bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4896: Real-time imaging of pancreatic cancer stem cells for identification of the selectively targeting therapy.
Authors: Tanaka Shinji , Adikrisna Rama , Matsumura Satoshi , Ban Daisuke , Ochiai Takanori , Irie Takumi , Kudo Atsushi , Nakamura Noriaki , Yamaoka Shoji , Arii Shigeki
Published: August 2014

Identification and purification of cancer stem cells (CSCs) should offer a clue of the therapeutic targets, but their heterogeneous expansion remains the significant obstacle of studies. One of the solutions might be establishment of real-time monitoring of CSC, based on fluorescence imaging with the intrinsically low proteasome activity. The monitoring system in human pancreatic cancer cells proved directly the asymmetric division of CSC to generate non-CSC. Real-time chemoresistance of the CSCs and remarkable tumorigenicity (as few as 10 cells) indicated their preclinical significance. The synthetic lethal screening was applied to identify a novel compound targeting specifically the pancreatic CSCs. It inhibited nuclear accumulation of beta-catenin in the pancreatic CSCs. Anti-CSC effects of the compound were confirmed by in vitro dynamic images and in vivo tumor analyses. The real-time monitoring system of CSCs is an innovative strategy providing a visible target that should lead to the discovery of successful therapies directed toward CSCs of aggressive cancers.

Citation Format: Shinji Tanaka, Rama Adikrisna, Satoshi Matsumura, Daisuke Ban, Takanori Ochiai, Takumi Irie, Atsushi Kudo, Noriaki Nakamura, Shoji Yamaoka, Shigeki Arii. Real-time imaging of pancreatic cancer stem cells for identification of the selectively targeting therapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4896. doi:10.1158/1538-7445.AM2013-4896

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.
Abstract 4900: Functional and mechanism analysis of LGR4 in human lung cancer cells.
Authors: Gong Xing , Xiong Wei , Yi Jing , Carmon Kendra S. , Liu Qingyun
Published: August 2014

LGR4 (leucine-rich repeat containing G protein-coupled receptor 4) and its two closely related homologues LGR5 and LGR6 (LGR4-6) are members of the seven transmembrane domain (7TM) receptors with critical functions in embryonic development and adult stem cells. Recently, we and others discovered that LGR4-6 function as receptors of R-spondins (RSPO) to potentiate Wnt signaling. RSPOs are a group of four secreted proteins (RSPO1-4) with essential roles in organ development, sex determination, carcinogenesis, etc. Particularly, RSPO2 is required for normal lung development through enhancement of Wnt signaling and LGR6 is expressed in adult lung stem cells in the mouse. Among the 900 or so 7TM receptors, LGR4 was found to be one of the few that were highly upregulated in both squamous cell carcinoma (SqCC) and adenocarcinoma (AC) of the lung. Alterations in the Wnt signaling pathways were found in a small percentage of lung cancer. Concurrent activation of β-catenin signaling enhances tumor growth and metastasis of lung cancer cells with KRAS mutation. Furthermore, RSPO3 and LGR4 are co-expressed at high levels in ∼20% of lung cancer cell lines. However, potential roles of RSPO3-LGR4 in lung carcinogenesis have not been investigated. We developed and validated a panel of LGR4 antibodies that can detect either native or denatured LGR4 with high specificity and sensitivity. Immunohistochemistry analyses confirmed that LGR4 was highly expressed in the majority of SqCC and AC of the lung. Knockdown of LGR4 in a lung cancer cell line with high levels of and LGR4 and RSPO3 leads to dramatic decrease in endogenous Wnt signaling and significant reduction in cell growth, migration, and colony formation in vitro. The effect of knockdown on tumor growth in vivo is being tested. Data from these expression and functional analyses of LGR4 in human lung cancer will be presented and discussed.

Citation Format: Xing Gong, Wei Xiong, Jing Yi, Kendra S. Carmon, Qingyun Liu. Functional and mechanism analysis of LGR4 in human lung cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4900. doi:10.1158/1538-7445.AM2013-4900
Abstract 4905: Novel gene expression profiles of poorly differentiated lung cancer are enriched in stem cell factors and predictive of worse clinical outcome.
Authors: Damelin Marc Isaac , Zhong Wenyan , Diesl Veronica K. , Follettie Maximillian T. , Geles Kenneth G.
Published: August 2014

Poorly differentiated non-small cell lung cancer (NSCLC) at the histopathological level has been associated with shorter patient survival. Analogously, at the cellular level, poorly differentiated tumor cells exhibit more aggressive phenotypes than their well-differentiated counterparts, including higher tumorigenic potential and higher metastatic capacity. Effective therapeutic targeting of the malignant undifferentiated cells will require a deeper understanding of their molecular drivers. To investigate the hierarchical basis of heterogeneous NSCLC tumors, we developed an improved method to study the undifferentiated and differentiated states of primary tumor cultures. The cultures were established in defined serum-free media from freshly resected tumors and were induced to differentiate either by culture in serum-containing media or by exposure to the air-liquid interface (ALI) in serum-free media with two variations. Gene expression profiles revealed similar patterns of change in all three conditions, which confirmed the undifferentiated state of the initial culture; however, differentiation in serum caused many extraneous changes in gene expression, which suggested that the ALI method represents a more physiologically relevant condition. Gene Set Enrichment Analysis demonstrated that the profile of the undifferentiated state was enriched in signatures of embryonic stem cell factors, metastasis and drug resistance. In addition, novel gene expression signatures of the undifferentiated state were predictive of shorter patient survival in a clinical dataset of NSCLC. These results establish a robust method for studying the cellular hierarchy in NSCLC that is independent of cell surface markers, and the data reveal several potential avenues for future therapeutic intervention.

Citation Format: Marc Isaac Damelin, Wenyan Zhong, Veronica K. Diesl, Maximillian T. Follettie, Kenneth G. Geles. Novel gene expression profiles of poorly differentiated lung cancer are enriched in stem cell factors and predictive of worse clinical outcome. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4905. doi:10.1158/1538-7445.AM2013-4905
Abstract 4914: ABCB5 expression in colorectal cancer circulating tumor cells correlates with metastatic disease progression.
Authors: Guo Qin , Ma Jie , Wilson Brian J. , Gasser Martin , Waaga-Gasser Ana Maria , Frank Markus H. , Frank Natasha Y.
Published: August 2014

Targeted personalized treatment approaches are critical for the development of successful therapies for advanced colorectal cancer (CRC). In this regard, circulating tumor cells (CTC) are of foremost interest as potential predictors of metastatic disease progression and patient therapeutic response. We have previously demonstrated that ATP-binding cassette member B5 (ABCB5) is expressed by cancer stem cells (CSC) in several human malignancies, including CRC, and that ABCB5 identifies therapy-refractory tumor subpopulations in CRC patients that correlate with disease progression. In order to evaluate the potential role of ABCB5 as a clinically relevant CTC marker, we utilized a human-to-mouse xenograft model system to examine the relationship of ABCB5-positive CRC-CTC to CRC metastasis. Human CRC tumor cells were grafted subcutaneously into immunocompromized NSG mice. 7 weeks after xenotransplantation, peripheral blood mononuclear cells and lungs were evaluated by qPCR for expression of human ABCB5 and GAPDH mRNAs. Expression analysis of these specimens revealed a significant positive correlation between peripheral blood human ABCB5 mRNA expression and aggregate metastatic disease load as determined by human GAPDH mRNA expression levels in lungs (r=0.8994, P=0.0147). Remarkably, no significant correlation existed between peripheral blood human GAPDH mRNA expression and metastatic disease load, indicating a unique and essential role of ABCB5-positive CSC-CTC in colorectal cancer metastatic disease progression. Significantly increased peripheral blood ABCB5 expression was also observed in a clinical series of UICC stages I-III colorectal cancer patients (n=105) compared to healthy controls (P<0.001). Thus, our results identify the CSC antigen ABCB5 as a novel molecular marker of metastasis-associated CRC-CTC and point to potential utility of ABCB5 as a prognostic indicator and predictor of therapeutic response in patients with advanced colorectal cancer.

Citation Format: Qin Guo, Jie Ma, Brian J. Wilson, Martin Gasser, Ana Maria Waaga-Gasser, Markus H. Frank, Natasha Y. Frank. ABCB5 expression in colorectal cancer circulating tumor cells correlates with metastatic disease progression. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4914. doi:10.1158/1538-7445.AM2013-4914
Abstract 4919: Myristoylated alanine-rich C kinase substrate (MARCKS) phosphorylation potentiates human lung cancer cell malignancy .
Authors: Chen Ching-Hsien , Thai Phillip , Wu Reen
Published: August 2014

Myristoylated alanine-rich C kinase substrate (MARCKS), a substrate of protein kinase C (PKC), is a key regulatory molecule controlling mucin secretion by airway epithelial cells in vitro and in vivo. Phosphorylated MARCKS (p-MARCKS) has been reportedly to promote inflammatory cell migration in several lung diseases. However, the functionality of MARCKS and its related phosphorylation in lung cancer malignancy has not been characterized. This study demonstrated MARCKS expression and elevated p-MARCKS in various lung cancer cell lines with high malignancy, such as CL1-0-F3, CL1-5, PC9, A549 and several tyrosine kinase inhibitor (TKI) resistant cell lines (H1650 and H1975), as compared with normal human bronchial epithelial (NHBE) cells and low metastasis cancer cell line. siRNA knockdown MARCKS expression resulted in an inhibition of cell migration, accompanying with a decrease of Slug expression in these malignant lung cancer cell lines. Treatment with myristoylated 24-amino-acid MARCKS N-terminus sequence (MANS) peptide, but not the control myristoylated random N-terminal sequence (RNS) peptide, suppressed MARCKS phosphorylation and impaired cell migration and wound healing ability in these lung cancer cell lines. Importantly, MANS peptide treatment resulted in a suppression of lamellipodia/filopodia formation and an enhancement of cell-cell contacts with increased E-cadherin expression. These results confirmed a crucial role for MARCKS, specifically its phosphorylation, in potentiating lung cancer cell migration and malignancy. This study has also suggested a potential usage of MANS or the MARCKS-related peptides in the treatment of lung cancer metastasis.

Citation Format: Ching-Hsien Chen, Phillip Thai, Reen Wu. Myristoylated alanine-rich C kinase substrate (MARCKS) phosphorylation potentiates human lung cancer cell malignancy . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4919. doi:10.1158/1538-7445.AM2013-4919
Abstract 4922: Overexpression of p62/IMP2 in breast cancer promotes cell migration.
Authors: Li Yang , Peng Bo , Lei Ningjing , Francia Giulio , Zhang Jianying
Published: August 2014

Invasion and metastasis are complex processes that are primarily responsible for most cancer-related deaths throughout the world, and which involve several different biological processes. The IMPs (IGF2 mRNA-binding Proteins) are a family of oncofoetal proteins that includes the members IMP1, p62/IMP2, and IMP3. These proteins are expressed during embryogenesis, and after birth their expression is lost in almost all tissues. Re-expression of IMPs is however evident in a number of adult malignancies. Indeed, p62/IMP2 was initially identified as an autoantigen with serum from a patient with hepatocellular carcinoma (HCC). p62/IMP2 is therefore a potential biomarker for the early diagnosis of HCC as well as of other cancers. Nonetheless, its function is largely unknown. To begin to understand the biology of p62/IMP2, we evaluated its expression in breast cancer by carrying out immunohistochemical analysis of 118 human sections from normal and malignant breast tissue samples. We observed a statistically significant (p<0.05) overexpression of p62/IMP2 in human breast tumors (72/104, 69%), compared with normal human breast tissue (2/14, 14%). Transfection of human p62/IMP2 cDNA into human MDA-MB-231 breast cancer cells (which lack p62/IMP2expression) produced clones with stable positive and negative p62/IMP2 expression, a result confirmed by both western blotting and immunofluorescence analysis. Analysis of the transfected clones, using a wound healing assay, showed that p62/IMP2 overexpression can significantly enhance MDA-MB-231 cell migration. Our results show that p62/IMP2 is expressed in human breast cancers, and that its expression can increase cell migration, which suggests is may promote the invasive behavior of breast cancers.

Citation Format: Yang Li, Bo Peng, Ningjing Lei, Giulio Francia, Jianying Zhang. Overexpression of p62/IMP2 in breast cancer promotes cell migration. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4922. doi:10.1158/1538-7445.AM2013-4922
Abstract 4923: Identification of invasive and metastatic potential of Tpl2 knockout keratinocytes.
Authors: Decicco-Skinner Katie L. , Jung Sarah , Tabib Tracy , Gwilliam Curtis , Alexander Hepzi , Goodheart Sarah , Morin Adam , Cvitan Alex , Wiest Jonathan
Published: August 2014

Skin cancer is the most common form of cancer in the United States, with an estimated two million cases diagnosed annually. Tpl2 (MAP3K8) is a serine threonine protein kinase in the mitogen-activated protein kinase (MAPK) signal transduction cascade. Tpl2 was identified by our laboratory as having a tumor suppressive function in skin carcinogenesis. Tpl-2 knockout mice develop significantly more tumors than matched wildtype controls and have a larger degree of inflammation when challenged with 12-O-tetradecanoylphorbol-13-acetate (TPA). However, it is unknown whether the tumors that develop in Tpl2 knockout mice are more aggressive and invasive than skin tumors in wildtype mice. Therefore, we compared the invasive and metastatic potential of keratinocytes from wildtype and Tpl2 knockout mice. Using various techniques including gene microarray, real-time polymerase chain reaction, and zymography we found MMP-2 and MMP-9 matrix metalloproteinases to be significantly up-regulated in Tpl-2−/- keratinocytes. Additionally, Tpl-2−/- keratinocytes have altered migration rates, significantly higher malignant conversion rates and increased angiogenesis when compared to wildtype keratinocytes. Moreover, protein arrays identified several angiogenic factors, in addition to the MMP's, induced in Tpl-2−/- keratinocytes. In summary, our studies demonstrate skin tumors from Tpl-2−/- mice have the potential to be more aggressive, invasive, and metastatic than tumors in control animals.

Citation Format: Katie L. Decicco-Skinner, Sarah Jung, Tracy Tabib, Curtis Gwilliam, Hepzi Alexander, Sarah Goodheart, Adam Morin, Alex Cvitan, Jonathan Wiest. Identification of invasive and metastatic potential of Tpl2 knockout keratinocytes. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4923. doi:10.1158/1538-7445.AM2013-4923
Abstract 4926: Loss of ZBRK1 contributes to the increase of KAP1 and promotes KAP1-mediated metastasis and invasion in cervical cancer.
Authors: Wang Wei-Jan , Lin Li-Fang , Li Chien-Feng , Yang Wen-Ming , Wang Dennis Ding-Hwa , Chang Wen-Chang , Lee Wen-Hwa , Wang Ju-Ming , Wang Ju-Ming
Published: August 2014

ZBRK1, a zinc finger protein that interacts with breast cancer 1 (BRCA1) and KRAB-ZFP-associated protein 1 (KAP1), has been suggested to serve as a tumor suppressor via repression of tumor metastasis/invasion. To date, the detailed molecular mechanisms for how BRCA1 and KAP1 participate in ZBRK1-mediated transcriptional repression, metastasis and invasion as well as the associated clinical relevance remain unclear. In this study, we demonstrated that both the N- and C-terminal domains of ZBRK1 are important for inhibiting cell proliferation and anchorage-independent growth in cervical cancer. Specifically, the N-terminal KRAB domain of ZBRK1 displayed a more crucial role in inhibiting metastasis and invasion through modulation of KAP1 function in a transcriptionally dependent manner. The loss of ZBRK1 results in an increase of KAP1 expression, which enhanced migration and invasion of cervical cancer cells both the in vitro and in vivo. Moreover, an inverse correlation of expression levels was observed between ZBRK1 and KAP1 following tumor progression from in situ carcinoma to invasive/metastatic cervical cancer specimens. Taken together, the current results indicate that a loss of ZBRK1 contributes to the increased expression of KAP1, potentiating its role to enhance metastasis and invasion.

Citation Format: Wei-Jan Wang, Li-Fang Lin, Chien-Feng Li, Wen-Ming Yang, Dennis Ding-Hwa Wang, Wen-Chang Chang, Wen-Hwa Lee, Ju-Ming Wang, Ju-Ming Wang. Loss of ZBRK1 contributes to the increase of KAP1 and promotes KAP1-mediated metastasis and invasion in cervical cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4926. doi:10.1158/1538-7445.AM2013-4926
Abstract 4928: Mechanisms of microglia-stimulated glioma invasion.
Authors: Coniglio Salvatore J. , Segall Jeffrey E.
Published: August 2014

The ability of glioma tumor cells to infiltrate the surrounding brain parenchyma makes complete removal of these tumors nearly impossible. We investigated how microglia, the resident macrophages of the brain, stimulate glioma cell invasion. Coculture with microglia stimulates the invasion of GL261 glioma cells in-vitro. Pharmacological inhibition of EGFR using Iressa strongly inhibits microglia-stimulated invasion. Furthermore, we demonstrate using novel CSF-1R (c-fms) inhibitors that CSF-1R signaling is also required for microglial enhancement of glioma invasion. GL261 cells were found to constitutively secrete CSF-1, the levels of which are unaffected by EGF stimulation, EGFR inhibition or coculture with microglia. GL261 tumors orthotopically injected into the brains of C57 mice fed with the CSF-1R inhibitor PLX3397 showed a dramatic reduction in microglia/macrophages infiltration compared with tumors from animals fed control chow. Tumors from the PLX3397-fed animals also showed a 50% reduction in invasion into the parenchyma. We discovered that GL261 cell secretion of CSF-1 is involved in upregulating EGFR ligands in microglia including AREG, EREG and TGFA. Microglia isolated from GL261 tumors express AREG mRNA whereas naïve microglia from control animals do not. Depletion of AREG from microglia using siRNA interfered with their ability to promote GL261 invasion in vitro. These data indicate that during invasion, glioma and microglia cells signal to each other using EGFR Ligands and CSF-1 similar to what has been observed in breast cancer models. The results of this study indicate the possibility of inhibiting glioblastoma invasion by targeting functions of tumor-associated microglia in addition to glioma cells.

Citation Format: Salvatore J. Coniglio, Jeffrey E. Segall. Mechanisms of microglia-stimulated glioma invasion. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4928. doi:10.1158/1538-7445.AM2013-4928
Abstract 4931: Inhibitor of DNA binding 4 (Id4) suppresses MMP2 mediated invasion of glioblastoma-derived cells by direct inactivation of twist-1 function.
Authors: Rahme Gilbert J. , Israel Mark A.
Published: August 2014

Invasion of normal tissues by high grade glioma is a key aspect of increased morbidity and mortality associated with these tumors. Malignant glioma comprise over 70% of primary brain tumors with a median survival ranging from 12 to 15 months for patients with glioblastoma multiforme (GBM), the highest grade of glial tumors. Inhibitor of DNA binding (Id) genes are highly expressed in development and tumorigenesis and some members (Id1, Id2 and Id3) have been linked to increased tumor invasion. In sharp contrast to these members of the Id gene family, we found that Id4 expression in GBM-derived cells decreased invasion in in vitro assays. Results of gain-of-function and loss-of-function experiments indicated that Id4 expression decreased GBM invasion and suppressed a gene, matrix metallo-protease 2 (MMP-2), which encodes a proteolytic enzyme key for the destruction of glial tumor extracellular matrix. Western blot and zymography analysis demonstrated that conditioned media from Id4 expressing cells had low levels of pro-MMP2 and cleaved MMP2. An antibody that is known to inactivate MMP-2 was used to demonstrate that MMP2 accumulated in media conditioned by Id4 deficient cells was sufficient to rescue the invasive activity lost in cells expressing high levels of Id4. These findings confirmed that MMP2 suppression by Id4 is responsible for the decrease in invasion observed in Id4 expressing glioma cells.

Twist-1 is a well described mediator of invasion. Co-IP and co-localization studies demonstrated an interaction suggesting a direct inhibition of Twist-1 by Id4. Other data indicate that Id4 also blocks Twist-1 induced transcription of MMP2. Importantly, Twist-1 overexpression can rescue the invasion defect induced by Id4 expression, providing further support that the Id4/Twist-1 interaction mediates the function of Id4 in suppressing GBM invasion. Analysis of The Cancer Genome Atlas (TCGA) data indicated a significantly better survival and prognosis for GBM patients with high Id4 expression (Z>1) suggesting that Id4 could have an important role in the survival of GBM patients. Our data provide strong evidence demonstrating that Id4 suppresses GBM invasion by inhibiting Twist-1 induced expression of MMP2. To our knowledge, this is the first report of an Id protein acting as an inhibitor of invasion rather than mediating the pro-invasive functions of the other Id-gene family members.

Citation Format: Gilbert J. Rahme, Mark A. Israel. Inhibitor of DNA binding 4 (Id4) suppresses MMP2 mediated invasion of glioblastoma-derived cells by direct inactivation of twist-1 function. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4931. doi:10.1158/1538-7445.AM2013-4931
Abstract 4933: Functional properties of PPFIA1, located at the 11q13 amplification region, in epithelial cancer cells.
Authors: Pehkonen Henna , Lepikhova Tatiana , Louhimo Riku , Peitsaro Nina , Imai Misa , Martinez Rafael , Kleftsröm Juha , Hautaniemi Sampsa , Monni Outi
Published: August 2014

PPFIA1 (liprin α1) is a member of the liprin (LAR protein-tyrosine phosphatase-interacting protein) family and is located at the 11q13 amplification region, which is one of the most common amplicons in multiple epithelial cancers. In squamous cell carcinoma of head and neck (HNSCC), this amplification occurs in 30-50% of the cases. In epithelial cancers, the size and structure of 11q13 amplicon is complex and consists of multiple amplicon cores that differ between different tumor types. In HNSCC, the amplicon core contains 10 genes that are amplified in cases with 11q13 amplification. This region contains well-established oncogenes, such as CCND1 and CTTN (cortactin), yet the role of several genes in this region is unknown. Our aim is to study the role of PPFIA1, which has recently been found to be involved in cell motility, modeling of the cell edge dynamics and axon guidance. PPFIA1 is amplified and overexpressed in several epithelial cancers, but the role of it is controversial. PPFIA1 is required for breast and cervical cancer cell invasion, but in contrast depletion of it results in increased invasion of HNSCC cells. We have overexpressed liprin α1 and cortactin in HNSCC cells with no 11q13 amplification and related phenotypes have been analysed in in vitro assays. Migration assays using matrigel coated inserts have shown that overexpression of cortactin increases invasive properties of the HNSCC cells with no 11q13 amplicon whereas liprin α1 has an opposite effect. We have also shown that liprin α1 localizes with cortactin in same vesicular structures, but they do not show physical interaction. Our aim is now to explore the molecular mechanisms behind these findings to assess the role of liprin α1 in vesicular transport and cell motility. We are also carrying out immunoprecipitation and mass spectrometry analyses to identify novel interaction partners for this protein. Our study will provide novel information on the potential specialized functions of liprin α1 in different epithelial cancers, which is likely to improve our understanding on the functional role of 11q13 amplification in malignant potential of cancer cells.

Citation Format: Henna Pehkonen, Tatiana Lepikhova, Riku Louhimo, Nina Peitsaro, Misa Imai, Rafael Martinez, Juha Kleftsröm, Sampsa Hautaniemi, Outi Monni. Functional properties of PPFIA1, located at the 11q13 amplification region, in epithelial cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4933. doi:10.1158/1538-7445.AM2013-4933
Abstract 4934: The role of Aurora A kinase-dependent phosphorylation of cortactin in invadopodia formation.
Authors: Kozyreva Varvara K. , Kelley Laura , McLaughlin Sarah L. , Pugacheva Elena N.
Published: August 2014

Aurora A kinase (AURKA) is a serine/threonine kinase known for its critical role in regulation of cell cycle progression. Overexpression and activation of AURKA is implicated in development of multiple types of human cancer. AURKA upregulation is considered as independent prognostic marker for breast cancer patients and associated with poor survival outcome. Recent work by our laboratory and others suggests a new role for AURKA in promotion of tumor cells migration and invasion through regulation of actin dynamics. However, the specific manner in which AURKA regulates actin-based machinery of migrating cancer cells is unknown. In our current work we show that phosphorylation of cortactin (CTTN) by AURKA directly regulates actin dynamics in breast cancer cells. CTTN is known to be regulated by oncogenic Src kinase. This phosphorylation is pivotal for formation of free barbed ends and further actin polymerization. Dynamic polymerization/depolimerization is required for invasion of cancer cells. Thus inhibition of Src-dependant phosphorylation of CTTN is critical for invadopodia maturation. In our current work we identify the phosphorylation site on CTTN targeted by AURKA and show that phosphorylation of CTTN by AURKA could potentially inhibit further phosphorylation of CTTN by Src leading to stabilization of invadopodia. Inhibition of AURKA activity or depletion of AURKA in cancer cells led to decrease in invasion and invadopodia maturation. In addition, we showed that adaptor protein NEDD9 which is known to bind both AURKA and Src also binds to CTTN and therefore potentially can mediate Src-CTTN-AURKA complex formation that regulates the sequential phosphorylation events necessary for invadopodia genesis. It is our expectation that AURKA-phosphorylated CTTN will inhibit Src-driven tyrosine-phosphorylation of CTTN, regulating a mechanistic switch between complementary actin polymerization and actin stabilization programs.

Citation Format: Varvara K. Kozyreva, Laura Kelley, Sarah L. McLaughlin, Elena N. Pugacheva. The role of Aurora A kinase-dependent phosphorylation of cortactin in invadopodia formation. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4934. doi:10.1158/1538-7445.AM2013-4934
Abstract 4947: Inhibition of Rapamycin induced AKT activation elicits differential anti-tumor response in head and neck cancers.
Authors: Radhakrishnan Padhma , Baraneedharan Ulaganathan , Dhandapani Muthu , Thyakumar Allen , Pinto Dency , Prasath Arun , Velu Ayyappan , Kamal A , Brijwani Nilesh , Nair Rohini , Basavaraja R , Jain Misti , Thiyagarajan Saravanan , Majumder Biswanath , Sundaram Mallik , Narayanan Prasad , Kekatpure Vikram D. , Majumder Pradip K.
Published: August 2014

The PI3K/AKT/mTOR pathway is an important signaling axis that is perturbed in majority of cancers. Biomarkers such as pS6RP, GLUT1 and tumor FDG uptake are being evaluated in patient stratification for mTOR pathway inhibitors. In the absence of a clear understanding of the underlying mechanisms in tumor signaling, the biomarker strategy for patient stratification is of limited use. Here, we show that no discernible correlation exists between FDG uptake and the corresponding Ki67, GLUT1, pS6RP expression in tumor biopsies from Head and Neck Cancer (HNC) patients. Correlation between GLUT1 and pS6RP levels in tumors was observed but elevated pS6RP was noticed even in the absence of concomitant AKT activation, suggesting other downstream molecules of PI3K/AKT and/or other pathways upstream of mTOR, are active in these tumors. Using an ex-vivo platform, we identified putative responders to Rapamycin, an mTOR inhibitor in these tumors. However, Rapamycin did not induce anti-tumor effect in the majority of tumors with activated mTOR, potentially attributable to the observation that Rapamycin induces feedback activation of AKT. Accordingly, treatment of these tumors with an AKT inhibitor and Rapamycin uniformly resulted in abrogation of mTOR inhibition induced AKT activation in all tumors but failed to induce anti-tumor response in a subset. Phosphoproteomic profiling of tumors resistant to dual AKT/mTOR inhibitors revealed differential activation of multiple pathways involved in proliferation and survival. Collectively, our data suggest that in addition to biomarker based segregation, functional assessment of patient tumor prior to treatment with mTOR/AKT inhibitors might be useful for patient stratification.

Citation Format: Padhma Radhakrishnan, Ulaganathan Baraneedharan, Muthu Dhandapani, Allen Thyakumar, Dency Pinto, Arun Prasath, Ayyappan Velu, A Kamal, Nilesh Brijwani, Rohini Nair, R Basavaraja, Misti Jain, Saravanan Thiyagarajan, Biswanath Majumder, Mallik Sundaram, Prasad Narayanan, Vikram D. Kekatpure, Pradip K. Majumder. Inhibition of Rapamycin induced AKT activation elicits differential anti-tumor response in head and neck cancers. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4947. doi:10.1158/1538-7445.AM2013-4947
Abstract 4951: The role of endothelin axis signaling pathway in astrocyte mediated chemoprotection of tumor cells.
Authors: Kim Seung Wook , Kim Sun Jin , Choi Hyun Jin , Lee Ho-Jeong , He Junqin , Wu Qiuyu , Lawson Erica J. , Fidler Isaiah J.
Published: August 2014

Purpose: More than 40% of patients with the breast cancer develop brain metastasis that are resistant to conventional chemotherapeutic agents. We have reported that reactive astrocytes establish gap junction communication channels with adjacent tumor cells and protect tumor cells from chemotherapy by up-regulation of survival genes in the tumor cells. We now report on the mechanism by which astrocytes up-regulate expression of the survival genes in tumor cells.

Materials and Methods: Human breast cancer cells, MDA-MB-231 cultured with murine astrocytes produce endothelin 1 (ET-1) leading to expression and activation of endothelin receptors (ETRs). Using small interfering RNA (siRNA) of ETAR and ETBR, and ETRs specific antagonists (BQ123, BQ788, and PD145065) demonstrated the correlation between the activation of the endothelin axis in tumor cells and the induction of survival genes (BCL2L1, GSTA5, and TWIST1) leading to chemoresistance.

Results: Co-culture of MDA-MB-231 cells and murine astrocytes induced up-regulation of ETRs (ETAR and ETBR) and activation of endothelin receptors axis in tumor cells as well as increased production of ET-1 by murine astrocytes. Activation of the ETRs by exogenous ET-1 up-regulated the expression of survival genes, such as BCL2L1, GSTA5 and TWIST1 via activation of phosphorylated AKT/MAPKinase signal transduction pathways, leading to resistance of tumor cells to several chemotherapeutic agents. Knockdown of both ETAR and ETBR by siRNAs or treatment of tumor cells with dual ETR inhibitor abolished the chemoprotection induced by astrocytes.

Conclusion: ET axis signaling pathway plays an essential role in astrocytes-mediated induction of chemoresistance of tumor cells by up-regulation of survival genes in tumor cells. Simultaneous blockade of both ETR can prevent tumor cells from developing resistance to chemotherapeutic agents.

Citation Format: Seung Wook Kim, Sun Jin Kim, Hyun Jin Choi, Ho-Jeong Lee, Junqin He, Qiuyu Wu, Erica J. Lawson, Isaiah J. Fidler. The role of endothelin axis signaling pathway in astrocyte mediated chemoprotection of tumor cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4951. doi:10.1158/1538-7445.AM2013-4951
Abstract 4952: A novel smoothened antagonist, TAK-441, delays castration-resistant progression in prostate cancer by disrupting paracrine hedgehog signaling.
Authors: Ghaffari Mazyar , Ibuki Naokazu , Iu Irene , Pandey Mitali , Fazli Ladan , Kashiwagi Masahide , Tojo Hideaki , Nakanishi Osamu , Gleave Martin E. , Cox Michael E.
Published: August 2014

Hedgehog (Hh) signaling is a highly conserved inter- and intracellular communication mechanism that governs organogenesis and is dysregulated in cancers of numerous tissues, including prostate. Up-regulated expression of the Hh ligands, Sonic (Shh) and Desert (Dhh), has been reported in androgen-deprived and castration-resistant prostate cancer (CRPC). In a cohort of therapy naive, short- and long-term neoadjuvant hormone therapy-treated (NHT), and CRPC specimens, we observed elevated Dhh expression predominantly in long-term NHT specimens and elevated Shh expression predominantly in CRPC specimens. Together with previously demonstrated reciprocal signaling between Shh-producing prostate cancer (PCa) cells and urogenital mesenchymal fibroblasts, these results suggest that castration-induced Hh expression promotes CRPC progression through reciprocal paracrine signaling within the tumor microenvironment. We tested whether the orally available Smoothened (Smo) antagonist, TAK-441, could impair castration-resistant progression of LNCaP PCa xenografts by disrupting paracrine Hh signaling. While TAK-441 or cyclopamine did not affect androgen withdrawal-induced Shh up-regulation or viability of LNCaP cells, castration-resistant progression of LNCaP xenografts was significantly delayed in animals treated with TAK-441. In TAK-441-treated xenografts, expression of murine orthologues of the Hh-activated genes, Gli1, Gli2, and Ptch1, was substantially suppressed, while expression of the corresponding human orthologues was unaffected. Since androgen-deprived LNCaP cells up-regulate Shh expression, but are not sensitive to Smo antagonists, these studies indicate that TAK-441 leads to delayed castration-resistant progression of LNCaP xenografts by disrupting paracrine Hh signaling with the tumor stroma. Thus, paracrine Hh signaling may offer unique opportunities for prognostic biomarker development, drug targeting and therapeutic response monitoring of PCa progression.

Citation Format: Mazyar Ghaffari, Naokazu Ibuki, Irene Iu, Mitali Pandey, Ladan Fazli, Masahide Kashiwagi, Hideaki Tojo, Osamu Nakanishi, Martin E. Gleave, Michael E. Cox. A novel smoothened antagonist, TAK-441, delays castration-resistant progression in prostate cancer by disrupting paracrine hedgehog signaling. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4952. doi:10.1158/1538-7445.AM2013-4952
Abstract 4956: Pharmacological inhibition of Bruton's Tyrosine Kinase (BTK) as a therapy for insulinoma and pancreatic ductal adenocarcinoma.
Authors: Massó-Vallés Daniel , Serrano Erika , Whitfield Jonathan R. , Buggy Joseph J. , Sodir Nicole M. , Affara Nesrine I. , Brown Swigart Lamorna , Evan Gerard I. , Soucek Laura
Published: August 2014

Myc, a pleiotropic transcription factor that is deregulated and/or over-expressed in most human cancers, instructs multiple extracellular programs that are required to sustain the complex microenvironment needed for tumor maintenance, including remodeling of tumor stroma, angiogenesis and inflammation. We previously showed in a model of pancreatic [[Unsupported Character - Symbol Font β]] cell tumorigenesis that acute Myc activation in vivo triggers rapid recruitment of mast cells to the tumor site and that this is absolutely required for angiogenesis and macroscopic tumor expansion. Moreover, systemic inhibition of mast cell degranulation with sodium cromoglycate induced death of tumor and endothelial cells in established tumors. Hence, mast cells are required both to establish and to maintain the tumors. While this intimates that selective inhibition of mast cell function could be therapeutically efficacious, cromoglycate is not a practical drug for systemic delivery in humans and no other systemic inhibitor of mast cell degranulation has hitherto been available.

Ibrutinib is a novel inhibitor of Bruton's tyrosine kinase (Btk) that blocks mast cell degranulation and is currently in clinical trials as a therapy for B cell non-Hodgkin's lymphoma. Here, we show that systemic treatment of insulinoma-bearing mice with Ibrutinib efficiently inhibits Btk, blocks mast cell degranulation and triggers collapse of tumor vasculature and tumor regression. We also show that pancreatic ductal adenocarcinoma (PDAC)-bearing mice treated with Ibrutinib survive longer and present reduced tumor stroma, suggesting that combinatorial therapy with Ibrutinib and standard of care is a feasible therapeutic approach. Conclusions: our data reinforce the notion that mast cell function is required for maintenance of certain tumor types and indicate that the Btk inhibitor Ibrutinib may be useful in treating pancreatic cancer.

Citation Format: Daniel Massó-Vallés, Erika Serrano, Jonathan R. Whitfield, Joseph J. Buggy, Nicole M. Sodir, Nesrine I. Affara, Lamorna Brown Swigart, Gerard I. Evan, Laura Soucek. Pharmacological inhibition of Bruton's Tyrosine Kinase (BTK) as a therapy for insulinoma and pancreatic ductal adenocarcinoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4956. doi:10.1158/1538-7445.AM2013-4956
Abstract 4960: COX-2 inhibition with celecoxib delays the progression of invasive mammary carcinoma in a murine model of collagen dense stroma.
Authors: Esbona Karla , Inman David R. , Eliceiri Kevin W. , Wilke Lee G. , Keely Patricia J.
Published: August 2014

Breast cancer is the most common invasive cancer in women causing over 40,000 deaths yearly in the United States. Increased mammographic density correlates with over four-fold greater risk for breast cancer, making it one of the most important risk factors known for this disease. High breast density is correlated to increased collagen in the breast tissue, and we have found that increased collagen in the Col1a1tm1jae mouse model promotes mammary tumor formation and progression. Elevated collagen density in vitro increases expression of PTGS2 (prostaglandin-endoperoxide synthase 2), the gene for COX-2, by over four fold. COX-2 over-expression is observed in 40% of invasive breast carcinoma cases and correlates with poor prognosis. Based on these findings, we hypothesized that inhibition of COX-2 may be an effective therapy in the context of mammary tumors arising in dense tissue. Celecoxib is a selective non-steroidal anti-inflammatory drug (NSAID) that specifically inhibits COX-2. To understand the mechanism by which COX-2 affects cell signaling and response to collagen matrix density, we utilized our previously characterized model of MMTV-PyVT tumors on a wild type (wt) or Col1a1tm1jae background. Col1a1tm1jae heterozygote and wt littermates were randomly assigned at 11 weeks of age to treatment with placebo or celecoxib at 400mg per kilogram body weight. Oral treatment was given daily for 21 days. We found that MMTV-PyVT tumors responded to celecoxib in a manner that is regulated by matrix density (p-value <.0001). Tumors that arose on the dense Col1a1tm1jae background were larger and more invasive (p-value <.0001). Endpoint tumor size was diminished in mice treated with a daily dose of celecoxib, which delayed the development of tumors and changed the structure of the dense matrix. The effect of celecoxib was not as prominent for masses which developed on the low density wt background. Immunohistochemistry of relevant markers in these tissues is ongoing and will further our understanding of the effects of COX-2 inhibition in dense matrices. These findings suggest that COX-2 has a direct role in modulating the configuration of dense matrices which promote a more invasive cancer effect. Moreover, these findings suggest that COX-2 may be an effective therapeutic target for women with dense breast tissue.

Citation Format: Karla Esbona, David R. Inman, Kevin W. Eliceiri, Lee G. Wilke, Patricia J. Keely. COX-2 inhibition with celecoxib delays the progression of invasive mammary carcinoma in a murine model of collagen dense stroma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4960. doi:10.1158/1538-7445.AM2013-4960
Abstract 4965: Metformin has an anticancer effect by repressing TWIST/N-cadherin signaling.
Authors: Rongbin Ge , Wang Zongwei , Olumi Aria F.
Published: August 2014

Introduction and Objective. Metformin, one of the most commonly used medications for treatment of type 2 diabetes, has emerged as a potential anticancer agent. The molecular mechanisms associated with the anti-cancer effect of metformin are poorly understood. We demonstrate, for the first time, that metformin inhibits prostate cancer proliferation through suppression of TWIST/N-cadherin signaling pathway.

Methods. RT–PCR, Western blot, immunofluorescence assays and confocal microscopy were applied to evaluate protein expression level. MTS assay and FACS analysis were applied to determine cellular proliferation. N-cadherin and TWIST-1 expression vectors were transfected into PC3 prostate cancer cells to establish stable cells with over-expression of N-cadherin and TWIST-1, respectively. Metformin-resistant prostate cancer cells were established by exposure to higher concentrations (10mM) of metformin over 4 weeks.

Results. Treatment with metformin (5mM) inhibited proliferation in three different types of cancer cells (PC3-prostate cancer cells; T24-bladder cancer cells and 786-O- kidney cancer cells). Metformin treatment suppressed expression of N-cadherin in all cell types. Similar findings were observed by confocal microscopy. In contrast to N-cadherin, expression of E-cadherin was not affected by metformin. Metformin-mediated repression of N-cadherin was dose and time- dependent in prostate cancer cells. PC3 prostate cancer cells with stable over-expression of N-cadherin became resistant to metformin-mediated inhibition. Stable PC3 prostate cancer cells, after selection for metformin, became resistant to metformin-mediated inhibition, and the metformin-resistant cancer cells had slightly higher baseline level of N-cadherin. In addition, in the metformin-resistant cells, N-cadherin levels were unchanged after treatment with metformin. The expression of AKT and AP-1, the downstream molecules of N-cadherin, closely correlated with expression of N-cadherin after treatment with metformin. Moreover, we also found that metformin inhibited expression of TWIST-1, a transcriptional activator of N-cadherin. Similar findings were observed by confocal microscopy. PC3 prostate cancer cells with stable over-expression of TWIST-1 became resistant to metformin-mediated inhibition.

Conclusions. We demonstrate that Metformin's anti-cancer therapeutic effect may be mediated through repression of the TWIST/N-cadherin signaling pathway.

Citation Format: Ge Rongbin, Zongwei Wang, Aria F. Olumi. Metformin has an anticancer effect by repressing TWIST/N-cadherin signaling. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4965. doi:10.1158/1538-7445.AM2013-4965

Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.