Lattice defects induced by microtubule-stabilizing agents exert a long-range effect on microtubule growth by promoting catastrophes.

Microtubules are dynamic cytoskeletal polymers that spontaneously switch between phases of growth and shrinkage. The probability of transitioning from growth to shrinkage, termed catastrophe, increases with microtubule age, but the underlying mechanisms are poorly understood. Here, we set out to test whether microtubule lattice defects formed during polymerization can affect growth at the plus end. To generate microtubules with lattice defects, we used microtubule-stabilizing agents that promote formation of polymers with different protofilament numbers. By employing different agents during nucleation of stable microtubule seeds and the subsequent polymerization phase, we could reproducibly induce switches in protofilament number and induce stable lattice defects. Such drug-induced defects led to frequent catastrophes, which were not observed when microtubules were grown in the same conditions but without a protofilament number mismatch. Microtubule severing at the site of the defect was sufficient to suppress catastrophes. We conclude that structural defects within the microtubule lattice can exert effects that can propagate over long distances and affect the dynamic state of the microtubule end.

Expression of Epsin3 and its interaction with Notch signalling in oral epithelial dysplasia and oral squamous cell carcinoma.

BACKGROUND: Most oral squamous cell carcinoma patients present with late-stage disease. Early detection of the disease is considered to be the most effective way of improving patient outcomes. Several biomarkers have been identified as indicators of oral cancer development and progression; however, none have been translated into clinical practice. In this study, we have investigated the role of Epsin3, an endocytic adaptor protein, and Notch1, a transmembrane signalling protein, in oral carcinogenesis with a view to explore their potential as biomarkers. METHODS: Oral cancer cell lines and a normal oral keratinocyte cell line were used together with tissue samples of normal oral mucosa (n = 21), oral epithelial dysplasia (n = 74) and early stage (Stages I and II) oral squamous cell carcinoma (n = 31). Immunocytochemical staining, immunoblotting and real-time quantitative polymerase chain reaction (PCR) were performed to assess protein as well as gene expression levels. RESULTS: The expression levels of Epsin3 and Notch1 mRNA and protein are variable across different oral squamous cell carcinoma derived cell lines. Epsin3 was upregulated in oral epithelial dysplasia and oral squamous cell carcinoma tissues compared with normal epithelium. Overexpression of Epsin3 resulted in a significant reduction of Notch1 expression in oral squamous cell carcinoma. Notch1 was generally downregulated in the dysplasia and oral squamous cell carcinoma samples. CONCLUSION: Epsin3 is upregulated in oral epithelial dysplasia and oral squamous cell carcinoma and has the potential to be used as a biomarker for oral epithelial dysplasia. Notch signalling is downregulated in oral squamous cell carcinoma, possibly through an Epsin3-induced de-activation pathway.

Genomics reveal population structure, evolutionary history, and signatures of selection in the northern bottlenose whale, Hyperoodon ampullatus.

Information on wildlife population structure, demographic history, and adaptations are fundamental to understanding species evolution and informing conservation strategies. To study this ecological context for a cetacean of conservation concern, we conducted the first genomic assessment of the northern bottlenose whale, Hyperoodon ampullatus, using whole-genome resequencing data (n = 37) from five regions across the North Atlantic Ocean. We found a range-wide pattern of isolation-by-distance with a genetic subdivision distinguishing three subgroups: the Scotian Shelf, western North Atlantic, and Jan Mayen regions. Signals of elevated levels of inbreeding in the Endangered Scotian Shelf population indicate this population may be more vulnerable than the other two subgroups. In addition to signatures of inbreeding, evidence of local adaptation in the Scotian Shelf was detected across the genome. We found a long-term decline in effective population size for the species, which poses risks to their genetic diversity and may be exacerbated by the isolating effects of population subdivision. Protecting important habitat and migratory corridors should be prioritized to rebuild population sizes that were diminished by commercial whaling, strengthen gene flow, and ensure animals can move across regions in response to environmental changes.

The Incidence and Prevalence of Cardiac Amyloidosis in a Large Community-Based Cohort in Alberta, Canada.

BACKGROUND: Despite the improved awareness of cardiac amyloidosis among clinicians, its incidence and prevalence is not well-described in a community setting. We sought to investigate the incidence and prevalence of cardiac amyloidosis in the community. METHODS AND RESULTS: In the adult population of Alberta, we examined 3 cohorts: (1) probable cases of cardiac amyloidosis: the presence of physician-assigned diagnosis of amyloidosis (International Classification of Diseases [ICD]-10 code E85; ICD-9 277.3) and 1 or more health care encounter for heart failure (HF) (ICD-10 I50; ICD-9 428); (2) possible cardiac amyloidosis: the presence of clinical phenotypes suggestive of amyloidosis; and (3) a comparator HF cohort without amyloidosis. Between 2004 and 2018, 982 of the 145,329 patients with HF were identified as probable cardiac amyloidosis. During the same period, the incidence rates of probable cardiac amyloidosis increased from 1.38 to 3.69 per 100,000 person-years and the prevalence rates increased from 3.42 to 14.85 per 100,000 person-years (Ptrend < .0001). Patients with probable cardiac amyloidosis were more likely to be male, have a higher comorbidity burden, greater health care use, and poorer outcomes as compared with patients with HF without amyloidosis. A much larger group of patients was identified as possible cardiac amyloidosis (n = 46,255), with similar increase in prevalence from 2004 to 2018 (from 416 to 850 per 100,000 person-years). CONCLUSIONS: The incidence and prevalence of cardiac amyloidosis has increased over the last decade. Given the advent of new therapies for cardiac amyloidosis and considering their high cost, it is imperative to devise strategies to screen, identify, and track patients with cardiac amyloidosis from administrative databases.

Resistance and resilience of genetic and phenotypic diversity to "black swan" flood events: A retrospective analysis with historical samples of guppies.

Rare extreme "black swan" disturbances can impact ecosystems in many ways, such as destroying habitats, depleting resources, and causing high mortality. In rivers, for instance, exceptional floods that occur infrequently (e.g., so-called "50-year floods") can strongly impact the abundance of fishes and other aquatic organisms. Beyond such ecological effects, these floods could also impact intraspecific diversity by elevating genetic drift or dispersal and by imposing strong selection, which could then influence the population's ability to recover from disturbance. And yet, natural systems might be resistant (show little change) or resilient (show rapid recovery) even to rare extreme events - perhaps as a result of selection due to past events. We considered these possibilities in two rivers where native guppies experienced two extreme floods - one in 2005 and another in 2016. For each river, we selected four sites and used archived "historical" samples to compare levels of genetic and phenotypic diversity before vs. after floods. Genetic diversity was represented by 33 neutral microsatellite markers, and phenotypic diversity was represented by body length and male melanic (black) colour. We found that genetic diversity and population structure was mostly "resistant" to even these extreme floods; whereas the larger impacts on phenotypic diversity were short-lived, suggesting additional "resilience". We discuss the determinants of these two outcomes for guppies facing floods, and then consider the general implications for the resistance and resilience of intraspecific variation to black swan disturbances.

Total synthesis of the actinoallolides and a designed photoaffinity probe for target identification.

The actinoallolides are a family of polyketide natural products isolated from the bacterium Actinoallomurus fulvus. They show potent biological activity against trypanosomes, the causative agents of the neglected tropical diseases human African trypanosomiasis (sleeping sickness) and Chagas disease, while exhibiting no cytotoxicity against human cell lines. Herein, we give a full account of our strategy evolution towards the synthesis of this structurally unique class of 12-membered macrolides, which culminated in the first total synthesis of (+)-actinoallolide A in 20 steps and 8% overall yield. Subsequent late-stage diversification then provided ready access to the congeneric (+)-actinoallolides B-E. Enabled by this flexible and efficient endgame sequence, we also describe the design and synthesis of a photoaffinity probe based on actinoallolide A to investigate its biological mode of action. This will allow ongoing labelling studies to identify their protein binding target(s).

A Unified Total Synthesis of the Actinoallolides, a Family of Potent Anti-Trypanosomal Macrolides.

Trypanosoma protozoan parasites are the causative agents of Chagas disease and sleeping sickness, two neglected tropical diseases where there is an urgent need for improved treatments and the evaluation of promising drug leads like the actinoallolides. Enabled by the highly stereocontrolled aldol reactions of three chiral ketone building blocks, an efficient first total synthesis of the potent anti-trypanosomal macrolide (+)-actinoallolide A has been achieved in 17 steps and 8 % overall yield. Our convergent route features an adventurous ring-closing metathesis to form the requisite trisubstituted (8E)-alkene in the 12-membered macrolactone, followed by the controlled installation of the labile transannular hemiacetal. Late-stage diversification then provides ready access to the congeneric (+)-actinoallolides B-E.

Comprehensive functional profiling of long non-coding RNAs through a novel pan-cancer integration approach and modular analysis of their protein-coding gene association networks.

BACKGROUND: Long non-coding RNAs (lncRNAs) are emerging as crucial regulators of cellular processes in diseases such as cancer, although the functions of most remain poorly understood. To address this, here we apply a novel strategy to integrate gene expression profiles across 32 cancer types, and cluster human lncRNAs based on their pan-cancer protein-coding gene associations. By doing so, we derive 16 lncRNA modules whose unique properties allow simultaneous inference of function, disease specificity and regulation for over 800 lncRNAs. RESULTS: Remarkably, modules could be grouped into just four functional themes: transcription regulation, immunological, extracellular, and neurological, with module generation frequently driven by lncRNA tissue specificity. Notably, three modules associated with the extracellular matrix represented potential networks of lncRNAs regulating key events in tumour progression. These included a tumour-specific signature of 33 lncRNAs that may play a role in inducing epithelial-mesenchymal transition through modulation of TGFß signalling, and two stromal-specific modules comprising 26 lncRNAs linked to a tumour suppressive microenvironment and 12 lncRNAs related to cancer-associated fibroblasts. One member of the 12-lncRNA signature was experimentally supported by siRNA knockdown, which resulted in attenuated differentiation of quiescent fibroblasts to a cancer-associated phenotype. CONCLUSIONS: Overall, the study provides a unique pan-cancer perspective on the lncRNA functional landscape, acting as a global source of novel hypotheses on lncRNA contribution to tumour progression.

Pangolin genomes and the evolution of mammalian scales and immunity.

Pangolins, unique mammals with scales over most of their body, no teeth, poor vision, and an acute olfactory system, comprise the only placental order (Pholidota) without a whole-genome map. To investigate pangolin biology and evolution, we developed genome assemblies of the Malayan (Manis javanica) and Chinese (M. pentadactyla) pangolins. Strikingly, we found that interferon epsilon (IFNE), exclusively expressed in epithelial cells and important in skin and mucosal immunity, is pseudogenized in all African and Asian pangolin species that we examined, perhaps impacting resistance to infection. We propose that scale development was an innovation that provided protection against injuries or stress and reduced pangolin vulnerability to infection. Further evidence of specialized adaptations was evident from positively selected genes involving immunity-related pathways, inflammation, energy storage and metabolism, muscular and nervous systems, and scale/hair development. Olfactory receptor gene families are significantly expanded in pangolins, reflecting their well-developed olfaction system. This study provides insights into mammalian adaptation and functional diversification, new research tools and questions, and perhaps a new natural IFNE-deficient animal model for studying mammalian immunity.

A miRNA-145/TGF-ß1 negative feedback loop regulates the cancer-associated fibroblast phenotype.

The dissemination of cancer cells to local and distant sites depends on a complex and poorly understood interplay between malignant cells and the cellular and non-cellular components surrounding them, collectively termed the tumour microenvironment. One of the most abundant cell types of the tumour microenvironment is the fibroblast, which becomes corrupted by locally derived cues such as TGF-ß1 and acquires an altered, heterogeneous phenotype (cancer-associated fibroblasts, CAF) supportive of tumour cell invasion and metastasis. Efforts to develop new treatments targeting the tumour mesenchyme are hampered by a poor understanding of the mechanisms underlying the development of CAF. Here, we examine the contribution of microRNA to the development of experimentally-derived CAF and correlate this with changes observed in CAF derived from tumours. Exposure of primary normal human fibroblasts to TGF-ß1 resulted in the acquisition of a myofibroblastic CAF-like phenotype. This was associated with increased expression of miR-145, a miRNA predicted in silico to target multiple components of the TGF-ß signalling pathway. miR-145 was also overexpressed in CAF derived from oral cancers. Overexpression of miR-145 blocked TGF-ß1-induced myofibroblastic differentiation and reverted CAF towards a normal fibroblast phenotype. We conclude that miR-145 is a key regulator of the CAF phenotype, acting in a negative feedback loop to dampen acquisition of myofibroblastic traits, a key feature of CAF associated with poor disease outcome.

Environmental extremes drive population structure at the northern range limit of Atlantic salmon in North America.

Conservation of exploited species requires an understanding of both genetic diversity and the dominant structuring forces, particularly near range limits, where climatic variation can drive rapid expansions or contractions of geographic range. Here, we examine population structure and landscape associations in Atlantic salmon (Salmo salar) across a heterogeneous landscape near the northern range limit in Labrador, Canada. Analysis of two amplicon-based data sets containing 101 microsatellites and 376 single nucleotide polymorphisms (SNPs) from 35 locations revealed clear differentiation between populations spawning in rivers flowing into a large marine embayment (Lake Melville) compared to coastal populations. The mechanisms influencing the differentiation of embayment populations were investigated using both multivariate and machine-learning landscape genetic approaches. We identified temperature as the strongest correlate with genetic structure, particularly warm temperature extremes and wider annual temperature ranges. The genomic basis of this divergence was further explored using a subset of locations (n = 17) and a 220K SNP array. SNPs associated with spatial structuring and temperature mapped to a diverse set of genes and molecular pathways, including regulation of gene expression, immune response, and cell development and differentiation. The results spanning molecular marker types and both novel and established methods clearly show climate-associated, fine-scale population structure across an environmental gradient in Atlantic salmon near its range limit in North America, highlighting valuable approaches for predicting population responses to climate change and managing species sustainability.

Toward aplyronine payloads for antibody-drug conjugates: total synthesis of aplyronines A and D.

The aplyronines are a family of antimitotic marine macrolides that disrupt cytoskeletal dynamics by dual targeting of both actin and tubulin. Given their picomolar cytotoxicity profile and unprecedented mode of action, the aplyronines represent an excellent candidate as a novel payload for the development of next-generation antibody-drug conjugates (ADCs) for cancer chemotherapy. Enabled by an improved second-generation synthesis of the macrolactone core 5, we have achieved the first total synthesis of the most potent congener aplyronine D together with a highly stereocontrolled synthesis of aplyronine A. To facilitate step economy, an adventurous site-selective esterification of the C7 hydroxyl group was performed to install the N,N,O-trimethylserine pharmacophore to directly afford aplyronines A and D. Toward the assembly of ADCs incorporating an aplyronine warhead, the C29-ester derivative 4 featuring an Fmoc-amino substituted linker attached to the actin-binding tail region was also prepared by adapting this flexible endgame.

Toward the total synthesis of patellazole B: synthesis of an advanced C1-C25 fragment corresponding to the macrocyclic skeleton.

The patellazoles are a family of complex marine macrolides that exhibit potent cytotoxicity against cancer cell lines. However, despite extensive characterisation efforts, their full stereochemical assignment has remained elusive. We report our approach towards the synthesis-enabled structural elucidation of patellazole B (4), a 24-membered macrolide with 16 stereocentres and a signature thiazole-containing side chain. Our plan hinges upon isolating the unknown stereocentres into a single C20-C25 fragment to facilitate the flexible assembly of various possible diastereomers of an advanced C1-C25 fragment. Towards this end, a highly convergent and modular synthesis of one candidate diastereomer 37, corresponding to the patellazole B macrocyclic skeleton, has been achieved based on the strategic application of stereocontrolled aldol methodology, combined with Suzuki and Heck cross-coupling reactions.

Oncogenic S1P signalling in EBV-associated nasopharyngeal carcinoma activates AKT and promotes cell migration through S1P receptor 3.

Undifferentiated nasopharyngeal carcinoma (NPC) is a cancer with high metastatic potential that is consistently associated with Epstein-Barr virus (EBV) infection. In this study, we have investigated the functional contribution of sphingosine-1-phosphate (S1P) signalling to the pathogenesis of NPC. We show that EBV infection or ectopic expression of the EBV-encoded latent genes (EBNA1, LMP1, and LMP2A) can up-regulate sphingosine kinase 1 (SPHK1), the key enzyme that produces S1P, in NPC cell lines. Exogenous addition of S1P promotes the migration of NPC cells through the activation of AKT; shRNA knockdown of SPHK1 resulted in a reduction in the levels of activated AKT and inhibition of cell migration. We also show that S1P receptor 3 (S1PR3) mRNA is overexpressed in EBV-positive NPC patient-derived xenografts and a subset of primary NPC tissues, and that knockdown of S1PR3 suppressed the activation of AKT and the S1P-induced migration of NPC cells. Taken together, our data point to a central role for EBV in mediating the oncogenic effects of S1P in NPC and identify S1P signalling as a potential therapeutic target in this disease. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Variability of left ventricular volume and ejection fraction measurements using contrast echocardiography: The influence of the left ventricular length measurements in a large cohort of patients during monitoring cardiotoxic effects of chemotherapy.

OBJECTIVE: To investigate the influence of length difference in left ventricular (LV) long axis between the apical four-chamber and two-chamber views on measurements of LV volumes and ejection fraction (EF). METHODS: Seven hundred consecutive cancer patients underwent contrast echocardiography from July 2010 to May 2014. All patients received the echocardiographic contrast agent Definity. Recordings of apical views were analyzed by a sonographer and then by a cardiologist. The end-diastolic and end-systolic LV volumes (EDV and ESV), and LV lengths as well as EF, were measured using the biplane Simpson's method. Inter-observer variability was assessed using relative mean error (RME) and Bland-Altman analysis. RESULTS: Six hundred ninety-two patients had contrast echocardiograms with complete endocardial definition. The LV length difference of the long axis measured by the cardiologist was ≤1 mm in 284 studies (41%), 2 mm in 146 studies (21%), 3 mm in 103 studies (15%), and ≥4 mm in 159 studies (23%). The limits of agreement (LOA) and RME increase with the increasing length difference. Compared to the groups with length difference <4 mm, the RME of the measurements of indexed EDV, indexed ESV, and EF was significantly greater in the group with length difference ≥4 mm (P < .05). CONCLUSION: These results highlight the need for reviewing the LV long axis length measurements in order to provide reproducible LV volumes and EF measurements and may be used as benchmarks for quality control. A length difference of ≤3 mm can be achieved in most of our patients and is associated with an excellent inter-observer agreement.

Structural Basis of Microtubule Stabilization by Discodermolide.

Microtubule-stabilizing agents (MSAs) are widely used in chemotherapy. Using X-ray crystallography we elucidated the detailed binding modes of two potent MSAs, (+)-discodermolide (DDM) and the DDM-paclitaxel hybrid KS-1-199-32, in the taxane pocket of ß-tubulin. The two compounds bind in a very similar hairpin conformation, as previously observed in solution. However, they stabilize the M-loop of ß-tubulin differently: KS-1-199-32 induces an M-loop helical conformation that is not observed for DDM. In the context of the microtubule structure, both MSAs connect the ß-tubulin helices H6 and H7 and loop S9-S10 with the M-loop. This is similar to the structural effects elicited by epothilone A, but distinct from paclitaxel. Together, our data reveal differential binding mechanisms of DDM and KS-1-199-32 on tubulin.

Induction of accelerated senescence by the microtubule-stabilizing agent peloruside A.

Chemotherapeutic agents can induce accelerated senescence in tumor cells, an irreversible state of cell cycle arrest. Paclitaxel, a microtubule-stabilizing agent used to treat solid tumors of the breast, ovary, and lung and discodermolide, another stabilizing agent from a marine sponge, induce senescence in cultured cancer cells. The aim of this study was to determine if the microtubule-stabilizing agent peloruside A, a polyketide natural product from a marine sponge, can induce accelerated senescence in a breast cancer cell line MCF7. Doxorubicin, a DNA-damaging agent, paclitaxel, and discodermolide were used as positive controls. Senescence-associated-ß-galactosidase activity was increased by peloruside A, similar to paclitaxel, discodermolde, and doxorubicin, with a potency heirarchy of doxorubicin > paclitaxel > discodermolide > peloruside, based on IC25 concentrations that inhibit proliferation. Clonogenic survival was significantly decreased by peloruside A, similar to doxorubicin and the two other microtubule-stabilizing agents. The tumor suppressor protein p53 increased after treatment, whereas pRb decreased in response to all four compounds. It was concluded that in addition to apoptosis, peloruside A causes accelerated senescence in a subpopulation of MCF7 cells that contributes to its potential anticancer activity in a breast cancer cell line.

Zampanolide, a Microtubule-Stabilizing Agent, Is Active in Resistant Cancer Cells and Inhibits Cell Migration.

Zampanolide, first discovered in a sponge extract in 1996 and later identified as a microtubule-stabilizing agent in 2009, is a covalent binding secondary metabolite with potent, low nanomolar activity in mammalian cells. Zampanolide was not susceptible to single amino acid mutations at the taxoid site of ß-tubulin in human ovarian cancer 1A9 cells, despite evidence that it selectively binds to the taxoid site. As expected, it did not synergize with other taxoid site microtubule-stabilizing agents (paclitaxel, ixabepilone, discodermolide), but surprisingly also did not synergize in 1A9 cells with laulimalide/peloruside binding site agents either. Efforts to generate a zampanolide-resistant cell line were unsuccessful. Using a standard wound scratch assay in cell culture, it was an effective inhibitor of migration of human umbilical vein endothelial cells (HUVEC) and fibroblast cells (D551). These properties of covalent binding, the ability to inhibit cell growth in paclitaxel and epothilone resistant cells, and the ability to inhibit cell migration suggest that it would be of interest to investigate zampanolide in preclinical animal models to determine if it is effective in vivo at preventing tumor growth and metastasis.

An Expedient Total Synthesis of Chivosazole†F: an Actin-Binding Antimitotic Macrolide from the Myxobacterium Sorangium Cellulosum.

A unified strategy for the chemical synthesis of the chivosazoles is described. This strategy is based on two closely related approaches involving the late-stage installation of the isomerization-prone (2Z,4E,6Z,8E)-tetraenoate motif, and an expedient fragment-assembly procedure. The result is a highly convergent total synthesis of chivosazole F through the orchestration of three mild Pd/Cu-mediated Stille cross-coupling reactions, including the use of a one-pot, site-selective, three-component process, in combination with controlled installation of the requisite alkene geometry.

Rationale and design of the multidisciplinary team IntervenTion in cArdio-oNcology study (TITAN).

BACKGROUND: Cancer is the leading cause of premature death in Canada. In the last decade, important gains in cancer survival have been achieved by advances in adjuvant treatment. However, many oncologic treatments also result in cardiovascular "toxicity". Furthermore, cardiac risk factors such as hypertension, dyslipidemia, and diabetes mellitus are known to contribute to the progression of cardiac damage and clinical cardiotoxicity. As such, for many survivors, the risk of death from cardiac disease exceeds that of recurrent cancer. While provision of care by multidisciplinary teams has been shown to reduce mortality and hospitalizations among heart failure patients, the effect of assessments and interventions by multidisciplinary specialists in cancer patients receiving cardiotoxic chemotherapy regimens is currently unknown. Accordingly, we will examine the effect of a multi-disciplinary team interventions in the early assessment, identification and treatment of cardiovascular risk factors in cancer patients receiving adjuvant systemic therapy. Our main hypothesis is to determine if the incidence of LV dysfunction in cancer patients undergoing adjuvant therapy can be reduced through a multidisciplinary team approach. METHODS/DESIGN: This is a randomized study comparing intensive multidisciplinary team intervention to usual care in the prevention of LV remodeling in patients receiving anthracycline or trastuzumab-based chemotherapy. Main objectives include early detection strategies for cardiotoxicity using novel biomarkers that reflect myocardial injury, remodeling and/or dysfunction; early identification and intensive treatment of cardiovascular risk factors; and early intervention with supportive care strategies including nutritional and pharmacist counselling, exercise training and cardiology team support. Secondary objectives include correlation of novel biomarkers to clinical outcomes; correlation of multidisciplinary interventions to adverse clinical outcomes; relationship of multidisciplinary interventions and chemotherapy dose density; preservation of lean muscle mass; and patient reported outcomes (symptom intensity and quality of life). DISCUSSION: Cardiac toxicity as a result of cancer therapies is now recognized as a significant health problem of increasing prevalence. To our knowledge, TITAN will be the first randomized trial examining the utility of multidisciplinary team care in the prevention of cardiotoxicity. We expect our results to inform comprehensive and holistic care for patients at risk for negative cancer therapy mediated sequelae. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01621659 Registration Date 4 June 2012.