tbuckley/cabot-search huggingface dataset:
Abstract LB-321: Cytoplasmic DEDD promotes G1- to S-phase cell cycle transition
Authors: Keon R. Schmidt, Yingjia Ni, Siyuan Zhang
Journal: Cancer Research (2017)

Abstract Death Effector Domain-Containing DNA-binding protein (DEDD), a highly conserved and ubiquitous protein, has been studied primarily for its role as a scaffold protein in cell death pathways. DEDD resides predominantly in the cytoplasm, but translocates to the nucleus to propagate the terminal apoptotic signal. Overexpression of nuclear DEDD, not cytoplasmic DEDD, has been shown to be sufficient to induce cytotoxic effects. This suggests that DEDD may have functional importance beyond directing apoptotic signals. Further, the cytoplasmic function of DEDD has yet to be characterized. Other DED-containing proteins, such as FADD, have been shown to interact with cyclin/cyclin-dependent kinase cell cycle regulatory molecules. Here, we show that DEDD is implicated in cell cycle regulation and can assume a pro- proliferative function when overexpressed in the cytoplasm. To glean phenotypic changes in cell cycle transitions, we utilized a two-dimensional approach with an EdU proliferation label and a propidium iodine DNA content label differentiated via flow cytometry analysis. Based on these labels, it can be determined whether a cell is in the G1-, S-, or G2-phase of the cell cycle. We have identified that overexpression of DEDD leads to an increase in S-phase cells when compared to control suggesting an easier transition through the G1/S checkpoint. Conversely, a knockdown of DEDD leads to a decrease in S-phase cells and an increase in G1-phase cells when compared to control indicating G1 arrest. Gain-of-function flow cytometry analysis was repeated by overexpressing a DEDD construct with disrupted nuclear localization sequences. The resulting phenotype mirrored that of the overexpressed wild-type DEDD construct. Thus, these results suggest that DEDD may be interacting with regulatory molecules regulating the G1/S checkpoint of the cell cycle and that the change in G1- to S-phase transition dynamics in response to manipulated DEDD expression is not attributable to the nuclear function of DEDD. Further studies will focus on elucidating the specific molecular interactions through which DEDD can carry out this novel cell cycle regulatory function. Citation Format: Keon R. Schmidt, Yingjia Ni, Siyuan Zhang. Cytoplasmic DEDD promotes G1- to S-phase cell cycle transition [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 LB-321. doi:10.1158/1538-7445.AM2017-LB-321
Abstract 3360: Targeted catalytic inhibition of EZH2 synergizes with low-dose HDACi in malignant rhabdoid tumors
Authors: Dean Popovski, Elizabeth M. Algar, Catherine R. Cochrane, Anette Szczepny, W. Samantha Jayasekara, David M. Ashley, Peter Downie, D. Neil Watkins, Jason E. Cain
Journal: Cancer Research (2017)

Abstract Malignant Rhabdoid Tumor (MRT) is a rare pediatric cancer of the kidney and CNS that is resistant to current treatment protocols. MRT is genetically characterized by homozygous inactivation of SMARCB1, a critical subunit of the SWI/SNF chromatin-remodeling complex. Next-generation sequencing data suggests that inactivation of SMARCB1 is the primary driver mutation, implicating epigenetic deregulation in the pathogenesis of MRT. Recently, we showed that sustained treatment of MRT cell lines with low-dose Panobinostat (LBH589), inhibited tumor growth by driving multi-lineage differentiation in vitro and in vivo. Furthermore, re-expression of physiological levels of SMARCB1 in G401 MRT cells phenocopied the low-dose LBH589 treatment and led to growth inhibition, senescence and terminal differentiation in vitro and in vivo. Enhancer of Zeste homolog 2 (EZH2), a core subunit of the Polycomb Repressive Complex 2 (PRC2), confers transcriptional silencing via the addition of methyl groups to Lysine 27 of Histone 3 (H3K27me3), and is a transcriptional target of SMARCB1. EZH2 expression and H3K27me3 were drastically reduced following sustained low-dose LBH589 treatment and re-expression of SMARCB1 in G401 MRT cells. Sustained siRNA knockdown of EZH2 in G401 cells resulted in reduced cell growth and changes in mRNA expression similar to those observed following low-dose LBH589 treatment and SMARCB1 re-expression. Treatment of MRT cells with the EZH2-catalytic domain inhibitor, GSK-126, had no effect on EZH2 expression and only partially reduced H3K27me3 and cell growth at doses 1nM-10μM suggesting important non-catalytic EZH2 function. However, MRT cells treated in combination with low-dose LBH589 and GSK-126, lost EZH2 and H3K27me3 expression and exhibited significantly reduced cell growth in vitro compared to single agent controls, revealing a synergistic relationship. Similar effects were observed in an in vivo xenograft model, with low-dose LBH589 and GSK-126 treatment leading to a marked reduction in tumor growth, not observed with single agent treatment. This data suggests EZH2 is an important mediator of MRT proliferation and differentiation and provides evidence for dual therapeutic targeting of EZH2 with low-dose HDACi in MRT. Citation Format: Dean Popovski, Elizabeth M. Algar, Catherine R. Cochrane, Anette Szczepny, W. Samantha Jayasekara, David M. Ashley, Peter Downie, D. Neil Watkins, Jason E. Cain. Targeted catalytic inhibition of EZH2 synergizes with low-dose HDACi in malignant rhabdoid tumors [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 3360. doi:10.1158/1538-7445.AM2017-3360
Abstract 2790: PRC2 mediated repression of SMARCA2 predicts for EZH2 inhibitor activity in tumors with SWI/SNF mutations
Authors: Thomas Januario, Xiaofen Ye, Russell Bainer, Bruno Alicke, Margaret Solon, Benjamin Haley, Zora Modrusan, Stephen Gould, Hartmut Koeppen, Robert L. Yauch
Journal: Cancer Research (2017)

Abstract A synthetic lethality caused by EZH2 inhibition in the context of SNF5 mutations is supported by both preclinical and recent clinical data, however the extent of the synthetic lethal relationship in the context of other SWI/SNF subunit mutations is not well understood. We determined that a subset of SMARCA4 mutant cancer models are sensitive to EZH2 inhibition. EZH2 inhibition resulted in a heterogenous phenotypic response characterized by senescence and/or apoptosis amongst models, and further lead to tumor growth inhibition in vivo. The differential sensitivity to EZH2 inhibition was not caused by a differential pharmacodynamic effect of the drug, nor differences in basal histone methylation or PRC2 subunit levels. However, expression of the SWI/SNF subunit, SMARCA2, delineated sensitivity amongst SMARCA4 mutant models tested. Expression of SMARCA2 further delineated sensitivity amongst other SWI/SNF mutant models tested, including SNF5 and ARID1A mutants. We determined that SMARCA2 is under PRC2 mediated suppression and the derepression of SMARCA2 was necessary for apoptosis, but not senescence, in response to EZH2 inhibition. SMARCA2 has been shown to be concurrently lost in a high percentage of SNF5 mutant malignant rhabdoid tumors and SMARCA4 mutant SCCOHT tumors, however we determined that ≈15% of SMARCA4 mutant NSCLCs concurrently lose SMARCA2. Our data supports monitoring SMARCA2 expression as a predictive biomarker for EZH2-targeted therapies that are currently being developed in the context of SWI/SNF mutant cancers. Citation Format: Thomas Januario, Xiaofen Ye, Russell Bainer, Bruno Alicke, Margaret Solon, Benjamin Haley, Zora Modrusan, Stephen Gould, Hartmut Koeppen, Robert L. Yauch. PRC2 mediated repression of SMARCA2 predicts for EZH2 inhibitor activity in tumors with SWI/SNF mutations [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 2790. doi:10.1158/1538-7445.AM2017-2790
Abstract 318: Identification of FERM domain-containing protein 5 (FRMD5) as a novel target of β-catenin/TCF7L2 complex
Authors: Yoichi Furukawa, Chi Zhu, Tomoyuki Ohsugi, Yumi Terakado, Rei Noguchi, Tsuneo Ikenoue, Kiyoshi Yamaguchi
Journal: Cancer Research (2017)

Abstract Deregulated Wnt signaling is one of the earliest steps in colorectal tumorigenesis. The impairment results most frequently from APC mutations, which leads to the accumulation of β-catenin and subsequent activation of TCF7L2. Although previous studies have identified a number of target genes of the activated β-catenin/TCF7L2 transcriptional complex such as cMYC and CCND1, the comprehensive effect of the activation on tumorigenesis remains to be elucidated. To understand the precise molecular mechanisms underlying colorectal cancer, we searched for novel genes regulated by the complex in colorectal tumors. We performed expression profile analysis of HCT116 and SW480 colon cancer cells treated with β-catenin siRNAs, and combined these data with public microarray data of LS174 cells treated with a dominant-negative form of TCF7L2. As a result, we identified a total of 134 genes that were regulated by both β-catenin and TCF7L2. Subsequent ChIP-sequence with TCF7L2 antibody selected 11 genes from the 134 genes as candidates of direct target genes. In this study, we focused on FERM domain-containing protein 5 (FRMD5) among the 11 candidates. Quantitative PCR confirmed that its expression was reduced by β-catenin siRNA in HCT116 and SW480 cells. ChIP-quantitative PCR analysis with ant-TCF7L2 antibody also corroborated the interaction of TCF7L2 with a region (hg19; chr15:44,449,680-44,450,487) within intron 1 of FRMD5. Reporter assay with plasmids containing this region revealed that the reporter activity was down-regulated by the knockdown of β-catenin. These data suggested that FRMD5 is a direct target of β-catenin/TCF7L2 complex, and that the region is involved in the transcriptional activation through an interaction with the complex. Consistently, its expression was elevated in colorectal tumors compared to normal colonic mucosa in public microarray data. To uncover the role of FRMD5 in colorectal carcinogenesis, we analyzed expression profile of HCT116 cells treated with FRMD5 siRNA, and combined the data with profile with β-catenin siRNA. Gene set analysis with 53 commonly up-regulated and 36 commonly down-regulated genes by both FRMD5 and β-catenin disclosed that the gene sets of DNA replication, cell cycle, and extracellular matrix (ECM) were altered by FRMD5. These data may be useful for the future studies of colorectal carcinogenesis. Citation Format: Yoichi Furukawa, Chi Zhu, Tomoyuki Ohsugi, Yumi Terakado, Rei Noguchi, Tsuneo Ikenoue, Kiyoshi Yamaguchi. Identification of FERM domain-containing protein 5 (FRMD5) as a novel target of β-catenin/TCF7L2 complex [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 318. doi:10.1158/1538-7445.AM2017-318
Abstract 2692: Inflammatory patterns exhibited by African American colon tumor-derived cell lines
Authors: Jenny E. Paredes Sanchez, Ping Ji, Maria Munoz-Sagastibelza, Laura Martello-Rooney, Jennie Williams
Journal: Cancer Research (2017)

Abstract Despite progress in closing the gap, health disparities still persist among African American (AA) colon cancer patients both in incidence and death rates. Previous studies from our group reported that colon tumors from AAs displayed hypermethylation of DNA regions in inflammatory genes such as NELL1, GDF1, ARHGEF4, and ITGA4 when compared to Caucasian Americans (CA). To assess potential differences in the inflammatory response, we utilized two AA colon cancer cell lines generated in our laboratory and compared them with the commercially available CAs colon cancer cell lines, Caco-2 and HT-29. Recent experiments by our group with the anti-inflammatory drugs Ibuprofen, Sulindac and Aspirin, showed significantly higher IC50 values in proliferation assays for AA cell lines compared to CA cell lines. Therefore, we evaluated the anti-inflammatory effects of these drugs by determining secretion of inflammatory cytokines and MAPKs activation in response to the pro-inflammatory cytokine TNF-alpha. The same parameters were tested for the anti-inflammatory cytokine IL-10. As hypothesized, our results in the CA cell lines demonstrated down-regulation of MAPKs activation in response to TNF-alpha after pre-treatment with Ibuprofen. On the contrary, Ibuprofen concentrations as high as the IC50 values for the CA cell lines were not able to induce down-regulation of MAPKs in the AA cell lines. Interestingly, IL-10 treatment was more effective in the AA compared to the CA cell lines, suggesting that the main anti-inflammatory cytokine of the colon will be more effective in controlling inflammation in AA colon tumors. Further studies are needed to elucidate the major differences in inflammatory responses between AA and CA colon cancer cell lines and their potential role in CRC health disparities. As it has been documented that AA colon cancer patients are less responsive to the chemotherapeutics Fluorouracil and Capecitabine, in future studies we will evaluate the effect of these therapeutic agents on AA and CA cell lines in terms of inflammation, cell viability, apoptosis and invasion. Citation Format: Jenny E. Paredes Sanchez, Ping Ji, Maria Munoz-Sagastibelza, Laura Martello-Rooney, Jennie Williams. Inflammatory patterns exhibited by African American colon tumor-derived cell lines [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 2692. doi:10.1158/1538-7445.AM2017-2692
AB0605 Vitamin d serum concentration in european systemic sclerosis patients: correlations with seasonality, organ involvement and standard oral supplementation
Authors: AC Trombetta, V Smith, E Gotelli, M Ghio, S Paolino, C Pizzorni, A Sulli, M Cutolo
Journal: Annals of the Rheumatic Diseases (2017)

<h3>Background</h3> Vitamin D deficiency is reported to interfere with immune responses and to correlate with course and outcome in several autoimmune diseases. In systemic sclerosis (SSc), low 25-hydroxyvitamin D (25(OH)D) serum concentration has been recognized. <h3>Objectives</h3> To investigate relations between 25(OH)D serum concentration and seasonality, clinical parameters as well as standard oral supplementation, in SSc patients. <h3>Methods</h3> 154 SSc patients (mean age 59±15 years, 24.7% diffuse form and 75.3% limited form) were evaluated, at any time of the year, in a retrospective survey. Serum 25(OH)D quantification was performed using the LIAISON 25-OH vitamin D assay (Diasorin, Italy). Pulmonary function test, chest x-ray, lung CT scan, electrocardiography, Doppler echocardiography, renal artery resistive index by eco color Doppler, Dual X-ray absorptiometry, were performed at the time of sample collection. Disease severity scale (DSS) was performed according to Medsger. Drug assumption (glucocorticoids, calcium channel blockers, cyclic intravenous iloprost, endothelin receptor antagonists) and supplementation with vitamin D analogues, were recorded. Non-parametric tests were used for statistical analysis. <h3>Results</h3> Average 25(OH)D serum concentration was found to be 18.7±9 ng/ml (&lt;20 classified as deficiency). A significant difference was observed among seasonal 25(OH)D serum concentration (winter: 14.6±7.8 ng/ml, spring: 17.2±7.9 ng/ml, summer 21.43±10 ng/ml, autumn 20.2±10; p<i>=0.032</i>) (Figure 1). A significant correlation was found between 25(OH)D serum concentration and presence/absence of bi-basal fibrotic changes at lung computed tomography (CT) scan (average values: 16.1±8 ng/ml and 20±10 ng/ml, respectively, <i>p=0.04</i>). Peripheral vascular <i>(p=0.03</i>), kidney (<i>p=0.02</i>), gastrointestinal (<i>p=0.05</i>) Medsger9s DSS parameters also were found to correlate with 25(OH)D serum concentration (Figure 1). Interestingly, no influence of treatment with vitamin D analogues (1,000 UI daily) was found regarding 25(OH)D serum concentration in treated (18.8±10 ng/ml) and in not treated (18.7±9 ng/ml) SSc patients (p=0.81). <h3>Conclusions</h3> In SSc is confirmed a serum 25(OH)D deficiency that we report to be associated with lung involvement, peripheral vascular, kidney and gastrointestinal Medsger9s DSS parameters, as well as with seasonality. Supplementation with vitamin D analogues did not influence present results. Therefore, for successful replacement, supra-physiological oral vitamin D3 doses or programmed UVB light exposure should be considered. <h3>Disclosure of Interest</h3> None declared
Leukopenia in Still's disease
Authors: E. Scopelitis
Journal: JAMA (1984)

Two patients, one a 14-year-old girl and the other a 20-year-old man, with typical manifestations of juvenile rheumatoid arthritis had leukopenia and thrombocytopenia, two heretofore unreported findings. The presence of leukopenia should not be used to exclude a diagnosis of Still's disease. (<i>JAMA</i>1984;252:2450-2452)
Abstract 4062: A computational driven protocol of metronomic oral vinorelbine in metastatic non small cell lung cancer
Authors: Diane-Charlotte Imbs, Raouf El Cheikh, Joseph Ciccolini, Raphaël Serre, Fabrice Barlesi, Dominique Barbolosi
Journal: Cancer Research (2017)

Abstract Over the last decade, metronomic chemotherapy (MC) has emerged as an alternative way to administrate chemotherapy. MC can be defined as regular administration of low/less-toxic doses without extended drug-free breaks. Because countless schedules are possible, testing them empirically looks like an unachievable goal. Therefore, mathematical modeling can be an effective tool to determine appropriate metronomic strategies. A phase Ia/Ib study based on a mathematical model of oral vinorelbine in metastatic NSCLC and malignant pleural mesothelioma was designed to confirm safety and evaluate efficacy of a new metronomic regimen (Elharrar et al. 2016). The optimized schedule providing weekly Day1 (D1), D2 and D4 with respective doses of 60, 30 and 60 mg was suggested by in silico simulations using a Pharmacokinetic-Pharmacodynamic (PKPD) model taking into account vinorelbine PK, PD toxicities and PD efficacy (Faivre et al. 2013). Trial recruitment will be two-staged, as 12 patients have been enrolled to confirm safety and consolidate the calibration of model parameters. An extension phase on 20-extra patients will be conducted to evaluate the efficacy of the optimized protocol. Monolix 4.3.3 was used for population PKPD analysis. A three-compartment model best described oral vinorelbine PK data. PK analysis revealed a high inter-individual variability on drug exposure (CV=73%). PD toxicity (neutropenia) was adequately described by a modified Friberg model (Friberg et al. 2002), considering continuous administrations of metronomic dosing regimen. On the 12 recruited patients, 3 (25%) presented either a stable disease (SD) or a partial response (PR). No direct link has been established between toxicity (grade 4 neutropenia) and drug exposure. However, responders to treatment were those presenting a higher vinorelbine area under the curve (p=0.02). Tumor assessments were used to adjust efficacy parameters. The model was used to simulate alternative metronomic scenarios targeting higher efficacy with similar toxicity. Simulations showed that the initial proposed schedule was the most appropriate in terms of efficacy/toxicity balance. Its efficacy will be evaluated in the second part of the study. This trial can be considered as a proof-of-concept study demonstrating the feasibility to run a computational-driven protocol to ensure an optimal efficacy/toxicity balance in cancer patients. Citation Format: Diane-Charlotte Imbs, Raouf El Cheikh, Joseph Ciccolini, Raphaël Serre, Fabrice Barlesi, Dominique Barbolosi. A computational driven protocol of metronomic oral vinorelbine in metastatic non small cell lung cancer [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 4062. doi:10.1158/1538-7445.AM2017-4062
Abstract 3428: Tamoxifen differentially regulates miR-29b-1 and miR-29a depending on endocrine sensitivity in breast cancer
Authors: Penn Muluhngwi, Carolyn M. Klinge
Journal: Cancer Research (2017)

Abstract Acquired endocrine-resistance occurs in ~ 40% of estrogen receptor α (ERα)+ breast cancer patients after tamoxifen (TAM) or aromatase inhibitor therapy. MicroRNAs (miRs) are dysregulated in breast cancer, but their contribution to endocrine-resistance is not yet completely understood. Microarray analysis of miRNAs in TAM-sensitive MCF-7 versus TAM-resistant LY2 breast cancer cells (derived from MCF-7 cells) identified differential regulation of miR-29b-1 and miR-29a. miR-29a and miR-29b-1, which are co-transcribed as a single primary-miR, were repressed by TAM in MCF-7 and stimulated by TAM in LY2 cells. We confirmed these observations by real time qPCR in MCF-7 and LY2 cells and observed that 4-OH-TAM (4-OHT) also downregulated miR-29b-1/a in LCC2 and LCC9 endocrine-resistant cells. These changes were at the primary transcriptional level. The role of these two miRs in endocrine-resistant breast cancer is unknown. We tested the hypothesis that the TAM-stimulated increase in miR-29b-1/a promotes endocrine-resistance by downregulating targets that contribute to TAM’s antiproliferative/pro-apoptotic activity. Our goals were to: 1) Determine if ERα was responsible for TAM regulation of miR-29b-1/a expression; 2) Determine the functional role(s) of miR-29b-1/a; 3) Identify specific miR-29b-1/a target genes that are differentially regulated by 4-OHT in MCF-7 versus LCC9 and LY2 cells. Knockdown of ERα blocked 4-OHT inhibition of miR-29b-1/a in MCF-7 and 4-OHT simulation of miR-29-b-1/a transcription in LCC9 and LY2 cells. Transient over-expression of miR-29b-1/a inhibited proliferation of MCF-7, LCC9, and LY2 cells and decreased migration and colony formation of LY2 cells. Repression of miR-29b-1/a has no significant effect on MCF-7, LCC9, or LY2 cell proliferation. Repression of miR-29-b-1/a did not sensitize the TAM-resistant cells to growth inhibition by 4-OHT. We observed that the bona fide miR-29 target gene, DICER1, was inhibited by 4-OHT in LY2 cells and anti-miR29b-1 or anti-miR-29a decreased the suppression of DICER1 by 4-OHT. These data suggest that 4-OHT-ERα increases miR-29b-1/a which target and downregulate DICER 1 in endocrine resistant breast cancer cells. Future studies will identify other targets of miR-29b-1/a to better understand the pathways leading to acquired endocrine resistance. Citation Format: Penn Muluhngwi, Carolyn M. Klinge. Tamoxifen differentially regulates miR-29b-1 and miR-29a depending on endocrine sensitivity in breast cancer [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 3428. doi:10.1158/1538-7445.AM2017-3428