bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A243: Identification of a target for collismycin A, a cytotoxic microbial product, by proteomic profiling.
Authors: Kawatani Makoto , Inoue Gyo , Muroi Makoto , Futamura Yushi , Aono Harumi , Uramoto Masakazu , Hongo Yayoi , Koshino Hiroyuki , Igarashi Yasuhiro , Takahashi-Ando Naoko , Osada Hiroyuki
Published: August 2014

Background: Collismycin A, a microbial product, has antiproliferative activity against tumor cells, the mechanism of which yet remains unknown. Recently, we reported an indirect drug target identification approach, termed “ChemProteoBase," which is based on specific changes in the intracellular proteome induced by chemical manipulations. Here, we report on the identification of a molecular target for collismycin A by using ChemProteoBase.

Materials and Methods: HeLa cells were treated with collismycin A for 18 h, and the resulting cell lysates were subjected to two-dimensional fluorescence differential gel electrophoresis (2D-DIGE). The gel images were linked to our database containing images that were generated by 134 well-characterized small molecule drugs and probes. The 296 spots that matched on all gel images were quantified, and then hierarchical cluster analysis and similarity ranking analysis were performed.

Results: Collismycin A inhibited cell growth of various human tumor cells with IC50 values ranging from 100 to 400 nM. Flow cytometry and western blot analyses showed that collismycin A arrested cell cycle at G1 phase with the marked decrease of cyclin D1. To predict the mechanism of action of collismycin A, we performed ChemProteoBase profiling. As a result, collismycin A was clustered with Dp44mT, an iron chelator, and Dp44mT was also ranked in the highest position of a similarity ranking among 134 compounds contained in the ChemProteoBase. HR-ESI-MS analysis revealed that collismycin A forms 2 : 1 chelator-iron complex. In addition, the antiproliferative activity of collismycin A was completely abolished by the addition of excessive amounts of Fe(II) or Fe(III) ion but not other metal ions including Cu(II), Zn(II), Mn(II) and Mg(II).

Conclusions: These results strongly suggest that collismycin A acts as an iron chelator, resulting in the inhibition of tumor cell growth. Recent studies have shown that iron contributes to tumor initiation, growth and metastasis, and several iron chelators are under preclinical or early clinical investigation as anticancer therapeutics. Therefore, a new iron chelator, collismycin A, might be useful for the treatment of cancers in which iron has been strongly implicated.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A243.

Citation Format: Makoto Kawatani, Gyo Inoue, Makoto Muroi, Yushi Futamura, Harumi Aono, Masakazu Uramoto, Yayoi Hongo, Hiroyuki Koshino, Yasuhiro Igarashi, Naoko Takahashi-Ando, Hiroyuki Osada. Identification of a target for collismycin A, a cytotoxic microbial product, by proteomic profiling. [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 A243.
Abstract A25: Using clique relaxations to identify highly connected clusters in molecular networks in cancer.
Authors: Kulemina Lidia V. , Pastukhov Grigory , Veremyev Alexander , Boginski Vladimir L.
Published: August 2014

Graph theory approaches are now increasingly used to navigate through big data from “omics” applications for delineating signature events in cancer subtypes, identification of new molecular targets and assigning significance of specific mutations. While usual suspects such as p53 and Rb are widely known to all researchers, ability to identify additional, highly relevant, potentially targetable genes implicated in cancer remains of great importance.

Identification of cancer signatures and driver mutations turned out to be more challenging/ more complex than we originally thought as frequency of specific mutations can vary significantly leaving some potentially highly relevant (and potentially targetable) events out of the picture. We proposed to identify such targetable genes as parts of large “highly connected” clusters (also known as functional modules) in the corresponding networks. Using our recently developed algorithms, we have been able to exactly identify the largest highly connected cluster in sparse networks with up to several billion nodes.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A25.

Citation Format: Lidia V. Kulemina, Grigory Pastukhov, Alexander Veremyev, Vladimir L. Boginski. Using clique relaxations to identify highly connected clusters in molecular networks in cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A25.
Abstract A29: PI3K regulates MEK/ERK signaling in breast cancer via the Rac-GEF, P-Rex1.
Authors: Ebi Hiromichi , Costa Carlotta , Faber Anthony , Juric Dejan , Della Pelle Patricia , Song Youngchul , Yano Seiji , Mino-Kenudson Mari , Benes Cyril H. , Engelman Jeffrey A.
Published: August 2014

The phosphatidylinositol 3-kinase (PI3K) pathway is genetically activated in excess of 70% of breast cancers, often throughPIK3CA mutation and HER2 amplification. Previous studies with PI3K inhibitors have suggested enhanced sensitivity in this subset of breast cancers, however, the mechanism underlying this sensitivity is mainly unknown. In this study, we investigated the signaling consequences of PI3K inhibition in PIK3CA mutant and HER2 amplified breast cancers, and unexpectedly observed suppression of ERK signaling in these cancers. In contrast to PI3K inhibitors, AKT inhibitors failed to block MEK/ERK signaling and to induce sustained apoptosis, suggesting that a different PI(3,4,5)P3-dependent pathway regulated ERK. We determined that suppression of ERK was due to loss of active Rac1, which led to suppression of PAK/c-RAF/MEK/ERK signaling. Expression of a constitutively active form of Rac1 abrogated the capacity for PI3K inhibitors to inhibit ERK, induce apoptosis, and have anti-tumor activity in vivo. Further studies identified P-Rex1 as the PI(3,4,5)P3-dependent guanine exchange factor for Rac1 responsible for regulation of the Rac1/PAK/c-RAF/MEK/ERK pathway in these breast cancer cells. Furthermore, the expression level of P-Rex1 in these breast cancer cells predicted for capacity for PI3K inhibitors to suppress ERK signaling and correlated with sensitivity to PI3K inhibitors. Thus, PI3K inhibitors have enhanced sensitivity in PIK3CA mutant and HER2 amplified breast cancers where PI3K inhibition downregulates both the AKT and Rac1/ERK pathways. In addition, P-Rex1 may serve as a biomarker to predict response to single-agent PI3K inhibitors within this subset of breast cancers.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A29.

Citation Format: Hiromichi Ebi, Carlotta Costa, Anthony Faber, Dejan Juric, Patricia Della Pelle, Youngchul Song, Seiji Yano, Mari Mino-Kenudson, Cyril H. Benes, Jeffrey A. Engelman. PI3K regulates MEK/ERK signaling in breast cancer via the Rac-GEF, P-Rex1. [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 A29.
Abstract A32: Novel biomarker algorithm to improve the differential diagnosis of ovarian cancer with in patients with ovarian tumor.
Authors: Lee Shin-Wha , Shin So-Jin , Kyung Min-Sun , Kim Young-Man , Kim Young-Tak
Published: August 2014

Objectives: The objective of this study was to analyze the concentration of serum multivariate markers and find the optimized combination to diagnose ovarian cancer in patients with ovarian tumor.

Methods: We collected serum samples prospectively from patients treated with ovarian tumors. Total 398 samples including malignant and benign ovarian tumor and normal controls, in testing set, were analyzed for their ovarian cancer-related 21 proteins, including CA125, HE4, CA19-9, CA15-3, CEA, Leptin, MIF, OPN, Prolactin, Cyfra21-1, IL-6, IL-8, MIP-1-alpha, Eotaxin, sEGFR, Apo AI, Apo CIII, Prealbumin(TTR), C-reactive protein(CRP), sNCAM, and sVCAM-1 by Luminex methods, which is a multiplexed immunoassay. In validation set, 6 protein markers were analyzed.

Results: More than half of the biomarkers tested were found to differ significantly between benign and malignant cases. Among them, as individual markers, 6 markers including CA-125 and HE4 provided the discrimination between benign and malignant cases. The diverse combination of these 6 biomarkers provided a higher level of discriminatory power than either marker considered alone. We identified that these multimarker panels could discriminate ovarian cancers from benign cases with more than 95% of sensitivity, 95% of negative predictive value and 85% of accuracy in 75% of specificity. These multimarkers showed the improved differentiation diagnosis in early stage cancer and pre-menopausal women comparing to the CA-125 alone.

Conclusions: We describe a blood-based assay using multimarkers that can distinguish women with ovarian cancer from those with benign conditions. Preliminary evaluation of the multimarker panels suggests it has the potential to improve the accuracy to diagnose ovarian cancers. While promising, the performance needs to be assessed in a blinded clinical validation study.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A32.

Citation Format: Shin-Wha Lee, So-Jin Shin, Min-Sun Kyung, Young-Man Kim, Young-Tak Kim. Novel biomarker algorithm to improve the differential diagnosis of ovarian cancer with in patients with ovarian tumor. [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 A32.
Abstract A36: High T790M detection rate in TKI-naïve NSCLC with EGFR sensitive mutation: Truth or artifact?.
Authors: Ye Xin , Zhu Zhong-zheng , Zhong Lei , Lu Yachao , Sun Yun , Yin Xiaolu , Yang Zhenfan , ZHU Guanshan , Ji Qunsheng
Published: August 2014

T790M in epidermal growth factor receptor (EGFR) accounts for about 50% of the acquired resistance to EGFR tyrosine kinase inhibitor (TKI) in patients with non-small cell lung cancer (NSCLC) carrying sensitive EGFR mutations. Earlier studies suggested that T790M mutation was also detected in about 2% of TKI-naive NSCLCs. Recently, three groups reported that, by using highly sensitive assays, T790M mutation was detected in about 40% of TKI-naive NSCLC with sensitive EGFR mutations. When we carefully studied these reports, we realized that all of those data were generated from formalin-fixed paraffin embedded (FFPE) tumor tissue samples, which raised a concern that the high mutation positivity could be consequence of formalin fixation. To address this, we assessed the T790M mutation in 36 pairs of frozen and FFPE tumor tissues of TKI-naïve NSCLC with sensitive EGFR mutations using an enzyme-based mutant-enriched PCR assay (ME-PCR) with 0.1% sensitivity. In addition, frozen and FFPE adjacent normal tissues from the same patients were also assessed for a further comparison. While 41.7% (15/36) T790M positive rate was detected in the tumor FFPE samples which was consistent with previous reports, only 1 of the 36 (2.8%) frozen counterparts was T790M positive. As suspected, 48.5% (16/33) of T790M mutation rate was also identified in FFPE adjacent normal tissues but none of the 35 frozen adjacent normal tissues was T790M positive. Our results indicate that the high T790M positivity detected in TKI-naïve NSCLC using some highly sensitive methods may in some cases be FFPE-derived artifacts.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A36.

Citation Format: Xin Ye, Zhong-zheng Zhu, Lei Zhong, Yachao Lu, Yun Sun, Xiaolu Yin, Zhenfan Yang, Guanshan ZHU, Qunsheng Ji. High T790M detection rate in TKI-naïve NSCLC with EGFR sensitive mutation: Truth or artifact?. [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 A36.
Abstract A41: Pre-clinical investigation of predictive biomarkers for drug candidates using a molecularly profiled large cancer cell line panel.
Authors: Aida Satoshi , Mizuno Hideaki , Sakamoto Hiroshi , Nakanishi Yoshito , Mutoh Hironori , Cai James , Burtscher Helmut , Aoki Masahiro , Aoki Yuko , Ishii Nobuya
Published: August 2014

To deliver investigational drugs to appropriate patients from the early clinical development stage, it would be ideal to identify biomarker candidates at the preclinical stage. To investigate prediction biomarkers in preclinical models, a large cell panel consisting of over 500 cell lines from various tumor types was molecularly profiled. To find their gene expression profiles, gene copy number variations, single nucleotide variations and gene fusions, we conducted a comprehensive analysis with GeneChip, CGH array, exon sequencing and RNA sequencing by collaborative efforts between Chugai Pharmaceutical and F. Hoffmann-La Roche in the CELLO/CACTEL program (CELl Line profiling in Oncology/Chugai ACcumulative Tumor EncycLopedia). We further integrated the multidimensional profiling data of in-house cell lines together with those of tumor tissues in the public domain into our CELLO/CACTEL database by vocabulary controlling among databases. Using 300 cell lines in a molecularly profiled cell panel, we investigated the drug sensitivity profiles of representative investigational drug candidates, and identified potentially novel predictive features for sensitivity to these drugs. In summary, the CELLO/CACTEL database provides an effective platform for exploring biomarkers at the preclinical stage.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A41.

Citation Format: Satoshi Aida, Hideaki Mizuno, Hiroshi Sakamoto, Yoshito Nakanishi, Hironori Mutoh, James Cai, Helmut Burtscher, Masahiro Aoki, Yuko Aoki, Nobuya Ishii. Pre-clinical investigation of predictive biomarkers for drug candidates using a molecularly profiled large cancer cell line panel. [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 A41.
Abstract A43: Investigation of dipeptidyl peptidase IV/CD26 role in cervical cancer cell lines.
Authors: Buffon Andréia , Beckenkamp Aline , Santana Danielle Bertodo , Nascimento Jéssica , Paccez Juliano , Zerbini Luiz Fernando , Wink Márcia Rosangela , Bruno Alessandra Nejar
Published: August 2014

Cervical cancer is a common type of cancer in women and an important public health problem, mainly in developing countries. The glycoprotein DPPIV/CD26 is expressed at the membrane of many cells. It is able to inactivate some bioactive peptides and chemokines, thereby regulating cell proliferation and survival, being involved in processes related to cancer. This enzyme is also present in a soluble form (DPPIV/sCD26), in biological fluids. In this study, we evaluated, the expression and enzymatic properties of the DPPIV/CD26 and its relation with tumoral mechanisms in cervical cancer cell lines. The cervical cancer cells exhibit DPPIV/CD26 enzymatic activity in both membrane bound and, its soluble form, which was confirmed by the inhibition of the enzymatic DPPIV/CD26 activity for sitagliptin phosphate. The CD26 mRNA expression was observed in the SiHa and C33A cells, while the HeLa cells showed no transcripts. The DPPIV/CD26 expression was correlated with the enzymatic activity in these cell lines. We also observed a higher migratory capacity of HeLa (cervical cancer cell line that less express CD26) compared to SiHa (cervical cancer cell line that more express CD26), moreover in the presence of the specific inhibitor we observed that SiHa cell line shows an increase in migration, thus confirming a relationship of this enzyme with the migratory ability. Our results show, that cervical cancer cells present DPPIV/CD26 enzymatic activity in both membrane bound form, as in its soluble form, revealing a differential expression as well as its relationship to cell migration and adhesion. Considering that DPPIV/CD26 plays an important role in tumor biology, this protein may become an important therapeutic target although additional work is required to elucidate the molecular mechanisms associated with DPPIV/CD26 in cervical cancer.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A43.

Citation Format: Andréia Buffon, Aline Beckenkamp, Danielle Bertodo Santana, Jéssica Nascimento, Juliano Paccez, Luiz Fernando Zerbini, Márcia Rosangela Wink, Alessandra Nejar Bruno. Investigation of dipeptidyl peptidase IV/CD26 role in cervical cancer cell lines. [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 A43.
Abstract A63: NVP-BEZ235, a dual PI3K/mTOR inhibitor, elicits an alternate route for induction of cell death in PTEN null prostate cancer cells.
Authors: Kim Jeong Eun , Hong Seoung-Woo , Shin Jae-Sik , Moon Jai-Hee , Kim Ye-Seul , Kim Kyu-pyo , Hong Yong Sang , Lee Jae-Lyun , Jin Dong-Hoon , Kim Tae Won
Published: August 2014

Dysregulation of the PI3K-AKT & mTOR pathway by (mutation and/or) deletion of tumor suppressor gene PTEN frequently occurs in human prostate cancer and is therefore considered to be attractive molecule as therapeutic targets. Here, we investigated the antitumor effect of NVP-BEZ235 in human prostate cancer cells dependent on PTEN genotype. In this setting, NVP-BEZ235 induced cell death in the PTEN-independent manner. However, NVP-BEZ235 selectively induced apoptotic cell death in prostate cancer cells presenting wild-type PTEN, DU145, but not in cells with deletion of PTEN, PC3. Treatment with NVP-BEZ235 resulted in autophagic cell death in PC3 cells with PTEN loss of function. Consistently, NVP-BEZ235 treatment did not result in the cleavage of caspase-3 and was link to active LC3-I/II as an indicator of autophagic cell death process, suggesting an alternate route for induction of cell death after exposure to NVP-BEZ235 in PTEN-null prostate cancer cells. These results suggest that PTEN/PI3K/Akt pathways are critical for prostate cancer survival and targeting PI3K signaling by NVP-BEZ235 may be beneficial in prostate cancer independent on PTEN genotype.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A63.

Citation Format: Jeong Eun Kim, Seoung-Woo Hong, Jae-Sik Shin, Jai-Hee Moon, Ye-Seul Kim, Kyu-pyo Kim, Yong Sang Hong, Jae-Lyun Lee, Dong-Hoon Jin, Tae Won Kim. NVP-BEZ235, a dual PI3K/mTOR inhibitor, elicits an alternate route for induction of cell death in PTEN null prostate cancer cells. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A63.
Abstract A76: Enhancement of cetuximab-induced antibody-dependent cellular cytotoxicity with lenalidomide in advanced solid tumors: A Phase I trial.
Authors: Bertino Erin M. , Rose Jeffrey S. , Wu Christina , Bekaii-Saab Tanios , Savvides Panayiotis S. , Goldberg Richard M. , Villalona Miguel , Lozanski Gerard , Carson William , Grever Michael , Otterson Gregory
Published: August 2014

Introduction: Antibody-dependent cellular cytotoxicity (ADCC) is one mechanism of action of monoclonal antibody (mAb) therapy. ADCC occurs via the innate immune system's ability to recognize mAb coated cancer cells and activate effector cells. Lenalidomide is an immunomodulatory agent with capacity to stimulate T cell proliferation, activate natural killer cells, and effect immune cytokines including IL-2, IL-12, and interferon gamma. Both preclinical and clinical data demonstrate the ability of lenalidomide to increase ADCC activity of mAb therapy. This Phase I CTEP sponsored trial aims to evaluate the combination of cetuximab with lenalidomide to enhance ADCC activity in advanced colorectal (CRC) and head and neck squamous cell cancers (HNSCC).

Patients/Methods: This Phase I dose escalation trial included patients with locally advanced or metastatic CRC (KRAS wild type) or HNSCC. Treatment consisted of cetuximab 500 mg/m2 IV every 2 weeks with lenalidomide orally days 1-21 every 28 days. Cetuximab dose was the same in all cohorts although dose reductions were permitted for toxicity. Three dose levels of lenalidomide were evaluated (15 mg, 20 mg, and 25 mg). Prior treatment with cetuximab, panitumumab, or other EGFR directed therapy was allowed. Planned correlative studies include measurement of ADCC using an in vitro chromium release assay, serum interferon gamma and NK cytokine profiles, and Fc gamma receptor polymorphisms.

Results: A total of 22 patients have been treated (19 CRC, 3 HNSCC). Grade 3 fatigue has been the only observed dose-limiting toxicity. One partial response was observed and 7 patients had stable disease as best response. Two patients remain on treatment. The recommended Phase II dose is cetuximab 500 mg/m2 with lenalidomide 25 mg daily days 1-21.

Conclusions: Cetuximab and lenalidomide was well-tolerated with minimal activity. Although response was not a primary endpoint, there is evidence of anti-tumor activity and clinical efficacy.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A76.

Citation Format: Erin M. Bertino, Jeffrey S. Rose, Christina Wu, Tanios Bekaii-Saab, Panayiotis S. Savvides, Richard M. Goldberg, Miguel Villalona, Gerard Lozanski, William Carson, Michael Grever, Gregory Otterson. Enhancement of cetuximab-induced antibody-dependent cellular cytotoxicity with lenalidomide in advanced solid tumors: A Phase I trial. [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 A76.
Abstract A86: Preclinical refinement of a highly-penetrative polymeric nanoparticle drug delivery system for the treatment of glioblastoma multiforme.
Authors: Strohbehn Garth W. , Atsina Komli-Kofi , Patel Toral R. , Piepmeier Joseph M. , Zhou Jiangbing , Saltzman W. Mark
Published: August 2014

Survival statistics for glioblastoma multiforme (GBM) have remained static despite years of research. Two challenges must be overcome to extend survival: drug delivery and resistance to current therapies. Recently, we have developed a highly-penetrative polymeric nanoparticle system capable of being safely delivered to brain parenchyma using convection-enhanced delivery (CED). We have previously shown that this system is capable of protecting and releasing in a controlled manner agents with activity against glioma stem cells (GSCs), significantly improving survival in a rat xenograft model of GSC-derived GBM. We describe here our efforts to further refine this potential therapeutic.

First, utilizing high-throughput small molecule screening of a library of generic and FDA- and internationally-approved compounds against GSCs of varying morphologies and genetic composition, we describe the discovery of a novel class of compounds with profound anti-proliferative activity against GSCs but with only very limited activity against normal glial cells. Identified compounds are notably small and lipophilic, making them ideal candidates for translation in our highly-penetrative polymeric nanoparticle system.

Second, building upon recent advances in magnetic resonance imaging technology, we describe the incorporation of supraparamagnetic iron oxide (SPIO) in our highly-penetrative polymeric nanoparticle system. We show that incorporation of SPIO does not alter size or in vitro properties of these nanoparticles. Further, we show that SPIO-loaded nanoparticles can be safely delivered to brain parenchyma using CED and can stably release their contents in a controlled fashion over a matter of weeks. These results represent important steps toward clinical application of a promising drug delivery technology.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A86.

Citation Format: Garth W. Strohbehn, Komli-Kofi Atsina, Toral R. Patel, Joseph M. Piepmeier, Jiangbing Zhou, W. Mark Saltzman. Preclinical refinement of a highly-penetrative polymeric nanoparticle drug delivery system for the treatment of glioblastoma multiforme. [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 A86.
Abstract A87: Overcoming NSCLC to SCLC transformation as a resistance mechanism in EGFR mutant lung cancer.
Authors: Niederst Matthew J. , Sequist Lecia V. , Lockerman Elizabeth L. , Costa Carlotta , Borger Darrell R. , Mino-Kenudson Mari , Iafrate Anthony J. , Engelman Jeffrey A.
Published: August 2014

The EGFR TKIs gefitinib and erlotinib produce dramatic responses in NSCLC patients with EGFR activating mutations, however, the efficacy of these drugs is severely limited by the development of acquired resistance. Recently, we and others have found that a subset of these cancers transform from NSCLC to SCLC as they acquire resistance to EGFR TKI. Here we report an initial characterization of the molecular mechanisms underlying the transformation from NSCLC to SCLC in samples and cell lines derived from resistant patients. Much like de novo SCLC, Rb and p53 are altered in the resistant tumors that transformed to SCLC, although loss of p53 and Rb function alone were insufficient to drive the transformation in NSCLC cell lines. In addition, we demonstrate that EGFR expression is lost in resistant samples, suggesting that in switching to SCLC these cancers become a cell type that is no longer dependent on EGFR activity and providing an explanation for lack of EGFR TKI sensitivity. Finally, we find that SCLC transformed cells are uniquely sensitive to the Bcl-2/Bcl-XL inhibitor Abt-263, offering a potential therapeutic option for these patients. Together, these results represent the first insights into the molecular and genetic details regarding this novel type of resistance to targeted therapy.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A87.

Citation Format: Matthew J. Niederst, Lecia V. Sequist, Elizabeth L. Lockerman, Carlotta Costa, Darrell R. Borger, Mari Mino-Kenudson, Anthony J. Iafrate, Jeffrey A. Engelman. Overcoming NSCLC to SCLC transformation as a resistance mechanism in EGFR mutant lung cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr A87.
Abstract A89: Loss of HLA molecules as melanoma resistance mechanism in immune checkpoint blockade therapy.
Authors: Anichini Andrea , de Braud Filippo G. , Montarini Roberta , Bersani Ilaria , Tragni Gabrina , de Cecco Loris , Canevari Silvana , Di Guardo Lorenza , Pilla Lorenzo , Del Vecchio Michele
Published: August 2014

Melanoma immunotherapy based on immune checkpoint blockade, by targeting of CTLA-4 or PD-1, has markedly improved the treatment of advanced disease, as shown by several recent trials. Monotherapy with CTLA-4-specific antibody (Ipilimumab) prolongs overall survival, while PD-1-specific antibodies (Nivolumab and Lambrolizumab) induce durable tumor regression in a large fraction of patients. Moreover, a recent trial based on combination checkpoint blockade (Ipilimumab plus Nivolumab) has shown an objective response rate of 53%, with tumor reduction of 80% in responding patients, without escalation of toxic effects. In spite of these highly relevant results, clinical benefit by immunotherapy targeting CTLA-4 or PD-1 remains limited to a fraction of patients. This points to the existence of immune escape mechanisms, which, in some tumors, may prevent effective elimination of neoplastic cells, in spite of the reactivated T cell immunity. This hypothesis was tested in a melanoma patient, treated with Ipilimumab, and that we recently reported (J. Clin. Oncol. 29:e783-8, 2011) to have a strong T cell infiltrate and evidence of T cell maturation/activation only in a regressing right adrenal metastasis, but not in the progressing controlateral lesion. To this end, we carried out DASL whole genome gene expression analysis and extensive immunohistochemistry (IHC) on paraffin-embedded neoplastic tissues. The results indicated that, in comparison to the progressing metastasis, the regressing lesion had a distinct gene expression profile characterized by enhanced expression of several genes involved in T cell differentiation to cytolytic effector stage. Most importantly, the regressing lesion retained expression of HLA molecules on neoplastic cells. In contrast, the progressing lesion showed almost complete loss of HLA class I and Class II molecules by the tumor, as documented by IHC. Taken together, these results suggest that lack/loss of expression of HLA molecules, by tumor cells, may represent a highly effective tumor resistance mechanism to immune checkpoint blockade. Moreover, pre-therapy IHC on tumor samples may allow to test whether HLA antigen expression/loss is a predictive marker for response/resistance to therapy targeting CTLA-4 or PD-1.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A89.

Citation Format: Andrea Anichini, Filippo G. de Braud, Roberta Montarini, Ilaria Bersani, Gabrina Tragni, Loris de Cecco, Silvana Canevari, Lorenza Di Guardo, Lorenzo Pilla, Michele Del Vecchio. Loss of HLA molecules as melanoma resistance mechanism in immune checkpoint blockade therapy. [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 A89.
Abstract A94: Understanding of differing sensitivity in EML4-ALK NSCLC patients to crizotinib and geldanamycin.
Authors: Rikova Klarisa , Hall Benjamin , Possemato Anthony , Mroszczyk Keri , Lee Kimberly A. , MacNeill Joan , Ren Jian Min , Guo Ailan , Mulhern Daniel , Wang Yi , Beausoleil Sean A. , Comb Michael J.
Published: August 2014

Non-small cell lung cancer (NSCLC) is the most common form of lung cancer, afflicting nearly 200,000 people in the United States each year. Abnormal ALK is found in about 5% of NSCLC cases, meaning more than 5,000 new patients could benefit from the tyrosine kinase inhibitor (TKI) crizotinib. However, not all patients benefit from such treatment, with the clinical response to crizotinib differing among patients who harbor the same molecular abnormality. Similarly, patients with ALK fusion proteins have shown varying sensitivity to the HSP90 inhibitor geldanamycin in preclinical studies.

We have chosen two NSCLC cell lines, H3122 and H2228, as a model to address these questions. Both cell lines harbor EML4-ALK fusions with differing sensitivity to the inhibitors crizotinib and geldanamycin. We used the established method of TMT peptide labeling coupled with serial peptide immunoprecipitation. To observe the effects of crizotinib and geldanamycin on ALK sensitive H3122 and non-sensitive H2228 NSCLC cell lines quantitative analysis was performed. Phosphotyrosine, acetylation, methylation, ATM/ATR substrate (s/tQ), Akt/AMPK subs AGC/CAMK/STE, and MAPK family kinase motif antibodies were used for immunoprecipitation allowing us to characterize and quantify post translational modifications before and after treatment.

In this study, we identify extensive signaling networks downstream of ALK across multiple spaces, including phosphorylation, acetylation, and methylation. These differences may be clinically significant and highlight the possibility that ALK inhibitors alone may only be effective in a subset of NSCLC ALK-positive patients with EML4-ALK inversion.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A94.

Citation Format: Klarisa Rikova, Benjamin Hall, Anthony Possemato, Keri Mroszczyk, Kimberly A. Lee, Joan MacNeill, Jian Min Ren, Ailan Guo, Daniel Mulhern, Yi Wang, Sean A. Beausoleil, Michael J. Comb. Understanding of differing sensitivity in EML4-ALK NSCLC patients to crizotinib and geldanamycin. [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 A94.
Abstract A97: PPME1 is a novel target for synthetic lethal therapy in human gliomas.
Authors: Westermarck Jukka , Kaur Amanpreet
Published: August 2014

Glioblastoma multiforme (GBM) is a devastating disease with very limited therapy choices. Although deregulated kinase pathways have been identified as drivers of GBM progression, inhibition of receptor tyrosine kinases or serine/threonine kinases has not been successful therapy mode for GBM. Therefore, there is an evident need for novel therapy strategies to overcome kinase inhibitor resistance in GBM.

Here we have identified a novel approach to induce very potent synthetic lethal cell killing in human glioma cells treated with multikinase inhibitors. We show that targeting of protein methylesterase PPME1, which functions as an inhibitor of human tumor suppressor protein phosphatase 2A (PP2A), causes dramatic cell killing in GBM cells in combination with structurally defined subgroup of indolocarbazole inhibitors currently in clinical trials. PPME1 silenced glioma cells are significantly sensitized to cell killing by indolocarbazole inhibitors both in vitro and in in vivo tumors. Synthetic lethality is specific for combination of PME-1-regulated PP2A activity and can be reversed by inhibition of specific PP2A complexes. Downstream of PP2A, PPME1 inhibition-elicited synthetic lethality involves regulation of HDAC4, a known survival factor in neuronal cells. Consequently, inhibition of HDAC4 phenocopies synthetic lethal cell killing seen in PME-1-depleted cells and expression of HDAC4 correlates with disease progression and with PME-1 status in human glioma. Biochemical evidence indicates that PPME1 and HDAC4 regulate expression and acetylation of same target proteins involved in regulation of cancer cell survival.

Thus, these results present novel synthetic lethal therapy approach for GBM via inhibition of PPME1 and HDAC4. These results also identify PME-1 as potential biomarker for glioma patient stratification for indolocarbazole inhibitors currently in clinical trials. Generally these results emphasize potential of concomitant inhibition of kinases and reactivation of their antagonist protein phosphatases as a cancer therapy approach.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):A97.

Citation Format: Jukka Westermarck, Amanpreet Kaur. PPME1 is a novel target for synthetic lethal therapy in human gliomas. [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 A97.
Abstract B108: A genome-scale shRNA synthetic lethal screen identifies enhancers of sensitivity to RAF inhibition.
Authors: Whittaker Steven R. , Luo Flora , Hsiao Jessica , Cowley Glenn S. , Root David E. , Garraway Levi A.
Published: August 2014

Genome-scale RNA interference screens have identified a dependency on BRAF for the proliferation of BRAF-mutant colorectal cancer (CRC) cell lines. Despite this, small molecule RAF inhibitors, such as vemurafenib, have been unsuccessful in clinical trials of patients with CRC, with a response rate of only 5%. CRC cell lines demonstrate intrinsic resistance to RAF inhibitors, in some cases through EGFR or MET activity. We designed a genome-scale RNA interference screen to identify loss of function events that could synergize with pharmacologic RAF inhibition. We transduced a pooled lentiviral library encoding 90,000 shRNAs targeting over 16,500 genes into the RKO CRC cell line, which displays robust resistance to PLX470. The shRNA-infected population was divided into two experimental arms, one treated with DMSO, the other treated with PLX4720. Following 16 population doublings, the abundance of each hairpin was assessed by PCR amplification of barcoded hairpin DNA, followed by massively parallel paired-end sequencing. The log-fold change in shRNA abundance between the PLX4720- and DMSO-treated controls was determined and RNAi gene enrichment (RIGER) used to rank individual shRNAs and nominate candidate genes that were required for survival of RKO cells exposed to PLX4720. Top-ranking genes that displayed synthetic lethality with RAF inhibition were validated in an arrayed secondary screen. shRNAs targeting MET scored highly, consistent with recent reports implicating HGF-MET signaling in resistance to BRAF inhibition, validating our approach. Furthermore, we describe the characterization of additional genes that sensitize cells to inhibition of BRAF. Ultimately, these studies aim to nominate pharmacologically targetable events that mediate RAF-inhibitor resistance in colorectal cancers.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B108.

Citation Format: Steven R. Whittaker, Flora Luo, Jessica Hsiao, Glenn S. Cowley, David E. Root, Levi A. Garraway. A genome-scale shRNA synthetic lethal screen identifies enhancers of sensitivity to RAF inhibition. [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 B108.
Abstract B119: Mechanisms of drug resistance to molecular target therapeutics against tyrosine kinases as EGFR, c-Met, and PDGFR in GBM.
Authors: Tsuda Masumi , Wang Lei , Tanino Mishie , Kimura Taichi , Nishihara Hiroshi , Tanaka Shinya
Published: August 2014

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor. Despite technological advances in surgery, combined with regimens of radiotherapy and new generation chemotherapy, the median survival is still 15 months. Several molecular therapeutics targeting protein tyrosine kinases have recently been attempted; however, the emerging drug resistance is a crucial issue. Here, we established cell lines acquired drug resistance to individual inhibitor for major tyrosine kinase as EGFR, c-Met, or PDGFR that highly expressed in GBM, and characterized the underlying mechanisms. While initial 50 days starting inhibitor treatment, the cells exhibited distinct morphological changes of epithelial-mesenchymal transition (EMT) concomitant with up-regulation of Snail, Slug, and Mmp-2. Of note, further continuous drug treatment produced stemness-like properties in the cells. PCR array and microarray analysis have identified marked enhancement of several stemness-related genes including Sox2 and CXCL12. These findings show that suppression of EMT and/or stemness features of GBM may be an effective strategy to avoid the acquisition of resistance for molecular target therapy in GBM.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B119.

Citation Format: Masumi Tsuda, Lei Wang, Mishie Tanino, Taichi Kimura, Hiroshi Nishihara, Shinya Tanaka. Mechanisms of drug resistance to molecular target therapeutics against tyrosine kinases as EGFR, c-Met, and PDGFR in GBM. [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 B119.
Abstract B124: Selective inhibition of HER2 signaling pathway reveals novel functions of FOXA1 in breast cancer.
Authors: Katika Madhumohan , Martin Ruthmma , Siv Gilfillan , Børresen-Dale Anne Lise , Lopez Sandra , Hurtado Toni
Published: August 2014

Breast cancer cell proliferation results from many different factors that activate multiple cellular signaling pathways, which are currently target therapies. Yet, how genomic pathways are influenced upon cell-signaling disruption has been poorly assessed. We explored how the inhibition of HER2 signaling pathway influences the function of the transcription factor FOXA1. By means of specific inhibitors targeting the kinase activity of HER2 (Lapatinib) and its downstream kinase MEK (AZD6244) we have identified HER2/MEK signaling pathway as a key supervisor of FOXA1 function in HER2+ breast cancer subtype. The HER2/MEK pathway regulates the function of acetyltransferase enzymes through phosphorylation. These acetyltransferases in turn control the binding of FOXA1 towards key genes required for the proliferation in HER2+ cancer cells. Importantly, the same mechanisms of FOXA1 regulation are needed to induce cell proliferation in ER+ breast cancer cells that do not overexpress HER2.

We also explored the function of FOXA1 upon Herceptin treatment, which is a monoclonal antibody that binds to the extracellular domain of HER2. Here, we demonstrate that treatment of breast cancer cells with Herceptin produces the activation of cytokine signaling pathways. Importantly, the cytokine pathway activation reprograms the chromatin interactions of FOXA1 towards genes playing a key role in the initiation of the cell-mediated cytotoxicity. All together, these findings supports the idea that FOXA1 integrates input signals originating from multiple cell-signaling pathways to generate output responses that culminate in control of proliferation and the response to anti-cancer therapies.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B124.

Citation Format: Madhumohan Katika, Ruthmma Martin, Gilfillan Siv, Anne Lise Børresen-Dale, Sandra Lopez, Toni Hurtado. Selective inhibition of HER2 signaling pathway reveals novel functions of FOXA1 in breast cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B124.
Abstract B133: Regulation of the androgen receptor function by a metabolic kinase in prostate cancer.
Authors: asim Mohammad , Massie Charlie , Zecchini Heather , Baridi Ajoeb , Gomes Nelma , Mohammed Hisham , Zecchini Vincent , Madhu Basetti , Qureshi Arham , Russell Roslin , Hessenkemper Wiebke , Sriranjan Rouchelle , Yang Carrie , Lynch Andy , Gregorengko Elena , Stark Rory , Rennie Paul , Griffiths John , Baniahmad Aria , Carroll Jasol , Mills Ian , Neal David
Published: August 2014

In a recent genome-wide study to identify androgen receptor target genes we found that the AR promotes tumor growth by enhancing the expression and activity of enzymes required for metabolic biosynthesis. This raises the possibility for effective therapeutic approaches directed towards AR target genes. Kinases are well-established drug targets. In this study we identify androgen regulated kinome and show that an important androgen regulated metabolic kinase is a drug target in prostate cancer. Our proteome study shows that this kinase interacts with the androgen receptor and regulates AR stability. Inhibition of this kinase significantly reduces AR protein levels and suppresses prostate cancer growth in cell-lines and ex vivo cultures. In clinical prostate cancer this kinase is highly over-expressed in metastatic prostate cancers and inhibition represses metastatic potential of prostate cancer cells. Our study therefore establishes this kinase for the first time as an AR target gene that regualtes AR itself as part of feedback loop and makes a case for further investigation of its inhibitors as novel AR antagonists in both localised and advanced disease.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B133.

Citation Format: Mohammad asim, Charlie Massie, Heather Zecchini, Ajoeb Baridi, Nelma Gomes, Hisham Mohammed, Vincent Zecchini, Basetti Madhu, Arham Qureshi, Roslin Russell, Wiebke Hessenkemper, Rouchelle Sriranjan, Carrie Yang, Andy Lynch, Elena Gregorengko, Rory Stark, Paul Rennie, John Griffiths, Aria Baniahmad, Jasol Carroll, Ian Mills, David Neal. Regulation of the androgen receptor function by a metabolic kinase in prostate cancer. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B133.
Abstract B134: Stathmin is involved in the maternal embryonic leucine zipper kinase pathway in human astrocytomas.
Authors: Uno Miyuki , Oba-Shinjo Sueli Mieko , Silva Roseli , Gimenez Marcela , Reis Gisele , Rosa Jose C. , Marie Suely K. N.
Published: August 2014

Introduction: Maternal Embryonic Leucine Zipper Kinase (MELK) is a serine/threonine kinase involved in several cell processes, including the cell cycle, proliferation, apoptosis and mRNA processing. MELK has shown multiple features consistent with the potential utility of this gene as an anticancer target, including in astrocytomas, the most common brain tumor in adults. Nevertheless the pathway of MELK in tumorigenesis is not well known yet.

Purpose: This study aim to analyze genes and proteins involved in the MELK pathway in the tumorigenesis of gliomas, enabling the discovery of new therapeutic targets.

Material and Methods: Analysis of the expression profile of a panel of protein relevant to the process of tumorigenesis that MELK is involved was performed by Proteomic analysis by two dimensional electrophoresis and mass spectrometry for human glioma cell line U87MG transfected with siRNA for the MELK compared to U87MG transfected with non-target control (NTC) cells. Analysis and validation of gene expression was performed by Quantitative real time PCR (qRT-PCR) using SYBR Green method in a series of 154 astrocytomas of different malignant grade (23 AGI, 26 AGII, 18 AGIII and 87 GBM) relative to 22 non neoplastic (NN) brain samples.

Results: Differentially expressed proteins in U87MG cell line transfected with siRNA for the MELK compared to NTC control cells were identified by proteomic analysis. One of the proteins with lower expression when MELK was silenced was Stathmin (STMN1). The analysis in astrocytoma samples showed lower significant STMN1 relative expression of astrocytoma samples when compared to NN. Spearman correlation for gene expression levels of MELK and STMN1 for GBM samples were statistically significant (r=0.66, p<0.003). We found significant differences of median survival times of two GBM groups: 39 with hypoexpression of both STMN1 and MELK (8 months), versus 9 with hypoexpression of STMN1 and hiperexpression of MELK (5 months), log rank=0.016.

Conclusions: STMN1 plays a role in regulation of the cell cycle and is defined as an oncoprotein. Thus, our results showed that STMN1 is involved in the MELK pathway suggesting that this protein plays an important role in glioma tumorigenesis.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B134.

Citation Format: Miyuki Uno, Sueli Mieko Oba-Shinjo, Roseli Silva, Marcela Gimenez, Gisele Reis, Jose C. Rosa, Suely K. N. Marie. Stathmin is involved in the maternal embryonic leucine zipper kinase pathway in human astrocytomas. [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 B134.