bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract B60: Analysis of the endocytic receptor MRC2 as a target for mesenchymal pancreatic cancer cells
Authors: Sinha Arkadeep , Watanabe Aprill , Winter Jordan , Allen Peter , Hostetter Galen , Haab Brian B. 
Published: August 2014

Abstract
The poor outcome of pancreatic cancer is hypothesized to be due to a subset of cancer cells that have elevated propensity to metastasize and are resistant to current chemotherapeutics. In vitro, the process of epithelial to mesenchymal transition (EMT) has been shown to grant cells with the aforementioned properties. Hence, it has been hypothesized that the process of EMT might have answers to controlling the metastatic cascade. Using gene expression microarrays, MRC2 expression was found to be upregulated when cells undergo EMT. MRC2 is a transmembrane protein known for its role in collagen degradation. Its role in the progression of metastatic pancreatic cancer and in vivo expression was assayed for validation as a drug target. MRC2 upregulation by TGF-β1 did not promote increased transition to a mesenchymal phenotype or migratory ability in the absence of a chemotactic gradient. However, using boyden chamber and matrigel invasion assays, it was observed that MRC2 affects chemotactic and invasive ability. Immunohistochemical analysis of over 250 pancreatic tumors revealed that MRC2 is upregulated in the cancer samples especially in the stromal compartment. MRC2 staining patterns were consistent with involvement in invasion, including elevation in individual, invading cancer cells and stromal elevations in peri-tumoral and poorly differentiated regions. Blinded immunohistochemical studies disclosed a correlation between elevated stromal MRC2 levels and poor prognosis. Flow cytometry is being used on primary tumors to confirm the dual stain results hinting towards the elevation of MRC2 on a subset of pancreatic cancer cells in vivo. Dual stains on tissue microarrays are also being used to identify the stromal cell population showing MRC2 elevation. Based on the role of MRC2 in chemotactic invasion and extracellular matrix remodeling, loss of cells expressing MRC2 might be a deterrent for metastasis. Since MRC2 is part of an endocytic pathway,upon confirmation of MRC2 as a marker of the mesenchymal cancer cells, it has the potential for use as an adjuvant targeted therapy for the treatment of pancreatic cancer.
Citation Format: Arkadeep Sinha, Aprill Watanabe, Jordan Winter, Peter Allen, Galen Hostetter, Brian B. Haab. Analysis of the endocytic receptor MRC2 as a target for mesenchymal pancreatic cancer cells. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B60.
Abstract B67: Metadherin mediates osteosarcoma invasion and metastasis
Authors: Zhu Limin , Buford Adrianna S. , Yang Yanwen , Zhang Pingyu , Wang Wei-Lien , Hughes Dennis P. 
Published: August 2014

Abstract
Osteosarcoma is the most common type of bone malignancy in children. It is a highly invasive mesenchymal tumor in which metastasis accounts for the vast majority of mortality and morbidity in patients. Understanding the mechanisms controlling metastasis in osteosarcoma and developing novel therapeutic options targeting metastasis are essential for improving patient survival in this disease. Recent studies have shown that Metadherin (MTDH) plays a key role in mediating metastasis in a variety of human cancers. This study examined the role of MTDH in osteosarcoma metastasis and elucidated the mechanisms underlying its oncogenic activity.
We used western blot, qPCR, and flow cytometry to measure the expression of MTDH in a panel of osteosarcoma cell lines. Patient-derived osteosarcoma samples were also examined for MTDH expression using immunohistochemistry. In parallel experiments we used MTDH-specific shRNA to down-regulate endogenous MTDH expression, and blocked cell surface MTDH by anti-MTDH antibodies. The impact of MTDH inhibition was assessed in vitro using migration assays and matrigel invasion assays. We also developed an osteosarcoma orthotopic xenograft model of NOD/SCID/IL2Rγ-deficient mice through intratibial injection of osteosarcoma cells with or without MTDH knockdown to study the relationship between MTDH expression and pulmonary metastatic potential of osteosarcoma cells.
Compared to normal human osteoblasts, all osteosarcoma cell lines tested displayed elevated MTDH expression as shown by western blot, qPCR and flow cytometry analyses. MTDH knockdown reduced migration and decreased invasion in matrigel. Inhibition of cell surface MTDH with an anti-MTDH antibody targeting the extracellular domain of MTDH also profoundly impeded osteosarcoma cell motility and invasiveness in vitro. In an orthotopic xenograft mouse model using CCHD cells, inhibition of MTDH delayed primary tumor growth and prohibited pulmonary metastasis. All mice in the control group developed lung metastases while fewer than 20% of the mice in the MTDH-knockdown group showed sign of metastasis at six weeks after inoculation. MTDH knockdown also reduced mean lung weight and mean number of pulmonary metastasis. Immunohistochemical analysis of tumor samples showed that lung metastases had elevated MTDH expression level compared to primary tumors.
Altogether these studies suggested that MTDH plays a critical role in promoting pulmonary metastasis of osteosarcoma and may serve as an attractive target for therapeutic intervention.
Citation Format: Limin Zhu, Adrianna S. Buford, Yanwen Yang, Pingyu Zhang, Wei-Lien Wang, Dennis P. Hughes. Metadherin mediates osteosarcoma invasion and metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B67.
Abstract B80: Deletion of Smad4 results in enhancement of lymphangiogenesis and node metastasis in head and neck squamous cell carcinoma
Authors: Oka Masako , Chen Xi , Wang Xiao-Jing , Lu Shi-Long 
Published: August 2014

Abstract
Lymph node metastasis is the single most important clinical prognostic factor in human head and neck squamous cell carcinoma (HNSCC). The 5-year overall survival is reduced by approximately 50% in HNSCC patients with node metastasis. Understanding the molecular mechanisms of lymph node metastasis in HNSCC is thus of pivotal importance for improving patient's survival. It has been shown that increased lymphatic vessel density in HNSCC tumors correlates with high metastasis rate to lymph nodes, suggesting a connection of enhancement of lymphangiogenesis and node metastasis in HNSCC. We have recently shown that deletion of Smad4, a tumor suppressor commonly inactivated in human HNSCC patients, in a genetically engineer mouse model developed head and neck squamous cell carcinomas with metastasis to cervical lymph nodes. Moreover, examining Smad4 expression and lymphangiogenesis marker podoplanin by immunohistochemistry in human HNSCC patients with node metastasis revealed a negative correlation between Smad4 and podoplanin, validating our initial findings from the Smad4 knockout mouse model. To further investigate the functional role of Smad4 in lymphangiogenesis and node metastasis, we restored Smad4 expression in a Smad4-deficient HNSCC cell line, Cal27. We then orthotopically injected both cell lines on the floor of mouth of nude mice, and observed tumor formation and cervical lymph node metastasis around 7 weeks. Analysis of tumor tissues showed that Smad4 restoration reduced lymphangiogenesis, as revealed by LYVE1, a lymphangiogenesis marker immunostaining. Furthermore, the rate of cervical lymph node metastasis is decreased upon the Smad4 restoration. The potential molecular mechanism of Smad4 in regulating lymphangiogenesis is currently undergoing. In conclusion, our studies have shown the deletion of Smad4 increases lymphangiogenesis and node metastasis from both HNSCC mouse models and human patient samples. Further investigation of the underneath molecular mechanism will be ultimately translated into novel therapeutical approaches for controlling lymph node metastasis and improving survival for human HNSCC patients.
Citation Format: Masako Oka, Xi Chen, Xiao-Jing Wang, Shi-Long Lu. Deletion of Smad4 results in enhancement of lymphangiogenesis and node metastasis in head and neck squamous cell carcinoma. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B80.
Abstract B88: Deficiency for endoglin in tumor vasculature weakens the endothelial barrier to metastatic dissemination
Authors: Cunha Sara I. 
Published: August 2014

Abstract
Therapy-induced resistance remains a significant hurdle to achieve long-lasting responses and cures in cancer patients. Here, we investigated the long-term consequences of genetically impaired angiogenesis by engineering multiple tumor models deprived of endoglin, a co-receptor for TGF-beta in endothelial cells actively engaged in angiogenesis. Tumors from endoglin-deficient mice adapted to the weakened angiogenic response and refractoriness to diminished endoglin signaling was accompanied by increased metastatic capability. Mechanistic studies in multiple mouse models of cancer revealed that deficiency for endoglin resulted in a tumor vasculature that displayed hallmarks of endothelial-to-mesenchymal transition; a process of previously unknown significance in cancer biology, but here shown to be associated with a reduced capacity of the vasculature to avert tumor cell intra- and extravasation. Nevertheless, tumors deprived of endoglin exhibited a delayed onset of resistance to anti-VEGF agents, illustrating the therapeutic utility of combinatorial targeting of multiple angiogenic pathways for the treatment of cancer.
Citation Format: Sara I. Cunha. Deficiency for endoglin in tumor vasculature weakens the endothelial barrier to metastatic dissemination. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B88.
Abstract B94: Gene expression profiling during EMT and MET identifies multiple transcription factors involved in the EMT transcriptional reprogramming
Authors: Voronkova Maria , Addison Joseph , Galeeva Renata , Denvir James , Chen Dongquan , Ivanov Alexey 
Published: August 2014

Abstract
Background and Objective: The Epithelial-to-Mesenchymal Transition (EMT) is a developmental program which is often reactivated in aggressive metastatic breast cancer. Several transcription factors (TFs), such as Snail and ZEB can act as master regulators of EMT, directly repressing the gene for E-cadherin. We sought to identify common gene expression signatures characteristic to both EMT and a reverse process, Mesenchymal-to-Epithelial Transition (MET).
Methods: Using Affymetrix Exon microarrays we characterized global gene expression changes in two cellular models: normal mammary epithelial HMLE cells induced to undergo EMT by expression of Snail1, Snail2 or ZEB1; and MDA-MB-231LN breast cancer cells induced to undergo MET by depletion of ZEB1 and ZEB2.
Results: We identified two large gene sets: 1) 1017 genes down-regulated during EMT and up-regulated during MET, which we designated as MET-specific; and 2) 438 genes up-regulated during EMT and down-regulated during MET, which we designated as EMT-specific. 14 TFs were found in the EMT category. Their functional validation showed that individual overexpression of several of these TFs in HMLE cells was sufficient to elicit partial EMT.
Discussion and Conclusions: Our comprehensive analysis of gene expression signatures common to EMT and MET identifies the EMT transcriptional program characteristic to invasive metastatic breast cancer.
Grant support: NIH NCRR grant P20 RR16440 and Susan G. Komen for the Cure grant KG110350.
Citation Format: Maria Voronkova, Joseph Addison, Renata Galeeva, James Denvir, Dongquan Chen, Alexey Ivanov. Gene expression profiling during EMT and MET identifies multiple transcription factors involved in the EMT transcriptional reprogramming. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr B94.
Abstract C27: Potential contributions of genome-stabilizing activity of NM23 to its metastasis suppressor function in melanoma
Authors: Jarrett Stuart G. , Novak Marian , Cook Gemma S. , Kaetzel David M. 
Published: August 2014

Abstract
Metastasis suppressor activity of NM23-M1 (NM23-H1 in human) in melanoma has been established using melanoma cell lines in culture and, more recently, in a model of UV-induced melanoma using NM23 knockout mice. While NM23-M1/H1 is clearly a suppressor of melanoma cell motility, we have recently shown it also exhibits genome-stabilizing activity, promoting repair of both spontaneous and UV-induced DNA damage via the nucleotide excision repair pathway. These findings suggest NM23 proteins may also inhibit metastasis by suppressing acquisition of metastasis-driving mutations and other genomic aberrations. To dissect the molecular mechanisms through which NM23 contributes to genomic stability, this study focused on the double-strand break repair (DSBR) pathway. All members of the NM23 family of proteins possess nucleoside diphosphate kinase (NDPK) activity, which could enhance nucleotide availability during polymerase-mediated repair, and 3'5' exonuclease activity which has been suggested to be critical in the non-homologous end-joining (NHEJ) pathway of DSBR. To first determine whether NM23 is indeed recruited to DSBs, these lesions were produced in the human melanoma cell line WM793 using a tamoxifen-inducible form of the restriction endonuclease I-PpoI via a retroviral vector. Induction of I-PpoI-catalyzed DSBs resulted in recruitment of both endogenous NM23 and recombinant Flag-tagged H1 (Flag-H1) to a known I-PpoI cleavage site within 30 min, as demonstrated by chromatin immunoprecipitation. The rapid appearance of NM23-H1 at the DSB coincided with that of the damage sensor ATM, and disappearance of histone 2B. Forced expression of NM23-H1 resulted in significantly enhanced repair of the known I-PpoI-induced DSB site, shown using a quantitative PCR across the lesion, indicating a functional contribution of the protein to DSBR. Induction of DSBs resulted in colocalization of Flag-H1 with γ-histone 2AX within small intranuclear foci, also consistent with recruitment of NM23-H1 directly to DSB lesions. Induction of DSBs using the DNA topoisomerase II inhibitor etoposide resulted in rapid nuclear colocalization within 5 minutes of Flag-H1 and ribonucleotide reductase, suggesting cooperative actions of these two enzymatic activities during DSBR. These studies are the first to demonstrate recruitment of NM23-H1 directly to sites of DNA damage, and suggest the possibility that NM23 deficiency in melanoma and other human cancers accelerates the acquisition of metastasis-driving mutations during cancer progression.
Citation Format: Stuart G. Jarrett, Marian Novak, Gemma S. Cook, David M. Kaetzel. Potential contributions of genome-stabilizing activity of NM23 to its metastasis suppressor function in melanoma. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr C27.
Abstract C33: Akt-EphA2 signaling axis promotes diffuse infiltrative invasion of glioma in vivo and regulates glioma stem cell properties
Authors: Miao Hui , Gale Nickolas W. , Wang Bingcheng 
Published: August 2014

Abstract
Glioblastoma multiforme (GBM) is among the most lethal types of human cancer. Diffuse infiltrative invasion is a major cause for the poor prognosis; however the underlying mechanisms remain to be fully elucidated. Using human glioblastoma stem-like cells (GSCs) that recapitulate the highly invasive propensity of primary glioblastomas, we find that ephrin receptor A2 (EphA2) critically regulates glioma invasion in vivo. ShRNA knockdown of EphA2 markedly diminished intracranial invasion. Conversely overexpression of EphA2 enhanced the invasion. The effects required Akt-mediated phosphorylation of EphA2 on serine 897. In vitro, the Akt-EphA2 signaling axis in GSCs was maintained in the absence of ephrin-A ligands and disrupted upon ligand stimulation. In accordance, GSCs invasion was significantly increased in brain slices from the Efna1;Efna3;Efna4 triple knockout mice compared with those from the wild type littermates. Mechanistically overexpression of wild type but not S897A mutant EphA2 promoted GSC self-renewal, which was correlated with the increased expression of stem cell markers. Taken together, the results show that EphA2 stimulates glioma invasiveness in vivo in cooperation with Akt, which is negatively regulated by ephrin-As in tumor microenvironment.
Citation Format: Hui Miao, Nickolas W. Gale, Bingcheng Wang. Akt-EphA2 signaling axis promotes diffuse infiltrative invasion of glioma in vivo and regulates glioma stem cell properties. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr C33.
Abstract C41: MenaINV dysregulation of receptor tyrosine kinase signaling
Authors: Oudin Madeleine J. , Hughes-Alford Shannon K. , Miller Miles , Asokan Sreeja B. , Bear James E. , Lauffenburger Doug A. , Gertler Frank B. 
Published: August 2014

Abstract
Mena, an actin regulatory protein, is upregulated in human breast cancer and its expression is associated with increased metastatic progression. An invasion-specific isoform, MenaINV, is upregulated selectively in invasive tumor cells and increases invasion and metastasis by potentiating tumor cell responses to EGF. MenaINV causes dysregulation of the tyrosine phosphatase PTP1B, leading to increased phosphorylation of EGFR and other downstream targets. We investigated whether MenaINV could similarly promote invasion through dysregulation of signaling downstream of other receptor tyrosine kinases (RTKs). The behavior of MDA-MB-231 triple negative breast cancer cells stably expressing MenaINV or the other cannonical, broadly expressed Mena lacking the “INV” exon was measured after growth factor treatment in two migration assays: a 2D protrusion assay on matrigel and collagen coated coverslips and a 3D invasion assay into collagen gels. We found that expression of MenaINV sensitized responses to other EGFR ligands including HB-EGF and amphiregulin. In addition, MenaINV expression enhanced responses mediated by two other RTKs associated with tumor progression, Met and IGFR, both known PTP1B substrates. Cells expressing MenaINV respond to 20-fold lower concentrations HGF and IGF than control cells. However, there was no effect of MenaINV on responses to the ERBB3 ligand neuregulin and the chemokine SDF-1.
Recently we reported that Mena can regulate cell motility in fibroblasts via its interaction with α5β1 integrin, which is known to co-traffic with EGFR and other RTKs to regulate invasion in tumor cells expressing mutant p53 or upon inhibition of αvβ3. We asked whether the direct interaction of Mena with α5β1 also contributes to invasion. Disrupting the interaction between the Mena isoforms and α5β1 in MDA-MB-231 cells affected how cells responded to EGF in a 3D collagen gel. In addition, fibroblasts that were null for Mena were unable to respond to a fibronectin gradient in a haptotaxis assay.
Overall, these results suggest that the effects of MenaINV on invasion and metastasis could be mediated via different RTKs, as well as through direct interaction with integrins and the extracellular matrix. Experiments are currently underway to investigate how MenaINV regulates signalling downstream of these RTKs and integrins, to understand the molecular mechanism underlying the pro-metastatic effect of MenaINV.
Citation Format: Madeleine J. Oudin, Shannon K. Hughes-Alford, Miles Miller, Sreeja B. Asokan, James E. Bear, Doug A. Lauffenburger, Frank B. Gertler. MenaINV dysregulation of receptor tyrosine kinase signaling. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr C41.
Abstract C71: DEAR1 orchestrates selective control over the epithelial-mesenchymal transition axis of TGFβ's function
Authors: Chen Nanyue , Balasenthil Seetharaman , Cao Yu , Killary Ann M. 
Published: August 2014

Abstract
Little is known about the cellular mechanisms that govern the context dependent roles of the critical cytokine TGFβ, which functions in breast cancer as either a tumor suppressor to restrict proliferation in early stage disease or a master driver of epithelial-mesenchymal transition during invasion and metastasis. We previously reported the discovery of the TRIM protein DEAR1(annotated as TRIM62) as a gene that is mutated and homozygously deleted in early onset breast cancers and functions as a dominant regulator of acinar morphogenesis in three dimensional (3D) culture, suggesting that DEAR1 is a novel tumor suppressor that regulates both polarity and tissue architecture. Herein we demonstrate that loss of function of DEAR1 in immortal mammary epithelial cells (HMECs) resulted in a failure of acinar morphogenesis in the presence of TGFβ and was required for TGFβ-induced cell migration, invasion and anoikis resistance, all of which key indicators of TGFB-driven EMT. However, DEAR1 loss did not affect TGFβ-induced proliferation suppression, indicative that DEAR1 exerts a selective negative control over TGFβ-mediated EMT oncogenic functions while preserving TGFβ's growth suppressive functions. These results indicate that the mechanisms governing the dual functions of TGFβ are separable and that it is possible to selectively block the deleterious arm of TGFβ's function. In addition, DEAR1 suppressed TGFβ-SMAD3 signaling by binding to and ubiquitinating SMAD3, the major effector of TGFβ-meditated EMT. Furthermore, treatment of DEAR1 knockdown HMECs with a SMAD3 inhibitor or SMAD3 shRNA rescued the DEAR1 loss of function phenotype as evidence by the downregulation of expression of EMT markers and inhibition of migration induced by TGFβ in strong support that DEAR1 specifically blocks TGFβ-induced EMT through the regulation of SMAD3 protein levels and suggestive that results could have clinical significance for stratifying breast cancers for targeted therapies aimed at the oncogenic arm of this pathway. These data demonstrate a significant role for DEAR1 in the control of TGFβ-induced EMT as well as present a novel paradigm for regulation of one of the most important pathways aberrant in human breast cancer.
Citation Format: Nanyue Chen, Ret., Seetharaman Balasenthil, Yu Cao, Ann M. Killary. DEAR1 orchestrates selective control over the epithelial-mesenchymal transition axis of TGFβ's function. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Invasion and Metastasis; Jan 20-23, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;73(3 Suppl):Abstract nr C71.