bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 995: The role of intracellular ATP in regulating glycolysis, HIF1α and drug resistance of cancer cells
Authors: Chen Jinyu , Weihua Zhang
Published: June 2012

Cancer is also considered to be a metabolic disease due to a shift of glucose metabolism from oxidative phosphorylation to anaerobic glycolysis. This study is to understand the effect of intracellular ATP of cancer cells on various metastatsis related phenotypes, including glycolysis, hypoxia stability and drug resistance. In this study, we delivered ATP directly into cancer cells by embedding ATP into liposomes. Normal cells and its corresponding tumor cells were measured for their whole cell ATP content. Glycolysis was evaluated by measurement of glucose consumption and lactate accumulation of cell culture media. Cell cycle was analyzed using flow cytometry after drug treatment and delivery of ATP. HIF-1α expression level was measured by western blot after delivery of ATP. In summary, normal cells have overall higher ATP content than tumor cells. After delivery of ATP, cells consumed less glucose and produced less lactate acid, which indicated a decrease in glycolysis. ATP liposomes prevented MDA-MB-231 cells from G2 arrest by adriamycin. HIF1a was down regulated after delivery of ATP. Taken together, ATP content is lower in cancer cells than normal cells, and intracellular ATP plays a role in regulating glycolysis, HIF-1α stability and drug resistance of cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 995. doi:10.1158/1538-7445.AM2011-995
Abstract DDT01-01: Preclinical profile of AZD4547: A selective inhibitor of FGF-receptors 1, 2, and 3
Authors: Brooks Nigel A.
Published: June 2012

The fibroblast growth factor/fibroblast growth factor receptor (FGF/FGFR) signaling axis comprises 18 ligands which exert their actions via 4 transmembrane tyrosine kinase receptors. FGFs signaling though their cognate receptors play an important role in normal organ, vascular and skeletal development. Deregulation of FGFR signaling through genetic modification or overexpression of the receptors (or their ligands) has been observed in numerous tumor settings, whilst the FGF/FGFR axis also plays an important role in driving tumor angiogenesis. A growing body of data demonstrates that inhibition of FGFR signaling can result in antiproliferative and/or proapoptotic effects, both in vitro and in vivo, thus confirming the validity of FGFR as a cancer therapeutic target.

AZD4547 is a small molecule inhibitor which competes with ATP for binding to FGF receptors 1, 2 and 3, thus inhibiting autophosphorylation and downstream signaling. Using in vitro kinase assays, we demonstrate that AZD4547 is a potent inhibitor of FGFR's 1,2 and 3 with IC50 values of 0.2, 2.5 and 1.8 nM respectively. AZD4547 is also highly selective vs. a panel of over 70 other kinases (no activity at 10 μM) and importantly vs. kinase insert domain receptor (KDR) (>120-fold window in cellular assays vs. FGFR2).

In vitro treatment of a large panel of cell lines (>100, representing several tumor types) with AZD4547 resulted in varying antiproliferative responses, the most potent of which were almost exclusively confined to those cell-lines in which FGFR signaling was deregulated by either gene amplification, mutation or translocation. Treatment of these sensitive cell lines with AZD4547 for 1 hr, demonstrated potent inhibition of phosphorylation of FGF receptors and downstream substrates including pFRS2α and p44/42 MAPK. The antiproliferative effects of AZD4547 appear to be cell line dependent and vary between potent G1-phase cell cycle arrest and apoptotic induction. Chronic in vivo dosing of AZD4547 up to 12.5 mg/kg qd was well tolerated and resulted in dose-dependent growth inhibition in KMS11 (FGFR3 translocated, multiple myeloma) and Snu16 (FGFR2 amplified, gastric) tumour xenograft models. This in vivo antitumor activity is correlated with exposure to AZD4547 and associated pharmacodynamic modulation of phospho-FGFR and downstream substrates. In addition to the single-agent efficacy, combining of AZD4547 with cytotoxic agents, currently used for the treatment of gastric cancer patients, revealed enhanced growth inhibition of Snu-16 xenografts.

Collectively, these data confirm the suitability of AZD4547 as a potent and selective agent for the therapeutic treatment of tumors with deregulated FGF/FGFR signaling.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr DDT01-01. doi:10.1158/1538-7445.AM2011-DDT01-01
Abstract DDT01-02: CH5424802: A selective ALK inhibitor
Authors: Sakamoto Hiroshi , Oikawa Nobuhiro , Tsukuda Takuo , Shimma Nobuo , Ishii Nobuya , Aoki Yuko
Published: June 2012

Recent development of targeted protein kinase inhibitors provides new opportunity in cancer treatment. On the other hand, there are some cases limiting the efficacy of cancer therapies, owing to narrow therapeutic index by inhibiting multiple kinase, and the emergence of resistant mutants. Thus, the development of kinase inhibitors with more potent and selective properties and effectiveness to resistant mutants is needed. Anaplastic lymphoma kinase (ALK) is a tyrosine kinase that is constitutively activated in some cancers, due to gene alterations such as chromosomal translocation, amplification, or point mutation. Here we have identified CH5424802, a potent, selective and orally available ALK inhibitor with a new chemical scaffold. CH5424802 showed preferential antitumor activity against cancers with gene alterations of ALK, such as non-small cell lung cancer (NSCLC) cells expressing EML4-ALK fusion, anaplastic large-cell lymphoma (ALCL) cells expressing NPM-ALK fusion, and neuroblastoma with gene amplification of ALK in vitro and in vivo. Also, CH5424802 could inhibit ALK L1196M, which corresponds to the gatekeeper mutation conferring common resistance to kinase inhibitors, and block the growth of EML4-ALK L1196M-driven cells. CH5424802 is currently being investigated in phase I/II clinical trials for patients with ALK-positive NSCLC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr DDT01-02. doi:10.1158/1538-7445.AM2011-DDT01-02
Abstract LB-113: Non-small cell lung cancer cells with high ALDH1 activity display cancer stem cell properties and show chemoresistance
Authors: Wong S , Leung E , Tin V , Wong M
Published: June 2012

Introduction Cancer stem cells (CSC) are believed to possess tissue stem cell-like properties such as self-renewal and toxicity resistance. These characteristics would facilitate tumor propagation and development of chemoresistance. The biology and regulation of CSC have mostly been studied in acute leukemia and certain solid tumors such as breast cancer. Relatively little data are available regarding CSC in non-small cell lung cancer (NSCLC) due to the lack of a specific CSC marker. This study aims to analyze the applicability of candidate CSC markers by utilizing chemotherapy treatment to enhance CSC proliferation in NSCLC cells. Methodology The expression or activity of 4 putative stem cell markers, CD24, CD44, CD133 and aldehyde dehydrogenase (ALDH1) were measured by flow cytometry in the NSCLC cell lines H1650, HCC827 and H358 before and after chemotherapy treatment for 24 hours. Tumor cells with enhanced marker expression after treatment were regarded as potential CSC, and were selected by fluorescence-activated cell sorting (FACS). Functional analysis was used to test for CSC properties in the marker+ and marker-subpopulations of untreated cells. The expression of genes involved in tissue stem cell functions were also compared by quantitative RT-PCR. Results Flow cytometry analysis showed amongst the 4 markers, only ALDH1+ subpopulation was significantly enhanced by chemotherapeutic treatment, suggesting ALDH1 could be a CSC marker. Untreated ALDH1+ cells formed significantly higher numbers and larger cell spheres in non-adherent culture medium than ALDH1− cells. Likewise, ALDH1+ cells formed significantly more and larger colonies in colony formation assay. Furthermore, MTT assay demonstrated higher resistance to cisplatin and etoposide treatments in ALDH1+ than ALDH1− cells. In addition, ALDH1+ cells showed more prominent tumorigenicity than ALDH1− cells in vivo; as few as 500 ALDH1+ cells formed xenograft tumor in SCID mice which were serially transplantable to 2nd and 3rd recipients, while no tumor was formed from ALDH− cells. Finally, expression analysis of sorted cells revealed higher expression of the pluripotency genes, OCT4, NANOG, BMI1 and SOX9, in ALDH1+ cells. Conclusion NSCLC cells expressing ALDH1 displayed higher capacity for cell renewal, tumorigenecity and drug resistance, as well as showed higher expression of pluripotency genes, suggesting that ALDH1 could be a useful CSC marker in NSCLC. Pathways mediated by the differentially expressed genes studied could be involved in CSC maintenance and/or chemoresistance in NSCLC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-113. doi:10.1158/1538-7445.AM2011-LB-113
Abstract LB-138: TAZ antagonizes the WWP1-mediated KLF5 degradation and promotes breast cell proliferation
Authors: Zhao Dong , Zhi Xu , Zhou Zhongmei , Chen Ceshi
Published: June 2012

Krüppel-like factor 5 (KLF5) is a PY motif-containing transcription factor promoting breast cell proliferation. The KLF5 protein is rapidly degraded through the proteasome after ubiquitinated by E3 ubiquitin ligases, such as WWP1 and SCFFbw7. In this study, we demonstrate that transcriptional co-activator with PDZ binding motif (TAZ) upregulated KLF5 through antagonizing the WWP1-mediated KLF5 ubiquitination and degradation. TAZ interacted with KLF5 through the WW domain and the PY motif, which is the binding site of WWP1. TAZ inhibited WWP1-mediated KLF5 ubiquitination and degradation. Overexpression of TAZ up-regulated the protein levels of KLF5 and FGF-BP, which is a well established KLF5 target gene. In addition, depletion of TAZ in both 184A1 and HCC1937 breast cells dramatically down-regulated protein levels of KLF5 and FGF-BP and inhibited cell growth. Furthermore, stable depletion of either TAZ or KLF5 significantly suppressed HCC1937 xenograft growth in SCID mice. Knockdown of LATS1, a TAZ upstream inhibitory kinase, up-regulated the protein levels of KLF5 and FGF-BP in 184A1 and promoted cell proliferation through TAZ. Finally, both KLF5 and TAZ are co-expressed in a subset of ER-negative breast cell lines. These results, for the first time, suggest that TAZ promotes breast cell growth partially through protecting KLF5 from WWP1-mediated degradation, and enhancing KLF5's activities. This study is supported by a grant from the American Cancer Society (RSG-08–199–01) and a grant from the Department of Defense (W81XWH-07–1–0191).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-138. doi:10.1158/1538-7445.AM2011-LB-138
Abstract LB-145: Absence of pro-apoptotic protein Bax extended the life span of ku70−/− mice with accelerated aging phenotype
Authors: Ngo Justine , Matsuyama Mieko , Watanabe Michiko , Gerson Stanton , Smith Mark , Matsuyama Shigemi
Published: June 2012

Bax is a proapoptotic Bcl-2 family protein. Previously, we found that Ku70 functions as a Bax inhibitor in the cell. Ku70 is 70 kDa protein expressed in the cytosol and nucleus, and Ku70 is required for the nonhomologous end-joining (NHEJ) pathway of DNA double strand break (DSB) repair in the nucleus. In the cytosol, Ku70 binds to Bax, and this interaction inhibits the cytotoxic activity of Bax. Ku70 null mice show a premature aging phenotype due to the absence of NHEJ-dependent DSB repair. We hypothesized that increased sensitivity to Bax-mediated cell death may contribute to the disease phenotype of Ku70 null mice. To determine our hypothesis, ku70−/−bax+/− and ku70−/−bax−/− mice were generated (all mice were on C57BL background). Interestingly, both ku70−/−bax+/− and ku70−/−bax−/− had a longer life spans than ku70−/− mice. The 50% mortality of ku70−/−, ku70−/−bax+/−, ku70−/−bax−/− was 21 weeks (n=36), 36 weeks (n=20), and 37 weeks (n=7) respectively. Some of these mutant mice developed T-lymphoma (ku70−/− (17%<), ku70−/−bax+/− (33%), and ku70−/−bax−/− (20%)). Ku70−/− MEFs (mouse embryonic fibroblasts) showed increased apoptosis sensitivity and accelerated cellular senescence during passage in comparison with wild type MEFs, as previously reported. ku70−/−bax+/− and ku70−/−bax−/− showed significantly higher survival in the apoptosis sensitivity test than ku70−/− MEFs. Cellular senescence of MEFs was analyzed including expressions of senescence associated β-galactosidase and phospho-γ H2AX. Bax deficiency did not show significant effects on the onset of cellular senescence of ku70−/− MEFs. The lung alveoli of ku70−/− mice were structurally normal (single alveolar cell layer); however, the lungs of ku70−/−bax+/− and ku70−/−bax−/− mice had abnormal multiple alveolar cell layers. The mechanism of this abnormal alveolar development is under investigation. We analyzed histology of several organs, blood cell count, and locomotion activities of these mutant mice. These data suggest that Bax-deficiency improved the overall health condition of Ku70 null mice. Previous studies demonstrated that p53 deletion was not able to extend the life span of Ku70 or Ku80 null mice due to increased cancer development (Li et al. 2009). In addition, p21 deletion was not able to extend the life span of Ku80 null mice even though p21 deletion significantly delayed cellular senescence of Ku80 null MEFs (Zhao et al, 2009). The present study suggests that increased Bax-mediated apoptosis rather than increased cellular senescence may be the major cause of the shortened life span of Ku70 null and NHEJ-defective mutant mice.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-145. doi:10.1158/1538-7445.AM2011-LB-145
Abstract LB-148: XBP1 regulates NFkappaB signaling in antiestrogen resistant breast cancer cells
Authors: Hu Rong , Eltayeb Ahreej , Shajahan Ayesha , Riggins Rebecca , Clarke Robert
Published: June 2012

Unfolded protein response (UPR), a stress-induced survival mechanism, may be hijacked by cancer cells to avoid cell death. Therefore, the functional role of UPR during drug resistance has attracted an increasing amount of attention recently. Antiestrogen therapy, used in the treatment of estrogen receptor-positive (ER+) breast cancer, induces UPR. Upon endoplasmic reticulum stress, three arms of UPR signaling become activated to cope with stress conditions. One critical player that is regulated by two arms of the UPR signaling is a transcriptional factor called X-box binding protein 1 (XBP1). XBP1 exists in two forms, the transcriptionally inactive unspliced XBP1(U) and the spliced, actived XBP1(S). We have previously shown that overexpression of XBP1(S) confers estrogen independence and antiestrogen resistance in ER+ breast cancer cells. Others subsequently reported that XBP1(S) expression in ER+ breast tumors correlates with poor clinical responsiveness to Tamoxifen. However, the underlying signaling mechanisms affected by XBP1(S) as well as the effects of splicing on antiestrogen resistance remain unclear. We hypothesize that XBP1(S) mediates antiestrogen resistance in part through regulating nuclear factor kappa B (NFkappaB) signaling, since we previously showed that NFkappaB expression and activity are up-regulated in antiestrogen resistant cells, possibly through up-regulation of IKKgamma (NEMO) and RelA (NFkappaB p65). We now show that XBP1 regulates the expression of RelA in breast cancer cells. Overexpression of XBP1 in MCF7 and LCC1 antiestrogen sensitive breast cancer cells results primarily in an increase in XBP1(S) and an induction of RelA expression at both the mRNA and protein levels. We also show that NFkappaB transcriptional activity is upregulated by XBP1 overexpression. Moreover, the antiestrogen resistance conferred by XBP1 overexpression in MCF7 cells requires activated NFkappaB signaling. The presence of small molecule NFkappaB inhibitor, Parthenolide, sensitizes XBP1 ovexpressing MCF7 cells to Tamoxifen. Depletion of endogenous XBP1 using siRNA in antiestrogen resistant LCC9, LY2, and MCF7-RR breast cancer cells decreases RelA expression and NFkappaB transcriptional activity. Taken together, our findings establish a regulatory link between the UPR/XBP1 pathway and pro-survival NFkappaB signaling. Currently, we are actively investigating the role of XBP1 splicing in regulating NFkappaB signaling and antiestrogen resistance with a non-splicible mutant of XBP1 (XBP1(nonS)). In future studies, we will identify the pathways induced by XBP1/NFkappaB signals and further delineate their role in antiestrogen resistance in ER+ breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-148. doi:10.1158/1538-7445.AM2011-LB-148
Abstract LB-153: Introduction of Th1 help by a novel cancer vaccine, helper/killer hybrid epitope long peptide (H/K-HELP): From basic to clinical study
Authors: Nishimura Takashi , Ohkuri Takayuki , Wakita Daiko , Kitamura Hidemitsu
Published: June 2012

Using mouse tumor model, we have demonstrated that there are strong immunosuppressive tumor escape mechanisms in tumor-bearing hosts. Especially, we have emphasized the following three mechanisms; (i) CD133+ cancer-stem cells (CSC) produced high levels of active TGF-β and they are resistant to CD8+ T cell-mediated immunosurveillance via inducing regulatory T cells (Tregs); (ii) Immature myeloid cells (ImC), which are abnormally increased in tumor-bearing mice, are classified into three distinct populations and MΦ-ImC and NeutSeg-ImC, but not NeutStab-ImC act as myeloid-derived suppressor cells (MDSC); (iii) IL-17-producing γδ T cells act as protumor cells during carcinogenesis and tumor progression via promoting angiogenesis. We have proposed that Th1-dominant immunity played a critical role for overcoming such immunosuppressive tumor-escape mechanisms to induce tumor-specific memory and CTL, which are essential for the cure of tumor. In addition, we have reported rational strategies such as Th1 cell therapy and its combination with chemo or radiation therapy. To apply these basic findings to a clinical trial, we first identified a novel helper epitopes of MAGE-A4 and Survivin tumor antigens, which can activate tumor-specific Th1 cells by combination with Th1 adjuvant, OK-432. To induce an efficient Th1-dependent antitumor immunity, we further developed a novel cancer vaccine, artificial helper/killer hybrid epitope long peptide (H/K-HELP) of MAGE-A4 or Survivin. In phase I study, H/K-HELP consisted of both killer and helper epitopes was mixed with adjuvants (OK-432 and Oil adjuvant) and subcutaneously administered into cancer patients 4 times with 2 wks interval. Both MAGE-A4-H/K-HELP and Survivin-H/K-HELP induced tumor-specific Th1 and Tc1 immune responses and tumor-specific C-fixing antibody (IgG1 and IgG3) responses in cancer patients. H/K-HELP vaccination inhibited the growth of tumor in patients with melanoma and colon cancer. Moreover, H/K-HELP vaccination induced a complete regression of chemo and radio-resistant lateral deep cervical node recurrence of triple-negative breast cancer. Thus, our results propose that H/K-HELP vaccination or its combination with Th1 cells will become a promising tumor vaccine/cell therapy of human cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-153. doi:10.1158/1538-7445.AM2011-LB-153
Abstract LB-217: Long term safety observed with CEQ508: An oral RNAi drug targeting β-catenin of GI polyps
Authors: Silva Alison D. , Vaze Moreshwar B. , Borrelli Alex , Kotadia Naimesh J. , Lamriben Lydia , Polisky Barry
Published: June 2012

Marina Biotech is developing a proprietary drug discovery and delivery platform called transkingdom RNAi (tkRNAi), to develop RNAi-based therapeutics in which non-pathogenic bacteria are engineered to: (1) express short hairpin RNA (shRNA), (2) invade via a specific cell surface receptor and (3) deliver shRNA to the cytoplasm of a targeted cell. CEQ508, an E. coli derivative delivered orally, is the first drug candidate utilizing this approach. CEQ508 expresses a shRNA directed against β-catenin, and has been shown in previous work to significantly reduce β-catenin mRNA levels in vitro and in vivo. In the colorectal cancer cell line, SW480, we observed 90% suppression of β-catenin mRNA. In the non-human primate distal ileum 65% knockdown of β-catenin mRNA was detected. β-catenin is a key oncogene implicated in Colorectal Cancer (CRC) and Familial Adenomatous Polyposis (FAP). FAP is a hereditary disease in which the formation of hundreds of polyps in the gastrointestinal tract ultimately leads to the development of colon cancer. CEQ508 will be tested in a Phase Ib/IIa clinical trial in FAP patients at Massachusetts General Hospital with first patient dosing expected in the first quarter of 2011. CEQ508 was recently granted orphan drug status for the intended treatment of FAP patients by the FDA's Office of Orphan Products Development.

In preparation for later pivotal clinical trials, we recently completed a 9 month GLP non-human primate toxicology study assessing the safety of daily, oral chronic administration of CEQ508. In this study, 18 animals were dosed with either CEQ508 or two control articles. No CEQ508-related adverse responses were identified in the following study parameters analyzed: clinical observations, body weights and temperatures, serum chemistry, coagulation, hematology, urinalysis, cytokines and gross pathology. Preliminary conclusions identify the No Observed Adverse Effect Level (NOAEL) for long-term daily oral administration of CEQ508 as 1×1011 colony forming units (cfu)/day. In addition to presenting additional details of long term toxicology study, a clinical update on our Phase Ib/IIa trial will be provided.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-217. doi:10.1158/1538-7445.AM2011-LB-217
Abstract LB-218: Profiling kinase inhibition in cancer cell extracts using active-site probes and targeted high resolution, accurate mass spectrometry
Authors: Bomgarden Ryan D. , Peterman Scott M. , Viner Rosa I. , Rosenblatt Michael M. , Etienne Chris L. , Rogers John C.
Published: June 2012

Protein kinases are enzymes that play key roles in signal transduction pathways which regulate cellular processes including growth, division, differentiation and metabolism. Kinase inhibitors are essential tools used by researchers to understand kinase function and are also therapeutic compounds used in treating cancer and other diseases. Active-site probes are one technology that can be used to determine the specificity and potency of kinase inhibitors. Desthiobiotin-ATP and -ADP are two nucleotide derivatives that have been shown to selectively label kinase active sites. Using these probes to enrich kinase active-site peptides, we identified over 150 kinases from K562 chronic myelogenous leukemia and A549 lung carcinoma cell extracts using high resolution, accurate mass (HR/AM) spectrometry. We also assessed specificity of kinase inhibitors including staurosporine and wortmannin by determining the relative quantitation of kinase active-site peptides after drug treatment. In addition, we validated kinase inhibitor targets using a parallel Western blot workflow. Overall, kinase inhibition measured using high resolution, accurate mass spectrometry had strong correlation with Western blot data and enabled global profiling of kinase inhibitor target and off-targets.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-218. doi:10.1158/1538-7445.AM2011-LB-218
Abstract LB-228: Resistance to BRAF inhibition in BRAF V600E colorectal cancer is associated with PI3K/AKT activation and hypermethylation
Authors: Mao Muling , Tsao Lawrence , Dayyani Farshid , Nanda Vashisht Gopal Yennu , Mills Gordon , Bollag Gideon , Davies Michael , Gallick Gary , Kopetz Scott
Published: June 2012

BRAF V600E mutation has been detected in approximately 8% of metastatic colorectal cancers (CRC) and results in constitutive activation of BRAF and the downstream MEK-ERK1/2 pathway. PLX4032, a selective inhibitor of BRAF V600E, has shown meaningful activity in melanoma (greater than 70% response) but only modest activity in BRAF V600E CRC (5%). The resistance of BRAF V600E CRC to BRAF inhibitors has been poorly understood. To explore these differences, BRAF V600E CRC cell lines were compared to BRAF V600E melanoma cell lines by reverse-phase proteomic array, which demonstrated higher levels of phospho-AKT and associated downstream pathway activation in CRC cell lines. Both colorectal cancer cells inherently resistant to PLX4720, an analog of PLX4032, and resistant subclones that were derived from BRAF V600E positive cells, showed increased expression of phospho-AKT and phospho-GSK3β, despite the sustained ability of PLX4720 to effectively inhibit MEK signaling. Silencing of PTEN, which in turn induced AKT activation, desensitized cells to the BRAF inhibitor. Furthermore, combined treatment of PLX4720 with two different PI3K inhibitors, LY294002 and GDC-0941, synergistically inhibited growth in a panel of BRAF V600E cells through both apoptosis and G1 phase arrest. It has been previously shown that BRAF V600E colorectal cancers are commonly associated with the CpG island methylation phenotype (CIMP), which is associated with epigenetically diminished PTEN expression. Combination treatment with the demethylating agent azacitadine and PLX4032 was also synergistic in cell lines with intact but suppressed PTEN, and was associated with PTEN re-expression. This was not seen in non-CIMP or PTEN BRAF V600E cell lines. Thus, colorectal cancer cells appear to escape BRAF targeting through a mechanism of increased PI3K/AKT activity, providing evidence to support investigation of new combination therapies with PI3K/AKT pathway inhibitors or demethylating agents.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-228. doi:10.1158/1538-7445.AM2011-LB-228
Abstract LB-23: In vivo exposure of infant leukemia to the BH3-mimetic ABT-263 selects for a cell death-resistant phenotype
Authors: High Laura M. , Papa Rachael A. , Armstrong Scott A. , Lock Richard B.
Published: June 2012

The development of acquired resistance to chemotherapy in the clinic remains a major obstacle to improve patient outcome and a better understanding of the underlying molecular events is essential to target refractory cancers, including leukemia. Infants with acute lymphoblastic leukemia involving translocations of the mixed-lineage leukemia (MLL) gene have a poorer prognosis than other age groups and this has been attributed to early relapse and resistance to traditional chemotherapies. The purpose of this study was to assess the in vivo sensitivity and mechanisms of resistance of a panel of 8 MLL xenografts established from primary biopsies in immune-deficient (NOD/SCID) mice to the BH3-mimetic and Bcl-2, Bcl-XL and Bcl-W inhibitor ABT-263. Leukaemia engraftment and progression were assessed by flow cytometric enumeration of the proportion of human CD45+ cells in the peripheral blood at weekly intervals. ABT-263 (100 mg/kg daily × 21 per oral gavage) significantly delayed the progression of 8/8 xenografts compared with vehicle-treated controls (p < 0.05), with progression delayed by between 2 and 27 days across the entire panel. However, quantification of Bcl-2 protein family members by immunoblot did not reveal that expression of a single member significantly correlated with in vivo ABT-263 sensitivity. Continuous ABT-263 treatment of xenografts in vivo resulted in the outgrowth of 5 independent ABT-263-resistant xenograft lines. Resistance was confirmed to be approximately 15-fold compared with passage-matched controls by in vitro cytotoxicity assay (n = 6; p < 0.0001). Subsequent inoculation of ABT-263-selected xenograft lines into NOD/SCID mice also confirmed their in vivo resistance compared with passage-matched controls. ABT-263-selected lines showed a 5-fold increase in cell viability compared with passage-matched control lines after 4 days of ex vivo culture (p = 0.02). Moreover, the ABT-263-selected cells were significantly resistant in vitro to 2 established drugs used in the treatment of pediatric acute lymphoblastic leukemia, dexamethasone (p = 0.001) and daunorubicin (p = 0.006). This cell death-resistant phenotype could not be attributed to altered protein expression of known ABT-263 resistance modifiers, including Bcl-2, Mcl-1 and Bim. In conclusion, this study has demonstrated that ABT-263 has significant in vivo efficacy against MLL xenografts derived from direct patient explants, but that ABT-263 resistance can readily arise in vivo leading to a cell death-resistant phenotype via a unique mechanism. (Supported in part by NCI NO1CM42216)

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-23. doi:10.1158/1538-7445.AM2011-LB-23
Abstract LB-242: Dissecting Cell Signaling Mediated by Multi-spanning Transmembrane Domain Association
Authors: Yin Hang
Published: June 2012

The association of protein transmembrane domains regulates many pivotal signal transduction pathways. Molecular recognition by polytopic membrane proteins is especially poorly understood due to their difficult preparation, characterization and analysis. Herein, we demonstrate a modular approach designed to study multi-spanning transmembrane domain association, using hydrophobic peptides representing individual transmembrane helices. Transmembrane helices have a high level of intrinsic stability due to the energetic requirement to sequester the polar backbone from the hydrophobic environment of the membrane causing them to adopt native-like structures in membrane-mimetic environments. Biophysical and biochemical experiments on individual transmembrane helices identified a novel protein-oligomerization hotspot for a representative membrane protein, latent membrane protein 1, and the key residue was confirmed as biologically relevant in the full-length protein. This generally applicable approach provides a novel strategy to study multi-spanning transmembrane proteins.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-242. doi:10.1158/1538-7445.AM2011-LB-242
Abstract LB-250: Establishment of a positive feedback between PGE2 and COX2 diverts DC differentiation into MDSCs and sustains their immunosuppressive functions in ovarian cancer
Authors: Obermajer Natasa , Muthuswamy Ravikumar , Lesnock Jamie , Edwards Robert P. , Kalinski Pawel
Published: June 2012

Myeloid-derived suppressor cells (MDSCs) are essential players in cancer-associated immune dysfunction. We report that the differentiation and functional stability of human monocytic MDSCs is driven by a single cancer-associated inflammatory mediator, prostaglandin E2 (PGE2), and depends on the establishment of a positive feedback between PGE2 and the key regulator of PGE2 synthesis, COX-2. PGE2 abrogates the differentiation of CD1a+ DC from monocytes, redirecting it towards CD14+CD33+CD34+ cells expressing all MDSC-associated suppressive factors: IDO, arginase, NOS2 and IL-10, and inducing their CTL-suppressive functions. Moreover, PGE2 promotes the expression of endogenous COX2 and autocrine secretion of PGE2 in MDSCs, establishing a positive feedback loop that stabilizes the MDSC phenotype. Undisturbed COX2 activity and persistent production of PGE2 by MDSCs, isolated from cancer patients, was required for their continued expression of CXCR4 and responsiveness to CXCL12. Moreover, PGE2 also proved to be the key factor promoting the production of CXCL12 in cancer microenvironment, a chemokine exerting multiple tumor-promoting effects either directly by acting on cancer cells or indirectly by inducing angiogenesis and recruiting other immunosuppressive cells, i.e. Tregs and pDCs. In accordance with the physiological role of PGE2 in the development and functional stability of human cancer -associated MDSCs, we observed that the frequencies of CD11b+ CD33+ MDSCs in the ovarian cancer (OvCa) ascites closely correlate with the local production of PGE2 and expression of COX2, while the OvCa ascites environment can promote the induction of MDSCs from differentiating monocytes in a COX2-dependent manner. Importantly. disruption of COX2-PGE2 feedback in fully-developed MDSCs isolated from cancer patients, using COX2 inhibitors or inhibitors of EP2/EP4-dependent PGE2 signaling, eliminates the production of all other suppressive factors and terminates the CTL-suppressive function of MDSCs as well as eliminates both the expression of CXCR4 on MDSCs and the production of CXCL12, highlighting the key role of PGE2 in the tumor-accumulation of immunosuppressive cells. The currently demonstrated key role of the positive COX2-PGE2 feedback loop in the differentiation and functional stability of MDSCs facilitates the targeting of MDSCs in cancer immunotherapy and facilitates the development of additional MDSC-targeting therapies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-250. doi:10.1158/1538-7445.AM2011-LB-250
Abstract LB-260: Transcriptional silencing disrupts two levels of arginine biosynthesis in glioblastoma multiforme: a novel, targeted therapeutic strategy for high grade gliomas
Authors: Syed Nelofer , O'Neill Kevin , Hughes Mark , LoNigro Christiana , Lattanzio Laura , Szlosarek Peter , Roncaroli Federico , Crook Timothy
Published: June 2012

Background: Changes in the structure and expression of enzymes involved in key metabolic pathways (such as isocitrate dehydrogenase) have been identified in glial brain tumours. To seek novel candidate brain tumour suppressors, we have performed pharmacological methylation reversal.

Methods: Methylation reversal was performed in human GBM cell lines and primary explants using 5′ azacytidine (5′AZA), coupled with micro-array analysis, in GBM. Gene expression was analysed using qPCR and western blotting and by immunohistochemistry in clinical cases of supra-tentorial adult GBM. Methylation was analysed using methylation specific PCR and quantitative pyrosequencing.

Results: Both ASS1, which encodes arginino succinate synthetase, and arginino succinate lyase (ASL) are down-regulated in GBM. Down-regulation correlates with aberrant, neoplasia-specific methylation in the CpG island of each gene and expression is restored by demethylation. Arginine starvation produced by exposure to the arginine-depleting agent pegylated arginine deiminase induces an adaptive transcriptional up-regulation of both ASS1 and ASL which is blocked in GBM cells by methylation. Cells lacking ASS1 or ASL are sensitive to arginine deprivation and die by apoptosis when treated with arginine deiminsase. In clinical cases of de novo GBM, treated by surgical debulking in our institution, ASS1 was silenced in 13/60 cases and ASL in 3/60. These cases had no expression of the proteins, as seen by immunohistochemistry, together with aberrant CpG methylation.

Conclusions: Taken together, these results identify a novel treatment strategy and suggest that ADI-PEG20 warrants evaluation in phase 2 clinical trial in ASS1 negative GBM.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-260. doi:10.1158/1538-7445.AM2011-LB-260
Abstract LB-67: From Patient to Advocate
Authors: Ford Peg
Published: June 2012

Peg Ford is a living example of two causes that have become her passion: early detection of ovarian cancer and timely referral of patients into the care of a gynecologic oncologist. Before Ms. Ford's experience with ovarian cancer, she had mostly chosen alternative healing methods. Impressed and appreciative of the diversity of care the western medical system now offers, she was directed toward advocacy to spread awareness of the benefits of interweaving both types of care.

She chose to pursue advocacy for many reasons, but most importantly to put ovarian cancer at the forefront of medical doctors' minds. Early diagnosis is crucial to saving more women's lives. The overall survival rate for ovarian cancer for five years is only 45 percent, but when the cancer is diagnosed early, survival rates greatly improve to over 90 percent. Until there is a screening test for ovarian cancer, women must rely on the awareness of medical doctors in all fields. She strives to ensure that all women have a great understanding of their bodies and act as their own advocates to get care in a timely fashion.

Ms. Ford's poster outlines her journey to becoming an advocate. After discovering an innovative educational program, “Survivors Teaching Students: Saving Women's Lives,” created by the Ovarian Cancer National Alliance, she successfully launched the program at UCSD School of Medicine for Third Year Medical Students. The course brings ovarian cancer survivors right into the classroom to share their stories with the goal of increasing awareness of the symptoms and risk factors needed for the early detection of ovarian cancer. Her poster reflects the outstanding success of the program in two short years.

Seeing the need and opportunity to reach practicing medical doctors, she teamed up with the esteemed Dr. Afshin Bahador, Gynecologic Oncologist, to participate in his grand rounds at major hospital campuses. Her commitment to tell her story whenever the opportunity presents itself: as a guest speaker, facilitator, or writer for community outreach efforts, blossoms into a voice for the ovarian cancer community on a local, state, national, and international level. Her poster outlines her diverse advocacy efforts from DoD Funding, a Research Advocacy Network's 2010 Scholar at ASCO, as a member of the Core Planning Group of COCAP, as a consumer reviewer for The Cochrane Collaboration, and as an attendee of the Salzburg Global Seminar in Salzburg, Austria. With her appreciation for the advances in research, her poster highlight's patient advocates' roles as the bridge between the scientific/medical world to the patient community and to work hand-in-hand to advance research and impact change to better serve both communities.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr LB-67. doi:10.1158/1538-7445.AM2011-LB-67
Abstract SY17-02: A systems approach to understanding tumor specific drug response
Authors: Akavia Uri David , Litvin Oren , Sanchez-Garcia Felix , Dylan Kotliar Helen C. , Kim Jessica , Garraway Levi A. , Pe'er Dana
Published: June 2012

Systematic characterization of cancer genomes has revealed a staggering complexity of aberrations among individuals, such that the functional importance and physiological impact of most tumor genetic alterations remains poorly defined. A major challenge involves the development of analysis methods to uncover biological insights from the data, including the identification of the key mutations that drive cancer and how these events alter cellular regulation.

We have developed Conexic, a novel Bayesian Network-based framework to integrate chromosomal copy number and gene expression data to detect to detect driver genes located in regions that are aberrant in tumors. The underlying assumption is that a driving mutation might be associated with a characteristic gene expression signature representing genes whose expression is modulated by the driver. Thus our score guided approach searches for genes that are both recurrently aberrant and associated with variance of expression patterns across tumor samples. This method not only pinpoints specific regulators within a large aberrant region, but also by associating drivers with gene modules whose expression vary with the driver, provides insight into the physiological roles of drivers and associated genes.

We demonstrated the utility of the CONEXIC framework using a melanoma dataset, our analysis correctly identified known drivers in melanoma (such as MITF) and connected these to many of their known targets, as well as the biological processes they regulate. In addition, it predicted multiple tumor dependencies TBC1D16 and RAB27A in melanoma and showed that tumors highly expressing these genes are dependent on the same gene for growth. Additionally, gene expression in the associated modules is altered following knockdown as predicted by our model. The identity of these drivers suggests that abnormal regulation of protein trafficking is important for cell survival in melanoma and highlights the importance of protein trafficking in this malignancy.

We also present more recent results of applying CONEXIC to additional cancers, including glioblastoma and ovarian cancers, as well as additional phenotypes including invasion and drug resistance. Together, these results demonstrate the ability of integrative Bayesian approaches to identify novel drivers with biological, and possibly therapeutic, importance in cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr SY17-02. doi:10.1158/1538-7445.AM2011-SY17-02
Abstract A13: Lineage-specific roles for the Ron receptor in prostate cancer
Authors: Paluch Andrew M. , Thobe Megan N. , Gray Jerilyn K. , Gurusamy Devikala , Waltz Susan E.
Published: June 2012

Prostate cancer is one of the leading causes of cancer-related death among men in the United States due, in part, to its aggressiveness and resistance to therapy following a remission period. Receptor tyrosine kinases are emerging as potential therapeutics in prostate cancer. One of these receptors, the Ron receptor tyrosine kinase, has been shown to be overexpressed in a variety of cancers where it modulates many cellular functions relevant to cancer such as invasion, inflammation, angiogenesis, and proliferation. Ron is expressed primarily on epithelial cells and macrophages, which are both important in regulating the prostate tumor microenvironment. Our laboratory has shown recently that crossing mice lacking the Ron receptor (Ron TK−/−) to TRAMP+ mice, which develop prostate adenocarcinomas by 30 weeks of age, leads to a significant decrease in prostate tumor mass, tumor vascularization, and proangiogenic chemokine secretion relative to TRAMP+ control mice. In addition, we have shown that loss of Ron in the myeloid lineage (monocytes and granulocytes) leads to decreases in prostate tumor establishment using an orthotopic model of prostate cancer. Given this, we therefore wished to understand what role the Ron receptor plays in specific cell types relevant to prostate cancer progression. By knocking out Ron in the prostate epithelium or myeloid lineage (monocytes, macrophages, and granulocytes) and crossing these mice onto a TRAMP background, we hope to investigate the effect of lineage-specific loss of Ron in mediating prostate cancer development and progression. We hypothesize that Ron receptor signaling in the prostate epithelium and in myeloid cells promotes prostate tumorigenesis via interdependent mechanisms. By understanding the interdependent mechanisms of Ron signaling in the prostate epithelium and myeloid lineage, our studies will identify a potential novel signaling pathway, its combined and cell-type specific role in regulating prostate tumorigenesis, and suggest novel avenues for the development of new therapies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr A13.
Abstract A19: The effect of sunitinib on the production of cytokine in H460 tumor-bearing SCID mice.
Authors: Tsai Yung-Jen , Huang Yuan-Jen , Hong Le-Mei , Chang Jia-Ming
Published: June 2012

Background: systemic inflammation is occurred patients with many different type of cancer which is associated with disease progression and therapeutic efficacy. The aim of this study was to investigate whether Interleukin 5 (IL-5), an interleukin produced by innate immune cells, and Interferon-gamma (INF-γ), the dimerized soluble cytokine produced by natural killer cells, may be stimulated by sunitinib in H460 tumor-bearing SCID mice.

Methods: NCI-H460, a lung carcinoma cell line was inoculated in SCID mice subcutaneously. The H460 tumor-bearing mice were treated with sunitinib at a dose of 40 mg/kg by gavage one per day for 15 days. At the end of treatment, mice were sacrificed and blood was withdrawn for cytokine analysis by cytometric bead-based array (CBA).

Results: results appeared that the tumor growth was inhibited by sunitinib treatment to 69.97 % inhibition. And with analysis of IL-5 and INF-γ, end levels of IL-5 and INF-γ were significantly enhanced which is correlated to sunitinib treatment.

Summary: The results indicated that analyzing IL-5 and INF-γ in treatment might be used as prognosis biomarkers for cancer treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the Second AACR International Conference on Frontiers in Basic Cancer Research; 2011 Sep 14-18; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2011;71(18 Suppl):Abstract nr A19.