bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3799: The PAK4 allosteric modulator (KPT-9274) attenuates the growth of renal cell carcinoma
Authors: Weiss Robert H. , Abu Aboud Omran , Baloglu Erkan , Senapedis William , Shacham Sharon
Published: July 2016

Renal cell carcinoma (RCC) is an increasingly prevalent cancer type that is frequently asymptomatic on presentation and is associated with poor responses and resistance even to the current targeted therapies. Thus, novel therapeutic approaches to treat this disease are urgently needed. P21-activated kinase 4 (PAK4) is a mediator of filopodia formation and stabilizes β-catenin transcriptional activity, both of which are integral to nephrogenesis and cancer. We hypothesized that inhibitors of the PAK4 signaling pathway would result in salutary effects on RCC. To test this, we evaluated the in vitro response of several human RCC cells and normal kidney proximal epithelial cells (NHKs) to the specific PAK4 Allosteric Modulators (PAMs; KPT-8752 and KPT-9274). 786-O (VHL-mutant RCC) and caki-1 (VHL-wt RCC) cells showed decreases in cell viability (MTT), induction of apoptosis and arrest in G2/M phase when incubated with these inhibitors. These responses were diminished in NHK cells which served as a “normal” control cell line. Target and specific pathway proteins (phospho-PAK4, Phospho-β-catenin, c-Myc and cyclin D1) were reduced after RCC, but not NHK, were incubated with KPT-8752 and KPT-9274. To confirm specificity of the inhibitor to PAK4, all these responses were reproduced in RCC cells using specific PAK4 siRNA. Since ∼85% of RCC cases are associated with mutation in vhl we used 786-0 xenograft mouse model to evaluate the clinical candidate KPT-9274. KPT-9274 was orally administered at 100 and 200 mg/kg BIDX5 for 4 weeks, resulting in clear attenuation of tumor growth at both doses. There was no obvious change in the health or weight of any of the animals when compared to vehicle group suggesting manageable tolerability. We are currently evaluating combination therapy and plan to test this inhibitor on a metastatic RCC model. In summary, PAK4 inhibitors show considerable promise as novel treatments of RCC as a single agent and warrants further investigation.

Citation Format: Robert H. Weiss, Omran Abu Aboud, Erkan Baloglu, William Senapedis, Sharon Shacham. The PAK4 allosteric modulator (KPT-9274) attenuates the growth of renal cell carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3799.
Abstract 3809: Protein arginine methyltransferase 1 (PRMT1) is a candidate therapeutic target for breast cancers
Authors: Silvestre David , Brisson Amélie , Marty-Prouvost Bérengère , Ye Mengliang , Bonsang Hélène , Maire Virginie , Loew Damarys , Gentien David , Meseure Didier , Reyal Fabien , Tucker Gordon C. , Roman-Roman Sergio , Dubois Thierry
Published: July 2016

Triple-negative breast cancer (TNBC) represents a subgroup of breast cancers associated with the most aggressive clinical behavior. No targeted therapy is currently available for the treatment of patients with TNBC. In the present study, we found that Protein Arginine Methyltransferase 1 (PRMT1) is overexpressed in TNBC at the mRNA level. At the protein level, PRMT1 is overexpressed in all breast cancer subtypes compared to normal breast tissues. The depletion of PRMT1 using siRNA in breast cancer cell lines triggered apoptosis, reduced cell viability and the ability to form colonies in an anchorage-independent manner. Treatment with a PRMT1 inhibitor blocked proliferation specifically in breast cancer cells, with no effect in normal breast cells. Importantly, the expression of PRMT1 is an indicator of prognosis and response to treatment specifically in TNBC patients. To address the cellular pathways regulated by PRMT1, we identified its protein partners by mass spectrometry and the transcriptomic changes following its depletion in TNBC cell lines. Interestingly, we found that PRMT1 directly activates key oncogenic pathways. Furthermore, we found a synergistic interaction between PRMT1 inhibitors and inhibitors for some of those pathways. We show that PRMT1 activity is necessary for breast cancer cell survival and oncogenic pathway activation. Altogether, our results point out PRMT1 as an emerging target for the treatment of breast cancers.

Citation Format: David Silvestre, Amélie Brisson, Bérengère Marty-Prouvost, Mengliang Ye, Hélène Bonsang, Virginie Maire, Damarys Loew, David Gentien, Didier Meseure, Fabien Reyal, Gordon C. Tucker, Sergio Roman-Roman, Thierry Dubois. Protein arginine methyltransferase 1 (PRMT1) is a candidate therapeutic target for breast cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3809.
Abstract 3814: Synthetic lethal approaches targeting E-cadherin-deficient cancers
Authors: Chen Augustine , Telford Bryony J. , Single Andrew , Beetham Henry , Simpson Kaylene J. , Guilford Parry
Published: July 2016

E-cadherin is a cellular adhesion protein that is frequently mutated in lobular breast cancer and diffuse gastric cancer. The E-cadherin protein which is encoded by the CDH1 gene has key roles in establishing and maintaining cell polarity and differentiation, the organization of cell migration and architecture and the mediation of signaling through various proliferation and survival pathways. E-cadherin also has a tumor suppressor role and its loss in cancer cells would preclude drug targeting by conventional therapy. To circumvent this, we have taken a synthetic lethal approach to exploit any vulnerability created by the loss of E-cadherin. In the therapeutic setting, synthetic lethality refers to a combination of a mutated gene and a drug targeted at a second gene or protein causing cell death (specifically in cancer cells). To identify the vulnerabilities created by E-cadherin loss, we performed a genome-wide siRNA knockdown screen in isogenic MCF10A cell lines with and without E-cadherin expression. From the functional screen, we identified broad classes of G-protein-coupled receptor (GPCR) signaling proteins and families of cytoskeletal proteins which were highly enriched among the synthetic lethal candidates. Indeed, we identified drug classes with linkages to several of the GPCR and cytoskeletal targets that showed evidence of E-cadherin synthetic lethality when we performed a 4,057 known drug screen. These included certain PI3K inhibitors (PI-103), anti-glucocorticoid (mifepristone), tyrosine kinase inhibitor (saracatinib) and multiple histone deacetylase inhibitors (vorinostat and entinostat). Interestingly, the combination of saracatinib and mifepristone gave a synergistic effect (combination index < 1.0) in targeting E-cadherin-deficient MCF10A cells. These results demonstrate that E-cadherin loss creates druggable vulnerabilities that have the potential to improve the management of both of sporadic and familial lobular breast cancer and diffuse gastric cancer.

Citation Format: Augustine Chen, Bryony J. Telford, Andrew Single, Henry Beetham, Kaylene J. Simpson, Parry Guilford. Synthetic lethal approaches targeting E-cadherin-deficient cancers. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3814.
Abstract 3824: Targeting MUC1-C oncoprotein inhibits AKT-S6K1-elF4A pathway regulated TIGAR translation in colorectal cancer
Authors: Ahmad Rehan , Alam Maroof , Al-Obaid Omar , Hasegawa Masanori , Kufe Donald
Published: July 2016

Colorectal cancer is third most common malignancy and is the second most common cause of cancer-related death. The MUC1 multi-domain oncoprotein is aberrantly overexpressed in colorectal cancer and has been linked to poor outcomes in this disease. However, it is not known if MUC1 is of functional significance to colorectal tumors. Here, we investigate the effects of the MUC1-C inhibitor (GO-203), which disrupts MUC1-C homo-oligomerization, on AKT-mTORC-S6K translation pathway in human colorectal cancer cells. The present study demonstrates that GO-203 treatment was associated with inhibition of AKT-S6K1 signaling in colorectal cancer cells. Targeting MUC1-C with GO-203 downregulates TP53-inducible glycolysis and apoptosis regulator (TIGAR) protein. We show that GO-203-induced suppression of TIGAR is mediated by inhibition of AKT and the downstream mTOR pathway. The results also demonstrate that targeting MUC1-C blocks eIF4A cap-dependent translation of TIGAR. TIGAR promotes the shunting of glycolytic intermediates into the pentose phosphate pathway and thus is of importance for maintaining redox balance. In concert with these results, GO-203-induced suppression of TIGAR was associated with decreases glutathione levels. GO-203 treatment also resulted increases in reactive oxygen species (ROS) and loss of mitochondrial transmembrane potential. Consistent with these results, GO-203 inhibited the growth of colon cancer cells in vitro and xenografts in nude mice. These findings thus indicate that MUC1-C is a potential target for the treatment of colorectal cancer.

Citation Format: Rehan Ahmad, Maroof Alam, Omar Al-Obaid, Masanori Hasegawa, Donald Kufe. Targeting MUC1-C oncoprotein inhibits AKT-S6K1-elF4A pathway regulated TIGAR translation in colorectal cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3824.
Abstract 3825: Disrupting p-STAT3-mediated VEGF-A paracrine and autocrine feed-forward loops by targeting SHP-1 suppresses triple negative breast cancer cell metastasis
Authors: Su Jung-Chen , Chiu Hao-Chieh , Liu Chun-Yu , Chen Kuen-Feng , Shiau Chung-Wai
Published: July 2016

Patients with metastatic triple-negative breast cancer (TNBC) relapse quickly, representing an unmet need for effective therapy. Regorafenib is a multi-receptor tyrosine kinase (RTK) inhibitor targeting tumor angiogenesis, oncogenesis and the tumor microenvironment and has been approved for metastatic colorectal cancer and advanced gastrointestinal stromal tumor. Recent studies suggest regorafenib also acts as a SHP-1 phosphatase agonist. Here, we investigated the potential of regorafenib to suppress metastasis of TNBC cells by mitigating autocrine and paracrine feed-forward loops of p-STAT3-mediated VEGF-A signaling through targeting the SHP-1/p-STAT3/VEGF axis. We found a significant correlation between cancer cell migration and SHP-1/p-STAT3/VEGF-A expression in a panel of human TNBC cells. Clinically VEGF-A expression is associated with disease-free and distant metastasis-free survival, independent of tumor stage. Regorafenib induced significant anti-migratory effects, in association with downregulation of p-STAT3 and VEGF-A. Overexpression and knockdown experiments validated the indispensable roles of SHP-1, p-STAT3 and VEGF-A in regorafenib-induced anti-migration. To exclude the role of RTK inhibition in regorafenib-induced inhibition of migration, we synthesized a regorafenib derivative, SC-78, that had minimal effect on VEGFR2 and PDGFR kinase inhibition, while having more potent effects on SHP-1/p-STAT3/VEGF-A signaling. SC-78 demonstrated superior in vitro anti-migration to regorafenib. Furthermore, VEGF-A dependent autocrine/paracrine loops were disrupted by regorafenib and SC-78. SC-78 revealed more potent in vivo efficacy than regorafenib in both xenograft and orthotopic models, as well as in a tail vein metastatic model. This study implies that the more potent SC-78 may be a promising lead for suppressing metastasis of TNBC, and the SHP-1/p-STAT3/VEGF axis is a potential therapeutic target for metastatic TNBC.

Citation Format: Jung-Chen Su, Hao-Chieh Chiu, Chun-Yu Liu, Kuen-Feng Chen, Chung-Wai Shiau. Disrupting p-STAT3-mediated VEGF-A paracrine and autocrine feed-forward loops by targeting SHP-1 suppresses triple negative breast cancer cell metastasis. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3825.
Abstract 3827: Preclinical characterization of DCR-BCAT as a component of combination therapy
Authors: Ganesh Shanthi , Cyr Wendy , Koser Martin , Chopda Girish , Chipumuro Edmond , Siddiquee Zakir , Craig Kevin , Shui Serena , Chen Dongyu , Lai Cheng , Dudek Hank , Wang Weimin , Brown Bob , Abrams Marc
Published: July 2016

Dicer-substrate siRNAs (DsiRNAs) are a potent class of RNA interference (RNAi) triggers capable of silencing any expressed mRNA with high specificity. DCR-MYC, a first-in-class DsiRNA targeting the MYC oncogene is currently in Phase 1b/II clinical trials [ASCO 2015, abstract 11006]. DCR-BCAT is an advanced preclinical development candidate that targets CTNNB1, the gene which encodes β-catenin. The β-catenin/Wnt pathway is consistently activated in human tumors, including >50% of hepatocellular carcinomas (HCC) and >80% of colorectal cancers (CRC). Robust preclinical and genetic evidence strongly suggests that inhibiting β-catenin function would yield broad therapeutic benefit in oncology, but efforts to target it using conventional drug modalities have been unsuccessful to-date. We have previously reported extensive preclinical pharmacology for DCR-BCAT in mouse tumor models of diverse origin. Here, we explore DCR-BCAT as a monotherapy and in combination with both standard-of-care and experimental therapeutics. Interestingly, when mice bearing HCC tumors were treated with a combination of CTNNB1 and MYC DsiRNAs, the antitumor efficacy was additive or synergistic relative to either single agent alone. Additionally, since up to 50% of colorectal tumors have both activated Wnt signaling and mutant KRAS, we also explored combination therapy of DCR-BCAT and FDA-approved MEK inhibitors. A major advantage of DCR-BCAT is that the improved nanoparticle formulation is more selective for siRNA delivery to tumors over liver and other normal tissues. These data support continued development of DCR-BCAT as a first-in-class RNAi therapeutic, and highlight the potential for use in combination with other promising agents.

Citation Format: Shanthi Ganesh, Wendy Cyr, Martin Koser, Girish Chopda, Edmond Chipumuro, Zakir Siddiquee, Kevin Craig, Serena Shui, Dongyu Chen, Cheng Lai, Hank Dudek, Weimin Wang, Bob Brown, Marc Abrams. Preclinical characterization of DCR-BCAT as a component of combination therapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3827.
Abstract 3835: An anti-MET IgG2 monoclonal antibody degrades both wild-type and exon 14 mutant MET receptor tyrosine kinase through a novel exon 14-independent mechanism and inhibits tumor growth
Authors: Robinson Brett S. , Mandiyan Sreekala , McMahon Gerald , Yang Yan
Published: July 2016

MET gene amplification and exon 14 mutations have been reported and implicated as oncogenic drivers in several types of cancer representing approximately 5-7% of NSCLC, 4-10% of gastric cancer, and 5-10% of colon cancers. Preclinical research and clinical data derived from patients with tumors containing MET gene amplification and exon 14 mutations showed significant growth inhibition and meaningful clinical benefit after treatment with MET-targeting tyrosine kinase inhibitors (TKIs), supporting the hypothesis that MET gene amplification and exon 14 mutations are actionable biomarkers. We have identified several anti-MET monoclonal antibodies that block MET-dependent signaling and tumor growth through: (1) binding to the Sema/PSI domain, (2) preventing HGF interaction with MET and (3) inducing receptor ubiqutination and degradation. One of the anti-MET antibodies, KTN0073, induces potent degradation of oncogenic exon 14 mutant MET, which has been reported to propagate prolonged MET signaling due to a defect in receptor degradation. Our data suggest that KTN0073 engages a pathway different from HGF-induced receptor degradation and protease-mediated shedding, which is independent of the 47 amino acids that are encoded by exon 14 in the intracellular juxtamembrane region and only partially inhibited by the TKI crizotinib. In summary, we report the use of an anti-MET monoclonal antibody to elucidate an exon 14-independent mechanism of MET degradation that could provide a novel way to design anti-MET therapeutics to inhibit growth of human tumors that are driven by HGF, MET amplification and exon 14 mutations. Based on this work, KTN0073-IgG2 anti-MET antibody has been humanized for further preclinical development to explore its potential as a therapeutic for the treatment of human MET expressing cancers.

Citation Format: Brett S. Robinson, Sreekala Mandiyan, Gerald McMahon, Yan Yang. An anti-MET IgG2 monoclonal antibody degrades both wild-type and exon 14 mutant MET receptor tyrosine kinase through a novel exon 14-independent mechanism and inhibits tumor growth. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3835.
Abstract 3842: Design and engineering of TRAIL fusion proteins for cancer therapy
Authors: Tam Eric M. , Hudson Hannah , Dake Tamara , Ghassemifar Sara , Raue Andreas , Hashambhoy-Ramsay Yasmin , Sazinsky Stephen L. , Daruwalla Anahita , Kohli Neeraj , Xu Lihui , Mc Donagh Charlotte F. , Schoeberl Birgit , Chai Diana H.
Published: July 2016

Protein-based agonists of apoptotic death receptors have shown remarkable preclinical efficacy but limited clinical response. The short circulating half-life of recombinant human TRAIL and the necessity of Fc-mediated clustering for potentiating agonistic antibodies against DR4 and DR5 have been proposed to be major impediments to the clinical success of this class. To address these limitations we have created Fc-scTRAIL, a single fusion polypeptide consisting of an IgG1 Fc region followed by three successive TRAIL monomers connected by two fifteen-amino acid linkers. While Fc-scTRAIL showed potent activity in vitro, we observed a low TM (48 °C) and rapid inactivation in serum indicating protein instability. Subsequently, we applied a directed evolution approach using yeast surface display to identify mutations that would stabilize the TRAIL trimer. When individual mutations were transferred to the Fc-scTRAIL format, we observed a dramatic increase in the TM (66-70 °C) while the combination of three mutations improved serum stability by ten-fold. Stabilized Fc-scTRAIL shows greater pro-apoptotic activity across a panel of cancer cell lines when compared to mapatumumab (anti-DR4) and drozitumab (anti-DR5), or the combination of antibodies even in the presence of anti-Fc cross-linking. Moreover, anti-Fc did not improve Fc-scTRAIL activity suggesting that the hexavalent design of the molecule maximizes death receptor activation. Currently, in vivo evaluation of Fc-scTRAIL for pharmacokinetic properties and activity is underway. We believe this format, when combined with an appropriate patient selection strategy, will result in improved clinical outcomes.

Citation Format: Eric M. Tam, Hannah Hudson, Tamara Dake, Sara Ghassemifar, Andreas Raue, Yasmin Hashambhoy-Ramsay, Stephen L. Sazinsky, Anahita Daruwalla, Neeraj Kohli, Lihui Xu, Charlotte F. Mc Donagh, Birgit Schoeberl, Diana H. Chai. Design and engineering of TRAIL fusion proteins for cancer therapy. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3842.
Abstract 3845: A novel selectivity determinant informs the development of next-generation stapled peptide inhibitors of anti-apoptotic BFL-1/A1
Authors: Huhn Annissa J. , Guerra Rachel M. , Bird Gregory H. , Walensky Loren D.
Published: July 2016

The development of selective inhibitors for the individual anti-apoptotic BCL-2 family proteins implicated in oncogenesis and chemoresistance remains a formidable but pressing challenge. Precisely tailored compounds would serve as ideal molecular probes and targeted therapies to respectively study and treat human cancers driven by discrete apoptotic blockades. The remarkable potential of this strategy is exemplified by ABT-199, a potent and selective small molecule BCL-2 inhibitor that is proving effective at reactivating apoptosis in BCL-2-dependent cancers. The BCL-2 protein homologue, BFL-1/A1, has emerged as a resistance factor in a series of human cancers, including melanoma, leukemia, and lymphoma, but remains undrugged. To identify binding and specificity determinants for targeting BFL-1/A1, we screened a library of hydrocarbon-stapled BH3 domain helices and identified a subclass of compounds that engage BFL-1/A1 with exquisite selectivity in vitro and in situ. The mechanistic basis for this specificity revealed a unique topographic feature of the BFL-1/A1 binding groove. Leveraging this natural BFL-1/A1 selectivity factor, we designed next-generation stapled peptide inhibitors that block BFL-1/A1's capacity to both bind BH3 domains and suppress BAX-mediated membrane poration. Our studies inform a new pharmacologic strategy for potent and selective inhibition of anti-apoptotic BFL-1/A1 in human cancer.

Citation Format: Annissa J. Huhn, Rachel M. Guerra, Gregory H. Bird, Loren D. Walensky. A novel selectivity determinant informs the development of next-generation stapled peptide inhibitors of anti-apoptotic BFL-1/A1. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3845.
Abstract 3856: The atomic basis for paclitaxel sensitization following loss of CRMP2 phosphorylation in ovarian cancer cells
Authors: Zheng Yiyan , Sethi Ritika , von Delft Frank , Ahmed Ahmed Ashour
Published: July 2016

The chemotherapeutic agent paclitaxel increases cancer cell microtubule stability, induces mitotic arrest and cancer cell death and improves survival of cancer patients. However, in ovarian and other cancers, it only elicits a response in less than half of patients who receive it. We have previously shown that enhancing microtubule stability in cells prior to paclitaxel treatment, further increases paclitaxel-induced microtubule stability and cancer cell death (Ahmed et al., Cancer Cell, 2007;12:514 and Ahmed et al., Cancer Research 2011;71:5806). We now report that the microtubule-associated protein CRMP2, and FER kinase are expressed in almost half of high-grade serous ovarian cancers and that inhibiting the phosphorylation of CRMP2 by FER is sufficient for enhancing paclitaxel-induced microtubule stability and cytotoxicity in multiple ovarian cancer cell lines.

We are also able propose a detailed mechanism underlying these observations. A combination of biochemistry, super-resolution fluorescence microscopy, total internal reflection fluorescence (TIRF) microscopy and electron microscopy reveals that CRMP2 induces microtubule nucleation, elongation, bundling and stability. Moreover, FER phosphorylates CRMP2 at 6 tyrosine residues, two of which (Tyr479 and Tyr499) are critical for modulating CRMP2 function; this agrees with site-directed mutagenesis in cancer cells which points to Tyr479 as a critical site for association between CRMP2 and microtubules. A comparison of the crystal structures of wild-type CRMP2 and Tyr479Glu/Tyr499Glu phosphomimetic mutants indicate that phosphorylation of these sites induces significant conformational changes that prevent CRMP2 from forming tetramers that are known to be critical for its microtubule bundling activity.

This then leads us to propose a molecular model of how CRMP2 associates with microtubules, explaining how targeting CRMP2 phosphorylation can be exploited for enhancing the therapeutic efficacy of paclitaxel.

Citation Format: Yiyan Zheng, Ritika Sethi, Frank von Delft, Ahmed Ashour Ahmed. The atomic basis for paclitaxel sensitization following loss of CRMP2 phosphorylation in ovarian cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3856.
Abstract 3864: The Jak1/2 inhibitor AZD1480 suppresses tumor growth and metastasis in genetically engineered mouse models of PTEN-deficient prostate cancer
Authors: De Velasco Marco A. , Kura Yurie , Ando Naomi , Fukushima Emiko , Hatanaka Yuji , Oki Takashi , Yoshimura Kazuhiro , Nozawa Masahiro , Davies Barry R. , Huszdar Dennis , Yoshikawa Kazuhiro , Nishio Kazuto , Uemura Hirotsugu
Published: July 2016

Activation of signal transducer and activator of transcription (STAT) 3 via the interleukin 6 (IL-6)/IL-6R/Janus kinase (JAK) signaling axis is a feature common in patients with advanced human prostate cancer and has been associated with poor prognosis. STAT3 can promote CRPC growth by activating the androgen receptor signaling pathway. It can also promote survival by modulating tumor cell proliferation, epithelial to mesenchymal transition, angiogenesis and immune response. However, recent preclinical data suggests that STAT3 may also act as a tumor suppressor in PTEN-deficient prostate cancer. In this study, we investigated the effectiveness of AZD1480, a potent JAK1/2 inhibitor, in genetically engineered mouse models of prostate cancer driven by the loss of PTEN and PTEN/P53. In vivo pharmacodynamic studies using conditional PTEN-deficient mice demonstrated that AZD1480 strongly inhibited STAT3 phosphorylation. Moreover, AZD1480 monotherapy in PTEN-deficient mice harboring castration-naïve or castration-resistant prostate tumors resulted in tumor growth reductions of 24.8%, P<0.001 and 15.8%, P<0.001, respectively, compared to vehicle treated control mice. Mice treated with AZD1480 also exhibited reduced levels of tumor cell proliferation and microvessel density, and increased apoptosis compared to controls. Clinically relevant outcomes were evaluated in a late-stage model of prostate cancer driven by the conditional inactivation of PTEN and P53. In this model, PTEN/P53 double knockout mice with established tumors were randomized to vehicle or AZD1480 treatment groups. Mice treated with AZD1480 demonstrated a modest but statistically significant improvement in overall survival compared to control mice, median time 20 days vs. 27 days, P = 0.03, respectively. Additionally, the metastatic tumor incidence decreased from 46.6% (7/15) in control mice to 20% (3/15) in AZD1480-treated mice. Our findings provide preclinical evidence supporting the potential use of Jak1/2 inhibitors for the targeted therapy of human prostate cancer.

Citation Format: Marco A. De Velasco, Yurie Kura, Naomi Ando, Emiko Fukushima, Yuji Hatanaka, Takashi Oki, Kazuhiro Yoshimura, Masahiro Nozawa, Barry R. Davies, Dennis Huszdar, Kazuhiro Yoshikawa, Kazuto Nishio, Hirotsugu Uemura. The Jak1/2 inhibitor AZD1480 suppresses tumor growth and metastasis in genetically engineered mouse models of PTEN-deficient prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3864.
Abstract 3897: A novel c-Met targeting antibody drug conjugate for NSCLC
Authors: Li Lingna , Fells Cathrine , Guo Julia , Muyot Pia , Gros Edwige , Zhang Yanliang , Sun Yingqing , Zhang Hong , Fu Yanwen , Zhu Tong , Cao Jian , Kaufmann Gunnar , Chen Gang , Miao Zhenwei
Published: July 2016

c-Met, the proto-oncogene transmembrane receptor tyrosine kinase, is involved in cell proliferation, survival, motility, and invasion in normal and tumor cells. It is widely expressed and associated with poor prognosis in breast, lung, liver, kidney and brain cancers. Hepatocyte growth factor (HGF) is the only known ligand of c-Met, also found in many tumors and cancers where activity is driven by the c-Met receptor. c-Met is accepted as an attractive anti-cancer target, but the development of cancer therapy targeting c-Met receptor or kinase remain very challenging. Clinical development of c-Met/HGF targeting antibodies has shown initial evidence of clinical efficacy but failed in phase III. Small molecule inhibitors often suffer from selectivity issues. Antibody drug conjugates (ADCs) which combine an antibody with highly potent cytotoxic agents, becomes an attractive approach against c-Met overexpressing cancers such NSCLC. We have identified an anti-c-Met antibody STI-0602 and generated ADCs from a panel of cytotoxic agents such as microtubulin inhibitor and DNA damaging agents. ADCs retained the binding to c-Met receptor and showed potent cell killing in a variety of c-Met-positive cell lines. ADCs also showed in vivo efficacy in a panel of c-Met-positive human NSCLC xenograft models like A549, H292, EBC-1, HCC827 and H1993, which suggest a potential therapy for c-Met overexpressing lung cancer and other cancers.

Citation Format: Lingna Li, Cathrine Fells, Julia Guo, Pia Muyot, Edwige Gros, Yanliang Zhang, Yingqing Sun, Hong Zhang, Yanwen Fu, Tong Zhu, Jian Cao, Gunnar Kaufmann, Gang Chen, Zhenwei Miao. A novel c-Met targeting antibody drug conjugate for NSCLC. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3897.
Abstract 3904: Overcoming resistance to HER2 inhibitors through cell based screening
Authors: Novotny Chris J. , Pollari Sirkku , Park Jin H. , Lemmon Mark A. , Schultz Peter G. , Shen Weijun , Shokat Kevan M.
Published: July 2016

Signaling from the human epidermal growth factor receptor (HER) family of proteins is dependent on a well-orchestrated series of interactions between family members to form either homo- or heterodimers. The heterodimeric complex formed by HER2 and HER3 is a particularly potent oncogenic signaling unit that can act as a driver of cancer growth and has also been shown to rescue a large number of cancers from a variety of targeted agents. The currently available therapies targeting HER2, such as Lapatinib or ado-trastuzumab emtansine, have dramatically improved patient outcomes in the clinic but preferentially target the protein in its monomeric state. Because of this, increasing the concentration of the HER2/HER3 heterodimer, either by growth factors or increasing the concentrations of HER2 and HER3 at the membrane, significantly diminishes their activity. In order to find a next generation inhibitor of the active HER2/HER3 oncogenic complex we screened 1 million small molecules against an engineered Ba/F3 cell line dependent on ligand stimulated HER2/HER3 signaling for survival. The removal of non-selective inhibitors using alternative Ba/F3 cell lines resulted in the identification of a single core scaffold hit. A medicinal chemistry campaign enabled by a co-crystal structure of a hit compound complexed to EGFR led to the development of a molecule capable of inhibiting the active state of HER2. As a result, this next generation HER2 inhibitor is capable of inhibiting growth factor stimulated HER2/HER3 heterodimers and mutationally activated forms of HER2, which are resistant to current clinical small molecule HER2 inhibitors.

Citation Format: Chris J. Novotny, Sirkku Pollari, Jin H. Park, Mark A. Lemmon, Peter G. Schultz, Weijun Shen, Kevan M. Shokat. Overcoming resistance to HER2 inhibitors through cell based screening. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3904.
Abstract 3916: A “moneyball” approach to predicting clinical trial toxicity events
Authors: Gayvert Kaitlyn , Madukhar Neel , Elemento Olivier
Published: July 2016

Over the past decade, significant strides have been made in the management and treatment of various diseases. Despite this progress, clinical attrition rates have continued to substantially rise. Clinical trials can fail for a variety of reasons, ranging from design issues to drug efficacy and safety problems. Drug-likeness approaches, as first proposed by Lipinski almost two decades ago, have become a key tool for the pre-selection of compounds that are likely to have manageable toxicity in clinical studies. However all these methods consider molecular properties of the drug itself alone. In general, these approaches struggle to simultaneously well-characterize the properties of both FDA approved drugs (which we term the sensitivity) and drugs that fail clinical trials (specificity).

We introduce an approach that integrates chemical properties of a compound, along with that of its targets, to provide a new quantitative measure that helps predict whether drugs in clinical trials will fail for toxicity reasons. When trained on failed clinical trials and FDA approved drugs, this method performs at a high accuracy, specificity and sensitivity (∼0.75), as well as high area under the ROC curve (>0.80). In comparison, none of the drug-likeness approaches were able to successfully maintain both high sensitivity and specificity. A feature analysis of the model indicates that it is critical to consider both structural properties and properties of the drug target, with the target's network connectivity and liver toxicity as two important features. The approach was further evaluated by testing the predictions of the trained model on an established independent dataset. We found that our method was able to significantly distinguish a representative set of bioavailable drugs from a representative set of toxic drugs (D = 0.2133, p<2.2e-16, Kolmogorov-Smirnov test). Additionally, we found that the measure is strongly correlated with severe toxicity events, such as pleural effusion (ρ = −0.9792) and neutropenia (ρ = −0.9613). Altogether, our method provides a novel, broadly applicable strategy that is able to identify drugs likely to possess manageable toxicity in clinical trials.

Citation Format: Kaitlyn Gayvert, Neel Madukhar, Olivier Elemento. A “moneyball” approach to predicting clinical trial toxicity events. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3916.
Abstract 3921: A screen of breast and colon cancers with HER2 antibody clone UMAB36 does not exhibit the cross-reactivity of clone 4B5 with HER4 protein
Authors: Zhou Lixin , Yuan Kehu , Ren Fangfang , Ki Lili , Zhou Min , Fu Wei , Huang Xiaozheng , Gonzalez Rachel M. , Shu Youmin , Shen Yi , Wang Guangli , Ma Donghui , He Wei-Wu , Chen Jian
Published: July 2016

Increased sensitivity and specificity of immunohistochemical (IHC) detection of HER2 expression is crucial as the role of Trastuzumab have expanded in the treatment of HER2 positive non-breast cancer patients such as gastric cancer patients. Non-specific nuclear and cytoplasmic staining of the HER2 antibody clone 4B5 has been reported by other labs. In this study, we evaluated the specificity of HER2 clone 4B5 and a new HER2 antibody clone UMAB36 using a suite of methods including protein lysate arrays, western blots, FISH and IHC correlation screens on 129 breast and 158 colon cancer cases for HER2 expression. The protein lysate array and western results revealed that clone 4B5 recognizes three proteins: HER2, HER4, and ZSCAN18, a nuclear transcription protein. In comparison, clone UMAB36 recognized only HER2 protein in the same protein lysate array and western screen as clone 4B5. False negative results, based on correlation of IHC with FISH HER2 positives, were generated using clone 4B5 in 1 breast and 5 gastric of the total 287 cancer cases screened. Comparatively, no false negative results were observed using clone UMAB36 in which there was a 100% correlation between IHC and FISH screen. In this study, areas of normal gastric tissue often stained positive by HER2 clone 4B5, so we performed further analysis of 470 normal gastric cases using Ventana's BenchMark instrument. The results show that 278 normal gastric cases had positive stain with clone 4B5 compared to 3 cases with clone UMAB36. The high background by clone 4B5 may be due HER4 being upregulated in adjacent normal gastric tissue. Our results indicate clone UMAB36 has higher specificity and sensitivity than clone 4B5 in screening gastric tumors.

Citation Format: Lixin Zhou, Kehu Yuan, Fangfang Ren, Lili Ki, Min Zhou, Wei Fu, Xiaozheng Huang, Rachel M. Gonzalez, Youmin Shu, Yi Shen, Guangli Wang, Donghui Ma, Wei-Wu He, Jian Chen. A screen of breast and colon cancers with HER2 antibody clone UMAB36 does not exhibit the cross-reactivity of clone 4B5 with HER4 protein. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3921.
Abstract 3924: AIRE is expressed and associated with good prognosis in breast cancer
Authors: Bianchi Francesca , De Cecco Loris , Triulzi Tiziana , Romero-Cordoba Sandra , Sommariva Michele , Storti Chiara , Aiello Piera , Tagliabue Elda , Balsari Andrea , Sfondrini Lucia
Published: July 2016

The transcription factor Autoimmune Regulator (AIRE) gene plays a fundamental role in tolerance process by promoting the ectopic expression of thousands of genes encoding for tissue-specific antigens (TSAs) in medullary thymic epithelial cells (mTECs). Beside the high expression of AIRE in mTECs, there are few evidences of AIRE expression in other lymphoid organs and very recently, AIRE was described to be expressed in human and mouse keratinocytes and in tumors originating in stratified and pseudostratified epithelia. Therefore, we evaluated the hypothesis that AIRE could be expressed by epithelial tumors and we focused on breast cancer, for which large public datasets are available.

Our analysis on the TCGA, the largest public breast cancer RNA-seq dataset, revealed that AIRE is expressed in 33% of the cases, and Aire protein expression was confirmed in 26% of 115 human primary breast cancer specimens by immunohistochemistry analysis. AIRE expression was revealed associated to a better relapse-free survival in the TCGA patients and also in two public gene expression microarray-based dataset developed on Agilent and Illumina platform (NKI-295 and KM-plotter). In all the datasets analyzed, AIRE expression resulted an independent strong prognostic factor for relapse-free survival, particularly in ER-positive tumors. Ingenuity Pathway Analysis (IPA) showed that AIRE-expressing tumors were enriched in translation-related pathways, accordingly with AIRE's described function in mTECs. Moreover, in breast cancer luminal cell lines MCF-7 and MDA-MB-361 transfected with AIRE-expressing vector, a significant increase of cell in G1 phase and activation of caspases cascade were observed, supporting the hypothesis that genotoxic stress, induced by AIRE-mediated proteins over-translation, leads to cycle arrest and apoptosis.

These data highlight for the first time AIRE expression in breast cancer and an association with a better prognosis was revealed. Imbalance of cellular homeostasis, caused by AIRE transcriptional function, is a new unusual mechanisms to trigger apoptosis in breast cancer cells.

Citation Format: Francesca Bianchi, Loris De Cecco, Tiziana Triulzi, Sandra Romero-Cordoba, Michele Sommariva, Chiara Storti, Piera Aiello, Elda Tagliabue, Andrea Balsari, Lucia Sfondrini. AIRE is expressed and associated with good prognosis in breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3924.
Abstract 3937: Nestin expression is associated with a basal-like phenotype and poor prognosis in breast cancer
Authors: Krüger Kristi , Wik Elisabeth , Klingen Tor Audun , Chen Ying , Aas Turid , Akslen Lars A.
Published: July 2016

Background:

Nestin, neuroepitheilal stem cell protein, is an intermediate filament protein first described in neural stem or progenitor cells, and its expression has been seen in several tissues, including different types of cancer.

In breast cancer, Nestin expression has been linked to the triple negative and basal-like phenotypes. We here evaluated Nestin and its association with clinico-pathologic markers and survival in two prospective Norwegian breast cancer cohorts.

Materials and methods:

Series I includes 546 women (50-69 years) diagnosed with primary invasive breast cancer (403 screen-detected and 143 interval cancers) as part of the prospective and population-based Norwegian Breast Cancer Screening Program (NBCSP) during 1996-2003 (Hordaland county).

Series II includes 282 women (50-69 years) with invasive cancers (199 screen-detected and 83 interval cancers) diagnosed as part of the NBCSP during 2004-2009 (Vestfold County).

Immunohistochemical staining of Nestin was done on tissue microarrays (TMAs). Expression in tumor cells was graded by a Staining Index (SI) (values 0-9).

Results:

Nestin positivity, observed in 9% and 13% of the breast cancer cases in Series I and II, was associated with higher histological grade (OR, odds ratio 14.3 and 8.1), high tumor cell proliferation by Ki-67 (OR 11.4 and 9.1), larger tumor diameter (OR 1.8 and 2.4), but not with lymph node status or HER2 status. Further, Nestin positivity was associated with negativity for estrogen (OR 14.9 and 11.9) and progesterone receptor (8.5 and 3.4), the triple negative phenotype (OR 29.1 and 17.4) and basal-like differentiation by positivity for Cytokeratin 5 (OR 9.1 and 8.7) or P-cadherin (OR 7.0 and 8.5).

By univariate survival analysis, Nestin positivity was associated with reduced breast cancer specific (p = 0.002 and p = 0.076) and overall survival (p = 0.005 and p = 0.039). When including the standard variables tumor size, histologic grade and lymph node status in a multivariate analysis, Nestin was still significantly associated with reduced breast cancer specific survival in the largest cohort (Series I).

Conclusion:

We found that Nestin expression in breast cancer is associated with aggressive features, the triple negative phenotype, basal-like differentiation, and reduced breast cancer specific survival.

Citation Format: Kristi Krüger, Elisabeth Wik, Tor Audun Klingen, Ying Chen, Turid Aas, Lars A. Akslen. Nestin expression is associated with a basal-like phenotype and poor prognosis in breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3937.
Abstract 3947: Atypical chemokine receptor ACKR3 expression is associated with aggressive behavior and poor prognosis in gastric cancer
Authors: Kim Nayoung , Baek Seung-Woo , Ryu Hyewon , Choi Yoon Seok , Song Ik Chan , Yun Hwan Jung , Jo Deog Yeon , Kim Samyong , Lee Hyo Jin
Published: July 2016

Chemokine and their receptors are key mediators of normal physiology and a large number of pathologic conditions such as cancer, and this family of receptors is the emerging therapeutic target in the field of cancer treatment. ACKR3 is an atypical chemokine receptor first cloned from a dog cDNA library as the orphan receptor and was initially named Receptor Dog cDNA 1 (RDC1). Shortly after demonstrating that RDC1 binds with its ligand, stromal cell-derived factor-1α (SDF-1α) and interferon-inducible T-cell α chemoattractant (I-TAC), RDC1 was officially deorphanized. Accumulating evidence of recent studies have suggested that expression of ACKR3 is augmented in most of tumor cells as compared to their normal counterparts and is involved in cell proliferation, survival, migration, invasion during the initiation and progression of cancer. However, there is little information regarding their expression and clinical relevance in gastric cancer. The expression status of ACKR3 was investigated in 221 specimens of primary gastric cancer using immunohistochemistry. The correlation of ACKR3 expression with the clinicopathological features and survival outcomes was analyzed as well. Immunohistochemical staining of gastric cancer tissue sections revealed diverse cytoplasmic and membrane staining patterns for ACKR3. One hundred-fourteen cases (51.6%) showed low ACKR3 expression according to an arbitrary scoring system (grade 0-1; grade 0, n = 26; grade 1, n = 88), and one hundred-seven cases (48.4%) showed high expression (grade 2-3; grade 2, n = 58; grade 3, n = 49). There were no significant differences in age, gender, histology, tumor location, lymphatic and venous invasion among the two groups. However, high CXCR7 expression in cancer cells tended to be associated with proportion of tumor size greater than 5 cm (P = 0.055) and was significantly correlated with depth of tumor invasion (P < 0.001), lymph node metastasis (P = 0.042), and higher stage (P = 0.002). Furthermore, patients with high ACKR3 expression showed worse overall survival rate of 47% compared to 56% in patients with low ACKR3 expression. In conclusion, ACKR3 is differentially expressed in gastric cancer cells, and high expression of ACKR3 is associated with aggressive tumor behavior and poor survival in patients with gastric cancer, suggesting that ACKR3 plays an important role during gastric cancer progression.

Citation Format: Nayoung Kim, Seung-Woo Baek, Hyewon Ryu, Yoon Seok Choi, Ik Chan Song, Hwan Jung Yun, Deog Yeon Jo, Samyong Kim, Hyo Jin Lee. Atypical chemokine receptor ACKR3 expression is associated with aggressive behavior and poor prognosis in gastric cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3947.