bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2196: Upregulation of survivin during immortalization is linked to repression of p16INK4a and confers resistance to oxidative stress
Authors: Petti Carlotta , Kan Chin-Yi , Dietrich Philipp A. , Lauryn Bracken , Xu Ning , Yuan Jun , Liu Tao , MacKenzie Karen L. 
Published: August 2012

Abstract
Survivin is an essential component of the chromosomal passenger complex and a member of the Inhibitor of Apoptosis (IAP) family. It is expressed at high levels in a large variety of malignancies, where it is implicated in cytoprotection and drug resistance. Nevertheless, the pathways that mediate the cytoprotective functions of survivin and the mechanisms underlying its upregulation in cancer have not been fully elucidated. Results from our past investigations revealed that survivin was upregulated during telomerase-mediated immortalization of human myofibroblasts (MRC-5) (1). Since the immortalization process is an essential step in human carcinogenesis, upregulation of survivin during immortalization may explain why survivin is abundant in virtually all cancers. The present study aimed to characterize the mechanism responsible for the upregulation of survivin during immortalization, and the functional consequences of its over expression in immortal cells. Results from whole genome expression analyses and qRT-PCR demonstrated that the upregulation of survivin during immortalization was paralleled by increased expression of the transcription factor E2F1. The chromatin immunoprecipitation (ChIP) assay confirmed that E2F1 directly interacted with the survivin gene (BIRC5) promoter in immortal cells. Moreover, it was shown that E2F1 binding to BIRC5 was corresponded with repression of tumor suppressor p16INK4a, an event that commonly occurs during immortalization and human tumorigenesis. Survivin and p16INK4a were also functionally linked by assays that showed either upregulation of survivin or repression of p16INK4a rendered telomerase-transduced MRC-5 cells resistant to oxidative stress. Conversely, siRNA-mediated down regulation of survivin activated caspases and enhanced the sensitivity of immortal MRC-5 cells to oxidative stress. Together these data show that repression of p16INK4a contributes to the upregulation of survivin, and thereby provides a survival advantage to cells that are subject to oxidative stress during immortalization. 1. Yuan et al., Oncogene (2009) 28, 2678-2689.
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 2196. doi:1538-7445.AM2012-2196
Abstract 220: TNFα activates NF-κB through RIP1 ubiquitination-dependent and independent pathways
Authors: Zhang Laiqun , Blackwell Ken , Workman Lauren , Habelhah Hasem 
Published: August 2012

Abstract
TNFα-induced NF-κB activation has long been believed to depend on TRAF2/5- and cIAP1/2-mediated RIP1 ubiquitination. Recently, HOIP/HOIL-1-mediated linear ubiquitination of NEMO/IKKγ has emerged as a new player in TNFα-induced NF-κB activation. However, the mechanisms by which these proteins mediate NF-κB activation have become more complex than ever before due to an accumulation of conflicting results. Several independent studies even challenged the notion that these proteins ever play essential roles in NF-κB activation. Here, we report the identification of immediate and delayed phases of IKK activation in TNFα-treated cells. TNFα-induced immediate IKK activation requires ubiquitination of RIP1 catalyzed by cooperative actions of TRAF2, cIAP1/2, UbcH5 and Ubc13, and that in the absence of any one of these components; those remaining are only capable of mediating delayed IKK activation by recruiting the HOIP/HOIL-1 complex. In RIP1-deficient cells, TRAF2 undergoes increased auto-ubiquitination through K63-linkage, yet it is not capable of mediating immediate IKK activation. Notably, depletion of either HOIP in RIP1-deficient cells or both TRAF2 and cIAP1/2 in wild-type cells completely impairs IKK activation. In addition, deletion of the TRAF2 RING domain also severely reduces the immediate phase of IKK activation. These data suggest that two RING finger E3 ligases (TRAF2 and cIAP1) and two E2 enzymes (UbcH5 and Ubc13) cooperate to catalyze immediate RIP1 ubiquitination and IKK activation, and that, in the absence of RIP1, TRAF2 and cIAP1/2 recruit HOIP/HOIL-1 and mediate the delayed phase of IKK activation. TRAF5 has no substantial role in TNFα-induced NF-κB activation. Importantly, in embryonic hepatocytes, RIP1 is completely degraded, yet these cells are not sensitized to TNFα-triggered cell death because of delayed IKK activation. Thus, this study provides evidences for the existence of RIP1 ubiquitination-dependent and -independent pathways that mediate NF-κB activation, and thereby clarifies molecular details of this important signaling mechanism.
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 220. doi:1538-7445.AM2012-220
Abstract 2200: Identification of GLI1 binding partners that regulate transactivation or cell transformation
Authors: Yoon Joon Won , Higashiyama Nicole , Lamm Marilyn , Iannaccone Philip M. , Walterhouse David O. 
Published: August 2012

Abstract
Activation of the GLI1 transcription factor and oncogene appears to play a role in the genesis of desmoplastic medulloblastomas, basal cell carcinomas, and some rhabdomyosarcomas. We identified interactions between GLI1 and proteins that enhance the transactivating or cell transforming function of GLI1. Such protein-protein interactions could potentially be targeted in the treatment of some GLI1-related malignancies. We focused on proteins interacting with GLI1 transactivation domains, believing these would be essential for transactivation and cell transformation. Previously, we identified an acidic alpha-helical transcription activation domain (TAD1; aa 1020-1091) at the carboxyl terminus of the GLI1 protein. We show that TAD1 physically interacts with the coactivator TAF9 in vitro by pull down assays and in rhabdomyosarcoma cells in vivo by proximity ligation assays and co-immunoprecipitation. Inhibition of this interaction reduces transactivation by GLI1 and the ability of GLI1 to transform RK3E cells. We identify a second GLI1 transactivation domain (TAD2; aa 635-740), which activates reporter gene transcription and accounts for the TAD1-independent cell transforming ability of GLI1. TAD2 contains conserved sequences among GLI1 family proteins, including a CBP binding domain identified in GLI3. However, consistent with in vitro data from others, we could not demonstrate interaction of TAD2 and CBP in rhabdomyosarcoma cells in vivo by proximity ligation assay. To identify TAD2 binding proteins, we performed yeast 2 hybrid screening and identified other transcription factors (Y-Box1, HSF2, RBMX2, and ZMYM2), cytoskeleton-associated proteins and membrane-associated proteins. Based on a previously described GLI1-p53 inhibitory loop that controls stem cell and tumor cell numbers, we demonstrate that p53 down-regulates TAD1 but not TAD2 function. Understanding the mechanism of transactivation and cell transformation by GLI1 can provide novel targeted approaches to inhibit the GLI1 transcription factor in 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 2200. doi:1538-7445.AM2012-2200
Abstract 2203: AP-1 activation and a functional SNP242 regulates the LY-6K gene expression in human breast cancer cells
Authors: Kong Hyun Kyung , Park Jong Hoon 
Published: August 2012

Abstract
Background: Lymphocyte antigen 6 complex locus K(LY-6K), a member of LY-6/uPAR receptor superfamily and cancer-testis antigen, is a novel breast cancer biomarker. Also LY-6K is target antigen for the head and neck squamous cell carcinoma, and lung and esophageal carcinoma. Elevated LY-6K induces cell invasion and metastasis through activating the Raf-1/MEK/ERK signaling pathway. However, the molecular mechanisms that mediate regulation of human LY-6K gene expression are completely unknown. Material and Methods: Within the pGL3-basic reporter vector, the −3050/+182 bp fragment, truncated and mutated fragment upstream of the LY-6K gene was subcloned and measured promoter activity. Subsequently, multiple cis elements were identified using several gene tool software (TFSEARCH, TRANSFAC, PROMO and MATCHTM) in the promoter of human LY-6K gene. We investigated the transcription factor and the effect of single nucleotide polymorphism (SNP) on LY-6K promoter activity and transcription factor binding using chromatin immunoprecipitation (ChIP) assays, electrophoretic mobility shift assays (EMSA), and supershift assays. Results: LY-6K gene was expressed in estrogen receptor (ERα) and progesterone receptor (PR)-negative breast cancer cell lines. A novel AP-1 binding site in the LY-6K promoter regulates LY-6K gene expression. A polymorphic C/G-SNP at the 242 nucleotide position in the promoter region (rs2585175, called SNP242) was validated to be located in a PAX-3 transcription binding motif, which is appear with the presence of the G-allele resulting in a ∼54% decrease in LY-6K promoter activity by interfering binding of AP-1 transcription factor. Discussion: The activity of the AP-1 transcription factor plays an important role in cell mobility of breast cancer cells via the promoting of LY-6K gene expression. LY-6K expression is dependent on not AP-1 transcription factor, but also functional SNP242 G-allele. These results suggested that the polymorphism rs2585175 (SNP242), in close proximity of the LY-6K promoter, lead to LY-6K downregulation, and thus, may reduce the risk of 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 2203. doi:1538-7445.AM2012-2203
Abstract 2204: BCL11B is a critical EWS/FLI up-regulated target in Ewing's sarcoma
Authors: Toomey Elizabeth , Lui Bianca , Lessnick Stephen 
Published: August 2012

Abstract
Objective: Ewing's sarcoma is a highly aggressive tumor of the bone and soft tissue that affects the pediatric and young adult population, and is characterized by the EWS/FLI chromosomal translocation. This fusion protein acts as an oncogenic transcription factor to dysregulate the expression of a number of genes that contribute to the transformed phenotype. One challenge is to define which of these dysregulated genes are important for the oncogenic phenotype of Ewing's sarcoma. To address this issue, we used a proteomics approach to identify new protein-protein interactions among target genes of EWS/FLI. This screen identified BCL11B, which had previously been identified in genome-wide transcriptional profiling studies by our group, and others, as an up-regulated target of EWS/FLI. Methods: To define the function of BCL11B in Ewing's sarcoma, we used retroviral mediated shRNA knock-down of EWS/FLI, followed by re-expression of the EWS/FLI cDNA, to verify that BCL11B expression is modulated by the fusion protein. Anchorage independent growth assays assessed the oncogenic potential of patient derived Ewing's sarcoma cell lines in which BCL11B had been knocked-down with shRNA. Luciferase assays and chromatin immunoprecipitation techniques were used to interrogate BCL11B regulation by EWS/FLI. Results: Our results show that BCL11B is up-regulated by EWS/FLI and is necessary for oncogenic transformation in patient derived Ewing's sarcoma cell lines. Our work addressing the mechanism of BCL11B regulation by EWS/FLI is on-going, but preliminary data suggests that BCL11B may be a direct target of EWS/FLI. Conclusion: This work identified BCL11B as an EWS/FLI up-regulated target that contributes to transformation in Ewing's sarcoma. It also provides a setting in which we can broaden our knowledge regarding the mechanisms used by EWS/FLI to up-regulate critical target 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 2204. doi:1538-7445.AM2012-2204
Abstract 2207: SUMOylation of EAPII/TTRAP/TDP2 modulates its function
Authors: Li Chunyang , Khuri Fadlo R. , Sun Shi-yong , Li Runzhao 
Published: August 2012

Abstract
ETS1 Associated Protein II (EAPII, also called TTRAP, TDP2) was originally identified by two-hybrid screening as a novel protein that interacts with both ETS1 and the cytoplasmic domain of CD40 receptor. EAPII may represent a novel component in signal transduction processes that regulates eukaryotic gene expression in response to extracellular signals. In support of this hypothesis, we have demonstrated that EAPII negatively modulates ETS1 transcriptional activity and attenuates synergistic transactivation by ETS1 and NFκB. However, the mechanism by which EAPII transduces signals is elusive. In this report, we provide the evidence of EAPII protein sumoylation in vivo. Sumoylation is an important posttranslational modification that involves conjugation of the small ubiquitin-like modifier (SUMO) to lysine residues of the targeting proteins. EAPII is sumoylated by both SUMO-1 and SUMO-2/3. Sumoylation analysis of cell fractions revealed that sumoylation by SUMO-2/3 mainly occurs in the nucleus while that by SUMO-1 in cytoplasm. Since EAPII protein possesses no SUMO consensus motif (≥KxE), we constructed a series of EAPII truncated mutations to determine the potential sumoylation site(s). Our data indicated that the noconsensus sumoylation site(s) may reside between amino acid residues 68 and 279. Interestingly, C-terminal deletion (Del 279-362) significantly increases the sumoylation, suggesting that the C-terminus might contain an inhibitory domain for EAPII sumoylation. It has been hypothesized that sumoylation may mediate extracellular signals in response to stresses, hypoxia and cytokines. Whether EAPII sumoylation interferes with its repressive activity on ETS1 transcription remains to be elucidated, and determination of the signaling pathways that may modulate EAPII sumoylation will provide a better understanding of the modulation of ETS1 functions in specific pathphysiological microenvironments.
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 2207. doi:1538-7445.AM2012-2207
Abstract 2211: Accessible chromatin structure permits factors Sp1 and Sp3 to regulate human TGFBI gene expression
Authors: Lee Jong-Joo , Park Joo-Hong , Park Keunhee , Song Min-Ji , Yang Wook-Jin , Kim Hyoung-Pyo 
Published: August 2012

Abstract
Transforming growth factor beta 1-induced (TGFBI) protein is an extracellular matrix (ECM) protein expressed widely in human tissues. The gene encoding this protein was first described as a major TGF-b-responsive gene in the lung adenocarcinoma cell line A549. TGFBI appears to mediate cell adhesion and migration through interaction with integrin, and increased TGFBI expression has been associated with inflammatory diseases including rheumatoid arthritis, atherosclerosis, cyclosporine nephropathy, and stab wound healing. TGFBI is ubiquitously expressed in healthy tissues, while disrupted TGFBI expression has been described in human tumor cell lines and in human primary tumor samples. A general function of this protein appears to be as a promoter or suppressor of cancer progression, depending on the tissue. Regulation of TGFBI expression by epigenetic mechanism such as DNA methylation and microRNA has been reported, but few studies have focused on how chromatin structure affects transcriptional activity relating to TGFBI expression. We show that both chromatin structure and regulatory elements in the TGFBI promoter region that bind factors Sp1 and Sp3 regulate constitutive expression of TGFBI. In this study, we investigated how human TGFBI expression is regulated in lung and breast cancer cells. We observed that the TGFBI promoter in A549 and MBA-MD-231 cells, which constitutively express TGFBI, existed in an open chromatin conformation associated with transcriptionally permissive histone modifications. Moreover, we found that TGFBI expression required Sp1 transcription elements that can bind transcription factors Sp1 and Sp3 in vitro. Occupancy of the TGFBI promoter by Sp1 and Sp3 in vivo was only observed in TGFBI-expressing cells, indicating that open chromatin conformation might facilitate the binding of Sp1 and Sp3 to the TGFBI promoter region. TGFBI promoter activity was impaired when Sp1 elements were mutated, but was increased when Sp1 or Sp3 factors was overexpressed. Furthermore, Sp1 inhibition in vivo by mithramycin A, as well as knockdown of Sp1 and/or Sp3 expression by short interfering RNA, significantly reduced TGFBI mRNA and protein levels. Thus, our data demonstrated that the expression of TGFBI is well correlated with chromatin conformation at the TGFBI promoter, and that factors Sp1 and Sp3 are the primary determinants for the control of constitutive expression of TGFBI gene.
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 2211. doi:1538-7445.AM2012-2211
Abstract 222: NEK6 promotes JB6 C141 cell transformation and activates STAT3 through its phosphorylation on Ser727
Authors: Lee Kun Yeong , Jeon Young Jin , Bode Ann M. , Dong Zigang 
Published: August 2012

Abstract
NEK6 (NIMA-related kinase 6) is a homologue of the Aspergillus nidulans protein NIMA (never in mitosis, gene A). We demonstrate that ectopic expression of NEK6 induces anchorage-independent transformation of JB6 Cl41 mouse epidermal cells. Tissue arrays and Western immunoblot analysis show that NEK6 is overexpressed in malignant tissues and several cancer cell lines. We also discovered that NEK6 interacts with STAT3, an oncogenic transcription factor, and phosphorylates STAT3 on Ser(727), which is important for transcriptional activation. Additional studies using NEK6 mutants suggested that the phosphorylation on both Ser(206) and Thr(210) of NEK6 is critical for STAT3 phosphorylation and anchorage-independent transformation of mouse epidermal cells. Notably, knockdown of NEK6 decreased colony formation and STAT3 Ser(727) phosphorylation. Based on our findings, the most likely mechanism that can account for this biological effect involves the activation of STAT3 through the phosphorylation on Ser(727). Because of the critical role that STAT3 plays in mediating oncogenesis, the stimulatory effects of NEK6 on STAT3 and cell transformation suggest that this family of serine/threonine kinases might represent a novel chemotherapeutic 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 222. doi:1538-7445.AM2012-222
Abstract 2224: Targeted PI3K/mTOR inhibition impairs tumor cell motility and bone metastatic outgrowth via modulation of p27
Authors: Besser Alexandra H. , Wander Seth A. , Zhao Dekuang , Hong Feng , Wei Jian Qin , Wang Bin , Ince Tan , Milikowski Clara , Nadji Mehrdad , Briegel Karoline , Bishopric Nanette , Slingerland Joyce M. 
Published: August 2012

Abstract
The pleiotropic oncogenic effects of PI3K/mTOR have stimulated development of catalytic PI3K and mTOR inhibitors for the treatment of cancer. Present data provide a novel rationale for the use of dual PI3K/mTOR inhibitors to oppose tumor motility, invasion and metastasis. Cytoplasmic mislocalization of p27 is implicated as a key downstream driver of PI3K/mTOR-dependent tumor cell motility in vitro and bone metastatic outgrowth in vivo. Here, we report that PI3K/mTOR-kinase inhibition with PF-04691502 impairs breast cancer metastasis to bone, in part via effects on p27. Low-dose PF-04691502 impaired motility and invasion of highly PI3K/mTOR activated, bone-metastatic MDA-MB-1833 cells in vitro without affecting apoptosis or proliferation. Moreover, drug pre-treatment impaired bone metastasis in vivo. PF-04691502 decreased cytoplasmic p27pT157 and p27pT198, and p27T157D/T198D overexpression conferred resistance to inhibition of motility by PF-04691502. p27 knockdown in MDA-MB-1833 relieved RhoA-ROCK inhibition, decreased cell motility/invasion in vitro, and bone metastasis in vivo. p27 knockdown also reversed EMT phenotypic markers in MDA-MB-1833, as did PI3K/mTOR inhibition, demonstrating that p27 may be critical for maintenance of the EMT cellular program. Indeed, loss of cytoplasmic p27 reversed expression of an EMT gene profile supporting the notion that p27 acts as a key mediator of metastasis downstream of PI3K/mTOR. Cytoplasmic p27 in human cancers may prove to be a useful predictive marker to assess both PI3K/mTOR activation and the potential efficacy of catalytic PI3K/mTOR inhibitors.
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 2224. doi:1538-7445.AM2012-2224
Abstract 2225: GSK3β plays a significant role in Ras driven tumors potentially through an upstream effect on AKT
Authors: Sweeting Raeshell S. , Kim Hong J. , Baldwin Albert S. 
Published: August 2012

Abstract
Pancreatic cancer is a highly aggressive cancer that is resistant to most drug therapies. Lung cancer is the number one cause of cancer deaths in the US and worldwide. Both of these tumors are known to have high levels of Ras oncogenic mutations (50 and 90% respectively). AKT is known to phosphorylate and inactive Glycogen Synthase Kinase 3 (GSK3). Additionally, GSK3 has been shown to play a role in oncogenesis in pancreatic cancer and lung cancer. Given the high level of AKT activity in transformed cells these two processes would appear to be at odds. However, much of the work on GSK3 has focused on the beta subunit. We have found that the alpha subunit plays a role in tumor proliferation and AKT activity. We see a significant effect of knockdown of GSK3β in Ras transformed pancreatic (Panc1, MiaPaca) and lung cancer (A549) cell lines in proliferation assays, with an approximately 70% decrease in growth compared to siControl cells. In contrast, the knockdown of the GSK3β subunit resulted in no decrease in cell proliferation in A549 cells compared to a 45% decrease in Panc 1 cells. Additionally, knockdown of GSK3β resulted in decreased levels of AKT activity by Western blot analysis as compared to siControl and GSK3β. Previous studies have focused on the role of the beta subunit of GSK3 in oncogenesis. Additionally, AKT has been studied as an upstream regulator rather than a downsteam target of GSK3. Our early studies suggest that the GSK3β subunit may play a significant role in the growth of Ras driven tumors cell lines upstream of AKT, and should be a potential target for therapeutic strategies.
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 2225. doi:1538-7445.AM2012-2225