bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2290: A novel function in metastasis for YY1 overexpression in the initiation of the EMT phenotype
Authors: Baritaki Stavroula , Huerta-Yepez Sara , Yeung Kam , Neonakis Ioannis , Bonavida Benjamin
Published: February 2011

Metastasis is the main cause of death in cancer patients. The underlying molecular mechanisms of the metastatic process and their regulation in different malignancies are unknown. Survival pathways, such as the constitutively activated NF-κB pathway, contribute to the initiation of metastasis, a process known as epithelial to mesenchymal transition (EMT). The EMT phenotype is characterized by several gene modifications such as inhibition of epithelial gene products (e.g. E-cadherin, cytokeratin 18) and upregulation of mesenchymal gene products (e.g. vimentin and fibronectin). In addition, the cells exhibit invasive properties. The metastasis-inducer transcription factor, Snail, is intimately involved in EMT and is transcriptionally regulated, in part, by NF-κB. A recent report demonstrated that Snail is transcriptionally regulated, in part, by the transcription factor Yin Yang 1 (YY1) and YY1 is downstream of NF-κB. We have reported that YY1 expression is a prognostic marker in prostate cancer and YY1 also regulates tumor cell resistance to apoptosis by cytotoxic therapeutics. Based on these findings, we hypothesized that the expression levels of YY1 in cancer may also regulate EMT directly and/or indirectly through its regulation of Snail transcription. This hypothesis was tested using the human metastatic prostate carcinoma cell lines, PC-3 and DU-145, that exhibit the EMT phenotype as models. The relationship between inhibition of YY1 and inhibition of EMT was established by several lines of evidence. Treatment of the tumor cells with the proteasome inhibitors, NPI-0052 or Bortezomib, inhibited NF-κB, Snail and YY1 activities and correlated with inhibition of EMT. The direct role of YY1 expression and activity in the regulation of EMT was shown by treating cells with YY1 siRNA and resulting in the inhibition of the EMT phenotype. In turn, inhibition of Snail resulted in upregulation of the expression of the metastasis-suppressor/immune surveillance cancer gene product, Raf-1 kinase inhibitor protein (RKIP). The upregulation of RKIP by YY1 siRNA was due to the inhibition of the RKIP transcription repressor Snail. These findings establish a novel role for YY1 in the regulation of EMT. The findings also establish the dysregulation of the circuitry NF-κB/Snail/YY1/RKIP in cancer and metastasis resulting in the initiation of EMT. Further, this dysregulation has also been recently reported by us to regulate tumor cell resistance to apoptotic-inducing stimuli. Therefore, this dysregulated circuitry and downstream regulated gene products may be considered as novel targets for the regulation of both metastasis and resistance.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2290.
Abstract 2313: Role of ferritin dysregulation in human breast cancer cells
Authors: Shpyleva Svitlana I. , Tryndyak Volodymyr P. , Kovalchuk Olga , Starlard-Davenport Athena , Chekhun Vasyl’ F. , Beland Frederick A. , Pogribny Igor P.
Published: February 2011

Breast cancer is the most common malignancy in women. Successful treatment of breast cancer relies on a better understanding of the molecular mechanisms involved in breast cancer initiation and progression. Recent studies have suggested a crucial role of perturbations in ferritin levels and tightly associated with this, the deregulation of intracellular iron homeostasis; however, the underlying molecular mechanisms for the cancer-linked ferritin alterations remain largely unknown and often with conflicting conclusions. Therefore, the present study was undertaken to define the role of ferritin in breast cancer. We determined that human breast cancer cells with an epithelial phenotype, such as MCF-7, MDA-MB-361, and T-47D cells, expressed low levels of ferritin light chain (FTL), ferritin heavy chain (FTH1), transferrin (Tf), iron regulatory protein 1 (IRP1), and IRP-2. In contrast, expression of these proteins was substantially elevated in breast cancer cells with an aggressive mesenchymal phenotype, such as Hs-578T, BT-549, and especially MDA-MB-231 cells. The up-regulation of FTH1 and FTL in MDA-MB-231 cells was accompanied by alterations in the subcellular distribution of these proteins as characterized by an increased level of nuclear ferritin and a lower level of the cellular labile iron pool as compared to MCF-7 cells. We established that FTH1 is a target of miR-200b, suggesting that FTH1 up-regulation in MDA-MB-231 cells may be triggered by the low expression of miR-200b. Ectopic up-regulation of miR-200b by transfection of MDA-MB-231 cells with miR-200b substantially decreased the level of FTH1. More importantly, miR-200b-induced down-regulation of ferritin was associated with an increased sensitivity of the MDA-MB-231 cells to the chemotherapeutic agent doxorubicin. These results suggest that perturbations in ferritin levels are associated with the evolution of breast cancer toward a more advanced malignant phenotype.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2313.
Abstract 2358: MUC13 mucin augments pancreatic tumorigenesis
Authors: Chauhan Subhash C. , Ebeling Mara C. , Maher Diane M. , Koch Michael D. , Friez Matthew H. , Watanabe Akira , Aburatani Hiroyuki , Lio Yuhlong , Pandey Krishan K. , Jaggi Meena
Published: February 2011

Pancreatic cancer is one of the most lethal malignancies with extremely poor prognosis. The high death rate of pancreatic cancer is attributed to a lack of reliable methods of early diagnosis and underlying molecular mechanisms associated with aggressive pathogenesis. MUC13, a newly identified transmembrane mucin, is known to be aberrantly expressed in ovarian, gastric and colon cancer. However, the expression and functions of MUC13 in pancreatic cancer are unknown. Herein, we have investigated the expression and functions of MUC13 mucin, in pancreatic cancer to determine its potential for early cancer diagnosis and its role in pancreatic cancer pathogenesis. The expression profile of MUC13 in pancreatic cancer was investigated using a recently generated monoclonal antibody (MAb, clone PPZ0020) and pancreatic tissue microarrays. The expression of MUC13 was significantly (p<0.005) higher in cancer samples compared to the normal/non-neoplastic pancreatic tissues. For the functional analyses, a full length MUC13 gene cloned in pcDNA3.1 was expressed in MUC13 null pancreatic cancer cell lines, MiaPaca and Panc1. The exogenous MUC13 expression induced morphological changes, including scattering of cells. These changes were abrogated through c-jun NH2-terminal kinase (JNK) chemical inhibitor (SP600125) or JNK2 siRNA. Additionally, a marked reduction in cell-cell adhesion and significant (p<0.05) increases in cell motility, invasion, proliferation, clonogenicity and tumorigenesis in a xenograft mouse model system were observed upon exogenous MUC13 expression. These cellular characteristics were correlated with the up-regulation of HER2, p21-activated kinase1 (PAK1), extracellular signal-regulated kinase (ERK) and S100A4 (metastasin) and suppression of p53. Inhibition of MUC13 expression by MUC13 siRNA or shRNA resulted in suppression of tumorigenic characteristics in HPAFII pancreatic cancer cells. These results, for the first time, suggest that MUC13 expression augments pancreatic cancer progression and has potential as a diagnostic and/or therapeutic target.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2358.
Abstract 236: Sleeping Beauty transposon integration within the Dlk1-Dio3 imprinted domain is associated with hepatocellular carcinoma development
Authors: Riordan Jesse D. , Keng Vincent W. , Ryan Barbara J. , Podetz-Pedersen Kelly M. , Copeland Neal G. , Jenkins Nancy A. , Largaespada David A. , Dupuy Adam J.
Published: February 2011

Hepatocellular carcinoma (HCC) is one of the most commonly diagnosed and deadliest cancers worldwide. In the United States, age-adjusted incidence has tripled over the last three decades. While traditional cancer treatments, such as radiation and chemotherapy, are ineffective in treating HCC, therapeutic approaches targeted at the underlying molecular causes are proving to be more efficacious. However, compared to other common cancers, relatively little is known about the molecular pathogenesis of HCC. We have used a Sleeping Beauty transposon-based insertional mutagenesis screen to identify novel oncogenes and tumor suppressors involved in HCC development and progression. This forward genetics approach identified a link between disruption of gene expression within the Dlk1-Dio3 imprinted domain and development of HCC in mice; over half of the induced HCCs contained transposon integrations within a ten kilobase region of this domain. Analysis of gene expression within the domain identified two consistent and significant events associated with transposon integration: activation of Delta-like 1 homolog (Dlk1) and inhibition of microRNA-370 (miR-370). These results led us to hypothesize that Dlk1 and miR-370 possess oncogenic and tumor suppressive functions, respectively, in HCC pathogenesis.

The Dlk1 gene encodes a Notch receptor ligand. Overexpression has been documented in a subset of human HCC cases, and the effects of modulating expression level in cultured hepatocytes are consistent with a tumor-promoting role. To test Dlk1's oncogenic potential in vivo, we drove overexpression in adult mouse livers using a hydrodynamic gene delivery technique. Hepatic nodule formation was observed in ∼50% of mice, supporting our hypothesis that Dlk1 functions as an oncogene in HCC.

miR-370 is a relatively uncharacterized microRNA, although it has been demonstrated to suppress proliferation of cultured cholangiocytes. Similarly, manipulation of miR-370 activity in cultured hepatocytes has proliferative consequences consistent with a tumor suppressor role. Efforts to examine the effect of modulating miR-370 activity in vivo are currently underway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 236.
Abstract 2364: Overexpression of SATB1 (Special AT-Rich Sequence-Binding Protein 1) in prostate cancer potentiates metastatic phenotype
Authors: Shukla Sanjeev , MacLennan Gregory T. , Fu Pingfu , Gupta Sanjay
Published: February 2011

One of the reasons for the most prostate cancer-related deaths is the growth of secondary tumors due to metastases and not the primary organ-confined carcinoma. Metastasis in cancer cells results in acquiring abilities of increased motility and invasiveness, to home in other parts of the body. The key regulator involved in the control of metastasis genes in prostate cancer is presently unknown. Special AT-rich sequence-binding protein 1 (SATB1) is a transcription factor and functions as genome organizer. SATB1 being a transcription factor tend to bind with AT rich base unpaired sequences of the target gene. SATB1 acquires a “3 D chickenwire” network by forming anchor loops around chromatin, recruits chromatin remodeling complexes on the anchorage sites, and regulates histone modifications by rendering DNA sequences accessible or inaccessible for transcription. Earlier studies suggested the role of SATB1 in breast cancer progression. We aimed to observe the role of SATB1 in prostate cancer progression. We used different grades of human prostate cancer specimens, non tumorigenic and aggressive prostate cancer cells. Immunohistochemical evaluation of SATB1 in prostate cancer specimens of various Gleason grades exhibited significantly increased expression with increase in Gleason grade. A progressive increase in nuclear SATB1 expression was observed as tumor grade increased along with its presence in the cytoplasm. Further, SATB1 protein levels were higher in human prostate cancer cell lines viz. HPV-CA-10, DU145, DUPro, PC-3, PC-3M compared to non-tumorigenic prostate epithelial cells PZ-HPV-7. Nuclear expression of SATB1 was higher in biologically aggressive subclones of prostate cancer cells. Introduction of SATB1 through transient infections into non-tumorigenic PZ-HPV-7 cells increased its invasiveness and migration capabilities, whereas these properties were inhibited by silencing SATB1 through shRNA techniques. Furthermore, knock down of SATB1 caused increased E-cadherin expression and simultaneous reduction in matrix metalloproteinase-9 expression, providing further evidence that SATB1 significantly influences the metastasis process. Taken together, our results suggest that SATB1 is a master regulator of the metastasis process in prostate cancer and, therefore, could be considered as an independent prognostic factor and a potential therapeutic target for prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2364.
Abstract 2393: Pathological angiogenesis in vascular tumors is driven by endothelial Akt1 and inhibited by rapamycin
Authors: Phung Thuy L. , Xue Qi , Antonello Zeus , Gerald Damien , Perruzzi Carole , Rojano Rafael , Cunningham Michael , Hochman Marcelo , Benjamin Laura E.
Published: February 2011

Vascular tumors are abnormal angiogenic proliferations of neoplastic endothelial cells with a wide spectrum of clinical diseases ranging from common hemangioma in children to malignant angiosarcoma in adults. To date, the mechanisms leading to vascular tumor formation are poorly understood and under-investigated. We found reduction in PTEN levels and increased Akt activation in benign and malignant human vascular tumors. Akt1 promoted the proliferation and migration of vascular tumor cells. Expression of constitutively active Akt1 in vascular endothelial cells was sufficient to induce hemangioma formation in vivo, and sustained endothelial Akt1 activation was necessary to maintain tumor growth. Inhibition of mTOR activity downstream of Akt1 with rapamycin blocked VEGF-induced angiogenesis in vascular tumor cells and tumor growth in animals. In vascular tumors, rapamycin inhibited the activities of both TORC1 (which phosphorylates p70 S6-Kinase downstream of mTOR) and TORC2 (which phosphorylates Akt) and may provide a mechanism for the high efficacy of rapamycin in these tumors. As a topical agent, rapamycin was effective in inhibiting cutaneous vascular tumors with minimal systemic blood levels of the drug. In summary, these studies showed that endothelial Akt1 plays a key role in vascular tumor formation, and topical rapamycin holds promising clinical utility in the treatment of cutaneous vascular tumors.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2393.
Abstract 2394: Spontaneous immune responses against XAGE-1b in patients with non-small cell lung cancer (NSCLC)
Authors: Ohue Yoshihiro , Eikawa Shingo , Mizote Yu , Okazaki Nami , Isobe Midori , Uenaka Akiko , Fukuda Minoru , Nakayama Eiichi , Oka Mikio
Published: February 2011

BACKGROUND: Cancer/testis (CT) antigen is expressed only in the testis in normal adult tissues and in various types of cancers. There is no expression of MHC antigen in the testis. Therefore, CT antigen is thought to be a promising target for cancer immunotherapy. The XAGE-1 gene has been identified as a CT-like antigen and consists of several isoforms. We recently reported that XAGE-1b was predominantly expressed in lung adenocarcinoma by immunohistochemistry using XAGE-1b mAb (clone USO 9-13). In this study, we investigated humoral and cellular immune responses against XAGE-1b in patients with non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS: Sera and PBMCs were obtained from NSCLC patients who visited Kawasaki Medical School Hospital between 2005 and 2009. Antibody response to XAGE-1b was analyzed by ELISA using synthesized XAGE-1b protein. CD4 and CD8 T-cell responses against XAGE-1b were examined by IFN-γ ELISA and/or secretion assay using 17 16- or 17-mer XAGE-1b-overlapping peptides (OLPs) spanning the entire XAGE-1b protein in antibody-positive patients. Epitope peptides recognized by antibody and T-cells were determined by ELISA using XAGE-1b OLPs.

RESULTS: Antibody positive frequencies of total 200 NSCLC patients and 69 stage IIIB/IV lung adenocarcinoma patients were 10.0% (20/200) and 18.8% (13/69), respectively. The peptide regions frequently recognized by the antibody were XAGE1b peptides 25-40, 29-44 and 33-48. CD4 and CD8 T-cell responses against XAGE-1b were observed in 14 (87.5%) of 16 patients and 6 (66.7%) of 9 patients, respectively, in the antibody-positive patients. No response was observed in 5 antibody-negative patients and 5 healthy donors. The XAGE-1b peptide regions dominantly recognized by CD4 and CD8 T-cells were XAGE-1b peptides 13-28 and 33-48 for CD4 and XAGE-1b peptide 29-44 for CD8. Furthermore, the minimal epitope peptides bound to HLA-DR4.1 and DP5 recognized by CD4 T-cell clones and those bound to HLA-A2 and Cw1 recognized by CD8 T-cell clones were determined.

CONCLUSION: Our findings indicate that CT antigen XAGE-1b is highly immunogenic in NSCLC patients inducing antibody, and CD4 and CD8 T-cell responses. Thus, XAGE-1b is a promising target antigen for immunotherapy against lung adenocarcinoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2394.
Abstract 240: Amplification status of GAS41 and MDM2 in lung adenocarcinomas
Authors: Pikor Larissa , Lockwood William W. , Vucic Emily A. , Lam Wan L.
Published: February 2011

Background: Lung cancer is the leading cause of cancer death worldwide. High mortality rates are attributed to inefficient therapeutic strategies and a lack of screening for early detection. Identification of genes involved in lung cancer development may yield new molecular targets for diagnosis and treatment. It is well documented that the lung cancer genome harbors genetic alterations. We hypothesize that novel oncogenes can be discovered through characterization of chromosomal regions frequently amplified in lung adenocarcinoma.

Methods: A panel of 169 matched lung adenocarcinoma tumors was studied. Genetic profiles describing copy number alterations and gene expression were generated by whole genome array comparative genomic hybridization and Affymetrix platforms respectively, and visualized using SIGMA2 software. Regions of DNA amplifications were identified using the GISTIC algorithm and integrated with expression data to determine if amplification is associated with overexpression in tumors relative to matched normal tissue. An MTT assay was used to investigate the effect of cell proliferation after shRNA-mediated knockdown in a cell line with DNA amplification. Survival analysis using multiple independent data sets was also performed to assess the clinical significance of gene amplification and overexpression.

Results: A preliminary genome wide screen revealed Glioma Amplified Sequence 41 (GAS41) at 12q13-15 as frequently amplified and overexpressed in lung cancer. GAS41 suppresses cell cycle checkpoint genes p21 and p14, causing indirect repression of the p53 tumor suppressor, promoting tumorigenesis. Amplification of this gene has been reported in the earliest stages of glioma and astrocytoma. GAS41 is amplified in 16.57% of the lung adenocarcinoma tumors (28 of 169) analyzed and consistently overexpressed. Knockdown of GAS41 slowed cell proliferation, consistent with its biological function. Additionally, patients expressing high levels of GAS41 mRNA showed markedly poorer outcomes than those with lower expression.

Conclusions: Our data highlights the tumorigenic potential of GAS41, suggesting that amplification of this gene may be a critical alteration in lung cancer. GAS41 amplification and subsequent activation may represent a novel mechanism driving lung tumorigenesis. The association of GAS41 expression with survival and its demonstrated effect on cell proliferation make it a potential prognostic marker and therapeutic target in lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 240.
Abstract 2405: Treatment of human dendritic cells with Saccharomyces cerevisiae (yeast) reduces number and function of regulatory T cells (Tregs) and enhances the ratio of antigen-specific effectors to Tregs
Authors: Cereda Vittore , Vergati Matteo , Huen Ngar-Yee , di Bari Maria Giovanna , Gulley James L. , Franzusoff Alex , Schlom Jeffrey , Tsang Kwong Y.
Published: February 2011

It has been demonstrated that recombinant Saccharomyces cerevisiae yeast vector containing the transgene encoding carcinoembryonic antigen (yeast-CEA) activates human dendritic cells (DCs) and stimulates CEA-specific T-cell responses. Numerous studies have shown that regulatory T cell (Treg) function plays an important role in immune modulation. We compared the effects of yeast-treated DCs and CD40L-matured DCs on the number and functionality of CD4+CD25+CD127-FoxP3+ Tregs. Human DCs were treated with yeast or CD40L and cocultured with isolated autologous CD4+ T cells for 5 days, then the phenotype and function of the CD4+ T cells were analyzed. CD4+CD25+CD127- T cells isolated from the coculture of CD4+ T cells plus yeast-treated DCs had a lower expression of FoxP3 and decreased suppressive function compared to CD4+CD25+CD127- T cells isolated from the coculture of CD4+ T cells plus CD40L-treated DCs. Also, compared to the coculture of CD4+ T cells plus CD40L-treated DCs, the coculture of CD4+ T cells plus yeast-treated DCs showed increases in the ratio of CD4+CD25+ activated T cells to Tregs and in the production of Th1-related cytokines (IL-2, TNF-α, IFN-γ) and IL-6. In addition, yeast-treated DCs used as antigen-presenting cells (APCs) incubated with CEA enhanced the proliferation of CEA-specific CD4+ T cells in carcinoma patients compared to the use of CD40L-matured DCs used as APCs. This is the first study to report on the role of yeast-treated human DCs in reducing Treg frequency and functionality and thus enhancing antitumor immune response. These results provide a rationale for the use of yeast as a vector in cancer vaccines.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2405.
Abstract 2407: Establishment of a clinically applicable human tyrosine hydroxylase DNA vaccine for anti-neuroblastoma immunotherapy
Authors: Shibina Anastasia , Nuebener Nicole , Seidel Diana , Stermann Alexander , Lode Holger N. , Gaedicke Gerhard
Published: February 2011

Background: Neuroblastoma (NB) is an aggressive neoplasm of the sympathetic nervous system in early childhood. Current treatment of high-risk NB consists of intensive myeloablative therapy followed by bone marrow transplantation. However, children with advanced stage disease or those with refractory disease have a poor prognosis. A promising adjuvant approach could be active immunotherapy with DNA vaccines encoding tumor-associated antigens, like tyrosine hydroxylase (TH), which is highly expressed on NB cells. We already established human TH (hTH) DNA vaccination in a syngeneic NB mouse model achieving complete remission of established mass disease and of metastasis. With regard to a clinical application important aspects of this xenogeneic TH DNA vaccination approach have to be readjusted for the use in humans.

Methods: For this purpose, hTHcDNA fused to mutated ubiquitin (Gly76[[Unsupported Character - [[Unsupported Character - ]]]]Ala76) was cloned into the FDA-approved, kanamycin encoding DNA plasmid pING. To examine the functionality of the new plasmid design, pING-hTH was transfected into HEK293 cells. Gene expression was verified by immunofluorescence and western-blot analysis. Furthermore, efficacy of the vaccine was tested in a syngeneic NB mouse model in a prophylactic setting employing attenuated Salmonella typhimurium SL7207 as DNA delivery system. Primary tumors were induced by s.c. injection of NXS2 NB cells and tumor growth was monitored over time. Furthermore, immunological mechanisms of tumor protection were evaluated.

Results: In vitro, functional hTH protein expression by the new plasmid design could be established in HEK293 cells. In vivo, xenogeneic TH DNA vaccination induced an anti-NB effect in mice receiving pING-hTH as indicated by a 48-52% reduction in s.c. tumor volume in contrast to empty vector controls. Immunization with hTH-pING DNA-vaccine further generated CTL-mediated responses against NXS2 NB cells and an increase in IFN-γ production. Furthermore, CD8+ T-cells presented at higher levels at primary tumor sites in hTH-vaccinated mice compared to controls.

Conclusion: The new vaccine design (hTH-pING) effectively induced an anti-NB immune response in vivo indicated by the suppression of s.c. primary tumors, which is mediated by NB-specific CTLs. Our findings open the possibility for developing a clinically applicable vaccination strategy for one of the most challenging childhood tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2407.
Abstract 241: A mutant DNA polymerase-delta associated with increased tumor progression causes random deletions in DNA
Authors: Loeb Lawrence A. , Schmitt Michael W. , Venkatesan Ranga N. , Pillaire Marie-Jeanne , Hoffmann Jean-Se'bastien
Published: February 2011

For many years, we have advanced the hypothesis that cancers exhibit a mutator phenotype. Recent support for this concept was gained by the increased frequency of random single-base substitutions measured in human tumors as well as by the large numbers of clonal mutations detected by DNA sequencing in a variety of human cancers. While these findings indicate that cancer cells accumulate large numbers of mutations, it remains unclear what types of alterations in the fidelity of DNA synthesis contribute most to the evolution of a tumor. In order to delineate the types of mutations that have the greatest impact on accelerating tumorigenesis, we studied the consequences of altered accuracy of synthesis by mutant DNA polymerases.

DNA polymerase δ (Pol δ) is responsible for replication of the lagging DNA strand during replication and functions in multiple DNA repair pathways. Based on homology to substitutions known to induce error-prone synthesis in other DNA polymerases, we constructed a series of single base substitutions at position L606 in the catalytic domain of human Pol δ. We found that Pol δ L606G introduces a high frequency of point mutations into DNA in vitro, but heterozygous mice expressing L606G do not exhibit a cancer phenotype. In contrast, Pol δ L606K synthesizes DNA in vitro with high accuracy; yet heterozygous mice expressing this mutant exhibit enhanced rates of tumor progression. Compared to either the wild type or L606G, the L606K mutant is defective in lesion bypass; cells expressing this mutant exhibit a decrease in the rate of fork progression. In addition, L606K cells exhibit an increase in spontaneous chromosomal aberrations, and comparative genomic hybridization analysis reveals an increased frequency of random deletions in tumors from mice expressing Pol δ L606K. These results indicate that mutations in a major replicating DNA polymerase can result in random deletions throughout the genome that have the potential to affect tumor progression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 241.
Abstract 2410: Development of a genetically-optimized whole tumor cell vaccine for ovarian cancer using HSV-derived glycoprotein D
Authors: Hagemann Andrea R. , Leskowitz Rachel , Cohen Gary H. , Coukos George , Powell Daniel J.
Published: February 2011

Background: Dendritic cell (DC) vaccines offer a promising addition to standard treatment for ovarian cancer with surgery and chemotherapy. We have previously shown that treatment of whole tumor cells with replication-deficient herpes simplex virus (HSV) results in a potent, specific T-Cell response to ovarian tumors. We sought to improve vaccine efficiency by isolating and comparing two specific components of HSV-treated SK-OV-3-pulsed DCs: glycoprotein D (gD) and IL12p70.

Methods: SK-OV-3 cells were treated with HSV1716 or transfected with HSV-1-derived gD engineered to express a similar amount of surface of gD. We further engineered these cells to express IL12p70 by lentiviral transduction. Theses cells were UVB-irradiated and pulsed with DCs. ELISA was used to measure the kinetics of the IL12p70 burst of each tumor-pulsed DC, as well as to compare the naïve, autologous lymphocyte priming responses of each cell line.

Results: IL12p70 was increased 3-fold with gD-SKOV3 compared to HSV-SKOV3, while following the same kinetic curve (646 ± 45.2 pg/mL v. 234 ± 24.2 pg/mL; p <0.01). gD-SKOV3 also resulted in a 2-fold higher priming response. Both the IL12p70 burst and priming response were blocked by treatment of SKOV3-gD cells with an antibody to gD. With the addition of IL12 to these cells, SKOV3-gD, but not SKOV3-HSV cells, resulted in significantly higher and more prolonged IL12 burst than that of SKOV3-IL12 cells alone.

Conclusions: Our in vitro results suggest a synergistic effect of IL12p70 and gD that is not seen with infection by intact HSV-1. We have isolated two key components from HSV, cytokine stimulation and gD-mediated blockade of immunosuppression, that in combination result in a more potent, specific immune response to ovarian cancer tumor cells. We can now utilize these key components to engineer a more efficient whole tumor cell vaccine for EOC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2410.
Abstract 2411: Intratumoral dendritic cell vaccine as neo-adjuvant immunotherapy of high-risk soft tissue sarcoma patients undergoing external beam radiation therapy (EBRT): Prospective phase I/II clinical trial
Authors: Iclozan Cristina , Finkelstein Steven E. , Ahmed Jamil , Bui Marilyn M. , Cotter Matthew J. , Ramakrishnan Rupal , Cheong David , Gonzalez Ricardo J. , Heysek Randy V. , Lenox Brianna C. , Sondak Vernon K. , Szekely Rosemary R. , Zager Jonathan S. , Letson G. Douglas , Antonia Scott J. , Gabrilovich Dmitry I.
Published: February 2011

Cell death inducing external beam radiation (EBRT) combined with experimental intratumoral injection of dendritic cells (DC) showed promise by initiating anti-autologous tumor-cell immune responses in mice. Here we performed first clinical trial testing this hypothesis in patients with large high-grade soft tissue sarcomas (STS). This type of cancer has a significant (>50%) risk of progressing to distant metastases. Patients with clinical stage T2N0M0 or T3N0M0 high-grade STS of the extremity/trunk/chest wall were treated with standard neo-adjuvant EBRT 5040 cGy / 180 cGy coordinated with experimental DC therapy consisting of DC progenitor apheresis, ex-vivo expansion and culture, and 4 × intratumoral injections of 10 million DC. Autologous DC product was performed according to standardized GMP laboratory procedures. T cell function was assessed by EliSpot (measuring IFN-γ production) and proliferation (thymidine uptake) in addition to phenotyping of peripheral blood mononuclear cells by flow cytometry.

Clinically, targeted accrual was reached with eighteen patients completing neo-adjuvant EBRT with experimental intratumoral DC therapy. All patients have completed full immunologic assessment. Ten patients (56%) were induced to produce significant immune responses against autologous tumor cell lysates or/and survivin antigens as determined using ELISPOT assays or cell proliferation. Interestingly, some of these responses persisted even 30 weeks after start of treatment. Extensive post treatment T cell infiltration was detected within tumors. No clinical toxicity has been observed. Suggestive clinical outcome on 14 patients followed 1 year reveal progress in 1/7 patients with robust response (detected at more than one time point), and 4/7 patients with weak (detected at one time point at the beginning of the study) or no response respectively. Thus, this data is promising for planning future combined treatment approaches as radiation therapy/immunotherapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2411.
Abstract 2422: The trimeric engineered fusion protein with CD154 peptide mimetic (OmpC-CD154p), induced apoptotic signaling in B-NHL cell lines mediated by caspase 3 and caspase 8 activation
Authors: Martinez-Miguel Bernardo , Paniagua Melisa Martinez , Huerta-Yepez Sara , Gonzalez-Bonilla Cesar , Vega-Paredes Mario , Martinez-Maza Otoniel , Bonavida Benjamin
Published: February 2011

CD154 (CD40-ligand) is a critical transmembrane molecule with potent immune-stimulatory properties and is clinical applied in gene therapy for leukemia and lymphoma. The interaction between CD40, a member of the tumor necrosis factor superfamily, and its ligand CD154 is essential for the development of humoral and cellular immune responses. Selective inhibition or activation of this pathway forms the basis for the development of new therapeutics against immunologically-based diseases and malignancies. Engagement of CD40-CD154 induces activation and proliferation of B lymphocytes and triggers apoptosis of carcinoma and B lymphoma cells. Several clinical trials have been reported targeting CD40 in cancer patients using recombinant CD154, mAbs and gene therapy, which were well tolerated and resulted in objective tumor responses. In addition to these therapies, CD154 mimetics have been considered with the objective to augment and potentiate the direct cytotoxic anti-tumor activity and for better accessibility to tumor sites. This approach was developed by us and we hypothesized that the genetic engineering of a fusion protein containing a CD154 peptide mimetic additional to be trimeric may be advantageous in that it may have a better affinity to CD40 on B cell malignancies and trigger cell death. The fusion partner may be a carrier targeting other surface molecules expressed on the malignant cells. This hypothesis was tested by the development of a gene fusion of Salmonella typhi OmpC protein expressing the CD154 Trp140-Ser149 amino acid strand. This OmpC-CD154p fusion protein binds CD40 and triggers the CD40 expressing B cells. In this study, we demonstrate that OmpC-CD154p treatment inhibits cell growth and proliferation, on B-NHL cell lines Raji and Ramos. In addition, significant apoptosis was achieved and the extent of apoptosis was a function of the concentration used and time of incubation. The anti-tumor effect was specific as treatment with OmpC alone had no effect. OmpC-CD154p treatment induced activation of caspase 3 active and caspase 8. These findings establish the basis for the development of new fusion proteins specificity targeting the tumor cells directly and mechanism mediated by extrinsic pathway.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2422.
Abstract 2442: VGX-100, a novel therapeutic monoclonal antibody targeting VEGF-C that inhibits tumor growth
Authors: Tester Angus , Phelan David , McColl Brad , Klupacs Robert , Baldwin Megan
Published: February 2011

Angiogenesis and lymphangiogenesis are important contributors to the growth and metastasis of a wide variety of tumor types. Therapeutic targeting of the angiogenic vascular endothelial growth factor (VEGF) is now an FDA-approved treatment for several cancers. Vascular endothelial growth factor-C (VEGF-C) has also been demonstrated to stimulate angiogenesis and lymphangiogenesis in a number of experimental systems, and is essential for development of the lymphatic system during embryogenesis. In addition, expression of VEGF-C drives tumor progression and metastasis in mouse models of cancer, and is associated with poor prognosis in many human cancers. Targeting VEGF-C is therefore a highly promising strategy for novel therapeutics, with the potential to disrupt both angiogenesis and lymphangiogenesis.

VGX-100 is a highly specific, fully human monoclonal antibody for VEGF-C that does not bind to other members of the VEGF family. In vitro testing demonstrates that VGX-100 blocks binding of VEGF-C to both VEGF receptor-2 and VEGF receptor-3, and inhibits the proliferation of blood vascular (HUVEC) and lymphatic endothelial cells in response to VEGF-C stimulation. Here we demonstrate anti-tumor efficacy through the use of xenograft models of human cancer, with VGX-100 treatment significantly inhibiting tumor growth in several models. These findings demonstrate that VGX-100 has great potential for development as a new cancer therapeutic, with potential clinical utility in combination with existing therapies or in patients refractory to existing anti-angiogenic agents.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2442.
Abstract 2450: Surface molecule CD229 represents a possible target for the treatment of multiple myeloma
Authors: Atanackovic Djordje , Panse Jens , Hildebrandt York , Jadczak Adam , Luetkens Tim , Kobold Sebastian , Lajmi Nesrine , Zander Axel R. , Cao Yanran , Bokemeyer Carsten , Kroeger Nicolaus
Published: February 2011

BACKGROUND AND OBJECTIVES: The majority of patients with multiple myeloma (MM) will eventually relapse and succumb to their disease even after high dose chemotherapy and autologous stem cell transplantation, possibly due to the persistence of BM-residing myeloma stem cells. Therefore, new treatment strategies incorporating new therapeutic targets - ideally to be expressed by the bulk of end-stage myeloma cells and their dormant progenitors - are needed to improve the outcome of myeloma patients.

DESIGN AND METHODS: We screened myeloma cell lines for the presence of a large number of immunoreceptors and verified expression of potential target molecules on cell lines and patient samples. The function of the respective proteins was evaluated using gene knockdown and their potential as targets for antibody therapies was investigated using in vitro cytotoxicity assays.

RESULTS: Of all immunoreceptors analyzed, SLAM family member CD229 showed the strongest expression and was also found on myeloma precursors. Primary myeloma cells of myeloma patients uniformly evidenced CD229 surface expression while the molecule was absent from most healthy human tissues. Flow cytometric analysis of CD229 expression facilitated the detection of myeloma cells in the bone marrow. CD229 seemed to promote the survival of myeloma cells while CD229 silencing increased their susceptibility towards chemotherapy. Importantly, targeting CD229 with a monoclonal antibody resulted in specific lysis of the tumor cells.

CONCLUSIONS: These results suggest that CD229 might represent an attractive diagnostic and therapeutic target for the treatment of MM.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2450.
Abstract 2454: High susceptibility to azoxymethane-induced ear duct and intestinal carcinogenesis in diabetic OLETF rats
Authors: Izumi Keisuke , Hafez Ezar , Takahashi Tetsuyuki , Ogawa Hirohisa
Published: February 2011

Diabetes and obesity are thought to be risk factors for colorectal cancer in humans. In our recent study, whole body X-irradiated Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a model animal of type 2 diabetes, developed low incidence of small intestine adenocarcinoma, but not in nondiabetic Long-Evans Tokushima Otsuka (LETO) rats. In the present study, six-week-old male OLETF and LETO rats (n=24) were given weekly s.c. injections of 15 mg/kg azoxymethane (AOM) for three weeks and killed after 30 weeks from the initial treatment. The incidences of ear duct tumors in LETO and OLETF rats were 0% and 67% (P<0.001), respectively. Those of small intestine tumors in these strains were 0% and 43% (P<0.001), respectively, and those of colon tumors were 46% and 79% (P<0.05), respectively. Serum triglyceride and free fatty acid levels in OLETF rats were significantly higher than those in LETO rats at sacrifice, but average serum insulin was lower than that in LETO rats. Fatty change of hepatocytes was common in OLETF rats, but not in LETO rats. Hepatic IGF-1, leptin and PAI-1 mRNA levels were not different in two strains. These data suggest that hyperlipidemia plays an important role in high susceptibility to AOM-induced carcinogenesis in OLETF rats.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2454.
Abstract 2459: Early changes in gene expression induced by tobacco smoke: Evidence for the importance of estrogen within lung tissue
Authors: Meireles Sibele I. , Esteves Gustavo H. , Hirata Roberto , Peri Suraj , Devarajan Karthik , Slifker Michael , Mosier Stacy L. , Vadhanam Manicka V. , Hurst Harrell E. , Neves E. Jordao , Reis Luiz F. L. , Gairola C. Gary , Gupta Ramesh C. , Clapper Margie L.
Published: February 2011

Lung cancer is the leading cause of cancer deaths in the U.S., surpassing breast cancer as the primary cause of cancer-related mortality in women. The goal of the present study was to identify early molecular changes in the lung induced by exposure to tobacco smoke and thus identify potential targets for chemoprevention. Female A/J mice were exposed to either tobacco smoke or HEPA-filtered air via a whole-body exposure chamber (6 h/day; 5 days/wk for 3, 8 and 20 wk). Gene expression profiles of lung tissue from control and smoke-exposed animals were established using a 15 K cDNA microarray. Cytochrome P450 1b1 (Cyp1b1), a Phase I enzyme involved in both the metabolism of xenobiotics and the 4-hydroxylation of 17β estradiol, was modulated to the greatest extent following smoke exposure. A panel of 10 genes were found to be differentially expressed between control and smoke-exposed animals at 3, 8 and 20 wk (P < 0.001). The interaction network of these differentially expressed genes revealed new pathways modulated by short-term smoke exposure including estrogen metabolism. In addition, 17β-estradiol was detected within murine lung tissue by gas chromatography coupled mass spectroscopy and immunohistochemistry. Identification of the early molecular events that contribute to lung tumor formation is anticipated to lead to the development of promising targeted chemopreventive therapies. In conclusion, the presence of 17β-estradiol within lung tissue when combined with the modulation of Cyp1b1 and other estrogen metabolism genes by tobacco smoke provides novel insight into a possible role for estrogens in lung cancer. (Supported by fellowships from the AACR-Pennsylvania Department of Health and the ASPO/CRPF, the Estate of Jane Villon, the Jerome M. Spencer and Arnold Zaslow Family Foundation and NIH CA-96310).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2459.