bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2074: Cool-1-mediated inhibition of c-Cbl modulates multiple critical properties of glioblastomas, including the ability to generate tumors in vivo
Authors: Stevens Brett M. , Folts Christopher J. , Bardin Addie L. , Noble Mark 
Published: August 2012

Abstract
Glioblastomas (GBMs), the most malignant glial tumors, differ from normal glial progenitor cells in many ways, but little is known about the molecular circuitry underlying these differences. We have discovered a novel means by which GBMs become chemo-resistant, based on inhibition of the redox/Fyn/c-Cbl pathway by overexpression of Cool-1. The protein c-Cbl, an E3 ubiquitin ligase, is responsible for the ubiquitination and degradation of multiple receptor tyrosine kinases critical for cell division and cell survival. In normal glial progenitor cells of the CNS, exposure to chemotherapy oxidizes cells, leading to sequential activation of Fyn and c-Cbl. However in GBM cells, exposure to BCNU or other chemical pro-oxidants does not lead to c-Cbl activation. Further studies have demonstrated that these agents do cause Fyn activation, suggesting that GBMs inhibit c-Cbl phosphorylation leading to decreased degradation of EGFR, accounting for increased EGFR signaling. We therefore set out to investigate the factors involved in the decreased c-Cbl activity specific to GBMs. In this work we discovered that oxidant-associated c-Cbl activation can be restored by suppressing expression of the protein Cool-1, found to be over-expressed in GBM. Our data further demonstrate that Cool-1 and c-Cbl formed complexes, that genetic reduction in Cool-1 levels restored normal c-Cbl-mediated degradation of RTKs (including EGFR) in response to exposure to pro-oxidants, and that restoration of normal c-Cbl activation has multiple effects on hallmarks of GBM. Cool-1 decreases lead to decreased migration and decreased numbers of cells in the cell cycle. Cool-1 inhibition leads to decreased number of cells that exhibit cancer stem cells characteristics including decreased antigen positivity and decreased sphere forming ability. In contrast, Cool-1/c-Cbl complexes were not found in normal brain or normal glial progenitors and Cool-1 knockdown did not reduce progenitor division. The translation of these findings into an in vivo intracranial xenograft model of GBM shows that Cool-1 is essential for tumorigenesis and decreasing Cool-1 levels leads to decreased tumor take, decreased tumor growth, and increased survival. In sum, the ability of Cool-1/c-Cbl interactions, to modulate a variety of tumor cell properties suggests that these interactions offer an attractive target for modulating GBM growth, particularly due to the absence of Cool-1/c-Cbl complexes in normal brain tissue and to the lack of effects of Cool-1 knockdown on division of normal glial progenitor 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 2074. doi:1538-7445.AM2012-2074
Abstract 2075: Overexpression of the peroxiredoxin family of antioxidant proteins in MCF7 breast cancer cells and investigation of possible regulatory mechanisms
Authors: Taparra Kekoa , Tehan Lauren , Rodriguez Braulio , Phelan Shelley A. 
Published: August 2012

Abstract
Peroxiredoxins are thiol-specific antioxidant proteins that protect cells from oxidative stress. There are six different peroxiredoxin proteins expressed in mammalian cells, and these proteins have been implicated in the regulation of cell signaling, proliferation and apoptosis. Many recent studies have found elevated peroxiredoxin levels in cancer, suggesting that cancer cells may upregulate peroxiredoxin expression as an adaptation to the cancerous state. We compared the expression of all six peroxiredoxins between MCF7 breast cancer cell line and the non-cancerous MCF-10A cell line. We found significant overexpression of five of the six peroxiredoxins (PrdxI-V) at both the mRNA and protein level. To explore possible mechanisms of peroxiredoxin upregulation, we first compared the lines for levels of reactive oxygen species (ROS) and the activity of particular kinases implicated in cancer biology. We found that MCF-7 cells express markedly higher levels of ROS, and increased activity of ERK 1/2 and JNK 1/2, as compared to MCF-10A cells. We hypothesized that elevated ROS and/or enhanced activity of these signal transduction pathways may mediate peroxiredoxin induction in these cells. MCF-7 cells were cultured under conditions of serum deprivation, ROS reduction, or kinase inhibition to examine the effects on peroxiredoxin expression. After 48 hours of serum deprivation, the expression of Prdx2 was reduced. Using NAC treatment, we inhibited ROS accumulation in MCF-7 cells and found a decrease in expression of both Prdx2 and Prdx3. Inhibition of ERK 1/2 activity by the inhibitor PD 98,059 resulted in little to no change in peroxiredoxin levels. Finally, treatment of MCF-7 cells with hydrogen peroxide led to a transient increase in Prdx1 at 4 hours, which returned to basal levels by 24 hours. Together, these data reveal overexpression of the peroxiredoxin family in MCF-7 cancer cells, and suggest that oxidative stress and redox-sensitive kinases may play a role in mediating the upregulation of particular peroxiredoxins. Studies examining the role of JNK and p38 in peroxiredoxin induction, as well as cell line differences in multimeric Prdx complexes, are currently underway.
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 2075. doi:1538-7445.AM2012-2075
Abstract 2076: Oxidative stress induced by sodium ascorbate:menadione sodium-bisulfate combination results in lysosomal and mitochondrial changes that lead to prostate cancer cell death
Authors: McGuire Karen , Neal Deborah , Fraizer Gail C. , Gilloteaux Jacques , Taper Henryk , Jamison James 
Published: August 2012

Abstract
Prostate cancer is a leading cause of death in American males and therapy targeting hormone refractory prostate cancer is urgently needed. Treatment of prostate cancer cell lines (LNCaP, LNCaP-C42, DU-145 and PC3) with either sodium ascorbate or menadione sodium-bisulfate alone induced cell killing (as measured by the MTT cell proliferation assay) only at high concentrations, while the combination (apatone) potentiated cytotoxicity 4- to 20-fold with exposure times as short as 1hr. Apatone treatment induces the reactivation of DNase I and II resulting in autoschizis, a caspase independent form of cell death. Cell cycle arrest (G1/S and G2/M blocks), increased hydrogen peroxide and lipid peroxidation levels, decreased cellular thiol levels, and increased intracellular Ca2+ levels were observed following apatone treatment. To further understand the mechanism(s) of action of this cytotoxic drug, the effects of apatone treatment on the lysosomal and mitochondrial membranes in DU-145 prostate cancer cells were measured by live cell fluorescence microscopy. Examination of lysosomal membranes using the metachromatic fluorochrome, acridine orange, revealed rapid permeabilization of the lysosomal membrane. The effect of apatone on mitochondrial membrane potential was also examined, using JC-1 staining, and revealed de-polarization of the mitochondria membrane, which occurred on a delayed time scale when compared to lysosomal activity. The in vivo anti-tumoral activity of apatone was evaluated in nude mice inoculated subcutaneously with DU-145 cells. Oral apatone significantly reduced the growth rate of the solid tumors (p&lt;0.05) without inducing significant bone marrow toxicity, changes in organ weight or pathologies associated with these organs. Overall, these results support an apatone induced cell death mechanism involving a non-apoptotic cell death pathway initiated by oxidative stress in a pro-oxidant tumor environment. This stress ultimately leads to damaged lysosomes, mitochondria and other cellular organelles. This novel mechanism of action has been demonstrated to be highly effective both in vitro and in vivo, indicating that the sodium ascorbate:menadione sodium-bisulfate combination (apatone) can provide another urgently needed therapy for the treatment of hormone refractory and possibly hormone dependent prostate cancer.
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 2076. doi:1538-7445.AM2012-2076
Abstract 2080: The role of ErbB2 in regulating survival in matrix-detached inflammatory breast cancer cells
Authors: Buchheit Cassandra L. , Angarola Brittany , Steiner Allison , Schafer Zachary 
Published: August 2012

Abstract
Inflammatory breast cancer (IBC) is a rare and highly invasive type of breast cancer, and patients diagnosed with IBC often face a very poor prognosis. IBC is characterized by the lack of primary tumor formation and the rapid accumulation of cancerous epithelial cells in the dermal lymphatic vessels. Given that normal epithelial cells require attachment to the extracellular matrix (ECM) for survival, a comprehensive examination of the molecular mechanisms underlying IBC cell survival in the lymphatic vessels is of paramount importance to our understanding of IBC pathogenesis. Here we demonstrate that in contrast to normal mammary epithelial cells, IBC cells evade ECM-detachment-induced apoptosis (anoikis) and maintain ATP levels following ECM detachment. Exogenous ErbB2 overexpression leads to increased ATP production and soft agar growth in IBC cells that normally lack ErbB2 amplification. Additionally, ErbB2 knockdown in KPL-4 cells, an IBC cell line characterized by high levels of ErbB2, resulted in diminished ATP levels, decreased colony growth, and increased caspase activation following ECM detachment. Further studies reveal that the protection from anoikis in IBC cells is dependent on activation of the ERK-MAPK pathway, but does not depend on modulation of the levels of the pro-apoptotic factor Bim. These results demonstrate that ErbB2 is necessary and sufficient for IBC cell survival in the absence of ECM attachment. Understanding the molecular mechanism utilized by IBC cells to survive in matrix-detached conditions could lead to more specific and effective therapeutics to prevent IBC metastasis from occurring and to treat patients in which metastasis has already occurred.
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 2080. doi:1538-7445.AM2012-2080
Abstract 2081: Mechanisms of the acquisition of anoikis resistance in breast cancer: Lessons from small molecule inhibitors
Authors: West Winston , Park Margaret A. 
Published: August 2012

Abstract
The Cox-2 inhibitor Celecoxib has been reported to possess chemopreventive and chemotherapeutic properties, specifically in hormonally-regulated tumors. OSU-03012 is a novel celecoxib derivative, with no COX-2 inhibitory activity, but an order of magnitude greater cell killing ability. We here show that this novel compound has a greater cytotoxicity against a model of anoikis-resistant (AnR) breast cancer. In parallel, anoikis resistance reduces AnR cell sensitivity to the ErbB1/2 dual inhibitor Lapatinib (GW572016, Tykerb, GSK). The two compounds synergize in parental breast cancer cells. Cell killing is achieved partially via induction of ER stress, as measured by eIF2-alpha phosphorylation. We have found that lapatinib resistance may be induced by the aberrant splicing of BCL-X, and that the sensitivity to OSU-03012 is likely due to PTEN dysregulation. In conclusion, these data identify a molecule that may be more efficacious against metastatic tumors, and partially defined its mechanism of action.
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 2081. doi:1538-7445.AM2012-2081
Abstract 2091: Ultrasensitive detection of mutations in the androgen receptor gene by ICE COLD-PCR
Authors: Shi Yanggu , Cubrich Courtney , Veys Stephanie , Richardson Katherine , Legendre Benjamin , Lin Rui , Wu Grant , Eastlake Phil 
Published: August 2012

Abstract
The Androgen Receptor plays an important role in prostate cancer, androgen-dependent (AD) and androgen-independent (AI) disease progression. Anti-androgen therapies are the hallmark of prostate cancer treatment; however spontaneous AR mutations are often detected in hormone-refractory, androgen-ablated and metastatic tumors. ICE COLD-PCR (Improved & Complete Enrichment CO-amplification at Lower Denaturation temperature) is a technology that preferentially enriches mutant DNA sequences in an excess of wild-type DNA through selective amplification of the mutant DNA population using an oligonucleotide complementary to wild-type sequence (RS-oligo). This RS-oligo prevents PCR amplification of wild-type sequences while allowing amplification of DNA containing any mutation covered in the RS-oligo region. We have developed an ICE COLD-PCR assay for the enrichment of mutations in the Androgen Receptor including the AR H875R, H875Y and T878A mutations. The mutant-enriched DNA was then analyzed by standard Sanger DNA sequencing. The analytical sensitivity for the ICE COLD-PCR assay was 1 in 10,000 (0.01%) for all the mutations, compared to 20% limit of detection by standard Sanger sequencing. The ICE COLD-PCR assay developed here provides a means to detect low level mutations in the Androgen Receptor and thus will provide a valuable methodology for the early diagnosis, treatment guidance, outcome prediction and relapse monitoring of prostate cancer.
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 2091. doi:1538-7445.AM2012-2091
Abstract 2094: Comparing exome with whole-genome next-generation sequencing in detecting somatic mutations
Authors: Yue Yong Gang , Ting Jason , Ma Xiwen , Barber Thomas D. 
Published: August 2012

Abstract
Exome sequencing has been used as an efficient and cost-effective method of identifying somatic mutations in tumors. In order to evaluate the effectiveness of the current exome sequencing technology, we have conducted a comparative study to evaluate exome and whole genome sequencing (WGS) in two pairs of hepatocelluar carcinoma (HCC) tumor and match normal controls. The exome sequences were captured via Agilent SureSelect Target Enrichment System (38 MB). Both exome and WGS sequencing data were generated by the Illumina Hiseq2000 platform. The NGS results showed identical profiles of chromosomal abnormalities, including ploidy changes and loss of heterozygosity, when compared to Affymetrix SNP 6.0 microarray genotyping. The total number of variants detected in transcribed region (CCDS) in each of the four samples was comparable between exome and WGS data sets, and the genotypes concordance rate was high. The somatic mutations detected in each tumor/normal pairs different slightly between the exome and WGS platforms. We manually inspected each of the discordant mutations, and found that the most of the somatic mutations missed by exome sequencing are predictable based on gaps in SureSelect coverage. On the other hand, we have also identified somatic mutations in exome that were not detected with the WGS approach. Follow up analysis indicated that those cases were caused by no or low coverage in either tumor of normal in each pair. These cases will likely be resolved by increasing depth of coverage (beyond 30X), and as costs per read decline, it is likely WGS will become the method of choice.
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 2094. doi:1538-7445.AM2012-2094
Abstract 2098: Reducing sequence artefacts from FFPE DNA for cancer diagnostics
Authors: Do Hongdo , Dobrovic Alexander 
Published: August 2012

Abstract
Non-reproducible sequence artefacts have been frequently detected in DNA extracted from formalin-fixed and paraffin-embedded (FFPE) tissues. Studies of ancient DNA reveal that deamination of cytosine to uracil is a major cause of DNA damage. We hypothesised that similar lesions may occur in FFPE DNA and examined the role of uracil lesions on generation of transitional G:C to A:T artefacts in FFPE DNA by treatment with uracil DNA glycosylase (UDG). High resolution melting (HRM)-based assays were used for rapid and cost-effective screening of artefacts. The artefact rate was assessed by limited copy number-HRM (LCN-HRM) in FFPE DNA samples in which multiple G:C to A:T artefacts were found. The effect of UDG treatment on detection of true sequence changes was examined by testing mutational hotspots at the EGFR, KRAS and AKT1 genes. A high HRM positive rate as judged by the formation of heteroduplexes was found in FFPE DNA by LCN-HRM. This was markedly reduced after treatment with UDG. UDG treatment specifically suppressed the formation of artefacts in FFPE DNA and did not affect the detection of true KRAS codon 12 and EGFR exon 19 and 20 mutations. In conclusion, this study reports for the first time that uracil lesions due to cytosine deamination is one of the major causes of artefacts in FFPE DNA and the use of uracil-DNA-glycosylase that removes uracil lesions on DNA can lead to a significant reduction of artefacts. This finding will thus greatly improve biomarker studies using DNA samples derived from FFPE tissues, which has immediate implications especially to diagnostic settings.
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 2098. doi:1538-7445.AM2012-2098
Abstract 2099: RNA from brush cytology to noninvasively screen for oral squamous cell carcinoma
Authors: Kolokythas Antonia , Schwartz Joel L. , Panda Suchismita , Bosman Mitchell J. , Pytynia Kristen , Yeung Alexander , Adami Guy R. 
Published: August 2012

Abstract
Much effort is invested in defining gene expression changes that can be monitored in surgical and biopsy samples of oral lesions to identify oral squamous cell carcinoma (OSCC), a cancer that strikes over 30000 people in the United States each year. There is an extensive list of genes shown to be differentially expressed in surgically obtained oral tumor tissue versus normal, non-malignant, tissue. These have been catalogued over the years and have the potential to inform OSCC characterization. At the same time noninvasive detection and diagnosis of OSCC is a goal that is being explored using a number of methods including brush oral cytology. Using RNA from oral cells obtained with brush cytology we tested levels of mRNAs of 22 genes shown to be differentially expressed in surgically obtained OSCC and normal tissue. Of these 10 showed differential expression in our training set of 12 tumor versus 18 non-malignant lesion samples all from tobacco users. Using Support Vector Machines an algorithm was developed that provided class prediction based on a subset 5 of these mRNAs. With the exception of one case, cross validation during training revealed that this OSCC classifier showed greater than 92% accuracy in differentiating OSCC from non-malignant oral lesions. We will report on its accuracy for correctly identifying OSCC samples in a validation set of RNA from brush cytology samples from an independent set of samples. This test of this methodology using RNA from brush cytology in identifying OSCC highlights the possibility of developing an RNA based classifier from brush cytology to screen for OSCC and perhaps pre-malignancies.
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 2099. doi:1538-7445.AM2012-2099
Abstract 2106: Long non-coding RNA signatures for melanoma detection in humans
Authors: Reilly Christopher , Perera Rochelle A. , Mazar Joseph , Perera Ranjan J. 
Published: August 2012

Abstract
Melanoma, an aggressive carcinoma that originates in the basal layer of human epidermis, has the highest mortality rate of skin cancers in industrialized countries. Unfortunately, current treatments for metastatic melanoma provide mostly palliative benefits to only a small proportion of patients. Despite the obvious need for improvement in assessment and treatment of metastatic melanoma, the intricate mechanisms underlying melanoma transformation remain unresolved and poorly understood. Thus, there is considerable interest in understanding the molecular basis of initiation and progression of human melanomas. Recent evidence indicates that long non-coding RNAs (lncRNAs), a subclass of noncoding RNA (ncRNA), are associated with carcinogenesis in melanoma as well as several other human cancers. The elucidation of the molecular function of these RNA species promises to bridge gaps in our knowledge of melanoma development in humans. The expression of selected lncRNAs (CR618740 and AF091731) in a panel of melanoma cell lines (pigmented and non-pigmented), melanocytes, and keratinocytes were assayed by DNA microarray (Ncode arrays from Lifetechnologies) and further confirmed by real-time polymerase chain reaction (qRT-PCR). Next, cell lines results were tested with patient samples. Our results indicate that the differential expression of lncRNAs is an indicator of the development of melanoma, and dysregulated expression of these markers may be involved in the transition of melanocytes to melanoma. Furthermore, the presence of significant correlation between melanoma cell line characteristics (stage, cell phenotype, types of mutations and others) and lncRNA expression data may imply novel causal connection between lncRNA expression and melanoma development. Importantly, this work will investigate the new possibility that lncRNAs play an essential role in cellular regulation and represent a potential platform for melanoma progression. Thus, unraveling the differential lncRNA expression in melanoma could initiate novel understanding of melanocyte homeostasis, tissue organization, and melanoma genesis in humans.
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 2106. doi:1538-7445.AM2012-2106