bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3430: Snail1 regulates invasion through uPA-uPAR signaling in prostate cancer
Authors: Randle Diandra D. , Odero-Marah Valerie
Published: June 2012

PURPOSE: Epithelial-mesenchymal transition (EMT) is a process by which cancer cells acquire mesenchymal properties, such as induction of N-cadherin, while epithelial-associated genes like E-cadherin are lost. This enables the cells to be more invasive, migratory and metastatic. Factors that can induce EMT include growth factors like transforming growth factor -β (TGF-β) and epidermal growth factor (EGF), and transcription factors like Snail1. Snail1-induced EMT promotes migration and invasion and we hypothesized that this may be mediated by urokinase (uPA) and its receptor (uPAR) activities. uPA, a serine protease, may be activated by integrin engagement to bind to its receptor, uPAR, and initiate a signaling cascade that regulates a variety of biological pathways including migration and invasion. DESIGN METHODS: 22Rv1, LNCaP and ARCaP human prostate cancer (PC) cells were stably transfected with empty vector control (Neo) or constitutively active Snail which led to increased cell migration and invasion. The levels of Snail, uPA, and uPAR were measured by Western Blot analysis. uPA activity in conditioned media was measured using the Elisa uPA activity assay kit. Also, cells were treated with PI3K and MAPK inhibitors at set time points. RESULTS: The data suggests that overexpression of Snail1 increased uPA and uPAR protein levels, while uPA activity was elevated in conditioned media from ARCaP, LNCaP and 22Rv1 cells transfected with Snail. In addition, MAPK inhibitor, UO126, inhibited ERK activity within 30 min up to 72 h, and decreased uPA activity within 24 h. CONCLUSION: Therefore, Snail-mediated cell migration and invasion in human prostate cancer cells may occur via the regulation of uPA/uPAR and MAPK activities.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3430. doi:10.1158/1538-7445.AM2011-3430
Abstract 3431: Regulation of integrins AlphaV Beta3 and focal adhesion kinase signaling by PTTG in induction of EMT
Authors: Shah Parag P. , Kakar Sham S.
Published: June 2012

Pituitary tumor transforming gene (PTTG) is a well-studied oncogene for its role in tumorigenesis. PTTG expression levels correlate with the tumor development, growth and metastasis and serve as a marker of malignancy in several cancer types including lung. Epithelial to mesenchymal transition (EMT) is a crucial step in tumor progression and metastasis, during which epithelial cells lose their polarity and cell-cell adhesion. Integrins are transmembrane proteins which bind ligands found in the extracellular matrix. Interactions between the extracellular matrix and the actin cytoskeleton commonly take place at focal adhesions on the cell surface that contain localized concentrations of integrins, signaling molecules, and cytoskeletal elements. Talin forms a direct interaction with the integrin cytoplasmic domain, and interacts with cytoskeletal elements (actin) and signaling factors. The present study was focused to define the regulation of integrins and FAK pathway by PTTG in induction of EMT. For our studies, we used lung cancer cell lines A549 and H1299 and infected with adenovirus expressing PTTG cDNA or adenovirus expressing control GFP. Using Real Time PCR and immunohistochemistry and FACS analysis, we observed that overexpression of PTTG in cells resulted in a significant increase in the expression of integrins αv and β3 in both cell lines compared to uninfected cells or cells infected with adenovirus expressing GFP. These results were confirmed by the down-regulation of PTTG expression using adenovirus expressing PTTG-specific siRNA that showed a significant decrease in the expression of integrins αv and β3. Western blot analysis revealed increased phosphorylation of FAK on overexpression of PTTG. Analysis of downstream signaling genes such as Paxillin, Metavinculin and Rac 1 by quantitative real time PCR analysis showed positive correlation between levels of PTTG and these genes. Treatment of A549 and H1299 cells with the αvβ3 antagonist echistatin (RGD peptide) and siRNA specific for integrin αv resulted in a decreased in phosphorylation of FAK as well as expression of downstream signaling genes Paxillin, Metavinculin and Rac 1. The Vinculin and Phallodoin are responsible for the functional link of FAK to the actin cytoskeleton. Disruption of actin cytoskeleton was confirmed with immunostaining. Taken together our results suggest for the first time an important role of PTTG in regulation of integrins αv and β3 leading to change in Focal Adhesion Kinase (FAK) pathway resulting in induction of EMT.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3431. doi:10.1158/1538-7445.AM2011-3431
Abstract 3434: Thromboxane a2 receptor beta is induced by the epithelial to mesenchymal transition of breast cancer cells and contributes to breast cancer motility and metastasis
Authors: Zhang Xuejing
Published: June 2012

Previous studies in our lab showed that thromboxane a2 receptor (TP) activation has profound effect on tumor cell cytoskeleton and contraction through activation of RhoA and depletion of TP reduces the metastatic dissemination of breast cancer cells in vivo. We report here that TP-beta expression is induced during epithelial-mesenchymal transition (EMT) and its activation is required for efficient migration and invasion of breast cancer cells. Elevated TP-beta expression is found associated with metastasis in tissues obtained from breast cancer patients. Breast cancer cell lines with high TP-beta expression present more malignant phenotype than the cells with low or no TP-beta expression. It is known that TP-alpha and TP-beta expressions are under the control of different promoter P1 and P3, respectively. Downregulation of E-cadherin in immortalized human mammary epithelial cells (Rao1) and breast cancer cells (MCF7) induces morphological changes of the cells to the mesenchymal type and upregulation of transcription factors that regulate EMT. Interestingly, TP-beta expression and P3 promoter activity are increased in the E-cadherin knock down cells, in contrast the level of TP-alpha remains unchanged. Further, beta-catenin/Tcf/LEF complexes are found to bind to and activate P3 promoter. Finally, a TP-beta specific inhibitor CAY10535 blocks the increased migration/invasion ability of MCF7 cells that is triggered during EMT. Together, these results indicate that beta-catenin released from membrane E-cadherin binding during EMT stimulates TP-beta expression by activating P3 promoter activity together with Tcf/LEF complexes and TP-beta activation enables enhanced migratory capacity, invasiveness of breast cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3434. doi:10.1158/1538-7445.AM2011-3434
Abstract 3437: Epithelial-mesenchymal transition spectrum characterized by an ovarian cancer cell line library defines an aggressive metastable state
Authors: Huang Ruby YJ , Wong Meng Kang , Chung Vin Yee , Ng Aloysius , Lee You Fei , Pietschmann Elke , Mori Seiichi , Matsumura Noriomi , Thiery Jean Paul
Published: June 2012

Epithelial-mesenchymal transition (EMT) has been implicated to be one of the driving mechanisms of carcinoma progression in many solid tumours, such as breast, colorectal, and ovarian cancer. It explains how carcinoma cells invade and metastasize by transforming an epithelial state via a metastable state to a mesenchymal state. Many studies have addressed the epithelial and mesenchymal states. However, understanding of the metastable state is still limited. In this study, we describe a model system for appraising the spectrum of EMT by using 42 well-characterized ovarian cancer cell lines. Phenotypic EMT characterization reveals 4 subgroups which represent different epithelial-mesenchymal compositions on the EMT spectrum. Genome-wide transcriptional characteristics and recurrent genomic alterations specific for each subgroup are also described. We also demonstrate that this EMT spectrum can be used to refine the analysis of data generated in cell-based functional studies. Ovarian cancer cells harbouring intermediate phenotypes are more migratory, invasive, anoikis resistant, and more spheroidogenic. This ovarian cancer cell line EMT spectrum allows fine tuning of the EMT process by further characterizing the metastable state, which can help reduce heterogeneity. Several candidate genes were applied in a human ovarian carcinoma collection to determine the EMT status by using methods such as quantitative PCR. We conclude that this EMT spectrum library can contribute to the identification of molecular features that serve as predictive diagnostic markers or therapeutic targets associated with EMT.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3437. doi:10.1158/1538-7445.AM2011-3437
Abstract 3438: Oncogenes-induced interferon-beta: modulation of tranformation phenotypes through interferon-ISG15 autocrine signaling
Authors: Tsai Yu-Chen , Pestka Sidney , Wang Lu-Hai , Runnels Loren W. , Liu Leroy F.
Published: June 2012

ISG15 (interferon-stimulated gene 15), an ubiquitin-like protein (UBL), is a new tumor marker whose expression has been correlated with disease progression in bladder cancer and suggested to be prognostic for breast cancer. However, the molecular basis for, and the function of, ISG15 overexpression in tumors remain unclear. Here, we show that ISG15 overexpression in both breast cancer cells and oncogenic Ras-transformed mammary epithelial cells (MCF-10A) is due to elevated secretion of interferon-β. Moreover, interferon-β-ISG15 autocrine signaling in oncogenic Ras-transformed MCF-10A cells results in increased colony formation efficiency. Interestingly, gain of epithelial-mesenchymal transition (EMT) characteristics, including appearance of spindle-shaped cell morphology and EMT markers, as well as increased cell migration, in Ras-transformed MCF-10A cells is also dependent on interferon-β-ISG15 autocrine signaling. Our results demonstrate for the first time that tumor cell-secreted interferon-β may modulate tumor cell growth and migration through ISG15, suggesting potential cancer therapeutic approaches by antagonizing interferon autocrine signaling.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3438. doi:10.1158/1538-7445.AM2011-3438
Abstract 3441: Cross-species expression profiling identifies Forkhead-Box Q1 as a promoter of epithelial-mesenchymal transition and breast cancer metastasis
Authors: Zhang Haijun , Meng Fanyan , Liu Gang , Zhang Bin , Zhu Jun , Wu Feng , Ethier Stephen P. , Miller Fred , Wu Guojun
Published: June 2012

Utilizing a cross-species expression profiling strategy that combines microarray techniques and metastatic cell lines of human and mouse origins, 22 up-regulated and 12 down-regulated genes were identified as an essential genetic program in highly-metastatic cell lines. The correlation of all gene expression levels and metastasis potential was confirmed by RT-PCR in a set of human and mouse cancer cells. Among these genes, Forkhead-Box Q1 (Foxq1) is a transcription factor with a function in metastasis that has not yet been reported upon. We showed that ectopic expression of Foxq1 increased cell migration and invasion in vitro; significantly enhanced lung metastatic capabilities of mammary epithelial cells in vivo and resulted in a marked epithelial to mesenchymal transition (EMT). In contrast, knockdown of Foxq1 expression led to the opposite change in vitro and in vivo. Neither ectopic expression nor knockdown of Foxq1 had significant effects in cell proliferation and colony formation in vitro. Additionally, we showed that Foxq1 repressed E-cadherin expression by binding to the E-box in its promoter region. Finally, we found that the expression of Foxq1 is regulated by TGF-β1, and that knockdown of Foxq1 blocked EMT induced by TGF-β1 treatment at morphological and molecular levels. Our study highlights the feasibility of cross-species expression profiling as a strategy in identifying metastasis-related genes. It also reveals that the inducement of EMT is a potential mechanism for the novel metastasis-promoting function of Foxq1 in breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3441. doi:10.1158/1538-7445.AM2011-3441
Abstract 3451: Interactions between N-myc and Sox9 promote medulloblastoma and determine cell fate decisions in cerebellar neural stem cells
Authors: Swartling Fredrik J. , Persson Anders I. , Lau Jasmine , Northcott Paul A. , Grimmer Matthew R. , Chesler Louis , Perry Arie , Phillips Joanna J. , Taylor Michael D. , Weiss William A.
Published: June 2012

The proto-oncogene MYCN (N-myc in mice) regulates normal brain development, and is often misexpressed in childhood brain tumors, including medulloblastoma. While most medulloblastoma arise independently of Sonic hedgehog (Shh), about ∼25% of are Shh-dependent and have a more favorable prognosis. We recently induced Shh-independent classic and large cell anaplastic medulloblastoma by driving MYCN from the glial Glutamate Transporter 1 promoter in a tet-regulated transgenic mouse model (Swartling et al, 2010). To characterize cell of origin, we used BrdU labeling in premalignant transgenic mice, demonstrating increased proliferation in cerebellar Bergmann glial cells. Bergmann glia showed high levels of glial marker GFAP as well as the transcription factor Sox9. Whereas neural stem cells (NSCs) from normal perinatal cerebellum contained a high proportion of Sox9-positive cells, primary cultures of tumor spheres showed low levels of Sox9, suggesting that MYCN suppresses Sox9 during medulloblastoma progression. To clarify mechanism, we transduced wild-type (WT) or mutationally-stabilized N-myc-T58A into GFAP-positive NSCs from perinatal murine cerebellum. Transplantation of N-myc-WT NSCs was insufficient for tumor formation. N-myc-T58A cerebellar NSCs generated both Shh-dependent and Shh-independent medulloblastoma, as a function of prenatal or postnatal cerebellar age, respectively. Expression of Sox9 correlated directly with Sonic Hedgehog (Shh) dependence in both murine and human medulloblastoma samples. In addition, forced expression of Sox9 induced Shh-dependence and self-renewal in the Shh-negative mouse medulloblastoma spheres. Our data suggest 1). A glial cell of origin for MYCN-driven medulloblastoma, and 2). Sox9 as a critical target for MYCN during medulloblastoma initiation, with activation of Sox9 leading to Shh-dependence, and inhibition of Sox9 leading to Shh-independent medulloblastoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3451. doi:10.1158/1538-7445.AM2011-3451
Abstract 347: Gene expression signature of the gross morphology and the specific role of EpCAM in hepatocellular carcinoma
Authors: Tanaka Shinji , Murakata Ayano , Mogushi Kaoru , Yasen Mahmut , Ban Daisuke , Noguchi Norio , Irie Takumi , Kudo Atsushi , Nakamura Noriaki , Inazawa Johji , Tanaka Hiroshi , Arii Shigeki
Published: June 2012

Tumor morphologies have been identified to associate with their malignant properties such as the invasive, metastatic and/or even recurrent potentials after the cancer treatment. Hepatocellular carcinoma (HCC) is known to demonstrate a variety of morphological appearances. Eggel's nodular type of HCC is morphologically subclassified into single nodular type (SN), single nodular type with extranodular growth (SNEG), and confluent multinodular type (CM), but their biomolecular differences remain unclear. In this study, the clinicopathologic characteristics as well as genome-wide gene expressions were analyzed in relation to the gross morphology of curatively resected HCC. Among 275 patients with nodular type HCC (124 SN-type, 91 SNEG-type and 60 CM-type), significantly poor prognosis was recognized in CM-type in overall survival (p=0.0020) as well as recurrence-free survival (p=0.0066) after the curative resection. The genome-wide expression patterns were evaluated by 3D principal component analysis using Kruskal-Wallis test, and p-value distribution histograms using Mann-Whitney U test. Both of the analyses on the gene expression signature revealed the significant deference in CM-type HCC compared to either SN or SNEG-type HCC. In particular, a stem cell marker EpCAM was dominantly expressed in CM-type HCC. Immunohistochemical studies confirmed the specific expression of EpCAM in HCC cancer cells of CM-type. In multivariate analysis, the gross morphology of CM type was significantly associated with EpCAM expression (p=0.0133), AFP-L3 level (p=0.0311) and the portal vein invasion (p=0.0138). Furthermore, EpCAM was predictive for poor prognosis in overall and recurrence-free survivals of patients with CM-type HCC (p=0.0082 and p=0.0043, respectively). Our studies suggested the distinct signature of gene expression closely related to the morphological progression in HCC. Especially, EpCAM might play a critical role in the aggressiveness of CM-type HCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 347. doi:10.1158/1538-7445.AM2011-347
Abstract 3476: Blockade of endothelial Notch diminishes tumor growth and perfusion
Authors: Patenaude Alexandre , Chang Linda , Diaz Erika , Fuller Megan , Wong Fred , Karsan Aly
Published: June 2012

Canonical Notch signaling comprises a family of receptors and ligands that modulate cell fate and differentiation. Upon ligand binding, Notch receptors undergo a series of cleavages that culminate in the translocation of the intracellular domain to the nucleus, resulting in transcriptional activation through the derepression and activation at CSL-bound promoters. Notch activity is essential for embryonic vascular development and was recently also shown to be important for adult neovascularization. Notably, blocking Notch signaling by inhibition of the ligand Dll4 increased endothelial proliferation and sprouting, but resulted in non-perfused vasculature and tumor growth inhibition. Moreover, Dll4 inhibition was shown to diminish vascular mural cells, such as pericytes, in tumors. Whether these effects of Dll4 blockade on tumor vasculature resulted specifically from Notch inhibition in endothelial cells remains to be fully elucidated. We investigated this question using a tetracycline-inducible binary transgenic system, in which Notch is blocked by the expression of a dominant-negative form of mastermind-like 1 (dnMAML-GFP) under the control of the VE-cadherin promoter. Lewis lung carcinoma (LLC) cells overexpressing VEGFA (LLC-VEGFA) were implanted subcutaneously in the dorsa of double transgenic (Tg) or control mice. Tumors in the double Tg mice were significantly smaller than in control single Tg mice. Moreover, blood vessel perfusion from LLC-VEGFA tumors was significantly reduced in the double Tg mice compared to the control Tg mice. However, neither the abundance nor the branching architecture of LLC-VEGFA tumor blood vessels appeared to be different in the double Tg mice. Pericyte abundance, maturation and distribution relative to blood vessels did not change in the double Tg mice. Flow cytometry of tumor-derived cells and fluorescence microscopy analysis of tumor cryosections confirmed that dnMAML-GFP is expressed specifically in endothelial cells. Our data suggest that specific blockade of Notch in endothelial cells, induced by dnMAML-GFP, affects tumor growth through a mechanism different from previously-reported Dll4 inhibition studies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3476. doi:10.1158/1538-7445.AM2011-3476
Abstract 350: High-throughput drug screens identify novel synthetic lethal interactions with MLH1-deficient cancers
Authors: Hewish Madeleine , Lord Chris J. , Martin Sarah A. , Cunningham David , Ashworth Alan
Published: June 2012

Mismatch Repair (MMR) deficiency occurs in some inherited and somatic malignancies as a consequence of mutation or epigenetic silencing. Since MMR-deficient tumours exhibit tolerance to many commonly used chemotherapeutic agents, there is an unmet clinical need to develop novel treatment strategies for this group of cancers.

We utilized an in vitro isogenic colorectal model, the MLH1-deficient HCT116, and its isogenic comparator HCT116+Chr3, to perform high throughput screening of chemical libraries to identify novel drugs which were relatively cytotoxic to MLH1-deficient tumour cells compared with their MLH1-proficient comparators. The assay readout was cellular viability. ‘Hit’ drugs were then validated across a range of drug concentrations to determine the likelihood of ‘off target’ effects and potential clinical applicability, and further validated in clonogenic assays. Amongst the validated hits were cytosine arabinoside (ara-C), ethinyl oestradiol and desferoxamine. Ara-C was selected for further investigation and validated in two other in vitro models of MLH1 deficiency. Other nucleoside analogs were also investigated for MLH1-deficient selectivity and a lesser degree of selectivity was observed with gemcitabine. Compatible with the defective cell cycle checkpoints of MLH1-deficient cells, we have subsequently demonstrated that the excess cytotoxicity is associated with an increase in apoptosis that coincides with release from initial G1/early S phase arrest, suggesting that MLH1-deficient cells undergo mitotic catastrophe.

In summary, we have used high throughput screening to identify possible new strategies for the treatment of MLH1-deficient cancers. Further mechanistic studies are ongoing. Combinations of drugs known to be MLH1-deficient selective are also being tested with a view to increasing the therapeutic window of a possible MLH1-deficient therapeutic strategy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 350. doi:10.1158/1538-7445.AM2011-350
Abstract 3503: Targeting chemo-resistant colon cancer cells by the combination of dasatinib and curcumin: A novel therapeutic strategy
Authors: Nautiyal Jyoti , Yu Yingjie , Kanwar Shailender S. , Patel Bhaumik B. , Majumdar Adhip P.
Published: June 2012

Metastatic colorectal cancer remains a serious health concern with poor patient survival. 5-Fluorouracil (5-FU) or 5-FU plus oxaliplatin (FOLFOX), the standard therapy for colorectal cancer, has met with limited success. Recurrence of the tumor after chemotherapy could partly be explained by the enrichment of the chemo-resistant sub-population of cancer stem cells (CSCs) that possess the ability for self-renewal and differentiation into different lineages in the tumor. Therefore development of therapeutic strategy that target CSCs is highly desirable in reducing the risk of relapse and metastasis. The current investigation was undertaken to examine the effectiveness of the combination therapy of dasatinib (a Src inhibitor) and curcumin (a dietary ingredient) in inhibiting the growth and other properties of carcinogenesis of chemo-resistant colon cancer cells that are enriched in CSCs. Human colon cancer cells HCT-116 (p53 wild type; K-ras mutant) and HT-29 (p53 mutant; K-ras wild type) were used to generate FOLFOX resistant {referred to as chemoresistant (CR)} cells. The CR cells showed higher expression of CSCs markers, cell invasion potential and ability to form colonospheres, compared to the corresponding parental cells. The combination therapy of dasatinib and curcumin demonstrated synergistic interactions in CR-HCT-116 and CR-HT-29 cells. This caused inhibition of cellular growth, invasion and colonosphere formation and reduction in CSC population as evidenced by decreased expression of CSC specific markers: CD133, CD44, CD166 and ALDH. In conclusion, we propose that the combination therapy of dasatinib and curcumin may be an effective therapeutic strategy for re-emergence of chemo-resistant colon cancer by targeting CSC sub-population.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3503. doi:10.1158/1538-7445.AM2011-3503
Abstract 3516: Combinations of chemotherapy with bevacizumab in a xenograft model of human ovarian carcinoma
Authors: Oliva Paolo , Decio Alessandra , Castiglioni Vittoria , Bassi Andrea , Belotti Dorina , Bani Maria Rosa , Giavazzi Raffaella
Published: June 2012

Ovarian cancer is the leading cause of death from gynecologic malignancy in women of the Western countries. The standard first-line therapy for this type of tumor is the combination of paclitaxel (PTX) and carboplatin. Vascular endothelial growth factor (VEGF) performs as an angiogenic and permeability factor in ovarian cancer, and its over-expression has been associated with poor prognosis. Inhibition of malignant ascites and tumor growth has been shown by blocking the VEGF/VEGFR pathway. Early clinical studies with bevacizumab, the monoclonal antibody directed against VEGF, have demonstrated efficacy in ovarian carcinoma patients as single and combined treatment.

The aim of this study was to evaluate the effect of chemotherapy in combination with bevacizumab given at different regimens in an in vivo model of human ovarian carcinoma xenograft. Nude mice were transplanted intraperitoneally with 1A9-luc ovarian carcinoma cells, over-expressing luciferase, that allows to monitor the tumor growth and dissemination in the peritoneal cavity of the mice by bioluminescence imaging analysis.

Mice were treated with PTX (20 mg/kg) or cisplatin (DDP, 3 mg/kg) as single therapy or in combination; bevacizumab (150 µg/mouse) was given concurrently for 3 weeks and either continued after the suspension of chemotherapy (maintenance regimen) or stopped.

Untreated mice developed heavy tumor burden in the peritoneal cavity with a median survival time (MST) of approximately 24 days. PTX or DDP given alone only marginally affected the survival of the mice. The addition of bevacizumab to PTX or DDP significantly improved the survival of the mice with an increased life span (ILS) of 117% and 75% respectively; this was ameliorated by the continuation of bevacizumab treatment after chemotherapy (ILS = 158% and ILS = 100% respectively).

The combined administration of PTX and DDP plus bevacizumab further improved the survival of the mice (ILS>190%); most importantly, maintaining the treatment with bevacizumab (up to 90 days) after the suspension of chemotherapy resulted in tumor free mice. Monitoring the tumor burden by bioluminescence imaging analysis confirmed the different tumor response among the treatment groups.

These findings show a benefit from the combination of PTX/DDP plus bevacizumab in ovarian carcinoma, and are in favor of the maintenance regimen with bevacizumab.

Supported by AIRC and Fondazione Cariplo

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3516. doi:10.1158/1538-7445.AM2011-3516
Abstract 3519: Histone deacetylase inhibitors upregulates thymidine phosphorylase gene and protein expression and synergize with capecitabine in breast cancer cells
Authors: Gennaro Elena Di , Cintio Alessandra Di , Piro Geny , Chianese Maria I. , Bruzzese Francesca , Budillon Alfredo
Published: June 2012

Capecitabine is a pro-drug which was designed to take advantage of the increased levels of thymidine phosphorylase (TP), a key enzyme for its conversion to 5-florouracil (5-FU), observed in tumours as opposed to normal tissues, potentially allowing for selective toxicity. Capecitabine is a valuable substitute for bolus or infusion 5-FU either as monotherapy or in combination with other cytotoxic drugs in the treatment of several tumor types including breast cancer. We have recently demonstrated for the first time, that the histone deacetylase-inhibitor (HDAC-I) vorinostat induces synergistic antitumour effects in combination with capecitabine by up-regulating, in vitro and in vivo, in colorectal cancer cells but not in ex vivo treated peripheral blood lymphocytes, the mRNA and protein expression of TP. We have also demonstrated that TP knockdown by a specific siRNA significantly impairs the synergistic apoptotic cell death induced by vorinostat/capecitabine combination. In this study we demonstrated a time and dose-dependent induction of TP mRNA and protein expression by several HDAC-Is in different breast cancer cell lines such MCF-7, SKBR3, MDA-MB-231and MDA-MB-468 cells. Interestingly, this effect was shared by pan-HDAC-Is such as panobinostat (LBH589), trichostatin A (TSA) or vorinostat and by class I HDAC-Is such as valproic acid (VPA) and entinostat (MS275), but not by the specific inhibitor of HDAC-6 tubacin, indicating that targeting class I HDACs is crucial for TP induction. Moreover, the mechanism of TP induction is dependent on a transcriptional effect since preliminary data showed that HDAC-Is did not interfere with TP protein stability. On these bases we investigated potential antitumor interaction between capecitabine and either vorinostat or panobinostat or VPA, demonstrating synergistic antiproliferative effects in all breast cancer cells independently of p53, ER or Her2 status. Overall, this study suggests that HDAC-Is, by upregulating TP expression, may improve the therapeutic index of capecitabine representing an innovative antitumour strategy for the treatment of breast cancer that warrants further clinical evaluation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3519. doi:10.1158/1538-7445.AM2011-3519
Abstract 3529: Evaluation of PRI vitamin D analogues, alone or with enhancers, as antileukemia agents
Authors: Zhang Jing , Baurska Hanna , Chen-Deutsch Xiangwen , Gocek Elzbieta , Harrison Jonathan S. , Kielbinski Marek , Danilenko Michael , Kutner Andrzej , Marcinkowska Ewa , Studzinski George P.
Published: June 2012

The physiological form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25D) has well established anti-cancer activity, but its potential use in the clinic is limited by the danger of life-threatening hypercalcemia. Efforts to overcome this difficulty include structural modifications of 1,25D, as well as enhancement of its activity by other compounds. In this study we have combined these two approaches by comparison of the efficacy of the induction of differentiation in AML using analogs synthesized in the Warsaw Pharmaceutical Research Institute(PRI), alone or with its enhancers carnosic acid (CA), a plant antioxidant, and SB202190 (SB), an inhibitor of p38MAPK α, β. The PRI analogs have previously been shown to have low calcemic activity in animals, and while the analogs PRI-1906 (24-ene-1,25-dihydroxy vitamin D2) and PRI-2191([24R]-1,24-dihydroxyvitamin D3) had greater activity on established AML cell lines than their congeners, their relative potency on AML blasts was not entirely clear. We therefore studied an additional cohort of 20 patients with AML, and when sufficient cell numbers were available the analogs were supplemented with CA and SB to form a “differentiation cocktail” for study ex vivo. In this series we found that there was variability in the differentiation responses between individual patients, but the majority (∼90 %) of the blast samples responded to 1,25D and to both analogs. The intensity of the response was greatly increased when the “differentiation cocktail” was used rather than the analog alone, and while there was a similarity between the potencies of PRI-1906 and PRI-2191, the most robust responses in this series were seen when PRI-1906, alone or with CA and SB, was used. The strength of responses correlated with the enhancement of VDR expression in treated cells studied by Western blots. We conclude that PRI analogs 1906 and 2191 supplemented with CA and SB merit further scrutiny as candidates for chemoprevention/ differentiation therapy of AML.

(Supported by USAPH NIH grant RO1 CA 44722-20 from NCI to GPS, the ISF grant 778/07 to MD, by Wroclaw Research Center EIT+ Operational Programme Innovative Economy, 1.1.2; POIG 01.01.02-02-003/08-00 to EM, and by the Foundation for Polish Science to EG).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3529. doi:10.1158/1538-7445.AM2011-3529
Abstract 3537: Synergistic effect of a Hedgehog pathway inhibitor in combination with erlotinib on multiple carcinoma cell lines
Authors: Sheng Qing , Li Hui , Do Hanh , Liu Natalie , Xu Zhidong , Jablons David , He Biao
Published: June 2012

The aberrant activation of Hedgehog(Hh)/Gli signaling has been implicated in a broad spectrum of malignant tumors. Targeted inhibition at the cell membrane of Hh pathway, for example with Smoothened(Smo) and Hh inhibitors, has shown promising preclinical and clinical anti-cancer activity. However, a growing body of evidence has revealed additional mechanisms in the activation of the Gli pathway that are independent of Hh/Smo regulation. These mechanisms are stimulated by the cross-talk between downstream components of the Hh/Smo and other oncogenic signaling pathways, such as the Epidermal Growth Factor Receptor (EGFR) pathway. Based on this, we hypothesized that the simultaneous inhibition of the EGFR pathway and Gli pathway would result in synergistic anti-tumor effects. To test this hypothesis, we used erlotinib, an EGFR tyrosine kinase inhibitor (TKI), in combination an Hh pathway inhibitor on various lung and mesothelioma cancer cell lines. It has been demonstrated that erlotinib and other TKIs are active in lung cancers with EGFR gene mutations, while not as effective in those with wild type EGFR. However in our studies, the application of the Hh pathway inhibitor sensitized EGFR wild type cells to erlotinib treatment with more than a 10-fold decrease of IC50 in multiple lung cell lines. In addition, the dual treatment resulted in promising synergism in both mesothelioma and lung cancer cell lines with a combination index of less than 0.7. To study the mechanism of crosstalk between the two pathways, we have examined the activities of EGFR, Hh and Wnt pathways in single and dual treatments. Based on our results, we believe that dual inhibition of Hh/Gli and EGFR pathways may be a promising targeted therapy for lung cancers and mesothelioma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3537. doi:10.1158/1538-7445.AM2011-3537
Abstract 3544: Jak/Stat signaling: A potential target for pancreatic cancer management
Authors: Jingjing Gong , Batth Izhar S. , Kumar Addanki P.
Published: June 2012

NexrutineR (Nx) isolated from the bark of Phellodendron amurense is being sold as an anti-inflammatory herbal supplement over the counter in the US. Recent studies from our laboratory demonstrated its potential as an anti-prostatic agent by targeting multiple signaling pathways including Akt/CREB/NFkB/Cyclin D1/Cox-2 both in vitro and in vivo. Given the importance of some of these signaling pathways in multiple cancers, we explored its role in pancreatic cancer (PanCA) using variety of cell lines. Human pancreatic cancer cells that differ in the status of K-Ras (BxPC-3 with wild type K-Ras and Capan-2 with mutant K-Ras), non- tumorigenic HPNE-Ras, MIAPC and ASPC-1 were tested for growth inhibition, apoptosis, necrosis, Cox-2 expression and activity following treatment with Nx. Our data indicate that Nx can significantly inhibit proliferation of these cell lines differentially through induction of apoptosis and necrosis without any significant effect on cell cycle profile. Investigation of molecular mechanism of action identified a role for Jak1 and transcription factors NFkB and Stat3. Western blotting data show that Nx can inhibit the protein levels of pStat3 and Jak1 effectively without influencing the protein levels of total Stat3. Similarly Nx treatment decreased the DNA binding activities of both NFkB and Stat3. Chromatin immunoprecipitation assays revealed the binding of Stat3 to Cox-2 promoter. In addition combining Nx with Gemcitabine (standard of care treatment for PanCA) demonstrated strong synergistic growth inhibitory activity through modulation of Stat3. Overall, the present study unveils a novel interplay between Jak1/Stat3 and NFkB signaling in pancreatic cancer cells. These data further suggest that the targeted disruption of Jak1/Stat3 and NFkB may represent a valid therapeutic approach in this cancer. Supported by NCCAM (APK).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3544. doi:10.1158/1538-7445.AM2011-3544
Abstract 3549: Synthetic triterpenoid CDDO-Me induces apoptosis in pancreatic cancer cells by inducing oxidative stress
Authors: Deeb Dorrah , Gao Xiaohua , Dulchavsky Scott A. , Gautam Subhash C.
Published: June 2012

Pancreatic ductal adenocarcinoma (PDA) is a highly lethal human malignancy with dismal prognosis and few effective therapeutic options. Novel agents that are safe and effective are urgently needed. Oleanolic acid-derived synthetic triterpenoids are potent antitumorigenic agents, but their efficacy for pancreatic cancer has not been investigated. We have found that methyl-2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oate (CDDO-Me), a oleanane-derived synthetic triterpenoid exhibits potent anticancer activity against human pancreatic cancer cell lines. CDDO-Me inhibited the growth of both K-ras mutated (MiaPaca2, Panc1 and Capan2) and wild-type K-ras (BxPC3) pancreatic cancer cells at very low concentrations. The growth inhibitory activity of CDDO-Me was due to the induction of apoptosis characterized by increased annexin-V-FITC and cleavage of PARP-1 and procaspases-3, -8 and-9. Killing of PDA cells by CCDO-Me involved the generation of reactive oxygen species (ROS) as determined from the oxidation of H2DCFD by flow cytometry and its inhibition by general purpose antioxidant NAC. CDDO-Me was also highly active against gemcitabine resistant MiaPaCa2 cells expressing markers of tumor-initiating cells (cancer stem-like cells?). An ongoing pilot experiment has shown the antitumor activity of CDDO-Me against BxPC3 xenograft in vivo. Together, these data demonstrated potential of CDDO-Me for treating pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3549. doi:10.1158/1538-7445.AM2011-3549
Abstract 355: Genetic alterations in 17β-hydroxysteroid dehydrogenase type 2 and 7 correlates with mRNA-expression but not estrogen levels in breast cancer
Authors: Straume Anne Hege , Knappskog Stian , Lønning Per Eystein
Published: June 2012

Background: Estrogens are believed to play an important role in both development and sustained growth of breast cancer. Estradiol (E2), the most biologically active estrogen, is often elevated in breast cancer tissue, and high plasma levels of E2 are correlated to increased breast cancer risk in postmenopausal women. Previously, we have shown that uptake of estrogen due to binding to the estrogen receptor (ER), is a probable determinant of intratumoral E2. Furthermore, we reported that increased expression of 17β-hydroxysteroid dehydrogenase type 7 (HSD17B7) might explain the increased ratio of E2 to estrone (E1) in breast tumors compared to non-tumorous breast tissue. Here we explored whether genetic alterations in HSD17B-isoforms might predict estrogen disposition in breast cancer.

Materials and methods: Tumor and normal breast tissue specimens were collected from 50 patients (37 postmenopausal and 13 premenopausal women) undergoing mastectomy. Samples were snap-frozen in the theatre. To evaluate potential mechanisms regulating intra-tumor and plasma estradiol levels, HSD17B2 and HSD17B7 were evaluated for mutation status, promoter hypermethylation and gene copy number. In addition, we quantified the transcription level of two HSD17B7 isoforms (HSD17B7_I and HSD17B7_II).

Results: We identified a novel single nucleotide polymorphism (SNP) in the HSD17B7 promoter region (transcription start + 56: T>C) and found it correlated to increased enzyme expression level (p = 0.016). Also, we observed a novel SNP in the HSD17B2 promoter region (transcription start + 35: C>T) associated with a lower expression level (p = 0.019). Nineteen patients were found to harbour HSD17B7-duplications predicting elevated mRNA-expression levels (p = 0.056). While some tumors revealed promoter hypermethylation in both HSD17B2 and 7, hypermethylation status was not associated with low mRNA-levels. None of these genetic alterations correlated to plasma or tissue estrogen levels.

Conclusion: Genetic alterations in HSD17B2 and 7 were found to influence the transcription level of these genes, but not estradiol levels in plasma or breast cancer tissue.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 355. doi:10.1158/1538-7445.AM2011-355
Abstract 3571: Exploratory biomarker discovery for clinical development of ARQ 087, a potent pan-FGFR kinase inhibitor
Authors: Yu Yi , Gu Xiubin , Nakuci Enkelada , Zhao Xiaolan , Chang Edward , Szwaya Jeff , Castro Jenn , Cousens Laura , Bull Cathy , Wang Yunxia , Savage Ron , Waghorne Carol , Chen Chang-Rung , France Dennis S. , Clark Edwin , Chan Thomas C.K.
Published: June 2012

Fibroblast growth factor receptor (FGFR) tyrosine kinase family members have gained increasing attention as potential therapeutic targets. Gene amplification, or gain-of-function translocations and mutations of these receptors, have been implicated in a variety of cancers including breast, gastric, bladder, ovarian, endometrial, lymphoma and myeloma. We have previously described the biological profiling of ARQ 087, a potent small-molecule pan-FGFR kinase inhibitor that shows anti-tumor activity in FGFR dysregulated tumor cells in vitro and in vivo. A number of cell lines with genetically-altered FGF receptors were identified that were sensitive in anti-proliferative assays to ARQ 087, including FGFR2 amplified gastric carcinoma lines KATO III and SNU-16, and endometrial lines AN3CA, MFE-296 and MFE-280 harboring FGFR2 mutants, as well as a breast cancer cell line with increased FGFR1 gene copy (MDA MB-157). Western blot pharmacodynamic analysis demonstrates that ARQ 087 inhibits FGFR phosphorylation and downstream pathway markers in these cell lines in a concentration-dependent manner. Using antibody arrays specific for known cytokines as well as regulatory proteins involved in angiogenesis and apoptosis, we have identified a number of protein biomarkers in cell lysates and in conditioned media of sensitive cell lines that changed in response to ARQ 087 exposure. Three proteins (cytochrome c, clusterin, and HTRA2) decreased in SNU-16 (ARQ 087-sensitive, FGFR amplified) but not DLD1 (ARQ 087-resistant, non FGFR expressing) cells. VEGF decreased and IL-1rα increased in SNU-16 but not in DLD1 conditioned media in response to ARQ 087. Furthermore, analysis of mouse plasma from animals bearing AN3CA tumors treated with ARQ 087 revealed a decrease in human VEGF, CXCL16, MMP-9, Serpin E1 and MIF and an increase in RANTES, IL-1β, IP-10, SDF-1, IL-1rα. TNFα, GM-CSF, IL-2, sTREM-1, sICAM-1, MIP-1β, IL-8. In summary, we have identified a number of cell lines from a broad cell line screening campaign that exhibited dysregulated FGFR pathway function and are sensitive to the anti-proliferative effects of ARQ 087. These cell lines, in turn, have been used as models in which to identify candidate biomarkers that may greatly facilitate subsequent clinical evaluation of this molecularly targeted anti-tumor agent.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3571. doi:10.1158/1538-7445.AM2011-3571