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In the presence of physiological monovalent cations, thousands of RNA G-rich sequences can form parallel G-quadruplexes (G4s) unless RNA-binding proteins inhibit, destabilize, or resolve the formation of such secondary RNA structures. Here, we have used a disease-relevant model system to investigate the biophysical properties of the RNA-binding protein HNRNPH1's interaction with G-rich sequences. We demonstrate the importance of two EWSR1-exon 8 G-rich regions in mediating the exclusion of this exon from the oncogenic EWS-FLI1 transcripts expressed in a subset of Ewing sarcomas, using complementary analysis of tumor data, long-read sequencing, and minigene studies. We determined that HNRNPH1 binds the EWSR1-exon 8 G-rich sequences with low nM affinities irrespective of whether in a non-G4 or G4 state but exhibits different kinetics depending on RNA structure. Specifically, HNRNPH1 associates and dissociates from G4-folded RNA faster than the identical sequences in a non-G4 state. Importantly, we demonstrate using gel shift and spectroscopic assays that HNRNPH1, particularly the qRRM1-qRRM2 domains, destabilizes the G4s formed by the EWSR1-exon 8 G-rich sequences in a non-catalytic fashion. Our results indicate that HNRNPH1's binding of G-rich sequences favors the accumulation of RNA in a non-G4 state and that this contributes to its regulation of RNA processing.
Assuntos
Quadruplex G , Processamento Alternativo , Sequência de Bases , Oncogenes , RNA/química , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismoRESUMO
BACKGROUND: Research shows that inactive young women are attracted to using mobile phone applications (apps) to increase physical activity. Apps can promote physical activity by delivering a range of behaviour change techniques to influence determinants of user behaviour. Previous qualitative research has examined user experiences with techniques in physical activity apps, however there is little research specifically among young women. This study aimed to explore young women's experiences using commercial physical activity apps to change their behaviour. METHODS: Young women were recruited online to use a randomly assigned app for two weeks to achieve a personal goal. Using photovoice, a qualitative participatory research method, participants generated insights about their experiences through photographs and semi-structured interviews. Thematic analysis was conducted on photograph and interview data. RESULTS: Thirty-two female participants, aged 18-24 years, completed the study. Behaviour change techniques tended to cluster around four key themes: logging and monitoring physical activity; reminders and prompts; workout videos and written instructions; and social features. Social support also strongly influenced participants' experiences. CONCLUSIONS: Results suggest that behaviour change techniques influenced physical activity in line with social cognitive models, and these models are useful to understand how apps can target user behaviour for young women. The findings identified factors important for young women that seemed to moderate their experiences, such as social norms about women's appearance, which should be further explored within the context of behaviour change models and app design.
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Aplicativos Móveis , Humanos , Feminino , Exercício Físico/psicologia , Pesquisa Qualitativa , Terapia Comportamental/métodos , Comportamento SedentárioRESUMO
PURPOSE: The purpose of this analysis was to explore associations between exercise behaviour among breast cancer survivors and three behavioural constructs from distinct theories: self-efficacy from social cognitive theory, motivation from self-determination theory, and habits from habit theory. METHODS: Breast cancer survivors (n = 204) completed a cross-sectional survey that collected demographic and disease characteristics, exercise levels, and self-efficacy, motivation, and habits. Multivariable linear regression models were used to identify constructs associated with total activity and resistance training. RESULTS: Participants were a mean (SD) age of 57.3 (10.8) years and most were diagnosed with early-stage disease (72%) and engaged in sufficient levels of total activity (94%), though only 45% completed ≥ 2 resistance training sessions/week. Identified motivation (êµ[95% CI] = 7.6 [3.9-11.3]) and habits (êµ[95% CI] = 4.4 [1.4-7.4]) were significantly associated with total activity (as were body mass index and disease stage), whilst identified motivation (êµ[95% CI] = 0.6 [0.3-0.9]) and coping self-efficacy (êµ[95% CI] = 0.02 [< 0.01-0.03]) were significantly associated with resistance training. The models explained 27% and 16% of variance in total activity and resistance training behaviour, respectively. CONCLUSION: Results suggest that incorporating strategies that support identified motivation, habits, and coping self-efficacy in future interventions could promote increased exercise behaviour among breast cancer populations. Future longitudinal research should examine associations with exercise in a more representative, population-based sample.
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Neoplasias da Mama , Feminino , Humanos , Pessoa de Meia-Idade , Motivação , Estudos Transversais , Autoeficácia , HábitosRESUMO
PURPOSE: The aims of this systematic review were to: (1) describe physical activity (PA) levels following diagnosis of primary brain cancer, (2) determine the relationship between PA levels and health outcomes, and (3) assess the effect of participating in an exercise intervention on health outcomes following a diagnosis of brain cancer. METHODS: PubMed, EMBASE, Scopus and CINAHL were searched for relevant articles published prior to May 1, 2020. Studies reporting levels of PA, the relationship between PA and health outcomes, and exercise interventions conducted in adults with brain cancer were eligible. The search strategy included terms relating to primary brain cancer, physical activity, and exercise. Two independent reviewers assessed articles for eligibility and methodological quality (according to Joanna Briggs Institute Critical Appraisal Tools). Descriptive statistics were used to present relevant data and outcomes. RESULTS: 15 studies were eligible for inclusion. Most adults with brain cancer were insufficiently active from diagnosis through to post-treatment. Higher levels of PA were associated with lower severity of brain cancer specific concerns and higher quality of life. Preliminary evidence suggests that exercise is safe, feasible and potentially beneficial to brain cancer symptom severity and interference, aerobic capacity, body composition and PA levels. However, the level of evidence to support these findings is graded as weak. CONCLUSIONS: Evidence suggests that it is likely appropriate to promote those with brain cancer to be as physically active as possible. The need or ability of those with brain cancer to meet current PA guidelines promoted to all people with cancer remains unclear.
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Neoplasias Encefálicas , Qualidade de Vida , Adulto , Neoplasias Encefálicas/terapia , Exercício Físico , HumanosRESUMO
The year 2021 marks the 20th anniversary of the first publications reporting the discovery of the gene silencing mechanism, RNA interference (RNAi) in mammalian cells. Along with the many studies that delineated the proteins and substrates that form the RNAi pathway, this finding changed our understanding of the posttranscriptional regulation of mammalian gene expression. Furthermore, the development of methods that exploited the RNAi pathway began the technological revolution that eventually enabled the interrogation of mammalian gene function-from a single gene to the whole genome-in only a few days. The needs of the cancer research community have driven much of this progress. In this perspective, we highlight milestones in the development and application of RNAi-based methods to study carcinogenesis. We discuss how RNAi-based functional genetic analysis of exemplar tumor suppressors and oncogenes furthered our understanding of cancer initiation and progression and explore how such studies formed the basis of genome-wide scale efforts to identify cancer or cancer-type specific vulnerabilities, including studies conducted in vivo. Furthermore, we examine how RNAi technologies have revealed new cancer-relevant molecular targets and the implications for cancer of the first RNAi-based drugs. Finally, we discuss the future of functional genetic analysis, highlighting the increasing availability of complementary approaches to analyze cancer gene function.
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Neoplasias/genética , Proteínas Oncogênicas/genética , Interferência de RNA , Proteínas Supressoras de Tumor/genética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Progressão da Doença , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Humanos , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológicoRESUMO
OBJECTIVE: A consistent body of evidence supports participating in physical activity (PA) post-cancer diagnosis as beneficial to function, quality-of-life and potentially survival. However, diagnosis of late stage disease, poor prognosis, receipt of high doses of adjuvant therapy and presence of severe acute and persistent treatment-related side-effects may alter how these findings translate to women with ovarian cancer. Therefore, the objectives of this review were to (I) describe PA levels post-diagnosis of ovarian cancer, (II) explore the relationship between PA levels and health outcomes, and (III) evaluate the effect of exercise interventions for women with ovarian cancer. METHODS: PubMed, EMBASE, Scopus and CINAHL were systematically searched to December 31, 2019. Two independent reviewers assessed articles for eligibility. Studies were eligible if they evaluated the relationship between PA levels or an exercise intervention and health outcomes following ovarian cancer. Methodological quality was assessed by two independent reviewers using the Joanna Briggs Institute Critical Appraisal Tools. Descriptive statistics were used to collate relevant data. RESULTS: 34 articles were eligible for inclusion. Results demonstrated that most women decrease PA from pre- to post-diagnosis and remain insufficiently active following diagnosis. Higher levels of PA were associated with higher health-related quality-of-life (HRQOL), and lower levels of anxiety and depression. Exercise appears safe and feasible during and following treatment and leads to improvements in HRQOL, fatigue and additional physical and psychological outcomes. CONCLUSIONS: Findings suggest that PA is relevant to health outcomes for women with ovarian cancer. Interventions that aid women to stay or become sufficiently active, including through exercise interventions during or following treatment have potential to improve the lives of those with ovarian cancer. Future work evaluating targeted interventions that can accommodate disease-specific challenges is now required to ensure scientific findings can translate into improved ovarian cancer care.
Assuntos
Carcinoma Epitelial do Ovário/fisiopatologia , Carcinoma Epitelial do Ovário/terapia , Exercício Físico/fisiologia , Neoplasias Ovarianas/fisiopatologia , Neoplasias Ovarianas/terapia , Carcinoma Epitelial do Ovário/psicologia , Exercício Físico/psicologia , Feminino , Humanos , Neoplasias Ovarianas/psicologia , Prognóstico , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
The mechanistic basis for the metastasis of Ewing sarcomas remains poorly understood, as these tumors harbor few mutations beyond the chromosomal translocation that initiates the disease. Instead, the epigenome of Ewing sarcoma cells reflects the regulatory state of genes associated with the DNA-binding activity of the fusion oncoproteins EWSR1::FLI1 or EWSR1::ERG. In this study, we examined the EWSR1::FLI1/ERG's repression of transcription factor genes, concentrating on those that exhibit a broader range of expression in tumors than in Ewing sarcoma cell lines. Focusing on one of these target genes, ETS1, we detected EWSR1::FLI1 binding and an H3K27me3-repressive mark at this locus. Depletion of EWSR1::FLI1 results in ETS1's binding of promoter regions, substantially altering the transcriptome of Ewing sarcoma cells, including the upregulation of the gene encoding TENSIN3 (TNS3), a focal adhesion protein. Ewing sarcoma cell lines expressing ETS1 (CRISPRa) exhibited increased TNS3 expression and enhanced movement compared with control cells. Visualization of control Ewing sarcoma cells showed a distributed vinculin signal and a network-like organization of F-actin; in contrast, ETS1-activated Ewing sarcoma cells showed an accumulation of vinculin and F-actin toward the plasma membrane. Interestingly, the phenotype of ETS1-activated Ewing sarcoma cell lines depleted of TNS3 resembled the phenotype of the control cells. Critically, these findings have clinical relevance as TNS3 expression in Ewing sarcoma tumors positively correlates with that of ETS1. Implications: ETS1's transcriptional regulation of the gene encoding the focal adhesion protein TENSIN3 in Ewing sarcoma cells promotes cell movement, a critical step in the evolution of metastasis.
Assuntos
Regulação Neoplásica da Expressão Gênica , Proteínas de Fusão Oncogênica , Proteína Proto-Oncogênica c-ets-1 , Proteína Proto-Oncogênica c-fli-1 , Proteína EWS de Ligação a RNA , Sarcoma de Ewing , Tensinas , Humanos , Proteína Proto-Oncogênica c-ets-1/genética , Proteína Proto-Oncogênica c-ets-1/metabolismo , Tensinas/metabolismo , Tensinas/genética , Sarcoma de Ewing/genética , Sarcoma de Ewing/patologia , Sarcoma de Ewing/metabolismo , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Linhagem Celular Tumoral , Proteína Proto-Oncogênica c-fli-1/genética , Proteína Proto-Oncogênica c-fli-1/metabolismo , Proteína EWS de Ligação a RNA/genética , Proteína EWS de Ligação a RNA/metabolismo , Adesões Focais/genética , Adesões Focais/metabolismoRESUMO
BACKGROUND: Exercise rehabilitation is a promising strategy for reducing cardiovascular disease risk among patients with breast cancer. However, the evidence is primarily derived from programs based at exercise centers with in-person supervised delivery. Conversely, most patients report a preference for home-based rehabilitation. As such, there is a clear need to explore strategies that can provide real-time supervision and coaching while addressing consumer preferences. Evidence from cardiac rehabilitation has demonstrated the noninferiority of a smartphone-based telerehabilitation approach (REMOTE-CR) to improve cardiorespiratory fitness in people with cardiovascular disease compared to a center-based program. OBJECTIVE: This study aims to assess the feasibility, safety, and preliminary efficacy of the REMOTE-CR program adapted for patients with breast cancer at risk of cardiotoxicity (REMOTE-COR-B). We will also assess the satisfaction and usability of REMOTE-COR-B. METHODS: We will conduct a single-arm feasibility study of the REMOTE-COR-B program among patients with stage I-III breast cancer who are at risk of cardiotoxicity (taking treatment type and dose, as well as other common cardiovascular disease risk factors into account) and who are within 24 months of completing primary definitive treatment. Participants (target sample size of 40) will receive an 8-week smartphone-based telerehabilitation exercise program involving remotely delivered real-time supervision and behavior change support. The platform comprises a smartphone and wearable heart rate monitor, as well as a custom-built smartphone app and web application. Participants will be able to attend remotely monitored exercise sessions during set operating hours each week, scheduled in both the morning and evening. Adherence is the primary outcome of the trial, assessed through the number of remotely monitored exercise sessions attended compared to the trial target (ie, 3 sessions per week). Secondary outcomes include additional trial feasibility indicators (eg, recruitment and retention), safety, satisfaction, and usability, and objective and patient-reported efficacy outcomes (cardiovascular fitness, quality of life, fatigue, self-reported exercise, self-efficacy, habit strength, and motivation). Adherence, feasibility, and safety outcomes will be assessed during the intervention period; intervention satisfaction and usability will be assessed post intervention; and objective and patient-reported efficacy outcomes will be assessed at baseline, post intervention (2-month postbaseline assessment), and at follow-up (5-month postbaseline assessment). RESULTS: Recruitment for this trial commenced in March 2023, and 7 participants had been recruited as of the submission of the manuscript. The estimated completion date for the project is October 2024, with results expected to be published in mid-2025. CONCLUSIONS: The REMOTE-COR-B intervention is a novel and promising approach to providing exercise therapy to patients with breast cancer at risk of cardiotoxicity who have unique needs and heightened safety risks. This project will provide important information on the extent to which this approach is satisfactory to patients with breast cancer, safe, and potentially effective, which is necessary before larger-scale research or clinical projects. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12621001557820; www.anzctr.org.au/ACTRN12621001557820.aspx. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/53301.
RESUMO
EWSR1 is a member of the FET family of nucleic acid binding proteins that includes FUS and TAF15. Here, we report the systematic analysis of endogenous EWSR1's cellular organization in human cells. We demonstrate that EWSR1, which contains low complexity and nucleic acid binding domains, is present in cells in faster and slower-recovering fractions, indicative of a protein undergoing both rapid exchange and longer-term interactions. The employment of complementary high-resolution imaging approaches shows EWSR1 exists in two visual modalities, a distributed state which is present throughout the nucleoplasm, and a concentrated state consistent with the formation of foci. Both EWSR1 visual modalities localize with nascent RNA. EWSR1 foci concentrate in regions of euchromatin, adjacent to protein markers of transcriptional activation, and significantly colocalize with phosphorylated RNA polymerase II. Our results contribute to bridging the gap between our understanding of the biophysical and biochemical properties of FET proteins, including EWSR1, their functions as transcriptional regulators, and the participation of these proteins in tumorigenesis and neurodegenerative disease.
Assuntos
Doenças Neurodegenerativas , Ácidos Nucleicos , Proteína EWS de Ligação a RNA , Humanos , Ácidos Nucleicos/química , Ácidos Nucleicos/metabolismo , RNA Polimerase II/metabolismo , Proteína EWS de Ligação a RNA/genética , Proteína EWS de Ligação a RNA/metabolismoRESUMO
Ester et al report the findings from a 2-arm cluster randomized controlled trial nested within a hybrid effectiveness-implementation study, which involved a 12-week exercise and behavior change program for rural and remote Canadians (Exercise for Cancer to Enhance Living Well [EXCEL]). The addition of 23 weeks of app-based physical activity monitoring to the EXCEL program did not result in significant between-group differences in physical activity at 6 months. While several behavior change techniques were included in the initial 12-week intervention, additional techniques were embedded within the mobile app. However, there is currently a lack of evidence regarding how many and which behavior change techniques are the most effective for people with cancer and if these differ based on individual characteristics. Potentially, the use of the mobile app was not required in addition to the behavior change support delivered to both groups as part of the EXCEL program. Further research should involve participants who may be in most need of behavioral support, for example, those with lower levels of self-efficacy. Suggestions for future research to tailor behavior change support for people with cancer are discussed.
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The aim of this systematic rapid review was to explore barriers, facilitators, perceptions and preferences of physical activity for people diagnosed with cancer, by cancer type and treatment stage. The search strategy, implemented through four databases, included terms relating to cancer, physical activity, barriers, facilitators, perceptions and preferences, and relevant study designs. Studies reporting the outcomes of interests for adults diagnosed with cancer and living in Western countries were included and grouped according to the Social-Ecological Model and the Health Belief Model, and pragmatically. A total of 118 studies, involving 15 cancers were included. Outcomes were most commonly explored within samples involving mixed cancers (32 studies) and breast cancer (31 studies), and at the post-treatment phase (52 studies). Across all cancers and during- and post-treatment, treatment- and disease-related side-effects were the most commonly identified barrier, social support and guidance was the most commonly identified facilitator, and promoting health and recovery was the most commonly identified perception of benefit of physical activity. Notable differences were identified in barriers, facilitators and perceptions across cancer types and treatment stages, with specific examples including: comorbidities were inconsistently reported as a barrier across cancers; time pressure was more commonly reported as a barrier post-treatment; and women with breast cancer reported inaccessibility of appropriate services more commonly during-treatment than post-treatment. Preference findings varied widely across cancer types and treatment phases. These findings can be used to aid efforts to improve physical activity levels post-cancer by providing healthcare professionals with information to facilitate individualised advice and services.
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The mechanistic basis for the metastasis of Ewing sarcomas remains poorly understood, as these tumors harbor few mutations beyond the chromosomal translocation that initiates the disease. Instead, the epigenome of Ewing sarcoma (EWS) cells reflects the regulatory state of genes associated with the DNA binding activity of the fusion oncoproteins EWSR1::FLI1 or EWSR1::ERG. In this study, we examined the EWSR1::FLI1/ERG's repression of transcription factor genes, concentrating on those that exhibit a broader range of expression in tumors than in EWS cell lines. Focusing on one of these target genes, ETS1, we detected EWSR1::FLI1 binding and an H3K27me3 repressive mark at this locus. Depletion of EWSR1::FLI1 results in ETS1's binding of promoter regions, substantially altering the transcriptome of EWS cells, including the upregulation of the gene encoding TENSIN3 (TNS3), a focal adhesion protein. EWS cell lines expressing ETS1 (CRISPRa) exhibited increased TNS3 expression and enhanced movement compared to control cells. The cytoskeleton of control cells and ETS1-activated EWS cell lines also differed. Specifically, control cells exhibited a distributed vinculin signal and a network-like organization of F-actin. In contrast, ETS1-activated EWS cells showed an accumulation of vinculin and F-actin towards the plasma membrane. Interestingly, the phenotype of ETS1-activated EWS cell lines depleted of TNS3 resembled the phenotype of the control cells. Critically, these findings have clinical relevance as TNS3 expression in EWS tumors positively correlates with that of ETS1.
RESUMO
We report systematic analysis of endogenous EWSR1's cellular organization. We demonstrate that EWSR1, which contains low complexity and nucleic acid binding domains, is present in cells in faster and slower-recovering fractions, indicative of a protein undergoing both rapid exchange and longer-term interactions. The employment of complementary high-resolution imaging approaches shows EWSR1 exists in in two visual modalities, a distributed state which is present throughout the nucleoplasm, and a concentrated state consistent with the formation of foci. Both EWSR1 visual modalities localize with nascent RNA. EWSR1 foci concentrate in regions of euchromatin, adjacent to protein markers of transcriptional activation, and significantly colocalize with phosphorylated RNA polymerase II. Interestingly, EWSR1 and FUS, another FET protein, exhibit distinct spatial organizations. Our results contribute to bridging the gap between our understanding of the biophysical and biochemical properties of FET proteins, including EWSR1, their functions as transcriptional regulators, and the participation of these proteins in tumorigenesis and neurodegenerative disease.
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PURPOSE: To determine the safety, feasibility, and potential effect of an 18-week exercise intervention for adults with primary brain cancer. MATERIALS AND METHODS: Eligible patients were 12-26-weeks post-radiotherapy for brain cancer. The individually-prescribed weekly exercise was ≥150-minutes of moderate-intensity exercise, including two resistance-training sessions. The intervention was deemed "safe" if exercise-related, serious adverse events (SAE) were experienced by <10% of participants, and feasible if recruitment, retention, and adherence rates were ≥75%, and ≥75% compliance rates were achieved in ≥75% of weeks. Patient-reported and objectively-measured outcomes were assessed at baseline, mid-intervention, end-intervention, and 6-month follow-up, using generalized estimating equations. RESULTS: Twelve participants enrolled (51 ± 19.5 years, 5 females). There were no exercise-related SAEs. The intervention was feasible (recruitment:80%, retention:92%, adherence:83%). Participants completed a median of 172.8 (min:77.5, max:560.8) minutes of physical activity per week. 17% met the compliance outcome threshold for ≥75% of the intervention. Improvements in quality of life (mean change (95% CI): 7.9 units (1.9, 13.8)), functional well-being (4.3 units (1.4, 7.2)), depression (-2.0 units (-3.8, -0.2)), activity (112.8 min (42.1, 183.4)), fitness (56.4 meters (20.4, 92.5)), balance (4.9 s (0.9, 9.0)), and lower-body strength (15.2 kg (9.3, 21.1)) were observed end-intervention. CONCLUSION: Preliminary evidence support that exercise is safe and beneficial to the quality of life and functional outcomes for people with brain cancer.Registration: ACTRN12617001577303.
The BRAin Cancer and Exercise (BRACE) study highlights the need for regular monitoring of disease- and treatment-related side effects which may present as barriers to exercise.Exercise prescription should be modified according to the presence and severity of disease- and treatment-related barriers.Adverse events observed, such as dizziness, highlight the importance of supervised exercise for people with brain cancer.If supervision is not possible, then exercise modes with low risk of harm from falls are recommended (e.g., walking, machine-based resistance training).
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BACKGROUND: Colorectal carcinomas (CRC) carry massive genetic and transcriptional alterations that influence multiple cellular pathways. The study of proteins whose loss-of-function (LOF) alters the growth of CRC cells can be used to further understand the cellular processes cancer cells depend upon for survival. RESULTS: A small-scale RNAi screen of ~400 genes conducted in SW480 CRC cells identified several candidate genes as required for the viability of CRC cells, most prominently CASP8AP2/FLASH. To understand the function of this gene in maintaining the viability of CRC cells in an unbiased manner, we generated gene specific expression profiles following RNAi. Silencing of CASP8AP2/FLASH resulted in altered expression of over 2500 genes enriched for genes associated with cellular growth and proliferation. Loss of CASP8AP2/FLASH function was significantly associated with altered transcription of the genes encoding the replication-dependent histone proteins as a result of the expression of the non-canonical polyA variants of these transcripts. Silencing of CASP8AP2/FLASH also mediated enrichment of changes in the expression of targets of the NFκB and MYC transcription factors. These findings were confirmed by whole transcriptome analysis of CASP8AP2/FLASH silenced cells at multiple time points. Finally, we identified and validated that CASP8AP2/FLASH LOF increases the expression of neurofilament heavy polypeptide (NEFH), a protein recently linked to regulation of the AKT1/ß-catenin pathway. CONCLUSIONS: We have used unbiased RNAi based approaches to identify and characterize the function of CASP8AP2/FLASH, a protein not previously reported as required for cell survival. This study further defines the role CASP8AP2/FLASH plays in the regulating expression of the replication-dependent histones and shows that its LOF results in broad and reproducible effects on the transcriptome of colorectal cancer cells including the induction of expression of the recently described tumor suppressor gene NEFH.
Assuntos
Proteínas Reguladoras de Apoptose/genética , Proteínas de Ligação ao Cálcio/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Histonas/genética , Interferência de RNA , Transcrição Gênica , Transcriptoma , Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Análise por Conglomerados , Neoplasias Colorretais/metabolismo , Biologia Computacional/métodos , Replicação do DNA , Perfilação da Expressão Gênica , Inativação Gênica , Humanos , Proteínas de Neurofilamentos/genéticaRESUMO
The volume of high-quality evidence supporting exercise as beneficial to cancer survivors has grown exponentially; however, the potential harms of exercise remain understudied. Consequently, the trade-off between desirable and undesirable outcomes of engaging in exercise remains unclear to clinicians and people with cancer. Practical guidance on collecting and reporting harms in exercise oncology is lacking. We present a harms reporting protocol developed and refined through exercise oncology trials since 2015.Development of the Exercise Harms Reporting Method (ExHaRM) was informed by national and international guidelines for harms reporting in clinical trials involving therapeutic goods or medical devices, with adaptations to enhance applicability to exercise. The protocol has been adjusted via an iterative process of implementation and adjustment through use in multiple exercise oncology trials involving varied cancer diagnoses (types: breast, brain, gynaecological; stages at diagnosis I-IV; primary/recurrent), and heterogeneous exercise intervention characteristics (face to face/telehealth delivery; supervised/unsupervised exercise). It has also involved the development of terms (such as, adverse outcomes, which capture all undesirable physical, psychological, social and economic outcomes) that facilitate the harms assessment process in exercise.ExHaRM involves: step 1: Monitor occurrence of adverse outcomes through systematic and non-systematic surveillance; step 2: Assess and record adverse outcomes, including severity, causality, impact on intervention and type; step 3: Review of causality by harms panel (and revise as necessary); and step 4: Analyse and report frequencies, rates and clinically meaningful details of all-cause and exercise-related adverse outcomes.ExHaRM provides guidance to improve the quality of harms assessment and reporting immediately, while concurrently providing a framework for future refinement. Future directions include, but are not limited to, standardising exercise-specific nomenclature and methods of assessing causality.
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Exercício Físico , Neoplasias , Humanos , Neoplasias/terapia , MamaRESUMO
To investigate drug mechanisms of action and identify molecular targets for the development of rational drug combinations, we conducted synthetic small interfering RNA (siRNA)-based RNAi screens to identify genes whose silencing affects anti-cancer drug responses. Silencing of RRM1 and RRM2, which encode the large and small subunits of the human ribonucleotide reductase complex, respectively, markedly enhanced the cytotoxicity of the topoisomerase I inhibitor camptothecin (CPT). Silencing of RRM2 was also found to enhance DNA damage as measured by histone gamma-H2AX. Further studies showed that CPT up-regulates both RRM1 and RRM2 mRNA and protein levels and induces the nuclear translocation of RRM2. The checkpoint kinase 1 (Chk1) was up-regulated and activated in response to CPT, and CHEK1 down-regulation by siRNA and small molecule inhibitors of Chk1 blocked RRM2 induction by CPT. CHEK1 siRNA also suppressed E2F1 up-regulation by CPT, and silencing of E2F1 suppressed the up-regulation of RRM2. Silencing of ATR or ATM and inhibition of ATM activity by KU-55933 blocked Chk1 activation and RRM2 up-regulation. This study links the known components of CPT-induced DNA damage response with proteins required for the synthesis of dNTPs and DNA repair. Specifically, we propose that upon DNA damage, Chk1 activation, mediated by ATM and ATR, up-regulates RRM2 expression through the E2F1 transcription factor. Up-regulation in RRM2 expression levels coupled with its nuclear recruitment suggests an active role for ribonucleotide reductase in the cellular response to CPT-mediated DNA damage that could potentially be exploited as a strategy for enhancing the efficacy of topoisomerase I inhibitors.
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Neoplasias da Mama/genética , Camptotecina/farmacologia , Neoplasias Colorretais/genética , Dano ao DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Ribonucleosídeo Difosfato Redutase/genética , Proteínas Mutadas de Ataxia Telangiectasia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/patologia , Proteínas de Ciclo Celular/genética , Quinase 1 do Ponto de Checagem , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Replicação do DNA/fisiologia , Proteínas de Ligação a DNA/genética , Fator de Transcrição E2F1/genética , Inibidores Enzimáticos/farmacologia , Feminino , Células HCT116 , Histonas/metabolismo , Humanos , Proteínas Quinases/genética , Proteínas Serina-Treonina Quinases/genética , RNA Interferente Pequeno , Ribonucleosídeo Difosfato Redutase/metabolismo , Inibidores da Topoisomerase I , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Regulação para Cima/fisiologiaRESUMO
Breast cancers can be classified into those that express the estrogen (ER) and progesterone (PR) receptors, those with ERBB2 (HER-2/Neu) amplification, and those without expression of ER, PR, or amplification of ERBB2 (referred to as triple-negative or basal-like breast cancer). In order to identify potential molecular targets in breast cancer, we performed a synthetic siRNA-mediated RNAi screen of the human tyrosine kinome. A primary RNAi screen conducted in the triple-negative/basal-like breast cancer cell line MDA-MB231 followed by secondary RNAi screens and further studies in this cell line and two additional triple-negative/basal-like breast cancer cell lines, BT20 and HCC1937, identified the G2/M checkpoint protein, WEE1, as a potential therapeutic target. Similar sensitivity to WEE1 inhibition was observed in cell lines from all subtypes of breast cancer. RNAi-mediated silencing or small compound inhibition of WEE1 in breast cancer cell lines resulted in an increase in gammaH2AX levels, arrest in the S-phase of the cell cycle, and a significant decrease in cell proliferation. WEE1-inhibited cells underwent apoptosis as demonstrated by positive Annexin V staining, increased sub-G1 DNA content, apoptotic morphology, caspase activation, and rescue by the pan-caspase inhibitor, Z-VAD-FMK. In contrast, the non-transformed mammary epithelial cell line, MCF10A, did not exhibit any of these downstream effects following WEE1 silencing or inhibition. These results identify WEE1 as a potential molecular target in breast cancer.
Assuntos
Neoplasias da Mama/enzimologia , Proteínas de Ciclo Celular/metabolismo , Ciclo Celular , Proliferação de Células , Proteínas Nucleares/metabolismo , Proteínas Tirosina Quinases/metabolismo , Interferência de RNA , Apoptose , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Inibidores de Caspase , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Proteínas de Ciclo Celular/antagonistas & inibidores , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular , Inibidores de Cisteína Proteinase/farmacologia , Feminino , Histonas/metabolismo , Humanos , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Inibidores de Proteínas Quinases/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/genética , Receptor ErbB-2/análise , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Fatores de TempoRESUMO
OBJECTIVE: The purpose of this commentary is to summarize the evidence of the feasibility and benefits of exercise for cancer patients with complex health profiles. Case studies are used to describe the therapeutic approach taken by exercise professionals. The information presented will assist the cancer care team in understanding their role in supporting these patients to move more. DATA SOURCES: Professional organizations, peer-reviewed manuscripts, and expert clinical opinion. CONCLUSION: Individually-tailored exercise is safe and feasible in the presence of complex health profiles, and all patients can benefit through exercise, regardless of individual circumstance or disease burden. However, to ensure patients benefit through physical activity, including exercise, a multidisciplinary approach, whereby all members of the health care team promote and encourage physical activity is needed. IMPLICATIONS FOR NURSING PRACTICE: There is a clear need for collaboration between the oncology team and exercise professionals, particularly when dealing with patients with complex health profiles. These patients are more likely to engage in exercise when they are advised and supported by their oncology team to do so. As such, promotion of physical activity and, when relevant, referral to an exercise professional is the responsibility of all members of the cancer team.
Assuntos
Terapia por Exercício/métodos , Oncologia/organização & administração , Neoplasias/terapia , Idoso , Terapia Combinada , Terapia por Exercício/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Equipe de Assistência ao Paciente/organização & administração , Guias de Prática Clínica como Assunto , Qualidade de VidaRESUMO
The PVT1 locus is identified as a cluster of T(2;8) and T(8;22) "variant" MYC-activating chromosomal translocation breakpoints extending 400 kb downstream of MYC in a subset (approximately 20%) of Burkitt's lymphoma (vBL). Recent reports that microRNAs (miRNA) may be associated with fragile sites and cancer-associated genomic regions prompted us to investigate whether the PVT1 region on chromosome 8q24 may contain miRNAs. Computational analysis of the genomic sequence covering the PVT1 locus and experimental verification identified seven miRNAs. One miRNA, hsa-miR-1204, resides within a previously described PVT1 exon (1b) that is often fused to the immunoglobulin light chain constant region in vBLs and is present in high copy number in MYC/PVT1-amplified tumors. Like its human counterpart, mouse mmu-miR-1204 represents the closest miRNA to Myc (~50 kb) and is found only 1 to 2 kb downstream of a cluster of retroviral integration sites. Another miRNA, mmu-miR-1206, is close to a cluster of variant translocation breakpoints associated with mouse plasmacytoma and exon 1 of mouse Pvt1. Virtually all the miRNA precursor transcripts are expressed at higher levels in late-stage B cells (including plasmacytoma and vBL cell lines) compared with immature B cells, suggesting possible roles in lymphoid development and/or lymphoma. In addition, lentiviral vector-mediated overexpression of the miR-1204 precursor (human and mouse) in a mouse pre-B-cell line increased expression of Myc. High levels of expression of the hsa-miR-1204 precursor is also seen in several epithelial cancer cell lines with MYC/PVT1 coamplification, suggesting a potentially broad role for these miRNAs in tumorigenesis.