bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract LB-104: Differences in repair of DNA cross-links between lymphocytes and tumor cells from colon cancer patients
Authors: Herrera Mercedes , Dominguez Gemma , Garcia Jose M. , Peña Cristina , Jimenez Carmen , Silva Javier , Garcia Vanesa , Gomez Irene , Diaz Raquel , Martin Paloma , Bonilla Felix
Published: February 2011

The more common approach to comet assay studies with cancer patients involves indirect measurement of the effect of antineoplastic drug or radiation regimen by assessing DNA damage in surrogate cells, such as peripheral blood lymphocytes of cancer patients, to predict how tumor cells may be affected. The aim of the present study was to compare the capability of different cells isolated from a series of 23 colon cancer patients to repair the damage induced by a cancer drug. We adapted the in vitro comet repair assay for nucleotide excision repair to measure the ability of lymphocytes and normal and tumor epithelial colon cells to remove DNA cross-links induced by oxaliplatin. The excision repair rate was measured quantitatively by the tail parameters: tail DNA, tail length, extent tail moment, and olive tail moment. Kruskal-Wallis analysis revealed significant differences in recognition and excision activity between different cell types (P < 0.001) for all the comet parameters studied. Hence, colon cells showed higher recognition and excision activity than lymphocytes and tumor cells displayed the highest repair capability. We found no significant correlation between the repair activity of tumor colon cells and lymphocytes in any of the comet parameters considered. Our data support the view that lymphocyte repair activity is not predictive of the repair ability of the tumor and that lymphocytes cannot act as surrogate cells.

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 LB-104.
Abstract LB-106: Inhibition of glycolysis with 2-deoxyglucose inhibits spontaneous metastasis in murine osteosarcoma
Authors: Thamm Douglas H. , Lori Janet , Sottnik Joseph L.
Published: February 2011

We recently reported on a re-analysis of previously published gene expression data from a large set of primary solid and metastatic tumors originating from different tissues using the latest available tools for normalization, identification of differentially expressed genes and pathway analysis (Ptitsyn A., et al, BMC Bioinformatics 2008;9 Suppl: S8). Analysis of multiple independent datasets indicated significantly reduced oxidative phosphorylation in metastases compared to primary solid tumors, implying a potential enhancement of the Warburg phenotype in metastatic progression. We thus sought to determine if inhibition of anaerobic glycolysis with the competitive inhibitor 2-deoxy-D-glucose (2-DG) would reverse this metastatic bioenergetic phenotype in highly metastatic cancer cells. We evaluated the effects of 2-DG on DLM8 osteosarcoma cell migration and Matrigel invasion via Boyden chamber assays, and modulation of in vitro production of matrix metalloproteases, VEGF, and cathepsin L were evaluated by gelatin zymography, ELISA and western analysis respectively. The effects of 2-DG administration in vivo was evaluated in an orthotopic, spontaneously metastatic, luciferase-transfected postsurgical model of murine osteosarcoma utilizing DLM8, which is syngeneic to C3H mice. DLM8 cells were implanted into the distal tibias of C3H mice, followed by amputation of the affected limb 16 days later. 2-DG or saline were administered postoperatively (500 mg/kg IP 3x/week, n=5 per group) until sacrifice. Presence of metastasis was evaluated using biweekly bioluminescence imaging and metastasis-free interval calculated using the Kaplan-Meier method. Concentrations of 2-DG associated with minimal antiproliferative activity dramatically inhibited DLM8 cell migration and invasion. There was a dose-dependent decrease in cathepsin L expression upon 2-DG exposure, and VEGF production was inhibited at high 2-DG concentrations, but there were no repeatable changes in MMP activity within the concentration range associated with inhibition of migration and invasion. Postoperative administration of 2-DG significantly delayed DLM8 metastasis (median metastasis-free interval 8 vs 34 days, p = 0.049). In conclusion, glycolysis inhibition with 2-DG is associated with an inhibition of osteosarcoma migration, invasion and in vivo metastasis, at concentrations associated with minimal antiproliferative activity.

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 LB-106.
Abstract LB-110: CDK4 activation is a key step in ELF alteration and haploinsufficeny of cdk4 prevents HCC formation in elf+/− mice
Authors: Baek Hye Jung , Pishvaian Michael J. , Cho Kwan Ho , Mishra Bibhuti , Reddy E. Premkumar , Mishra Lopa , Kim Sang Soo
Published: February 2011

Transforming growth factor (TGF-) is an important regulator of cell growth and the loss of TGF- signaling occurs early in carcinogenesis. Embryonic liver fodrin (ELF), an interaction protein of Smads, is involved in TGF- signaling. Significantly, elf+/− mice spontaneously developed the hepatocellular cancer (HCC) and lots of human HCC exhibited decreased or absent ELF expression. Here, we investigated how alteration of ELF led the deregulation of cell cycle progression and eventually formed the HCC. Up regulation of ELF expression led the decreased phosphorylation of Rb protein with the remarkable reduction of CDK4 than other CDKs and cyclins. Then, inhibition and downregulation of CDK4 by inhibitor and siRNA rescued the abnormality of G1/S transition and over-activation of Rb phosphorylation caused by infection of ELF shRNA in SNU475 HCC cell line. We further demonstrated the biochemical communications using immunoprecipitation that ELF interacted CDK4, and Smad3 in competitive way and TGF-ß-dependent manner. In addition, haploinsufficieny of cdk4 in elf+/− mice displayed the dramatic decrement of HCC formation than elf+/− mice with decreased Ki-67 and c-myc expressed hepatocyte in liver tissue. Thus, in response to ELF deficiency, the activation of CDK4 contributes to the phosphorylation of Rb protein, which leading to facilitated G1/S transition. Our data highlight CDK4 as an attractive target for pharmacologic inhibition and importance of elf+/− model to demonstrate pre-clinical efficacy in the treatment of HCC with ELF alteration.

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 LB-110.
Abstract LB-111: Overexpression of esophageal squamous cell carcinoma (ESCC)-associated genes located within the homogeneously staining region (HSR) in chromosome 17p
Authors: Liu Christina D. , Pak K. C. , Hu L. , Guan X.y. , Tsao George S.W. , Law S. , Lam K Y. , Tang Johnny C. O.
Published: February 2011

The homogeneously staining region (HSR) has been shown to contain amplified genes that give selective advantages to the progression of cancer-cell growth. In this study, fluorescent in situ hybridization and array comparative genomic hybridization analysis were conducted on SLMT-1 (an ESCC cell line of Hong Kong Chinese origin) and revealed a HSR which was derived from chromosome 17p13.3. To identify the potential novel oncogene(s) with overexpression in ESCC, the overexpression study of the non-tumor suppressor genes within the region 17p13.3 was conducted in 15 ESCC cell lines by utilizing reverse transcription and multiplex PCR analysis. Eight non-tumor suppressor genes within this region were studied and three genes Timm22, JC-1 and JC-2 showed high percentages of overexpression compared with the non-tumor esophageal epithelial cell line NE1. Forty-six percent (7/15) of cell lines showed overexpression for Timm22 and both JC-1 and JC-2 were overexpressed in seventy-three percent (11/15) of ESCC cell lines. Further investigation on the JC-1, which showed the highest overexpression rate among the cell lines, was performed for its oncogenic properties. The entire coding sequence of JC-1 cloned into the mammalian expression vector pcDNA3.1(-) was transfected into mouse fibroblast NIH-3T3 cells. The JC-1-transfected NIH-3T3 cells showed an enhanced growth rate as determined by MTS assay, ncreased ability to form foci under anchorage dependent growth and increased migration rate in vitro. Thus, the results of the present study contribute to the investigation of potential novel oncogenes with overexpression in ESCC and may enrich our understanding of molecular pathogenesis of ESCC in the long run.

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 LB-111.
Abstract LB-127: Synthetic lethal RNAi screen of the human kinome with cytarabine (AraC) in leukemia cells
Authors: Hagelstrom R. Tanner , Bogenberger James , Buechel Megan , Bhagavatula Keerthi , Azorsa David O. , Tibes Raoul
Published: February 2011

Cytarabine is the backbone of therapy for acute myeloid leukemia (AML) patients, yet due to a high incidence of relapse and treatment-related complications novel, less toxic treatment regimens incorporating AraC need to be designed. To increase the therapeutic effect of cytarabine we developed and performed an RNAi synthetic lethal screening assay using siRNA, targeting 572 human kinases in combination with AraC in human myeloid cell lines TF-1 and THP-1. Several genes that enhance the effectiveness of cytarabine were identified. Among the top candidate genes, a trend became apparent in which several key regulators of the cell cycle as well as DNA repair genes where among the strongest sensitizers (CHEK1, PKMYT, CDC2, AURKB and ATR). The effectiveness of targeting these genes in combination with AraC was verified using a highly robust siRNA drug-dose response assay (siDDR) that validated CHEK1 as strong sensitizer, PKMYT as moderate sensitizer, and did not confirm CDC2 or AURKB as sensitizers. Since CHEK1 is emerging as a potential treatment target in combination chemotherapy in solid tumors, we obtained two commercially available CHEK1 inhibitors, PD 407824 and SB 218078 (both Tocris). PD 407824 strongly sensitized to AraC in the range of 2 to 10 fold decrease in several lines (MV 4;11, THP-1, HL60, HEL, ML-2) whereas in a few no sensitization was observed (MDS-L, U937). Calcusyn software was utilized to ensure the effect was more than simply additive in effect. Less effect was observed for SB 218078, which was surprisingly found to be antagonistic in some lines (TF-1, U937, ML-2, HL-60). Both compounds have slightly different target spectrum's that include CHEK1 plus other kinases. Interestingly, the sequence of addition of the compounds dramatically affected the outcome, with the greatest effects seen when CHEK1 inhibitors were added before AraC. In cases where AraC was added first or simultaneously, the effect was less pronounced or was not seen at all. Herein we present the “first-in-class” human kinome synthetic lethal screen in leukemia suspension cells in combination with AraC. In this unbiased functional genomics screen a strong convergence of hits emerged around G2/M cell cycle and DNA repair control. This information can immediately inform clinical drug development, channel resources and serve to direct development of new therapies in acute myeloid leukemias combining AraC with the first clinical available CHEK1 inhibitors.

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 LB-127.
Abstract LB-128: Synthetic lethal RNAi screening identifies inhibition of Bcl-2 family members as sensitizers to 5-Azacytidine in myeloid cells
Authors: Bogenberger James , Shi Chang-Xin , Hagelstrom Tanner , Gonzales Irma , Choudhary Ashish , Tiedemann Roger , Azorsa David , Stewart Keith , Tibes Raoul
Published: February 2011

In order to identify novel targets and clinically exploitable vulnerabilities, we performed high-throughput RNA-interference (RNAi) synthetic lethality screening using myeloid cell lines TF-1 and ML-2 in combination with the hypomethylating agent 5-Azacytidine. A custom small interfering RNA (siRNA) library targeting nearly 1000 cancer-associated genes, including the human kinome, was utilized. Bcl-XL emerged as the strongest 5-Azacytidine sensitizing target in the erythroid cell line TF-1 but not in ML-2 cells. Additional siRNA sequences targeting Bcl-XL were transfected into a panel of myeloid cell lines and tested in drug dose response experiments using a ten-point serial dilution of 5-Azacytidine. The erythroid differentiated myeloid cell lines TF-1 and HEL both exhibited a 3 to 4-fold reduction in the IC50 of 5-Azacytidine upon knockdown of Bcl-XL, whereas IC50 values for non-erythroid, myeloid cell lines ML-2, THP-1 and MDS-L were unchanged. Furthermore, we tested lentiviral delivery of short-hairpin RNA (shRNA) targeting Bcl-XL in additional cell lines. Lentiviral knockdown of Bcl-XL confirmed 2 to 3-fold 5-Azacytidine sensitization in TF-1 and HEL cells while U937, HL-60, ML-2, THP-1 and MDS-L were not sensitized by Bcl-XL knockdown. Interestingly, while Bcl-XL knockdown with shRNA potentiated the effects of 5-Azacytidine in TF-1 and HEL, Bcl-XL knockdown alone resulted in considerable reductions in cell viability in TF-1 and HEL cells. These results demonstrate erythroid lineage-specific responses to Bcl-XL knockdown and suggest that Bcl-XL may represent an erythroid lineage-specific therapeutic vulnerability. To begin to explore this possibility we examined the putative BH3 mimetics Gossypol, Obatoclax and ABT-737 with 5-Azacytidine drug dose response experiments in myeloid cell lines. Neither Gossypol nor Obatoclax potentiated the effects of 5-Azacytdine. In striking contrast, ABT-737 resulted in a 2 to 4-fold reduction in the IC50 of 5-Azacytidine in all cell lines tested to date (TF-1, HEL, ML-2 and THP-1). ABT-737 sensitization to 5-Azacytidine was dose dependent. Furthermore, Combination Index (CI) values calculated with Calcusyn software demonstrate synergy between ABT-737 and 5-Azacytidine at clinically relevant concentrations. These results suggest that inhibition of anti-apoptotic Bcl-2 family members with a BH3 mimetic may represent an effective strategy for 5-Azacytidine combination therapy that can be directly translated into design of combination clinical trials in patients with myeloid leukemias.

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 LB-128.
Abstract LB-13: The role of p38/MAPK14 in Sonic Hedgehog-driven CGNP proliferation
Authors: Cemile Guldal G. , Mainwaring Lori , Parathath Susana , Kenney Anna M.
Published: February 2011

Development of the cerbellum occurs primarily postnatally and is marked by a rapid proliferation of cerebellar granule neuron precursors (CGNPs). This proliferation requires the activity of the mitogen Sonic Hedgehog (Shh). The rapid proliferation stage of CGNPs has led to speculation that they are the cells of origin for some classes of medulloblastoma, the most common solid pediatric tumor. Since MAP kinases play important roles in many aspects of development, proliferation, and cancer we investigated if any of the three major classes of MAP kinases were involved in Shh-driven CGNP proliferation. We have previously shown that p42/p44 ERK MAP kinases are not involved in Shh signaling in CGNP proliferation. We have also shown that JNK/SAP kinases are not involved in Shh-driven proliferation. However, p38/MAPK14 is induced and activated in proliferating CGNPs compared to CGNPs that exit the cell cycle and differentiate in the absence of Shh. Other known pathway components upstream and downstream of MAPK14, such as ASK1, MKK3 and ATF-2, are also activated in the presence of Shh. Antioxidants such as lipoic acid and n-acetyl-cysteine that relieve oxidative stress reduced Shh-induced activation of MAPK14 and caused a marked decrease in CGNP proliferation measured by Ki67 and BrdU staining. We are currently investigating the role of oxidative stress and MAPK14 in CGNP proliferation by over-expressing and knocking down MAPK14 in CGNPs under oxidative stress conditions. Preliminary data suggests that knocking down MAPK14 reduces CGNP proliferation. Elucidating the role of MAPK14 pathway in CGNP proliferation will not only help us understand normal cerebellum development but may also lead to possible therapies for diseases where constitutive Shh signaling has been shown to play a role such as some classes of medulloblastoma and Gorlin's syndrome.

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 LB-13.
Abstract LB-131: Mathematical model for tumor growth
Authors: ji Jiang , tu Guangde , zou Mei
Published: February 2011

Cancer is a leading cause of morbidity and mortality among humans worldwide. Theoretical studies could provide biologists with complementary and valuable insight into the mechanisms that may control the development of solid tumors. Based on our studies on membrane formation kinetics, a novel growth model is established for solid tumor development, which is consistent with the experimental data. According to the concept of the proliferation-active cells in the tumor tissue, two parameters, the effective cell division cycle for mitosis and the effective infiltration distance relevant to the nutrient support, are introduced in the model. The two parameters introduced can be further applied when the drug effects were considered. We have reviewed over 200 literatures and selected more than 50 of them having experimental data from different cell lines for theoretical studies. The growth curves generated by our model are consistent with many experimental data including lung cancer, breast cancer, liver cancer, ovarian cancer and colon cancer. Thus, the model obtained is very important not only for cancer research but also for searching anti-cancer drug and therapies.

In the figure below, we have displayed growth curves for colon carcinoma cell line. The dash lines are simulation curves of the model and the dots are the corresponding experimental data.

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 LB-131.
Abstract LB-134: Analysis of restored FFPE samples on high-density SNP arrays
Authors: Pokholok Dmitry K. , Le Jennie M. , Steemers Frank J. , Ronaghi Mostafa , Gunderson Kevin L.
Published: February 2011

Millions of Formalin Fixed Paraffin Embedded (FFPE) cancer tissue samples currently present in the US and worldwide provide an enormous, invaluable repository to the discovery of biomarkers in cancer research, drug development, diagnosis and treatment of diseases. However, the processes of fixation and storage of FFPE samples lead to degradation and base modification with chemical residues. This degraded FFPE DNA is inefficiently amplified in the Infinium® whole genome amplification (WGA) step leading to poor performance in the Infinium® assay.

In this study, FFPE DNA (100 ng input) was restored through a treatment with DNA polymerase, DNA repair enzyme, ligase, and modified Infinium® WGA reaction conditions. Canonical genotype cluster files were generated by creating artificially degraded Coriell DNAs and processing the samples through the restoration process and Infinium® assay. Results of genotyping on high density HumanCytoSNP-12 BeadChip®, featuring approximately 300k SNPs indicated that even highly degraded samples which show initial call rates of 40-70% can be successfully restored to a state that achieved call rates of greater than 90%, at a concordance greater than 99.0%, and associated standard deviation of log intensity less than 0.4. In general, over 80% of FFPE samples, which passed a QC assay metric were successfully restored and genotyped. Infinium® genotyping of restored DNA from a collection of tumor FFPE samples confirmed the presence of genomic aberrations around known cancer genes. Finally, we further demonstrated that paired sample analysis using canonical genotype clusters provide improved precision in CNV and LOH analysis compared to single sample analysis.

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 LB-134.
Abstract LB-143: Sustained siRNA delivery by mesoporous silicon particles
Authors: Tanaka Takemi , Lingegowda Mangala , Nieves-Alicea René , Vivas-Mejia Pablo E. , Lopez-Berestein Gabriel , Sood Anil K. , Ferrari Mauro
Published: February 2011

RNA interference (RNAi) is a powerful approach for silencing genes associated with a variety of pathologic conditions; however, in vivo RNAi delivery has remained a major challenge due to lack of safe, efficient, and sustained systemic delivery. Here, we report on a novel approach to overcome these limitations using a multistage vector comprised of mesoporous silicon particles (S1MP) loaded with neutral nanoliposomes (DOPC) containing siRNA targeted against the oncoprotein, EphA2 that is overexpressed in a majority of cancers, including ovarian. Our delivery methodology resulted in sustained EphA2 gene silencing for at least 3 weeks in two independent orthotopic mouse models of ovarian cancer following a single intravenous administration of S1MP loaded with EphA2-siRNA-DOPC. Furthermore, a single administration of S1MP loaded with-EphA2-siRNA-DOPC substantially reduced tumor burden, angiogenesis and cell proliferation as compared to a non-coding control siRNA alone (SKOV3ip1: 54%, HeyA8: 57%), with no significant changes in serum chemistries or in pro-inflammatory cytokines. In summary, we have provided the first in vivo therapeutic validation of a novel, multistage siRNA delivery system for sustained gene silencing with broad applicability to pathologies beyond ovarian neoplasms.

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 LB-143.
Abstract LB-144: In vivo detection of bone metastases in a mouse model by positron emission tomography (PET) with [F-18]-labeled tyrosine derivative (D-FMT)
Authors: Zitzmann-Kolbe Sabine , Strube Anne , Frisk Anna-Lena , Käkönen Sanna-Maria , Tsukada Hideo , Hauff Peter , Berndorff Dietmar , Gekeler Volker , Graham Keith
Published: February 2011

Objective: Detection and localization of metastatic lesions in advanced stages of cancer is still a difficult obstacle for diagnosis and subsequent treatment decisions for an optimized cancer patient management and therapy control. Whole body molecular imaging applying positron emission tomography (PET) allows the sensitive detection of radioactive labeled molecules, which specifically accumulate in tumor tissue. This offers a promising tool to assess the stage of the disease comprehensively. At present [F-18]-fluorodeoxyglucose (FDG) is the mostly used PET-tracer in oncology. However, FDG has the disadvantageof limited specificity by accumulating also in inflammatory cells due to their increased glucose metabolism. To overcome this problem, amino acids have been radiolabeled to study their potential imaging characteristics. D-[F-18]-fluoromethyl tyrosine (D-FMT, (R)-2-amino-3-(4-[F-18]fluoromethoxy-phenyl)-propionic acid) has shown good uptake into HeLa tumors in nude mice with no accumulation in sterile induced inflammation sites. The aim of this study was to investigate if D-FMT can also be used to image bone metastases besides primary soft tissue tumors.

Methods: Human 786-O/luciferase renal cell adenocarcinoma cells were injected intracardially, which gave rise to the formation of several bone metastases. The radiosynthesis of D-FMT was carried out using an indirect labeling method via the [F-18]-fluoromethyl bromide synthon. Micro-PET imaging was performed 51 and 65 days after tumor cell inoculation.

Results: The formation of metastases was monitored using bioluminescence imaging indicating the presence of tumor cells in the regions of hind limbs, forelimbs, spine and skull. A bone scan with [F-18]-fluoride confirmed skeletal metabolic activity at sites of osteolytic bone metastases. The i.v. application of [F-18]-D-FMT showed a very specific accumulation of the amino acid tracer in these bone metastases and, together with the low background, allowed very good imaging of these lesions. Based on the PET scan of [F-18]-D-FMT, sites of accumulation were excised. All imaged metastases could be verified histologically.

Conclusion: These data suggest D-FMT as a new potential imaging tracer for the detection of primary tumors as well as bone metastases. In addition, the sensitivity of this tracer suggests the possibility for substantial benefit in detecting soft tissue metastases as well.

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 LB-144.
Abstract LB-149: Identification of novel genes that cooperate with increased eIF4E expression to generate medulloblastoma using the Sleeping Beauty transposon system
Authors: Mainwaring Lori A. , Kenney Anna
Published: February 2011

Medulloblastoma is a malignant brain tumor that arises in the cerebellum of young children and occasionally is observed in adults. Increasing evidence suggests that different cell populations represent distinct cells of origin for the various medulloblastoma subtypes, and that these subtypes can be associated with aberrant activation of specific signaling pathways. Current mouse models recapitulate the Shh pathway driven tumors however few models are available to study other medulloblastoma subtypes as genetic events that drive tumorigenesis remain unknown. To address this problem we used the Sleeping Beauty transposon system to uncover novel mutations that contribute to medulloblastoma. Based on earlier work in normal CGNPs, we found that the translation initiation factor eIF4E is critical for regulating CGNP proliferation and the mRNA translation machinery is uniformly upregulated across medulloblastoma subtypes. Using a mouse model wherein eIF4E is ubiquitously over-expressed under control of the -actin promoter (T-Eif4e) we investigated cerebellum development and found that the CGNPs have increased proliferation in vitro in the absence of Shh as well as an expanded proliferative zone in vivo; however these mice do not develop medulloblastoma. Because eIF4E is an oncogene and been shown to cooperate with other known oncogenes in different cell types to accelerate tumorigenesis, we investigated whether eIF4E can cooperate with other mutated genes to generate medulloblastoma. Using a CGNP-specific promoter to drive transposase expression (“Math1-SB”), we crossed these mice with two different lines that carry the Sleeping Beauty transposon (T2/Onc 68 or T2/Onc 76) on different chromosomes. The progeny were then crossed with the T-Eif4e mice and observed for medulloblastoma occurrence; no tumors arise as a result of Math1-SB-mediated transposase activity alone. However, compared to the latency of tumors generated in SmoA1 mice, which have constitutive activation of the Shh pathway, tumors in T-eIF4E/Math1-SB/T2Onc animals arose earlier and were highly proliferative based on Ki-67 staining. They also expressed Otx2, which is associated with a medulloblastoma subtype that does not contain Shh or Wnt pathway mutations. Sequencing of the tumors to identify the genes whose activity is induced (novel oncogenes) or repressed (novel tumor suppressors) by transposon insertion will reveal genes that cooperate with eIF4E to induce medulloblastoma, and may lead to development of new mouse models for medulloblastoma as well as increased insight into genetic events contributing to these 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 LB-149.
Abstract LB-150: Role of EGFR signaling in an inducible mouse model of astrocytomas
Authors: Song Yurong , Zhang Qian , Miller C. Ryan , Threadgill David , McCarthy Ken D. , Van Dyke Terry
Published: February 2011

No effective therapy currently exists for astrocytomas, particularly the most biologically aggressive subtype, glioblastoma multiforme (GBM). Recently, The Cancer Genome Atlas (TCGA) project reported the most extensive genetic analysis of GBMs enhancing our ability to query altered signaling pathways potentially involved. Yet, an understanding of disease etiology requires extensive modeling in mammalian genetic systems coupled with analyses of biological contributions of disease. Here we genetically perturbed the primary molecular pathways (pRb and Ras) reported by TCGA in genetically engineered mouse models (GEM). Alterations were induced specifically in adult GEM astrocytes via a tamoxifen-inducible, human GFAP promoter-driven CreERTM allele. GEM with astrocyte RB pathway inactivation alone (T) developed low-grade astrocytomas (grade II). Constitutive KRAS activation alone (R) did not produce detectable brain pathology. GEM harboring both inactivated RB and constitutively active KRAS (TR) in astrocytes developed high-grade astrocytomas (grade III) with low frequency of GBM development (grade IV). EGFR level and its ligands in TR tumors were elevated compared to T alone, suggesting EGFR signaling pathway may play an important role in tumor progression. We reasoned that tumor progression would be delayed if we knocked out EGFR in TR brain. Surprisingly, we found that addition of EGFR inactivation produced tumors with higher frequency of GBM. These results suggest other pathways other than EGFR may compensate for EGFR loss, which in turn contributes to tumor progression. These highly penetrant, inducible GEM models provide a unique system for delineating the downstream pathways and resulting biological abnormalities critical to astrocytoma pathogenesis and for preclinical drug and biomarker development. Initial studies have begun to define the relative contribution to disease of each disrupted pathway, including potential targets for therapeutic intervention.

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 LB-150.
Abstract LB-152: Characterization of the first mouse model of anaplastic thyroid carcinoma
Authors: Dima Mariavittoria , Cristofano Antonio Di
Published: February 2011

Although anaplastic thyroid carcinoma is a rather uncommon malignancy, it accounts for the vast majority of deaths from thyroid cancer. Despite considerable efforts, its dismal prognosis has not changed in decades. Building on the increasing knowledge of the molecular events involved in anaplastic carcinoma pathogenesis, we have generated a mouse model in which the Pten and p53 tumor suppressor genes have been selectively deleted in the thyroid follicular cells. By six months of age, double mutant mice develop undifferentiated, aggressive thyroid carcinomas arising, like in most human patients, from pre-existing follicular carcinomas. These tumors are invariably locally invasive, and often metastasize to the lungs. Similar to their human counterpart, they display loss of expression of most thyroid differentiation and functional markers, including Thyroid peroxidase (Tpo), Thyroglobulin (Tg), and the therapeutically relevant Sodium-iodide symporter (Nis). A combined approach, using both double mutant mice and several stable cell lines derived from tumors that developed in these mutants, is uncovering the molecular pathways involved in the transformation and dedifferentiation process, as well as pointing to novel potential targets for therapeutic intervention.

In conclusion, this compound mouse mutant represents a unique, clinically relevant model of thyroid anaplastic carcinoma, and an invaluable tool for both basic and preclinical studies.

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 LB-152.
Abstract LB-155: Molecular targeted therapy of stem cell leukemia-lymphoma induced by ZNF198-FGFR1
Authors: Ren Mingqiang , Cowell John K.
Published: February 2011

Chimeric ZNF198-FGFR1 tyrosine kinase induces patients developing stem cell leukemia-lymphoma syndrome (SCLL), a novel hematological malignancy characterized by rapid transformation to acute myeloid leukemia and T-lymphoblastic lymphoma. Current therapy is inadequate. Using array comparative genomic hybridization (aCGH) we have previously demonstrated that a loss of TCR is a crucial event that perturbed the final maturation stages of T cell development and induced double positive T-lymphoma formation. However, TCR knockout mice did not show T-cell lymphoma development, which indicates that deletion of TCR is unsufficient to induce T-lymphoblastic lymphoma formation. Here we demonstrate that the constitutive activation of Notch1 is frequently seen in the lymphoma from ZNF198-FGFR1 transduced and transplanted mice, in consistent with high expression of the majority of known downstream targets of Notch1. Using ZNF112 cells, a newly derived cell lines from one disease mouse bone marrow, as a model system we found that both DAPT (a γ-secretase inhibitor to block Notch signaling) and transcriptional knockdown of either Notch1 or its co-activator MAML1 via shRNA in ZNF112 cells can significantly delay or prevent the leukemogenesis in syngeneic transplanted mice. These data demonstrate the importance of Notch signaling in the etiology of this disease and provide an important clinical implication that tyrosine kinase inhibitors plus drugs inhibiting Notch signaling can be a promising strategy to treat SCLL patients.

This work was supported by grant CA076167 from the National Institutes of Health.

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 LB-155.
Abstract LB-16: Altered circadian rhythm components are resynchronized by melatonin in human prostate cancer
Authors: Jung Brittney D. , Huang Wei , Ahmad Nihal
Published: February 2011

Prostate cancer (PCa) is a major age-related malignancy as increasing age correlates with increased risk for developing this neoplasm. Similarly, alterations in circadian rhythms, because of modifications in various core clock components, have also been associated with the aging population and cancer risk. The pineal hormone melatonin is known to regulate circadian rhythm, which is under the control of a core set of genes: Per-, Clock- and Bmal-family members. The circulating serum levels of melatonin have been shown to decrease in patients with cancer including PCa. Interestingly, melatonin has been shown to have anti-proliferative effects in certain cancers. We have recently found that melatonin imparts anti-proliferative effects in vitro and in vivo via inhibiting Sirt1 that is a class III histone deacetylase and involved in the regulation of aging and several other metabolic processed. In this study, we challenged the hypothesis that melatonin imparts anti-proliferative effects in prostate cancer via resynchronization of deregulated core clock circuitry at the cellular level. First, we determined if the core clock genes circuitry is disrupted in PCa. Interestingly, we found that Clock and Per2 protein levels were downregulated whereas Bmal1 protein levels were up regulated in PCa cells (LNCaP, 22R 1, DU145, PC3), compared to normal prostate epithelial cells as assessed by Western blot analysis. Further, we employed the automated quantitative analysis (AQUA) system to asses the levels of Clock, Per2 and Bmal1 in a tissue microarray (TMA) containing clinical specimens of benign prostate hyperplasia (BPH), high-grade intraepithelial neoplasias (HGPIN), localized PCa, aggressive PCa with metastases as well as benign prostate tissue. We found that compared to benign tissues, in all proliferative prostate diseases Clock and Per2 levels were downregulated whereas Bmal1 levels were up regulated. In addition, a forced over-expression of Per2 was found to result in a significant loss of viability of PCa cells. Further, we found that melatonin (1mM and 2mM; 48 h) treatment causes an increase in Per2 and Clock and decrease in Bmal1 (at the protein and mRNA levels) in human PCa cells. Furthermore, as shown by the COSOPT algorithm, we found that melatonin treatment resulted in a resynchronization of oscillatory circadian rhythm genes (Dbp and Per2) while having no effect on non-oscillatory genes. Our data support our hypothesis and suggest that melatonin should be thoroughly investigated as an agent for the management of PCa and other age-related malignancies.

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 LB-16.
Abstract LB-163: Genetic and pharmaceutical approaches for the study of complement factors as alternative therapy for ovarian cancer
Authors: Nunez-Cruz Selene , Qu Hongchang , Rafail Stavros , Connolly Denise , Gimotti Phyllis , Lambris John , Coukos George , Scholler Nathalie
Published: February 2011

Chronic inflammation is now clearly established as a key player in the process of carcinogenesis. Complement factors can be activated under various chronic inflammatory conditions, suggesting that they could contribute in promoting tumor development. However, the role of complement in ovarian cancer (OC) progression remains poorly investigated. OC is the second most common gynecologic cancer and the fourth leading cause of cancer death in women. Developing alternative therapies is required to decrease OC high mortality rate. To determine the role of complement in cancer establishment and progression, we used genetic and pharmaceutical approaches. We first crossed complement component 3 knockout (C3KO) mice with transgenic mice expressing the Simian Virus 40 TAg under the control of the Müllerian Inhibiting Substance type II Receptor promoter (Tg-MISIIR-TAg). Tg-MISIIR-TAg mice develop bilateral OC resembling human serous OC with ∼100% penetrance. We found that C3KO/MISIIR-TAg mice developed no or very small tumors at 16 weeks of age compared to control wild-type C3/MISIIR-TAg and C3/MISIIR-TAg heterozygote littermates. We also found that tumor-infiltrating leukocytes were functionally altered with changes of secretion profiles for cytokines and angiogenic factors. Second, we orthotopically implanted fluorescent ovarian carcinoma cells (MOV1Kat) in Tg-MISIIR-TAg mice treated with complement C5aR inhibitor peptide or control peptide. MOV1 cell line was isolated from Tg-MISIIR-Tag tumor and transducted with a Far-red fluorescent protein, Katushka, using TurboFP635 Lentivirus mammalian vector to permit in vivo optical imaging (IVIS). Our results showed that the pharmacological inhibition of C5a-binding to C5aR receptor promoted tumor regression.

Altogether, our results indicated an important and understudied role of complement for ovarian cancer. We propose that complement inhibitors could be used as therapeutic agents for the treatment of ovarian 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 LB-163.
Abstract LB-165: Novel metabolic metyltransferase mediates radiation resistance in glioblastomas
Authors: Palanichamy Kamalakannan , Gordon Nicolaus , Patel Disha , Shirai Katsuyuki , Chakravarti Arnab
Published: February 2011

Purpose: Nicotinamide-N-methyltransferase(NNMT) is an enzyme involved in the metabolism of drugs and xenobiotic compounds. It is known to be highly expressed in a variety of cancers and has been investigated for its potential use as a diagnostic or prognostic marker. Furthermore, clinical data has shown that high NNMT expression is correlated with adverse patient outcome. In our glioblastoma (GBM) patient data set and other publically available data set NNMT is one among the top 25 genes which is differentially regulated when compared with normal adjacent tissue and also with various grades of brain tumor. NNMT is highly expressed in grade IV compared to low grade astrocytomas. Kaplan-Meier survival plots for NNMT gene shows that higher expression is associated with poor survival benefit and the median survival was found to be more than doubled in patient group with low expression of NNMT. Despite all this, the mechanistic behavior of NNMT in the malignant phenotype remains uncharacterized. We plan to gain an understanding of the signaling pathways with which NNMT interacts and elucidate its role in radioresistance.

Experimental Design: The in vitro radiosensitivity assays were evaluated using wild type, NNMT-knockdown and NNMT-overexpression GBM cell lines. The assay conducted includes MTS, DNA damage and repair, Clonogenic survival assay, comet assay, Annexin V apoptosis assay, matrigel invasion assays, ATP assay, etc. The cell line after treatment was lysed and probed for pro-and anti-survival signaling pathways.

Results and Discussion: We explored the expression profile of NNMT in established (ATCC) and in our panel of primary GBM cell lines. The expression levels correlates with relative radioresistance exhibited by the cell line. It appears NNMT knockdown cell lines exhibited an enhanced radiosensitivity. Currently we are probing signaling cascades which are differentially regulated in the NNMT knockdown and overexpression cell lines and also the differential response to radiation treatment based on differing levels of NNMT expression. The results will be presented at the meeting.

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 LB-165.
Abstract LB-167: Identification of ionizing radiation (IR)-responsive mRNA in p53-deficient human non-small cell lung cancer (NSCLC) grown in three-dimensional cell culture system
Authors: Kwon Jee Young , Kim Jong Suk , Seo Young Rok
Published: February 2011

Non-small cell lung cancer (NSCLC) has been known as the most common human malignancy. The p53 tumor suppressor gene is mutated in approximately 50 % of NSCLC. For treatment of lung cancer, radiotherapy using -ray is general treatment. However, many patients suffer from recurred disease. Therefore, the definite mechanism of radiation based on in vivo mimic system is required for effective remedical value to NSCLC. Most of radiation biology studies were performed in conventional monolayer culture system which can not represent in vivo tumor environment. Hence, study applying in vivo mimic three-dimensional culture system is necessary to elucidate the molecular mechanism of solid tumor. Here, we analyzed gene expression profile induced by ionizing radiation (IR) in H1299 cells grown as spheroid in three-dimensional cell culture system. Our data showed that different gene expression profiles among monolayer culture system, three-dimensional small spheroid and three-dimensional large spheroid system. Particularly, genes related with microenvironment including adhesion junction and hypoxia had different expression level in three-dimensional spheroid system compare with monolayer culture system. This study suggested that in vivo mimic three-dimensional cell culture engineering approach might provide critical clues for understanding of cellular responses in p53 mutated or deleted lung cancer cells against IR. (* This work was supported by Nuclear Research Development Program of the Korea Science and Engineering Foundation (KOSEF) grant funded by the Korean government (MEST). (Grand code: 2007-2001431, 2008-2001694, 2009-0078295) from Korea Science and Engineering Foundation)

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 LB-167.
Abstract LB-169: Sulfasalazine sensitizes glioblastoma cells to radiation treatment
Authors: Sleire Linda , Wang Jian , Heggdal Jan , Pedersen Paal-Henning , Enger Per Øyvind
Published: February 2011

Glioblastomas (GBMs) are lethal cancers with a limited response to ionizing radiation. Recent studies suggest that Sulfasalazine (SAS), a drug used to treat inflammatory bowel disease, inhibits the xCT antiporter system in glioma cells, thereby blocking their uptake of cystine. Since the availability of cystine is a rate limiting step in intracellular antioxidant production, we wanted to investigate whether sulfasalazine sensitizes glioma cells to radiation. SAS effect on glioma cell growth was investigated using a electric cell substrate impedance sensing (ECIS) instrument. All cell lines showed altered growth curves in response to SAS treatment. Further, U251 glioma cells were treated with escalating doses of SAS, alone or in combination with radiation (8 Gy). Immunocytochemistry for the apoptotic marker Annexin V as well as DAPI staining to assess nuclear integrity were conducted to estimate cell death following treatment.

All treatment groups exhibited increased rates of cell death compared to untreated controls. However, a combination of SAS and radiation resulted in higher levels of cell death, than radiation or SAS administered alone. In order to assess whether this can be exploited therapeutically, we are currently preparing to treat nude rats harbouring gliblastoma biopsy xenografts with SAS, alone or in combination with radiation.

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 LB-169.