Sir Peter MacCallum Department of Oncology - Research Publications
Now showing items 1-12 of 1381
Aspiration and severe exacerbations in COPD: a prospective study
(EUROPEAN RESPIRATORY SOC JOURNALS LTD, 2021-01-01)
Rationale: Swallow may be compromised in COPD leading to aspiration and adverse respiratory consequences. However, prevalence and consequences of detectable aspiration in stable COPD are not known. Objectives: We tested the hypothesis that a significant number of patients with stable COPD will have detectable aspiration during swallow (prandial aspiration) and that they would experience more frequent severe acute exacerbations of COPD (AECOPD) over the subsequent 12 months. Methods: Patients (n=151) with verified and stable COPD of all severities were recruited at a tertiary care hospital. Videofluoroscopy was conducted to evaluate aspiration using Rosenbek's scale for penetration-aspiration during 100-mL cup drinking. AECOPD was documented as moderate (antibiotics and/or corticosteroid treatment) or severe (emergency department admission or hospitalisation) over the ensuing 12 months. Measurements and main results: Aspiration was observed in 30 out of 151 patients (19.9%, 18 males, 12 females; mean age 72.4 years). Patients with aspiration had more overall AECOPD events (3.03 versus 2 per patient; p=0.022) and severe AECOPD episodes (0.87 versus 0.39; p=0.032). Severe AECOPD occurred in more patients with aspiration (50% of patients versus 18.2%; OR 4.5, CI 1.9-10.5; p=0.001) and with silent aspiration (36.7% versus 18.2%; OR 2.6, CI 1.1-6.2; p=0.045). Aspiration was related to a shorter exacerbation-free period during the 12-month follow-up period (p=0.038). Conclusions: Prandial aspiration is detectable in a subset of patients with COPD and was predictive of subsequent severe AECOPD. Studies to examine if the association is causal are essential to direct strategies aimed at prevention of aspiration and AECOPD.
Outcomes of cancer survivorship education and training for primary care providers: a systematic review
PURPOSE: To identify published literature regarding cancer survivorship education programs for primary care providers (PCPs) and assess their outcomes. METHODS: PubMed, Embase, and CINAHL databases were searched between January 2005 and September 2020. The Quality of Cancer Survivorship Care Framework and Kirkpatrick's 4-level evaluation model were used to summarize program content and outcomes, respectively. Data extraction and critical appraisal were conducted by two authors. RESULTS: Twenty-one studies were included, describing self-directed online courses (n=4), presentations (n=2), workshops and training sessions (n=6), placement programs (n=3), a live webinar, a fellowship program, a referral program, a survivorship conference, a dual in-person workshop and webinar, and an in-person seminar and online webinar series. Eight studies described the use of a learner framework or theory to guide program development. All 21 programs were generally beneficial to PCP learners (e.g., increased confidence, knowledge, behavior change); however, methodological bias suggests caution in accepting claims. Three studies reported positive outcomes at the patient level (i.e., satisfaction with care) and organizational level (i.e., increased screening referrals, changes to institution practice standards). CONCLUSIONS: A range of cancer survivorship PCP education programs exist. Evidence for clinical effectiveness was rarely reported. Future educational programs should be tailored to PCPs, utilize an evidence-based survivorship framework, and evaluate patient- and system-level outcomes. IMPLICATIONS FOR CANCER SURVIVORS: PCPs have an important role in addressing the diverse health care needs of cancer survivors. Improving the content, approach, and evaluation of PCP-focused cancer survivorship education programs could have a positive impact on health outcomes among cancer survivors.
Telehealth in cancer care: during and beyond the COVID-19 pandemic
The COVID-19 pandemic has precipitated the rapid uptake of telehealth in cancer care and in other fields. Many of the changes made in routine clinical practice could be embedded beyond the duration of the pandemic. This is intended as a practical guide to cancer clinicians and others in establishing and improving the quality of consultations performed by telehealth.
The DNA methylation landscape of advanced prostate cancer
(NATURE PUBLISHING GROUP, 2020-08-01)
Although DNA methylation is a key regulator of gene expression, the comprehensive methylation landscape of metastatic cancer has never been defined. Through whole-genome bisulfite sequencing paired with deep whole-genome and transcriptome sequencing of 100 castration-resistant prostate metastases, we discovered alterations affecting driver genes that were detectable only with integrated whole-genome approaches. Notably, we observed that 22% of tumors exhibited a novel epigenomic subtype associated with hypermethylation and somatic mutations in TET2, DNMT3B, IDH1 and BRAF. We also identified intergenic regions where methylation is associated with RNA expression of the oncogenic driver genes AR, MYC and ERG. Finally, we showed that differential methylation during progression preferentially occurs at somatic mutational hotspots and putative regulatory regions. This study is a large integrated study of whole-genome, whole-methylome and whole-transcriptome sequencing in metastatic cancer that provides a comprehensive overview of the important regulatory role of methylation in metastatic castration-resistant prostate cancer.
HOXA13 in etiology and oncogenic potential of Barrett's esophagus
(NATURE RESEARCH, 2021-06-07)
Barrett's esophagus in gastrointestinal reflux patients constitutes a columnar epithelium with distal characteristics, prone to progress to esophageal adenocarcinoma. HOX genes are known mediators of position-dependent morphology. Here we show HOX collinearity in the adult gut while Barrett's esophagus shows high HOXA13 expression in stem cells and their progeny. HOXA13 overexpression appears sufficient to explain both the phenotype (through downregulation of the epidermal differentiation complex) and the oncogenic potential of Barrett's esophagus. Intriguingly, employing a mouse model that contains a reporter coupled to the HOXA13 promotor we identify single HOXA13-positive cells distally from the physiological esophagus, which is mirrored in human physiology, but increased in Barrett's esophagus. Additionally, we observe that HOXA13 expression confers a competitive advantage to cells. We thus propose that Barrett's esophagus and associated esophageal adenocarcinoma is the consequence of expansion of this gastro-esophageal HOXA13-expressing compartment following epithelial injury.
Live-imaging of endothelial Erk activity reveals dynamic and sequential signalling events during regenerative angiogenesis
(ELIFE SCIENCES PUBLICATIONS LTD, 2021-05-18)
The formation of new blood vessel networks occurs via angiogenesis during development, tissue repair, and disease. Angiogenesis is regulated by intracellular endothelial signalling pathways, induced downstream of vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs). A major challenge in understanding angiogenesis is interpreting how signalling events occur dynamically within endothelial cell populations during sprouting, proliferation, and migration. Extracellular signal-regulated kinase (Erk) is a central downstream effector of Vegf-signalling and reports the signalling that drives angiogenesis. We generated a vascular Erk biosensor transgenic line in zebrafish using a kinase translocation reporter that allows live-imaging of Erk-signalling dynamics. We demonstrate the utility of this line to live-image Erk activity during physiologically relevant angiogenic events. Further, we reveal dynamic and sequential endothelial cell Erk-signalling events following blood vessel wounding. Initial signalling is dependent upon Ca2+ in the earliest responding endothelial cells, but is independent of Vegfr-signalling and local inflammation. The sustained regenerative response, however, involves a Vegfr-dependent mechanism that initiates concomitantly with the wound inflammatory response. This work reveals a highly dynamic sequence of signalling events in regenerative angiogenesis and validates a new resource for the study of vascular Erk-signalling in real-time.
A phase 2 study of momelotinib, a potent JAK1 and JAK2 inhibitor, in patients with polycythemia vera or essential thrombocythemia.
(Elsevier BV, 2017-09)
Momelotinib is a potent inhibitor of JAK1 and JAK2 that demonstrated efficacy in patients with primary and secondary myelofibrosis. This phase 2, open-label, randomized study evaluated the efficacy and safety of oral once-daily momelotinib (100mg and 200mg) for the treatment of polycythemia vera (PV) and essential thrombocythemia (ET). The primary endpoint for PV was overall response rate (ORR), defined as the proportion of patients with hematocrit <45%, white blood cell count <10×109/L, platelet count ≤400×109/L, and resolution of palpable splenomegaly, each lasting ≥4 weeks. The definition of ORR for ET excluded the hematocrit component. A total of 39 patients (28 PV, 11 ET) were enrolled, with 28 patients receiving ≥12 weeks of treatment. The study was terminated due to limited efficacy. Two patients (ORR 5.1%) met the primary efficacy endpoint (both PV 200mg). Predose plasma levels of momelotinib were stable over time. A total of 31 (79.5%) patients experienced momelotinib-related adverse events (AEs), the most frequent being headache (23.1%), dizziness (18.0%), somnolence (15.4%), nausea (15.4%), and fatigue (15.4%). Three patients experienced serious AEs (7.7%), with 1 considered related to momelotinib (dyspnea). Peripheral neuropathy occurred in 7 (17.9%) patients (4 PV, 3 ET).
High-content siRNA 3D co-cultures to identify myoepithelial cell-derived breast cancer suppressor proteins
(NATURE RESEARCH, 2021-05-28)
Understanding how cancer cells interact with the surrounding microenvironment early in breast cancer development can provide insight into the initiation and progression of invasive breast cancers. The myoepithelial cell layer surrounding breast ducts acts as a physical barrier in early breast cancer, preventing cancer cells from invading the surrounding stroma. Changes to the expression profile and properties of myoepithelial cells have been implicated in progression to invasive carcinoma. Identifying the molecular drivers of myoepithelial cell-mediated tumour suppression may offer new approaches to predict and block the earliest stages of cancer invasion. We employed a high-content approach to knock down 87 different genes using siRNA in an immortalised myoepithelial cell line, prior to co-culture with invasive breast cancer cells in 3D. Combined with high-content imaging and a customised analysis pipeline, this system was used to identify myoepithelial proteins that are necessary to control cancer cell invasion. This dataset has identified prospective myoepithelial suppressors of early breast cancer invasion which may be used by researchers to investigate their clinical validity and utility.
CRISPR/Cas9 mediated deletion of the adenosine A2A receptor enhances CAR T cell efficacy
(NATURE RESEARCH, 2021-05-28)
Adenosine is an immunosuppressive factor that limits anti-tumor immunity through the suppression of multiple immune subsets including T cells via activation of the adenosine A2A receptor (A2AR). Using both murine and human chimeric antigen receptor (CAR) T cells, here we show that targeting A2AR with a clinically relevant CRISPR/Cas9 strategy significantly enhances their in vivo efficacy, leading to improved survival of mice. Effects evoked by CRISPR/Cas9 mediated gene deletion of A2AR are superior to shRNA mediated knockdown or pharmacological blockade of A2AR. Mechanistically, human A2AR-edited CAR T cells are significantly resistant to adenosine-mediated transcriptional changes, resulting in enhanced production of cytokines including IFNγ and TNF, and increased expression of JAK-STAT signaling pathway associated genes. A2AR deficient CAR T cells are well tolerated and do not induce overt pathologies in mice, supporting the use of CRISPR/Cas9 to target A2AR for the improvement of CAR T cell function in the clinic.
Care plus study: a multi-site implementation of early palliative care in routine practice to improve health outcomes and reduce hospital admissions for people with advanced cancer: a study protocol
BACKGROUND: Current international consensus is that 'early' referral to palliative care services improves cancer patient and family carer outcomes. In practice, however, these referrals are not routine. An approach which directly addresses identified barriers to early integration of palliative care is required. This protocol details a trial of a standardized model of early palliative care (Care Plus) introduced at key defined, disease-specific times or transition points in the illness for people with cancer. Introduced as a 'whole of system' practice change for identified advanced cancers, the key outcomes of interest are population health service use change. The aims of the study are to examine the effect of Care Plus implementation on (1) acute hospitalisation days in the last 3 months of life; (2) timeliness of access to palliative care; (3) quality and (4) costs of end of life care; and (5) the acceptability of services for people with advanced cancer. METHODS: Multi-site stepped wedge implementation trial testing usual care (control) versus Care Plus (practice change). The design stipulates 'control' periods when usual care is observed, and the process of implementing Care Plus which includes phases of planning, engagement, practice change and evaluation. During the practice change phase, all patients with targeted advanced cancers reaching the transition point will, by default, receive Care Plus. Health service utilization and unit costs before and after implementation will be collated from hospital records, and state and national health service administrative datasets. Qualitative data from patients, consumers and clinicians before and after practice change will be gathered through interviews and focus groups. DISCUSSION: The study outcomes will detail the impact and acceptability of the standardized integration of palliative care as a practice change, including recommendations for ongoing sustainability and broader implementation. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN 12619001703190 . Registered 04 December 2019.
BRD4 methylation by the methyltransferase SETD6 regulates selective transcription to control mRNA translation
(AMER ASSOC ADVANCEMENT SCIENCE, 2021-05-01)
The transcriptional coactivator BRD4 has a fundamental role in transcription regulation and thus became a promising epigenetic therapeutic candidate to target diverse pathologies. However, the regulation of BRD4 by posttranslational modifications has been largely unexplored. Here, we show that BRD4 is methylated on chromatin at lysine-99 by the protein lysine methyltransferase SETD6. BRD4 methylation negatively regulates the expression of genes that are involved in translation and inhibits total mRNA translation in cells. Mechanistically, we provide evidence that supports a model where BRD4 methylation by SETD6 does not have a direct role in the association with acetylated histone H4 at chromatin. However, this methylation specifically determines the recruitment of the transcription factor E2F1 to selected target genes that are involved in mRNA translation. Together, our findings reveal a previously unknown molecular mechanism for BRD4 methylation-dependent gene-specific targeting, which may serve as a new direction for the development of therapeutic applications.