bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 5630: Nanotherapeutic silencing of HuR: Targeting a tumor-promoting response in ovarian cancer
Authors: Sawicki Janet A. , Huang Yu-Hung , Yeo Charles J. , Gogoi Radhika P. , Love Kevin , Anderson Daniel G. , Witkiewicz Agnieszka K. , Brody Jonathan R.
Published: August 2012

HuR is a RNA-binding protein that post-transcriptionally regulates genes involved in the normal cellular response to cancer-associated stressors (e.g., DNA damage, nutrient depletion, hypoxia, and therapeutic agents). When triggered by stress, HuR translocates from the nucleus to the cytoplasm where it potently influences translation of key tumor promoting mRNAs by mRNA stabilization and direct facilitation of translation. Previously, it has been shown that HuR expression is a prognostic marker in ovarian cancers. Thus, we tested the effects of manipulating HuR expression levels on ovarian tumor growth characteristics and tested the hypothesis that silencing HuR through delivery of an HuR siRNA would be effective in suppressing the growth of ovarian tumors. Following treatment of A2780 ovarian cancer cells in culture with an adenovirus containing the HuR coding sequence, HuR expression was increased by ∼40% above control cells as determined by qRT-PCR. When these cells were plated in soft agar, the Adeno-HuR-treated cells markedly enhanced anchorage independent growth properties compared to control cells treated with an Adeno-GFP virus. When OvCAR-3 xenografts in nude mice were injected with lipidoid-siHuR formulated nanoparticles (2 injections/wk, 7 mg/kg/injection), HuR expression was reduced by 80% as determined by immunoblot analysis of resected tumors, and tumor growth was suppressed 2.6-fold after 3 weeks compared to control tumors (siLuciferase- and PBS-treated) (p = 0.0004). After 4 weeks of treatment, all control mice were sacrificed due to large tumor size. siHuR-treated mice continued to receive 2 injections/week for an additional 4 weeks during which time tumor size was maintained at 4-5X the baseline size. In our patient cohort, we also detected HuR activation (i.e., cytoplasmic HuR positivity) in twenty-four of thirty-four patients (71%), providing evidence that the majority of patients have activated HuR. Mechanistically, in A2780 ovarian cancer cells, we detected HuR binding to tumor-promoting target mRNAs including dCK, DR5, and HuR itself. These data provide evidence that silencing HuR, even as a monotherapeutic strategy, may be a promising therapeutic approach for the treatment of ovarian cancer. Studies combining HuR inhibition with other chemotherapies (including gemcitabine), and studies exploring targeting strategies, are ongoing. This work was supported by the Marsha Rivkin Center for Ovarian Cancer Research.

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 5630. doi:1538-7445.AM2012-5630
Abstract 5633: BreastDefend suppresses growth and breast-to-lung cancer metastasis in an orthotopic model of human breast cancer
Authors: Jiang Jiahua , Thyagarajan-Sahu Anita , Loganathan Jagadish , Eliaz Isaac , Terry Colin , Sandusky George , Sliva Daniel
Published: August 2012

We have recently demonstrated that a natural dietary supplement BreastDefend (BD), which contains extracts from medicinal mushrooms (Coriolus versicolor, Ganoderma lucidum, Phellinus linteus), medicinal herbs (Scutellaria barbata, Astragalus membranaceus, Curcuma longa), and purified biologically active nutritional compounds (diindolylmethane and quercetin), inhibits proliferation and metastatic behavior of invasive human breast cancer cells MDA-MB-231 in vitro. In the present study we have evaluated whether BD suppresses growth and breast-to lung cancer metastasis in an orthotopic model of human breast cancer cells implanted in mice. An oral application of BD (100 mg/kg of body weight for 4 weeks) by intragastrical gavage did not affect body weight or activity of liver enzymes and did not show any sign of toxicity in liver spleen, kidney, lung and heart tissues in mice. Moreover, BD significantly decreased the change in tumor volume over time when compared to the control group (p=0.002). BD treatment also markedly decreased the incidence of breast-to-lung cancer metastasis from 67 % (control) to 20% (BD) (p<0.05) and number of metastasis from 2.8 [0.0, 48.0] in the control group to 0.0 [0.0, 14.2] in the BD treatment group (p<0.05). Finally, anti-metastatic activity of BD in vivo was further confirmed by the down-regulation of expression of PLAU (urokinase plasminogen activator, uPA) and CXCR4 (C-X-C chemokine receptor-4) genes in breast tumors. In conclusion, BD may be considered as a biological therapeutic agent against invasive breast cancers.

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 5633. doi:1538-7445.AM2012-5633
Abstract 5636: Preclinical data of a microRNA-based therapy for hepatocellular carcinoma
Authors: Bader Andreas G. , Daige Christopher L. , Kelnar Kevin , Priddy Leslie , Dysart Sarah , Wiggins Jason , Zhao Jane , Leatherbury Neil , Omotola Michael , Stoudemire Jay , Lammers Paul , Brown David
Published: August 2012

MicroRNA (miRNA) mimics have emerged as a novel class of therapeutics with promising anti-oncogenic activity. These mimics are modeled after naturally occurring tumor suppressor miRNAs that are ubiquitously expressed in normal cells but frequently show a loss-of-function in human malignancies. The premise for the strong inhibitory activity is based on the observation these endogenous miRNAs control multiple oncogenic pathways commonly deregulated in cancer. Therefore, “miRNA replacement therapy” acts in accordance with our current understanding of cancer as a pathway disease that can only be successfully treated when intervening with multiple cancer pathways. We have identified a series of key tumor suppressor miRNAs, including miR-34, and validated the therapeutic potential in cultured cancer cells and mouse models of cancer. The translation of this potential into future medicines, however, was hampered by the lack of a robust clinically relevant delivery system. To facilitate a rapid route to the clinic, we have screened a panel of external delivery systems that are in pre-clinical development or have already reached the clinic featuring another oligonucleotide. Here, we present the pharmacologic and pharmacodynamic parameters of miRNA mimics complexed in ionizable NOV340 liposomes (SMARTICLEs, Marina Biotech, Bothell, WA) in an orthotopic tumor model of hepatocellular carcinoma. Treatment of mice carrying existing tumors mimics led to significant tumor regression, prolonged survival and lacked notable drug-related side effects. Some of the mice appeared to be tumor-free. The data demonstrate the therapeutic utility of the NOV340/miRNA formulation and support the initiation of IND-enabling studies.

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 5636. doi:1538-7445.AM2012-5636
Abstract 5638: New synthetic analogs of migrastatin as potent cell migration inhibitors to block overall metastasis in lung cancer and colorectal carcinoma
Authors: Lecomte Nicolas
Published: August 2012

Tumour metastasis is the leading cause of death within cancer patients. Therefore the development of new small molecules targeting this process is crucial in the therapeutic arsenal. Migrastatin is a biologically active natural product isolated from Streptomyces that shows a high potency inhibition of tumor cell migration. Upon completing the first total synthesis of migrastatin, sets of structurally simplified synthetic analogs were developed. In the light of extensive in vitro screening leading to informative structureαactivity relationship, a new generation of analogs was launched which demonstrated higher levels of in vitro inhibitory activity, stability and synthetic accessibility. We investigated two promising ether-derivative analogs, the migrastatin core ether (ME) and the carboxymethyl-ME (CME). Both compounds exhibited high efficacy in blocking tumor cell migration in vitro with IC50 values in the micromolar range, more than two orders of magnitude less than the LD50 values. In the light of these results, in vivo efficacy of these compounds in inhibiting tumor metastasis was assessed in human tumor xenograft models established in NOD/SCID IL2R gamma null (NSG) mice. First in a human Small-Cell Lung Cancer (SCLC) primary xenograft model, developed by subcutaneous injection of tumor cells, ME and CME compounds were found to be highly potent in inhibiting overall metastasis even at the lowest dosage used (degree of inhibition: 96% and 99%, for ME and CME at 10mg/kg or 12mg/kg respectively). Next, in a human Colorectal Carcinoma (CRC) xenograft model, developed by intrasplenic injection of tumor cells, ME at the highest dosage (100mg/kg) was found to significantly reduce the metastatic spread to the liver, the lungs and the GI tract (degree of inhibition: 97%, 84% and 95% respectively). CME and ME selectively inhibited tumor cell migration in vitro and in vivo but neither compound inhibited tumor proliferation at the primary site of tumor injection or at the metastatic site if tumor metastases occurred prior inhibition by drug treatment. All together these very encouraging findings suggest that these analogs have promise as potent anti-metastatic agents in epithelial tumors.

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 5638. doi:1538-7445.AM2012-5638
Abstract 5646: Allele-specific shRNA to Nanog family members inhibits 3-D growth of colorectal carcinoma through the intrinsic apoptotic pathway
Authors: Zhang Jingyu , Thorgeirsson Snorri S. , Jessup J. Milburn
Published: August 2012

Nanog and NanogP8 modulate stemness of human colorectal cancer (CRC) as measured by directly affecting spherogenicity, tumorigenicity and metastatic potential. As a result, we tested whether targeting NanogP8 (the dominant Nanog member expressed in human CRC lines and liver metastases) by specific lentiviral (LV) shRNA inhibits the growth of CRC in 3-D spheroids in suspension culture. We first designed allele-specific shRNAs to NanogP8 and Nanog, genes that differ only in 5 nucleotides in a 915 nt ORF, and demonstrated that the shRNA to NanogP8 (shNp8-1) and Nanog (shNG-1) specifically inhibited their target in PA-1, a human embryonal carcinoma line expressing only Nanog, or CX-1, a CRC that expresses predominantly NanogP8. When Clone A or CX-1 CRC cells transfected with Luc2 were cultured for 24 hours in suspension in serum-free medium (SFM), transduced with LV shNP8-1, shNG-1 or a control shRNA (shNeg) at a multiplicity of infection (MOI) 8 and cultured for another 72 hours in SFM, all of the LV vectors transduced 40 - 75% of the cells in 3-D constructs. shNp8-1 transduction significantly reduced the mass of cells and luciferase activity by 50%. Apoptosis was induced because CRC treated with shNp8-1 had significantly more annexin V+ cells than did shNEG or untreated parental cells. Previous work in our lab demonstrated that caspase 8 was important in anoikis - the apoptosis caused by suspension of cells whose growth generally requires adherence. Caspase 3, 8 and 9 activity was measured by fluorogenic substrates in Clone A and CX-1 cells at 4 days of suspension culture, 3 days after LV treatment. Caspase 3 activity was increased by shNp8-1 by 2.5 to 3-fold in both CX-1 and Clone A compared to untreated cells. shNp8-1 treatment increased Caspase 9 activity by ∼50% in both CRC lines compared to untreated cells whereas shNEG and shNG-1 transduction did not increase Caspase 9 activity significantly. Treatment with a Caspase 9 peptidomimetic blocked apoptosis and increased CX-1 survival significantly. When cells were harvested at the end of the 4 day apoptosis assay and replated in a standard colony forming assay, CX-1 cells transduced with shNp8-1 LV produced 33% fewer colonies than did the shNEG and shNG-1 controls. These results indicate that shNp8-1 transduction may activate apoptosis through a Caspase 9-dependent pathway and that this treatment may have long term effects that inhibit tumor regrowth after treatment. Supported by Center for Cancer Research funds and Department of Defense IDEA grant W81XWH-11-1-0327.

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 5646. doi:1538-7445.AM2012-5646
Abstract 5660: Vaccinia virus GLV-1h153 in combination with 131I-iodine shows increased efficiency in treating triple-negative breast cancer in vivo
Authors: Gholami Sepideh , Chen Chun-Hao , Lou Emil , Marano Andrew A. , Mojica Kelly M. , Chen Nanhai G. , Aguilar Richard J. , Belin Laurence J. , Longo Valerie A. , Zanzonico Pat , Szalay Aladar A. , Fong Yuman
Published: August 2012

BACKGROUND: Triple-negative breast cancers (TNBC) are aggressive tumors due to their inherent biology and the lack of receptors for hormonal/targeted therapy, namely estrogen, progesterone, and Her2/neu. The human sodium iodide symporter (hNIS) is a naturally occurring protein in some human breast and thyroid tissue which enables cells to concentrate iodine, including radioiodide. In this study, we investigated the therapeutic efficacy of a new oncolytic vaccinia virus, GLV-1h153 carrying the hNIS, in combination with radioiodine in a TNBC murine model. METHODS: GLV-1h153, a replication-competent vaccinia virus, was tested against the TNBC cell lines MDA-MB-231, MDA-MB-468, HCC-1937, and HCC-1143 at multiplicities of infections (MOI) of 0.1, 1.0, and 5. Cytotoxicity and viral replication were determined. Mammary fat pad tumors were generated in athymic nude mice with MDA-MB-231 cells. A subset of xenografts were infected with GLV-1h153 and ∼150 μCi of 124I-iodine was administered. Serial Focus 120 microPET were obtained for 131I dosimetry calculations. For the combination therapy study, 14 days after cell implantation, xenografts were treated with intratumoral injection of GLV-1h153 or PBS. One week after viral injection (day 21), xenografts were further randomized into 4 treatments groups: GLV-1h153 alone, GLV-1h153 and iodine (∼5 mCi of 131I), iodine alone, or PBS and followed for tumor growth. RESULTS: Greater than 90% cell kill was achieved in all cell lines within 5 days at an MOI of 5.0. GLV-1h153 replicated efficiently in all cell lines with a peak titer of 2.6 x107 viral plaque forming units per ml (>1300-fold increase from the initial viral dose) by day 4 in cell line MDA-MB-468. Only infected tumors were identified via PET scanning compared to controls. In vivo, administration of systemic radioiodine in combination with GLV-1h153 resulted in greater tumor regression, 24 mm3 compared to 146 mm3 for the viral-treated group only (p<0.05; days 21-40), a six-fold difference. CONCLUSION: GLV-1h153 infected, replicated in, and killed all TNBC cell lines effectively. This study is the first to our knowledege to demonstrate killing of TNBC by a novel vaccinia virus in combination with radioactive 131I-iodine in an in vivo xenograft model. Our results suggest that GLV-1h153 is a promising therapeutic agent in combination with 131I and merits further testing in the clinical setting.

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 5660. doi:1538-7445.AM2012-5660
Abstract 5671: Differential roles of caveolin-1 variants in cell death in breast cancer
Authors: Clarke Robert , Dobbin Zachary C. , Hickman F.Edward , Shajahan Ayesha N.
Published: August 2012

Paclitaxel, an anti-microtubule agent, is an effective chemotherapeutic drug in breast cancer. Nonetheless, resistance to paclitaxel remains a major clinical challenge. The need to better understand the resistant phenotype, and to find biomarkers that could predict tumor response to paclitaxel is urgent. In estrogen receptor α (ER+) breast cancer cells, phosphorylation of caveolin-1 (CAV1) on Y14 facilitates mitochondrial apoptosis by increasing BCL2 phosphorylation in response to low dose paclitaxel (10 nM). Two variants of CAV1 exist; the full-length form CAV1α (wild-type CAV1 or wtCAV1) and a truncated form CAV1β. The precise cellular functions of CAV1 variants are unknown. Only wtCAV1 has the Y14 region at the N-terminus and we now show that CAV1 variants play distinct roles in paclitaxel-mediated cell death/survival. CAV1β is increased in paclitaxel resistant cells compared to sensitive cells. Expression of wtCAV1, but not CAV1β, in sensitive cells significantly increased their responsiveness to paclitaxel. These activities reflect the essential role for Y14 phosphorylation since wtCAV1 expression, but not a phosphorylation-deficient mutant (Y14F), inactivates BCL2 and BCLxL through activation of c-jun N-terminal kinase (JNK). MCF-7 cells that express Y14F are resistant to paclitaxel and are re-sensitized by co-treatment with ABT-737, a BH3-mimetic small molecule inhibitor. Thus, we highlight novel roles for CAV1 variants in cell death: wtCAV1 promotes cell death whereas CAV1β promotes cell survival by preventing inactivation of BCL2/BCLxL via JNK in paclitaxel-mediated apoptosis.

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 5671. doi:1538-7445.AM2012-5671
Abstract 992: Credentialing UHRF1 as a target for prostate cancer therapy
Authors: Walker David , Haffner Michael , Deshpande Neha , Wyhs Nicolas , Marzo Angelo De , Yegnasubramanian Srinivasan , Nelson William
Published: August 2012

Alterations in DNA methylation are a hallmark of prostate carcinogenesis. UHRF1 is an essential component in the machinery required for the maintenance of DNA methylation in actively dividing cells. In S-phase, UHRF1 binds nascent hemimethylated DNA and recruits DNA methyltransferases to copy the methylation pattern to the daughter DNA strand in a manner analogous to semi-conservative replication. Additionally, it has been shown that UHRF1 interacts with methylated histones and histone methyltransferases, making it an important epigenetic regulator in proliferating cells. Because of its ties to epigenetic gene silencing and cell proliferation, we hypothesized that UHRF1 could serve as a target for prostate cancer treatment. In this study, we have taken steps to credential UHRF1 as a therapeutic target in prostate cancer and have developed a high-throughput UHRF1-DNA binding assay to screen for UHRF1 inhibitors. We show that UHRF1 is overexpressed in a panel of prostate cancer cell lines and it appears to track with proliferation in prostate cancer tissue. Through loss-of-function studies in prostate cancer cell lines PC3 and DU145, we show that long-term UHRF1 depletion leads to a decrease in clonogenic survival and an overall reduction in global levels of DNA methylation. Further, we find that UHRF1 is required to maintain DNA methylation and epigenetic silencing of hypermethylated genes in prostate cancer cells. Additionally, ChIP experiments revealed that UHRF1 can be bound at the promoter CpG islands of epigenetically silenced genes in prostate cancer cells. With the goal of ultimately developing UHRF1 inhibitors, we have developed a time-resolved fluorescence resonance energy transfer (TR-FRET)-based assay, compatible with high-throughput screening, that can detect the binding of the SRA domain of UHRF1 to hemimethylated DNA. In summary, we have shown that UHRF1 plays a critical role in maintaining the DNA methylation of epigenetically silenced genes in prostate cancer and have developed an assay for high-throughput screening of UHRF1 inhibitors.

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 992. doi:1538-7445.AM2012-992
Abstract 995: Transient low doses of DNA demethylating agents exert durable antitumor effects on hematological and epithelial tumor cells
Authors: Tsai Hsing-Chen , Li Huili , Neste Leander Van , Cai Yi , Robert Carine , Rassool Feyruz V. , Shin James J. , Harbom Kirsten M. , Beaty Robert , Pappou Emmanouil , Harris James , Yen Ray-Whay Chiu , Ahuja Nita , Brock Malcolm V. , Stearns Vered , Feller-Kopman David , Lin Yi-Chun , Welm Alana L. , Issa Jean-Pierre , Minn Il , Matsui William , Jang Yoon-Young , Sharkis Saul J. , Baylin Stephen B. , Zahnow Cynthia A.
Published: August 2012

Reversal of gene promoter DNA hypermethylation and associated abnormal gene silencing is an attractive approach to cancer therapy. The DNA methylation inhibitors, decitabine (5-aza-2′-deoxycytidine) and azacitidine (5-azacytidine) are proving efficacious clinically for hematological neoplasms, especially at lower, less toxic, doses. Experimentally, high doses induce rapid DNA damage and cytotoxicity, but these may not explain the prolonged time to response often seen in patients. We now show that transient exposure of cultured and primary leukemic and epithelial tumor cells to decitabine or azacitidine at clinically-relevant nanomolar doses, without causing immediate cytotoxicity, produces a “memory” for anti-tumor responses, including potent inhibition of subpopulations of cancer, stem-like cells which often resist other therapies. These inhibitory effects are accompanied by sustained decreases in genome-wide promoter DNA methylation with associated gene re-expression, and anti-tumor changes in multiple key cellular regulatory pathways, such as cell cycle events mediated through FOXM1, cell invasion and motility, and granulocyte and breast cancer cell maturation. Notably, most of the key pathways altered by decitabine or azacitidine involve high priority targets for pharmacologic anti-cancer strategies, which provides molecular basis for possible combination therapies. Thus, low dose decitabine and azacitidine regimens may potentially have broad applicability for cancer management.

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 995. doi:1538-7445.AM2012-995
Abstract 996: MBD-capture coupled with next generation sequencing elucidates genome-wide crosstalk between epigenetic marks and its role in cancer
Authors: Putiri Emily L. , Robertson Keith D.
Published: August 2012

Aberrations in DNA methylation are a hallmark of cancer, and these epigenetic changes lead to tumor suppressor gene silencing by hypermethylation, global genomic hypomethylation, and genomic instabilities. Post-translational histone modifications are important epigenetic marks that have been implicated in regulating DNA methylation patterning. Several known histone marks, including methylation of histone H3 at lysines 4 and 27 and monoubiquitylation of histone H2A (H3K4me, H3K27me, and H2Aub, respectively), are believed to differentially regulate DNA methyltransferase activity on DNA. The histone mark H3K4me is associated with gene activation, and H3K27me and H2Aub are associated with loci of transcriptional repression and DNA methylation, especially at hypermethylated genes in cancer. Recent studies have examined the genome-wide distribution of these histone modifications or have studied how their distribution relates to DNA methylation within specific loci, but these studies have not ascribed specific roles to these histone modifications in DNA methylation patterning, nor do we understand why only subsets of genes throughout the genome become hypermethylated in cancer. This poster demonstrates how the histone marks H3K4me, H3K27me, and H2Aub affect genome-wide DNA methylation patterning and transcriptional regulation, and we highlight several epigenetic targets of H3K27me and H2Aub epigenetic repression that participate in the pathogenesis of cancer. We have used siRNA transfection in NCCIT human embryonic carcinoma cells to target critical subunits of the complexes that establish each of these histone modifications. Through these siRNA treatments, we assessed the roles of each mark in establishing DNA methylation patterns throughout the genome and how these patterns relate to genome-wide gene expression. The effects of histone mark deficiency were analyzed by an assay that isolates methylated-CpG-containing DNA (MBD-capture) coupled to massively parallel DNA sequencing to identify sequences with altered methylation patterns. These sequencing results were correlated with patterns of gene expression determined by expression microarray analysis to identify gene targets whose epigenetic misregulation results in alterations in gene expression. In total, this poster demonstrates how histone modifications contribute to the control of the human DNA methylome and postulates how these marks exert downstream effects toward the pathogenesis of 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 996. doi:1538-7445.AM2012-996
Abstract LB-116: Immunodeficient pigs as a large animal model for human tumors
Authors: Balivada Sivasai , Basel Matthew T. , Pyle Marla , Beck Amanda P. , Cino-Ozuna Ada G. , Kerrigan Maureen A. , Hill Jennifer L. , Wyatt Carol R. , Rowland Robert R. R. , Troyer Deryl L.
Published: August 2012

Currently, SCID mice are the major biomedical model for the study of human cancer and other diseases; however, they can be a poor model because there is a large discrepancy in body size and physiology between rodents and humans. Since most new anticancer drugs are first evaluated in rodents, most fail in phase I and phase II clinical trials. Thus, there is a tremendous demand for more sophisticated animal models, which may improve the translation efficiency from preclinical to clinical studies. We recently identified pigs that are severely immunocompromised. Here we tested these pigs as a model for human tumors. Three immunodeficient (ID) pigs and three normal (WT) pigs, six weeks of age, were tested for their ability to allow xenotransplanted human tumors to grow. Each pig was transplanted with 4 million A375 human malignant melanoma cells subcutaneously into the left ear and 4 million PANC-1 human pancreatic carcinoma cells subcutaneously into the right ear on day 0. The ID pigs were euthanized 6, 14, or 23 days after cell transplantation, based on their health condition. Palpable melanoma tumors were identified on day 13 after cell transplantation in the two remaining ID pigs. After euthanasia, full necropsy was performed on all pigs; tissues were collected from ears and other organs for histopathological analysis. Melanoma and pancreatic tumor xenotransplants were identified histologically in all three ID pigs. The presence of human cancer cells in these pigs was further verified with anti-human mitochondrial immunohistochemistry. No transplanted tumors were found, grossly, histologically, or immunohistochemically, in the WT pigs. We propose that this genetic line of ID pigs may prove to be a useful large animal model for human tumors.

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 LB-116. doi:1538-7445.AM2012-LB-116
Abstract LB-122: A phase I dose escalation study of NVP-BGJ398, a selective pan FGFR inhibitor in genetically preselected advanced solid tumors
Authors: Wolf Jurgen , LoRusso Patricia M. , Camidge Ross D. , Perez Jose Manuel , Tabernero Josep , Hidalgo Manuel , Schuler Martin , Tian Gary G. , Soria Jean Charles , Delord Jean Pierre , Campone Mario , Bachelot Thomas , van der Noll Ruud , Ringeisen Francois P. , Nogova Lucia , Sequist Lecia V. , Schellens Jan HM
Published: August 2012

The family of fibroblast growth factors (FGFs) and FGF receptors (FGFRs) plays a critical role in cell proliferation and survival. A variety of genetic alterations (e.g. amplifications, mutations, and translocations) of these receptors and ligands have been found in diverse types of tumors. NVP-BGJ398 is a potent, selective, and orally bioavailable inhibitor of the FGFR tyrosine kinases. It inhibits the proliferation of various FGFR-dependent cell lines at nano-molar concentrations including breast and lung cancers harboring FGFR1 amplification, FGFR2-amplified gastric cancer cell lines and FGFR3-mutated bladder cancers. Objectives of the study: The purpose of this phase I-First In Human dose-escalation study is to determine the maximum tolerated dose (MTD) and/or recommended phase II dose (RPTD) of NVP-BGJ398 when administered orally to adult patients with advanced solid tumors. Secondary objectives include safety, tolerability, pharmacokinetics and preliminary anti-tumor activity in FGFR-dependent cancer. Methods: Patients received BGJ398 daily in a 28-day cycle in escalating dose cohorts starting from 5mg once daily. After cohort 3, patients had to have FGFR1 or FGFR2 amplification or FGFR3 mutation. Dose limiting toxicities (DLTs) were pre-defined and included both severe events and those resulting in significant dosing delays. Preliminary data: 26 patients have been treated, including 10 patients with FGFR1-amplified breast and 3 patients with FGFR1-amplified squamous cell lung cancer. The dose was escalated from 5 mg to 150 mg over 7 dose cohorts. One DLT of delayed dose occurred following a grade 3 AST/ALT event at 100 mg. Adverse events (AE) were generally grade 1-2. The most frequently observed AEs were diarrhea (37%) fatigue (37%) and nausea (32%) Hyperphosphatemia was observed, with increasing frequency at higher doses of NVP-BGJ398, and could be managed with phosphate binders and diuretics. One lung cancer patient with an FGFR1/CEP8 ratio of 2.6 by FISH analysis responded to 100 mg of NVP-BGJ398 with a 33% reduction in target lesions by CT scan at 8 weeks, confirmed at 12 weeks, and a substantial SUV decrease on PET. These observations provide early evidence that inhibition of the FGFR pathway is effective in patients with FGFR dependent cancers.

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 LB-122. doi:1538-7445.AM2012-LB-122
Abstract LB-139: In situ Treg immunomodulation at a single tumor site with CpG and immune checkpoint antibodies cures metastatic disease
Authors: marabelle aurelien , Kohrt Holbrook , Brody Joshua , Torchia James , rajapaksa ranjani , Luong Richard , Zhou Gang , Levitsky Hyam , Tse Victor , Levy Ronald
Published: August 2012

Background: CD4+CD25+FOXP3+ regulatory T-cells (Tregs) infiltrate all tumor sites and play a central role in maintaining immune tolerance to cancers. Scientific question: Is the local immunomodulation of Tregs from a single tumor site sufficient to trigger a systemic anti-tumor immune response able to eradicate distant tumor sites ≤ Results: We found that tumor infiltrating Tregs preferentially express CTLA4 (CD152) and OX40 (CD134) compared to their counterparts in the blood and other lymphoid organs, both in mice and in human lymphomas. We show in a murine lymphoma model that OX40 and CTLA4 upregulation occurs specifically on Tregs directed against tumor antigens. Injections of low doses of anti-CTLA4 and anti-OX40 together with CpG, a TLR-9 agonist, directly into a single tumor site depletes the Tregs from the injected tumor but not from distant ones. This immunomodulation subsequently triggers an anti-tumor immune response able to cure mice with established disseminated disease. This triple combination is uniquely required as neither CpG alone nor mAbs without CpG are effective. Significance: immunomodulatory antibodies are currently under clinical development for cancer therapy. Their major toxicity is the triggering of auto-immune diseases. We show here that after injections of very little doses of these antibodies with CpG at one tumor site, their serum levels become undetectable. However, these doses are sufficient to trigger a systemic anti-tumor response able to eradicate distant sites. Impact: we recently have published positive results of intra-tumoral CpG in patients with follicular Lymphoma (Brody, Levy, et al. JCO, 2010). Anti-CTLA4 has just been approved by the FDA/EMEA in patients with metastatic melanoma. Anti-Ox40 antibodies are currently being tested in phase I/II clinical trials. Therefore, the combination described here can be tested in patients with injectable sites of lymphoma. Together, these results are in favor of a paradigm shift in cancer therapy where the immune system is targeted rather than the tumor itself.

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 LB-139. doi:1538-7445.AM2012-LB-139
Abstract LB-143: ErbB2, EphrinB1, Src kinase and PTPN13 signaling complex regulates MAP kinase signaling in human cancers
Authors: Vermeer Paola D. , Bell Megan , Lee Kimberly , Vermeer Daniel W. , Wieking Bryant , Drapkin Ronny I. , Ganesan Shridar , Lee John
Published: August 2012

Tyrosine kinases, like the ErbB and Src families, can mediate potent oncogenic growth and are successful therapeutic targets of human cancers. However, many cancer cells overcome or successfully modulate these downstream signaling cascades in the absence of growth factor or kinase over-expression. We have previously identified a cellular phosphatase, PTPN13 that significantly modulates mitogenic signaling and can function as tumor suppressors. Decreased PTPN13 expression enhances ErbB2-mediated MAP Kinase activation, and is also associated with decreased survival in breast cancer. Here we show that PTPN13 regulates a signaling complex consisting of ErbB2, Src, and EphrinB1. To our knowledge, this signaling complex has not been previously described. Co-immunoprecipitation, proximity ligation assay and immunofluoroscence studies demonstrate that EphrinB1, a PTPN13 substrate, interacts with ErbB2. In addition, the oncogenic V660E ErbB2 mutation enhances this interaction, while Src kinase mediates EphrinB1 phosphorylation and subsequent MAP Kinase signaling. Decreased PTPN13 function further potentiates these changes. The association of oncogene kinases (ErbB2, Src), a signaling transmembrane ligand (EphrinB1) and a phosphatase tumor suppressor (PTPN13) suggest that EphrinB1 may be a relevant therapeutic target in cancers harboring ErbB2-activating mutations and decreased PTPN13 expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-143. doi:1538-7445.AM2012-LB-143
Abstract LB-151: Spred1 and neurofibromin interact to negatively regulate Ras/Raf/MEK/ERK signaling
Authors: Stowe Irma B. , Stowe Timothy , McCormick Frank , Mercado Ellen
Published: August 2012

The Ras/Mitogen Activated Protein Kinase (MAPK) plays a critical role in cell signaling downstream of receptor tyrosine kinases. The conserved Sprouty family proteins function as feedback regulators of Ras/MAPK signaling. Loss of function mutations in one family member, SPRED1, cause Legius syndrome, an autosomal dominant human disorder that resembles neurofibromatosis type 1 (NF1). Spred1 functions as a negative regulator of the Ras/MAPK pathway, however, the underlying molecular mechanism is poorly understood. We found Spred1 functioned by reducing Ras-GTP levels; SPRED1 loss-of function mutations identified in Legius syndrome patients were unable to regulate Ras activity levels. The N-terminal EVH1 domain of Spred1 was found to be crucial for its inhibitory function. Thus, we utilized tandem affinity purification of wild-type Spred1 and EVH1 domain mutants found in Legius syndrome to identify novel binding partners of the N-terminus. Analysis of protein complexes by mass spectrometry revealed neurofibromin, the NF1 gene product, as a novel Spred1 interacting protein. We show that neurofibromin is a Spred1 binding partner that is necessary for Spred1's inhibitory function. Spred1 requires neurofibromin to down-regulate Ras-GTP levels, and the interaction with Spred1 is required for neurofibromin localization to the plasma membrane. This novel mechanism leads to a better understanding of the regulation of the neurofibromin tumor suppressor protein.

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 LB-151. doi:1538-7445.AM2012-LB-151
Abstract LB-152: PIK3CA mutation spectrum in urothelial carcinoma reflects cell context-dependent signalling and phenotypic outputs
Authors: Ross Rebecca L. , Askham Jon M. , Knowles Margaret A.
Published: August 2012

Activating p110α mutations are frequently observed in urothelial carcinoma (UC). Their specific effects in urothelial cells and the reason for the large excess of helical domain mutations relative to kinase domain mutations have not been studied. Thus we investigated the phenotypic consequences of hotspot and UC-specific rare PIK3CA mutations in immortalized normal human urothelial cells (NHUC) and mouse fibroblasts (NIH3T3). Our results show that in NHUC, all PIK3CA mutants activate the AKT pathway. The potency of AKT downstream activation by helical and kinase domain mutants was related to the frequency of mutation occurrence in UC (E545K>E542K>H1047R). In NIH3T3, the H1047R kinase domain mutant induced significantly higher levels of AKT activation relative to helical domain mutant forms and this was reflected in their abilities to promote anchorage-independent growth. In NHUC, only E542K and E545K helical domain mutant forms conferred a significant proliferative advantage at confluence and in nutrient limiting conditions. Both types of mutant forms induced NHUC cell motility, though no significant differences were found between helical and kinase domain mutant forms. Our findings indicate that the cellular consequences of mutant PIK3CA are both cell type- and mutation-specific. This provides a rationale for the observed PIK3CA mutation spectrum in UC and suggests that helical domain mutations may confer a selective advantage in the urothelium in vivo by overcoming normal contact-mediated inhibitory signals and allowing nutrient-independent proliferation.

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 LB-152. doi:1538-7445.AM2012-LB-152
Abstract LB-205: Identification of tumorigenic cells in KrasG12D-induced lung adenocarcinoma
Authors: Yu John , Cho Huan-Chieh
Published: August 2012

We established an inducible KrasG12D-driven lung adenocarcinoma in CCSP-rtTA/TetO-Cre/LSL-KrasG12D mice that enable pursuits of the cellular and molecular processes involved in Kras-induced tumorigenesis. To investigate the cellular origin of this cancer, we first report a strategy using FACS fractionation that could highly enrich bronchiolar Clara and alveolar type II cells, respectively. The EpCAM+MHCII− cells (bronchiolar origin) were more enriched with tumorigenic cells in generating secondary tumors than EpCAM+MHCII+ cells (alveolar origin) in primary tumors that had been already initiated with oncogenic Kras activation. In addition, secondary tumors derived from EpCAM+MHCII− cells showed diversity of tumor locations compared to those derived from EpCAM+MHCII+ cells. In the alveolar region, secondary tumors from EpCAM+MHCII− cells expressed not only bronchiolar epithelial marker, panCK, but also differentiation marker, proSPC, consistent with the notion that cancer-initiating cells display not only the abilities for self-renewal but also the features of differentiation to generate heterogeneous tumors with phenotypic diversity. Furthermore, high level of ERK1/2 activation and colony-forming ability as well as lack of Sprouty-2 expression were also observed in EpCAM+MHCII− cells. Therefore, these results suggest that bronchiolar Clara cells are the origin of cells and tumorigenesis for KrasG12D-induced neoplasia in the lungs.

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 LB-205. doi:1538-7445.AM2012-LB-205
Abstract LB-206: A new platform for diagnosis and therapeutic targeting of cancer stem cells
Authors: Ertem Server A. , Moore Malcolm AS
Published: August 2012

The present failure of most current therapies to cure cancers is thought to be the relative resistance of cancer initiating cells (CIC), also known as cancer stem cells, to chemotherapy and radiation. Following repeated cancer treatments, tumors can remain with a high percentage of CIC and become more aggressive and resistant to further treatment. What has been missing up to now is a therapy directed at CIC also known as cancer stem cells. Without elimination of these cells, cancer recurrence is inevitable. We believe that the major objective of cancer therapy should be to target CIC specifically. However, there has not been a reliable method for detecting CIC within tumors that would allow prospective isolation of these cells in sufficient numbers for analysis, characterization and evaluation of novel therapeutics. This has proved to be a major barrier to development of effective CIC targeted cancer therapeutics. Advances in cancer therapy will depend on development of reliable early detection methods and targeting strategies specific for CIC. We have discovered a unique cell type with cancer initiating cell characteristics in metastatic cancers. These cells have a protective pericellular coat, divide rapidly and grow as chains of cells - thus the name catena = chain. In xenograft studies in mice, nearly every catena cell was shown to be a CIC. Catena are resistant to standard therapies (e.g. paclitaxel, cisplatin) and more than 1,000 pharmaceutical agents that are in development for cancer treatment. Catena lack all of the biomarkers currently used for cancer detection and are undetectable by current diagnostic tests that utilize monoclonal antibodies (e.g. to CA125, HE4, Mesothelin, WT1, CD44, EPCAM, CD133). We subsequently developed the CATENAE cell culture technology to propagate these cells in vitro while maintaining their cancer initiating properties. This technology provides for the first time adequate number of CIC for detailed analysis and could be the key to both better therapies and more efficient detection of cancer at an early stage when it is curable.

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 LB-206. doi:1538-7445.AM2012-LB-206
Abstract LB-208: Notch2 in vivo genetic labeling reveals novel epithelial subtypes within mammary luminal lineage
Authors: Sale Sanja , Lafkas Daniel , Artavanis-Tsakonas Spyros
Published: August 2012

Identification and characterization of normal epithelial subtypes in mammary gland is a fundamental step in understanding mammary development as well as carcinogenesis. In this study we utilized an inducible lineage tracing approach in combination with reconstitution assays and conditional in vivo cell ablation to systematically map the fate and define cellular hierarchy of normal mammary epithelial cells (MECs) in postnatal mammary gland. We used a set of novel genetically engineered mice designed to follow Notch receptor expressing cell lineages given that Notch activity has been associated with early precursor and stem cells in many tissues. We focused our attention on Notch2 expressing cells, which allowed us to define two novel epithelial subtypes within ductal and alveolar lineage displaying distinct morphological and functional characteristics. We operationally term them as LumS (Luminal Small) and LumL (Luminal Large) cells. LumS cells are positioned in regular intervals alongside ductal longitudinal axis and are grouped in a chain formation around a single large luminal cell forming a stereotypical “pit”. LumL cells are large, oval shaped and appear as either singlets or doublets. They are mostly, although not exclusively, positioned in close proximity to branching points. In lactating glands LumL cells also appear as singlets or doublets within each alveolus. Functional assays demonstrate that LumS and LumL cells are not multipotent stem cells but rather differentiated luminal subtypes that are involved in determining location of the future tertiary alveolar structures as well as branching morphogenesis. It remains to be determined whether LumS and LumL populations are the cells of origin for breast cancer subtypes. We note with interest however that a single nucleotide polymorphism (SNP) in Notch2 locus has recently been identified as a novel genetic risk factor for breast cancer and Notch2 mRNA was found to be enriched in ER+ luminal tumors suggesting the possibility of clonal expansion of one or more Notch2+ lineages.

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 LB-208. doi:1538-7445.AM2012-LB-208