bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract LB-41: Raising awareness of ovarian cancer: a rare disease with no screening test
Authors: Leighton Susan L. 
Published: August 2012

Abstract
Approximately 21,000 women are diagnosed with ovarian cancer annually. Although a relatively rare disease, it is extremely difficult to detect as there is no screening test available. There are symptoms even in early stages which are dismissed by patients as not being serious and often initially being attributed to benign causes by health professional not aware of the symptom complex associated with ovarian cancer. Awareness is the only tool currently available to help improve detection. Lilies of the Valley, an ovarian cancer support and awareness group in Huntsville, Alabama, has as its mission to educate, raise awareness and disseminate information about ovarian cancer to ovarian cancer patients and survivors, the general public and the medical community in the Tennessee Valley region. The Ovarian Cancer National Alliance has its mission to remain objective in providing information to the ovarian cancer community; it does not endorse any particular treatment, therapy, clinical trial or product. These two organizations raise awareness through two very unique and innovative programs, TEAL Talks and the Survivors Teaching Students: Saving Women's Lives. This poster examines the roles of these organizations and these programs in improving early detection of ovarian cancer through patient and health professional awareness.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-41. doi:1538-7445.AM2012-LB-41
Abstract LB-421: Dual shRNA technique to screen gene-to-gene interaction
Authors: Kim Marianne K. H , Annunziata Christina 
Published: August 2012

Abstract
Background: Synthetic lethality screening in human cells is one of the most powerful tools to identify potential therapeutic targets in a genotype specific manner and this screening has been performed in isogenic models of matched cell-line pairs. The procedure of establishing and isolating isogenic cell lines can be arduous. And despite this laborious work, specific target(s) identified in this specific isogenic cell line may not be valid in other similar cells and experimental conditions. Therefore, we have optimized a fast and robust dual shRNA technique to screen gene-to-gene interaction. Methods and Results: To create a matched cell line pair, we utilized a bicistronic vector containing the transmembrane and extracellular domains of the mouse T-cell surface glycoprotein CD8 alpha, co-expressed with a specific shRNA, to model a specific gene deficiency. This retroviral vector was transduced into target cells, and the positively transduced cells were isolated at two days post-infection using MACS separation columns with mouse CD8a-specific microbeads. This yielded greater than 95% purity. At this time point, the decreased expression of specific gene by shRNA was minimal. After recovery from beads purification, the second bicistronic shRNA vector was introduced. This second vector contained a puromycin selectable marker with GFP and an shRNA targeting the proposed synthetic lethal gene. After second transduction, cells were selected under puromycin allowing two doubling times. The purity was 96-98% based on GFP signal measured by FACS at the end of puromycin selection. The dual-gene knockdown by sequentially introduced shRNAs achieved 70-90% depletion of each gene product. This level of knockdown was maintained for up to three weeks without significant loss of purity. After maintaining the cells in culture for several weeks CD8a purity did decrease to 70-80%, but was restored to 98-99% purity after re-applying the separation columns. The second level of purity was maintained even longer than single purification. Conclusion: In summary, we have developed a fast and efficient dual shRNA technique to apply to shRNA experimentation, obviating the need for establishing conventional isogenic cell line models. Due to its fast and simple procedure, this can be simultaneously performed in multiple cell lines. This technique can easily be adapted to screen shRNA libraries for the discovery of unknown synthetic lethal interactions.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-421. doi:1538-7445.AM2012-LB-421
Abstract LB-9: Cyclooxygenase-2/15-prostaglandin dehydrogenase derived endogenous canonical NF-κB inhibitors
Authors: Snyder Nathaniel W. , Revello Sonia D. , Liu Xiaojing , Zhang Suhong , Arora Jasbir S. , Blair Ian A. 
Published: August 2012

Abstract
In colon, breast, and lung cancers, up-regulation of cyclooxygenase-2 (COX-2) and down-regulation of 15-prostaglandin dehydrogenase (15-PGDH) has been hypothesized to lead to a pro-proliferative, angiogenic, and chronically inflamed state. Prostaglandin E2 has been thought to drive the feed forward aspect of this pathology; however, other endogenous lipids may be involved in this process. COXs also mediate the metabolism of arachidonic acid (AA) to hydroxyeicosatetraenoic acids (HETEs), which can then be further oxidized by dehydrogenases to the corresponding keto-products. We have previously established that 11-oxo-eicosatetraenoic acid (oxo-ETE) is a major COX-2/15-PGDH derived metabolites formed from human cells expressing COX-2 treated with AA. 11-oxo-ETE has been identified from human isolates yet currently has no known receptors or known physiologic function. Earlier studies had indicated that molecules possessing a similar α,β-unsaturated ketone moiety may act as canonical Nuclear Factor-κB (NF-κB) inhibitors. Therefore, the present study was aimed to investigate the signaling of this novel COX-2/15-PGDH-derived eicosanoid. The stability and uptake of 11-oxo-ETE into human umbilical vein endothelial cells (HUVECs) was quantified with stable isotope dilution chiral liquid chromatography coupled with electron capture atmospheric pressure chemical-ionization/mass spectrometry. Tumor necrosis factor (TNF)-α induced NF-κB p50/p65 subunit nuclear translocation and consensus DNA binding was reduced by pre-incubation with 11-oxo-ETE. Dosage and reduction in NF-κB were consistent with the levels for the prostaglandin analog 15-deoxy-prostaglandin J2 (15d-PGJ2). Using a HEK293 line stably expressing a firefly luciferase reporter driven by a 5x-NF-κB consensus sequence repeat, 11-oxo-ETE and its methyl ester were shown to significantly inhibit NF-kB signaling induced by TNF-α treatment. Ethacrynic acid (EA) was used in an additional experiment to inhibit cellular glutathione-S-transferases, and this increased the ability of 11-oxo-ETE to inhibit NF-κB signaling in the reporter assay. In vitro biochemical studies also revealed inhibition of the activating kinase Inhibitor of nuclear factor-κB kinase subunit β (≥KKβ) by 11-oxo-ETE. In summary, the present study has established that the COX-2/15-PGDH derived 11-oxo-ETE can enter target endothelial cells and inhibit NF-κB p50/p65 mediated signaling.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-9. doi:1538-7445.AM2012-LB-9
Abstract PL02-02: Lgr5 ctem cells in self-renewal and cancer
Authors: Clevers Hans 
Published: August 2012

Abstract
The intestinal epithelium is the most rapidly self-renewing tissue in adult mammals. We originally defined Lgr5 as a Wnt target gene, transcribed in colon cancer cells. Two knock-in alleles revealed exclusive expression of Lgr5 in cycling, columnar cells at the crypt base. Using an inducible Cre knock-in allele and the Rosa26-LacZ reporter strain, lineage tracing experiments were performed in adult mice. The Lgr5+ve crypt base columnar cells (CBC) generated all epithelial lineages throughout life, implying that it represents the stem cell of the small intestine and colon. Similar obserations were made in hair follicles and stomach epithelium.
Single sorted Lgr5+ve stem cells can initiate ever-expanding crypt-villus organoids in 3D culture. Tracing experiments indicate that the Lgr5+ve stem cell hierarchy is maintained in these organoids. We conclude that intestinal crypt-villus units are self-organizing structures, which can be built from a single stem cell in the absence of a non-epithelial cellular niche. The same technology has now been developed for the Lgr5+ve stomach stem cells.
Intestinal cancer is initiated by Wnt pathway-activating mutations in genes such as APC. As in most cancers, the cell of origin has remained elusive. Deletion of APC in stem cells, but not in other crypt cells results in progressively growing neoplasia, identifying the stem cell as the cell-of-origin of adenomas. Moreover, a stem cell/progenitor cell hierarchy is maintained in early stem cell-derived adenomas, lending support to the “cancer stem cell”-concept.
Fate mapping of individual crypt stem cells using a multicolor Cre-reporter revealed that, as a population, Lgr5 stem cells persist life-long, yet crypts drift toward clonality within a period of 1-6 months. Lgr5 cell divisions occur symmetrically. The cellular dynamics are consistent with a model in which the resident stem cells double their numbers each day and stochastically adopt stem or TA fates after cell division. Lgr5 stem cells are interspersed between terminally differentiated Paneth cells that are known to produce bactericidal products. We find that Paneth cells are CD24+ and express EGF, TGF-a, Wnt3 and the Notch ligand Dll4, all essential signals for stem-cell maintenance in culture. Co-culturing of sorted stem cells with Paneth cells dramatically improves organoid formation. This Paneth cell requirement can be substituted by a pulse of exogenous Wnt. Genetic removal of Paneth cells in vivo results in the concomitantloss of Lgr5 stem cells. In colon crypts, CD24+ cells residing between Lgr5 stem cells may represent the Paneth cell equivalents.
We conclude that Lgr5 stem cells compete for essential niche signals provided by a specialized daughter cell, the Paneth cell.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr PL02-02. doi:1538-7445.AM2012-PL02-02
Abstract PL04-02: Ras and Raf signaling: From biology to therapeutics
Authors: Marais Richard M. 
Published: August 2012

Abstract
The protein kinase BRAF is mutated in about 50% of human melanomas and the small G-protein NRAS is mutated in another 20% of cases. We have developed mouse models of melanoma driven by oncogenic BRAF, NRAS and KRAS. These studies have established that acquisition of BRAF, NRAS or KRAS mutations can be founder events in melanomagenesis and we are currently using these models to investigate gene-gene and gene-environment interactions in cutaneous melanoma. We are also investigating other targets of BRAF in melanoma cells and have shown that BRAF drives melanoma cell migration and invasion by down-regulating expression of the cyclic GMP phosphodiesterase PDE5A. 2011 was a landmark year in melanoma research with the registration of vemurafenib and ipilimumab, drugs that show clinical benefit in patients with advanced disease. Critically, BRAF inhibitory drugs achieve objective clinical responses in about 80% of melanomas that harbour mutations in BRAF. Surprisingly however, these drugs also drive paradoxical activation of CRAF in melanoma cells that harbour mutations in NRAS, or in cells in which RAS is activated due to increased upstream signalling. This is due to the induction of BRAF/CRAF heterodimers and CRAF homodimers and importantly, activation of the pathway by this paradox can drive tumourigenesis in some circumstances. We have used a two-stage skin carcinogenesis model to show that BRAF inhibitors are not tumour promoters pre se, but rather that they work by accelerating the growth of tumours carrying pre-existing mutations in HRAS. Thus, we conclude that BRAF inhibitors appear to accelerate the inevitable in susceptible patients, but do not induce these lesions de novo. Notably, concurrent administration of a MEK inhibitor with a BRAF drug blocks the development of these skin lesions, providing a rationale for combining BRAF and MEK inhibitors in melanoma patients. Unexpectedly, we have also found that the ABL/CKIT inhibitor nilotinib also drives paradoxical activation of the RAF pathway because it possesses weak off-target activity against BRAF and CRAF. The consequence of this paradoxical activation is that nilotinib provides a survival advantage to chronic myeloid leukaemia (CML) cells that are resistant to nilotinib, but also provides an Achilles heel to these cells because they become dependent on MEK signalling in the presence of nilotinib. Thus, MEK inhibitors cooperate with nilotinib to drive synthetic lethality in nilotinib-resistant CML cells. Thus, paradoxical activation of the RAF proteins by small molecular weight drugs can have important consequences to patient responses, creating specific clinical problems in some circumstances, but therapeutic opportunities in others.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr PL04-02. doi:1538-7445.AM2012-PL04-02
Abstract SY02-03: Bromodomain inhibition in cancer
Authors: Bradner James E. 
Published: August 2012

Abstract
Cellular states are maintained by coordinated gene expression programs, attributable to master regulatory transcription factors. Toward the pharmacologic control of cellular states we have undertaken a chemical biological approach to inhibit chromatin-dependent transcriptional signaling. Transcriptional activation by master regulatory proteins is facilitated by chromatin remodeling at promoter/enhancer regions, in particular side-chain acetylation of lysine residues on nearby histone tails. Context-specific lysine acetylation prompts molecular recognition by transcriptional co-activator proteins possessing acetyl-lysine recognition modules, or bromodomains. Perhaps owing to perceptions regarding the feasibility of abrogating protein-protein interactions, research toward the direct inhibition of human bromodomains (or epigenetic reader proteins, in general) has received comparatively little attention. Based on the above rationale, we have developed chemical and biochemical platforms for the development and characterization of novel bromodomain inhibitors. Recently, we reported the first potent, small-molecule inhibitor of human bromodomains, JQ1, which exhibits selectivity for the BET family of bromodomain-containing transcriptional co-activators. Of broad relevance to cancer, we will present research demonstrating that c-Myc expression is critically dependent on BRD4 function and localization to discrete upstream regulatory regions. Exposure of cancer cells to JQ1 prompts immediate down-regulation of c-Myc expression leading to suppression of a transcriptional program associated with proliferation, survival and metabolic adaptation. In translational models of Myc-dependent hematologic malignancies, the efficacy of JQ1 treatment establishes a mechanistic rationale for the leveraged clinical development of drug-like JQ1 derivatives. Toward this objective, we have completed chemical optimization of novel, drug-like inhibitors of BET bromodomains as reagents capable of supporting human clinical investigation. This research has established the feasibility of inhibiting epigenetic reader proteins with efficient, cell-permeable, small molecules. In support of an open-innovation model of chemical biology, we have created a chemical probe allowing the broad study of chromatin biology, which has already been provided to more than 150 academic, governmental and industrial laboratories worldwide. Together, we have rapidly identified mechanism-based opportunities for clinical translation in cancer, inflammation and metabolic diseases.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr SY02-03. doi:1538-7445.AM2012-SY02-03
Abstract SY04-01: Skin stem cells in silence, action, and cancer
Authors: Fuchs Elaine 
Published: August 2012

Abstract
Stem cells have the ability to self-renew long term and differentiate into one or more tissues. Typically, stem cells are used sparingly to replenish cells during normal homeostasis. This is particularly true of adult tissues which undergo relatively infrequent or periodic turnover. However, stem cells must also have the ability to respond quickly in response to injury, where they must be mobilized to undergo rapid tissue regeneration. How stem cells balance self-renewal and differentiation is of fundamental importance to our understanding of normal tissue maintenance and wound repair. Moreover, increasing evidence suggests that the regulatory circuitry governing this balancing act is at the root of some types of tumors both in mice and in humans.
The skin is an excellent model system to understand how stem cells function in normal tissue generation and how this process goes awry in cancer. Using skin as our paradigm, we've been dissecting how extrinsic signaling to stem sets off a cascade of changes in transcription that governs the activation of stem cells during tissue development, homeostasis and hair regeneration. Our findings have provided us with new insights into our understanding of the process of stem cell activation, and in so doing have revealed mechanisms which are also deregulated in a variety of different human cancers. As importantly in understanding how stem cells are activated is learning about the signals that instruct stem cells to stop making tissue.
Our recent discoveries on this topic have led us to the realm of identifying cancer stem cells (tumor-initiating cells) of squamous cell carcinomas of the skin. The second most abundant form of cancer world-wide, skin squamous cell carcinomas also establish a paradigm for many life-threatening cancers of lung, esophagus, breast, cervix, prostate, throat and oral tissues. We've demonstrated that when purified and introduced directly into the skin of a host recipient, a single cancer stem cell from a skin squamous cell carcinoma can generate a new squamous cell carcinoma that is similar in properties to the parent tumor. We show that cancer stem cell numbers and aggressiveness are predicated on the tumor microenvironment and on the ability of cancer stem cells to respond to it. The striking differences between the microenvironments of cancer stem cells and their normal counterparts seems likely to contribute to why their expression profiles are also markedly distinct. Our findings have major implications for our understanding of stem cells and cancer.
[This work was supported by the HHMI and grants from the National Institutes of Health and The Emerald Foundation]
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr SY04-01. doi:1538-7445.AM2012-SY04-01
Abstract SY37-02: Cell polarity proteins and cancer progression
Authors: Muthuswamy Senthil K. 
Published: August 2012

Abstract
The Partitioning defective protein 3 (Par3) is known to regulate asymmetric cell division, cell junction biogenesis and epithelial morphogenesis, but its role in cancer is unclear. We report that expression of Par3 is downregulated in both human breast cancers and in lung metastasis of ErbB2 transgenic mice. Downregulation of Par3 cooperated with ErbB2 to induce invasion and metastasis in vivo. Interestingly, the metastatic behavior was not associated with an overt mesenchymal phenotype. However, loss of Par3 activated a Tiam1/Rac/GTP/IRSp53/WAVE2/Arp2/3 pathway that disrupted cortical actin, blocked E-cadherin junction maturation and decreased epithelial cell-cell cohesion. Cortical actin and Arp2/3 localization were disrupted in tumor cells in vivo. Thus, we identify Par3 as a novel regulator of metastatic behavior in tumor epithelial cells.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr SY37-02. doi:1538-7445.AM2012-SY37-02
Abstract SY37-03: Targeting developmental pathways in colon cancer cells and stem cells
Authors: de Sauvage Frederic J. 
Published: August 2012

Abstract
The small intestine epithelium renews every 2 to 5 days, making it one of the most regenerative mammalian tissues. Genetic inducible fate mapping studies have identified two principal epithelial stem cell pools in this tissue. One pool consists of columnar Lgr5-expressing cells that cycle rapidly and are present predominantly at the crypt base. The other pool consists of Bmi1-expressing cells that largely reside above the crypt base. In the absence of Lgr5-expressing cells, progeny production by Bmi1-expressing cells increased, indicating that Bmi1-expressing stem cells compensate for the loss of Lgr5-expressing cells. Interestingly, both stem cell compartments can serve as cell of origin for the development of colorectal cancer in mice. The Pathways that regulate self-renewal, commitment as well as the interplay between these two populations remain to be clearly defined but are likely to involve Wnt Notch Hedgehog. The Notch, Wnt and Hedgehog signaling pathways play critical roles during embryonic development. These factors modulate proliferation or differentiation of numerous cell types and are also involved in the regulation of the self-renewal and/or differentiation of embryonic and adult stem cells. It is however becoming increasingly clear that these pathways are involved in tumorigenesis when reactivated in adult tissues through mutations or overexpression of pathway components. Aberrant reactivation of the Hedgehog (Hh) pathway in adult tissues can lead for example to the development of cancers such as basal cell carcinoma (BCC) and medulloblastoma is often the result of inactivating mutations in PATCHED (PTCH) or activating SMOOTHENED (SMO) mutations. Notch1 mutations are found in most T-cell acute lymphoblastic leukemias and activation of the Wnt pathway, often through APC (adenomatous polyposis coli) gene mutations, is observed in a majority of colon adenocarcinomas. However all 3 pathways play a role in normal gut homeostasis and may be involved in some aspect of colon tumorigenesis.
In addition to the development of agents targeting these pathways in tumors where they are mutated we will discuss the effect on inhibiting Wnt, Notch and Hedgehog signaling on stem cells in the normal intestine and in tumors.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr SY37-03. doi:1538-7445.AM2012-SY37-03