bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4315: A novel role for the high affinity IL13 receptor in glioblastoma multiforme
Authors: Prasol Melanie S. , Moon Kyung-Sub , Lesniak Maciej S. , Balyasnikova Irina V.
Published: August 2012

IL13 Receptor alpha 2 (IL13Ra2) is one of two receptors for IL13 and is found to be highly expressed in a number of cancers including, ovarian, head and neck, pancreatic and glioblastoma multiforme (GBM). IL13Ra2 has been found to be expressed mostly in high grade GBMs but not in low grade gliomas or normal brain tissue. IL13Ra2 has a short intracellular domain that lacks a signaling domain and possesses a high affinity for IL13. It is thought that in GBMs IL13Ra2 acts primarily as a decoy receptor for IL13. However, recent evidence from pancreatic and ovarian cancer lines indicates that IL13Ra2 initiates signaling pathways that influence cell invasion and adhesion properties of cancer cells. We hypothesize the IL13Ra2 might play a role in GBMs distinct for its decoy receptor function. This study is designed to determine if IL13Ra2 possess functional properties and can modulate the behavior of glioma cells through its interaction with IL13. We examined the effect of IL13 interaction with IL13Ra2 in multiple glioma cell lines in vitro. A BrdU based proliferation assay was utilized to determine the effect of IL13 on the proliferation rate of glioma cells. Migration of glioma cells was also examined over a 24 hour period following exposure to IL13. A shRNA mediated knockdown of IL13Ra2 in glioma cells was also produced and the resultant phenotype analyzed by phalloidin staining for cytoskeletal actin and in the migration assay. Treatment of IL13Ra2 expressing glioma cell lines with IL13 did not influence their proliferation rates in vitro. However, cells that had been treated with IL13 demonstrated an increased migration response. Knockdowns were found to have decreased migration rates, both in the presence and absence of IL13. Knockdowns were also found to have dramatic changes in phenotype with increased cellular adhesion and altered actin structure. When the actin structure was examined following IL13 treatment, normal cells appeared to have an increase in peripheral actin and filopodia, while in knockdown cells treated cells did not appear different from untreated controls. Our data indicate that IL13 interaction with IL13Ra2 might contribute to changes in the phenotype of glioma cells that promote their invasive properties. Further research is needed to determine the underlying mechanism.

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 4315. doi:1538-7445.AM2012-4315
Abstract 4317: Stim1 and Orai1 are critical regulators of melanoma invasion and anoikis
Authors: Yang Shengyu , Sun Jianwei , He Huifang
Published: August 2012

Store-operated calcium (SOC) influx is the major calcium entry mechanism in non-excitable cells regulating a plethora of physiological and pathological processes. The internal store calcium sensor and plasma membrane pore-forming unit are recently identified to be Stim1 and Orai1, respectively. We were the first to demonstrate the critical roles of Stim1 and Orai1 in breast tumor cell migration and metastasis (Cancer Cell, 2009, 15:124). There are still a few important questions remained to be answer: Whether Stim1 and Orai1 play a role in the dissemination of other tumors? How do Stim1 and Orai1 dysregulate and reorganize actin cytoskeleton to promote tumor cell invasion and metastasis? Do Stim1 and Orai1 contribute to tumor progression in cancer patients? Our recent data suggested that Stim1 and Orai1 were important regulators of tumor cell migration and invasion in multiple tumors. SOC inhibitors block cell migration and invasion in all the tumors tested. Stim1 and Orai1 promote tumor cell invasion and degradation of extracellular matrix by promoting the formation of invadopodia. Stim1 and Orai1 regulate invadopodia formation through facilitating SOC calcium influx and activation of non-receptor tyrosine kinase Src. The activation of Src by SOC influx also contributes to anoikis resistance in tumor cells. We were able to further demonstrate that the expression levels of Stim1 correlate with tumor progression and metastasis in multiple solid tumors. Therefore, our data suggested that Stim1 overexpression in tumors may promote tumor metastasis through calcium influx and Src activation, which facilitate extracellular matrix degradation and promote anchorage-independent 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 4317. doi:1538-7445.AM2012-4317
Abstract 432: Differences in molecular background of colorectal liver and lung metastases
Authors: Knijn Nikki , van Lin Simone , Vink-Borger Elisa , van Vliet Shannon , Mekenkamp Leonie , Riemersma Sietske , Tebar Maria , Klomp Marjolein , Meijer Jos , Teerenstra Steven , Punt Kees , Nagtegaal Iris
Published: August 2012

BACKGROUND: Mutations in the KRAS oncogene occur in 30-60% of the patients with colorectal cancer (CRC). Constitutively activation of the KRAS protein leads to growth, proliferation, and survival of CRC cells. KRAS mutation is an early event during colorectal carcinogenesis, therefore all tumor cells including metastatic cells are expected to have the same mutation status. We investigated the KRAS mutation status in primaries and metastatic tissue of patients with liver and lung metastasis. METHODS: Patients with histological confirmed CRC who underwent surgical resection of the primary tumor and biopsy or surgical resection of the corresponding liver (n = 304) or lung metastasis (n = 90) were included. KRAS mutation analysis was performed for codons 12 and 13 using sequencing analysis. We used Next Generation Sequencing (NGS) to further evaluate a patient with a discordance in KRAS mutation status between the primary and metastasis. RESULTS: KRAS mutations were detected in 35.3% of the 304 primary tumors with liver metastases. In 11 cases (3.6%), we found a discordance between primary tumor and metastasis: 5 primary tumors had a KRAS mutation with a wild-type metastasis, 1 primary tumor was wild type with a KRAS mutation in the metastasis, and in 5 cases the primary tumor and the metastasis had a different KRAS mutation. NGS of the patient with a wild type primary tumor and a KRAS mutation in the liver metastases revealed a KRAS mutation in 7.5% of the primary tumor cells. KRAS mutations were detected in 46.7% of the 90 primary tumors with lung metastases. The KRAS mutation frequency in lung metastases was 55.6%. A discordance in KRAS mutation status between primary tumors and metastasis was observed in 8 cases (8.9%). In all these patients the primary tumors had a KRAS wild-type while the lung metastasis showed a KRAS mutation. CONCLUSION: We observed a higher KRAS mutation frequency in primary CRC with lung metastases compared to primary CRC with liver metastases (p=0.038). Increased discordance in the lung metastases might indicate that these originate in very small subclones of the primary.

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 432. doi:1538-7445.AM2012-432
Abstract 4322: Iron increases the invasiveness of prostate cancer cells in vitro: Mechanisms and inhibition by the antioxidant ebselen
Authors: Guo Wenji , Schlicht Michael , Kucynda Theresa , Zhou Ping , Valyi-Nagy Klara , Kajdacsy-Balla André
Published: August 2012

The effect of iron on PC-3 prostate cancer cell invasiveness was investigated using Neuroprobe filter membrane transmigration assays. PC-3 cells were pre-incubated with ferric ammonium citrate (FAC) for 6 hours. Excess iron was removed before the assay. The PC-3 cells were placed on an extracellular membrane preparation (Matrigel®) in the upper wells of the chamber and allowed to migrate onto the underside of a porous membrane that allowed cell transmigration. The number of cells migrating to the underside of the membrane was determined and used as a marker of cell invasion. Pre-treatment with 100 µM FAC caused a 4-fold increase in PC-3 cell invasion when measured at 24 hours (P< 0.05). The FAC concentrations that induced PC-3 invasion were 100 times smaller than concentrations which interfered with cell viability or proliferation rate. Western blot analysis suggested that the effect of FAC exposure on PC-3 cell invasion was mediated by p42/44 MAP kinase activity. Furthermore, the antioxidant ebselen, a hydrogen peroxide inhibitor, decreased FAC-induced PC-3 cell invasion. We also examined the mRNA expression of invasion-related genes using a cDNA array and found a positive correlation between the exposures to FAC and the invasion phenotype of prostate cancer cells. The data demonstrated that the upregulation of genes, such as fractalkine and plasminogen, after FAC treatment may be associated with iron-induced invasion of prostate cancer. Our data suggest that iron overload may be detrimental to patients with prostate cancer and that the effect of iron on invasion may be inhibited by ebselen.

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 4322. doi:1538-7445.AM2012-4322
Abstract 4325: CD99 suppresses osteosarcoma cell migration by favouring the oncosoppressor N-cadherin/beta-catenin signalling pathway in contrast to ezrin.
Authors: Manara Maria Cristina , Zucchini Cinzia , Pinca Simona , de Sanctis Paola , Guerzoni Clara , Scotlandi Katia
Published: August 2012

CD99 is a 32-kDa highly glycosylated transmembrane protein encoded by MIC2 gene which shares no homology with any known family of proteins except Xga and mouse CD99L2 proteins. Located in the pseudoautosomal region of chromosomes X and Y, MIC2 encodes two distinct products by alternative splicing of gene transcripts: a long form (32-kDa), corresponding to the full-length protein (CD99wt) and a short form harbouring a deletion in the intracytoplasmic domain (CD99 sh). CD99 is involved in multiple cellular events including cell adhesion, apoptosis, differentiation of T- cells and thymocytes, transendothelial migration of leukocytes, maintenance of cellular morphology and regulation of intracellular membrane protein trafficking either in physiology and in pathological conditions. In osteosarcoma, CD99 is expressed at low levels and functions as a tumor suppressor. The two alternative spliced isoforms are associated to distinct functional outcomes: CD99sh expression increases, whereas wtCD99 significantly inhibits migration, invasiveness and metastasis of osteosarcoma cells (Manara MC, 2006; Scotlandi K 2007). In this study, we specifically analyzed modulation of cell-cell contacts, reorganization of the actin cytoskeleton, and modulation of signalling pathways by comparing osteosarcoma cells characterized by different metastasis capabilities and CD99 expression, to identify molecular mechanisms responsible for metastasis. Our data indicate that expression of CD99wt induces recruitment of beta-catenin to adherens injunctions through N-cadherin up-regulation. In addition, forced expression of CD99wt inhibits the expression of several molecules crucial to remodeling the actin cytoskeleton, such as ACTR2 (also named ARP2), ARPC1A and ROCK II as well as ezrin, an ezrin/radixin/moesin (ERM) family member that has been clearly associated with tumor progression and metastatic spread either in experimental models and clinical samples of osteosarcoma. Functional studies by siRNA and/or specific inhibitors point to ROCKII as a crucial intracellular mediator regulating osteosarcoma metastasis capabilities.

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 4325. doi:1538-7445.AM2012-4325
Abstract 4327: Loss of the APC tumor suppressor alters breast cancer cell migration and invasion
Authors: Odenwald Matthew A. , Prosperi Jenifer R. , Goss Kathleen H.
Published: August 2012

Metastasis is responsible for the majority of deaths attributable to cancer, but the molecular events that drive the metastatic phenotype are not completely understood. The adenomatous polyposis coli (APC) tumor suppressor is frequently inactivated in colorectal cancer as well as other tumor types, such as breast cancer, and has been implicated specifically in early tumor progression. However, it is not known whether APC also plays an important role in the later stages of cancer pathogenesis, including invasion and metastasis. Preliminary data indicated that transient knockdown of APC in 4T07 mouse mammary tumor cells led to marked morphological changes from mesenchymal-like to epithelial-like phenotypes, leading to the hypothesis that APC can effect the mesenchymal-to-epithelial transition and may alter cancer metastasis. To test this hypothesis, 4T07 cells were stably infected with lentiviral APC short-hairpin (sh)RNAs, and knockdown of APC expression was verified by quantitative real-time PCR and immunofluorescence (IF) with an APC antibody. We found that APC depletion altered the mesenchymal morphology of these cells to a more epithelial phenotype. The localization of β-catenin at the ends of cell protrusions was dependent on APC; however, APC knockdown did not result in cytosolic or nuclear accumulation of β-catenin. Consistent with the observed morphology change, APC depletion significantly impaired the ability of 4T07 cells to migrate in wound-filling assays and invade through a Matrigel-coated membrane. Together, these results suggest that APC loss impacts the morphology, migration and invasion of breast cancer cells, all key features of metastatic capacity. Current efforts are aimed at uncovering the mechanism by which APC alters these properties and translating these findings to our understanding of breast cancer metastasis in vivo.

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 4327. doi:1538-7445.AM2012-4327
Abstract 4328: Specific epidermal growth factor receptor autophosphorylation sites promote epithelial cell chemotaxis and restitution
Authors: Yamaoka Toshimitsu , Frey Mark , Polk D.Brent , Oki Yasunari , Murata Yasunori , Sugiyama Tomohide , Kusumoto Sojiro , Ishida Hiroo , Shirai Takao , Nakashima Masanao , Okuda Kentaro , Ohnishi Tsukasa , Hirose Takashi , Ohmori Tohru , Adachi Mitsuru
Published: August 2012

BACKGROUND: Cell migration is required for the physiological processes of wound repair, resolution of inflammation, and organogenesis, but is also involved in the pathology of tumor invasion. Thus, investigation of the regulatory mechanisms of cell migration is important for both understanding basic intestinal biology and identifying potential therapeutic targets for disorders such as inflammatory bowel diseases and colon cancer. HYPOTHESIS: Upon ligand binding, epidermal growth factor (EGF) receptor (R) autophosphorylates on c-terminal tyrosines, generating docking sites for signaling partners that stimulate proliferation, restitution, and chemotaxis. Specificity for individual EGFR tyrosines in cellular responses has been hypothesized but not well documented. Here we tested the requirement for particular tyrosines, and associated downstream pathways, in mouse colon epithelial cell chemotactic migration. We compared these requirements to those for the phenotypically distinct restitution (wound healing) migration. METHODS: Wild-type, Y992/1173F, Y1045F, Y1068F, and Y1086F EGFR constructs were expressed in EGFR-/- cells; EGF-induced chemotaxis or restitution were determined by Boyden chamber or modified scratch wound assay, respectively. Pharmacological inhibitors of p38, phospholipase C (PLC), Src, MEK, JNK/SAPK, phosphatidylinositol 3-kinase (PI 3-kinase), and protein kinase C (PKC) were used to block EGF-stimulated signaling. Pathway activation was determined by immunoblot analysis. RESULTS: Unlike wild-type EGFR, Y992/1173F and Y1086F EGFR did not stimulate colon epithelial cell chemotaxis towards EGF; Y1045F and Y1068F EGFR partially stimulated chemotaxis. Only wt EGFR promoted colonocyte restitution. Inhibition of p38, PLC, and Src blocked chemotaxis; JNK, PI 3-kinase, and PKC inhibitors blocked restitution but not chemotaxis. All four EGFR mutants stimulated downstream signaling in response to EGF, but Y992/1173F EGFR was partially defective in PLCγ activation while both Y1068F and Y1086F EGFR failed to activate Src. CONCLUSIONS: Specific EGFR tyrosines play key roles in determining cellular responses to ligand. Chemotaxis and restitution, which have different migration phenotypes and physiological consequences, have overlapping but not identical EGFR signaling requirements.

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 4328. doi:1538-7445.AM2012-4328
Abstract 4329: Modulation of metastatic behavior in breast cancers harboring p53 mutations
Authors: Morrison Bethanie L. , Bernal Federico
Published: August 2012

The mutation of p53 generally occurs during the later stages of cancer and leads to the increased metastatic potential of triple negative (ER_/PR_/Her2_) breast cancer. The low survival rates of advanced metastatic cancer make it critical not only to understand the mechanisms underlying the functional implications of p53 mutation, but also to identify ways to regulate its impact in cancer cell physiology. We have previously described the design, synthesis, and evaluation of a stabilized α-helix of p53 (SAH-p53) capable of inhibiting the p53-HDM2 and p53-HDMX interactions in order to restore the functionality of p53. Despite having low expression of both HDM2 and HDMX and mutations in p53, SAH-p53 treatment of the triple negative breast cancer cell lines MDA-MB-231 and HS578T results in a modest decrease in proliferative activity. While mutant p53 is known to promote metastatic behavior of breast cancer cells, the propensity of triple negative breast cancer cells to migrate and invade through Matrigel in the presence of EGF was decreased by treatment with SAH-p53. The anti-proliferative and anti-migratory effects of SAH-p53 treatment are independent of each other, yet both are accompanied by an alteration in cell morphology that includes the loss of cell membrane integrity and actin cytoskeletal organization. The surface level of β1 integrin, which is typically kept constant by mutant p53, is decreased in the presence of SAH-p53, pointing to possible alterations in integrin recycling. SAH-p53 also causes a change in the localization of the adhesion protein and stem cell marker CD44. Moreover, it has been suggested that mutant p53 enhances invasive properties by interacting with and inhibiting isoforms of p63, which have been implicated in the regulation of cell adhesion. Treatment of the triple negative breast cancer cells with a stabilized α-helix of p63 showed a significant decrease in cell viability as well as an enhanced inhibition of migration when treated simultaneously with SAH-p53. Targeted therapy for triple negative breast cancer is currently very limited and patients must rely on standard chemotherapeutic regimens. These data show that the use of SAH-p53 and SAH-p63 peptides provides a novel avenue to study the molecular interactions that drive metastatic behavior originated by p53 gain-of-function mutations.

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 4329. doi:1538-7445.AM2012-4329
Abstract 4330: Transcriptional regulation of gp170 by YY1 and prognostic significance in childhood acute lymphoblastic leukemia (ALL)
Authors: Andres-Antonio Gabriela , Rangel-Santiago Jesus , Tirado-Rodriguez Ana B. , Dorantes-Acosta Elisa , Vega Mario I. , Aquino-Jarquin Guillermo , Lopez Briseida , Jimenez Elba , Pelayo Rosana , Bonavida Benjamin , Medina-Sanson Aurora , Huerta-Yepez Sara
Published: August 2012

Leukemia is the most common cancer among children under the age of 15 years in the United States and many developed countries. In recent years, there has been the emergence of novel therapeutic drugs for this disease. However, the development of drug resistance by the tumor cells remains the most important obstacle in the treatment of leukemia. A widely studied mechanism of tumor resistance to chemotherapeutic drugs is through the expression of the multi-drug resistance (MDR) genes. P-glycoprotein 170 (gp170) is an MDR1 gene product which serves as an ATP-dependent cell membrane transporter; it facilitates the efflux of xenobiotics from the cells to prevent damage for prolonged drug activity, including chemotherapeutics agents. In addition to MDR1, several reports in different cancers have indicated that the transcription factor Yin Yang 1 (YY1) is over-expressed and regulates tumor cell response to chemotherapeutic drugs. TESS analysis demonstrated that the gp170 proximal promoter contains four putative binding sites for the YY-1 protein. We also hypothesized that the YY1 may too be over-expressed in ALL and that its expression may be correlated with the expression of gp170. These hypotheses were examined first by reporter systems analyze, the gp170 protein was cloned and we developed a luciferase reporter assay. Examination of the putative YY1 binding sites that were individually mutated (deleted), showed revealed that mutation at the site –1860 abolished the activity. Mutation at the site –1920 abolished approximately 50% and mutation at –1230 site abolished approximately 25%. Further, CHIP analysis demonstrated that YY1 transcription factor binds directly to the gp170 gene MDR1 promoter. In addition, we examined the expression of YY1 and gp170 in childhood ALL (n= 84). The expression of YY1 and gp170 was determined evaluated by IHC in tumor tissues and the frequency of positive cells was determined. For comparison, normal controls were also analyzed (n=53). The findings demonstrate that were a significant increase in the frequency of positive cells in ALL compared to controls for both YY1 (38% vs. 8%, p=0.001) and for gp170 (42% vs. 12%, p=0.001). There was a good correlation between the expression of YY1 and gp170 (Pearson's test, r=0.4, p=0.001). The findings suggest that YY1 transcriptionally regulates the mdr1 and may be a therapeutic target in MDR positive ALL and its inhibition may reverse resistance to chemotherapeutic drugs.

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 4330. doi:1538-7445.AM2012-4330
Abstract 4331: Analysis of stem cell-like compartments in Embryonal Rhabdomyosarcoma modulated by Sonic Hedgehog signaling
Authors: Satheesha Sampoorna , Walter Dagmar , Bornhauser Beat , Schäfer Beat W.
Published: August 2012

Rhabdomyosarcoma (RMS) is a heterogeneous group of malignancies with features of impaired skeletal muscle differentiation and represents the majority of the soft tissue cancers in the pediatric age group. Current treatment regimens offer some clinical respite but at a significant risk of averse side effects and secondary tumors later in life. Identifying and targeting sub-populations with higher tumorigenic potential and self renewal capacity not only decreases tumor burden but also lowers the probability of relapse. Using the sphere formation assay we could select for self-renewing cells from the heterogeneous monolayer cultures of embryonal RMS cell lines, RD and Rh36, which had multipotent differentiation ability in vitro and greater tumorigenic potential in vivo. Preliminary results suggest that the self renewing ability of RMS cells could be modulated by Hedgehog signaling, a developmental pathway important in RMS biology. Microarray analysis of the sphere cultures revealed Prominin 1 (CD133) as one of the surface markers with significantly higher expression. The CD133-positive cellular sub-population was more resistant to DNA damaging agents and had a greater capacity for tumor formation in an orthotopic xenotransplantation model. Embryonal RMS patients with higher expression of CD133 had a significantly lower overall survival. Ongoing work seeks to validate the importance of Hedgehog signaling in the embryonal RMS stem cell-like compartment.

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 4331. doi:1538-7445.AM2012-4331
Abstract 4333: Difference in the synergistic effect of cytotoxicity in pediatric brain stem gliomas and adult glioblastomas to combination treatment with temozolomide and molecular target-specific agents
Authors: Kim Dong Ok , Shin Hong Kyung , Ra Yoon Hwan , Park Jun Bum , Ra Young Shin
Published: August 2012

Brain stem glioma (BSG) in children is comparable to adult glioblastoma (GBM) with regard to poor survival and resistance to chemo-radiation therapy. Temozolomide (TMZ) is an alkylating agent and rapidly penetrates the central nervous system (CNS), making it a standard chemotherapeutic agent for adults with malignant glioma. Despite some improvement of survival, radiation with TMZ monotherapy rarely provides long-term control. This study aimed to determine combination effect of conventional anticancer agent, TMZ and molecular target-specific agents such as Sunitinib, Tandutinib, Cediranib and Rapamycin in BSG and GBM. The drug combination effects were tested by cell proliferation inhibition in glioma cells from six children with BSG and five established GBM cell lines. The half-maximal inhibitory concentration (IC50) of each agent was estimated 48hr after treatment of agents by cell proliferation assay. The values of IC50 in brain stem gliomas were higher as much as 1.5 to 4 times than those of GBM cell lines in all of agents, suggesting that brain stem gliomas are more resistant to not only TMZ, but also to various molecular target specific agents. O6-methylguanine methyltransferase (MGMT) promoter methylation status was determined by methylation-specific PCR after bisulfite treatment. As a result, MGMT promoter methylation was detected in all of GBM cell lines, whereas incomplete methylated or unmethylated MGMT was shown in six brain stem gliomas from pediatric patients. For combination therapy, IC10 of each agent plus IC10 of TMZ was treated in each cell for 48hr to assess cytotoxicity. TMZ+Cediranib, +Rapamycin, +Sunitinib showed some tumor proliferation inhibition in 60%, 40%, 20% of 5 GBM cell line respectively. In BSGs, however TMZ-Sunitinib and TMZ-Cediranib presented considerable tumor growth inhibition in 2 (33%), 1 (16%) among 6 BSGs although most BSGs were unmethylated in MGMT promoter. BSGs in children showed different chemotherapeutic effect and MGMT promoter methylation status compared to GBM in adult. The combination therapy of TMZ and molecular target-specific agents showed more synergistic effects in cytotoxicity for BSG and GBM than TMZ only. Also children with BSG can be more effectively treated with TMZ with multiple molecular targeted agents such as Sunitinib than adult GBM. These results can be translated clinically to develop new chemotherapeutic trials for children with BSG.

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 4333. doi:1538-7445.AM2012-4333
Abstract 4343: Ionizing radiation reduces VLA4 mediated adhesion of macrophage via generation of ROS
Authors: Yuan Ye , Wu Shiyong
Published: August 2012

Adhesion molecules have direct connection with radiation-associated atherosclerosis which is an adverse effect observed after radiation therapy, but the mechanism is still not fully understood. Considerable interest has been focused on the effect of radiation on endothelial cells. Previous work has demonstrated that adhesion molecules of endothelium are up-regulated after exposure to ionizing radiation, which facilitates adhesion of leukocytes and lymphocytes. However, as the initiator in the atherosclerosis development, not enough attention was paid to macrophages which are exposed to the same radiation. In this study, we report that the adhesion between very late Antigen-4 (VLA-4) and its ligand vascular cell adhesion molecule-1 (VCAM-1), the most important adhesion molecules for atherosclerotic lesion formation, was reduced after a clinical dose of radiation (5 Gy). All the adhesion evaluations were tested under flow conditions by using a parallel plate flow chamber to mimick physiological shear stress. We found that the adhesion decreased after irradiation despite macrophage surface expression of VLA-4 was up-regulated in a time dependent manner. Total level of alpha-4 integrin increased whereas beta-1 had no change. Pretreatment with free radical scavenger N-acetylcysteine (NAC) did not change integrin expression but eliminated the adhesion difference following irradiation. Taken together, we hypothesize high levels of ROS generated by ionizing radiation inhibits the affinity of VLA-4 to VCAM-1, in which integrin expression is not the dominant factor.

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 4343. doi:1538-7445.AM2012-4343
Abstract 435: Targeted exome sequencing to understand tumor progression and identify targeted therapies
Authors: Greenawalt Danielle , Hardwick James , Zhang Theresa , Ferguson Mark , Lewis Patrick , Hunstman Shane , O'Brien Shawn , Tu Zhidong , Lezhnin Sergey , Loboda Andrey , Kerzner Cathy , Yeatman Timothy J. , Dalton William , Dai Hongyue
Published: August 2012

There is a large effort in the public domain to systematically perform DNA and RNA sequencing on large numbers of tumor samples. These efforts will bring us to a greater understanding of tumor biology and lead to identification of new tumor drivers. However, these efforts may fall short in allowing us to understand the progression of tumor resistance, relapse and metastasis, factors which make tumors difficult to treat and increase mortality rates. We are currently performing targeted DNA sequencing on 4000 tumor samples. We have selected 1321 genes, 5 GB of the genome to sequence. Genes were selected through a thorough review of the literature, mutation databases and key pathways in tumorigenesis such as growth factor signaling, DNA damage, p53 signaling, cell cycle and apoptosis. Our effort not only includes a diverse panel of breast, colon, ovarian, and kidney tumors but we have also sequenced pancreatic, liver, esophageal, cervix, endometrial, melanoma, CLL, DLBCL and carcinoid tumors. Our dataset also includes approximately 300 matched tumor-metastatic pairs and an additional 550 metastatic samples. Clinical phenotypes, treatment information, gene expression profiling and copy number variation data is available for all samples. To achieve the next level of care for cancer patients we must understand the biology of the tumors we are trying to treat, which are often metastatic and standard of care resistant. We believe that increasing our efforts in targeted DNA sequencing of key tumor and metastatic samples will allow us to achieve these goals.

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 435. doi:1538-7445.AM2012-435
Abstract 4350: Normal stem cells exhibit hypersensitivity and cell death in response to ionizing radiation
Authors: Misri Sandeep , Jacobs Keith , Hallahan Dennis E. , Sharma Girdhar G.
Published: August 2012

Radiotherapy is an efficient method of treating cancer. Several decades of clinical observation in patients treated with radiation/ radiomimetic drugs has, however, revealed undesirable consequences to the normal tissue. Ionizing radiation induced normal tissue injury manifests through symptoms such as hair loss, skin regeneration defects, erosion of intestinal epithelium, hematopoietic anomalies, diminished sperm counts, infertility, neuro-cognitive impairments etc. The phenomenon of “stem cell drop-out” can be attributed as the underlying cause for these side effects. However, insufficient research has been conducted for investigating the relative radiosensitivity of undifferentiated stem/ progenitor cells compared to their differentiated progenies and the underlying molecular mechanisms of this differential radiation response (DNA damage response and IR induced apoptotic response). We demonstrate stem cell specific apoptosis and hypersensitivity to low dose IR in various stem cell niches in vivo. Further, this stem cell hypersensitivity observed in the mouse tissue niches, is recapitulated in multiple primary cell culture models of undifferentiated stem cells and isogenic differentiated cells grown in appropriate stem cell culture/ differentiation conditions. Cell cycle parameters, checkpoint response and radiosensitive phases of these cells have been studied. Towards characterizing the novel associations between cellular differentiation, DNA damage response and apoptotic response, we have studied alterations in transcription profiles of stem and isogenic differentiated cells with and without radiation. Our investigation has uncovered transcriptional induction and suppression of genes that are unique to differentiation states. Results of our studies will be presented.

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 4350. doi:1538-7445.AM2012-4350
Abstract 4351: Exposure to ionizing radiation causes long-term increase in serum estradiol and activation of PI3K-Akt signaling pathway in mouse mammary gland
Authors: Suman Shubhankar , Johnson Michael D. , Fornace Albert J. , Datta Kamal
Published: August 2012

Purpose: Exposure to ionizing radiation is an established risk factor for breast cancer. Radiation exposure during infancy, childhood and adolescence confer the highest risk. Although radiation is a proven mammary carcinogen, it remains unclear where it acts in the complex multi-stage process of breast cancer development. In this study, we investigated the long-term pathophysiological effects of ionizing radiation at a dose (2Gy) relevant to fractionated radiotherapy. Methods and Materials: Adolescent (6 to 8 weeks old; n=10) female C57BL/6J mice were exposed to 2 Gy of total body ≤ radiation and the mammary glands were harvested and serum and urine samples were collected 2 and 12 months post-exposure. Molecular pathways involving estrogen receptor alpha (ERalpha) and phosphatidylinositol-3-OH kinase (PI3K)-Akt signaling were investigated by immunohistochemistry and western blot. Results: Serum estrogen and urinary levels of the oncogenic estrogen metabolite (16alphaOHE1) were significantly increased in irradiated animals. Immunostaining for the cellular proliferative marker Ki-67 and cyclin-D1 showed increased nuclear accumulation in sections of mammary glands from irradiated versus control mice. Marked increase in p85alpha, a regulatory sub-unit of the PI3K was associated with increase in Akt, phospho-Akt, phospho-BAD, phospho-mTOR, and c-Myc in irradiated samples. Persistent increase in nuclear ERalpha in mammary tissues at 2- and 12-month after radiation exposure was also observed. Conclusions: Taken together our data not only supports epidemiological observations associating radiation and breast cancer but it also for the first time specifies molecular events that could be involved in radiation-induced breast 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 4351. doi:1538-7445.AM2012-4351
Abstract 4352: Radiotherapy-induced plasma cytokine changes and skin toxicity in breast cancer patients
Authors: Liu Zhi , Thomas Venetta , Wright Jean L. , Takita Cristiane , Poitevien Martine , Abreu-Molnar Diana , Zhao Wei , Reis Isildinha , Hu Jennifer
Published: August 2012

Breast cancer is the most common neoplasm and the second leading cause of cancer death in American women. Radiotherapy (RT) is an effective adjuvant treatment after breast-conserving surgery for early-stage breast cancer. However, the majority of breast cancer patients undergoing RT develop acute skin reactions. We pilot tested the effects of RT on immune system and inflammatory cytokines in 12 breast cancer patients (6 with high and 6 with low skin toxicity). Using the Human Cytokine ELISA Plate Array I (Signosis Inc., Sunnyvale, CA), we evaluated 31 plasma cytokines in RT-related skin toxicity. The National Cancer Institute Common Terminology Criteria for Adverse Effects (version 3.0) was used to evaluate skin toxicity grade. Our data showed that RT induced epidermal growth factor (EGF); at baseline EFG was not detectable while post RT-treatment significant levels of EFG was observed (mean+SD: 395±620.4, p=0.0496). Interleukin (IL)-2 was significantly elevated by RT (6.5x106±1.01x106 vs. 4.85x106±1.44x106, p=0.0004). Adiponectin was significantly higher at post RT (3.09x106±1.31x106) than pre RT (1.77x106±1.52x106, p=0.0002). RT-related changes of IL-4 was significantly associated with skin toxicity at week 3 (p=0.018); IL-4 was decreased in patients without toxicity (-668.3±1691.5) and increased in patients with grade 2 toxicity (1830.0±1365.4). IL-12 showed similar trend but with marginal significance (p=0.076). RT-related changes of EGF was significantly associated with skin toxicity at week 6 (p=0.045); EGF was not changed in patients with no or low toxicity (grade 0/1) and increased in patients with grade 2/3 toxicity (592.5±686.4). In summary, our pilot data suggest that RT induces EGF, IL-2, and adiponectin. RT-related changes of IL-4 and EGF were associated with skin toxicity. Our ongoing study with a targeted sample size of 1,000 may shed light on the molecular mechanisms of cytokines in RT-related skin toxicity of breast cancer 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 4352. doi:1538-7445.AM2012-4352
Abstract 4354: Proteomic analysis of acute radiation response following whole brain irradiation: Is Sirt2 a key player of radiation-induced neurotoxicity
Authors: Shukla Sudhanshu , Shankavaram Uma , Smart DeeDee
Published: August 2012

Radiation therapy (RT) is one of the most effective and widely used treatments of both primary and metastatic intracranial tumors. Recent technical advances in RT and multimodality approach to treatment have increased the life span of patients. However, a major concern remains as to radiation's effect on long term neurotoxicity and cognitive impairment. Acute and sub acute effects of RT following whole brain RT appear to be reversible, but we hypothesize that these acute changes provide a platform for alteration of the central nervous system (CNS) microenvironment that is responsible for delayed irreversible neurotoxicity. To improve the quality of life of patients and to improve efficacy of whole brain RT, we require effective and targeted approaches to minimize cognitive dysfunction. In order to understand the acute molecular events involved after RT and to identify potential markers that lead to long-term neurotoxicity and dementia, we performed quantitative mass spectroscopy using the iTRAQ (isobaric tag of relative and absolute quantitation) technique on C57 Bl/6 mouse brain tissue extract 72 hours following whole brain RT versus sham-irradiated controls. We found significant changes up- and down-regulation of critical proteins in multiple canonical pathways to be affected, but interestingly some of the most significant changes were in proteins vital to Huntington and Parkinson's signaling pathways. Additionally, we explored the role of Sirtuin 2 (Sirt2), a Class III histone deacetylase which is abundant in CNS and has been shown to mediate oxidative stress response in animal models of neurodegeneration which produce dementia, within the context of whole brain RT. Our aim was to investigate if Sirt2 might be a potential target to mitigate neurotoxic effects induced by RT. Our proteomic analysis of the brain tissue extracts of Sirt2 genomic knockout mice shows that the absence of Sirt2 affects several metabolic and signaling pathways including Huntington, Parkinson's, as well as mitochondrial-mediated signaling. Several factors were found to be uniquely and differentially expressed in Sirt2 knockout tissues under radiation condition. This study indicates that Sirt2 might be a key player in radio sensitization of the CNS and a potential clinical target for minimizing radiation-induced neurocognitive dysfunction.

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 4354. doi:1538-7445.AM2012-4354
Abstract 4358: Notch signaling regulates tumor-induced angiogenesis in SPARC-overexpressed neuroblastoma
Authors: Gorantla Bharathi , Bhoopathi Praveen , Gondi Christopher S. , Rao Jasti S.
Published: August 2012

Despite existing aggressive treatment modalities, survival for advanced stage neuroblastoma remains poor with significant long-term illness in disease survivors. Advance stage disease features are associated with tumor vascularity, and as such, angiogenesis inhibitors may prove useful along with current therapies. SPARC (also known as BM-40 or osteonectin), a matricellular protein, is known to inhibit the proliferation and migration of endothelial cells stimulated by growth factors and induces endothelial cell apoptosis. Here, we sought to determine the effect of SPARC on neuroblastoma tumor cell-induced angiogenesis and to decipher the molecular mechanisms involved in angiogenesis inhibition. SPARC overexpression in neuroblastoma cells inhibited neo-vascularization in vivo as determined by the mouse dorsal air sac model. In addition, conditioned medium from SPARC-overexpressed neuroblastoma cancer cells (pSPARC-CM) inhibited endothelial tube formation in vitro. SPARC-overexpressed tumor cell conditioned medium decreased proliferation (as determined by MTT assay and Ki-67 immunofluorescence) and induced apoptosis in endothelial cells (as determined by TUNEL assay). Furthermore, SPARC-overexpressed tumor cell conditioned medium inhibited expression of the pro-angiogenic molecules VEGF, FGF, PDFG, and MMP-9 as determined by human angiogenesis-PCR array. In addition to the inhibition of growth factors, SPARC-overexpressed tumor cell conditioned medium inhibited Notch signaling molecules in HMEC cells as determined by Western blotting. Conditioned medium from neuroblastoma cells overexpressed with Notch intracellular domain after SPARC overexpression, induced growth factors and led to increased tube formation in vitro. In vivo endothelial cell death was confirmed by co-localization studies with TUNEL assay, and an endothelial marker, CD31, in tumor sections from SPARC-overexpressed mice. Our data collectively suggest that SPARC overexpression induces endothelial cell apoptosis in vivo and inhibits angiogenesis both in vitro and in vivo.

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 4358. doi:1538-7445.AM2012-4358
Abstract 4427: Role of cytochrome P450 (CYP)1A2 in the sustained induction of CYP1A1 by the carcinogen, 3-methylcholanthrene (MC) in mouse heptoma cells (hepa-1)
Authors: Moorthy Bhagavatula , Kondraganti Sudha R. , Wang Lihua , Jiang Weiwu , Chu Chun
Published: August 2012

Humans are constantly exposed to environmental carcinogenic polycyclic aromatic hydrocarbons (PAHs) through cigarette smoke, diesel exhausts, charcoal-broiled meats, etc. Cytochrome P4501A (CYP1A) enzymes play important roles in the activation of PAHs such as 3-methylcholanthrene (MC) to carcinogenic DNA-binding metabolites. We reported earlier that MC causes persistent induction of hepatic and pulmonary CYP1A1 in mice for several weeks after MC ithdrawal, and that the phenomenon of sustained hepatic CYP1A1 induction is lost in Cyp1a2-null mice. In this study, we tested the hypothesis that MC elicits induction of persistent CYP1A1 nduction in hepa-1 cells, and that CYP1A2 contributes mechanistically to this henomenon. Hepa-1 cells were treated ith the MC (2.5 µM), or dimethylsulfoxide (DMSO) as control, and at selected ime points, CYP1A1 promoter activity, CYP1A1 enzyme activities, contents, and CYP1A1 mRNA levels were studied. We fund that MC markedly and persistently induced CYP1A1 promoter activity, transcription, apoprotein expression, and the CYP1A1 associated ethoxyresorufin O-deethylase (EROD) activities for up to 5 days. Transfection of CYP1A2 siRNA resulted in knockdown of CYP1A2 mRNA by 70%, but a statistically significant increase of basal CYP1A1 mRNA by 35-40%. The induction of CYP1A1 promoter ctivity, CYP1A1 mRNA, CYP1A1 protein, and EROD activity by MC were not affected by CYP1A2 siRNA at the 24 h time point, but was significantly ttenuated by Cyp1a2 siRNA on day 5. These results suggest that CYP1A2, possibly via a metabolite, contributes to the sustained induction of CYP1A1 by MC in hepa-I cells. Further investigations into the mechanisms of persistent induction of CYP1A1 by MC could lead to novel preventative/therapeutic strategies against PAH-mediated carcinogenesis in humans. (Supported in part by 2R01 ES009132.)

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 4427. doi:1538-7445.AM2012-4427