bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3264: AZD8186: a potent selective inhibitor of PI3Kβ targeting PTEN-deficient tumours dependent on dysregulated PI3Kβ signalling.
Authors: Hancox Urs , Cosulich Sabina , Dry Hannah , Hanson Lynsey , Crafter Clare , Barlaam Bernard , Fitzek Martina , Ward Lara , Cumberbatch Marie , Powell Steve , Ellston Rebecca , Lawson Mandy , Wedge Steve , Harrington Liz , Green Stephen , Barry Simon T.
Published: August 2014

AZD8186 is a novel potent small molecule that targets the lipid kinase PI3Kβ with selectivity vs PI3Kα. AZD8186 reduces pAKT-S473 in the PTEN deficient MDA-MB-468 cell line with an IC50 <5nM, while in the PI3Kα-dependent PIK3CA mutant line BT474 it is 200 fold less potent. AZD8186 also demonstrates cellular activity versus PI3Kβ, inhibiting IgM-dependent pAKT-S473 with an IC50 of 15nM. In cell line panels, sensitivity to AZD8186 is associated in part with loss of PTEN function suggesting that targeting tumours that have lost normal levels of PTEN function through deletion, mutation or down regulation might enrich for sensitivity to AZD8186. Deficiencies in PTEN are described in a number of tumour types such as prostate, squamous lung, breast, renal and glioblastoma. AZD8186 has single anti-tumour activity in pre-clinical models representing each of these settings, which is associated with dynamic regulation of a number of key pathway biomarkers. Clinically, agents such as AZD8186 are likely to be used in combination. The use of AZD8186 in conjunction with either androgen therapy or docetaxol has been explored in cell lines and pre-clinical disease models. Combining AZD8186 with MDV-3100 resulted in synergistic inhibition of LNCAP prostate tumour cell growth, demonstrating the potential to combine with androgen therapy. Moreover in HCC70 (breast) and PC3 (prostate) tumour xenografts AZD8186 shows increased benefit in combination with docetaxel, demonstrating the ability to combine with cytotoxic chemotherapy. Exploration of dose and schedule revealed that efficacy can be maintained in combination with docetaxol at a lower dose of AZD8186 than required for monotherapy activity. Moreover efficacy was maintained when the frequency of AZD8186 dosing was reduced using a shorter intermittent schedule. Understanding how AZD8186 combines with standards of care for PTEN null disease segments provides important insight into how agents targeting PI3Kβ-dependent tumours may be used most effectively in the clinic.

[Current affiliation for S. Cosulich is Novartis, Basel, Switzerland.]

Citation Format: Urs Hancox, Sabina Cosulich, Hannah Dry, Lynsey Hanson, Clare Crafter, Bernard Barlaam, Martina Fitzek, Lara Ward, Marie Cumberbatch, Steve Powell, Rebecca Ellston, Mandy Lawson, Steve Wedge, Liz Harrington, Stephen Green, Simon T. Barry. AZD8186: a potent selective inhibitor of PI3Kβ targeting PTEN-deficient tumours dependent on dysregulated PI3Kβ signalling. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3264. doi:10.1158/1538-7445.AM2013-3264
Abstract 3681: Aspirin acetylates glucose 6 phosphate dehydrogenase and inhibits its activity in colon cancer cells.
Authors: Ai Guoqiang , Hagen Fred K. , Gunaje Jayarama B.
Published: August 2014

Epidemiological studies have demonstrated a significant correlation between regular aspirin use and reduced colon cancer incidence and mortality. Although a consensus is emerging on the view that aspirin has significant anti-cancer properties, it is not yet clear which pathways or molecular targets might be involved. We hypothesized that aspirin's anti-cancer effect may occur through acetylation of a panel of protein targets, including novel candidates with modulated functional activity, as a result of aspirin-mediated acetylation. In the present study, using anti-acetyl lysine antibody, we determined aspirin-mediated protein acetylation profiles in three different colon cancer cell lines namely HCT-116, HT-29 and GC3/c1, by treating cells with aspirin at different concentration, and analyzing them in Western Blot. We observed that in all cell lines tested, aspirin induced acetylation of multiple proteins in a concentration dependent fashion spanning a molecular weight range from 20 to 200 kDa. Aspirin's acetylation targets included the tumor suppressor protein p53, and glucose 6 phosphate dehydrogenase (G6PD), an enzyme in the pentose phosphate pathway. Mass spectrometry analysis of the recombinant G6PD, treated with aspirin in vitro, revealed acetylation of up to 14 distinct lysine residues, including lysine 235 at its active site. In vitro G6PD assay in lysates isolated from the cancer cell lines showed that aspirin caused a 70% decrease in the G6PD enzyme activity in HCT116 cells; however, the reduction in the enzyme activity was less in HT-29/GC3/c1 cells (up to 30%). Inhibition of G6PD activity leading to a reduction in ribonucleotide synthesis and cell proliferation may represent an important mechanism by which aspirin exerts its anticancer effects.

Citation Format: Guoqiang Ai, Fred K. Hagen, Jayarama B. Gunaje. Aspirin acetylates glucose 6 phosphate dehydrogenase and inhibits its activity in colon cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3681. doi:10.1158/1538-7445.AM2013-3681
Abstract 3728: Anti-Notch1 antibody (OMP-52M51) impedes tumor growth and cancer stem cell frequency (CSC) in a chemo-refractory breast cancer xenograft model with an activating Notch1 mutation and screening for activated Notch1 across multiple solid tumor types.
Authors: Cancilla Belinda , Cain Jennifer , Wang Min , Beviglia Lucia , Shah Jalpa , Gurney Austin , Lewicki John , Esserman Laura , Hoey Tim , Kapoun Ann M.
Published: August 2014

The Notch pathway plays a central role in embryonic development, the regulation of stem and progenitor cells, and is implicated in many human cancers. Notch1 is also known to be activated by oncogenic mutations in tumors including T cell leukemia, chronic lymphocytic leukemia and non-small cell lung cancer. Here we report the discovery of similar mutations in breast cancer. We have developed a primary human xenograft model from a patient bearing an activating Notch1 mutation and have shown that blocking Notch signaling in this model with a novel anti-Notch1 antibody, OMP-52M51, impeded tumor growth and reduced cancer stem cell (CSC) frequency. OMP-52M51 is a humanized antibody that binds with high affinity and selectivity to human Notch1 and antagonizes Notch signaling.

Additionally, we sought to determine the frequency of Notch pathway activation across a large panel of human tumors (n>600) by an immunohistochemistry assay that detects the activated form of Notch1 using a polyclonal antibody that specifically recognizes the Notch1 intracellular domain (ICD). Using this test and a rigorous H-score cut-off of 30, we found elevated Notch1 in 7-29% of the following cancers: chemo-resistant breast, gastric, cholangiocarcinoma, esophageal, hepatacellular carcinoma (HCC), and small cell lung cancer (SCLC).

The class of patients that showed the highest frequency of elevated Notch1.ICD was chemo-resistant breast cancer (∼30%). This frequency was significantly higher than in unselected breast cancer patients, suggesting that Notch1 signaling plays a significant role in breast cancer chemoresistance. Interestingly, the human xenograft model which showed sensitivity to OMP-52M51 was derived from a patient that failed to respond to pre-operative chemotherapy and developed metastatic disease following surgery. Thus, chemo-resistant breast cancer as well as the other tumors with high Notch1.ICD may represent important classes of patients who could benefit from anti-Notch1 therapy in the clinic.

Citation Format: Belinda Cancilla, Jennifer Cain, Min Wang, Lucia Beviglia, Jalpa Shah, Austin Gurney, John Lewicki, Laura Esserman, Tim Hoey, Ann M. Kapoun. Anti-Notch1 antibody (OMP-52M51) impedes tumor growth and cancer stem cell frequency (CSC) in a chemo-refractory breast cancer xenograft model with an activating Notch1 mutation and screening for activated Notch1 across multiple solid tumor types. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3728. doi:10.1158/1538-7445.AM2013-3728
Abstract 4000: Genistein-induced reduction of Wnt/beta-catenin pathway activity in colorectal cancer cell lines correlates with inhibition of proliferation and colony growth in soft agar .
Authors: Pintova Sofya , Planoutis Kestutis , Planutiene Marina , Holcombe Randall F.
Published: August 2014

Introduction. The majority of colorectal cancers (CRC) have mutationally-driven constitutive activation of the Wnt pathway. Despite this, tumor cells remain responsive to Wnt signals arising at the cell membrane through the interaction of extracellular Wnt ligands and cell surface frizzled receptors; the strength of the Wnt signal can be modified by Wnt pathway inhibitors (sFRP) in the tumor microenvironment. Genistein, a natural product from soy, is known to remove epigenetic blockage of sFRP promoters and decrease nuclear beta-catenin expression, a marker for Wnt pathway activation. In this study we have examined the effect of genistein on Wnt throughput in CRC cell lines and on proliferation in tissue culture and growth in soft agar.

Methods. Human CRC cell lines HT29, DLD1 and RKO were transfected with Wnt/beta-catenin reporter plasmids and treated with different concentrations of genistein. Pathway activity was measured using a super TOP-flash luminescence reporter construct. Proliferation was estimated with an MTT assay. A soft agar assay was utilized to define non-adherent colony formation.

Results. Genistein reduced proliferation of HT29 and DLD1 at 50uM, with an inhibitory P50 at 100uM. RKO cells were inhibited at lower concentrations. Inhibition of soft agar colony growth occurred at similar concentrations. Wnt/beta-catenin activity was significantly inhibited at 75uM for HT29 (p=0.025) and at 50uM for DLD1. The reduction in proliferation and colony growth correlated with reduced Wnt signaling, with the latter most strongly correlated (R2=0.81 vs. 0.47 for the former). Cells growing independently of anchorage were more sensitive to genistein treatment than those attached to the plastic : colony counts decreased for RKO 8-fold at 50 uM while proliferation on plastic decreased less than 4x; colony counts decreased for HT29 7-fold for at 100 uM while proliferation on plastic decreased less than 2x.

Conclusions. Genistein reduces Wnt/beta-catenin activity in CRC cell lines; this reduction correlates with cell proliferation in vitro and with soft agar colony growth. Cells growing in an anchorage-independent fashion appear more sensitive to genistein treatment. Further investigation into the mechanisms of this effect in CRC is ongoing. These data suggest that genistein may be a useful adjunctive therapy for patients with CRC.

Citation Format: Sofya Pintova, Kestutis Planoutis, Marina Planutiene, Randall F. Holcombe. Genistein-induced reduction of Wnt/beta-catenin pathway activity in colorectal cancer cell lines correlates with inhibition of proliferation and colony growth in soft agar . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4000. doi:10.1158/1538-7445.AM2013-4000
Abstract 427: c-Met reduces response to radiation in breast cancer.
Authors: Veenstra Cynthia , Pérez-Tenorio Gizeh , Fornander Tommy , Skoog Lambert , Nordenskjöld Bo , Stål Olle
Published: August 2014

The c-Met receptor promotes cell survival and proliferation by activating signalling pathways. c-Met is abundant in several cancers and in some cases it interferes with treatment response. In vitro, c-Met has been shown to be up-regulated and activated after radiation treatment, which renders the cells resistant to apoptosis and radiation. Therefore, it was hypothesised that high c-Met expression could influence response to radiation in breast cancer. In this study, it was aimed to determine the number of MET gene copies and c-Met protein expression in breast tumours. Tumours of 172 post-menopausal patients with primary breast cancer were analysed for MET using qPCR. Increased MET copy number (three or more copies) was found in 34% of the tumours. Five or more gene copies were found in 4.7% of the patients and indicated a significantly higher risk of developing distant metastasis. For the patients that received radiotherapy as the only postoperative treatment, the number of MET copies was associated with increased risk of distant metastasis. In terms of loco-regional recurrence, it was found that increased MET copy number was associated with worse response to postoperative radiation therapy compared with chemotherapy. c-Met protein analysis by immunohistochemistry in tumours of 208 pre-menopausal patients with primary breast cancer revealed that patients with low expression of c-Met responded better to radiotherapy compared with patients with a high c-Met expression. These results suggest that radiotherapy in combination with a Met inhibitor may be an option for patients with increased c-Met expression, to overcome radio-resistance.

Citation Format: Cynthia Veenstra, Gizeh Pérez-Tenorio, Tommy Fornander, Lambert Skoog, Bo Nordenskjöld, Olle Stål. c-Met reduces response to radiation in breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 427. doi:10.1158/1538-7445.AM2013-427
Abstract 4437: Regulation of FANCD2 by the mTOR pathway contributes to the resistance of cancer cells to DNA double strand breaks.
Authors: Shen Changxian , Oswald Duane , Phelps Doris , cam hakan , Pelloski Christopher E. , Pang Qishen , Houghton Peter J.
Published: August 2014

Deregulation of the mTOR pathway is closely associated with tumorigenesis. Accordingly mTOR inhibitors such as rapamycin and mTOR-selective kinase inhibitors have been tested as cancer therapeutic agents. Inhibition of mTOR results in sensitization to DNA damaging agents, however the molecular mechanism is not well understood. We found that a mTOR-selective kinase inhibitor, AZD8055, significantly enhanced sensitivity of a pediatric rhabdomyosarcoma xenograft to radiotherapy and sensitized rhabdomyosarcoma cells to interstrand crosslinker (ICL) melphalan. Sensitization correlated with drug-induced downregulation of a key component of the Fanconi anemia (FA) pathway, FANCD2 through mTOR regulation of FANCD2 gene transcripts via mTORC1-S6K1. Importantly, we show that FANCD2 is required for the proper activation of ATM-Chk2 checkpoint in response to ICL and that mTOR signaling promotes ICL-induced ATM-Chk2 checkpoint activation by sustaining FANCD2. In FANCD2 deficient lymphoblasts, FANCD2 is essential to suppress endogenous and induced DNA damage, and FANCD2-deficient cells demonstrated impaired ATM-Chk2 and ATR-Chk1 activation, which was rescued by re-introduction of wild type FANCD2. Pharmacological inhibition of PI3K-mTOR-Akt pathway in Rh30 rhabdomyosarcoma cells attenuated ICL-induced activation of ATM, accompanied with the decrease of FANCD2. These data suggest that the mTOR pathway may promote the repair of DNA double strand breaks by sustaining FANCD2 and provide a novel mechanism of how the FA pathway modulates DNA damage response and repair.

Citation Format: Changxian Shen, Duane Oswald, Doris Phelps, hakan cam, Christopher E. Pelloski, Qishen Pang, Peter J. Houghton. Regulation of FANCD2 by the mTOR pathway contributes to the resistance of cancer cells to DNA double strand breaks. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4437. doi:10.1158/1538-7445.AM2013-4437
Abstract 4532: Fluorine-18- carboplatin derivative for imaging and therapeutic applications.
Authors: Dewkar Gajanan K. , Jose Purnima , Lamichhane Narottam , Thadigiri Celina , Sundaresan Gobalakrishnan , Farrell Nicholas , Zweit Jamal
Published: August 2014

DNA-damaging agents, such as cisplatin and other platinum drugs are the largest class of anti-cancer drugs. They are most important in the clinical use for the treatment of various cancers, although ovarian cancer cells often become resistant. Besides resistance, non-specific uptake in normal tissues and related toxicity is a dose limiting factor and affects their overall effectiveness. Knowledge of the drug concentration in the tumor as well as its overall concentration in the body of a patient will be helpful in accurately predicting the overall responsiveness of a patient to the drug. This type of knowledge can be accomplished by the development of a drug analog with positron emission tomography (PET) imaging capability, so that the accumulation of the drug in the tumor and normal organs can be tracked and quantified during the course of therapy to predict its effectiveness in a patient. Therefore, we developed a novel fluorinated carboplatin derivative, towards a hybrid agent for imaging and therapy. We synthesized 19F fluorinated carboplatin derivative using 2-(5-fluoro-pentyl)-2-methyl malonic acid by co-ordination with cis-platinum aqua complex. It was then used to treat various cell lines and compared with Cis-platin and Carboplatin at different concentrations ranging from 0.001 μM to 100 μM for 72 hrs and 96 hrs. LC50 values calculated from cell viability indicate that fluorinated carboplatin is a more potent drug than Carboplatin but less effective than Cisplatin.

Table 1: LC50 values of fluorinated carboplatin and known platinum drugs Cell line Cisplatin (μM) Carboplatin(μM) Fluorinated Carboplatin (μM) 72 hrs 96 hrs 72 hrs 96 hrs 72 hrs 96 hrs COLO 205 28.78 1.35 >100 48.98 92.52 31.56 SK-OV-3 4.34 1.28 33.7 18.94 20.3 12.56 FaDu 2.77 <2 34.72 11.26 21.54 8.55 A549 11.01 3.07 56.56 31.78 41.18 24.8 A498 13.35 3.42 152.83 39.34 57.25 18.5 LNCaP 19.2 7.18 113.51 63.4 80.09 46.06 RWPE-1 6.27 <1 65.19 36.8 34.69 10.2 KB 3-1 4.13 2.04 59.82 26.08 22.76 13.46

We have also developed a microfluidic method to synthesize [18F]-2-(5-fluoro-pentyl)-2-methyl malonic acid, which will co-ordinate with cis-platinum aqua complex to yield 18F labeled carboplatin derivative. Our approach to synthesis various derivatives of 18F labeled fluorinated carboplatin will allow us to develop anticancer drugs with PET imaging capabilities.

Citation Format: Gajanan K. Dewkar, Purnima Jose, Narottam Lamichhane, Celina Thadigiri, Gobalakrishnan Sundaresan, Nicholas Farrell, Jamal Zweit. Fluorine-18- carboplatin derivative for imaging and therapeutic applications. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4532. doi:10.1158/1538-7445.AM2013-4532
Abstract 4755: Combination of PV-10 immuno-chemoablation and systemic anti-CTLA-4 antibody therapy in murine models of melanoma.
Authors: Wachter Eric A. , Blair Savannah , Singer Jamie , Dees Craig
Published: August 2014

Rose bengal disodium (PV-10) is an investigational small molecule ablative agent currently entering pivotal phase 3 clinical testing as a monotherapy for locoregional control of cutaneous metastatic melanoma. Upon intralesional (IL) administration, PV-10 localizes to the injected tumor tissues while clearing rapidly from healthy tissue. Tumor infiltration with PV-10 leads to rapid necrosis of the injected lesion, with complete resolution common within 2-8 weeks. In phase 2 testing in 80 patients with Stage IIIB-IV(M1c) melanoma, IL PV-10 elicited an objective response in injected tumors in 51% of patients (CR:25%, PR:26%) after 1-4 treatment cycles. In addition to this direct ablative effect on injected tumors, some patients achieved an objective response in their monitored untreated tumors (CR:26%, PR:7% in 42 subjects with monitored untreated lesions) in an apparent immune-mediated bystander response that highly correlated with successful ablation of their injected tumors. Treatment was generally well tolerated, with adverse events confined mainly to the injection site and no grade 4 or 5 adverse events associated with use of PV-10. Recent nonclinical testing in the B16-F10 murine melanoma tumor line has confirmed that PV-10 ablation induces tumor-specific immunity, resulting in marked suppression of synchronous lung metastases upon ablation of a flank tumor and tumor-specific IFN-γ production. In this study we assess potential benefit of combination of PV-10 immuno-chemoablation with the hamster anti-murine CTLA-4 antibody 9H10 in bilateral flank and lung metastasis models (B16-F10 melanoma in C57BL/6 mice). Results from these models will be reported and could support clinical development of combination therapy in advanced melanoma patients, such as stage IV patients with substantial tumor burden in locations inaccessible to PV-10 injection. The rapid reduction in tumor burden and tumor specific immunologic stimulation provided by PV-10 may complement the immune stimulation of anti-CTLA-4 antibodies such as ipilimumab without increased toxicity.

Citation Format: Eric A. Wachter, Savannah Blair, Jamie Singer, Craig Dees. Combination of PV-10 immuno-chemoablation and systemic anti-CTLA-4 antibody therapy in murine models of melanoma. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4755. doi:10.1158/1538-7445.AM2013-4755
Abstract 493: Antitumoral efficacy of therapeutic human anti-KIR antibody (BMS-986015/IPH2102) in a preclinical xenograft tumor model.
Authors: Sola Caroline , Chanuc Fabien , Thielens Ariane , Fuseri Nicolas , Palacios Isabelle , Blery Mathieu , André Pascale , Vivier Eric , Ugolini Sophie , Graziano Robert , Romagne François , Bonnafous Cécile
Published: August 2014

Natural Killer cells (NK cells) are lymphocytes able to recognize and kill tumors for which the expression of Major Histocompatibility Complex (MHC) class I molecules is altered. This “missing self” recognition is mediated in humans by the lack of engagement of MHC class I i.e. Human Leucocyte Antigens (HLA) molecules with NK cell inhibitory receptors that include Killer Immunoglobulin-like Receptors (KIR). Some tumors escape NK cell immune surveillance by increasing the expression of HLA molecules on their surface. Consequently, blocking interactions between KIR and HLA molecules constitutes an interesting therapeutic strategy. The anti-KIR2DL1/2/3-specific monoclonal antibody, BMS-986015/IPH2102, is a human IgG4 that is being developed for treating both hematologic malignancies and solid tumors.

In rodents, the MHC class I inhibitory system regulating NK cell activation is based on lectin-like family Ly49 but the KIR molecules are not expressed. The objective of this study was to develop a preclinical model to assess the efficacy of the drug candidate used in clinical trials, BMS-986015/IPH2102. Mice expressing the human NK inhibitory KIR2DL3, on the surface of NK cells were generated on a RAG-1deficient background (KIRtgRAG mice). The human B cell lymphoma cell line, 721.221, transduced with HLA-Cw3 molecule, a ligand of KIR2DL3, was intra-venously engrafted in these mice. The expression of HLA-C by tumor cells was sufficient to allow them to escape control of NK cells, leading to mice death in around 30 days. IPH2102 treatment increased mice survival in a dose dependent manner when injected at the same time as the tumor challenge. This protective effect was NK cell mediated and directly correlated with the duration of KIR saturation. Interestingly, BMS-986015/IPH2102 treatment also improved survival in therapeutic conditions i.e. when the antibody was injected 5 days after the tumor, also in a NK cell dependent manner.

In conclusion, this study showed efficacy of BMS-986015/IPH2102 as single agent in a HLA-Cw3-expressing tumor model and this xenogenic pre-clinical model will be an excellent tool to investigate the therapeutic benefits of combination treatments.

Citation Format: Caroline Sola, Fabien Chanuc, Ariane Thielens, Nicolas Fuseri, Isabelle Palacios, Mathieu Blery, Pascale André, Eric Vivier, Sophie Ugolini, Robert Graziano, François Romagne, Cécile Bonnafous. Antitumoral efficacy of therapeutic human anti-KIR antibody (BMS-986015/IPH2102) in a preclinical xenograft tumor model. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 493. doi:10.1158/1538-7445.AM2013-493
Abstract 4963: The dynamic change of CD47 expression promotes tumor burden, metastases and resistance of breast cancer cells to radiotherapy.
Authors: Menaa Cheikh , Fan Ming , Lu Hsien-Chen , Alexandrou Aris , Juma Shuaib , Perks Julian , Li Jian Jian
Published: August 2014

Immune tolerance towards malignant cells is responsible for tumor progression and metastases. Despite their immunogenicity, cancer cells developed sophisticated mechanisms by which they are able to neutralize and/or evade the immune-surveillance. Recently, the overexpression of CD47 has been suggested to participate in the immune escape mechanism in several malignant diseases. However, mechanisms involved in CD47 expression, especially in response to anticancer agents are not yet known. In this study, we found that CD47 is overexpressed in breast cancer cells (MCF7, MDA-231, 4T1 cells) compared to non-transformed breast epithelial cells (MCF10A) and this expression is further enhanced in response to radiation (5Gy). The expression of CD47 was found to be regulated by NF-κB through a specific responsive element in the CD47 promoter as assessed by gene deletion and ChiP assays. Furthermore, using syngeneic orthotopic 4T1 mouse model, we found that CD47 is critical for both tumor burden and metastases, since anti-CD47 (100 μg/day/mice) was able to reduce tumor growth when the antibody was injected during 4T1 inoculation (day 0) or 15th after tumor growth. Consequently, tumor size and lesions were reduced and mouse survival was increased in the presence of anti-CD47 and this effect was further enhanced with radiation (4 Gy/day for 5 days). Taken together, these data suggest that CD47 expression is a marker for tumor aggressiveness and resistance to anti-cancer agents and therefore could be a potential target to treat metastatic and recurrent tumors.

Citation Format: Cheikh Menaa, Ming Fan, Hsien-Chen Lu, Aris Alexandrou, Shuaib Juma, Julian Perks, Jian Jian Li. The dynamic change of CD47 expression promotes tumor burden, metastases and resistance of breast cancer cells to radiotherapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4963. doi:10.1158/1538-7445.AM2013-4963
Abstract 5541: Therapeutic targeting of CRM1 in ovarian cancer.
Authors: Miyake Takahito M. , Pradeep Sunila , Zand Behrouz , Dalton Heather J. , Wen Yunfei , Armaitz Pena Guillermo N. , Kauffman Michael , McCauley Dilara , Shacham Sharon , Wiktorowicz John E. , Sood Anil K.
Published: August 2014

Background: CRM1 is a nuclear export protein which increases cell viability through nuclear export signal-dependent protein exclusion of tumor suppressor proteins. Selective Inhibitor of Nuclear Exprot (SINE) is a novel class of drugs that selectively inhibit CRM1. Here, we tested the biological effects of targeting CRM1.

Methods and results: To explore the efficacy of SINE CRM1 anatgonists in ovarian cancer, we tested the selective small molecule KPT-185(in vitro) against human ovarian cancer cell lines. KPT-185 reduced cell viability in multiple (A2780, A2780CP20, IGROV-1 and SKOV3) human ovarian cancer cell lines with IC50 levels ranging from 0.2 - 0.75μM. Nuclear localization and significantly increased expression of tumor suppressor proteins (e.g., p53, p21 and Fox03a) was noted in response to KPT-185 treatment. Moreover, synergistic reduction in cell viability was noted with topotecan, cisplatin and liposomal doxorubicin (interaction index was 0.45, 0.78 and 0.59, respectively). Using the A2780 in vivo orthotopic ovarian cancer model, oral administration of KPT-330 (in vivo) monotherapy at 20mg/kg twice a week resulted in 90% tumor reduction (p<0.01). In combination with topotecan, there was 98% reduction (p<0.01) in tumor growth. KPT-330 also showed significant tumor growth inhibition in combination with weekly paclitaxel or bevacizumab. Histological examination of obtained tumor samples showed 2.5-fold increase in number of caspase-3 positive cells (p<0.01) and 0.4-fold decreased of Ki67 positive cells (p<0.05) in KPT-330 treated group. In each experiment, KPT-330 was well tolerated and no significant changes in mouse body weight were noted.

Conclusion: CRM1 inhibitor is a potent inhibitor of ovarian cancer growth and merits additional development.

Citation Format: Takahito M. Miyake, Sunila Pradeep, Behrouz Zand, Heather J. Dalton, Yunfei Wen, Guillermo N. Armaitz Pena, Michael Kauffman, Dilara McCauley, Sharon Shacham, John E. Wiktorowicz, Anil K. Sood. Therapeutic targeting of CRM1 in ovarian cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5541. doi:10.1158/1538-7445.AM2013-5541
Abstract 5647: Receptor tyrosine kinase plasticity as a mechanism of acquired resistance to cetuximab in vitro: potential for co-targeting with antibody mixtures.
Authors: Kjaer Ida , Kragh Michael , Horak Ivan D. , Pedersen Mikkel Wandahl
Published: August 2014

Cetuximab is an EGFR-blocking antibody that belongs to the first generation of monoclonal antibodies approved for treatment of head and neck squamous cell carcinoma and metastatic colorectal cancer. Although anti-EGFR therapy is clinically successful, development of cetuximab resistance is an increasing problem in the clinic. Thus, a better understanding of the mechanisms responsible for development of cetuximab resistance is valuable for development of the next generation of antibody therapeutics.

Here we report the establishment of a number of cetuximab-resistant clones derived from the cetuximab-sensitive head and neck squamous carcinoma cell line HN5. Initial characterization of the cetuximab-resistant cells shows that the total level of EGFR is lower compared to the parental cells, but that the cetuximab binding is unaltered. However, cetuximab resistant clones remain dependent on EGFR for growth and proliferation, as a mixture of antibodies targeting non-overlapping epitopes on EGFR is able to partially overcome the cetuximab-induced resistance. Inititial results indicate that the antibody mixture overcomes cetuximab resistances by inducing efficient EGFR internalization followed by lysosomal degradation of the receptor. Removal of EGFR from the cell surface blocks interactions of EGFR with other receptor tyrosine kinases (RTKs) and intracellular proteins as compensatory response to cetuximab inhibition.

The observed level of inhibition of the resistant clones by the anti-EGFR antibody mixture did not, however, induce as efficient growth inhibition as in the parental cells, indicating additional resistance mechanisms. Indeed we were able to show that adding antibodies to other RTKs to the anti-EGFR antibody mixture restored sensitivity of the resistant cells to a level similar to parental cells.

In conclusion, our results demonstrate that cetuximab resistant clones remain partially dependent on EGFR for growth and proliferation. Additional RTKs are activated as a compensatory response to the EGFR inhibition, demonstrating the plasticity of the RTK family. Our results provide a rationale for targeting multiple RTKs to overcome acquired resistance to currently approved mAbs or to delay the emerge of resistance if used upfront.

An update will be presented.

Citation Format: Ida Kjaer, Michael Kragh, Ivan D. Horak, Mikkel Wandahl Pedersen. Receptor tyrosine kinase plasticity as a mechanism of acquired resistance to cetuximab in vitro: potential for co-targeting with antibody mixtures. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5647. doi:10.1158/1538-7445.AM2013-5647
Abstract 5657: Polyamidoamine dendrimers induce epigenetic changes in cultured normal and malignant human lung epithelial cells.
Authors: Kohonen Pekka J. , Feliu Neus T. , Palmberg Lena , Karlsson Hanna L. , Wallberg Annika E. , Grafström Roland C. , Fadeel Bengt
Published: August 2014

Dendrimers constitute structurally well-defined nanomaterials that are potentially useful for a vast range of biomedical applications, including targeted cancer therapy. Polyamidoamine (PAMAM) dendrimers are a relatively unexplored material subclass from consideration of low-dose studies of toxicological and biological effects, including epigenetic changes that may link to altered cell differentiation and risk of transformation. The present study assessed cell viability, histone modifications, genome-wide DNA methylation and gene expression changes in primary human bronchial epithelial cells (PBEC) and the human alveolar epithelial cell line A549 following exposure to 4th generation PAMAM dendrimers with hydroxyl (-OH) or amino (-NH2) terminating groups. The preliminary results show that these PAMAMs can regulate DNA methylation and histone modification at micromolar levels without significant effect on cell viability (lactate dehydrogenase assay). Specific changes in DNA methylation patterns implicated inflammation-related genes, although with different results in the two model systems. The results imply epigenetic regulation of gene expression by PAMAMs, and follow up work now investigates this hypothesis. Close attention to safety issues is of paramount importance for the sustainable development of the nanotechnologies, especially for biomedical applications, and the present data may shed light on potential long-term/low-dose effects of engineered nanomaterials.

Citation Format: Pekka J. Kohonen, Neus T. Feliu, Lena Palmberg, Hanna L. Karlsson, Annika E. Wallberg, Roland C. Grafström, Bengt Fadeel. Polyamidoamine dendrimers induce epigenetic changes in cultured normal and malignant human lung epithelial cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5657. doi:10.1158/1538-7445.AM2013-5657
Abstract 658: Methylation profile of CCNA1, MGMT, HIC1, TIMP3, AIM1, DAPK and CDH1 genes in head and neck cancer.
Authors: Arantes Lidia Maria R B , de Carvalho Ana Carolina , Melendez Matias Eliseo , Tajara Eloiza Elena , Goloni-Bertollo Eny Maria , Carvalho André L. ,   Head and Neck Genome Project GENCAPO
Published: August 2014

Head and neck carcinomas are among the most frequent tumor types worldwide, with around 500,000 new cases diagnosed per year. The most common variant is the squamous cell carcinoma from the upper aerodigestive tract (HNSCC), representing 90% of these malignancies. Activation of proto-oncogenes and inactivation of tumor suppressor genes are the major genetic alterations involved in carcinogenesis. The increase in methylation in the promoter region of a tumor suppressor gene, or the lack of methylation of a proto-oncogene promoter region, can lead to progressive reduction/enhancement of its expression, resulting in its silencing, thus selecting cells with proliferative advantage. Promoter hypermethylation is considered a tumor marker in a variety of malignant neoplasias, including HNSCC. The objective of this work was to analyze the hypermethylation profile of CCNA1, MGMT, HIC1, TIMP3, AIM1, DAPK and CDH1 genes in DNA tumor samples of HNSCC patients included in Head and Neck Genome Project (GENCAPO). In this study, DNA was extracted from 33 tumor samples from HNSCC patients. Extracted DNA was submitted to bisulfite treatment and analyzed using Quantitative Methylation-Specific PCR (Q-MSP), this real-time PCR methodology allows a more objective, robust, and rapid assessment of promoter methylation status. Criteria for positive methylation of promoter regions by Q-MSP range from 0.01 to 100%. Our results showed that at least two of these genes were found methylated in 100% of the samples analyzed. In addition, the presence of promoter hypermethylation of Cyclin A1 (CCNA1) was significantly associated to absence of tobacco consumption (P=0.042). However, methylated DNA tumors were not associated with tumor site (CCNA1, P=0.55; MGMT, P=0.29; HIC1, P=1.00; TIMP3, P=1.00; AIM1, P=1.00 and DAPK, P=1.00) nor clinical stage (CCNA1, P=0.64; MGMT, P=0.38; HIC1, P=1.00; TIMP3, P=0.57; AIM1, P=0.55 and DAPK, P=1.00). In conclusion, the results suggest that hypermethylation of the CCNA1 gene is significantly associated to tobacco consumption in head and neck squamous cell carcinoma patients.

Citation Format: Lidia Maria R B Arantes, Ana Carolina de Carvalho, Matias Eliseo Melendez, Eloiza Elena Tajara, Eny Maria Goloni-Bertollo, André L. Carvalho, Head and Neck Genome Project GENCAPO. Methylation profile of CCNA1, MGMT, HIC1, TIMP3, AIM1, DAPK and CDH1 genes in head and neck cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 658. doi:10.1158/1538-7445.AM2013-658
Abstract 978: Synergistic activity of EP-100 and chemotherapies in cancer cell lines.
Authors: Leuschner Carola , Gavini Shashi , Alila Hector W.
Published: August 2014

EP-100, a targeted anti-cancer drug comprised of a lytic peptide fused to Luteinizing Hormone Releasing Hormone (LHRH), is in Phase 2 clinical trial in tumors that over-express LHRH receptors in combination with paclitaxel. It kills cancer cells by membrane disruption. EP-100 was tested in combination with paclitaxel, vinorelbine, doxorubicin, cisplatinum, vincristine and 5 fluorouracil (5FU) in vitro. The sequence of adding EP-100 to the chemotherapeutics was tested in consideration of their half-lives (hours) than EP-100 (minutes). EP-100 was added to the cells before or after treatment with the chemotherapeutics to determine the order of treatment for maximum synergy. Cells were cultured in the presence of each single agent and in combination with EP-100 for 72h. Data were analyzed as IC50 values for each single drug and the combination with EP-100. Combination indices (CI) on interaction of EP-100 and each chemotherapeutic were determined. EP-100 alone was cytotoxic at low uM concentrations in LHRH receptor (+), multi-drug resistant human uterine sarcoma cell line MES-SA-Dx5 and a human breast cancer cell line MDA-MB-231 after 72 h incubation. Both cell lines were resistant to paclitaxel, vinorelbine, vincristine, 5-FU and cisplatinum. MES-SA-Dx5 cells were resistant to doxorubicin. Addition of EP-100 to each of the chemotherapeutics increased sensitivity to all of the drugs except 5-FU (Table 1). Combinations of EP-100 with paclitaxel, vincristine, vinorelbine, doxorubicin and cisplatinum resulted in potentiation of activity in a synergistic manner for both uterine sarcoma and breast cancer cell lines. The combination effects were synergistic with CIs of 0.2. The sequence of exposure was most potent when EP-100 was given first followed by incubation with paclitaxel, doxorubicin or vinorelbine.

Table 1 In vitro activities (IC50 - nM) MES-SA-Dx5 Combination Index Potentiation MDA-MB-231 Combination Index Potentiation EP-100 Alone 3044 ± 558 1400 ± 300 Paclitaxel 33.7 ± 2.2 86.2 ± 5.9 EP100+Paclitaxel 0.014 ± 0.002 0.001 6000 15.9 ± 0.8 0.22 5.7 Vincristine 124.7 ± 16.3 26.3 ± 4.1 EP-100+Vincristine 5.7 ± 0.9 0.02 21.7 1.8 ± 0.1 0.09 15 Doxorubicin 32.6 ± 4.3 1.26 ± 0.4 EP-100+Doxorubicin 3.3 ± 0.6 0.09 9.6 1.1 ± 0.04 NA 1 Vinorelbine 63.22 ± 15.9 23.7 ± 3.4 EP-100+Vinorelbine 6.0 ± 1.6 0.06 10.5 3.1 ± 0.9 0.1 7.6 CDDP 54.5 ± 5.8 19.9 ± 6.2 EP-100 + CDDP 8.0 ± 2.6 0.2 6.8 8.1 ± 1.9 0.1 2.5

These results indicate that EP-100 synergizes with paclitaxel, doxorubicin, vinorelbine, vincristine and cisplatinum but not 5-FU in drug resistant human uterine sarcoma and breast cancer cells.

Citation Format: Carola Leuschner, Shashi Gavini, Hector W. Alila. Synergistic activity of EP-100 and chemotherapies in cancer cell lines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 978. doi:10.1158/1538-7445.AM2013-978
Abstract SY31-03: Genome regulation by long noncoding RNAs.
Authors: Chang Howard Y.
Published: August 2014

The central dogma of gene expression is that DNA is transcribed into messenger RNAs, which in turn serves as the template for protein synthesis. The discovery of extensive transcription of large RNA transcripts that do not code for proteins, termed long noncoding RNAs (lncRNAs) provide an important new perspective on the centrality of RNA in gene regulation. An emerging theme from multiple model systems is that LncRNAs form extensive networks of ribonucleoprotein (RNP) complexes with numerous chromatin regulators, and target these enzymatic activities to appropriate locations in the genome. Consistent with this notion, long noncoding RNAs can function as modular scaffolds to specify higher order organization in RNP complexes and in chromatin states. I will discuss how this mode of regulation is particularly relevant to cancer and the maintenance of genome integrity.

Citation Format: Howard Y. Chang. Genome regulation by long noncoding RNAs. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr SY31-03. doi:10.1158/1538-7445.AM2013-SY31-03
Abstract A20: IDH mutations and 2-HG selectively affect histone methylation in the endogenous setting
Authors: Lin Fallon , Saenz-Vash Veronica , Zhai Huili , Fletcher Joy , Acker Mike , Jiang David , Gounarides John , Levell Julian , Pagliarini Raymond
Published: August 2014

Highly recurrent somatic mutations in the isocitrate dehydrogenase (IDH) 1 and 2 enzymes have been identified in a variety of tumor types including GBM and glioma subtypes, acute myelogenous leukemia, chondrosarcoma, and cholangiocarcinoma, among others. Mutant IDH proteins gain a novel function: the production of the “oncometabolite” 2-hydroxyglutarate (2-HG), which accumulates in the tumors of affected patients. The similarity of 2-HG to a-ketoglutarate, a cofactor required for the function of a large number of cellular enzymes, has led to the hypothesis that 2-HG may alter the function of one or more of these enzymes. Current literature has shown that 2-HG is able to inhibit a number of epigenetic factors (i.e. Jmj-domain histone demethylases, and the TET family of methylcytosine oxidases) though most of these studies have been carried out using over-expression systems that can potentially force non-relevant phenotypes. To this end, we explored histone methylation changes in a variety of cells that harbor endogenous heterozygous IDH1/2 mutations. Using an LC-MS based method to detect histone modifications, we profiled IDH MUT vs. WT cells to evaluate which global histone methylation changes correlated with mutant IDH status and whether these changes were widespread or discrete. This unbiased search highlighted IDH-dependent modifications of Histone 3 on Lysine 9 (H3K9) as the histone mark of highest interest for further study. We followed up by assessing the sufficiency and necessity of IDH mutation and 2-HG to alter H3K9 methylation using immunoblotting techniques. Our results suggest that H3K9 methylation is particularly sensitive to mutant IDH and 2-HG, which may give us further insight into the mechanism of how mutant IDH drives tumorgenicity.

Citation Format: Fallon Lin, Veronica Saenz-Vash, Huili Zhai, Joy Fletcher, Mike Acker, David Jiang, John Gounarides, Julian Levell, Raymond Pagliarini. IDH mutations and 2-HG selectively affect histone methylation in the endogenous setting. [abstract]. In: Proceedings of the AACR Special Conference on Chromatin and Epigenetics in Cancer; Jun 19-22, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2013;73(13 Suppl):Abstract nr A20.
Abstract A32: Aberrant gene repression with H3K27me3 modification in human small cell lung cancer
Authors: Kaneda Atsushi , Sato Teruyuki , Tsuji Shingo , Isagawa Takayuki , Nukiwa Toshihiro , Ishikawa Yuichi , Aburatani Hiroyuki
Published: August 2014

Small cell lung cancer (SCLC), approximately 15% of all the lung cancer cases, is a subtype of lung cancer with poor prognosis. Expression profiling analysis of 23 SCLC cases and 42 normal tissues revealed that EZH2 and other PRC2 members were highly expressed in SCLC. ChIP-seq analysis for H3K27me3 in 3 SCLC cell lines, Lu130, H209 and DMS53, showed that genes enriched with H3K27me3 mark in SCLC were not only PRC2-target genes in ES cells, but also other genes, such as cellular adhesion-related genes. These H3K27me3(+) genes in SCLC were significantly repressed in expression, and introduction of them into SCLC cell lines lead to growth inhibition. Shorter overall survival of clinical SCLC cases correlated to repression of those H3K27me3(+) genes, including PRC target genes. Treatment with a PRC2 inhibitor resulted in growth inhibition of SCLC cell lines, indicating that high expression of PRC2 would contribute to gene repression in SCLC, and may play a role in genesis of SCLC.

Citation Format: Atsushi Kaneda, Teruyuki Sato, Shingo Tsuji, Takayuki Isagawa, Toshihiro Nukiwa, Yuichi Ishikawa, Hiroyuki Aburatani. Aberrant gene repression with H3K27me3 modification in human small cell lung cancer. [abstract]. In: Proceedings of the AACR Special Conference on Chromatin and Epigenetics in Cancer; Jun 19-22, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2013;73(13 Suppl):Abstract nr A32.
Abstract A34: Nucleosome dynamics of cell differentiation
Authors: Li Zhaoyu
Published: August 2014

Nucleosome occupancy is fundamental for establishing chromatin architecture. However, little is known about the relationship between nucleosome dynamics and initial cell lineage specification. Here, we determine the mechanisms that control global nucleosome dynamics during embryonic stem (ES) cell differentiation into endoderm. Both nucleosome depletion and de novo occupation occur during the differentiation process, with higher overall nucleosome density after differentiation. The variant histone H2A.Z and the winged helix transcription factor Foxa2 both act to regulate nucleosome depletion and gene activation, thus promoting ES cell differentiation, whereas DNA methylation promotes nucleosome occupation and suppresses gene expression. Nucleosome depletion during ES cell differentiation is dependent on Nap1l1-coupled SWI/SNF and INO80 chromatin remodeling complexes. Thus, both epigenetic and genetic regulators cooperate to control nucleosome dynamics during ES cell fate decisions. Currently, we determine whether chromatin remodeling complexes are involved in nucleosome occupation.

Citation Format: Zhaoyu Li. Nucleosome dynamics of cell differentiation. [abstract]. In: Proceedings of the AACR Special Conference on Chromatin and Epigenetics in Cancer; Jun 19-22, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2013;73(13 Suppl):Abstract nr A34.