The potential for carbon dioxide removal by enhanced rock weathering in the tropics: An evaluation of Costa Rica

Tropical environments show great potential to sequester CO2 by enhanced rock weathering (ERW) of powdered mafic rocks applied to agricultural fields. This study seeks to assess carbon dioxide reduction (CDR) potential in the humid tropics (1) by experimental weathering of mafic rock powders in conditions simulating humid tropical soils, and (2) from weathering rates determined from a Holocene tropical soil chronosequence where parent material is andesitic sediments. Experimentally determined weathering rates by leaching of basaltic andesites from Costa Rica (Arenal and Barva) for 50 t ha-1 applications indicate potential sequestration of 2.4 to 4.5 t CO2 ha-1 yr-1, whereas the USGS basalt standard BHVO-1 yields a rate of 11.9 t ha-1 yr-1 (influenced by more mafic composition and finer particle size). The chronosequence indicates a rate of 1.7 t CO2 ha-1 yr-1. The weathering experiment consisted of 0.6 mm of powdered rock applied atop 12 mm of Ultisol at 35 °C. To simulate a tropical soil solution, 100-mL aliquots of a dilute solution of oxalic acid in carbonated DI water were rained onto soils over a 14-day period to simulate soil moisture in the humid tropics. Solutions were collected and analyzed by ICPMS for concentrations of leached cations. A potential ERW scenario for Costa Rica was assessed assuming that one-half of lowland agricultural kaolinitic soils (mainly Ultisols, common crop and pasture soils, excluding protected areas) were to receive 50 t ha-1 of annual or biennial applications of powdered mafic rock. With an experimentally determined humid tropical CDR rate for basaltic andesite (3.5 t ha-1 yr-1) and allowances for carbon costs (e.g. emissions from processing and delivery) that reduce CDR to a net 3.2 t ha-1 yr-1, potential annual CDR of this tropical nation is ∼2-4 million tons, amounting to ∼25-50 % of annual CO2 emissions (mainly from transportation in Costa Rica).

From little things big things grow: enhancement of an acoustic telemetry network to monitor broad-scale movements of marine species along Australia's east coast

BACKGROUND

Acoustic telemetry has become a fundamental tool to monitor the movement of aquatic species. Advances in technology, in particular the development of batteries with lives of > 10 years, have increased our ability to track the long-term movement patterns of many species. However, logistics and financial constraints often dictate the locations and deployment duration of acoustic receivers. Consequently, there is often a compromise between optimal array design and affordability. Such constraints can hinder the ability to track marine animals over large spatial and temporal scales. Continental-scale receiver networks have increased the ability to study large-scale movements, but significant gaps in coverage often remain.

METHODS

Since 2007, the Integrated Marine Observing System's Animal Tracking Facility (IMOS ATF) has maintained permanent receiver installations on the eastern Australian seaboard. In this study, we present the recent enhancement of the IMOS ATF acoustic tracking infrastructure in Queensland to collect data on large-scale movements of marine species in the northeast extent of the national array. Securing a relatively small initial investment for expanding receiver deployment and tagging activities in Queensland served as a catalyst, bringing together a diverse group of stakeholders (research institutes, universities, government departments, port corporations, industries, Indigenous ranger groups and tourism operators) to create an extensive collaborative network that could sustain the extended receiver coverage into the future. To fill gaps between existing installations and maximise the monitoring footprint, the new initiative has an atypical design, deploying many single receivers spread across 2,100 km of Queensland waters.

RESULTS

The approach revealed previously unknown broad-scale movements for some species and highlights that clusters of receivers are not always required to enhance data collection. However, array designs using predominantly single receiver deployments are more vulnerable to data gaps when receivers are lost or fail, and therefore "redundancy" is a critical consideration when designing this type of array.

CONCLUSION

Initial results suggest that our array enhancement, if sustained over many years, will uncover a range of previously unknown movements that will assist in addressing ecological, fisheries, and conservation questions for multiple species.

Measurement properties of the WHO Disability Assessment Schedule 2.0 for evaluating functional status after inpatient surgery

BACKGROUND

Expert recommendations propose the WHO Disability Assessment Schedule (WHODAS) 2.0 as a core outcome measure in surgical studies, yet data on its long-term measurement properties remain limited. These were evaluated in a secondary analysis of the Measurement of Exercise Tolerance before Surgery (METS) prospective cohort.

METHODS

Participants were adults (40 years of age or older) who underwent inpatient non-cardiac surgery. The 12-item WHODAS and EQ-5DTM-3L questionnaires were administered preoperatively (in person) and 1 year postoperatively (by telephone). Responsiveness was characterized using standardized response means (SRMs) and correlation coefficients between change scores. Construct validity was evaluated using correlation coefficients between 1-year scores and comparisons of WHODAS scores across clinically relevant subgroups.

RESULTS

The analysis included 546 patients. There was moderate correlation between changes in WHODAS and various EQ-5DTM subscales. The strongest correlation was between changes in WHODAS and changes in the functional domains of the EQ-5D-3L-for example, mobility (Spearman's rho 0.40, 95 per cent confidence interval [c.i.] 0.32 to 0.48) and usual activities (rho 0.45, 95 per cent c.i. 0.30 to 0.52). When compared across quartiles of EQ-5D index change, median WHODAS scores followed expected patterns of change. In subgroups with expected functional status changes, the WHODAS SRMs ranged from 'small' to 'large' in the expected directions of change. At 1 year, the WHODAS demonstrated convergence with the EQ-5D-3L functional domains, and good discrimination between patients with expected differences in functional status.

CONCLUSION

The WHODAS questionnaire has construct validity and responsiveness as a measure of functional status at 1 year after major surgery.

A Compound Heterozygous Mutation in Calpain 1 Identifies a New Genetic Cause for Spinal Muscular Atrophy Type 4 (SMA4)

Spinal Muscular Atrophy (SMA) is a heterogeneous group of neuromuscular diseases characterized by degeneration of anterior horn cells of the spinal cord, leading to muscular atrophy and weakness. Although the major cause of SMA is autosomal recessive exon deletions or loss-of-function mutations of survival motor neuron 1 (SMN1) gene, next generation sequencing technologies are increasing the genetic heterogeneity of SMA. SMA type 4 (SMA4) is an adult onset, less severe form of SMA for which genetic and pathogenic causes remain elusive.Whole exome sequencing in a 30-year-old brother and sister with SMA4 identified a compound heterozygous mutation (p. G492R/p. F610C) in calpain-1 (CAPN1). Mutations in CAPN1 have been previously associated with cerebellar ataxia and hereditary spastic paraplegia. Using skin fibroblasts from a patient bearing the p. G492R/p. F610C mutation, we demonstrate reduced levels of CAPN1 protein and protease activity. Functional characterization of the SMA4 fibroblasts revealed no changes in SMN protein levels and subcellular distribution. Additional cellular pathways associated with SMA remain unaffected in the patient fibroblasts, highlighting the tissue specificity of CAPN1 dysfunction in SMA4 pathophysiology. This study provides genetic and functional evidence of CAPN1 as a novel gene for the SMA4 phenotype and expands the phenotype of CAPN1 mutation disorders.

Experiences of Inuit in Canada who travel from remote settings for cancer care and impacts on decision making

BACKGROUND

Inuit experience the highest cancer mortality rates from lung cancer in the world with increasing rates of other cancers in addition to other significant health burdens. Inuit who live in remote areas must often travel thousands of kilometers to large urban centres in southern Canada and negotiate complex and sometimes unwelcoming health care systems. There is an urgent need to improve Inuit access to and use of health care. Our study objective was to understand the experiences of Inuit in Canada who travel from a remote to an urban setting for cancer care, and the impacts on their opportunities to participate in decisions during their journey to receive cancer care.

METHODS

We are an interdisciplinary team of Steering Committee and researcher partners ("the team") from Inuit-led and/or -specific organizations that span Nunavut and the Ontario cancer health systems. Guided by Inuit societal values, we used an integrated knowledge translation (KT) approach with qualitative methods. We conducted semi-structured interviews with Inuit participants and used process mapping and thematic analysis.

RESULTS

We mapped the journey to receive cancer care and related the findings of client (n = 8) and medical escort (n = 6) ("participant") interviews in four themes: 1) It is hard to take part in decisions about getting health care; 2) No one explains the decisions you will need to make; 3) There is a duty to make decisions that support family and community; 4) The lack of knowledge impacts opportunities to engage in decision making. Participants described themselves as directed, with little or no support, and seeking opportunities to collaborate with others on the journey to receive cancer care.

CONCLUSIONS

We describe the journey to receive cancer care as a "decision chain" which can be described as a series of events that lead to receiving cancer care. We identify points in the decision chain that could better prepare Inuit to participate in decisions related to their cancer care. We propose that there are opportunities to build further health care system capacity to support Inuit and enable their participation in decisions related to their cancer care while upholding and incorporating Inuit knowledge.

Physical performance is enhanced in old mice fed a short term diet medicated with rapamycin, acarbose, and phenylbutyrate

Loss of physical performance, as seen in humans by decreased grip strength and overall physical fitness, is generally accepted to be a consequence of aging. Treatments to delay or reduce these changes or increase resilience to them are generally not available. In this preliminary study, 20-month-old male and female C57BL/6 mice were given either a standard mouse diet or a formulated mouse diet containing rapamycin (14 ppm), acarbose (1000 ppm), and phenylbutyrate (1000 ppm), or a diet containing one half dose of each drug, for 3 months. At the end of the study, performance on a rotarod and grip strength test was compared. In general, mice fed the full dose drug cocktail diet performed better on these assays, with significant improvements in rotarod performance in females fed the full dose cocktail and in grip strength in males fed the full dose cocktail, and females fed the low dose cocktail. These observations provide support for the concept that short term treatment with a cocktail of drugs that targets multiple aging pathways can increase resilience to aging, and suggests that this prototype cocktail could be part of a clinical therapeutic strategy for delaying age-related loss of physical performance in people.

Identifying the nature and extent of public and donor concern about the commercialisation of biobanks for genomic research

Various forms of private investment are considered necessary for the sustainability of biobanks, yet pose significant challenges to public trust. To manage this tension, it is vital to identify the concerns of relevant stakeholders to ensure effective and acceptable policy and practice. This research examines the aspects of commercialisation that are of most concern to the Australian public (n = 800) and patients who had donated their tissue to two large disease specific (cancer) public biobanks (n = 564). Overall, we found a commercialisation effect (higher support for public relative to private) in relation to funding, research location and access to stored biospecimens. The effect was strongest for research locations and access compared to funding. A latent class analysis revealed the pattern of concern differed, with the majority (34.1%) opposing all aspects of commercialisation, a minority supporting all (15.7%), one quarter (26.8%) opposing some (sharing and selling tissue) but not others (research locations and funding), and a group who were unsure about most aspects but opposed selling tissue (23.5%). Patient donors were found to be more accepting of and unsure about most aspects of commercialisation. Members of the (general) public who were motivated to participate in biobanking were more likely to oppose some aspects while supporting others, while those who indicated they would not donate to a biobank were more likely to oppose all aspects of commercialisation. The results suggest that approaches to policy, engagement and awareness raising need to be tailored for different publics and patient groups to increase participation.

"Always Events® "… just another quality improvement tool … or is it?

INTRODUCTION

Always Events® are defined as "those aspects of the care experience that should always occur when patients, their family members or other care partners, and service users interact with health care professionals and the health care system". It is a quality improvement methodology that starts by asking our patients the simple question "what matters to you?" and then through coproduction, works out a way to achieve this.

METHODS AND RESULTS

This article tells our story and highlights the value of undertaking an Always Event® within the Radiology department at Warrington and Halton Hospitals. It will demonstrate how this approach combines research, an evaluation of findings and implementation of those findings within a very short timeframe. Embedded within the article are comments from our staff, volunteers and patients which reflect upon their experiences, our limitations, the outcomes we achieved and the impact it has had upon our patients and staff.

CONCLUSION AND IMPLICATIONS FOR PRACTICE

It was important to our patients that they would be informed of how long they would wait for their examination once they booked in at x-ray reception. By undertaking an Always Event® this process is now embedded in our departments everyday activities with over 90% of our patients now being informed of their waiting time. This continued collaboration has really emphasised the value of listening to our patients, and the benefits this can lead to. It has also encouraged a positive research culture within our department (optimisation studies, working with industry, quality projects), helping to progress our profession and resulting in a quality service for our patients.

Energy metabolism and mitochondrial defects in X-linked Charcot-Marie-Tooth (CMTX6) iPSC-derived motor neurons with the p.R158H PDK3 mutation

Charcot-Marie-Tooth (CMT) is a group of inherited diseases clinically and genetically heterogenous, characterised by length dependent degeneration of axons of the peripheral nervous system. A missense mutation (p.R158H) in the pyruvate dehydrogenase kinase 3 gene (PDK3) has been identified as the genetic cause for an X-linked form of CMT (CMTX6) in two unrelated families. PDK3 is one of four PDK isoenzymes that regulate the activity of the pyruvate dehydrogenase complex (PDC). The balance between kinases (PDKs) and phosphatases (PDPs) determines the extend of oxidative decarboxylation of pyruvate to generate acetyl CoA, critically linking glycolysis and the energy producing Krebs cycle. We had shown the p.R158H mutation causes hyperactivity of PDK3 and CMTX6 fibroblasts show hyperphosphorylation of PDC, leading to reduced PDC activity and ATP production. In this manuscript we have generated induced pluripotent stem cells (iPSCs) by re-programming CMTX6 fibroblasts (iPSC^CMTX6). We also have engineered an isogenic control (iPSC^isogenic) and demonstrated that genetic correction of the p.R158H mutation reverses the CMTX6 phenotype. Patient-derived motor neurons (MN^CMTX6) show increased phosphorylation of the PDC, energy metabolism defects and mitochondrial abnormalities, including reduced velocity of trafficking mitochondria in the affected axons. Treatment of the MN^CMTX6 with a PDK inhibitor reverses PDC hyperphosphorylation and the associated functional deficits founds in the patient motor neurons, demonstrating that the MN^CMTX6 and MN^isogenic motor neurons provide an excellent neuronal system for compound screening approaches to identify drugs for the treatment of CMTX6.

MIS Distal Metatarsal Metaphyseal Osteotomy in the treatment of metatarsalgia: MOXFQ patient reported outcomes

INTRODUCTION

The aim of this paper is to present validated patient reported outcomes for MIS Distal Metatarsal Metaphyseal Osteotomy (DMMO) in the treatment of metatarsalgia. The study aims to evaluate the DMMO procedure, report patient satisfaction with the operated foot and report any complications of this procedure.

PATIENTS AND METHODS

Between 2014 and 2016, patients who had failed conservative treatment for metatarsalgia were identified in the orthopaedic outpatient clinic. Twenty four consecutive patients requiring DMMO plus/minus toe straightening were prospectively studied. Patients requiring additional procedures at the time of surgery were excluded. Patients completed the validated Manchester-Oxford Foot Questionnaire (MOXFQ) three weeks pre-operatively and 1 year postoperatively. The MOXFQ results were analysed using Paired t-tests. A supplementary question was asked regarding patient satisfaction with the operated foot.

RESULTS

There were 20 women and 4 men with a mean age of 64 years (sd 8.6). Statistically significant differences were found between the pre and postoperative MOXFQ. The postoperative MOXFQ score demonstrated a poorer result for two patients, no change for two patients and improvement in 20 patients, with four of these patients recording the lowest possible score. There was a 29.5 point improvement in mean metric MOXFQ Index score. Seventy-nine percent (n = 19) of patients were satisfied or very satisfied with the operated foot. The average recoil of the metatarsal heads following DMMO was M2 4.01 mm, M3 4.55 mm, M4 4.16 mm. There was one delayed union and no non-unions. Further reported complications were a gastric bleed, pulmonary embolism (VTE), and one intra operative broken burr.

CONCLUSION

Our study demonstrates a clinically important and statistically significant improvement in patient reported outcomes following DMMO, with 79% of patients satisfied or very satisfied with this procedure. The average recoil of the metatarsal heads following DMMO was M2 4.01 mm, M3 4.55 mm, M4 4.16 mm with one delayed union and no non-unions.

Abstract TS1-2: Proteogenomic Landscape of Prospectively Collected Breast Cancer

A persistent central deficiency in our knowledge of cancer concerns how genomic changes drive the proteome and phosphoproteome to execute phenotypic characteristics. Furthermore increasing evidence implicating epigenetic and post-translational changes in cancer biology reinforce the notion that molecular profiles based on nucleic acids are incomplete and are critically complemented by analyses of proteins and their post-translational modifications. We present the first integrated proteogenomic study on a prospectively collected breast cancer cohort, and provide new insights including on taxonomy, metabolic dependencies, and immune milieu. 122 invasive ductal breast cancer samples were collected under the auspices of the National Cancer Institute’s Clinical Proteomics Tumor Analysis Consortium using rigorous protocols to minimize ischemic time and other pre-analytical variability. Samples underwent comprehensive genomic and proteomic characterization, providing whole exome, whole genome, copy number, RNAseq, global proteome, phosphoproteome, and acetylome data. Multi-omics clustering by nonnegative matrix factorization revealed basal-, luminal A-, and HER2-enriched clusters, as well as a combined luminal A/B cluster. Luminal A and A/B clusters were distinguished by differential expression of cytoskeletal signatures possibly driven by YAP1 overexpression and hyper-phosphorylation in the luminal A subset. Kinase outlier analysis revealed luminal A enrichment of PEAK1, an atypical kinase that regulates YAP1 expression. PTPN2, recently shown to synergize with anti-PD1 therapy, was an outlier in basal tumors, suggesting therapeutic opportunities in that difficult-to-treat subtype. Acetylation plays a dominant role in mitochondrial metabolism, and downregulation of deacetylase SIRT3 in basal and HER2-enriched samples was associated with upregulation of TCA cycle- and amino acid metabolism-related proteins suggesting metabolic dependencies that could be exploited. Immunological subtyping of the breast cohort identified immune-cold, immune-hot, immune-excluded and interferon-independent clusters associated with distinct patterns of tumor-infiltrating lymphocytes. Basal tumors generally overexpressed PDL1 relative to other subtypes, whereas the newly described immuno-oncology target SIGLEC15 was overexpressed in luminal tumors. While these and other analyses are intended to provide new insights into breast cancer biology and facilitate testable therapeutic hypotheses, the larger purpose of the program is to provide a resource to the breast cancer and broader scientific communities. To facilitate this, these and previously published data will be integrated to provide a sample set of 199 proteogenomically characterized breast cancers for further exploration.

Citation Format: M Gillette, K Krug, S Satpathy, E Jaehnig, A Karpova, K Clauser, L Tang, L Blumenberg, R Kothadia, K Ruggles, B Zhang, L Ding, P Mertins, DR Mani, M Ellis, S Carr. Proteogenomic Landscape of Prospectively Collected Breast Cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr TS1-2.

Abstract PD6-02: A randomized, controlled trial of high dose vs. standard dose vitamin D for aromatase inhibitor-induced arthralgia in breast cancer survivors

Background: Approximately half of women on aromatase inihbitor (AI) therapy develop AI-induced arthralgia (AIA), and many discontinue the medication because of this common side effect. While Vitamin D has been studied as a treatment for AIA, trial results have been conflicting thus far.

Patients and Methods: All subjects were post menopausal women who were beginning adjuvant AI therapy for stage I-III hormone receptor positive breast cancer. Patients were randomized 1:1 to receive standard dose vitamin D3 (800 IU daily for 52 weeks) or high dose vitamin D3 (50,000 IU weekly for 12 weeks, followed by 2000 IU daily for 40 weeks). All patients also took oral calcium 600 mg daily. The primary endpoint was development of AIA, as defined by pre-specified changes in the Health Assessment Questionnaire II (HAQ-II). Secondary endpoints include compliance with AI therapy, and correlation between grip strength and development of AIA. Exploratory endpoint was measurement of inflammatory cytokine reduction in each arm. The trial was designed to enroll 184 patients, but this futility analysis was performed after 93 patients were enrolled. The futility boundary for stopping the trial early was calculated as p = 0.47.

Results: All 93 patients (46 in the high dose arm, and 47 in the standard dose arm) enrolled in the study at the time of the interim analysis were evaluable. The HAQ-II was completed at 12 weeks in 76% on the high dose arm, and 68% in the standard dose arm. Subjects who did not complete the questionnaire were deemed as study failures (i.e. development of AIA was assumed). In the high dose arm, 25 patients (54%) developed AIA, compared to 27 patients (57%) in the standard dose arm. The one-tailed p value is 0.3818, and the Z-score is 0.3, yielding only a 38% conditional power that that study would find a significant difference between the two arms. Thus, the study was terminated early for futility. There was no significant difference between the two arms in adherence to AI therapy. The grip strength and inflammatory cytokine data are pending at this time. They will be ready by the time of the conference.

Conclusions: There was no significant signal for benefit of high dose vitamin D supplementation, as compared to standard dose vitamin D, for AIA prevention in post menopausal women taking adjuvant AI therapy. These results further characterize the role of Vitamin D in AIA, and they inform future clinical trials in this arena. Further research is necessary, as this remains an important cause of non-adherence to this highly effective therapy.

Citation Format: Niravath P, Wang T, Hilsenbeck SG, Lipscomb K, Pavlick A, Jiralerspong S, Nangia J, Ellis M, Ademuyiwa F, Cherian M, Frith A, Ma C, Park H, Rigden C, Suresh R, Osborne CK, Rimawi MF. A randomized, controlled trial of high dose vs. standard dose vitamin D for aromatase inhibitor-induced arthralgia in breast cancer survivors [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD6-02.

Class IIa HDACs do not influence beta-cell function under normal or high glucose conditions

Inhibiting Class IIa Histone Deacetylase (HDAC) function is a promising approach to therapeutically enhance skeletal and cardiac muscle metabolic health in several chronic diseases including type 2 diabetes. However, the importance of Class IIa HDACs in the beta-cell remains unknown. As beta-cell function is vital to maintaining glycaemia it is essential that the importance of Class IIa HDACs in the beta-cell is determined. Here we used the INS-1E cell line cultured in normal glucose (11.1 mM) or hyperglycaemic (20 mM) conditions for 48 hrs to represent cells in a normal and diabetic environment respectively. Cells cultured in high glucose showed significantly reduced insulin secretory function and increased apoptotic signalling compared to cells cultured in normal glucose. Class IIa HDACS, HDAC-4 and -5, were not regulated at the transcript or protein level under normal or hyperglycaemic conditions suggesting that they may not play a role in beta-cell dysfunction. Furthermore, overexpression of wild-type HDAC-4 and -5 or dominant negative HDAC-4 and -5 did not alter insulin secretion, insulin mRNA expression or apoptotic signalling under normal or hyperglycaemic conditions. This suggests that Class IIa Histone Deacetylases do not play an important physiological role in the beta-cell under normal or diabetic conditions. Thus, Class IIa Histone Deacetylase inhibitors are not likely to have a detrimental effect on beta-cells supporting the use of these inhibitors to treat metabolic diseases such as type 2 diabetes.

APP deficiency results in resistance to obesity but impairs glucose tolerance upon high fat feeding

The amyloid precursor protein (APP) generates a number of peptides when processed through different cleavage mechanisms, including the amyloid beta peptide that is implicated in the development of Alzheimer's disease. It is well established that APP via its cleaved peptides regulates aspects of neuronal metabolism. Emerging evidence suggests that amyloidogenic processing of APP can lead to altered systemic metabolism, similar to that observed in metabolic disease states. In the present study, we investigated the effect of APP deficiency on obesity-induced alterations in systemic metabolism. Compared with WT littermates, APP-deficient mice were resistant to diet-induced obesity, which was linked to higher energy expenditure and lipid oxidation throughout the dark phase and was associated with increased spontaneous physical activity. Consistent with this lean phenotype, APP-deficient mice fed a high-fat diet (HFD) had normal insulin tolerance. However, despite normal insulin action, these mice were glucose intolerant, similar to WT mice fed a HFD. This was associated with reduced plasma insulin in the early phase of the glucose tolerance test. Analysis of the pancreas showed that APP was required to maintain normal islet and β-cell mass under high fat feeding conditions. These studies show that, in addition to regulating aspects of neuronal metabolism, APP is an important regulator of whole body energy expenditure and glucose homeostasis under high fat feeding conditions.

Abstract P2-09-16: Tumor infiltrating lymphocytes (TILs) as a biomarker for resistance to palbociclib (Pal) in the NeoPalAna trial

Background: Cyclin-dependent kinase (CDK) 4/6 inhibitors improve disease free survival for patients (pts) with advanced hormone receptor positive (HR+) and HER2 negative (HER2-) breast cancer (BC). However, there are no established biomarkers that identify sensitive versus resistant tumors. We have recently reported results from the phase II neoadjuvant NeoPalAna trial (NCT01723774 ) which demonstrated that Pal enhanced the anti-proliferative activity when added to anastrozole (Ana) monotherapy in HR+HER2- BC. Interestingly, a small group of pts (15%) were resistant to Pal, exhibiting persistent tumor cell proliferation (Ki67 >2.7%) on Ana plus Pal. Several studies have evaluated the prognostic and predictive importance of TILs in BC, particularly in triple negative and HER2+ subtypes. Studies evaluating TILs in HR+ BC is limited. Here we evaluated the utility of TILs in identifying Pal-resistant tumors.

Methods: Serial biopsies were collected from pts at 4 time points: baseline (BL), cycle 1 day 1 (C1D1) following 28 days of Ana monotherapy, cycle 1 day 15 (C1D15) at 2 weeks post the addition of Pal, and at surgery (Surg). TILs were evaluated using published recommendations by the TILs international working group. Agilent 4X44 whole genome gene expression arrays performed on fresh frozen biopsies at BL, C1D1, and C1D15 were analyzed for pathways and gene signatures that differentiate Pal-resistant (Pal-r) (C1D15 Ki67 >2.7%) from Ana-sensitive (Ana-s) (C1D1 Ki67 ≤2.7%) or Pal- sensitive (Pal-s) (C1D1 Ki67 >2.7% but C1D15 Ki67 ≤2.7%) tumors defined by Ki67 response. TILs at each time point were pairwise compared between response groups using Wilcoxon rank sum test and Benjamini-Hochberg adjusted two-sided p-values were reported. Change between 2 time points within a response group was evaluated by Wilcoxon signed rank test.

Results: The TILs were significantly different between Ana-s and Pal-s groups [BL p=0.03, C1D1 p=0.01, C1D15 p=.02], as well as between Ana-s and Pal-r groups [BL p=0.03, C1D1 p=0.04, C1D15 p=0.02]. Overall Pal-r samples showed the highest TILs at all time points, while Ana-s samples showed the lowest TILs. There was no significant change between time points.

Elevated TILs in Pal-r group was further supported by microarray gene expression analysis which demonstrated a large group of genes associated MHC Class-I (15+ HLA and proteasome genes) as well as Immune–inflammation pathways (18+ T cell & lymphocyte markers, signaling genes) being up regulated at BL in the Pal-r group (n=5). Pal-r samples showed a similar trend in subsequent time points although the numbers of samples were small. Many genes within this immune-inflammatory group of genes were correlated with Ki67 change at C1D15 from BL, suggestive of a potential relationship with resistance.

Conclusions: Our data shows Pal resistance was consistently associated with higher TILs at BL and post treatment, which correlated with increased expression of inflammation-immune group genes. TILs may have utility to be used as a biomarker to identify Pal resistant BC. Our data is hypothesis generating and raises the possibility of immune therapy to overcome Pal resistance in BC.

Citation Format: Sanati S, Barve R, Luo J, Hoog J, Head R, Ellis M, Ma C. Tumor infiltrating lymphocytes (TILs) as a biomarker for resistance to palbociclib (Pal) in the NeoPalAna trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-09-16.

Abstract GS2-02: Direct regulation of estrogen receptor-α (ER) transcriptional activity by NF1

Inactivating germline mutations in the NF1 gene (encoding neurofibromin) cause neurofibromatosis type 1. In addition to peripheral nervous system tumors, NF1 patients are at higher risk for other cancers, including breast cancer. Tumor exome-sequencing studies demonstrate that approximately 20% of all human cancers have somatic NF1 mutations. NF1 has been best known for its ability to inactivate Ras as a GAP (GTPase Activating Protein). However, this function is served by a small GAP domain in a very large protein. Recurrent missense mutations inactivating the GAP activity are infrequent. In contrast, it is common to detect frameshift (FS) and nonsense (NS) NF1 mutations, which can create an NF1-null state deleting not only GAP, but also, potentially, undefined NF1 functions whose loss could also drive tumorigenesis.

As we reported at SABCS previously, in 600+ patients treated by tamoxifen adjuvant monotherapy, we found that FS/NS NF1 mutations independently correlate with relapse risk (HR=2.6, p=0.03). To explore this finding, we silenced NF1 in preclinical models of ER+ breast cancer, which markedly enhanced ER transcriptional activities, causing estradiol (E2) hypersensitivity and converted tamoxifen into an agonist (in vitro and in vivo). Most important, these activities depend on ER, but not on NF1's GAP activity. These findings readily explain the poor patient outcomes associated with NS/FS NF1 mutations, and reveal a previously unrecognized function for NF1 in ER regulation.

In the presence of an agonist, liganded ER repels co-repressors and recruits co-activators, while the reverse is true with an antagonist such as tamoxifen. Many co-regulators contain leucine/isoleucine rich motifs, which bind directly to the ligand-binding domain (LBD) in ER. NF1 has several of these motifs that are much more highly conserved in species with a functional ER pathway, and some of these are mutated in cancers (e.g., in our patient cohort). Furthermore, we found that NF1 canbind directly to ER, and that this binding is mediated between the ER LBD and the NF1 leucine-rich regions. Like a classic co-repressor, wildtype NF1 (but not mutants lacking GAP activity or the Leu-rich motif) binds to ER, and is recruited by ER to the ERE in the presence of tamoxifen, but not E2.

Further preclinical treatment studies indicate that while NF1-deficient ER+ breast cancer should not be treated by tamoxifen or AIs, fulvestrant remains effective. Furthermore, when fulvestrant is combined with dabrafinib and trametinib to inhibit Ras effectors Raf and MEK, apoptosis is induced in vitro, and tumor regression is observed in vivo. In conclusion, we have demonstrated that NF1 is a dual negative regulator at the intersection of two potent oncogenic signaling pathways, Ras and ER, and that NF1-deficient ER+ breast cancer patients may be more effectively treated by co-targeting the Ras and ER signaling. These patients, up to 10% of those with advanced ER+ breast cancer, can be readily identified for treatment by ctDNA analysis. A clinical trial is under development.

Citation Format: Chang EC, Zheng Z, Philip L, Burcu C, Lei J, Singh P, Anurag M, Chan D, Li JD, Du XP, Shafaee MN, Banks K, Sacker S, Song W, Nguyen T, Cao J, Chen X, Haricharan S, Kavuri M, Kim B-J, Zhang B, Gutmann DH, Lanman RB, Foulds C, Ellis M. Direct regulation of estrogen receptor-α (ER) transcriptional activity by NF1 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS2-02.

Abstract P2-02-12: Cell free DNA analysis identifies actionable ERBB2 amplifications in patients with HER2 negative breast cancer

Identification of ERBB2 (HER2) overexpression in metastatic breast cancer informs utilization of HER2 targeted therapy. The NCCN recommends HER2 expression re-evaluation at the first disease recurrence in patients with negative or equivocal tissue status given results discrepancies due to inadequate tissue biopsy, tumoral heterogeneity, biopsy technique or fixation as well as discordance in ERBB2 (HER2) expression between primary and metastatic lesions. We examined the incidence of ERBB2 (HER2) negative to positive “flips” (e.g. to ERBB2-amplified in plasma) in a cohort of patients who underwent a blood-based cell-free DNA (cfDNA) assay at a CLIA-certified/CAP-accredited/NYSDOH-approved molecular diagnostic laboratory.

Laboratory database was queried for samples from patients with a breast cancer diagnosis. The query was filtered to ensure patients with multiple cfDNA timepoints were counted only once. Patients without a pathology report submitted at any cfDNA collection timepoint or the pathology report did not include ERBB2 (HER2) status, results were inconclusive or quantity not sufficient were excluded. Between March 2014 and April 2017, 1,853 unique patients were identified with reported ERBB2 (HER2) status. For patients with more than one cfDNA timepoint collected (N=349; 18.8%), the earliest pathology report was referenced. 1,386 patient tumor samples were negative for HER2 overexpression (74.8%), 325 (17.5%) were positive, and 142 (7.7%) were equivocal. Twenty-nine of the 1,386 patients with reported tumor negative HER2 status had amplification on subsequent cfDNA analysis (2.1%).

All 29 patients were female. Most patients (N=21) had a single cfDNA timepoint collected. Median age at cfDNA blood draw was 58 years (range 28–68). Median length of time between reported tissue negative status and cfDNA blood draw was 405 days (range 21–4,060). Median plasma ERBB2 copy number was 2.44 (greater than 50th-centile per laboratory data) (range 2.15–16.5).

Clinical follow-up was obtained for 19 patients (65%). Nine patients were lost to follow-up or succumbed to disease prior to initiation of a new therapeutic regimen. One patient was known HER2 positive prior to receipt of the cfDNA results. In the remaining nine patients, six initiated targeted HER2 therapy following receipt of the cfDNA results, with five of six (83%) demonstrating a clinical response. In one patient with known ER/PR positive, HER2 negative disease, progressing through multiple lines of therapy, addition of trastuzumab and pertuzumab to her paclitaxel regimen following identification of the cfDNA ERBB2 amplification resulted in a significant reduction in CEA levels (238 to 37.9 ng/mL) by week five. In a second patient, following identification of the cfDNA ERBB2 amplification, she was treated with trastuzumab and pertuzumab along with docetaxel and had a dramatic response. She continues on trastuzumab and pertuzumab alone.

Although a modest sample size, this is the second cfDNA series demonstrating that ERBB2 (HER2) status may flip from negative to positive upon recurrence or metastasis, and that targeting plasma-detected ERBB2 amplification with anti-HER2 has clinical benefit. cfDNA is a viable alternative to tissue rebiopsy in this patient population.

Citation Format: Raymond VM, Diaz J, Banks KC, Ahn E, Brufsky A, Ellis M, Lippman M, Lee C, Pluard T, Schreeder M, Schwab R, Lanman RB. Cell free DNA analysis identifies actionable ERBB2 amplifications in patients with HER2 negative breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P2-02-12.

Metformin, beta-cell development, and novel processes following beta-cell ablation in zebrafish

PURPOSE

Type 1 and 2 diabetes are characterized by a loss of insulin-producing beta-cells. Current treatments help maintain blood glucose levels but cannot provide a cure. As such, a vital target for the cure of diabetes is a way to restore beta-cell mass. The drug metformin can protect cultured beta-cells/islets from hyperglycemia-induced dysfunction and death. Further, treatment of pregnant mice with metformin results in an enhanced beta-cell fraction in the embryos; however, whether this occurs via a direct effect is unknown.

METHODS

We utilized the external embryogenesis of the zebrafish to determine the direct effect of metformin treatment on the pancreas of the developing embryo and following beta-cell ablation.

RESULTS

During development metformin did not alter beta-cell or alpha-cell mass but had a small effect to increase delta-cell mass as measured by in situ hybridization. Further metformin significantly increased beta-cell number. Following beta-cell ablation, both glucagon and somatostatin expression were upregulated (>2-fold). Additionally, while metformin showed no effect to alter beta-cell mass or number, somatostatin expression was further increased (>5-fold).

CONCLUSIONS

We showed that direct exposure to metformin during embryogenesis does not increase insulin-expressing area but does increase beta-cell number. Further, we identified novel consequences of beta-cell ablation to alter the expression of other pancreatic hormones that were enhanced by metformin. Therefore, this study provides a greater understanding of the beta-cell development/regenerative processes and the effect of metformin, bringing us closer to identifying how to increase beta-cells in humans.

Review: Effects of Ractopamine Hydrochloride (Paylean) on welfare indicators for market weight pigs

This review summarizes the effects of ractopamine hydrochloride (RAC) dose (5, 7.5, 10, and 20 mg/kg) on market weight pig welfare indicators. Ractopamine hydrochloride (trade name Paylean) is a β-adrenergic agonist that was initially approved in the U.S. in 1999 at doses of 5 to 20 mg/kg to improve feed efficiency and carcass leanness. However, anecdotal reports suggested that RAC increased the rate of non-ambulatory (fatigued and injured) pigs at U.S. packing plants. This led to the addition of a caution statement to the Paylean label, and a series of research studies investigating the effects of RAC on pig welfare. Early research indicated that: (1) regardless of RAC administration, fatigued (non-ambulatory, non-injured) pigs are in a state of metabolic acidosis; (2) aggressive handling increases stress responsiveness at 20 mg/kg RAC, while 5 mg/kg reduces stress responsiveness to aggressive handling. Given this information, dosage range for Paylean was changed in 2006 to 5 to 10 mg/kg in market weight pigs. Subsequent research on RAC demonstrated that: (1) RAC has minimal effects on mortality, lameness, and home pen behavior; (2) RAC fed pigs demonstrated inconsistent prevalence and intensity of aggressive behaviors; (3) RAC fed pigs may be more difficult to handle at doses above 5 mg/kg; and (4) RAC fed pigs may have increased stress responsiveness and higher rates of non-ambulatory pigs when subjected to aggressive handling, especially when 20 mg/kg of RAC is fed.

Possible maternal offloading of metals in the plasma, uterine and capsule fluid of pregnant ragged-tooth sharks (Carcharias taurus) on the east coast of South Africa

We studied the possible metal offloading onto the progeny of three pregnant female ragged-tooth sharks (Carcharias taurus) (C. taurus). The presences of five metals, i.e. aluminium (Al), arsenic (As), cadmium (Cd), lead (Pb) and selenium (Se) were validated by mass spectrometry in the maternal plasma as well as the intracapsular and uterine fluids (UF) in which embryos develop. Metals were ranked in a decreasing concentration as follows: Plasma: As > Al > Se > Pb > Cd; ICF: As > Se > Al > Cd > Pb and UF: As > Se > Al > Cd > Pb. As was present in the highest concentration in all three sharks. Al, Pb and Cd were found to be the highest within the plasma, while concentrations of Se were similar in all three fluids. These results indicate that C. taurus embryos are exposed to metals during early development, but the impact of this exposure remains unknown. To the best of our knowledge, this is the first investigation to confirm the presence of metals in the fluids that surround the developing C. taurus embryos, a species that is already listed as vulnerable.

Predicting pork loin chop yield using carcass and loin characteristics

The objective was to determine the predictive ability of carcass length for the number of equal-thickness chops obtained from a boneless pork loin. Longer pork carcasses are assumed to yield longer loins and, therefore, an increased number of chops. Loins were collected from pigs (1,238 total) raised under commercial conditions and marketed when the mean pig weight in a pen reached 138 kg. Pigs were slaughtered over 7 wk in a commercial facility. Carcass length was measured at 1 d postmortem on the left side of each carcass from the anterior edge of the symphysis pubis bone to the anterior edge of the first rib. Carcasses were fabricated, and boneless loins (North American Meat Processors number 414) were vacuum packaged and transported to the University of Illinois Meat Science Laboratory. Loins were stored at 4°C for 14 d. At the end of the aging period, loins were weighed, measured for stretched length (stretched to maximum length without distortion) and compressed length (compressed to minimum length without distortion), and sliced into 2.54-cm-thick chops. Boneless chops were counted and weighed. Carcass length ranged from a minimum of 78.2 cm to a maximum of 96.5 cm and the number of boneless chops ranged from a minimum of 13 to a maximum of 20 chops. Data were analyzed using the regression procedure of SAS. The dependent variable was the number of boneless chops. Coefficient of determination () was calculated for carcass length, boneless loin weight, compressed loin length, and stretched loin length. Carcass length explained 15% ( < 0.0001) of the variation in the number of loin chops. Loin weight explained 33% ( < 0.0001) of the variation in the number of loin chops. Compressed loin length and stretched loin length explained 28 and 8% ( < 0.0001), respectively, of the variation in the number of loin chops. Multiple linear regression was used to determine a predictive equation for the number of loin chops using the stepwise selection option of all independent variables. The combination of boneless loin weight, compressed loin length, 10th-rib carcass fat depth, and carcass length explained 45% of the variation ( < 0.0001; C(p) = 16.76) in the number of loin chops using a required statistic at the SLENTRY and SLSTAY level = 0.15. Overall, carcass length is a poor predictor of the number of equal-thickness loin chops that can be derived from a boneless pork loin.

Evaluation of a semi-automated software program for the identification of vertebral fractures in children

AIM

To assess observer reliability and diagnostic accuracy in children, of a semi-automated six-point technique developed for vertebral fracture (VF) diagnosis in adults, which records percentage loss of vertebral body height.

MATERIALS AND METHODS

Using a semi-automated software program, five observers independently assessed T4 to L4 from the lateral spine radiographs of 137 children and adolescents for VF. A previous consensus read by three paediatric radiologists using a simplified algorithm-based qualitative technique (i.e., no software involved) served as the reference standard.

RESULTS

Of a total of 1,781 vertebrae, 1,187 (67%) were adequately visualised according to three or more observers. Interobserver agreement in vertebral readability for each vertebral level for five observers ranged from 0.05 to 0.47 (95% CI: -0.19, 0.76). Intra-observer agreement using the intraclass correlation coefficient (ICC) ranged from 0.25 to 0.61. The overall sensitivity and specificity were 18% (95% CI: 14-22) and 97% (95% CI: 97-98), respectively.

CONCLUSION

In contrast to adults, the six-point technique assessing anterior, middle, and posterior vertebral height ratios is neither satisfactorily reliable nor sensitive for VF diagnosis in children. Training of the software on paediatric images is required in order to develop a paediatric standard that incorporates not only specific vertebral body height ratios but also the age-related physiological changes in vertebral shape that occur throughout childhood.