Publications by authors named "Tamara L Jones"

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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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Ewing sarcoma cells depend on the EWS-FLI1 fusion transcription factor for cell survival. Using an assay of EWS-FLI1 activity and genome-wide RNAi screening, we have identified proteins required for the processing of the EWS-FLI1 pre-mRNA. We show that Ewing sarcoma cells harboring a genomic breakpoint that retains exon 8 of EWSR1 require the RNA-binding protein HNRNPH1 to express in-frame EWS-FLI1.

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The use of molecularly targeted drugs as single agents has shown limited utility in many tumor types, largely due to the complex and redundant nature of oncogenic signaling networks. Targeting of the PI3K/AKT/mTOR pathway through inhibition of mTOR in combination with aromatase inhibitors has seen success in particular sub-types of breast cancer and there is a need to identify additional synergistic combinations to maximize the clinical potential of mTOR inhibitors. We have used loss-of-function RNAi screens of the mTOR inhibitor rapamycin to identify sensitizers of mTOR inhibition.

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Chromosomal copy number alterations (aneuploidy) define the genomic landscape of most cancer cells, but identification of the oncogenic drivers behind these imbalances remains an unfinished task. In this study, we conducted a systematic analysis of colorectal carcinomas that integrated genomic copy number changes and gene expression profiles. This analysis revealed 44 highly overexpressed genes mapping to localized amplicons on chromosome 13, gains of which occur often in colorectal cancers (CRC).

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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.

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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.

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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.

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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.

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Here we describe a novel strategy using multiplexes of synthetic small interfering RNAs (siRNAs) corresponding to multiple gene targets in order to compress RNA interference (RNAi) screen size. Before investigating the practical use of this strategy, we first characterized the gene-specific RNAi induced by a large subset (258 siRNAs, 129 genes) of the entire siRNA library used in this study ( approximately 800 siRNAs, approximately 400 genes). We next demonstrated that multiplexed siRNAs could silence at least six genes to the same degree as when the genes were targeted individually.

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A new species of non-coding RNA, microRNAs (miRNAs) has been identified that may regulate the expression of as many as one third to one half of all protein encoding genes. MicroRNAs are found throughout mammalian genomes, but an association between the location of these miRNAs and regions of genomic instability (or fragile sites) in humans has been suggested [1]. In this review we discuss the possible role of altered miRNA expression on human cancer and conduct an analysis correlating the physical location of murine miRNAs with sites of genetic alteration in mouse models of cancer.

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