bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 2352: Critical structural determinants of maspin necessary for maspin's subcellular localization, biological, and biochemical functions
Authors: Dzinic Sijana , Meng Yonghong , Sheng Shijie 
Published: February 2011

Abstract
Maspin (serpin B5), is the sole member of the serine protease inhibitor superfamily whose homozygous deletion results in embryonic lethality. Furthermore, maspin stands alone as the only non-inhibitory clade B serpin, despite the accumulating evidence for maspin's tumor suppressive effects in the progression of many types of cancer including breast, prostate, and lung. In addition, maspin is exclusively an epithelial-specific serpin with distinctive functions in the nucleus, cytosol, and the extracellular space. Our previous research discovered a novel maspin partnership with serine protease-like molecules such as the zymogen form of urokinase type plasminogen activator (pro-uPA) and histone deacetylase 1 (HDAC1). Structural analyses revealed several distinctive maspin motifs and domains that may be important for partnership of maspin with its target proteins as well as subcellular localization during tumor progression. In this study we aimed to determine if these structural motifs/domains of maspin, in addition to the earlier identified reactive center loop (RCL), are indeed important for maspin complex molecular interactions and biological activities. We utilized the prostate cancer cell line DU145, expressing low endogenous levels of maspin, to deliver wild type maspin and five rational maspin mutants by adenovirus. Different maspin mutants exhibited different affinities for the pro-uPA/uPAR complex on the cell surface and different affinities for intracellular HDAC1 and cytosolic heat shock protein 90 (HSP 90). Based on our biophysical evidence, a unique KDEL motif located downstream of the RCL domain, seems to play a critical role in dictating the subcellular localization and secretion of maspin. It has been shown that the majority of proteins that have a KDEL motif at the extreme C-terminus are endoplasmic reticulum resident proteins. Our study with maspin provides the first evidence that an internal KDEL motif may suffice to direct protein subcellular localization. This finding sheds a new light into the aberrant maspin subcellular localization during tumor progression.
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 2352.
Abstract 2359: Modeling the kinetics of metastatic progression
Authors: Eleswarapu Ananth , Hong Sung-Hyeok , Mendoza Arnulfo , Khanna Chand 
Published: February 2011

Abstract
Background: Metastasis has previously been described as an inefficient process - that is, many tumor cells do not survive the process of early metastasis. Metastatic cells must survive exposure to a foreign microenvironment, which can induce cell death, and to the circulation, which provides mechanical sheer stress and immune cells. By observing the kinetics of tumor growth in both ex vivo and in vivo models of metastasis, we hope to determine the relative contributions of circulatory flow and a foreign microenvironment to metastatic inefficiency.
Methods: We have developed a novel Pulmonary Metastasis Assay (PuMA), in which we observe the progression of fluorescence-tagged tumor cells in an ex vivo whole organ lung culture. The PuMA model exposes metastatic cells to a foreign microenvironment, but not to the circulation. The intravital videomicroscopy (IVVM) model exposes tumor cells to both the circulation and a foreign microenvironment. We performed serial assessments of tumor burden for the first seven days after arrival of metastatic cells to the lungs, to compare kinetics of tumor growth in both circulation-dependent and circulation-independent models of metastasis.
Results: Both the PuMA and IVVM models displayed metastatic inefficiency. The kinetics of metastatic inefficiency and recovery in the PuMA is similar to that seen in IVVM, with periods of 1) decline in tumor burden, 2) a plateau of several days, and 3) an escape, in which tumor burden grows beyond its baseline value. The magnitude of the initial decline in tumor burden, however, is greater in the IVVM model (85% decrease from baseline, at 24 hours after metastasis), than in the PuMA model (43% decrease at 24 hours).
Conclusions: These data indicate that there is a significant circulation-independent contribution to metastatic inefficiency (as seen in the decrease in tumor burden in our PuMA model), as well a circulation-dependent contribution (as seen in the greater decrease in our IVVM model). We believe that the PuMA model will be a valuable tool in studying signaling pathways that affect survival in foreign environment. Studies are now underway to use the PuMA, in combination with pharmaceutical and genetic targeting, to study the effect of individual signaling pathways on survival during early metastasis.
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 2359.
Abstract 2365: Cancer cell necrosis induces tumor growth by releasing HMGB1
Authors: Kitadai Yasuhiko , Luo Yi , Ohmori Hitoshi , Fujii Kiyomu , Sasahira Tomonori , Chihara Yoshitomo , Kuniyasu Hiroki 
Published: February 2011

Abstract
HMGB1 secreted from cancer cells accelerates invasion and metastasis of them. HMGB1 is released from necrotic cells. In the present study, we examined the differential effect on HMGB1 of apoptosis inducer (AI) from necrosis inducer (NI). CT26 mouse colon cancer cells were treated with trichostatin A (TSA) as AI or doxorubicin (DXR) as NI. DXR treatment increased HMGB1 in cultured medium (CM), whereas TSA did not increase. DXR-treated CM accelerated cell growth and invasion, whereas TSA-treated CM did not accelerate. CT26 cells were inoculated in the bilateral dorsal subcutaneous tissues of mice, which were treated with DXR or TSA by intratumoral injection. After treatment, serum HMGB1 concentrations by DXR and TSA treatments were 228 ng/ml and 21 ng/ml, respectively. After DXR treatment, contralateral tumor and the remnant tumor showed more pronounced growth or re-growth than those treated with TSA. By the lung metastasis model by caudal vein inoculation and the liver metastasis model by intrasplenic inoculation of CT26 cells, lung and liver metastasis was more enhanced by DXR treatment than those by TSA treatment. Metastasis enhancement by DXR treatment was abrogated by anti-HMGB1 co-treatment. Re-growth of linoleic acid-induced quiescent cells was found in DXR-treated mice but not in TSA-treated mice. These finding suggest that HMGB1 released from necrotic cancer cells treated with NI might enhance re-growth and metastasis of remnant cancer cells.
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 2365.
Abstract 2369: The adhesion molecule MCAM/MUC18 regulates the expression of Id-1 and contributes to melanoma invasion and metastasis
Authors: Zigler Maya , Villares Gabriel J. , Dobroff Andrey S. , Braeuer Russell R. , Wang Hua , Huang Li , Alani Rhoda M. , Bar-Eli Menashe 
Published: February 2011

Abstract
The acquisition of the metastatic phenotype of melanoma is associated with increase of the melanoma cell adhesion molecule MCAM/MUC18. We have previously shown that MUC18 plays a major role in promoting cellular invasion by regulating MMP-2 expression and activity. Here, we aim to establish the molecular mechanism by which MUC18 regulates melanoma cell invasion to promote tumor growth and metastasis. Utilizing lentivirus-incorporated small hairpin RNA, we stably silenced MUC18 expression in the metastatic melanoma cell lines A375SM and C8161 and conducted cDNA gene expression microarray analyses. We identified the Inhibitor of DNA Binding-1 (Id-1) to be down regulated by 5.7 fold as a result of MUC18 silencing. Id-1 expression has been shown to correlate with the progression of melanoma and to promote cell invasion by regulating MT1-MMP. We have found that Id-1 expression decreased significantly after MUC18 silencing in both A375SM and C8161, thereby corroborating our microarray results. Additionally, we found that MUC18 regulates Id-1 expression at the transcriptional level through regulation of ATF-3. ATF-3 was upregulated by 6 fold in our cDNA microarray analysis. ChIP analysis showed increase binding of ATF-3 to the Id-1 promoter after MUC18 silencing. Moreover, mutation of the ATF-3 binding site on the Id-1 promoter increased Id-1 promoter activity in MUC18 silenced cells. To further confirm the specificity of regulation of Id-1 and ATF-3 by MUC18, we rescued MUC18 and found that their expression was indeed inverted. Moreover, overexpression of Id-1 in MUC18 silenced cells demonstrated rescue of the invasive phenotype as well as increased activity of MMP-2 and the transcription of MT1-MMP. Collectively, our results suggest that MUC18 contributes to the malignant phenotype of melanoma via regulation of Id-1 expression.
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 2369.
Abstract 2370: A novel Src/Ezrin pathway regulates local invasion and metastasis of breast
Authors: Mak Hannah , Naba Alexandra , Varma Sonal , Meens Jalna , Arpin Monique , SenGupta Sandip , Elliott Bruce E. 
Published: February 2011

Abstract
The membrane cytoskeletal crosslinker, ezrin, is frequently over-expressed in human breast cancer, and is required for motility and invasion of epithelial cells. Our group recently showed that ezrin acts co-operatively with the non-receptor tyrosine kinase, Src, in transformation of epithelial cells, requiring phosphorylation of specific tyrosines on ezrin by Src (Srivistava et al. MBC, 16:1481-90, 2005; Naba et al. EMBO J. 27:38-50, 2008). We showed that Src binds to ezrin Y190 via its SH2 domain and that ezrin Y145 and Y477 are phosphorylated by Src. Expression of Y145F or Y477F ezrin mutants, which cannot be phosphorylated by Src, delays cell spreading of epithelial cells on fibronectin substratum. Furthermore, ezrin is required for metastasis in a breast tumor xenograft model (Elliott et al. BCR 7:R365-73, 2005). We therefore examined whether Src/ezrin interaction regulates invasion and metastasis of breast cancer, using a mouse breast tumor (AC2M2) xenograft model. Transplanted tumor cells expressing vector alone rapidly infiltrated into surrounding stroma, underlying abdominal muscle, visceral organs and metastasized to lung and other sites. Interestingly, both Y145F and Y477F ezrin mutants had little effect on primary tumor growth rate. However, Y145F ezrin showed a marked attenuating effect on pulmonary metastasis. Furthermore, transplanted mouse breast carcinoma cells over-expressing Y477F ezrin formed cohesive tumors that were circumscribed by normal stroma with no detectable infiltration into underlying muscle. Marked lymphovascular involvement, a prognostic indicator of relapse in clinically advanced human breast cancers, was evident in control tumors but not in tumors expressing Y477F ezrin. In a preliminary IHC analysis, total ezrin showed strong cytoplasmic and weak membranous staining in the cortical region of control primary tumors, but showed strong membranous and weak cytoplasmic staining in Y477F ezrin-expressing primary tumors. The cohesive phenotype of Y477F ezrin is likely a consequence of a defect in cell adhesion as described by Naba et al. Thus, the precise state of ezrin phosphorylation may elicit different effects on local invasion and metastasis. Our study implicates a role of the Src/ezrin pathway in regulating local invasion and metastasis of breast carcinoma cells, and provides a clinically relevant model for assessing the Src/ezrin pathway as a potential prognostic marker and treatment target for invasive breast cancer. (Funded by CBCRA 17374 and ARC 4823)
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 2370.
Abstract 2372: The metastasis efficiency modifier ribosomal RNA processing 1 homologue (RRP1B) is a chromatin-associated factor
Authors: Crawford Nigel P.S. , Yang Hailiu , Mattaini Katherine R. , Hunter Kent W. 
Published: February 2011

Abstract
Previous experiments using the polyoma middle T (PyMT) mouse model of mammary tumorigenesis have demonstrated that host germline variation modulates metastasis in breast cancer. Recent work using the PyMT model has identified novel metastasis susceptibility genes, an example of which includes Rrp1b (ribosomal RNA processing 1 homolog B). Over-expression of Rrp1b in a mouse mammary tumor cell line induces a gene expression signature that predicts survival in a well characterized Dutch breast cancer dataset. Additionally, a polymorphism was identified within human RRP1B (G1421A; P436L), which is associated with differential survival in multiple breast cancer cohorts.
Here we extend the analysis of RRP1B function by demonstrating that the Rrp1b activation gene expression signature accurately predicts survival in three additional publicly available breast carcinoma gene expression datasets. We have also investigated the mechanism of action of RRP1B by defining protein binding partners for this germline-encoded metastasis modifier. Tandem affinity purification demonstrated that RRP1B physically interacts with many nucleosome binding factors, all of which have been implicated in regulation of gene expression. Examples include the linker histone H1X, poly(ADP-ribose) polymerase 1, tripartite motif-containing 28 (TIF-1β/KAP1), and cold shock domain protein A. These interactions were confirmed by co-immunofluorescence (Co-IF) and co-immunoprecipitation (Co-IP). Additionally, co-IF experiments demonstrated that RRP1B is localized to the perinuclear and perinucleolar regions, which is a particularly interesting given that factors localized to these regions are often involved in heterochromatinization and gene silencing. Furthermore, co-IP and co-IF demonstrated that RRP1B interacts with heterochromatin protein-1α and acetyl-histone H4 lysine 5, suggesting that RRP1B may well regulate gene expression through interactions with heterochromatin and euchromatin.
Finally, we investigated the effects of ectopic expression of the 436Pro and 436Leu RRP1B allelic variants that have previously been associated with differential survival in breast cancer. Gene expression analyses demonstrate that, compared with ectopic expression of wildtype 436 Pro RRP1B in HeLa cells, the variant 436Leu RRP1B differentially modulates various transcription factors controlled by TRIM28 and CSDA. These data suggest that RRP1B, a tumor progression and metastasis susceptibility candidate gene, is potentially a dynamic modulator of transcription and chromatin structure.
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 2372.
Abstract 2376: Endothelial cells acquire abnormalities by factors from tumor cells
Authors: Kosuke Akiyama , Ohga Noritaka , Hida Yasuhiro , Akino Tomoshige , Hirata Naoya , Takuro Kurosu , Ishikawa Shuhei , Kondo Miyako , Maishi Nako , Kawamoto Taisuke , Inoue Nobuo , Shindoh Masanobu , Hida Kyoko 
Published: February 2011

Abstract
Recently, it has been reported that tumor microenvironment is important for tumor progression and metastasis. We have reported that tumor endothelial cells (TECs) differ from their normal counterparts, in many aspects. For example, TECs upregulate several genes, have cytogenetical abnormalities and respond differently to the growth factors such as epidermal growth factor receptor (EGFR) or some anticancer drugs (Hida et al., Cancer Res 2004, Cancer Sci 2008). In this study, we focused on the interaction between tumor cells and endothelial cells to address the mechanism of TEC abnormality.
We demonstrate that cultured conditioned medium (CM) from melanoma cells cause several phenotypic changes in Human Microvascular Endothelial Cells (HMVEC). The cell proliferation of HMVEC was stimulated by melanoma CM. Furthermore, the expression level of Multi Drug Resistance Gene (MDR) was upregulated by melanoma CM treatment and HMVEC got less sensitive to Paclitaxel. It was suggested that some factors released from melanoma cause abmormalities in HMVEC phenotype. The study to elucidate mechanisms of these results are ongoing.
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 2376.
Abstract 2377: Aminopeptidase A plays a role in VEGF-induced migration and proliferation through direct activation by VEGFR2 kinase activity
Authors: Sikkema Arend H. , de Bont Eveline S. , Diks Sander H. , Elst Arja ter , Ruijtenbeek Rob , Boender Piet J. , Hoving Eelco W. , Kamps Willem A. , den Dunnen Wilfred F. , Peppelenbosch Maikel P. 
Published: February 2011

Abstract
Tyrosine kinases pose attractive targets for cancer therapy, as their abnormal signaling activity results in enhanced proliferation, migration and angiogenesis. Previously we have been able to generate a comprehensive description of the biological kinase activity present in pediatric brain tumor tissue lysate by the application of a peptide microarray containing 144 different tyrosine kinase peptide substrates. To establish which peptide substrates present on the array are most sensitive and discriminative for VEGFR activity we measured the peptide phosphorylation applying recombinant VEGFR1, 2 and 3. Furthermore, a panel of recombinant kinases with highly diverse VEGFR sequence homology was included to study substrate specificity.
An aminopeptidase A (APA) derived peptide proved to be highly phosphorylated by VEGFR 1 and 2. No phosphorylation of this peptide could be observed applying any of the other kinases, arguing that this peptide is discriminative for VEGFR1 and 2 activity. In the peptide array data of pediatric brain tumors, phosphorylation of the APA peptide was observed, suggestive for VEGFR activation.
Based on these results we hypothesize that APA can be activated through direct phosphorylation by VEGFR2 and exert functional effects on endothelial cell proliferation and migration. To test this hypothesis we stimulated human umbilical vein endothelial cells (HUVECs) with VEGF and observed phosphorylation of Aminopeptidase A.
Literature states that inhibition of APA suppresses VEGF-induced migration and proliferation of endothelial cells and inhibits angiogenesis. Based on our data we hypothesize that these APA-mediated effects of VEGF stimulation are induced through direct activation by VEGFR2 kinase activity.
Concluding, peptide microarray technology is able to provide a selective view on tyrosine kinase activation, as has been shown here for VEGFR1 and 2.
Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.
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 2377.
Abstract 2379: Rap1 regulates angiogenesis in prostate tumors
Authors: Menon Jyotsana , Doebele Robert S. , Schulze-Hoepfner Frank T. , Rosner Marsha Rich 
Published: February 2011

Abstract
Prostate cancer is the most frequently diagnosed malignancy in men and the second leading cause of cancer related deaths in the United States of America. Advanced stage prostate cancer is associated with poor prognosis since no effective therapies are available when the disease has progressed into a hormone refractory state. This grim prognosis indicates the need for novel approaches to the treatment of advanced stage prostate cancer. One such therapeutic strategy is anti-angiogenic therapy, which interferes with the blood supply of the tumor instead of targeting tumor cells directly. Here we focus on the role of Rap1, a small GTPase homologous to Ras, and its upstream activator, Epac, a guanine nucleotide exchange factor for Rap1, in angiogenesis. In previous studies, we showed that treatment of primary human microvascular endothelial cells (HMVEC) with 8 CPT-2Me-cAMP (8-CPT), a specific agonist of Epac, or introduction of constitutively active Rap1 into these cells blocked VEGF-mediated chemotaxis and inhibited angiogenesis in mice. To test the efficacy of Epac/Rap1 activation in a tumor model, we injected an Epac agonist, 8-CPT, in a PC-3 human prostate tumor xenograft model. Surprisingly, although 8-CPT did not alter tumor growth in PC-3 cells, the drug significantly reduced tumor size in PC-3 cells expressing constitutively active Rap1. Tumor analysis showed an increase in HIF-1α,VEGF and CD31 immunostaining in Rap1-expressing tumors, and a significant decrease in their levels upon treatment of the mice with the Epac agonist 8-CPT. Similar reductions in VEGF and Glut-1 mRNA levels and HIF-1α protein were observed in Rap1-PC-3 cells following 8-CPT treatment when cells were cultured under hypoxic conditions. On the basis of these results, we propose that expression of Rap1 in the PC-3 human prostate tumor cell line promotes hypoxic induction of angiogenesis and increases the susceptibility of the cells to anti-angiogenic agents.
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 2379.