bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 3907: Emergent properties of EWS/FLI regulation via GGAA-microsatellites in Ewing's sarcoma
Authors: Gangwal Kunal , Enriquez Camille A. , Close Devin , Hill Christopher P. , Lessnick Stephen L. 
Published: February 2011

Abstract
ETS proteins are a family of transcription factors that play important roles in the development of cancer. The Ewing's sarcoma EWS/ETS fusion oncoproteins control a number of cancer-relevant phenotypes in that disease. We recently demonstrated that EWS/FLI, the most common EWS/ETS fusion in Ewing's sarcoma, regulates a portion of its target genes, including the critical target NR0B1, via GGAA-containing microsatellites in their promoters. Given the unusual nature of microsatellites as EWS/FLI response elements, we sought to elucidate the mechanism of EWS/FLI activity at these sites. In addition to EWS/FLI, we found that other Ewing's sarcoma associated EWS/ETS fusions are capable of mediating gene regulation via the NR0B1 microsatellite. Furthermore, regulation via the GGAA microsatellite was specific to Ewing's sarcoma fusion proteins as two other ETS family members, ETS1 and ELF1, could not cause transcriptional activation, highlighting a neomorphic function of the Ewing's sarcoma fusion proteins. The stoichiometry of this interaction is 2 protein molecules for each DNA molecule, suggesting that EWS/FLI binds these elements as a homodimer. The isolated FLI ETS domain bound microsatellite sequences in a nearly identical fashion to full-length EWS/FLI, thus indicating that residues required for homodimeric binding are localized to the ETS domain. These data suggest a new paradigm for ETS family member binding to DNA at cancer-relevant genetic loci, and highlight emergent properties of EWS/FLI that are required for the development of Ewing's sarcoma.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3907.
Abstract 3910: DLX4 homeprotein enhances the invasiveness of Hs578T ER-negative breast cancer cells
Authors: Fu Yebo , Lian Yi , Kim Kyung Soon , Lee Norman , Fu Sidney W. 
Published: February 2011

Abstract
Tumor invasion and metastasis remain a major cause of mortality in breast cancer patients. It was reported that BP1, a homeobox isoform of DLX4, is overexpressed in 80% of breast cancer patients and in 100% of estrogen receptor negative (ER-) tumors. The prevalence of BP1 positive cells and the intensity of BP1 immunoreactivity increased with the extent of ductal proliferation and tumorigenesis. These findings imply that BP1 may play an important role in ER- breast cancer. We sought to determine the effects and mechanisms of BP1 on cell proliferation and metastasis using ER- Hs578T cells as a model. Cells were transfected with either pcDNA3.2 plasmid containing BP1 gene, or pcDNA3.2 vector, then selected and cloned. Overexpression of BP1 increased cell proliferation rate by 2-5 fold (p&lt;0.005), and enhanced the in vitro invasive activity by 25-65 fold (p&lt;0.001). Microarray experiments were performed to identify differentially expressed genes when BP1 is overexpressed. The gene expression profile of the transfected cell lines were compared, resulting in 71 differentially expressed genes with a fold-change of &gt;=2.0. Of those genes, 49 were up-regulated and 22 were down-regulated. Further analysis has identified several important molecular pathways using the differentially expressed gene list, including CREB signaling, BCL2L1, AKT signaling, apoptosis, androgen receptor pathways, etc. CREB1, as an oncogenic transcription factor, induces transcription of genes in response to hormonal stimulation of the cAMP pathway. CREB1 can be activated through phosphorylation by a number of kinases, including AKT, protein kinase A, and calcium/calmodulin-dependent kinases and regulates genes whose deregulated expression promotes oncogenesis, including cyclins, BCL2 family members, and EGR1. It was reported that BP1 can directly bind to and activate the expression of BCL1, which is an antiapoptotic gene and considered to be an oncogene. BCL2L1 is a BCL2 protein family member that acts as anti- or pro-apoptotic regulators involving in a wide variety of cellular activities. These data demonstrated that overexpression of BP1 significantly enhanced cell proliferation and metastatic potential in ER- Hs578T cells. Further analysis with more ER- cell lines and patient samples is warranted to establish BP1 as a therapeutic target.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3910.
Abstract 3918: PEA3 is a novel transcriptional activator of Notch-1 and Notch-4 in breast cancer: Opportunity for a new combination strategy
Authors: Clementz Anthony G. , Rizzo Paola , Miele Lucio , Osipo Clodia 
Published: February 2011

Abstract
Women diagnosed with triple-negative breast cancer have the worst overall prognosis and frequently present with metastatic tumors. To date, there are no targeted therapies available to combat this aggressive form of breast cancer due to the lack of expression of well-known targets such as ERα, PR, or HER2/neu. Therefore, there is an immediate need to identify novel targets that are responsible for the proliferation, survival, and invasive phenotype. Notch-1 and Notch-4, both potent breast oncogenes, are overexpressed in triple-negative breast cancers-associated with the poorest overall survival. PEA3 (polyomavirus enhancer activator 3), a member of the Ets family of transcription factors, is overexpressed in triple-negative breast cancer and also correlates with aggressive behavior and poor overall survival. Here, we provide new evidence for transcriptional regulation of Notch in triple negative breast cancer and other subtypes of breast cancer. With focus on triple-negative breast cancer cells (MDA-MB-231), our results show that PEA3 is a transcriptional activator of both Notch-1 and Notch-4 as determined by using a PEA3 siRNA and measuring both transcripts and proteins. Chromatin immunoprecipitation confirmed enrichment of PEA3 within the promoter regions of both Notch-1 and Notch-4. Notch-1 recruitment appears to be AP-1 independent, whereas PEA3 recruitment on the Notch-4 promoter is dependent upon c-JUN. Furthermore, results showed that either c-Jun or Fra-1 were required for Notch-4 transcription while c-FOS was a repressor. Importantly, the combined inhibition of Notch signaling (via a gamma-secretase inhibitor, GSI) and PEA3 (via siRNA) arrested the cells in G1, decreased cell viability, reduced tumorgenicity in vitro, and increased apoptosis. Taken together, our results indicate that PEA3 is a novel transcriptional activator of both Notch-1 and Notch-4. PEA3-mediated Notch-1 transcription is AP-1 independent while Notch-4 transcription requires both PEA3 and AP-1 most probably composed of the c-Jun: Fra-1 complex. Moreover, both PEA3 and Notch signaling are essential for proliferation and survival of MDA-MB-231 breast cancer cells. Thus, dual targeting of both PEA3 and Notch pathways might provide a new therapeutic strategy for triple-negative breast cancer as well as additional therapeutic targeting in other breast cancer subtypes.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3918.
Abstract 3923: ATM and KAP1 are required for nonhomologous end-joining in transcriptionally active chromatin
Authors: Hawkins Amy J. , White David E. , Golding Sarah E. , Akopiants Konstantin , Rauscher Frank J. , Povirk Lawrence F. , Valerie Kristoffer 
Published: February 2011

Abstract
The effect of ATM signaling on nonhomologous end joining (NHEJ) was investigated using a novel, chromosomally-integrated, viral vector that allows for inducing tandem I-SceI-mediated DNA double strand breaks (DSBs). The DSBs can then be analyzed for NHEJ repair events by fluorescence- and PCR-based methods. Using highly specific kinase inhibitors and this repair system, we show that inhibiting ATM reduces NHEJ by 80% in human U87 glioma cells. PCR products that span the repaired DSBs were analyzed by cleavage with a restriction enzyme that exclusively cuts the DNA repaired by high-fidelity repair. This analysis showed that the extent of high-fidelity repair was reduced by 40% when the ATM kinase was inhibited. KAP1 is a DNA damage-induced phosphorylation target of ATM that is linked to the modulation of chromatin structure. The ATM kinase inhibitor used in our studies blocks radiation-induced phosphorylation of KAP1 on serine 823/4. Knocking down KAP1 via shRNA had no effect on homologous recombination repair, but reduced NHEJ by 80%. Simultaneous treatment of cells with the ATM inhibitor and trichostatin A, a histone deacetylase inhibitor that promotes chromatin decondensation, abrogated the effect of the ATM inhibitor. These data are consistent with the hypothesis that ATM regulates DNA accessibility in chromatin. Together, these results suggest that ATM is critical for NHEJ of I-SceI DSBs and for high-fidelity repair of breaks within transcriptionally-active chromatin. The requirement for ATM in this system is likely a consequence of its signaling to chromatin modulating proteins that dynamically act on chromatin architecture surrounding DSBs.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3923.
Abstract 3927: Distinct roles of hMLH1-hMRE11 in homologous recombination and heteroduplex DNA repair at a single chromosomal locus
Authors: Her Chengtao , Xu Keqian , Tompkins Joshua D. , Wu Xiling 
Published: February 2011

Abstract
Increasing evidence indicates that the mismatch repair protein hMLH1 and DNA double-strand break (DSB) repair protein hMRE11 play multifunctional roles in various processes of DNA repair and damage response in human cells. Our previous studies have revealed a physical interaction between these two proteins and have suggested a role for hMRE11 in heteroduplex DNA repair and hMLH1-dependent DNA damage-induced G2 arrest. Here, we analyzed the effects of hMLH1-hMRE11 on homologous recombinational repair of an induced DSB and consequential heteroduplex repair at a single chromosomal locus by a newly developed reporter system. The results of these studies indicate that hMLH1 and hMRE11 display a synergistic anti-recombination effect and the hMLH1-mediated anti-recombination is at least partially dependent on its interaction with hMRE11, whereas the repair of heteroduplex DNA requires functional hMLH1 and hMRE11. Consistent with these results, chromatin immunoprecipitation (ChIP) analysis of the reporter locus demonstrates that DSB triggers the loading of hMLH1 and hMRE11 proteins to both the proximal region and the site containing heteroduplex DNA. However, in contrast to the proximal regions, loading of hMLH1-hMRE11 at the site of heteroduplex DNA also requires hMSH2, suggesting the involvement of DNA mismatch repair. In summary, our studies have provided evidence to suggest that, in addition to DNA damage response, hMLH1-hMRE11 are involved in at least two other DNA damage repair processes: anti-recombination and heteroduplex DNA repair. Our results implicate that mutations impairing the hMLH1-hMRE11 interaction might promote spontaneous chromosomal recombination between ectopic repetitive sequences and thereby increasing gene conversion and genomic instability.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3927.
Abstract 3930: Radiation-induced dicentrics: Tracking by parallel sequencing
Authors: Vaughan Andrew T.M , Shih Shyh-Jen , Singh Sheetal , Do To Uyen 
Published: February 2011

Abstract
Radiation and cytotoxic drugs exert much of their lethal effects by creating aberrations, such as dicentrics, that are lethal at a subsequent mitosis. Their accurate enumeration in experimental and clinical settings would provide valuable information on the efficacy of radiation and radiation/chemotherapy combinations. In this study a method was sought that could rapidly and efficiently quantitate this process using next generation sequencing. The use of modern molecular technology for aberration analysis has been restricted by the random nature of the breaks induced in individual chromosome that inhibit their detection. To overcome this problem, a common fragile site at 11q23 that is readily cleaved in response to a broad range of cytotoxic agents was used. Using irradiated human TK6 lymphoblastoid cells and blood samples taken from patients undergoing chemotherapy, partner chromosomes that are ligated to this location were detected using inverse PCR to capture the breakpoint. In order to enhance the efficiency of the process, amplified inverse PCR material was processed for Solexa type parallel sequencing. Here individual amplicons, representing the total content of a treated sample, are attached to a flow cell and their sequence recorded by sequential additions of fluorescent bases. Each aberration was then reconstructed with reference to a standard human genome database. In one specific sample of treated TK6 cells, two translocations involving Chr. 2 and 18 and two dicentrics involving Chr. 3 and 13 were found linked to the Chr 11q23 fragmentation site. In addition, aberrations were found in patients’ blood 6 months after initiation of therapy. Thus translocations that are rarely lethal could be readily discriminated from dicentric type rearrangements that are predominately lethal. The advantage of this analytical process is that all normal sequence is also recorded allowing the fractional content of all aberrations to be recorded in response to dose or time. In order to mitigate concerns over the arbitrary nature of aberrations induced at a common fragile site, a zinc finger nuclease was constructed targeting a region adjacent to the fragile site at 11q23. With this zinc finger system repetitive DNA breaks at the predicted site generated micro rearrangements (insertions/deletions) that were produced at far higher rates than translocations or dicentric type rearrangements measured by parallel processing. In summary, a novel analytical system for detecting a lethal class (dicentrics) of chromosome rearrangements has been described that is suitable for therapy monitoring both in-vitro and in-vivo.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3930.
Abstract 3938: Altered nucleotide excision repair gene expression after cisplatin treatment in melanoma
Authors: Bowden Nikola A. , Ashton Katie A. , Avery-Kiejda Kelly A. , Zhang Xu Dong , Hersey Peter , Scott Rodney J. 
Published: February 2011

Abstract
Melanoma incidence rates in Australia are the highest in the world. Two of the hallmark features of melanoma are the development of disease as a result of chronic repeated ultraviolet (UV) radiation exposure and the limited efficacy of cisplatin in treatment. These features have one commonality; both result in large helix distorting DNA damage that is recognised and repaired by the DNA repair system, nucleotide excision repair (NER). The aim of this study was to examine the expression of NER gene transcripts in melanoma cell lines treated with cisplatin.
One melanocyte, three primary melanoma (MM200, IgR3, Me4405) and two metastatic melanoma (Mel-RM and Sk-Mel-28) cell lines were used for this study. The cells were treated with cisplatin (10μg/mL) and RNA was harvested at 0, 6 and 24 hours after treatment. Thirteen NER gene transcripts were measured by semi-quantitative real-time PCR. The relative expression of each gene was calculated and t-tests were used to identify significantly altered expression in melanoma compared to melanocytes and between timepoints.
The genes involved in the global genome repair (GGR) DNA damage recognition pathway; XPC, DDB1 and DDB2 (XPE) showed significantly decreased relative expression (RE) in the melanomas compared to the melanocytes, 24 hours after cisplatin treatment. In contrast, the genes involved in the transcription coupled repair (TCR) DNA damage recognition pathway, ERCC8 (CSA) and ERCC6 (CSB) showed low RE in all cell lines at all time points. Furthermore, the genes involved in the convergent NER pathway revealed no significant change in RE 24 hours after cisplatin treatment in the melanomas, however, an increase in RE was seen in the melanocytes. Overall, the basal expression levels of all genes investigated were greater in the melanoma cell lines compared to the melanocytes.
The GGR DNA damage recognition arm of the NER pathway is essential to maintain genomic stability through the identification of helix distorting DNA adducts arising from UV radiation and genotoxic chemicals. The findings from this study revealed reduced GGR transcript levels 24 hours after cisplatin treatment. This finding may be the first step towards identifying the biological mechanisms underlying the limited efficacy of cisplatin in melanoma.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3938.
Abstract 3944: Base excision repair and gene expression profiling in malignant melanoma
Authors: Ashton Katie A. , Bowden Nikola A. , Kairupan Carla F. , Avery-Kiejda Kelly A. , Zhang Xu Dong , Hersey Peter , Scott Rodney J. 
Published: February 2011

Abstract
Melanoma is a potentially deadly skin tumour and its incidence continues to increase worldwide. Despite the many efforts to elucidate the molecular mechanisms involved in melanoma development, these pathways still remain relatively unknown. For this reason, new methods are required to identify new biological targets implicated in melanoma. Our pilot study examined whole genome gene expression (Illumina Ref8 V2) in 82 melanoma samples and 8 control melanocyte cell lines. Gene transcripts with significantly altered expression (p&lt;0.05) and greater than 2-fold change were identified for the melanomas compared to the melanocytes (GeneSpring GX V10), revealing a number of new targets not previously described in melanoma. Interestingly, a number of genes involved in the DNA repair, immune response and cell cycle arrest pathways were differentially expressed in the melanomas. With respect to the DNA repair pathways, we identified that key components of the base excision repair (BER) pathway were significantly altered in melanoma. Sequencing analysis confirmed several alterations in genes involved in the BER pathway and the frequency of these variants were further confirmed in an independent cohort of 105 formalin-fixed paraffin embedded (FFPE) melanoma patients. Hierarchical cluster analysis showed that melanoma patients with sequence variants in the BER pathway had altered gene expression profiles compared to those melanoma patients with no known variants in this pathway. Taken together, these results suggest that the BER pathway may be implicated in the development of melanoma, which may lead to the introduction of mutation screening and gene expression profiling for the management of melanoma.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3944.
Abstract 3953: C-Kit and Mitf signaling: Novel involvement of the PI3K/Akt and p38 pathways
Authors: Phung Bengt , Schepsky Alexander , Steingrimsson Eirikur , Rönnstrand Lars 
Published: February 2011

Abstract
The development of melanocyte from melanoblast is regulated by the tyrosine kinase receptor c-Kit and the basic-helix-loop-heliz-leucine zipper transcription factor Mitf. It is established that Mitf activity is controlled by c-Kit activation and subsequent phosphorylation of the Erk/Mapk pathway. Serine phosphorylation (activation) of Mitf not only leads to upregulation of Mitf target gene expression but also ubiquitin dependent proteosomal degradation of Mitf. There is little knowledge surrounding the dysregulation between c-Kit and Mitf signaling that is often found in melanocyte progression to melanoma. The aim of our study is, therefore, to identify the signal transduction pathways involved in c-Kit mediated regulation of Mitf.
In our study, we found c-Kit tyrosine phosphorylation sites and novel signaling pathways involved in the regulation of Mitf. Phosphorylation of c-Kit at Tyr721 has been shown to activate the PI3K pathway and Tyr568 and Tyr568/570 are responsible for Src kinase mediated activation of Erk/Mapk pathway. We demonstrate that Y721F, Y568F and Y568/570F mutation of c-Kit prevented Mitf mobility shift, indicating that these tyrosine phosphorylation sites are involved in Mitf regulation. Further, we observe that treatment of c-Kit and Mitf transfected HEK293T cells with LY294002 (PI3K inhib.), Akt IV (Akt inhib.), SU6656 (Src kinase inhib.), SB203580 (p38 inhib.) or U0126 (Mek inhib.) prevented c-Kit mediated Mitf mobility shift. Similar results were also observed in the murine melanocyte, Melan- A cell line where Mitf and c-Kit are endogenously expressed. In order to further verify c-Kit's role as Mitf regulator, we examined tyrosinase (downstream target of Mitf) promoter activity using a luciferase reporter construct. Ligand stimulation of c-Kit increased the Mitf target promoter activity.
In conclusion, for the first time, we demonstrate that the signal transduction between c-Kit and Mitf is dependent on, 1) c-Kit Tyr721/PI3K/Akt pathway, 2) p38 pathway and 3) c-Kit Tyr568 or Tyr568/570 / Src kinase mediated Erk pathway. C-Kit activation leading to downstream were also shown to promote the transcriptional activity of Mitf. Our results reveal novel mechanisms by which c-Kit signaling regulates Mitf, with implication for understanding of both melanocyte development and melanoma.
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3953.