Efficacy and cost-effectiveness of an outcall program to reduce carer burden and depression among carers of cancer patients (PROTECT) : rationale and design of a randomized controlled trial

Published: 6 January 2014BACKGROUND: Carers provide extended and often unrecognized support to people with cancer. The aim of this study is to test the hypothesis that excessive carer burden is modifiable through a telephone outcall intervention that includes supportive care, information and referral to appropriate psycho-social services. Secondary aims include estimation of changes in psychological health and quality of life. The study will determine whether the intervention reduces unmet needs among patient dyads. A formal economic program will also be conducted. METHODS/DESIGN: This study is a single-blind, multi-centre, randomized controlled trial to determine the efficacy and cost-efficacy of a telephone outcall program among carers of newly diagnosed cancer patients. A total of 230 carer/patient dyads will be recruited into the study; following written consent, carers will be randomly allocated to either the outcall intervention program (n = 115) or to a minimal outcall / attention control service (n = 115). Carer assessments will occur at baseline, at one and six months post-intervention. The primary outcome is change in carer burden; the secondary outcomes are change in carer depression, quality of life, health literacy and unmet needs. The trial patients will be assessed at baseline and one month post-intervention to determine depression levels and unmet needs. The economic analysis will include perspectives of both the health care sector and broader society and comprise a cost-consequences analysis where all outcomes will be compared to costs. DISCUSSION: This study will contribute to our understanding on the potential impact of a telephone outcall program on carer burden and provide new evidence on an approach for improving the wellbeing of carers.Patricia M Livingston, Richard H Osborne, Mari Botti, Cathy Mihalopoulos, Sean McGuigan, Leila Heckel, Kate Gunn, Jacquie Chirgwin, David M Ashley and Melinda William

Targeting DNA Damage Response and Replication Stress in Pancreatic Cancer

Background and aims: Continuing recalcitrance to therapy cements pancreatic cancer (PC) as the most lethal malignancy, which is set to become the second leading cause of cancer death in our society. The study aim was to investigate the association between DNA damage response (DDR), replication stress and novel therapeutic response in PC to develop a biomarker driven therapeutic strategy targeting DDR and replication stress in PC. Methods: We interrogated the transcriptome, genome, proteome and functional characteristics of 61 novel PC patient-derived cell lines to define novel therapeutic strategies targeting DDR and replication stress. Validation was done in patient derived xenografts and human PC organoids. Results: Patient-derived cell lines faithfully recapitulate the epithelial component of pancreatic tumors including previously described molecular subtypes. Biomarkers of DDR deficiency, including a novel signature of homologous recombination deficiency, co-segregates with response to platinum (P < 0.001) and PARP inhibitor therapy (P < 0.001) in vitro and in vivo. We generated a novel signature of replication stress with which predicts response to ATR (P < 0.018) and WEE1 inhibitor (P < 0.029) treatment in both cell lines and human PC organoids. Replication stress was enriched in the squamous subtype of PC (P < 0.001) but not associated with DDR deficiency. Conclusions: Replication stress and DDR deficiency are independent of each other, creating opportunities for therapy in DDR proficient PC, and post-platinum therapy

Breast-cancer-secreted miR-122 reprograms glucose metabolism in premetastatic niche to promote metastasis

Reprogrammed glucose metabolism as a result of increased glycolysis and glucose uptake is a hallmark of cancer. Here we show that cancer cells can suppress glucose uptake by non-tumour cells in the pre-metastatic niche, by secreting vesicles that carry high levels of the miR-122 microRNA. High miR-122 levels in the circulation have been associated with metastasis in breast cancer patients and we show that cancer-cell-secreted miR-122 facilitates metastasis by increasing nutrient availability in the pre-metastatic niche. Mechanistically cancer-cell-derived miR-122 suppresses glucose uptake by niche cells in vitro and in vivo by downregulating the glycolytic enzyme pyruvate kinase (PKM). In vivo inhibition of miR-122 restores glucose uptake in distant organs, including brain and lungs, and decreases the incidence of metastasis. These results demonstrate that by modifying glucose utilization by recipient pre-metastatic niche cells, cancer-derived extracellular miR-122 is able to reprogram systemic energy metabolism to facilitate disease progression

Assortative mating biases marker-based heritability estimators

Many traits are subject to assortative mating, with recent molecular genetic findings confirming longstanding theoretical predictions that assortative mating induces long range dependence across causal variants. However, all marker-based heritability estimators implicitly assume mating is random. We provide mathematical and simulation-based evidence demonstrating that both method-of-moments and likelihood-based estimators are biased in the presence of assortative mating and derive corrected heritability estimators for traits subject to assortment. Finally, we demonstrate that the empirical patterns of estimates across methods and sample sizes for real traits subject to assortative mating are congruent with expected assortative mating-induced biases. For example, marker-based heritability estimates for height are 14% - 23% higher than corrected estimates using UK Biobank data

Cep192 Controls the Balance of Centrosome and Non-Centrosomal Microtubules during Interphase

<div><p>Cep192 is a centrosomal protein that contributes to the formation and function of the mitotic spindle in mammalian cells. Cep192’s mitotic activities stem largely from its role in the recruitment to the centrosome of numerous additional proteins such as gamma-tubulin and Pericentrin. Here, we examine Cep192’s function in interphase cells. Our data indicate that, as in mitosis, Cep192 stimulates the nucleation of centrosomal microtubules thereby regulating the morphology of interphase microtubule arrays. Interestingly, however, cells lacking Cep192 remain capable of generating normal levels of MTs as the loss of centrosomal microtubules is augmented by MT nucleation from other sites, most notably the Golgi apparatus. The depletion of Cep192 results in a significant decrease in the level of centrosome-associated gamma-tubulin, likely explaining its impact on centrosome microtubule nucleation. However, in stark contrast to mitosis, Cep192 appears to maintain an antagonistic relationship with Pericentrin at interphase centrosomes. Interphase cells depleted of Cep192 display significantly higher levels of centrosome-associated Pericentrin while overexpression of Cep192 reduces the levels of centrosomal Pericentrin. Conversely, depletion of Pericentrin results in elevated levels of centrosomal Cep192 and enhances microtubule nucleation at centrosomes, at least during interphase. Finally, we show that depletion of Cep192 negatively impacts cell motility and alters normal cell polarization. Our current working hypothesis is that the microtubule nucleating capacity of the interphase centrosome is determined by an antagonistic balance of Cep192, which promotes nucleation, and Pericentrin, which inhibits nucleation. This in turn determines the relative abundance of centrosomal and non-centrosomal microtubules that tune cell movement and shape.</p></div

Cep192 is required for efficient polarization and cell migration.

<p>A) Phase-contrast images from a 2-D scratch assay performed on control Cep192 siRNA treated U2OS cells. U2OS cells were plated into Ibidi Culture-Insert dishes following siRNA treatment and the cell-free zone was generated by removing the insert. B) Quantification of the efficiency at which control and Cep192 siRNA-treated cells moved into the cell-free zone (determined by measuring the cell free area at the indicated timepoint). Vertical bars represent S.E.M. P<0.0001. N = 3 experiments per condition.</p

MT nucleation following Ice Depolymerization in Cep192-2 Flp-In T-Rex U2OS cells.

<p>A) Following 40 minutes of ice depolymerization, cells were incubated in 37°C media for 30 seconds to allow regrowth. Cells were fixed and stained with EB1 and Cep192. B) Following Cep192 depletion fewer MTs regrew(6.0±0.297 MTs/centrosome) than in controls (11.0±0.319 MTs/centrosome). Induction of Cep192-2 rescued the MT nucleating capacity (12.3±0.611 MTs/centrosome) of the centrosome to control levels. Depletion of Pericentrin lead to a significant increase in the number of MTs attached to the centrosome (16.4±1.54) relative to controls. Vertical bars represent S.E.M. P values are <0.001, P = 0.0691, and P = 0.0096, respectively. N≥14 cells per experiment from 3 independent experiments per condition.</p

Cep192 depletion increases extra-centrosomal MT growth in RPE1 Centrin-GFP cells.

<p>A) MT regrowth after ice depolymerization was used to quantify the relative proportion of MTs nucleated from centrosomal and extra-centrosomal sites. The images in this panel are immunofluorescence micrographs of control and Cep192 siRNA treated RPE1 triple-labeled for MTs, the Golgi marker GM130, and Centrin (Centrin is GFP-tagged). After 25 seconds of MT regrowth, control cells contained an average of 1.57 MTs/cell non-centrosomal MTs (neither end attached to the centrosome), while Cep192 depleted cells contained an average of 4.05 non-centrosomal MTs. Vertical bars represent S.E.M. P = 0.0002. N≥28 cells per experiment from 3 independent experiments.</p

Optimized siRNA-mediated knockdown of Cep192.

<p>A) Western blot of control and Cep192 siRNA-treated U2OS cell lysates probed with anti-Cep192 and GAPDH (loading control) antibodies. Densitometry measurements using ImageJ indicated a significant (98%) decrease in Cep192 after siRNA treatment; P<0.0001. Values quantified from 3 separate blots. B) Quantitative immunofluorescence analysis revealed a >90% decrease in centrosome-associated Cep192 staining after siRNA treatment. Vertical bars represent S.E.M. P value <0.0001. N≥37 centrosomes per experiment from 3 independent experiments. C) Immunofluorescence micrographs of control and Cep192 siRNA-treated U2OS cells (72 hours after siRNA treatment) double-labeled for Cep192 (green) and MTs (red). Controls showed robust radial arrays of centrosome-associated MTs arrays while siRNA-treated cells were devoid of Cep192 staining and displayed predominantly non-radial MT arrangements.</p