bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract IA03: Genomic and epigenomic targets in small cell lung cancer.
Authors: Rudin Charles M.
Published: August 2014

Recent comprehensive analyses of the genome, transcriptome, and proteome of small cell lung cancer (SCLC) have provided new insights into the biology of this particularly aggressive cancer type. As has been known for several years, most SCLC demonstrate concomitant loss or inactivation of two key tumor suppressors, p53 and RB; conditional loss of these genes in a mouse model results in lung cancer with many of the properties of human SCLC. Amplification and aberrant expression of MYC family members, including L-MYC and N-MYC, are strongly implicated in SCLC. Other important oncogenes amplified in subsets of SCLC include SOX2, a key developmental transcription factor, and the receptor tyrosine kinase FGFR1. Several key epigenetic control genes are mutated or disregulated in SCLC, including EZH2. Recent analyses of the SCLC methylome suggest that these cancers may be categorized into subsets based on global gene expression and methylation patterns. Taken together with recent proteomic studies highlighting additional potential targets including PARP1, these recent observations are providing a new landscape of investigational therapeutic opportunities for SCLC.

Citation Format: Charles M. Rudin. Genomic and epigenomic targets in small cell lung cancer. [abstract]. In: Proceedings of the AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer; 2014 Jan 6-9; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2014;20(2Suppl):Abstract nr IA03.
Synergistic Simvastatin and Metformin Combination Chemotherapy for Osseous Metastatic Castration-Resistant Prostate Cancer
Authors: Babcook Melissa A. , Shukla Sanjeev , Fu Pingfu , Vazquez Edwin J. , Puchowicz Michelle A. , Molter Joseph P. , Oak Christine Z. , MacLennan Gregory T. , Flask Chris A. , Lindner Daniel J. , Parker Yvonne , Daneshgari Firouz , Gupta Sanjay
Published: August 2014

Docetaxel chemotherapy remains a standard of care for metastatic castration-resistant prostate cancer (CRPC). Docetaxel modestly increases survival, yet results in frequent occurrence of side effects and resistant disease. An alternate chemotherapy with greater efficacy and minimal side effects is needed. Acquisition of metabolic aberrations promoting increased survival and metastasis in CRPC cells includes constitutive activation of Akt, loss of adenosine monophosphate-activated protein kinase (AMPK) activity due to Ser-485/491 phosphorylation, and overexpression of 3-hydroxy-3-methylglutaryl–Coenzyme A reductase (HMG-CoAR). We report that combination of simvastatin and metformin, within pharmacologic dose range (500 nmol/L to 4 μmol/L simvastatin and 250 μmol/L to 2 mmol/L metformin), significantly and synergistically reduces C4-2B3/B4 CRPC cell viability and metastatic properties, with minimal adverse effects on normal prostate epithelial cells. Combination of simvastatin and metformin decreased Akt Ser-473 and Thr-308 phosphorylation and AMPKα Ser-485/491 phosphorylation; increased Thr-172 phosphorylation and AMPKα activity, as assessed by increased Ser-79 and Ser-872 phosphorylation of acetyl-CoA carboxylase and HMG-CoAR, respectively; decreased HMG-CoAR activity; and reduced total cellular cholesterol and its synthesis in both cell lines. Studies of C4-2B4 orthotopic NCr-nu/nu mice further demonstrated that combination of simvastatin and metformin (3.5–7.0 μg/g body weight simvastatin and 175–350 μg/g body weight metformin) daily by oral gavage over a 9-week period significantly inhibited primary ventral prostate tumor formation, cachexia, bone metastasis, and biochemical failure more effectively than 24 μg/g body weight docetaxel intraperitoneally injected every 3 weeks, 7.0 μg/g/day simvastatin, or 350 μg/g/day metformin treatment alone, with significantly less toxicity and mortality than docetaxel, establishing combination of simvastatin and metformin as a promising chemotherapeutic alternative for metastatic CRPC. Mol Cancer Ther; 13(10); 2288–302. ©2014 AACR.
Abstract A11: Synthetic lethal screens in zebrafish
Authors: Sidi Samuel
Published: August 2014

This abstract is being presented as a short talk in the scientific program. A full abstract is printed in the Proffered Abstracts section (PR07) of the Conference Proceedings.

Citation Format: Samuel Sidi. Synthetic lethal screens in zebrafish. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr A11.
Abstract B04: A chemical genetic screen identifies novel ATM/ATR pathway inhibitors that sensitize p53-deficient cells to DNA-damaging agents without affecting ATR kinase catalytic activity
Authors: Kawasumi Masaoki , Bradner James E. , Tolliday Nicola , Thibodeau Renee , Sloan Heather , Brummond Kay M. , Nghiem Paul
Published: August 2014

An important goal in cancer therapy has been to selectively sensitize cancers to existing drugs that typically work by inducing DNA damage. In particular, many cancers are p53-defective and chemoresistant, thus novel approaches to target p53-defective cancers are needed. One promising strategy to sensitize p53-deficient cells has been to inhibit DNA damage response kinases such as ATM/ATR via ATP-competitive kinase inhibitors. To better understand ATM/ATR activation mechanisms and discover novel probes for the ATM/ATR pathway, we performed a phenotype-based screen of 9,195 small-molecule compounds for inhibitors of hydroxyurea-induced phosphorylation of Chk1, a key ATR substrate. After subsequent biological screens, we selected 4 compounds that inhibited ATR and ATM pathways; 3 were known bioactive agents and 1 was a diversity-oriented-synthetic product. These compounds sensitized p53-deficient cells to diverse DNA-damaging agents. Xenograft experiments were performed on one compound, and it showed synergistic suppression of p53-deficient tumor growth with cisplatin. Importantly, these compounds did not suppress ATR kinase catalytic activity in vitro, unlike typical ATM/ATR kinase inhibitors that are ATP-competitive. To identify molecular targets of one compound, “MARPIN” (ATM and ATR pathway inhibitor), we defined its active site through structure-activity relationship analysis, resulting in synthesis of inactive derivatives of MARPIN. Identification of proteins that specifically bind MARPIN, but not its inactive derivatives, is underway. This phenotype-based chemical genetic screen identified novel ATM/ATR pathway inhibitors that are mechanistically distinct from kinase catalytic inhibitors, and these compounds could serve as probes to identify previously unrecognized druggable targets in DNA damage response pathways.

Citation Format: Masaoki Kawasumi, James E. Bradner, Nicola Tolliday, Renee Thibodeau, Heather Sloan, Kay M. Brummond, Paul Nghiem. A chemical genetic screen identifies novel ATM/ATR pathway inhibitors that sensitize p53-deficient cells to DNA-damaging agents without affecting ATR kinase catalytic activity. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr B04.
Abstract B31: Pak1 and β-catenin inhibition blocks tumor progression in ErbB2-driven breast cancer models
Authors: Arias-Romero Luis E. , Villamar-Cruz Olga , Chernoff Jonathan
Published: August 2014

p21-activated kinase-1 (Pak1) is frequently upregulated in human breast cancer and is required for transformation of mammary epithelial cells by ErbB2. However, its role in tumorigenesis in vivo, and the particular signaling pathways affected, are not defined.

In this work, we examined the distinct roles of Pak1 and Pak2 in cellular and animal models of ErbB2-driven breast cancer. We found that inhibition of Pak1, but not Pak2, impedes transformation by ErbB2 in a 3D cell culture system, but that loss of either Pak1 or Pak2 causes loss of both Erk and Akt activation. A phospho-proteomic screen revealed that Pak1-deficient, but not Pak2-deficient, ErbB2 cells showed almost total loss of β-catenin expression that is accompanied by a significant reduction in almost all known β-catenin target genes. In MMTV-ErbB2 transgenic mice, loss of Pak1 prolonged survival, and mammary tissues of such mice showed loss of β-catenin. Expression of a β-catenin mutant bearing a phospho-mimetic mutation at Ser 675, a specific Pak1 phosphorylation site, restored the ability of ErbB2 to transform Pak1-deficient mammary epithelial cells. Lastly, we showed that small molecule inhibitors of Pak or β-catenin blocked transformation by ErbB2 in 3D culture and tumorigenesis by ErbB2 in mouse xenografts, and combined inhibition by both agents was synergistic. These findings establish Pak1 as a new target in ErbB2-driven breast cancer and define a new mechanism of action primarily through the β-catenin, but not the Erk or Akt, signaling pathways.

Citation Format: Luis E. Arias-Romero, Olga Villamar-Cruz, Jonathan Chernoff. Pak1 and β-catenin inhibition blocks tumor progression in ErbB2-driven breast cancer models. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr B31.
Abstract B39: MYC, a downstream target of BRD-NUT, is necessary and sufficient for the blockade of differentiation in NUT midline carcinoma
Authors: Walsh Erica M. , Grayson Adlai R. , Cameron Michael J. , Godec Jernej , Ashworth Todd , Aserlind Alexandra B. , Wang Hongfang , Evan Gerard , Kluk Michael J. , Bradner James E. , Aster Jon C. , French Christopher A.
Published: August 2014

NUT midline carcinoma (NMC) is an aggressive type of squamous cell carcinoma that is defined by the presence of BRD-NUT fusion oncogenes, which encode chimeric proteins that block differentiation and maintain tumor growth. BRD-NUT oncoproteins contain two bromodomains whose binding to acetylated histones is required for the blockade of differentiation in NMC, but the mechanisms by which BRD-NUT act remain uncertain. Here we provide evidence that MYC is a key downstream target of BRD4-NUT. Expression profiling of NMCs show that the set of genes whose expression is maintained by BRD4-NUT is highly enriched for MYC upregulated genes, and MYC and BRD4-NUT protein expression is strongly correlated in primary NMCs. More directly, we find that BRD4-NUT associates with the MYC promoter and is displaced by acetyl histone mimetic BET inhibitor, JQ1, which prevents binding of BET bromodomains to acetylated histones. BRD4-NUT is also required to maintain MYC expression in NMC cell lines, as shown by a dramatic decrease in MYC expression upon JQ1 treatment and knockdown of BRD4-NUT with NUT specific siRNAs. Moreover, both siRNA knockdown of MYC and a dominant-negative form of MYC, omomyc, induce differentiation of NMC cells. Conversely, differentiation of NMC cells induced by knockdown of BRD4-NUT is abrogated by enforced expression of MYC. Together, these findings suggest that MYC is a downstream target of BRD4-NUT that is required for maintenance of NMC cells in an undifferentiated, proliferative state. Our findings support a model in which dysregulation of MYC by BRD-NUT fusion proteins has a central role in the pathogenesis of NMC.

Citation Format: Erica M. Walsh, Adlai R. Grayson, Michael J. Cameron, Jernej Godec, Todd Ashworth, Alexandra B. Aserlind, Hongfang Wang, Gerard Evan, Michael J. Kluk, James E. Bradner, Jon C. Aster, Christopher A. French. MYC, a downstream target of BRD-NUT, is necessary and sufficient for the blockade of differentiation in NUT midline carcinoma. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr B39.
Abstract IA10: Targeting intratumoral genetic heterogeneity through rationally designed combination therapy
Authors: Lauffenburger Douglas A. , Zhao Boyang , Pritchard Justin R. , Hemann Michael T.
Published: August 2014

Deep sequencing of distinct tumor biopsies from a single cancer has revealed dramatic genetic intratumoral heterogeneity in patients. Additionally, sequencing of tumors at multiple time points has led to the characterization of minor tumor subclones prior to treatment that expand to become the predominate tumor subpopulation at relapse. These data suggest an urgent need to directly address the issue of intratumoral heterogeneity in the design of chemotherapeutic regimens. Here we model tumor heterogeneity using RNA interference (RNAi), and show, both in vitro and in vivo, how optimized drug combinations can yield predictable effects on the composition of heterogeneous tumors. The ability to predict population trajectories has allowed us to mathematically optimize combination therapies to minimize the effect of heterogeneity in three-component heterogeneous tumors. We discover that for certain ensembles of tumor cells, knowledge of the predominant subpopulation is insufficient in deriving an optimal drug combination for the heterogeneous tumor. With optimized drug combinations, our in vitro and in vivo validations confirmed that we can control the predicted trajectories of a heterogeneous tumor, with improved survival in mice. Such approaches will enable us to gain a better understanding of the underlying design principles for combination therapy in the context of intratumoral diversity and construct drug regimens that are optimized for more complex tumors.

Citation Format: Douglas A. Lauffenburger, Boyang Zhao, Justin R. Pritchard, Michael T. Hemann. Targeting intratumoral genetic heterogeneity through rationally designed combination therapy. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr IA10.
Abstract IA18: Gene-drug interaction screens in cancer using isogenic cell models
Authors: Nijman Sebastian
Published: August 2014

With the complete molecular characterization of the major cancer types in sight, it is clear that only a minority of the cancer genes represent readily accessible drug targets. Furthermore, mechanistic biomarkers that predict response to targeted therapies remain scant. To address these challenges, we employ large-scale chemical genetic screens in isogenic cells to systematically uncover gene-drug interactions. For instance, using a panel of engineered cell lines we have recently identified several known and novel breast cancer vulnerabilities and a mechanism of resistance to drugs inhibiting the PI3K/mTOR pathway. We have performed similar screens in an isogenic lung cancer model that attempts to capture some of the higher order gene-drug interactions. In addition, I will present our efforts concerning the generation of a collection of haploid human knockout cells covering the majority of expressed genes that represents a powerful platform empowering haploid genetics in human cells.

Citation Format: Sebastian Nijman. Gene-drug interaction screens in cancer using isogenic cell models. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr IA18.
Abstract IA20: Framing therapeutic opportunities in tumor-activated gametogenic programs
Authors: Whitehurst Angelique
Published: August 2014

Tumors frequently activate genes whose expression is otherwise restricted to gametogenic tissues. These genes, the Cancer/Testes-antigens (CTA, CT-antigens), were originally identified by virtue of the humoral immune response they invoked in cancer patients. Given their germ line biased expression pattern, CT-antigens may afford the potential for an extraordinary therapeutic window, if they are required for tumor cell proliferation and survival. However, functional roles for CT-antigens in tumorigenesis and any efficacy as therapeutic intervention points have not been extensively investigated. Recently, our group and others have implicated CT-antigens in supporting mitotic fidelity, p53 silencing and retinoic acid signaling to promote tumorigenesis. This data indicates that gametogenic genes anomalously expressed in tumors can functionally buttress neoplastic phenotypes. To generate a more comprehensive understanding of the functional roles of CTAs in the tumorigenic setting, we have employed an unbiased, multi-dimensional, loss of function discovery platform to systematically assess the contribution of CT-antigens to a range of oncogenic signaling pathways and phenotypes. This effort has revealed that distinct CTA's can support many of the hallmarks of cancer, including: 1) enhanced energy production 2) hijacking developmental programs that promote self-renewal and metastases 3) modulation of cell-fate programs that support proliferation 4) adaption to low oxygen conditions inherent in the tumor microenvironment and 5) activation of survival and inflammatory signaling. These findings suggests that reactivation of these primordial genes may impact a broad spectrum of signaling mechanisms and cell biological behaviors that promote tumor growth and survival. Thus, CT-antigens present previously unrecognized tumor-specific vulnerabilities that may be exploited for therapeutic intervention.

Citation Format: Angelique Whitehurst. Framing therapeutic opportunities in tumor-activated gametogenic programs. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr IA20.
Abstract PR15: Primary resistance to MAPK inhibition in BRAF-mutant cancer is determined by kinetics of feedback release
Authors: Sos Martin L. , Gordan John D. , Shokat Kevan M.
Published: August 2014

Activating mutations in the serine/threonine kinase BRAF are among the most common genetic lesions across all cancers. Despite the clinical success of drugs that either inhibit the oncogene or its downstream effects on the MAPK pathway, only subgroups of BRAF-mutant patients enriched in different tumor lineages will respond to these therapeutics. Here, we show that MAPK-inhibition results in feedback-mediated reactivation of RAS signaling and a resulting paradoxical activation of BRAF/CRAF dimerization. We find, that the formation of paradoxical BRAF/CRAF dimers is dependent on the levels of GTP-RAS whereas transcriptional regulation of ERK signaling modulators as well as activation of receptor tyrosine kinases does not primarily contribute to this process. Using inhibitor-coupled beads, we provide evidence that MAPK inhibition leads to hyperactivation of BRAF and CRAF that results in reactivation of downstream effectors and therefore leads to primary resistance to MAPK inhibition. This feedback-dependent resistance can be suppressed by either genetic depletion of BRAF or the combination of MEK and RAF inhibitors. Overall, our data provide novel insights into the kinetics of primary resistance to MAPK inhibitors in BRAF-mutant tumors and might help to improve the efficacy of targeted therapies in these patients.

This abstract is also presented as Poster B03.

Citation Format: Martin L. Sos, John D. Gordan, Kevan M. Shokat. Primary resistance to MAPK inhibition in BRAF-mutant cancer is determined by kinetics of feedback release. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Synthetic Lethal Approaches to Cancer Vulnerabilities; May 17-20, 2013; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(5 Suppl):Abstract nr PR15.
Abstract A127: Long-term cell culture models enable drug response determination for epigenetic therapeutics.
Authors: Hnilo Jim , Snead Katie , Bernards Karen , Nelson Brian , McKinley Keith , Waikins Kate , Crane Jonathan M. , Warrior Usha , Shah O. Jameel
Published: August 2014

There has been renewed interest in the field of cancer epigenetics from the pharmaceutical and biotech sectors owing to the discovery of druggable epigenetic modulators that undergo oncogenic mutation and thus represent attractive cancer drug targets. A challenge in this field has been that inhibition of some epigenetic targets results in a significantly delayed drug response that is not revealed by conventional, short-term cell growth assays. We therefore set out to define the two- and three-dimensional assay conditions necessary to yield robust cell line profiling data for therapeutics requiring an extended assay duration. The Eurofins Panlabs’ OncoPanel is a collection of 240 genomically characterized cell lines for which doubling times have been meticulously recorded and compiled over the last several years. Using historical doubling times to compute seeding densities, we demonstrate here that subconfluent, exponential growth can be achieved in the majority of OncoPanel cell lines over the course of 6- or 10-day, two-dimensional growth assays. The EZH2-selective inhibitor, GSK343, elicits a drug response that is dependent both on assay duration and EZH2 mutational status, whereas other less targeted inhibitors show little or no preference for either condition, illustrating the utility of this assay. Similar results were obtained using three-dimensional tumor spheroid assays. Collectively, these data demonstrate the advantages of cell line profiling under long-term assay conditions when drug response reflects a protracted mechanism of action.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A127.

Citation Format: Jim Hnilo, Katie Snead, Karen Bernards, Brian Nelson, Keith McKinley, Kate Waikins, Jonathan M. Crane, Usha Warrior, O. Jameel Shah. Long-term cell culture models enable drug response determination for epigenetic 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 A127.
Abstract A217: Impact of pharmacokinetic (PK) variability on dose finding in phase 1 oncology studies.
Authors: Zhou Xiaofei , Liu Yi , Venkatakrishnan Karthik
Published: August 2014

Background: The key objective of Phase 1 dose escalation studies in patients for oncology compounds is to define the maximum tolerated dose (MTD) or biologically active dose range with high confidence. Small patient numbers and inter-patient heterogeneity are unavoidable factors in traditional “3+3” designs and contribute to uncertainty in MTD determination. It is hypothesized that PK variability in systemic exposures can increase uncertainty in defining the dose-toxicity (and dose-pharmacodynamics) relationship, thereby impacting the accuracy of dose finding in Ph 1. We herein performed simulations to quantitatively assess the impact of PK variability on MTD selection.

Materials and Methods: Three virtual scenarios of varying steepness of the exposure-toxicity relationship and 4 scenarios of PK variability (coefficient of variation [CV]: 80% [High], 40% [Moderate], 20% [Low], 0% [None]) were considered for simulations. Dose-linear PK was assumed and a standard “3+3” escalation design was used for simulations. The hypothetical starting dose was 1 mg and dose escalations used a modified Fibonacci scheme. 10,000 simulations were performed for each of the 12 scenarios, and the frequency of each dose selected as MTD was reported. The selected MTD was defined to have 20-33% dose-limiting toxicity rate.

Results: The simulation results are summarized as follows:

Regardless of the dose-toxicity relationship, increases in PK variability lead to a higher likelihood of underestimation of the MTD. Selecting the correct MTD is approximately 3 - 4 times more likely with low PK variability than with high PK variability.

Conclusions: Substantial PK variability can compromise the accuracy of MTD or recommended phase 2 dose determination in Ph 1/ Ph 1b dose escalation studies, emphasizing the importance of controlling PK variability in dose-finding oncology studies through optimal drug formulations and inclusion/ exclusion criteria that are customized to the predicted ADME (Absorption, Distribution, Metabolism, Excretion) properties of the development candidate.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A217.

Citation Format: Xiaofei Zhou, Yi Liu, Karthik Venkatakrishnan. Impact of pharmacokinetic (PK) variability on dose finding in phase 1 oncology studies. [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 A217.
Abstract A221: Novel PARP6 inhibitors demonstrate in vivo efficacy in xenograft models.
Authors: Mayo Michele F. , Grosskurth Shaun , Wang Xin , Petteruti Philip , Nadella Prasad , Reimer Corinne , Mikule Keith
Published: August 2014

The poly (ADP-ribose) polymerase (PARP) family of enzymes are functionally implicated in DNA repair, transcriptional regulation, glucose metabolism, mitosis, and other cellular mechanisms. To date, the focus has been on defining the role of PARPs 1-3 in DNA damage repair. Currently, PARP1-3 inhibitors are in clinical trials for BRCA1/2 mutant ovarian and breast cancers. The roles of other PARP family members are starting to emerge. Using a cell-based assay measuring multi-polar spindle induction, PARP6 was identified as novel target with therapeutic potential. AZ482 and AZ108 were developed as potent PARP6 inhibitors. These compounds exhibited a unique and selective growth inhibition profile when screened in large panels of tumor cells and suitable pharmacokinetics in vivo. In sensitive hematological and solid tumor models, these compounds had low nanomolar potency in vitro and anti-tumor efficacy in vivo. Mechanistic studies suggest PARP6 inhibitors disrupt spindle pole clustering resulting in mitotic catastrophe and may show selectivity toward tumor cell lines with supernumary centrosomes.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A221.

Citation Format: Michele F. Mayo, Shaun Grosskurth, Xin Wang, Philip Petteruti, Prasad Nadella, Corinne Reimer, Keith Mikule. Novel PARP6 inhibitors demonstrate in vivo efficacy in xenograft 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 A221.
Abstract A225: Identification of a promising PI3K inhibitor for the treatment of multiple myeloma through structural optimization.
Authors: Han Kunkun , Xu Xin , Chen Guodong , Zeng Yuanying , Zhu Jingyu , Du Xiaolin , Zhang Zubin , Cao Biyin , Liu Zhaopeng , Mao Xinliang
Published: August 2014

Multiple myeloma (MM) is an incurable malignancy of plasma cells, which is associated with the overactivated phosphatidylinositol 3-kinases (PI3Ks)/AKT signaling pathway. Stimulated by interleukin 6 and or insulin-like growth factor 1, PI3K/AKT plays a key role in MM survival and chemoresistance, while genetic knockdown of these PI3-kinases by small interfering RNA (siRNA) leads to MM cell apoptosis and decreased proliferation. Therefore, PI3K is granted as a promising therapeutic target for MM. We previously identified the small molecule compound S14161 an inhibitor of pan-Class I PI3K isoforms by a high throughput screening strategy (Mao et al., 2011). S14161 displayed potent preclinical activity against MM and leukemia in vitro and in vivo. In the present study, we synthesized a panel of S14161 analogs based on the structure-activity relationship, of which BENC-511 was demonstrated to be more potent than S14161 in suppressing PI3K activity and inducing MM cell death. BENC-511 was derived from S14161 by removing 4-fluorophenyl group at the 2-position of the chromene core. Different from S14161, BENC-511 presented as a specific inhibitor for PI3K α and δ, but had no inhibitory effects on PI3K β, γ, AKT, or mTOR in the cell-free enzymatic assays. BENC-511 inhibited phosphorylation of AKT and its downstream signals mTOR, P70S6K, and 4E-BP-1 at low micromolar concentrations. Consistent with its effects on PI3K activity and cancer cell proliferation, BENC-511 induced MM cell apoptosis. Notably, addition of insulin-like growth factor 1 and interleukin-6, two important triggers for PI3K activation in MM cells, partly blocked BENC-511-induced MM cell death. BENC-511 also showed potent anti-myeloma activity in vivo. Oral administration of BENC-511 decreased tumor growth up to 80% within 3 weeks in two independent MM xenograft models, but presented minimal toxicity. Suppression of BENC-511 on MM tumor growth was associated with decreased PI3K/AKT activity and increased cell apoptosis. Because of its robust potential and low toxicity (LD50 oral >1.5 g/kg), BENC-511 could be developed as a promising agent for the treatment of multiple myeloma by targeting the PI3K/AKT signaling pathway.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A225.

Citation Format: Kunkun Han, Xin Xu, Guodong Chen, Yuanying Zeng, Jingyu Zhu, Xiaolin Du, Zubin Zhang, Biyin Cao, Zhaopeng Liu, Xinliang Mao. Identification of a promising PI3K inhibitor for the treatment of multiple myeloma through structural optimization. [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 A225.
Abstract A231: Let 7a regulates IL-6 expression in malignant mesothelioma.
Authors: Tanino Mishie A. , Kohsaka Shinji , Yachi Kazuhiro , Tsuda Masumi , Kimura Taichi , Nishihara Hiroshi , Tanaka Shinya
Published: August 2014

IL-6-dependent signaling pathway leading to Stat3 phosphorylation is reported to be involved in malignant phenotype of mesothelima. Altered expression of microRNA (miR) is observed in many cancers, however, the mechanism how miR regulates IL-6 expression in masothelioma is still unknown. We performed immunohistochemistry for phosphorylated Stat3 (pStat3) in 12 human mesotheliomas. Next, using 7 mesothelioma cell lines, mRNA expression of IL-6 and IL-6R, together with several miRs that regulated IL-6, and Stat 3 phosphorylation were examined by RT-PCR and immunoblotting. Five of 12 mesotheliomas showed strong expression of pStat3 in their nuclei and let 7a was identified as one of the candidate molecules that regulate IL-6 expression in mesothelioma by using 3’UTR reporter system. Moreover, IL-6 was found to regulate miR-153, miR-340, and miR-410 expressions. These findings suggest that let 7a, miR-153, -340, and 410 may be involved in malignant phenotype through regulation of IL-6 pathway in mesothelioma.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A231.

Citation Format: Mishie A. Tanino, Shinji Kohsaka, Kazuhiro Yachi, Masumi Tsuda, Taichi Kimura, Hiroshi Nishihara, Shinya Tanaka. Let 7a regulates IL-6 expression in malignant mesothelioma. [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 A231.
Abstract A234: In vivo RNAi screening to identify major players in pancreatic tumor maintenance and growth.
Authors: Fenoglio Silvia , Soto-Feliciano Yadira , Hannon Gregory , Hemann Michael
Published: August 2014

Pancreatic cancer is one of the leading causes of cancer-related death in the United States and no effective therapeutic options are currently available. The lethality of pancreatic cancer, due to the aggressiveness of the disease and the lack of effective treatment, underscores the urgency for a clinical solution. Nevertheless the multiple failures suffered in clinical trials involving diverse compounds and approaches point to the necessity of a better understanding of the disease, in particular of the molecular and cellular mechanisms underlying tumor development and progression. We aim to identify new therapeutic targets for pancreatic cancer treatment by performing in vivo RNAi screens, either in combination with Gemcitabine treatment to isolate modulators of drug response or without any treatment seeking for genes that play a fundamental role in tumor growth and maintenance.

Our model system is a cancer cell line derived from a genetically engineered mouse model that develops spontaneous pancreatic ductal adenocarcinoma (PDAC) after activation of a kras mutant (G12D) allele concomitantly with the deletion of the tumor suppressor p53 specifically in the pancreas. This cell line can be effectively transplanted orthotopically in syngeneic mice and preliminary data suggest that we can represent about 3.000 hairpins out of 10.000 per tumor when injecting 30.000 cells orthotopically in the pancreas in the absence of chemotherapy. Genes with established function in pancreatic cancer like Claudin4 and PDGFR scored as hits in the screening, and about 8 more were selected for further validation. In addition, our data show that the transplanted tumors are partially resistant to Gemcitabine treatment in vivo, despite the in vitro sensitivity, which indicate that the system is suitable for a synthetic lethal screen. We have established a model system suitable for in vivo screening in pancreatic cancer, either with or without chemotherapy. We challenged the complexity of pancreatic cancer by functional screening in order to focus our attention on potential key player of tumor progression with plausible clinical relevance.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A234.

Citation Format: Silvia Fenoglio, Yadira Soto-Feliciano, Gregory Hannon, Michael Hemann. In vivo RNAi screening to identify major players in pancreatic tumor maintenance and growth. [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 A234.
Abstract A255: Antitumor activity and antioxidant status of fungal lovastatin against Dalton's lymphoma ascites in Swiss albino mice.
Authors: Velusamy Kavitha , Balraj Janani , Muthusamy Palaniswamy , Jayaraman Angayarkanni
Published: August 2014

Lovastatin, an inhibitor of the rate-limiting enzyme in the cholesterol biosynthetic pathway, hydroxymethylglutaryl coenzyme A reductase, has shown interesting antiproliferative activities in cell culture and in animal models of cancer. The present study was carried out to evaluate the anticancer potentials of lovastatin against Dalton's lymphoma ascites (DLA). The lovastatin given orally to mice at the dose of 5, 25, 50 mg/kg body weight for 10 days caused significant reduction in percent increase in body weight when compared to the mice of the DLA control group. Restoration of hematological and biochemical parameters towards normal was also observed. Tumor control animals inoculated with DLA showed a major decrease in the level of catalase (CAT), superoxide dismutase (SOD) and increase in thio-barbituric acid reactive substances (TBARS) levels in liver. Treatment with lovastatin (5, 25, and 50 mg/kg body weight) doses given orally caused a reversal of these changes towards the normal. This confirms the potent hepatoprotective and antioxidant nature of lovastatin. Lovastatin (50 mg/kg body wt, i.p) was effective to accelerate the apoptosis in the ascites tumor bearing mice that was evident from the fragmentation of DNA in gel electrophoresis. Further the morphological analysis of DLA cells aspirated from the lovastatin treated animals showed a significant (P<0.01) increase of apoptotic cells than the control animals. The proapoptotic and antioxidant activities of the lipid lowering drug lovastatin may further suggest its possible therapeutic use as a cancer chemopreventive agent.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A255.

Citation Format: Kavitha Velusamy, Janani Balraj, Palaniswamy Muthusamy, Angayarkanni Jayaraman. Antitumor activity and antioxidant status of fungal lovastatin against Dalton's lymphoma ascites in Swiss albino mice. [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 A255.
Abstract A26: Translation of isoform-level gene signature into robust diagnostic assay for glioblastoma subtyping.
Authors: Bi Yingtao , Pal Sharmistha , Macyszyn Luke , Showe Louise C. , O'Rourke Donald , Davuluri Ramana V.
Published: August 2014

Translating the molecular signatures from classification strategies into robust diagnostic assays is essential for cancer therapy guidance and prognosis determination. To develop a clinically applicable molecular stratification assay for Glioblastoma multiforme (GBM) with significant prognostic value, we designed a novel classification system based on isoform-level gene expression profiles; an avenue unexplored for diagnostic and prognostic use. Using isoform-level expression clustering of The Cancer Genome Atlas (TCGA) samples, we identified four GBM subgroups with significant (p=0.0103) survival differences. A four-class classifier, built with 121 transcript-variants, assigns GBM patients’ molecular subtype with 92% accuracy. The classifier was translated to a high-throughput RT-qPCR assay and validated on an independent cohort of 206 glioblastoma samples. We found that proneural patients have the worst prognosis except for younger patients (<40 years), while a better prognosis is observed for neural group among older patients (≥40 years). The isoform-level classifier, transformed from a high-dimensional platform to a low-dimensional RT-qPCR platform, provides a quantitative and reproducible stratification of GBM patients with prognostic significance, a requirement towards personalized medicine. The resulting diagnostic assay from the classifier has immediate clinical implications towards prioritizing patients for standard care versus aggressive therapy regimen.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A26.

Citation Format: Yingtao Bi, Sharmistha Pal, Luke Macyszyn, Louise C. Showe, Donald O'Rourke, Ramana V. Davuluri. Translation of isoform-level gene signature into robust diagnostic assay for glioblastoma subtyping. [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 A26.
Abstract A261: NPV-LDE-225 (Erismodegib) inhibits human prostate cancer stem cell growth in NOD/SCID IL2γnull mice by regulating Bmi-1 and microRNA-128.
Authors: Nanta Rajesh , Meeker Daniel , Rodova Mariana , Van Veldhuizen Peter J. , Shankar Sharmila , Srivastava Rakesh K.
Published: August 2014

Prostate cancer stem cells (CSCs) are defined by their extensive self-renewal, differentiation, and tumor initiation properties. It is now clear that CSCs are involved in tumor growth and recurrence, and resistance to conventional treatments. Thus, the strategy that suppresses stemness and consequently tumorigenic potential of CSCs could be considered for the management of prostate cancer. The objectives of this study were to examine the molecular mechanisms by which NPV-LDE-225 / Erismodegib (smoothened inhibitor) regulates stem cell characteristics in prostate cancer. Effects of NPV-LDE-225 on CSC's viability, sphere formation, apoptosis, transcriptional activity, and epithelial-mesenchymal transition (EMT) were measured. NPV-LDE-225 inhibited cell viability and spheroid formation, and induced apoptosis by activation of caspase-3 and cleavage of PARP. NPV-LDE-225 induced expression of Bax and Bak, and inhibited the expression of Bcl-2, Bcl-XL, XIAP, cIAP1, cIAP2 and survivin. NPV-LDE-225 inhibited Gli transcriptional activity, Gli-DNA interaction, and the expression of Gli1, Gli2, Patched1 and Patched 2 in prostate CSCs. Interestingly, NPV-LDE-225 induced PDCD4 and apoptosis and inhibited cell viability by suppressing miR-21. Furthermore, NPV-LDE-225 inhibited pluripotency maintaining factors Nanog, Oct4, cMyc and Sox-2. The inhibition of Bmi-1 by NPV-LDE-225 was regulated by up-regulation of miR-128. NPV-LDE-225 suppressed EMT by up-regulating E-cadherin and inhibiting N-cadherin, Snail, Slug and Zeb1 through regulating miR-200 family. Finally, NPV-LDE-225 inhibited CSC tumor growth which was associated with the suppression of Gli1, Gli2, Patched-1, Patched-2, Cyclin D1 and PCNA, and cleaved caspase-3 and PARP in tumor tissues derived from NOD/SCID IL2Rϒnull mice. Overall, our findings suggest that inhibition of the Shh signaling pathway in CSCs is a potential therapeutic strategy for prostate cancer.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A261.

Citation Format: Rajesh Nanta, Daniel Meeker, Mariana Rodova, Peter J. Van Veldhuizen, Sharmila Shankar, Rakesh K. Srivastava. NPV-LDE-225 (Erismodegib) inhibits human prostate cancer stem cell growth in NOD/SCID IL2γnull mice by regulating Bmi-1 and microRNA-128. [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 A261.
Abstract A284: Anaplastic lymphoma kinase (ALK) inhibitors for cancer treatment.
Authors: Lee Kwangho , Kim Hyoung Rae , Cho Sung Yun , Jung Hee Jung , Ha Jae D. , Yun Chang-Soo , Kim Pilho , Park Chi Hoon , Lee Chong Ock
Published: August 2014

Anaplastic lymphoma kinase (ALK), a receptor tyrosine kinase, has been recently elucidated as a potential target for various cancers due to its implications of tumorigenesis by ALK gene mutations, overexpressions, and amplifications. ALK was first identified in 1994 as a part of nucleophosmin NPM-ALK fusion gene in 60% of anaplastic large-cell lymphoma (ALCL). In late 2007, EML4-ALK fusion gene was found in 3∼7% of non-small cell lung cancer (NSCLC), and a kind of ALK fusion genes are found one by one in various cancers such as DLBCL, inflammatory myofiblastic tumor (IMT), plasmacytoma, esophageal cancer, and ovarian cancer. More over mutated ALK is much implicated in neuroblastoma and thyroid carcinoma. Crizotinib (Xalkori) was the first small molecule inhibitor which was approved as a treatment of NSCLC including ALK fusion gene by FDA in 2011. Crizotinib, a potent inhibitor of both c-Met and ALK tyrosine kinases is a 3-benzyloxy-2-aminopyridine derivative derived from c-Met inhibitors and surprisingly its overall clinical benefit was 57 %. However, its clinical efficacy is limited by drug-resistance mutations, particularly the gatekeeper L1196M mutation. Unlike their aminopyridine-based core scaffold, a pyrimidine-based inhibitor has been identified for the ALK-related inhibition and shown a potent activity to EML4-ALK wild type and other mutants including EML4-ALK L1196M. In this paper, we designed and synthesized a new series of pyrimidine derivatives to discover a new ALK inhibitor which is well-matched with crizotinib and LDK378 in docking study. KRCA-0008 has been identified as a highly potent and selective ALK inhibitor with potency profiles (ALK wt, IC50=12 nM). It has excellent activities both ALK mutants (L1196M, C1156Y, F1174L, R1275Q) and BaF3 ALK L1196M cell line. PK profiles were excellent and KRCA-0008 was safe in Ames test, chromosomal aberration assay, micronucleus asssay, and acute toxicity. Also, we observed KRCA-0008 is chemically and metabolically very stable and no CYP and hERG inhibitions. In vivo xenograft mouse model (H3122 NSCLC) model study, KRCA-0008 shows moderate tumor growth inhibition without significant body weight change.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A284.

Citation Format: Kwangho Lee, Hyoung Rae Kim, Sung Yun Cho, Hee Jung Jung, Jae Du Ha, Chang-Soo Yun, Pilho Kim, Chi Hoon Park, Chong Ock Lee. Anaplastic lymphoma kinase (ALK) inhibitors for cancer treatment. [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 A284.
Abstract A294: Antitumor activity of AMG900, an Aurora kinase inhibitor, alone or in combination with chemotherapeutic agents on H295A adrenocortical carcinoma cell line.
Authors: Borges Kleiton S. , Andrade Augusto F. , Silveira Vanessa S. , Antonio David S.M , Vasconcelos Elton J.R. , Antonini Sonir R.R. , Tone Luiz G. , Scrideli Carlos A.
Published: August 2014

Pediatric adrenocortical tumors (ACT) are rare malignancies and in advanced disease the treatment has a small impact on overall survival. Previous study from our group suggests that AURKA and AURKB overexpression in pediatric ACT may be related to more aggressive disease. These genes are involved in the maintenance of the genome integrity during cell cycle division and they have been considered as new targets to cancer treatment. The present study shows the previous results of the effects of the new Aurora kinase inhibitor AMG900, associated or not with standard chemotherapeutic agents on adrenocortical carcinoma cell line H295A.

Cell proliferation was assessed by Giemsa staining and apoptosis was performed by flow cytometry. Quantitative RT-PCR assays were used to determine the mRNA expression after AMG900 exposition. Drug combination analysis was made based on Chou-Talalay method. Hormones dosage assay was carried out to evaluate the effects of the Aurora kinase inhibitor on hormone secretion.

AMG900 inhibited cell proliferation and caused apoptosis in a dose dependent manner in H295A cells. Moreover, it acted synergistically with doxorubicin, cisplatin and etoposide in the apoptosis induction, but only with doxorubicin in the proliferation inhibition. AMG900 treatment induced the mRNA expression of the genes p53, p21, and GDF15 and effectively inhibited dehydroepiandrosterone, androstenedione, cortisol and testosterone secretion.

These data suggest that Aurora kinase inhibition by AMG900 may be a new therapeutic approach to adrenocortical carcinoma treatment.

Financial Support: FAPESP (10/07020-9 and 12/09391-0)

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A294.

Citation Format: Kleiton S. Borges, Augusto F. Andrade, Vanessa S. Silveira, David S.M Antonio, Elton J.R. Vasconcelos, Sonir R.R. Antonini, Luiz G. Tone, Carlos A. Scrideli. Antitumor activity of AMG900, an Aurora kinase inhibitor, alone or in combination with chemotherapeutic agents on H295A adrenocortical carcinoma cell line. [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 A294.