bluuebunny/crossref_metadata_2025 huggingface dataset:
Targeted Delivery of Glucan Particle Encapsulated Gallium Nanoparticles Inhibits HIV Growth in Human Macrophages
Authors: Soto Ernesto R. , O’Connell Olivia , Dikengil Fusun , Peters Paul J. , Clapham Paul R. , Ostroff Gary R.
Published: November 2016

Glucan particles (GPs) are hollow, porous 3–5 μm microspheres derived from the cell walls of Baker’s yeast (Saccharomyces cerevisiae). The 1,3-β-glucan outer shell provides for receptor-mediated uptake by phagocytic cells expressing β-glucan receptors. GPs have been used for macrophage-targeted delivery of a wide range of payloads (DNA, siRNA, protein, small molecules, and nanoparticles) encapsulated inside the hollow GPs or bound to the surface of chemically derivatized GPs. Gallium nanoparticles have been proposed as an inhibitory agent against HIV infection. Here, macrophage targeting of gallium using GPs provides for more efficient delivery of gallium and inhibition of HIV infection in macrophages compared to free gallium nanoparticles.
Short‐Term Efficacy of Pudilan Keyanning Toothpaste in Treatment of Minor Recurrent Aphthous Ulcers
Authors: Yang Yingming , Zhang Tao , Dong Zibo , Wu Yang , Hong Xiao , Hu Tao
Published: November 2016

Aim. To examine the potential of Pudilan Keyanning toothpaste (PKT) to treat minor aphthous ulcers (MiAU). Method. A double‐blind clinical trial was conducted in which 80 volunteers were randomly assigned to the PKT group (N = 40) or the control group (N = 40). The control group used a placebo toothpaste containing no Pudilan extract. At baseline, after 3 days, and after 6 days the following parameters were recorded for the target ulcers: healing rate, healing period, pain (visual analogue scale, VAS), areas of the target ulcerated lesions, degree of exudation, and hyperemia. Results. At the end of the study, the healing rate in the PKT group was 80%, compared to 50% in the control group (p < 0.05). At day 6, the VAS scores, ulcer area, degree of exudation, and hyperemia were significantly different between the two groups, with better performance observed in the PKT group (p < 0.05). Conclusion. PKT toothpaste appears to promote effective healing of MiAU.
Some Remarks on Quasi-Generalized CR-Null Geometry in Indefinite Nearly Cosymplectic Manifolds
Authors: Massamba Fortuné , Ssekajja Samuel
Published: November 2016

Attention is drawn to some distributions on ascreen Quasi-Generalized Cauchy-Riemannian (QGCR) null submanifolds in an indefinite nearly cosymplectic manifold. We characterize totally umbilical and irrotational ascreen QGCR-null submanifolds. We finally discuss the geometric effects of geodesity conditions on such submanifolds.
A Hybrid Signal Processing of RR Intervals from QTc Variation Searching Arrhythmia and Improving Heart Rate Variability Assessment in Acute Large Artery Ischemic Stroke
Authors: Rangsungnoen S. , Chanbenjapipu P. , Mathuradavong N. , Suwanprasert K.
Published: November 2016

Sudden death caused by abnormal QTc and atrial fibrillation (AF) has been reported in stroke. Heart rate variability (HRV) is reduced with missing beats of RRI during arrhythmic episode and abnormal QTc variation during acute stroke. In this study, we develop a hybrid signal processing by Pan Tompkins QRS detection and Kalman filter estimator for meaningful missing beats and searching AF with prolonged QTc. We use this hybrid model to investigate RRIs of Lead II ECG in thirty acute stroke patients with long QTc and AF (LQTc-AF) and normal QTc without AF (NQTc-nonAF) and then assess them by HRV. In LQTc-AF Kalman, higher mean heart rate with lower mean RRIs compared to NQTc-nonAF Kalman was characterized. LQTc-AF Kalman showed significant increase in SDNN, HF, SD2, SD2/SD1, and sample entropy. SDNN and HF associated with high RMSSD, pNN50, and SD1 reflect predominant parasympathetic drive for sympathovagal balance in LQTc-AF Kalman. Greater SD2, SD2/SD1, and sample entropy indicate more scatter of Poincaré plot. Compared with conventional Labchart, fractal scaling exponent of α1 (DFA) is higher in LQTc-AF Kalman. Remarkable complexity with parasympathetic drive in LQTc-AF Kalman suggests an influence of missing beats during stroke.
Abstract A01: Trichodermin induces G1/S cell cycle arrest in ovarian cancer cells
Authors: Chen Yi C. , Gao Ying
Published: November 2016

Ovarian cancer is a major health concern for women as it is prominent among gynecologic cancers. Trichodermin is a sesquiterpene isolated from Nalanthamala psidii and found to induce apoptosis in human chondrosarcoma cells. In this study, A2780/CP70 and OVCAR-3 ovarian cancer cell lines were treated with trichodermin to determine whether it had an anti-cancer effect. Our data presented that trichodermin reduced the viability of both ovarian cancer cells by inducing G1/S cell cycle arrest rather than apoptosis. The underlying mechanism might be that trichodermin down-regulated the expression of Cyclin D1 via inhibiting AhR and c-Myc expression. Therefore, trichodermin is promising in ovarian cancer treatment.

Citation Format: Yi C. Chen, Ying Gao. Trichodermin induces G1/S cell cycle arrest in ovarian cancer cells. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr A01.
Abstract A08: Mechanistic basis of Palbociclib combinatorial activity in ER+ breast cancer and non-breast indications
Authors: Dann Stephen , Chionis John , Choating Liu , Chen Enhong , Wei Ping , Eisele Koleen , Shields David J. , Rejto Paul A. , VanArsdale Todd
Published: November 2016

Phosphorylation of the retinoblastoma protein (Rb) by cyclin-dependent kinases 4 and 6 (CDK4/6) is a critical checkpoint for G1/S cell cycle progression and commitment to cellular proliferation. Human malignancies often subvert these control mechanisms through a range of genetic and biochemical adaptations. Accordingly, tumors that depend on CDK4/6 activity for proliferation and survival are particularly sensitive to inhibition of this pathway by palbociclib (Ibrance™), a highly selective inhibitor of CDK4/6 kinase activities. Treatment regimen of palbociclib with letrozole significantly improved progression-free survival in a randomized phase 2 study of women with advanced estrogen receptor-positive (ER+), HER2-negative breast cancer. Likewise, in ER+ breast cancer models palbociclib and estrogen antagonists combine for greater anti-proliferative activity, increased hallmarks of cellular senescence and prolonged durability of response following drug removal. Dual inhibition of CDK4/6 and ER signaling demonstrated robust anti-tumor activity in xenograft studies. The addition of Palbociclib to other targeted therapeutics elicits improved activity in pre-clinical models of several non-breast indications and these effects also manifest through modulation of cellular proliferation, senescence and growth arrest. Data will be presented on the molecular basis of combination benefit with Palbociclib in ER+ breast and other oncology indications.

Citation Format: Stephen Dann, John Chionis, Liu Choating, Enhong Chen, Ping Wei, Koleen Eisele, David J. Shields, Paul A. Rejto, Todd VanArsdale. Mechanistic basis of Palbociclib combinatorial activity in ER+ breast cancer and non-breast indications. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr A08.
Abstract A20: Excess centrosomes induce p53-dependent senescence in endothelial cells
Authors: Yu Zhixian , Kushner Erich , Bautch Victoria
Published: November 2016

Excess centrosomes (>2 centrosomes/cell), which are prevalent in both tumor cells and tumor endothelial cells, lead to aneuploidy and chromosome instability. Therefore, understanding how excess centrosomes affect cell behaviors is critical for studying tumor progression and tumor angiogenesis. As demonstrated by previous literature, cells with excess centrosomes routinely undergo bipolar cell division to produce viable progeny. However, we found that endothelial cells were not able to maintain the percentage of cells with excess centrosomes, suggesting that excess centrosomes had a negative impact on endothelial cell cycle. We used a tetracycline-inducible Polo-like kinase 4 (Plk4)-expressing system to induce excess centrosomes in human umbilical vein endothelial cells (HUVEC). Doxycycline treatment induced ~30% centrosome over-duplication, which decreased to <5% in 6 days. We found that HUVEC with excess centrosomes activated p53 by phosphorylating p53 at Ser33. Complete down-regulation of p53 helped maintain the frequency of cells with excess centrosomes. Excess centrosomes-induced p53 activation was independent of DNA damage, as demonstrated by lack of p53 Ser15 phosphorylation or γH2AX foci. Excess centrosomes induced senescence but not apoptosis, as shown by senescence-associated beta-galactosidase (SA-β-gal) activity and Galactosidase Beta 1 (GLB1) antibody staining, and the induced senescence can be blocked by p53 down-regulation. Since endothelial cells maintain different cell shapes and behavior in a 3-dimensional (3D) environment compared to 2D, we asked whether excess centrosomes induce senescence in 3D. We used a sprouting angiogenesis assay and found that centrosome over-duplicated ECs in 3D sprouts showed SA-β-gal activity, suggesting that they underwent senescence. In summary, we show that excess centrosomes induced p53-dependent senescence in endothelial cells in both 2D and 3D. Our work provides a novel association between excess centrosomes and senescence, which will help to better understand regulation of the tumor microenvironment.

Citation Format: Zhixian Yu, Erich Kushner, Victoria Bautch. Excess centrosomes induce p53-dependent senescence in endothelial cells. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr A20.
Abstract A30: The effects of Berberis vulgaris on bacterial inhibition and the p53 gene in cancerous Caenorhabditis elegans
Authors: Bhatt Jesal P.
Published: November 2016

Recently, there has been an interest in the use of natural products to inhibit bacterial growth rather than manufactured antibiotics due to the problem of bacterial resistance. This study aims at finding the most effective natural antibacterial remedy. The disk diffusion method was used to compare the antibacterial properties of manuka honey, barberry, aloe vera, and colloidal silver. After a 48-hour incubation period, the zone of inhibition was measured for the following bacteria: Bacillus megaterium, Serratia marcescens, Pseudomonas fluorescens, Rhodospirillum rubrum, and Escherichia coli. Barberry was the most efficient natural product (p=0.02). Further tests were performed to determine whether barberry contained strong anticancer properties. Barberry was tested on Caenorhabditis elegans (C.elegans), strain JR1279, exposed to ultraviolet-C radiation and the population was counted daily. Prior to this experiment, barberry had never before been tested on a model organism. The purpose of this experiment would determine if barberry could increase the lifespan of the C.elegans by the addition of this reagent. It was shown that the C.elegans exposed to barberry had a longer lifespan than those that were not exposed to barberry (p=0.01), indicating that barberry could be a potential anticancer cancer supplement.

Citation Format: Jesal P. Bhatt. The effects of Berberis vulgaris on bacterial inhibition and the p53 gene in cancerous Caenorhabditis elegans. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr A30.
Abstract A31: Reprimo, a potential tumor suppressor gene TP53-dependent, modulates negatively cell migration and invasion in the MDA-MB-231 breast cancer cell line
Authors: Buchegger Kurt , Viscarra Tamara , Ili Carmen Gloria , Riquelme Ismael , Letelier Pablo , Corvalan Alejandro , Brebi Priscilla , Huang Tim Hui-Ming , Roa Juan Carlos
Published: November 2016

Background: Reprimo, a highly glycosylated protein, is a new downstream effector of p53-induced cell cycle arrest at the G2/M checkpoint, and a putative tumor suppressor gene frequently silenced via methylation of its promoter region in several malignances. The aim of this study was to characterize the epigenetic inactivation and its biological function in BC cell lines.

Methods: The correlation between Reprimo methylation and loss of mRNA expression was assessed in six breast cancer cell lines by methylation specific PCR (MSP), 5-Aza-2′-deoxycytidine treatment and qRT-PCR assays. MDA-MB-231 cells were chosen to investigate the phenotypic effect of Reprimo in cell proliferation, cell cycle, cell death, cell migration and invasion.

Results: In the cancer methylome system (CMS) (web-based system for visualizing and analyzing genome-wide methylation data of human cancers), the CpG island region of RPRM (1,1Kb) was hypermethylated in breast cancer compared to normal breast tissue. Downregulation of RPRM mRNA by methylation was confirmed in MDA-MB-231 and BT-20 cell lines. In addition, overexpression of RPRM in MDA-MB-231 cells resulted in decreased rates of cell migration, wound healing and invasion in vitro (P < 0.0001). However, RPRM overexpression did not alter cell viability, rate of death cell and G2/M cell cycle transition in this biological model.

Conclusion: Taken together, these data suggest that RPRM is involved in decreased cell migration and invasion in vitro, acting as a potential tumor suppressor gene in the MDA-MB-231 cell line.

Citation Format: Kurt Buchegger, Tamara Viscarra, Carmen Gloria Ili, Ismael Riquelme, Pablo Letelier, Alejandro Corvalan, Priscilla Brebi, Tim Hui-Ming Huang, Juan Carlos Roa. Reprimo, a potential tumor suppressor gene TP53-dependent, modulates negatively cell migration and invasion in the MDA-MB-231 breast cancer cell line. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr A31.
Abstract A33: Biomarkers of Cdk5 driven neuroendocrine tumors
Authors: Carter Angela M. , Telange Rahul , Oltmann Sarah , Nwariaku Fiemu , Robinson Bruce , Grubbs Elizabeth , Bibb James
Published: November 2016

Background: Neuroendocrine (NE) cancers originate from secretory cells of the body's various endocrine structures. Surgical resection is the primary treatment for these tumors. However, the majority of NE cancers are metastatic at the time of detection and no effective adjuvant therapies exist for primary NE tumors or their metastases. Patients often develop two or more NE cancers, a syndrome termed multiple endocrine neoplasia (MEN). DNA sequencing has lead to breakthroughs in the identification of genes mutated in four types of familial MEN syndromes: Menin, RET, and CDNK1B. Unfortunately, a large percentage of NE cancers are sporadic, resulting from somatic mutations, and a high percentage of these do not harbor menin, RET, or CDNK1B mutations. Our lab has determined that Cdk5 promotes growth in multiple types of NE cancer. Phosphoproteomic studies revealed a selective set of proteins potentially phosphorylated downstream of Cdk5 activation. We hypothesize that these phosphoproteins will serve as biomarkers to identify tumors that will be responsive to anti-Cdk5 therapies.

Methods: Phosphorylation state-specific antibodies were generated to novel phosphoprotein sites by inoculation of New Zealand White rabbits with phosphopeptides specific to each site. Antibodies were isolated from rabbit sera by affinity purification using phosphopeptide columns. Human NE cell lines were treated with Cdk5 inhibitors and monitored for effects on phosphoprotein levels. Phosphoprotein levels were examined in growing and arrested medullary thyroid carcinoma tumors isolated from an inducible/arrestable (NSE-tTA; tetO-p25GFP) mouse model and in normal lung versus small cell lung cancer tumors isolated from a triple conditional knockout (p130 f/f; p53 f/f; Rb f/f) mouse model. Phosphoprotein levels were examined in control tissue and human medullary thyroid carcinoma, gastrointestinal NETs, and pancreatic NETs.

Results: Phosphorylation state-specific antibodies were successfully generated to 10 novel phosphoproteins. Cdk5 inhibition decreases phosphorylation levels of 5 of these 10 proteins in several types of NE cell lines. Levels of 4 of these phosphoproteins are elevated in human NE tumors.

Conclusion: Four novel phosphoproteins downstream of Cdk5 comprise a set of biomarkers for Cdk5-dependent human NE tumors. The combination of these biomarkers with pathway specific therapies currently under development will constitute a coupled diagnostic-therapeutic regimen for personalized treatment of NE cancer patients.

Citation Format: Angela M. Carter, Rahul Telange, Sarah Oltmann, Fiemu Nwariaku, Bruce Robinson, Elizabeth Grubbs, James Bibb. Biomarkers of Cdk5 driven neuroendocrine tumors. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr A33.
Abstract B08: Retinoblastoma protein orchestrates cellular apoptosis in non-small cell lung cancer in response to CDK4/6 inhibition: novel targets and key mechanisms
Authors: Thangavel Chellappagounder , Boopathi Ettickan , Liu Yi , Haber Alex , Perepelyuk Maryna , Addya Sankar , Shoyele Sunday , Dicker Adam P. , Knudsen Karen E. , Den Robert B.
Published: November 2016

Introduction: The retinoblastoma tumor suppressor protein (RB) is a critical mediator of cell proliferation via its regulation of cell cycle by binding to E2Fs. One of the mechanisms of RB activation is through CDK4/6 inhibition. Currently, multiple selective CDK4/6 inhibitors are being utilized in the clinical setting and are thought to drive cellular cytostasis. In this study, we demonstrate that RB activation not only results in cellular senescence, but for the first time, induces apoptosis by repressing IAPs (inhibitor of apoptosis protein).

Experimental Procedures: Isogenic pairs of RB knockdown and control cells were interrogated in vitro, and in xenograft tumors for CDK 4/6 inhibitor response. Cellular senescence and apoptosis were quantified. Molecular mechanism was determined using microarray, chromatin immunoprecipitation, and co-immunoprecipitation assays.

Summary: CDK4/6 inhibition diminished cell growth in an RB dependent manner both in in vitro and in vivo models. Immunohistochemistry from the xenografts demonstrated increased levels of apoptosis in the RB proficient isogenic lines. This was confirmed via western blot analysis for Caspase-3. Mechanistically, microarray analysis demonstrated that RB activation downregulated several key anti-apoptotic proteins (e.g. FOXM1, Survivin). ChIP assay and in silico modeling showed that FOXM1 and Survivin are repressed by RB/E2F binding. In the RB deficient setting, immunoprecipitation demonstrates that FOXM1 and Survivin interact directly with Caspase-3 resulting in decreased apoptosis. This was reversed using a competitive assay with overexpression of the SMAC (second mitochondrial) protein.

Conclusion: Data from multiple isogenic NSCLC models demonstrate that RB activation via CDK4/6 inhibitors results in apoptosis in an RB dependent manner. Mechanistically, RB represses transcription of multiple IAPs (including FOXM1 and Survivin), which allows pro-apoptotic factors such as SMAC to activate Caspase-3. These findings suggest that CDK4/6 inhibitors should be viewed as cytotoxic, as opposed to purely cytostatic, agents and warrant further clinical investigation.

Citation Format: Chellappagounder Thangavel, Ettickan Boopathi, Yi Liu, Alex Haber, Maryna Perepelyuk, Sankar Addya, Sunday Shoyele, Adam P. Dicker, Karen E. Knudsen, Robert B. Den. Retinoblastoma protein orchestrates cellular apoptosis in non-small cell lung cancer in response to CDK4/6 inhibition: novel targets and key mechanisms. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr B08.
Abstract B11: Re-wired E2F function in response to RB loss as a potential driver of castration-resistant prostate cancer
Authors: Mandigo Amy C. , McNair Chris , Schiewer Matthew J. , Xu Kexin , Li Fugen , Myles Brown , Knudsen Karen E.
Published: November 2016

Prostate cancer (PCa) is the most frequently diagnosed non-cutaneous malignancy, and second leading cause of cancer death in males in the United States, causing over 30,000 deaths per year. A crucial component to the development and progression of PCa is the activity of the androgen receptor (AR). AR promotes proliferation and is required for PCa cell growth and survival. As such, targeting the AR-signaling axis through androgen deprivation therapy (ADT) is the first line of therapy for PCa. However, cells invariably become resistant to this therapy and men relapse with the incurable form of the disease, castration-resistant prostate cancer (CRPC). It has been shown that an underlying mechanism of this resistance revolves around the retinoblastoma (RB) tumor suppressor protein. RB functions to repress tumor development by negatively regulating the activity of the E2F family of transcription factors thus, resulting in a decrease in AR levels. RB additionally controls cell cycle progression through its ability to bind and inhibit E2F1 mediated transcription of genes required for G1/S progression. Surprisingly, genome-wide assessment of E2F activity in the absence of RB has been understudied. To better understand the molecular pathways that are altered upon RB loss and the roles they play in CRPC, RNA-Seq and ChIP-Seq analyses were performed in isogenic RB cell lines in both hormone sensitive and CRPC models. Data to be discussed reveal new insight into the differential effects of RB loss on AR and E2F1 function and role as potential drivers of late stage disease.

Citation Format: Amy C. Mandigo, Chris McNair, Matthew J. Schiewer, Kexin Xu, Fugen Li, Brown Myles, Karen E. Knudsen. Re-wired E2F function in response to RB loss as a potential driver of castration-resistant prostate cancer. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr B11.
Abstract B27: Kinetochore-microtubule attachments as a precision therapy target
Authors: Herman Jacob A. , Paddison Patrick J. , DeLuca Jennifer , Olson James
Published: November 2016

Glioblastoma multiforme (GBM) is an aggressive and refractory cancer with limited therapeutic strategies and poor survival. One challenge in treating this disease is the ability of single glioblastoma stem-like cells (GSCs) to initiate tumors. To expand the therapeutic repertoire for GBM we performed RNAi screening in GSCs and a proposed cell of origin, neural crest stem cells (NSCs). In these screens we identified multiple regulators of kinetochore-microtubule attachments as specifically required for GSC survival. Kinetochores are composed of hundreds of proteins that form dynamic attachments between microtubules and chromosomes and are essential for genetic fidelity. Antimitotic agents, including those that target kinetochore proteins, are attractive therapeutics because cell division is essential for tumor expansion, but also because mitotic errors can trigger p53-independent apoptotic signals. However, as mitosis is an essential process, most antimitotic drugs have extremely limited therapeutic windows. We demonstrate that specific activities of the mitotic pseudokinase BubR1 are completely dispensable for non-transformed cells, yet become required for survival in a subset of GBM tumors. Through mutational studies we demonstrate that inactivating either BubR1's GLEBS or KARD domain causes lethal chromosome alignment defects in most GSCs and has no observable on-target toxicity in non-transformed cells. We further demonstrate that this cancer-specific requirement arises from oncogenic activation of the MAP kinase pathway, which ultimately hyperactivates Aurora B kinase at kinetochores. Increased phosphorylation of kinetochore proteins weakens their binding to microtubules and can be indirectly measured by a decrease in the distance between sister kinetochore pairs upon microtubule attachment. In limited samples, this measure serves as a functional biomarker for samples that require BubR1 for chromosome alignment. This work has identified multiple precision targets for GBM with dramatic therapeutic windows; moreover, we have initiated development of a biomarker to identify patients that would respond to such a therapy.

Citation Format: Jacob A. Herman, Patrick J. Paddison, Jennifer DeLuca, James Olson. Kinetochore-microtubule attachments as a precision therapy target. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr B27.
Abstract B34: Inhibition of breast cancer cell metastasis with a non-cyclooxygenase inhibitory derivative of sulindac by suppressing TGFbeta/miR-21 signaling
Authors: Yi Bin , Chang Hong , Feng Xiangling , Ma Ruixia , Piazza Gary A , Xi Yaguang
Published: November 2016

Compelling efficacy on intervention of tumor occurrence and progression by nonsteroidal anti-inflammatory drugs (NSAIDs) has been intensively reported in numerous preclinical and clinical studies. However, the toxicities related to cyclooxygenase (COX) inhibition resulting in suppression of physiologically important prostaglandins limit their clinical use for human cancer chemoprevention. A novel derivative of the NSAID, sulindac sulfide (SS), referred as sulindac sulfide amide (SSA) was recently developed, which lacks COX inhibitory activity, yet shows greater suppressive effect than SS on growth of variable cancer cells. In this study, we focus on the inhibitory activity of SSA on breast tumor cell motility, which has not been studied previously. Our results showed that SSA could inhibit breast tumor cell invasion and migration at sub-cytotoxic concentrations; whereas we previously reported that SS has similar activity on breast and colon tumor cells but at a concentration (50 µM) over 10 times higher than SSA (4 µM). We found that miR-21, a well-documented oncogenic miRNA for promoting tumor cell metastasis, could be downregulated by SSA and involved in mediation of anti-invasive activity of SSA in breast tumor cells. When studying the mechanisms responsible for the regulation of miR-21 by SSA, we demonstrated that TGFbeta signaling suppressed by SSA could ultimately result in downregulation of miR-21 through the transcriptional control. Reduction of Smad2 and Smad3 phosphorylation was the direct response to SSA treatment in metastatic breast tumor MDA-MB-231 cells. By using ChIP assay, we demonstrated that phosphorylated Smad2/3 could bind to the promoter of miR-21 gene. Therefore, in this project, we demonstrate that a non-COX inhibitory derivative of sulindac can inhibit breast tumor metastasis through a new mechanism involving the TGFbeta/miR-21 signaling axis. This study is supported by the NIH/NCI R01 Grant (1R01CA192395) and the American Cancer Society Research Scholar Grant (RSG-13-265-01-RMC).

Citation Format: Bin Yi, Hong Chang, Xiangling Feng, Ruixia Ma, Gary A Piazza, Yaguang Xi. Inhibition of breast cancer cell metastasis with a non-cyclooxygenase inhibitory derivative of sulindac by suppressing TGFbeta/miR-21 signaling. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr B34.
Abstract IA15: The consequences of pRb inactivation: insights from a proteomic analysis of Rb loss
Authors: Nicolay Brandon N. , Danielian Paul S. , Kottakis Filippos , Lapek John D. , Sanidas Ioannis , Miles Wayne O. , Dehnad Mantre , Tschöp Katrin , Gierut Jessica J. , Manning Amity L. , Morris Robert , Haigis Kevin , Bardeesy Nabeel , Lees Jacqueline A. , Haas Wilhelm , Dyson Nicholas J.
Published: November 2016

The retinoblastoma tumor suppressor protein associates with chromatin and regulates gene expression. The transcriptional signatures associated with RB1/Rb mutation are thought to give a picture of the cellular changes that occur when pRB is lost. We used proteomic profiling to examine the changes caused by the ablation of Rb in mouse lung and colon tissues, and compared these with transcript profiles. While the transcription of classic E2F target genes increased similarly in Rbko lung and colon, effects on protein levels were context-dependent. Proteomic changes were identified that were similar between Rb-mutant tissues but, unexpectedly, the major feature of these changes was a decrease in proteins that function in mitochondria. Consistent with this, mutation of RB1 in cultured human cells reduced the number of mitochondrial number and caused mitochondrial dysfunction. Rbko cells had reduced oxygen consumption rate, reduced reserve capacity, an accumulation of depolarized mitochondria and displayed an altered flux of Carbon through the TCA cycle that was evident both in vivo and in vitro. These defects impair cell proliferation under conditions of mitochondria stress. Collectively, these results suggest that the most consistent changes in the proteome of Rbko tissues may not stem from changes in the levels of cell proliferation proteins, but from changes in mitochondrial function. Analysis of transcripts that are induced in Rbko tissues without a corresponding change in protein levels suggests that there may be a mechanism of post-transcriptional control that coordinately suppresses E2F-induced mRNAs.

Citation Format: Brandon N. Nicolay, Paul S. Danielian, Filippos Kottakis, John D. Lapek, Jr., Ioannis Sanidas, Wayne O. Miles, Mantre Dehnad, Katrin Tschöp, Jessica J. Gierut, Amity L. Manning, Robert Morris, Kevin Haigis, Nabeel Bardeesy, Jacqueline A. Lees, Wilhelm Haas, Nicholas J. Dyson. The consequences of pRb inactivation: insights from a proteomic analysis of Rb loss. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr IA15.
Abstract IA19: Mechanisms of alternative telomere recombination
Authors: Greenberg Roger A.
Published: November 2016

Telomere length maintenance is a requisite feature of cellular immortalization and a hallmark of human cancer. While most human cancers express telomerase activity, approximately 10-15% employ a recombination-dependent telomere maintenance pathway known as Alternative Lengthening of Telomeres (ALT), an incompletely understood process that is characterized by multi-telomere clusters. We have recently shown that a DNA double-strand break (DSB) response at ALT telomeres triggers long-range movement and clustering between chromosome termini, resulting in homology-directed telomere synthesis (Cho et. al. Cell 2014). Damaged telomeres initiate increased random surveillance of nuclear volumes before displaying rapid directional movement and association with recipient telomeres over micron-range distances. This phenomenon required Rad51 and the Hop2-Mnd1 heterodimer, implicating a specialized homology searching mechanism that exhibits similarities to meiotic recombination in ALT dependent telomere maintenance. This presentation will describe unpublished data that defines signaling events that are responsible for homology directed telomere synthesis during ALT. Using a novel methodology to purify nascent telomeres, we have identified the basic requirements for break induced telomere synthesis, including the specific DNA polymerases and helicases involved. Data derived from this approach reveals mechanisms of homology directed DNA synthesis that substantially differ from either normal replicative DNA synthesis or from existing models of break induced replication that have been defined in yeast. These data reveal an ordered series of events necessary for ALT telomere synthesis and have implications for homology directed DNA repair at other genomic locations.

This work was supported by NIH grants GM101149, CA138835, and CA17494, and funds from the Abramson Family Cancer Research Institute and Basser Research Center for BRCA

Citation Format: Roger A. Greenberg. Mechanisms of alternative telomere recombination. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr IA19.
Abstract IA27: Perturbation of host cellular regulatory networks by human papillomaviruses
Authors: Münger Karl
Published: November 2016

Human papillomaviruses (HPVs) are small viruses with ~8,000 bp double-stranded, circular genomes. There are over 200 HPV types and they all infect epithelial cells. While most HPV infections are subclinical others cause overt lesions. Most HPV-associated lesions are benign but some “high-risk” HPVs cause lesions that have a propensity for malignant progression and approximately 10% of all human cancers worldwide are caused by high-risk HPV infections. HPV-associated cancers generally represent non-productive infections, i.e. viral proteins are synthesized but no infectious virus is produced. HPV-associated cancers retain expression of two viral genes, E6 and E7, and continued expression of these two viral genes is necessary for cancer cell proliferation and survival. High-risk HPV E6 and E7 encode small, non-enzymatic proteins of ~150 and ~100 amino acids, respectively. These viral proteins exert their oncogenic activities by associating with and functionally reprogramming critical cellular regulatory nodes; indeed, they have been reported to affect the majority of the “Hallmarks of Cancer” as defined by Hanahan and Weinberg (Cell 144:646). In addition to targeting a number of well-known tumor suppressor pathways including TP53 and RB1, E6 and E7 also, directly and indirectly, affect many other cellular signaling pathways. As a result, HPV E6/E7 expressing cells develop unexpected vulnerabilities to perturbation of signaling pathways that are readily tolerated in normal cells.

Citation Format: Karl Münger. Perturbation of host cellular regulatory networks by human papillomaviruses. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr IA27.
Abstract PR01: Therapeutic targeting of cdk4 in bladder cancer
Authors: Rubio Carolina , López-Calderón Fernando , Segovia Cristina , Dueñas Marta , Martínez-Fernández Mónica , Otero Irene , Rosa Federico de la , Villacampa Felipe , Castellano Daniel , Paramio Jesús M.
Published: November 2016

Bladder cancer (BC) is a current clinical and social problem. At diagnosis, 70% of the patients display non-muscle invasive tumor (NMIBC), a relatively indolent disease treated by transurethral resection followed by local instillation in some cases. Unfortunately, NMIBC displays an extremely high recurrence rate, and these recurrent tumors may display tumor progression showing muscle invasive (MIBC) characteristics. MIBC is treated, in most cases, by cystectomy and platinum-based chemotherapy. Nonetheless, the metastatic spreading occurs very often with fatal consequences. Various targeted therapies are being clinically and preclinically tested for BC management. Palbociclib (PD-0332991) is a cdk4/6 inhibitor currently tested for the treatment of other malignancies characterized by the presence of a functional RB1 gene. Since RB1 mutation occurs in only 20-30% of BC, we hypothesized the potential use of Palbociclib for BC management. A series of BC cell lines of known genomic characteristics and differing in their RB1 status, were tested for their sensitivity to Palbociclib. Unexpectedly, we observed a similar response to Palbociclib in pRb wt and pRb mutant cell lines in vitro and in xenografts in vivo, although with different biochemical and cell cycle effects. Genomic characterization of these treated cells shows strong gene expression divergence as a consequence of Palbociclib treatment in pRb wt and mutant cells. Nonetheless, bioinformatic analyses revealed FoxM1 as a possible common regulator of some downregulated genes in both cases. Importantly, FoxM1 has been demonstrated a bona fide cdk4 substrate and may confer cis-platinum resistance. We observed reduced FoxM1 phosphorylation upon Palbociclib treatment in all cell lines tested, and also increased sensitivity to cis-platinum. Remarkably, we found that phosphorylated FoxM1 is a potential poor prognosis factor in human NMIBC clinical samples. Future studies, using various NMBIC and metastatic MIBC transgenic mouse models based on the genetic inactivation of Rb1 with other tumor suppressor genes, will precede the possible development of appropriate clinical trials testing the use of Palbociclib in the management of BC patients.

This abstract is also being presented as Poster A04.

Citation Format: Carolina Rubio, Fernando López-Calderón, Cristina Segovia, Marta Dueñas, Mónica Martínez-Fernández, Irene Otero, Federico de la Rosa, Felipe Villacampa, Daniel Castellano, Jesús M. Paramio. Therapeutic targeting of cdk4 in bladder cancer. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr PR01.
Abstract PR03: Extended inhibition of CDK4/6 inhibits mTORC1 signaling and induces therapeutic senescence in vemurafenib resistant melanoma
Authors: Yoshida Akihiro , Diehl J. Alan
Published: November 2016

Dysregulation of the p16-cyclin D1-CDK4/6-Rb pathway occurs frequently in melanoma; however, the therapeutic efficacy of CDK4/6 inhibition remains to be critically evaluated. We demonstrate that CDK4/6 inhibition inhibits melanoma progression through induction of senescence. Palbociclib, a specific CDK4/6 inhibitor, rapidly induces cell cycle within 24h and continued exposure for 8-days or longer induces senescence. The induction of senescence correlates with inhibition of mTOR and more specifically mTORC1 signaling. Vemurafenib, a specific BRAFV600E inhibitor, has significant clinical efficacy in BRAFV600E positive melanomas but its impact is hampered by a rapid acquisition of resistance. Strikingly, we found that vemurafenib-resistant tumors remain sensitive to palbociclib suggesting that initial treatment with vemurafenib followed by palbociclib with or without mTOR inhibitors might provide an avenue to overcome recurrence of vemurafenib resistant, metastatic disease. Taken together these results support palbociclib as a promising therapeutic for treatment of melanoma.

This abstract is also being presented as Poster A14.

Citation Format: Akihiro Yoshida, J. Alan Diehl. Extended inhibition of CDK4/6 inhibits mTORC1 signaling and induces therapeutic senescence in vemurafenib resistant melanoma. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr PR03.
Abstract PR05: RB localizes to DNA double strand breaks and promotes DNA end resection and homologous recombination through the recruitment of SWI/SNF complex
Authors: Velez-Cruz Renier , Manickavinayaham Swarnalatha , Biswas Anup K. , Clary Regina Weaks , Johnson David G.
Published: November 2016

The retinoblastoma (RB) tumor suppressor is widely recognized as a master regulator of the transcriptional program that controls entry into the S phase of the cell cycle. RB works by binding to members of the E2F family of transcription factors and recruiting chromatin-remodelers and modifiers to the promoters of E2F target genes. Here we show that RB localizes to DNA double strand breaks (DSBs) dependent on E2F1 and ATM kinase activity. Moreover, RB promotes DNA end resection and homologous recombination, and its loss results in genome instability. RB mediates this important role in repair by recruiting the SWI/SNF chromatin remodeler BRG1 to DSBs. In agreement with these results, loss of BRG1 also results in impaired DNA end resection and HR. RB is recruited to DSBs through a DNA damage-inducible phospho-specific interaction between E2F1 and TopBP1. A knock-in mutation of the ATM phosphorylation site on E2F1 (S29A) prevents the interaction between E2F1 and TopBP1 and recruitment of RB, E2F1 and BRG1 to DSBs. This E2F1 mutation also impairs DNA repair, increases genomic instability and renders knock-in mice hypersensitive to IR. We uncover a novel, non-transcriptional function for RB in HR, which could contribute to genome instability associated with RB loss in human cancers and explain their sensitivity to DSB-inducing agents.

This abstract is also being presented as Poster B09.

Citation Format: Renier Velez-Cruz, Swarnalatha Manickavinayaham, Anup K. Biswas, Regina Weaks Clary, David G. Johnson. RB localizes to DNA double strand breaks and promotes DNA end resection and homologous recombination through the recruitment of SWI/SNF complex. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr PR05.
Long-Chain Polyunsaturated Fatty Acids and Clinical Outcomes of Preterm Infants
Authors: Lapillonne Alexandre , Moltu Sissel J.
Published: November 2016

Long-chain polyunsaturated fatty acids (LCPUFAs) play specific roles during the perinatal period and are very important nutrients to consider. The possible effects of LCPUFAs, particularly docosahexaenoic acid (DHA), on various clinical outcomes of preterm infants are discussed in this paper. Since DHA accumulates in the central nervous system during development, a lot of attention has focused on the effects of DHA on neurodevelopment. Experimental studies as well as recent clinical trials show that providing larger amounts of DHA than currently and routinely provided is associated with better neurological outcomes at 18 months to 2 years. This early advantage, however, does not seem to translate into detectable change in visual and neurodevelopmental outcomes or behavior when assessed in childhood. There is growing evidence that, in addition to effects on development, omega-3 LCPUFAs may reduce the incidence or severity of neonatal morbidities by affecting different steps of the immune and anti-inflammatory response. Studies in preterm infants suggest that the omega-3 LCPUFAs may play a significant role by reducing the risk of bronchopulmonary dysplasia, necrotizing enterocolitis and possibly retinopathy of prematurity and sepsis. Overall, evidence is increasing to support the benefits of high-dose DHA for various health outcomes of preterm infants. These findings are of major clinical relevance mainly because infants born preterm are at particularly high risk for a nutritional deficit in omega-3 fatty acids, predisposing to adverse neonatal outcomes. Further studies are warranted to address these issues as well as to more precisely determine the LCPUFA requirement in order to favor the best possible outcomes of preterm infants.
QuickSF: A New Technique in Surfactant Administration
Authors: Maiwald Christian A. , Neuberger Patrick , Vochem Matthias , Poets Christian
Published: November 2016

Background: Recent studies indicate an increasing use of less invasive surfactant administration. Different techniques have been shown with distinct risks and benefits. The aim of this study was to develop a new method that simplifies this procedure. Objectives: An applicator was developed and tested on a manikin to make tracheal surfactant application easier and faster. Methods: A device for oral administration of a catheter into the trachea was developed. After refining, it was tested by 9 neonatologists on a manikin. The primary aim was device feasibility, which was defined as successful intubation within 30 s. Results: The first device showed success in 30 of 33 measurements (90.9%). After refinement, the final device showed successful intubation in all 27 trials (100%). Conclusion: The new technique was feasible in this manikin test and should be confirmed in a clinical study.
Designated Stroke Center Status and Hospital Characteristics as Predictors of In-Hospital Mortality among Hemorrhagic Stroke Patients in New York, 2008-2012
Authors: Gatollari Hajere J. , Colello Anna , Eisenberg Bonnie , Brissette Ian , Luna Jorge , Elkind Mitchell S.V. , Willey Joshua Z.
Published: November 2016

Background: Although designated stroke centers (DSCs) improve the quality of care and clinical outcomes for ischemic stroke patients, less is known about the benefits of DSCs for patients with intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH). Hypothesis: Compared to non-DSCs, hospitals with the DSC status have lower in-hospital mortality rates for hemorrhagic stroke patients. We believed these effects would sustain over a period of time after adjusting for hospital-level characteristics, including hospital size, urban location, and teaching status. Methods and Results: We evaluated ICH (International Classification of Diseases, Ninth Revision; ICD-9: 431) and SAH (ICD-9: 430) hospitalizations documented in the 2008-2012 New York State Department of Health Statewide Planning and Research Cooperative System inpatient sample database. Generalized estimating equation logistic regression was used to evaluate the association between DSC status and in-hospital mortality. We calculated ORs and 95% CIs adjusted for clustering of patients within facilities, other hospital characteristics, and individual level characteristics. Planned secondary analyses explored other hospital characteristics associated with in-hospital mortality. In 6,352 ICH and 3,369 SAH patients in the study sample, in-hospital mortality was higher among those with ICH compared to SAH (23.7 vs. 18.5%). Unadjusted analyses revealed that DSC status was related with reduced mortality for both ICH (OR 0.7, 95% CI 0.5-0.8) and SAH patients (OR 0.4, 95% CI 0.3-0.7). DSC remained a significant predictor of lower in-hospital mortality for SAH patients (OR 0.6, 95% CI 0.3-0.9) but not for ICH patients (OR 0.8, 95% CI 0.6-1.0) after adjusting for patient demographic characteristics, comorbidities, hospital size, teaching status and location. Conclusions: Admission to a DSC was independently associated with reduced in-hospital mortality for SAH patients but not for those with ICH. Other patient and hospital characteristics may explain the benefits of DSC status on outcomes after ICH. For conditions with clear treatments such as ischemic stroke and SAH, being treated in a DSC improves outcomes, but this trend was not observed in those with strokes, in those who did not have clear treatment guidelines. Identifying hospital-level factors associated with ICH and SAH represents a means to identify and improve gaps in stroke systems of care.