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1.
J Am Acad Dermatol ; 83(1): 131-138, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32430142

RESUMO

BACKGROUND: The product of the Physician Global Assessment and body surface area (PGA×BSA) is simpler to use than the Psoriasis Area and Severity Index (PASI), which lacks sensitivity in patients with mild psoriasis. OBJECTIVE: To compare the PGA×BSA versus the modified PASI (mPASI) for assessing disease severity and therapeutic response to calcipotriol/betamethasone dipropionate (Cal/BD) foam. METHODS: This post hoc analysis evaluated the efficacy of Cal/BD foam in mild, moderate, and severe psoriasis, as assessed by the PGA×BSA and mPASI, using data from 3 randomized controlled trials (NCT01536886, NCT01866163, NCT02132936). Spearman correlation and Bland-Altman plots were used to compare the PGA×BSA with the mPASI. RESULTS: Proportions of patients receiving Cal/BD foam achieving 75% response for PGA×BSA and mPASI at weeks 1, 2, and 4 were similar and significantly greater than with vehicle (P ≤ .002 at all timepoints); at week 4, mean improvements were 51.0% and 50.7%, respectively. Spearman correlations for mild, moderate, and severe psoriasis were moderate to high between PGA×BSA and mPASI at baseline (r = .51, .72, and .86, respectively; n = 126, 465, and 58, respectively) and high at week 4 (r = .80, .81, and .89, respectively; n = 121, 452, and 58, respectively) (P < .001). LIMITATIONS: Pooled data from different trials were not prespecified for post hoc analysis. Interrater reliability was not assessed. CONCLUSION: Pooled data analysis showed that the PGA×BSA and mPASI correlation was higher with increasing psoriasis severity.


Assuntos
Anti-Inflamatórios/uso terapêutico , Betametasona/análogos & derivados , Superfície Corporal , Calcitriol/análogos & derivados , Fármacos Dermatológicos/uso terapêutico , Psoríase/diagnóstico , Psoríase/tratamento farmacológico , Índice de Gravidade de Doença , Adulto , Idoso , Betametasona/uso terapêutico , Calcitriol/uso terapêutico , Interpretação Estatística de Dados , Feminino , Humanos , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
2.
J Drugs Dermatol ; 19(2): 121-126, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32129954

RESUMO

Objective: Investigate the effect of fixed-combination calcipotriene 0.005% plus betamethasone dipropionate 0.064% (Cal/BD) foam on target lesion severity in plaque psoriasis. Design: Post-hoc analysis was conducted on data from a Phase 3, randomized, double-blind, multicenter clinical study of Cal/BD foam in the treatment of psoriasis vulgaris for 4 weeks (PSO-FAST; NCT01866163). Participants: In PSO-FAST, 426 patients (≥18 years) with psoriasis vulgaris (≥mild severity) were randomized 3:1 to Cal/BD foam (n=323) or vehicle foam (n=103), applied once daily. Measurements: Assessments included (1) target lesion severity (redness, scaliness, and thickness) at baseline and weeks 1, 2, and 4; and (2) the proportion of patients with ≥50% reduction in total sign score (TSS-50) from baseline at weeks 1, 2, and 4. Results: A greater proportion of patients achieved considerable improvement (a score of 0 or 1) in the severity of target lesions after 4 weeks of treatment with Cal/BD foam vs vehicle foam at week 4 (redness: 76.2% vs 21.4%; P<.001; scaliness: 91.3% vs 61.2%; P<.001; and thickness: 83.3% vs 35.0%; P<.001, respectively). Rapid onset of efficacy was observed as early as week 1. Significantly more patients also achieved TSS-50 at week 4 with Cal/BD foam vs vehicle foam for their target lesions regardless of treatment area, including the elbows and knees (P<.05 for all). Conclusions: Significant improvements in target lesion severity were achieved with up to 4 weeks of treatment with once-daily Cal/BD foam for adults with plaque psoriasis versus vehicle foam, with rapid onset of efficacy observed at week 1. J Drugs Dermatol. 2020;19(2)121-126. doi:10.36849/JDD.2020.4750


Assuntos
Betametasona/análogos & derivados , Calcitriol/análogos & derivados , Psoríase/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Betametasona/administração & dosagem , Calcitriol/administração & dosagem , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
3.
EMBO Rep ; 17(11): 1532-1541, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27670884

RESUMO

BRCA1 mutations strongly predispose affected individuals to breast and ovarian cancer, but the mechanism by which BRCA1 acts as a tumor suppressor is not fully understood. Homozygous deletion of exon 2 of the mouse Brca1 gene normally causes embryonic lethality, but we show that exon 2-deleted alleles of Brca1 are expressed as a mutant isoform that lacks the N-terminal RING domain. This "RING-less" BRCA1 protein is stable and efficiently recruited to the sites of DNA damage. Surprisingly, robust RAD51 foci form in cells expressing RING-less BRCA1 in response to DNA damage, but the cells nonetheless display the substantial genomic instability. Genomic instability can be rescued by the deletion of Trp53bp1, which encodes the DNA damage response factor 53BP1, and mice expressing RING-less BRCA1 do not show an increased susceptibility to tumors in the absence of 53BP1. Genomic instability in cells expressing RING-less BRCA1 correlates with the loss of BARD1 and a defect in restart of replication forks after hydroxyurea treatment, suggesting a role of BRCA1-BARD1 in genomic integrity that is independent of RAD51 loading.


Assuntos
Instabilidade Genômica , Proteínas Supressoras de Tumor/genética , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética , Animais , Proteína BRCA1 , Sequência de Bases , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Dano ao DNA , Reparo do DNA , Proteínas de Ligação a DNA , Éxons/genética , Feminino , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA , Deleção de Sequência , Proteínas Supressoras de Tumor/química , Proteínas Supressoras de Tumor/deficiência , Proteínas Supressoras de Tumor/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/deficiência , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/genética
4.
J Biol Chem ; 289(35): 24617-29, 2014 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-25016020

RESUMO

PALB2 links BRCA1 and BRCA2 in homologous recombinational repair of DNA double strand breaks (DSBs). Mono-allelic mutations in PALB2 increase the risk of breast, pancreatic, and other cancers, and biallelic mutations cause Fanconi anemia (FA). Like Brca1 and Brca2, systemic knock-out of Palb2 in mice results in embryonic lethality. In this study, we generated a hypomorphic Palb2 allele expressing a mutant PALB2 protein unable to bind BRCA1. Consistent with an FA-like phenotype, cells from the mutant mice showed hypersensitivity and chromosomal breakage when treated with mitomycin C, a DNA interstrand crosslinker. Moreover, mutant males showed reduced fertility due to impaired meiosis and increased apoptosis in germ cells. Interestingly, mutant meiocytes showed a significant defect in sex chromosome synapsis, which likely contributed to the germ cell loss and fertility defect. Our results underscore the in vivo importance of the PALB2-BRCA1 complex formation in DSB repair and male meiosis.


Assuntos
Proteína BRCA1/metabolismo , Infertilidade Masculina/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Sequência de Aminoácidos , Animais , Proteína BRCA1/química , Dano ao DNA , Reparo do DNA , Proteína do Grupo de Complementação N da Anemia de Fanconi , Recombinação Homóloga , Humanos , Marcação In Situ das Extremidades Cortadas , Infertilidade Masculina/genética , Masculino , Camundongos , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Proteínas Supressoras de Tumor/química
5.
J Patient Rep Outcomes ; 7(1): 39, 2023 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-37079188

RESUMO

BACKGROUND: Sleep disturbance, pain, and fatigue are key symptoms/impacts of axial spondyloarthritis (axSpA). Three customized Patient-Reported Outcomes Measurement Information System (PROMIS®) Short Forms (Sleep Disturbance, Pain Interference, and Fatigue) have been proposed for use in axSpA to assess these key disease concepts. This study was designed to further understand the patient experience of axSpA and evaluate the content validity of the three customized PROMIS® Short Forms to support their use in axSpA clinical trials. METHODS: Non-interventional, cross-sectional, qualitative (concept elicitation [CE] and cognitive debriefing [CD]) study. Participants took part in 90-min telephone interviews. The CE section used open-ended questions to elicit information about axSpA symptoms and impacts. The CD section involved a 'think-aloud' exercise where participants read out each instruction, item, and response option for the customized PROMIS® Short Forms and shared their feedback. Participants also discussed the relevance of the items, response options and recall period. Verbatim interview transcripts were subject to thematic and content analysis. RESULTS: In total, there were 28 participants (non-radiographic axSpA, n = 12; ankylosing spondylitis, n = 16), from the US (n = 20) and Germany (n = 8). Mean age was 52.8 years, and 57% were male; mean time since diagnosis was 9.5 years. The CE section identified 12 distinct symptoms that characterized axSpA: pain, sleep problems, fatigue/tiredness, stiffness, swelling, vision/eye issues, restricted body movements, headache/migraine, spasms, change in posture/stature, balance/coordination problems, and numbness. Pain, sleep problems, and fatigue/tiredness were experienced by ≥ 90% of participants, occurring simultaneously and exacerbating one another. Participants reported axSpA impacted their lives across six domains of health-related quality of life (HRQoL): physical functioning (100%), emotional wellbeing (89%), work/volunteering (79%), social functioning (75%), activities of daily living (61%) and cognitive functioning (54%). Impacts were most frequently associated with pain, stiffness, and fatigue. CD showed the PROMIS® instruments were conceptually comprehensive and well understood, with all items relevant to ≥ 50% of participants. CONCLUSIONS: Pain, sleep problems and fatigue are pivotal symptoms of axSpA and associated with HRQoL impacts. These results were used to update a conceptual model of axSpA which was originally developed based on a targeted literature review. Interpretability and content validity of the customized PROMIS® Short Forms were confirmed, with each deemed to adequately assess key impacts associated with axSpA, making them suitable for use in axSpA clinical trials.


Assuntos
Qualidade de Vida , Espondilite Anquilosante , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Atividades Cotidianas , Estudos Transversais , Espondilite Anquilosante/diagnóstico , Dor , Cognição , Fadiga
6.
J Clin Aesthet Dermatol ; 13(5): 12-18, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32802249

RESUMO

BACKGROUND: There are a variety of treatment options currently available for plaque psoriasis affecting the scalp, yet scalp psoriasis remains one of the most frustrating and difficult-to-manage forms of the disease. OBJECTIVE: We investigated the efficacy of fixed-combination calcipotriene 0.005% plus betamethasone dipropionate 0.064% (Cal/BD) foam for the treatment of scalp psoriasis. METHODS: Additional (including post-hoc) analysis was conducted on data from a Phase II, randomized, double-blind, multicenter study of Cal/BD foam for the treatment of psoriasis vulgaris (NCT01536938). A total of 302 patients, ages 18 years or older, with psoriasis vulgaris of at least mild severity (scalp involvement of at least 10%) were included; 100, 101, and 101 patients were randomized to once-daily Cal/BD foam, Cal foam, or BD foam, respectively. Assessments included a severity score for lesion redness, scaliness, and plaque thickness, modified Psoriasis Area and Severity Index (mPASI) score, proportion of patients with reduction of 50 percent or greater in total sign score (TSS-50), and proportion of patients with at least a 75-percent reduction in mPASI score (mPASI-75). RESULTS: Patients achieved greater improvements in their scalp psoriasis with Cal/BD foam versus BD or Cal foam alone at Week 4 considering mPASI, mPASI-75, and TSS-50 outcomes. After four weeks of treatment, more patients receiving Cal/BD foam had a severity score for redness, scaliness, and thickness indicating "none" or "mild" versus BD foam or Cal foam alone. Improvements on the scalp appear to be consistent with those on the trunk and limbs. CONCLUSION: Scalp lesion severity improved considerably and rapidly with a four-week regimen of Cal/BD foam, suggesting that Cal/BD foam is an effective topical treatment option for scalp psoriasis.

7.
J Med Econ ; 23(6): 641-649, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31985301

RESUMO

Background: The fixed-dose combination foam formulation of calcipotriene 0.005% plus betamethasone dipropionate 0.064% (Cal/BD) has demonstrated efficacy and a favorable safety profile for the treatment of plaque psoriasis. Recently, a topical lotion of the combination of halobetasol 0.01% plus tazarotene 0.045% (HP/TAZ) was approved for treating adult plaque psoriasis. Currently, no head-to-head studies have compared Cal/BD foam with HP/TAZ lotion.Objective: Compare the effectiveness and drug incremental cost per responder (ICPR) of Cal/BD foam vs. HP/TAZ lotion in moderate-to-severe plaque psoriasis.Methods: An anchor-based, matching-adjusted indirect comparison was conducted for PGA treatment success (Physician's Global Assessment of "clear" or "almost clear," [PGA 0/1] with at least a 2-point improvement) using individual patient data from 3 randomized clinical studies of Cal/BD foam and published data from 2 randomized, Phase 3 clinical studies of HP/TAZ lotion. The number needed to treat and ICPR were also calculated.Results: After reweighting of patients in the Cal/BD foam studies to match summary baseline characteristics of the HP/TAZ lotion study patients and anchoring to vehicle effect, 4 weeks of Cal/BD foam produced a significantly greater rate of treatment success than 8 weeks of HP/TAZ lotion treatment (51.4 vs. 30.7%; treatment difference = 20.7%, p < .001). The number needed to treat with Cal/BD foam was also less than HP/TAZ lotion (1.9 vs. 3.3). Using US wholesale acquisition costs and equal weekly consumption rates, the incremental cost per PGA 0/1 responder relative to vehicle for Cal/BD foam was $3,988 and was 37% lower compared with HP/TAZ lotion ($6,294).Conclusions: The indirect comparison analyses showed that Cal/BD foam was associated with a greater rate of treatment success, lower ICPR, and quicker treatment response than HP/TAZ lotion in adult patients with moderate-to-severe plaque psoriasis.


Assuntos
Fármacos Dermatológicos/economia , Fármacos Dermatológicos/uso terapêutico , Psoríase/tratamento farmacológico , Administração Cutânea , Adulto , Idoso , Betametasona/análogos & derivados , Betametasona/economia , Betametasona/uso terapêutico , Calcitriol/análogos & derivados , Calcitriol/economia , Calcitriol/uso terapêutico , Clobetasol/análogos & derivados , Clobetasol/economia , Clobetasol/uso terapêutico , Fármacos Dermatológicos/administração & dosagem , Combinação de Medicamentos , Humanos , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Ácidos Nicotínicos/economia , Ácidos Nicotínicos/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Índice de Gravidade de Doença
8.
Basic Clin Androl ; 28: 14, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30473791

RESUMO

BACKGROUND: Bacterial infection and inflammation of the testis impairs fertility, yet an understanding of inflammatory responses of the testis is incomplete. We are interested in identifying gene pathways involved in the detection and clearance of infectious microbes in the male reproductive tract. In previous studies in our lab focused on hypoxia-responsive genes of the testis, preliminary experiments suggested that genes classically categorized as hypoxia genes are also activated during antimicrobial responses. The purpose of this study was to identify hypoxia and inflammatory gene pathways that contribute to antimicrobial protection of the testis and to consider possible cross-talk and interactions between these pathways. Inflammation was induced in Sprague-Dawley rats using P. aeruginosa or E. coli lipopolysaccharide (LPS). Levels of hypoxia-inducible factor-1 (HIF-1α) protein and nuclear factor kappa B (NF-κB) were measured, and hypoxia and inflammatory gene expression patterns in testis were analyzed by gene expression profiling using real-time quantitative PCR arrays. RESULTS: In LPS-treated rats, HIF-1α protein increased with no change in Hif-1α mRNA. Western Blot analysis also demonstrated no change in NF-κB and inhibitory NFKB alpha (IκBα) protein levels following LPS treatment. Five hypoxia pathway genes (Angptl4, Egr1, Ier3, Pai1, and Glut1), and 11 inflammatory pathway genes (Ccl12, Cc13, Cd14, Cxcl10, Icam1, Il10, Il1b, Il6, Nfkbia, Tlr2, Tnf) up-regulated after 3 h of inflammation. Angptl4, Ccl12, Cc13, Cd14, Egr1, Nfkbia, Tlr2, and Tnf remained elevated at 6 h. Six genes were up-regulated at 6 h only (Bhlhe40, C3, Jak2, Nlrp3, Slc11a1, Tlr1). One gene (Tlr5) was down-regulated after 3 h and no genes at 6 h. Electrophoretic mobility shift assay results suggest a decrease in NF-κB binding activity following LPS treatment. CONCLUSIONS: Testicular HIF-1α is up-regulated following LPS-induced inflammation. In contrast to other tissues, in which HIF-1α is up-regulated through transcriptional activation via NF-κB, we conclude that HIF-1α in the testis is not up-regulated through an increase in Hif-1α mRNA or through NF-κB-dependent mechanisms. Hypoxia pathway genes and genes involved in Toll-like receptor (TLR) and cytokine-mediated signaling comprise major functional categories of up-regulated genes, demonstrating that both hypoxia and classic inflammatory pathways are involved in inflammatory responses of the testis.


CONTEXTE: L'infection et l'inflammation bactériennes du testicule altèrent la fertilité; cependant la compréhension des réponses inflammatoires du testicule est. encore incomplète. Nous nous sommes intéressés à l'identification des voies des gènes impliqués dans la détection et l'élimination des microbes infectieux dans l'appareil reproductif masculin. Dans de précédentes études menées dans notre laboratoire, et centrées sur des gènes sensibles à l'hypoxie, les expérimentations préliminaires suggéraient que les gènes classiquement catégorisés comme gènes de l'hypoxie étaient aussi activés au cours des réponses antimicrobiennes. Le but de la présente étude était d'identifier les voies des gènes qui contribuaient à la protection antimicrobienne du testicule et d'examiner de potentiels intermodulations et interactions entre ces voies.L'inflammation a été induite chez des rats Sprague-Dawley en utilisant des lypopolysaccharides (LPS) de P. aeruginosaet d'E. coli. Les taux de protéine du facteur-1 inductible par l'hypoxie (HIF1- α) et du facteur nucléaire kappa B (NF- kB) ont été mesurés; les profils d'expression des gènes de l'hypoxie et de l'inflammation dans le testicule ont été analysés par profilage de l'expression génique par PCR quantitative en temps réel. RÉSULTATS: Chez les rats traités par LPS, la protéine HIF-1 α a augmenté sans modification de Hif-1αmRNA. L'analyse par Western Blot a aussi montré l'absence de modifications des taux de NF-kB et de la protéine inhibitrice NFKB alpha (IkB α) après traitement. Cinq gènes de la voie hypoxie (Angptl4, Egr1, Ier3, Pai1,et Glut1), et 11 gènes de la voie inflammatoire (Ccl12, Cc13, Cd14, Cxcl10, Icam1, Il10, Il1b, Il6, Egr1, Nfkbia, Tlr2, et Tnf) ont été régulés à la hausse après 3 heures d'inflammation. Angptl4, Ccl12, Cc13, Cd14, Egr1, Nfkbia, Tlr2, et Tnfsont restés élevés à 6 heures. Six gènes n'ont ont été régulés à la hausse qu'à 6 heures (Bhlhe40, C3, Jak2, Nlrp3, Slc11a1, Tlr1). Un gène (Tlr5) a été régulé à la baisse après 3 heures et aucun gène à 6 heures. Les résultats du test de décalage de la mobilité électrophorétique suggèrent une baisse de l'activité de liaison de NF- kB après traitement par LPS. CONCLUSIONS: HIF-1α testiculaire est. régulé à la hausse après inflammation induite par LPS. Contrairement à d'autres tissus, dans lesquels HIF-1α est. régulé à la hausse par activation transcriptionnelle via NF- kB, nous concluons que HIF-1α dans le testicule n'est. pas régulé à la hausse par une augmentation de Hif-1 αmRNA ou par des mécanismes NF-kB-dépendants. Les gènes de la voie hypoxie et les gènes impliqués dans le récepteur Toll-like (TLR) et dans la signalisation médiée par les cytokines comprennent des catégories fonctionnelles majeures de gènes régulés à la hausse, ce qui démontre qu'à la fois les voies de l'hypoxie et les voies classiques de l'inflammation sont impliquées dans les réponses inflammatoires du testicule.

9.
Cell Cycle ; 17(7): 881-891, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29620483

RESUMO

'BRCAness' is a term used to describe cancer cells that behave similarly to tumors with BRCA1 or BRCA2 mutations. The BRCAness phenotype is associated with hypersensitivity to chemotherapy agents including PARP inhibitors, which are a promising class of recently-licensed anti-cancer treatments. This hypersensitivity arises because of a deficiency in the homologous recombination (HR) pathway for DNA double-strand break repair. To gain further insight into how genetic modifiers of HR contribute to the BRCAness phenotype, we created a new mouse model of BRCAness by generating mice that are deficient in BLM helicase and the Exo1 exonuclease, which are involved in the early stages of HR. We find that cells lacking BLM and Exo1 exhibit a BRCAness phenotype, with diminished HR, and hypersensitivity to PARP inhibitors. We further tested how 53BP1, an important regulator of HR, affects repair efficiency in our BRCAness model. We find that deletion of 53BP1 can relieve several of the repair deficiencies observed in cells lacking BLM and Exo1, just as it does in cells lacking BRCA1. These results substantiate the importance of BRCAness as a concept for classification of cancer cases, and further clarify the role of 53BP1 in regulation of DNA repair pathway choice in mammalian cells.


Assuntos
Enzimas Reparadoras do DNA/genética , Reparo do DNA/efeitos dos fármacos , Exodesoxirribonucleases/genética , Pontos de Checagem da Fase G2 do Ciclo Celular/genética , RecQ Helicases/genética , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética , Animais , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Linfócitos B/patologia , Linfócitos B/efeitos da radiação , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteína BRCA2/genética , Proteína BRCA2/metabolismo , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , DNA/genética , DNA/metabolismo , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Enzimas Reparadoras do DNA/deficiência , Exodesoxirribonucleases/deficiência , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos da radiação , Raios gama , Deleção de Genes , Expressão Gênica , Instabilidade Genômica , Humanos , Camundongos , Camundongos Knockout , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Cultura Primária de Células , RecQ Helicases/deficiência , Troca de Cromátide Irmã , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/deficiência
10.
J Cell Biol ; 216(11): 3521-3534, 2017 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-28912125

RESUMO

The BLM gene product, BLM, is a RECQ helicase that is involved in DNA replication and repair of DNA double-strand breaks by the homologous recombination (HR) pathway. During HR, BLM has both pro- and anti-recombinogenic activities, either of which may contribute to maintenance of genomic integrity. We find that in cells expressing a mutant version of BRCA1, an essential HR factor, ablation of BLM rescues genomic integrity and cell survival in the presence of DNA double-strand breaks. Improved genomic integrity in these cells is linked to a substantial increase in the stability of RAD51 at DNA double-strand break sites and in the overall efficiency of HR. Ablation of BLM also rescues RAD51 foci and HR in cells lacking BRCA2 or XRCC2. These results indicate that the anti-recombinase activity of BLM is of general importance for normal retention of RAD51 at DNA break sites and regulation of HR.


Assuntos
Quebras de DNA de Cadeia Dupla , Linfócitos/enzimologia , Neoplasias/enzimologia , Rad51 Recombinase/metabolismo , RecQ Helicases/metabolismo , Reparo de DNA por Recombinação , Animais , Proteína BRCA1/genética , Proteína BRCA1/metabolismo , Proteína BRCA2/deficiência , Proteína BRCA2/genética , Linhagem Celular Tumoral , Sobrevivência Celular , Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Instabilidade Genômica , Genótipo , Humanos , Linfócitos/patologia , Camundongos Knockout , Mutação , Neoplasias/genética , Neoplasias/patologia , Fenótipo , Estabilidade Proteica , Interferência de RNA , Rad51 Recombinase/genética , RecQ Helicases/deficiência , RecQ Helicases/genética , Transfecção , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/deficiência , Proteína 1 de Ligação à Proteína Supressora de Tumor p53/genética
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