bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3767: Highly effective inhibitory agent identified by high-throughput screening of genetically characterized anaplastic thyroid cancer cell lines
Authors: Pinto Nicole C. , Black Morgan , Ruicci Kara , Yoo John , MacNeil Danielle , Fung Kevin , Datti Alessandro , Prokopec Stephenie , Boutros Paul , Barrett John , Nichols Anthony
Published: July 2016

Introduction

While most types of thyroid cancer are treatable, anaplastic thyroid cancer (ATC) is the most lethal human malignancy. Current treatment strategies are largely ineffective with only 10% of patients surviving longer than one year. As such, new treatments are desperately needed to improve patient survival in this aggressive cancer.

Objective

Identify highly effective drugs using high-throughput screening methods with a large panel of kinase inhibitors that can be used in the treatment of ATC.

Methods

High-throughput screening (HTS) of 13 genetically characterized ATC cell lines was carried out over a 6-dose range using 320 kinase inhibitors. Dose-response curves were generated and drugs with high potency were identified. Drugs with the highest activity were selected for further evaluation including investigating mechanism of action and cell death, and assays for migration and invasion.

Results

Based on HTS studies, Lestaurtinib was identified as a highly effective agent with submicromolar mean inhibitory concentrations in all 13 ATC cell lines. Lestaurtinib was found to inhibit STAT5 phosphorylation, as well as cell line migration and invasion. The anti-proliferative effect of Lestaurtinib did not cause apoptosis, autophagy or cell senescence.

Conclusions

With the use of HTS, we have identified many (>20) kinase inhibitors as highly effective agents in the control of ATC. The kinase inhibitor Lestaurtinib was effective at controlling ATC cell proliferation, invasion and migration. Future in vivo analysis of Lestaurtinib with patient-derived xenografts are planned to continue preclinical development of this drug with the ultimate goal of improving outcomes for patients suffering with ATC.

Citation Format: Nicole C. Pinto, Morgan Black, Kara Ruicci, John Yoo, Danielle MacNeil, Kevin Fung, Alessandro Datti, Stephenie Prokopec, Paul Boutros, John Barrett, Anthony Nichols. Highly effective inhibitory agent identified by high-throughput screening of genetically characterized anaplastic thyroid cancer cell lines. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3767.
Abstract 3768: Targeting of epithelial-to-mesenchyme transition by a novel small molecule inhibitor attenuates prostate and breast cancer invasiveness and bone metastases
Authors: Kroon Jan , van Hooij Onno , Zoni Eugenio , van der Mark Maaike , van der Horst Geertje , Tijhuis Johan , van Rijt-van de Westerlo Cindy , Verhaegh Gerald , Viëtor Henk , Wellink Antoine , Maas Peter , Schalken Jack , van der Pluijm Gabri
Published: July 2016

Transformed epithelial cells can activate embryonic programs of epithelial plasticity and switch from a sessile, epithelial phenotype to a motile, mesenchymal phenotype also referred to as epithelial-to-mesenchymal transition (EMT). EMT is associated with poor prognosis in patients with osteotropic cancers. E-cadherin (CDH1) is an essential homotypic cell adhesion molecule that is often down regulated during this process.

EMT-like processes are increasingly linked to therapy resistance and metastasis-initiating cells, thus providing the rationale for the development of novel small-molecule inhibitors that a) block the acquisition of an invasive phenotype in osteotropic cancer cells via EMT or b) revert their invasive, mesenchymal phenotype into epithelial phenotype (MET) by upregulation of CDH1 expression.

High throughput screening of >43,000 LMW compounds, followed by compound design & optimization in vitro led to the identification ten candidate therapeutic compounds. These compounds displayed significant inhibitory effects on cancer cell invasion (>80%) and induced E-cadherin (re)expression, most likely through interference with the binding of transcriptional repressors to the CDH1 E-box elements. We identified a unique compound, OCD155, can effectively and dose-dependently block the acquisition of an invasive phenotype in osteotropic prostate and breast cancer cells (PC-3M-Pro4luc2 and MDA-MB-231/Bluc). When tested in our in vivo models of prostate and breast cancer bone metastasis, treatment of mice with OCD155 strongly and dose-dependently inhibited skeletal metastasis (number of metastases, tumor burden) according to preventive and curative protocols. At the dosages tested, no adverse effects of OCD155 were observed (body weight, liver toxicity parameters). To the best of our knowledge, our studies are the first to demonstrate the efficacy of new small molecule EMT inhibitor in the treatment of experimental skeletal metastasis.

Citation Format: Jan Kroon, Onno van Hooij, Eugenio Zoni, Maaike van der Mark, Geertje van der Horst, Johan Tijhuis, Cindy van Rijt-van de Westerlo, Gerald Verhaegh, Henk Viëtor, Antoine Wellink, Peter Maas, Jack Schalken, Gabri van der Pluijm. Targeting of epithelial-to-mesenchyme transition by a novel small molecule inhibitor attenuates prostate and breast cancer invasiveness and bone metastases. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3768.
Abstract 3772: SHP-1 determines the radiosensitivity of liver cancer cell and dovitinib acts as a novel radiosensitizer in hepatocellular carcinoma via targeting SHP-1/STAT3 signaling
Authors: Hung Man-Hsin , Huang Chao-Yuan , Tai Wei-Tien , Tsai Ming-Hsien , Shin Chih-Ting , Wu Szu-Yuan , Shiau Chung-Wai , Chen Kuen-Feng
Published: July 2016

Background

Hepatocellular carcinoma (HCC) is one of the most lethal human malignancies and curative therapy is not an option for most patients. There is growing interest in the potential benefit of radiotherapy (RT)-integrated therapy. This study aimed to investigate the biological impacts of a novel tumor suppressor Src homology 2 (SH2) domain-containing phosphatase 1 (SHP-1) and its downstream effecter, STAT3, in regulating the radiosensitivity of HCC cells. Furthermore, we explored the efficacy and mechanism of an investigational drug, dovitinib, used in combination with RT.

Material and methods

To understand the impacts of SHP-1/STAT3 signaling affects radiosensitivity, HCC cells with ectopic expression of STAT3, SHP-1 and a catalytic mutant SHP-1 were treated with or without radiotherapy and analyzed by flow cytometry and colony formation assay. Furthermore, five HCC cell lines (PLC5, Hep3B, SK-Hep1, HA59T and Huh-7) were treated with dovitnib, RT or both. The in vitro and in vivo effects of above-mentioned treatments were analyzed.

Results

By sub-G1 analysis and colony formation, we found that HCC cell with ectopic expression of SHP-1 was much more sensitive to RT-induced apoptotic effects, while overexpression of STAT3 or catalytic-dead mutant SHP-1 restored RT-induced reduction of HCC cell survival. Next, we investigated the effects of dovitinib, which showed that dovitinib treatment resulted in SHP-1-mediated downregulation of p-STAT3 and promoted potent apoptosis of HCC cells. Ectopic expression of STAT3, or inhibition of SHP-1 diminished the effects of dovitinib on HCC cells. Furthermore, by ectopic expression and purified recombinant proteins of various mutant forms of SHP-1, the N-SH2 domain of SHP-1 was found to be required for dovitinib treatment.

Importantly, we found that dovitinib potentiated the in vitor and in vivo effects of RT in HCC cells through affecting the SHP-1/STAT3 signaling.

Conclusions

SHP-1/STAT3 signaling is critically associated with the radiosensitivity of HCC cells. A combination therapy with RT and the SHP-1 agonist, such as dovitinib, resulted in enhanced in vitro and in vivo anti-HCC effects.

Citation Format: Man-Hsin Hung, Chao-Yuan Huang, Wei-Tien Tai, Ming-Hsien Tsai, Chih-Ting Shin, Szu-Yuan Wu, Chung-Wai Shiau, Kuen-Feng Chen. SHP-1 determines the radiosensitivity of liver cancer cell and dovitinib acts as a novel radiosensitizer in hepatocellular carcinoma via targeting SHP-1/STAT3 signaling. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3772.
Abstract 3774: KD06 is a novel anti-cancer drug that causes cell death in triple-negative breast cancer cell lines and tumor xenografts
Authors: Ebelt Nancy D. , Taveres Clint D J , Xie Xuemei , Naguib Youssef W. , Jose Jiney , Ruwona Tinashe B. , Devkota Ashwini K. , Park Jihyun , Kaoud Tamer S. , Anslyn Eric V. , Chang Jeffrey T. , Cui Zhengrong , Bartholomeusz Chandra , Dalby Kevin N.
Published: July 2016

Development and screening of small molecule compounds for anti-cancer activity has been of prime interest to the scientific community following the success of targeted, large anti-cancer molecules such as therapeutic antibodies. Small molecules pass more easily through cell membranes and may cross the blood-brain barrier. KD06 is a small molecule triptan-like compound whose parent molecule binds and inhibits serotonin receptors. This compound increases apoptosis of the triple-negative breast cancer cell lines MDA-MB-231 and MDA-MB-157 via caspase activation. Treatment with KD06 also causes increased autophagy as well as activation of ER stress responses. The growth of tumor xenografts of MDA-MB-231 cells in nude mice are significantly inhibited by twice weekly treatment with 30mg/kg KD06. Analysis of signaling changes by KD06 using reverse phase protein array (RPPA) revealed significant decreases in Akt/mTOR signaling leading to decreased activation of the translation initiation factor 4E-BP1. Other notable changes included decreased expression of proteins important for mitosis such as Cyclin B1, Aurora B and PLK1, and increased phosphorylation of EGFR and increased expression of PDGFR. Analysis of PIP3 and ATP levels showed no change after treatment with KD06, indicating that decreased signaling through Akt/mTOR is not likely due to PI3K inhibition or AMPK activation. Immunofluorescence with KD06 treated cells revealed a change in cell shape after 4 hours of treatment that was reminiscent of cells treated with microtubule binding drugs. Akt localization was affected. These results imply that KD06 may have anti-cancer activity through its effect on microtubule dynamics, inhibiting proper localization and signaling of molecules important for survival and protein translation such as Akt and mTOR.

Citation Format: Nancy D. Ebelt, Clint D J Taveres, Xuemei Xie, Youssef W. Naguib, Jiney Jose, Tinashe B. Ruwona, Ashwini K. Devkota, Jihyun Park, Tamer S. Kaoud, Eric V. Anslyn, Jeffrey T. Chang, Zhengrong Cui, Chandra Bartholomeusz, Kevin N. Dalby. KD06 is a novel anti-cancer drug that causes cell death in triple-negative breast cancer cell lines and tumor xenografts. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3774.
Abstract 378: Exploring intermittent dosing schedules for the Pan PI3K/mTor inhibitor PQR309
Authors: Jorga Karin , Schmitz Debora , Cmiljanovic Natasa , Fabbro Doriano , Dimitrijevic Sasa
Published: July 2016

Introduction

PQR309 is a novel oral balanced dual pan-PI3K and mTOR inhibitor currently in clinical development for the treatment of solid tumors and hematological malignancies. Eighty mg PQR309 given once daily (q.d.) has been established as the MTD in patients with advanced solid cancers. This dose and regimen was associated with plasma concentrations that were pharmacologically active in pre-clinical experiments. However, there is emerging evidence that continuous inhibition of PI3K/mTOR may not be needed to achieve the full effect of PQR309 on tumor growth inhibition and therefore further intermittent dosing regimens will be explored.

Methods

In vivo xenograft studies in nude male rats bearing PC3-derived tumors were conducted with continuous and intermittent dosing schedules to estimate effective plasma concentrations. Pharmacokinetic (PK) data from cancer patients were used to establish a 2-compartment PK model with first order absorption. The model was applied to simulate PK profiles after various intermittent dosing schedules including 2 daily administrations followed by a 5 day wash-out period in a 7 day cycle (2 days ON/5 days OFF) and a regimen with administrations on days 1 and 4 in a 7 day cycle (eg MON/THUR).

Results

A maximum plasma concentration (Cmax) of 800-1200ng/mL PQR309 and an impulse interval of 72 hours or less was associated with maximum effect in the rat xenograft model. In rats PQR309 is rapidly eliminated from plasma but in humans the compound has an elimination half-life of about 40 hours and accumulates upon multiple dosing. The applied model predicts that PQR309 administration given 2 days ON/5 days OFF will build up drug exposure to reach levels that strongly inhibit the targeted signalling pathways. During the 5 day wash-out period, PQR309 levels will decrease significantly, thereby reducing the probability of adverse events. For the alternative dosing regimen MON/THUR, the model predicts a sharp Cmax lasting for a few hours followed by a decrease in drug levels over the following 3 or 4 days, thus minimizing accumulation and drug exposure that could lead to adverse events.

Conclusions

Both intermittent regimens are expected to strongly inhibit the targeted signalling pathways with high transient concentrations around Cmax followed by wash-out periods for healthy tissue recovery to optimize the benefit/risk of the compound. These regimens are currently being explored in clinical studies.

Citation Format: Karin Jorga, Debora Schmitz, Natasa Cmiljanovic, Doriano Fabbro, Sasa Dimitrijevic. Exploring intermittent dosing schedules for the Pan PI3K/mTor inhibitor PQR309. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 378.
Abstract 3783: Co-treatment of metastasis-derived colon cancer cells with bromoethyl indole (BEI) enhances camptothecin or TNF alpha-induced cell death
Authors: Chowdhury Rupak , Miller Sonni A. , Gales Dominique , White Jason , Manne Upender , Samuel Temesgen
Published: July 2016

Colorectal cancer is still the third most deadly cancer in the United States. Currently, there are limited choices of targeted anticancer agents that are durably effective against colorectal cancer. Therefore, chemotherapeutic regimens containing the drugs Camptothecin (CPT), 5-FU and Oxaliplatin remain the mainstays for the treatment of advanced colorectal cancer. We recently found that the indole-derivative small compound Bromoethyl Indole (BEI) potently inhibits the proliferation of colon cancer cells and also suppresses NF-kB activation. In this study, we investigated if the combination of BEI with either CPT or TNFα would enhance cell death in vitro. Metastasis-derived parental or engineered NF-kB-reporter colon cancer cells were used to examine 1) the activation of NF-kB signaling by clinically used drugs, 2) the potential for BEI to inhibit drug-induced NF-kB activation, and 3) the potential for combination treatment to enhance cell death in vitro. Cells were treated with either the drugs alone or in combination with BEI at varying concentrations. NF-kB-inducing concentration of CPT (0.6 to 2.5 μM), TNFα (25 to 50 ng/ml), and BEI concentrations of 1 to 50 μM range were tested. Cell cycle profiles and cell death markers were assessed to determine the effects of single or co-treatments. The expressions of Bcl-xL and cIAP2 (BIRC3) proteins were examined to monitor the targets of NF-kB activation.

Our results show that 1) both TNFα and CPT induce NF-kB signaling in metastasis-derived colon cancer cells, 2) combination of BEI and TNFα or CPT inhibits such a drug-induced NF-kB activation and reduces the expression of NF-kB responsive genes, 3) sequential treatment of the cells with CPT and BEI delivers the best outcome, increasing cell death by up to 3-fold compared to either CPT or BEI alone, and 4) co-treatment of the cells with TNFα and BEI increases cell death by up to 2-fold compared to either TNFα or BEI alone, 5) BEI is most effective in inducing cell death at concentrations between 2 and 10 μM.

We anticipate that BEI will improve the therapeutic index of some chemotherapeutic drugs. Therefore, the potential benefit for combination of BEI with NF-kB activating drugs needs to be evaluated in vivo.

Citation Format: Rupak Chowdhury, Sonni A. Miller, Dominique Gales, Jason White, Upender Manne, Temesgen Samuel. Co-treatment of metastasis-derived colon cancer cells with bromoethyl indole (BEI) enhances camptothecin or TNF alpha-induced cell death. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3783.
Abstract 3790: Targeting the one-carbon metabolism protein MTHFD2 for cancer therapy: Exploiting the unique redox status of cancer cells
Authors: Glasauer Andrea , Steckel Michael , Haegebarth Andrea , Bauser Marcus , Toschi Luisella
Published: July 2016

Two well-established hallmarks of cancer are the need for nucleotides to support continuous cell proliferation and the requirement for cancer cell redox balance. In that respect cancer cells are characterized by an increased rate of reactive oxygen species (ROS) production which can be toxic to cancer cells. In this sense, cancer cells often display an increased ROS scavenging capacity, through antioxidants and NADPH that prevents ROS levels from reaching cytotoxic levels. Mitochondrial methylenetetrahydrofolate dehydrogenase 2 (MTHFD2) is a critical component of one-carbon metabolism and promotes the reaction of 5, 10-methylene tetrahydrofolate to 10-formyl tetrahydrofolate which is coupled to purine synthesis and the production of NAD(P)H. In its role, MTHFD2 is required for maintaining nucleotide biosynthesis and cancer cell redox balance. Recent studies have shown that MTHFD2 expression is elevated in many cancers compared to normal tissue and expression is correlated with poor survival in breast cancer. In order to validate MTHFD2 as a potential cancer target we show that genetic knockdown of MTHFD2 led to impaired cancer cell survival and proliferation. In breast cancer cells MTHFD2 inhibition caused a decrease in NADPH, an increase in the levels of oxidized glutathione and also promoted the expression of DNA damage and death markers specifically in cancer cells with high MTHFD2 protein expression. Interestingly, ROS-scavenging antioxidants reversed these phenotypes in the presence of MTHFD2 knockdown. Normal cells and low MTHFD2 expressing breast cancer cells had a higher tolerance for the inhibition of the protein. Based on our data, MTHFD2 inhibition leads to the impairment of cancer cells’ antioxidant capacity and ROS-mediated cell death. Therefore, MTHFD2 inhibition may have clinical potential for the treatment of patients with breast cancer, and potentially various other cancers.

Citation Format: Andrea Glasauer, Michael Steckel, Andrea Haegebarth, Marcus Bauser, Luisella Toschi. Targeting the one-carbon metabolism protein MTHFD2 for cancer therapy: Exploiting the unique redox status of cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3790.
Abstract 3801: Pro-chemotherapeutic effects of antibody against extracellular domain of claudin-4 in bladder cancer
Authors: Kuwada Masaomi , Chihara Yoshitomo , Luo Yi , Sasaki Takamitsu , Fujimoto Kiyohide , Kondou Masuo , Kuniyasu Hiroki
Published: July 2016

Bladder cancer displays an aggressive phenotype in the muscle-invasive phase, and is associated with a high mortality rate. Therefore, novel molecular therapeutic targets are needed to improve patient survival. A monoclonal antibody against the extracellular domain of the claudin-4 (CLDN4) tight junction protein was established by immunizing rats with a plasmid vector encoding human CLDN4. A hybridoma clone, producing a rat monoclonal antibody recognizing CLDN4 (clone 4D3), was obtained. Immunohistochemistry by using the 4D3 antibody showed that CLDN4 expression was associated with local invasion, nodal metastasis, distant metastasis, and advanced stage in 86 cases of bladder cancer. The 4D3 antibody inhibited growth, invasion, and survival, associated with abrogation of the intratumoral microenvironment; lowered concentrations of epidermal growth factor and vascular endothelial growth factor were found in 3-dimentional cultures of T24 and RT4 cells. In combination with cisplatin therapy, 4D3 enhanced cisplatin cytotoxicity by increasing cellular permeability, leading to increased intracellular cisplatin concentrations. In mouse models of subcutaneous tumors and lung metastasis, 4D3 enhanced tumor growth inhibition, alone and with concurrent cisplatin treatment. The anti-tumor activity of the newly established 4D3 antibody suggests that it may be a powerful tool in CLDN4-targeting therapy, and in combination with chemotherapy.

Citation Format: Masaomi Kuwada, Yoshitomo Chihara, Yi Luo, Takamitsu Sasaki, Kiyohide Fujimoto, Masuo Kondou, Hiroki Kuniyasu. Pro-chemotherapeutic effects of antibody against extracellular domain of claudin-4 in bladder cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3801.
Abstract 3803: Development of genetic and chemical tools for understanding the recruitment of DOT1L in MLL-fusion driven leukemia and normal hematopoiesis
Authors: Grigsby Sierrah , Chase Jennifer , Ropa James , Serio Justin , Shen Chenxi , Larsen Martha , Donover Preston , Reichman Melvin , Muntean Andrew , Maillard Ivan , Nikolovska-Coleska Zaneta
Published: July 2016

Leukemias harboring rearrangements of mixed-lineage leukemia gene (MLL1) are associated with poor clinical outcomes, and new therapeutic approaches are needed. Rearrangements of the MLL1 gene generate fusion oncoproteins which drive the high expression of the clustered homeobox (HOX) genes and induce leukemic transformation. Genome wide histone methylation studies have revealed that the abnormal expression of MLL1 fusion target genes is associated with high levels of histone H3 lysine 79 (H3K79) methylation. Recruitment of DOT1L (disruptor of telomeric silencing 1-like), a unique histone methyltransferase that catalyzes methylation of H3K79, proved to be essential for the transforming activity of multiple MLL fusion proteins. To gain insights into the unique functions of DOT1L in MLL-driven leukemia, we elucidated the mechanisms of DOT1L recruitment to the MLL fusion partners. The binding site was mapped to a short segment of 10 amino acids in DOT1L and peptides derived from this region disrupted the interaction between DOT1L and MLL-AF9. DOT1L mutants lacking these 10 residues did not support transformation by MLL-AF9. This discovery has established a foundation for disease-specific therapies that target chromatin modifications in highly malignant leukemias. Applying high throughput screening approach several different chemical classes of small molecules that disrupt the protein-protein interactions between DOT1L and oncogenic MLL-fusion proteins were identified and validated. To evaluate if the AF9-binding domain of DOT1L is critical for its functions in normal hematopoietic stem cells as opposed to leukemias driven by MLL fusion proteins, genetic tools were developed to functionally investigate the importance of the DOT1L AF9-binding domain in MLL-AF9-driven leukemia and its role in the physiological functions of DOT1L in normal hematopoiesis. Our findings demonstrate that pharmacological inhibition of the DOT1L complex through disrupting the AF9-DOT1L interactions may provide therapeutic benefits in an array of malignancies with abnormal HOXA gene expression.

Citation Format: Sierrah Grigsby, Jennifer Chase, James Ropa, Justin Serio, Chenxi Shen, Martha Larsen, Preston Donover, Melvin Reichman, Andrew Muntean, Ivan Maillard, Zaneta Nikolovska-Coleska. Development of genetic and chemical tools for understanding the recruitment of DOT1L in MLL-fusion driven leukemia and normal hematopoiesis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3803.
Abstract 3806: Phosphaplatins are potent inducers of pigment epithelial- derived factor (PEDF)
Authors: Belkacemi Louiza , Rivera Armando , Yang Lu , Bose Rathindra N. , Zhang Shaun X.
Published: July 2016

Pigment Epithelial Derived Factor (PEDF) is a secreted glycoprotein that exhibits several biological activities, most notably as a potent anti-angiogenic agent as well as a neurotrophic factor. As such, this molecule has potential application as therapeutics for cancer and a variety of neurological diseases. However, prior art methods directed towards enhancing and stabilizing PEDF expression in vivo have met with little success. Therefore, methods that could lead to the stable expression of PEDF in vivo are still needed. We have recently shown that PEDF protein is overexpressed in tumor cells treated with platinum based drugs; phosphaplatins that are platinum-(II) and platinum-(IV) complexes coordinated to a pyrophosphate moiety. The objective of this study is to extend our previous findings by measuring PEDF expression in both malignant cells and normal neuronal tissues after treating them with these compounds. We also investigated the impact of PEDF upregulation on important biological processes such as apoptosis, proliferation and invasion of tumor cells. Our data showed that there was a significant upregulation (over 4-fold) of PEDF in brain of mice treated with phosphoplatins when compared to the control animals. The compounds were found to stimulate PEDF expression in cultured neuronal cells when assessed in vitro (P<0.05 vs. untreated control groups). In tumor cells, phosphoplatins upregulated PEDF expression in a dose-dependent manner in various tumor cell lines. In one particular mouse breast tumor cell line (4T1), the data showed that phosphaplatin doses in the range of 25 to 100 μM stimulated the expression of PEDF at 12 and 24 hrs, which declined thereafter. Remarkably, a subsequent treatment of the tumor cells with phosphaplatins at 24 hrs prevented the decline of PEDF expression, suggesting a direct correlation between phosphaplatins and PEDF overexpression. The upregulation of PEDF in the tumor cells was paralleled by increased apoptosis and decreased cell proliferation and invasion. In summary, phosphaplatins mediated overexpression of PEDF in vivo suggests a potential neuroprotective effect of these compounds. While in tumors, phosphaplatins may exhibit antitumor activity via multiple effects, including anti-angiogenesis, enhanced apoptosis, and decreased proliferation and invasion, predominately through stimulating overexpression of PEDF.

Citation Format: Louiza Belkacemi, Armando Rivera, Lu Yang, Rathindra N. Bose, Shaun X. Zhang. Phosphaplatins are potent inducers of pigment epithelial- derived factor (PEDF). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3806.
Abstract 3808: Novel compound conferring selectivity for cancer cells
Authors: Jaunky Dilan B. , Forgione Pat , Piekny Alisa
Published: July 2016

There is a need to develop novel compounds that can effectively treat a broad range of cancers on their own, or in combination with approved therapies. As personalized medicine is developed, combinatorial approaches will become more common making it crucial to increase the repertoire of available drugs. In the past, drugs often were developed to target a biologically-relevant molecule, but structural limitations, stability and solubility issues, or lack of selectivity have hindered the clinical use of many of these drugs. Our approach was to first find a ‘high-quality’ compound that is selective for cancer cells, then characterize its mechanism of action and identify its target. High throughput screening (HTS) helped to rapidly identify a subset of compounds with selective toxicity toward MCF-7 (breast cancer) cells. Some of these compounds were further tested for their efficacy in HeLa (cervical cancer) cells, and we found one that selectively causes mitotic arrest at 250 nM in comparison to non-cancerous HFF-1 (foreskin fibroblast) cells. At 200 nM, this compound synergizes with drugs known to affect microtubule dynamics and cause mitotic arrest including Nocodazole and Paclitaxel (currently in use as an anti-cancer drug), causing them to be more effective at lower concentrations. Excitingly, this compound also provides a shielding effect for HFF-1 cells treated with Paclitaxel. To learn the mechanism of action for this compound, we performed immunofluorescence microscopy on HeLa and HFF-1 cells treated with a range of concentrations. We found that the mitotic spindle is improperly organized in HeLa cells at 250 nM, but not in HFF-1 cells. Interestingly, microtubules are completely gone in mitotic HeLa cells and are reduced in mitotic HFF-1 cells treated with >500 nM. Given that this compound synergizes with drugs that directly bind to tubulin subunits to modify their dynamics of assembly and disassembly, and differently affects cancerous vs. healthy cells, we hypothesize that it has a unique mechanism of action and may affect microtubule nucleation. We are continuing to characterize the compound, and will identify its molecular target. In addition, we are generating further iterations to explore the Structure-Activity Relationship, and optimize its efficacy. Our in vitro data shows that our approach has the potential to identify novel compounds with the potential for therapeutic use.

Citation Format: Dilan B. Jaunky, Pat Forgione, Alisa Piekny. Novel compound conferring selectivity for cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3808.
Abstract 3813: Potent compounds targeting the human MutT homolog 1 (hMTH1) activity and their cytotoxicity evaluation
Authors: Zhou Wenjuan , Ma Liying , Hu Biao , Li Lingyu , Wang Bo , Liu Hong-Min , Zhao Wen
Published: July 2016

Recently, it has been reported that MTH1, a sanitizing protein for the oxidized dNTP pool, plays an important role in cancer-associated damage in the dNTP pool and is required for survival in cancer cells. To study the antitumor mechanism of MTH1 and screen effective anti-cancer drugs, the current study was designed to set up an in vitro expressing and activity evaluation system for MTH1, which will be used for MTH1 specific inhibitor screening. Briefly, the acquired recombinant vector pET-28b-MTH1 was transfected into E.Coli BL21(DE3). The MTH1 protein expression was induced by IPTG and purified by Ni2+ affinity chromatography. Through converting dGTP to dGMP and pyrophosphate by MTH1, the latter of which can then be hydrolyzed to inorganic pyrophosphate by inorganic pyrophosphatase, the MTH1 activity is evaluated through measuring the amount of inorganic pyrophosphate after reacting with malachite green and ammonium molybdate at 630nm. Using this method, we have successfully generated a reliable in vitro evaluation system for MTH1 activity. Furthermore, five brand new series of hybrids with total more than one hundred compounds were virtually designed and synthesized. Their potential MTH1 inhibitory effects were screened based on our system. We found that some of them exhibited moderate to excellent inhibitory activity toward MTH1 with nanomole IC50 values, which also showed significant cytotoxicity on several gastric cancer cell lines by MTT assay (with IC50 below 10μM). On the other hand, our studies in human gastric cancer patients also indicated that MTH1 expression levels were significantly enhanced in these patients’ cancer tissues, compared to the para-cancer ones. Our findings suggest that MTH1 may be a potential therapeutic target in gastric cancer. Compounds specifically designed to target MTH1 activity may represent a novel and useful strategy for anti-gastric cancer drug discovery.

*Corresponding author: Wen Zhao, Ph.D, Tel.: 01186-15003898187. Email: zhaowen100@139.com

Funding Sources.

This work was supported by National Natural Science Foundation of China (Project No. 81430085, No. 21372206 and No. 81172937 for H.-M.L.; Project No. 81270270 and No. 81470524 for W.Z.); Ph.D Educational Award from Ministry of Education (No. 20134101130001, for H.-M.L. and No. 20134101110013, for W.Z.); The 2013 Scientific Innovation Talent Award from Department of Education of Henan Province (No. 13HASTIT029, for W.Z.).

Citation Format: Wenjuan Zhou, Liying Ma, Biao Hu, Lingyu Li, Bo Wang, Hong-Min Liu, Wen Zhao. Potent compounds targeting the human MutT homolog 1 (hMTH1) activity and their cytotoxicity evaluation. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3813.
Abstract 3823: Staphylococcal nuclease and tudor domain containing 1 (SND1) in development and progression of hepatocellular carcinoma
Authors: Jariwala Nidhi , Rajasekaran Devaraja , Gredler Rachel , Akiel Maaged , Robertson Chadia , Fisher Paul , Sanyal Arun , Sarkar Devanand
Published: July 2016

Staphylococcal nuclease and tudor domain containing 1 (SND1) is identified as an oncogene in hepatocellular carcinoma (HCC) and overexpression of SND1 has been correlated with HCC progression. Here, we present effect of liver specific overexpression of human SND1 in a novel transgenic mouse model. We observe greater tumor load and tumor volume in transgenic mice than wildtype mice, when subjected to chemical carcinogenesis. Approximately 30% of transgenic animals manifest spontaneous tumorigenesis with age. Liver specific expression of cancer stem cell markers such as EpCAM and CD133 as well as inflammatory markers was found to be higher in transgenic mice. SND1 overexpressing hepatocytes show increased activation of insulin and NFκB signaling pathways compared to wildtype hepatocytes. However, no significant differences in liver weight or liver function was noted among transgenic and wildtype animals. Overall, our findings confirm that overexpression of SND1 in vivo plays a vital role in development and progression of HCC. Thus, molecular targeting of SND1 seems to be potential therapeutic intervention for HCC management in patients.

Citation Format: Nidhi Jariwala, Devaraja Rajasekaran, Rachel Gredler, Maaged Akiel, Chadia Robertson, Paul Fisher, Arun Sanyal, Devanand Sarkar. Staphylococcal nuclease and tudor domain containing 1 (SND1) in development and progression of hepatocellular carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3823.
Abstract 3829: Preclinical development of a combination inhibitor strategy to block K-Ras effector signaling and autophagy for pancreatic cancer treatment
Authors: Bryant Kirsten L. , Hayes Tikvah K. , Zeitouni Daniel , George Samuel D. , Kher Swapnil , Samatar Ahmed A. , Wood Kris C. , Kimmelman Alec C. , Der Channing J.
Published: July 2016

Pancreatic cancer is the 4th leading cause of cancer deaths in the US and the 5-year survival rate is a dismal 6%. The KRAS oncogene is mutated in ∼95% of pancreatic ductal adenocarcinoma (PDAC) and targeting KRAS is one of four key priorities for pancreatic cancer research, as outlined by the NCI. We hypothesize that inhibition of K-Ras effector signaling is the most promising approach to achieve this goal, and that concurrent inhibition of mutant KRAS-mediated metabolic reprogramming, in particular upregulated autophagy, is needed to disrupt resistance mechanisms that render PDAC cells unaffected by inhibition of either pathway alone. Our preliminary data show that PDAC cells increase levels of autophagic signaling upon KRAS silencing as a compensatory mechanism for the cell to maintain anabolic processes, particularly due to the loss of upregulated glycolytic signaling and macropincytotic scavenging. Furthermore, we show that ERK inhibitor treatment, just like KRAS silencing, increases autophagic flux in PDAC cells. Additionally, we have demonstrated in vitro that chloroquine (CQ), an inhibitor of autophagy, synergistically enhances the anti-proliferative capacity of two different ERK inhibitors, one of which is under clinical evaluation. Finally, we show that signaling pathways that promote resistance to ERK inhibitor treatment alone are incapable of promoting resistance to the combination treatment with CQ. Overall, our studies support the further clinical evaluation of duel ERK and autophagy inhibition as a treatment for PDAC.

Citation Format: Kirsten L. Bryant, Tikvah K. Hayes, Daniel Zeitouni, Samuel D. George, Swapnil Kher, Ahmed A. Samatar, Kris C. Wood, Alec C. Kimmelman, Channing J. Der. Preclinical development of a combination inhibitor strategy to block K-Ras effector signaling and autophagy for pancreatic cancer treatment. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3829.
Abstract 3831: Oncogenic BRAF and concomitant RAS or PTEN/PI3K mutations determine together the response to RAS/RAF/PI3K signaling network inhibition
Authors: Garay Tamas M. , Molnar Eszter , Rittler Dominika , Berger Walter , Döme Balazs , Timar Jozsef , Hegedus Balazs
Published: July 2016

Background: BRAF is key component in the growth factor signaling cascade that is often impaired in tumors. Although oncogenic BRAF mutation is considered to be the driver mutation in a variety of malignancies, the response to RAS/RAF/PI3K signaling network inhibition is not uniform among BRAF mutant tumors. Accordingly, we investigated the in vitro effect of RAS/RAF/PI3K signaling network inhibitors (panRAF, mutant BRAF specific, MEK and PI3K/mTOR inhibitors) in relation with BRAF concomitant RAS or PTEN/PI3K mutations in a panel of human cancer cell lines.

Methods: Altogether 12 human cancer cell lines were investigated in vitro to assess the effect of inhibitors acting at the different levels of the RAS/RAF signaling network. The seven melanoma, two colon, two lung and one breast cancer cell lines were divided into 3 groups according to their mutational status: BRAF-mutant with no PTEN/PI3K/RAS mutations (A375, WM35, SK-MEL-28, CRL5885), BRAF + PTEN-PI3K (A2058, WM239, HT29, SW1417) and BRAF + RAS double mutant (WM3629, WM3670, MDA-MB-231, CRL5922). Effect of inhibitors on proliferation, clonogenic potential and migration were investigated SRB and clonogenic assays and videomicroscopy measurements, respectively. Both single agent and combination treatments were applied.

Results: In single agent treatments panRAF and PI3K/mTOR inhibitors did not show mutation dependent differences in proliferation, however, mutant-BRAF and MEK specific inhibitors were more effective in cells without concomitant PTEN/PI3K or RAS mutations. Interestingly, not only the combination of BRAF and MEK inhibitors but the combination of PI3K/mTOR and MEK inhibition showed additive inhibitory effect on proliferation in all subgroups. Importantly, a distinct pattern emerged for the mutational subgroup specific migration inhibitory effects in comparison to the inhibition of proliferation.

Conclusion: BRAF mutant cells carrying various concomitant PTEN/PI3K/RAS alterations display distinct response to RAS/RAF/PI3K network inhibition in terms of proliferation as well as migration. Our data suggests that combination treatments acting concurrently on different targets of the RAS/RAF/PI3K network can be more effective as single therapies.

Citation Format: Tamas M. Garay, Eszter Molnar, Dominika Rittler, Walter Berger, Balazs Döme, Jozsef Timar, Balazs Hegedus. Oncogenic BRAF and concomitant RAS or PTEN/PI3K mutations determine together the response to RAS/RAF/PI3K signaling network inhibition. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3831.
Abstract 3833: Restoration of wildtype structure and function of mutant p53 by thiosemicarbozones using a novel zinc metallochaperone based mechanism
Authors: Yu Xin , Blanden Adam R. , Tsang Ashley T. , Zaman Saif , Gelleran John , Augeri David , Kimball S. David , Loh Stewart N. , Carpizo Darren R.
Published: July 2016

NSC319726 (ZMC1) is a small molecule that reactivates mutant p53 by restoration of WT structure and function to the most common p53 missense mutant (p53-R175H). We identified that ZMC1 functions as a zinc-metallochaperone, providing an optimal concentration of zinc to facilitate proper folding of p53 protein, and increasing cellular reactive oxygen species to transactivate the newly conformed p53-R175H (via post-translational modifications). ZMC1 was identified from an in silico screen of the NCI anti-cancer drug screen along with two other thiosemicarbazones (TSCs), NSC319725 and NSC328784. We investigated these TSCs to determine if they could reactivate mutant p53 using a zinc metallochaperone mechanism. We found that indeed these compounds could reactivate mutant p53 by functioning as zinc metallochaperones. In distinction, Triapine the only TSC in clinical development, does not function as a zinc metallochaperone and is not a mutant p53 reactivator.

Citation Format: Xin Yu, Adam R. Blanden, Ashley T. Tsang, Saif Zaman, John Gelleran, David Augeri, S. David Kimball, Stewart N. Loh, Darren R. Carpizo. Restoration of wildtype structure and function of mutant p53 by thiosemicarbozones using a novel zinc metallochaperone based mechanism. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3833.
Abstract 3841: Curcumin enhances the efficacy of docetaxel- induced apoptosis of prostate cancer cell
Authors: Banerjee Saswati , Singh Santosh K. , Lillard James W. , Singh Rajesh
Published: July 2016

Despite the different prostate cancer (PCa) treatment therapies it continues to be one of the leading causes of death in men. Docetaxel is a well-established chemotherapeutic agent used to target metastatic PCa, however long-term treatment with docetaxel results in drug resistant and toxicity in PCa cells. Combining agents is common to improve outcomes, but the combination should not significantly increase toxicity. Curcumin is a non-toxic natural compound with multifaceted chemo preventive potential. In current study we evaluated whether curcumin can reinforce the effect of docetaxel on PCa cell lines (RWPE-1, C4-2b, DU145 and PC3). PCa cell lines were treated with curcumin or docetaxel alone or in combination followed by cell viability (MTT assay) and apoptosis assay (TUNEL assay and flow-cytometric analysis of annexin V/propidium iodide-stained cells). The expressions of pro- and anti-apoptotic markers were quantitated with real-time PCR and western blot assay. Our results indicate that curcumin combined with docetaxel led to lower cell viability than treatment with docetaxel or curcumin alone. Annexin V staining followed by flow cytometric analysis demonstrated that curcumin treatment enhanced the docetaxel-induced apoptosis of PCa cells, which was further confirmed by TUNEL assay. The down-regulation of the anti-apoptotic proteins (Bcl2, Mcl-1) and upregulation of pro-apoptotic proteins (Bax, Bid etc.) further confirm that we can considerably reduce docetaxel dose using synergistic combination therapy with curcumin. Thus, our results strongly suggest that we can reduce dose levels of docetaxel and compensate it with non-toxic curcumin and it could be a potential therapeutic contender in enhancing the efficacy of docetaxel in PCa treatment.

Citation Format: Saswati Banerjee, Santosh K. Singh, James W. Lillard, Rajesh Singh. Curcumin enhances the efficacy of docetaxel- induced apoptosis of prostate cancer cell. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3841.
Abstract 3849: The antidiabetic drug metformin increases pro-apoptotic effect of TRAIL therapy by reducing X-linked inhibitor of apoptosis protein (XIAP) levels in triple-negative breast cancer cells
Authors: Strekalova Elena , Malin Dmitry , Cryns Vincent
Published: July 2016

Most metastatic tumors, such as triple negative breast cancer (TNBC) respond poorly to conventional chemotherapy. We have previously demonstrated that targeting TNF-related apoptosis-inducing ligand receptor-2 (TRAIL-R2) might be an effective pathway against metastatic TNBC. However, many TNBCs are resistant to TRAIL receptor agonists. Here we demonstrate that diabetes drug metformin, previously linked to preventing and treating several types of cancer, enhances sensitivity of TNBC cells to recombinant TRAIL and TRAIL-R2 agonistic humanized monoclonal antibody (lexatumumab)-induced apoptosis. We have demonstrated that combination of metformin with lexatumumab or TRAIL augments response to TRAIL therapy and reduce cancer cell viability via induction of apoptosis and inhibiting long-term survival of three different metastatic TNBC cell lines. Intriguingly, metformin treatment also sensitized transformed MCF10A-RasV12 cells, but not untransformed MCF10A-Vector cells, to TRAIL agonist therapy. This effect was associated with reduction of X-linked Inhibitor of Apoptosis Protein (XIAP) levels after metformin treatment. Similar to metformin treatment, inhibition of XIAP by small interfering RNA sensitized breast cancer cells to TRAIL-induced apoptosis. Moreover, metformin treatment in combination with TRAIL more efficiently inhibited primary tumor growth and lung metastases in orthotopic model of TNBC. Overall, our results demonstrate that metformin treatment in combination with targeting TRAIL receptors may be a good strategy to augment the antitumor effects of TRAIL receptors agonistic therapy and provide the foundation for a clinical trial combining dietary metfomin and TRAIL agonists.

Citation Format: Elena Strekalova, Dmitry Malin, Vincent Cryns. The antidiabetic drug metformin increases pro-apoptotic effect of TRAIL therapy by reducing X-linked inhibitor of apoptosis protein (XIAP) levels in triple-negative breast cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3849.