bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 5053: Tumor cell clustering - Identification of new regulators
Authors: LOBJOIS Valérie , Ducommun Bernard 
Published: July 2016

Abstract
Cancer cell aggregation is a key process involved at different stages of tumor evolution, during primary tumor growth, metastatic cells dissemination and secondary tumor evolution. Thus, understanding principles that govern and modulate the ability of cancer cells to aggregate might pave the way for new therapeutic opportunities.
We investigated cancer cell aggregation independently of cell migration or matrix adhesion and demonstrated that the cell-cell adhesion protein E-cadherin and the desmosome proteins DSG2 and DSC2 are both involved this process (Saias, 2015). Strikingly, elevated expression of these proteins in primary tumors has also been reported to be associated with blood detection of clusters of highly metastatic circulating tumor cells and poor prognosis (Aceto, 2014). We also reported that Myosin IIa applies a counter force that slows down aggregation indicating that acto-myosin cytoskeleton tension favors aggregation.
To further decipher the regulation of this process, we developed arrays of hydrogel microwells and robust microscopy-based quantification assay to monitor the kinetics of aggregation of tumor cells in the absence of cell - substrate adhesion. We performed a candidate approach and found that several other members of the cadherin superfamily are involved in the aggregation process. We also conducted a small molecule screen to identify other pathways involved in regulating aggregation of tumor cells. We will report unpublished results on the characterization of the molecular bases of aggregation properties in various tumor cell types and on the identification of new regulatory mechanisms that modulate this process.
- Saias L, Gomes A, Cazales M, Ducommun B, Lobjois V. Cell-cell adhesion and cytoskeleton tension oppose each other in regulating tumor cell aggregation. Cancer Res. (2015) 75(12); 1-8
- Aceto N, Bardia A, Miyamoto DT, Donaldson MC, Wittner BS, Spencer JA, et al. Circulating tumor cell clusters are oligoclonal precursors of breast cancer metastasis. Cell 2014;158:1110-22.
Citation Format: Valérie LOBJOIS, Bernard Ducommun. Tumor cell clustering - Identification of new regulators. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5053.
Abstract 5055: SPEN stimulates primary cilia formation, cell migration and is associated with metastasis in breast cancer
Authors: Légaré Stéphanie , Chabot Catherine , Basik Mark 
Published: July 2016

Abstract
The primary cilium (PC) is a microtubule-based and non-motile organelle that functions as animal cells’ antennae, regulating a number of signalling pathways, including the mTOR, PDGFR and Wnt pathways, in addition to being essential for activation of the canonical Hedgehog (Hh) pathway. In breast cancer, the PC is a structure that is frequently lost due to transcription- and mutation-driven alterations in cilium-related genes. In a study aiming to delineate the hormone-independent transcriptional program regulated by SPEN, a gene that we have identified as a tumour suppressor gene in estrogen receptor (ER)-positive breast cancers, we found that SPEN was co-expressed (R&gt;0.95) with a number of genes involved in ciliary biology (P = 1.64E-19), including the ciliogenic transcription factors RFX2, RFX3 and FOXJ1. Interestingly, the overexpression of SPEN resulted in the restoration of the PC in T47D cells, which have previously been shown to lack this structure. Consistent with the re-establishment of a PC in T47D cells, SPEN-overexpressing T47D cells had decreased mTOR signalling, hyperactivation of PC-dependent pathways, including the Hh and PDGFR pathways, and increased migration. Silencing SPEN expression in the non-tumorigenic MCF10A cells, which express high endogenous levels of SPEN and show a high prevalence of PC (36%), considerably decreased PC levels in MCF10A cells and was accompanied with increased mTORC1 activity as well as attenuated cell migration. We also found that SPEN silencing in MCF10A cells decreased the expression of the ciliogenic transcription factor RFX3 and that SPEN interacts with DNA upstream of RFX3 gene transcription start site in chromatin immunoprecipitation experiments. Collectively, these observations indicate that SPEN may mediate its effects, at least in part, through the transcriptional regulation of RFX3. Accordingly, RFX3 expression levels were strongly positively correlated (R = 0.55, P&lt;0.0001) with SPEN levels in a cohort of 82 clinical samples from triple negative breast cancer patients. Notably, high SPEN RNA levels were also predictive of early metastasis in two independent cohorts of 77 (HR = 2.25, P = 0.03) and 170 (HR = 2.23, P = 0.004) ER-negative breast cancer patients. Together, our findings highlight a role for SPEN in the regulation of PC formation and support important functions in the inhibition of mTORC1 and activation of Hh and PDGFR pathways as well as cell migration, a process that may contribute to early metastasis in ER-negative breast cancers.
Citation Format: Stéphanie Légaré, Catherine Chabot, Mark Basik. SPEN stimulates primary cilia formation, cell migration and is associated with metastasis in breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5055.
Abstract 5068: Carcinoma-associated fibroblast-derived CXCL12 enhances MDA-MB-231 tumor cell migration though mDia2 formin suppression
Authors: Dvorak Kaitlyn , Eisenmann Kathryn M. 
Published: July 2016

Abstract
The tumor microenvironment (TME) is a heterogeneous region comprised of tumor cells, stromal cells, and secreted factors that make the environment favorable for cancer formation and progression. An important step in the shift to a pro-cancerous environment is the transformation of normal stromal fibroblasts to carcinoma-associated fibroblasts (CAFs). CAFs are a critical cell type to understand. They are present in a majority of solid tumors and can have a direct effect to enhance adjacent tumor cell motility via their innate ability to secret cytokines, chemokine and growth factors into the TME. We sought to understand how CAF-derived chemokines impact breast tumor cell motility through modification of the F-actin cytoskeleton. We collected cultured media (CM) from WS19T fibroblasts, a patient-derived breast tumor CAF cell line. CAF-CM dramatically enhanced wound-closure in MDA-MB-231 monolayers, relative to normal fibroblast cultured media. The chemokine CXCL12 (SDF1 alpha) has been identified as a potential secreted CAF-directed signal driving tumor cell migration. To determine if CXCL12 was the soluble factor in CAF-CM promoting tumor cell migration, MDA-MB-231 cells were preincubated with AMD3100, an inhibitor of the CXCL12 receptor, CXCR4 prior to CAF-CM application and wounding. AMD3100 effectively blocked CAF-CM-induced MDA-MB-231 migration. CXCL12 incubation with MDA-MB-231 cells equally promoted MDA-MB-231 wound closure, supporting the notion that CXCL12 is secreted by CAFs to promote MDA-MB-231 motility. We previously showed a link between CXCL12 directed CXCR4 signaling and a critical regulator of the dynamic F-actin cytoskeleton, mammalian Diaphanous-related formin (mDia2). This formin regulates the assembly and bundling of unbranched actin filaments and plays a role in tumor cell migration and invasion programs. Western blotting CAF-CM-treated MDA-MB-231 cells revealed a near complete loss of mDia2 protein. mDia1 and ROCK expression were unaffected with CAF-CM treatment. These data were consistent with treatment with a functional mDia FH2-domain inhibitor SMIFH2, which likewise suppresses mDia2 protein levels in MDA-MB-231 cells. It remains unclear if CAF-derived CXCL12 first suppresses mDia2 FH2 activity, leading to loss of mDia2 protein, thus promoting tumor cell motility. Current experiments are designed to address this gap in the knowledge, potentially indicating a role for CAF-derived soluble factors in modulating mDia2 protein function and expression in migrating tumor cells.
Citation Format: Kaitlyn Dvorak, Kathryn M. Eisenmann. Carcinoma-associated fibroblast-derived CXCL12 enhances MDA-MB-231 tumor cell migration though mDia2 formin suppression. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5068.
Abstract 5072: Paracrine interactions between Schwann cells and cancer cells promotes perineural invasion via L1cam secretion
Authors: Na’ara Shorook , Gil Ziv , Amit Moran 
Published: July 2016

Abstract
Cancerous neural invasion (CNI) is a well-known route of cancer spread in head and neck cancer. Patients with CNI suffer from severe morbidity due to neuropathic pain and most succumb to cancer within months. The exact mechanism that drives cancer cells to disseminate along nerves remained to be defined. The overall objective of our research was to identify candidate proteins and host cells that contribute to CNI. L1 cell adhesion molecule (L1cam) is a 200kDa transmembrane glycoprotein of the immunoglobulin superfamily. In many human cancers, L1cam is constitutively over-expressed, and its expression is generally associated with poor prognosis and metastases formation. Immunohistochemical analysis of the neural niche in human cancer specimens showed overexpression of L1cam in both cancer cells and Schwann cells. To address the role of L1cam in vitro, we used the Dorsal Root Ganglia. Treatment of Cancer Cells with Anti L1cam mAb resulted in a significant reduction in CNI of cancer cells. Next, we used Schwann cells conditioned media (SCCM) to study the role of soluble Schwann cells derived L1cam. Immunopercipitation of L1cam in SCCM resulted in a significant reduction in L1cam concentration and led to reduced cancer cell migration, invasion, and motility. To study the role of SCCM as a chemo attractant to cancer cells we utilized a modified in-vitro nerve invasion assay that consists of 3 layers Fibroblasts-ECM-Schwann. In this model blocking the activity of L1cam in Schwann cells inhibited the cancer cells invasion through these layers. Finally, in-vivo studies in transgenic mice treated with L1cam mAb triweekly, showed a significant reduction in CNI in the tumors compared to the control group. Taken together, our results identify a paracrine interaction between Schwann cells in the neural niche and the cancer cells promotes perineural invasion via L1cam secretion.
Citation Format: Shorook Na’ara, Ziv Gil, Moran Amit. Paracrine interactions between Schwann cells and cancer cells promotes perineural invasion via L1cam secretion. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5072.
Abstract 5079: Sunitinib suppresses ovarian cancer metastasis through the negative modulation of TGF-β-mediated epithelial-mesenchymal transition
Authors: Chen Zibo , Chang Lin-lin , Zhou Tian-yi , Wang Dan-dan , Chen Ying , Zhu Hong , Ying Meidan , Yang Bo , He Qiao-jun 
Published: July 2016

Abstract
The mechanism of the negative regulation TGF-β mediated of epithelial-mesenchymal transition by sunitinib to inhibit ovarian cancer metastasis. We evaluated the inhibitory ability possessed by sunitinib against SKOV3 ovarian cancer cells motility by wound-healing and transwell assays. The results showed that sunitinib inhibited the migration of SKOV3 cells. The results obtained from wound-healing and transwell assays showed that sunitinib suppressed the motility of ovarian cancer SKOV3 cells in a concentration-dependent manner. In another,the effects of sunitinib on TGF-β-induced E-cadherin protein levels was assessed by western-blot, qRT-PCR and immunofluorescence assay. As a result, sunitinib attenuated the downregulation of E-cadherin protein level induced by TGF-β. Western-blot, qRT-PCR and immunofluorescence analyses displayed that the TGF-β stimulation reduced E-cadherin protein level, which could be attenuated by sunitinib. Our recent work reveals that the protein level of snail and the transcriptional activity of smad in sunitinib-treated cells were examined by western-blot and SBE-luciferase assay. Our results imply that sunitinib abolished TGF-β-induced upregulation of snail protein and decreased the transcriptional activity of smad complexes. The western-blot analyses revealed that sunitinib inhibited the upregulation of snail protein level caused by TGF-β treatment. The SBE reporter was constructed by linking the Smad-binding elements promoter upstream of luciferase reporter gene. A remarkable increment of transcriptional activity of Smads complexes was observed in SKOV3 cells exposed to TGF-β, which was significantly prohibited by sunitinib. The current study explores the prohibition of EMT, illustrates the anti-metastatic activities of sunitinib and the underlying mechanisms.
[Keywords] Sunitinib; EMT; TGF-β; E-cadherin; Snail; Smad signal pathway
Citation Format: Zibo Chen, Lin-lin Chang, Tian-yi Zhou, Dan-dan Wang, Ying Chen, Hong Zhu, Meidan Ying, Bo Yang, Qiao-jun He. Sunitinib suppresses ovarian cancer metastasis through the negative modulation of TGF-β-mediated epithelial-mesenchymal transition. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5079.
Abstract 5084: Real-time, quantitative cellular analysis of migration and invasion
Authors: Roddy Meagan , Rauch John , O’Clair Lindy , Appledorn Daniel M. 
Published: July 2016

Abstract
Chemotactic-driven cell migration is an important biological process impacting many areas of life science research including immunology, cancer and developmental biology. The dominant high-throughput solution for measuring cellular chemotaxis in vitro is the Boyden-chamber. However, traditional Boyden chamber products have inherent liabilities including: a) the inability to directly visualize the cell migration process, b) a requirement of tens of thousands of cells per well, c) the need to label cells for quantitation, d) a relative insensitivity to surface integrin signaling, and e) high random migration artifacts. Microfluidic solutions have sought to eliminate some of these deficiencies, specifically by providing the ability to visualize the cell migration process, but at the expense of relatively low throughput and cumbersome quantitation methods. Using a live-cell imaging approach and real-time image analysis quantitation, we have developed a new technology which eliminates most of the deficiencies of existing Boyden chambers and most importantly, provides direct visualization of both migration and invasion as it occurs. Integrated metrics precisely quantify the chemotactic response using significantly fewer cells (500-5000 cells per well) in a 96-well format. We exemplify this novel image based technique by studying the migration and invasion of both non-tumor and tumor-derived cell lines. Using Fetal bovine serum (FBS) as a chemoattractant, HT-1080 and NIH-3T3 cells were evaluated for their ability to directionally migrate across a coated surface or invade through a basement membrane extract by embedding the cells in an extracellular matrix prior to seeding. Qualitatively, we observed significant morphological differences between migrating and invading cells, the latter adopting a mesenchymal morphology reminiscent of cells that have undergone epithelial-mesenchymal transition (EMT) and exhibiting thinner, spindle-like morphology as they invade through the matrix. Using both cell count and cell area metrics, we observed a significant difference between migration and invasion kinetics of the relatively non-invasive cell line, NIH-3T3, and the highly invasive human fibrosarcoma derived cell line, HT-1080. Moreover, we observed significant and selective inhibition of HT-1080 cell invasion in the presence of GM6001, a broad inhibitor of Matrix Metalloproteinases (MMPs) with an IC50 of 25.7 nM. This new, real-time, quantitative cellular analysis technique illustrates a novel method to simultaneously study migration and invasion of tumor cells.
Citation Format: Meagan Roddy, John Rauch, Lindy O’Clair, Daniel M. Appledorn. Real-time, quantitative cellular analysis of migration and invasion. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5084.
Abstract 5087: EMT in cancer cells promotes the extracellular matrix remodeling by cancer-associated fibroblasts
Authors: Neri Shinya , Ishii Genichiro , Ochiai Atsushi , Menju Toshi , Sonobe Makoto , Date Hiroshi 
Published: July 2016

Abstract
Microenvironmental factors in tumor tissue induce epithelial-mesenchymal transition (EMT) in cancer cells. However, it remains unclear how EMT-induced cancer cells affect mechanisms of invasion by cancer-associated fibroblasts (CAFs). In this study, we investigated how EMT-induced cancer cells develop supportive functions of CAFs in the process of local invasion. Using an in vitro collagen invasion assay model, EMT-induced cancer cells invaded the collagen matrix to a greater extent compared to control cells when they were cultured alone. Interestingly, CAFs co-cultured with EMT-induced cancer cells invaded to a greater extent compared to those with control cancer cells. We revealed that platelet-derived growth factor (PDGF)-B was upregulated in EMT-induced cancer cells, and the invasion ability of CAFs decreased by shRNA knockdown of PDGF-B in EMT-induced cancer cells. Treatment of a PDGF receptor inhibitor cancelled the increased invasion abilities of CAFs and EMT-induced cancer cells. Our results indicated that EMT-induced cancer cells enhanced the CAF invasion ability through the secretion of PDGF-BB as well as increased the invasion ability themselves, suggesting that EMT-induced cancer cells in the tumor microenvironment could not only exhibit their increased invasion but also promote CAF invasion which might lead to local invasion of cancer cells.
Citation Format: Shinya Neri, Genichiro Ishii, Atsushi Ochiai, Toshi Menju, Makoto Sonobe, Hiroshi Date. EMT in cancer cells promotes the extracellular matrix remodeling by cancer-associated fibroblasts. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 5087.
Abstract 509: HER2 genomic amplification in circulating tumor DNA from patients with cetuximab-resistant colorectal cancer
Authors: TAKEGAWA. NAOKI 
Published: July 2016

Abstract
Background: Patients with metastatic colorectal cancer (mCRC) harboring wild-type KRAS benefit from epidermal growth factor receptor (EGFR)-targeted therapy. However, patients who are treated with anti-EGFR antibodies will eventually develop the resistance to those agents. We previously found that HER2 amplification was one of the mechanisms conferring resistance to anti-EGFR antibody therapy and could therefore be a potential therapeutic target (Yonesaka et al, STM 2011). The aim of this study was to detect HER2 amplification in circulating tumor DNA (ctDNA) from patients with CRC and acquired resistance to anti-EGFR antibody therapy.
Methods: We analyzed plasma ctDNA using digital polymerase chain reaction (PCR) from 18 patients with CRC, who had been treated with anti-EGFR antibody-based therapy (cetuximab) and subsequently acquired resistant cetuximab. We aimed to obtain at least 100 droplets for HER2 and EFTUD2 to accurately assess the ratio. Digital PCR data were analyzed using the QuantaSoft analytical software package (Bio-Rad). The copy number concentration of each gene (HER2 and EFTUD2) was estimated from the Poisson distribution. HER2 amplification with digital PCR was defined as a HER2 ratio (HER2/EFTUD2 copy number ratio) of 1.25 accordingly (Gevensleven H et al, CCR 2013). HER2 gene copy number was analyzed using fluorescence in situ hybridization also in tumor samples before and after acquisition of resistance to cetuximab-based therapy.
Results: Our data showed various HER2 copy number in plasma ctDNA from CRC patients (median: 1.09; range: 0.94-5.18). 22% (4/18) of patients in the cohort exhibited HER2 amplification. One of these patients was found to be positive for HER2 amplification in matched tumor specimens collected after cetuximab therapy, at which point the
patient had acquired cetuximab resistance, despite being negative for HER2 amplification prior to therapy (pre: 1.14, post: 2.78).
Conclusion: Analysis of plasma ctDNA by digital PCR could be useful for detecting HER2 amplification in patients with CRC who were resistant to anti-EGFR antibody therapy. We are now conducting another, large-scale study for evaluating HER2 amplification by ctDNA in CRC patients using digital PCR.
Citation Format: NAOKI TAKEGAWA. HER2 genomic amplification in circulating tumor DNA from patients with cetuximab-resistant colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 509.