bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract A02: Cyclin A2 and CDK2 as Novel Targets of Aspirin and Salicylic acid: a Potential Role in Cancer Prevention
Authors: Dachineni Rakesh , Ai Guoqiang , D Ramesh Kumar , Sadhu Satya , Tummala Hemachand , Gunaje Jayarama B. 
Published: November 2016

Abstract
Data emerging from the past 10 years have consolidated the rationale for investigating the use of aspirin as a chemopreventive agent; however, the mechanisms leading to its anti-cancer effects are still being elucidated. We hypothesized that aspirin's chemopreventive actions may involve cell cycle regulation through modulation of the levels or activity of cyclin A2/cyclin dependent kinase-2 (CDK2). In this study, HT-29 and other diverse panel of cancer cells were used to demonstrate that both aspirin and its primary metabolite, salicylic acid, decreased cyclin A2 (CCNA2) and CDK2 protein and mRNA levels. The down regulatory effect of either drugs on cyclin A2 levels was prevented by pretreatment with lactacystin, an inhibitor of proteasomes, suggesting the involvement of 26S proteasomes. In-vitro kinase assays showed that lysates from cells treated with salicylic acid had lower levels of CDK2 activity. Importantly, three independent experiments revealed that salicylic acid directly binds to CDK2. Firstly, inclusion of salicylic acid in naïve cell lysates, or in recombinant CDK2 preparations, increased the ability of the anti-CDK2 antibody to immunoprecipitate CDK2, suggesting that salicylic acid may directly bind and alter its conformation. Secondly, in 8-anilino-1-naphthalene-sulfonate (ANS)-CDK2 fluorescence assays, pre-incubation of CDK2 with salicylic acid, dose-dependently quenched the fluorescence due to ANS. Thirdly, computational analysis using molecular docking studies identified Asp145 and Lys33 as the potential sites of salicylic acid interactions with CDK2. These results demonstrate that aspirin and salicylic acid down-regulate cyclin A2/CDK2 proteins in multiple cancer cell lines, suggesting a novel target and mechanism of action in chemoprevention.
Citation Format: Rakesh Dachineni, Guoqiang Ai, Ramesh Kumar D, Satya Sadhu, Hemachand Tummala, Jayarama B. Gunaje. Cyclin A2 and CDK2 as Novel Targets of Aspirin and Salicylic acid: a Potential Role in Cancer Prevention. [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 A02.
Abstract A03: SCFCyclin F connects AKT signaling to the core cell cycle oscillator
Authors: Emanuele Michael J. , Choudhury Rajarshi , Kernan Jennifer , Mills Christine Allie , Lahiri Debojyoti , Burke Daniel J. 
Published: November 2016

Abstract
Cell proliferation is governed by the presence of growth factors, and in their absence normal cells cease to progress through the cell cycle. The waves of Cyclin Dependent Kinase (CDK) activity constituting the core of the cell cycle oscillator are driven by cyclin synthesis and its subsequent destruction by the Anaphase Promoting Complex/Cyclosome (APC), a multi-subunit E3 ubiquitin ligase that controls degradation of Cyclins A and B. How growth factor signaling is integrated into the core cell cycle machinery remains largely elusive. Modular Cullin RING ubiquitin ligases (CRLs) represent the largest E3 ligase family in humans, and control the destruction of hundreds of proteins involved in virtually all aspects of cellular physiology. Here we establish a bi-directional ubiquitylation circuit between the APC substrate receptor Cdh1, and Cyclin F, a substrate receptor for the SCF (Skp1-Cul1-F box) family of CRL E3 ubiquitin ligases. We demonstrate that Cdh1 is regulated by SCF(Cyclin F), and conversely, Cyclin F is regulated by APC(Cdh1). AKT modulates the circuit by phosphorylating Cyclin F, enhancing SCF(Cyclin F) ligase assembly, and thereby catalyzing Cdh1 degradation. Later in the cell cycle, CDK phosphorylates Cdh1, preventing its degradation by altering its localization, and allowing both proteins to accumulate. The mutually antagonistic relationship between Cdh1 and Cyclin F represents the first described direct, reciprocal ubiquitylation circuit. Further, phospho-dependent ligase assembly signifies a novel regulatory mechanism for SCF ligases. We propose that AKT is part of a positive feedback loop involved in cell cycle control. This discovery connects growth factor signaling to the core cell cycle machinery, and has potential implications in malignancies where AKT is activated.
Citation Format: Michael J. Emanuele, Rajarshi Choudhury, Jennifer Kernan, Christine Allie Mills, Debojyoti Lahiri, Daniel J. Burke. SCFCyclin F connects AKT signaling to the core cell cycle oscillator. [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 A03.
Abstract A07: The identification of combinations for the CDK4 and CDK6 inhibitor, abemaciclib
Authors: Xueqian Gong , Chio Li-Chun , Webster Yue , Lallena Maria Jose , Boehnke Karsten , Torres Raquel , Iversen Phil , Dios Alfonso De , Smith Ian , Reinhard Christoph , Peng Sheng-Bin , Dempsey Jack , Burke Teresa , Chen Shih-Hsun , Stewart Trent , Beckmann Richard , Wu Wenjuan , Buchanan Sean G. 
Published: November 2016

Abstract
We developed a combination screening protocol to look for synergistic interactions with abemaciclib, an inhibitor of cyclin dependent kinases 4 and 6 (CDK4 and CDK6). Abemaciclib (LY2835219), has shown cytostatic effects in some cell lines while inducing senescence and apoptosis in particularly sensitive cell lines. Abemaciclib, combined with various compounds, was screened across panels of genomically characterized tumor cells. These screens identified several synergistic interactions that improved the activity of abemaciclib in cancer cells lines that respond to abemaciclib monotherapy (e.g. mantle cell lymphoma, ER+ breast cancer) but additionally revealed certain combinations with synergy in Rb wild-type cancers that do not respond optimally to single agent abemaciclib treatment. Most interestingly, MEK inhibitors and LY3009120, a novel Raf dimer inhibitor that inhibits all three Raf isoforms (Cancer Cell 28:384-98) were found to potentiate the cytostatic effects of abemaciclib in these cell lines leading to apoptosis in vitro and tumor regression in vivo. Further analysis of the effects of combined inhibition of CDK4 and CDK6 and Raf isoforms on downstream signaling pathways provides mechanistic clues that may help explain the observed synergy.
Citation Format: Gong Xueqian, Li-Chun Chio, Yue Webster, Maria Jose Lallena, Karsten Boehnke, Raquel Torres, Phil Iversen, Alfonso De Dios, Ian Smith, Christoph Reinhard, Sheng-Bin Peng, Jack Dempsey, Teresa Burke, Shih-Hsun Chen, Trent Stewart, Richard Beckmann, Wenjuan Wu, Sean G. Buchanan. The identification of combinations for the CDK4 and CDK6 inhibitor, abemaciclib. [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 A07.
Abstract A15: Sin3B: a non-classical tumor suppressor
Authors: Bainor Anthony J. , Ueberheide Beatrix , David Gregory 
Published: November 2016

Abstract
Perturbations in cell cycle regulators elicit hyperproliferation and the inability of cells to exit the cell cycle, which are common occurrences in cancer. Recently, we have demonstrated that Sin3B, an essential component of the mammalian histone deacetylase repressor complex, is required for oncogene-induced senescence both in vitro and in vivo. Surprisingly, primary Sin3B-null cells are not readily transformed upon ectopic expression of oncogenic Ras. Thus, these observations indicate that loss of Sin3B uncouples the ability to undergo senescence from the sensitivity to transformation in primary cells. To better understand the relationship between Sin3B, senescence and transformation, we have generated novel immortalized cell lines genetically inactivated for Sin3B. Our results indicate that in these Sin3B-deleted cells, expression of oncogenic Ras promotes transformation and provides a proliferative advantage. Interestingly, we have demonstrated that the paired amphipathic helix 2 (PAH2) domain is crucial for the tumor suppressive nature of Sin3B. To elucidate the molecular bases for these effects, immunoprecipitation and mass-spectrometry was performed to identify the proteins associated with Sin3B and its loss-of-function mutants. We have now identified novel interactors of the Sin3B complex and defined crucial domains responsible for the complex's assembly. These observations suggest that Sin3B functions as a non-classical tumor suppressor which serves to limit the transformative potential of cancer cells. The restoration of Sin3B functionality and downstream pathways may prove useful in the design of targeted therapies to treat advanced disease.
Citation Format: Anthony J. Bainor, Beatrix Ueberheide, Gregory David. Sin3B: a non-classical tumor suppressor. [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 A15.
Abstract A17: Cell cycle control through DREAM and MMB complexes
Authors: Guiley Keelan , Rubin Seth M. 
Published: November 2016

Abstract
The loss of cell cycle control is the most recognized trait of cancer cells. The ability of cells to exit the cell cycle has recently been shown to be dependent upon a large multi-protein repressor complex called DREAM. This complex represses the expression of all cell cycle genes during reversible cell cycle exit. In cycling cells, DREAM is disassembled and some of DREAM associated proteins form a new complex to promote cell cycle gene expression. These proteins that can act together both as repressors and activators of cell cycle gene expression are called the MuvB core. The MuvB core interacts with B-Myb during S phase to promote late cell cycle gene expression. This activator complex is called MMB and its integrity is required for proper cell division. The purpose of this project is to determine how the MuvB core interacts with B-Myb, and if MuvB can be targeted by therapeutics to restore proper cell cycle control in cancer. We have structurally and functionally characterized the mechanism of DREAM assembly and regulation, however MMB regulation remains poorly understood. DREAM has been suggested as a therapeutic target in cancer cells that arrest in response to drug treatment to evade apoptosis. Disruption of DREAM could force evasive cancer cells back into the cell cycle and elicit a response to chemotherapeutic treatment. Until recently, a DREAM interface to target was unavailable. I solved the x-ray crystal structure of MuvB core protein LIN52 complexed with RB tumor suppressor protein p107 and functionally characterized how this interaction is regulated in DREAM assembly. This is a suitable DREAM interface to target given disruption of this interface drives cell cycle entry. I have found that LIN52 also interacts with B-Myb and have obtained crystals of this subcomplex that diffract to 2.4 Å resolution. Therefore, I hypothesize that the MuvB core protein LIN52 mediates interactions with various transcription factors throughout the cell cycle to drive gene specificity through cooperative binding. I will test this hypothesis with two aims: 1) solve the x-ray crystal structure of B-Myb complexed with the MuvB core and investigate the cooperative DNA binding of MuvB and B-Myb; 2) Disrupt LIN52 interactions to disassemble DREAM in drug resistant cancer cells. Completion of these aims will unveil the mechanism of B-Myb activation in cancer and determine if LIN52 is a viable cancer therapeutic target.
Citation Format: Keelan Guiley, Seth M. Rubin. Cell cycle control through DREAM and MMB complexes. [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 A17.
Abstract A27: Cell cycle control and drugs targeting the bioenergetics of cancer
Authors: Shorr Robert 
Published: November 2016

Abstract
Differences in responsiveness to chemotherapeutics among patients may be associated with multiple cell types that can be found in tumors and the circulation. Recurrent or refractory disease may result from natural selection of cells in response to therapy. To design new drugs and make better use of existing drugs differences between diseased and disease causing cells in response to a specific drug requires investigation. The Warburg Effect is characteristic of the majority of cancer cell types both in tumors and the circulation. Drugs that target the underlying biochemistry of essential bioenergetic processes unique to cancer have been shown to have activity against a broad scope of cell types and disease indications while maintaining a favorable safety profile. Recent studies have shown that CPI 613 may have concentration dependent differences in the nature of response, cell death or cell cycle arrest, when tested against H460, BXPC3 and SF539 cancer cells. Understanding the mechanisms of cell cycle arrest is an important factor in choosing other drugs to be used in combination to maximize patient benefit. Results evaluating drug effects on G2/M control proteins will be presented.
Note: This abstract was not presented at the conference.
Citation Format: Robert Shorr. Cell cycle control and drugs targeting the bioenergetics of 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 A27.
Abstract A34: Estrogen induces RAD51C expression and localization to sites of DNA damage
Authors: Holz Marina K. 
Published: November 2016

Abstract
Homologous recombination (HR) is a conserved process that maintains genome stability and cell survival by repairing DNA double-strand breaks (DSBs). The RAD51-related family of proteins is involved in repair of DSBs, consequently, deregulation of RAD51 causes chromosomal rearrangements and stimulates tumorigenesis. RAD51C has been identified as a potential tumor suppressor and a breast and ovarian cancer susceptibility gene. Recent studies implicated estrogen as a DNA-damaging agent that causes DSBs. We found that in estrogen receptor (ER)α-positive breast cancer cells, estrogen transcriptionally regulates RAD51C expression in ERα-dependent mechanism. Moreover, estrogen induces RAD51C assembly into nuclear foci at DSBs, which is a precursor to RAD51 complex recruitment to the nucleus. These findings provide insight into the mechanism of genomic instability in ERα-positive breast cancer and suggest that individuals with mutations in RAD51C that are treated with estrogen would be more susceptible to accumulation of DNA damage, leading to cancer progression.
Citation Format: Marina K. Holz. Estrogen induces RAD51C expression and localization to sites of DNA damage. [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 A34.
Abstract B01: pRb activates mitochondrial metabolism and promotes differentiation through the histone demethylase Kdm5a
Authors: Váraljai Renáta , Islam Abul B.M.M.K. , Dyson Nicholas J. , Benevolenskaya Elizaveta V. 
Published: November 2016

Abstract
While largely studied for its role in cell cycle progression, pRb tumor suppressor is also responsible for differentiation. Cells isolated from Rb knockout animals (Rb1-/-), when induced for differentiation, display defects in induction of differentiation markers. Previous studies in our laboratory identified a critical pRB-interacting protein, Kdm5a, which loss rescued the differentiation defect. Kdm5a is a histone demethylase that is specific to the chromatin modification characteristic of active chromatin, histone H3 lysine 4 trimethylation. We found that Kdm5a binds to many genes with function in the mitochondria. Analysis of Rb1-/- mouse embryonic fibroblasts (MEFs) revealed that the mitochondrial genes were down-regulated, but expression of these genes was rescued upon knockout of Kdm5a. Strikingly, overexpression of the factor required for mitochondrial biosynthesis Pgc-1α or the mitofusin protein Mfn2, was sufficient to rescue the differentiation defect in Rb1-/- MEFs. The rescue of differentiation by loss of Kdm5a or by activation of mitochondrial biogenesis revealed the mitochondrial activation as an essential step in restoring differentiation. Here we investigate which specific mitochondrial function is involved in the differentiation rescue, using metabolic flux analysis and gas chromatography tandem mass spectrometry. We present the evidence that Rb1-deficient MEFs have a decreased oxidative capacity compared to the wild type MEFs, while loss of Kdm5a results in a highly increased respiration and TCA cycle metabolites. Overexpression of Pgc-1α and Mfn2 increased oxidative capacity in parallel with the differentiation rescue. In contrast, knockdown of Mfn2 inhibited oxidation as well as differentiation. Similar experiments conducted in Pgc-1α-/- MEFs were consistent with the role for Pgc-1α in increasing oxidative capacity. The data on establishing the link between mitochondrial function and differentiation are important because they may have implications in developing restorative, differentiation-based therapies.
Citation Format: Renáta Váraljai, Abul B.M.M.K. Islam, Nicholas J. Dyson, Elizaveta V. Benevolenskaya. pRb activates mitochondrial metabolism and promotes differentiation through the histone demethylase Kdm5a. [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 B01.
Abstract B03: Physical and functional interactions between two tumor suppressors, BIN1 and RB1
Authors: Folk Watson P. , Kumari Alpana , Cassimere Erica , Johnson Joanna , Sakamuro Daitoku 
Published: November 2016

Abstract
The bridging integrator 1 (BIN1) protein was originally identified as a cellular adaptor protein that interacts with the transcription factor c-MYC and inhibits cell proliferation. However, BIN1 inhibits tumor cell growth by both a BIN1 MYC-binding domain (MBD)-dependent mechanism and an MBD-independent mechanism. Consistently, BIN1 promotes skeletal muscle differentiation in vitro where c-MYC is not detectable, suggesting that an undefined BIN1-interacting protein other than c-MYC determines BIN1-mediated growth arrest in an MYC-independent manner.
Here we show the functional interplay between BIN1 and the RB1 tumor suppressor for growth arrest. BIN1 interacts with RB1 in differentiated (i.e. growth-arrested) C2C12 skeletal myotube cells, whereas such interaction was largely reduced in undifferentiated (i.e. actively proliferating) C2C12 myoblast cells. Acting through the coiled-coil BAR domain, an essential effector region for BIN1-mediated growth suppression, BIN1 physically interacts with the C pocket domain of RB1 in vitro and in vivo. The RB1-BIN1 protein-protein interaction is functionally germane. First, adenovirus E1A viral oncoprotein, which is known to stimulate cell proliferation in rodent fibroblast model systems by interacting with RB1, disrupted the RB1-BIN1 interaction in vitro. Second, the cancer suppression mediated by overexpressed BIN1 was partly attenuated by the co-transfection of short-hairpin RNA against RB1. Third, an MBD-independent BIN1-associated transcriptional corepressor activity was attenuated when endogenous RB1 was silenced. Fourth, serum stimulation-dependent phosphorylation of the RB-C pocket domain at serine 807/811, critical phosphorylation sites for RB1 inactivation by cyclin-dependent kinases 4 and 6 (CDK4/6), was largely reduced in BIN1-proficient cells. Conversely, the effect of PD-0332991, a chemical inhibitor of CDK4/6, on the growth suppression of RB-proficient cancer cells was more profound in BIN1-deficient cancer cells. Collectively, these data suggest that BIN1 and RB1 physically interact with one another and cooperate to induce growth arrest during cellular differentiation and cancer suppression.
Citation Format: Watson P. Folk, Alpana Kumari, Erica Cassimere, Joanna Johnson, Daitoku Sakamuro. Physical and functional interactions between two tumor suppressors, BIN1 and RB1. [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 B03.
Abstract B14: Feedback regulation between atypical E2Fs and APC/CCdh1 coordinates cell cycle progression.
Authors: Boekhout Michiel , Yuan Ruixue , Wondergem Annelotte P. , Segeren Hendrika A. , Liere Elsbeth A. van , Awol Nesibu , Jansen Imke , Wolthuis Rob MF , Bruin Alain de , Westendorp Bart 
Published: November 2016

Abstract
E2F transcription factors control the oscillating expression pattern of multiple target genes during the cell cycle. Activator E2Fs, E2F1-3, induce an upswing of E2F targets, which is essential for the G1-to-S phase transition, whereas atypical E2Fs, E2F7 and E2F8, mediate a downswing of the same targets during late S, G2, and M phase. Expression of atypical E2Fs is induced by E2F1-3, but it is unknown how atypical E2Fs are inactivated in a timely manner. Using molecular assays, time lapse microscopy, and flow cytometry we now demonstrate that E2F7 and E2F8 are substrates of the Anaphase Promoting Cyclosome/Complex (APC/C). Removal of CDH1, or mutating the CDH1-interacting KEN boxes, stabilized E2F7/8 from anaphase onwards and during G1. Expressing KEN-mutant E2F7 during G1 severely impairs S-phase entry and eventually results in cell death. Furthermore, we show that E2F8, but not E2F7, interacts also with APC/CCdc20. Importantly, atypical E2Fs can activate the APC/CCdh1 by repressing its inhibitors Emi1, cyclin A, and cyclin E. In conclusion, we uncovered a feedback loop between atypical E2Fs and APC/CCdh1, which ensures balanced expression of cell cycle genes and normal cell cycle progression.
Citation Format: Michiel Boekhout, Ruixue Yuan, Annelotte P. Wondergem, Hendrika A. Segeren, Elsbeth A. van Liere, Nesibu Awol, Imke Jansen, Rob MF Wolthuis, Alain de Bruin, Bart Westendorp. Feedback regulation between atypical E2Fs and APC/CCdh1 coordinates cell cycle progression.. [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 B14.