels of eribulin were detected in surrounding normal brain. Eribulin is an FDA-approved drug for refractory breast cancer and can be safely repositioned for treatment of glioblastoma patients. Thus, our results suggest that eribulin may serve as a novel therapeutic option for glioblastoma. Based on these data, an investigator-initiated registration-directed clinical trial to evaluate the safety and efficacy of eribulin in patients with recurrent GBM (UMIN000030359) has been initiated.


Assuntos
Neoplasias Encefálicas/tratamento farmacológico , Encéfalo/diagnóstico por imagem , Furanos/administração & dosagem , Glioblastoma/tratamento farmacológico , Cetonas/administração & dosagem , Regiões Promotoras Genéticas/efeitos dos fármacos , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Reposicionamento de Medicamentos , Feminino , Furanos/farmacologia , Glioblastoma/diagnóstico por imagem , Glioblastoma/genética , Humanos , Injeções Intraperitoneais , Cetonas/farmacologia , Camundongos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Telomerase/genética , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Nat Methods ; 16(6): 489-492, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31133759

RESUMO

Modular domains of long non-coding RNAs can serve as scaffolds to bring distant regions of the linear genome into spatial proximity. Here, we present HiChIRP, a method leveraging bio-orthogonal chemistry and optimized chromosome conformation capture conditions, which enables interrogation of chromatin architecture focused around a specific RNA of interest down to approximately ten copies per cell. HiChIRP of three nuclear RNAs reveals insights into promoter interactions (7SK), telomere biology (telomerase RNA component) and inflammatory gene regulation (lincRNA-EPS).


Assuntos
Cromatina/química , Cromatina/genética , Células-Tronco Embrionárias/metabolismo , Regulação da Expressão Gênica , RNA Longo não Codificante/genética , RNA/química , Telomerase/química , Animais , Células Cultivadas , Cromossomos , Células-Tronco Embrionárias/citologia , Genoma , Camundongos , Regiões Promotoras Genéticas , RNA/genética , Telomerase/genética
19.
Diagn Pathol ; 14(1): 39, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31077238

RESUMO

BACKGROUND: One of the major challenges remaining in the classification of thyroid tumor is the determination of whether a nodule is benign or malignant. We aimed to characterize the mutational profiles of follicular thyroid tumor and to identify markers with potential diagnostic and prognostic implications. METHODS: Targeted sequencing with a panel of 18 thyroid cancer-related genes was performed on 48 tissue samples from follicular thyroid adenoma (FTA), 32 follicular tumors of uncertain malignant potential (FT-UMP), 17 well-differentiated tumors of uncertain malignant potential (WDT-UMP) and 53 samples from follicular thyroid carcinoma (FTC). The correlation of mutation profiles and clinicopathological features and prognosis were also analyzed. RESULTS: We identified 95 nonsilent mutations spanning 14 genes. Specifically, TERT promoter (TERTp) mutations were exclusively detected in FTC. A total of 80% EIF1AX exon 2 mutations (4/5) and 75% TSHR mutations (3/4) occurred in FTA, whereas the rest of them occurred in FT-UMP. KRAS mutations and TP53 mutations were only presented in borderline or malignant tumors. H/N-RAS mutations were detected in all four subtypes, but were most commonly found in WDT-UMP (p = 0.031). All N-RAS mutations were located at codon 61. BRAF V600E and RET fusion were absent in the entire cohort. In FTC cases, EIF1AX mutations were all located at intron 5/exon 6 and correlated with advanced disease (p = 0.032). Both EIF1AX and TERTp mutations predicted shorter disease-free survival (p = 0.007, p = 0.024, respectively). Further analysis revealed that TERTp mutations were correlated with shorter disease-free survival in patients with minimally invasive /encapsulated angioinvasive FTC (p = 0.017), but not in those with widely invasive FTC (p = 0.297). CONCLUSION: TERTp, EIF1AX, TSHR, H/N/K-RAS and TP53 mutations may have diagnostic or prognostic potential in follicular thyroid tumors. TERTp mutations may predict a poor outcome in patients with minimally invasive/encapsulated angioinvasive FTC.


Assuntos
Adenocarcinoma Folicular/genética , Biomarcadores Tumorais/genética , Telomerase/genética , Neoplasias da Glândula Tireoide/genética , Adenocarcinoma Folicular/diagnóstico , Adenocarcinoma Folicular/patologia , Intervalo Livre de Doença , Humanos , Estimativa de Kaplan-Meier , Mutação , Prognóstico , Regiões Promotoras Genéticas/genética , Estudos Retrospectivos , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/patologia
20.
Poult Sci ; 98(8): 3257-3267, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31064004

RESUMO

Telomerase reverse transcriptase (TERT) is a catalytic subunit of telomerase that adds TTAGGG repeats to the 3'-overhang of telomeres. In the present study, we detected that the duck TERT (dTERT) gene was highly expressed in small intestine and kidney, followed by heart, leg muscle, spleen, pancreas, gonad, and liver at neonatal stage. From embryonic to neonatal stage, the highest dTERT mRNA in liver appeared at stage E19 (19 days at embryonic stage), while for the leg muscle the maximum expression occurred at E26. We also measured the relative telomerase activity (RTA) and relative telomere length (RTL) in the examined tissues and found that the changed tendency of RTA and RTL was not very consistent with that of TERT. In silico analysis revealed that there were three CpG islands (S1, S2, and S3) within the 5' regulatory region of the dTERT gene. Bisulfite sequencing PCR (BSP) assay showed that liver (D7, 7 days after birth) which expressed significantly lower dTERT mRNA had an obviously higher methylation level of S1 compared with small intestine (D7) or liver (E19). Quantitative real-time PCR analysis revealed that the expression of DNA methyltransferase DNMT1 in liver (D7) was significantly higher than that in small intestine (D7) or in liver (E19). In vitro, dTERT expression was upregulated and the methylation status of S1 decreased in both duck embryonic fibroblasts and small intestinal epithelial cells following treatment with the demethylation reagent, 5-aza-2'-deoxycytidine (5-aza-dC), further suggesting that dTERT is epigenetically regulated by DNA methylation. This work lays a solid foundation for further study of TERT function and regulation in avian species.


Assuntos
Metilação de DNA , Patos/genética , Regulação da Expressão Gênica no Desenvolvimento , Telomerase/genética , Animais , Células Cultivadas , Simulação por Computador , Ilhas de CpG , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Decitabina/farmacologia , Patos/crescimento & desenvolvimento , Patos/metabolismo , Embrião não Mamífero , Telômero
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