Genes responsive to rapamycin and serum deprivation are clustered on chromosomes and undergo re-organization within local chromatin environments.

Supplementary materials are available at University of Toronto: https://tspace.library.utoronto.ca/handle/1807/9982

A prognostic index for operable, node-negative breast cancer

Clinical data and samples from patients diagnosed, more than 10 years previously, with operable node-negative breast cancer (participants in the Scottish Adjuvant Tamoxifen trial), were revisited, Cases with two distinct categories of outcome were selected; more than 10 years disease-free survival ('good outcome') or distant relapse within 6 years of diagnosis ('poor outcome'). An initial set of cases was analysed for a range of putative prognostic markers and a prognostic index, distinguishing the two outcome categories, was calculated. This index was then validated by testing its predictive power on a second, independent set of cases. A combination of histological grade plus immunochemical staining for BCL-2, p27 and Cyclin D 1, generated a useful prognostic index for tamoxifen-treated patients but not for those treated by surgery alone, The value of the index was confirmed in a second set of tamoxifen-treated, early stage breast cancers. Over-all, it correctly predicted good and poor outcome in 79 and 74% of cases, respectively (odds ratio 11.0). Other markers assessed added little to prediction of outcome. In the case of molecular assays, sensitivity and reliability were compromised by the age of the tissue specimens and the variability of fixation protocols. In selecting patients for adjuvant systemic chemotherapy, the proposed index improves considerably on current international guidelines and matches the performance reported for 'gene-expression signature' analysis. (C) 2004 Cancer Research UK.</p

The Nuclear Lamina: Protein Accumulation, Disease and Clearance

This article belongs to the Special Issue Protein Structure, Function and Dynamics in Diseases and Therapeutics© 2020 by the authors. Cellular health is reliant on proteostasis—the maintenance of protein levels regulated through multiple pathways modulating protein synthesis, degradation and clearance. Loss of proteostasis results in serious disease and is associated with aging. One proteinaceous structure underlying the nuclear envelope—the nuclear lamina—coordinates essential processes including DNA repair, genome organization and epigenetic and transcriptional regulation. Loss of proteostasis within the nuclear lamina results in accumulation of proteins, disrupting these essential functions, either via direct interactions of protein aggregates with the lamina or by altering systems that maintain lamina structure. Here we discuss the links between proteostasis and disease of the nuclear lamina, as well as how manipulating specific proteostatic pathways involved in protein clearance could improve cellular health and prevent/reverse disease.College of Graduate Studies and Postdoctoral Studies (U of S); Vanier Canada Scholarship; University of Saskatchewan Devolved Scholarship program; Alzheimer Society of Saskatchewan; the Saskatchewan Health Research Foundation; Natural Sciences and Engineering Council of Canada (NSERC); Canadian Institutes of Health Research (CIHR

Rapamycin reduces fibroblast proliferation without causing quiescence and induces STAT5A/ B-mediated cytokine production

Supplemental data for this article can be accessed on the publisher’s website.© 2015 The Author(s) & Taylor & Francis Group, LLC. Rapamycin is a well-known inhibitor of the Target of Rapamycin (TOR) signaling cascade; however, the impact of this drug on global genome function and organization in normal primary cells is poorly understood. To explore this impact, we treated primary human foreskin fibroblasts with rapamycin and observed a decrease in cell proliferation without causing cell death. Upon rapamycin treatment chromosomes 18 and 10 were repositioned to a location similar to that of fibroblasts induced into quiescence by serum reduction. Although similar changes in positioning occurred, comparative transcriptome analyses demonstrated significant divergence in gene expression patterns between rapamycin-treated and quiescence-induced fibroblasts. Rapamycin treatment induced the upregulation of cytokine genes, including those from the Interleukin (IL)-6 signaling network, such as IL-8 and the Leukemia Inhibitory Factor (LIF), while quiescent fibroblasts demonstrated up-regulation of genes involved in the complement and coagulation cascade. In addition, genes significantly up-regulated by rapamycin treatment demonstrated increased promoter occupancy of the transcription factor Signal Transducer and Activator of Transcription 5A/B (STAT5A/B). In summary, we demonstrated that the treatment of fibroblasts with rapamycin decreased proliferation, caused chromosome territory repositioning and induced STAT5A/B-mediated changes in gene expression enriched for cytokines.Brunel Progeria Research Fund (UK), Canadian Institutes of Health Research, NSERC Discovery Grant, NSERC USRA program, Royal Society Research Grant (UK), University of Saskatchewan NSERC President’s Fund, Saskatchewan Innovation and Opportunity Fund