Citations

Background: The Afirma ® Gene Expression Classifier (GEC) risk stratifies The Bethesda System for the Reporting of Thyroid Cytopathology class III/IV (indeterminate) thyroid nodules (ITNs) as suspicious for malignancy or benign. Several authors have published studies describing the diagnostic accuracy of the GEC. However, the quality of these methods has not been rigorously examined. Summary: In this study, MEDLINE and EMBASE were searched for studies published between January 1, 2010, and June 30, 2016, examining the sensitivity, specificity, negative predictive value, and positive predictive value of the GEC. The Quality of Diagnostic Accuracy Studies 2 was customized to evaluate the methods of included studies in each of four domains: nodule selection, index test execution, reference standard assignment, and flow and timing. Signaling questions were used to identify sources of potential bias in calculation of diagnostic accuracy, and issues of applicability were assessed. Three panelists applied the Quality of Diagnostic Accuracy Studies 2 tool to each study included, and divergence was resolved in conference. In 12 studies evaluated, the most common methodologic flaw was lack of reference standard diagnosis assignment to un-excised GEC-benign ITNs. Exclusion of these ITNs from the analyses resulted in unreliable estimates of specificity and negative predictive value. Other flaws identified included restriction to ITNs that had already been selected for referral for thyroidectomy or lobectomy. Conclusions: Future studies should define and assign a “true negative” label to GEC-benign nodules that do not develop malignant signs or symptoms during a pre-specified period of follow-up, and these nodules should be included in calculations of diagnostic accuracy.

Background Renovascular hypertension ( RVH ) impairs cardiac structure and left ventricular ( LV ) function, but whether mitochondrial injury is implicated in RVH ‐induced myocardial damage and dysfunction has not been defined. We hypothesized that cardiac remodeling in swine RVH is partly attributable to cardiac mitochondrial injury. Methods and Results After 12 weeks of hypercholesterolemic ( HC )‐ RVH or control (n=14 each), pigs were treated for another 4 weeks with vehicle or with the mitochondrial‐targeted peptide ( MTP ), Bendavia (0.1 mg/kg subcutaneously, 5 days/week), which stabilizes mitochondrial inner‐membrane cardiolipin (n=7 each). Cardiac function was subsequently assessed by multidetector‐computed tomography and oxygenation by blood‐oxygen‐level–dependent magnetic resonance imaging. Cardiolipin content, mitochondrial biogenesis, as well as sarcoplasmic‐reticulum calcium cycling, myocardial tissue injury, and coronary endothelial function were assessed ex vivo. Additionally, mitochondrial cardiolipin content, oxidative stress, and bioenergetics were assessed in rat cardiomyocytes incubated with tert‐butyl hydroperoxide ( tBHP ) untreated or treated with MTP . Chronic mitoprotection in vivo restored cardiolipin content and mitochondrial biogenesis. Thapsigargin‐sensitive sarcoplasmic reticulum Ca 2+ ‐ ATP ase activity that declined in HC ‐ RVH normalized in MTP ‐treated pigs. Mitoprotection also improved LV relaxation (E/A ratio) and ameliorated cardiac hypertrophy, without affecting blood pressure or systolic function. Myocardial remodeling and coronary endothelial function improved only in MTP ‐treated pigs. In tBHP ‐treated cardiomyocytes, mitochondrial targeting attenuated a fall in cardiolipin content and bioenergetics. Conclusions Chronic mitoprotection blunted myocardial hypertrophy, improved LV relaxation, and attenuated myocardial cellular and microvascular remodeling, despite sustained HC ‐ RVH , suggesting that mitochondrial injury partly contributes to hypertensive cardiomyopathy.

Abstract Alternative NF-κB signaling is crucial for B cell activation and Ig production, and it is mainly regulated by the inhibitor of κ B kinase (IKK) regulatory complex. Dysregulation of alternative NF-κB signaling in B cells could therefore lead to hyperactive B cells and Ig overproduction. In our previous, study we found that deleted in breast cancer 1 (DBC1) is a suppressor of the alternative NF-κB pathway to attenuate B cell activation. In this study, we report that loss of DBC1 results in spontaneous overproduction of Ig in mice after 10 mo of age. Using a double mutant genetic model, we confirm that DBC1 suppresses B cell activation through RelB inhibition. At the molecular level, we show that DBC1 interacts with alternative NF-κB members RelB and p52 through its leucine zipper domain. In addition, phosphorylation of DBC1 at its C terminus by IKKα facilitates its interaction with RelB and IKKα, indicating that DBC1-mediated suppression of alternative NF-κB is regulated by IKKα. Our results define the molecular mechanism of DBC1 inhibition of alternative NF-κB activation in suppressing B cell activation.

Abstract CD40 and BAFFR signaling play important roles in B cell proliferation and Ig production. In this study, we found that B cells from mice with deletion of Dbc1 gene (Dbc1−/−) show elevated proliferation, and IgG1 and IgA production upon in vitro CD40 and BAFF, but not BCR and LPS stimulation, indicating that DBC1 inhibits CD40/BAFF-mediated B cell activation in a cell-intrinsic manner. Microarray analysis and chromatin immunoprecipitation experiments reveal that DBC1 inhibits B cell function by selectively suppressing the transcriptional activity of alternative NF-κB members RelB and p52 upon CD40 stimulation. As a result, when immunized with nitrophenylated-keyhole limpet hemocyanin, Dbc1−/− mice produce significantly increased levels of germinal center B cells, plasma cells, and Ag-specific Ig. Finally, loss of DBC1 in mice leads to higher susceptibility to experimental autoimmune myasthenia gravis. Our study identifies DBC1 as a novel regulator of B cell activation by suppressing the alternative NF-κB pathway.

Abstract The gene KDM6A/UTX was recently identified as a putative tumor suppressor (van Haaften et al). The gene is frequently lost in a variety of malignancies but most commonly in esophageal squamous cell carcinomas (8%) and multiple myeloma (10%). The initial characterization of UTX abnormalities in multiple myeloma utilized a mixture of 58 cell lines and patient samples. To establish the frequency of UTX inactivation in multiple myeloma we studied the copy number profiling dataset (n=239) available from the Multiple Myeloma Genomics Initiative (MMGI) and our internal dataset of 68 human myeloma cell lines which were characterized by array-based CGH (Agilent 400k), whole exome sequencing, and mRNA sequencing. We identified homozygous deletions in 2.5% of patients and 26.5% of cell lines. There are no mutations in the available whole genome and exome sequencing data from 38 patients in the MMGI that partially overlaps the 239 copy number samples sequencing. However, in the cell lines another 14.3% of samples showed loss of UTX through a variety of mechanisms (missense, nonsense, frameshifts, single exon deletions and insertions of LINE elements) detected by exome and mRNA sequencing, bringing the total percentage of cell lines with UTX inactivation to 40.8%. The increased frequency of UTX inactivation in cell lines likely suggests that it is associated with a more aggressive disease or promotes the growth of the tumor outside of the normal bone marrow microenvironment. As part of the cell line characterization phase of the project we found that ARD has a homozygous deletion encompassing the entire UTX locus while its isogenic counterparts, ARP-1 and CAG, express wild-type UTX at a level comparable to other cell lines without UTX abnormalities. To ensure these isogenic cell lines represent the same tumor not different tumors from the same individual we cloned the immunoglobulin receptor rearrangements in all there lines, which confirmed these are derived from the same original tumor. To develop this model system we first generated single cell clones from each of the three cell lines. Six clones from each were randomly selected and their DNA content was determined by flow cytometry. In all cases the clones matched the parental population in ploidy (ARD 3.2N, ARP 3.3N, CAG 3.8N). We randomly select one subclone from each cell line to characterize in detail using spectral karyotyping, array-based CGH, whole exome sequencing, mRNA sequencing, and CHIP-seq for H3K4me3, H3K27ac, H3K27me1, H3K27me2, and H3K27me3. The detailed characterization of this isogenic model system will make it an excellent platform for future work aimed at understanding how UTX loss contributes to myelomagenesis. Citation Format: Kristi Allen, Venkata Yellapantula, Quan Zhao, David Edwards, Marta Chesi, Leif Bergsagel, John Carpten, Jonathan Keats. Characterization of an isogenic model system for KDM6A/UTX loss in multiple myeloma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5209. doi:10.1158/1538-7445.AM2013-5209

ABSTRACT Piperacillin-tazobactam (PTZ) is known to cause false-positive results in the Platelia Aspergillus enzyme-linked immunoassay (EIA), due to contamination with galactomannan (GM). We tested 32 lots of PTZ and 27 serum specimens from patients receiving PTZ. GM was not detected in the lots of PTZ; one serum specimen (3.7%) was positive. PTZ formulations commonly used in the United States today appear to be a rare cause for false-positive GM results.