bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4390: Metronomic maintenance chemotherapy of orally active pemetrexed for effective treatment of lung cancer
Authors: Mahmud Foyez , Kweon Seho , Chang Hyo Won , Nam Hae Yoon , Kim Mi Ra , Park Jung Je , Kim Sang Yoon , Byun Youngro
Published: August 2015

At present, most of the anticancer drugs are given parenterally, showing drug concentration above the maximum tolerable concentration (MTC) followed by rapid elimination from the plasma that causes enhanced side effects and lower efficacy. In contrast, low dose oral maintenance therapy may increase therapeutic efficacy by increasing the exposure time to cancer cells and also reduce the side effects by maintaining the drug concentration below MTC level. Pemetrexed is a folate antagonist approved for maintenance chemotherapy in lung cancer. However, a major limitation of Pemetrexed is the poor oral bioavailability which imposes IV administration. In this context, we have developed a physical complex of Pemetrexed with lysine conjugated deoxycholic acid (DCK) in water (mole ratio 1:2) for the purpose of oral delivery. The DSC thermogram of Pemetrexed/DCK complex showed the complex formation due to disappearance of exothermic and endothermic peaks from Pemetrexed. The pharmacokinetic studies of Pemetrexed/DCK were done in SD rats and analyzed by HPLC method. In antitumor study, low dose continuous oral therapy from 2.5 mg/kg to 20 mg/kg showed substantial tumor inhibition in SCC7 tumor bearing C3H mice. We also evaluated maintenance chemotherapy as oral Pemetrexed/DCK administration in A549 tumor bearing nude mice. We found that 5 mg/kg dose of oral Pemetrexed successfully inhibited tumor progression and also showed additional antitumor effects when given with Cisplatin as maintenance chemotherapy. In the context of oral anticancer drugs, we need to consider the toxicities in GI tracts (GIT). For this purpose, apoptosis in GI tracts and morphology of different organs were assessed by TUNEL and H&E staining. One month toxicity studies have been conducted in nude mice and we found that 5 mg/kg oral dose did not produce any abnormalities in hematological and serological parameters in mice having intact morphology of GI tracts. Our studies offer safe and effective oral maintenance chemotherapy of pemetrexed for cancer patients at home.

Citation Format: Foyez Mahmud, Seho Kweon, Hyo Won Chang, Hae Yoon Nam, Mi Ra Kim, Jung Je Park, Sang Yoon Kim, Youngro Byun. Metronomic maintenance chemotherapy of orally active pemetrexed for effective treatment of lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4390. doi:10.1158/1538-7445.AM2015-4390
Abstract 4391: Evaluation of tumor targeting activity by elastin like polypeptide containing cell penetrating peptide and IL-4 receptor targeting peptide
Authors: Lee Young-Jin , Sarangthem Vijaya , Kim Yun-Jae , Hur Kuen , Lee Byung-Heon , Park Rang Woon
Published: August 2015

The tumor specific internalization of therapeutics drug is been a great importance for cancer therapy. Targeted macromolecular carrier has been used as drug cargos since it improve the cellular uptake of cytotoxic drug in the tumor, while preventing cellular uptake by healthy tissues. Because of favorable pharmokinetic profile, elastin like polypeptide (ELPs) has been used as macromolecular drug carrier for cancer therapy. Fusion with cell-penetrating peptides (CPPs) such as TAT, assist easy penetration and internalization of macromolecular drug conjugates into wide variety of tumor types. For therapeutic peptide to be more penetrable and more effective towards specific tumor tissue, here we have designed a chimeric polypeptide cargo, TAT-AP1-ELP containing TAT, IL-4 receptor (IL4R) targeting peptide AP-1and thermal sensitive elastin-like polypeptides (ELPs). Then it was successfully expressed and purified from E coli using inverse temperature cycling method. Cellular uptake and intracellular localization of TAT-AP1-ELP was monitored through flow cytometry and confocal microscopy. Flow cytometry analysis data shown that both TAT-AP1-ELP and TAT-ELP showed various extends of penetration ability to different cancer cells but not to normal cells. Further a greater cellular uptake was observed in IL4R highly expressing cancer cells when treated with TAT-AP1-ELP compared to TAT-ELP at 37°C in dose-dependent manner. Confocal imaging verified the better cellular accumulation of TAT-AP1-ELP than TAT-ELP in IL4R highly expressing cancer cells. Importantly, the FNR 675-labeled TAT-AP1-ELP polymer showed better tumor accumulation in MDA-MB 231 xenograft mouse model. Thus in this study we demonstrate the improved activity of CPP, fused with targeting modalities in order to enhance intra tumor accumulation of therapeutic peptides.

Citation Format: Young-Jin Lee, Vijaya Sarangthem, Yun-Jae Kim, Kuen Hur, Byung-Heon Lee, Rang Woon Park. Evaluation of tumor targeting activity by elastin like polypeptide containing cell penetrating peptide and IL-4 receptor targeting peptide. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4391. doi:10.1158/1538-7445.AM2015-4391
Abstract 4396: Nanocarrier for monoclonal antibody delivery
Authors: Gdowski Andrew , Ranjan Amalendu , Mukerjee Anindita , Vishwanatha Jamboor
Published: August 2015

Antibodies represent a large class of drugs that have a number of different therapeutic uses. The use of monoclonal antibodies against potential intracellular protein-protein interactions in cancer cells has remained largely unexplored. This lack of consideration is due largely to a number of factors that include poor intracellular uptake and rapid lysosomal degradation of monoclonal antibodies within cells. Encapsulating monoclonal antibodies within biodegradable nanoparticles is one strategy that can improve antibody cellular uptake and protect from lysosomal degradation so that the antibody can be released inside the cell and remain functional against the therapeutic target.

Purpose: The purpose of this study is to characterize a human monoclonal antibody encapsulated within poly(lactic-co-glycolytic) acid (PLGA) nanoparticles. We hypothesized that encapsulation of an antibody within PLGA nanoparticles is feasible and will release in a favorable manner.

Method: Anti-AnnexinA2 (AnxA2) monoclonal antibody was encapsulated within PLGA nanoparticles utilizing a water/oil/water double emulsion solvent evaporation method. Nanoparticles and released antibodies were characterized through a number of different modalities.

Results: Our results show encapsulation efficiency ranging from 16-22% with a mean of 18.725% (SEM 1.289) depending on initial concentration of antibody used in the nanoparticle formulation. Nanoparticles were formed in a favorable mono disperse manner as evidenced through dynamic light scattering. All of the formulations created maintained a hydrodynamic size below 250nm. Release kinetics revealed that at day 12 the cumulative release of the antibody is approximately 35%. In addition after release the antibody maintained functionality as evidenced through Western Blot analysis and immunocytochemistry.

Conclusions: Encapsulation of a monoclonal antibody within polymeric PLGA nanoparticles is feasible, exhibits sustained release kinetics, and maintains functionality upon release. This encapsulation technique may be used as a method to load antibodies in targeted nanoparticles and release the antibodies inside cancer cells to interfere with aberrantly expressed proteins. Future experiments will focus on utilizing this monoclonal antibody encapsulation approach to screen intracellular protein-protein interactions as potential new therapeutic cancer targets.

Note: This abstract was not presented at the meeting.

Citation Format: Andrew Gdowski, Amalendu Ranjan, Anindita Mukerjee, Jamboor Vishwanatha. Nanocarrier for monoclonal antibody delivery. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4396. doi:10.1158/1538-7445.AM2015-4396
Abstract 4403: Antitumor properties of ouabain in lipid double emulsion integrated with tumor cell membrane fractions
Authors: Wu Jun , Mondala Mariele , Hsieh Meng-Yin , Roberts Eugene , Ermel Richard
Published: August 2015

Cell membrane proteins such as integrins are crucial for cell-cell recognition, binding and communication, cell-stromal interaction and adhesion, tumor invasion and metastasis. It was reported that cell-size hydrophobic beads coated with tumor membrane molecules could stimulate the lymphokine activated killer (LAK) cells to release IFN-alpha and TNF-alpha, and interrupted the recognition between LAK cells and tumor cells (Chong AS, 1988, 1991). Lipid double emulsion is a convenient formulation method to integrate lipid materials, hydrophilic and hydrophobic drugs in uniformed particles to achieve combinational chemotherapy. However the nonspecific uptake of double emulsion particles in vivo limits its targeting therapeutic potential. In current study, we sought to coat double emulsion particles with tumor cell membrane fraction to mimic the tumor cell surface in order to enhance the interaction and uptake of emulsion particles into tumor cells. Canine osteosarcoma cells and lymphoma cells were chosen for this study because canine cancers develop in immunocompetent environments and share many similar features observed in human cancers, such as long periods of latency for initiation, progression and development, metastasis, acquired drug resistance and recurrence. We use ouabain as therapeutic warhead in the emulsion particles because ouabain is known to have extremely high anticancer potential at nanomolar concentration level from our previous studies. The major obstacle of applying ouabain in vivo therapy is that the therapeutic dose window of ouabain is very narrow. Therefore in an attempt to mitigate such narrow therapeutic margin of safety, ouabain was formulated in lipid double emulsion by using microfluidic synthesis method and membrane emulsification method. The double emulsion particles were further coated with osteosarcoma cell membrane fraction. Our preliminary results showed enhanced antitumor activities of ouabain in tumor cell mimic-double emulsion or nanoemulsion against canine osteosarcoma cells and lymphoma cells in vitro and in orthotopic xenograft models in vivo, suggesting a promising therapeutic benefit in canine cancer targeting therapy.

Citation Format: Jun Wu, Mariele Mondala, Meng-Yin Hsieh, Eugene Roberts, Richard Ermel. Antitumor properties of ouabain in lipid double emulsion integrated with tumor cell membrane fractions. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4403. doi:10.1158/1538-7445.AM2015-4403
Abstract 442: Decreased tumor progression by the knockdown of interleukin 17 receoptor A in the B16F10 melanoma model
Authors: Chen Ya-Shan , Liu Chao-Lin , Chen Hui-Shan , Wu Su-Ting , Shen Chia-Rui
Published: August 2015

Introduction: Interleukin 17 (IL-17), correlating with advanced stage or poor prognosis of cancer patients, appears to contribute to tumor progression. Here we demonstrated the presence of IL-17 receptor A (IL-17RA) on the tumor cells directly promoting tumor growth, angiogenesis and metastasis.

Methods: B16F10 and its derived IL-17RA deficient melanoma cells were stimulated with recombinant IL-17 (γmIL-17) or subcutaneously implanted into C57BL/6 mice. Cell proliferation, cell invasion, tumor growth, metastasis and angiogensis were monitored and anti-tumor immunity was also assessed.

Results: As compared with those in the control B16F10 cells, the γmIL-17 inducing cell proliferation, migration and invasion were significantly reduced in the derived IL-17RA-deficient cells. The tumor growth and metastasis were also apparently reduced in the mice bearing the IL-17RA deficient tumors. In fact, not ony the expression of MMP2 and MMP9 but also the production of VEGF and HGF were reduced both in vitro and in vivo. Additionally, the increased levels of IFNγ+ and Granzyme B+ immune cells as well as the reduced numbers of Tregs and MDSCs appeared in the mice bearing the IL-17RA deficient tumors, indicating the lack of IL-17 enhancing the CTL activity and other anti-tumor immunity.

Conclusion: These findings support the hypothesis that IL-17/IL-17RA signaling directly promotes tumor growth as well as recruits MDSCs and Treg cells, resulting in tumor progression. It suggests IL-17RA on tumors as a potential therapeutic target for cancer therapy.

Citation Format: Ya-Shan Chen, Chao-Lin Liu, Hui-Shan Chen, Su-Ting Wu, Chia-Rui Shen. Decreased tumor progression by the knockdown of interleukin 17 receoptor A in the B16F10 melanoma model. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 442. doi:10.1158/1538-7445.AM2015-442
Abstract 4428: Metformin effects on ABCB1 expression and proliferation in pancreatic cancer cell lines with different ABCB1 genotypes/haplotypes
Authors: Lyn-Cook Beverly D. , Osborne Taylor , Joseph Stancy , Word Beverly , Pang Li , Hammons George
Published: August 2015

Pancreatic cancer carries a poor prognosis and survival rate. Developing effective agents or repurposing agents with low toxicity, such as metformin, an insulin-lowering drug, has recently been investigated for pancreatic cancer. Metformin has long been associated with decreased cancer risk, particularly in diabetic patients. Although its major action is inhibiting hepatic glucose production, it also improves insulin sensitivity in peripheral tissues. This study demonstrates that metformin modulates the ATP-binding cassette gene, ABCB1, expression in pancreatic cancer cell lines with different ABCB1 genotypes. Metformin (100μM or 200μM) alone (p = 0.0212 or p = 0.0161) or in combination with gemcitabine (15nM) (p = 0.0248 or p = 0.0174) significantly decreased ABCB1 expression in Mia pancreatic cells after 24 hr and/or 72 hr treatments. This correlated to increased cell death. Metformin in combination with indole-3-carbinol also significantly (p = 0.0317) decreased ABCB1 expression. However, a sex or genotype difference was noted when two female pancreatic cell lines, SU86.86 and AsPC1, were used. Metformin did not down-regulate ABCB1 expression and was chemoresistance in these two cell lines. AsPC1 and SU86.86 both carry the 2677GG-3435CC ABCB1 haplotype compared to MiaPaca-2 which carries the 2677TT-3134TT ABCB1 haplotype. The 2677TT and 3435TT genotypes/haplotypes are known to be associated with lower risk of developing pancreatic cancer but these data demonstrate that these genotypes are also more sensitive to metformin treatment compared to the 2677GG or 3435CC genotypes. Further research is needed to ascertain whether sex or genotype is contributing to different efficacy of metformin in pancreatic cancer cells with different genotypes.

Citation Format: Beverly D. Lyn-Cook, Taylor Osborne, Stancy Joseph, Beverly Word, Li Pang, George Hammons. Metformin effects on ABCB1 expression and proliferation in pancreatic cancer cell lines with different ABCB1 genotypes/haplotypes. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4428. doi:10.1158/1538-7445.AM2015-4428
Abstract 4431: Musashi enhances GS3K-beta and promotes stemness-related chemoresistance in glioblastoma
Authors: Chen Hsiao-Yun , Chiou Shih-Hwa
Published: August 2015

Glioblastoma multiforme (GBM), one of the deadly malignant brain tumor, and is easily to recur and develop resistance to clinical chemotherapeutics. It has been demonstrated that cisplatin treatment select for resistance but also for a more oncogenic phenotype characterized by high self-renewal and oncogenic resistance. Musashi (MSI), a neural stem cell marker, is found to be elevated in several cancer tissues and positively regulates cancer progression. In this report, we found that MSI promoted tumourigenicity and enhances drug resistance of human GBM cells in response to cisplatin, a chemodrug. We further showed that MSI could activate and interact with phosphorylated-GS3K-β, and lead to a protective effect against mitigating cisplatin-induced cell death. Knockdown of MSI effectively suppressed the phosphorylation of GS3K-β and blocked β-catenin translocating into nucleus in cisplatin-resistant GBM cells, while overexpressing MSI reversed these effects. Notably, MSI could further upregulate β-catenin-driven stemness signature, and expression of Oct-4, Nanog, and ABCG2, thereby enhanced tumorigenicity and chemoresistance of GBM cells. Moreover, the result of in vivo animal study demonstrated that knockdown MSI effectively suppressed stem-like properties, synergistically enhanced the chemotherapeutic effect, and significantly improved survival rate in GBM-transplanted immunocompromised mice. Taken together, our findings indicated that MSI-1 may provide a positive contribution to oncogenic resistance, in partly, through interplaying with GS3K-β and modulating WNT/stemness mechanism.

Note: This abstract was not presented at the meeting.

Citation Format: Hsiao-Yun Chen, Shih-Hwa Chiou. Musashi enhances GS3K-beta and promotes stemness-related chemoresistance in glioblastoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4431. doi:10.1158/1538-7445.AM2015-4431
Abstract 4458: The HIV-derived protein Vpr52-96 has anti-glioma activity in vitro and in vivo
Authors: Kuebler Jens , Kirschner Stefanie , Hartmann Linda , Welzel Grit , Engelhardt Maren , Herskind Carsten , Veldwijk Marlon R. , Schultz Christian , Felix Manuela , Glatting Gerhard , Maier Patrick , Wenz Frederik , Brockmann Marc A. , Giordano Frank A.
Published: August 2015

Background: Patients with actively replicating human immunodeficiency virus (HIV) are highly radiosensitive and exhibit adverse reactions even at low irradiation doses. A major underlying cause is high intra- and extracellular levels of a virus-encoded peptide termed viral protein R (Vpr). As Vpr efficiently crosses the blood-brain barrier and accumulates in astrocytes, we examined whether it may be utilized as a drug in the treatment of glioblastoma multiforme (GBM).

Methods: Four glioblastoma-derived cell lines with and without lentivirus-mediated Methylguanine-DNA methyltransferase (MGMT) overexpression (U251, U87, U251-MGMT, U87-MGMT) were exposed to Vpr, temozolomide (TMZ), conventional photon irradiation (2-6 Gy) or to combinations. Caspase assays were employed to detect apoptosis. Colony formation assays were used to analyse clonogenic survival. Dose escalation was performed using n = 12 NOD/SCID/γc−/− (NSG) mice in a classical 3+3 manner. This strain was also used as an orthotopic implant model of glioma using luciferase-expressing U87 cells (n = 18). Continuous Vpr administration was achieved using osmotic pumps, irradiation (3×5 Gy) was performed using a small-animal irradiation device and intracerebral tumor growth was monitored using repetitive contrast-enhanced micro CT scans.

Results: Vpr showed high rates of acute toxicities with a LD50 of 4.0±1.1 μM for U251 and a LD50 of 15.7±7.5 μM for U87 cells. Caspase assays revealed Vpr-induced apoptosis in U251 but not in U87 cells. Vpr also efficiently inhibited clonogenic survival both in U251 and U87 cells and showed additive effects with irradiation. In contrast to TMZ, Vpr acted independently of the MGMT expression status. Dose escalation in mice (n = 12) was feasible and resulted in no evident renal or liver toxicity. Similar to irradiation with 3 × 5 Gy (n = 8), Vpr treatment of orthotopically implanted NSG mice (n = 5) delayed tumor growth and significantly (p = 0.041; log-rank test) prolonged overall survival compared to untreated animals (n = 5).

Conclusion: The HIV-encoded peptide Vpr exhibits all properties of an effective chemotherapeutic drug and may be a useful agent in the treatment of GBM.

Citation Format: Jens Kuebler, Stefanie Kirschner, Linda Hartmann, Grit Welzel, Maren Engelhardt, Carsten Herskind, Marlon R. Veldwijk, Christian Schultz, Manuela Felix, Gerhard Glatting, Patrick Maier, Frederik Wenz, Marc A. Brockmann, Frank A. Giordano. The HIV-derived protein Vpr52-96 has anti-glioma activity in vitro and in vivo. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4458. doi:10.1158/1538-7445.AM2015-4458
Abstract 446: Reciprocal paracrine signaling between epithelial and stromal cells alters the pancreatic tumor microenvironment
Authors: Stout Matthew C. , Cole Danielle R. , Campbell Paul M.
Published: August 2015

Despite considerable clinical and basic research efforts, the 5-year survival rate of pancreatic ductal adenocarcinoma (PDAC) remains a dismal 6 percent in the United States. Much of the mortality of the disease is a result, in part, of the unique microenvironment of PDAC tumors. The stroma, a heterogeneous population including fibroblasts, immune cells, vasculature and extracellular matrix, comprises the bulk of the PDAC tumor volume. We and others hypothesize that disparate cell populations within this tumor microenvironment are receptive to paracrine signaling from one another to drive tumor survival and metastatic progression. Previous work has shown that the ELR+ CXC-chemokines and their CXCR2 receptor are upregulated in PDAC and can promote tumor-associated phenotypes such as angiogenesis. Our current research seeks to demonstrate that the ubiquitous PDAC oncogene, K-Ras, affects additional elements of the tumor microenvironment through paracrine CXCR2 chemokine signaling. In particular, we are interested on the interdependence of proliferation, migration, senescence, survival and death between fibroblasts and pancreatic epithelial cells. We show that activated epithelial K-Ras increases CXCL release and CXCR2 expression, but remarkably, paracrine signals from PDAC cells decrease the number of fibroblasts. These data suggest potentially both pro and antitumor effects of paracrine signaling in pancreatic cancer. Experiments are ongoing to further investigate how CXC chemokines modulate the tumor microenvironment in order to reveal novel therapeutic targets and diagnostic biomarkers.

Citation Format: Matthew C. Stout, Danielle R. Cole, Paul M. Campbell. Reciprocal paracrine signaling between epithelial and stromal cells alters the pancreatic tumor microenvironment. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 446. doi:10.1158/1538-7445.AM2015-446
Abstract 4463: Riluzole effectively modulates cell cycle and cell death in a molecularly diverse set of breast cancer cell lines
Authors: Dolfi Sonia C. , Medina Daniel J. , Ganesan Shridar , Vazquez Alexei , Hirshfield Kim M.
Published: August 2015

Metabotropic glutamate receptor 1 (GRM1) has an established oncogenic role in melanoma. Growing evidence supports a similar role in breast cancer. We have previously shown that GRM1 is not only expressed in human breast cancers, but that levels of expression correlate with clinical outcomes with tamoxifen treatment, and that GRM1 knockdown reduces breast cancer cell viability and growth. Others have shown that GRM1 modulating drugs also reduce viability and growth of estrogen receptor (ER) negative breast cancer cell lines. Riluzole, a postulated inhibitor of glutamate release, has been evaluated in pre-clinical studies in melanoma. Early clinical trials have shown promising results for this disease. However, the mechanistic effects of riluzole have not been well-defined. Therefore, we evaluated the functional activity of riluzole in breast cancer.

A molecularly diverse set of ER+ and ER- breast cancer cell lines with variable GRM1 expression were evaluated. Cell lines were treated with either riluzole or BAY 36-7620 (non-competitive GRM1 antagonist) or their combination. Treatment with either drug reduces cell number and viability, inhibits cell proliferation, and alters expression of cell cycle and apoptotic pathway genes as determined by gene microarray analysis. Drug treatment produces cell line-dependent effects on markers for proliferation, cell cycle, DNA damage, and apoptosis. Riluzole induces G2/M arrest in all cell lines tested. More specifically, riluzole induces mitotic arrest as demonstrated by changes in histone H3 phosphorylation at serine 10 and cyclin B level. Treatment with BAY 36-7620 induces a modest G2/M arrest and increase in the sub G1 population in a subset of cell lines. However, BAY 36-7620 does not induce mitotic arrest. The combination of riluzole and BAY 36-7620 results in increased cell death and decreased proliferation in all cell lines tested.

Our data suggest that either riluzole or BAY 36-7620 induce breast cancer cell death. However, riluzole may modulate the activity of intracellular targets independent of GRM1. As riluzole is an FDA-approved drug, it could be quickly moved into a clinical trial and may provide a novel therapeutic approach in the treatment of breast cancer.

Citation Format: Sonia C. Dolfi, Daniel J. Medina, Shridar Ganesan, Alexei Vazquez, Kim M. Hirshfield. Riluzole effectively modulates cell cycle and cell death in a molecularly diverse set of breast cancer cell lines. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4463. doi:10.1158/1538-7445.AM2015-4463
Abstract 4474: Dual targeting of the stress-p53 pathway as a potential anti-cancer therapy
Authors: Lu Hua , Zhang Qi , Zeng Shelya X. , Wu Rui-Zhi , Zhang Yiwei , Nguyen Daniel , Zhou Xiang , Liao Jun-ming , Cao Bo
Published: August 2015

The “ribosomal stress (RS)-p53 pathway” is triggered by any stressor or genetic alteration that disrupts ribosomal biogenesis, and mediated by several ribosomal proteins (RPs), such as RPL11 and RPL5, which inhibit MDM2 and activate p53. IMPDH2 is a rate-limiting enzyme in de novo guanine nucleotide biosynthesis and crucial for maintaining cellular guanine deoxy- and ribonucleotide pools needed for DNA and RNA synthesis. It is highly expressed in many malignancies. We previously showed that inhibition of IMPDH2 leads to p53 activation by causing RS. Surprisingly, our current study reveals that Inauzhin (INZ), a novel non-genotoxic p53 activator by inhibiting SIRT1, can also inhibit cellular IMPDH2 activity, and reduce the levels of cellular GTP and GTP-binding nucleostemin that is essential for rRNA processing. Consequently, INZ induces RS and the RPL11/RPL5-MDM2 interaction, activating p53. These results support the new notion that INZ suppresses cancer cell growth by dually targeting SIRT1 and IMPDH2.

Note: This abstract was not presented at the meeting.

Citation Format: Hua Lu, Qi Zhang, Shelya X. Zeng, Rui-Zhi Wu, Yiwei Zhang, Daniel Nguyen, Xiang Zhou, Jun-ming Liao, Bo Cao. Dual targeting of the stress-p53 pathway as a potential anti-cancer therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4474. doi:10.1158/1538-7445.AM2015-4474
Abstract 4493: Ironing out breast cancer: investigation of a novel iron chelator
Authors: Greenshields Anna , Hoskin David , Coombs Melanie , Grant Taryn
Published: August 2015

Introduction: Breast cancer is the second leading cause of cancer-related death in women. Current breast cancer therapy is hindered by dose-limiting toxicities, demonstrating the need for less toxic alternatives. As cancer cells have an increased requirement for iron, we hypothesized that iron withdrawal using a highly selective iron chelator (DIBI) developed by Chelation Partners Incorporated (CPI) would enhance breast cancer cell killing by chemotherapeutic drugs and ionizing radiation.

Results: DIBI inhibited the growth of a panel of breast cancer cell lines while similar doses had limited effects on the growth of normal fibroblasts. In breast cancer cells, DIBI-mediated iron chelation increased transferrin receptor 1 mRNA expression and decreased the expression of ferroportin1 mRNA, which is indicative of decreased intracellular iron stores. Iron citrate reversed the inhibitory effect of DIBI, confirming the iron-specific activity of the compound. On the basis of iron-binding capacity, a comparison between DIBI and two conventional iron chelators demonstrated that DIBI was more effective at inhibiting breast cancer cell proliferation. DIBI-treated breast cancer cells showed a dose-dependent reduction in rounds of cell division, as well as arrest in the S-phase of the cell cycle. Higher doses of DIBI also induced apoptosis in breast cancer cells. In addition, DIBI treatment of breast cancer cells induced double-stranded DNA breaks, which are likely important for its anticancer activity. Pretreatment of breast cancer cells with DIBI enhanced the grow-inhibitory effects of ionizing radiation and conventional chemotherapeutic agents, suggesting that DIBI may increase the effectiveness of current breast cancer therapies. Combination treatment with cisplatin and DIBI demonstrated that DIBI enhanced both the cytotoxic and cytostatic anticancer effects of cisplatin.

Conclusion: These findings suggest that selective sequestration of iron from the tumor microenvironment may prevent or diminish tumor progression. In the future, treating patients with this novel iron chelator in combination with conventional therapies may increase the effectiveness of current breast cancer treatments.

Citation Format: Anna Greenshields, David Hoskin, Melanie Coombs, Taryn Grant. Ironing out breast cancer: investigation of a novel iron chelator. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4493. doi:10.1158/1538-7445.AM2015-4493
Abstract 4496: Genomics-based resistome analysis revealed endogenous adenosine kinase levels as a chief determinant of specificity for a novel nucleoside analog lymphoma inhibitor
Authors: Nayar Utthara , Reichel Jonathan , Sadek Jouliana , Hernandez-Hopkins Denise , Akar Gunkut , Zhou Hufeng , Sahai Michelle A. , Barelli Peter , Guasparri Ilaria , Totonchy Jennifer , Hassane Duane , Sei Shizuko , Shoemaker Robert H. , Warren J. David , Elemento Olivier , Kaye Kenneth M. , Cesarman Ethel
Published: August 2015

We used KSHV-infected primary effusion lymphoma (PEL) cells as a model to search for novel drugs through a combination of screening and genomic approaches. We discovered 6-ethylthioinosine (6-ETI), a nucleoside analog, as a highly effective and selective inhibitor of PEL. This compound induces necrosis accompanied by S-phase arrest without affecting known oncogenic viral proteins. To understand the selectivity towards PEL, we performed unbiased genomic analysis of 6-ETI-resistant subclones using RNASeq, which revealed that 6-ETI is activated through phosphorylation by cellular adenosine kinase (ADK). PEL cell lines have higher basal levels of ADK than resistant lymphoma cell lines, and resistant lymphoma cell lines could be sensitized by cell crowding-induced ADK upregulation. Finally, 6-ETI was shown to be highly efficacious against incipient and established tumors in a mouse model of PEL, with no apparent toxicity. Thus, we have successfully used RNASeq-based “resistome” analysis to identify the mechanism of specificity for a new and preclinically effective nucleoside analog.

Citation Format: Utthara Nayar, Jonathan Reichel, Jouliana Sadek, Denise Hernandez-Hopkins, Gunkut Akar, Hufeng Zhou, Michelle A. Sahai, Peter Barelli, Ilaria Guasparri, Jennifer Totonchy, Duane Hassane, Shizuko Sei, Robert H. Shoemaker, J. David Warren, Olivier Elemento, Kenneth M. Kaye, Ethel Cesarman. Genomics-based resistome analysis revealed endogenous adenosine kinase levels as a chief determinant of specificity for a novel nucleoside analog lymphoma inhibitor. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4496. doi:10.1158/1538-7445.AM2015-4496
Abstract 4505: Activity and avascular penetration of FTY720 (fingolimod) and its non-immune suppressant analogue (OSU2S) within three dimensional tissue culture model of colorectal cancer
Authors: Zaahkouk Samir A. , Elbehairi Serag Eldin I. , El-Sayed Aly F. , Bakry Sayed , Khedr Alaa , Omar Hany A. , Al-Abd Ahmed M.
Published: August 2015

Fingolimod (FTY-720) and its non-immunosuppressive analogue (OSU2S) possess anticancer activity against hepatocellular carcinoma attributed to interference with protein kinase Cδ (PKCδ) signaling. Avascular penetration represents a major limitation for the treatment of solid tumors nonetheless colorectal cancer. Herein, we are assessing the differential antiproliferative activity of OSU2S compared to FTY720 against multicellular spheroids of HCT-116 and HT-29 colorectal cancer cell lines. In addition, we are comparing the avascular penetration properties of OSU2S to FTY720 within the avascular multicellular layers model.

The IC50's of FTY720 and OSU2S were calculated in monolayer and spheroid culture models of HCT-116 and HT-29 cells using Emax model. Generally, OSU2S was found to be 1.5 to 3 folds more potent than FTY720 in both cell lines using monolayer and spheroid culture systems. The ratios between the IC50's of FTY720 in spheroid compared to monolayer cultures of HCT-116 and HT-29 cells were found to be to 5.7 and 3.4 folds, respectively. On the other hand, the ratios between the IC50's of OSU2S in spheroid compared to monolayer cultures of HCT-116 and HT-29 cells were found to be 4.5 and 3.4 folds, respectively. This might be attributed to avascular penetration problem for OSU2S and FTY720 in colorectal cancer. The pre-calculated IC50's of FTY720 and OSU2S induced significant increase in the cleaved fraction of PKCδ in both monolayer and spheroid model in HCT-116 and HT-29 cells. The influence of FTY720 and OSU2S on cell cycle analysis was studied using DNA flow cytometry analysis. Both FTY720 and OSU2S changed the cell cycle distribution of both HCT-116 and HT-29 cell lines in the monolayer culture and to a lesser extent in the spheroid culture model. The avascular penetration of OSU2S through multicellular layers of HCT-116 was 1.9 and 1.2 fold faster than FTY720 after 12 and 24 h of penetration, respectively. Also, OSU2S was faster than FTY720 in penetrating multicellular layers of HT-29 by 2.1 to 1.7 folds after 12 and 24 h of penetration, respectively. In conclusion, OSU2S possess better antiproliferative and avascular penetration profile within colorectal cancer cells compared to FTY720.

Citation Format: Samir A. Zaahkouk, Serag Eldin I. Elbehairi, Aly F. El-Sayed, Sayed Bakry, Alaa Khedr, Hany A. Omar, Ahmed M. Al-Abd. Activity and avascular penetration of FTY720 (fingolimod) and its non-immune suppressant analogue (OSU2S) within three dimensional tissue culture model of colorectal cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4505. doi:10.1158/1538-7445.AM2015-4505
Abstract 4538: Multivalent targeting based delivery of therapeutic peptide using AP1-ELP carrier for effective cancer therapy
Authors: Devi Sarangthem V. , Kim Yun Jae , Lee Young-Jin , Hur Kuen , Lee Byung-Heon , Park Rang Woon
Published: August 2015

The main objectives of drug delivery for almost all cancer therapies are to improve the therapeutic index of anticancer drugs by increasing the amount of drug delivered to the specific tumor site and decreasing its exposure to healthy tissues. Elastin like Polypeptides (ELPs) retain all the advantages of polymeric drug delivery systems, as they are composed of non-toxic and biodegradable amino acid, derived from mammalian tropoelastin. IL-4 receptors (IL-4R) are found to be highly expressed in a wide variety of human tumors and studies have reported that IL-4/IL-4R interactions amplify the expression of some anti-apoptotic proteins, so prevent drug-induced cancer cell death. Thus we have designed multivalent IL-4R targeted based macromolecular carriers, AP1-ELP polymers, in order to examine the therapeutic efficacy in delivering the therapeutic peptide (KLAKLAK)2 to tumor cells. As for the study AP1-ELP polymer, containing six IL-4R binding peptide (AP1) was conjugated with proapoptotic peptide (KLAKLAK)2 on the C-terminal site by cloning. The resultant AP1-ELP-(KLAKLAK)2 construct was successfully expressed and purified from E coli using inverse temperature cycling method. Confocal imaging verified the better cellular accumulation of AP1-ELP-(KLAKLAK)2 in IL-4R highly expressing cancer cells. The cytotoxic effect towards IL-4R highly expressing tumor cells were highly enhanced when treated with AP1-ELP-(KLAKLAK)2 compared to control. FACS analysis data confirmed the significant increase of apoptotic cells when treated with AP1-ELP-(KLAKLAK)2 compared to ELP-(KLAKLAK)2 in dose dependent manner. Ex vivo biodistridution study displayed an increase in intra-tumoral uptake and localization of FNR-675 labeled AP1-ELP-(KLAKLAK)2 than ELP-(KLAKLAK)2. Additionally, AP1-ELP-(KLAKLAK)2 significantly inhibit the tumor growth when injected intravenously in MDA-MB 231 xenograft mouse model. Thus AP1-ELP-(KLAKLAK)2 polymer enhanced apoptotic and antitumor activity against IL-4R highly expressing tumor cells suggesting the clinical potential of our polymer.

Citation Format: Sarangthem V. Devi, Yun Jae Kim, Young-Jin Lee, Kuen Hur, Byung-Heon Lee, Rang Woon Park. Multivalent targeting based delivery of therapeutic peptide using AP1-ELP carrier for effective cancer therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4538. doi:10.1158/1538-7445.AM2015-4538
Abstract 4539: Nitroxide-aspirin conjugates: A new class of NSAIDs
Authors: Moody Terry W. , Jensen Robert T. , Thomas Komba , Fairfull-Smith Kathryn E. , Bottle Steven E. , Ridnour Lisa , Wink David A.
Published: August 2015

Novel nitroxide-aspirin conjugates were synthesized and tested using human lung cancer cell lines. Previously, cyclooxygenase (COX2) was found to be elevated in lung cancer biopsy specimens relative to normal tissue (He et al., 2012; PlosOne 7:e31087). Lung cancer cellular proliferation is inhibited by nonsteroidal anti-inflamatory drugs (NSAIDs) such as indomethacin and aspirin (Hida et al., 1998; Anticancer Res. 18: 775). Dithiolethione-valproate conjugates inhibit COX-2 activity, increase E-cadherin expression and decrease the proliferation of non-small cell lung cancer (NSCLC) cells (Moody et al., 2010, Lung Cancer 68: 154). Here the effects of nitroxide-aspirin conjugates were investigated on NSCLC cells. 1KT121A, a 4-carboxy Tempo-aspirin conjugate, inhibited the proliferation of NCI-H1299 or A549 cells with IC50 values of 125 uM using the MTT assay whereas aspirin and tempol had IC50 values of 750 and >1000 uM, respectively. 1KT121A, which has an ester link, was approximately 5-fold more potent at inhibiting NSCLC cellular proliferation than aspirin plus tempol or 2KT106A, which is a Tempo-aspirin conjugate with an amide link. 1KT121A was more potent than 2KT106A or tempol plus aspirin at reducing prostaglandin E2 levels in A549 cells. Similar results were obtained if the nitroxide moiety was changed from 4-carboxy Tempo to 3-carboxy proxyl or 5-carboxy-1,1,3,3-tetramethylisoindolin-yloxyl (CTMIO). 1KT121A potentiated the ability of gefitinib, an EGF receptor tyrosine kinase inhibitor, to kill NSCLC cells. Because 1KT121A increased E-cadherin and reduced vimentin, it may impair epithelial-mesenchymal transitions of NSCLC cells. All of the nitoxide analogues were antioxidants based on the ability to inhibit reactive oxygen species in NSCLC cells treated with hydrogen peroxide. Nitroxide-aspirin conjugates represent a novel class of NSAIDs which are antioxidants that inhibit NSCLC proliferation.

Citation Format: Terry W. Moody, Robert T. Jensen, Komba Thomas, Kathryn E. Fairfull-Smith, Steven E. Bottle, Lisa Ridnour, David A. Wink. Nitroxide-aspirin conjugates: A new class of NSAIDs. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4539. doi:10.1158/1538-7445.AM2015-4539
Abstract 4543: Characterization of the liposomal formulation of eribulin mesylate (E7389) in mice
Authors: Asano Makoto , Hyodo Kenji , Yu Yanke , Schuck Edgar , Matsui Junji , Ishihara Hiroshi , Kikuchi Hiroshi , Nomoto Kenichi
Published: August 2015

E7389 (eribulin mesylate, Halaven, Eisai) is a fully synthetic analog of the marine sponge natural product halichondrin B. It has been approved in US and more than 50 countries worldwide for treatment of advanced breast cancer. To improve the therapeutic index of E7389, a liposomal formulation of E7389, E7389-LF is under development. In this study, we characterized the pharmacokinetics of E7389-LF and E7389 (aqueous formulation) in mice and evaluated the anti-tumor activity of E7389-LF and E7389 in mouse xenograft model. In general the pharmacokinetics of E7389-LF was characterized by a small volume of distribution, slow clearance, and slow elimination in all liposomal formulations tested. Plasma AUC of E7389-LF was more than 600 fold larger than that of E7389 in tumor bearing mice. Tumor AUC of E7389-LF was also observed. Moreover, free E7389 (not liposome encapsulated and not protein bound) was measured in mouse plasma by ultracentrifugation method. The concentration ratio of E7389 in ultracentrifuged mouse plasma (UCM) vs E7389 in plasma after a 2 mg/kg i.v. of E7389 ranged from 54.19% to 65.41%, which was similar to the free fraction in the mouse plasma. The respective concentration ratio of E7389 in UCM vs E7389 in plasma after a 2 mg/kg i.v. of E7389-LF ranged from 0.07% to 0.59%, and the exposure, expressed as AUC, of UCM/plasma ratio was determined to be 0.2%. The free E7389 exposure, measured by UCM, after E7389-LF administration was about 1.5 fold of that after E7389 administration. Anti-tumor activity of E7389-LF and E7389 was evaluated in a human pharynx carcinoma, FaDu, xenograft model. E7389-LF showed dose-dependent anti-tumor effect with regression of tumors at 2.5 mg/kg dose, which was significantly better than that after E7389 administration in this model. These findings suggest that E7389-LF showed better anti-tumor activity than that of E7389 in human FaDu xenograft mouse model.

Citation Format: Makoto Asano, Kenji Hyodo, Yanke Yu, Edgar Schuck, Junji Matsui, Hiroshi Ishihara, Hiroshi Kikuchi, Kenichi Nomoto. Characterization of the liposomal formulation of eribulin mesylate (E7389) in mice. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4543. doi:10.1158/1538-7445.AM2015-4543
Abstract 4552: Apatorsen enhances 5-FU sensitivity in colon cancer cell SW480
Authors: Shimada Takehiro , Tsuruta Masashi , Akimoto Shingo , Koishikawa Kaoru , Okabayashi Koji , Hasegawa Hirotoshi , Kitagawa Yuko
Published: August 2015

[Background] Heat Shock Protein (HSP) 27 is a chaperone protein of small molecular weight, which protects cells in response to various stresses. Previously we elucidated that HSP27 was a key molecule in determining 5-Fluorouracil (5-FU) resistance in colorectal cancer (CRC). Thus, apatorsen, an antisense oligonucleotide that suppresses HSP27 levels intracellularly, might overcome 5-FU resistance in CRC. In this basic research, we evaluated the feasibility of adding apatorsen with 5-FU against CRC.

[Methods] Human CRC cell line SW480 was treated with apatorsen (1nM, 10nM, 100nM) for 48 hours continuously. HSP27 protein level was determined by immunoblot and densitometry analysis. Next, the cells were exposed by various concentrations of 5-FU for 48 hours following treatment with apatorsen. The in vitro growth inhibition rates (IR) were assessed by MTT assay and we evaluated the change of 5-FU resistance, which was estimated as the drug concentration inducing 50% IR (IC50).

[Results] Apatorsen (0, 1, 10, 100nM) successfully suppressed HSP27 protein levels (100, 86.6, 61.0, 50.5%) in a dose-dependent manner. In cell viability assays, apatorsen changed the IC50 of 26.65μg/ml in control into 15.55 (58.3%), 11.28 (42.3%), and 9.18 (34.4%) respectively.

[Summaries] Apatorsen significantly enhanced 5-FU sensitivity in the CRC cell line SW480 by suppressing HSP27 levels. HSP27 may serve as a reliable target in enhancing 5-FU chemotherapy for CRC. Therefore, apatorsen is a promising treatment requiring further investigation.

Citation Format: Takehiro Shimada, Masashi Tsuruta, Shingo Akimoto, Kaoru Koishikawa, Koji Okabayashi, Hirotoshi Hasegawa, Yuko Kitagawa. Apatorsen enhances 5-FU sensitivity in colon cancer cell SW480. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4552. doi:10.1158/1538-7445.AM2015-4552