Preclinical efficacy of hK2 targeted [177Lu]hu11B6 for prostate cancer theranostics

Androgen ablating drugs increase life expectancy in men with metastatic prostate cancer, but resistance inevitably develops. In a majority of these recurrent tumors, the androgen axis is reactivated in the form of increased androgen receptor (AR) expression. Targeting proteins that are expressed as a down-stream effect of AR activity is a promising rationale for management of this disease. The humanized IgG1 antibody hu11B6 internalizes into prostate and prostate cancer (PCa) cells by binding to the catalytic cleft of human kallikrein 2 (hK2), a prostate specific enzyme governed by the AR-pathway. In a previous study, hu11B6 conjugated with Actinium-225 (225Ac), a high linear energy transfer (LET) radionuclide, was shown to generate an AR-upregulation driven feed-forward mechanism that is believed to enhance therapeutic efficacy. We assessed the efficacy of hu11B6 labeled with a low LET beta-emitter, Lutetium-177 (177Lu) and investigated whether similar tumor killing and AR-enhancement is produced. Moreover, single-photon emission computed tomography (SPECT) imaging of 177Lu is quantitatively accurate and can be used to perform treatment planning. [177Lu]hu11B6 therefore has significant potential as a theranostic agent. Materials and Methods: Subcutaneous PCa xenografts (LNCaP s.c.) were grown in male mice. Biokinetics at 4-336 h post injection and uptake as a function of the amount of hu11B6 injected at 72 h were studied. Over a 30 to 120-day treatment period the therapeutic efficacy of different activities of [177Lu]hu11B6 were assessed by volumetric tumor measurements, blood cell counts, molecular analysis of the tumor as well as SPECT/CT imaging. Organ specific mean absorbed doses were calculated, using a MIRD-scheme, based on biokinetic data and rodent specific S-factors from a modified MOBY phantom. Tumor tissues of treated xenografts were immunohistochemically (IHC) stained for Ki-67 (proliferation) and AR, SA-β-gal activity (senescence) and analyzed by digital autoradiography (DAR). Results: Organ-to-blood and tumor-to-blood ratios were independent of hu11B6 specific activity except for the highest amount of antibody (150 µg). Tumor accumulation of [177Lu]hu11B6 peaked at 168 h with a specific uptake of 29 ± 9.1 percent injected activity per gram (%IA/g) and low accumulation in normal organs except in the submandibular gland (15 ± 4.5 %IA/g), attributed to a cross-reaction with mice kallikreins in this organ, was seen. However, SPECT imaging with therapeutic amounts of [177Lu]hu11B6 revealed no peak in tumor accumulation at 7 d, probably due to cellular retention of 177Lu and decreasing tumor volumes. For [177Lu]hu11B6 treated mice, tumor decrements of up to 4/5 of the initial tumor volume and reversible myelotoxicity with a nadir at 12 d were observed after a single injection. Tumor volume reduction correlated with injected activity and the absorbed dose. IHC revealed retained expression of AR throughout treatment and that Ki-67 staining reached a nadir at 9-14 d which coincided with high SA- β-gal activity (14 d). Quantification of nuclei staining showed that Ki-67 expression correlated negatively with activity uptake. AR expression levels in cells surviving therapy compared to previous timepoints and to controls at 30 d were significantly increased (p = 0.017). Conclusions: This study shows that hu11B6 labeled with the low LET beta-emitting radionuclide 177Lu can deliver therapeutic absorbed doses to prostate cancer xenografts with transient hematological side-effects. The tumor response correlated with the absorbed dose both on a macro and a small scale dosimetric level. Analysis of AR staining showed that AR protein levels increased late in the study suggesting a therapeutic mechanism, a feed forward mechanism coupled to AR driven response to DNA damage or clonal lineage selection, similar to that reported in high LET alpha-particle therapy using 225Ac labeled hu11B6, however emerging at a later timepoint

Enhanced annealing of mismatched oligonucleotides using a novel melting curve assay allows efficient in vitro discrimination and restriction of a single nucleotide polymorphism

<p>Abstract</p> <p>Background</p> <p>Many SNP discrimination strategies employ natural restriction endonucleases to discriminate between allelic states. However, SNPs are often not associated with a restriction site and therefore, a number of attempts have been made to generate sequence-adaptable restriction endonucleases. In this study, a simple, sequence-adaptable SNP discrimination mechanism between a 'wild-type' and 'mutant' template is demonstrated. This model differs from other artificial restriction endonuclease models as <it>cis- </it>rather than <it>trans-</it>orientated regions of single stranded DNA were generated and cleaved, and therefore, overcomes potential issues of either inefficient or non-specific binding when only a single variant is targeted.</p> <p>Results</p> <p>A series of mismatch 'bubbles' that spanned 0-5-bp surrounding a point mutation was generated and analysed for sensitivity to S1 nuclease. In this model, generation of oligonucleotide-mediated ssDNA mismatch 'bubbles' in the presence of S1 nuclease resulted in the selective degradation of the mutant template while maintaining wild-type template integrity. Increasing the size of the mismatch increased the rate of mutant sequence degradation, until a threshold above which discrimination was lost and the wild-type sequence was degraded. This level of fine discrimination was possible due to the development of a novel high-resolution melting curve assay to empirically determine changes in Tm (~5.0°C per base-pair mismatch) and to optimise annealing conditions (~18.38°C below Tm) of the mismatched oligonucleotide sets.</p> <p>Conclusions</p> <p>The <it>in vitro </it>'cleavage bubble' model presented is sequence-adaptable as determined by the binding oligonucleotide, and hence, has the potential to be tailored to discriminate between any two or more SNPs. Furthermore, the demonstrated fluorometric assay has broad application potential, offering a rapid, sensitive and high-throughput means to determine Tm and annealing rates as an alternative to conventional hybridisation detection strategies.</p

Flexibility of a Eukaryotic Lipidome – Insights from Yeast Lipidomics

Mass spectrometry-based shotgun lipidomics has enabled the quantitative and comprehensive assessment of cellular lipid compositions. The yeast Saccharomyces cerevisiae has proven to be a particularly valuable experimental system for studying lipid-related cellular processes. Here, by applying our shotgun lipidomics platform, we investigated the influence of a variety of commonly used growth conditions on the yeast lipidome, including glycerophospholipids, triglycerides, ergosterol as well as complex sphingolipids. This extensive dataset allowed for a quantitative description of the intrinsic flexibility of a eukaryotic lipidome, thereby providing new insights into the adjustments of lipid biosynthetic pathways. In addition, we established a baseline for future lipidomic experiments in yeast. Finally, flexibility of lipidomic features is proposed as a new parameter for the description of the physiological state of an organism

Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk

BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat

Arrhythmia and death following percutaneous revascularization in ischemic left ventricular dysfunction: Prespecified analyses from the REVIVED-BCIS2 trial

BACKGROUND: Ventricular arrhythmia is an important cause of mortality in patients with ischemic left ventricular dysfunction. Revascularization with coronary artery bypass graft or percutaneous coronary intervention is often recommended for these patients before implantation of a cardiac defibrillator because it is assumed that this may reduce the incidence of fatal and potentially fatal ventricular arrhythmias, although this premise has not been evaluated in a randomized trial to date. METHODS: Patients with severe left ventricular dysfunction, extensive coronary disease, and viable myocardium were randomly assigned to receive either percutaneous coronary intervention (PCI) plus optimal medical and device therapy (OMT) or OMT alone. The composite primary outcome was all-cause death or aborted sudden death (defined as an appropriate implantable cardioverter defibrillator therapy or a resuscitated cardiac arrest) at a minimum of 24 months, analyzed as time to first event on an intention-to-treat basis. Secondary outcomes included cardiovascular death or aborted sudden death, appropriate implantable cardioverter defibrillator (ICD) therapy or sustained ventricular arrhythmia, and number of appropriate ICD therapies. RESULTS: Between August 28, 2013, and March 19, 2020, 700 patients were enrolled across 40 centers in the United Kingdom. A total of 347 patients were assigned to the PCI+OMT group and 353 to the OMT alone group. The mean age of participants was 69 years; 88% were male; 56% had hypertension; 41% had diabetes; and 53% had a clinical history of myocardial infarction. The median left ventricular ejection fraction was 28%; 53.1% had an implantable defibrillator inserted before randomization or during follow-up. All-cause death or aborted sudden death occurred in 144 patients (41.6%) in the PCI group and 142 patients (40.2%) in the OMT group (hazard ratio, 1.03 [95% CI, 0.82–1.30]; P =0.80). There was no between-group difference in the occurrence of any of the secondary outcomes. CONCLUSIONS: PCI was not associated with a reduction in all-cause mortality or aborted sudden death. In patients with ischemic cardiomyopathy, PCI is not beneficial solely for the purpose of reducing potentially fatal ventricular arrhythmias. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01920048

Percutaneous revascularization for ischemic left ventricular dysfunction: Cost-effectiveness analysis of the REVIVED-BCIS2 trial

BACKGROUND: Percutaneous coronary intervention (PCI) is frequently undertaken in patients with ischemic left ventricular systolic dysfunction. The REVIVED (Revascularization for Ischemic Ventricular Dysfunction)-BCIS2 (British Cardiovascular Society-2) trial concluded that PCI did not reduce the incidence of all-cause death or heart failure hospitalization; however, patients assigned to PCI reported better initial health-related quality of life than those assigned to optimal medical therapy (OMT) alone. The aim of this study was to assess the cost-effectiveness of PCI+OMT compared with OMT alone. METHODS: REVIVED-BCIS2 was a prospective, multicenter UK trial, which randomized patients with severe ischemic left ventricular systolic dysfunction to either PCI+OMT or OMT alone. Health care resource use (including planned and unplanned revascularizations, medication, device implantation, and heart failure hospitalizations) and health outcomes data (EuroQol 5-dimension 5-level questionnaire) on each patient were collected at baseline and up to 8 years post-randomization. Resource use was costed using publicly available national unit costs. Within the trial, mean total costs and quality-adjusted life-years (QALYs) were estimated from the perspective of the UK health system. Cost-effectiveness was evaluated using estimated mean costs and QALYs in both groups. Regression analysis was used to adjust for clinically relevant predictors. RESULTS: Between 2013 and 2020, 700 patients were recruited (mean age: PCI+OMT=70 years, OMT=68 years; male (%): PCI+OMT=87, OMT=88); median follow-up was 3.4 years. Over all follow-ups, patients undergoing PCI yielded similar health benefits at higher costs compared with OMT alone (PCI+OMT: 4.14 QALYs, £22 352; OMT alone: 4.16 QALYs, £15 569; difference: −0.015, £6782). For both groups, most health resource consumption occurred in the first 2 years post-randomization. Probabilistic results showed that the probability of PCI being cost-effective was 0. CONCLUSIONS: A minimal difference in total QALYs was identified between arms, and PCI+OMT was not cost-effective compared with OMT, given its additional cost. A strategy of routine PCI to treat ischemic left ventricular systolic dysfunction does not seem to be a justifiable use of health care resources in the United Kingdom

Altered emotion perception in insomnia disorder

Study Objectives: Chronic insomnia is a prevalent sleep disorder that negatively affects daytime functioning and confers risk for the future development of psychiatric disorder. Patients with insomnia often report problems with emotion regulation and impaired social interactions. Moreover, experimental sleep loss in healthy adults is associated with altered reactivity to and interpretation of emotional information. In the current study, we investigated socioemotional processing in patients with chronic insomnia disorder relative to healthy good sleepers. Design: Between-groups comparison. Setting: Sleep Research Laboratory. Participants: Patients with well-defined psychophysiological insomnia (PI; n = 16), free from psychiatric disorder, and an age- and sex-matched control group of good sleepers (GS; n = 15). Interventions: N/A. Measurement and Results: All participants completed a facial expression recognition task, between 18:00 and 19:00, requiring participants to categorize and rate the intensity of four emotional expression categories: anger, fear, happiness, and sadness. People with PI did not differ from GS with respect to categorization of facial expressions. However, in terms of intensity judgements, across all emotion categories, patients tended to rate faces as less emotionally intense (Cohen's d = 0.70). Specifically, they rated expressions displaying sadness and fear as significantly less emotionally intense than healthy GS (both P &#60; 0.05; Cohen's d = 0.77 and 0.89, respectively). Measures of sleepiness (Psychomotor Vigilance Test, Karolinska Sleepiness Scale) or self-reported sleep were not reliably associated with emotional intensity ratings. However, anxiety and depression were negatively related to intensity ratings. Conclusion: For the first time we show that chronic insomnia is associated with reduced ratings of emotion intensity for face expressions displaying sadness and fear. Further work is required to elucidate possible mechanisms and pathways underlying insomnia-related emotional impairment

Silicon RF-Photonic Filter and Down-Converter

An RF-photonic filter and down-converter system based on a compact and fully tunable silicon optical filter has been demonstrated and analyzed. Its frequency down-conversion was implemented using optical heterodyne detection with an injection locked laser. This system filters a 1.25 GHz-wide signal with > 20 dB filter rejection and a very broad 20 GHz center tuning range. The frequency down-conversion process is operated in a low-IF mode to avoid laser low frequency noises. Measured system Spurious-Free Dynamic Range (SFDR) of 94.3 dB*Hz2/3 [dB*Hz superscript 2/3] has been limited by the optical losses from I/O coupling and measurement setup. We examined experimentally that 105.3 dB*Hz2/3 [dB*Hz superscript 2/3] SFDR is achievable if the encountered optical loss were reduced to the filter's intrinsic loss. Based on the excellent agreements between measured and simulated results, we explore the critical improvements of the silicon photonic devices needed for the system to achieve 118 dB*Hz2/3 [dB*Hz superscript 2/3] SFDR and briefly review the status of the component technologies.United States. Defense Advanced Research Projects Agency. Electronic and Photonic Integrated Circuit (EPIC) ProgramUnited States. Defense Advanced Research Projects Agency. Microsystems Technology Office (Contract No. HR0011-05-C-0027

Demonstration of a Tunable Microwave-Photonic Notch Filter Using Low-Loss Silicon Ring Resonators

We present a fully tunable multistage narrowband optical pole-zero notch filter that is fabricated in a silicon complementary metal oxide semiconductor (CMOS) foundry. The filter allows for the reconfigurable and independent tuning of the center frequency, null depth, and bandwidth for one or more notches simultaneously. It is constructed using a Mach-Zehnder interferometer (MZI) with cascaded tunable all-pass filter (APF) ring resonators in its arms. Measured filter nulling response exhibits ultranarrow notch 3 dB BW of 0.6350 GHz, and nulling depth of 33 dB. This filter is compact and integrated in an area of 1.75 mm2. Using this device, a novel method to cancel undesired bands of 3 dB bandwidth of < 910 MH[superscript 2] in microwave-photonic systems is demonstrated. The ultranarrow filter response properties have been realized based on our developed low-propagation loss silicon channel waveguide and tunable ring-resonator designs. Experimentally, they yielded a loss of 0.25 dB/cm and 0.18 dB/round trip, respectively.United States. Defense Advanced Research Projects Agency (project EPIC)Massachusetts Institute of Technology. Microsystems Technology Laboratories (Contract HR0011-05-C-0027