bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3568: Characterization of AZD4547: An orally bioavailable, potent and selective inhibitor of FGFR tyrosine kinases 1, 2 and 3
Authors: Gavine Paul R. , Mooney Lorraine , Kilgour Elaine , Thomas Andrew P. , Al-Kadhimi Katherine , Beck Sarah , Coleman Tanya , Baker Dawn , Mellor Martine J. , Brooks Nigel AN , Klinowska Teresa
Published: June 2012

The fibroblast growth factor/fibroblast growth factor receptor (FGF/FGFR) signalling axis plays an important role in normal organ, vascular and skeletal development. Deregulation of FGFR signalling through genetic modification or over-expression of the receptors (or their ligands) has been observed in numerous tumour settings, whilst the FGF/FGFR axis also plays a key role in driving tumor angiogenesis. A growing body of data demonstrates that inhibition of FGFR signalling can result in anti-proliferative and/or pro-apoptotic effects, both in vitro and in vivo, thus confirming the validity of FGFR as a 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 signalling. 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 1.8nM respectively. AZD4547 is also highly selective vs a panel of over 70 other kinases (no activity at 10μM) 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) with AZD4547 resulted in varying anti-proliferative responses, the most potent of which were almost exclusively confined to those cell-lines in which FGFR signalling was de-regulated. Treatment of these sensitive cell lines with AZD4547 for 1hr, demonstrated potent inhibition of phosphorylation of FGF receptors and downstream substrates including p44/42 MAPK. The anti-proliferative 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 12.5mg/kg qd was well tolerated and resulted in dose-dependent growth inhibition in a KMS11 tumour xenograft model. This in vivo anti-tumor activity is correlated with exposure to AZD4547 and associated pharmacodynamic modulation of phospho-FGFR. These data confirm the novelty of AZD4547 as a potent and selective agent for the therapeutic treatment of tumors with deregulated FGF/FGFR signalling.

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 3568. doi:10.1158/1538-7445.AM2011-3568
Abstract 3582: Targeting the FAK amino terminus F2 subdomain to disrupt growth factor receptor protein interactions, signaling and function
Authors: Ucar Deniz A. , Magis Andrew , He Di-Hua , Ostrov David , Hochwald Steven N.
Published: June 2012

Introduction: Focal adhesion kinase (FAK), IGF-1R and the c-MET are tyrosine kinases that induce cell proliferation, invasion, metastases and survival. We have previously shown that FAK physically interacts with growth factor receptors in pancreatic cancer cells and is involved in tumor progression. Since IGF-1R and c-MET have significant structural similarity, we hypothesize that both interact with a similar conserved amino acid “patch” on FAK. We also hypothesize that this patch can be targeted with small molecules to inhibit pancreatic cancer essential signaling pathways and induce apoptosis.

Methods: Based on Lipinski rules, we screened a chemical library of 240,000 compounds against a conserved patch on the F2 subdomain of FAK using in silico high throughput screening. We obtained the top scoring compounds from the National Cancer Institute Developmental Therapeutics Program and evaluated their effects on: 1) FAK protein interactions with c-MET and IGF-1R, 2) FAK, IGF-1R and c-MET kinase activity, 3)cell viability and apoptosis, and 4) growth of Panc-1 and Miapaca-2 pancreatic cancer cells in both orthotopic and direct xenograft mouse tumor models.

Results: Based on co-immunoprecipitation assays, our lead compound blocked the interaction of FAK with both c-MET and IGF-1R in pancreatic cancer cells, without altering their kinase activity. Treatment with our lead compound led to decreased phosphorylation of AKT, inhibited cell viability and induced apoptosis in a dose-dependent manner (range 2-20μM). In addition, the combination of our lead compound with either 5-FU or gemcitabine chemotherapy resulted in a synergistic decrease in pancreatic cancer cell viability. More importantly, 10mg/kg of lead compound via subcutaneous injection, effectively (p<0.05) caused pancreatic tumor regression in vivo in both an orthotopic and direct xenograft model of pancreatic cancer. Conclusions: Our data suggest that targeting the protein interactions of FAK with growth factor receptors including c-MET and IGF-1R has specific therapeutic effects that can increase the sensitivity of pancreatic cancer cells to conventional chemotherapy.

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 3582. doi:10.1158/1538-7445.AM2011-3582
Abstract 3596: SCH727965, a cyclin-dependent kinases inhibitor, induces apoptosis in sarcoma cells through caspase 3- dependent pathway
Authors: Fu Wei , Ma Le , Chu Baoky , Wang Xue , Bagui Tapan K. , Bui Marilyn M. , Gemmer Jennifer , Altiok Soner , Letson Douglas G. , Pledger W. Jack
Published: June 2012

Sarcoma is a rare cancer in adults (1% of all adult cancers), but rather prevalent in children (about 15% of all childhood cancers). Toward the goal of developing new treatment options for sarcoma, we show that the cyclin dependent kinase inhibitor SCH 727695 (SCH) induces the apoptosis of several sarcoma cell lines including those resistant to doxorubicin and dasatinib. Also responsive to SCH were cell lines prepared in our laboratory from patients who had received adjuvant chemotherapy and explant derived from a human sarcoma xenograft in mice. Apoptosis occurred at low nanomolar concentrations of SCH, as did CDK inhibition. SCH activated the mitochondrial pathway of apoptosis as evidenced by caspase-9 cleavage and accumulation of cytoplasmic cytochrome c. SCH induced cell death in sarcoma cells that differ in RB and p53 expression. Amounts of the apoptotic proteins Bax and Bim increased in mitochondria, whereas amounts of the anti-apoptotic proteins Mcl-1 and Bcl-xL declined. Sarcoma cells apoptosed when co-depleted of CDK1 and CDK2 but not when depleted of other CDK combinations. We suggest that SCH triggers the apoptosis of sarcoma cells by inactivating CDK1 and CDK2 and that SCH may be useful for treatment of drug-resistant sarcomas.

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 3596. doi:10.1158/1538-7445.AM2011-3596
Abstract 3603: Development of novel small molecule PIM kinase inhibitors
Authors: Baldino Carmen M. , Caserta Justin , Lee Chee-Seng , Flanders Yvonne , Dumas Stephane , Li Jixian , Xu Chunping , Ning Jinying , Chen Taiping , Chen Yiyou
Published: June 2012

The PIM family of serine/threonine kinases, regulated by cytokines and growth factors, is over-expressed in multiple cancer types, including prostate tumors and hematologic malignancies. Recent reports of PIM kinase inhibitors have been implicated with anti-tumor growth activity in cancer cells and xenograft models, thus providing evidence that PIM kinases are attractive targets for anticancer drug development. Jasco Pharmaceuticals has developed a proprietary focused screening library of small molecules designed to inhibit PIM kinase activity. Kinase panel screening of the focused set identified nanomolar inhibitors from a novel chemical series. To further characterize the compounds, Jasco Pharma has established a research partnership with Crown BioScience for access to its cancer cell line and human primary tumor (HuPrime) xenograft models. The initial efforts of this partnership involved the identification of cancer cell lines which express high levels of PIM kinases for anti-proliferation studies and MOA exploration. Medicinal chemistry optimization provided a cluster of compounds with low single-digit micromolar anti-proliferation activity. These improved compounds have been demonstrated to act through a PIM driven mechanism of action, decreasing the levels of the proto-oncogene c-myc and the phosphorylation of the proteins BAD and 4E-BP1. In order to select the compounds with better in vivo drug activity, we performed in vivo PK followed by plasma protein binding assay (PPB) and drug-drug interaction (DDI) analysis instead of the whole series of in vitro ADME property assays. Four compounds were picked up for in vivo efficacy study according to their potency, in vivo pk characteristics, results of PPB and DDI. Preliminary results indicated that one compound had significant anti-tumor activity in MV-4-11 tumor models.

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 3603. doi:10.1158/1538-7445.AM2011-3603
Abstract 3605: KW-2450, a novel orally-active dual IGF1R/IR inhibitor: Antitumor effects in vitro and in vivo
Authors: Maekawa Yoshimi , Koizumi Fumito , Kashima Naomi , Suzuki Masayo , Umehara Hiroshi , Takahashi Hiroko , Nakamura Hiroaki , Nara Shinji , Nakazato Tomoyuki , Kanda Yutaka , Takahashi Takeshi , Akinaga Shiro , Shiotsu Yukimasa , Soga Shiro
Published: June 2012

KW-2450 is an orally active, multi-kinase inhibitor which inhibits both insulin-like growth factor receptor (IGF-1R) and insulin receptor (IR) with an IC50 of 7.39 nmol/L and 5.64 nmol/L, respectively. KW-2450 also exhibits inhibitory activities (>90% at 100 nmol/L) against several protein tyrosine kinases such as FAK, FLT1, FLT3, JAK2, KDR, TRKA, and Aurora A. KW-2450 inhibited the growth of various types of malignant cells, and the reduction of phosphorylated IGF-1R or IR and their downstream signalling such as phosphorylation of AKT and ERK were observed from 10 to 30 nmol/L in vitro.

The PK/PD study of KW-2450 was conducted in a human colon cancer HT-29/GFP xenograft model. The plasma concentrations of KW-2450 were measured by LC/MS/MS method and the phosphorylation status of IGF-1R (P-IGF-1R) and AKT (P-AKT) in tumor tissue were examined by Western blotting. A single oral administration of KW-2450 showed inhibition of P-IGF-1R and P-AKT in tumor tissue in accordance with the increasing plasma concentration and peaked 2 hours after the administration of the drug at doses of 10 to 80 mg/kg. In this model, KW-2450 showed a statistically significant suppression of tumor growth by oral administration at a dose of 40 mg/kg once a day for 14 days. In addition, KW-2450 at a dose of 10 mg/kg showed a potent growth inhibitory activity against a human myeloma KMS-12-BM xenograft model, which is sensitive to the compound in vitro.

In mice, KW-2450 induced an increase of plasma glucose levels at 20 mg/kg and higher in a dose-dependent manner. However, the increase in glucose was transient and it returned to normal levels within 2 hours at 20 mg/kg, 4 hours at 40 mg/kg and 8 hours at 80 mg/kg. A similar trend was seen in insulin levels which return to normal levels within 4 hours at 10 mg/kg, 8 hours at 20 and 40 mg/kg, and 24 hours at 80 mg/kg. In summary, these pharmacological studies revealed that KW-2450 could act as a potent and selective dual IGF-1R/IR inhibitor and exert antitumor effects on various types of malignant cells in vitro and in vivo, although this compound shows multi kinase inhibitory activity in a cell free system.

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 3605. doi:10.1158/1538-7445.AM2011-3605
Abstract 3607: MET inhibitor sensitivity and resistance
Authors: Krumbach Rebekka , Kelter Gerhard , Maier Armin , Fiebig Heinz-Herbert , Beckers Thomas
Published: June 2012

MET, the receptor for HGF regulates proliferation, migration and metastasis of tumor cells. However, similar to EGFR-targeted drugs, highly sensitive tumors are rare, and the reasons for response to MET targeting agents are not yet clear.

In this study we identified patient-derived tumor xenografts and cell lines sensitive to the clinically developed small molecule MET inhibitors SGX-523, PF-04217903 and JNJ-38877605. Two different assays were applied, namely a monolayer assay measuring cell proliferation and a soft agar assay measuring colony formation of xenografts derived tumor cells ex vivo. In the monolayer assay out of a panel of 42 cell lines of 15 histotypes only the Asian gastric cancer cell line MKN45 was strongly affected by MET inhibition. The NSCLC cell lines LXFA 526L and LXFL 1121L showed moderate inhibition. In the colony formation assay 68 tumors of 15 histotypes were tested. The most sensitive tumor was the xenograft GXA MKN45, which was potently inhibited by all compounds. Other tumors sensitive to at least two of the MET inhibitors were from various tumor entities: NSCL adenocarcinoma (LXFA 526, LXFA 1647) and large cell carcinoma (LXFL 1121), renal cancer (RXF 616) and liver cancer (LIXF 658). Consistent with the function of MET in anchorage independent growth, the growth inhibiting effect of the compounds on tumor cells was more pronounced in the colony formation assay compared to the monolayer assay, highlighting the importance of a three dimensional matrix for MET inhibitor efficacy.

Molecular characterization of the tumors was done to understand the basis for sensitivity or resistance. We identified LXFA 526 and LXFA 1647 with high levels of phosphorylated MET, whereas LXFL 1121 produces large amounts of the ligand HGF. Nevertheless, tumors like LXFL 1176 or RXF 1220 with activated MET were resistant. LXFL 1176 carries an activating mutation of KRAS which could cause independence from MET signaling.

For tumors which responded only weakly to small molecule MET inhibitors, combinations of MET inhibitors with selected standard-of-care chemotherapeutic drugs and targeted agents were studied and data are presented.

In conclusion, only selected NSCL and gastric cancer are sensitive to MET inhibition due to defined genetic alterations. Although MET inhibitors are not broadly active as single agents, combinations with selected drugs have high clinical potential.

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 3607. doi:10.1158/1538-7445.AM2011-3607
Abstract 3609: Homology structure-based design, synthesis and biological evaluation of a series of novel Axl and Mer kinase inhibitors
Authors: Mollard Alexis , Warner Steven L. , Call Lee , Wade Mark , Bearss Jared , Verma Anupam , Yang Mei , Sharma Sunil , Bearss David J. , Vankayalapati Hariprasad
Published: June 2012

Axl and Mer kinases belong to the TAM family that was first identified as a transforming gene in chronic myeloid leukemia. Its intracellular region has the typical receptor tyrosine kinase (RTK) structure and its extracellular domain is similar to cadherin-type adhesion molecules in that it is composed of fibronectin type II and immunoglobulin (Ig) motifs. Axl binds various growth factors, with vitamin K-dependent protein growth-arrest-specific gene 6 (GAS6) being the best studied. Axl is involved in mesenchymal and neuronal development as well as in cell survival, adhesion and blood vessel function. High levels of Axl are found in various tumors, including malignant glioma and metastatic colon, ovarian and breast cancers, and it plays a role in cancer invasion. Recent development of Axl inhibitors suggested that inhibition of Axl activity may be impact both tumor angiogenesis and tumor growth. We describe here the design, synthesis, molecular modeling, and biological evaluation of a series of small molecule, inhibitors of Axl and Mer kinases. Our initial lead compound was identified via cross-docking experiments utilizing the homology model of Axl kinase and screening of a diverse in-house chemical library. We subsequently carried out structure-activity relationship studies and optimized the lead structure which has 2 to 6.1 μM inhibition activity to 2-fold improvement in the Axl and Mer kinase activities to 730 nM. As a starting point for further optimization, it was considered that the modest of these series could be improved by introducing a spacer at the aryl piperazine moiety and focused on maximizing the in vitro potency, addressing the SAR and molecular properties. We further explored Leu620, hydrophobic, Gly543, Phe547 and DFG motif sites through scaffold hoping lead to the identification of an electron-withdrawing functional groups lead to the compound HCI-2084 and HCI-2091 which exhibited potent Axl kinase inhibition activity of 7 and 12 nM in Axl kinase assay and 30-50 nM is panel of cancer cell lines. These novel series of compounds were synthesized in two-step procedure via a standard cross-coupling reaction or with various substituted aryl amine derivatives under amination conditions. In a subsequent step we employed Buchwald-Hartwig amination reaction to prepare target molecules. Due to the ready synthesis accessibility, we extensively investigated the SAR improving the RO5, solubility and permeability parameters. The details of these results will be presented.

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 3609. doi:10.1158/1538-7445.AM2011-3609
Abstract 3624: Therapeutic targeting of glioblastoma multiforme using anti-EMP2 antibodies
Authors: Fu Maoyong , Goodglick Lee , Gordon Lynn K. , Braun Jonathan , Wadehra Madhuri
Published: June 2012

Despite recent advances in molecular classification, surgery and radiotherapy, and the integration of novel molecular targeted therapies, the clinical outcome of patients with malignant brain tumors remains extremely poor. In particular, the prognosis for patients with glioblastoma multiforme (GBM), the most common and aggressive form of brain tumors, yields only a median survival of 12 months; the 5-year survival rate of less than 5%. In this report, we show that epithelial membrane protein-2 (EMP2) is a novel tetraspan protein upregulated at both the mRNA and protein levels in 95% of patients with GBM.

We have started to characterize the functional consequence of EMP2 up-regulation in GBM cells. Within these cells, EMP2 appears to orchestrate the membrane expression of proteins required for cell migration and invasion. Specifically, our past results as well as our current preliminary results strongly suggest that EMP2 modulates the repertoire of integrin heterodimers on the cell surface and stabilizes the FAK complex and signaling required for cell migration and GBM progression. We further show that this upregulation is sufficient to induce tumor growth in a number of xenograft models using immunocompromised mice.

The high expression of EMP2 on the membrane of GBM cells caused us to predict that we could exploit this increase in expression using anti-EMP2 recombinant antibodies. Using both anti-EMP2 antibody fragments (diabodies) as well as a humanized anti-EMP2 IgG1, we show that anti-EMP2 antibodies specifically induce apoptosis both in vitro and in vivo using GBM xenograft models. We have also started characterizing any potential toxicity that may arise from anti-EMP2 therapy. Importantly, no systemic or histological toxicity was observed at therapeutic doses. Thus, we predict that EMP2 expression can be targeted in GBM to develop a novel therapeutic strategy, and it may have broad applicability given that EMP2 expression is upregulated in a number of other tumors such as ovarian and 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 3624. doi:10.1158/1538-7445.AM2011-3624
Abstract 3628: The forced interaction of α4 integrin and CD44 by the novel peptide HYD1 may be a determinant of HYD1-induced cell death in multiple myeloma
Authors: Gebhard Anthony W. , Emmons Michael F. , Argilagos Raul F. , McLaughlin Mark , Koomen John , Cress Anne E. , Hazlehurst Lori A.
Published: June 2012

Our laboratory has previously shown that treatment with the novel d-amino acid peptide HYD1 (kikmviswkg) induces necrotic cell death in multiple myeloma (MM) cell lines. Furthermore, we have implicated the adhesion receptor VLA-4 as being involved in this process via shRNA silencing strategies. However, reducing α4 integrin only demonstrated partial protection indicating that other components of the HYD1 binding complex may be required for cell death. Thus, in the present study, we investigated the possible role of other adhesion molecules and/or complexes that may contribute to HYD1-induced cell death. Using an unbiased approach, we performed a total membrane pull-down with biotin conjugated HYD1 and NeutrAvidin beads on NCI-H929 MM cells. Samples were then loaded on an SDS-PAGE gel and analyzed by Mass Spectrometry. Data were then mined with the Scaffold 3 proteome software to determine pertinent hits. The adhesion receptor CD44 was determined to have the most peptide match hits and was confirmed as a valid hit via Western Blot analysis. Preliminary data using ELISA based binding studies with biotin-HYD1 as bait shows that recombinant CD44 directly binds to biotin-HYD1 in a concentration dependent manner. In order to identify complexes involved in HYD1-induced cell death, membrane immunoprecipitation assays were performed using CD44 and α4 integrin mAbs in both the presence and absence of HYD1. While Western Blot analysis confirmed basal levels of complex interactions between α4 integrin and CD44, the complex was significantly enhanced in the presence of HYD1. These data not only indicate a possible role of CD44 in HYD1-induced cell death, but also the ability of HYD1 to induce interactions among adhesion molecules and complexes. Further studies, including CD44shRNA targeting strategies, as well as looking at other adhesion molecules will be needed in order to confirm the role of individual cell surface receptors identified in the biotin-HYD1 complex in mediating HYD1 induced cell death.

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 3628. doi:10.1158/1538-7445.AM2011-3628
Abstract 3638: MM-302, HER2-targeted liposomal doxorubicin, does not impair cardiomyocyte function in vitro
Authors: Reynolds Joseph , Klinz Stephan , Leonard Shannon , Geretti Elena , Lee Helen , Eckelhofer Isabelle , Gaddy Daniel , Hendriks Bart , Wickham Tom
Published: June 2012

In HER2+ (ErbB2+) breast cancer, the ability to combine anthracyclines, such as doxorubicin, with anti-HER2 targeted therapies is limited clinically due to potential synergistic cardiotoxicity: doxorubicin directly damages heart cells and HER2 is an important mediator of cardiac repair signaling. Herein we detail findings for MM-302, a novel HER2-targeted liposomal doxorubicin formulation. The liposomal encapsulation is designed to protect the heart from doxorubicin exposure and the HER2-targeting component mediates uptake in HER2-positive cells without blocking HER2 signaling. In order to study the potential effects of MM-302 on the heart, we performed studies using Embryonic Stem Cell (ESC)-derived cardiac cells. Total cell uptake of free doxorubicin and MM-302 into ESC-derived cardiac cells was measured using HPLC. We found that, despite expressing low levels of HER2, the ESC-derived cardiac cells do not take up MM-302, whereas doxorubicin freely enters the cells in a time and dose-dependent manner over a 3 hour time course. Subsequent to delivery, cell viability was assessed in response to free doxorubicin or MM-302 at 24 hours post 3-hour exposure. Doxorubicin resulted in cell death in a dose-dependent manner, whereas MM-302 had no effect on cardiac cell viability. To understand the mechanism underlying the cardiotoxicity associated with doxorubicin exposure, and to differentiate MM-302 from existing therapies, we measured cell functional responses in ESC-derived cardiac cells, including cell stress (phopsho-p53), DNA damage (gamma-H2AX) and apoptosis (cleaved-PARP) with high-content microscopy. We demonstrated that, while doxorubicin treatment results in DNA damage, cell stress, apoptosis, and ultimately cell death in a dose-dependent manner, MM-302 does not. Our findings demonstrate that MM-302 provides a means to deliver doxorubicin to high HER2-expressing cancer cells, while sparing exposure, accumulation, and toxicity in non-target (low HER2-expressing) cells, such as cardiomyocytes. This opens an exciting avenue for potentially introducing a novel anthracycline product for the treatment of HER2+ 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 3638. doi:10.1158/1538-7445.AM2011-3638
Abstract 3643: Phosphatidylserine-targeting antibody combined with Sorafenib has strong anti-tumor activity against human hepatocellular carcinomas in mice
Authors: Cheng Xiaoyun , Thorpe Philip E.
Published: June 2012

Hepatocellular Carcinoma (HCC) is the third leading cause of cancer-related deaths in the world. The incidence of the HCC is increasing in the United States. HCC is refractory to most forms of therapy. Sorafenib is the only chemotherapeutic agent approved for the treatment of advanced HCC. Therefore, there is a huge unmet need for a new systemic therapy for HCC patients. A promising approach would be to combine sorafenib with bavituximab to treat HCC. Bavituximab is a vascular targeting antibody that is in Phase IIb clinical trials in patients with non-small cell lung cancer (NSCLC). Bavituximab targets phosphatidylserine (PS), which is normally intracellular but becomes exposed on the external surface of vascular endothelium in tumors. Bavituximab binds to PS-expressing tumor vascular endothelial cells and causes monocytes and macrophages to attack the vessels by antibody-dependent cellular cytotoxicity (ADCC). This results in death of tumor cells through deprivation of oxygen and nutrients. Chemotherapy and irradiation increase the exposure of PS on tumor vessels and enhance the anti-tumor activity of bavituximab-related antibodies in multiple rodent tumor models. We hypothesized that sorafenib would also induce exposure of PS on HCC vasculature because it interferes with anti-apoptotic signaling by VEGF and other angiogenic growth factors. We found that sorafenib induced PS exposure on human microvascular endothelial cells in vitro and in vivo. Treatment of mice bearing subcutaneous C3A, Huh7 or PLC/PRF/5 HCC tumors with sorafenib increased PS exposure on tumor vessels from 21% to 51% in PLC/PRF/5 tumors, from 22% to 67% in C3A tumors, and from 32% to 52% in Huh7 tumors. Combining a murine version of bavituximab with sorafenib significantly improved the anti-tumor effect in the PLC/PRF/5 xenograft model. The combination inhibited tumor growth by 95%, as compared with 80% for sorafenib alone (p<0.05). Bavituximab in combination with sorafenib has promise as a new systemic therapy for the treatment of advanced HCC patients.

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 3643. doi:10.1158/1538-7445.AM2011-3643
Abstract 3651: Phosphatidylserine-targeting antibody induces differentiation of myeloid-derived suppressor cells into M1-like macrophages
Authors: Huang Xianming , Ye Dan , Thorpe Philip E.
Published: June 2012

Introduction: The phosphatidylserine (PS)-targeting antibody, bavituximab, is currently in Phase IIb clinical trials in patients with lung cancer. Bavituximab, and its murine counterpart, 2aG4, induce the attack of monocytes and macrophages on PS-expressing tumor vascular endothelium and tumor cells and inhibit the immunosuppressive effects of PS in the tumor microenvironment. Myeloid-derived suppressor cells (MDSC) are one of the major cells responsible for the immunosuppressed state in tumors. In this study, we tested the influence of 2aG4 on the differentiation of MDSC into M1-like tumor associated macrophages (TAMs). Methods: MDSC were isolated from 4T1 tumor bearing mice with anti-Gr1-coated magnetic beads. The purified MDSC were then cultured for 5 days in the presence of 2aG4 or control C44 antibody. For in vivo studies, PC3 tumor-bearing mice were treated with 2aG4 for 30 days and MDSC and TAMs in tumors and spleens were analyzed by FACS and immunohistochemistry. Results: 2aG4 treatment of purified MDSC switched their cytokine production from an immunosuppressive IL-10-dominated response to a pro-inflammatory IL-12- and TNFα -dominated response. The percentage of Gr1+ cells decreased to 8% in the 2aG4-treated cultures (P<0.0001) but only to 50 – 57% in the PBS and C44-treated cultures. Treatment with 2aG4 induced the differentiation of MDSC into M1-like macrophages that expressed lower CD206 and produced more NO than control cultures. Treatment of mice bearing PC3 prostate tumors with 2aG4 decreased the percentage of MDSC from 7% to 4% (P<0.001) in the tumors and from 28% to 20% (P<0.001) in the spleens. The antibody treatment also increased the ratio of M1 to M2 TAMs in PC3 tumors from 0.7% to 1.4% (P<0.001). Conclusion: Taken together, our results suggest that 2aG4 causes the differentiation of MDSCs into macrophages having an M1-like phenotype. 2aG4 treatment decreased IL-10 production and increased IL-12 and TNFα-production. These results suggest that 2aG4 treatment reactivates innate immunity in tumors.

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 3651. doi:10.1158/1538-7445.AM2011-3651
Abstract 3659: Mast cell interactions with T-regulatory cells determine the outcome of colon cancer
Authors: Khazaie Khashayarsha
Published: June 2012

Mast cells (MCs) are a bone marrow-derived, long-lived, heterogeneous cellular population that act both as positive and negative regulators of immune responses. They are arguably the biggest chemical factory in the body, and influence other cells through both soluble mediators and cell to cell interaction. MCs are commonly seen in various tumors and have been attributed alternatively with tumor rejection or promotion properties. Tumor infiltrating MCs are derived both from sentinel resident MC progenitors as well as from recruited progenitor cells (1). MC directly influence tumor cell proliferation and invasion (2, 3), but also help shape the tumor microenvironment (1) and modulate immune responses to tumors. Best known for orchestrating inflammation and angiogenesis, the role of MCs in modulating adaptive immune responses has only recently attracted attention. MCs are responsible for expansion of lymph nodes, and recruitment of dendritic cells. MC mediate immune suppression by Treg but can also reverse suppressive properties of Treg (4) or convert Treg into TH17 pro-inflammatory cells The central role of MC in the control of innate and adaptive immunity endows them with the ability to tune the nature of host responses to cancer and ultimately determine the outcome of disease and fate of the cancer patient (5) (6).

1. Maltby S, Khazaie K, McNagny KM. Mast cells in tumor growth: Angiogenesis, tissue remodelling and immune-modulation. Biochim Biophys Acta. 2009;1796(1):19-26. PMCID: 2731828.

2. Strouch MJ, Cheon EC, Salabat MR, Krantz SB, Gounaris E, Melstrom LG, et al. Crosstalk between mast cells and pancreatic cancer cells contributes to pancreatic tumor progression. Clin Cancer Res. 2010;16(8):2257-65.

3. Cheon EC, Khazaie K, Khan MW, Strouch MJ, Krantz SB, Phillips J, et al. Mast cell 5-Lipoxygenase activity promotes intestinal polyposis in APCΔ468 mice. Cancer Research. 2010;(in press).

4. Gounaris E, Blatner NR, Dennis K, Magnusson F, Gurish MF, Strom TB, et al. T-regulatory cells shift from a protective anti-inflammatory to a cancer-promoting proinflammatory phenotype in polyposis. Cancer Res. 2009;69(13):5490-7.

5. Blatner NR, Bonertz A, Beckhove P, Cheon EC, Krantz SB, Strouch M, et al. In colorectal cancer mast cells contribute to systemic regulatory T-cell dysfunction. Proc Natl Acad Sci U S A. 2010;107(14):6430-5. PMCID: 2851977.

6. Colombo MP, Piconese S. Polyps Wrap Mast Cells and Treg within Tumorigenic Tentacles. Cancer Res. 2009.

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 3659. doi:10.1158/1538-7445.AM2011-3659
Abstract 366: Novel self-folding tricyclic cholic acid-peptide hybrids as nanotherapeutic ligands targeting prostate and breast cancers and human embryonic stem cells
Authors: Olivos David J. , Saunders Mary R. , Maeda Yoshiko , Lam Kit S.
Published: June 2012

Prostate cancer is the second leading cause of death in American men accounting for 10% of all cancer-related mortalities. According to NCI statistics from 2005-2007, 1 in 6 men will be diagnosed with prostate cancer during their lifetime. Despite the use of chemotherapy for the treatment of advanced or metastatic disease, cellular resistance to anticancer drugs and adverse side effects to healthy organs limit therapeutic efficacy. A targeted pro-apoptotic drug delivery system has been developed for the selective destruction of malignant tumors and tumorigenic stem cells. A novel self-folding tricyclic branched library was synthesized. Fixed hydrophobic amino acids near the N-terminus (position 5) of twin branched peptide arms fold back onto the hydrophobic face of the planar cholic acid molecule to form a compact tricyclic molecule. The novel bracelet library was screened using a One Bead Two Compounds (OB2C) combinatorial chemistry approach. Receptors expressed on cancerous cells serve as the targets for the tricyclic molecules to induce apoptotic signaling. Receptors for LDO 18, found on prostate cancer and stem cells, serve as the carrier vector, enabling the targeted delivery of the anticancer drug to the tumor mass. This approach spares normal tissues from toxic side effects of the peptidomimetic compounds. Preliminary studies suggest that tumors of ovarian and breast origin can also be targeted using LDO18. Lead therapeutic compounds will be conjugated to LDO18 nanocarriers along with LHRH analogues to evaluate the efficacy and combined potency to prostate, ovarian, and breast cancer xenografts in nude mice and orthotropic models.

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 366. doi:10.1158/1538-7445.AM2011-366
Abstract 3668: Single-dose activity of PSMA ADC against prostate cancer xenograft and explant tumors
Authors: Magargal Wells W. , Olson William C.
Published: June 2012

Introduction: Prostate-specific membrane antigen (PSMA) is an attractive target for antibody-targeted therapy of prostate cancer due to its abundant and selective expression on the surface of prostate cancer cells. We have generated a novel antibody-drug conjugate (ADC) by linking a fully human PSMA monoclonal antibody to monomethylauristatin-E (MMAE), a potent tubulin inhibitor. Here, we describe the use of PSMA ADC to treat SCID mice bearing LNCaP xenografts or LuCaP explants derived from surgical resections of prostate cancer patients.

Methods: PSMA expression in LNCaP and LuCaP tumor cells was evaluated by flow cytometry. Activity of PSMA ADC, assessed by decrease in tumor volume, was evaluated in LNCaP xenograft and LuCaP explant models. SCID mice were implanted subcutaneously with cultured LNCaP tumor cells or disaggregated human LuCaP 70 or LuCaP 77 prostate tumor tissue obtained from tumor-bearing mice. When average tumor size reached ∼300mm3, animals were randomized into groups of 9-10 mice and each animal was treated with a single intravenous dose of vehicle control, a control ADC of irrelevant specificity, or PSMA ADC. Treatment effects were assessed by measuring tumor volume and overall survival for up to 41 days post-treatment.

Results: Surface expression of PSMA was assessed by flow cytometry, with a rank order of expression as follows: LNCaP > LuCaP 70, LuCaP 77, LuCaP 105 > LuCaP 96.1 > LuCaP 35V, LuCaP 141. Single-dose PSMA ADC demonstrated significant activity against LNCaP xenografts at a dose of 5 mg/kg (p<0.0001 relative to either vehicle or control ADC) and against LuCaP 77 explants at a dose of 10 mg/kg (p=0.0003 relative to either vehicle or control ADC). A trend toward delayed tumor growth was observed in the LuCaP 70 tumor model.

Conclusion: Single-dose PSMA ADC showed activity against LNCaP xenografts and LuCaP explants derived from surgical resections of prostate cancer patients.

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 3668. doi:10.1158/1538-7445.AM2011-3668
Abstract 367: Engineering of targeted nanoparticles for cancer therapy using internalizing aptamers isolated by cell-uptake selection
Authors: Xiao Zeyu , Levy-Nissenbaum Etgar , Aizu Wataru , Langer Robert , Farokhzad Omid
Published: June 2012

There has been a substantial interest in the development of targeted nanoparticles (NPs) that provide increased efficacy and lower toxicity for cancer therapy. One of the major obstacles has been the paucity of optimal targeting ligands that can discriminate between the expression of antigens on cancer cells and normal cells, and subsequently deliver a therapeutic payload into the cancer cells. Using prostate cancer (PCa) as a model disease, we have addressed the difficulty by developing a “cell-uptake selection” strategy to isolate PCa-specific internalizing 2′-O-methyl RNA aptamers (Apts). Twelve cycles of selection and counter-selection were done to obtain a panel of PCa-specific internalizing Apts, with little or no internalization into non-prostate and normal prostate cells. After Apt characterization, size minimization, improvement of nuclease stabilization, and conjugation of the Apts with fluorescently-labeled polymeric NPs, the NP-Apt bioconjugates exhibit PCa specificity and enhancement in cellular uptake when compared to non-targeted NPs lacking the internalizing Apts. Furthermore, when docetaxel (Dtxl), a chemotherapeutic agent used for the treatment of PCa, was encapsulated within the NP-Apt, a significant improvement in cytotoxicity was achieved in targeted PCa cells. Further application of this Apt by conjugating with gold nanorods demostrated remarkable anti-tumor efficacy in vivo. To our knowledge, this is the first report of designing selection to enrich cancer cell-specific internalizing aptamers rather than highest affinity aptamers in previously reported selection process. A similar cell-uptake selection strategy may be used for developing specific internalizing ligands for a myriad of other diseases and can potentially facilitate delivering various molecules, including drugs and siRNAs, into 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 367. doi:10.1158/1538-7445.AM2011-367
Abstract 3679: Preliminary results from a patient group, excluded from the National Lung Cancer Screening Trial, who are at high risk for lung cancer- heavy smokers with HIV
Authors: Hulbert Alicia , Hooker Craig , Brown Travis , Horton Karen , Wrangle John , Fishman Elliott , Pelosky Kristen , Lee Beverley , Shin James , Rutlege Marian , Sam Celis , Pridham Genevieve , Lee Sue , Luong Eli , Carter Yvonne , Brown Robert , Herman James , Brock Malcolm
Published: June 2012

Purpose: Within the HIV population, the incidence of lung cancer is estimated to be 2-4 times that of the general population. Of the non AIDS associated malignancies, lung cancer is the leading cause of death among HIV patients who develop malignancy because of its advanced stage of presentation. The National Lung Cancer Screening Trial recently reported a 20% reduction in mortality for patients undergoing low dose computed tomography (CT) screening, but individuals with HIV diagnosis were excluded. To report the results of an observational pilot study of lung cancer CT screening in a cohort of HIV heavy smokers.

Materials and Methods: A prospective cohort study was performed with 185 asymptomatic individuals with confirmed HIV diagnosis who had smoked 20 pack-years or more. All participants had baseline (prevalence) chest CT scanning and 107 patients (58.2%) also received at least one subsequent annual (incidence) examination of the chest and upper abdomen. All patients underwent hand held spirometry testing, cytologic analysis of sputa, and detailed health status questioning.

Results: Of the 185 individuals, there were 31.4% females, 68.6% males, 90.3% African-Americans, 8.7% Caucasian, and 1.1% Hispanic. The median age at enrolment was 48 years, and the median number of smoking pack-years was 34. Non-calcified nodules were detected in 4 participants (2.1%) by low-dose prevalent CT compared to no nodules on incident CT scans. Only one patient with malignancy was detected (0.54%) on prevalent scanning and none on incident scanning. Stage of malignancy was advanced. No biopsies were undertaken for benign disease. CT evidence of COPD and coronary artery disease were present in 24% and 27% of patients, respectively. Additional CT findings of clinical importance were noted in the chest in 132 (71.7%) patients and extrathoracically in 30 (16.3%) of patients, respectively.

Conclusion: The prevalence results of this pilot study are in line with other observational studies of greater sample size for HIV indeterminate patients. Although the sample size is small, it suggests no elevated incidence of lung cancer in HIV heavy smokers. Although the rate of incident scanning is low, CT screening of HIV patients is feasible. This justifies accruing a larger sample of HIV patients perhaps from an already well defined, large, prospective cohort of HIV heavy smokers.

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 3679. doi:10.1158/1538-7445.AM2011-3679
Abstract 3681: Vascular endothelial growth factor receptor tyrosine kinase inhibitor inhibited mutated epidermal growth factor receptor-driven tumors ex vivo and in vivo
Authors: Kubo Toshio , Ohashi Kadoaki , Osawa Masahiro , Takeda Hiromasa , Ichihara Eiki , Ninomiya Takashi , Takigawa Nagio , Harita Shingo , Nakata Yasunari , Tanimoto Mitsune , Kiura Katsuyuki
Published: June 2012

We previously established a non-smoking-related lung cancer mouse model employing an epidermal growth factor receptor (EGFR) L858R transgenic mouse using an SP-C promoter. The mice developed pulmonary atypical adenomatous hyperplasia (AAH), multifocal adenocarcinoma, and died due to multiple invasive lung tumors at 4, 7, and approximately 40 weeks of age, respectively. We demonstrated the marked chemopreventive effect of gefitinib, an EGFR tyrosine kinase inhibitor, in a non-smoking-related lung cancer mouse model and presented a novel concept of molecular targeted chemoprevention of lung cancer in non-smokers. In this study, we focused on the expression of vascular endothelial growth factor receptor (VEGFR) -2 and vascular endothelial growth factor (VEGF) in a non-smoking-related lung cancer mouse model.

Surprisingly, we found that VEGFR-2 and EGFR were activated in the transgenic mice at 3 weeks of age by Western blotting, before the histological detection of AAH and adenocarcinoma. And fluorescent immunostaining of lung tissues in transgenic mice showed activation of VEGFR-2 occurred in tumor cells themselves or cells in an initial stage of carcinogenesis, not only in vascular endothelial cells. We also found that VEGFR-2 was activated in the lung cancer cell lines (PC-9, H3255) harboring EGFR mutation, and that EGFR-L858R transfected 293T cells expressed more phosphorylated VEGFR-2 than non-transfected 293T cells. EGFR-L858R-transfected 293T cells were more sensitive than non-transfected 293T cells to cediranib (Recentin), a pan-VEGFR tyrosine kinase inhibitor. In this mouse model, cediranib (5 mg/kg/day, 5 days/week, 12 weeks, p.o.) inhibited surface lung tumors (long axis diameter >1 mm, 0 ± 0.4 versus 4.9 ± 3.2, p < 0.01); however, cediranib could not completely suppress tumor formation microscopically.

If VEGFR-2 is activated during an early phase of carcinogenesis due to EGFR mutations, these data suggest that inactivation of VEGFR-2 may be effective in preventing carcinogenesis of non-smoking-related lung cancer. These findings provide t the new concept of VEGFR-2 role in chemoprevention.

Recentin (cediranib) is a trademark of the AstraZeneca group of companies.

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 3681. doi:10.1158/1538-7445.AM2011-3681