bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3061: Colocalization of NQO1 with the mitotic spindle in human cells
Authors: Siegel David , Kepa Jadwiga K. , Ross David 
Published: August 2012

Abstract
NAD(P)H:quinone oxidoreductase 1 (NQO1) is a flavoenzyme that catalyzes the two-electron reduction of quinones. NQO1 has also been shown to reduce superoxide to hydrogen peroxide and regulate ubiquitin independent 20S proteasome degradation of proteins such as p53. In normal tissues NQO1 is expressed primarily in epithelium, endothelium and adipocytes where it is believed to play a protective role. NQO1 is also expressed at relatively high levels in many human solid tumors where it has been targeted for its ability to bioactivate anti-tumor quinones. Interestingly, immunohistochemical staining for NQO1 expression in formalin-fixed human non-small cell lung cancer tissue sections revealed strong staining for NQO1 on the mitotic spindles of cells in mitosis. Immunocytochemical studies in combination with confocal microscopy using human nontransformed and transformed cells (HUVEC, HBMEC, astrocytes) as well as human cancer cell lines confirmed NQO1 staining of mitotic spindles. Staining of mitotic spindles for NQO1 was not observed in cells genotyped as homozygous for the NQO1*2 polymorphism or in cells pretreated with siRNA directed against NQO1. Double-labeling experiments using anti-alpha-tubulin and anti-NQO1 antibodies demonstrated colocalization of NQO1 with spindle microtubules. Pretreatment with NQO1 inhibitors (ES936 or dicumarol) did not prevent binding of NQO1 to mitotic spindles suggesting that binding is independent of the redox state of the enzyme. In cells not undergoing mitosis there was no apparent association of NQO1 with the cytoskeleton suggesting that binding of NQO1 to microtubules may be specific for mitotic spindles. Previous immunocytochemical studies by other investigators have shown that p53 and 20S proteasome could also be found in association with the mitotic spindle. Whether NQO1 binds directly to spindle microtubules or the binding of NQO1 to the spindle is dependent upon the association with other proteins such as p53 or 20S proteasome is currently under investigation (Supported by NIH grant R01ES018943).
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 3061. doi:1538-7445.AM2012-3061
Abstract 3064: An alternative mechanism of action for paclitaxel in breast cancer
Authors: Zasadil Lauren M. , Weaver Beth A. 
Published: August 2012

Abstract
Paclitaxel is a microtubule-stabilizing drug that binds to the β-tubulin subunit and accumulates in mitotic cells. As a chemotherapeutic agent, paclitaxel is used for the treatment of a variety of cancers including breast. Currently, no biomarker is available to predict which patients will benefit from paclitaxel treatment. Paclitaxel studies in cells focus primarily on relatively high concentrations of the drug, which cause cells to die following long-term mitotic arrest. The clinically relevant concentration of paclitaxel is currently unknown, although it is widely speculated to be in the low nM range. Cells exposed to low concentrations of paclitaxel complete mitosis with minimal delay, but frequently contain multipolar spindles. In chromosomally stable breast cancer cells, low concentrations of paclitaxel are sufficient to increase aneuploidy within two days of exposure. These data suggest that the mechanism of cell death due to low dose paclitaxel is likely to be quite different from the mechanism of cell death caused by high dose paclitaxel. They also predict that chromosomally instable (CIN) cells may be more sensitive to cell death caused by low doses of paclitaxel. CIN cells have an existing level of chromosomal missegregation, which is likely to be exacerbated by treatment with low doses of paclitaxel. Since missegregation of large numbers of chromosomes per division causes rapid cell death, these cells may be more likely to die after low dose paclitaxel treatment as a result of losing both copies of a vital chromosome. Chromosomally stable cells, which do not normally missegregate chromosomes with each division, would be more resistant to death following paclitaxel treatment than CIN cells. These data suggest that CIN may be used as a biomarker to determine which tumors are most likely to be sensitive to treatment with clinically relevant concentrations of paclitaxel.
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 3064. doi:1538-7445.AM2012-3064
Abstract 3065: Interferon consensus sequence-binding protein (ICSBP) regulates the transforming growth factor-beta type I receptor expression in osteosarcoma cells
Authors: Sung Jee Young , Kim Yong-Nyun , Park Byung-Kiu 
Published: August 2012

Abstract
Transforming growth factor-beta (TGF-β), known as a tumor suppressor, may exert tumor promoting activity in the advanced stage of cancer. Previously, we reported that interferon consensus sequence-binding protein (ICSBP), also known as interferon regulatory factor-8, up-regulates TGF-βtype I receptor (TGF-βR I), and augments growth in HL-60 leukemic cells. In the current study, we demonstrate that ICSBP expression up-regulates TGF-βR I and increase in cell growth in U2OS human osteosarcoma cells. To further investigate the mechanism of TGF-βR I up-regulation by ICSBP, we tested the possibility that ICSBP regulates promoter activity of TGF-βR I gene. We analyzed the promoter region of the human TGF-βR I gene in U2OS cells to find putative transcription elements regulated by ICSBP. Luciferase reporter gene assays indicated that ICSBP expression could enhance TGF-βR I gene expression, and by promoter deletion analysis we identified a functional ICSBP-dependent region located at nucleotides −300 to −1 in the TGF-βR I promoter. We also performed chromatin immunoprecipitation using anti-ICSBP and found that there are putative ICSBP binding sites in −300 to −1 region. In conclusion, ICSBP increased TGF-βR I expression by binding to TGF-βR I promoter (−300/−1) in U2OS cells. Exploration for the specific ICSBP binding sequences within TGF-βR I promoter (−300/−1) is under way, which may be helpful in understanding the regulatory mechanism involved in TGF-βR I expression by ICSBP.
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 3065. doi:1538-7445.AM2012-3065
Abstract 3129: XPC protein attenuation and deficiency in tobacco smoke-induced DNA hypermethylation of tumor suppressor genes
Authors: Wang Gan , Xu Xiaoxin S. , Wang Le 
Published: August 2012

Abstract
DNA hypermethylation of tumor suppressor genes is a hallmark for many types of cancer, including lung cancer. The mechanism that leads to hypermethylation of these tumor suppressor genes in tumor cells is not fully understood. Importantly lung cancer is strongly associated with environmental factors, especially cigarette smoking. DNA damage generated by environmental carcinogens and their metabolites is believed to play an important role in lung cancer development. XPC is a DNA damage recognition protein required for nucleotide excision repair (NER) and many other DNA damage responses (e.g. checkpoint regulation and apoptosis). Attenuated levels of XPC protein have been detected in a majority of lung cancer patients. We studied the role of XPC protein attenuation and deficiency in cigarette smoke-caused DNA hypermethylation. Using primary human normal fibroblast (NF) and XPC-deficient human fibroblasts (XPC−), our DNA methylation studies revealed that the XPC deficiency caused greatly elevated levels of DNA hypermethylation in Brca1, Mlh1, and Xpc genes after exposure to tobacco smoke condensate (TSC). Our chromatin immunoprecipitation (ChIP) results indicated that the XPC deficiency led to a more increased binding of DNA methyltransferase 3A (DNMT3A) at the promoters of these genes following the TSC treatment; however, this binding was partially diminished when the XPC cells were treated with caffeine prior to the TSC treatment. The results of our IP studies further revealed that the ATR protein interacted with DNMT3A. In addition, our western blots revealed that the level of ATR protein phosphorylation at serine 428 was greatly increased in XPC cells after the TSC treatment. These results suggest that the XPC protein attenuation and deficiency may cause lung cancer as a result of tobacco smoking through activation of the ATR protein, which enhances the binding of DNMT3A at selected target sequences, resulting in hypermethylation of important tumor suppressor genes.
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 3129. doi:1538-7445.AM2012-3129
Abstract 3133: Regulatory sequences of the ATP-Binding Cassette Transporter A1 gene are hypermethylated in prostate cancer resulting in loss of gene expression
Authors: Lee Byron H. , Robinet Peggy , Smith Jonathan , Magi-Galluzzi Cristina , Klein Eric A. , Ting Angela H. 
Published: August 2012

Abstract
Introduction/Objective: Cholesterol homeostasis is altered in prostate cancer resulting in increased levels of cholesteryl esters and free cholesterol, but the mechanism behind these perturbations is not complete understood. We examine the role of DNA methylation in the regulation of ABCA1 expression. Methods: Genome wide methylation analysis using MBD-isolated Genome Sequencing (MiGS) was performed on the normal prostate epithelial cell line PrEC, the prostate cancer cell lines LNCaP and DU 145, 3 benign prostate specimens obtained from radical cystoprostatectomy, and 6 prostate cancer specimens obtained from radical prostatectomy. Bisulfite genomic sequencing was performed on the ABCA1 CpG island in PrEC and LNCaP to verify the methylation patterns discovered by MiGS. Real time RT-PCR was performed to assess ABCA1 mRNA levels in PrEC and LNCaP. LNCaP was treated with 5-aza-2′-deoxycytidine (5-aza), the LXR agonist T0901317, or a combination of the two drugs; and ABCA1 CpG island methylation was assessed by methylation-specific PCR (MSP) and gene expression was assessed by real time RT-PCR. Results: MiGS analysis revealed that ABCA1 CpG island methylation was present in LNCaP and 6 prostate cancer specimens but not PrEC, DU 145, or 3 benign prostate specimens. Bisulfite genomic sequencing primers were used to amplify fragments from the CpG island spanning −404 to +1,301 of the ABCA1 gene. LNCaP showed dense methylation in the entire region while PrEC showed only minimal methylation from −236 to −404. Real time RT-PCR revealed that there was 10-fold more ABCA1 mRNA in PrEC when compared with LNCaP. Treatment of LNCaP with 10µM T0901317 for 24 hours increased ABCA1 mRNA to 14 fold above untreated LNCaP without detectable changes in DNA methylation. Treatment with 5µM 5-aza for 1 week increased ABCA1 mRNA to 50 fold above control and resulted in loss of DNA methylation in the ABCA1 CpG island as detected by MSP. The combination of 5µM 5-aza and 10µM T0901317 increased ABCA1 mRNA expression in LNCaP to 320 fold above control. Conclusions: ABCA1 is hypermethylated in a subset of prostate cancers, but not normal prostate, resulting in loss of gene expression. Therapeutic strategies aimed at reducing intracellular cholesterol content solely by inhibiting HMG-CoA reductase may be hindered by this acquired deficiency in cholesterol export.
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 3133. doi:1538-7445.AM2012-3133
Abstract 3135: Epigenetic regulation of miR-1275 through histone H3 lysine 27 trimethylation during human glioma stem-like cell differentiation
Authors: Katsushima Keisuke , Shinjo Keiko , Ohka Fumiharu , Fujii Makiko , Osada Hirotaka , Sekido Yoshitaka , Natsume Atsushi , Kondo Yutaka 
Published: August 2012

Abstract
Functional and morphological heterogeneity characterizes aggressive glioblastoma and contributes to invasion, metastasis and drug resistance. The molecular mechanisms underlying this heterogeneity are poorly understood. Recent studies have revealed that tumors contain a minor population of tumor-initiating cells, called cancer stem cells (CSCs). The CSCs are considered able to aberrantly differentiate into diverse cell types. Such stem-like cancer cells have been well characterized in glioblastoma multiforme, and are referred to as glioma stem-like cells (GSCs). Using GSCs as a model, we investigated the roles of micro-RNA (miR) in GSCs differentiation. miR-microarray showed that 19 and 48 miRs were commonly upregulated and downregulated in two GSC lines during the differentiation, respectively. Among those miRs, quantitative-PCR analysis showed that miR-1275 was consistently downregulated during the GSC differentiation, while the expression of its target, oligodendrocyte specific protein (OSP/CLDN11), a marker of oligodendrocyte, was upregulated. Compellingly, inhibition of miR-1275 using specific antisense oligonucleotide increased the expression of OSP in GSC. Epigenetic analysis revealed that level of histone H3 lysine 27 trimethylation(H3K27me3) was enriched in the promoter of pri-miR-1275 during the GSC differentiation. Treatment of 3-Dezaneplanocin-A, an inhibitor of H3K27me3, impaired the GSC differentiation in parallel with sustained miR-1275 expression. In general, astrocytic component is the most prevalent in glioblastomas, while a subset of cases also contain an oligodendroglial component in the tumors. Our results illuminated the epigenetic regulatory pathways of miR-1275 closely associated with oligodendroglial differentiation, which may contribute to the tissue heterogeneity formation of glioblastomas.
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 3135. doi:1538-7445.AM2012-3135
Abstract 3136: C-Myc-mediated transcriptional repression of HPP1 in colon cancer by recruitment of HDACs
Authors: Wang Jian , Abul Elahi , Hernandez Jonathan , Clark Whalen , Achille Alex , Hao Jihui , Seto Ed , Shibata David 
Published: August 2012

Abstract
Background: Epigenetic gene silencing plays a critical role in tumorigenesis. HPP1, a putative tumor suppressor gene is downregulated in a number of tumor types including colon cancer. As a mechanism of suppression, promoter hypermethylation of HPP1 is known to be important, however the contributions and mechanisms of histone deacetylation have not been described. Additionally, the c-myc oncogene also contributes to the suppression of HPP1 via promoter binding to a cognate E-box site. We sought to elucidate the role of histone deacetylation and the potential interplay with c-myc in the transcriptional regulation of HPP1. Methods: The HPP1 non-expressing cell lines, HCT-116 and DLD-1, were treated with the DNA methylation inhibitor, 5-aza-2′-deoxycitidine (5-Aza-DC) and/or histone deacetylation (HDAC) inhibitors, including sodium butyrate (SB), Vorinostat (SAHA), trichostatin A (TSA) and valproic acid (VPA). Knockdowns of c-Myc and HDAC-1, 2, 3 and 4 were performed using siRNA. Protein and mRNA expression of HPP1 were determined by Western Blot and RT-PCR respectively. Furthermore, Chromatin immunoprecipitation (ChIP) and ChIP-re-ChIP experiments were used to demonstrate the binding of c-Myc and HDACs to the HPP1 promoter. Co-IP assays were used to test the physical interaction between c-Myc and HDAC3. After knockdown of HDAC3 using siRNA in HCT116, ChIP was also used to test the activity of acetylated histone 4 (AcH4). Results: 5-Aza-DC as well as HDAC inhibitors, including SB, TSA, SAHA and VPA, resulted in the re-expression of HPP1 in HCT-116 and DLD-1 cells. Individual HDAC inhibitors administered in combination with 5-Aza-DC resulted in a synergistic effect on HPP1 re-expression. Concordantly, knockdown of HDAC2 and HDAC3 in HCT116 cells, and HDAC1 and HDAC3 in DLD-1 cells by siRNA significantly enhanced HPP1 expression. Co-IP, ChIP and double ChIP experiments confirmed binding of c-myc to the HPP1 promoter as a complex with dominant recruitment of HDAC3. By ChIP assay, the levels of AcH4 increased significantly in HCT116 after knockdown of HDAC3. Conclusions: We have demonstrated that HDAC-1, -2 and -3 contribute to the epigenetic regulation of HPP1. Moreover, c-myc binds to the HPP1 promoter and mediates epigenetic suppression via the dominant recruitment of HDAC3 with subsequent enhancement of histone deacetylation. Our findings may lead to a greater biologic understanding for the application of the targeted use of HDAC inhibitors for anti-cancer therapy.
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 3136. doi:1538-7445.AM2012-3136
Abstract 3137: Epigenetic regulators influencing dual histone reader TRIM24 in estrogen receptor-mediated transcription in breast cancer
Authors: Yiu Teresa T. , Barton Michelle C. 
Published: August 2012

Abstract
Nuclear receptor-mediated regulation of gene expression, including estrogen-receptor-alpha (ERα), relies on a complex network of proteins that impose either repression or activation of gene expression. Among these, epigenetic “reader” proteins recognize combinatorial PTMs on histones, through distinct structure domains such as tandem plant homeodomains (PHD) and bromodomains (Bromo). We recently reported that tripartite motif-containing 24 (TRIM24), by means of its C-terminal tandem PHD finger and Bromo domains, recognizes unmethylated histone H3 lysine K4 (H3K4me0) and acetylated histone H3 lysine K23 (H3K23ac) within the same histone tail. In the presence of estrogen, dual chromatin reader TRIM24 preferentially recognizes these two histone marks, binds to ERα and regulates estrogen-dependent target genes. Depletion of TRIM24 inhibits breast cancer cell growth and enhances tamoxifen-induced growth inhibition. In addition, overexpression of TRIM24 correlates with decreased overall survival in breast cancer patients. We believe that TRIM24 can be a potential biomarker for breast cancer development, as well as a target for therapeutic treatment. The goal of my research is to target TRIM24 in breast cancer by identifying upstream epigenetic regulators that may influence TRIM24's function in ERα-regulated transcriptional activation. For TRIM24-regulated ERα target genes, estrogen stimulation results in a global loss of H3K4me2 at estrogen-responsive elements (EREs), where TRIM24 and ERα are recruited. Global binding profile of TRIM24 by ChIP-seq also shows that TRIM24 preferentially binds to regions depleted of H3K4me2, suggesting that upstream regulators may determine TRIM24 binding to chromatin. Demethylation of histones is mediated by specific enzymes called histone demethylases (HDMs). When we increase H3K4me2 at EREs by inhibiting the enzymatic activity of HDM, recruitment of both TRIM24 and ERα to target genes is diminished. As a result, activation of TRIM24-regulated estrogen-responsive genes is impaired. Previous work has suggested that the presence of threonine T6 phosphorylation on histone H3 (H3T6ph) prevents HDMs from demethylating H3K4me2. H3T6ph may therefore impose an inhibitory mark for LSD1-mediated demethylation of H3K4me2, and serves as an added layer of regulation for TRIM24 binding to histones, affecting subsequent function of TRIM24 as an ERα coactivator. These results may give insights into future therapeutic studies of targeting TRIM24 in breast 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 3137. doi:1538-7445.AM2012-3137
Abstract 3138: Epigenetic regulation of Src pathway in pancreatic adenocarcinomas
Authors: Padin-Iruegas Elena , Evgenyeva Elena , Herranz Michel , Abdulkader Ihab , Brozos Elena , Pombo Maria , Antúnez Jose Ramón , Ruibal Alvaro , López Rafael 
Published: August 2012

Abstract
Purpose: Src cascade is crucial in tumor growth and metastasis development. Nowadays, one of the most relevant mechanisms for gene control is epigenetic mechanisms, both methylation and acetylation. We study the epigenetic regulation of Src pathway in pancreatic adenocarcinomas. The main purpose of this study was to obtain translational results, we can apply in the clinical practice. Methods: 70 pancreatic adenocarcinomas and normal tissue from the same patient were analyzed. DNA from laser microdissected paraffin embedded sample was obtained, bisulfite treated, methylation specific PCR (MSP) amplified, and agarose visualized. Some cases were bisulfite sequenced for verification. Rassf1a, Cox2, Socs, E-Cadherin, DAP-kinase, TIMP3, TWIST1, p16 and Cyclin-D2 genes were analyzed due to their implication with Src pathway. All patients signed informed consent and detail clinic histories were reviewed. Results: We found gene hypermethylation in all the selected targets ranged between 23.5% (DAP-K) to 73% (TWIST1), i.e. RASSF1α (48.7%); p16 (38.2%)… Bisulfite promoter sequence confirms MSP results. Patient clinical profile clustered in some well defined groups. Epigenetic profile also showed very nice association. Combine clinical and epigenetic profile showed a specific and characteristic correlation between some clinical parameters and specific gene methylation profile. In this sense, for instance, we found a perfect match between just RASSF1α promoter hypermethylation with clinical parameters: pTNM and tumor localization. Conclusions: Gene hypermethylation control seems important in pancreatic adenocarcinoma behavior. Src pathway could be implicated in tumoral development, both directly and indirectly (through i.e. EGFR, HER2/Neu, Integrins and SPARC). Src pathway methylation control could be important in development and progression of pancreatic carcinoma (up to 73%). An “epigenetic fingerprint” of pancreatic adenocarcinoma was found from clinical and epigenetic clustering analysis.
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 3138. doi:1538-7445.AM2012-3138