bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 1595: Analysis of circulating epithelial and EMT-like CTCs in pancreatic cancer using a sensitive microfluidic CTC capture device
Authors: Zeinali Mina , Murlidhar Vasudha , Fouladdel Shamileh , Hafner Mathius , Shao Shimeng , Azizi Ebrahim , Wicha Max S. , Cuneo Kyle , Simeone Diane M. , Nagrath Sunitha
Published: August 2015

Background & Aims: A critical factor in the poor outcomes in pancreatic cancer is due to it's silent nature until late in the disease process, so early detection has remained a major issue in this type of cancer. Detection, quantification, and molecular characterization of Epithelial circulating tumor cells (CTCs) as well as Epithelial-to-Mesenchymal Transition (EMT)-like CTCs in peripheral blood have been recognized as a means of “liquid biopsy” technique in the diagnosis of cancer and metastasis.

Methods: A modified version of CTC chip, CTC Carpet chip was used to investigate the inextricable relationship between circulating epithelial and EMT-like CTCs in 40 pancreatic cancer patients at both protein and RNA levels.

Results: The recovery from whole blood spiked with different cancer cell line was validated, achieving a mean efficiency of ∼100% for both HT-29 and Panc-1 cell lines compared to <80% for PC-3 cell line. Out of 40 patients, 38 patients had ≥5 CK+ CTCs with a mean of 21.84 per mL and all 40 samples had ≥ 15 Vim+ CTCs with mean of 89.77 per mL of whole blood. Up to 67 CK+ epithelial and 257 Vim+ EMT like CTCs were detected in these set of samples. The results indicated the significant differences between the numbers of Epithelial CTCs vs. EMT-like CTCs in both stage I-II and IV of these 40 pancreatic cancer patients’ samples.

Conclusion: Although the isolation of CTCs from pancretic cancer is possible nowadays, investigation of their clinical utility has proven less successful than the other cancer types, due to poor sensitivity of many CTC assays for patients with PDAC. Herein, we present an integrated microfluidic technology- and biology-based translational approach using bioengineering tools to identify and study the biological relevance of rare CTCs including both circulating epithelial and EMT-like tumor cells simultaneously from the peripheral blood of pancreatic cancer patients by using multiple markers of interest.

Citation Format: Mina Zeinali, Vasudha Murlidhar, Shamileh Fouladdel, Mathius Hafner, Shimeng Shao, Ebrahim Azizi, Max S. Wicha, Kyle Cuneo, Diane M. Simeone, Sunitha Nagrath. Analysis of circulating epithelial and EMT-like CTCs in pancreatic cancer using a sensitive microfluidic CTC capture device. [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 1595. doi:10.1158/1538-7445.AM2015-1595
Abstract 163: Investigation of molecular mechanisms by which PCA3 modulates prostate cancer cell survival
Authors: Goulart Ana Emilia , Ferreira Luciana B. , de Freitas Paula Priscilla , Batoreu Nadia , BONAMINO MARTIN H. , Gimba Etel Rodrigues Pereira
Published: August 2015

PCA3 is a prostate-specific non coding RNA (ncRNA), involved in the control of prostate cancer (PCa) cell survival, through modulating androgen receptor (AR) signaling. We aimed to investigate whether several cancer related genes, including those involved in epithelial-mesenchymal transition (EMT) and AR co-regulators could modulate LNCaP cell survival in response to PCA3 downregulation. We also aimed to promote PCA3 stable silencing through a lentiviral vector containing a PCA3 short hairpin RNA (shRNA) specific sequence. Small interfering RNA (siRNA) or lentivirus vector-based shRNA were used to downregulate PCA3 expression. Upon PCA3 downregulation, cells were analyzed by qRT-PCR to investigate mRNA expression. Flow cytometry was performed to analyze the percentage of LNCaP GFP + cells and trypan blue staining to analyze the number of viable cells after PCA3 stable silencing. Among 14 AR co-regulators genes investigated, 12 were upregulated in siPCA3-transfected cells in relation to controls. We also found that among 84 cancer-related genes tested, 16 were differentially expressed in LNCaP siPCA3-transfected cells when compared to transfected cells with a scramble sequence. Of these, 30% are genes coding for signal transduction molecules and transcription factors. Gene expression profile of EMT-related genes revealed that E-cadherin, Claudin-3, Cytokeratin-18, Snail, Twist and Slug are upregulated in LNCaP siPCA3-transfected cells compared to control, while Claudin-4, Cytokeratin-8 and Vimentin are downregulated. LNCaP cells transduced with lentiviral vectors carrying the GFP gene and shPCA3 stably dowregulated PCA3 expression, producing a reduction of 60% of LNCaP GFP+ cells compared to shScr transduced or non-transduced LNCaP cells. Our results suggest that the decrease in the number of LNCaP viable cells upon siPCA3 transfection is not modulated by the classical EMT program. Observed upregulation of most tested AR co-regulators upon PCA3 silencing indicates that this non-coding RNA could negatively modulate the transcription of these genes. Our data further suggest that that this ncRNA perform a regulatory role in gene expression, being able to modulate gene expression of several signaling pathways related to cancer. Finally, stable silencing of PCA3 expression using lentivirus vector shows potential as a PCa therapeutic approach by negatively modulating cell survival.

Citation Format: Ana Emilia Goulart, Luciana B. Ferreira, Paula Priscilla de Freitas, Nadia Batoreu, MARTIN H. BONAMINO, Etel Rodrigues Pereira Gimba. Investigation of molecular mechanisms by which PCA3 modulates prostate cancer cell survival. [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 163. doi:10.1158/1538-7445.AM2015-163
Abstract 1630: Effects of rhBMP-2 on osteosarcoma tumorigenesis
Authors: Piperdi Sajida , Geller David , Park Amy , Chung So Hak , Gorlick Richard
Published: August 2015

Introduction: Osteosarcoma (OS) is the most common primary bone malignancy in children and young adults. Complete surgical extirpation of bulk tumor is essential to successful treatment of OS. While historically ablative surgery such as amputations were the mainstay of treatment, wide excision has been shown to provide equivalent survival results, permitting for limb-salvage surgery in over 90% of cases. Following tumor resection, structural allograft bone is often employed to reconstruct the involved extremity. Bone Morphogenetic Protein-2 (BMP-2), a member of the TGF beta superfamily, possesses tremendous osteoinductive potential and could theoretically be used to promote bone healing but has been historically contraindicated due to concern it may stimulate residual tumor. To date, the role of BMP-2 in OS remains unclear and its effect on OS remains controversial. The purpose of this investigation is to evaluate the effect of exogenous recombinant human BMP-2 (rhBMP-2) on osteosarcoma. We hypothesize that exposure of osteosarcoma to rhBMP-2 will not stimulate tumor growth or development.

Methods: Functional assays were performed using five standard osteosarcoma cell lines (143B, MG-63, SaOS-2, U20S, and HOS) and three patient derived xenograft cell lines (OS17, OS31, LM7). The concentration of rhBMP-2 utilized varied between 0.5 to 2 μg/ml. Motility (random migration) was measured by wound healing scratch assay. Migration (both haptotaxis and chemotaxis) was quantitatively measured using Boyden Chamber assay. Invasion was also measured using Boyden chamber over which a thin layer of extracellular matrix is applied. Comparison between different concentrations of rhBMP-2 upon different time points on osteosarcoma cell lines and characterizations are completed and underway.

Results: Preliminary findings suggest that exogenous rhBMP-2 does not increase the ability of osteosarcoma cells to migrate and invade in all tested lines (143B, MG-63, OS17). Quantitative migration decreases with increasing concentration of rhBMP-2 over a 5-hour time course in all tested lines (143B, SaOS-2, MG-63, OS17). Invasion did not increase with increasing rhBMP-2 concentration in any tested line (143B, SaOS-2, OS17).

Conclusions and Future Directions: Preliminary results support the contention that exposure of osteosarcoma to exogenous rhBMP-2 does not increase in vitro tumorigenesis. In fact, findings suggest that rhBMP-2 may have a protective effect in that tumor migration decreases following exposure. Continued characterization using additional tumor lines is ongoing.

Citation Format: Sajida Piperdi, David Geller, Amy Park, So Hak Chung, Richard Gorlick. Effects of rhBMP-2 on osteosarcoma tumorigenesis. [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 1630. doi:10.1158/1538-7445.AM2015-1630
Abstract 1642: Antitumor activity of lurbinectedin toward ovarian clear cell carcinoma
Authors: Takahashi Ryoko , Mabuchi Seiji , Matsumoto Yuri , Kawano Mahiru , Sasano Tomoyuki , Kuroda Hiromasa , Kozasa Katsumi , Sawada Kenjirou , Kimura Tadashi
Published: August 2015

Objectives:Lurbinectedin is a marine-derived covalent DNA minor groove binder and is structurally similar to trabectedin except for the C subunit. Lurbinectedin (PM01183) is a newly developed antitumor agent that is currently being investigated in phase I/II clinical trials in patients with solid tumors including ovarian cancer. The objective of this study is to investigate the effectiveness of lurbinectedin as a single agent or as combination with existing antitumor agent against ovarian clear cell carcinoma which is regarded as an aggressive chemoresistant histological subtype.

Methods:Using human ovarian clear cell carcinoma cell lines, the anti-tumor effects of lurbinectedin, SN38, topotecan, doxorubicin, cisplatin and paclitaxel as single agent were assessed by MTS assay. Then the cytotoxicities of combination treatments involving lurbinectedin and 1 of the 4 agents were evaluated by isobologram analysis to examine which of these combinations displayed synergistic effects. The antitumor activities of the combination treatments were also examined using cisplatin-resistant and paclitaxel-resistant ovarian clear cell carcinoma sublines, which were derived from the parental clear cell carcinoma cells by continuously exposing them to cisplatin or paclitaxel. Finally, using nude mice inoculated with clear cell carcinoma cells, we examined the growth-inhibitory effect of lurbinectedin in vivo.

Results:Lurbinectedin showed significant antitumor activity toward chemosensitive and chemoresistant CCC cells in vitro. Mouse xenografts of CCC cells revealed that lurbinectedin significantly inhibits tumor growth. Concurrent exposure to lurbinectedin and SN-38 resulted in synergistic interactions in CCC cell lines. The combination of lurbinectedin plus SN-38 also had strong synergistic effects on both the cisplatin-resistant and paclitaxel-resistant CCC cell lines. Treatment with everolimus significantly enhanced the antitumor activity of single agent lurbinectedin and combination of lurbinectedin plus SN-38.

Conclusions:Lurbinectedin is a promising agent for CCC as a first-line chemotherapy and as a second-line treatment of recurrent CCC that had previously been treated with cisplatin or paclitaxel. Moreover, lurbinectedin combined with irinotecan may be more efficacious for the management of CCC.

Citation Format: Ryoko Takahashi, Seiji Mabuchi, Yuri Matsumoto, Mahiru Kawano, Tomoyuki Sasano, Hiromasa Kuroda, Katsumi Kozasa, Kenjirou Sawada, Tadashi Kimura. Antitumor activity of lurbinectedin toward ovarian clear cell carcinoma. [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 1642. doi:10.1158/1538-7445.AM2015-1642
Abstract 1655: Targeting RFX-1 as a novel therapeutic strategy in hepatocellular carcinoma
Authors: Su Jung-Chen
Published: August 2015

Regulatory factor X (RFX) 1 is a transcription factor that has been linked to negative regulation of tumor progression; however, its biological function and signaling cascades are unknown. In this study, we identify RFX-1 is a negative regulator of cell proliferation in human HCC. We demonstrated that ectopic expression of RFX-1 suppressed the colony forming ability of HCC cell lines through activating SHP-1 expression. In addition, nude mice bearing RFX-1-overexpressing tumors showed a repression of growth rate compared to the control group. Notably, we demonstrated that mRNA and protein level of RFX-1 is highly correlated with SHP-1 in 101 clinical HCC patients, indicating that RFX-1 might be a tumor suppressor of human HCC. To identify the RFX-1 activator for HCC therapy, we screened in-house small molecule library and found that one of small molecules, SC-2001, targeted RFX-1 and exhibited potent anti-tumor effect on HCC cells. In addition, we proved that SHP-1 activation and STAT3 dephosphorylation induced by SC-2001-activated RFX-1. Furthermore, genetic knockdown of RFX-1 reversed SC-2001-induced cell growth inhibition. Importantly, by a mouse xenograft model, silencing of RFX-1 could rescue the anti-HCC tumor effect caused by SC-2001 in vivo, implying that RFX-1 is a promising target for HCC therapy. Taken together, our results indicated that RFX-1/SHP-1/STAT3 signaling might a potential strategy for HCC therapy, and SC-2001 is a promising lead compound for drug development of HCC target therapy.

Citation Format: Jung-Chen Su. Targeting RFX-1 as a novel therapeutic strategy in hepatocellular carcinoma. [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 1655. doi:10.1158/1538-7445.AM2015-1655
Abstract 1658: Proteolytic processing pathways for topoisomerase covalent complexes
Authors: Sun Yilun , Nitiss Karin C. , Nitiss John L.
Published: August 2015

DNA topoisomerase II (Top2) is the target of several important anti-cancer agents, including doxorubicin and etoposide. Clinically active Top2 agents, termed Top2 poisons, act by blocking the enzyme reaction at a step where the protein is covalently bound to DNA. This leads to the accumulation of Top2/DNA complexes that act as DNA damaging agents that can trigger cell death. Surviving Top2-induced damage likely requires the repair of the enzyme induced damage and has been hypothesized to include pathways that proteolyze the protein bound to DNA followed by nucleolytic removal of the remaining peptide that is bound to DNA by a phosphotyrosyl linkage. This model of repair suggests that inhibition of proteolysis would lead to elevated levels of intact Top2/DNA complexes, and increased sensitivity to Top2 poisons such as etoposide. We have tested this model using the proteasome inhibitor carfilzomib in a pediatric rhabdomyosarcoma cell line (Rh30). We found that carfilzomib enhanced cell killing by etoposide, and that co-treatment of Rh30 cells with carfilzomib led to increases in both Top2 alpha and Top2 beta covalent complexes. These results suggest that proteasomal degradation of both Top2 isoforms is important for repairing DNA damage arising from etoposide. We are also interested in identifying the determinants of Top2 degradation following treatment with etoposide, especially proteins that recognize the trapped enzyme as DNA damage. We used a yeast genetic model system to address this question. We showed that the proteasome inhibitor MG132 greatly enhanced the sensitivity of yeast cells to etoposide, and that co-treatment of MG132 and etoposide led to elevated levels of Top2/DNA complexes compared to etoposide alone. We found that deletion of the human RNF4 homolog Slx5/Slx8 (a SUMO dependent ubiquitin ligase) also leads to an increase in Top2 covalent complexes induced by etoposide. We found that deletion of the genes encoding either Slx5 or Slx8 along with the repair protein Tdp1 led to much higher levels of cell killing compared to single deletions. These results suggest that there are at least two independent pathways for repairing Top2 damage, one dependent on Slx5/Slx8 dependent protein degradation and a second pathway dependent on nucleolytic removal of Top2. We suggest that Slx5/Slx8 plays a role in targeting Top2 for degradation following etoposide treatment. Our results also provide a rationale for the combination of a proteasome inhibitor with etoposide as an approach of increasing the efficacy of etoposide.

Citation Format: Yilun Sun, Karin C. Nitiss, John L. Nitiss. Proteolytic processing pathways for topoisomerase covalent complexes. [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 1658. doi:10.1158/1538-7445.AM2015-1658
Abstract 1673: Galunisertib combined with sorafenib affects proliferation, EMT and delays tumor growth in mice and in hepatocellular carcinoma (HCC) patient samples ex vivo
Authors: Tijeras-Raballand Annemilai , Serova Maria , Neuzillet Cindy , Albuquerque Miguel , Colnot Nathalie , Barral Matthias , Dohan Anthony , Barral Matthias , Bonnin Philippe , Pocard Marc , Paradis Valérie , Raymond Eric , Faivre Sandrine , de Gramont Armand
Published: August 2015

Introduction: The TGF-β pathway that has been associated with hepatocellular carcinoma (HCC) progression, can be targeted by galunisertib, a selective ATP-mimetic TGF-β receptor (TβR)-I inhibitor currently under clinical investigation in HCC patients after sorafenib failure or ineligible for sorafenib treatment. Our study aimed to investigate the tumor effects of galunisertib with or without sorafenib in different models of HCC and in freshly grown HCC specimens from patients.

Material and methods: Transgenic mice developing stage-defined HCC were treated for 12 weeks (W) with either vehicle, sorafenib (30mg/kg), galunisertib (100mg/kg) or sorafenib plus galunisertib. Human hepatocarcinoma HUH7 cells were subcutaneously injected in nude mice and treated daily with either vehicle, sorafenib (60mg/kg) or sorafenib combined with galunisertib (100mg/kg). Ex vivo experiments were realized in surgical specimens from HCC patients that were cut into 300μM and grown in specific media. Slices were randomly exposed to galunisertib (10μM), sorafenib (5μM) and sorafenib plus galunisertib for 48h. At the end of treatments, tumor samples were analyzed by IF or IHC.

Results: In transgenic mice, the number of liver tumor macronodules was significantly lower in all treatment arms compared to control placebo (p3 fold decrease in proliferation (Ki67 expression) and 3-5 fold increase in apoptosis induction (caspase-3 expression).

Conclusion: In vivo and ex vivo, TGF-β signalling inhibition using galunisertib in combination with sorafenib in HCC models showed promising data on downstream signaling pathway, angiogenesis and tumor growth inhibition and may prevent sorafenib-induced EMT.

Citation Format: Annemilai Tijeras-Raballand, Maria Serova, Cindy Neuzillet, Miguel Albuquerque, Nathalie Colnot, Matthias Barral, Anthony Dohan, Matthias Barral, Philippe Bonnin, Marc Pocard, Valérie Paradis, Eric Raymond, Sandrine Faivre, Armand de Gramont. Galunisertib combined with sorafenib affects proliferation, EMT and delays tumor growth in mice and in hepatocellular carcinoma (HCC) patient samples ex 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 1673. doi:10.1158/1538-7445.AM2015-1673
Abstract 1677: Annexin A2 antibody inhibits the progression of triple-negative and herceptin-resistant breast cancer by blocking epidermal growth factor receptor functions
Authors: Chaudhary Pankaj , Gibbs Lee Daniel , Vishwanatha Jamboor K.
Published: August 2015

Short Description:

Annexin A2 (AnxA2), a calcium-dependent phospholipid binding protein, is abundantly present at the surface of triple-negative and Herceptin-resistant breast cancer cells. Interactions between cell-surface AnxA2 and tyrosine kinase receptors have an important role in the tumour microenvironment and act together to enhance tumour growth. The mechanism supporting this role is still unknown.

Methods:

Triple-negative (MDA-MB-231) and Herceptin-resistant (JIMT-1) breast cancer cell lines were grown in complete DMEM and DMEM/F12 medium respectively, in a humidified incubator at 37°C with 5% CO2. The membrane function of AnxA2 was blocked by incubating cells with anti-AnxA2 antibodies. Western blotting, immunoprecipitation, immunofluorescence, 1-(4,5-Dimethylthiazol-2-yl)-3,5-diphenylformazan (MTT), flow cytometry, Clonogenic, and wound-healing assays were performed in this study

Results:

We demonstrate that in triple-negative and Herceptin-resistant breast cancer cells a large amount of AnxA2 is specifically translocated to the outer membrane domain. In addition, AnxA2 interacts with extracellular domain of epidermal growth factor receptor (EGFR) at the cell surface and has an important role in cancer cell proliferation and migration by modulating EGFR functions. Blocking AnxA2 function at the cell surface by anti-AnxA2 antibody suppressed the EGF-induced EGFR tyrosine phosphorylation and internalization by blocking its homodimerization. Furthermore, addition of AnxA2 antibody significantly inhibited the EGFR-dependent PI3K-AKT and Raf-MEK-ERK downstream pathways under both EGF-induced and basal growth conditions, resulting in lower cell proliferation and migration.

Conclusions: These studies indicate that association of AnxA2 with EGFR in the membrane domain might play a positive regulatory role in keeping EGFR signaling events in an activated state in triple negative and Herceptin-resistant breast cancer thus making AnxA2 an important therapeutic target.

Citation Format: Pankaj Chaudhary, Lee Daniel Gibbs, Jamboor K. Vishwanatha. Annexin A2 antibody inhibits the progression of triple-negative and herceptin-resistant breast cancer by blocking epidermal growth factor receptor functions. [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 1677. doi:10.1158/1538-7445.AM2015-1677
Abstract 1692: Antibody-drug conjugates to target cell surface TACE-cleaved amphiregulin in breast cancer
Authors: Jenkins Edmund C. , Levano Kelly S. , Jung Eric H. , Levy Matthew , Kenny Paraic A.
Published: August 2015

Approximately 70% of breast cancer cases are Estrogen Receptor (ER) positive. In many cases, these patients are well-served by endocrine therapies such as tamoxifen and aromatase inhibitors, however the emergence of endocrine-resistant disease in up to 40% of these patients is a major clinical concern. This necessitates treatment with more toxic chemotherapies which are often successful at delaying tumor progression, but are not curative.

Recent work from our group and others has demonstrated that Amphiregulin, an Epidermal Growth Factor Receptor (EGFR) ligand, is a critical effector of ER signaling in both normal development and breast cancer pathogenesis, and is expressed in both endocrine-sensitive and endocrine-resistant breast cancer. Like other EGFR ligands, Amphiregulin is proteolytically processed at the cell surface to release a soluble EGFR-binding signaling domain and a residual cell-associated stalk. In this project, we are developing antibodies that selectively recognize the residual transmembrane Amphiregulin cleavage product with the goal of developing antibody-drug conjugates with which to selectively target tumor cells with high levels of Amphiregulin shedding.

We have generated six humanized antibodies that recognize the cell-associated neo-epitope revealed following the TACE-mediated proteolytic release of Amphiregulin. Using both flow Cytometry and immunofluorescence, we demonstrate that these antibodies selectively recognize cleaved over full-length Amphiregulin in estrogen receptor positive breast cancer cells. Conjugation of these antibodies with a pH-sensitive dye, pHrodo, demonstrates robust and rapid antibody internalization in live cells. Conjugation of these antibodies with monomethyl auristatin E results in the disruption of the microtubule network of breast cancer cells followed by cell death. We propose that these agents may have utility in the treatment of breast and other cancers in which Amphiregulin expression and processing play a prominent role.

This study is supported by the Department of Defense Breast Cancer Research Program (W81XWH-14-1-0294).

Citation Format: Edmund C. Jenkins, Kelly S. Levano, Eric H. Jung, Matthew Levy, Paraic A. Kenny. Antibody-drug conjugates to target cell surface TACE-cleaved amphiregulin in breast 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 1692. doi:10.1158/1538-7445.AM2015-1692
Abstract 1694: Preclinical evaluation of a novel bispecific targeted toxin for the treatment of sarcomas
Authors: Borgatti Antonella , Winter Amber , Stuebner Kathleen , Koopmeiners Joseph , Modiano Jaime F. , Vallera Daniel
Published: August 2015

Introduction: EGFuPA is a bispecific ligand-targeted toxin consisting of epidermal growth factor (EGF) and urokinase (uPA) on the same molecule with truncated Pseudomonas exotoxin. The toxin was mutated to remove amino acids recognized by B-cells. EGFuPA is uniquely designed to simultaneously target EGF receptors (EGFR) and/or urokinase receptors (uPAR) on tumor cells and uPAR in the microenvironment. EGFuPA is safe and effective in laboratory animals and has excellent in vitro activity against sarcomas. Because EGFuPA crosses species platforms, an adaptive phase 1/2 study was undertaken using canine hemangiosarcoma (HSA) as a model of a highly aggressive, metastatic vascular sarcoma. We hypothesized that six-month survival would exceed 50% for dogs enrolled. Canine HSA is a tumor derived from blood vessel forming cells, which can overexpress both uPAR and EGFR rendering it an excellent target for the drug. It bears similarity to human angiosarcoma.

Methods: Enrollment began in November 2012. Dogs with histologically confirmed, non-metastatic stage-I or II splenic HSA were eligible after splenectomy. EGFuPA was administered intravenously for one cycle on Days 1, 3, and 5. Adjuvant doxorubicin was given according to standard of care (SOC) protocols starting seven days after the last dose of EGFuPA.

Results: EGFuPA was detectable in the systemic circulation 5 minutes post-infusion with clearance by 15 minutes. The drug was well tolerated with self-limiting, reversible hypovolemia at the highest dose. Thus far, 50 μg/kg appears to be the optimal dose. When compared to a historical control group of 19 dogs treated with SOC between 2008 and 2011, median survival is significantly longer for all 16 dogs treated with EGFuPA (SRCBST group, 240 vs. 129 days, p = 0.03) and for the 10 dogs in the Optimal Dose group (MS not reached, p = 0.01). Six-month survival for the Optimal Dose group was 65%. Overall survival at 400 days was 7% for the SOC group, 32.7% for the SRCBST group, and 56% for the Optimal Dose group. Outcomes were not affected by the presence of neutralizing antibodies.

Conclusions: A biologically active dose of EGFuPA was established and found to be safe in companion dogs with HSA in the minimal residual disease setting. The unique nature of its bispecific targeting and the observed significant, biologic activity warrants consideration of EGFuPA for a phase 1 study for drug-refractory sarcomas in human patients.

Citation Format: Antonella Borgatti, Amber Winter, Kathleen Stuebner, Joseph Koopmeiners, Jaime F. Modiano, Daniel Vallera. Preclinical evaluation of a novel bispecific targeted toxin for the treatment of sarcomas. [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 1694. doi:10.1158/1538-7445.AM2015-1694
Abstract 1713: IL-24 inhibits lung cancer cell migration and invasion by disrupting the SDF-1/CXCR4 signaling axis
Authors: Panneerselvam Janani , Jin Jiankang , Shanker Manish , Lauderdale Jason , Bates Jonathan , Wang Qi , Zhao Daniel , Archibald Stephen , Hubin Timothy , Ramesh Rajagopal
Published: August 2015

Introduction

The stromal cell derived factor (SDF)-1/chemokine receptor (CXCR)-4 signaling pathway plays a key role in lung cancer metastasis. Therefore, disrupting the SDF-1/CXCR4 signaling axis will reduce the incidence of lung metastasis. In the present study we investigated whether interleukin (IL)-24 can inhibit the SDF-1/CXCR4 axis and suppress lung cancer cell migration and invasion in vitro. Further, the efficacy of IL-24 in combination with CXCR4 antagonists was investigated.

Methods

Human H1299 lung tumor cell line was stably transfected with a tetracycline-inducible plasmid vector carrying the IL-24. Upon addition of doxycycline (Dox; 1μg/ml), cells were induced to express IL-24 protein. The expression levels of CXCR4 and its downstream molecular mechanisms in H1299 cells were analyzed. The inhibitory effect of IL-24 on SDF-1/CXCR4 axis is determined by RT-qPCR, western blot, luciferase reporter assay, flow-cytometry and immuno-cytochemistry and the consequence of its inhibition on cell migration, and invasion.

Results

Endogenous CXCR4 protein expression levels varied among four human lung cancer cell lines with H1299 cells showing the highest expression. Doxycycline-induced IL-24 expression in the H1299-IL-24 cell line resulted in reduced CXCR4 mRNA and protein expression. IL-24 post-transcriptionally regulated CXCR4 mRNA expression by decreasing the half-life of CXCR4 mRNA (>40%). Associated with CXCR4 inhibition was the reduced protein expression of pAKTS473, pmTORS2448, pPRAS40T246 and HIF-1α. IL-24 inhibited tumor cell migration and invasion both in the presence and absence of the CXCR4 agonist, SDF-1. However, the combinatorial effect of either IL-24 combined with CXCR4 inhibitors (AMD3100, SJA5) or with CXCR4 siRNA demonstrated enhanced inhibitory activity on tumor cell migration.

Conclusions

Our study results demonstrate that IL-24 inhibits lung tumor cell migration and invasion by disrupting the SDF-1/CXCR4 signaling pathway and exhibits enhanced anti-metastatic activity when combined with CXCR4 inhibitors.

Citation Format: Janani Panneerselvam, Jiankang Jin, Manish Shanker, Jason Lauderdale, Jonathan Bates, Qi Wang, Daniel Zhao, Stephen Archibald, Timothy Hubin, Rajagopal Ramesh. IL-24 inhibits lung cancer cell migration and invasion by disrupting the SDF-1/CXCR4 signaling axis. [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 1713. doi:10.1158/1538-7445.AM2015-1713
Abstract 1740: Allosteric Hsp70-family inhibitors as targeted anticancer therapeutics
Authors: Koren John , Xu Chao , Rodina Anna , Shrestha Liza , Taldone Tony , Chiosis Gabriela
Published: August 2015

Background: Hsp70, a molecular chaperone responsible, in part, for the folding of nascent peptides following translation, has been implicated as a survival factor and a poor prognostic marker in cancer cells. These pro-cancer mechanisms originate in the ability of Hsp70 to preserve and maintain oncogenic and transformative proteins responsible for the cancer phenotype. Hsp70 is a stress response protein such that expression increases under proteomic/proteotoxic stress events. This increased expression is also evident in cancer cells, an environment under proteomic stress brought on by transformation, and is known to be protective against programmed cell death.

Hypothesis: We predict that by interrupting the chaperoning capacity of Hsp70 through allosteric inhibition, we can destabilize oncogenic proteins dependent on Hsp70 for structure and function. Additionally, as Hsp70 is a survival factor, we believe that a loss of Hsp70 activity will result in cancer specific cell death both in vitro and in vivo.

Approach: Using chemical tools, primarily novel allosteric Hsp70 inhibiting small molecules, we will determine the fate of oncogenic proteins dependent on Hsp70 for stability. We will also examine the cellular response to the disruption of cancer-specific networks which require Hsp70. In vivo tumor models will be used to examine the pharmacokinetics and pharmacodynamics of small molecule Hsp70 inhibitors and to evaluate the therapeutic potential of Hsp70 inhibition.

Significance: The stress response machinery is responsible for the stability of proteins, maintenance of signaling pathways, and evasion from programmed cell death while a cell is under stress; stressors including oncogenic transformation. These pathways maintained by the molecular chaperones have been directly linked to deleterious cancer phenotypes including aggressiveness and the emergence of therapeutic resistances. Targeted therapeutics, and uniquely those targeting the molecular chaperone system, can provide therapeutic options capable of ablating the specific mechanisms involved in proteomic stability and cell survival unique to each tumor cell; effects which can be delivered with minimal effect to normal tissue. This work highlights the potential for therapeutics targeting Hsp70 as anti-cancer agents.

Citation Format: John Koren, Chao Xu, Anna Rodina, Liza Shrestha, Tony Taldone, Gabriela Chiosis. Allosteric Hsp70-family inhibitors as targeted anticancer therapeutics. [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 1740. doi:10.1158/1538-7445.AM2015-1740
Abstract 1757: The new molecular target therapy of Hsp90 inhibition in esophageal squamous cell carcinoma
Authors: Yamamura Masahiro , Nohno Tsutomu , Yamauchi Akira , Katase Naoki , Okawaki Makoto , Sawaki Akira , Matsumoto Hideo , Hirai Toshihiro , Yamaguchi Yoshiyuki
Published: August 2015

Heat shock protein 90 (HSP90) has numerous cellular functions, including promotion of proper protein folding, and stabilizes a number of oncogenic proteins, many of which are overexpressed in cancers. The objective of this study is to evaluate an antitumor effect of HSP90 inhibitor, AUY922, in esophageal squamous cell carcinoma(ESCC) cell lines. ESCC cell lines were treated with AUY922 to examine the effect on proliferation assay, apoptosis assay, Western blotting, and chemotaxis assay. AUY922 inhibited cell proliferation in ESCC cells in a dose- and time-dependent manner. Growth inhibitory effect of AUY922 for ESCC cells was higher than CDDP. With flowcytometry and immunostaining, we showed that AUY922 induced apoptosis in ESCC cells and inhibited chemotaxis of ESCC cells. These antitumor effects of AUY922 were due to inhibition of cell proliferation through suppression of phosphorylation of the client proteins. The HSP90 inhibitor is useful as an antitumor drug in ESCC by inhibiting proliferation of ESCC cells through novel mechanism.

Citation Format: Masahiro Yamamura, Tsutomu Nohno, Akira Yamauchi, Naoki Katase, Makoto Okawaki, Akira Sawaki, Hideo Matsumoto, Toshihiro Hirai, Yoshiyuki Yamaguchi. The new molecular target therapy of Hsp90 inhibition in esophageal squamous cell carcinoma. [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 1757. doi:10.1158/1538-7445.AM2015-1757
Abstract 1761: Small molecule restoration of wildtype structure and function of mutant p53 using a novel zinc metallochaperone based mechanism
Authors: Yu Xin , Blanden Adam R. , Narayanan Sumana , Jayakumar Lalithapriya , Lubin David , Augeri David J. , Kimball S. David , Loh Stewart N. , Carpizo Darren R.
Published: August 2015

NSC319726 (ZMC1) is a small molecule that reactivates mutant p53 by restoration of WT structure/function to the most common p53 missense mutant (p53-R175H). We investigated the mechanism by which ZMC1 reactivates p53-R175H and provide evidence that ZMC1: 1) restores WT structure by functioning as a zinc-metallochaperone, providing an optimal concentration of zinc to facilitate proper folding; 2) increases cellular reactive oxygen species that transactivate the newly conformed p53-R175H (via post-translational modifications), inducing an apoptotic program. We not only demonstrate that this zinc metallochaperone function is possessed by other zinc-binding small molecules, but that it can reactivate other p53 mutants with impaired zinc binding. This represents a novel mechanism for an anti-cancer drug and a new pathway to drug mutant p53.

Citation Format: Xin Yu, Adam R. Blanden, Sumana Narayanan, Lalithapriya Jayakumar, David Lubin, David J. Augeri, S. David Kimball, Stewart N. Loh, Darren R. Carpizo. Small molecule restoration of wildtype structure and function of mutant p53 using a novel zinc metallochaperone based mechanism. [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 1761. doi:10.1158/1538-7445.AM2015-1761
Abstract 1763: Activation of p53/miR-34a tumor suppressor network by Chinese herbal recipe JP-1 in human lung cancer cells
Authors: Yao Chih-Jung , Sheng Peter , Hu Tsai-Shu , Wang-Peng Jacqueline , Lai Gi-Ming
Published: August 2015

Non-small cell lung cancer (NSCLC) is one of the most common cancers worldwide. In spite of the recent progress in targeted therapy, most of the patients eventually expired due to the inevitable recurrence and drug resistance. New integrated therapeutics with evidence based molecular mechanism is urgently needed. MiR-34a, a direct target of p53, is a well-characterized tumor suppressor miRNA in a variety of cancers. How to restore the p53/miR-34a regulatory axis has becomes an important novel strategy for cancer therapy. Here, we show that a Chinese herbal recipe JP-1 activates p53/miR-34a tumor suppressor network in human NSCLC A549 cells (p53 wild type). Treatment of A549 cells with JP-1 extract (38% ethanol) induced profound apoptosis accompanied with marked elevation of p53 and its downstream p21 and Bax protein levels. Accordingly, increase of miR-34a was also observed. Analyzing the miR-34a downstream targets in JP-1-treated cells, we found the decrease of survival factors such as Sirt1 and survivn. Nevertheless, JP-1 also decreased Axl, an important invasion-related miR-34a downstream, while increased E-cadherin expression. The JP-1-activated p53/miR-34a tumor suppressor network coincided with mitochondrial-dependent apoptosis induction and EMT (epithelial-mesenchymal transition) inhibition. In agreement with this, JP-1 induced phospho-AMPKα but inhibited phospho-AKT protein level. Our results might interpret the clinical benefit observed in JP-1-treated patients and suggest its potential as a complementary medicine for NSCLC.

Note: This abstract was not presented at the meeting.

Citation Format: Chih-Jung Yao, Peter Sheng, Tsai-Shu Hu, Jacqueline Wang-Peng, Gi-Ming Lai. Activation of p53/miR-34a tumor suppressor network by Chinese herbal recipe JP-1 in human lung cancer cells. [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 1763. doi:10.1158/1538-7445.AM2015-1763
Abstract 1767: Anti-proliferative and anti-invasive action of omega-3 polyunsaturated fatty acids in stomach cancer cells
Authors: Shin Soyeon , Jeong Soyeon , Kim Soyeon , Heo Jun-Young , Kweon Gi-Ryang , Park Seung-Kiel , Park Jong-Il , Lim Kyu
Published: August 2015

The American Cancer Society has been reported that about 22,220 cases of stomach cancer will be diagnosed and about 10,990 patients will die from this type of cancer in 2014. Omega-3 polyunsaturated fatty acids (ω3-PUFA), including docosahexaenoic acid (DHA) have been suggested to have anti-cancer effects by epidemiological and clinical studies. However, their underlying anti-cancer mechanisms are still unclear in stomach cancer. This study was designed to examine the impact of ω3-PUFA on stomach cancer and the molecular mechanism of their action. DHA reduced cells viability in a dose- and time-dependent manner in human stomach cancer cells including AGS cells. The DHA-induced cells death was in part due to apoptosis, since the cells exhibited increases of apoptotic markers including cleaved PARP and TUNEL-positive cells. DHA also led to autophagic vesicle formation an increase levels of lipidated form LC3B and stimulated the autophagic flux, indicating the involvement of both apoptosis and autophagy in the cytotoxic effect of stomach cancer cells by ω3-PUFA. Moreover, AGS stable cell expressing the ω3-desaturase (fat-1) gene (AGS-fsc) or control vector stable cell (AGS-csc) were eatablished, and the effect of endogenous high level of ω3-PUFA was investigated in AGS cells. The cell proliferation, invasion and colony-formation were inhibited in AGS-fsc compared to AGS-csc. Taken together, these results indicate that ω3-PUFA induce anti-cancer action is related to anti-proliferation and anti-invasive action in stomach cancer cells. Thus, utilization of ω3-PUFA may represent a promising therapeutic approach for chemoprevention and treatment of human stomach cancer. [This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(2014R1A1A2008915) and by the Korea government(MSIP) (No. 2007-0054932)]

Citation Format: Soyeon Shin, Soyeon Jeong, Soyeon Kim, Jun-Young Heo, Gi-Ryang Kweon, Seung-Kiel Park, Jong-Il Park, Kyu Lim. Anti-proliferative and anti-invasive action of omega-3 polyunsaturated fatty acids in stomach cancer cells. [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 1767. doi:10.1158/1538-7445.AM2015-1767
Abstract 1777: The characterization of the effects of the strigolactones on the heat shock response
Authors: Wang Victor S. , Kyin Nu Nu , Pollock Claire , Lee Hyjoung , Li Xin , Prandi Cristina , Kapulnik Yoram , Koltai Hinanit , Whitesell Luke , Yarden Ronit
Published: August 2015

Strigolactones (SLs) are a novel class of plant hormones that inhibit the self-renewal of undifferentiated meristem cells in shoots regulating above-ground plant architecture. Data from our lab have shown that SL analogues are able to inhibit the growth and survival of a wide array of cancer-derived cell lines including: prostate, colon, lung, breast and osteosarcoma (U2OS) while minimally affecting cultured normal cells. Treatment of cancer cells with SL analogues leads to the activation of stress-related signaling including p38MAPKs and JNK1/2, as well as the activation of the heat shock master regulator, heat shock transcription factor 1 (HSF1), and heat shock response (HSR) gene expression. We further show that SLs generate reactive oxygen species (ROS) and that SL treatments of cancer cells leads to the activation of GRP78, the master regulator of the unfolded protein response (UPR). To further characterize the relationship between SLs, HSR and UPR, several clones of HSF1 shRNA knockdown, in U2OS cells were generated and are currently being studied. Interestingly, while wild type mouse embryonic fibroblast (MEF) cells are refractory to SLs treatments, we demonstrate that HSF1 knockout in MEFs enhances the sensitivity of the cells to SLs treatments. Taken together, our data suggest that the HSR and UPR are recruited as cell survival mechanisms against the SLs treatments, giving rise to possible future chemotherapeutic combinatorial treatment options.

Citation Format: Victor S. Wang, Nu Nu Kyin, Claire Pollock, Hyjoung Lee, Xin Li, Cristina Prandi, Yoram Kapulnik, Hinanit Koltai, Luke Whitesell, Ronit Yarden. The characterization of the effects of the strigolactones on the heat shock response. [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 1777. doi:10.1158/1538-7445.AM2015-1777
Abstract 1799: Mithramycin A as a radiation sensitizer
Authors: Scroggins Bradley T. , Burkeen Jeffery F. , Chung Eun Joo , White Ayla O. , Chung Su I. , Hudak Kathryn E. , Citrin Deborah E.
Published: August 2015

Introduction: Radiation therapy (RT) is used in the treatment of many cancers to reduce or eliminate tumor burden. In many cases RT is not curative and recurrence often occurs. Therefore agents that enhance the effectiveness of RT are necessary to improve cancer management. We investigated the use of the DNA binding antibiotic mithramycin A as a radiosensitizer of solid tumors. Mithramycin A binds to GC rich regions of double stranded DNA displacing transcription factors, such as SP1. Mithramycin A has also been shown to inhibit DNA double strand break repair by mechanisms unrelated to its effect on transcription.

Methods: Human cancer cells (A549/lung, HT29/colon, DU145/prostate, and UM-UC3/bladder) were grown at 37°C and 5% CO2 in RPMI1640 media. Cells were treated with 25 nM mithramycin A 1 hour prior to radiation and then allowed to grow for 7-10 days after RT. Clonogenic colonies were counted to determine the effect of mithramyicn A on radiation sensitivity. The effects of mithramycin A treatment and RT on DNA damage repair was measured by counting nuclear gamma-H2AX foci and neutral Comet assay. Cell cycle changes induced by mithramycin A and RT were measured by flow cyctometry. Mitotic catastrophe was analyzed by nuclear fragmentation. In vivo radiosensitzation of mithramycin A (1mg/kg) was quantified using growth delay of A549 tumor xenografts in both single dose (4 Gy) and fractionated RT (4x 2Gy) dosing schedules.

Results: Mithramycin A treatment of cell lines in vitro prior to RT increased radiosensitivity with a range of dose modifying factors between 1.17-1.48. DNA damage repair after RT was not affected by mithramycin A treatment. Cell cycle distribution was altered by mithramycin A treatment with fewer cells in S-phase after treatment. Mitotic catastrophe after combined treatment with mithramycin A and RT was significantly elevated above the level of either agent alone. In vivo A549 tumor xenografts treated with both mithramycin A and a single dose RT had more than an additive growth delay compared to either agent alone.

Conclusion: Mithramycin A treatment sensitized human cancer cells to radiation therapy in in vitro assays and an in vivo model system through an increase in mitotic catastrophe. A more detailed analysis of the mechanism of action is ongoing.

Citation Format: Bradley T. Scroggins, Jeffery F. Burkeen, Eun Joo Chung, Ayla O. White, Su I. Chung, Kathryn E. Hudak, Deborah E. Citrin. Mithramycin A as a radiation sensitizer. [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 1799. doi:10.1158/1538-7445.AM2015-1799