bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 549: Interleukin-11 induces survivin expression in brain endothelial cells
Authors: Liu Zhi , Yuan Robin , Armstrong Don , Louie Stan , Schönthal Axel H. , Chen Thomas C. , Hofman Florence
Published: February 2011

The tumor vasculature, which provides nutrients and oxygen to cancer cells, is particularly relevant in the highly vascular primary brain tumor, glioblastoma multiforme (glioma). The tumor-associated blood vessels within gliomas have been shown to be abnormal in their structure and function as compared to the normal vasculature. Previous studies from this laboratory have shown that these tumor-associated brain endothelial cells are resistant to chemotherapy; and this resistance is a result, in part, of the overexpression of survivin in these cells. Survivin, a member of the inhibitor of apoptosis gene family, is responsible for drug resistance in cancer cells, yet little is known about its role and regulation in the endothelial cells of the tumor vasculature. The mechanism of this survivin overexpression in the brain vasculature is the focus of this report. Here we present data showing that Interleukin (IL)-11, a cytokine known to stimulate survivin, is produced by human gliomas and is responsible for the increase in survivin in the brain endothelial cells. To demonstrate this, we examined glioma cell lines for IL-11 production. Our studies showed that the glioma cell lines, U87 and U251, secrete high levels of IL-11, as compared to normal cells. Furthermore, when brain endothelial cells are treated with exogenous IL-11, they exhibit increased levels of survivin, similar to the elevated basal level of tumor-associated endothelial cells. These studies suggest that tumor-derived IL-11 may play an important role in the overexpression of survivin in endothelial cells. Since survivin is important in chemoresistance, IL-11 or its receptor may be a relevant target for regulating survivin in the glioma vasculature, and thereby mediating an effective chemosensitizing mechanism and anti-vascular therapy for brain tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 549.
Abstract 5490: In vitro and in vivo evaluation of LipoFufol, a new triple stealth liposomal formulation of modulated 5-FU: impact on efficacy and toxicity
Authors: Ciccolini Joseph , Fanciullino Raphaelle , Giacometti Sarah , Vacus Joël , Mignard Caroline , Koob Zina , Iliadis Athanassios
Published: February 2011

5-FU is a mainstay for treating various solid tumors in adults, including digestive cancers. At bedside, treatment efficacy is often hampered by drug resistance and severe toxicities, mostly due to impaired liver detoxification related to dihydropyrimidine dehydrogenase (DPD) deficiency. We have developed a stealth liposomal formulation of 5-FU combined with two modulators (2′-deoxy-inosine and folinic acid) designed to exhibit higher antiproliferative properties while being less affected by liver uptake and subsequent DPD-related dysregulations. Lipofufol is a 100 nm diameter, pegylated liposome that proved to be stable at room temperature for at least 4 weeks. When used in vitro in the highly 5-FU-resistant human colorectal cell line SW620, mean IC50 values for standard 5-FU, 5-FU + folinic acid and LipoFufol were 29 µM, 14µM and 2µM respectively, indicative of a greater antiproliferative effect. Pharmacokinetics study was performed in rodents after I.V. administration and showed that liposomal 5-FU clearance was strongly reduced by 62% (e.g. 0.087 l/h VS. 0.231 l/h), as compared with standard 5-FU. Toxicity study was undertaken to check whether Lipofufol could be less toxic in DPD-deficient individuals, and confirmed that milder (e.g., neutrophils count: −75% VS. −96%) and shorter (e.g., 6 VS. 11 days) neutropenia was observed in DPD-deficient rats treated with liposomal 5-FU, as compared with deficient animals exposed to standard 5-FU. Tolerance studies and search for MTD were further performed in tumor-bearing mice and showed that LipoFufol could be administered safely up to 20 mg/kg I.V. on a 3QW basis for 3 consecutive weeks. In mice bearing LS174t human colorectal orthotopic xenografts, longer survival was achieved in animals treated with 20 mg/kg Lipofufol, as compared with animals treated with 80 mg/kg of standard 5-FU (e.g., 80% VS. 40% survival at 3 weeks). Overall, our data show that Lipofufol exhibits a greater anticancer efficacy both in vitro and in vivo, including in highly resistant models, with an optimized and safer pharmacokinetics profile skipping, at least in part, the DPD deficiency issue.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5490.
Abstract 5499: Kinase inhibitor selectivity profiling utilizing a versatile TR-FRET kinase binding assay platform
Authors: Lebakken Connie S. , Koepnick Elizabeth , Bruinsma Rica , Riddle Steve
Published: February 2011

There is great potential for the utilization of selective kinase inhibitors in the treatment of many clinical indications, especially in oncology and autoimmune conditions. Kinase inhibitor selectivity profiling has become an important tool during lead development to understand a compound's selectivity, potential off-target effects and possible new indications for the compound. We have utilized the LanthaScreen® Eu Kinase Binding Assay platform to develop a simple, robust means for profiling compounds across the kinome utilizing pre-plated reagents and controls. The assay is based on competitive displacement of a tracer (a fluorophore conjugated to a kinase inhibitor scaffold) from specific kinases of interest. Binding of the tracer to a kinase is detected by addition of a europium-labeled anti-tag antibody. Binding of the tracer and antibody to a kinase results in a high degree of FRET, whereas displacement of the tracer with a kinase inhibitor results in a loss of FRET. This platform is useful to explore activation-state binding selectivity, time-dependent binding, and binding to kinases for which substrates have not been identified. The assay detects both ATP-competitive as well as non-competitive, allosteric kinase inhibitors. We will present data demonstrating the utility of these reagents for kinase profiling efforts with a variety of kinase inhibitors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5499.
Abstract 55: Glucose metabolism influences migration of high-grade glioma in vitro by modification of TGF-beta2
Authors: Leukel Petra , Seliger Corinna , Vollmann Arabel , Doerfelt Anett , Bogdahn Ulrich , Hau Peter
Published: February 2011

Introduction: Lactate dehydrogenase type A (LDH-A) is a key metabolic enzyme catalyzing pyruvate into lactate and is excessively expressed in several human tumors. Transforming growth factor-beta2 (TGF-beta2) is a key regulator of invasion in high-grade gliomas, partially remodeling the extracellular matrix (ECM) and inducing proteinases. Thrombospondin1 (THBS-1) is an extracellular protein important for activation and processing of TGF-beta2. A microarray of LDH-A knocked-down glioma cell RNA showed down regulation of THBS-1 and TGF-beta2. In this study, we tested the hypothesis that LDH-A influences TGF-beta2 activation by up regulation of THBS-1 leading to an enhanced migration of high-grade glioma in vitro.

Methods: We performed LDH-A knock-down by transient transfection of glioma cells with small interfering RNA directed against LDH-A (siLDH-A). Expression levels of TGF-beta2 and THBS-1 in siLDH-A transfected cells were investigated using microarrays, RT-PCR, Western Blot and ELISA. Migration of transfected cells was investigated by Boyden Chamber and scratch assays.

Results: siLDH-A suppresses TGF-beta2 in high-grade glioma and decreases the expression of THBS-1 on the RNA and protein level. THBS-1 leads to an increased level of activated TGF-beta2 in supernatants of siLDH-A treated cells. In migration assays, siLDH-A leads to a decreased migration of high-grade glioma cells.

Discussion: We demonstrate, for the first time, that knockdown of LDH-A can decrease the RNA and protein level of TSP-1 and consecutively the processing of TGF-beta2. Additionally, knockdown of LDH-A decreases the RNA level of TGF-beta2. Both results may contribute to an enhanced level of TGF-beta2 and increased migration, given that LDH-A is expressed. An increased expression of LDH-A has been found in aerobic glycolysis, a mechanism well known from several human cancers. Recent paper showed that LDH-A is able to bind RNA. Thus we suppose LDH-A could influence the level of TGF-beta2 RNA by RNA stabilization. Together with our recent results that show that TGF-beta enhances migration in high-grade gliomas, we demonstrate a new panel of interactions between lactate metabolism and TGF-beta2 that might be crucial for glioma migration and possibly invasion.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 55.
Abstract 5500: Biochromatography for the screening of new drugs for the estrogen related receptors
Authors: Sanghvi Mitesh , Moaddel Ruin , Frazier Chester , Gandhari Mukesh , Wainer Irving W.
Published: February 2011

Estrogen related receptors, ERRα, ERRβ, and ERRγ, form a subfamily of orphan nuclear receptors that have significant amino acid homology with the estrogen receptors ERα and ERβ. ERRs have been identified in breast cancer tumors and ERRα has been associated with a negative response to treatment while ERRγ is considered an indicator of a positive response. We have recently demonstrated that ERRα and ERRγ are expressed in cell lines derived from astrocytoma and glioblastoma tumors. We have also demonstrated that there are different levels of expression of ERRα and ERRγ in the cell lines and this difference may be the source of the variation of these tumors to anticancer agents. MTT assays were performed to measure the metabolic activity of T98G cells treated with the ERRγ antagonists.

While ERRs share significant Ligand binding domain (LBD) homology with ERs, they have different responses to characterized ER agonists and antagonists. For example, the ER agonist estradiol is inactive in ERR expressing cell lines, the ER agonist diethyl stilbestrol is an antagonist of all three ERR subtypes, 4-hydroxytamoxifen does not affect ERRα and acts instead as an ERRγ antagonist. In addition, we have recently demonstrated that ERRα and ERRγ antagonists can effectively inhibit tumor growth. Based on this observation, we have created liquid chromatographic columns containing immobilized LBDs of the ERRα and ERRγ. In the initial study, the LBD of ERRγ was covalently immobilized onto the surface of an aminopropyl silica liquid chromatography stationary phase. The protein was immobilized via the N-terminus to create the ERRγ-column. The column was characterized using frontal chromatographic techniques and a series of tamoxifen derivatives were studied. Additionally, we have identified a second site to which diethylstilbestrol (DES) binds.

Acknowledgement

This research was supported entirely or in part by the Intramural Research Program of the NIH, National Institute on Aging.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5500.
Abstract 5503: Dual fluorescence high throughput screen detects MUC16 selective therapeutic candidates
Authors: Thapi Dharmarao , Normand Guillaume , Ivnitski-Steele Irena D. , Ostrovnaya Irina , Shum David , Spriggs David R. , Djaballah Hakim
Published: February 2011

BACKGROUND: The MUC16 gene encodes the CA125 ovarian cancer antigen. This glycoprotein is expressed in the majority of Epithelial Ovarian Cancers (EOC) but has limited expression elsewhere in the adult human. Expression of the carboxy-portion of MUC16 results in increased invasion, soft agar growth and in vivo growth.

OBJECTIVES: We sought to develop a suitable microscopy based assay system to screen for and identify small molecules which have a differential effects against MUC16+ cells compared to the isogenic MUC16 negative ovarian cancer cell lines. Using this assay we seek to identify MUC16 specific small molecules for development of potential chemotherapy drug candidates against ovarian cancer.

METHODS: Carboxy-terminus portions of the Human MUC16 gene were introduced into SK-Ov-3 and A2780 EOC cell lines and labeled with the red fluorescent protein (mCherry) vector. Control lines were labeled with green fluorescent protein (GFP) vector. Relative toxicity of tested compounds on MUC16+ (mCherry) and MUC16- (GFP) cell populations was assessed by cell viability using ratiometric fluorescence intensities of both co-cultured isogenic cells. Compounds with differential activity were selected, resupplied and tested in a 96 well plate viability assay for confirmation.

RESULTS: Both A2780 and SK-Ov-3 isogenic pairs had similar in vitro growth characteristics. A small scale pilot screen of 3,119 compounds was completed for each pair of isogenic cells. Six compounds, including Quinacrine, Ellipticine and Acriflavinium were relatively selective for MUC16+ A2780 cells and these three compounds were among the hits identified in the secondary SK-Ov-3 dual fluorescence screen. Caspase3 apoptosis assay was used to confirm Quinacrine as the most selective inhibitor in the MUC16+ cells.

CONCLUSIONS: MUC16 +/− dual fluorescence screen is an example of a high throughput screening strategy to identify potentially specific modulators of key oncogenic targets.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5503.
Abstract 5506: Novel toxin library for the discovery of oncology therapeutics
Authors: Zacny Valerie , Higley John S. , Cunningham Casey , Poma Eric E.
Published: February 2011

The A subunit of Shiga-like Toxin 1 (SLT1) is a ribosome-inactivating protein that works by catalyzing the depurination of the 28 S rRNA. The A subunit lacks the ability to bind and internalize into cells, and is normally dependent on the B subunit of SLT1 for this function. A toxin variant library has been created by inserting random amino acid stretches into an exposed loop structure of the A subunit. The inserts can confer binding and internalization properties to the SLT1 A variants but do not inhibit the A subunit's ability to intoxicate. This toxin library has been expressed in a phage display system that can be rapidly screened for variants with specific cell kill activity and predictable PK/PD properties. The library is being used to develop novel therapeutics for oncology.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5506.
Abstract 5512: Zirconium phosphate nanoparticle matrix as potential delivery system for cisplatin to cancer cells in vitro
Authors: González Millie , Díaz Agustín , Colón Jorge , Clearfield Abraham , Ortíz Mayra , Báez Adriana
Published: February 2011

Cisplatin (cis-diamminedichloroplatinum(II), have been shown to be active against ovarian and testicular cancer, Hodgkin's lymphoma, and certain other malignancies, however, its clinical effectiveness is limited by significant side effects and the emergence of drug resistance. Delivery of anticancer drugs such as cisplatin to the tumor cells without damaging healthy organs or tissues is highly difficult if not impossible. In the last several years nanoparticle-mediated drug delivery is being studied as a novel valuable mean for overcoming this problem. We developed a novel nanoparticle intercalated formulation of cisplatin on a layered matrix of zirconium phosphate (ZrP). It was expected that cisplatin, while being excluded from the external medium within ZrP layers will remain biologically inactive and that cisplatin will be released selectively in the tumor cell. The purpose of this study was to determine the cytotoxicity and effectiveness of ZrP nanoparticles in the delivery of cisplatin. Cell viability was measured by MTT assay. Flow cytometry analysis was used to determine cisplatin-induced apoptosis, and cell cycle distribution. ZrP alone did not affect the viability of breast cancer cells (MCF-7), human leukemic lymphoblast (CEM) and human peripheral blood lymphocytes (PBLs) after 24 hours in contact with different concentrations of ZrP. Cisplatin intercalated into ZrP at the highest concentration (30 μM cisplatin) reduced in 40% the cell viability of MCF-7 and CEM. The IC50 of cisplatin alone in MCF-7 was 10 μM. The side scatter plot showed that normal PBLs scatter plot is different from PBLs that have been in contact with cisplatin-intercalated ZrP for 18 hours. These PBLs carrying ZrP were displaced to the right quadrant suggesting an increased granularity that can be associated to the incorporation of ZrP nanoparticles. Moderate cisplatin-induced apoptosis was evident in cells treated with ZrP-intercalated cisplatin for 18 hours. The cell cycle analysis showed that ZrP alone does not cause cell cycle arrest. Our results suggest that application of ZrP nanoparticle-mediated drug transport in cancer chemotherapy is highly promising and more studies are warranted.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5512.
Abstract 5529: Silencing H-ferritin by siRNA delivered by cationic liposomes increases chemotherapeutic sensitivity for treating malignant tumor
Authors: Liu Xiaoli , Madhankumar A.b. , Slagle-Webb Becky , Sheehan Jonas M. , Surguladze Nodar , Connor James R.
Published: February 2011

Cancer cells have a robust appetite for iron to support their rapid growth and high metabolic rates. The high levels of iron uptake require a mechanism to limit iron induced oxidative damage. This function is the responsibility of ferritin; an intracellular iron storage protein. Ferritin has been found in the nucleus of tumor cells where it appears to protect DNA from iron induced oxidative damage and promote transcription. Therefore, we hypothesized that silencing H-ferritin gene expression could increase the sensitivity of malignant tumors to radiation and chemotoxins. Potentially targets of H-ferritin disrupted iron homeostasis in tumor cells result in proving effective at negatively affecting tumor growth. To test our hypothesis, H-ferritin siRNA was delivered to U251 human astrocytoma cells, malignant peripheral nerve sheath tumor (MPNST) cells and a breast cancer cell line (MCF-7) via our cationic liposomes. Western immunoblotting analysis demonstrated that the siRNA delivered in this manner decreased H-ferritin protein expression by 70 to 80% in all three cell lines within 48 hours. The results from SRB assay displayed decrease H-ferritin was associated with a decrease in the LD50 for carmustine (BCNU) from greater than 100 µM to 40 μM in the U251 cells, 30 µM in MCF7 cells and 18 µM in MPNST cells. In addition, the results of MTS assay revealed the presence of H-ferritin siRNA was associated with a 50% increase in cell death of U251 cells at 20 Gy of radiation. The in vivo efficacy of siRNA delivered by cationic-liposomes was tested in the Athymic nude mice subcutaneous glioma tumor model. Intratumoral injections of cationic liposomes containing H-ferritin siRNA reduced the required effective dose of BCNU for tumor suppression by more than 50%. The interaction of H-ferritin with DNA was investigated in vitro by supercoil relaxation assay, which demonstrated that H-ferritin maintained DNA in a relaxed form that would promote transcription of DNA even in the presence of radiation and chemotoxins. The outcome of study for Caspase-3 activity exposed that transfection with H-ferritin siRNA was associated with activation of apoptotic caspase pathway. Overall, our data demonstrated that silencing the H-ferritin gene appears to be an effective way to sensitize tumors to radiation and chemotherapy. As importantly, we have demonstrated that siRNA can be delivered effectively by cationic liposomes in an in vivo tumor model.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5529.
Abstract 553: Host cell OGR1 plays an important role in TRAMP cell tumorigenesis
Authors: Yan Libo , Wei Gang , Li Hui , Zhao Zhenwen , Singh Lisam Shanjukumar , Xu Yan
Published: February 2011

Ovarian cancer G protein coupled receptor 1 (OGR1) was previously cloned from an ovarian cancer cell line HEY. We have recently shown that OGR1 is a new tumor metastasis suppressor gene in prostate cancer. To further understand the physiological role of OGR1, we have generated OGR1 knockout (KO) mice. These mice are viable and grossly normal under regular physiological conditions. To exam the role of host cell OGR1 in prostate cancer development, TRAMP-C2 cells (a mouse prostate cancer cell line) were subcutaneously (s.c.) injected into OGR1 KO mice, significantly reduced tumorigenesis were observed when compared to that in wild type (WT) mice. 100% (20 of 20) of wild type mice developed tumors, while only 12.5% (4 of 32) of OGR1 deficient mice developed small tumors. To test whether OGR1 deficiency in host cells inhibits tumorigenesis of other mouse prostate tumor cells, RM-9 cells (an aggressive and poorly immunogenic mouse prostate tumor cells) were subcutaneously injected into OGR1 KO and WT mice (2 mice/group). All 4 mice developed big tumors at 10 days post tumor cell injection. No significant difference was observed between WT and OGR1 KO mice. Thus, host OGR1 deficiency differentially affected tumorigenesis of TRAMP and RM-9 cells, suggesting a tumor cell type specific effect. OGR1 are highly expressed in immune cells. We are currently testing whether these cells are functionally involved in host OGR1's effects. In addition, fibroblasts have a prominent role in the progression, growth and spread of cancers. The infiltration of fibroblasts in TRAMP-C2 tumors from WT and OGR1 KO mice were tested. Decreased fibroblast infiltration was observed in tumors from the KO vs. WT mice. The expression of OGR1 in mouse fibroblasts were confirmed by RT-PCR. Our results suggest that fibroblasts may be involved in OGR1's effect on tumorigenesis. Our new findings may lead to novel therapeutic strategies for prostate and/or other cancers.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 553.
Abstract 5531: Preparation and cellular delivery of doxorubicin nanoemulsion for cancer therapy
Authors: Pamujula Sarala , Chinta Dakshina Murthy Devanga , King Ashley , Kishore Vimal , Mandal Tarun K.
Published: February 2011

Purpose: The aim of this study is to formulate a novel nanoemulsion of doxorubicin to enhance the therapeutic efficacy of the drug.

Method: Four different multiple emulsions (W1/O/W2) were prepared (A, B, C, and D) by homogenization of a mixture of aqueous and oil phases. The resultant primary emulsions were later pass through a high pressure homogenization to further reduce the globules size to nanometer range. The formulation A is a control nanoemulsion, consisted of only deionized water as W1 phase. The W1 phase of the other three formulations (B, C, and D) consisted of aqueous solution of BSA (as an emulsion stabilizer), doxorubicin, and a mixture of BSA and doxorubicin, respectively. For all four formulations, the oil phase (O) consisted of a 2:1 mixture of soyabean oil and Span 80, and the outer aqueous phase (W2) consisted of prolaxamer P-85 and Vitamin E TPGS. The nanoemulsions were evaluated for stability, polydispersity index, size, and viscosity. Anticancer efficacy of these formulations was evaluated by Alamar Blue Assay and Colony Forming Assay using MCF-7 cells as a model malignant breast cancer cell line.

Results: The stability of nanoemulsions was found to be significantly better for the formulations containing BSA. Presence of BSA or doxorubicin resulted in a significant increase in viscosity from 2.09 to 10.6 cP. Cell culture studies showed that doxorubicin nanoemulsions had higher localization in cytoplasm as compared to the nucleus. In regard to cellular uptake (intracellular quantification of doxorubicin), the following results were obtained at 2h, 24h, 48h, and 120h post-incubation, respectively: 42%, 30%, 37%, and 22% with doxorubicin solution; 12%, 19%, 21%, 33% with formulation C; and 0.25%, 6%, 10%, 19% with formulation D. The results of Alamar Blue Assay showed IC50 values of 0.97μM (solution), 1.62μM (formulation C) and 1.91μM (formulation D). The results of Colony Forming Assay (12days-post-treatment with equivalent to 0.86 μM doxorubicin) showed 74% (solution), 86% (formulation C) and 92.6% (formulation D) growth inhibitions.

Conclusions: The presence of BSA within the aqueous phase enhances the stability of nanoemulsions. In comparison to doxorubicin solution, the nanoemulsions produce higher anticancer efficacy. This exploratory study will be followed by more detailed studies to confirm this preliminary finding.

Acknowledgements: This work was funded in part by the NASA grant # NCC3-946-S4, Louisiana Board of Regents RC/EEP (2007-10), NIH grant# 5P20CA118768-02, and Louisiana Cancer Research Consortium. We are thankful to Dr. Thomas Wiese of the College of Pharmacy, XULA, for providing the Cell culture lab facilities.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5531.
Abstract 5533: Anti-proliferative and anti-tumor effects of a novel vitamin D derivative, either alone or in a liposomal formulation in malignancies of kidney, pancreas and prostate
Authors: Ray Rahul , Lambert James R. , Persons Kelly S. , Eddy Vikram J.
Published: February 2011

1,25-dihydroxyvitamin D3 (1,25(OH)2D3) has well-known potential in cancer-therapy; but such a potential is marred by its severe toxicity in pharmacological doses. 1α,25-dihydroxyvitamin D3-3-bromoacetate (1,25(OH)2D3-3-BE) is a novel derivative of 1,25(OH)2D3 which enables covalent attachment of 1,25(OH)2D3 inside the ligand-binding pocket of nuclear vitamin D receptor, thus increasing the half-life of 1,25(OH)2D3 and potentially reducing its therapeutic dose with less toxicity. We have observed that 1,25(OH)2D3-3-BE strongly hinders the growth of cells representing malignancies of prostate (androgen-sensitive and androgen-insensitive), pancreas and kidney. However, growth of normal kidney and prostate cells is not affected by this compound. Inhibition of cell-growth by 1,25(OH)2D3-3-BE involves hindrance to cell-cycling, and enhancement of apoptosis and autophagy; and includes several mechanisms involving VDR-mediated nuclear pathway and inhibition of Akt-phophorylation. We have also observed that 1,25(OH)2D3-3-BE strongly inhibits the growth of prostate and renal tumors in mouse xenograft models. In anticipation of its therapeutic potential we prepared a liposomal formulation of 1,25(OH)2D3-3-BE to enhance its efficacy further by potentially preventing its premature degradation and tumor-targeting. We report that liposomal 1,25(OH)2D3-3-BE is a significantly stronger growth-inhibiting compound than naked 1,25(OH)2D3-3-BE in prostate, kidney and pancreatic cancer cells. This property is also manifested in a mouse xenograft model of androgen-insensitive prostate tumor. In summary, 1,25(OH)2D3-3-BE and its liposomal formulation demonstrate a strong translational therapeutic potential in cancers of kidney, pancreas and prostate.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5533.
Abstract 5534: Liposome accumulation within leukemia engrafted bone marrow is significantly enhanced when the formulation contains cytarabine plus daunorubicin
Authors: Johnstone Sharon A. , Xie Sherwin , Harasym Troy , Mayer Lawrence , Tardi Paul G.
Published: February 2011

CPX-351 is a liposome formulation designed to deliver a synergistic, fixed ratio of cytarabine and daunorubicin in vivo. It has been shown to be highly efficacious against a variety of mouse leukemia models and encouraging evidence of anti-leukemic activity has been observed in clinical trials. In this report we investigate liposome biodistribution properties that may contribute to the enhanced efficacy of CPX-351. In order to model bone marrow leukemia development, we utilized the human leukemia CCRF-CEM tumor which has been shown to efficiently engraft to the bone marrow of SCID Rag2M mice. Liposomes were prepared in the presence or absence of cytarabine and daunorubicin to compare the plasma clearance and biodistribution to bone marrow, liver, lung, spleen and kidney following multiple treatments. The plasma clearance of empty liposomes and CPX-351 were similar in both leukemia and non-leukemia bearing mice. Both liposomal formulations had similar organ distribution profiles in the presence or absence of leukemia; however lipid delivery to the bone marrow was markedly augmented by the presence of encapsulated drug. Accumulation of CPX-351 lipid in the bone marrow was 20 to 50% higher than for empty liposomes and this phenomenon was further enhanced in leukemia bearing mice. Leukemia-laden bone marrow accumulated 75% more CPX-351 lipid than the empty liposomes on the first injection and accumulation increased an additional 20% with subsequent injections. We attribute the increased efficacy of CPX-351 over the free drug cocktail of cytarabine and daunorubicin to elevated exposure of the tumor tissue to chemotherapeutic agents. This increased exposure is not only due to the prolonged circulation of the drug in the liposomes, but also due to the increased bone marrow uptake of the liposomes when drugs are present. Additionally the lipid accumulation is further increased with successive treatments of the leukemia. The results suggest that the liposomal drugs alter either the bone marrow microenvironment or resident cell populations in a manner that facilitates subsequent uptake and/or retention of CPX-351.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5534.
Abstract 5539: Analysis of antitumor activity of IL-13PE in combination with gemcitabine for human pancreatic ductal adenocarcinoma therapy
Authors: Fujisawa Toshio , Nakashima Hideyuki , Nakajima Atsushi , Joshi Bharat H. , Puri Raj K.
Published: February 2011

Previously, we have identified an overexpression of IL-13Rα2 in 71% of human pancreatic ductal adenocarcinoma (PDA) specimens. We have also demonstrated that these receptors can be a target for a receptor directed chimeric cytotoxin, IL-13PE, which consists of IL-13 and a truncated Pseudomonas exotoxin (IL13-PE). In the present study, we examined the anti-tumor activities of IL13-PE in combination with gemcitabine, an established first line therapy for advanced pancreatic cancer. Both these agents were cytotoxic to two pancreatic cancer cell lines (HS766T and MIA-PaCa2) with IC50 of 1.1 - 51 ng/ml and 19 - 98 nmol/L, respectively. Upon combination of these two agents, we observed a synergistic cytotoxicity in these two cell lines (IC50: 0.4 ng/ml with 0.01 nmol/L gemcitabine in HS766T and 21 ng/ml with 1 nmol/L gemcitabine in MIA-PaCa2). In addition, we have demonstrated a synergistic anti-tumor activity in an orthotopic mouse model of human PDA developed in athymic nude mice. This study showed complete eradiation of tumors as assessed by whole body imaging of GFP-transfected tumors in 57% of mice in an early cancer model and also resulted in a prolongation in survival. In contrast, single therapy with either IL13-PE or gemcitabine did not produce complete eradiation, but tumor volumes were significantly decreased. In advanced cancer models, IL13-PE and gemcitabine also produced a dramatic reduction and retardation of tumor growth and enhanced survival compared to animals treated with either agent alone. Furthermore, silencing of IL-13Rα2 by RNAi in tumor cells prior to tumor implantation revealed that the combination of IL13-PE and gemcitabine was less effective in this model indicating that IL-13Rα2 is an essential target in PDA for complete elimination of tumors. Mechanistically, gemcitabine increased IL-13Rα2 mRNA expression in vitro and in vivo, which in turn, resulted in a synergism of combination therapy and improved induction of apoptosis in PDA cell lines. Based on these data, we conclude that combination therapy of IL13-PE and gemcitabine may be an additional therapeutic option for management of pancreatic ductal cancer patients for better clinical outcome.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5539.
Abstract 5540: Targeting type 1 insulin-like growth factor receptor enhances radiosensitivity in human liposarcoma cell lines
Authors: Kuang Jonathan , Knittel Tony Z. , Goldstein David , Yang Jia Lin
Published: February 2011

Soft tissue sarcoma (STS) is currently treated by surgery and adjuvant or neoadjuvant radiotherapy. About 20 - 30% of patients develop local recurrence and 50% will eventually die of their disease. Adjuvant cytotoxic therapies improve disease free survival but overall survival is minimally effected. New treatments are required. As with many cancers there is an imbalance between cell growth and cell death and this also the case with STS. Cell growth signals such as those from the insulin-like growth factor receptor (IGF-1R) increases resistance to radiotherapy. We proved that IGF-1R family members are highly expressed in sarcoma tissue samples, particularly IGF-1R 80% positive, which is also significantly associated with histologic grade. This study investigates whether inhibiting IGF-1R can improve the sensitivity of radiotherapy in liposarcomas.

Expression of IGF-1R and/or activated IGF-1R in 3 liposarcoma cell lines was detected by western blot and immunoprecipitation respectively. Crystal violet staining and/or clonogenic assays were used to assess anti-proliferative effects of irradiation and IGF-1R inhibitor (tyrphostin AG1024) or IGF-1R downstream pathway inhibitors (LY294002 and SB202190). Irradiation was performed using Therapax DXT300 Orthovoltage Radiation System.

We found that the IGF-1R inhibitor can enhance radiotherapy, particularly in the 2 radio-insensitive sarcoma cell lines (combination index <1 = synergism, CI <0.1 for 449B; CI 0.1-0.3 for 778). The drug reduction index (DRI) at IC50 measures how much the dose of x-ray may be reduced when drug and x-ray were combined at the IC50 effect level compared with the dose of x-ray alone. The DRI for 449B and 778 was 3 and 5 fold for x-ray reduction respectively. In addition, we found that radiation can induce activation of IGF-1R in the sarcoma cell line detected with peak time at 4 hours. Using the IGF-1R inhibitor pre-treatment achieved more inhibitory effect than concurrent inhibitor plus X-ray or X-ray alone group. The greatest enhancement of radiosensitivity was observed with pre-treatment of AG1024 followed by combination therapy, resulting in an 80% decrease in cell survival fraction at the highest dose combination. We also used PI3K and p38 pathway inhibitors singly or together compared with the IGF-1R inhibitor in the presence or absence of X-ray or IGF-1 and discovered that both pathways are involved in radioresistance and the inhibition is at least partially IGF-1R dependent.

Targeting the IGF-1R to radiosensitize liposarcomas is a novel treatment strategy that can potentially improve the prognosis of some patients with low radiosensitive liposarcoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5540.
Abstract 5546: Improved gastrointestinal repair post irradiation with AEOL 10150
Authors: Booth Catherine , Tudor Gregory , MacVittie Thomas , Day Brian , McManus John
Published: February 2011

Background

Gastrointestinal toxicity, often manifested as ulceration and diarrhoea (mucositis) occurs following exposure to radiation and many chemotherapeutics. Potential treatments include prophylactic damage limitation or therapeutic/mitigatory wound repair dosing regimes. Treatments that are effective mitigators also have biodefence applications. In both the clinic or following nuclear terrorism effective agents may be given in combination with haematological therapies, in addition to standard supportive care agents.

Methods

AEOL 10150 [5,10,15,20-tetrakis(1,3-diethylimidazolium-2-yl) porphyrinato] manganese (III) pentachloride was administered to C57BL/6 male mice s.c. daily from 24hrs following a single dose of 13Gy total body X-irradiation. AEOL 10150 was administered at a 2x initial loading dose of 40 or 20mg/kg and then subsequently each day at 20 or 10mg/kg respectively. Animals were euthanized 4 and 6 days post irradiation and the number of regenerating small intestinal crypts measured. In a parallel study the levels diarrhoea and animal viability were measured animals exposed to 15Gy partial body X-irradiation (partially lead shielded to protect the bone marrow).

Results

Treatment with AEOL 10150 increased the number of surviving regenerating crypt observed in histological cross sections of the small intestine 4 days post irradiation. This was highly significant at both doses (p<0.001 for the 40/20mg/kg schedule and p=0.009 for the 20/10 mg/kg schedule). By day 6, where crypt numbers had increased from day 4, numbers were increased but not statistically significant. Levels of crypt fission, necessary to restore crypt numbers, were also increased. At the highest treatment dose animal mortality was only marginally reduced (p=0.115) but the severity and duration of observed diarrhoea was significantly reduced (p=0.021 and p=0.010 respectively).

Conclusion

AEOL 10150 demonstrated efficacy in both histological and physiological readouts of radiation induced gastrointestinal toxicity. Studies are currently ongoing to investigate whether other dosing schedules can further improve gastrointestinal repair.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5546.
Abstract 5553: Liposomal rhenium by convection enhanced delivery for primary brain tumors
Authors: Brenner Andrew , Trevino Abram , Rogge Jessica , Goins Beth , Giles Francis , Phillips William
Published: February 2011

Introduction: While adjuvant external beam radiation prolongs survival in glioblastoma, doses must be limited to approximately 60Gy secondary to lack of benefit and increased toxicity with higher doses. Despite maximum radiation, 90% of tumors recur at the original site. Convection enhanced delivery (CED) of radiation has the potential of administering higher doses locally to the tumor while reducing toxicity to normal brain parenchyma. Lipid nanocarriers offer the potential of distribution though the tumor as well as retention within the tumor. We hypothesized that a radionuclide liposome generated with a specially developed chemistry for loading a large quantity of rhenium, delivered by CED, would allow a higher dose of radiation to be delivered safely and effectively.

Methods: Intracranial xenografts were established in nude rats with luciferase expressing U87 glioma cell line. To establish the correct volume of administration, liposomes were labeled with technetium99 and administered intratumorally by CED in volumes of 50 and 100ul at variable rates and imaged by SPECT/CT. Once volume and rate were established, an initial dose range finding study was performed with Re186 doses from 25 to 125uCi. The maximum tolerated dose was then assessed for efficacy as well as to confirm absence of toxicity. Tumor growth was followed by in vivo bioluminescent imaging and 7T MRI. Rats were sacrificed when moribund or when marked neurologic deficit was observed. Rat brains were evaluated by standard histologic methods for residual tumor, gliosis and necrosis.

Results: Technetium liposomes in smaller volumes appeared to have better local retention with up to 60% retained at 22 hours post injection. Rats bearing U87 tumors treated with liposomal Rhenium186 tolerated the maximum administered dose of 125uCi (∼550Gy) without apparent toxicity, evidence of necrosis or gliosis. Efficacy was confirmed with rats treated at maximum dose, with all rats in the maximum dose continuing to survive and gain weight to 70 days post tumor inoculation, as compared to control rats which expired between 38 and 44 days.

Conclusions: High doses (approx 550Gy) can be delivered to intracranial tumors in tumor bearing rats by CED of rhenium nanoliposomes. No evidence of neurotoxicity or histological changes suggestive of normal tissue injury are observed despite these very high doses. Rhenium liposomes delivered by CED show significant antiglioma activity with prolonged survival of treated tumor bearing rats. Further experiments are warranted to evaluate the potential of Rhenium 186 liposome in the treatment of glioblastoma and other primary brain tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5553.
Abstract 5555: Quantitative Proteomic Profiling of Matched Normal and Tumor Breast Tissues
Authors: Sutton Chris , Rustogi Nitin , Scally Andrew , Gurkan Cemal , Loizidou Maria , Hadjisavvas Andreas , Kyriacou Kyriacos
Published: February 2011

Introduction - Quantitative proteomic profiling of breast tissue has proven difficult due to its inherent histological complexity. Substantial differences in stroma, vasculature and cellular composition of normal and tumors have further exacerbated analysis. In order to address these issues, a novel strategy for proteomics analysis was developed to determine differences between normal and disease tissue and between patients with adenoma and invasive carcinoma.

Methods - A dual lysis buffer method for extracting proteins, in combination with sonication, was used to maximise recovery from normal and diseased breast biopsies. Protein extracts from matched normal breast and tumors of three patients (one with adenoma and two with invasive carcinoma) were trypsin-digested, were iTRAQ (isobaric tag for relative and absolute quantitation) labelled, pooled and the resulting peptide mixture separated using isoelectricfocusing in the first dimension and reverse phase nanoHPLC in the second dimension. The eluate from nanoHPLC was collected onto matrix assisted laser desorption/ionisation plates, analysed by MALDI MS and MS/MS, the subsequent data searched against a sequence database to identify proteins in the original sample.

Results - A total of 481 proteins with associated normal: tumor iTRAQ ratios for each patient. iTRAQ ratios were indicative of increased or decreased levels of each protein in tumor compared to normal tissue. Proteins were categorised by location as blood (13% of the identified proteins), extracellular (12%) and cellular (75%). The average ratios for each group of proteins provided a gross indication of the relative levels of each tissue component in the matched normal and tumor biopsies and demonstrated marked difference in adenoma compared to invasive carcinoma. iTRAQ ratios were normalised to enable comparison of significantly changed proteins between patients. There were many cellular proteins in common between the two invasive carcinoma patients (54 increased and 51 decreased in tumors) but few between either of the invasive carcinoma patients and the adenoma patient.

Discussion - A number of proteins significantly increased or decreased have previously been associated with breast cancer (Tropomyosin beta chain, Periostin, Small breast epithelial mucin and Breast cancer estrogen-inducible protein were increased and Selenium-binding protein 1, Secreted frizzled-related protein 1 precursor and Kinectin were decreased), supporting the approach we have developed for proteomics analysis of breast tissues.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5555.