bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 4972: In vivo whole genome shRNA screen reveals novel targets to block cancer metastasis
Authors: Stoletov Konstantin , Bond David , Leong Hon Sing , Woolner Emma , Raha Srijan , Robertson Amy , Wong Francis , Zijlstra Andries , Lewis John D. 
Published: May 2015

Abstract
The formation of invasive, rapidly growing metastatic lesions is a critical step in cancer metastasis, the cause of more than 90% of cancer deaths. Development of novel therapeutic approaches that block the invasion step of metastasis is one of the highest priorities for clinical cancer research. For this reason we completed the first genome-wide in vivo shRNA screen for genes that directly contribute to invasive metastatic lesion formation. Using state of the art intravital imaging, we identified over fifty novel regulators of invasive metastatic colony formation in vivo. Interactome analysis links these genes to key cellular processes including: transcriptional regulation of gene expression, mRNA processing and cytoskeletal remodeling. The target list was then prioritized based on clinical gene expression profiles that negatively correlated with key cancer endpoints including metastasis, cancer-specific and overall survival. Pharmacological and shRNA-mediated knockdown of the high priority targets in human cancer cell lines such as prostate cancer and melanoma specifically blocked cancer cell migration and invasion in vitro and in vivo. Moreover, shRNA-mediated knockdown of these genes blocked human cancer cell metastasis in the avian embryo and mouse preclinical models of metastasis. Finally, immunohistochemical analysis on clinical prostate cancer and melanoma tissue samples showed strong correlation with disease progression and metastasis. In summary, we have identified numerous novel genes that that are functionally involved in cancer invasion and metastasis that may serve as predictive markers for disease aggressiveness and represent exciting new pharmacological targets to block cancer invasion and metastasis.
Citation Format: Konstantin Stoletov, David Bond, Hon Sing Leong, Emma Woolner, Srijan Raha, Amy Robertson, Francis Wong, Andries Zijlstra, John D. Lewis. In vivo whole genome shRNA screen reveals novel targets to block cancer metastasis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4972. doi:10.1158/1538-7445.AM2014-4972
Abstract 4978: Targeting of phosphatidylserine by monoclonal antibodies enhances activity of immune checkpoint inhibitors in tumors
Authors: Gong Jian , Nguyen Van , Yin Shen , Archer Rich , Hutchins Jeff , Freimark Bruce 
Published: May 2015

Abstract
Phosphatidylserine (PS) is a phospholipid normally residing in the inner leaflet of the plasma membrane and becomes exposed on tumor vascular endothelial cells (ECs) and tumor cells. PS exposure becomesenhanced in response to chemotherapy, irradiation, and oxidative stresses in the tumor microenvironment. PS exposure in tumors promotes an immunosuppressive microenvironment which includes the recruitment of myeloid derived suppressor cells (MDSCs), immature dendritic cells, and M2-like macrophages as well as the production of anti-inflammatory cytokines. Binding of PS targeting antibodies on tumor endothelial cells, tumor cells and their secreted microparticles triggers an Fc-FcR mediated pro-inflammatory cellular and cytokine response that reverses the immunosuppressive PS meditated checkpoint, thereby enhancing anti-tumor immunity. A chimeric PS-targeting antibody, bavituximab, is being used in combination with chemotherapy to treat patients with solid tumors in multiple late-stage clinical trials. Using multiple syngeneic tumors in immune competent mice, we demonstrate PS targeting antibodies enhance the anti-tumor activity of anti-CTLA-4 and anti-PD-1 antibodies. Tumor growth inhibition correlates with infiltration of immune cells in tumors and induction of adaptive immunity. The combination of these mechanisms promotes strong, localized, anti-tumor responses without the side-effects of systemic immune activation.
Citation Format: Jian Gong, Van Nguyen, Shen Yin, Rich Archer, Jeff Hutchins, Bruce Freimark. Targeting of phosphatidylserine by monoclonal antibodies enhances activity of immune checkpoint inhibitors in tumors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4978. doi:10.1158/1538-7445.AM2014-4978
Abstract 498: Blunting the radical scavenging property of mitochondria-targeted, triphenylphosphonium-linked antioxidants failed to mitigate their anti-proliferative and antitumor effects
Authors: Cheng Gang , Zielonka Jacek , Joseph Joy , Kalyanaraman Balaraman 
Published: May 2015

Abstract
Reactive oxygen species (ROS), including superoxide and hydrogen peroxide, are implicated in cancer cell proliferation. Therefore, strategies to mitigate ROS levels were proposed as a viable mechanism to inhibit cancer cell proliferation. As mitochondria are believed to be a major contributor to intracellular ROS production, mitochondria-targeted antioxidants (MTAs) (e.g., Mito-Q, Mito-CP, Mito-Vitamin-E or Mito-chromanol) were successfully used to stop proliferation and kill cancer cells in vitro and attenuate tumor growth in vivo. MTAs also inhibited mitochondrial oxygen consumption and ATP production. In this study, we tested whether the antioxidant moiety and related antioxidant function of MTAs or other mitochondrial mechanism is responsible for inhibiting tumor cell proliferation and resulting cytotoxicity. To this end, we compared the anti-proliferative and antitumor effects of Mito-CP, a mitochondrially-targeted nitroxide exhibiting superoxide dismutase (SOD)-like activity, and a synthetic analog of Mito-CP (Mito-CP acetamide), lacking the nitroxide moiety and SOD-like activity. Both Mito-CP and Mito-CP acetamide were equally potent in different cancer cell types (breast, pancreatic, colon, skin, bladder and lung). Additionally, both compounds inhibited mitochondrial function and decreased intracellular ATP levels to the same extent. We conclude that MTAs such as Mito-CP, Mito-Vitamin-E exert their antiproliferative effects in cancer cells due to mitochondrial localization and targeting cellular bioenergetics and not due to their antioxidative activity. Results from this study strongly question the present dogma on mitochondrial ROS involvement in cancer cell proliferation.
Citation Format: Gang Cheng, Jacek Zielonka, Joy Joseph, Balaraman Kalyanaraman. Blunting the radical scavenging property of mitochondria-targeted, triphenylphosphonium-linked antioxidants failed to mitigate their anti-proliferative and antitumor effects. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 498. doi:10.1158/1538-7445.AM2014-498
Abstract 4994: E2F1 deficiency causes increased migration through upregulation of MYLK
Authors: Meng Peng , Ghosh Rita 
Published: May 2015

Abstract
Malignant melanoma is an extremely aggressive disease with high metastatic potential. Several studies have shown that the transcription factor E2F1 is overexpressed in melanoma. E2F1 belongs to the family of E2F transcription factors; is more abundant in melanoma cells than in normal melanocytes, which highlights its relevance to melanoma biology. E2F1 participates in a variety of biological processes such as proliferation, apoptosis, development, differentiation, DNA damage and repair, oxidative metabolism, and self-renewal by virtue of its transcriptional activator functions. However, its role in many of these biological processes in melanoma is not yet fully addressed. In this study, we show that E2F1 deficiency increased migration and invasion of melanoma cells, which was associated with increased MYLK at both RNA and protein level. MYLK is a calcium-calmodulin (Ca2+//CaM)-dependent myosin light chain kinase, which phosphorylates Ser-19 of myosin II after activation. This process is implicated in the regulation of smooth muscle contraction. In non-smooth muscle, MYLK is known to be involved in many inflammatory diseases through regulation of tight junction and intestinal epithelial barrier function. MYLK is also involved with proliferation and migration in cancers of the breast, prostate and colon, but its expression and role in melanoma cells is unknown. ML-7, the specific inhibitor for MYLK abrogated the increased migration and invasion due to E2F1 deficiency. Transient knockdown of MYLK also significantly abrogated the increased migration and invasion from E2F1 deficiency. Our results strongly suggest that E2F1 deficiency enhanced migration and invasion through regulating MYLK expression. We also found increased pERK in E2F1 knockdown cells, which suggest that ERK activation may be involved in the up-regulation of MYLK. All of our data taken together suggests that E2F1-mediated inhibition of melanoma cell migration occurs through a complex cross-talk between E2F1-ERK-MYLK and is not through a simple linear relationship between signaling molecules. Supported by R21 CA125719 (RG).
Citation Format: Peng Meng, Rita Ghosh. E2F1 deficiency causes increased migration through upregulation of MYLK. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4994. doi:10.1158/1538-7445.AM2014-4994
Abstract 4995: Role of MICAL1 in NEDD9 invasive signaling
Authors: Holmes Casey O. , Brock Amanda M. , Sobash Philip T. , Tiedeken Jessica A. , Rosenzweig Steven A. 
Published: May 2015

Abstract
Metastasis is the final step leading to patient death in most solid tumors, including head and neck squamous cell carcinoma (HNSCC). For metastasis to proceed, tumor cells must become mobile and invasive, losing their communal behavior. A goal of our work is to delineate the downstream effectors of growth factor signaling pathways that contribute to invasion. Using a phosphotyrosine proteomics screen we previously identified neural precursor cell expressed, developmentally down-regulated 9 (NEDD9; CasL) as a mediator of VEGF and IGF-1 signaling to invasion in HNSCC cells. NEDD9 tyrosine phosphorylation led to matrix metalloproteinase9 (MMP9) expression and secretion, invadopodia formation and enhanced invasion. To determine the molecular details of NEDD9 protein:protein interactions leading to invasion, we have generated a series of NEDD9 substrate domain tyrosine (Y to F, YXXP) and SH3 domain mutants. Mutation of all 13 YXXP motifs to FXXP blocked NEDD9 tyrosine phosphorylation, MMP9 expression and invadopodia formation. Of note, we found that NEDD9 co-immunoprecipitated with Molecule Interacting with CasL 1 (MICAL1). To further define this interaction and its downstream impact, stable NEDD9 or MICAL1 silenced HNSCC cell lines expressing select shRNAs were generated, with each exhibiting reduced migration and invasion. MICAL shRNA transfected cell lines also exhibited decreased MMP9 secretion, consistent with our findings that lack of MICAL1 decreases cell invasion and with findings of other labs that MICALs interact with Rab proteins altering intracellular trafficking. Further, we have verified that MICAL1 and NEDD9 form complexes in cells based on coimmunoprecipitation analyses. Better understanding of this pathway will undoubtedly lead to the identification of novel therapeutics for the prevention of invasion and metastasis. Supported by NIH R01CA134845 (SAR), P30 CA138313 and NIH/NCRR UL1 TR000062/TL1 TR000061 from the South Carolina Clinical & Translational Research Institute (COH).
Citation Format: Casey O. Holmes, Amanda M. Brock, Philip T. Sobash, Jessica A. Tiedeken, Steven A. Rosenzweig. Role of MICAL1 in NEDD9 invasive signaling. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4995. doi:10.1158/1538-7445.AM2014-4995
Abstract 500: Heat shock protein gp96 regulates LRP6-Wnt-Survivin pathway and myeloma progression
Authors: Hua Yunpeng , White-Gilbertson Shai , Kellner Joshua , Rachidi Saleh , Li Zihai , Liu Bei 
Published: May 2015

Abstract
Multiple myeloma (MM) is an incurable plasma cell neoplasm whose pathogenesis is closely linked to dysregulated unfolded protein response (UPR) in the endoplasmic reticulum (ER). Constitutive activation of UPR in mice causes myeloma, as demonstrated by transgenic expression of a master UPR transcription factor XBP1s. However, the underlying mechanism remains unknown. Heat shock protein gp96 (grp94) is an ER paralogue of the cytosolic HSP90 and its expression can be induced by the accumulation of misfolded proteins. As one of the most abundant proteins in the ER lumen, gp96 is a key downstream chaperone in the ER to mediate UPR. However, the roles of individual ER HSPs in plasma cell and myeloma have not been reported. In this study, we demonstrated that the persistence of plasma cells as well as the development of myeloma in XBP1s-transgenic mice is critically dependent on gp96 in vivo. Furthermore, we demonstrated that gp96 silencing in human MM cells led to significant reduction of surface expression of Wnt coreceptor LRP6 and the downstream canonical Wnt signaling. gp96 knockdown causes severe compromise in MM cell growth which can be significantly rescued by GSK3β inhibitors. In the absence of gp96, MM cells undergo mitotic catastrophe and apoptosis which correlated with decreased expression of survivin, a downstream molecule of Wnt in controlling cell survival. This is the first study to uncover the critical roles of gp96 in the initiation and progression of multiple myeloma, suggesting that blockade of gp96 is a novel therapeutic strategy against multiple myeloma.
Citation Format: Yunpeng Hua, Shai White-Gilbertson, Joshua Kellner, Saleh Rachidi, Zihai Li, Bei Liu. Heat shock protein gp96 regulates LRP6-Wnt-Survivin pathway and myeloma progression. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 500. doi:10.1158/1538-7445.AM2014-500
Abstract 5004: Iqgap2 is downregulated in colorectal cancer (crc) and involved in cellular migration
Authors: Gröschl Benedikt , Bettstetter Marcus , Widmann Tamara , Hofstädter Ferdinand , Dietmaier Wolfgang 
Published: May 2015

Abstract
IQGAP2 is a member of three IQGAP scaffolding proteins and involved in cytoskeletal reorganization and adhesion of cells. It has been described as a putative tumor suppressor affecting tumor development and progression. Our aim in this study was to analyze the role of IQGAP2 in colorectal cancer (CRC).
By means of microarray analyses we previously found IQGAP2 expression to be downregulated in CRC and suppressed by Maspin. Here we measured IQGAP2 expression by RT-qPCR in 17 MSI-H (high microsatellite instability) and 19 MSS (microsatellite stable) CRCs as well as in three MSI and three MSS CRC cell lines, respectively. Furthermore, we analyzed the methylation status of the IQGAP2 promoter and studied the subcellular localization of the IQGAP2 protein. Using an in vitro system for overexpressing and silencing IQGAP2 we investigated the effect of IQGAP2 on cellular migration applying Real-Time Cell Analyzer (RTCA) technology.
Stably overexpressing Maspin transfected CRC cell line SW480 showed IQGAP2 loss on mRNA and protein level. IQGAP2 expression was reduced in 86% (30/36) of tumors compared to normal tissue (p&lt;0.001) and lower in MSS tumors compared to MSI tumors (p=0.039). Consistently, IQGAP2 mRNA levels were also downregulated in CRC cell lines. None of the cell lines, tumor or normal tissue samples analyzed showed IQGAP2 promoter methylation. Immunofluorescence analysis of CRC cells revealed IQGAP2 distribution in plasma membranes and more intensely in areas of cell-cell contacts. Migration assays showed increased cellular migration after IQGAP2 knockdown and impaired migration after overexpression of IQGAP2.
We provide evidence that IQGAP2 expression is regulated by Maspin and may have an important effect on cellular migration in colorectal cancer.
Citation Format: Benedikt Gröschl, Marcus Bettstetter, Tamara Widmann, Ferdinand Hofstädter, Wolfgang Dietmaier. Iqgap2 is downregulated in colorectal cancer (crc) and involved in cellular migration. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5004. doi:10.1158/1538-7445.AM2014-5004
Abstract 5006: A 3-dimensional cell invasion assay compatible with high content screening
Authors: Fronczak Jennifer A. , Gajeski Matthew S. , Beckman Erica L. , Vollmer Laura , Vogt Andreas , Krishnan Gopal 
Published: May 2015

Abstract
The transition from non-invasive phenotype to invasive phenotype of tumor cells marks the switch from a benign tumor that can be successfully treated via surgery to a more malignant form of cancer. Understanding the mechanisms underlying this hallmark event, which enables tumor cells to invade through extracellular matrix, is critical for discovering pathways and new targets to develop anti-metastatic strategies. Previously, we developed a cell based assay for the study of cell migration in 96-well plates. A self-dissolving biocompatible gel (BCG) is utilized to form uniformly sized, cell-free detection zones in collagen I coated 96-well plates. When cells are seeded into these wells, they pattern in an annular monolayer surrounding the BCG. Once the BCG dissolves, an overlay of collagen I is applied to the assay wells, following which cells can invade in 3-dimensions into the detection zone previously occupied by the BCG. This “Oris™ Pro” cell invasion assay presents a straightforward, accessible and quantifiable cell method to study cell invasion, and can be used for example to evaluate candidate drugs targeting tumor invasion. Microscopic visual assessment of cell invasion in the presence of inhibitors is made by use of cell stains at multiple time-points. In this study we demonstrate the use of this assay platform for robust and reproducible analysis of HT-1080 and MDA- MB-231 cell invasion in 3-D. The presentation will discuss (i) factors that influence cell invasion, including density of collagen overlay and time; (ii) microscopic monitoring of cell invasion in the presence of potential inhibitors throughout the duration of the experiment; and (iii) the qualitative and quantitative readouts that can be obtained using this 3-dimensional cell invasion assay.
Citation Format: Jennifer A. Fronczak, Matthew S. Gajeski, Erica L. Beckman, Laura Vollmer, Andreas Vogt, Gopal Krishnan. A 3-dimensional cell invasion assay compatible with high content screening. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5006. doi:10.1158/1538-7445.AM2014-5006
Abstract 5007: RSK isoform regulation of migration and invasion in glioblastoma
Authors: Prechtl Amanda , Sulzmaier Florian , Jiang Pengfei , Kesari Santosh , Ramos Joe 
Published: May 2015

Abstract
Glioblastoma (GBM) is associated with high mortality in patients due in large part to the highly migratory and invasive nature of glioma cells. The 90kDa ribosomal S6 Kinases (RSKs) are a family of serine/theronine kinases that are an integral component of the extracellular signal regulated kinase (ERK)/ mitogen activated protein kinase (MAPK) pathway, which is highly active in many types of cancer. The RSK family contains four human isoforms (RSK1-4) that regulate a variety of cellular processes including cell proliferation, survival, and motility, however a role for individual RSK isoforms in GBM cell invasion has not clearly been defined. Here, we analyze the roles of RSK1-4 in glioblastoma cell invasion. Using transwell assays and a novel three-dimensional tumor spheroid assay, we found that the highly specific RSK inhibitor, BI-D1870, decreases glioblastoma cell motility and invasion. To identify which RSK isoform was associated with this decrease in invasion, we knocked down each RSK isoform using lentiviral mediated shRNA transduction and found that different RSK isoforms could decrease invasion depending on the cell line, without significantly affecting proliferation. Additionally, RSK2 knockdown in primary patient-derived glioblastoma cells decreased cell migration, and Kaplan-Meier analysis revealed that patients overexpressing RSK2 had a poorer prognosis compared to those expressing normal levels of RSK2. Our studies support a differential role for individual RSKs in glioblastoma invasion, suggesting that targeting RSKs may provide an effective means for the treatment of glioblastoma.
Citation Format: Amanda Prechtl, Florian Sulzmaier, Pengfei Jiang, Santosh Kesari, Joe Ramos. RSK isoform regulation of migration and invasion in glioblastoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5007. doi:10.1158/1538-7445.AM2014-5007
Abstract 5018: Combination immunotherapy with PD-L1 blockade and Poly I:C in a murine breast cancer model
Authors: Soliman Hatem , Nelson Ashley R. 
Published: May 2015

Abstract
Background: Programmed death ligand 1 (PDL1) is commonly expressed on the surface of many tumor cells, including breast cancer. The activity of tumor infiltrating lymphocytes (TIL) is inhibited by PDL1. Blocking PDL1 with monoclonal antibodies can prevent this immune suppression and enhance anti-tumor activity. Polyinosinic-polycytidylic acid (Poly I:C) is a Toll like receptor 3 (TLR3) agonist which was shown to synergize with anti-PDL1 antibodies in a B16 melanoma model (Celis et. al, Blood 2010). We sought to investigate if synergy could be demonstrated in a murine breast cancer model.
Methods: Five week old female BALB/c mice were injected with 3x106 4T1 cells in a mammary fat pad and divided into 4 groups with ten mice/group (PBS control, 200µg anti-PDL1 antibody (10F.9G2 Bioxcell) D1,5 IP, 50µg Poly I:C (Invivogen) D1,6,11,16 IV, anti-PDL1+Poly I:C). Treatment started when tumors were palpable and measured twice weekly. The mice were sacrificed 20 days later with tumors, spleens, and lymph nodes harvested. Tumors were measured twice weekly. All experiments were carried out under approved IACUC #4277R per institutional guidelines. Statistical analysis performed using Prism Graphpad.
Results: Mean tumor measurements (mm2) at day 20 for control=207.5, anti-PDL1=188.5, Poly I:C=182.6, anti-PDL1+Poly I:C=149.4. Two way ANOVA was statistically significant at p&lt;.0001. Mean tumor weight (gm) at day 20 of anti-PDL1+Poly I:C=.99 vs control=1.23 p=.002 using t test.
Conclusions: The combination of anti-PDL1 and Poly I:C TLR3 agonist demonstrates improved anti-tumor activity against established 4T1 orthotopic murine breast tumors compared to control or either agent alone. Characterization of TIL infiltrates in tumor specimens and immune activation in harvested lymphocytes is ongoing and will be presented. This data provides preliminary evidence supporting continued investigation of the combination of PDL1 and Poly I:C immunotherapy for breast cancer.
Citation Format: Hatem Soliman, Ashley R. Nelson. Combination immunotherapy with PD-L1 blockade and Poly I:C in a murine breast cancer model. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5018. doi:10.1158/1538-7445.AM2014-5018