bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5191: Periostin signaling in breast cancer stem cells
Authors: Lambert Arthur W. , Ozturk Sait , Thiagalingam Sam
Published: August 2012

Recent evidence suggests that the molecular heterogeneity inherent to breast cancer, which underlies metastasis, resistance to treatment and disease recurrence, can be driven by a distinct subpopulation of tumor cells referred to as cancer stem cells. Breast cancer stem cells are associated with epithelial-mesenchymal transition (EMT) and the basal-like molecular subtype of tumors, exhibit a CD44+/CD24- expression profile and have an enhanced capacity to form mammospheres. However, the extracellular cues and intracellular pathways that cancer stem cells rely on remain unclear. Using a cell line model of breast cancer progression we found a carcinoma line that was enriched for cancer stem cells. Using microarray expression profiling we identified periostin, a secreted extracellular matrix protein, to be overexpressed in this cell line and numerous other basal-like cell lines. Periostin was also overexpressed in populations that were enriched for cancer stem cells through other means such as cell sorting or growth as mammospheres. Furthermore, cancer stem cell-like populations displayed increased surface levels of the alpha-v beta-3 integrin heterodimer, a known receptor for periostin, suggesting that hyperactivation of periostin signaling may be a common feature of the cancer stem cell state. In support of this, cells with high levels of alpha-v beta-3 integrin form significantly more mammospheres and exhibit an enhanced capacity for growth on soft agar, a surrogate marker of tumorigenesis. Conversely, treatment of cells with an alpha-V beta-3 inhibitory antibody decreased mammosphere formation in a dose-dependent manner. Knockdown of periostin expression does not seem to alter the proportion of CD44+/CD24- cells but it does influence their ability to grow as mammospheres and the activity of aldehyde dehydrogenase (ALDH), another marker of cancer stem cells. Finally, as periostin is a TGF-beta inducible gene, we are currently testing the role of periostin in TGF-beta induced EMT and have seen evidence for an attenuation of this process. Ongoing studies are aimed at characterizing the intracellular pathways regulated by periostin and determining the effect of periostin expression on chemotherapeutic resistance and metastasis, two properties which may be enhanced by the presence of cancer stem cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5191. doi:1538-7445.AM2012-5191
Abstract 5193: The importance of primo vascular system (PVS) on cancer metastasis and therapeutic intervention: A new dimension of cancer stem cell
Authors: Islam Ashraful , Thomas Shelia D. , Sedoris Kara J. , Miller Donald M.
Published: August 2012

The ability of cancer cells especially immature and multi-potent cancer stem cells to escape from conventional therapeutic intervention has been long investigated. The exact mechanisms and safe harboring of this population of cells have yet to be identified. The primo vascular system (PVS) which is composed of new types of micro-conduits named primo-vessels (PV) and primo-nodes (PN) has recently emerged as a third component of circulatory system. In this study, we have shown the existence of PVS and their networks in murine xenograft of human histiocytic lymphoma cells (U937) using trypan blue. These PVs are thread-like, elastic, multi-lumen structure and appears to radiate from PN, perpendicular of the conventional venuoles-arteriols and reside in close proximity to the tumor. PNs are about 500-600 μM membranous sac-like structures, containing numerous tiny cells evident by DAPI staining. Isolation of RNA from PVS signifies the presence of intact transcriptional machinery in the cells. Hematoxylin and Eosin (H&E) staining of PVS shows the presence of loose and abortive structure lined by fibroblast but filled with lightly dense fibers, cells, lacuna and nerve-like structures. To further characterize the origin and type of cells within the PVS, immunostaining with antibodies for CD68, CD45 and lysozyme has revealed the cells are same immunophenotype as of U937. RT-PCR arrays demonstrates a hundred to thousand fold up regulation of human cancer stem cell specific transcription factors most notably KLF4, an upstream regulator of NANOG which maintain the pluripotent and undifferentiated state of stem cells. These results suggest that PVS close to the tumor could be the safe haven for a selective population of cancer stem cell. Further understanding of the biological properties and responsiveness to therapy of these cells will shed light on new dimensions of anti-cancer interventions.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5193. doi:1538-7445.AM2012-5193
Abstract 5196: CDF inhibits cell migration by inactivating cancer stem cell markers, and expression of VEGF, IL-6 and miR-21 in human pancreatic and prostate cancer cells under hypoxic condition
Authors: Bao Bin , Ali Shadan , Ahmad Aamir , Azmi Asfar S. , Banerjee Sanjeev , Kong Dejuan , Li Yiwei , Padhye Subhash , Sarkar Fazlul H.
Published: August 2012

Hypoxia has been well recognized to cause therapeutic resistance associated with solid tumors and considered to play critical roles in other of biological events including cell growth and proliferation, cell survival, angiogenesis, immunosurveillance, tumor invasion and metastasis. Hypoxia-inducible factor (HIF) 1α, a master transcription factor that regulates hypoxia responsive genes, plays critical roles in the adaptation of tumor cells to a hypoxic microenvironment. Tumor hypoxia and over-expression of HIF-1α have been reportedly associated with resistance to radiation therapy and chemotherapy, increased risk of invasion and metastasis and poor clinical prognosis, all of which leads to higher mortality of patients diagnosed with solid tumors. Emerging evidence suggest that hypoxia and HIF signaling pathways leads to the acquisition of epithelial-to-mesenchymal transition (EMT), maintenance of cancer stem cell (CSC) functions, and causing inflammatory tumor microenvironment, which contributes to therapeutic resistance; however, the exact mechanisms by which hypoxia/HIF regulates these events are not fully understood. Here, we demonstrates that hypoxia increases the productions of VEGF and IL-6, and increased expression of CSC marker genes such as Nanog, Oct4, EZH2 as well as miR-21, an oncogenic miRNA, in human pancreatic cancer (AsPC-1 and MiaPaCa-2) and prostate cancer (PC-3 and LNCaP) cells. The treatment of these cells with CDF, a novel curcumin analog that was previously shown to be biologically superior than curcumin as an anti-tumor agent both in vitro and in vivo, inhibited the productions of VEGF, IL-6, Nanog, Oct4 and EZH2 mRNAs, as well as down regulated the expression of miR-21 in these cells under hypoxic condition. CDF also decreased cell migration in pancreatic and prostate cancer cells under hypoxic condition as documented by wound healing assay. Taken together, these data suggest for the first time that the anti-tumor effect of CDF could in part be due to inhibition of tumor hypoxic pathways including the inhibition of CSC markers and thereby reconditioning the tumor microenvironment, which would be useful for overcoming therapeutic resistance.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5196. doi:1538-7445.AM2012-5196
Abstract 521: 4, 4′-Dichlorodiphenyltrichloroethane (DDT) and Triclosan (TCS) decrease tumor-cell-binding capacity and cell-surface protein expression of human natural killer cells
Authors: Hurd-Brown Tasia D. , Udoji Felicia , Martin Tamara , Whalen Margaret
Published: August 2012

4, 4′-Dichlorodiphenyltrichloroethane (DDT) and Triclosan (TCS) are organochlorine compounds that contaminate the environment, are found in human blood, and have been shown to decrease the tumor-cell killing (lytic) function of human natural killer (NK) cells. NK cells defend against tumor cells and virally infected cells. This study examined concentrations of DDT and PCP that decrease lytic function for alteration of NK binding to tumor targets. Levels of either compound that caused loss of binding function were then examined for effects on expression of cell-surface proteins needed for binding. CD16 is an Fc receptor and CD56 is a cognate of neural cell adhesion molecules, both of which are present on NK cells and involved in recognition and lysis of NK target. NK cells exposed to 2.5 µM DDT for 24 h (which caused a greater than 55% loss of lytic function) showed a decrease in NK binding function of about 23%, and a decrease in CD16 of 20%. NK cells exposed to 5 µM TCS for 24 h showed a decrease in ability to bind tumor cells of 44% and a decrease in expression of CD56 of about 34%. This same treatment caused a decrease in lytic function of greater than 87%These results indicated that only a portion of the loss of NK lytic function seen with exposures to these compounds could be accounted for by loss of binding function and also accompanied by loss of cell-surface protein expression. Supported by NIH grant 1U54CA163066-01 and S06 GM008092-35

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 521. doi:1538-7445.AM2012-521
Abstract 5220: Dclk1 labels quiescent pancreatic progenitor and cancer initiating cells
Authors: Westphalen Christoph Benedikt , Quante Michael , Worthley Daniel , Asfaha Samuel , Remotti Helen , Olive Kenneth P. , Wang Timothy C.
Published: August 2012

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related death in the US. Despite major efforts pancreatic cancer has the highest mortality rate of all major cancers with a 5-year survival rate below 5% while the survival rate for the disease has not improved substantially in nearly 40 years. Recently, doublecortin-like kinase 1 protein (Dclk1) was proposed as a marker of putative quiescent stem cells in the gastrointestinal tract and in the pancreas although no genetic fate mapping was performed. Additionally, it was demonstrated that Dclk1 cells expand in the setting of inflammation, hyperplasia and metaplasia. While clinical relevant mouse models of PDAC exist the identity of the cell of origin for pancreatic cancer is still debated. Aim: In order to investigate the role of Dclk1 cells in pancreatic health and disease we generated a BAC transgenic mouse line (Dclk1-CreERT) that expresses tamoxifen-inducible Cre recombinase under the control of the endogenous Dclk1 gene regulation. Results: Using genetic lineage tracing, we demonstrate that Dclk1 labels rare long-lived, quiescent progenitor cells in the pancreas that can give rise to ductal and acinar tissue. Furthermore, Dclk1 cells were found to expand in the setting of pancreatic inflammation and malignancy. Importantly, the Dclk1 lineage contributed significantly to pancreatic regeneration after caerulein-induced pancreatitis. Finally, expression of mutant K-Ras (G12D) in Dclk-1 cells leads to rapid onset (2-3 months) of invasive pancreatic ductal adenocarcinoma that could be further accelerated by caerulein-induced pancreatic injury (1-2 months). Conclusion: Dclk1 labels rare quiescent progenitor cells in the pancreas. These cells take part in the regeneration of the gland after injury and are capable of giving rise to pancreatic cancer. Therefore, we propose that Dclk1 could label the cell of origin in pancreatic cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5220. doi:1538-7445.AM2012-5220
Abstract 5228: Inhibition of myeloid cell PI3Kγ is a potential therapeutic approach to treat pancreatic cancer
Authors: Hardamon Chanae R. , Schmid Michael C. , Lowy Andrew M. , Bouvet Michael , Varner Judith A.
Published: August 2012

Tumor inflammation plays a significant role in initiating and perpetuating tumor growth, angiogenesis and metastasis. While normal inflammatory responses aid in wound healing, fighting infections, and destroying pathogens, tumor inflammation is self-perpetuating and plays a role in facilitating the disease, in part by inducing immunosuppression. Gr1+CD11b+ myeloid cells are the most prevalent inflammatory cells found in tumors, where they directly promote tumor angiogenesis and immunosuppression. Recent studies in our laboratories have shown that the phosphatidylinositol 3-kinase (PI3K) catalytic subunit isoform p110γ, which is expressed exclusively by Gr1+CD11b myeloid cells, directly promotes myeloid cell invasion and consequently, tumor immunosuppression. Genetic and pharmacological suppression of PI3Kγ activity substantially reduces myeloid cell trafficking to orthotopic Pdx1Cre;Kras+; p53+/- and other pancreatic ductal carcinomas, reduces expression of immunosuppressive factors, and inhibits pancreatic tumor growth and metastasis. These studies indicate that PI3Kγ inhibitors may be useful therapeutics for pancreatic ductal carcinoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5228. doi:1538-7445.AM2012-5228
Abstract 523: γα T cells are activated by protein-bound polysaccharide krestin (PSK) and contribute to the antitumor effect of PSK
Authors: Inatsuka Carol , Yang Yi , Gad Ekram , Rastetter Lauren , Disis Mary , Lu Hailing
Published: August 2012

Gamma delta (γδ) T cells play an important role in anti-tumor immunity, and novel methods to augment γδ T cell function are highly desired. It has recently been shown that toll-like receptor (TLR) agonists may modulate the function of γδ T cells, so we questioned whether protein-bound polysaccharide krestin (PSK), a mushroom extract with TLR2 agonist activity, can activate γδ T cell. Using splenocytes from neu-transgenic mice, we found that γδ T cells produce IFN-γ after PSK treatment and have up-regulated expression of CD25 and CD69. The expression of CD107a in γδ T cells was also enhanced by PSK. To investigate whether the effect of PSK on γδ T cells is direct or indirect via activation of dendritic cells (DC), purified γδ T cells were cultured either alone or together with bone marrow derived DC (BMDC) in a co-culture or trans-well system and then stimulated with PSK. Results showed that direct cell-to-cell contact between γδ T cells and DC is required for optimal activation of γδ T cells. In the absence of DC, PSK can co-stimulate γδ T cells with anti-γδ TCR or anti-CD3 mAb. Oral administration of PSK in neu-transgenic mice with implanted breast tumors resulted in increased percentage of γδ T cells among splenocytes and increased expression of NKG2D on γδ T cells. Depleting γδ T cells during PSK treatment decreased the anti-tumor effect of PSK. All together, these results demonstrated that γδ T cells are activated by PSK and contribute to the anti-tumor effect of PSK.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 523. doi:1538-7445.AM2012-523
Abstract 524: Cytokine therapy by allogenic IFN-alpha-expressing murine colorectal cancer cells suppresses outgrowth of established tumors in a murine hepatocellular carcinoma model
Authors: Ishii Shigeaki , Hirosihi Kazumasa , Eguchi Junichi , Sakaki Masashi , Doi Hiroyoshi , Omori Risa , Kajiwara Atsushi , Imawari Michio
Published: August 2012

Although several effective therapies for hepatocellular carcinoma (HCC) have been developed, many patients with both advanced cirrhosis and HCC are not able to receive those treatments because of their poor liver function. Thus, it is needed to establish a new effective therapy that has lesser side effects for those patients. We previously reported that immunotherapy by interferon-alpha (IFNa) and dendritic cells effectively suppressed outgrowth of established tumors and showed preventive effects in the murine colorectal cancer, MC38 cell model. We also revealed that tumor-specific cytotoxic T cell responses were important for these anti-tumor effects. In this study, we investigated the antitumor effect of allogenic cytokine (IFNa and IL-4)- expressing MC38 cells in the murine hepatocellular carcinoma, BNL model. There were no differences in cell growth between BNL cells and BNL cells co-incubated with cytokine-expressing MC38 cells in vitro. Balb/c mice were injected with 5x105 of BNL cells on their flank. Once BNL tumors were established, these mice received therapeutic injection of cytokine-expressing MC38 cells (2.5x105/mouse or 5x105/mouse) and tumor size was measured twice weekly. While tumor growth of the mice injected with MC38-IL4 was not suppressed (control; 421.0±146.9mm2, MC38-IL4 (5x105); 351.3±126.1mm2, p=0.33), injection of MC38-IFNa cells significantly suppressed the tumor growth by dose-dependent manner (MC38-IFNa: 5x105 cells; 183.5±46.2mm2, p=0.02). When we injected mice with both IFNa cells and IL-4 cells, any additive anti-tumor effects were not observed (mice injected both modified MC38: 5x105 cells each; 182±44.6 mm2, p=0.01). A BNL-specific cytolysis was detected when splenocytes of mice injected with MC38-IFNa were used as effector cells in a chromium-release assay. Furthermore, immunohistocemistrical analysis revealed that CD4+ T cells, CD8+ T cells and especially Gr-1+ cells infiltrated established BNL tumors of mice injected with MC38-IFNa. Our results suggest that the immunotherapy with allogenic IFNa-expressing cells has potent antitumor effects, and that it would be applicable for treatment to advanced HCC patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 524. doi:1538-7445.AM2012-524
Abstract 5251: Branching morphogenesis in the mammary gland is regulated by sprouty-2
Authors: Sigurdsson Valgardur , Ingthorsson Saevar , Hilmarsdottir Bylgja , Franzdottir Sigridur R. , Steingrimsson Eirikur , Magnusson Magnus K. , Gudjonsson Thorarinn
Published: August 2012

Branching morphogenesis is a conserved mechanism used by many species for organogenesis and tissue maintenance. Receptor tyrosine kinases (RTKs), including the epidermal growth factor receptor (EGFR), and their intracellular regulators, the sprouty protein family is believed to be a critical regulator of branching morphogenesis. In this study, we show that, Sprouty-2 (Spry-2) is predominantly expressed in the luminal epithelial cells both in ducts and lobuli in the human breast gland. We have also analyzed the expression of Spry-2 and EGFR pathway in virgin, lactating and pregnant mouse mammary gland. Spry-2 is expressed at branching epithelial buds during pregnancy with increased expression during lactation. The expression of phosphorylated EGFR (Y1068) shows a similar expression pattern as Spry-2. Using D492 a breast epithelial cell line with stem cell properties, that generate branching structures in 3D laminin rich gel we show that Spry-2 expression increases during the formation of branching. Immunostaining locates expression of Spry-2 and active EGFR at the tip of lobular-like, branching ends. Interestingly, knocking down (KD) spry-2 expression using shRNA resulted in increased migration. Spry-2 knockdown also gives larger and more complex branching structures indicating loss of negative feedback control of branching morphogenesis. In co-culture with endothelial cells, D492 spry-2 KD cells generate predominantly spindle like colonies reminiscent of epithelial to mesenchymal tansition. In conclusion, these data indicate that Spry-2 is an important regulator of branching morphogenesis and dysregulation of sprouty expression can lead to aberrant development related to breast cancer, such as epithelial to mesenchymal transition in the mammary gland.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5251. doi:1538-7445.AM2012-5251
Abstract 526: Cancer immunoediting by the innate immune system in the absence of adaptive immunity
Authors: Bui Jack , O'Sullivan Timothy , Saddawi-Konefka Robert , Vermi William , Smyth Mark , Schreiber Robert
Published: August 2012

Cancer immunoediting is the process whereby the immune system protects against cancer formation and sculpts the immunogenicity of developing tumors cells. Although the full process is known to depend on innate and adaptive immunity, it remains unclear whether innate immunity alone is capable of immunoediting. By comparing the incidence and immunogenicity of 3′methylcholanthrene (MCA)-induced sarcomas in syngeneic wild-type, RAG2-/-, and RAG2-/- x γc-/- mice, we show that the innate immune system can edit the immunogenicity of primary tumors. Specifically, RAG2-/-x γc-/- mice displayed the highest incidence of MCA sarcomas, followed by RAG2-/- mice, and WT mice have the lowest incidence at four separate doses of MCA. Moreover, when cell lines were generated from MCA sarcomas, the cell lines derived from MCA sarcomas growing in RAG2-/-x γc-/- mice had the highest immunogenicity, followed by cell lines from RAG2-/- mice, and cell lines from WT mice had the lowest immunogenicity. These results show that the innate immune system can edit tumors in the absence of adaptive immunity. To examine the cellular basis of editing by the innate immune system, we analyzed the innate cells that infiltrate tumors formed from transplanting highly immunogenic MCA sarcoma cell lines into RAG2-/- or RAG2-/-x γc-/- mice. We found that M1 macrophages were detected at high levels in immunogenic tumors in RAG2-/- but not RAG2-/- x γc-/- mice. The accumulation of M1 macrophages required IFNγ and was associated with effective tumor editing. In the absence of γc and IFNγ, M2 macrophages were abundant, and editing was impaired. Notably, M1 macrophages can be elicited by administration of CD40 agonistic antibodies, thereby restoring cancer editing activity in RAG2-/-x γc-/- mice. Our results suggest that crosstalk between natural killer cells and M1 macrophages, through IFNγ, can be elicited in highly immunogenic tumors, leading to cancer immunoediting. Our highly immunogenic cell lines will provide a system to dissect the cellular and molecular basis of cancer immunoediting by the innate immune system.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 526. doi:1538-7445.AM2012-526
Abstract 5329: Induction of VEGF-C expression via mGluR5 in the lymph node metastases of oral cancer by the SDF-1/CXCR4 system
Authors: Uchida Daisuke , Kuribayashi Nobuyuki , Tamatani Tetsuya , Nagai Hirokazu , Miyamoto Youji
Published: August 2012

Previously, we identified a metastasis-candidate gene, metabotropic glutamate receptor (mGluR)-5, which is a target gene of stromal cell-derived factor (SDF)-1/CXCR4 system in oral cancer. In this study, we examined the role of mGluR5 on the lymph node metastasis of oral cancer. We used 2 kinds of mGluR5-specific antagonists, 2-Methyl-6-(phenylethynyl)pyridine (MPEP) and 3-((2-Methyl-1,3-thiazol-4-yl)ethynyl)pyridine (MTEP). These antagonists did not affect the growth of oral cancer cells, but did inhibit the SDF-1/CXCR4 dependent-migration of the cells. In order to confirm the drug toxicities, these antagonists were intraperitoneally injected into wild-type mice for 4 weeks. All the mice injected with MPEP (5 mg/kg) and MTEP (5 mg/kg) did not show side effects, such as hematotoxicity, allergic reaction and body weight loss. When the CXCR4 expressing-oral cancer cells were transplanted into masseter muscle of nude mice, these antagonists significantly inhibited lymph node metastases of the cells. Although SDF-1/CXCR4 dependent production of angiogenic factors, including interleukin-6, interleukin-8, and vascular endothelial growth factor (VEGF)-A were observed, mGluR5 antagonists did not influence the production of these factors. However, induction of a lymphangiogenic factor, VEGF-C was specifically inhibited by the treatment with these mGluR5 antagonists. These results suggested that SDF-1/CXCR4 system induce lymph node metastases by the production of VEGF-C via upregulation of mGluR5.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5329. doi:1538-7445.AM2012-5329
Abstract 5335: Identification and molecular characterization of pancreatic tumor-initiating cells
Authors: Vorvis Christina , Poultsides George A. , Norton Jeffrey A. , Iliopoulos Dimitrios
Published: August 2012

Pancreatic cancer has the worst prognosis of any major malignancy with complex etiology involving both environmental and genetic factors. Despite increasing knowledge in tumor biology, the treatment efficacy in pancreatic cancers has not improved significantly over the past decade. Thus, the identification of novel molecular pathways involved in pancreatic oncogenesis and the development of new and potent therapeutic options are highly desirable. The realization that tumors themselves function as complex organs birthed the concept that cancer cells with tumor-initiating properties of stem cells may be the key drivers of the complex machinery behind oncogenesis. Tumor-initiating cells (TICs) have been studied extensively in the hematopoietic system, however it is not known which subpopulation has the highest tumor-initiating potential in pancreatic cancer. We have identified that the CD133+/CD44+/ALDH1+ cell population derived from 31 pancreatic adenocarcinomas and 6 pancreatic cancer cell lines, has the highest tumorigenic potential, assessed by in vivo dilution tumor propagation assays in highly immunodeficient (NOD-SCID IL2Rγ-/-) mice. In addition, this population has the highest sphere-forming capacity and is highly resistant to gemcitabine treatment in comparison to the other subpopulations. RNA-sequencing analysis in CD133−/CD44−/ALDH1− and CD133+/CD44+/ALDH1+ subpopulations derived from BxPC3 pancreatic cells revealed the transcriptomic alterations between these cell types. Furthermore, gene network analysis revealed enrichment of inflammatory and lipid metabolism networks in pancreatic TICs, suggesting the potential role of inflammation and lipid metabolism in pancreatic TIC function. In addition, a gene network-based FDA-approved chemical library screen revealed that metformin perturbs the activated networks in pancreatic TICs leading to the suppression of their growth. Metformin suppressed pancreatic cancer growth, through suppression of pancreatic TICs, in different pancreatic cancer mouse models. Overall, we propose the identification of a novel pancreatic cancer subpopulation which harbors tumor-initiating properties and is regulated by inflammatory signals, contributing to our understanding of how inflammation is linked to pancreatic oncogenesis in the molecular level. Furthermore, by following a novel strategy, we have identified that metformin suppresses pancreatic tumor growth and relapse through inhibition of pancreatic TIC growth.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5335. doi:1538-7445.AM2012-5335
Abstract 5364: Correlation of immune responses and overall survival in a phase II study of belagenpumatucel-L, an allogeneic tumor cell vaccine, in non-small cell lung cancer (NSCLC)
Authors: Shawler Daniel L. , Tong Alex , Liu Lily , Carrier Ewa , Davis Charles S. , Nemunaitis John , Fakhrai Habib
Published: August 2012

This study examines the correlative/predictive value of cellular- and humoral-mediated immune response on the clinical responsiveness of patients who received belagenpumatucel-L, a therapeutic vaccine comprised of 4 TGF-β2 antisense gene-modified allogeneic non-small cell lung cancer (NSCLC) cell lines in a phase II clinical trial in which subjects with stage III/IV NSCLC received intradermal injections of the vaccine every 4-8 weeks. We performed assays of cellular (ELISPOT) and humoral (antibody ELISA) immunity on 36 subjects in the trial and correlated these data with the long term assessment of overall survival. All but one subject in the study showed an increase in immune reactivity in at least one of the cellular or humoral assays. Eleven subjects who demonstrated an aggregate increase in both cellular and humoral immune reactivity (positive by three of four criteria tested) had a median survival of 32.5 months (95% CI, 25.2 to 39.8). This was significantly better than the median survival of only 11.6 months (95% CI, 5.6 to 17.6) for the 25 subjects who showed an increase in one or none of the measured immune parameters (p=0.015, log-rank test). The demonstration of a statistically significant correlation between cellular and humoral immune responses and overall survival in subjects treated with belagenpumatucel-L suggest that both compartments of the immune system likely impact the clinical response and are important for the induction of clinically significant antitumor immunity by the vaccine.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5364. doi:1538-7445.AM2012-5364
Abstract 5412: CCR4+CCR6+Th17 cells suppress autologous CD8+ T cell responses in patients with hepatocellular carcinoma
Authors: Zhao Fei , Hoechst Bastian , Gamrekelashvili Jaba , Ormandy Lars , Voigtländer Torsten , Wedemeyer Heiner , Ylaya Kris , Hewitt Stephen , Wang Xin , Manns Michael , Korangy Firouzeh , Greten Tim
Published: August 2012

The role of Th17 cells in cancer patients remains unclear and controversial. We have noticed an increase in Th17 related cytokines (IL-17 and IL-23) in tumor supernatants derived from primary liver cancer, which prompted us to examine Th17 cells in patients with hepatocellular carcinoma (HCC). First we analyzed the frequency of CD4+IL-17+ cells in peripheral blood from patients with HCC, which was increased in comparison to healthy controls. In order to further analyze the function of these cells, we generated Th17 cells in vitro in the presence of IL-1beta, IL-6 and IL-23 cytokines, anti-IL-4 and anti-IFN-gamma antibodies. Th17 cells were than stained using an IL-17 capture antibody and purified by FACS sorting. In vitro primed Th17 cells were further purified into CCR4+CCR6+ and CCR4negCCR6+ Th17 cells. When cultured with autologous CD8+ T cells, CCR4+CCR6+Th17 cells suppressed the lytic function, proliferation and cytokine secretion of both antigen specific and CD3/CD28/CD2 stimulated autologous CD8+ T cells. In contrast, CCR4negCCR6+ CD4+ T cells, which also secrete IL-17, did not affect the CD8+ T cells. Suppression of CD8+ T cells by CCR4+CCR6+Th17 cells was partially dependent on TGF-beta, since neutralization of TGF-beta in cocultures reversed their suppressor function. Based on these findings we evaluated the frequency CCR4+CCR6+Th17 and CCR4negCCR6+Th17 cells in patients with HCC separately. Our analysis revealed also an increase in the frequency of CCR4+CCR6+Th17 cells but not CCR4negCCR6+Th17 cells in peripheral blood of HCC patients and ex vivo isolated CCR4+CCR6+CD4+ T cells from peripheral blood of patients. Finally we demonstrated the suppressor activity of freshly isolated CCR4+CCR6+T cells on autologous CD8+ T cell proliferation. In summary our study not only underlies the importance of analysis of subsets within Th17 cells to understand their function, but also suggests Th17 cells as yet another immune evasion mechanism in HCC. This has important implications when studying the mechanisms of carcinogenesis as well as designing effective immunotherapy protocols for patients with cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5412. doi:1538-7445.AM2012-5412
Abstract 5416: Myeloid-derived suppressor cells (MDSC) are increased and correlated with immune suppression and chronic inflammation in patients with cancer
Authors: Gonda Kenji , Shibata Masahiko , Shimura Tatsuo , Nakamura Izumi , Ohki Shinji , Ohtake Tohru , Suzuki Shinichi , Ohto Hitoshi , Takenoshita Seiichi
Published: August 2012

Chronic inflammation plays a key role in the progress of malignant diseases and has been reported to relate with immune suppression seen in patients with advanced diseases. MDSC: myeloid-derived suppressor cells found as a new type of immune suppressor cells are enhanced by inflammation and have been reported to be present in blood circulation, lymphnodes and tumor tissues in patients with cancer. The suppression of immune function via depleting arginine and producing immune-suppressing cytokines including IL-10 has also been reported. In order to investigate MDSC in patients, peripheral blood mononuclear cells (PBMC) were collected from 18 normal healthy volunteers, 53 patients with gastrointestinal cancer, 65 with breast cancer, 8 with thyroid cancer, and 5 with ovarian cancer. These cells were used for the detection of MDSC (CD11b+CD14−CD33+) by flow cytometry. PBMC was also used for the PHA-blastogenesis of lymphocytes which is a marker of cell mediated immunity (stimulation indices: SI) and for the production assay of cytokines including IL-6 and IL-10. MDSC (%PBMC) of whole patients (5.68 + 5.92%), those of gastrointestinal cancer patients (3.76 + 4.90%) and those of breast cancer patients (2.92 + 4.13%) were significantly higher than those of normal volunteers (p<0.005, p=0.05, p<0.05, respectively, vs 1.59 + 1.08%). MDSC were inversely correlated with the SI (r=−0.271, p<0.05) in patients with gastrointestinal cancer and positively correlated with IL-6 production in whole patients(r=0.287, p=0.05) and with IL-10 production in patients with breast cancer (r=0.363, p<0.05). They were also significantly correlated to neutrophil counts (r=0.287, p<0.05) and neutrophil/lymphocyte ratios (NLR, r=0.623, p=0.05), and inversely correlated to lymphocyte counts (r=−0.251, p<0.01). Thus MDSC were successfully detected in peripheral blood and were significantly higher in patients with cancer. There were strong relationships among the inhibition of cell-mediated immunity, production of type 2 cytokines and inflammatory markers such as NLR. Therefore, MDSC seemed to work as a suppressor of immune reaction and may be an important marker of chronic inflammation in patients with cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5416. doi:1538-7445.AM2012-5416
Abstract 5421: Stage specific inhibitory effect and associated mechanisms of insositol hexaphosphate on tumor progression and angiogenesis in TRAMP model
Authors: Raina Komal , Ravichandran Kameswaran , Jain Anil , Gu Mallikarjuna , Sharma Yogesh , Wadhwa Ritambhara , Agarwal Rajesh
Published: August 2012

Prostate cancer (PCa) is the leading cause of cancer-related deaths in elderly men in US; ACS’ statistical estimates for 2011 report ∼240,890 new PCa cases and 33,720 associated deaths. In recent years, transgenic adenocarcinoma of the mouse prostate (TRAMP) has been the most frequently employed PCa model to evaluate chemopreventive efficacy of various agents. This model closely mimics human form of the disease, wherein prostate carcinogenesis progresses in a step-wise manner with the age of the mouse. The well defined stages of prostate tumor growth, progression and angiogenesis in TRAMP model provide unique opportunity to assess ‘stage specific’ preventive efficacy of an agent. Accordingly, employing TRAMP model, here we assessed stage-specific efficacy of inositol hexaphosphate (IP6) feeding on PCa initiation and growth, progression and angiogenesis, and elucidated the molecular events involved in IP6 effects during these stages. Different groups of male TRAMP mice starting at 4, 12, 20 and 30 weeks of age were fed with regular drinking water or 2% IP6 in regular drinking water for 8-10 weeks. At the end of the study, histopathological analysis of prostate showed that all the mice fed with IP6 at different time-points display less severe prostatic lesions compared to non-IP6 fed positive control mice. During early stages of prostate tumor development, IP6 mediated its chemopreventive effect mostly via anti-proliferative and pro-apoptotic mechanisms. Feeding of IP6 to animals burdened with higher stages of prostate tumor significantly decreased tumor grade via anti-proliferative effect and inhibition of angiogenesis as evidenced by decreased expression of platelet endothelial cell adhesion molecule-1 (PECAM-1/CD-31), vascular endothelial growth factor (VEGF) hypoxia-inducible factor-1a (HIF-1a) and inducible nitric oxide synthase (iNOS). These effects of IP6 also correlated with an alteration of epithelial-mesenchymal transition (EMT) as was evidenced by a decreased expression of mesenchymal markers Snail-1 in the prostatic tissue and retention of epithelial characteristics determined by localization of E-cadherin. Together, the findings in the present study are both novel and highly significant in establishing the dual efficacy of IP6, where it inhibits initiation and progression of primary prostatic tumor and also exerts protective efficacy against angiogenesis. These effects of IP6 should have potential implications to control PCa growth and improve the morbidity and survival time in PCa patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5421. doi:1538-7445.AM2012-5421
Abstract 5425: The catalytic subunit of DNA-dependent protein kinase is downstream of ATM and feeds forward oxidative stress in selenium-induced senescence response
Authors: Cheng Wen-Hsing , Rocourt Caroline R. , Wu Min , Chen Benjamin P.
Published: August 2012

Selenium induces a senescence response through induction of ataxia-telangiectasia mutated (ATM) and reactive oxygen species (ROS). Although a role of the DNA-PK complex, including the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs), Ku70 and Ku80, in DNA double strand break repair is established, it is unclear how these proteins function in the response to selenium-induced oxidative stress and senescence induction. In this study we demonstrate that pre-treating normal human diploid fibroblasts with DNA-PK kinase inhibitor NU 7026 suppresses selenium-induced senescence response. Selenium treatment induces phosphorylation of DNA-PKcs on Thr-2647 and Ser-2056, the extent of which is decreased in the presence of ATM kinase inhibitor KU 55933 or the antioxidant N-acetylcysteine or 2,2,6,6-tetramethylpiperidine-1-oxyl. In contrast, the selenium-induced phosphorylation of ATM on Ser-1981 is not affected by NU 7026. Cells deficient in DNA-PKcs or pre-treated with NU 7026 or N-acetylcysteine are defective in selenite-induced ROS formation. Opposed to DNA-PKcs, Ku70 and Ku80 are dispensable for selenite-induced ROS and γH2A.X formation and removal. Taken together, these results indicate a distinct role of DNA-PKcs from Ku70 and Ku80, in which this kinase can respond to and feed forward selenium-induced ROS formation and is placed downstream of ATM in the resultant senescence response.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5425. doi:1538-7445.AM2012-5425
Abstract 543: Estrogen metabolism within prostatic micro-milieu: insights to prostatic carcinogenesis
Authors: Al-Abd Ahmed M. , Abdel-Naim Ashraf B. , Khedr Alaa , Gazzaz Faten S. , Mosli Hisham A.
Published: August 2012

Prostatic cancer is amongst the most common neoplasm in men. Inflammation and accelerated proliferation are important underlying causes for prostatic carcinogenesis. The role of estrogen in prostate physiology and pathophysiology has been growing rapidly. However some estrogen metabolites are more potent relative to parent estrogen. In the current work, the reciprocal role between inflammation and estrogen metabolism in prostatic microenvironment was investigated. Prostatitis was induced in normal and estrogen treated male rats by intraprostatic injection of 2% carragenan solution. After 48 h, animals were euthanized and prostate glands were collected. Prostatic inflammation and proliferation were confirmed by gross visual, histological and elevated TNF-α, PGE2 and cyclin-D1. Expression of estrogen metabolizing enzymes was assessed using real time PCR and estrogen metabolites within prostate tissue were assayed using LC-MS/MS. Inflammation combined with estrogen exposure showed exaggerated inflammatory and proliferative response. Estrogen metabolizing enzymes were over expressed in response to prostatic inflammation with sequential accumulation of catechol estrogens within prostatic tissues. Catechol estrogens were found to accelerate prostatic epithelial cell proliferation and alter their genetic stability. In conclusion, the current work provides experimental evidence that prostatic inflammation enhances estrogen metabolism to generate catechol estrogens within prostatic microenvironment. These may contribute in prostatic inflammation and accelerated proliferation and subsequently prostatic carcinogenesis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 543. doi:1538-7445.AM2012-543
Abstract 5449: Down-regulation of miR-200b and induction of ZEB1 and ZEB2 promote arsenic-transformed cell migration and invasion
Authors: Wang Zhishan , Fisher Theresa , Yang Chengfeng
Published: August 2012

Arsenic is one of the most common environmental contaminants and a well-recognized human carcinogen. Long-term exposure to arsenic causes human bronchial epithelial cell (HBEC) malignant transformation and lung cancer. However, the mechanism of arsenic lung carcinogenesis is not clear; and the migratory and invasive properties of arsenic-transformed cells have been rarely studied. We found that arsenic-transformed HBECs (As-HBECs) were highly migratory and invasive. MicroRNA-200b (miR-200b) expression was down-regulated and epithelial-to-mesenchymal transition-inducing transcription factors ZEB1 (zinc-finger E-box-binding homeobox factor 1) and ZEB2 were up-regulated in As-HBECs. Akt and extracellular signal-regulated protein kinase 1/2 (Erk1/2) were strongly activated in As-HBECs. Stably expressing miR-200b in As-HBECs abolished Akt and Erk1/2 activation, and completely suppressed cell migration and invasion. Pharmacological inactivation of Akt but not Erk1/2 significantly decreased cell migration and invasion. Inhibition of Akt reduced the expression of ZEB1 and ZEB2 and impaired As-HBEC migration and invasion. Our findings indicate that Akt activation plays a critical role in enabling arsenic-transformed HBEC migration and invasion through promoting ZEB1 and ZEB2 expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5449. doi:1538-7445.AM2012-5449
Abstract 5458: GADD45α nickel induction inhibits JNKs/p38 activity by promoting PP2Cα expression
Authors: Yu Yonghui , Li Jingxia , Wan Yu , Gao Jimin , Huang Chuanshu
Published: August 2012

Growth arrest and DNA damage (GADD) 45α is a member of GADD inducible gene family, which can be induced in cell response to oxidative stresses. GADD45α upregulation is able to induce MKK4/JNK activation in some published experimental systems. However, we demonstrated here that the depletion of GADD45α in mouse embryonic fibroblasts (MEFs) (GADD45α-/-) resulted in an increase in the phosphorylation of MKK4/7, MKK3/6 and consequently specific up-regulated the activation of JNK/p38 and their downstream transcription factors, such as c-Jun and ATF2, in comparison to those in GADD45α+/+ MEFs due to nickel exposure. This up-regulation of MKK-JNK/p38 pathway in GADD45α-/- could be rescued by the re-constitutional expression of HA-GADD45α in GADD45α-/-, GADD45α-/- (HA-GADD45α). Subsequent studies indicated that GADD45α deletion repressed expression of PP2Cα, the phosphotase of MKK3/6 and MKK4/7. Collectively, our results demonstrate a novel function and mechanisms responsible for GADD45α regulation of MKK/MAPK pathway, further provides insight into understanding the big picture of GADD45α in the regulation of cellular responses to oxidative stress and environmental carcinogens.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5458. doi:1538-7445.AM2012-5458