bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract C18: Identification of epigenetically silenced tumor suppressor genes in colorectal cancer
Authors: Khamas Ahmed , Ishikawa Toshiaki , Iida Satoru , Ishiguro Megumi , Shimokawa Kazuro , Mizushima Hiroshi , Uetake Hiroyuki , Sugihara Kenichi
Published: June 2012

Background: The importance of gene inactivation by promoter CpG island hypermethylation has encouraged the unearthing of silenced tumor suppressor genes (TSGs) in various cancers. We aimed to identify and examine novel methylation silenced TSGs in colorectal cancer (CRC).

Method: We employed Oligonucleotide microarray to find changes in global gene expression of five colon cancer cell lines (HCT116, RKO, Colo320, SW480, and HT29) that were analyzed before and after treatment with the demethylating agent 5-aza-2′-Deoxycitidine (5-aza-dC), expression of the responding genes was compared with microarray expression data of CRC tissue samples. Five genes (ASPP1, GADD45B, LIFR, SCARA5, and THSD1), which had a putative 5′ CpG islands in their promoter, were subjected to methylation-specific PCR (MSP) using 13 colon cell lines and 23 paired tumor and normal CRC tissues.

Result: Seventy-two genes were up-regulated in demethylated cell lines and were simultaneously down-regulated in primary colorectal carcinomas, including genes that were known to be frequently hypermethylated and silenced in CRC. Among 13 colon cancer cell lines, hypermethylation was identified for three of five candidate genes, LIFR (61%), SCARA5 (15%), and THSD1 (23%). The methylation status of LIFR, SCARA5, and THSD1 was subsequently investigated in 23 colorectal tumors, hypermethylation was detected in (87%), (17%), and (9%), respectively. Data from normal colorectal mucosa demonstrated that the observed promoter hypermethylation was cancer-specific in the latter two genes.

Conclusion: The use of a refined microarray screening led to the identification of two TSGs affected by hypermethylation with a cancer-specific manner in CRC. SCARA5 and THSD1 may have a role in CRC tumorigenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C18.
Abstract C3: Selective denuding of nanoparticles for tumor targeting
Authors: Berlin Jacob M.
Published: June 2012

Targeted delivery of therapeutics to tumors is highly desired both to deliver fragile compounds that cannot reach the tumor on their own and to limit off-target toxicity. Nanovectors, nanoparticles capable of transporting and delivering one or more bioactive molecules, are an emerging class of targeted drug delivery platforms. Targeting of nanovectors to tumors is conventionally achieved both by designing them to be approximately 50–200 nm in diameter in order to take advantage of the enhanced permeation and retention (EPR) effect common to tumors and/or functionalizing the nanovectors with ligands that bind specifically in the tumor environment. In order for these strategies to be successful, the nanovectors must have an extended circulation time in the blood. One result of this is accumulation and prolonged retention of many nanovectors in the liver and spleen, which raises toxicity concerns. Here we demonstrate a dramatically different strategy making use of nanovectors composed of insoluble ultrasmall nanoparticles cores functionalized with responsive solubilizing polymer shells. The responsive polymers are designed to be cleaved from the insoluble nanoparticles core in the tumor microenvironment, which results in the deposition of the insoluble nanoparticles at the tumor site. On the other hand, because the particles are ultrasmall, if they remain unchanged they are rapidly cleared from the body, dramatically reducing potential side effects.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C3.
Abstract C33: N-terminal fragment of Bit1 apoptotic protein induces autophagy in tumor cells
Authors: Chen Renwei , Braun Gary B. , Luo Xiuquan , Sugahara Kazuki N. , Teesalu Tambet , Ruoslahti Erkki
Published: June 2012

Bit1 is a proapoptotic mitochondrial protein associated with anoikis, cell death resulting from the loss of cell attachment to extracellular matrix. Upon cell detachment, Bit1 is released into the cytoplasm, where it complexes with the Groucho family protein amino-terminal enhancer of split, and triggers cell death through a caspase-independent pathway. Bit1 consists of 179 amino acids; the N-terminal 62 amino acid mitochondrial localization domain, a transmembrane domain, and the C-terminal peptidyl-tRNA hydrolase domain. In the present study, we localized the Bit1 cell death domain (BCDD) to the N-terminal 62 amino acids of Bit1 by introducing truncated Bit1 proteins into the cytoplasm with cDNAtransfection and protein transduction. BCDD was more potent than the full-length Bit1 protein, when equivalent amounts of cDNA was transfected. Treatment of cultured prostate and breast cancer cells with recombinant proteins in which BCDD was fused with two cell-internalizing peptides, one of which is tumor specific, also caused cell death. Bit1 and BCDD shared the characteristics previously attributed to Bit1-induced cell death. In addition, we found that the cells exhibited the signs of autophagy. These results define the cell death domain in Bit1 and reveal autophagy as the main mechanism of Bit1-induced cell death. Tumor-targeted exogenous BCDD may have potential as an anticancer agent.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C33.
Abstract C4: Inhalational chemotherapy for malignant gliomas
Authors: Chen Thomas C. , Hofman Florence H. , Cho Heeyon , Wang Weijun
Published: June 2012

Perillyl alcohol (POH) is a monoterpene that has been used orally for the treatment of systemic cancer, based on its mechanism of action as a ras inhibitor and a cell cycle inhibitor. Unfortunately, it had significant gastrointestinal side effects, and was never well received as an oral anticancer agent. Recently, POH has been administered intranasally in a Phase I/II trial for the treatment of recurrent malignant gliomas in Brazil. It is well tolerated when delivered intranasally, with a 50% progression free survival (PFS) of 6 months in patients with recurrent GBM, with radiographic reduction in size in some patients. Similar efficacy compared to bevacizumab (Avastin; Genentech) was obtained in recurrent GBM patients treated with intranasal POH alone. We have recently synthesized a pharmaceutical grade of POH with >98% purity. Synthesized POH inhibits vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), and transforming growth factor-beta 2 (TGF-B2). Cytotoxicity, as measured by colony formation assay (CFA), demonstrated a IC50 of 0.5 mM. We have since conjugated POH to a number of different pharmaceutical agents, including temozolomide (TMZ). Data on these conjugates demonstrate increased cytotoxic activity compared to individual drugs alone or in combination. TMZ-POH is much more potent than POH alone (IC50 10–30 uM), and is effective in TMZ resistant glioma cells, inhibits glioma cancer stem cells, and is not toxic to normal astrocytes. Our goal is to use our synthesized POH and TMZ-POH in upcoming Phase I/II trials for recurrent malignant gliomas. Further definition of the perillyl alcohol derivatives will lead to a pipeline of new compounds which will enable further expansion of the intranasal delivery repertoire. Animal models demonstrating efficacy of intranasal delivery of POH and TMZ-POH is currently underway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C4.
Abstract C45: Inhibition of antiapoptotic BCL2 members facilitates interferon regulatory factor-1 (IRF1) mediated prodeath signaling in breast cancer cells
Authors: Schwartz Jessica L. , Hu Rong , Shajahan Ayesha N. , Clarke Robert
Published: June 2012

Antiestrogens (AEs) have long been a standard treatment for estrogen receptor-positive (ER+) breast cancer patients. However, antiestrogen resistance, either de novo or acquired, is a major hurdle for effective therapy in breast cancer patients. To address this, the underlying mechanisms of antiestrogen resistance must be understood. Antiestrogens are known to induce apoptosis in sensitive breast cancer cells. The tumor suppressor gene interferon regulatory factor-1 (IRF1) plays a key role in signaling to proapoptotic BH3 only BCL2 (B-cell lymphoma 2) family members (i.e., BIK, PUMA, and BMF). In an attempt to understand IRF1-mediated signaling in AE sensitivity, AE-sensitive and -resistant breast cancer cells were made to overexpress IRF1 or a dominant negative IRF1 (dnIRF1; lacks the transactivation domain of IRF1 but retains the DNA-binding domain). We found that IRF1 regulates the transcription of proapoptotic BIK, BMF, and PUMA, which are necessary to induce apoptosis in AE-sensitive cells. Conversely, AE-resistant breast cancer cells have low IRF1 expression and increased levels of antiapoptotic BCL2 and BCLW. Previous work by our group showed that the inflammatory cytokine IFNγ can be used to induce IRF1 expression in AE-resistant cells, and restores the responsiveness of these cells to fulvestrant (Faslodex; ICI 182,780) through BH3-mediated apoptosis, suggesting a key role of IRF1 in endocrine-resistant breast cancer. We also discovered that the pan BCL2 inhibitor GX15-070 (obatoclax) significantly reduces cell proliferation and, in combination with fulvestrant or tamoxifen, results in a synergistic inhibition of cell growth in AE-resistant breast cancer cells. Treatment with obatoclax in AE-resistant cells results in a reduction in Beclin1 (BECN1) protein levels with a corresponding increase in cleaved caspase-7, indicating a possible role of autophagy and apoptosis in GX15-070-induced cell death. Moreover, overexpression of BECN1 in AE-resistant cells enhances obatoclax-mediated cell death. Collectively, our data demonstrate that a combination of obatoclax and an antiestrogen increases the levels of free BH3 domain proteins, thus facilitating mitochondrial dysfunction, and rendering breast cancer cells more susceptible to tumor cell death by IRF1-mediated signaling.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C45.
Abstract C46: ErbB-1 and ErbB-2 overexpression in canine mammary cancer and their role as targets in comparative oncology
Authors: Weichselbaumer Marlene , Singer Josef , Jensen-Jarolim Erika , Stockner Thomas , Mechtcheriakova Diana , Sobanov Yury , Bajna Erika , Wrba Friedrich , Horvat Reinhard , Thalhammer Johann G. , Willmann Michael
Published: June 2012

In human medicine, passive immunotherapy is a well-established tool to fight cancer. Cetuximab and trastuzumab are famous examples of effective monoclonal antibody therapies for the treatment of ErbB-1 (EGFR) overexpressing colon tumors and for ErbB-2 (HER2/neu) overexpressing metastatic breast cancer.

Mammary carcinomas of dogs are the most important cause of tumor-related death in females. It is known that these tumors also express tumor markers similar to human breast cancer and that regarding the idea of comparative oncology cancer in pet dogs are a valuable model for speeding up drug development. Therefore, we aimed to investigate more closely canine ErbB-1 and ErbB-2 and the applicability of cetuximab and trastuzumab in the dog.

Screenings with FDA-approved immunohistochemical diagnostic tests of canine mammary tumor samples showed 3/10 ErbB-1 and 4/10 ErbB-2 overexpression, which seems similar to the expression pattern in human breast cancer patients. Sequence analyses revealed amino acid sequence identities of 91% between human and canine ErbB-1 and 92% for ErbB-2. Modeling of those proteins showed that the human cetuximab epitope differs in only four amino acids compared to the canine counterpart and that the trastuzumab binding site is identical in human and canine ErbB-2 except for only one amino acid. Using flow cytometry analyses cetuximab and trastuzumab binding could be confirmed in four canine mammary carcinoma cell lines. Furthermore, cell viability assays showed that incubation of canine cell lines with both antibodies inhibited tumor cell proliferation, even though there are lower numbers of ErbB molecules on canine than on human cells, which was confirmed by a flow cytometry-based assay.

This comparative oncology study indicates that ErbB-1 and ErbB-2 are highly conserved molecules with significant concordance in terms of structure and expression pattern between human and canine cancer. Importantly, the canine homologous molecules are susceptible to cetuximab and trastuzumab targeting, which may open up new avenues towards antibody-based immunotherapies in companion dogs and improvements in anticancer drug development.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C46.
Abstract C58: Heterotetramers of ERBB2 and ERBB3 generate qualitatively distinct signals from heterodimers and provide most of the neuregulin-induced phosphorylation of ERBB2
Authors: Zhang Qian , Park Eisun , Kani Kian , Landgraf Ralf
Published: June 2012

The efficient tyrosine phosphorylation of the orphan ERBB2 (HER2) receptor in heterodimer with the kinase-impaired ERBB3 presents a highly potent source of mitogenic signal. However, it is also a conceptual challenge to our established model of dimer-based signal generation through transphosphorylation. Proposed and mutually not exclusive models for ERBB2 phosphorylation in complex with ERBB3 include autophosphorylation in cis after complex formation and allosteric activation of its kinase domain by ERBB3 in trans, phosphorylation of ERBB2 in trans by the low but detectable kinase activity of ERBB3, or phosphorylation of ERBB2 in proxy. Proxy activation refers to phosphorylation between ERBB2 receptors of activated heterodimers in higher order complexes.

We previously reported that the ligand-induced activation and growth stimulation through ERBB2/ERBB3 can be efficiently inhibited by an aptamer directed against the extracellular portion of ERBB3. Studies of the exact mode of inhibition now reveal that the aptamer neither acts by interfering with ligand binding nor by suppressing heterodimer formation. Combined biochemical studies and homology models identified the binding site of the aptamer and suggest that it interferes with the transition from activated heterodimers to heterotetramers. This inhibits the proxy activation of ERBB2 and associated MAPK activation while heterodimerization, the phosphorylation of ERBB3, and downstream activation of AKT are largely insensitive to inhibition.

The fact that ERBB2 appears to receive most of its tyrosine phosphorylation through a proxy mechanism is consistent with reports of a prevalence of tetramers in the context of EGFR activation. Furthermore, our study demonstrates for the first time that mechanistically definable and dissectible higher order ERBB complexes contribute to signaling in a manner that is qualitatively distinct from the signal that emanates from isolated dimers. This forces us to fundamentally reinterpret approaches to therapeutic intervention that are at present conceptually centered around modulating the formation of dimers but often generate experimental and clinical outcomes that do not readily reconcile with dimer-based models.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C58.
Abstract C66: Impacts of ERK signaling on the regulation of antioxidant enzymes and ROS levels in human lung cancer cells exposed to lead acetate
Authors: Yang Jia-Ling , Wang Chun-Yu
Published: June 2012

Lead compounds (Pb) are widespread environmental contaminants that have been evaluated as group 2A carcinogens. Recently, we showed that EGFR activation is an immediate response to Pb as a primary upstream molecule to initiate SFK and PKCα activation, and subsequently links to the Ras→Raf-1→MKK1/2→EKK signaling cascade. Also, activation of this signaling plays a defensive role against Pb genotoxicity. Here, we explore whether Pb disturbs the intracellular levels of antioxidant enzymes and reactive oxygen species (ROS), and whether ERK signaling modulates the oxidative stress elicited by Pb in CL3 human non-small-cell lung adenocarcinoma cells. We found that Pb lowered the protein levels of glutathione peroxidase-1 (GPX1) and catalase, yet it induced superoxide dismutase 2 (SOD2). The phenomena were reverted upon ERK inactivation or depletion. By contrast, forced expression of the MKK1/2→ERK signaling decreased GPX1 and catalase, but enhanced SOD2 protein levels. The activities of GPX1 and catalase, but not SOD2, were declined in Pb-treated cells, and blockage of ERK activation partially rescued the decreased GPX1 activity. On the other hand, Pb elevated intracellular ROS, and ERK inactivation further enhanced its levels. The antioxidant N-acetyl-cysteine markedly prevented the cytotoxicity of Pb during ERK inactivation. These results suggest that ERK activation could mediate in scavenging ROS toxicants following Pb; yet, this signaling also participates in down-regulation of GPX1 and catalase as well as up-regulation of SOD2 at the protein levels, which probably enhances the intracellular H2O2. Thus, ERK exhibits dual and opposing roles in modulating oxidative stress caused by Pb.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C66.
Abstract C70: Integrative analysis of pharmacologic, genomic, and transcriptomic assays in cancer
Authors: Liu Manway , Reddy Anupama , Huang Alan , Caponigro Giordano , Lehar Joseph
Published: June 2012

We describe an integrative analysis approach leveraging the publicly available Cancer Cell Line Encyclopedia to uncover regulatory pathways in cancer. Six different lines of evidence are considered in identifying candidate factors associated with disease: 1) gene mutation status, 2) copy number variations, 3) RNAi growth inhibitions, 4) pharmacological growth inhibitions, 5) baseline gene expression data, and 6) physical protein-protein interactions. As each of these evidence sources measure a different aspect of cellular regulation, they may be considered in combination to uncover regulatory mechanisms associated with tumorigenesis. For example, gene mutation status or copy number variation data may be combined with baseline gene expressions to identify genes that are differentially expressed in cell lines with aberrant or deactivated versions of specific tumor suppressors and oncogenes.

To assess our approach, we applied it to identification of genes involved in the well-known RAS-RAF regulatory signaling pathway in both tissuespecific and nonspecific contexts. The RAS-RAF signaling pathway plays a key role in cellular differentiation and proliferation and is frequently associated with tumorigenesis. Specifically, we identified differentially expressed genes in BRAF mutant vs. wild-type cell lines, genes associated with high and low RAF copy number alteration cell lines, genes correlating in expression to growth inhibition by RAF-targeting compounds, and genes that either rescue or sensitize cell lines to BRAF knockdown by RNA interference. We further considered these genes within the overall context of physical interactions between their protein products. Highlighting the significant, research potential of our approach, our RAF-focused analysis identified both well-known and novel genes, supported by different lines of evidence, that mediate RAS-RAF signaling across multiple tissues. Positive control genes include members of the classical pathway, such as MAPK1, MAP2K1, and PI3K.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr C70.
Abstract IA3: Discovery in cancer genomics by next-generation sequencing and data analysis
Authors: Mardis Elaine
Published: June 2012

The combined use of next-generation sequencing and advanced analytical approaches has transformed our view of the cancer genome. Not only has large-scale characterization of the genomes of tumors been informative but we also can produce important companion datasets of expressed RNAs and of methylation sites, and then integrate these data to obtain a fuller picture of tumor biology. Scaling these methods and analyses to investigate hundreds of tumors with shared tissues of origin has enabled an appreciation of the multitude of genes that can be impacted by various forms of alteration from point mutations through gross structural changes, along with a pathways-based understanding of somatic alterations. The availability of extensive clinical data allows correlation of specific alterations to clinical outcomes, response to therapy and other critically important factors that enable the translation of genomic discoveries into clinical practice. My talk will survey the different data-driven approaches currently being applied to tumor:normal pairs, then discuss results from whole genome sequencing and analysis of large numbers of breast tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr IA3.
Abstract IA4: Normalizing the tumor microenvironment to enhance therapeutic outcome
Authors: Jain Rakesh K.
Published: June 2012

A solid tumor is like an aberrant organ – comprised of cancer cells and a variety of host cells embedded in an extra-cellular matrix – nourished by blood vessels and drained by lymphatic vessels. Using an array of imaging technologies and animal models, we have shown that blood and lymphatic vessels as well as matrix associated with tumors are abnormal and these abnormalities can create a hostile tumor microenvironment (e.g., hypoxia, high interstitial fluid pressure). These abnormalities can fuel tumor progression as well as prevent treatments from reaching and attacking tumor cells. To this end, we proposed that “normalizing” tumor vessels and matrix would allow cancer therapies to penetrate the mass more uniformly and to function more effectively. We then showed first in mice and then in cancer patients that antiangiogenic drugs - originally designed to destroy tumor vessels - could, paradoxically, also “normalize” them, creating a window of opportunity to attack the cancer most effectively. More crucially, the extent of vascular normalization closely associated with the overall survival of patients receiving anti-angiogenic therapy. More recently, we have shown that the drugs approved by the FDA for lowering blood pressure can “normalize” the collagen matrix and improve the delivery of molecular and nanomedicine (3, 4). At this meeting, I will present emerging data on new targets for normalizing the tumor microenvironment and how normalization can potentiate the outcome of tumor vaccine therapy.

References:

1. Jain RK. Normalization of the tumor vasculature: An emerging concept in anti-angiogenic therapy of cancer. Science. 2005;307:58–62.

2. Goel S et al. Normalization of the vasculature for treatment of cancer and other diseases. Physiological Reviews. 2011;91:1071–1121.

3. Jain RK, Stylianopoulos T. Delivering nanomedicine to solid tumors. Nature Reviews Clinical Oncology. 2010;7:653–64.

4. Diop-Frimpong B, Chauhan VP, Krane S, Boucher Y, Jain RK. Losartan inhibits collagen I synthesis and improves the distribution and efficacy of nanotherapeutics in tumors. PNAS. 2011;108:2909–14.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr IA4.
Abstract PR3: The BLM helicase facilitates RNA polymerase l-mediated ribosomal RNA transcription
Authors: Grierson Patrick , Lillard Kate , Behbehani Gregory , Combs Kelly , Bhattacharyya Saumitri , Samir Acharya , Groden Joanna
Published: June 2012

Bloom's syndrome (BS) is an autosomal recessive disorder that is invariably characterized by cancer predisposition and idiopathic growth retardation. The BLM helicase, mutations of which lead to BS, localizes to the nucleolus of the cell, the site of RNA polymerase l-mediated ribosomal RNA (rRNA) transcription. rRNA transcription is fundamental for ribosome biogenesis and therefore protein synthesis, cellular growth and proliferation; its inhibition limits cellular growth and proliferation as well as bodily growth. Disorders with defective ribosome biogenesis, such as Diamond-Blackfan anemia and Shwachman-Diamond syndrome, display similar cancer predisposition and growth abnormalities to BS. The objective of this study was to investigate a potential mechanism underlying the proportional dwarfism of BS. We tested the hypothesis that the BLM helicase facilitates rRNA transcription as a component of an RNA polymerase I-associated complex, which when deficient has the potential to lead to proportional dwarfism. We report that nucleolar BLM facilitates RNA polymerase I-mediated rRNA transcription using H3-uridine pulse-chase assays and nuclear run-on assays in cells with an innate or experimentally induced BLM deficiency. In vitro helicase assays demonstrate that BLM unwinds GC-rich hybrid RNA/DNA nucleic acid substrates predicted to form in the nucleolus during rRNA transcription; the persistence of such structures inhibits progression of the RNA polymerase I transcription complex. Immunofluorescence studies using actinomycin D at a concentration that inhibits RNA polymerase I demonstrate the dependence of BLM nucleolar localization upon ongoing RNA polymerase l-mediated rRNA transcription. Finally, in vivo protein co-immunoprecipitation shows that BLM physically associates with RNA polymerase I in the nucleolus. These studies suggest that nucleolar BLM interacts with RNA polymerase I and facilitates rRNA transcription by modulating rDNA structure. Given the intricate relationship between rDNA metabolism and growth, our data may help to understand the etiology of the proportional dwarfism in Bloom's syndrome. Furthermore, this work provides greater understanding of the mechanisms regulating rRNA transcription and ribosome biogenesis, processes currently being exploited in cancer therapeutics.

This abstract is also presented as Poster B34.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr PR3.
Abstract PR-04: Physical activity and risk of breast cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC): Results for different tumor subtypes
Authors: Steindorf Karen
Published: June 2012

Physical activity has been identified as protective factor for invasive breast cancer risk in several studies, whereas studies on in situ carcinoma are rare. Studies investigating whether this association is valid for all breast cancer subtypes defined by the estrogen receptor (ER) and the progesterone receptor (PR) status yielded inconsistent results.

Material and methods: The study is based on data from 283,680 female participants from the multinational EPIC-cohort study, for whom detailed information on recreational household and occupational physical activity as well as smoking habits, dietary habits, anthropometry and socio-demographic variables were assessed at the baseline examination between 1992 and 2000. Adjusted hazard ratios (HR) were estimated by proportional hazards models. For outcome variables with more than 2 levels competing risk models were applied. During a median follow-up period of 11.7 years, 9,947 incident breast cancer cases were identified, including 1,060 carcinoma in situ. Out of the 8,887 invasive breast cancer cases the estrogen receptor status, the progesterone receptor status and the combined status of the tumor could be assessed for 6,007 (67.6%), 4,814 (54.2%), and 4798 (53.9%) cases, respectively.

Results: For invasive tumors, breast cancer risk was inversely associated with high levels of total physical activity (HR=0.85, 95% confidence interval (CI): 0.77–0.93, p-trend<0.001) and of recreational activity (HR=0.88, 95%-CI: 0.82–0.94, p<0.001), comparing the highest to the lowest activity quartile. Effects for postmenopausal breast cancer (HR=0.81, 95%-CI: 0.70–0.93, p=0.002 for total physical activity, HR=0.89, 95%-CI: 0.81–0.97, p=0.005 for recreational activity) were slightly stronger than for premenopausal breast (HR=0.87, 95%-KI: 0.72–1.04, p=0.082 for total physical activity, HR=0.84, 95%-KI 0.72–0.98, p=0.032 recreational activity). The analyses by hormone receptor status indicated differential effects with stronger effects of total physical activity for hormone receptor positive (ER+/PR+) breast tumors, compared to the other combinations (p-value for test of heterogeneity: p=0.043). More detailed analyses showed that primarily the PR status (p-heterogeneity: 0.006) rather than the ER status (p-heterogeneity 0.235) dominated this result. For in situ carcinoma no associations for any of the physical activity variables were found.

Conclusions: The protective effects for physical activity on breast cancer risk could be confirmed. The results of this largest prospective study on physical activity and different hormone receptor status indicate that physical activity primarily reduces the risk for PR+ and ER+/PR+ tumors. The result strengthens the hypothesis that the reduction of breast cancer risk by physical activity is at least partly related to hormonal pathways.

Citation Information: Cancer Prev Res 2011;4(10 Suppl):PR-04.
Drug-Specific Th2 Cells and IgE Antibodies in a Patient with Anaphylaxis to Rituximab
Authors: Vultaggio Alessandra , Matucci Andrea , Nencini Francesca , Pratesi Sara , Petroni Giulia , Cammelli Daniele , Alterini Renato , Rigacci Luigi , Romagnani Sergio , Maggi Enrico
Published: June 2012

Rituximab (RTX) is currently used in the treatment of lymphoproliferative diseases and of several rheumatologic disorders and is a frequent cause of acute infusion reactions, usually classified as cytokine release syndrome (CRS). Some infusion reactions to RTX raise concern for immediate type I hypersensitivity, even if to date RTX-specific IgE antibodies have not been reported. To improve knowledge of the mechanisms of reactions to RTX, we investigated humoral and cellular immune responses to this drug in a patient suffering from rheumatoid arthritis who displayed two immediate infusion-related reactions. RTX-exposed tolerant patients and healthy untreated subjects were used as controls. Non-isotype-specific and IgE anti-RTX antibodies were positive in the serum samples collected from the reactive patient but not in those from the control groups. Only the reactive patient also displayed skin testing positivity with RTX. More importantly, RTX-stimulated peripheral blood mononuclear cells from the reactive patient, but not from the controls, displayed a dose-dependent proliferative response associated with a Th2 cytokine production profile. Our results show the presence of RTX-specific Th2-type cells and IgE antibodies, thus suggesting that type I hypersensitivity may be an additional mechanism to CRS in the development of RTX reactions.
Gallic Acid as a Cancer-Selective Agent Induces Apoptosis in Pancreatic Cancer Cells
Authors: Liu Zuojia , Li Dan , Yu Lijun , Niu Fenglan
Published: June 2012

Background: Gallic acid (GA) is a plant phenol isolated from water caltrop which is reported to have anti-inflammatory and anti-cancer effects. In this study, the antiproliferative effect of GA on human pancreatic cancer cell lines CFPAC-1 and MiaPaCa-2 as well as hepatocytes HL-7702 as normal cells was examined. Particularly, the mechanism of GA-induced apoptosis in MiaPaCa-2 cells in vitro was further studied. Methods: Cell viability was measured using SRB assay, and apoptosis was detected by Hoechst staining and annexin V-PI staining assays. Mitochondrial membrane potential was detected by rhodamine-123 staining. Flow cytometry analysis was employed to detect the apoptosis-related events. Results: GA inhibited the proliferation of CFPAC-1 and MiaPaCa-2 cells in a time- and dose-dependent manner, with IC50S of 102.3 ± 2.4 and 135.2 ± 0.6 µM at 48 h, respectively. GA treatment led to the increased proportion of cell apoptosis from 12.5 ± 0.72 to 78.3 ± 2.48% at the concentrations of 6.25 and 25.0 µg/ml, which was evidenced again by chromatins staining assay. Also, GA activated caspase-3, caspase-9, and reactive oxygen species, elevated Bax expression and [Ca2+]i and reduced mitochondrial membrane potential (ΔΨm) in MiaPaCa-2 cells. Remarkably, when compared with human normal cells HL-7702 (IC50 >100 µg/ml), GA showed selective toxicity for cancer cells. Conclusions: GA can function as a cancer-selective agent by inducing apoptosis in MiaPaCa-2 cells via the mitochondria-mediated pathways. To the best of our knowledge, GA should open up new opportunities for the therapy of pancreatic cancer.
Costs of Secondary Prevention of Stroke by Carotid Endarterectomy
Authors: Hædersdal Carsten , Søndergaard Mette Posborg , Olsen Tom Skyhøj
Published: June 2012

Background: We estimated the costs to the Danish National Health Service of preventing stroke due to carotid artery stenosis by carotid endarterectomy (CEA), including costs of identifying patients, Doppler ultrasound (DUS) examination and CEA. Methods: Estimations are based on patients with stroke, transient ischemic attacks (TIA) or amaurosis fugax referred for carotid DUS in the municipality of Frederiksberg, Denmark (127,184 residents), within an 18-month period in 2008–2009. Results: In total, 372 patients with stroke (n = 194), TIA (n = 157) or amaurosis fugax (n = 21) were referred for DUS. We identified 12 patients with 50–70% stenosis and 20 patients with >70% stenosis. Six had CEA, all of whom had stenosis >70%. Waiting time from symptom to CEA was a median of 38 days. Costs of preventing 1 recurrent stroke in the study period [number needed to treat (NNT) = 13] was in the range of EUR 207,675–333,918. If CEA had been performed within 2 weeks after onset of symptoms (NNT = 4), costs would be in the range of EUR 63,900–102,744. Conclusion: Costs of preventing stroke by CEA were high. Substantial reductions of costs (by about 2/3) can be achieved if CEA is performed <2 weeks after the ischemic event.
Complex Regional Pain Syndrome following Spine Surgery: Clinical and Prognostic Implications
Authors: Wolter T. , Knöller S.M. , Rommel O.
Published: June 2012

Background: Complex regional pain syndrome (CRPS) has been reported following spinal surgery, but its frequency after spinal surgery is unknown. The aim of this study was to determine the frequency of spinal surgery preceding CRPS and to examine these patients regarding the course of the disease and prognostic factors. Methods: We examined 35 CRPS patients regarding the symptoms and signs of CRPS, the type of CRPS (I or II), the origin and grade of the disease, the type of surgeries prior to CRPS onset, the course of the disease, and the therapies following diagnosis of CRPS. Results: In 6 patients, CRPS began during the postoperative course (lumbar spine surgery, n = 5; cervical spine surgery, n = 1). Four of these patients suffered from CRPS II. The course of the disease in the 6 patients was not different from that of patients with CRPS of other origins. First symptoms of CRPS could be observed 1–14 days after surgery. Conclusions: CRPS is a rare complication after spinal surgery, but spinal surgery precedes the onset of CRPS of the lower limb in almost one-third of the cases. The first typical symptoms of CRPS emerge within 2 weeks after spinal surgery.
Combined Therapy with Sonic Hedgehog Gene Transfer and Bone Marrow-Derived Endothelial Progenitor Cells Enhances Angiogenesis and Myogenesis in the Ischemic Skeletal Muscle
Authors: Palladino Mariangela , Gatto Ilaria , Neri Valentina , Stigliano Egidio , Smith Roy C. , Pola Enrico , Straino Stefania , Gaetani Eleonora , Capogrossi Maurizio , Leone Giuseppe , Hlatky Lynn , Pola Roberto
Published: June 2012

We have previously demonstrated that sonic hedgehog (Shh) gene transfer improves angiogenesis in the setting of ischemia by upregulating the expression of multiple growth factors and enhancing the incorporation of endogenous bone marrow (BM)-derived endothelial progenitor cells (EPCs). In this study, we hypothesized that combined therapy with Shh gene transfer and BM-derived EPCs is more effective than Shh gene therapy alone in an experimental model of peripheral limb ischemia. We used old mice, which have a significantly reduced angiogenic response to ischemia, and compared the ability of Shh gene transfer, exogenous EPCs, or both to improve regeneration after ischemia. We found a significantly higher capillary density in the Shh + EPC-treated muscles compared to the other experimental groups. We also found that Shh gene transfer increases the incorporation and survival of transplanted EPCs. Finally, we found a significantly higher number of regenerating myofibers in the ischemic muscles of mice receiving combined treatment with Shh and BM-derived EPCs. In summary, the combination of Shh gene transfer and BM-derived EPCs more effectively promotes angiogenesis and muscle regeneration than each treatment individually and merits further investigation for its potential beneficial effects in ischemic diseases.
Outcome of Patients Presenting with ST Elevation Myocardial Infarct and Cardiogenic Shock: A Contemporary Single Center’s Experience
Authors: Greenberg Gabriel , Assali Abid , Assa-Vaknin Hanna , Brosh David , Teplitsky Igal , Battler Alexander , Kornowski Ran , Lev Eli I.
Published: June 2012

Objectives: Acute ST elevation myocardial infarction (STEMI) presenting with cardiogenic shock (CS) is associated with dismal prognosis. In the last years, significant advances have been made in reperfusion techniques and pharmacological treatment. Therefore, we aimed to assess the outcome of these patients during the past decade and identify major factors that impact their prognosis. Methods: We identified 170 patients who presented with STEMI, CS, and underwent primary percutaneous coronary intervention (PCI) between 2001 and 2011. Patients were allocated into two groups based on period of presentation: 2001–2005 (n = 70) and 2006–2011 (n = 100). Clinical outcomes up to 6 months were evaluated. Results: Patients in the latter period were younger, and had lower rates of renal failure and higher rates of stent use. Despite these differences, mortality did not differ and remained high in both periods (52–59% at 6 months). Time frames from onset of symptoms to arrival to the emergency department and to performance of coronary intervention were similar in both periods. Intra-aortic balloon pump use was similar in both periods. In multivariate analysis, factors associated with 1-month mortality were: diabetes (OR = 3.6, 1.4–9.4, p = 0.007), LVEF <40% (OR = 1.8, 1.3–2.6, p = 0.001), GFR <60 ml/min/m2 (OR = 1.8, 1.3–2.4, p < 0.009) and glycoprotein IIb/IIIa inhibitor use (OR = 0.5, 0.2–1.1, p = 0.08). The combination of diabetes and renal failure was associated with particularly high mortality. Conclusions: Prognosis of patients presenting with STEMI, CS, and treated with primary PCI during the past decade, remains poor. Better risk-stratification may help improve their grave outcome.
Intussusceptive Angiogenesis: A Biologically Relevant Form of Angiogenesis
Authors: De Spiegelaere Ward , Casteleyn Christophe , Van den Broeck Wim , Plendl Johanna , Bahramsoltani Mahtab , Simoens Paul , Djonov Valentin , Cornillie Pieter
Published: June 2012

Angiogenesis, i.e. the development and growth of blood vessels, is a major topic of research as it plays an important role in normal development and in various pathologies. Recent evidence revealed the existence of different mechanisms of blood vessel growth, including sprouting and intussusceptive angiogenesis, vascular mimicry, and blood vessel cooption. The latter two have only been observed in tumor growth, but sprouting and intussusceptive angiogenesis also occur in healthy, physiologically growing tissues. Despite this variety of angiogenic mechanisms, most of the current research is focused on the mechanism of sprouting angiogenesis because this mechanism was first described and because most existing experimental models are related to sprouting angiogenesis. Consequently, the mechanism of intussusceptive angiogenesis is often overlooked in angiogenesis research. Here, the mechanism of intussusceptive angiogenesis is reviewed and the current techniques and models for investigating intussusceptive angiogenesis are summarized. In addition, other mechanisms of vascular growth are briefly reviewed.
Evolutionary Change in the Brain Size of Bats
Authors: Yao Lu , Brown J.-P. , Stampanoni Marco , Marone Federica , Isler Karin , Martin Robert D.
Published: June 2012

It has been widely recognized that mammal brain size predominantly increases over evolutionary time. Safi et al. [Biol Lett 2005;1:283–286] questioned the generality of this trend, arguing that brain size evolution among bats involved reduction in multiple lineages as well as enlargement in others. Our study explored the direction of change in the evolution of bat brain size by estimating brain volume in fossil bats, using synchrotron radiation X-ray tomographic microscopy. Virtual endocasts were generated from 2 Hipposideros species: 3 specimens of Oligocene Hipposideros schlosseri (∼35 Ma) and 3 of Miocene Hipposideros bouziguensis (∼20 Ma). Upper molar tooth dimensions (M2 length × width) collected for 43 extant insectivorous bat species were used to derive empirical formulae to estimate body mass in the fossil bats. Brain size was found to be relatively smaller in the fossil bats than in the average extant bat both with raw data and after allowing for phylogenetic inertia. Phylogenetic modeling of ancestral relative brain size with and without fossil bats confirmed a general trend towards evolutionary increase in this bat lineage.
Evaluation of Anti-Quorum-Sensing Activity of Fermentation Metabolites from Different Strains of a Medicinal Mushroom, Phellinus igniarius
Authors: Zhu Hu , Liu Wei , Wang Shou-xian , Tian Bao-zhen , Zhang Shuai-shuai
Published: June 2012

Aims: This study aimed to evaluate the different abilities of various Phellinus igniarius strains inhibiting quorum sensing (QS), to search for novel QS inhibitors from them and to analyze their inhibitory activity, with a view to their possible use in controlling infections. Methods: The bioactive metabolites produced by P. igniarius cultures were tested for their abilities to inhibit QS-regulated behavior. All P. igniarius strains were cultured in potato-dextrose medium by large-scale submerged fermentation. The culture supernatant was condensed into 0.2-fold volumes by freeze drying. The condensed supernatant was sterilized by filtration through a 0.22-µm membrane filter and added to Chromobacterium violaceum CV026 cultures, which were used to monitor QS inhibition. Inhibitory activity was measured by quantifying violacein production using a microplate reader. Results: The bioactive metabolites produced by 10 P. igniarius strains could inhibit violacein production, a QS-regulated behavior in C. violaceum. Furthermore, these strains could be roughly categorized into three groups on the basis of their inhibitory activities. Conclusions:P. igniarius strains can produce QS-inhibitory compounds and have different abilities to inhibit QS.
Contribution of Flow-Dependent Vasomotor Mechanisms to the Autoregulation of Cerebral Blood Flow
Authors: Koller Akos , Toth Peter
Published: June 2012

Regulation of cerebral blood flow (CBF) is the result of multilevel mechanisms to maintain the appropriate blood supply to the brain while having to comply with the limited space available in the cranium. The latter requirement is ensured by the autoregulation of CBF, in which the pressure-sensitive myogenic response is known to play a pivotal role. However, in vivo increases in pressure are accompanied by increases in flow; yet the effects of flow on the vasomotor tone of cerebral vessels are less known. Earlier studies showed flow-sensitive dilation and/or constriction or both, but no clear picture emerged. Recently, the important role of flow-sensitive mechanism(s) eliciting the constriction of cerebral vessels has been demonstrated. This review focuses on the effect of hemodynamic forces (especially intraluminal flow) on the vasomotor tone of cerebral vessels and the underlying cellular and molecular mechanisms. A novel concept of autoregulation of CBF is proposed, suggesting that (in certain areas of the cerebrovascular tree) pressure- and flow-induced constrictions together maintain an effective autoregulation, and that alterations in these mechanisms may contribute to the development of cerebrovascular disorders. Future studies are warranted to explore the signals, the details of signaling processes and the in vivo importance of these mechanisms.
Etodolac Blocks the Allyl Isothiocyanate-Induced Response in Mouse Sensory Neurons by Selective TRPA1 Activation
Authors: Inoue Naoki , Ito Sunao , Nogawa Masaki , Tajima Koyuki , Kyoi Takashi
Published: June 2012

Background and Purpose: The excitability of nociceptors is modulated by the transient receptor potential cation channel, ankyrin subfamily, member 1 (TRPA1). We have previously reported that etodolac, a nonsteroidal anti-inflammatory drug, attenuates mechanical allodynia in a mouse model of neuropathic pain by a mechanism that is independent of cyclooxygenase inhibition. Here, we investigate the role of TRPA1 in the mechanism of the antinociceptive action of etodolac in vitro and in vivo. Experimental Approach: Ca2+ influx was measured in HEK-293 cells expressing mouse TRPA1 and in mouse dorsal root ganglion (DRG) neurons. The effect of etodolac on the nociceptive behavior induced in mice by the TRPA1 agonist allyl isothiocyanate (AITC) was also measured. Results: Etodolac induced Ca2+ influx in HEK-293 cells expressing mouse TRPA1 and in mouse DRG neurons. The Ca2+ influx induced by etodolac was inhibited by pretreatment with the TRPA1-specific antagonist HC-030031. In contrast, etodolac did not induce Ca2+ influx in cells expressing TRPV1, TRPV2 or TRPM8. In addition, pretreatment with etodolac inhibited the Ca2+ influx induced by AITC. Conclusion and Implication: Etodolac showed a selective TRPA1 agonist action, providing evidence that etodolac desensitizes nociceptors by the selective activation of TRPA1. Etodolac may be clinically useful in the treatment of neuropathic pain.