bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2206: Molecular interaction of HIF-1α and the androgen receptor in prostate cancer
Authors: Price Douglas K. , Reece Kelie M. , Troutman Sarah M. , Pressler Heather M. , Pisle Stephen T. , Figg William D. 
Published: August 2012

Abstract
Background: Prostate cancer is the most common noncutaneous cancer among men in the United States, and its progression is largely controlled by the androgen receptor (AR). Androgen deprivation therapy (ADT) is an initially effective treatment for prostate cancer, but most tumors eventually become castrate resistant. Tumor hypoxia also appears to be associated with a poor prognosis in prostate cancer. HIF-1α regulates the transcription of genes that allow tumor survival and growth in low oxygen conditions. Our laboratory has data showing that in response to castration and anti-androgen therapy in mice, there was a strong transcriptional relationship between HIF-1α and AR, as measured by quantitative RT-PCR, suggesting an interaction between the two proteins. Thus, the purpose of this study was to determine if there is a molecular interaction between HIF-1α and AR in prostate cancer cells. Methods: We used Western blot analysis to examine the expression levels of HIF-1α and AR in LNCaP prostate cancer cells to determine if they are upregulated together at the protein level. Four experimental conditions were tested: control (no treatment), DHT for induction of AR expression, CoCl2 for induction of HIF-1α, and a combination treatment of DHT and CoCl2. Immunoprecipitation experiments were carried out to determine if there is an association between HIF-1α and AR. In addition, cells were fractionated into nuclear and cellular cells extracts, followed by Western blot analysis to determine where in the cells this interaction occurs. Results: Western blot analysis of cell lysates showed synergistic upregulation of both HIF-1α and AR expression only under combined CoCl2 and DHT treatment conditions. In addition, immunoprecipitation experiments showed that HIF-1α and AR exist in a complex with one another, and fractionation experiments indicated this complex occurs in the nucleus. Conclusions: Our results demonstrate that HIF-1α and AR associate with one another in cells. Binding assays are in progress to determine the nature of this interaction. In addition, we are examining the cellular consequences of this protein interaction, as it is possible that upregulation of HIF-1α in response to low androgen contributes to the development of tumor resistance to ADT.
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 2206. doi:1538-7445.AM2012-2206
Abstract 2208: JNK2 regulates the hif-1α mRNA stability in a nucleolin-dependent manner
Authors: Zhang Dongyun , Li Jingxia , Zhang Min , Zuo Zhenghong , Yu Yonghui , Huang Chuanshu 
Published: August 2012

Abstract
HIF-1α mRNA is regarded as constitutively and ubiquitously expressed no matter the level of oxygen tension. But most recently, more and more labs found that HIF-1α mRNA could be regulated by natural antisense transcripts, potential microRNAs, and low O2 pressure in the renal medulla in rats and in sea bass. In our current studies, we found that nucleolin, the classic histone chaperon, was able to physically bind to hif-1α mRNA and maintained its stability. Knocking down nucleolin by shRNA obviously reduced HIF-1α protein induction in response to nickel treatment resulting from the impaired expression of hif-1α mRNA. Both the promoter luciferase assay and mRNA degradation rate assay by ActD clearly showed that nucleolin knocking down did not change hif-1α transcription, but rather affected its mRNA stability. Further work found JNK2 could regulate nucleolin expression and subsequently affect its function in stabilizing hif-1α mRNA, by which we provided more evidence for the oncogenic role of JNK2 and nucleolin in regulating the cancer environments by controlling HIF-1α expression.
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 2208. doi:1538-7445.AM2012-2208
Abstract 2209: Cellular characterization of chromatin state via high throughput ChIP assay
Authors: Li Zirong , Rosenfeld John , Kovelman Robert 
Published: August 2012

Abstract
Expression of eukaryotic genes during development requires complex spatial-temporal regulation. This complex regulation is often achieved through the coordinated interaction of transcription regulatory elements in the promoters of the target genes. The identification and mapping of regulatory elements in genome scale is crucial to understand how gene expression is regulated. Chromatin immunoprecipitation is a standard method for assessing the occupancy of DNA binding proteins in vivo in their native chromatin context using antibodies. However, standard chromatin immunoprecipitation procedure is time consuming, labor intensive and not suited for analyzing many samples simultaneously. Recently, we have developed a simple high throughput chromatin immunoprecipitation protocol that utilizes high capacity protein A/G coated magnetic beads and 96 well plates. This protocol requires fewer steps and less hands-on time, has higher sensitivity and more reliable performance as compared to conventional approaches. The method is also compatible with multi-channel pipetting and liquid handling systems. We have successfully used this protocol to map various clinically relevant chromatin marks and controls across several cell types to quantitatively measure chromatin states. This analysis included a variety of marks corresponding to repressed, poised and active promoters, strong and weak enhancers, putative insulators, transcribed regions, as well as large-scale repressed and inactive domains. This study demonstrates the utility of this approach for the characterization of model cellular systems in perturbation studies with chemical probes.
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 2209. doi:1538-7445.AM2012-2209
Abstract 221: p21-activated kinase 1 (Pak1) phosphorylates BAD directly at serine 111 in vitro and indirectly through Raf-1 at serine 112
Authors: Field Jeffrey M. , Ye Diana Z. , Jin Shenghao , Zhou Ya 
Published: August 2012

Abstract
Cell survival depends on the balance between protective and apoptotic signals. When the balance of signals tips towards apoptosis, cells undergo programmed cell death. This balance has profound implications in diseases including cancer. Oncogenes and tumor suppressors are mutated to promote cell survival during tumor development, and many chemotherapeutic drugs kill tumor cells by stimulating apoptosis. BAD is a pro-apoptotic member of the Bcl-2 family of proteins, which can be phosphorylated on numerous sites to modulate binding to Bcl-2 and 14-3-3 proteins and inhibit its pro-apoptotic activities. One of the critical phosphorylation sites is the serine 112 (S112), which can be phosphorylated by several kinases including Pak1. We mapped the Pak phosphorylation sites by making serine to alanine mutations in BAD and testing them as substrates in in vitro kinase assays. We found that the primary phosphorylation site is not S112 but serine 111 (S111), a site that is sometimes found phosphorylated in vivo. In transfection assays of HEK293T cells, we showed that Pak1 required Raf-1 to stimulate phosphorylation on S112. Mutating either S111 or S112 to alanine enhanced binding to Bcl-2, but the double mutant S111/112A bound better to Bcl-2. Moreover, BAD phosphorylation at S111 was observed in several other cell lines, and treating one of them with the Pak1 inhibitor 2,2α-Dihydroxy-1,1α-dinaphthyldisulfide (IPA-3) reduced phosphorylation primarily at S112 and to a smaller extent at S111, while Raf inhibitors only reduced phosphorylation at S112. Together, these findings demonstrate that Pak1 phosphorylates BAD directly at S111, but phosphorylated S112 through Raf-1. These two sites of BAD serve as redundant regulatory sites for Bcl-2 binding.
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 221. doi:1538-7445.AM2012-221
Abstract 2210: Global levels of H3K27me3 track with differentiation in vivo and are deregulated by MYC in prostate cancer
Authors: Pellakuru Laxmi Gurunatham , Iwata Tsuyoshi , Gurel Bora , De Marzo Angelo M. 
Published: August 2012

Abstract
Both embryonic stem cells and various cancer cell types contain abundant amounts of decondensed chromatin. However, the molecular mechanisms responsible for altering chromatin states in stem cells and cancer cells are not well understood. One factor may be the oncogenic transcription factor, MYC. MYC is overexpressed in many tumor types and affects a wide array of essential cellular processes including ribosome and mitochondrial biogenesis, metabolism, and cell cycle progression. MYC is also a key factor in reprogramming of somatic adult cells into induced pluripotent stem cells. Less well known is that MYC also affects global chromatin structure where it is required to maintain open or active chromatin. We hypothesize that in prostate cancer, MYC affects global chromatin structure keeping it in a more open conformation thus maintaining the cells in a less differentiated state resembling that of stem cells. We show by immunohistochemistry that compared to the more differentiated luminal cells, less differentiated stem-like cells in the basal compartment of the human and mouse prostate contain lower levels of the polycomb heterochromatin mark, H3K27me3. This link to the differentiated state of normal cells is also found in a number of other human and rodent tissues characterized by hierarchical differentiation and rapid turnover of stem cell compartments. Further, in MYC-driven prostate cancers in mice, global levels of H3K27me3 are reduced in both prostatic intraepithelial neoplasia (PIN) and invasive adenocarcinoma lesions. This pattern of global H3K27me3 reduction in PIN and invasive prostate cancers is also observed in humans, correlates with global chromatin decondensation, and correlates with increased markers of disease aggressiveness (e.g. Gleason score and pathological stage). In prostate and breast cancer cells, experimentally forced reductions in MYC levels result in increased global levels of H3K27me3. These findings suggest that increased levels of decondensed chromatin in normal stem/progenitor cells and in cancer cells are associated with global loss of the H3K27me3 polycomb mark, and furthermore, MYC overexpression could be one mechanism for this H3K27me3 deregulation.
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 2210. doi:1538-7445.AM2012-2210
Abstract 2217: Stress-induced NQO1 controls stability of C/EBPα against 20S proteasomal degradation to regulate p63 expression with implications in protection against chemical-induced skin cancer
Authors: Patrick Brad A. , Jaiswal Anil K. 
Published: August 2012

Abstract
In previous studies we have illustrated a role of cytosolic NAD(P)H:quinone oxidoreductase 1 (NQO1) in stabilization of tumor suppressor transcription factor p63 against 20S proteasomal degradation, resulting in thinning of epithelium and chemical-induced skin cancer [Oncogene (2011) 30, 1098-1107]. Current studies demonstrate that an intermediate pathway involving NQO1 control of C/EBPα against 20S proteasomal degradation also contributes to the upregulation of p63 expression and protection. Western and immunohistochemistry analysis revealed that disruption of NQO1 gene in mice and mouse keratinocytes led to degradation of C/EBPα and profound decrease of p63 gene expression. p63 promoter mutagenesis, transfection and ChIP assays identified C/EBPα binding site between nucleotide position −185 to −174 that allows C/EBPα to enhance p63 gene expression. Coimmunoprecipitation and immunoblot analysis demonstrated that 20S proteasomes directly interacted and degraded C/EBPβ. NQO1 direct interaction with C/EBPα led to stabilization of C/EBPα against ubiquitin-independent 20S proteasomal degradation and NQO1 protection of C/EBPα required binding of cofactor NADH. Exposure of skin and keratinocytes to stress agents benzo(a)pyrene, UVB, antioxidant t-BHQ and ionizing radiation led to induction of NQO1 and stabilization of C/EBPα protein resulting in an increase in p63 RNA and protein in wild type but not in NQO1-null mice. Collectively, the current data combined with previous suggest that stress-mediated induction of NQO1 acts both through stabilization of p63-transactivating C/EBPα and through direct stabilization of p63 to control keratinocyte differentiation leading to normal skin development and possibly contribute to protection against chemical/radiation-induced skin carcinogenesis. The studies are significant in light of the knowledge that 2-4% human individuals are homozygous and 23% are heterozygous for NQO1P187S mutation and might be susceptible to stress-induced skin diseases.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2217. doi:1538-7445.AM2012-2217
Abstract 2218: Radiation-induced hypomethylation triggers urokinase plasminogen activator (uPA) transcription in meningioma cells
Authors: Velpula Kiran Kumar , Gogineni Venkateswara Rao , Nalla Arun Kumar , Dinh Dzung H. , Rao Jasti S. 
Published: August 2012

Abstract
Our previous studies have shown the role of radiation-induced urokinase plasminogen activator (uPA) expression in meningioma tumor progression. In the present study, we investigated whether modulation of DNA methylation profiles could regulate uPA expression. Radiation treatment induced hypomethylation in meningioma cells with a decrease in DNMT1 and MBD expression. However, oxidative damage by H2O2 or pretreatment of irradiated cells with NAC did not show any influence on these proteins, thereby indicating a radiation-specific change in the methylation patterns among meningioma cells. Further, we identified that hypomethylation is coupled to an increase in uPA expression in these cells. Azacytidine treatment induced a dose-dependent surge of uPA expression while pretreatment with Sodium butyrate inhibited the radiation-induced uPA expression; these results complement our prior findings. Methylation-specific PCR on bisulfite treated genomic DNA revealed a diminished methylation of uPA promoter in irradiated cells, which supports the role of epigenetics in uPA gene regulation. Transfection with shRNA expressing plasmids targeting CpG islands of the uPA promoter showed a marked decline in uPA expression with subsequent decreases in invasion and proliferation of meningioma cells. Further, radiation treatment is coupled to the recruitment of SP1 transcription into the nuclear extracts, which was abrogated by shRNA treatment. Our experiments to study the signaling events demonstrated the activation of MEK-ERK in radiation treated cells while U0126 (MEK/ERK inhibitor) blocked hypomethylation, recruitment of SP1, and uPA expression. In agreement with our in vitro data, low DNMT1 levels and high uPA were found in intracranial tumors given radiation treatment as compared to untreated tumors. In conclusion, our data suggest radiation-mediated hypomethylation triggers uPA expression in meningioma 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 2218. doi:1538-7445.AM2012-2218
Abstract 2221: Dimerization and DNA binding specificities unravelled by the structure of MITF
Authors: Pogenberg Vivian , Ogmundsdottir Margret H. , Bergsteinsdottir Kristin , Milewski Morlin , Deineko Viktor , Phung Bengt , Schepsky Alexander , Hoek Keith , Wilmanns Matthias , Steingrimsson Eirikur 
Published: August 2012

Abstract
The regulatory protein MITF (microphthalmia associated transcription factor) is essential for melanocyte development and acts as a master regulator of this cell type. Mice carrying loss-of-function mutations in Mitf lack melanocytes altogether and in humans, MITF mutations result in the pigmentation and deafness syndromes Waardenburg and Tietz. In melanoma, MITF plays a critical role as a lineage-survival oncogene and may act as a molecular switch downstream of the Braf pathway, determining whether the cells proliferate or form metastasis. Here we describe the crystal structure of MITF in presence and absence of DNA and use complementary functional experiments to show that Isoleucine 212 of the basic region is critical for discriminating between target sequences. The structures also reveal a kink between the second helix and the Leucine Zipper of MITF which has not been described in other related proteins. This kink is due to a shift in the heptad repeats of the Zipper region and is important for selection of dimerization partners. Our results provide new and important insights into the mechamisms of MITF mediated transcription regulation.
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 2221. doi:1538-7445.AM2012-2221
Abstract 2222: Oncogene-mediated alterations in chromatin conformation
Authors: Rickman David S. , Soong T. David , Moss Benjamin , Mosquera Juan Miguel , Dlabal Jan , Terry Stephane , MacDonald Theresa , Bunting Karen , Demichelis Francesca , Melnick Ari , Elemento Olivier , Rubin Mark A. 
Published: August 2012

Abstract
Emerging evidence suggests that chromatin adopts a non-random three dimensional (3D) topology and that the organization of genes into structural hubs and domains affects their transcriptional status. How chromatin conformation changes in diseases such as cancer is poorly understood. Moreover, how oncogenic transcription factors, which bind to thousands of sites across the genome, influence gene regulation by globally altering the topology of chromatin requires further elucidation. To address these questions, we performed unbiased high-resolution mapping of intra- and inter-chromosome interactions upon over-expression of ERG, an oncogenic transcription factor frequently over-expressed in prostate cancer as a result of a gene fusion. By integrating data from genome-wide chromosome conformation capture (Hi-C), ERG binding and gene expression, we demonstrate for the first time that an oncogenic transcription factor can induce global, reproducible and functionally coherent changes in chromatin organization. We also show using spectral karyotyping that ERG over-expression is associated with a specific translocation involving chromosomes 13 and 15 at loci that are enriched in ERG binding. The results presented here have broader implications, as many driving genetic lesions in other cancer types involve altered levels of transcription factors due to genomic alterations (e.g. EWS-FLI1, c-Myc, n-Myc, PML-RARα).
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 2222. doi:1538-7445.AM2012-2222
Abstract 2228: mTORC2 is a promising therapeutic target in epithelial ovarian cancer
Authors: Hisamatsu Takeshi , Mabuchi Seiji , Hashimoto Kae , Isobe Aki , Sawada Kenjiro , Kimura Tadashi 
Published: August 2012

Abstract
Purpose: The mammalian target of rapamycin (mTOR) is frequently activated in epithelial ovarian cancer, and is regarded as an attractive therapeutic target for therapy. Preclinical investigations using rapamycin and its analogs have demonstrated significant growth-inhibitory effects on the growth of ovarian cancer, but those researches were focused only on mTOR Complex 1 (mTORC1), not on mTOR Complex 2 (mTORC2). We investigated the activity of mTORC2 and its role in epithelial ovarian cancer. Experimental design: Using human ovarian cancer samples and cell lines, (serous adenocarcinoma and clear cell carcinoma), we first examined the expression and activity of mTORC2. We next investigated the role of mTORC2 on the proliferation and invasiveness of overian cancer cells by knocking down the expression of rictor. Moreover, using 2 pairs of everolimus-sensitive parental and everolimus-resistant sublines, we examined whether mTORC2 is involved in the mechanism of acquired resistance to everolimus. Results: mTORC2 is frequently activated in human ovarian cancer, especially in clear cell carcinoma of the ovary. mTORC2 stimulated the proliferation and invasiveness of ovarian cancer cells in vitro. mTORC2 was hyperactivated in everolimus-resistant sublines compared to their parental cell lines. Inhibition of mTORC2 activity by siRNA sensitize the everolimus-resistant ovarian cancer cells to everolimus. Conclusion: mTORC2 is frequently activated in epithelial ovarian cancer, and is a promising therapeutic target.
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 2228. doi:1538-7445.AM2012-2228