bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4283: Src phosphorylates splicing factor 45 (SPF45) and regulates SPF45 nucleocytoplasmic shuttling, cell migration and invasion.
Authors: Liu Yuying , Conaway Lashardai Neniara , Bethard Jennifer Rutherford , Bradley Amber Thompson , Eblen Scott 
Published: August 2014

Abstract
Src phosphorylates splicing factor 45 (SPF45) and regulates SPF45 nucleocytoplasmic shuttling, cell migration and invasion
Yuying Liu1, LaShardai Conaway1, Jennifer Rutherford Bethard1, Amber Thompson Bradley1 and Scott T. Eblen1,2
From Department of Cell and Molecular Pharmacology and Experimental Therapeutics1 and the Hollings Cancer Center2
Medical University of South Carolina, Charleston, SC, 29425
SPF45 is a bifunctional protein involved in splicing and DNA repair and is overexpressed in several forms of cancer. Previously, we have shown that SPF45 overexpression regulates ovarian cancer cell proliferation and adhesion in a MAP kinase phosphorylation-dependent manner. In this study, we investigated novel roles of SPF45 and their regulation by the tyrosine kinase Src. We show by cell fractionation that endogenous SPF45 localizes in both the nucleus and cytoplasm and that exposure of cells to UV irradiation or osmotic shock increased SPF45 cytoplasmic accumulation. Consistent with this result, heterokaryon assays using SKOV-3 cells stably expressing Myc-SPF45 showed that SPF45 shuttles between the nucleus and cytoplasm and that pretreatment of the cells with the Src family kinase inhibitor PP2 inhibited nucleocytoplasmic shuttling. Src strongly induced SPF45 tyrosine phosphorylation and co-immunoprecipitated with SPF45 after co-transfection into COS-1 cells. Src phosphorylated SPF45 in vitro on five tyrosine residues (Y100, Y108, Y194, Y214 and Y246), as determined by mass spectrometry. Sequential mutation of these sites to phenylalanine inhibited SPF45 tyrosine phosphorylation in cells co-transfected with Src, with mutation of all 5 sites (Myc-SPF45-Y5F) completely inhibiting SPF45 tyrosine phosphorylation. Myc-SPF45-Y5F stably expressed in SKOV-3 cells showed reduced nucleocytoplasmic shuttling compared to wild type Myc-SPF45. SKOV-3-Myc-SPF45 cells demonstrated enhanced migration and invasion compared to vector control cells, while SKOV-3-Myc-SPF45-Y5F cells migrated significantly less than SKOV-3-Myc-SPF45 cells. These data are the first to show that SPF45 is a shuttling protein, a Src substrate, and that Src phosphorylation of SPF45 regulates nucleocytoplasmic shuttling and SPF45-induced cell migration and invasion.
Citation Format: Yuying Liu, Lashardai Neniara Conaway, Jennifer Rutherford Bethard, Amber Thompson Bradley, Scott Eblen. Src phosphorylates splicing factor 45 (SPF45) and regulates SPF45 nucleocytoplasmic shuttling, cell migration and invasion. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4283. doi:10.1158/1538-7445.AM2013-4283
Abstract 4286: Hepatocyte growth factor-mediated gastrin-releasing peptide induces IL-8 expression through Ets-1 in gastric cancer cells.
Authors: Koh Sung Ae , Lee Kyung Hee , Choi Eun Young , Kim Min Kyung , Jang Byung Ik , Kim Se Won , Kim Sang Woon , Song Sun Kyo , Kim Jae Ryong 
Published: August 2014

Abstract
Gastric cancer cells secrete a variety of pro-angiogenic molecules, including IL-8 and VEGF. However, factors regulating the expression of pro-angiogenic genes for gastric cancer remain largely undefined. We investigated the role of HGF-induced activation of GRP and Ets-1 transcription factor in expression of the pro-angioigenic factor, IL-8.
The genes associated with angiogenesis induced by HGF were screened using cDNA microarray technology in two gastric cancer cell lines (NUGC-3 and MKN-28). First, GRP RNA and protein were confirmed to be up-regulated. Then, expression of GRP, Ets-1, and IL-8 were further estimated by Western blot analysis. A role for Ets-1 in HGF-induced up-regulation of IL-8 was determined by knockdown of Ets-1 with Ets-1 sh-RNA and a chromatin immune precipitation assay.
The levels of GRP, Ets-1, and IL-8 were up-regulated in cells treated with HGF in a dose-dependent manner. HGF-induced expression of Ets-1 and IL-8 was increased more by GRP treatment, and inhibited by pre-treatment with an ERK 1/2 inhibitor (PD098059). HGF-induced up-regulation of IL-8 was repressed by Ets-1 knockdown. HGF enhanced the binding activity of Ets-1 to the IL-8 promoter in control cells, but not in the Ets-1 shRNA cells. We confirmed the functional role of HGF-induced Ets-1 in activation of the IL-8 promoter by the reporter gene assay. Down-regulation of IL-8 also decreased in vitro cell invasion.
In conclusion, HGF mediated the GRP induction of IL-8 expression through Ets-1, which thus might serve as a promising target for gastric cancer therapy.
Key words: HGF, GRP, Ets-1, IL-8
Citation Format: Sung Ae Koh, Kyung Hee Lee, Eun Young Choi, Min Kyung Kim, Byung Ik Jang, Se Won Kim, Sang Woon Kim, Sun Kyo Song, Jae Ryong Kim. Hepatocyte growth factor-mediated gastrin-releasing peptide induces IL-8 expression through Ets-1 in gastric cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4286. doi:10.1158/1538-7445.AM2013-4286
Abstract 4287: Intracellular trafficking of androgen receptor splice variant AR8.
Authors: John Ciny , Lu Michael L. 
Published: August 2014

Abstract
In a classic paradigm, the intracellular trafficking of a ligand-stimulated androgen receptor involves receptor dimerization, dissociating from chaperones (such as HSPs), interact with nuclear membrane importin and Ran-GTPase to gain access to nucleus; once there, it complexes with transcriptional regulators and binding to target sites. Despite the compelling evidence for AR non-genomic signaling events, the molecular mechanism of how does AR signaling from cytoplasmic or membrane remains undetermined. Several recent studies suggested that membrane association of AR is mediated by palmitoylation of AR at cysteine-806. Two plamitoylation enzymes, DHHC7 and DHHC21, have been implicated in the process of AR palmitoylation. In the current study, we determined the intracellular trafficking of a newly identified AR isoform, AR8. AR8 is a splice variant of the original full-length AR. AR8 was demonstrated to be up-regulated in castration-resistant prostate cancer cells. Structurally, AR8 protein sequence is different from other AR variants with a substitution of all the amino acids after N-terminal domain (NTD) of a conventional AR with an unique C-terminal sequence. Coincidentally, two cysteine residues within the unique c-terminus, positions 558 and 560, were identified to be palmitoylated. The palmitoylation was determined to be responsible for the localization of AR8 to plasma membrane. Using a fluorescent protein mCherry-tagged AR8 and confocal microscopy, we confirmed the plasma membrane localization of AR8 as previously described. We determined that AR8 co-localized with a Golgi marker GM-130 at peri-nuclear regions by immunofluorescence microscopy. The result was further substantiated by co-localizing mCherry-AR8 with galactosyltransferase (GalT) golgi-targeting sequence-fused GFP (GalT-GFP; green fluorescent protein) at Golgi compartments. We also demonstrated that mCherry-AR8 co-localized with EGFR-GFP (epidermal growth factor receptor-GFP) on the plasma membrane within in the cholesterol rich raft domain. Using time-lapse confocal microscopy, we observed that AR8 co-migrated with EGFR in a retrograde fashion and become associated with endosomal compartments at the onset of EGF (5ng/ml) stimulation. Part of these endosomes was later fused with lysosomes as evident from co-localizations of mCherry-AR8 with GFP-LAMP-1. Although the significance of AR8 expression in the progression of prostate cancer remains to be determined, our observations underline a potential intracellular trafficking pathway associated with AR8 are consistent with the original report that EGF stimulation promotes the interactions between AR8 and EGFR.
Citation Format: Ciny John, Michael L. Lu. Intracellular trafficking of androgen receptor splice variant AR8. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4287. doi:10.1158/1538-7445.AM2013-4287
Abstract 429: Damage-induced apoptosis in primary human lymphocytes is a genetic program modified by gender and age.
Authors: Applebaum Mark A. , Skol Andrew , Bond Gareth , Onel Kenan 
Published: August 2014

Abstract
Apoptosis is a core pathway deregulated in hematologic and other cancers. Although there are considerable functional and genetic data on the regulation of apoptosis in vitro and in model organisms, little is known about how these pathways are modified in primary cells freshly isolated from people, who are continually subjected to a variety of different and often unquantified environmental stimuli. We hypothesize that these exposures may have important and as yet unappreciated modifying effects on apoptosis that may have implications for cancer risk or response to therapy. To test this, we isolated peripheral blood mononuclear cells (PBMCs) from 90 normal healthy individuals and treated them with 5 Gy ionizing radiation (IR). Damage-induced apoptosis was measured at 24 hours after IR by TUNEL. We observed surprising heterogeneity in apoptosis among individuals, ranging from 21-65 percent. To determine whether this diversity in response was programmed or stochastic, we repeated the experiment 3 times in 10 individuals spanning the entire IR-induced apoptotic range and found results to be completely reproducible within individuals, suggesting that it resulted from a genetic program. We then assessed the association with individual characteristics. Whereas neither race nor age was associated with IR-induced apoptosis, gender was significantly associated (Mean: 44.8% vs 32.9%; p = 1.02 x 10-8). Moreover, when stratified by gender, age was significantly associated with IR-induced apoptosis in males (p = 0.026) but not females (p = 0.94). Thus, we conclude that IR-induced apoptosis in freshly isolated human PBMCs results from an intrinsic genetic program modified by age, but only within males. Genetic models to explain this will be discussed.
Citation Format: Mark A. Applebaum, Andrew Skol, Gareth Bond, Kenan Onel. Damage-induced apoptosis in primary human lymphocytes is a genetic program modified by gender and age. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 429. doi:10.1158/1538-7445.AM2013-429
Abstract 4292: RasGRP3 contributes to Ras signaling, growth, and migration of human lung cancer cell lines.
Authors: Yang Jing , Esch Timothy , Yang Dazhi , Blumberg Peter 
Published: August 2014

Abstract
Elevated levels of Ras activity are a prominent feature in human lung cancer. In approximately 20% of lung cancer cases, Ras activation is achieved by mutation of the Ras proto-oncogene. Here, we explore the possible contribution of RasGRP3 to Ras signaling in lung cancer. RasGRP3 is a Ras guanyl nucleotide exchange factor which has been shown to be expressed in prostate tumor and melanoma cell lines, contributing to the level of Ras activation, cell proliferation, and tumor xenograft growth. Here, we report that RasGRP3 is expressed in multiple human lung cancer cell lines but not in normal human bronchial epithelial cells. Likewise, initial analysis reveals its expression in human lung tumors but not in normal lung tissue. Suppression of endogenous RasGRP3 expression in lung cancer cell lines showing reduced H-Ras-GTP and K-Ras-GTP formation as well as Akt phosphorylation downstream from epidermal growth factor (EGF) or phorbol 12-myristate 13-acetate (PMA) stimulation. Additionally, suppression of RasGRP3 inhibited translocation of the NF-kB p50 and p65 subunits from the cytoplasm to the nuclear fraction and modulated several other transcriptional factors as well. Conversely, expression of exogenous RasGRP3 elevated H-Ras-GTP and K-Ras-GTP and activated AKT phosphorylation in the lung cancer H496 cell line, which itself only expresses RasGRP3 at low levels. These changes in signaling were mirrored at the cellular level. Downregulation of endogenous RasGRP3 inhibited cell proliferation, impeded cell migration and reduced colony formations in soft agar. Our results suggest that RasGRP3 may provide an addition targetable signaling element in lung cancer.
Citation Format: Jing Yang, Timothy Esch, Dazhi Yang, Peter Blumberg. RasGRP3 contributes to Ras signaling, growth, and migration of human lung cancer cell lines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4292. doi:10.1158/1538-7445.AM2013-4292
Abstract 4295: PHLPP suppresses epithelial-mesenchymal transition and cancer cell invasion by negatively regulating RAF1 activity.
Authors: Li Xin , Stevens Payton D. , Gao Tianyan 
Published: August 2014

Abstract
PHLPP belongs to a family of protein phosphatases that have previously been shown to inhibit Akt-mediated cell proliferation and survival signaling in cancers. Here, we demonstrate that PHLPP exerts its tumor suppressor function by negatively regulating the RAF/MEK/ERK pathway to inhibit cell migration and invasion. Specifically, we identify the oncogenic protein kinase RAF1 as an interacting protein and a novel substrate of PHLPP. PHLPP dephosphorylates the S338 site of RAF1 and inactivates the kinase both in vitro and in cells. Loss of PHLPP expression largely increases the amplitude and duration of RAF/MEK/ERK signaling in cells, whereas overexpression of PHLPP inhibits the pathway. Functionally, knockdown of PHLPP induces epithelial-mesenchymal transition (EMT)-like phenotype, which coincides with a significant increase in migration and invasion in colon cancer cells. Furthermore, we show that upregulation of transcription factors ZEB1 and ZEB2 is responsible for increased invasiveness observed in PHLPP knockdown cells. Taken together, we have identified a novel role of PHLPP in suppressing EMT and cell motility in colon cancer cells by directly antagonizing RAF1 function.
Citation Format: Xin Li, Payton D. Stevens, Tianyan Gao. PHLPP suppresses epithelial-mesenchymal transition and cancer cell invasion by negatively regulating RAF1 activity. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4295. doi:10.1158/1538-7445.AM2013-4295
Abstract 4301: Transformation by the D816V mutant of c-Kit is dependent on the PI3-kinase isoform p110δ but independent of its lipid kinase activi.
Authors: Sun Jianmin , Mohlin Sofie , Lundby Alicia , Hellman Ulf , Påhlman Sven , Olsen Jesper V. , Rönnstrand Lars 
Published: August 2014

Abstract
Gain-of-function mutations of the receptor tyrosine kinase c-Kit are frequently seen in several malignanices with the D816V mutation being the most common. In this study we demonstrate that a mutant of c-Kit/D816V that is deficient in binding of the p85 subunit of PI3-kinase (M724A) has lost its ability to induce ligand-independent cell survival and proliferation while c-Kit/D816V induced PI3-kinases activity was only marginally reduced. Furthermore, inhibitors of PI3-kinase were unable to block c-Kit/D816V-induced cell survival. These data suggest that PI3-kinase plays a role in c-Kit/D816V induced cell transformation which is independent of its lipid kinase activity. By mass spectrometry, we identified a heavily tyrosine-phosphorylated 110 kDa protein associated with p85 to be the p110δ subunit of PI3-kinase and the site of phosphorylation as Tyr 523, and the phosphorylation is not dependent on the lipid kinase activity of PI3-kinase. Knockdown of p110δ in c-Kit/D816V expressing Ba/F3 cells led to reduced cell survival and proliferation while the PI3-kinase activity remained almost intact. The c-Kit/D816V expressing Ba/F3 cells lost their ability to form colonies in semi-solid culture if p110δ was knocked down. Additionally, knockdown of p110δ λεδ τo ρεδυχεδ τυμoρ σιζε, τυμoρ ωειγητ ανδ blood vessel formation ωηεν c-Kit/D816V expressing Ba/F3 cells were subcutaneously injected into nude mice. Taken together, these results suggest a kinase independent role of p110δ in the D816Vmutant of c-Kit mediated cell transformation and suggest that p110δ could potentially be a selective therapeutic target for c-Kit/D816V expressing tumors.
Citation Format: Jianmin Sun, Sofie Mohlin, Alicia Lundby, Ulf Hellman, Sven Påhlman, Jesper V. Olsen, Lars Rönnstrand. Transformation by the D816V mutant of c-Kit is dependent on the PI3-kinase isoform p110δ but independent of its lipid kinase activi. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4301. doi:10.1158/1538-7445.AM2013-4301
Abstract 4307: Paradoxical activation of the MEK/ERK pathway promotes melanoma invasion and metastasis.
Authors: Sanchez-Laorden Berta , Viros Amaya , Girotti Maria Romina , Martin Matthew , Pedersen Malin , Zambon Alfonso , Niculescu-Duvaz Dan , Springer Caroline , Marais Richard 
Published: August 2014

Abstract
Melanoma is the most deadly form of skin cancer. An important feature of melanoma is its ability to metastasize and this contributes to its poor prognosis. RAS is mutated in ∼20% of melanomas and its downstream kinase BRAF is mutated in a further 50% of cases, these oncogenes regulate proliferation and survival through the MEK-ERK cascade. Selective inhibitors of BRAF such as vemurafenib have a remarkable clinical activity in patients with BRAF mutant melanomas with response rates of approximately 60-80%. In cells expressing activating BRAF mutations, vemurafenib blocks activation of the MAPK pathway. However, in cells expressing wild type BRAF and constitutively active upstream components that activate the MAPK pathway, BRAF inhibitors drive the paradoxical activation of this pathway. Here we show that kinase-dead BRAF promotes melanoma cell invasion and metastasis in the presence of oncogenic RAS. Notably, drugs that target BRAF mimic these effects and also induce RAS mutant melanoma cell invasion. The underlying mechanism is driven by paradoxical activation of the MEK-ERK pathway, resulting in increased secretion of the chemokine IL8 and subsequent secretion of extracellular matrix proteases, which induce invasion. We also show that BRAF inhibitors promote melanoma metastasis in an allograft model and that BRAF inhibitors induce invasion of drug-resistant BRAF mutant melanoma cells. We conclude that paradoxical activation of the MAPK pathway by BRAF inhibitors can drive melanoma invasion and metastasis in RAS mutant melanoma and in drug-resistant BRAF mutant melanoma cells.
Citation Format: Berta Sanchez-Laorden, Amaya Viros, Maria Romina Girotti, Matthew Martin, Malin Pedersen, Alfonso Zambon, Dan Niculescu-Duvaz, Caroline Springer, Richard Marais. Paradoxical activation of the MEK/ERK pathway promotes melanoma invasion and metastasis. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4307. doi:10.1158/1538-7445.AM2013-4307
Abstract 431: Nuclear WRAP53 is associated with positive response to radiotherapyand improved overall survival in head and neck squamous cell carcinoma.
Authors: Roberg Karin B. , Garvin Stina , Tiefenböck Katharina , Farnebo Lovisa , Farnebo Marianne 
Published: August 2014

Abstract
Purpose: Today there are no reliable predictive markers for radiotherapy response in head and neck squamous cell carcinoma (HNSCC), leading to both under-and over-treatment of patients, personal suffering and negative socio-economic effects. There is therefore a great need to develop new markers to provide patients with these tumors individualized and more effective treatment. WRAP53 is a natural antisense transcript to p53 that regulates levels of endogenous p53 mRNA and the induction of p53 in response to DNA damage. In addition, WRAP53 protein has been shown to be an essential component of nuclear organelles called Cajal bodies and involved in a variety of vital cellular functions such as splicing and telomerase activity. The aim of this study was to investigate WRAP53 as a potential predictive marker of radiotherapy response in head and neck squamous cell carcinoma (HNSCC) patients.
Materials and methods: Investigations were performed on tumor biopisies from patients classified as responders or non-responders to radiotherapy. Protein expression was examined using immunohistochemistry. After downregulation of WRAP53 by siRNA, assessment of intrinsic radiosensitivity was performed on two HNSCC cell lines.
Results: Nuclear WRAP53 expression was significantly associated with better response to radiotherapy (binary regression analysis, p = 0.029) and patients with nuclear WRAP53 had a significantly better survival (p = 0.014). Downregulation of WRAP53 with siRNA in vitro increased resistance to radiation (p &lt; 0.001).
Conclusions: Our study suggests that the nuclear location of WRAP53 is of importance in mediating tumor response to radiotherapy. Further studies are needed to investigate nuclear WRAP53 as a potential predictive marker of radiotherapy response in HNSCC.
Citation Format: Karin B. Roberg, Stina Garvin, Katharina Tiefenböck, Lovisa Farnebo, Marianne Farnebo. Nuclear WRAP53 is associated with positive response to radiotherapyand improved overall survival in head and neck squamous cell carcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 431. doi:10.1158/1538-7445.AM2013-431