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1.
ESMO Open ; 8(4): 101594, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37517364

RESUMO

BACKGROUND: Leptomeningeal metastases (LM) are devastating complications of epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC). Although osimertinib, a third-generation EGFR-tyrosine kinase inhibitor (TKI), has better penetration into the central nervous system than first-generation EGFR-TKIs, data on the distinct activity of EGFR-TKIs in untreated advanced EGFR-mutated NSCLC with LM are lacking. PATIENTS AND METHODS: We retrospectively reviewed patients treated with EGFR-TKIs for TKI-untreated common EGFR-mutated NSCLC with LM between July 2002 and July 2021 at the National Cancer Center Hospital. The patients were divided into two groups: patients treated with osimertinib (Osi group) and those treated with gefitinib or erlotinib [first-generation (1G)-TKI group]. RESULTS: Of the 967 patients, 71 were eligible, including 29 in the Osi group and 42 in the 1G-TKI group. The median progression-free survival (PFS) and overall survival (OS) in the Osi group were better than those in the 1G-TKI group (PFS: 16.9 months versus 8.6 months, P = 0.007, and OS: 26.6 months versus 20.0 months, P = 0.158). The LM-overall response rate (ORR) and LM-PFS were significantly better in the Osi group than in the 1G-TKI group (LM-ORR: 62.5% versus 25.7%, P = 0.007; LM-PFS: 23.4 months versus 12.1 months, P = 0.021). In the subgroup analysis of EGFR mutation status, LM-PFS for patients with exon 19 deletion was significantly longer in the Osi group than in the 1G-TKI group (32.7 months versus 13.4 months, P = 0.013), whereas those with L858R mutation in exon 21 did not differ between the two groups. In the multivariate analysis, osimertinib and exon 19 deletion were significant factors for better LM-PFS and OS. CONCLUSION: Osimertinib can be more effective for untreated common EGFR-mutated NSCLC patients with LM, especially those with exon 19 deletion, compared to first-generation TKIs.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Receptores ErbB/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Inibidores de Proteínas Quinases/uso terapêutico , Estudos Retrospectivos
2.
Eur Cell Mater ; 42: 90-109, 2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-34284523

RESUMO

While it is known that the degenerated intervertebral disc (IVD) is one of the primary reasons for low-back pain and subsequent need for medical care, there are currently no established effective methods for direct treatment. Nuclear factor-κB (NF-κB) is a transcription factor that regulates various genes' expression, among which are inflammatory cytokines, in many tissues including the IVD. NF-κB decoy is an oligodeoxynucleotide containing the NF-κB binding site that entraps NF-κB subunits, resulting in suppression of NF-κB activity. In the present preclinical study, NF-κB decoy was injected into degenerated IVDs using the rabbit anular-puncture model. In terms of distribution, NF-κB decoy persisted in the IVDs up to at least 4 weeks after injection. The remaining amount of NF-κB decoy indicated that it fit a double-exponential-decay equation. Investigation of puncture-caused degeneration of IVDs showed that NF-κB decoy injection recovered, dose-dependently, the reduced disc height that was associated with reparative cell cloning and morphological changes, as assessed through histology. Gene expression, by quantitative real-time polymerase chain reaction (qRT-PCR), showed that NF-κB decoy attenuated inflammatory gene expression, such as that of interleukin-1 and tumor necrosis factor-α, in rabbit degenerated IVDs. NF-κB decoy also reduced the pain response as seen using the "pain sensor" nude rat xenograft-radiculopathy model. This is the first report demonstrating that NF-κB decoy suppresses the inflammatory response in degenerated IVDs and restores IVD disc height loss. Therefore, the intradiscal injection of NF-κB decoy may have the potential as an effective therapeutic strategy for discogenic pain associated with degenerated IVDs.


Assuntos
Degeneração do Disco Intervertebral , Disco Intervertebral , Dor Lombar , Radiculopatia , Animais , Modelos Animais de Doenças , Xenoenxertos , Degeneração do Disco Intervertebral/genética , NF-kappa B , Oligodesoxirribonucleotídeos/farmacologia , Punções , Coelhos , Ratos
3.
Phys Rev Lett ; 126(23): 236801, 2021 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-34170165

RESUMO

Spin-charge conversion via spin-orbit interaction is one of the core concepts in the current spintronics research. The efficiency of the interconversion between charge and spin current is estimated based on Berry curvature of Bloch wave function in the linear-response regime. Beyond the linear regime, nonlinear spin-charge conversion in the higher-order electric field terms has recently been demonstrated in noncentrosymmetric materials with nontrivial spin texture in the momentum space. Here, we report the observation of the nonlinear charge-spin conversion in a nominally centrosymmetric oxide material SrIrO_{3} by breaking inversion symmetry at the interface. A large second-order magnetoelectric coefficient is observed at room temperature because of the antisymmetric spin-orbit interaction at the interface of Dirac semimetallic bands, which is subject to the symmetry constraint of the substrates. Our study suggests that nonlinear spin-charge conversion can be induced in many materials with strong spin-orbit interaction at the interface by breaking the local inversion symmetry to give rise to spin splitting in otherwise spin degenerate systems.

4.
Benef Microbes ; 12(1): 43-53, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33393445

RESUMO

The genus Bifidobacterium comprises various bacterial species, and the complement of species within the human intestinal tract differs from individual to individual. The balance of these bifidobacterial species remains poorly understood, although it is known that the abundance of bifidobacteria increases following the ingestion of prebiotics. We previously conducted a randomised, placebo-controlled, double-blind, crossover study of 2 g/day lactulose ingestion for 2 weeks in 60 Japanese women. To study the effect of lactulose ingestion on each bifidobacterial species, here, we measured the abundance of each of the principal bifidobacterial species. After lactulose ingestion, the log cell counts of the Bifidobacterium adolescentis group (8.97±0.08 vs 9.39±0.08, P=0.0019), Bifidobacterium catenulatum group (9.45±0.10 vs 9.65±0.10, P=0.0032) and Bifidobacterium longum group (9.01±0.07 vs 9.29±0.07, P=0.0012) were significantly higher than in the placebo ingestion control group. However, the log cell counts were similar for Bifidobacterium breve (8.12±0.12 vs 8.33±0.12, P=0.20), Bifidobacterium bifidum (9.08±0.12 vs 9.42±0.14, P=0.095) and Bifidobacterium animalis subspecies lactis (8.65±0.53 vs 8.46±0.46, P=0.77). Cluster analysis of the log cell count data at the bifidobacterial species level revealed three distinct clusters, but the combinations and ratios of the constituent bifidobacteria were not affected by lactulose ingestion. Furthermore, principal coordinate analysis of the intestinal microbiota in the lactulose and placebo ingestion groups using Illumina MiSeq showed no significant differences in the intestinal microbiota as a whole. These results suggest that 2 g/day lactulose ingestion for 2 weeks significantly increases the abundance of intestinal bifidobacteria, but does not affect the intestinal microbiota as a whole.


Assuntos
Bifidobacterium/crescimento & desenvolvimento , Microbioma Gastrointestinal , Lactulose/metabolismo , Adulto , Idoso , Bifidobacterium/classificação , Bifidobacterium/genética , Bifidobacterium/isolamento & purificação , Estudos Cross-Over , Método Duplo-Cego , Fezes/microbiologia , Feminino , Humanos , Japão , Pessoa de Meia-Idade , Adulto Jovem
6.
Eur Rev Med Pharmacol Sci ; 24(9): 5127-5139, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32432777

RESUMO

OBJECTIVE: Phenotypic screening is one of the most practical approaches to the identification of mediators of behaviour, since it is difficult to model brain function in vitro, at a cellular level. We used a zebrafish (Danio rerio) behavioural assay to discover novel, natural, neuroactive compounds. MATERIALS AND METHODS: A zebrafish behavioural assay was performed for seven natural compounds, obtained from plants. The behavioural profiles were compared to those of known psychoactive drugs. We characterised a natural compound exhibiting a behaviour profile similar to that of suvorexant, using in silico, in vitro and microarray expression analysis. RESULTS: The behavioural analysis performed in this study classified central nervous system drugs according to their mechanism. Zebrafish treated with a natural compound, 8b-(4'-Hydroxytigloyloxy) costunolide (8b), showed behaviour profiles similar to those of zebrafish treated with suvorexant, a known orexin antagonist. This behavioural assay was validated using in silico and in vitro assays, which revealed that the new compound was a dual orexin receptor antagonist. In addition, transcriptome analysis suggested that 8b might regulate the nuclear factor-κB (NF-κB) related pathway. CONCLUSIONS: We conclude that zebrafish phenotypic screening, combined with in silico assays and gene expression profiling, is a useful strategy to discover and characterize novel therapeutic compounds, including natural products.


Assuntos
Azepinas/farmacologia , Comportamento Animal/efeitos dos fármacos , Produtos Biológicos/farmacologia , Antagonistas dos Receptores de Orexina/farmacologia , Plantas/química , Triazóis/farmacologia , Peixe-Zebra , Animais , Azepinas/química , Produtos Biológicos/química , Células HEK293 , Humanos , Simulação de Acoplamento Molecular , Antagonistas dos Receptores de Orexina/química , Receptores de Orexina/metabolismo , Triazóis/química
7.
Benef Microbes ; 10(6): 629-639, 2019 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-31131617

RESUMO

Sixty healthy Japanese women with a defaecation frequency of 2-4 times/week participated in this randomised, double-blind crossover trial. Participants received 2 g/day lactulose for 2 weeks and placebo in a random order, separated by a washout period of 3 weeks. Eight participants were excluded who did not satisfy the conditions, and therefore data from 52 were analysed. The primary outcome was defaecation frequency and the secondary outcomes were the number of defaecation days, faecal consistency, faecal volume, and the number and percentage of Bifidobacterium in faeces. The defaecation frequency (times/week) was significantly higher during lactulose (4.28±0.23) than placebo (3.83±0.23) treatment (delta (Δ) 0.45 [95% confidence interval (CI) 0.10-0.80], P=0.013). The defaecation days (days/week) was significantly higher during lactulose (3.77±0.17) than placebo (3.47±0.17) treatment (Δ0.30 [95% CI 0.04-0.56], P=0.024). Faecal consistency using the Bristol Stool Scale (/defaecation) was significantly higher during lactulose (3.84±0.10) than placebo (3.68±0.10) treatment (Δ0.16 [95% CI 0.00-0.31], P=0.044). Faecal volume (/week) was significantly higher during lactulose (21.73±3.07) than placebo (17.65±3.07) treatment (Δ4.08 [95% CI 0.57-7.60], P=0.024). The number of Bifidobacterium in faeces (log colony forming units/g faeces) was significantly higher during lactulose (9.53±0.06) than placebo (9.16±0.06) treatment (Δ0.37 [95% CI 0.23-0.49], P<0.0001). The percentage of Bifidobacterium in faeces was also significantly higher during lactulose (25.3±1.4) than placebo (18.2±1.4) treatment (Δ7.1 [95% CI 2.9-11.4], P=0.0014). Finally, straining at defaecation (/defaecation) during lactulose (3.62±0.24) treatment was significantly lower than during placebo (3.97±0.24) treatment (Δ0.35 [95% CI -0.69 - -0.02], P=0.037). No significant difference was observed between lactulose and placebo with regard to flatulence. Severe adverse effects did not occur. Thus, oral ingestion of 2 g/day lactulose had a prebiotic effect, increasing the number and percentage of bifidobacteria in faeces, softening the faeces, and increasing defaecation frequency, but without increasing flatulence.


Assuntos
Fezes/microbiologia , Lactulose/administração & dosagem , Prebióticos/administração & dosagem , Administração Oral , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bifidobacterium/isolamento & purificação , Estudos Cross-Over , Defecação , Método Duplo-Cego , Feminino , Voluntários Saudáveis , Humanos , Japão , Pessoa de Meia-Idade , Adulto Jovem
8.
Transplant Proc ; 50(10): 3228-3231, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30577190

RESUMO

BACKGROUND: The rising demand for living renal donors has led to the recruitment of older donors. Findings vary, but these grafts appear to survive as long as grafts from standard criteria deceased and expanded criteria deceased donors. We investigated the effects of donor age ≥65 years and the presence or absence of donor antihypertensive therapy on patient condition 1 year after transplantation, and retrospectively examined 1-year (273 patients), 3-year (217 patients), and 5-year (140 patients) patient and graft survival. METHODS: We divided 273 donor-recipient pairs into Group Y (donor age <65 years, n = 224) and Group O (donor age ≥65 years, n = 49). Group O was subdivided into donors receiving treatment for hypertension (subgroup O-1, n = 16) and those not receiving treatment for hypertension (subgroup O-2, n = 33). We compared results of 1 hour post-transplant biopsies and looked at a small number of 1 year post-transplant biopsies. RESULTS: Although a significantly larger percentage of recipients from younger donors were undergoing preemptive transplantation, and the incidence of arteriosclerosis was significantly higher in the Group O kidneys, there were no significant differences between the 2 groups in terms of patient or graft survival at 1, 3, or 5 years; serum creatinine levels; or number of episodes of acute rejection. The presence or absence of donor antihypertensive treatment had no effect. CONCLUSIONS: We found that donor age ≥65, with or without antihypertensive treatment, had no effect on graft or patient survival.


Assuntos
Sobrevivência de Enxerto , Transplante de Rim/mortalidade , Transplante de Rim/métodos , Doadores Vivos , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Hipertensão/complicações , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
9.
Transplant Proc ; 50(1): 299-304, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29407325

RESUMO

BACKGROUND: Recently, myeloid-derived suppressor cells (MDSCs) have attracted considerable attention because of their cancer-promoting and immunosuppressive effects. The glucocorticoid dexamethasone (Dex) is an important immunosuppressive agent used to treat autoimmune diseases and organ transplant rejection. However, the mechanism by which it modulates the immune system is not completely understood. MATERIAL AND METHODS: In this study, we investigated the mechanisms by which Dex modulated the immune response in mice given an allogeneic cardiac transplant. RESULTS: Dex injection significantly prolonged heart graft survival compared with phosphate-buffered saline-injected controls. Dex treatment increased the number of splenic MDSCs. Moreover, Gr-1high/CD11b+ MDSCs and CD3+/CD4+/Foxp3+ regulatory T cells (Tregs) were significantly increased in the Dex group compared with controls. Administration of anti-Gr-1 antibody (Ab) to the Dex group significantly shortened mouse heart graft survival. In addition, anti-Gr-1 Ab treatment significantly reduced Tregs in the Dex + anti-Gr-1 co-treatment group compared with the Dex group. These observations suggest that Dex treatment increased both MDSCs and Tregs, and that MDSCs regulated the incidence of Tregs in this immunosuppressive pathway. CONCLUSION: An important role of Dex in the prevention of the rejection of cardiac grafts in mice is to expand MDSCs and Tregs.


Assuntos
Aloenxertos/efeitos dos fármacos , Dexametasona/farmacologia , Sobrevivência de Enxerto/efeitos dos fármacos , Transplante de Coração , Coração/efeitos dos fármacos , Imunossupressores/farmacologia , Células Supressoras Mieloides/efeitos dos fármacos , Aloenxertos/imunologia , Animais , Sobrevivência de Enxerto/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia
10.
Transplant Proc ; 49(5): 1053-1055, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28583525

RESUMO

BACKGROUND: Hepatitis C virus (HCV) infection is known to affect long-term patient and graft survivals after kidney transplantation (KT). Recently, combination therapy with the use of 2 oral direct-acting antivirals, daclatasvir (DCV) and asunaprevir (ASV) reportedly showed a high rate of HCV eradication. We report the safety and efficacy of DCV and ASV therapy in 2 KT patients. METHODS: The safety and viral responses were investigated in a prospective study of KT patients infected with HCV genotype 1. Two patients received 60 mg DCV once daily plus 100 mg ASV twice daily for 24 weeks. RESULTS: A 69-year-old woman and a 57-year-old man underwent DCV and ASV therapy for 24 weeks. In both cases, the HCV genotype was 1b. Case 1 had undergone KT twice and had received treatment with pegylated interferon and ribavirin. She received DCV and ASV therapy 12 years after the 2nd KT, and had undetectable virus after only 6 weeks of treatment and at 24 weeks after the end of treatment (SVR24). The post-transplantation immunosuppressive therapy at that time comprised tacrolimus, mycophenolate mofetil, and prednisolone. The other case, after failure of interferon treatment, received DCV and ASV therapy 27 years after his KT and achieved SVR24. His immunosuppressive regimen at that time was mizoribine and prednisolone. DCV and ASV therapy did not affect renal graft function or tacrolimus blood concentrations. CONCLUSIONS: DCV and ASV therapy had high antiviral effect and a low rate of adverse events in KT patients.


Assuntos
Antivirais/uso terapêutico , Hepatite C Crônica/tratamento farmacológico , Imidazóis/uso terapêutico , Isoquinolinas/uso terapêutico , Transplante de Rim/efeitos adversos , Sulfonamidas/uso terapêutico , Idoso , Carbamatos , Quimioterapia Combinada , Feminino , Hepacivirus , Humanos , Imunossupressores/uso terapêutico , Interferons/uso terapêutico , Masculino , Pessoa de Meia-Idade , Prednisolona/uso terapêutico , Estudos Prospectivos , Pirrolidinas , Ribavirina/uso terapêutico , Resultado do Tratamento , Valina/análogos & derivados
11.
Transplant Proc ; 49(5): 1187-1188, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28583553

RESUMO

INTRODUCTION: There is no obvious criterion about kidney transplantation for patients with pretransplant malignancy. Minimum tumor-free waiting periods differ according to type of cancer, staging, site of occurrence, response to therapy, and risk of cancer recurrence. We report a case of living donor kidney transplantation (LDKT) in a patient after brachytherapy for prostate cancer. CASE REPORT: The patient was a 65-year-old man with chronic kidney disease due to chronic glomerular nephritis. He received hemodialysis 3 times a week. His prostate-specific antigen level (PSA) was high (6.57 ng/mL), and he was diagnosed with prostate cancer (T1cN0M0, Gleason Score 3 + 4 = 7, 3/10) by needle biopsy in urology. He was treated with maximum androgen blockade (MAB) therapy and brachytherapy in May 2014. He underwent LDKT from a spousal donor at our department in December 2015, because urologists concluded that the prostate cancer was completely cured. Immunosuppression consisted of induction with basiliximab and maintenance with tacrolimus, mizoribine, and steroids. The postoperative course was uneventful. He discharged at postoperative day 29 with a serum creatinine level of 1.30 mg/dL. Three months after LDKT, his PSA level was 0.477 ng/mL, and there was no evidence of prostate cancer recurrence. CONCLUSION: This is the first case of LDKT for patients with prostate cancer after brachytherapy in combination with MAB. There is no recurrence of prostate cancer so far; however, careful follow-up including PSA is necessary and important.


Assuntos
Transplante de Rim/métodos , Doadores Vivos , Neoplasias da Próstata/complicações , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/cirurgia , Idoso , Braquiterapia , Humanos , Masculino , Neoplasias da Próstata/radioterapia
12.
Transplant Proc ; 49(5): 955-958, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28583566

RESUMO

BACKGROUND: Advances in immunosuppressants enable organ transplantation for sensitized patients. However, influences of pre-formed donor-specific anti-human leukocyte antigen (HLA) antibodies (DSA) have not been fully understood in renal transplantation (RT). On the other hand, immunocomplex capture fluorescence analysis (ICFA) is a reliable method to detect donor-specific anti-HLA antibodies and HLA antigen complexes. Graft ICFA can detect DSA in an allograft (g-DSA). METHODS: To elucidate the consequences of pre-formed DSA, 198 patients who underwent living-donor RT were enrolled for this study (observation period: 57.8 ± 34.9 months); 187 patients in the DSA- group (excluding ABO-incompatible cases) and 11 patients in the DSA+ group. Before RT, all DSA+ patients had undergone rituximab administration and plasmapheresis. For a graft ICFA, the biopsy specimen (1 × 105 cells) was dissolved, and HLA antigens were captured by anti-HLA beads. Finally, DSA-HLA complexes were detected by means of PE-conjugated anti-human IgG antibodies and analyzed by use of a Luminex system. A ratio (sample/blank beads, mean of fluorescence intensity) was calculated: ≥1.0 was determined as positive g-DSA. RESULTS: There were no significant differences in 5-year graft survival (87.9%/100% in the DSA-/DSA+ groups, respectively). In terms of antibody-mediated rejection (AMR), within 1 month after RT, pathologically determined AMR occurred 3.2% and 63.4% in the DSA- and DSA+ groups, respectively (P < .0001). However, interestingly, more than half of them (57.1%) indicated only subclinical AMR, that is, no fluctuation of S-Cr. As representative of 2 cases of subclinical AMR, g-DSA deposition could be confirmed (1.15 ± 0.04) at 1 hour after reperfusion by graft ICFA. Furthermore, g-DSA shifted to 2.20 ± 0.98 at 3 weeks after transplantation, along with a decline in s-DSA mean of fluorescence intensity (1718-506.5). CONCLUSIONS: Although pathologically determined AMR occurred more frequently in pre-formed DSA+ recipients, it can be argued that a successful de-sensitization protocol inhibits further production of DSA and graft destruction.


Assuntos
Anticorpos/imunologia , Rejeição de Enxerto/imunologia , Antígenos HLA/imunologia , Transplante de Rim/métodos , Doadores Vivos , Adulto , Feminino , Sobrevivência de Enxerto , Humanos , Imunossupressores , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Transplante Homólogo
13.
Oncogenesis ; 5: e213, 2016 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-27043659

RESUMO

Ultraconserved regions (UCRs) are >200 bp genomic segments with perfect human-to-rodent sequence identity. Transcribed UCRs constitute a new category of noncoding RNAs whose functions remain poorly understood. The human transformer 2ß (TRA2B) gene contains a 419-bp UCR spanning the 276-bp exon 2 and its neighboring introns. TRA2B exon 2 has premature stop codons, whereas an exon 2-containing splice variant (TRA2ß4) was expressed preferentially in the nuclei of human colon cancer cells. TRA2ß4 knockdown p53-independently stimulated CDKN1A transcription and increased p21, resulting in the appearance of senescent cells. Biotin pull-down and RNA immunoprecipitation assays revealed that TRA2ß4 interacted with Sp1 through a Sp1-binding sequence (485-GGGG-488) in a stem-loop structure of exon 2. Mutation of this sequence (485-AAGG-488) disrupted the stem-loop structure, blocked the interaction with Sp1 and increased CDKN1A transcription. Overexpression of TRA2ß4 significantly decreased CDKN1A mRNA levels and accelerated cell growth, but the introduction of the mutation in the Sp1-binding sequence completely canceled these effects. Taken together, TRA2ß4 may sequester Sp1 from occupying promoters of target genes including CDKN1A, promoting cell growth by interrupting the senescence-related gene expression program. This novel function of TRA2ß4 may uncover an oncogenic function of transcribed UCRs.

14.
Sci Rep ; 6: 18757, 2016 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-26729303

RESUMO

The locations of proteins and epigenetic marks on the chromosomal DNA sequence are believed to demarcate the eukaryotic genome into distinct structural and functional domains that contribute to gene regulation and genome organization. However, how these proteins and epigenetic marks are organized in three dimensions remains unknown. Recent advances in proximity-ligation methodologies and high resolution microscopy have begun to expand our understanding of these spatial relationships. Here we use polymer models to examine the spatial organization of epigenetic marks, euchromatin and heterochromatin, and origins of replication within the Schizosaccharomyces pombe genome. These models incorporate data from microscopy and proximity-ligation experiments that inform on the positions of certain elements and contacts within and between chromosomes. Our results show a striking degree of compartmentalization of epigenetic and genomic features and lead to the proposal of a diffusion based mechanism, centred on the spindle pole body, for the coordination of DNA replication in S. pombe.


Assuntos
Replicação do DNA , DNA Fúngico , Modelos Biológicos , Schizosaccharomyces/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Núcleo Celular/genética , Eucromatina/genética , Fase G1/genética , Genoma Fúngico , Genômica , Heterocromatina/genética , Histona-Lisina N-Metiltransferase , Metiltransferases/genética , Metiltransferases/metabolismo , Origem de Replicação , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Deleção de Sequência
15.
Mon Not R Astron Soc ; 457(4): 4089-4113, 2016 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32848283

RESUMO

We present a statistical analysis of the first four seasons from a "second-generation" microlensing survey for extrasolar planets, consisting of near-continuous time coverage of 8 deg2 of the Galactic bulge by the OGLE, MOA, and Wise microlensing surveys. During this period, 224 microlensing events were observed by all three groups. Over 12% of the events showed a deviation from single-lens microlensing, and for ~1/3 of those the anomaly is likely caused by a planetary companion. For each of the 224 events we have performed numerical ray-tracing simulations to calculate the detection efficiency of possible companions as a function of companion-to-host mass ratio and separation. Accounting for the detection efficiency, we find that 55 - 22 + 34 % of microlensed stars host a snowline planet. Moreover, we find that Neptunes-mass planets are ~ 10 times more common than Jupiter-mass planets. The companion-to-host mass ratio distribution shows a deficit at q ~ 10-2, separating the distribution into two companion populations, analogous to the stellar-companion and planet populations, seen in radial-velocity surveys around solar-like stars. Our survey, however, which probes mainly lower-mass stars, suggests a minimum in the distribution in the super-Jupiter mass range, and a relatively high occurrence of brown-dwarf companions.

16.
Oncogene ; 34(26): 3463-73, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25151962

RESUMO

Homeodomain-interacting protein kinase 2 (HIPK2) is a potential tumor suppressor that has a crucial role in the DNA damage response (DDR) by regulating cell-cycle checkpoint activation and apoptosis. However, it is unclear whether HIPK2 exerts distinct roles in DNA damage repair. The aim of this study was to identify novel target molecule(s) of HIPK2, which mediates HIPK2-dependent DNA damage repair. HIPK2-knockdown human colon cancer cells (HCT116) or hipk1/hipk2 double-deficient mouse embryonic fibroblasts could not remove histone H2A.X phosphorylated at Ser139 (γH2A.X) after irradiation with a sublethal dose (10 J/m(2)) of ultraviolet (UV)-C, resulting in apoptosis. Knockdown of HIPK2 in p53-null HCT116 cells similarly promoted the UV-C-induced γH2A.X accumulation and apoptosis. Proteomic analysis of HIPK2-associated proteins using liquid chromatography-tandem mass spectrometry identified heterochromatin protein 1γ (HP1γ) as a novel target for HIPK2. Immunoprecipitation experiments with HCT116 cells expressing FLAG-tagged HIPK2 and one of the HA-tagged HP1 family members demonstrated that HIPK2 specifically associated with HP1γ, but not with HP1α or HP1ß, through its chromo-shadow domain. Mutation of the HP1box motif (883-PTVSV-887) within HIPK2 abolished the association. HP1γ knockdown also enhanced accumulation of γH2A.X and apoptosis after sublethal UV-C irradiation. In vitro kinase assay demonstrated an HP1γ-phosphorylating activity of HIPK2. Sublethal UV-C irradiation phosphorylated HP1γ. This phosphorylation was absent in endogenous HIPK2-silenced cells with HIPK2 3'UTR siRNA. Overexpression of FLAG-HIPK2, but not the HP1box-mutated or kinase-dead HIPK2 mutant, in the HIPK2-silenced cells increased HP1γ binding to trimethylated (Lys9) histone H3 (H3K9me3), rescued the UV-C-induced phosphorylation of HP1γ, triggered release of HP1γ from histone H3K9me3 and suppressed γH2A.X accumulation. Our results suggest that HIPK2-dependent phosphorylation of HP1γ may participate in the regulation of dynamic interaction between HP1γ and histone H3K9me3 to promote DNA damage repair. This HIPK2/HP1γ pathway may uncover a new functional aspect of HIPK2 as a tumor suppressor.


Assuntos
Proteínas de Transporte/fisiologia , Proteínas Cromossômicas não Histona/metabolismo , Dano ao DNA , Proteínas Serina-Treonina Quinases/fisiologia , Animais , Proteínas de Transporte/antagonistas & inibidores , Proteínas de Transporte/metabolismo , Células Cultivadas , Homólogo 5 da Proteína Cromobox , Proteínas Cromossômicas não Histona/antagonistas & inibidores , Proteínas Cromossômicas não Histona/genética , Dano ao DNA/efeitos dos fármacos , Dano ao DNA/genética , Embrião de Mamíferos , Genes Supressores de Tumor , Células HCT116 , Células HEK293 , Histonas/metabolismo , Humanos , Camundongos , Fosforilação , Ligação Proteica , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , RNA Interferente Pequeno/farmacologia
18.
Cell Death Differ ; 22(5): 815-25, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25342468

RESUMO

RNA-binding proteins and microRNAs are potent post-transcriptional regulators of gene expression. Human transformer 2ß (Tra2ß) is a serine/arginine-rich-like protein splicing factor and is now implicated to have wide-ranging roles in gene expression as an RNA-binding protein. RNA immunoprecipitation (RIP) with an anti-Tra2ß antibody and microarray analysis identified a subset of Tra2ß-associated mRNAs in HCT116 human colon cancer cells, many of which encoded cell death-related proteins including Bcl-2 (B-cell CLL/lymphoma 2). Tra2ß knockdown in HCT116 cells decreased Bcl-2 expression and induced apoptosis. Tra2ß knockdown accelerated the decay of BCL2α mRNA that encodes Bcl-2 and full-length 3' UTR, while it did not affect the stability of BCL2ß mRNA having a short, alternatively spliced 3' UTR different from BCL2α 3' UTR. RIP assays with anti-Tra2ß and anti-Argonaute 2 antibodies, respectively, showed that Tra2ß bound to BCL2α 3' UTR, and that Tra2ß knockdown facilitated association of miR-204 with BCL2α 3' UTR. The consensus sequence (GAA) for Tra2ß-binding lies within the miR-204-binding site of BCL2 3' UTR. Mutation of the consensus sequence canceled the binding of Tra2ß to BCL2 3' UTR without disrupting miR-204-binding to BCL2 3' UTR. Transfection of an anti-miR-204 or introduction of three-point mutations into the miR-204-binding site increased BCL2 mRNA and Bcl-2 protein levels. Inversely, transfection of precursor miR-204 reduced their levels. Experiments with Tra2ß-silenced or overexpressed cells revealed that Tra2ß antagonized the effects of miR-204 and upregulated Bcl-2 expression. Furthermore, TRA2ß mRNA expression was significantly upregulated in 22 colon cancer tissues compared with paired normal tissues and positively correlated with BCL2 mRNA expression. Tra2ß knockdown in human lung adenocarcinoma cells (A549) increased their sensitivity to anticancer drugs. Taken together, our findings suggest that Tra2ß regulates apoptosis by modulating Bcl-2 expression through its competition with miR-204. This novel function may have a crucial role in tumor growth.


Assuntos
Regiões 3' não Traduzidas , Processamento Alternativo , Apoptose , Neoplasias do Colo/metabolismo , MicroRNAs/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , RNA Neoplásico/metabolismo , Proteínas de Ligação a RNA/metabolismo , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Células HEK293 , Células HeLa , Humanos , MicroRNAs/genética , Proteínas do Tecido Nervoso/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , RNA Neoplásico/genética , Proteínas de Ligação a RNA/genética , Fatores de Processamento de Serina-Arginina
19.
Phys Rev Lett ; 113(12): 121301, 2014 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-25279618

RESUMO

Bosonic superweakly interacting massive particles (super-WIMPs) are a candidate for warm dark matter. With the absorption of such a boson by a xenon atom, these dark matter candidates would deposit an energy equivalent to their rest mass in the detector. This is the first direct detection experiment exploring the vector super-WIMPs in the mass range between 40 and 120 keV. With the use of 165.9 day of data, no significant excess above background was observed in the fiducial mass of 41 kg. The present limit for the vector super-WIMPs excludes the possibility that such particles constitute all of dark matter. The absence of a signal also provides the most stringent direct constraint on the coupling constant of pseudoscalar super-WIMPs to electrons. The unprecedented sensitivity was achieved exploiting the low background at a level 10(-4) kg-1 keVee-1 day-1 in the detector.

20.
Science ; 345(6192): 46-9, 2014 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-24994642

RESUMO

Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth's) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun. However, the planet's temperature is much lower, <60 Kelvin, because the host star is only 0.10 to 0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host itself orbits a slightly more massive companion with projected separation of 10 to 15 AU. This detection is consistent with such systems being very common. Straightforward modification of current microlensing search strategies could increase sensitivity to planets in binary systems. With more detections, such binary-star planetary systems could constrain models of planet formation and evolution.

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