bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 963: IDH2(R140Q) knock-in mouse recapitulating human type II D-2-hydroxyglutaric aciduria
Authors: Wang Fang , Travins Jeremy , Lin Zhizhong , Silverman Lee , Chen Yue , Lu Yuxuan , Yang Hua , Su Michael , Cang Yong , Ellwood-Yen Kate , Jin Shengfang
Published: May 2015

A single amino acid substitution, R140Q, in isocitrate dehydrogenase 2 (IDH2) confers a novel enzymatic activity that converts α-ketoglutarate (αKG) to D-2-hydroxyglutarate (D-2-HG). This gain-of-function mutation has been identified in patients with type II D-2-hydroxyglutaric aciduria (D-2-HGA), a rare and severe neurometabolic disorder that presents with a range of clinical findings, including seizures, hypotonia, developmental delay, cardiomyopathy, dysmorphic features and early death. There are no effective therapies for this inherited autosomal dominant disease. Here, we report the generation and characterization of a mouse genetic model that recapitulates key features of type II D-2-HGA. A single amino acid replacement, R140Q, was introduced via homologous recombination into the endogenous mouse IDH2 gene locus, to create heterozygous IDH2(R140Q) knock-in (KI) mice. These KI mice produce significantly elevated levels of D-2-HG in all tissues tested, and exhibit multiple defects consistent with symptoms from D-2-HGA patients, including early mortality, brain lesions, and cardiac hypertrophy. Echocardiogram reveals impaired systolic function with a diffusely hypokinetic left ventricle and low ejection fraction.

The IDH2(R140Q) knock-in mouse model provides a valuable tool to elucidate the underlying disease mechanism of D-2-HGA and to evaluate ways to mitigate the disease.

Citation Format: Fang Wang, Jeremy Travins, Zhizhong Lin, Lee Silverman, Yue Chen, Yuxuan Lu, Hua Yang, Michael Su, Yong Cang, Kate Ellwood-Yen, Shengfang Jin. IDH2(R140Q) knock-in mouse recapitulating human type II D-2-hydroxyglutaric aciduria. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 963. doi:10.1158/1538-7445.AM2014-963
Abstract 967: A novel regulator of Wnt-signaling in colorectal cancer
Authors: Betge Johannes , Voloshanenko Oksana , Erdmann Gerrit , Demir Kubilay , Ebert Matthias P. , Boutros Michael
Published: May 2015

Background: Active Wnt signaling is a hallmark of colorectal cancer (CRC). Alterations in Wnt pathway components activate the pathway and thereby initiate and drive carcinogenesis. Recent efforts have aimed at a comprehensive structural characterization of the genomes of a variety of cancer types including colorectal cancer. The function of many altered genes, however, is still elusive.

Methods: We used an integrative genomics approach, combining functional genomic data from a genome-wide RNAi screen for Wnt-regulators in colon cancer cells and structural genomic data to identify novel oncogenes in CRC that regulate Wnt/β-catenin signaling. Candidates were validated and characterized in vitro with molecular biologic- and biochemical assays and in silico with bioinformatic analyses.

Results: Synovial sarcoma translocation gene on chromosome 18-like 1 (SS18L1) is a homolog of the synovial sarcoma driving translocation gene SS18. It was one of the top hits in the genome-wide RNAi screen and it showed significant gene amplifications (8%) and mRNA upregulation (35%) in the TCGA CRC cohort. Silencing of SS18L1 in CRC cells led to decreased TCF4/Wnt-reporter luciferase activity and decreased levels of canonical target gene AXIN2 in qPCR and Western analyses. GFP-tagged SS18L1 was localized nuclear, suggesting involvement in transcriptional regulation by β-catenin. Indeed, we found interaction of SS18L1 with β-catenin and TCF4, as well as with known interacting proteins CBP and p300 by co-immunoprecipitation. Furthermore, interaction of SS18L1 with β-catenin deletion mutants indicated binding of SS18L1 to β-catenin. Copy number of the SS18L1 gene in the CRC cohort of TCGA was positively correlated with RNA expression levels of the gene. Analysis of differentially expressed genes in SS18L1 overexpressing tumors showed enrichment of Wnt-pathway related genes.

Conclusions: Our data suggests that SS18L1 regulates Wnt-signaling by interacting with the complex of β-catenin, TCF4 and CBP/p300. Gene copy number gains and increased mRNA expression levels are detected in CRC. SS18L1 may act as an oncogene in CRC enhancing cell proliferation.

Citation Format: Johannes Betge, Oksana Voloshanenko, Gerrit Erdmann, Kubilay Demir, Matthias P. Ebert, Michael Boutros. A novel regulator of Wnt-signaling in colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 967. doi:10.1158/1538-7445.AM2014-967
Abstract 977: Characterizing the regulation and function of miR-155 in hypoxia biology
Authors: Czochor Jennifer , Glazer Peter M.
Published: May 2015

Aberrant expression of microRNAs has been correlated with the initiation and progression of many diseases. One such microRNA, miR-155, is an oncogenic microRNA that has been associated with several different types of cancer, including lung, breast, and lymphoma. We are studying the role of miR-155 in promoting hypoxia-driven tumor phenotypes such as therapy resistance and genomic instability. Previously, we have shown that miR-155 expression is induced under hypoxic conditions and that over-expression of miR-155 under normal oxygen conditions confers resistance to ionizing radiation therapy. Additionally, we have shown that by knocking down expression of miR-155 under hypoxic conditions, we were able to sensitize these cells to ionizing radiation. Here, we demonstrate that miR-155 expression is tightly linked to genomic instability, another characteristic of hypoxia. We have found that over-expression of miR-155 drives increased mutation frequency as measured by a mutation reporter assay screen both in vitro and in vivo. These results are consistent with a recent finding that miR-155 over-expression targets mismatch repair proteins, MLH1, MSH2, and MSH6. An increase in mutation frequency could be due to a decrease in mismatch repair function. Surprisingly, we have also found that loss of miR-155 increases the baseline level of double strand breaks observed in a fibroblast cell line. Taken together, this data suggests that a finite regulation of miR-155 is necessary to maintain cellular homeostasis. Our goal is to gain a better understanding of the role of miR-155 in promoting hypoxic cancer cell survival.

Citation Format: Jennifer Czochor, Peter M. Glazer. Characterizing the regulation and function of miR-155 in hypoxia biology. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 977. doi:10.1158/1538-7445.AM2014-977
Abstract 979: microRNA-mediated leukemia-initiating cell activity
Authors: Velu Chinavenmeni S. , Chaubey Aditya , Phelan James D. , Meyer Sara , Horman Shane R. , Wunderlich Mark , Guzman Monica L. , Jegga Anil G. , Zeleznik-Le Nancy J. , Chen Jianjun , Mulloy James C. , Cancelas Jose A. , Jordan Craig T. , Aronow Bruce J. , Marcucci Guido , Bhat Balkrishen , Gebelein Brian , Grimes H. Leighton
Published: May 2015

The HoxA9 transcription activator and the Gfi1 transcriptional repressor compete for the regulation of common target genes. We exploited HoxA9 versus Gfi1 antagonism to identify the genes encoding microRNA-21 and microRNA-196b as transcriptional targets of Hox-based leukemia oncoproteins. Therapeutic inhibition of microRNA-21 and microRNA-196b significantly inhibits in vitro colony forming activity, and quantitatively depletes in vivo leukemia-initiating-cell activity of Hox-based leukemias leading to leukemia-free survival of murine AML and significant delay in disease onset in xenograft models. A novel microRNA target identification platform both validates therapeutic intervention and reveals biological impact of disrupting microRNA function. These data establish microRNA as functional effectors of endogenous HoxA9 and Hox-based leukemia oncoproteins, provide a concise in vivo platform to test RNA therapeutics, and suggest therapeutic value for microRNA antagonists in AML.

Citation Format: Chinavenmeni S. Velu, Aditya Chaubey, James D. Phelan, Sara Meyer, Shane R. Horman, Mark Wunderlich, Monica L. Guzman, Anil G. Jegga, Nancy J. Zeleznik-Le, Jianjun Chen, James C. Mulloy, Jose A. Cancelas, Craig T. Jordan, Bruce J. Aronow, Guido Marcucci, Balkrishen Bhat, Brian Gebelein, H. Leighton Grimes. microRNA-mediated leukemia-initiating cell activity. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 979. doi:10.1158/1538-7445.AM2014-979
Abstract 98: A novel mouse model for intestinal serrated polyposis
Authors: Cotton Jennifer , Huang He , Rajurkar Mihir , Mao Junhao
Published: May 2015

Serrated polyps have recently been proposed to comprise at least 30% of the origins of human colorectal cancer (CRC). Unlike adenomatous polyps, which are initiated by APC/β-catenin mutations, the genetic and molecular mechanisms underlying the serrated pathway that leads to serrated polyp initiation and progression remain poorly understood.

Here we describe a novel genetically modified mouse model of serrated polyposis via conditional activation of SMAD7, an inhibitory SMAD protein, in the intestinal epithelia. We show that SMAD7 activation is sufficient to drive serrated polyp initiation and progression to aggressive adenocarcinoma in both mouse intestine and colon. Mechanistically, we find that SMAD7-induced foci formation in non-transformed intestinal epithelial cells in vitro and serrated polyposis in vivo are Wnt/β-catenin independent. Furthermore, we find that, in addition to its regulation of TGFβ/BMP pathway, SMAD7 interacts with BRAF/MAPK signaling to regulate serrated polyposis. Taken together, our studies implicate for the first time the involvement of SMAD7 in serrated polyposis and reveal a potential novel molecular mechanism underlying the serrated polyp pathway.

Citation Format: Jennifer Cotton, He Huang, Mihir Rajurkar, Junhao Mao. A novel mouse model for intestinal serrated polyposis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 98. doi:10.1158/1538-7445.AM2014-98
Abstract CT208: Absolute bioavailability of dacomitinib (PF-00299804): Comparison of oral and intravenous administration in healthy volunteers
Authors: Giri Nagdeep , LaBadie Robert R. , Liang Yali , Boutros Tanya , Goldberg Zelanna , Bello Carlo L.
Published: May 2015

Background: Dacomitinib (D) is a highly selective, irreversible small molecule inhibitor of the human epidermal growth factor receptor family of tyrosine kinases in clinical development for the treatment of non-small cell lung cancer (NSCLC). A 45-mg once daily oral dose is currently being evaluated in Phase 3 for NSCLC therapy in multiple settings. D has not previously been administered clinically as an intravenous dose. The absolute bioavailability (F%) of D in rats, dogs and monkeys was found to range from 56% to 100% at doses between 20 and 50 mg/kg. The current study was conducted to estimate the absolute bioavailability of D after oral administration (Test) relative to intravenous (IV, Reference) administration.

Methods: A total of 14 healthy volunteers (HV) were enrolled in this Phase 1, open-label, 2-period, 2-treatment, fixed sequence study. Each HV received 2 treatments of D: Reference (20 mg IV infusion over 1 hour) and Test (45 mg oral), with a washout period of at least 16 days between each. Plasma samples to determine concentrations of D and its metabolite, PF-05199265, were collected at intervals up to 216 hours post-dose after IV or oral dose, and safety was assessed. F% was estimated as the ratio of dose-normalized adjusted geometric means of AUCinf for oral D and IV D using a mixed-effect model with treatment as a fixed effect and subject as a random effect. Corresponding 90% confidence intervals (CIs) were to be obtained from the same model.

Results: The mean AUCinf, Cmax and CL/F for D after a single 45-mg oral dose were 1487 ng*hr/mL, 19.84 ng/mL and 30.27 L/hr, respectively. The mean AUCinf, Cmax and CL for D after a single 20-mg IV dose were 847 ng*hr/mL, 52 ng/mL and 23.61 L/hr, respectively. Mean pharmacokinetic parameters following a single oral dose in this study were similar to those observed in other single oral dose studies in HV.

Conclusions: Assuming that clearance of D is similar via oral or IV administration at the administered doses, the absolute bioavailability of D was estimated to be 80.01% (90% CI: 74.90%, 85.47%). Single oral doses of D in both treatments were generally safe and well tolerated in the HV evaluated in this study.

Citation Format: Nagdeep Giri, Robert R. LaBadie, Yali Liang, Tanya Boutros, Zelanna Goldberg, Carlo L. Bello. Absolute bioavailability of dacomitinib (PF-00299804): Comparison of oral and intravenous administration in healthy volunteers. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT208. doi:10.1158/1538-7445.AM2014-CT208
Abstract CT234: Dabrafenib stimulates radioiodine uptake in BRAF V600E mutant advanced papillary thyroid cancer
Authors: Rothenberg Stephen M. , McFadden David G. , Palmer Edwin L. , Daniels Gilbert H. , Wirth Lori J.
Published: May 2015

Purpose: To determine whether the selective BRAF inhibitor dabrafenib can stimulate radioactive iodine uptake in BRAF V600E mutated advanced papillary thyroid cancer (PTC) that is unable take up iodine.

Patients and Methods: Ten patients with unresectable or metastatic PTC were enrolled. All had tumors with a BRAF V600E mutation and complete absence of radioiodine uptake on iodine-131 whole body scan obtained within 14 months of study entry. Each patient received dabrafenib (150 mg twice daily) for 3 weeks followed by thyrotropin alfa-stimulated iodine-131 whole body scan. If new iodine uptake occurred, dabrafenib was continued for an additional two weeks, followed by the administration of a therapeutic dose of iodine-131.

Results: All ten patients completed the study. Dabrafenib resulted in new iodine-131 uptake in six of the ten patients. All six were treated with radioioactive iodine, leading to a complete response in one patient, a partial response in a second patient and stable disease in three patients. Four of six treated patients had decreases in serum thyroglobulin. No toxic effects of grade 2 or higher were attributable to dabrafenib. One patient developed a new squamous cell carcinoma of the skin which was successfully excised with clear margins.

Conclusion: Dabrafenib produces increases in iodine uptake in patients with iodine-refractory advanced BRAF V600E mutant PTC and is well tolerated. Additional studies to determine efficacy are warranted.

Citation Format: Stephen M. Rothenberg, David G. McFadden, Edwin L. Palmer, Gilbert H. Daniels, Lori J. Wirth. Dabrafenib stimulates radioiodine uptake in BRAF V600E mutant advanced papillary thyroid cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT234. doi:10.1158/1538-7445.AM2014-CT234
Abstract CT323: Pemetrexed versus docetaxel in patients with EGFR-mutant lung adenocarcinoma previously treated with epidermal growth factor receptor tyrosine kinase inhibitors
Authors: Kyu-Sik Kim , Lee Bo Ram , Yoon Sung Hoon , Yu Jinyeong , Oh Injae , Kim Young Chul , Song Sangyun , Choi yooduk , Ban Hee Jung
Published: May 2015

Background: Patients with epidermal growth factor receptor (EGFR) mutation positive adenocarcinoma exhibited marked response to EGFR tyrosine kinase inhibitors (TKIs). In most cases, the patients showed disease progression after EGFR TKI treatment. We evaluated the efficacy and safety of pemetrexed versus docetaxel after the failure of EGFR TKI in patients with adenocarcinoma with EGFR mutation.

Methods: Patients harboring EGFR mutant adenocarcinoma who received weekly docetaxel (35-40 mg/m2 on days 1 and 8 every 3 weeks) or pemetrexed (500 mg/m2 every 3 weeks) at a single university-affiliated hospital following failure of first line EGFR TKI treatment were retrospectively reviewed.

Results: 44 patients were included between 2012 and 2013. Patients who had previously treated with EGFR TKI as first line treatment were received docetaxel (n=11) or pemetrexed (n=33) in second- or later-line treatment. The efficacy of docetaxel was superior to that of pemetrexed (ORR: 36.4% vs. 6.1%, p = 0.011, DCR: 72.7% vs. 39.4%, p = 0.055). Progression-free survival of docetaxel was 6.2 months versus 1.9 months with pemetrexed. (HR 0.55; 95% CI 0.25-1.22; p = 0.140). There were no significant differences in either the grade 3-4 hematologic or nonhematologic toxicities between the 2 regimens.

Conclusion: Pemetrexed shows unfavorable result compared to docetaxel in patients with acquired drug resistance after EGFR TKI treatment. We will have to study the efficacy of pemetrexed versus docetaxel after EGFR TKI treatment prospectively.

Citation Format: Kim Kyu-Sik, Bo Ram Lee, Sung Hoon Yoon, Jinyeong Yu, Injae Oh, Young Chul Kim, Sangyun Song, yooduk Choi, Hee Jung Ban. Pemetrexed versus docetaxel in patients with EGFR-mutant lung adenocarcinoma previously treated with epidermal growth factor receptor tyrosine kinase inhibitors. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT323. doi:10.1158/1538-7445.AM2014-CT323
Abstract CT337: Phase I/Ib study of the PARP inhibitor (PARPi) olaparib (O) with carboplatin (C) in triple negative breast cancer (TNBC) at low genetic risk (NCT00647062)
Authors: Chiou Victoria L. , Kohn Elise C. , Annunziata Christina M. , Minasian Lori , Zujewski JoAnne , Yu Minshu , Ji Jay , Doroshow James , Gordon Nicolas , Houston Nicole , Lee Jung-Min
Published: May 2015

Background: PARPi O demonstrates single agent activity in breast and ovarian cancer (Br/OvCa) pts with germline BRCA1/2 mutation (gBRCAm), and with BRCA-like phenotype. Subsets of TNBC are known to respond to therapies targeting DNA repair mechanisms. We hypothesize that O and C combination can be safely tolerated in TNBC pts and may result in benefit.

Methods: Pts with recurrent or unresectable TNBC, BRCAPro score <10% or absent gBRCAm, and normal end-organ function were eligible. An open-label 3x3 dose escalation included daily oral O capsule formulation (200mg then 400 mg q12h, d1-7) with C/AUC3-5 on d2 q21d (dose level [DL]1-3). No more than 8 O/C cycles were given, followed by daily O until progression. Pts were evaluated for toxicity every 3 weeks by CTCAEv3.0, and every two cycles for response using RECISTv1.0.

Results: 25 women (median age 52 [39-76]) were treated. All pts except one received prior therapy (median 5 [0-12]; prior platinum in 3pts). DLT was thrombocytopenia (DL 2: O 400mg/C AUC4 [1/6pts] and DL3: O 400mg/C AUC 5 [2/3pts]). MTD was reached at DL3 (C/AUC 5 with O 400mg capsule q12h d1-7 q21d). The expansion dose was O 400mg q12h d1-7, C/AUC 4. Gr 3/4 AEs included neutropenia (36%), thrombocytopenia (12%), and anemia (12%). 2 pts required C dose reduction and early discontinuation due to delayed marrow recovery. 13 pts (52%) needed peg-filgrastim, 6 (24%) blood transfusion, and 3 (12%) erythropoietin on at least one cycle. Responses (N=22 evaluable) included 1 CR (46+ mo), 2 PR (3, 5 mo), and 8 with SD ≥4 mo (36%; median 5 [4-7]), for a disease control rate of 50%. The pt who achieved CR had a strong family history of Br/OvCa. Peripheral blood mononuclear cells preC1, d3 or d7, and prior to C2 were collected for PAR incorporation ELISA. Paired tumor biopsies (pre/post-cycle1) were obtained from expansion cohort patients for biomarker proteomics and apoptosis endpoints; results will be presented.

Conclusions: RP2D O capsule formulation 400 mg q12h d1-7 with C AUC4 q21d is tolerable in heavily pretreated TNBC pts. Interactive marrow suppression was observed.

Citation Format: Victoria L. Chiou, Elise C. Kohn, Christina M. Annunziata, Lori Minasian, JoAnne Zujewski, Minshu Yu, Jay Ji, James Doroshow, Nicolas Gordon, Nicole Houston, Jung-Min Lee. Phase I/Ib study of the PARP inhibitor (PARPi) olaparib (O) with carboplatin (C) in triple negative breast cancer (TNBC) at low genetic risk (NCT00647062). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT337. doi:10.1158/1538-7445.AM2014-CT337
Abstract CT343: Phase II study of low-dose rate thoracic radiotherapy for treatment of intrathoracic relapsed or progressive small cell lung cancer
Authors: Jones Guy C. , Mitchell James B. , Johnson Bruce E. , Camphausen Kevin , Glatstein Eli , Simone Charles B.
Published: May 2015

Purpose: Standard therapy for limited-stage (LS) small cell lung cancer (SCLC) and extensive-stage (ES) SCLC with thoracic-only disease is a combination of chemotherapy with radiotherapy, which is associated with high rates of grade ≥3 esophagitis. Low dose rate (LDR) radiotherapy may reduce normal tissues toxicity, without sacrificing tumor response. This phase II trial was conducted to assess the toxicity, local control, and survival using LDR radiotherapy to treat thoracic relapsed or progressive ES-SCLC.

Methods: Eligible patients had ECOG performance status 0-2 with histologically confirmed ES-SCLC with relapse or progression predominantly in the chest after chemotherapy. Radiotherapy was delivered twice daily in 150cGy fractions to 4500cGy to an involved field. Dose rate was 5cGy per minute.

Results: Seventeen ES-SCLC patients were enrolled at the National Cancer Institute. Fifteen evaluable patients were a median of 59 years at enrollment with relapsed or progressive thoracic disease following a median of 2 prior courses of chemotherapy (range 1-3). Four were treated concomitantly with radiotherapy to other sites of extrathoracic metastases. Radiotherapy was well tolerated with acute grade 1 esophagitis in 60% but no acute or late grade ≥2 toxicity. No clinical pneumonitis was reported. Evaluable patients had responsive thoracic disease (50% complete, 50% partial responses) with no local failures on post-radiotherapy imaging at 3 and 6 months. All patients survived a median of 13.9 months and mean of 30.4 months following ES-SCLC diagnosis and 3.3 months and 19.8 months following radiotherapy completion, with 1-year and 2-year survivals after radiotherapy of 27% and 20%, respectively.

Conclusion: LDR radiotherapy for ES-SCLC was a well-tolerated salvage therapy for treatment failure after chemotherapy. Toxicity was significantly less than historical controls, and thoracic tumor response was not compromised with LDR techniques. This trial serves as the basis of a planned multi-center, prospective trial of consolidative or salvage LDR radiotherapy for ES-SCLC.

Citation Format: Guy C. Jones, James B. Mitchell, Bruce E. Johnson, Kevin Camphausen, Eli Glatstein, Charles B. Simone. Phase II study of low-dose rate thoracic radiotherapy for treatment of intrathoracic relapsed or progressive small cell lung cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT343. doi:10.1158/1538-7445.AM2014-CT343
Abstract CT416: Intratumoral administration of an Oncolytic Polio/Rhinovirus Recombinant (PVSRIPO) in recurrent glioblastoma (GBM): Preliminary results of the Phase I clinical trial
Authors: Desjardins Annick , Sampson J H. , Peters K B. , Ranjan T , Vlahovic G , Threatt S , Herndon J E. , Boulton S , Lally-Goss D , McSherry F , Friedman A , Friedman H S. , Bigner D D. , Gromeier M
Published: May 2015

Background: PVSRIPO is the live attenuated, oral (SABIN) serotype 1 poliovirus vaccine containing a heterologous internal ribosomal entry site stemming from human rhinovirus type 2. An oncofetal cell adhesion molecule and tumor antigen widely expressed ectopically in malignancy, nectin-like molecule-5, is recognized by PVSRIPO. We report the preliminary results of a phase I clinical trial evaluating the intratumoral administration via convection-enhanced delivery (CED) of PVSRIPO.

Methods: Eligibility criteria for adult patients included: recurrent supratentorial GBM; 1-5 cm in diameter; ≥1cm away from the ventricles; ≥4 weeks after chemotherapy, bevacizumab (BEV) or study drug; adequate organ function; KPS >70%; and positive anti-poliovirus titer. Dose was rapidly escalated using a two-step continual reassessment method with anticipated accrual of 1 patient each on dose levels 1-4, and up to 21 patients at dose level 5.

Results: Thus far, ten patients have been treated (1 each at levels 1 and 3, 2 at level 2, 2 at level 4, 4 at level 5). One dose limiting toxicity (patient #8) was observed at level 5, a grade 4 intracranial hemorrhage at the time of catheter removal, which required de-escalation to level 4. Grade 3 adverse events possibly related to study include hemiparesis (n=1) and lymphopenia (n=1). No grade 5 study related adverse events were observed. Eight patients remain alive, with two patients now 20 and 19 months post PVSRIPO, respectively. Two patients having previously failed BEV died six months post-infusion after initiating hospice care due to persistence of baseline neurologic deficits. After observing prolonged steroid use in 5 of 7 patients treated on dose levels 3 to 5 and after results of new immunogenic analysis became available, it was agreed upon that dose level 2 is probably the optimal dose level. The study has been amended to treat a total of 6 patients at dose level 2.

Conclusion: Infusion of PVSRIPO via CED in the clinical setting is safe thus far and observed efficacy outcomes are intriguing. Dose expansion at dose level 2 is ongoing.

Citation Format: Annick Desjardins, J H. Sampson, K B. Peters, T Ranjan, G Vlahovic, S Threatt, J E. Herndon, S Boulton, D Lally-Goss, F McSherry, A Friedman, H S. Friedman, D D. Bigner, M Gromeier. Intratumoral administration of an Oncolytic Polio/Rhinovirus Recombinant (PVSRIPO) in recurrent glioblastoma (GBM): Preliminary results of the Phase I clinical trial. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT416. doi:10.1158/1538-7445.AM2014-CT416
Abstract LB-1: PKR promotes genetic instability and evolution of MDS to acute leukemia in mice by negatively regulating DDR and DNA repair in a novel mechanism
Authors: Cheng Xiaodong , Byrne Michael , Bennett Richard Lynn , May Stratford William
Published: May 2015

The interferon-inducible, dsRNA-dependent protein kinase, PKR, is reported to be involved in diverse cytoplasmic functions. However, PKR has recently been reported to be expressed in the nucleus of high-risk MDS and leukemia patients but its nuclear function is not known.

We confirm that increased nuclear activated PKR does occur in AML cell lines compared to normal MEF and bone marrow stem/progenitor cells. Increased nuclear PKR is associated with impaired DNA damage response (DDR) and double strand break (DSB) repair following ionizing irradiation (IR). Knock-down and pharmacological inhibition of PKR reveals that activated nuclear PKR may function to suppress the γ-H2AX response characteristic of DDR following IR. Mechanistically, we find that nuclear PKR binds and co-immunoprecipitates with ATM in a mechanism that inhibits ATM phosphorylation. This leads to inefficient initiation of DDR (as measured by retarded γ-H2AX response) as well as inhibition of interaction between ATM, γ-H2AX, and MRN as part of the DDR complex. As a result, activated nuclear PKR retards DDR and leads to insufficient DSB repair as detected by prolonged Olive Tail Moment in a neutral Comet assay. However, since DNA repair can be restored by inhibiting PKR (by either knock-down or treatment with a PKR inhibitor), this supports a negative regulatory role for PKR in DDR and DSB repair Additional studies further demonstrate that PKR may block DDR by inhibiting ATM activity indirectly by binding with and activating PP2A, a known ATM protein phosphatase. Furthermore, in support of PKR inhibiting DSB repair, in vivo studies reveal that age-related or IR-induced genetic instability is more prevalent in PKR Tg vs WT mice and markedly lower in PKR knock-out mice as measured by the loss of GPI-linked CD24 on reticulocytes (a measure of increased somatic mutation rates due to loss of X-linked GPI activity). Interestingly, an increased somatic mutation rate and a more rapid evolution from MDS to acute leukemia is observed for double transgenic TgPKR/NHD13 vs Wt/NHD13 mice, which is significantly higher than evolution observed in PKRnull/NHD13 mice. Collectively, these data identify a novel function for PKR in suppressing DDR and DSB repair, which may enhance genetic instability and play a fundamental role in the evolution of MDS to acute leukemia.

Citation Format: Xiaodong Cheng, Michael Byrne, Richard Lynn Bennett, Stratford William May. PKR promotes genetic instability and evolution of MDS to acute leukemia in mice by negatively regulating DDR and DNA repair in a novel mechanism. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-1. doi:10.1158/1538-7445.AM2014-LB-1
Abstract LB-100: Discovery of HM61713 as an orally available and mutant EGFR selective inhibitor
Authors: Lee Kwang-Ok , Cha Mi Young , Kim Mira , Song Ji Yeon , Lee Jae-Ho , Kim Young Hoon , Lee Young-Mi , Suh Kwee Hyun , Son Jeewoong
Published: May 2015

Introduction: Activating mutations of EGFR are well known as oncogenic driver mutations in lung adenocarcinoma. Currently, EGFR TKIs including Gefitinib and Erlotinib are used as the first line therapy in NSCLC patients harboring EGFR activating mutations. However, drug resistance caused by T790M mutation limits the efficacy of these 1st generation EGFR TKIs. Currently, some of the next generation EGFR TKIs are under investigation for the treatment of lung cancer patients having T790M mutation. In our current presentation, to obtain HM61713, an EGFR mutant selective inhibitor, as a clinical candidate and the evaluation of HM61713 for mutant EGFR cancer model will be introduced.

Method: Novel analogues were designed and synthesized to find active compounds for the T790M mutation as well as EGFR activating mutations with good selectivity over wild- type EGFR. Finally, HM61713 was selected as a clinical candidate through multi-optimization processes including both in vitro and in vivo pharmacologcal studies.

Results: HM61713 was designed as an irreversible kinase inhibitor having a Michael acceptor, which covalently binds to a cysteine residue near the kinase domain of mutant the EGFR. In a cell wash out test, HM61713 inhibited phospho-EGFR for a long duration with a half-life of over 24 hours. From in vitro study, HM61713 showed potent activities for H1975 (L858-T790M) and HCC827 (exon 19 del.) with GI50 values of 9.2 nM and 10 nM, respectively. Instead, it showed low potency for H358 (wild type EGFR NSCLC) with GI50 of 2,225 nM. In xenograft studies using H1975 and HCC827, HM61713 resulted in good efficacy without showing any side effects.

Conclusion: HM61713 showed excellent in vitro and in vivo activities for H1975 harboring L858R-T790M mutation as well as HCC827 having exon 19 deletion mutation with selectivity over wild-type EGFR. Currently, HM61713 is undergoing phase I study (NCT01588145) for NSCLC patients after the failure of 1st generation EGFR TKIs in Korea.

Citation Format: Kwang-Ok Lee, Mi Young Cha, Mira Kim, Ji Yeon Song, Jae-Ho Lee, Young Hoon Kim, Young-Mi Lee, Kwee Hyun Suh, Jeewoong Son. Discovery of HM61713 as an orally available and mutant EGFR selective inhibitor. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-100. doi:10.1158/1538-7445.AM2014-LB-100
Abstract LB-102: A tumor-specific tissue penetrating peptide inhibits metastasis
Authors: Sugahara Kazuki N. , Braun Gary B. , Mendoza Tatiana H. de , Kotamraju Venkata R. , Teesalu Tambet , Ruoslahti Erkki , French Randall P. , Lowy Andrew M.
Published: May 2015

Neuropilin-binding tumor-penetrating peptides increase vascular and tissue permeability in tumors, allowing drugs conjugated to the peptide and even free drugs co-injected with the peptide to widely distribute within the tumor tissue (Sugahara KN et al, Cancer Cell 16:510, 2009; Science 328:1031, 2010). Thus, the peptides provide an elegant way to enhance therapeutic index of anti-cancer drugs. However, the ability of the peptides to increase vascular permeability has raised concerns that the peptides might enhance metastasis by promoting cell seeding from the primary tumor. Here, we show a recent unexpected finding that a prototypic tumor-penetrating peptide, iRGD (amino acid sequence: CRGDK/RGPD/EC), is a potent metastasis inhibitor. iRGD did not cause systemic tumor cell dissemination or metastasis in mice bearing breast tumors with low metastatic potential. iRGD treatment of mice bearing aggressive orthotopic pancreatic tumors resulted in significant decrease in spontaneous metastasis formation. Primary tumor growth was not affected by the treatment. Another tumor-penetrating peptide, iNGR, also inhibited metastasis, while conventional RGD peptides or a scrambled iRGD peptide that lack neuropilin affinity failed to do. These results indicate that the anti-metastatic effect of iRGD was dependent on its neuropilin-binding peptide motif. In vitro migration assays demonstrated that iRGD potently inhibits tumor cell migration and serves as a chemorepellent of tumor cells in a neuropilin-dependent manner. Chemorepulsion assays based on live cell imaging confirmed the findings, and further demonstrated that iRGD dramatically collapses tumor cell protrusions leading to an instantaneous retraction of tumor cells from iRGD-bound surfaces.

Our finding refutes the hypothesis that iRGD may cause enhanced metastasis. The mechanism of the anti-metastatic effect may involve neuropilin-mediated chemorepulsion of tumor cells. Collectively, iRGD may simultaneously achieve tumor-specific drug delivery and metastasis inhibition when utilized for cancer treatment.

Citation Format: Kazuki N. Sugahara, Gary B. Braun, Tatiana H. de Mendoza, Venkata R. Kotamraju, Tambet Teesalu, Erkki Ruoslahti, Randall P. French, Andrew M. Lowy. A tumor-specific tissue penetrating peptide inhibits metastasis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-102. doi:10.1158/1538-7445.AM2014-LB-102
Abstract LB-11: Discovery, synthesis, and structure-activity relationship of N-benzyl-2-phenylpyrimidin-4-amine derivatives as potent USP1/UAF1 deubiquitinase inhibitors with anticancer activity against non-small cell lung cancer
Authors: Dexheimer Thomas S. , Rosenthal Andrew S. , Luci Diane , Liang Qin , Villamil Mark A. , Jadhav Ajit , Simeonov Anton , Zhuang Zhihao , Maloney David J.
Published: May 2015

Protein ubiquitination is a dynamic and reversible post-translational modification that has been linked to many essential cellular processes in eukaryotes. In addition, deregulation of ubiquitin conjugation or deconjugation has been implicated in the pathogenesis of many human diseases, including cancer. For example, the deubiquitinating enzyme USP1 (ubiquitin-specific protease 1) in association with its WD40-repeat protein binding partner, UAF1 (USP1-associated factor 1), is a known regulator of DNA damage tolerance and repair and has been proposed as a promising target for anticancer therapy. To further evaluate the USP1/UAF1 complex as a therapeutic target, we conducted a quantitative high throughput screen of >400,000 compounds and subsequent medicinal chemistry optimization in pursuit of small molecules that inhibit the deubiquitinating activity of USP1/UAF1. These efforts lead to the identification of ML323 and a series of N-benzyl-2-phenylpyrimidin-4-amine derivatives, which possess nanomolar USP1/UAF1 inhibition and exhibit excellent selectivity over related proteases. Moreover, we demonstrate a strong correlation between compound IC50 values for USP1/UAF1 inhibition in vitro and activity in non-small cell lung cancer cells, specifically increasing the level of ubiquitinated-PCNA and decreasing cell survival. Taken together, our results establish the druggability of the USP1/UAF1 deubiquitinase complex and its potential as molecular target for anticancer therapies.

Citation Format: Thomas S. Dexheimer, Andrew S. Rosenthal, Diane Luci, Qin Liang, Mark A. Villamil, Ajit Jadhav, Anton Simeonov, Zhihao Zhuang, David J. Maloney. Discovery, synthesis, and structure-activity relationship of N-benzyl-2-phenylpyrimidin-4-amine derivatives as potent USP1/UAF1 deubiquitinase inhibitors with anticancer activity against non-small cell lung cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-11. doi:10.1158/1538-7445.AM2014-LB-11
Abstract LB-116: Cep55, a master regulator of cytokinesis in breast cancer pathogenesis
Authors: Kalimutho Murugan , Simmons Jacinta , Fernando Winnie , Saunus Jodi , Spring Kevin , Lakhani Sunil , Al-Ejeh Fares , Khanna Kum Kum
Published: May 2015

Defects in the number, structure, and function of centrosomes can generate mono- or multipolar mitotic spindles and cytokinesis failure resulting in aneuploidy and chromosome instability, which are common characteristics of tumour cells. Centrosomal proteins thus play central roles in the execution of proper cell division. Cep55 is a centrosomal protein required for proper segregation of two daughter cells during cytokinesis. It often elevated in wide range of cancer types including breast cancer. To ascertain the functional role of Cep55 in breast cancer pathogenesis, we performed publically available data mining as well as IHC staining in a cohort of breast cancer patients and found that elevated levels of Cep55 is significantly associated with p53 mutation, basal like subtype, relapse free and distant-metastasis free survival. Immunoblot analysis of non-malignant and breast cancer cell lines revealed higher expression of Cep55 protein in basal like subtype. RNAi mediated Cep55 depletion in cultured human breast cancer cells resulted in decreased cell proliferation, induction of apoptosis in-vitro and failure to establish xenografts in-vivo. Moreover, these cells failed to establish lung colonisation due to less proliferative, migrative and invasive capacity in experimental metastasis models. In an initial effort to identify causal effective of Cep55 mediated breast cancer pathogenesis, we found that Cep55-depleted cells that survive following long term culture have restored their ploidy compared with aneuploid cells that have constitutively high levels of Cep55. Moreover, these non-tumorigenic cells also have defect in major signalling networks assessed by Kinexus proteomic array. In line with this finding, we found that constitutive overexpression of Cep55 in non-transformed mammary epithelial cells, MCF-10a induced ERK1/2 and STAT3 signalling possibly due to increase in chromosome instability. Taken together, these results indicate that Cep55 promotes breast cancer initiation, progression and lung colonisation through pleiotropic effect and genomic instability that likely contribute to aneuploidy state of breast cancer tumours

Citation Format: Murugan Kalimutho, Jacinta Simmons, Winnie Fernando, Jodi Saunus, Kevin Spring, Sunil Lakhani, Fares Al-Ejeh, Kum Kum Khanna. Cep55, a master regulator of cytokinesis in breast cancer pathogenesis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-116. doi:10.1158/1538-7445.AM2014-LB-116
Abstract LB-124: Histone deacetylase 5 stabilizes HIF-1α through Hsp70 deacetylation in cytosol
Authors: Chen Shuyang , Yin Chengqian , Lao Taotao , Liang Dongming , Sang Nianli
Published: May 2015

Hypoxia is frequently associated with solid tumors and ischemic disorders, which are the top two leading causes of mortality in the world. Hypoxia-inducible factor 1 is a major regulator of angiogenesis and cellular adaptation to hypoxia. Accordingly HIF-1 function has been considered a therapeutic target for multiple diseases. Histone deacetylase (HDAC) activity has been involved in regulating HIF function and some HDAC inhibitors (HDACIs) have been documented to repress HIF-1 function. However, histone deacetylases encompass multiple members, each has different cellular functions. HDACIs in clinical application or under development generally inhibit more than one HDAC. It is unclear which specific member of the HDAC family is required for HIF-1 function. We present data here to show that histone deacetylase 5 (HDAC5) is required for HIF-1α protein stability. Knockdown of HDAC5 impaired hypoxic accumulation of HIF-1α and HIF-1 function. Furthermore, overexpression of HDAC5 enhanced HIF-1α stability and nuclear accumulation. Specifically, HDAC5 mutant exclusively localized at cytosol is sufficient for this function, stabilizing HIF-1α more efficiently than wild-type HDAC5. We further demonstrate that heat shock 70 kD protein (Hsp70) is a cytosolic substrate of HDAC5; and acetylation of Hsp70 promotes its association with HIF-1α and HIF-1α degradation. Taken together, our data suggest that deacetylation of Hsp70 catalyzed by HDAC5 facilitates the stabilization and hypoxic accumulation of HIF-1α. These findings also suggest that HDAC5 could be a potential target for therapies based on modulating HIF-1 function.

Citation Format: Shuyang Chen, Chengqian Yin, Taotao Lao, Dongming Liang, Nianli Sang. Histone deacetylase 5 stabilizes HIF-1α through Hsp70 deacetylation in cytosol. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-124. doi:10.1158/1538-7445.AM2014-LB-124
Abstract LB-13: Hyaluronic acid-based CD44 targeted nanoparticle delivery of combination MDR1 siRNA/paclitaxel to overcome drug resistance in ovarian cancer
Authors: Yang Xiaoqian , lyer Arun , hornicek Francis , Amiji Mansoor , Duan Zhenfeng
Published: May 2015

A major obstacle in the success of chemotherapy in ovarian cancer is the emergence of multidrug resistance (MDR). Overexpression of the MDR1 gene and corresponding P-glycoprotein (Pgp) efflux pumps is one of the best characterized MDR mechanisms. Although MDR1 siRNA based strategies are emerging as highly promising approaches to reverse MDR, the systemic delivery still remains a great challenge. In the present study, CD44 targeting hyaluronic acid (HA) based self-assembling nanoparticle systems were designed with MDR1 siRNA to evaluate its delivery efficiency and combination anticancer therapeutic efficacy with paclitaxel in vitro and in vivo. The results showed that HA-poly(ethyleneimine)/HA-poly(ethylene glycol) (HA-PEI/HA-PEG) nanoparticle successfully delivered MDR1 siRNA into MDR ovarian cancer cell lines, SKOV-3TR and OVCAR8TR. Western blot analysis, calcein AM retention assay, and MTT assay further demonstrated that HA-PEI/HA-PEG nanoparticles loaded with MDR1 siRNA efficiently down-regulated the expression of MDR1 and inhibited the functional activity of Pgp, and subsequently increase cell sensitivity to paclitaxel. HA-PEI/HA-PEG/MDR1 siRNA nanoparticle therapy followed by paclitaxel treatment produced a significant inhibitory effect on the drug-resistant tumor growth as compared with control groups in MDR ovarian cancer xenograft mouse models. These results indicated CD44-targeted HA-PEI/HA-PEG nanoparticle platform is an effective siRNA delivery system for potential siRNA-based anticancer therapeutics in ovarian cancer.

Citation Format: Xiaoqian Yang, Arun lyer, Francis hornicek, Mansoor Amiji, Zhenfeng Duan. Hyaluronic acid-based CD44 targeted nanoparticle delivery of combination MDR1 siRNA/paclitaxel to overcome drug resistance in ovarian cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-13. doi:10.1158/1538-7445.AM2014-LB-13
Abstract LB-14: Polyisoprenylated cysteinyl amides as targeted small molecule anti-Ras therapies
Authors: Lamango Nazarius S. , Aguilar Byron J. , Nkembo Augustine T. , Duverna Randolph , Amissah Felix , Poku Rosemary A. , Ablordeppey Seth Y.
Published: May 2015

Pancreatic cancer harbors the highest reported rates of K-Ras mutations, lacks effective therapies and is the most challenging to treat. It is thus the most deadly neoplasm with a 5-year survival rate of only 6%. We reveal here that polyisoprenylated methylated protein methyl esterase (PMPMEase) is overexpressed in 93% of pancreatic duct adenocarcinoma. We further present novel compounds with the potential to serve as effective targeted therapies for pancreatic and other cancers with hyperactive growth signaling pathways mediated by Ras and related G-proteins. The design and synthesis of the polyisoprenylated cysteinyl amide inhibitors (PCAIs) of PMPMEase incorporate three key elements to obtain compounds to selectively disrupt polyisoprenylation-mediated protein-protein interactions; the farnesyl group for high affinity interactions, a substituted amide bioisostere of the scissile ester bond of the endogenous substrates and an ionizable appendage group designed to mitigate the excessive hydrophobicity of the farnesyl cysteinyl amide that constitutes the pharmacophore. The PCAIs inhibited PMPMEase with Ki values ranging from 3.7 to 20 μM. The 48 h EC50 values for pancreatic cancer Mia PaCa-2 and BxPC-3 cell lines were as low as 1.9 μM while Salirasib (farnesylthiosalicylic acid, FTS) and farnesylthiosalicylamide were not effective even at 20 μM. The PCAIs thus have the potential to serve as a novel class of targeted therapies for cancers with hyperactive G-proteins and the growth factor receptors whose signals they transmit.

Citation Format: Nazarius S. Lamango, Byron J. Aguilar, Augustine T. Nkembo, Randolph Duverna, Felix Amissah, Rosemary A. Poku, Seth Y. Ablordeppey. Polyisoprenylated cysteinyl amides as targeted small molecule anti-Ras therapies. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr LB-14. doi:10.1158/1538-7445.AM2014-LB-14