bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract C289: The kinin B1 receptor enhances the host protective response against murine melanoma aggressiveness.
Authors: Maria Andrea G. , Dillenburg-Pilla Patrícia , dos Reis Rosana Inácio , Medeiros Elaine Floriano , Tefé-Silva Cristiane , Ramos Simone Gusmão , Pesquero João Bosco , Costa-Neto Claudio Miguel
Published: August 2014

The incidence of malignant melanoma has significantly increased in the last few decades and advanced cases of this disease are still resistant to all types of therapies and represent a therapeutic challenge. Tumor development and growth depend on alterations that lead to an unlimited replicative potential, evasion of apoptosis and escape from immune response and also, on a permissive microenvironment. Chronic and persistent inflammation may also contribute to cancer development, and the relationship between the kinin B1 receptor and inflammation is well established. Furthermore, previous studies have shown that the kinin B1 receptor attenuates primary melanoma and metastasis. In this study, we show the role of the B1 receptor in the host tumor microenvironment during melanoma progression. To investigate this phenomenon, we inoculated B16F10 cells in wild type and B1 receptor-knockout mice, tumors were removed and several approaches were evaluated such as proliferation and cell survival pathways by western blotting, vascularization and mitosis by histology and cytokines expression levels by real time PCR. Our results show that the presence of the B1 receptor in the microenvironment did not represent a significant factor to modulate tumor size and time of appearance. Nevertheless, molecular analysis revealed that the lack of the B1 receptor resulted in development of tumors with more aggressive features. The melanomas that developed in the B1 receptor-knockout mice had the same vascularization as melanomas developed in the wild type animals but presented higher number of cells in mitosis, and the proliferative signaling pathways in the B1 receptor-knockout tumors were more strongly activated. Likewise, these tumors had lower levels of p38 and JNK activation, and higher levels of IL-10. Additionally, the tumors that developed in the B1 receptor-knockout mice were able to disrupt the skin near the tumor area. Taken together, our results suggest that the B1 receptor has an important role in supporting the host immune response against melanoma aggressiveness.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C289.

Citation Format: Andrea G. Maria, Patrícia Dillenburg-Pilla, Rosana Inácio dos Reis, Elaine Floriano Medeiros, Cristiane Tefé-Silva, Simone Gusmão Ramos, João Bosco Pesquero, Claudio Miguel Costa-Neto. The kinin B1 receptor enhances the host protective response against murine melanoma aggressiveness. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C289.
Abstract C294: Involvement of iNOS/NO and ROS in a reciprocal interaction of glioma and microglia cells via TNF-α and MCP-1 production.
Authors: Chen Yen-chou
Published: August 2014

The tumor microenvironment plays a critical role in glioblastoma invasion and progression, and microglia is one of the most abundant immune cells in the tumor. Using transwell co-culture methods with glioma cells (U87 and C6) and microglia cells BV-2, increased migration of glioma cells U87 and C6 by microglia BV2 cells or NO donor sodium nitro prusside (SNP) accompanied by increased NO production was observed, and BV2 co-culture-induced migration of U87 and C6 was blocked by adding a nitric oxide synthase (NOS) inhibitor N-nitro L-arginine methyl ester (NAME). The conditioned mediums (CM) derived from both glioma cells U87 and C6 (U87-CM and C6-CM) were prepared, CMs from glioma cells significantly induced iNOS protein and NO production cells in according with an occurrence of activated macrophages and without alternations in cell viability and cell cycle progression in microglia BV2. ERK inhibitor U0126 and JNK inhibitor SP600125 suppressed U87-CM and C6-CM-induced iNOS/NO production with respectively blocking phosphorylated ERK (pERK) and JNK (pJNK) protein expression stimulated by U87-CM and C6-CM. A significant increase in intracellular peroxide by U87-CM and C6-CM was detected via DCHF-DA assay, and vitamin C (Vit C) and N-acetyl cysteine (NAC)-reduced intracellular peroxide levels with inhibition of iNOS/NO production and pERK/pJNK protein stimulated by U87-CM and C6-CM were identified in BV-2 cells. Contribution of ROS, pERK, and pJNK to the migration of glioma cells was further demonstrated in the transwell co-culture system of glioma U87 and C6 with microglia BV-2 cells. Furthermore, TNF-α, MCP-1, CSF-1, and TGF-β were applied, and TNF-α and MCP-1 induced iNOS protein expression in time and concentration-dependent manners, and expression of TNF-α and MCP-1 mRNA in U87 and C6 cells were detected by RT-PCR. Neutralization of TNF-α or MCP-1 in U87-CM and C6-CM using TNF-α or MCP-1 antibody inhibited iNOS protein expression, and increased intracellular peroxide by TNF-α or MCP-1 was identified in BV2 cells. The reciprocal activation of glioma cells and microglia via ROS-dependent iNOS/NO elevation at least in part mediated by TNF-α and MCP-1 is elucidated.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C294.

Citation Format: Yen-chou Chen. Involvement of iNOS/NO and ROS in a reciprocal interaction of glioma and microglia cells via TNF-α and MCP-1 production. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C294.
Abstract C3: Tumor-derived soluble uPAR regulates tumor angiogenesis via PTEN.
Authors: Prager Gerald W. , Unseld Matthias , Poettler Marina , Zielinski Christoph
Published: August 2014

The urokinase receptor uPAR (CD87), a GPI-anchored protein, is frequently over-expressed in tumor cells. uPAR provokes numerous cellular functions by focusing proteolytic activity on the cell surface, but also by inducing intracellular signal transduction via transmembrane interaction partners, thus inducing cell migration and invasion as well as cell survival. Soluble tumor-derived uPAR has recently been described to activate endothelial cells and was suggested to promote angiogenesis. Consistently, high uPAR expression in tumor cells or high serum levels of circulating uPAR predict worse prognosis of breast, lung or colorectal cancer patients. In this study, we found that tumor-derived soluble uPAR is a key regulator of PTEN expression in endothelial cells. HEK cells deficient in endogenous uPAR or uPAR deficient endothelial cells derived from uPAR -/- mice had high PTEN mRNA as well as protein levels, while reconstitution of endogenous as well as addition of soluble exogenous uPAR decreased PTEN levels. uPAR, thereby, led to an integrin-dependent activation of the NFkB pathway, a known transcription pathway inhibitor of PTEN. As a consequence of PTEN downregulation, the downstream PKB/Akt signalling pathway became activated, which led to an enhanced migratory as well as cell survival activity in endothelial cells. Cross-breeding of uPAR -/- mice with endothelial cell-specific PTEN +/- mice, thereby led to a rescue of the high migratory phenotype of PTEN heterozygous endothelial cells in vitro and angiogenesis formation in a directed in vivo angiogenesis assay (DIVAA). From our date we conclude that tumor-derived uPAR is a major regulator of PTEN expression in endothelial cells, which leads to the induction of the PI3K/Akt-pathway and an enhanced angiogenic phenotype.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C3.

Citation Format: Gerald W. Prager, Matthias Unseld, Marina Poettler, Christoph Zielinski. Tumor-derived soluble uPAR regulates tumor angiogenesis via PTEN. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C3.
Abstract C38: Comparative evaluation of three real-time PCR assays for the detection of PIK3CA somatic mutations in formalin-fixed paraffin embedded breast carcinomas.
Authors: Harlé Alexandre , Lion Maëva , Rouyer Marie , Lozano Nicola , Merlin Jean-Louis
Published: August 2014

Background: Mutations of the PIK3CA gene encoding for the p110α catalytic subunit of Phosphatidylinositol 3-kinases (PI3K) are found in approximately 25% of breast carcinomas. Most of PIK3CA mutations are reported as activators of the PI3K/AKT/mTOR pathway and lead to resistance to anti-HER2 therapies, and have an interest in molecular diagnosis for anti-mTOR and/or anti-PI3K therapies. Highly sensitive methods are required to detect PIK3CA mutations in paraffin-embedded tumor tissues.

Methods: Forty-seven formalin-fixed paraffin embedded breast carcinomas tissues samples were assessed using two allele specific assays (Cobas® PIK3CA Mutation Test and PCR ARMS Scorpions®) and one non-specific real-time high resolution melting PCR assay (HRM) after macrodissection and DNA extraction. Cobas® allow the detection of 17 mutations on exons 1, 4, 7, 9 and 20 of PIK3CA, ARMS focuses on the detection on the four common hotspots (E542K, E545K/D, H1047R and H1047L) representing 90% of PIK3CA mutations and HRM allows the detection of all mutations located on the whole exons 9 and 20 of PIK3CA. Kappa statistics were used to compare the three assays.

Results: Among the 47 samples, 18 (38.3%) were found to bear a PIK3CA mutation with Cobas®, 13 (27.7%) with ARMS and 19 (40.4%) with HRM. One sample was found to bear 3 mutations of PIK3CA (E542K, H1047X and H1049R). Calculated kappa were 0.893 (p<1.10-9) between Cobas® and HRM and 0.659 (p<1.10-9) between Cobas® and ARMS. Because the ARMS assay only focused on the 4 most common PIK3CA mutations, more than 10% of the samples were identified as false negative wild-type tumors although they had a mutation of PIK3CA as identified with Cobas® and HRM assays.

Conclusion: Cobas® and HRM assays allowed to detect more extensively PIK3CA mutations than ARMS assay. ARMS assay only focusing on the 4 hotspots PIK3CA mutations seems to be inadequate with routine use since generating false negative PIK3CA wild-type results. Cobas® and HRM assays are significantly comparable for the detection of PIK3CA mutations, but Cobas® enables the characterization of the mutation.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C38.

Citation Format: Alexandre Harlé, Maëva Lion, Marie Rouyer, Nicola Lozano, Jean-Louis Merlin. Comparative evaluation of three real-time PCR assays for the detection of PIK3CA somatic mutations in formalin-fixed paraffin embedded breast carcinomas. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C38.
Abstract C41: BRAFV600 serum/plasma analysis: Predictive value of survival in melanoma treated with BRAF inhibitors.
Authors: Gonzalez Cao Maria , Martin Algarra Salvador , Muñoz Eva , Mayo de las Casas Clara , Manzano Jose Luis , Cortes Javier , Molina-Vila Miguel Angel , Berros Jose Pablo , De Mattos-Arruda Leticia , Sanmamed Miguel , Gonzalez Alvaro , Alvarez Carlos , Karachaliou Niki , Rosell Rafael
Published: August 2014

Background: BRAF mutation is present in 50% of metastatic melanoma patients. Treatment with BRAF inhibitors improves survival of BRAF mutant melanoma patients, with a median progression free survival time of 6 months. Twenty percent of patients are refractory to BRAF inhibitors, and others have early resistance development. Pretreatment analysis of BRAFV600 mutation in cell free DNA from serum or plasma could help to select patients for BRAF inhibitor treatments. We have investigated the sensitivity of the assay and its predictive value. Methods: Analysis of BRAFV600 mutation was performed in cell free DNA (cf DNA) from serum and plasma of 22 metastatic melanoma patients before starting a BRAF inhibitor treatment. Results: Six patients were women, median age was 62 years old (58-81). Four patients (18%) had complete response to treatment. Eleven patients (50%) had partial response to treatment. Two patients (9%) had progression disease as their best response. Median progression free survival time (PFS) for patients with complete response, partial response, stable disease and progression disease were: not reached, 4.6 months, 3 months and one month, respectively (p<0.00001). Twelve patients (54.5%) had BRAF positive analysis pretreatment in serum/plasma. From BRAF serum/plasma positive patients 1 had CR (8%) and 7 PR (58%). From BRAF serum/plasma negative patients: 3 (30%) CR and 4 (40%) PR. Median PFS for patients treated with BRAF inhibitors was 3.5 months for BRAF serum/plasma positive patients and 13.57 months for BRAF serum/plasma negative patients (p=0.026) Conclusion: BRAFV600 serum/plasma analysis is a good predictor of survival for patients treated with BRAF inhibitors.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C41.

Citation Format: Maria Gonzalez Cao, Salvador Martin Algarra, Eva Muñoz, Clara Mayo de las Casas, Jose Luis Manzano, Javier Cortes, Miguel Angel Molina-Vila, Jose Pablo Berros, Leticia De Mattos-Arruda, Miguel Sanmamed, Alvaro Gonzalez, Carlos Alvarez, Niki Karachaliou, Rafael Rosell. BRAFV600 serum/plasma analysis: Predictive value of survival in melanoma treated with BRAF inhibitors. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C41.
Abstract C50: Down-regulation of Bcl2 sensitizes radiation resistance prostate cancer cells to ionizing radiation.
Authors: Wang Tao , Carraway Robert E. , Briggs Joshua , Chen Huazhen , FitzGerald Thomas J.
Published: August 2014

Radiation therapy (RT) is an important treatment for primary prostate cancer (PCa). However, intermediate and high risk patients can relapse and recurrent disease can be resistant to RT. Bcl2 is one of the critical regulators of apoptotic cell death. Previously, we selected from the DU145 cell line (DU) a subset of cells (DUIR) that survive fractionated high dose ionizing radiation (IR) in vitro. In the current work, we have identified Bcl2 as an important regulator that determines IR resistance and IR-induced aggressiveness in PrCa cells. DUIR has undergone epithelial-mesenchymal transition (EMT) as defined by reduced E-cadherin and enhanced vimentin expression. DUIR cells display higher levels of neurotensin receptor 1 (NTR1), neuron specific enolase (NSE) and chromogranin B, resembling a neuroendocrine (NE) phenotype. DUIR survives better than DU when exposed to IR (6-10 Gy) or to zinc-directed toxins, and DUIR grows faster in response graded levels of serum or NT. NTR1 antagonist (SR48692) blocks the response to NT. NT stimulation reduces apoptosis while SR486923 enhances apoptosis in DUIR cells exposed to IR. The expression level of Bcl2 is dramatically higher in DUIR than in DU. To assess the role of Bcl2 in the ability of cells to survive IR, we generated stable cell lines using lentivirus caring Bcl2 specific shRNA. Down-regulation of Bcl2 sensitized the cells to IR, as shown by decreased proliferation, decreased clonogenicity, increased apoptosis (cleaved PARP and caspase 3/7 activity), and increased DNA breakage (γ-H2AX foci), as compared to control cells. Our study indicates that PCa cells that survive high dose IR display an aggressive phenotype characterized by NE and EMT features with resistance to IR or drug induced cell death. The up-regulation of Bcl2 plays an important role in cell survival following IR. These findings define a mechanism of cellular resistance to IR therapy and they suggest that strategies aimed to limit the effects of Bcl2 could be beneficial.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C50.

Citation Format: Tao Wang, Robert E. Carraway, Joshua Briggs, Huazhen Chen, Thomas J. FitzGerald. Down-regulation of Bcl2 sensitizes radiation resistance prostate cancer cells to ionizing radiation. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C50.
Abstract C51: eIF2alpha phosphorylation determines cell susceptibility to oxidative stress via Akt activation.
Authors: Koromilas Antonis E. , Kamindla Rajesh , Papadakis Andreas I. , Kazimierczak Urszula , Peidis Philippos , Wang Shuo , Tenkerian Clara , Krishnamoorthy Jothi-Latha , Hatzoglou Maria , Haj Fawaz G. , Ferbeyre Gerardo , Kaufman Randal J.
Published: August 2014

Eukaryotic cells respond to various forms of stress by blocking mRNA translation initiation via the phosphorylation of the alpha (α) subunit of eIF2 at serine 51 (S51) (eIF2αP). Herein, we demonstrate that increased eIF2αP facilitates the adaptation of cells to oxidative stress through the regulation of Akt. Specifically, genetic inactivation of either eIF2αP or the ER-resident kinase PERK in primary mouse or human fibroblasts increases reactive oxygen species (ROS) production leading to increased DNA damage, Akt hyperactivation and induction of senescence. Contrary to the primary cells, immortalized and tumor cells are tolerant to elevated levels of intrinsic ROS caused by eIF2αP inactivation. Nevertheless, eIF2αP-deficient immortalized or tumor cells are more susceptible than eIF2αP-proficient cells to extrinsic oxidative stress caused by hydrogen peroxide or doxorubicin treatment. Extrinsic oxidative stress leads to the induction of either senescence or death in eIF2αP-deficient tumor cells in vitro and in vivo via impaired Akt activation. Our work concludes that Akt acts downstream of eIF2αP to convey either a pro-senescent or a pro-survival role in a cell-context dependent manner in response to oxidative stress. Also, eIF2αP is a potential pharmacological target for tumor treatment in combinational therapies with drugs that induce oxidative stress.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C51.

Citation Format: Antonis E. Koromilas, Rajesh Kamindla, Andreas I. Papadakis, Urszula Kazimierczak, Philippos Peidis, Shuo Wang, Clara Tenkerian, Jothi-Latha Krishnamoorthy, Maria Hatzoglou, Fawaz G. Haj, Gerardo Ferbeyre, Randal J. Kaufman. eIF2alpha phosphorylation determines cell susceptibility to oxidative stress via Akt activation. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C51.
Abstract C55: Discovery and optimization of inhibitors of the KIFC1 motor protein.
Authors: Lamb Michelle L. , Wu Jiaquan , Mikule Keith , Wang Wendy , Su Nancy , Petteruti Philip , Gharahdaghi Farzin , Code Erin , Zhu Xiahui , Jacques Kelly , Lai Zhongwu , Zhang Tao , Boulay David , Grewal Gurmit , Keen Nicholas , Yang Bin , Chuaqui Claudio , Chuaqui Claudio , Chen Huawei
Published: August 2014

KIFC1, a kinesin-14 family protein, plays an essential role in centrosomal bundling, a strategy employed by cancer cells to avoid multipolar mitosis in the presence of amplified centrosomes. However, its function is not required for normal diploid cell division, suggesting that KIFC1 is an attractive therapeutic target for human cancers. We have recently reported the first small molecule inhibitor of KIFC1, AZ82 [1]. AZ82 binds specifically to the KIFC1/microtubule (MT) binary complex, and inhibits the MT-stimulated KIFC1 enzymatic activity with a KI of 0.043 µM. AZ82 effectively engaged with the minus-end directed KIFC1 motor in HeLa cells to reverse the monopolar spindle phenotype induced by the inhibition of the plus end-directed kinesin Eg5 by AZD4877, consistent with what was observed with genetic knock down of KiFC1 by siRNA. Additionally, treatment with AZ82 caused centrosome declustering in BT-549 breast cancer cells with amplified centrosomes. Here we further describe the chemistry approach and related structure-activity relationships that led to the discovery of AZ82.

[1] http://pubs.acs.org/doi/abs/10.1021/cb400186w

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C55.

Citation Format: Michelle L. Lamb, Jiaquan Wu, Keith Mikule, Wendy Wang, Nancy Su, Philip Petteruti, Farzin Gharahdaghi, Erin Code, Xiahui Zhu, Kelly Jacques, Zhongwu Lai, Tao Zhang, David Boulay, Gurmit Grewal, Nicholas Keen, Bin Yang, Claudio Chuaqui, Claudio Chuaqui, Huawei Chen. Discovery and optimization of inhibitors of the KIFC1 motor protein. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C55.
Abstract C58: GS-19, a novel GSK inhibitor suppresses the growth of pancreatic cancer cells by inhibiting EGFR/AKT/STAT-3 signaling.
Authors: Ranjan Alok , Srivastava Sanjay K. , Gupta Parul , Birkenfeld Ashlee , Hua Duy , Lu Jianyu
Published: August 2014

The American Cancer Society estimates that over 43,000 new cases of pancreatic cancer are diagnosed each year in the United States, with a five-year survival rate below 6%. Conventional therapies are often of limited use because of the resistance development and cancer relapse. Therefore, identification of novel strategies to control and treat pancreatic cancer is of great importance. GS-19 is a novel compound designated as a GSK inhibitor and shown good activity in neural protective assay using MC65 cells. In this study, we determined the cytotoxic effects of GS-19 in pancreatic cancer cells. GS-19 treatment inhibited the growth of Panc-1 and BxPC-3 cells in a concentration-dependent manner. Both the cell lines treated with GS-19 exhibited G-1 cell cycle arrest as well as apoptosis. Western blot analysis of both BxPC-3 and Panc-1 cells treated with GS-19 inhibited the activation (phosphorylation) and expression of key survival signaling proteins such as EGFR, STAT3 and AKT. The apoptosis induced by GS-19 was associated with cleavage of caspase-3 and PARP. Taken together, our results suggest that GS-19 suppress pancreatic cancer cell growth by inhibiting EGFR/AKT/STAT-3 signaling. However, further mechanistic studies are in progress to establish the role of EGFR/AKT/STAT-3 signaling in pancreatic cancer cells and correlate it with G1 cell cycle arrest and apoptosis induced by GS-19. The studies in part were supported by R01 grant CA129038 awarded by NIH to S.K.S

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C58.

Citation Format: Alok Ranjan, Sanjay K. Srivastava, Parul Gupta, Ashlee Birkenfeld, Duy Hua, Jianyu Lu. GS-19, a novel GSK inhibitor suppresses the growth of pancreatic cancer cells by inhibiting EGFR/AKT/STAT-3 signaling. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C58.
Abstract C60: Exposure of low doses of quercetin on DNA oxidation in Pectobacterium carotovorum KD 100 and Agrobacterium tumefaciens GV 3103.
Authors: Boadi William Y. , Johnson Damitea , Dumenyo Korsi
Published: August 2014

Oxidative stress may be a key factor in the onset of certain diseases, including cancer. Oxy-radicals play important roles in the initiation, promotion, and progression of carcinogenesis. During the course of DNA excision and repair of oxidized, deaminated or alkylated bases apurinic/apyrimidinic (AP) or abasic sites are formed. The flavonoid quercetin was investigated for its ability to inhibit the oxidation of plasmid from Pectobacterium carotovorum KD 100 and Agrobacterium tumefaciens GV 3103 using the Fenton's chemistry. Utilizing a Colorimetric Assay Kit (Oxford Biomedical Research #FR09, Oxford, MI) for DNA damage quantification, AP sites were measured for plasmid following incubation with low doses of quercetin (1, 2, 2.5, 3, 3.5 µM) or without for 12 or 24 hr. With the increasing concentrations of quercetin the number of AP sites in each sample significantly decreased more for Pectobacterium carotovorum KD 100 compared to Agrobacterium tumefaciens GV 3103 in a time- and dose-dependent manner in comparison to their respective controls for the 12 and 24 hr incubation periods. The differences in decrease in AP sites can be linked to structural differences between the two bacterial strains and/or decreased oxidation for each sample with increased quercetin aliquots.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C60.

Citation Format: William Y. Boadi, Damitea Johnson, Korsi Dumenyo. Exposure of low doses of quercetin on DNA oxidation in Pectobacterium carotovorum KD 100 and Agrobacterium tumefaciens GV 3103. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C60.
Abstract C71: Phase II study of maintenance therapy with pazopanib or pemetrexed in patients with advanced non-small cell lung cancer (NSCLC) who have not progressed following platinum-based chemotherapy.
Authors: Konduri Kartik , Smith David , Compton Natalie , Elmore Lockheed Denise , Chakrabarti Debasis , Bhatt Kamal
Published: August 2014

Background: Platinum-based chemotherapy combinations are the standard of care in first-line treatment of advanced NSCLC. Maintenance therapy with a chemotherapeutic agent (continuation maintenance) or a targeted agent (switch maintenance) has been explored to delay recurrence. The purpose of this trial (NCT01313663) was to evaluate the clinical activity and safety profile of pazopanib as switch maintenance in patients with stable disease or better as best response after induction therapy in advanced NSCLC.

Methods: Eligible patients had received 4-6 cycles of induction therapy with cisplatin/carboplatin plus pemetrexed and should have had best response of complete response, partial response, or stable disease before entering the study. In this 2-arm, open-label, phase II study, patients were randomized to receive either oral pazopanib 800 mg daily or intravenous pemetrexed 500 mg/m2 on Day 1 of a 21-day cycle. The primary endpoint was to estimate the hazard ratio (HR) for investigator-assessed progression-free survival; secondary endpoints included overall survival, best overall response, and safety.

Results: Planned enrollment was 200 patients. The trial was terminated due to evolving standards of care that resulted in a slow enrollment rate. Twenty patients were randomized and 19 received treatment (10 received pazopanib; 9 received pemetrexed). Progression-free survival was 10.3 weeks in the pemetrexed arm and 12.7 weeks in the pazopanib arm (HR = 0.92; 90% confidence interval: 0.32, 2.65). However, the number of evaluable patients was too small to draw conclusions for efficacy, as evidenced by the width of the 90% confidence interval for the HR. Best response was stable disease (2 patients in each arm). All patients experienced at least 1 adverse event (AE). Hepatic toxicities were more common with pazopanib, but low enrollment prevented a complete characterization of AE frequency. There were no fatal serious adverse events (SAEs) in the pazopanib arm and there were 2 fatal SAEs in the pemetrexed arm (respiratory failure and pneumonia).

Conclusions: Low accrual and early termination prevented evaluation of the primary endpoint. No new safety signals emerged.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C71.

Citation Format: Kartik Konduri, David Smith, Natalie Compton, Denise Elmore Lockheed, Debasis Chakrabarti, Kamal Bhatt. Phase II study of maintenance therapy with pazopanib or pemetrexed in patients with advanced non-small cell lung cancer (NSCLC) who have not progressed following platinum-based chemotherapy. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C71.
Abstract C75: Rucaparib (CO-338) accumulation and persistence of PARP inhibition in vitro and in vivo and efficacy of intermittent vs continuous schedules.
Authors: Murray James C. , Thomas Huw D. , Berry Philip , Kyle Suzanne , Jones Christopher , Plummer Ruth , Boddy Alan V. , Curtin Nicola J.
Published: August 2014

Background: Preclinical studies show that both duration and extent of PARP inhibition is critical for synthetically lethality in tumors with defects in homologous recombination repair (HRR). Rucaparib is undergoing clinical evaluation in HRR-defective tumors. Our aim was to determine whether multiple daily doses or an intermittent schedule will give the required “coverage” for anticancer activity.

Methods: The accumulation of 14C-rucaparib and duration of PARP inhibition was determined in SW620 and BRCA2 mutant Capan-1 cells after a 30 minute pulse. Rucaparib concentration in plasma brain and Capan-1 tumor xenografts and PARP inhibition in brain and tumor was determined at intervals up to 1 week after a single dose of rucaparib. The efficacy of continuous and discontinuous schedules of rucaparib was determined in mice bearing Capan-1 xenografts.

Results: Rucaparib accumulates in cells via a carrier-mediated transporter (Km of 8.4 ± 1.2 μM and Vmax of 469 ± 22 pmol/106cells/10 min) PARP activity in Capan-1 cells was suppressed by 80% for 72 hr after a pulse of 50 or 400 nM rucaparib, and still 40% reduced 7 days after 400 nM. Rucaparib was cleared rapidly from the plasma but it was detectable for up to 72 hr and suppressed PARP activity in the tumors for 7 days, being 25% and 10% of control after 10 mg/kg and 150 mg/kg, respectively. Peak levels in the brain were 2-10% of those in the tumor and only modest, transient PARP inhibition was observed in the brain. Tumor growth was suppressed by rucaparib at 150 mg/kg po on a weekly schedule as effectively as 10 mg/kg po on a daily x5 every week for 6 weeks.

Conclusion: Rucaparib accumulates in human tumor cells and PARP inhibition by rucaparib is durable after a 30 min pulse. PARP is inhibited in tumor xenografts for up to 1 week after a single dose and when the drug concentrations are no longer detectable. Weekly dosing with rucaparib inhibits tumor growth.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C75.

Citation Format: James C. Murray, Huw D. Thomas, Philip Berry, Suzanne Kyle, Christopher Jones, Ruth Plummer, Alan V. Boddy, Nicola J. Curtin. Rucaparib (CO-338) accumulation and persistence of PARP inhibition in vitro and in vivo and efficacy of intermittent vs continuous schedules. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C75.
Abstract C86: Tethered Hsp90 inhibitors carrying optical or radioiodinated probes reveal selective internalization of ectopic Hsp90 in malignant breast tumor cells.
Authors: Barrott Jared J. , Smith Aaron P. , Osada Takuya , Ramanujam Nimmi , Zalutsky Michael R. , Lyerly Kim , Haystead Timothy A. J.
Published: August 2014

Hsp90 inhibitors have demonstrated unusual selectivity for tumor cells despite its ubiquitous expression. This phenomenon has remained unexplained but could be influenced by ectopically expressed Hsp90 in tumors. We have synthesized novel Hsp90 inhibitors that can carry optical or radioiodinated probes via a PEG tether. We show that these tethered inhibitors selectively recognize cells expressing ectopic Hsp90 and become internalized. The internalization process is blocked by Hsp90 antibodies, suggesting that active cycling of the protein is occurring at the plasma membrane. In mice, we show exquisite accumulation of the fluor-tethered versions within breast tumors at very sensitive levels. Cell-based assays with the radiolabeled version showed picomolar detection in cells that express ectopic Hsp90. Our findings show that fluor-tethered or radiolabeled inhibitors targeting ectopic Hsp90 can be used to detect breast cancer malignancies through non-invasive imaging.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C86.

Citation Format: Jared J. Barrott, Aaron P. Smith, Takuya Osada, Nimmi Ramanujam, Michael R. Zalutsky, Kim Lyerly, Timothy A. J. Haystead. Tethered Hsp90 inhibitors carrying optical or radioiodinated probes reveal selective internalization of ectopic Hsp90 in malignant breast tumor cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C86.
Abstract C98: Quizartinib (AC220) potentiates the antineoplastic activity of wild-type ABCG2 and ABCB1 substrates.
Authors: Kumar Priyank , Kathawala Rishil J. , Zhang Hui , Anreddy Nagaraju , Chen Yanglu , Gupta Kanav , Trombetta Louis D. , Cheng Zhe S.
Published: August 2014

Quizartinib (AC220), a novel and potent class II receptor tyrosine kinase inhibitor that has better therapeutic and pharmacokinetic profile amongst its class. Quizartinib is currently under clinical trials for FLT3 ITD and wild-type AML and is tested in combination with chemotherapy. This study examined the effects of quizartinib on ABC transporter-mediated multidrug resistance (MDR). Cytotoxic studies showed that 0.75, 1.5, and 3 μM are the three less toxic concentrations for normal as well as cancer cells. Out of these three concentrations, quizartinib at 3 μM showed a significant reversal of MDR mediated by ABCG2 and ABCB1 in different MDR cell models, when compared to the positive controls, fumetrimorgin C and verapamil at 3 μM, respectively. Interestingly, quizartinib did not show a significant reversal of the MDR associated with the two mutants (R482T and R482G) ABCG2 overexpression. Results also showed that quzartinib at 3 μM significantly reversed wild-type ABCG2-mediated drug resistance by antagonizing the drug efflux function of wild-type ABCG2 and increasing the intracellular accumulation of [3H]-mitoxantrone in wild-type ABCG2-overexpressing cells. However, quizartinib at 3 μM did not reverse ABCC1- and ABCC10-mediated drug resistance in HEK/ABCC1 and HEK/ABCC10 cell lines. Hence these results conclude that quizartinib potentiates the antineoplastic activity of wild-type ABCG2 and ABCB1 substrates.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C98.

Citation Format: Priyank Kumar, Rishil J. Kathawala, Hui Zhang, Nagaraju Anreddy, Yanglu Chen, Kanav Gupta, Louis D. Trombetta, Zhe S. Cheng. Quizartinib (AC220) potentiates the antineoplastic activity of wild-type ABCG2 and ABCB1 substrates. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C98.
Abstract CN03-01: Drug testing in genetically engineered murine models.
Authors: Sharpless Norman E.
Published: August 2014

Traditional xenograft testing has a poor track record of predicting the efficacy in humans of a novel anticancer compound. Autochthonous tumors occurring in genetically engineered mice more faithfully recapitulate some aspects of human cancers, and therefore may have advantages for preclinical efficacy assessment. The UNC Lineberger Mouse Phase I Unit (MP1U) was founded to allow for medium-throughput testing of novel therapeutics in credentialed cancer GEMMs. The MP1U harnesses the power of murine genetics to produce multi-allelic cancer models featuring autochthonous tumors with physiological tumor-stroma interface and an intact immune response. Promising anticancer compounds are tested alone and in combination in these models, using cohort sizes comparable to human Phase II trials (15-50 subjects per treatment). Agents are considered "active" if they induce sustained and pronounced tumor regression, whereas tumor growth inhibition (TGI) is not considered predictive of human efficacy. Pharmacokinetic and pharmacodynamic assessment is included in efficacy trials, as is serial tumor imaging if needed. The goal is to make testing in the MP1U as close to human Phase I/II anticancer trials as possible, while still taking advantage of the powerful experimental features of murine tumor models. Results of testing with a variety of novel agents will be presented to illustrate the promise and power of GEMM testing.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):CN03-01.

Citation Format: Norman E. Sharpless. Drug testing in genetically engineered murine models. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr CN03-01.
Abstract CN04-04: Targeting death receptors and SMAC mimetics.
Authors: Fulda Simone
Published: August 2014

Evasion of apoptosis is a hallmark of human cancers and contributes to tumor formation and progression as well as resistance to current cancer therapies, which largely rely on intact cell death pathways in cancer cells. Apoptosis resistance can be caused by aberrant expression of antiapoptotic proteins, for example Inhibitor of Apoptosis (IAP) proteins, which are expressed at high levels in many human cancers. Since IAP proteins block apoptosis at the core of the apoptotic machinery by inhibiting effector caspases, they present promising therapeutic targets.

Smac mimetics are small-molecule inhibitors that mimick the IAP-binding motif of the endogenous IAP antagonist Smac and are among the most widely used strategies to antagonize IAP proteins. In addition to their use as single agents, Smac mimetics have been used in combination with various cytotoxic stimuli to trigger cell death in cancer cells, in particular together with death receptor ligands such as soluble TRAIL or TRAIL receptor agonists. For example in pancreatic cancer_ one of the most lethal types of cancer_ IAP antagonists were shown to synergize with TRAIL receptor agonists to induce apoptosis and suppress tumor growth in preclinical in vitro and in vivo models. Furthermore, Smac mimetics and TRAIL acted in concert to trigger apoptosis in CLL, even in patients with poor prognostic features such chemoresistant disease, p53 mutation or chromosome 17p deletion. Thus, Smac mimetics may open new perspectives to overcome resistance to death receptor-mediated apoptosis in various forms of human cancers.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):CN04-04.

Citation Format: Simone Fulda. Targeting death receptors and SMAC mimetics. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr CN04-04.
Abstract CN05-01: PARP inhibitors: Trapping of PARP and rational for combinations.
Authors: Pommier Yves G. , Murai Junko , Morris Joel , Doroshow James H.
Published: August 2014

Poly(ADPribose) polymerases (PARPs) are promising targets of several anticancer drugs in clinical development. We will review the genetic and biochemical evidence that PARP inhibitors act as cytotoxic anticancer agents by trapping PARP-DNA complexes (1). We will also show that PARP inhibitors differ from each other by their ability to trap PARP. They can be ranked by decreasing potency for PARP trapping: BMN-673 ≫ Niraparib > Olaparib = Rucaparib ≫ Veliparib, while all the PARP inhibitors are relatively similar with respect to PARP catalytic inhibition. We propose that PARP trapping results from allosteric effect whereas catalytic inhibition results from competition with NAD+. We will also discuss the rationale for combining PARP inhibitors with topoisomerase I inhibitors, and its dependence on PARP catalytic inhibition, and the rationale for combination with temozolomide, which depends both on catalytic inhibition and PARP trapping.

1. Murai J, Huang S-yN, Das BB, Renaud A, Zhang Y, Doroshow JH, Ji J, Takeda S, Pommier Y. Trapping of PARP1 and PARP2 by Clinical PARP Inhibitors. Cancer Research 2012; 72: 5588-99.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):CN05-01.

Citation Format: Yves G. Pommier, Junko Murai, Joel Morris, James H. Doroshow. PARP inhibitors: Trapping of PARP and rational for combinations. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr CN05-01.
Abstract PL03-04: Protein methyltransferase inhibitors as personalized cancer therapeutics.
Authors: Copeland Robert A.
Published: August 2014

The protein methyltransferases (PMTs) constitute a class of enzymes that catalyze the methylation of lysine or arginine residues on histones and other proteins. A number of PMTs have been shown to be genetically altered in cancers through, for example, gene amplification, chromosomal translocations, point mutations and synthetic lethal relationships. The enzymes DOT1L and EZH2 provide two representative examples of altered PMTs that act as genetic drivers of specific human cancers. The enzymatic activity of DOT1L is associated with a chromosomal translocation that is universally found in patients with MLL-rearranged leukemia. Point mutations at Y641 of EZH2 are found in a subset of non-Hodgkins lymphoma patients; the enzymatic activity of both wild type and mutant EZH2 are required for pathogenesis in these patients. Also, deletion of the INI1 (SMARCB1 or hSNF5) subunit of the SWI/SNF chromatin-remodeling complex occurs in nearly all malignant rhabdoid tumors (MRTs), a childhood cancer with a particularly poor prognosis. An antagonistic relationship has been demonstrated between the biochemical action on chromatin of the SWI/SNF complex and EZH2 (in the context of the polycomb repressive complex 2), that is relieved in MRTs due to the INI1 deletion. MRTs therefore demonstrate increased reliance on the enzymatic activity of EZH2 for proliferation and we have shown that MRT cells deficient in INI1 are selectively killed by inhibition of EZH2 in cell culture and in mouse xenograft models. Drug discovery efforts have yielded potent, selective inhibitors of each of these targets that have now transitioned into Phase I clinical trials. These inhibitors affect the appropriate histone methyl marks in cells, lead to selective cell killing that is dependent on genetic alteration of the target enzyme and effect tumor growth inhibition in xenograft models. These data portend the effective use of selective PMT inhibitors as a novel modality for future personalized cancer therapeutics.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):PL03-04.

Citation Format: Robert A. Copeland. Protein methyltransferase inhibitors as personalized cancer therapeutics. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr PL03-04.
Abstract PL04-02: Targeting MEK in KRAS mutant lung cancer.
Authors: Jänne Pasi A.
Published: August 2014

Despite all of the success in targeted therapies for NSCLC, treatment of KRAS mutant NSCLC has been much more challenging. In Caucasian patients, KRAS mutant NSCLC is the most common subset of NSCLC. Therapeutic development of agents specifically targeting KRAS have been unsuccessful. However, recent preclinical and clinical studies suggest that targeting MEK may have some efficacy in KRAS mutant NSCLC.

MEK inhibitors selumetinib (AZD6244) and trametinib (GSK1120212) are undergoing clinical development in previously treated KRAS mutant NSCLC patients. A randomized phase II clinical trial of selumetinib/docetaxel vs. docetaxel demonstrated a significant improvement in radiographic response (RR) rate (37% vs. 0%) and progression free survival (PFS) (5.3 vs. 2.1 months) and a numerical increase in overall survival (OS) (9.4 vs. 5.2 months) all in favor of the selumetinib combination. A phase III trial comparing selumetinib/docetaxel to docetaxel alone is currently underway. The trametinib study compared single agent trametinib to docetaxel in a similar patient population. In this study, the PFS was similar for both trametinib and docetaxel (11.7 and 11.4 weeks, respectively) as was the RR (12% in each arm). Additional studies are underway.

Recent preclinical studies also suggest that the presence or absence of the tumor suppressor gene, LKB1, may impact the efficacy of selumetinib/docetaxel in a murine model of KRAS mutant NSCLC. LKB1 loss is detected in ∼ 30% of KRAS mutant cancers. In addition, there may be differences in patient outcomes based on the subtype of KRAS mutations. The impact and strategies to evaluate LKB1 loss and the subtypes of KRAS mutations in ongoing clinical trials of MEK inhibitors will be discussed.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):PL04-02.

Citation Format: Pasi A. Jänne. Targeting MEK in KRAS mutant lung cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr PL04-02.