Publications by authors named "Chirgwin J"

Purpose Of Review: To describe the contributions of osteocytes to the lesions in Paget's disease, which are characterized by locally overactive bone resorption and formation.

Recent Findings: Osteocytes, the most abundant cells in bone, are altered in Paget's disease lesions, displaying increased size, decreased canalicular length, incomplete differentiation, and less sclerostin expression compared to controls in both patients and mouse models. Pagetic lesions show increased senescent osteocytes that express RANK ligand, which drives osteoclastic bone resorption.

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Multiple myeloma (MM) is a malignancy of plasma cells whose antibody secretion creates proteotoxic stress relieved by the N-end rule pathway, a proteolytic system that degrades N-arginylated proteins in the proteasome. When the proteasome is inhibited, protein cargo is alternatively targeted for autophagic degradation by binding to the ZZ-domain of p62/ sequestosome-1. Here, we demonstrate that XRK3F2, a selective ligand for the ZZ-domain, dramatically improved two major responses to the proteasome inhibitor bortezomib (Btz) by increasing: i) killing of human MM cells by stimulating both Btz-mediated apoptosis and necroptosis, a process regulated by p62; and ii) preservation of bone mass by stimulating osteoblast differentiation and inhibiting osteoclastic bone destruction.

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In this work, we describe an interprofessional healthcare symposium driven by the challenges faced by the local asylum-seeking/refugee population in Montreal. McGill University medical, nursing, dietetics, and social work students partnered with local experts to provide attendees with tools to better meet the needs of Montreal's migrant population. This student-led initiative, unique in its interdisciplinary and comprehensive nature, increased awareness of the needs of an underserved population while promoting student engagement in health advocacy and interprofessional collaboration.

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We previously reported that measles virus nucleocapsid protein (MVNP) expression in osteoclasts (OCLs) of patients with Paget disease (PD) or targeted to the OCL lineage in MVNP-transgenic mice (MVNP mice) increases IGF1 production in osteoclasts (OCL-IGF1) and leads to development of PD OCLs and pagetic bone lesions (PDLs). Conditional deletion of Igf1 in OCLs of MVNP mice fully blocked development of PDLs. In this study, we examined whether osteocytes (OCys), key regulators of normal bone remodeling, contribute to PD.

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Background: Late recurrences in postmenopausal women with hormone receptor-positive breast cancers remain an important challenge. Avoidance or delayed development of resistance represents the main objective in extended endocrine therapy (ET). In animal models, resistance was reversed with restoration of circulating estrogen levels during interruption of letrozole treatment.

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Purpose: Women with hormone receptor-positive early breast cancers have a persistent risk of relapse and biomarkers for late recurrence are needed. We sought to identify tumor genomic aberrations associated with increased late-recurrence risk.

Experimental Design: In a secondary analysis of Study of Letrozole Extension trial, a case-cohort-like sampling selected 598 primary breast cancers for targeted next-generation sequencing analysis of gene mutations and copy-number gains (CNGs).

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Purpose: Sexual dysfunction is an important concern of premenopausal women with early breast cancer. We investigated predictors of sexual problems in two randomized controlled trials.

Methods: A subset of patients enrolled in TEXT and SOFT completed global and symptom-specific quality-of-life indicators, CES-Depression and MOS-Sexual Problems measures at baseline, six, 12 and 24 months.

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We report that transgenic mice expressing measles virus nucleocapsid protein (MVNP) in osteoclasts (OCLs) (MVNP mice) are Paget's disease (PD) models and that OCLs from patients with PD and MVNP mice express high levels of OCL-derived IGF1 (OCL-IGF1). To determine OCL-IGF1's role in PD and normal bone remodeling, we generated WT and MVNP mice with targeted deletion of Igf1 in OCLs (Igf1-cKO) and MVNP/Igf1-cKO mice, and we assessed OCL-IGF1's effects on bone mass, bone formation rate, EphB2/EphB4 expression on OCLs and osteoblasts (OBs), and pagetic bone lesions (PDLs). A total of 40% of MVNP mice, but no MVNP/Igf1-cKO mice, had PDLs.

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Background: Smartphone technology represents an opportunity to deliver practical solutions for people affected by cancer at a scale that was previously unimaginable, such as information, appointment monitoring, and improved access to cancer support services. This study aimed to determine whether a smartphone application (app) reduced the unmet needs among people newly diagnosed with cancer.

Methods: A single blind, multisite randomized controlled trial to determine the impact of an app-based, 4-month intervention.

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Background: In the phase III SOLE trial, the extended use of intermittent versus continuous letrozole for 5 years did not improve disease-free survival in postmenopausal women with hormone receptor-positive breast cancer. Intermittent therapy with 3-month breaks may be beneficial for patients' quality of life (QoL).

Methods: In the SOLE QoL sub-study, 956 patients completed the Breast Cancer Prevention Trial (BCPT) symptom and further QoL scales up to 24 months after randomisation.

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Bone is a common site of metastasis for breast, prostate, lung, kidney and other cancers. Bone metastases are incurable, and substantially reduce patient quality of life. To date, there exists no small-molecule therapeutic agent that can reduce tumor burden in bone.

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Objectives: Industry-supported decision impact studies demonstrate that Oncotype Dx (ODX) changes treatment recommendations (TR) in 24-40% of hormone receptor+/HER2- patients. ODX is not reimbursed by third-party payers in Australia, potentially resulting in more selective use. We sought to evaluate the impact of self-funded ODX on TRs.

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Semaphorin 4D (Sema4D; CD100) is a transmembrane homodimer 150-kDa glycoprotein member of the Semaphorin family. Semaphorins were first identified as chemorepellants that guide neural axon growth. Sema4D also possesses immune regulatory activity.

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Background: Informal caregivers provide extended support to people with cancer but they receive little support from the health care system to assist them in their caring role. The aim of this single-blind, multi-centre, randomised controlled trial was to test the efficacy of a telephone outcall program to reduce caregiver burden and unmet needs, and improve psychological well-being among cancer caregivers, as well as evaluating the potential impact on patient outcomes.

Methods: Cancer patient/caregiver dyads (N = 216) were randomised to a telephone outcall program (n = 108) or attention control group (n = 108).

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Caregivers have been largely neglected in health literacy measurement. We assess the construct validity, and internal consistency of the Health Literacy of Caregivers Scale-Cancer (HLCS-C), and present a revised, psychometrically robust scale. Using data from 297 cancer caregivers (12.

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Background: In animal models of breast cancer, resistance to continuous use of letrozole can be reversed by withdrawal and reintroduction of letrozole. We therefore hypothesised that extended intermittent use of adjuvant letrozole would improve breast cancer outcome compared with continuous use of letrozole in postmenopausal women.

Methods: We did the multicentre, open-label, randomised, parallel, phase 3 SOLE trial in 240 centres (academic, primary, secondary, and tertiary care centres) in 22 countries.

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More efficient therapies that target multiple molecular mechanisms are needed for the treatment of incurable bone metastases. Halofuginone is a plant alkaloid-derivative with antiangiogenic and antiproliferative effects. Here we demonstrate that halofuginone is an effective therapy for the treatment of bone metastases, through multiple actions that include inhibition of TGFβ and BMP-signaling.

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Multiple myeloma is incurable once osteolytic lesions have seeded at skeletal sites, but factors mediating this deadly pathogenic advance remain poorly understood. Here, we report evidence of a major role for the cell adhesion molecule CD166, which we discovered to be highly expressed in multiple myeloma cell lines and primary bone marrow cells from patients. CD166 multiple myeloma cells homed more efficiently than CD166 cells to the bone marrow of engrafted immunodeficient NSG mice.

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Purpose: To evaluate the benefit of low-dose cyclophosphamide and methotrexate (CM) maintenance, which previously demonstrated antitumor activity and few adverse effects in advanced breast cancer, in early breast cancer.

Patients And Methods: International Breast Cancer Study Group (IBCSG) Trial 22-00, a randomized phase III clinical trial, enrolled 1,086 women (1,081 intent-to-treat) from November 2000 to December 2012. Women with estrogen receptor- and progesterone receptor-negative (< 10% positive cells by immunohistochemistry) early breast cancer any nodal and human epidermal growth factor receptor 2 status, were randomly assigned anytime between primary surgery and 56 days after the first day of last course of adjuvant chemotherapy to CM maintenance (cyclophosphamide 50 mg/day orally continuously and methotrexate 2.

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Purpose: To investigate adherence to endocrine treatment and its relationship with disease-free survival (DFS) in the Breast International Group (BIG) 1-98 clinical trial.

Methods: The BIG 1-98 trial is a double-blind trial that randomly assigned 6,193 postmenopausal women with hormone receptor-positive early breast cancer in the four-arm option to 5 years of tamoxifen (Tam), letrozole (Let), or the agents in sequence (Let-Tam, Tam-Let). This analysis included 6,144 women who received at least one dose of study treatment.

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In multiple myeloma, an overabundance of monoclonal plasma cells in the bone marrow induces localized osteolytic lesions that rarely heal due to increased bone resorption and suppressed bone formation. Matrix-embedded osteocytes comprise more than 95% of bone cells and are major regulators of osteoclast and osteoblast activity, but their contribution to multiple myeloma growth and bone disease is unknown. Here, we report that osteocytes in a mouse model of human MM physically interact with multiple myeloma cells in vivo, undergo caspase-3-dependent apoptosis, and express higher RANKL (TNFSF11) and sclerostin levels than osteocytes in control mice.

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Background: Aromatase inhibitor induced musculoskeletal syndrome is experienced by approximately half of women taking aromatase inhibitors, impairing quality of life and leading some to discontinue treatment. Evidence for effective treatments is lacking. We aimed to understand the manifestations and impact of this syndrome in the Australian breast cancer community, and strategies used for its management.

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Aims: The aims of this analysis were to examine levels of unmet needs and depression among carers of people newly diagnosed with cancer and to identify groups who may be at higher risk, by examining relationships with demographic characteristics.

Methods: One hundred and fifty dyads of people newly diagnosed with cancer and their carers, aged 18 years and older, were recruited from four Australian hospitals. People with cancer receiving adjuvant cancer treatment with curative intent, were eligible to participate.

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