bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract PR-5: Signal pathway profiling of cancer cell lines derived from serially passaged human tumorgrafts for guiding drug development
Authors: Yang Feng , Li Yue , Aggarwal Amit , Manro Jason , Li Shuyu Dan , Donoho Greg , Kelter Gerhard , Beckers Thomas , Fiebig Heinz-Herbert , Yingling Jonathan M. , Tucker-Kellogg Greg , Stancato Louis
Published: June 2012

Effective chemotherapeutic treatment of cancer is stymied by a lack of understanding of tumorigenic pathway defects in individual tumors. Combining large scale measurement technologies with appropriate informatics and statistical approaches is a promising approach to detect such aberrations in signaling pathways and provide rationale(s) for driving the choice of targeted chemotherapies. We have attempted to address these by generating a high resolution understanding of pathway defects in 30 solid tumor cell lines, which were established directly from patient-derived xenografts representing 13 histologies. We simultaneously interrogated ∼100 unique protein signaling events using reverse phase protein arrays (RPPA), along with profiling the same cell lines on Affymetrix expression and Agilent CGH platforms. An in silico validation of the RPPA data was conducted by a) clustering analysis that revealed lineage-independent pathway perturbations, b) combining it with baseline genomic and expression data that elucidated and confirmed several underlying genomic defect(s) associated with protein-level changes, c) studying similarity of protein-protein correlations and KEGG cancer pathways that showed high concordance between the two. We developed signaling cascade maps that estimate tumorigenic pathway activation level for individual samples, which can then be used to propose an appropriate therapeutic intervention. Using proliferation assay data from several known targeted agents, we confirmed our observations and ascertained patterns of protein expression that predict for chemosensitivity. In summary, we propose that the methods described here represent a novel approach to analysis of gene/pathway changes associated with tumorigenesis and will be useful in building models of cancer cell protein circuitry applicable to the development of both drugs and patient stratification biomarkers.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):PR-5.
Abstract A105: A small RNA interference screen of genes involved in DNA repair identifies genes mediating radiosensitivity in glioblastoma.
Authors: Tandle Anita T. , Shankavaram Uma , Tofilon Philip J. , Caplen Natasha , Camphausen Kevin
Published: June 2012

Purpose: Glioblastoma multiforme (GBM) is the most common primary brain tumor in the USA. Standard treatment for primary GBM includes surgical resection, followed by concurrent chemotherapy and radiotherapy (RT). As a result of the major role RT plays in the treatment of GBM, there is much interest in identifying the determinants of radiosensitivity to improve the efficacy of clinically tolerable radiation doses. Also, presence of GBM stem cells within tumor makes it remarkably resistant to current radio- and chemotherapies. Here we have studied DNA repair genes as a determinant of radiosensitivity in GBM.

Materials and Methods: We performed a small interfering RNA (siRNA) screen of 206 genes involved in DNA damage repair to identify genes whose knockdown can increase tumor sensitivity to RT. siRNA screens were performed in two different GBM tumor cells; U251 and U87-MG and in one GBM stem cell line, GBAM1. At 72 hrs, after transfection, cells were irradiated for 24 hrs. As a marker of DNA damage and repair, γH2AX activity was analyzed by ELISA after 24 hrs in unirradiated and irradiated cells.

Results: We identified several genes which upon downregulation increased radiosenstiivity of GBM tumor cells. The various genes includes DNA double strand break repair genes, genes involved in translesion DNA synthesis and DNA damage signaling genes. Nevertheless, we observed differences between GBM tumor cells and stem cells. In tumor cells, some of the radiosensitizer genes were BRCA2, PHB, PTCH, SMC5, ERCC5 and POL G. On the other hand, GBM stem cells showed radiosensitization with downregulation of RFC1, UBE2A, RPA1 RAD54L, XPA, FANCL and TOP2A genes. There was one gene common between GBM tumor cells and stem cells, REV1L. Rev1-like protein is as a scaffold that recruits DNA polymerases involved in translesion DNA synthesis (TLS) of damaged DNA. This is an ongoing study. We are further validating role of some of these targets in both tumor cells and stem cells.

Conclusions: We observed inherent differences in radiosensitivity between GBM tumor cells and stem cells. Identification of tumor cell specific and stem cell specific targets may help us in determining better treatment options for GBM.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A105.
Abstract A11: Antitumor activity of targeted and cytotoxic agents in xenograft models correlates with clinical response: A pharmacokinetic-pharmacodynamic analysis.
Authors: Wong Harvey , Choo Edna F. , Alicke Bruno , Ding Xiao , La Hank , McNamara Erin , Thiel Frank-Peter , Tibbitts Jay , Friedman Lori S. , Hop Cornelis ECA , Gould Stephen E.
Published: June 2012

Immunodeficient mice transplanted subcutaneously with human tumors (xenografts) are a widely used model of preclinical efficacy in the discovery and development of anti-cancer agents. We performed a retrospective population pharmacokinetic-pharmacodynamic (PK-PD) analysis of xenograft efficacy data that accounts for differences in clinical and preclinical drug exposure in order to improve their predictive value. In addition, we investigated the ability of xenograft studies to predict clinical response with newer molecular targeted agents. Data from preclinical and clinical studies with three cytotoxic chemotherapeutic agents (docetaxel, carboplatin, and 5-fluorouracil) and five molecular targeted agents (erlotinib, sunitnib, dasatinib, trastuzumab, and vismodegib) were included in this analysis. Anti-cancer agents were administered at a range of doses to xenograft mice bearing tumors relevant to the cancer of interest. No correlation was observed when comparing clinical response to % tumor growth inhibition (%TGI) at the maximum tolerated dose (MTD) in mice. PK-PD modeling was used to simulate %TGI in xenografts using human exposures at clinically relevant doses. These simulated %TGI in xenografts driven by human drug exposures were found to correlate (r=0.92; p=0.0005) with clinical response, illustrating the importance of taking into account species differences in drug exposure when interpreting xenograft data. Distinct differences were observed in the anti-tumor activity of sunitinib in Colo205 colorectal (simulated %TGI = 64%) and 786-O renal cell adenocarcinoma (simulated %TGI = 81%) xenografts, and vismodegib in medulloblastoma allografts (simulated %TGI =102%) and D5123 colorectal xenografts (simulated %TGI = 33%). These differences were consistent with the underlying biology of these models and demonstrate the importance of understanding tumor biology when selecting relevant xenograft models for molecular targeted agents. Based on these analyzes, agents that lead to greater than 60% tumor growth inhibition in preclinical models at clinically relevant exposures are more likely to lead to responses in the clinic.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A11.
Abstract A149: Quantitative detection of the EGFR activating and resistance mutations in plasma DNA of lung cancer patients.
Authors: Taniguchi Kazuya , Uchida Junji , Yoji Kukita , Nishino Kazumi , Kumagai Toru , Akazawa Yuki , Okuyama Takako , Okami Jiro , Higashiyama Masahiko , Imamura Fumio , Kato Kikuya
Published: June 2012

EGFR-TKIs are effective therapeutic agents for EGFR-mutation-positive lung cancer patients, but most patients develop resistance to EGFR-TKIs. A secondary EGFR T790M mutation is reported to correlate with acquired resistance and accounts for about half of the resistance cases.

Circulating tumor DNA (ctDNA) is a promising target for monitoring T790M mutations in non-invasive cancer diagnostics and evaluations, although detection of rare mutation alleles is technically demanding. BEAMing (beads, emulsion, amplification, magnetics) is currently the most sensitive technique which can quantitate the mutated allele. With the technique, we can detect one mutated allele in 10,000 normal alleles.

Activating mutations were identified from plasma DNA in 72% (31/43). The T790M mutation was identified in 43% (10/23) of the patients with progressive disease during EGFR-TKI treatment. The T790M mutation appeared in 13–94% of alleles with activating mutations.

Judging from this incidence, BEAMing could detect T790M in the majority of eligible cases. The major advantage over other techniques is the ability to calculate the fraction of T790M-positive alleles in cancer cells, irrespective of normal cell DNA contamination.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A149.
Abstract A156: GA201 (RG7160) pretreatments and combination therapies improve efficacy without negatively affecting antitumoral ADCC.
Authors: Nicolini Valeria , Herter Sylvia , Lang Sabine , Walhauer Inja , van Puijenbroek Erwin , Dunn Claire , Umana Pablo , Gerdes Christian A.
Published: June 2012

GA201 is a humanized and glycoengineered IgG1 antibody which targets EGFR with boosted antibody dependent cell cytotoxicity (ADCC) in phase 2 clinical trials.

Pretreatment with corticosteroids and/or anti-histaminics are of normal practice for monoclonal antibody therapy to prevent potential infusion reactions. GA201 follows a premedication regimen of anti-histaminics and hydrocortisone. Due to the dual GA201 mode of action, evaluation on the impact of these drugs on ADCC is critical and was previously assessed preclinically for potential negative impacts on immune effector cells and their capacity to mediate tumor cell killing.

Combination phase II studies with GA201 + chemotherapy regimens are currently under investigation in NSCLC as first-line treatment (chemotherapy selection based on histology Cisplatin + gemcitabine for squamous and cisplatin + pemetrexed for non squamous) and in CRC as second-line treatment (FOLFIRI for KRAS-mutant CRC or cetuximab + FOLFIRI for KRAS-wildtype CRC). These combinations and others where tested prior use in the clinics to evaluate preclinical efficacy and their impact on the immune effectors in vitro, and in vivo.

Chemotherapy combos showed additive or synergistc effect in anti-tumor efficacy as assessed in orthotopic xenograft models and all pre-medications and chemotherapies tested showed no negative impact on ADCC supporting their combination with GA201 in the clinics.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A156.
Abstract A163: A role for epigenetic reprogramming in retinoblastoma tumorigenesis.
Authors: Benavente Claudia A. , Dyer Michael A.
Published: June 2012

Retinoblastoma is an aggressive childhood cancer of the developing retina that is initiated by the biallelic loss of the RB1 gene. In addition to its role in tumor initiation, loss of the RB1 gene has been shown to induce genome instability, thus promoting tumor progression. In an attempt to identify the mutations that cooperate with RB1 loss, we performed whole-genome sequencing of retinoblastomas. However, the overall mutational rate was very low, with RB1 being the only known cancer gene mutated. We then evaluated RB1's role in genome stability and considered non-genetic mechanisms of cancer pathway deregulation. Since RB1 has been implicated in regulating major epigenetic processes, including miRNA regulation, DNA methylation, and histone modification, we hypothesized that RB1 inactivation may contribute to the rate of retinoblastoma tumorigenesis through non-genetic mechanisms that deregulate tumor suppressor and oncogenic pathways. We performed sister chromatid cohesion, kinetochore structure, and spectral karyotype analyzes, and evaluated double strand break repair using comet assay, γ-H2AX and TP53BP1 foci immunostaining, and found that the human retinoblastoma genome is stable. Nonetheless, chromatin immunoprecipitation (ChIP-on-chip) and DNA methylation analyzes pointed that multiple cancer pathways are epigenetically deregulated in human retinoblastoma. For example, the proto-oncogene spleen tyrosine kinase (SYK) is epigenetically upregulated in retinoblastoma and is required for tumor cell survival. Targeting SYK with a small-molecule inhibitor induced retinoblastoma tumor cell death in vitro and in vivo. Thus, RB1 inactivation may allow preneoplastic cells to acquire multiple hallmarks of cancer through epigenetic mechanisms, resulting directly or indirectly from RB1 loss. These data provide novel targets for chemotherapeutic interventions of retinoblastoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A163.
Abstract A179: Structural and biochemical analysis of ERBB4 mutations in cancer.
Authors: Kurppa Kari , Denessiouk Konstantin , Johnson Mark S. , Elenius Klaus
Published: June 2012

Genes encoding the ErbB receptor tyrosine kinases (EGFR/ERBB1, ERBB2, ERBB3, and ERBB4) are key regulators of cellular proliferation, survival, and differentiation, and thus represent potent proto-oncogenes. In particular, mutations or copy number variations of EGFR or ERBB2 are present in human malignancies and serve as biomarkers for targeted therapies. Recently, somatic mutations of the ERBB4 gene have been identified in various cancer types, such as non-small cell lung cancer and melanoma, indicating a role for mutated ERBB4 as a potential drug target. However, the structural and functional consequences of the ERBB4 mutations remain to be fully elucidated.

We used both a structural as well as a biochemical approach to address the functional effects of the ERBB4 mutations for ErbB4 signaling. A 3D model of the active ErbB4 dimer was generated and the effects of the mutations were modeled in both active and inactive ErbB4 conformation. The biochemical effects of the mutations on ErbB4 signaling were analyzed in vitro using assays measuring the kinase activity of ErbB4 as well as activation of downstream signaling pathways.

Although all structural subdomains of ERBB4 have been reported to be affected by somatic mutations, our analyzes indicated that the mutations cluster to regions important for activation of the receptor, such as the dimerization interface and the kinase domain active site. Some of the mutations were structurally non-hazardous and probably represent passenger mutations. Consistently, the biochemical analyzes indicated for the presence of both functionally non-significant and activating mutations.

These observations suggest for the presence of both driver as well as passenger mutations of ERBB4 in human cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A179.
Abstract A244: Characterization of a novel potent and selective CDK4/6 inhibitor and a resistance mechanism.
Authors: Dai Kang , Li Cong , Liang Lingming , Rong Minqing , Orf Jessica , Keegan Kathy , Li Zhihong , Fu Jiasheng , Ma Ji , Carlson Timothy , McGee Larry , Medina Julio , Kamb Alexander , Wickramasinghe Dineli
Published: June 2012

CDK4 and CDK6 are two highly related cyclin D-dependent cell cycle regulatory kinases. CDK4/6 activity promotes G1 to S phase transition by phosphorylating the retinoblastoma (Rb) tumor suppressor protein. Here, we report the characterization of a potent, selective and orally-available small molecule inhibitor of CDK4/6 for treating Rb-positive cancer. The inhibitor was over 1000-fold more potent in inhibiting CDK4 than CDK1. It also showed Rb-dependent anti-proliferative activity both in cancer cell lines and in xenograft tumor models. A greater degree of variation in sensitivity to the inhibitor was observed in colon cancer cell lines compared to the other cell lines tested. To understand this difference in sensitivity, we isolated CDK4/6 inhibitor-resistant colon cancer cells by growing sensitive cells in the presence of the inhibitor. Gene expression in the parental and the resistant cells was analyzed and compared. Cyclin E1, a CDK2 cyclin, was found to be the most significantly overexpressed gene in the resistant cells. Consistent with this, CDK2-associated cyclin E1 protein and CDK2 kinase activity were also significantly increased in the cells. These results suggest that high expression of cyclin E1 may make tumors less sensitive to CDK4/6 inhibition and could be a potential sensitivity marker for patient selection for treatment with a CDK4/6 inhibitor.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A244.
Abstract A28: Apoptosis induction with the MEK inhibitor AZD6244 and BH3 mimetic ABT-737 in melanoma.
Authors: Niglio Scot A. , Rosenberg Stephen , Jeong Byeong-Seon , Shin Seung-Shick , Mehnert Janice , White Eileen , Goydos James
Published: June 2012

Over sixty percent of patients with melanoma have the activating B-RAFV600E mutation leading to increased activation of the mitogen activated protein kinase (MAPK) pathway. The downstream effects of MAPK pathway activation are increased proliferation, invasiveness, and survival through the regulation of down-stream targets such as the pro-apoptotic protein BIM. Prior studies have shown that inhibiting MAPK kinase (MEK), downstream of constitutively active B-RAF, can up-regulate BIM, leading to increased apoptosis in melanoma cell lines. However, single agent MEK inhibition has had limited effectiveness in the clinical setting for late-stage melanoma patients, likely due to an inadequate induction of apoptosis. We hypothesized that combining the clinically relevant MEK inhibitor, AZD6244 (ARRY142886) with a BCL-2 inhibitor, ABT-737, would lead to increased apoptosis over single agent therapies in melanoma cells via BIM activation and pan-BCL-2 inhibition. We compared single treatments of AZD6244 and ABT737 to the combination of these agents in a panel of melanoma tumor cell lines chosen by mutational status in both a monolayer system and an anchorage independent system. The combination of AZD6244 and ABT-737 had a synergistic effect on decreasing cell viability and increasing apoptosis compared to single agent treatments regardless of B-RAF mutational status. Western blotting revealed dramatic increases in cleaved caspase 3 and PARP with combinational treatment compared to single agent therapy. These early pre-clinical experiments indicate that AZD6244 combined with ABT-737 may be an effective combination therapy for patients with late-stage melanoma. Currently, we have plans to conduct in vivo studies to translate these results into the clinic.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A28.
Abstract A31: Induction of autophagy's mechanism in laryngeal squamous cancer cells by Trisenox.
Authors: Pereira Debora Lima , dos Santos Ferreira Ana Carolina , da Cunha Vasconcelos Flavia , de Faria Giselle Pinto , Kwee Jolie Kiemlian
Published: June 2012

Introduction: A major problem in cancer treatment is the development of resistance to multiple chemotherapeutic agents. Laryngeal cancer is one of the most common worldwide malignancies of head and neck. Despite extensive research into molecular changes in laryngeal carcinogenesis, reliable molecular markers with predictive and prognostic value are still lacking. Trisenox is indicated for induction of remission and consolidation in patients with acute promyelocytic leukemia (APL), but is not applied at the clinical practice yet. However, many studies have demonstrated their effects in solid tumors. Among the numerous mechanisms implicated in chemoresistance, glutathione (GSH) and associated enzymes play a pivotal function in hematopoietic and solid tumors. Several studies report that depletion of GSH by L-buthionine-sulfoximine (BSO) sensitizes tumor cells to chemotherapeutic-ROS inducers such as Cisplatin and Trisenox. Our previous studies showed the combination of Trisenox and BSO, an important GSH-inhibitor, was synergistic and reduced the Laryngeal Squamous Carcinoma Cell line Hep-2 cell viability up to 60%. However, the mechanism of Trisenox-death induction is poorly understood. Here we investigated the pathway involved in the cytotoxic effect mediated by the combined BSO and Trisenox treatment in Hep-2 lineage.

Materials and Methods: The Laryngeal Squamous Carcinoma Cell line Hep-2 were maintained in RPMI culture medium and previously incubated with BSO. After 24h, the cells were treated with 1.0 and 4.0μM Trisenox for 72h. Acridine Orange assay was used through flow cytometer and imunnofluorescence to evidence the autophagic vacuoles. To evaluate the autophagic induction, we used 3-Metil-Adenine (3-MA), a known autophagy-inhibitor, in combination with Trisenox and BSO.

Results: We observed that the BSO potentiates the Trisenox-autophagic induced acid vesicules formation assessed by acridine orange in both flow cytometer and immunofluorescence assays. In addition, previous treatment with 3-MA inhibited up to 20% of the cytotoxic effect of 1.0 and 4.0μM Trisenox.

Conclusion: This study showed that BSO enhances the Trisenox-cytotoxic effects in laryngeal tumor cells through autophagic mechanisms. Trisenox might represent an attractive basis for laryngeal squamous cancer treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A31.
Abstract A36: An anticancer drug combination and regimen database for research and clinical optimization.
Authors: Fernandez Eric , Robertson Martin , Snell Chris , Fell David A. , Chassagnole Christophe , Jackson Robert C.
Published: June 2012

Physiomics and pharmacometrics have collaborated to design a new database of anti-cancer drugs and therapeutic treatment information aimed at researchers in oncology and clinicians. This database, accessible through the web, offers data on more than 130 anti-cancer drugs (small molecules and biologics) used in research and in the clinic. It contains information on drug combination as well as a several hundreds of cancer chemotherapy regimens routinely used in the clinic. These data are classified according to tumor type, species, or source (in vitro, in vivo or simulated). It will be constantly expanded and curated with the most recent information. Furthermore, it provides ways to standardize the expression and nomenclature of chemotherapy regimens unambiguously and uniformly is of paramount importance to improve efficacy, as well as to reduce medication errors. Individual drug information covers pharmacokinetic profiles, mechanism of action and of resistance, dose-response effect, dosing limits, therapeutic index, and immunosuppression data. Drug combinations are also referenced. The database covers synergy or antagonism, as well as a combination therapeutic index and cross-resistance information. Some drug combination having level of synergy depending on the drug schedule, drug sequence and administration timings are also referenced and thoroughly discussed.

The user can also browse and compare chemotherapeutic regimens, analyze the overall drug dose over a course of treatment, by tumor type, in animal and clinical models.

Advanced functions include the ability to do statistical analysis on drug usage and dosing in various contexts. It can also help determine which drug candidates are likely to be used in combination with a new chemical or biological entity, given the mechanism of action and other PK/PD data. Also, it will allow users to design new combinations and regimens, which obey dosing constraints, such as MLD and MTD.

Finally, data can be exported and used in spread sheets, modeling software or simulation packages.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A36.
Abstract A42: ALK and cMET expression in glioblastoma multiforme: Implications for therapeutic targeting.
Authors: Hudson Lori , Kulig Kimary , Young Debra , McLendon Roger , Abernethy Amy
Published: June 2012

Introduction: Mutations in the anaplastic lymphoma kinase (ALK) gene result in aberrant tyrosine kinase signaling and are implicated in a variety of human cancers. In vitro and xenograft studies implicate pleiotrophin (PTN) signaling via ALK in growth and progression of glioblastoma (GBM). In addition, expression levels of the proto-oncogene cMET correlate with glioma malignancy and grade, with its overexpression linked to shorter survival time and poorer treatment outcomes. Antibody targeting of ALK or cMET inhibits GBM growth in xenograft models, suggesting both as potential therapeutic targets. The relative expression, mutation frequency, and clinicopathological features correlated with ALK, cMET, or both in GBM is unknown. Here we describe our preliminary results of the prevalence of these biomarkers in GBM patient tumor samples.

Methods: GBM tumor samples were selected from patients seen at a single institution (DUMC) since 2010. Immunohistochemistry (IHC) was used for both cMET and ALK detection. Clone 5A4 was used for ALK and clone 8F11 for cMET (Novocastra). ALK positivity by IHC was defined as ≥10% focal or ≥ 25% overall staining. Positivity of cMET by IHC was defined as ≥ 25% overall staining.

Fluorescent in situ hybridization (FISH) for ALK employed a dual-color break-apart probe (Vysis, Abbott). Counting 100 cells, cases were classified as having an ALK gain or amplification as follows: Signal Scoring: ≤2 Intact; 3–5 Gain; >5 Amplified and ≥10% Amp; ≥15% Gain; <15% Intact. IHC and FISH assays were run on two separate blocks of tissue for all cases.

Results: As shown in the Table, cMET expression by IHC was detected in 65%, ALK expression by IHC in 25%, and ALK gene amplification or gain by FISH in 60% of cases. Thus, the majority of cases were positive for cMET or ALK by FISH, with 55% positive for both.

Conclusion: Our pilot results show cMET and ALK protein expression in a significant number of GBM samples, with 55% having concurrent ALK amplification/gain along with cMET expression. Consistent with preclinical models, these data suggest a role for cMET and/or ALK in the pathogenesis of GBM. With the advent of cMET and ALK inhibitors, our study provides important data on the prevalence of these biomarkers as possible drug targets in GBM. Our ongoing study will evaluate more cases and explore relationships between clinical characteristics and outcomes relative to ALK and/or cMET expression.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A42.
Abstract A60: Comprehensive protein-protein interactions analysis to verify the key cancer and stem cell maintains mechanism in hepatocellular carcinoma.
Authors: Mori Taisuke , Kanai Yae , Fujimori Shigeo , Miyamoto-Sato Etsuko
Published: June 2012

Groundbreaking work demonstrated that ectopic expression of four transcription factors/TF, Oct4, Klf4, Sox2, and c-Myc, or less number TF could reprogram somatic cells to induced pluripotent stem cells (iPSCs) were subsequently generated using not only genetic manipulation but also protein induction. This work showed that the proteins might have huge complexity protein-protein interaction. The idea that cancer cells possess the partially same as stem cell properties such as self-renewing, drug resistance, and progression by same mechanism. Here we focus on evaluating large-scale protein-protein interaction (PPIs) of interacting regions (IRs) data at the domain level for “stemmness” TF-related protein complexes using a high-throughput mRNA display screen: In Vitro Virus/IVV method; Miyamoto-Sato E. et al., PLoS ONE. 2010). As a result of these global protein-protein interactions analysis with “stemness” molecules showed 440 interactions, Oct4:70, Sox2:96, Nanog:89, Klf4:37, Lin28:76, c-Myc:62 respectively. Especially we find unique hub protein X that is interaction with Nanog, Sox2, Klf4 and more stemness proteins. Now we are working on a further analysis to reveal the function of the unique hub protein X. Together this work suggest a novel resource for the assessment of cancer and stemcell function in various contexts, notably in the self-renewal of stem cells and progression of cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A60.
Abstract A61: Darinasparsin (Z101) inhibits prostate cancer stem cells via inhibition of hedgehog signaling.
Authors: Bertino Joseph R. , Bansal Nitu , Lewis John , Youssoufian Hagop
Published: June 2012

An orally available form of Darinasparsin (D) an organic arsenical, is currently in Phase I trials. The parenteral form of D has shown antitumor activity in Phase II studies, in particular in patients with T-Cell Lymphoma. We tested D in four prostate cancer cell lines and after a 72h exposure, IC50's ranged from 2.5 to 12 micromolar, Du 145 cells being the most sensitive. Given the reports that arsenic trioxide inhibited Hedgehog signaling (Kim et al, PNAS 107:13432,2110), we tested the effect of D on Hedgehog signaling in prostate stem cells, isolated by adherence to collagen I, expression of CD 44, and lack of expression of CD24. D showed potent inhibition of DU 145 prostate cells adhering to collagen, inhibited prostate spheroid growth (IC50:2uM) and prostate stem cell colony formation. Western analysis showed that D decreased levels of the transcription factor Gli2, a downstream effector of Hedgehog signaling. Combination studies with taxotere, a FDA approved drug for the treatment of patients with advanced prostate cancer, showed synergistic cell kill at high fixed doses of the drugs. In contrast the combination of D with cabazitaxel showed less than additive effects. These studies encourage additional preclinical studies and a clinical trial of D in patients with advanced prostate cancer, alone and in combination with taxotere.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A61.
Abstract A8: LY2228820 dimesylate, a p38-MAPK inhibitor, modulates angiogenic endothelial cord formation in vitro and in vivo.
Authors: Tate Courtney , Blosser Wayne , Wyss Lisa , Pratt Susan , Stewart Julie , Stancato Louis
Published: June 2012

LY2228820 dimesylate is a highly selective small molecule inhibitor of p38-mitogen-activated protein kinase (p38-MAPK) that is currently under clinical investigation for human malignancies. p38-MAPK is implicated in a wide range of biological processes, in particular those processes that support tumorigenesis. One such process, angiogenesis, is required for tumor growth and metastasis, and many new cancer therapies are therefore directed against the tumor vasculature. p38-MAPK is activated in endothelial cells upon growth factor stimulation and is involved in the secretion of growth factors and cytokines, but the role this activation plays in angiogenesis is not well defined. Using an in vitro co-culture endothelial cord formation assay (a surrogate of angiogenesis), we investigated the role of p38-MAPK in growth factor and tumor-driven angiogenesis by pharmacological inhibition of p38-MAPK using LY2228820 dimesylate and by shRNA gene knockdown. Inhibition of p38-MAPK by LY2228820 dimesylate led to a significant decrease in growth factor (VEGF, FGF, EGF) and IL-6 induced endothelial cord formation and an even more dramatic decrease in tumor-driven cord formation from a variety of tumor cell lines representing a range of histologies. Inhibition of p38-MAPK in tumor cells led to decreased cytokine secretion of VEGF, EGF, IL-6, IL-8, and other proangiogenic factors. Small molecule inhibitor results were substantiated by similar results obtained using p38-MAPK specific shRNA. Consequently, it appears that p38-MAPK plays a role in endothelial cell angiogenesis and tumor cell cytokine secretion. LY2228820 dimesylate effects on an in vivo angiogenesis Matrigel plug assay revealed a significant decrease in hemoglobin content (a measure of functional neoangiogenesis) which correlated with decreased pericyte coverage of the vessels. These results implicate p38-MAPK in tumor angiogenesis, and suggest that in vivo inhibition of p38-MAPK may lead to increased vascular permeability and/or induction of vascular normalization.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A8.
Abstract B116: Imaging of primary tumor and metastases in mice using near-infrared fluorescent-labeled phosphatidylserine-targeting antibodies.
Authors: Gong Jian , Archer Rich , Peacock Matthew , Hughes Christopher , Freimark Bruce
Published: June 2012

Phosphatidylserine (PS) is a phospholipid normally residing in the inner leaflet of the plasma membrane that becomes exposed on tumor vascular endothelial cells and tumor cells in response to chemotherapy, irradiation and oxidative stresses in the tumor microenvironment. Binding of antibodies targeting PS on the tumor endothelial cells and tumors leads to recruitment of immune cells and engagement of the immune system to destroy tumor vasculature. The antibodies also enhance anti-tumor immunity by blocking the immunosuppressive action of PS. In Phase II trials a chimeric anti-PS antibody, bavituximab, is being used in combination with chemotherapy to treat patients with solid tumors. In the present study, we demonstrate imaging of primary tumor and metastases using real-time, near infrared fluorescence imaging of antibodies that specifically target PS. Tumor formation, proliferation rate and location of metastases were monitored by bioluminescence imaging (BLI) and near-infrared optical imaging of PS exposure using a near infrared dye-labeled (NIR) PGN635 F(ab')2 antibody fragment. PGN635 binds PS through the interaction of beta-2-glycoprotein 1 (2GP1) in the same manner as bavituximab binding to 2GP1 in humans. Specific co-localization of BLI and NIR-labeled PGN635 F(ab')2 was observed in tumors compared to a NIR-labeled isotype control antibody. Chemotherapy was shown to enhance the binding of PS-targeting antibodies to both primary and metastatic tumors. These data provide a rationale to image PS expression as a way to localize primary tumors or metastases and to monitor induced PS expression during the course of chemotherapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B116.
Abstract B117: Early detection of a metabolic tumor response to p70S6 kinase/AKT inhibition by LYS6KAKT1 using in vivo choline proton magnetic resonance spectroscopy.
Authors: Zhu Mingming , Shannon Harlan E. , Trowbridge Melissa , Cockman Michael D. , Rothstein Emily C. , Geeganage Sandaruwan , Fischl Anthony S.
Published: June 2012

As part of a comprehensive drug discovery platform aimed at targeting the PI3K pathway, we have developed a potent small molecule dual inhibitor of p70 S6 kinase and AKT targeting two key nodes of the pathway. LYS6KAKT1 is a potent, highly selective ATP competitive inhibitor against p70S6 kinase and AKT with an IC50 of 6 nM and 14 nM respectively. LYS6KAKT1 inhibits phosphorylation of S6 ribosomal protein and phosphorylation of GSK3b in U87MG glioblastoma cells as well as phosphorylation of other downstream AKT substrates such as PRAS40 and FOXO (Geeganage et al, Abstract 62, 22nd Molecular Targets and Cancer Therapeutics, 16–19 November 2010). In vivo, LYS6KAKT1 demonstrate potent phospho-S6 inhibition in nude mice bearing glioblastoma cells, with an ED50 value of 3 mg/kg and an ED90 value of 8 mg/kg 4 hours after a single oral dose. Based on pre-clinical observations, LYS6KAKT1 is currently being evaluated in Phase I clinical studies for cancer. The purpose of this study was to investigate the effect of LYS6KAKT1 on tumor choline metabolites, a potential tumor response biomarker for PI3K pathway inhibition. Proton Magnetic Resonance Spectroscopy ([1H] MRS) was used to monitor the changes in tumor choline metabolites following treatment of U87MG xenografts in athymic nude mice. LYS6KAKT1 (12.5 or 25 mg/kg, PO, BID) significantly reduced total choline tumor metabolites after 7-days of dosing (p = 0.0006, n = 36). The total tumor choline metabolites, after 7 days of dosing, correlated significantly with relative changes in tumor volumes (r = 0.68, p < 0.0001, N = 36). The present findings indicate that reductions in tumor choline metabolites as measured by [1H] MRS in U87MG xenografts correlate with efficacy as measured by reduction in tumor volume and delay in tumor growth. The present data also indicate that tumor choline metabolites may serve as a potential non-invasive tumor response biomarker for efficacy of LYS6KAKT1.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B117.
Abstract B128: A phase IB study of the MEK inhibitor GSK1120212 combined with everolimus in patients with solid tumors: Interim results.
Authors: Infante Jeffrey R. , Patnaik Amita , Jones Suzanne F. , Papadopoulos Kiriakos P. , Bendell Johanna C. , Rasco Drew W. , Bellew Kevin M. , Cox Donna S. , Durante Michael G. , Park Joohyun J. , Burris Howard A. , Le Ngocdiep T. , Tolcher Anthony W.
Published: June 2012

Background: GSK1120212 (MEK) is a reversible, highly selective allosteric inhibitor of MEK1/MEK2. MEK was combined with everolimus (EVE), an mTOR inhibitor, to provide simultaneous inhibition of the MAPK and PI3K/mTOR pathways. This Phase I escalation study evaluated the safety, tolerability, pharmacokinetics (PK), and anti-tumor activity of MEK+EVE and assessed the recommended Phase II regimen (RP2R).

Materials and Methods: Advanced solid tumor patients (pts) with adequate end-organ function received MEK (0.5–2mg) orally once daily (QD). EVE (5–7.5mg) was given orally with various schedules (QD, QOD, 5/7D, or 7/14D).

Results: Sixty-seven pts (21 pancreatic, 14 colorectal, 6 melanoma, 4 breast, 3 neuroendocrine and 19 other cancers) received ≥ 1 dose of MEK + EVE. Cohorts 4A and 5 exceeded the maximum tolerated dose. Dose-limiting toxicities (DLTs) were G3 mucositisa (n=5), G4 thrombocytopenia (n=1), G3 acneiform rash/fatigue/dehydration (n=1) and G3 hypokalemia secondary to diarrhea. All DLTs were reversible. 2 pts had fatal serious adverse events (pneumonia, GI hemorrhage); both considered unrelated to study drugs. The most common adverse events (AEs) (≥ 25%) were mucositisa (67%), skin-related toxicities (66%), fatigue (60%), diarrhea (45%), nausea (40%), vomiting (37%), pyrexia (30%) and decreased appetite (28%). G3/G4 AEs included mucositisa (12% G3), AST elevation (10% G3) and hyperglycemia (7% G3). Mucositisa led to dose interruptions, reductions, and discontinuations in 27%, 9%, and 1% of pts, respectively.

There was no PK interaction when MEK was coadministered with EVE, and PK results were consistent with previous reports when either agent was administered alone. There did not appear to be a relationship between EVE or MEK exposure and mucositisa incidence or severity. 62 pts had measurable disease at baseline and 5 achieved a partial response: 3 confirmed (1 adenoid cystic carcinoma, on-going >13 months; 1 squamous cell lung, 6 months, withdrawn due to co-morbidity; 1 melanoma, 6 months), and 2 unconfirmed (1 laryngeal, 1 pancreatic cancer). 18 pts had stable disease with median duration on study treatment of 18.5 (range: 5.9–52.9) weeks.

Conclusion: Despite evidence of clinical activity in this heavily pretreated patient population, the toxicity profiles limit the ability to give MEK+EVE. Although multiple dosing schedules were explored, an RP2R was not identified.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B128.
Abstract B147: P-Rex1 is required for efficient melanoma metastasis.
Authors: Lindsay Colin R. , Lawn Samuel , Campbell Andrew , Faller William , Rambow Florian , Mort Richard , Timpson Paul , Li Ang , Cammareri Patrizia , Rafferty Mairin , Murphy Ian , McDermott Enda , Sheahan Kieran , Gallacher William , Van Kempen Leon , Beermann Friedrich , Der Channing , Larue Lionel , Welch Heidi , Ozanne Brad , Sansom Owen
Published: June 2012

Background: P-Rex1 is a Rac-specific Rho GTPase guanine nucleotide exchange factor that has recently been implicated in cancer for the first time. As Rac has a central role in control of cell motility, we assessed the role of P-Rex1 in melanoma, a cancer where metastasis is the major cause of death. This was the first evaluation of P-Rex1 in a genetically modified animal model of cancer. We also investigated the function of P-Rex1 in melanoblasts, as the molecular pathways that drive their developmental migration are believed to underpin the movement of metastatic melanoma cells.

Methods: P-Rex1−/− mice were crossed to mice carrying the DCT-lacZ transgene, a melanoblast reporter line, and a Tyr::NrasQ61K/°; INK4a−/− metastatic melanoma mouse model. Allograft tail vein (TV) injections were performed to further assess the endogenous function of P-Rex1 in metastasis. Panels of human melanoma cell lines and tissue were investigated with microarray, tissue culture, and immunohistochemical techniques.

Results: P-Rex1−/− mice have a melanoblast migration defect during development (p=0.01), evidenced by a white belly. They were resistant to metastasis when crossed to the Tyr::NrasQ61K/°; INK4a−/− murine model of melanoma (1/30 mice with metastases vs 13/30 in control cohort; p=0.001). When melanocytes derived from this model were TV-injected into immune-competent allografts, endogenous P-Rex1 was found to facilitate metastatic incidence, growth, and organ spread following the intravasation stage of the metastatic cascade (p=0.02). Mechanistically, this was associated with P-Rex1 driving invasion in a Rac-dependent manner. In humans, P-Rex1 was elevated in the great majority of melanoma cell lines, with mRNA levels above the median statistically associated with metastasic propensity (p=0.005). Tissue immunohistochemistry revealed an association between tumor progression and P-Rex1 expression.

Conclusions: P-Rex1 is a key component of melanoma progression, invasion and metastatic signaling, supporting the value of pharmacological inhibition of P-Rex1 activation of Rac for treatment of metastatic or high risk primary melanomas.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B147.
Abstract B165: Structural and biological studies on analogues of the natural product histone methyltransferase inhibitor chaetocin.
Authors: Cherblanc Fanny L. , Lo Ya-Pei , Bignell Elaine M. , Alcazar-Fuoli Laura , Brown Robert , Chapman-Rothe Nadine , Rzepa Henry S. , Fuchter Matthew J.
Published: June 2012

Epigenetic mechanisms play a critical role in the regulation of gene expression, and how such regulation becomes aberrant in cancer. Along with DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), histone methyltransferases (HKMTs) have recently appeared as new promising drug targets for epigenetic cancer therapies. While several HDAC and DNMT inhibitors have been clinically validated, to date only few HKMT inhibitors have been reported. Chaetocin, a fungal metabolite belonging to the 3,6-epidithio-diketopiperazine (ETP) class was first described as a specific inhibitor of the histone methyltransferase SU(VAR)3–9.(1) Like other fungal metabolites of the ETP class however, it exhibits a broad range of antibacterial and cytostatic activity, including a remarkable cytotoxicity against HeLa cells. Since the broad cytotoxicity of the ETPs is due to the presence of the disulfide bridge of the 3,6-epidithio-diketopiperazine (causing protein crosslinking, reactive oxygen species generation, or zinc chelation), we reasoned that access to semi-synthetic derivatives devoid of such functionality, would provide valuable insight into the chemical biology of this natural product, particularly its reported HKMT activity. We developed conditions to extract and purify the natural product culture (Chaetomium virescens var. thielavioideum), followed several semi-synthetic approaches to obtain chaetocin analogues. Comparison of experimental and computationally simulated chiroptical spectroscopy allowed unambiguous structural characterization of our products. Evaluation of our compounds in a number of in vitro HKMT assays revealed a total loss in inhibitory potency upon modification of the disulfide bridge. These studies thus demonstrate the ETP functionality of chaetocin to be responsible for its reported HKMT activity. In conclusion, we have synthetically prepared distinct and novel chaetocin analogues from the natural product and explored their HKMT activity, implicating the ETP functionality as the active pharmacophore.

Reference:

1. Greiner, D.; Bonaldi, T.; Eskeland, R.; Roemer, E.; Imhof, A. Nat. Chem. Biol. 2005, 1, 143.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr B165.