Second Data Release from the European Pulsar Timing Array: Challenging the Ultralight Dark Matter Paradigm

Pulsar Timing Array experiments probe the presence of possible scalar or pseudoscalar ultralight dark matter particles through decade-long timing of an ensemble of galactic millisecond radio pulsars. With the second data release of the European Pulsar Timing Array, we focus on the most robust scenario, in which dark matter interacts only gravitationally with ordinary baryonic matter. Our results show that ultralight particles with masses 10^{-24.0}  eV≲m≲10^{-23.3}  eV cannot constitute 100% of the measured local dark matter density, but can have at most local density ρ≲0.3  GeV/cm^{3}.

Spatially Resolved Whole Transcriptome Analysis of Histologically-Characterized Tissue Microarray of Patient-Matched Primary and Recurrent Glioblastomas to Identify Underlying Mechanisms of Treatment Resistance

PURPOSE/OBJECTIVE(S)

Glioblastoma multiforme (GBM) is a lethal CNS malignancy. Radiation therapy increases overall survival, but tumors often recur in high-radiation dose regions. Additionally, recent investigations have underscored the importance of intra-tumoral heterogeneity as a driver of GBM biology. The purpose of this investigation is to characterize transcriptome differences in primary and recurrent GBM patient clinical samples using a digital spatial profiling approach to better appreciate treatment resistance mechanisms.

MATERIALS/METHODS

To address the lack of understanding of molecular mechanisms of resistance in GBM, patient-matched primary and recurrent GBM pathological specimens were identified within the brain tissue biorepository and tissue cores were selected for generation of a tissue microarray (TMA). Hematoxylin and eosin staining with histomorphological (cellular tumor, pseudopalisading necrosis, invasive edge, and perivascular inflammation) scoring were performed in a blinded fashion for every core. This array was then molecularly characterized using digital spatial profiling of the transcriptome. Quality assurance including filtering of lowly expressed genes followed by downstream analyses of the data were performed using the manufacturer's recommended methods within their Bioconductor library. Gene Set Enrichment Analysis (GSEA) was then performed on the ranked gene lists.

RESULTS

After recommended filtering, 6171 genes and 248 regions of interest remained for downstream analysis representing 22 unique patients across four different tumor histomorphological types. Significance testing revealed 679 genes that were differentially expressed between primary and recurrent tumor samples (at FDR<1%). On GSEA analysis, the chromosomal positional locus that contains genes most strongly up-regulated is 12q14, a locus that was previously identified as genomically amplified in multiple patient-derived xenograft lines after radiation selection. Additionally, recurrent tumors display a transcriptional profile more similar to the mesenchymal subtype, whereas primary tumors have a more classical transcriptional phenotype. The epithelial-to-mesenchymal transition pathway is particularly strongly up-regulated in recurrent tumors.

CONCLUSION

Recurrent selection at previously identified genomic loci and molecular pathways underscores a possible conserved set of pathways for treatment resistance. This analysis has yielded a set of gene and molecular pathways that will guide future work in our lab targeting treatment resistance using novel therapeutics and radiation techniques in GBM. Future directions include assessing the feasibility of mapping these clinical samples onto our previously generated panel of comprehensively characterized patient-derived xenograft lines.

NGLY1 deficiency: a prospective natural history study

N-glycanase 1 (NGLY1) deficiency is a debilitating, ultra-rare autosomal recessive disorder caused by loss of function of NGLY1, a cytosolic enzyme that deglycosylates other proteins. It is characterized by severe global developmental delay and/or intellectual disability, hyperkinetic movement disorder, transient elevation of transaminases, (hypo)alacrima and progressive, diffuse, length-dependent sensorimotor polyneuropathy. A prospective natural history study (NHS) was conducted to elucidate clinical features and disease course. Twenty-nine participants were enrolled (15 onsite, 14 remotely) and followed for up to 32 months, representing ~29% of the ~100 patients identified worldwide. Participants exhibited profound developmental delays, with almost all developmental quotients below 20 on the Mullen Scales of Early Learning, well below the normative score of 100. Increased difficulties with sitting and standing suggested decline in motor function over time. Most patients presented with (hypo)alacrima and reduced sweat response. Pediatric quality of life was poor except for emotional function. Language/communication and motor skill problems including hand use were reported by caregivers as the most bothersome symptoms. Levels of the substrate biomarker, GlcNAc-Asn (aspartylglucosamine; GNA), were consistently elevated in all participants over time, independent of age. Liver enzymes were elevated for some participants but improved especially in younger patients and did not reach levels indicating severe liver disease. Three participants died during the study period. Data from this NHS informs selection of endpoints and assessments for future clinical trials for NGLY1 deficiency interventions. Potential endpoints include GNA biomarker levels, neurocognitive assessments, autonomic and motor function (particularly hand use), (hypo)alacrima and quality of life.

Spatial mapping of the DNA adducts in cancer

DNA adducts and strand breaks are induced by various exogenous and endogenous agents. Accumulation of DNA damage is implicated in many disease processes, including cancer, aging, and neurodegeneration. The continuous acquisition of DNA damage from exogenous and endogenous stressors coupled with defects in DNA repair pathways contribute to the accumulation of DNA damage within the genome and genomic instability. While mutational burden offers some insight into the level of DNA damage a cell may have experienced and subsequently repaired, it does not quantify DNA adducts and strand breaks. Mutational burden also infers the identity of the DNA damage. With advances in DNA adduct detection and quantification methods, there is an opportunity to identify DNA adducts driving mutagenesis and correlate with a known exposome. However, most DNA adduct detection methods require isolation or separation of the DNA and its adducts from the context of the nuclei. Mass spectrometry, comet assays, and other techniques precisely quantify lesion types but lose the nuclear context and even tissue context of the DNA damage. The growth in spatial analysis technologies offers a novel opportunity to leverage DNA damage detection with nuclear and tissue context. However, we lack a wealth of techniques capable of detecting DNA damage in situ. Here, we review the limited existing in situ DNA damage detection methods and examine their potential to offer spatial analysis of DNA adducts in tumors or other tissues. We also offer a perspective on the need for spatial analysis of DNA damage in situ and highlight Repair Assisted Damage Detection (RADD) as an in situ DNA adduct technique with the potential to integrate with spatial analysis and the challenges to be addressed.

Phosphodiesterase 10A (PDE10A) as a novel target to suppress β-catenin and RAS signaling in epithelial ovarian cancer

A leading theory for ovarian carcinogenesis proposes that inflammation associated with incessant ovulation is a driver of oncogenesis. Consistent with this theory, nonsteroidal anti-inflammatory drugs (NSAIDs) exert promising chemopreventive activity for ovarian cancer. Unfortunately, toxicity is associated with long-term use of NSAIDs due to their cyclooxygenase (COX) inhibitory activity. Previous studies suggest the antineoplastic activity of NSAIDs is COX independent, and rather may be exerted through phosphodiesterase (PDE) inhibition. PDEs represent a unique chemopreventive target for ovarian cancer given that ovulation is regulated by cyclic nucleotide signaling. Here we evaluate PDE10A as a novel therapeutic target for ovarian cancer. Analysis of The Cancer Genome Atlas (TCGA) ovarian tumors revealed PDE10A overexpression was associated with significantly worse overall survival for patients. PDE10A expression also positively correlated with the upregulation of oncogenic and inflammatory signaling pathways. Using small molecule inhibitors, Pf-2545920 and a novel NSAID-derived PDE10A inhibitor, MCI-030, we show that PDE10A inhibition leads to decreased ovarian cancer cell growth and induces cell cycle arrest and apoptosis. We demonstrate these pro-apoptotic properties occur through PKA and PKG signaling by using specific inhibitors to block their activity. PDE10A genetic knockout in ovarian cancer cells through CRISP/Cas9 editing lead to decreased cell proliferation, colony formation, migration and invasion, and in vivo tumor growth. We also demonstrate that PDE10A inhibition leads to decreased Wnt-induced β-catenin nuclear translocation, as well as decreased EGF-mediated activation of RAS/MAPK and AKT pathways in ovarian cancer cells. These findings implicate PDE10A as novel target for ovarian cancer chemoprevention and treatment.

Comparison of trans-radial access and femoral access in cardiogenic shock patient who had undergone primary percutaneous coronary intervention from SMART RESCUE trial

Introduction

Throughout the years of percutaneous coronary intervention (PCI), the debate regarding access route, whether it being trasns-radial or femoral, is an ongoing agenda yet to be solved. Recent guidelines suggest trans-radial approach as an option to be considered in acute coronary syndrome (ACS). However, data on cardiogenic shock patients undergoing PCI is relatively sparse.

Purpose

Compare the clinical implication of trans-radial and femoral approach in cardiogenic shock patients who had undergone PCI.

Method

Cardiogenic shock patients who had undergone PCI from January 2014 to December of 2018 were enrolled. Patients were divided according to their access route respectfully. Primary outcome was composite endpoints including all-cause death, re-admission due to heart failure, myocardial infarction (MI) and cerebrovascular accident.

Result

A total of 694 (572 via femoral approach, 122 via radial approach) cardiogenic shock patients who received PCI were enrolled. Mean age femoral and radial groups was 66.59±12.51 and 66.66±12.8 respectfully. Disease severity was higher for femoral patients compared to radial patients as represented by their LM involvement, mechanical organ support (extracorporeal membrane oxygenation, continuous renal replacement therapy, mechanical ventilation), left ventricular ejection fraction (LVEF) and vasoactive inotropic score. Cox regression analysis after adjusting for conventional risk factors showed that femoral route was a poor prognosticator with respect to composite endpoints (HR=2.059, 95% CI 1.249–3.397, p value = 0.005). Radial approach patients had higher survival probability compared to femoral approach patients (Figure 1).

Conclusion

Radial approach in cardiogenic shock patients who are in need for PCI with relatively less severe clinical condition could be a reasonable option for access route.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): Inha University Hospital

Development and Psychometric Validation of a Novel Self-Report Measure of ICD-11 Gaming Disorder

Video game use is associated with addiction-like behaviors in 6 to 15.6 percent of video game players. There were no formal diagnostic criteria for video game addiction until gaming disorder (GD) was added to the International Classification of Diseases 11th Edition (ICD-11), and there are no published instruments designed to diagnose GD. The aims of the current study were to develop a self-report measure of GD (using the Lee Morrell Gaming Disorder Questionnaire [LMGDQ]) and test its factor structure, reliability, validity, and relationships with participant demographic characteristics. Participants included 3,481 adult video game players (M = 25.08, SD = 7.02; 79.8 percent cisgender male; 77.4 percent Caucasian) who completed an online survey. Factor analyses suggested retaining 14 items and indicated the presence of two factors. The scale had excellent reliability (α = 0.919), and LMGDQ scores were positively correlated with existing scales measuring problematic video game use as well as video game use and age, p values <0.01. Participants who were Asian and Asian American, cisgender men, single and dating, unemployed, had completed some high school or their GED, and who played massively multiplayer online role-playing games the most reported significantly greater LMGDQ scores, p values <0.05. Results suggest that the LMGDQ is a psychometrically sound and valid measure of GD.

An in vivo model of glioblastoma radiation resistance identifies long non-coding RNAs and targetable kinases

Key molecular regulators of acquired radiation resistance in recurrent glioblastoma (GBM) are largely unknown, with a dearth of accurate preclinical models. To address this, we generated 8 GBM patient-derived xenograft (PDX) models of acquired radiation therapy–selected (RTS) resistance compared with same-patient, treatment-naive (radiation-sensitive, unselected; RTU) PDXs. These likely unique models mimic the longitudinal evolution of patient recurrent tumors following serial radiation therapy. Indeed, while whole-exome sequencing showed retention of major genomic alterations in the RTS lines, we did detect a chromosome 12q14 amplification that was associated with clinical GBM recurrence in 2 RTS models. A potentially novel bioinformatics pipeline was applied to analyze phenotypic, transcriptomic, and kinomic alterations, which identified long noncoding RNAs (lncRNAs) and targetable, PDX-specific kinases. We observed differential transcriptional enrichment of DNA damage repair pathways in our RTS models, which correlated with several lncRNAs. Global kinomic profiling separated RTU and RTS models, but pairwise analyses indicated that there are multiple molecular routes to acquired radiation resistance. RTS model–specific kinases were identified and targeted with clinically relevant small molecule inhibitors. This cohort of in vivo RTS patient-derived models will enable future preclinical therapeutic testing to help overcome the treatment resistance seen in patients with GBM.

Examining utilization of kidneys as a function of procurement performance

Questions have arisen around new metrics for organ procurement organizations (OPO) due to the perception that low-performing OPOs may be limited by local centers' acceptance of marginal organs. We reviewed 2013-2019 Organ Procurement and Transplantation Network (OTPN) and National Centers for Health Statistics (NCHS) data to explore the relationship between objectively measured OPO performance and utilization of deceased donor kidneys. We found that although donor recovery declined with rising age and kidney donor profile index (KDPI), OPO performance differences were evident within each age/KDPI group. By contrast, the number of discards per donor did not vary with OPO performance. Centers in donor service areas (DSAs) with lower-performing OPOs had higher local utilization and greater import of high-KDPI kidneys than did those with higher-performing OPOs. Lower rates of donor availability relative to waitlist additions may contribute to observed center acceptance behavior. Differences in center-level performance were highly visible in Scientific Registry of Transplant Recipients (SRTR) organ acceptance metrics, while SRTR OPO metrics did not detect large or persistent variation in procurement performance. Cumulatively, our findings suggest that objective measures of procurement performance can inform discussions of organ utilization, allowing for alignment of metrics in all elements of the procurement-transplantation system.

Repair-Assisted Damage Detection Reveals Biological Disparities in Prostate Cancer between African Americans and European Americans

Simple Summary

Prostate cancer is the most diagnosed cancer among men in the United States. African American men are diagnosed with and succumb to prostate cancer at higher rates than other demographic groups. Previously published works described the biological differences in prostate tumors that may contribute to poorer outcomes in African American men compared to European American men. This study was designed to explore the DNA lesion profiles found in prostate tissues. Using tissue microarrays, we found that prostate tumors from African American patients have more uracil and pyrimidine damage, elevated UNG levels, and reduced XRCC1 levels than European American tumors, which may indicate defects in the base excision repair pathway. In addition, these men had higher UMP and lower expression of folate cycle metabolites, suggesting that metabolic rewiring may also contribute to the dysregulation of base excision repair.

Abstract

African Americans (AA) are two times more likely to be diagnosed with and succumb to prostate cancer (PCa) compared to European Americans (EA). There is mounting evidence that biological differences in these tumors contribute to disparities in patient outcomes. Our goal was to examine the differences in DNA damage in AA and EA prostate tissues. Tissue microarrays with matched tumor-benign adjacent pairs from 77 AA and EA PCa patients were analyzed for abasic sites, oxidative lesions, crosslinks, and uracil content using the Repair Assisted Damage Detection (RADD) assay. Our analysis revealed that AA PCa, overall, have more DNA damage than EA PCa. Increased uracil and pyrimidine lesions occurred in AA tumors, while EA tumors had more oxidative lesions. AA PCa have higher levels of UMP and folate cycle metabolites than their EA counterparts. AA PCa showed higher levels of UNG, the uracil-specific glycosylase, than EA, despite uracil lesions being retained within the genome. AA patients also had lower levels of the base excision repair protein XRCC1. These results indicate dysfunction in the base excision repair pathway in AA tumors. Further, these findings reveal how metabolic rewiring in AA PCa drives biological disparities and identifies a targetable axis for cancer therapeutics.

Procurement characteristics of high- and low-performing OPOs as seen in OPTN/SRTR data

To meet new Centers for Medicare and Medicaid Services (CMS) metrics, organ procurement organizations (OPOs) will benefit from understanding performance across decedent and hospital types. We sought to determine the utility of existing data-reporting structures for this purpose by reviewing Scientific Registry of Transplant Recipient (SRTR) OPO-Specific Reports (OSRs) from 2013 to 2019. OSRs contain both the Standardized donation rate ratio (SDRR) metric and OPO-reported numbers of "eligible deaths" and donors by hospital. Donor hospitals were characterized using information from Homeland Infrastructure Foundation-Level Data, Dartmouth Atlas Hospital Service Area data, and the US Census Bureau. Hospital data reported by OPOs showed 51% higher eligible death donors and 140% higher noneligible death donors per 100 inpatient beds in CMS ranked top versus bottom-quartile OPOs. Top-quartile OPOs by the CMS metric recovered 78% more donors than those in the bottom quartile, but were indistinguishable by SDRR rankings. These differences persisted across hospital sizes, trauma case mix, and area demographics. OPOs with divergent performance were indistinguishable over time by SDRR, but showed changes to hospital-level recovery patterns in SRTR data. Contemporaneous recognition of underperformance across hospitals may provide important and actionable data for regulators and OPOs for focused quality improvement projects.

Guiding Chemically Synthesized Peptide Drug Lead Optimization by Derisking Mast Cell Degranulation-Related Toxicities of a NaV1.7 Peptide Inhibitor

Studies have shown that some peptides and small molecules can induce non IgE-mediated anaphylactoid reactions through mast cell activation. Upon activation, mast cells degranulate and release vasoactive and proinflammatory mediators, from cytoplasmic granules into the extracellular environment which can induce a cascade of severe adverse reactions. This study describes a lead optimization strategy to select NaV1.7 inhibitor peptides that minimize acute mast cell degranulation (MCD) toxicities. Various in vitro, in vivo, and PKPD models were used to screen candidates and guide peptide chemical modifications to mitigate this risk. Anesthetized rats dosed with peptides demonstrated treatment-related decreases in blood pressure and increases in plasma histamine concentrations which were reversible with a mast cell stabilizer, supporting the MCD mechanism. In vitro testing in rat mast cells with NaV1.7 peptides demonstrated a concentration-dependent increase in histamine. Pharmacodynamic modeling facilitated establishing an in vitro to in vivo correlation for histamine as a biomarker for blood pressure decline via the MCD mechanism. These models enabled assessment of structure-activity relationship (SAR) to identify substructures that contribute to peptide-mediated MCD. Peptides with hydrophobic and cationic characteristics were determined to have an elevated risk for MCD, which could be reduced or avoided by incorporating anionic residues into the protoxin II scaffold. Our analyses support that in vitro MCD assessment in combination with PKPD modeling can guide SAR to improve peptide lead optimization and ensure an acceptable early in vivo tolerability profile with reduced resources, cycle time, and animal use.

Opportunity to increase deceased donation for United States veterans

Recent changes to organ procurement organization (OPO) performance metrics have highlighted the need to identify opportunities to increase organ donation in the United States. Using data from the Organ Procurement and Transplantation Network (OPTN), Scientific Registry of Transplant Recipients (SRTR), and Veteran Health Administration Informatics and Computing Infrastructure Clinical Data Warehouse (VINCI CDW), we sought to describe historical donation performance at Veteran Administration Medical Centers (VAMCs). We found that over the period 2010-2019, there were only 33 donors recovered from the 115 VAMCs with donor potential nationwide. VA donors had similar age-matched organ transplant yields to non-VA donors. Review of VAMC records showed a total of 8474 decedents with causes of death compatible with donation, of whom 5281 had no infectious or neoplastic comorbidities preclusive to donation. Relative to a single state comparison of adult non-VA inpatient deaths, VAMC deaths were 20 times less likely to be characterized as an eligible death by SRTR. The rate of conversion of inpatient donation-consistent deaths without preclusive comorbidities to actual donors at VAMCs was 5.9% that of adult inpatients at non-VA hospitals. Overall, these findings suggest significant opportunities for growth in donation at VAMCs.

Suppression of Colon Tumorigenesis in Mutant Apc Mice by a Novel PDE10 Inhibitor that Reduces Oncogenic β-Catenin

Previous studies have reported that phosphodiesterase 10A (PDE10) is overexpressed in colon epithelium during early stages of colon tumorigenesis and essential for colon cancer cell growth. Here we describe a novel non-COX inhibitory derivative of the anti-inflammatory drug, sulindac, with selective PDE10 inhibitory activity, ADT 061. ADT 061 potently inhibited the growth of colon cancer cells expressing high levels of PDE10, but not normal colonocytes that do not express PDE10. The concentration range by which ADT 061 inhibited colon cancer cell growth was identical to concentrations that inhibit recombinant PDE10. ADT 061 inhibited PDE10 by a competitive mechanism and did not affect the activity of other PDE isozymes at concentrations that inhibit colon cancer cell growth. Treatment of colon cancer cells with ADT 061 activated cGMP/PKG signaling, induced phosphorylation of oncogenic β-catenin, inhibited Wnt-induced nuclear translocation of β-catenin, and suppressed TCF/LEF transcription at concentrations that inhibit cancer cell growth. Oral administration of ADT 061 resulted in high concentrations in the colon mucosa and significantly suppressed the formation of colon adenomas in the Apc^+/min-FCCC mouse model of colorectal cancer without discernable toxicity. These results support the development of ADT 061 for the treatment or prevention of adenomas in individuals at risk of developing colorectal cancer. PREVENTION RELEVANCE: PDE10 is overexpressed in colon tumors whereby inhibition activates cGMP/PKG signaling and suppresses Wnt/β-catenin transcription to selectively induce apoptosis of colon cancer cells. ADT 061 is a novel PDE10 inhibitor that shows promising cancer chemopreventive activity and tolerance in a mouse model of colon cancer.

Organizing a Successful Practice and Considering Tax and Estate Planning

To care for your family and to do "good" for your alma mater, religious organization, and the other charities you love, you need to do "well," which is to build a successful practice. To achieve a successful practice, following the principles of the dozen A's is helpful: Ability, Availability, Amicability, Approachable, Attuned, Aware, Attentive to patients, Attentive to others, Attentive to details, Apology (ability to apologize and accept apology gracefully), Assimilate, Affordable. Another way to put it is "skills to treat, heart to care at a sensible price."

Genetic screening reveals phospholipid metabolism as a key regulator of the biosynthesis of the redox-active lipid coenzyme Q

Mitochondrial energy production and function rely on optimal concentrations of the essential redox-active lipid, coenzyme Q (CoQ). CoQ deficiency results in mitochondrial dysfunction associated with increased mitochondrial oxidative stress and a range of pathologies. What drives CoQ deficiency in many of these pathologies is unknown, just as there currently is no effective therapeutic strategy to overcome CoQ deficiency in humans. To date, large-scale studies aimed at systematically interrogating endogenous systems that control CoQ biosynthesis and their potential utility to treat disease have not been carried out. Therefore, we developed a quantitative high-throughput method to determine CoQ concentrations in yeast cells. Applying this method to the Yeast Deletion Collection as a genome-wide screen, 30 genes not known previously to regulate cellular concentrations of CoQ were discovered. In combination with untargeted lipidomics and metabolomics, phosphatidylethanolamine N-methyltransferase (PEMT) deficiency was confirmed as a positive regulator of CoQ synthesis, the first identified to date. Mechanistically, PEMT deficiency alters mitochondrial concentrations of one-carbon metabolites, characterized by an increase in the S-adenosylmethionine to S-adenosylhomocysteine (SAM-to-SAH) ratio that reflects mitochondrial methylation capacity, drives CoQ synthesis, and is associated with a decrease in mitochondrial oxidative stress. The newly described regulatory pathway appears evolutionary conserved, as ablation of PEMT using antisense oligonucleotides increases mitochondrial CoQ in mouse-derived adipocytes that translates to improved glucose utilization by these cells, and protection of mice from high-fat diet-induced insulin resistance. Our studies reveal a previously unrecognized relationship between two spatially distinct lipid pathways with potential implications for the treatment of CoQ deficiencies, mitochondrial oxidative stress/dysfunction, and associated diseases.

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Mitochondrial CoQ deficiency results in oxidative stress and a range of pathologies

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The drivers of mitochondrial CoQ deficiency remain largely unknown

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PEMT deficiency is the first identified positive regulator of mitochondrial CoQ

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PEMT deficiency increases CoQ by increasing the mitochondrial SAM-to-SAH ratio

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PEMT deficiency prevents insulin resistance by increasing mitochondrial CoQ

Abstract 1213: PDE10A as a novel target to suppress Wnt/β-catenin signaling and other oncogenic pathways in ovarian cancer

Objective: A leading theory for ovarian carcinogenesis proposes that the inflammation associated with incessant ovulation is a driver of oncogenesis. Consistent with this theory, epidemiological studies have shown that nonsteroidal anti-inflammatory drugs (NSAIDs) decrease ovarian cancer risk. Previous studies suggest, however, that the antineoplastic activity of NSAIDs does not require the traditional cyclooxygenase (COX) enzyme inhibition, and rather may be exerted through phosphodiesterase (PDE) inhibition. PDEs represent a potentially unique chemopreventive target for ovarian cancer given that ovulation is regulated by cyclic nucleotide signaling. This study evaluates the effects of phosphodiesterase 10A (PDE10A) inhibition as a novel chemopreventive and therapeutic approach for ovarian cancer.

Methods: We investigated the effects of PDE10A small molecule inhibitors, Pf-2545920 and MCI-030 (a novel non-COX inhibitory NSAID-derivative), and PDE10A knockout by CRISPR/Cas9 gene editing in various ovarian cancer cell lines using in vitro assays that measured cell proliferation, cell viability, cell cycle arrest, apoptosis, cell migration and invasion. Downstream signaling pathways affected by PDE10A inhibition and gene knockout (KO) were assessed by western-blotting, confocal microscopy, and RNA sequencing.

Results: Analysis of The Cancer Genome Atlas (TCGA) ovarian cancer database and an institutional cohort of ovarian cancer patients revealed that high PDE10A mRNA expression was associated with significantly worse overall survival. PDE10A expression was also positively correlated with oncogenic and inflammatory signaling pathways in the TCGA dataset. PDE10A inhibition with Pf-2545920 or MCI-030 decreased ovarian cancer cell proliferation, while inducing cell cycle arrest and apoptosis. Using inhibitors to block PKA (H89) and PKG (KT5823) kinase activity, we demonstrated that the pro-apoptotic effects of PDE10A inhibition were mediated by activation of cGMP/PKG and cAMP/PKA signaling. SKOV3 and OV-90 PDE10A KO cells showed decreased colony formation, cell proliferation, and migration and invasion properties compared to their wild-type (WT) counterparts. Moreover, PDE10A inhibition decreased Wnt-induced β-catenin nuclear translocation as well as decreased EGF-mediated activation of RAS/MAPK and AKT pathways in ovarian cancer cells. RNA sequencing of SKOV3 PDE10A KO clones revealed that pathways associated with cancer, Wnt and TGF-β signaling were downregulated compared to WT control cells.

Conclusions: Our data demonstrate that PDE10A has pro-tumorigenic effects in ovarian cancer cells and its high expression in ovarian cancer patients is associated with poor prognosis. Altogether, our results warrant future studies of PDE10A as a novel target for ovarian cancer chemoprevention and/or treatment.

Citation Format: Rebecca M. Barber, Elaine Gavin, Alla Musiyenko, Wito Richter, Kevin J. Lee, Annelise Wilhite, Joel F. Andrews, Steve McClellan, Ileana Aragon, Antonio Ward, Xi Chen, Adam Keeton, Kristy Berry, Gary A. Piazza, Jennifer M. Scalici, Luciana Madeira da Silva. PDE10A as a novel target to suppress Wnt/β-catenin signaling and other oncogenic pathways in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1213.

Associations between DNA Damage and PD-L1 Expression in Ovarian Cancer, a Potential Biomarker for Clinical Response

Simple Summary

This work establishes that ovarian tumors contain persistent oxidative DNA damage levels that can be measured using Repair Assisted Damage Detection (RADD). The persistent DNA damage correlates with increased protein expression of PD-L1, establishing a link between genomic instability and PD-L1 expression across ovarian tumors. DNA damage may be a potential biomarker for immunotherapy.

Abstract

Programmed death ligand-1 (PD-L1) inhibitors are currently under investigation as a potential treatment option for ovarian cancer. Although this therapy has shown promise, its efficacy is highly variable among patients. Evidence suggests that genomic instability influences the expression of PD-L1, but little is known about this relationship in ovarian cancer. To examine the relationship between PD-L1 expression and genomic instability, we measured DNA damage using Repair Assisted Damage Detection (RADD). We then correlated the presence of persistent DNA damage in the ovarian tumor with protein expression of PD-L1 using immunohistochemistry. Ovarian tumors showed a high prevalence of oxidative DNA damage. As the level of oxidative DNA damage increased, we saw a significant correlation with PD-L1 expression. The highest correlation between DNA damage and PD-L1 expression was observed for mucinous ovarian tumors (r = 0.82), but a strong correlation was also observed for high grade serous and endometrioid tumors (r = 0.67 and 0.69, respectively). These findings link genomic instability to PD-L1 protein expression in ovarian cancer and suggest that persistent DNA damage can be used as a potential biomarker for patient selection for immunotherapy treatment.

Micro-electromechanical-system-tuned resonant filters spanning the 8-12 µm band

The spectral band covering ∼8-12µm is atmospherically transparent and therefore important for terrestrial imaging, day/night situational awareness systems, and spectroscopic applications. There is a dearth of tunable filters spanning the band. Here, we propose and demonstrate a new, to the best of our knowledge, tunable-filter method engaging the fundamental physics of the guided-mode resonance (GMR) effect realized with a non-periodic lattice. The polarization-dependent filter is fashioned with a one-dimensional Ge grating on a ZnSe substrate and interrogated with a ∼1.5mm Gaussian beam to show clear transmittance nulls. To expand the tuning range, the device parameters are optimized for sequential operation in TM and TE polarization states. The theoretical model exhibits a tunable range exceeding 4 µm, thus covering the band fully. In the experiment, a prototype device exhibits a spectral range of 8.6-10.0 µm in TM and 9.9-11.7 µm in TE polarization or >3µm total. With additional efforts in fabrication, we expect to achieve the full range.

EGFR signaling promotes resistance to CHK1 inhibitor prexasertib in triple negative breast cancer

Aim: Innate resistance to the CHK1 inhibitor prexasertib has been described, but resistance mechanisms are not understood. We aimed to determine the role epidermal growth factor receptor (EGFR) plays in innate resistance to prexasertib in triple negative breast cancer (TNBC).

Methods: Using a panel of pre-clinical TNBC cell lines, we measured the sensitivity to prexasertib. We examined the effect activation of EGFR had on prexasertib sensitivity. We measured the synergy of dual blockade of EGFR with erlotinib and CHK1 with prexasertib in TNBC cell lines and xenografts.

Results: EGFR overexpression and activation increased resistance to CHK1 inhibition by prexasertib. EGFR promoted the phosphorylation of BCL2-associated agonist of cell death (BAD), inactivating its pro-apoptotic functions. Inhibition of EGFR reversed BAD phosphorylation, increasing sensitivity to prexasertib.

Conclusion: The use of prexasertib as a monotherapy in TNBC has been limited due to modest clinical responses. We demonstrated that EGFR activation contributes to innate resistance to prexasertib in TNBC and potentially other cancers. EGFR expression status should be considered in clinical trials examining prexasertib’s use as a monotherapy or combination therapy.

No pulsed radio emission during a bursting phase of a Galactic magnetar

Fast radio bursts (FRBs) are millisecond-duration radio transients of unknown physical origin observed at extragalactic distances^1-3. It has long been speculated that magnetars are the engine powering repeating bursts from FRB sources^4-13, but no convincing evidence has been collected so far¹⁴. Recently, the Galactic magnetar SRG 1935+2154 entered an active phase by emitting intense soft γ-ray bursts¹⁵. One FRB-like event with two peaks (FRB 200428) and a luminosity slightly lower than the faintest extragalactic FRBs was detected from the source, in association with a soft γ-ray/hard-X-ray flare^18-21. Here we report an eight-hour targeted radio observational campaign comprising four sessions and assisted by multi-wavelength (optical and hard-X-ray) data. During the third session, 29 soft-γ-ray repeater (SGR) bursts were detected in γ-ray energies. Throughout the observing period, we detected no single dispersed pulsed emission coincident with the arrivals of SGR bursts, but unfortunately we were not observing when the FRB was detected. The non-detection places a fluence upper limit that is eight orders of magnitude lower than the fluence of FRB 200428. Our results suggest that FRB-SGR burst associations are rare. FRBs may be highly relativistic and geometrically beamed, or FRB-like events associated with SGR bursts may have narrow spectra and characteristic frequencies outside the observed band. It is also possible that the physical conditions required to achieve coherent radiation in SGR bursts are difficult to satisfy, and that only under extreme conditions could an FRB be associated with an SGR burst.

Exploiting DNA repair defects in triple negative breast cancer to improve cell killing

Background:

The lack of molecular targets for triple negative breast cancer (TNBC) has limited treatment options and reduced survivorship. Identifying new molecular targets may help improve patient survival and decrease recurrence and metastasis. As DNA repair defects are prevalent in breast cancer, we evaluated the expression and repair capacities of DNA repair proteins in preclinical models.

Methods:

DNA repair capacity was analyzed in four TNBC cell lines, MDA-MB-157 (MDA-157), MDA-MB-231 (MDA-231), MDA-MB-468 (MDA-468), and HCC1806, using fluorescence multiplex host cell reactivation (FM-HCR) assays. Expression of DNA repair genes was analyzed with RNA-seq, and protein expression was evaluated with immunoblot. Responses to the combination of DNA damage response inhibitors and primary chemotherapy drugs doxorubicin or carboplatin were evaluated in the cell lines.

Results:

Defects in base excision and nucleotide excision repair were observed in preclinical TNBC models. Gene expression analysis showed a limited correlation between these defects. Loss in protein expression was a better indicator of these DNA repair defects. Over-expression of PARP1, XRCC1, RPA, DDB1, and ERCC1 was observed in TNBC preclinical models, and likely contributed to altered sensitivity to chemotherapy and DNA damage response (DDR) inhibitors. Improved cell killing was achieved when primary therapy was combined with DDR inhibitors for ATM, ATR, or CHK1.

Conclusion:

Base excision and nucleotide excision repair pathways may offer new molecular targets for TNBC. The functional status of DNA repair pathways should be considered when evaluating new therapies and may improve the targeting for primary and combination therapies with DDR inhibitors.

Unpolarized resonant notch filters for the 8-12 µm spectral region

The long-wave infrared (LWIR) spectral region spanning ∼8-12µm is useful for many scientific and industrial applications. As traditional multilayer film components are not straightforwardly realized at these bands, we provide design, fabrication, and testing of polarization independent bandstop filters based on the guided-mode resonance (GMR) effect. Focusing on the zero-contrast grating architecture, we successfully fabricate prototype filters in the Ge-on-ZnSe materials system. Applying mask-based photolithography and dry etching, photoresist patterns form the desired Ge grating structures. The resulting devices exhibit clean transmittance nulls and acceptably high sidebands. Moreover, we verify polarization independent notch filtering by assembling two identical GMR filters with gratings oriented orthogonally. This approach to realize effective GMR elements will be useful for various fields including photonic and optoelectronic devices operating in the LWIR region.

Abstract 3464: Vitamin D supplementation to improve doxorubicin-induced cardiotoxicity in triple negative breast cancers

Doxorubicin (Dox) is a first-line treatment for triple negative breast cancer (TNBC), which lacks the molecular targets for hormone or growth factor therapy. Although highly effective as a chemotherapeutic agent, Dox induces severe side effects including cardiotoxicity that can cause patients to stop treatment early and impact the long-term health of patients in remission. Reactive oxygen species (ROS) are the predominant contributing factor to Dox-induced cardiotoxicity. Here, we sought to use the antioxidant vitamin D to provide a cardioprotective environment to prevent or reduce cardiotoxicity in a mouse model of TNBC. Supplementation with vitamin D (10,000 IU/kg) in chow for two weeks significantly increased the active vitamin D metabolite (25(OH)VD3) in plasma from 61.2 ± 4.5 nM (Mean ± SEM) to 85.0 ± 6.3 nM (P &lt; 0.05). Supplemented and normal chow mice were then inoculated with the syngeneic 4T1 mouse model of TNBC, and subjected to 10 mg/kg Dox once per week for two weeks. Cardiotoxicity was monitored through non-invasive echocardiography weekly. After two weeks, mice on standard chow with moderate levels of vitamin D exposed to 10 mg/kg Dox showed clear signs of cardiotoxicity represented by a decrease in cardiac output from 9.7 ± 0.5 mL/min in control mice to 4.8 ± 0.9 mL/min in mice treated with Dox (P &lt; 0.001); a decrease in ejection fraction from 49.2% ± 1.9 in control mice to 35.7% ± 5.9 in Dox mice (P &lt; 0.05); and a decrease in fractional shortening from 24.4% ± 1.2 in control mice to 16.9% ± 3.1 in Dox mice (P &lt; 0.05). Mice treated with Dox also showed detectable levels of cardiac troponin (0.04 ± 0.01 ng/mL) in circulating plasma indicative of cardiac damage, while troponin levels in control mice were undetectable. Vitamin D supplementation during exposure to Dox prevented cardiotoxicity in all parameters tested with levels of cardiac output of 7.4 ± 0.9 mL/min compared to 4.8 ± 0.9 mL/min in Dox mice; ejection fraction of 55.3% ± 3.4 compared to 35.7% ± 5.9 in Dox mice (P &lt; 0.01); and fractional shortening of 28.1% ± 2.1 compared to 16.9% ± 3.1 in Dox mice (P &lt; 0.01). Cardiac troponin levels were also undetectable similar to control mice. Vitamin D supplementation during Dox exposure resulted in cardiac function not significantly different than control, untreated mice. These data support further examination of vitamin D supplementation during chemotherapy to prevent cardiac toxicity and to enhance long-term outcome of TNBC patients.

Citation Format: Kevin J. Lee, Griffin Wright, Leigh Ann Wiggins, Michele Schuler, Natalie R. Gassman. Vitamin D supplementation to improve doxorubicin-induced cardiotoxicity in triple negative breast cancers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3464.

Role of a modified ultrafast MRI brain protocol in clinical paediatric neuroimaging

AIM

To establish a role for modified ultrafast magnetic resonance imaging (MRI) of the brain in clinical paediatric patients based on clinically acceptable image quality and diagnostic accuracy.

MATERIALS AND METHODS

A prospective study was conducted with institutional review board approval on an ultrafast MRI brain protocol consisting of sagittal T1-weighted, axial T2-weighted, axial fluid-attenuated inversion recovery (FLAIR), axial diffusion-weighted imaging (DWI), and axial T2∗-weighted sequences. Preliminary investigations revealed that the default ultrafast T2-weighted sequence was prone to pulsation artefacts. A modified ultrafast T2-weighted sequence was therefore developed to replace the default ultrafast T2-weighted sequence. Thirty-five patients with clinical indication for neuroimaging underwent ultrafast MRI, modified ultrafast T2-weighted sequence and standard MRI at 3 T. Image quality of ultrafast MRI sequences were graded as clinically "diagnostic" or "non-diagnostic" and compared against the corresponding standard MRI sequences as the reference standard. The modified ultrafast T2-weighted sequence surpassed the default ultrafast T2-weighted sequence in image quality. The ultrafast MRI protocol was therefore replaced with the modified ultrafast T2-weighted sequence creating a modified ultrafast MRI protocol. The clinical reports of modified ultrafast MRI were compared against standard MRI for diagnostic concordance, categorised further as "normal", "clinically significant", or "clinically minor" abnormalities.

RESULTS

Ultrafast T1-weighted, FLAIR, and DWI sequences had comparable image quality to standard MRI sequences. The ultrafast T2∗-weighted sequence had significantly higher non-diagnostic images (42.9%) compared to the standard MRI sequence (2.9%). The default ultrafast T2-weighted sequence had significantly higher non-diagnostic images compared to the modified ultrafast T2-weighted sequence and standard T2-weighted sequence (82.9%, 5.7%, 8.6%, respectively). There was 100% concordance for normal and clinically significant abnormalities and 23% discordance for clinically minor abnormalities. Modified ultrafast MRI takes 5 minutes 41 seconds compared to standard MRI time of 14 minutes 57 seconds.

CONCLUSION

The modified ultrafast MRI protocol for brain imaging demonstrates clinically acceptable image quality in four out of five sequences and has high accuracy in diagnosing normal and clinically significant abnormalities when compared against the standard MRI protocol for brain imaging. It could potentially benefit a select group of paediatric patients who require neuroimaging.

TEK is a novel prognostic marker for clear cell renal cell carcinoma

OBJECTIVE

Clear cell renal cell carcinoma (ccRCC) is the most common type of kidney cancer. However, effective therapeutics for ccRCC are lacking. Novel biomarkers could provide critical information when determining prognoses for patients with ccRCC. In this study, we sought to determine if the expression of receptor tyrosine kinase (TEK) could be a potential novel prognostic biomarker for ccRCC. TEK, originally identified as an endothelial cell-specific receptor, plays an important role in the modulation of vasculogenesis and remodeling. Altered TEK expression has been observed in tumor tissues (e.g., oral squamous cell carcinomas, leukemia) and breast, gastric and thyroid cancers. However, the role of TEK in ccRCC remains unknown.

PATIENTS AND METHODS

Differential TEK expression between non-metastatic (stage M0) and metastatic (stage M1) ccRCC patient cohorts was determined from The Cancer Genome Atlas (TCGA) and the International Cancer Genome Consortium (ICGC). Furthermore, TEK expression was assessed as a prognostic factor using the time-dependent area under the curve (AUC) of Uno's C-index, the AUC value of the receiver operating characteristics (ROC) at 5 years, Kaplan-Meier survival curves and multivariate analyses.

RESULTS

A Kaplan-Meier curve analysis revealed that the downregulation of TEK expression was associated with a poor prognosis for patients with ccRCC with good discrimination (p<0.0001 and p=0.0044 for the TGCA and ICGC cohorts, respectively). Analyses of C-indices and receiver operating characteristic AUC values further support this discriminative ability. Moreover, multivariate analyses showed the prognostic significance of TEK expression levels (p<0.001).

CONCLUSIONS

Although additional clinical investigations will be needed, our results suggest that TEK is a potential biomarker for ccRCC.

Otolaryngologist as a Political Leader?

Otolaryngologists are in a good position to advocate for our patients and our specialty. We can do it as a volunteer or as a full-time job running for political office at the state or federal level. To be taken seriously, we need to offer solutions besides citing the problems. We encourage otolaryngologists to work with our Academy and its ENT-PAC (Ear, Nose, Throat Political Action Committee). Medicine is a great profession and Otolaryngology-Head and Neck Surgery is an even better specialty.

The interplay of sun damage and genetic risk in Australian multiple and single primary melanoma cases and controls

BACKGROUND

Skin phenotype, host genotype and ultraviolet (UV) damage play a role in the development of melanoma.

OBJECTIVES

To ascertain whether the level of UV damage at the site of melanomas was associated with genetic polymorphisms.

METHODS

Deep phenotyping was performed on 1244 individuals; 281 with multiple primary melanomas (MPMs), 304 with single primary melanoma (SPM) and 659 convenience controls. Genotype data was generated using the Illumina CoreExome microarray platform, assaying over 500 000 single-nucleotide polymorphisms. A subset of variants were combined to assess a polygenic risk score (PRS) for melanoma.

RESULTS

Most MPM cases were diagnosed in patients aged > 40 years, in sites with visible chronic UV damage. Women and those diagnosed at age ≤ 40 years were less likely to have perilesional UV damage. Patients with MPM had higher frequencies of MITF E318K, MC1R R-alleles and the ASIP risk haplotype. Individuals who had melanoma in a visibly UV-damaged site were more likely to carry MC1R rs75570604 [odds ratio (OR) 2·5], 9q31.2 rs10816595 (OR 1·4) and MTAP rs869329 (OR 1·4). These same alleles were more common in patients with MPM who were diagnosed at age ≤ 40 years. The mean PRS was significantly higher in MPM than in SPM and controls. Naevus count was comparable in early-onset MPM cases and those diagnosed at age > 40 years.

CONCLUSIONS

Our cohort demonstrated higher frequencies of previously reported alleles associated with melanoma. MPM melanomas more commonly occur in UV-damaged areas, and these individuals are more likely to carry MC1R red hair colour alleles. Awareness of the interplay of genetic vulnerability with UV damage can stratify risk and guide recommendations for melanoma screening. What's already known about this topic? Skin phenotype, host genotype and ultraviolet (UV) damage all play a role in melanoma development. One of the main risk factors is a personal history of melanoma; second and subsequent primary melanomas account for over 20% of all melanomas registered in Queensland. Multiple loci are associated with melanoma risk, including many low-penetrance loci, which may have a cumulatively significant risk. Population-wide screening programmes for melanoma are not yet economically viable. What does this study add? Patients diagnosed with melanoma at age ≤ 40 years were more likely than older patients to have melanomas in non-UV-damaged sites. Patients with multiple melanomas had higher frequencies of MITF E318K, MC1R R-alleles, and the ASIP extended risk haplotype than patients with single melanoma. CDKN2A, MC1R and MTAP variants were more frequent in patients who developed melanomas at a younger age, but also in those whose melanomas were all on visibly UV-damaged sites. What is the translational message? Incorporating these genetic findings into the known risk factors of skin phenotype and visible UV damage may allow for a more customized and economically feasible approach to early detection of melanoma, particularly in younger patients. Plain language summary available online.

Prospective randomized comparison of cerebrospinal fluid aspiration and conventional popping methods using 27-gauge spinal needles in patients undergoing spinal anaesthesia

Background

Performing spinal anaesthesia using the conventional popping method with a 27-gauge (27G) spinal needle is technically difficult. In this study, we compared the aspiration and conventional popping method for spinal anaesthesia using 27G Quincke-type needles.

Methods

This prospective, randomized study enrolled 90 patients, aged 19 to 65 years, with American Society of Anesthesiologists physical status I-III, who were undergoing spinal anaesthesia. Patients were randomly assigned to one of two groups using a computer-generated random number table: patients receiving spinal anaesthesia using the aspiration method, in which the needle is advanced with continuous aspiration, or the conventional popping method. The primary outcome measure was the success rate of the first attempt to perform dural puncture. Number of attempts and passages, withdrawal cases, successful attempt time, total procedure time, and actual depth of dural puncture were recorded.

Results

Eighty-eight patients were included in the study. In the aspiration group, the success rate of first attempt for dural puncture was 93.3%, compared with 72.1% in the popping group (P = 0.019). Success involving needle withdrawal was recorded in 4 (8.9%) patients in the aspiration group and 13 (30.2%) in the popping group (P = 0.024). In the popping group, the number of attempts was significantly higher (P = 0.044), and total procedure time was significantly longer (P = 0.023). Actual depths of dural puncture were deeper in the popping group than in the aspiration group (P = 0.019).

Conclusions

The aspiration method using a 27G Quincke-type needle offers clinical benefits for dural puncture compared with the conventional popping method for spinal anaesthesia.

Trial registration

Clinical research information service number: KCT0002815, registered 21/Apr/2018. Retrospectively registered.

Defective base excision repair in the response to DNA damaging agents in triple negative breast cancer

DNA repair defects have been increasingly focused on as therapeutic targets. In hormone-positive breast cancer, XRCC1-deficient tumors have been identified and proposed as targets for combination therapies that damage DNA and inhibit DNA repair pathways. XRCC1 is a scaffold protein that functions in base excision repair (BER) by mediating essential interactions between DNA glycosylases, AP endonuclease, poly(ADP-ribose) polymerase 1, DNA polymerase β (POL β), and DNA ligases. Loss of XRCC1 confers BER defects and hypersensitivity to DNA damaging agents. BER defects have not been evaluated in triple negative breast cancers (TNBC), for which new therapeutic targets and therapies are needed. To evaluate the potential of XRCC1 as an indicator of BER defects in TNBC, we examined XRCC1 expression in the TCGA database and its expression and localization in TNBC cell lines. The TCGA database revealed high XRCC1 expression in TNBC tumors and TNBC cell lines show variable, but mostly high expression of XRCC1. XRCC1 localized outside of the nucleus in some TNBC cell lines, altering their ability to repair base lesions and single-strand breaks. Subcellular localization of POL β also varied and did not correlate with XRCC1 localization. Basal levels of DNA damage correlated with observed changes in XRCC1 expression, localization, and measure repair capacity. The results confirmed that XRCC1 expression changes indicate DNA repair capacity changes but emphasize that basal DNA damage levels along with protein localization are better indicators of DNA repair defects. Given the observed over-expression of XRCC1 in TNBC preclinical models and tumors, XRCC1 expression levels should be assessed when evaluating treatment responses of TNBC preclinical model cells.

Design and synthesis of 1,2,4-triazolo[1,5-a]pyrimidine derivatives as PDE 4B inhibitors endowed with bronchodilator activity

A series of 1,2,4-triazolo[1,5-a]pyrimidine derivatives was designed, synthesized, and screened for their phosphodiesterase (PDE 4B) inhibitory activity and bronchodilation ability. Compound 7e showed 41.80% PDE 4B inhibition at 10 µM. Eight compounds were screened for their bronchodilator activity, where compounds 7f and 7e elicited promising bronchodilator activity with EC₅₀ values of 18.6 and 57.1 µM, respectively, compared to theophylline (EC₅₀  = 425 µM). Molecular docking at the PDE 4B active site revealed a binding mode and docking scores comparable to those of a reference ligand, consistent with their PDE 4B inhibition activity.

Phenotypic and genotypic analysis of amelanotic and hypomelanotic melanoma patients

BACKGROUND

Amelanotic/hypomelanotic melanoma is associated with poorer outcomes due to a more advanced disease stage at diagnosis.

OBJECTIVE

To determine phenotypic risks and genotypic associations with amelanotic/hypomelanotic melanoma to develop a clinical and genetic profile that could assist in identifying high-risk individuals.

METHODS

The Brisbane Naevus Morphology Study conducted from 2009 to 2016 has recruited a core of 1254 participants. Participants were drawn from a combination of volunteers from dermatology outpatient clinics, private dermatology clinics, the Brisbane Longitudinal Twin Study and QSkin study. Case participants had a personal history of melanoma and control participants no personal history of melanoma. We specifically examined seven known candidate pigmentation and melanoma genes and pigmentary phenotypic characteristics in participants with amelanotic/hypomelanotic melanoma compared to pigmented melanomas. This assayed single nucleotide polymorphisms in MC1R, TYR, HERC/OCA2, IRF4, MTAP, PLA2G6 and MITF.

RESULTS

Forty-seven participants had at least one amelanotic/hypomelanotic melanoma, and 389 had pigmented melanomas, with amelanotic/hypomelanotic melanoma patients significantly older than pigmented melanoma participants (63.3 ± 13.0 vs. 54.6 ± 15.3 years; P < 0.001). Amelanotic/hypomelanotic melanoma patients were more likely than pigmented melanoma patients to have red hair (34% vs. 15%; P = 0.01), severe hand freckling (13% vs. 5%; P = 0.01) and propensity to sunburn (63% vs. 44%; P = 0.01). MC1R R/R genotype was much more frequent in our amelanotic/hypomelanotic melanoma population (31.1% vs. 11%; P < 0.001; OR 26.4 vs. 5.9; control 1.0). Amelanotic/hypomelanotic melanoma was associated with TYR rs1126809*A/A [OR (CI 95%) 2.7 (1.1-6.8) vs. 1.2 (0.8-1.9)] and PLA2G6 rs11570734*A/A [OR (CI 95%) 3.7 (1.0-13.6) vs. 1.3 (0.9-2.0)]. The MTAP melanoma risk SNP genotype, associated with darker pigmentation, (rs4636294*A/A) was less common in amelanotic/hypomelanotic melanoma patients [OR (CI 95%) 0.8 (0.3-2.1) vs. 2.0 (1.3-3.1)].

CONCLUSIONS

Knowledge of phenotypic and genotypic associations of amelanotic/hypomelanotic melanoma can help predict risks and associations of this difficult to diagnose melanoma, which may ultimately assist clinical management and patient skin self-examination.

Longitudinal Preterm Cerebellar Volume: Perinatal and Neurodevelopmental Outcome Associations

Impaired cerebellar development is an important determinant of adverse motor and cognitive outcomes in very preterm (VPT) infants. However, longitudinal MRI studies investigating cerebellar maturation from birth through childhood and associated neurodevelopmental outcomes are lacking. We aimed to compare cerebellar volume and growth from term-equivalent age (TEA) to 7 years between VPT (< 30 weeks' gestation or < 1250 g) and full-term children; and to assess the association between these measures, perinatal factors, and 7-year outcomes in VPT children, and whether these relationships varied by sex. In a prospective cohort study of 224 VPT and 46 full-term infants, cerebellar volumes were measured on MRI at TEA and 7 years. Useable data at either time-point were collected for 207 VPT and 43 full-term children. Cerebellar growth from TEA to 7 years was compared between VPT and full-term children. Associations with perinatal factors and 7-year outcomes were investigated in VPT children. VPT children had smaller TEA and 7-year volumes and reduced growth. Perinatal factors were associated with smaller cerebellar volume and growth between TEA and 7 years, namely, postnatal corticosteroids for TEA volume, and female sex, earlier birth gestation, white and deep nuclear gray matter injury for 7-year volume and growth. Smaller TEA and 7-year volumes, and reduced growth were associated with poorer 7-year IQ, language, and motor function, with differential relationships observed for male and female children. Our findings indicate that cerebellar growth from TEA to 7 years is impaired in VPT children and relates to early perinatal factors and 7-year outcomes.

Tinnitus: A Stepchild in Our Specialty

Many patients are not satisfied with their doctor's answer when they complain about tinnitus. The proposed classification can be used to communicate with patients as well as guide future research. Type A itemizes the treatable causes of tinnitus. Type B itemizes tinnitus with a lack of medical explanation. Type C tinnitus is caused by diagnosable and treatable conditions, as listed in tinnitus type A, but the tinnitus persists after the successful treatment of the other symptoms.

Postnatal Brain Growth Assessed by Sequential Cranial Ultrasonography in Infants Born <30 Weeks' Gestational Age

BACKGROUND AND PURPOSE

Brain growth in the early postnatal period following preterm birth has not been well described. This study of infants born at <30 weeks' gestational age and without major brain injury aimed to accomplish the following: 1) assess the reproducibility of linear measures made from cranial ultrasonography, 2) evaluate brain growth using sequential cranial ultrasonography linear measures from birth to term-equivalent age, and 3) explore perinatal predictors of postnatal brain growth.

MATERIALS AND METHODS

Participants comprised 144 infants born at <30 weeks' gestational age at a single center between January 2011 and December 2013. Infants with major brain injury seen on cranial ultrasonography or congenital or chromosomal abnormalities were excluded. Brain tissue and fluid spaces were measured from cranial ultrasonography performed as part of routine clinical care. Brain growth was assessed in 3 time intervals: <7, 7-27, and >27 days' postnatal age. Data were analyzed using intraclass correlation coefficients and mixed-effects regression.

RESULTS

A total of 429 scans were assessed for 144 infants. Several linear measures showed excellent reproducibility. All measures of brain tissue increased with postnatal age, except for the biparietal diameter, which decreased within the first postnatal week and increased thereafter. Gestational age of ≥28 weeks at birth was associated with slower growth of the biparietal diameter and ventricular width compared with gestational age of <28 weeks. Postnatal corticosteroid administration was associated with slower growth of the corpus callosum length, transcerebellar diameter, and vermis height. Sepsis and necrotizing enterocolitis were associated with slower growth of the transcerebellar diameter.

CONCLUSIONS

Postnatal brain growth in infants born at <30 weeks' gestational age can be evaluated using sequential linear measures made from routine cranial ultrasonography and is associated with perinatal predictors of long-term development.

Iris pigmented lesions as a marker of cutaneous melanoma risk: an Australian case-control study

BACKGROUND

Iris naevi and iris freckles have a frequency of 4% and 50% in the European population, respectively. They are associated with dysplastic naevi, but few studies have examined their link to cutaneous melanoma.

OBJECTIVES

To assess whether iris pigmented lesions are a predictive indicator for cutaneous melanoma.

METHODS

This is a melanoma case-control study of 1254 European-background Australians. Sun exposure and melanoma history, a saliva sample for DNA analysis and eye photographs taken with a digital camera were collected from 1117 participants. Iris images were assessed by up to four trained observers for the number of iris pigmented lesions. The data were analysed for correlations between iris pigmented lesions and melanoma history.

RESULTS

Case participants over the age of 40 had similar numbers of iris pigmented lesions to age matched controls (mean 5·7 vs. 5·2, P = 0·02), but in younger case and control participants there was a greater difference (mean 3·96 vs. 2·19, P = 0·004). A logistic regression adjusted for age, sex, skin, hair and eye colour, skin freckling and naevus count found that the presence of three or more iris pigmented lesions increases the melanoma risk 1·45-fold [95% confidence interval (CI) 1·07-1·95]. HERC2/OCA2 rs12913832 and IRF4 rs12203592 influenced both eye colour and the number of iris pigmented lesions. On the HERC2/OCA2 A/A and A/G genotype background there was an increasing proportion of blue eye colour when carrying the IRF4 T allele (P = 3 × 10^-4 ) and a higher number of iris pigmented lesions with the IRF4 T/T homozygote (P = 3 × 10^-9 ).

CONCLUSIONS

Iris pigmented lesion count provides additional predictive information for melanoma risk above that from conventional risk factors.

Adolescent mental health and behavioural predictors of being NEET: a prospective study of young adults not in employment, education, or training

BACKGROUND

Young adults who are not in employment, education, or training (NEET) are at risk of long-term economic disadvantage and social exclusion. Knowledge about risk factors for being NEET largely comes from cross-sectional studies of vulnerable individuals. Using data collected over a 10-year period, we examined adolescent predictors of being NEET in young adulthood.

METHODS

We used data on 1938 participants from the Victorian Adolescent Health Cohort Study, a community-based longitudinal study of adolescents in Victoria, Australia. Associations between common mental disorders, disruptive behaviour, cannabis use and drinking behaviour in adolescence, and NEET status at two waves of follow-up in young adulthood (mean ages of 20.7 and 24.1 years) were investigated using logistic regression, with generalised estimating equations used to account for the repeated outcome measure.

RESULTS

Overall, 8.5% of the participants were NEET at age 20.7 years and 8.2% at 24.1 years. After adjusting for potential confounders, we found evidence of increased risk of being NEET among frequent adolescent cannabis users [adjusted odds ratio (ORadj) = 1.74; 95% confidence interval (CI) 1.10-2.75] and those who reported repeated disruptive behaviours (ORadj = 1.71; 95% CI 1.15-2.55) or persistent common mental disorders in adolescence (ORadj = 1.60; 95% CI 1.07-2.40). Similar associations were present when participants with children were included in the same category as those in employment, education, or training.

CONCLUSIONS

Young people with an early onset of mental health and behavioural problems are at risk of failing to make the transition from school to employment. This finding reinforces the importance of integrated employment and mental health support programmes.

Nutritional status, exclusive breastfeeding and management of acute respiratory illness and diarrhea in the first 6 months of life in infants from two regions of Indonesia

BACKGROUND

Infant morbidity and mortality rates remain high in Indonesia, with acute respiratory illnesses (ARI) and diarrhea the leading two health problems in children under 5 years. We aimed to describe the nutritional status, feeding practice and case management of ARI and diarrhea of infants from two regions of Indonesia during the first 6 months of life.

METHODS

This study was an observational study conducted in parallel to an immunogenicity and efficacy trial of an oral rotavirus vaccine (RV3-BB) in the Klaten and Yogyakarta regions, Indonesia. Mothers were interviewed at 3 time points: within the first 6 days of their infant's life, and at 8-10 and 22-24 weeks of age. Questions asked included pregnancy history, infant nutritional status, feeding status and health of infants within up to 2 weeks prior to the assessment.

RESULTS

Between February 2013 and January 2014, 233 mother-infant pairs were recruited. 60% (136/223) of infants were exclusively breastfed (EBF) until 6 months of age with the strongest support for EBF reported by mothers themselves 70% (101/223) and 25% (36/223) from their partners. At 6 months, 6% (14/223) of infants were underweight and severely underweight; 4% (8/ 223) wasted and severely wasted; and 12% (28/223) were stunted and severely stunted. Non-recommended medication use was high, with 54% (21/39) of infants with reported cough within 2 weeks of an assessment receiving cough medication, 70% (27 /39) an antihistamine, 26% (10/39) a mucolytic and 15% (6 /39) an oral bronchodilator. At age 22-24 week, infants with reported diarrhea within 2 weeks of an assessment had low use of oral rehydration solutions (ORS) (3/21;14%) and zinc therapy (2/ 21;10%).

CONCLUSION

In this unique observational study, breastfeeding rates of 60% at 6 months were below the Indonesian national target of >75%. Adherence to WHO guidelines for management of ARI and diarrhea was poor, with high use of non-recommended cough medications and oral bronchodilators in the first 6 months of life and low use of ORS and zinc therapy. Ongoing education of primary health care workers and parents regarding management of common illness is needed in Indonesia.

Angiosome based time series analysis of deep tissue perfusion using diffuse speckle contrast analysis

An angiosome is a three dimensional volume of biological tissue which a specific artery governs. Although proven useful for vascular surgery, the direct relationship between arterial flow and microcirculation in specific angiosome remains controversial. Here, we present new optical approach, a four-channel diffuse speckle contrast analysis (DSCA) which can simultaneously measure blood perfusion at different foot area. Based on the hypothesis that same angiosome will support similar low frequency oscillation, we investigated cross-correlation among different DSCA channels. Our preliminary results show that the LFO signal from the channel closest to posterior tibial artery is leading the signal from the other channels.

The NO/cGMP pathway in duodenal motor, mechano- and chemosensory responses to acid: A randomized, placebo-controlled study with sildenafil in healthy volunteers

BACKGROUND

Altered duodenal sensorimotor responses to acid have been reported in a subset of patients with functional dyspepsia. To investigate whether NO is involved in these abnormalities, the effect of sildenafil (activates the NO pathway) on duodenal motor and sensory responses to acid in healthy humans was evaluated.

METHODS

A barostat-manometry catheter including an infusion tube was positioned in the duodenum of 12 healthy volunteers. Duodenal motility and dyspeptic symptoms were evaluated during the whole study. A first series of stepwise isobaric distensions was performed while participants scored their perception of upper abdominal sensations at the end of every distension step. Next, the duodenum was infused with sildenafil 50 mg or saline, followed by duodenal acid infusion. During duodenal acidification, a second sequence of stepwise isobaric distensions with the assessment of sensations was repeated.

KEY RESULTS

Acid infusion did not induce dyspeptic symptoms with both placebo and sildenafil pretreatment. Duodenal motility decreased after sildenafil infusion, whereas it was not affected by placebo. Acid-induced increase in motility was, however, observed in both conditions, and no difference between the conditions was found. Duodenal acidification decreased thresholds for discomfort and increased perception scores during duodenal distensions in both groups, but again no difference was observed between placebo and sildenafil pretreatment.

CONCLUSIONS AND INFERENCES

Sildenafil does not affect duodenal motor, mechanosensory, and chemosensory responses to acid in healthy controls. Therefore, it is less likely that the NO pathway plays a role in the altered response to acid in functional dyspepsia patients.

Mining ZINC Database to Discover Potential Phosphodiesterase 9 Inhibitors Using Structure-Based Drug Design Approach

In view of the emerging clinical indications for Phosphodiesterase 9 inhibitors e.g. treatment of Alzheimer, diabetes, cancer, and the limited number of its selective inhibitors which possess a single chemical scaffolds, a structure-based approach was undertaken to mine the ZINC database by virtual screening to identify novel PDE9 inhibitors. The database, which was never reported to have been used before for discovery of PDE9 inhibitors, was screened against the ligand binding pocket of the PDE9 complex (PDB:4GH6) using molecular docking programs, MOE and AutoDock Vina in PyRx. Three different scoring functions were used to evaluate the docking poses and scores of the compounds, and the compounds were selected through consensus selection, thus reducing the margin of error in docking. The highest scoring compounds were then selected and purchased for in vitro testing as PDE9 inhibitors and cancer growth inhibitory agents. This led to the discovery of three previously unreported potent PDE 9 inhibitory compounds with two unique chemical scaffolds. Consistent with the role of PDE9 in cancer cell growth, the compounds also inhibited the growth of breast tumor cell lines, MCF-7 and MDA-468 at concentrations comparable to those that inhibited PDE9.

Abstract 5243: Novel non-COX inhibitory sulindac derivative with β-catenin suppressing activity reduces the formation of colorectal adenomas and adenocarcinomas in the APC +/min-FCCC mouse model

Sulindac can reduce the number and size of precancerous colonic adenomas in patients with familial adenomatous polyposis (FAP), but is not recommended for long-term use as a cancer chemopreventive drug because of potentially fatal toxicities associated with cyclooxygenase (COX) inhibition. Here we characterize the antineoplastic properties of a novel sulindac derivative, ADT-061, that lacks COX-1 and COX-2 inhibitory activity. ADT-061 potently and selectively inhibited colon tumor cell growth in vitro with IC50 values of 0.3-0.5 μM by inducing apoptosis without affecting the growth of normal colonocytes at concentrations 100x higher. By comparison, sulindac sulfide (SS) inhibited colon tumor cell growth with IC50 values of 40-60 μM, and had only modest tumor cell selectivity. While SS non-selectively inhibits multiple cyclic GMP phosphodiesteraes (PDE) isozymes, previous studies have suggested an important role for PDE10 in colon cancer (Li et al, Oncogene, 2014; Lee et al, Oncotarget, 2015). At concentrations comparable to its IC50 values, ADT-061 selectively inhibits PDE10 to induce an increase in intracellular cGMP levels and activate protein kinase G (PKG). ADT-061 also suppressed nuclear levels of β-catenin and induced cell cycle arrest and apoptosis, within the same concentration range that inhibits tumor cell growth. With attractive drug-like properties, the chemopreventive activity ADT-061was assessed using the APC+/min-FCCC mouse model of spontaneous colorectal tumorigenesis. Prior to treatment, colonoscopy exams were performed on all APC+/min-FCCC mice (males, 6-7 weeks of age) to ensure the absence of colorectal adenomas. At 7-8 weeks of age, mice were assigned (19 per group) to receive either unsupplemented chow (control) or chow supplemented with ADT-061 (1500ppm) for 14 weeks. No discernible toxicity was observed during the experimental period. Double-blinded pathological analysis of fixed colon tissues revealed that ADT-061 not only reduced the multiplicity of colonic adenomas by 50% (Mean ± SEM, control vs. ADT-061, 3.95 ± 0.81 vs. 1.95 ± 0.58, P &lt; 0.05), but also decreased the incidence of colonic adenomas by 36.7% (control vs. ADT-061, 94.7% vs. 57.9%, respectively). ADT-061 treatment reduced the multiplicity of polypoid adenomas (36%), flat adenomas (100%, P &lt; 0.05), and microadenomas (69%). The formation of colonic adenocarcinomas found in 15.8% of untreated mice was completely inhibited in mice treated with ADT-061. These data indicate that ADT-061 inhibits colon tumorigenesis when given to APC+/min-FCCC mice prior to the detection of gross colonic tumors. These observations support further evaluation of ADT-061 and analogs for colorectal cancer chemoprevention.

Citation Format: Kevin J. Lee, Xi Chen, Jacob Valiyaveettil, Ashley S. Lindsey, Joel Andrews, Veronica Ramirez-Alcantara, Adam B. Keeton, Gary A. Piazza, Harry Cooper, Margie Clapper, Wen-Chi L. Chang. Novel non-COX inhibitory sulindac derivative with β-catenin suppressing activity reduces the formation of colorectal adenomas and adenocarcinomas in the APC+/min-FCCC mouse model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5243. doi:10.1158/1538-7445.AM2017-5243