bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 593: Kinetic risk assessment with biomarkers of systemic inflammation in patients with metastatic renal cell carcinoma
Authors: Harris Wayne B. , Kucuk Omer , Carthon Bradley , Liu Yuan , Pattaras John , Ogan Kenneth , Master Viraj
Published: August 2015

Background: Empiric prognostic scoring systems for metastatic renal cell carcinoma (mRCC) are routinely employed as baseline risk stratification tools for clinical trials. However, these systems have limited clinical utility after therapeutic intervention has begun. The goal of the current study was to develop clinically useful, hypothesis-driven, kinetic risk assessment tools based exclusively on biomarkers of systemic inflammation.

Methods: A retrospective chart review was conducted with authorization from the Emory University Institutional Review Board. Inclusion criteria included treatment at the Winship Cancer Institute with a targeted agent for mRCC as well as concomitant serum C-reactive protein (CRP) and albumin levels on at least three occasions that were at least 10 days apart. The modified Glasgow Prognostic Score (mGPS) was used to quantify the intensity of systemic inflammation and to formulate the Inflammation Intensity Index for kinetic risk assessment.

Findings: Intensity of systemic inflammation was assessed 2465 times in 135 patients with cohorts used for training (n = 55; cutoff date 06/30/2012) and validation (n = 80; cutoff date 06/30/2014). Kinetic risk was assigned on the basis of time to onset of refractory systemic inflammation. The median overall survival (OS) was 44.7, 19.8, 13.0, and 6.7 months for kinetic risk categories A, B, C and D, respectively, with a median follow up of 29.3 months for the combined cohorts and none lost to follow up (censored log rank p <.0001). OS was 40.6 months for whites (n = 99) vs. 9.8 months for blacks (n = 30; p <.0001).

Conclusions: The correlation of dramatic differences in OS with the onset of refractory systemic inflammation provides strong evidence in support of the clinical utility of the Inflammation Intensity Index and, as a consequence, the underlying theoretical constructs, including a plausible biological hypothesis for differences in clinical outcome by race.

Citation Format: Wayne B. Harris, Omer Kucuk, Bradley Carthon, Yuan Liu, John Pattaras, Kenneth Ogan, Viraj Master. Kinetic risk assessment with biomarkers of systemic inflammation in patients with metastatic renal cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 593. doi:10.1158/1538-7445.AM2015-593
Abstract 597: Coding and noncoding gene targets in pediatric soft tissue sarcomas
Authors: Mitra Sheetal A. , Mitra Anirban P. , Buckley Jonathan D. , Triche Timothy J.
Published: August 2015

BACKGROUND: Genomic studies on pediatric soft tissue sarcomas (STS) such as rhabdomyosarcoma (RMS) and Ewing family of tumors (EFT) have shown that the overall burden of somatic mutations in these tumors is relatively low when compared to most adult tumors. This observation along with recent studies suggest that other features such as chromosomal translocations that appear predominantly in these tumors may play an important role in their biology. Genes resulting from these translocations are known to regulate protein-coding genes that are required for tumor formation. Our studies on these tumors show that these chimeric fusion genes can hijack the cellular machinery that comprises both protein-coding and non-coding networks for tumorigenesis. RESULTS: Gene expression signature of the more aggressive RMS subset that comprises of PAX-FKHR-positive alveolar RMS suggested that the protein-coding NOS1 is most strongly associated and prognostically significant gene in this group. Functional assays confirmed that PAX-FKHR directly regulated its expression. Decreasing NOS1 expression using lentiviral vectors resulted in a decrease in cell survival and reduced tumor growth in vivo. Similar expression analyses comparing EFT, which express the fusion gene EWS-FLI1, with other tumors and normal tissues showed that the non-coding features were more strongly associated with EFT than the coding genes. EWS-FLI1 directly regulates a long intergenic non-coding RNA (lincRNA), FEZF1-AS1. Matrigel assays and tail vein injection models suggested that the lincRNA promotes cell invasion and migration. Chromatin-RNA immunoprecipitation assays revealed interaction of the lincRNA with DNA regions, both coding and non-coding, which are involved in invasion and metastasis. CONCLUSIONS: Fusion genes in pediatric STS activate genomic regions that facilitate tumor pathogenesis by regulating the interactive network between coding and non-coding genes. While fusion-positive RMS are dependent on NOS1 for survival, EFT need lincRNA FEZF1-AS1 for cell migration and tumor propagation. EFT are known to be highly metastatic tumors and our results underscore the complex regulatory networks that are required for cellular migration in these tumors. Understanding the importance of these gene interactions will help development of effective tumor-specific drug therapies that improve treatment while decreasing unwanted side-effects.

Citation Format: Sheetal A. Mitra, Anirban P. Mitra, Jonathan D. Buckley, Timothy J. Triche. Coding and noncoding gene targets in pediatric soft tissue sarcomas. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 597. doi:10.1158/1538-7445.AM2015-597
Abstract 598: Circulating peptides for predicting subsequent cardiotoxicity in cancer patients with chemotherapies
Authors: Fan Jia , Meng Qing H. , Bone Christopher , Igo Stephen , Hu Ye
Published: August 2015

In recent years with the development of new anticancer therapies, cardiotoxicity has been a known adverse event resulting from direct myocyte damage, and leads to increased treatment-associated mortality. However, the effective approach of early diagnosis and monitoring treatment-induced cardiac dysfunction is not available because its underlying mechanism is still unclear. Traditional screening that relied on left ventricular ejection fraction (LVEF) is lack of sensitivity to early detect subclinical changes or predict the subsequent declines in cardiac functions with treatment. A more noninvasive approach to early diagnose and monitor treatment-induced cardiotoxicity is in an urgent need. Our group has developed nanoporous silica thin films (Nanotraps) for peptide enrichment prior to mass spectrometry (MS) analysis as a robust technology platform for accurate and reproducible peptide biomarkers detection. Cancer patients with chemotherapies were split into three groups, non-toxicity (NT, n = 36), slight cardiotoxicity (SCT, n = 26) and cardiotoxicity (CT, n = 23). After statistical analysis and sequencing by LC-MS/MS, two peptides candidates (a fragment from serum amyloid A-1525 (SAA-1525)) and Hepcidin-25) were identified with significant up-regulation in cardiotoxic groups (with the cut off ratio of 1.5-fold and p-value ≤ 0.01 among cohorts). The area under curve (AUC) values of SAA-1525 and hepcidin-25 are 0.929 and 0.844 for distinguishing CT from NT, respectively (95% CI = 0.839-1.000 and 0.696-0.993); if combining two peptides as a biomarker pattern, the AUC value can be increased to 0.942 (95% CI = 0.864-1.00). SCT patients could also be classified by this two-marker pattern (AUC = 0.771, 95%CI = 0.606-0.936). In addition, we investigated the proteolytic process analysis of cathepsin B, which was identified as the key protease to generate SAA-1525. SAA-1525 was detected in the mixture of recombinant SAA1 full protein and purified cathepsin B, and its expression level increased with reaction time and enzyme amount. Both cathepsin B inhibitors, E64 and ALLM, could stop the generation of SAA-1525. Our study provides strong evidence to support the application of circulating peptides as minimally invasive way for predicting/monitoring chemotherapy-induced cardiotoxicity.

Citation Format: Jia Fan, Qing H. Meng, Christopher Bone, Stephen Igo, Ye Hu. Circulating peptides for predicting subsequent cardiotoxicity in cancer patients with chemotherapies. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 598. doi:10.1158/1538-7445.AM2015-598
Abstract 599: A panel of mass spectrometry based serum protein tests for predicting graft-versus-host disease (GvHD) and its severity
Authors: Roder Heinrich , Hoffmann Andreas-Claudius , Roder Joanna , Koldehoff Michael
Published: August 2015

Allogeneic hematopoietic stem cell transplantation (AHSCT) has been shown to provide longterm disease-free survival for otherwise fatal malignant or nonmalignant hematological disorders. Acute and chronic graft-versus-host disease (aGvHD and cGvHD) are a major complication following AHSCT and are associated with a substantial morbidity and mortality. Identification of patients (pts) likely to develop severe forms of GvHD could allow the selection of more aggressive therapeutic regimens for patients assessed to be at high risk.

Serum samples and clinical data were available from 124 pts (age 18-70) who had received AHSCT. Five pts suffered no GvHD, 15 de novo cGvHD, 21 aGvHD but no cGvHD and 83 both aGvHD and cGvHD (overlap). Of pts with aGvHD 51% had grade I disease and of pts with cGvHD 53% had limited disease. Matrix assisted laser desorption/ionization (MALDI) mass spectra were acquired from the samples using the deep MALDI method, allowing a deep probing of the proteome. Spectra were preprocessed and spectral features defined. The integrated intensities of these features were combined with the clinical data using deep learning based machine learning to create classifiers able to stratify patients into groups depending on occurrence and severity of GvHD.

Classifiers could be developed with significant power to predict occurrence and severity of GvHD. The area under the curves (AUCs) obtained for the clinical questions investigated and examples of the sensitivity and specificity achievable are summarized in the table.

AUCSensitivity/SensitivityaGvHD ?0.7463%/80% or 80%/65%Grade II or severe aGvHD?0.6560%/67%cGvHD post aGvHD?0.7563%/75%severe vs mild cGvHD?0.6867%/69%

It is possible to provide information on occurrence and severity of GvHD from mass spectral analysis of post-transplant serum samples. If validated, this panel of tests could provide additional information useful for clinicians choosing treatment regimens for pts following AHSCT.

Citation Format: Heinrich Roder, Andreas-Claudius Hoffmann, Joanna Roder, Michael Koldehoff. A panel of mass spectrometry based serum protein tests for predicting graft-versus-host disease (GvHD) and its severity. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 599. doi:10.1158/1538-7445.AM2015-599
Abstract 625: The frequency of gene amplifications in cancer revealed by a droplet digital PCR (ddPCR) based pan-cancer gene panel test
Authors: So Austin P. , Wong Amy , Pecson Jennifer , Putcha Girish , Jensen Gregory , Lucero Michael , Stone Gary , Gillman Jason , Mishra Pravin , Loughmiller David , Haslem Derrick S. , Nadauld Lincoln
Published: August 2015

The development of molecular assays designed to detect gene amplifications has largely been hampered by technical challenges such as limited DNA quantity and tumor heterogeneity, which demand methods of very high precision and sensitivity. The recent introduction of affordable digital PCR platforms, such as droplet digital PCR (ddPCR), that are capable of providing single molecule resolution of target abundances thus provides a unique opportunity to address this gap in molecular diagnostics. A ddPCR-based test was therefore developed under CLIA-CAP guidelines to determine the amplification status of 12 commonly amplified genes targeted by FDA approved drugs. Termed the Amplinome Test, this test was applied to 49 clinical samples received over a period of 6 months and compared to the results obtained from a commercially available clinical sequencing test applied that also reports copy number alterations (CNAs). An overall concordance rate of 90% (532/588 calls) was observed between the two tests across the entire gene set, 5 of which were identified as amplified. There were 56 discordant copy number amplifications between the two testing modalities. The vast majority (55/56) of discordant calls arose from gene amplifications identified by the Amplinome test, but not detected by sequencing, indicating an 11-fold increase in sensitivity in detecting amplifications. One discordant call (HER3) was identified as amplified via sequencing, but confirmed to be unamplified via FISH. At the patient level, the Amplinome test identified 5-fold more patients as having actionable amplifications in at least one of the 12 assayed genes versus clinical sequencing (29 vs. 6). Clinical management was altered in 14 of the 29 patients with an actionable CNA identified on the Amplinome test; those patients received targeted therapy directed against the amplified gene. The ddPCR-based Amplinome test thus provides a highly sensitive method for measuring gene amplifications in cancer that alters patient management, and suggests that the prevalence of actionable amplifications may be significantly underestimated by standard clinical next-generation sequencing tests.

Citation Format: Austin P. So, Amy Wong, Jennifer Pecson, Girish Putcha, Gregory Jensen, Michael Lucero, Gary Stone, Jason Gillman, Pravin Mishra, David Loughmiller, Derrick S. Haslem, Lincoln Nadauld. The frequency of gene amplifications in cancer revealed by a droplet digital PCR (ddPCR) based pan-cancer gene panel test. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 625. doi:10.1158/1538-7445.AM2015-625
Abstract 659: Sustained inhibition of HER3 and EGFR is necessary to induce regression of HER2-amplified gastrointestinal carcinomas
Authors: Leto Simonetta Maria , Sassi Francesco , Catalano Irene , Migliardi Giorgia , Zanella Eugenia Rosalinda , Bertotti Andrea , Trusolino Livio
Published: August 2015

Purpose: Preclinical studies in HER2-amplified gastrointestinal cancer models have shown that co-targeting HER2 with a monoclonal antibody and a small molecule is superior to monotherapy with either inhibitor, but the underlying cooperative mechanisms remain unexplored. We investigated the molecular underpinnings of this synergy to identify key vulnerabilities susceptible to alternative therapeutic opportunities.

Experimental Design: The signaling consequences of HER2, HER3 and EGFR (HERs) blockade were evaluated in HER2-overexpressing colorectal and gastric cancer cell lines by Western blotting. HERs’ canonical downstream transducers were quantitatively gauged by multiplex phospho-proteomics. The in vivo outcome of antibody-mediated HER2 blockade by trastuzumab, reversible HER2 inhibition by lapatinib, and irreversible HER2 inhibition by afatinib was assessed in patient-derived tumorgrafts and cell-line xenografts by monitoring tumor growth curves and by using antibody-based proximity assays for phosphoprotein analysis.

Results: Trastuzumab monotherapy reduced HER3 phosphorylation, with minor consequences on downstream transducers. Lapatinib alone acutely inhibited all HER receptors and effectors but led to delayed rephosphorylation of HER3 and EGFR and partial restoration of ERK and AKT activity. When combined with lapatinib, trastuzumab prevented HER3/EGFR reactivation and caused prolonged inhibition of ERK/AKT. Afatinib alone was as effective as trastuzumab plus lapatinib in counteracting the reinstatement of HER3, EGFR, and downstream signaling activation. In vivo, the combination of trastuzumab and lapatinib - or monotherapy with afatinib - resulted in overt tumor shrinkage.

Conclusions: Only prolonged inhibition of HER3 and EGFR, achievable by dual blockade with trastuzumab and lapatinib or irreversible HER2 inhibition by single-agent afatinib, led to regression of HER2-amplified gastrointestinal carcinomas.

Citation Format: Simonetta Maria Leto, Francesco Sassi, Irene Catalano, Giorgia Migliardi, Eugenia Rosalinda Zanella, Andrea Bertotti, Livio Trusolino. Sustained inhibition of HER3 and EGFR is necessary to induce regression of HER2-amplified gastrointestinal carcinomas. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 659. doi:10.1158/1538-7445.AM2015-659
Abstract 661: Increasing sensitivity of SAIT301, a specific monoclonal antibody of c-Met, with paclitaxel combination in c-Met positive gastric cancer
Authors: Kang Sun Kyoung , Kim Jeong Min , Lee Won Suk , Kwon Woo Sun , Kim Tae Soo , Shim Seon-hui , Kim Kyung-Ah , Lim Ho-Yeong , Chung Hyun Cheol , Rha Sun Young
Published: August 2015

The c-Met is frequently overexpressed and related to a worse prognosis in gastric carcinoma (GC). This study aimed to determine a c-Met targeting monoclonal antibody (SAIT301) with effects on the proliferation and to increase efficacy of SAIT301 administered in combination with paclitaxel in gastric cancer cell lines. Anticancer effect of SAIT301 was assessed using CCK-8 assay in 52 GC cell lines. c-Met status was identified using RTK array and qPCR. Cell cycle distribution was determined with flow cytometry. Expression levels of c-Met and cleaved PARP, apoptosis induction marker, were determined by western blot analysis. Combination index (CI) evaluated by CalcuSyn software. We screened 52 cell lines for growth inhibition by SAIT301.Among 11 c-Met positive GC cells, 5 cell lines were sensitive to SAIT301 (5/11, 45%) with 40∼60% inhibition rate at 5 μg/ml.SAIT301 sensitivity of 5 cell lines has a tendency of correlation between MET amplification, c-Met/p-Met co-expression, low Cbl level or exon14 deletion of MET. Next, we performed combination treatment with SAIT301 and paclitaxel in 5 cell lines. The results exhibited increasing anti-proliferative effects with synergism. In cell cycle analysis, SAIT301 increased the percentage of cells in the G1 phase, while paclitaxel increased the G2/M phase(3-19%). Combination of SAIT301 and paclitaxel significantly increased in sub G1(2-17%) and G2/M arrest(4-19%). Western blot analysis showed paclitaxel induced c-Met expression. In addition, SAIT301 and paclitaxel combination down-regulated c-Met expression and enhanced PARP cleavage more than monotherapy. Our results indicate that the SAIT301 combined with paclitaxel therapy had synergistic effects in the treatment of c-Met positive gastric cancer.

Citation Format: Sun Kyoung Kang, Jeong Min Kim, Won Suk Lee, Woo Sun Kwon, Tae Soo Kim, Seon-hui Shim, Kyung-Ah Kim, Ho-Yeong Lim, Hyun Cheol Chung, Sun Young Rha. Increasing sensitivity of SAIT301, a specific monoclonal antibody of c-Met, with paclitaxel combination in c-Met positive gastric cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 661. doi:10.1158/1538-7445.AM2015-661
Abstract 684: Nelfinavir inhibits the growth of small cell lung cancer cells and patient-derived xenograft tumors
Authors: Kawabata Shigeru , Connis Nick , Zhang Chunyu , Gills Joell J. , Hann Christine L. , Dennis Phillip A.
Published: August 2015

Small cell lung cancer (SCLC) is an aggressive lung cancer with a poor prognosis that is characterized by frequent metastasis at the time of diagnosis. Although SCLC is more responsive to chemotherapy and radiation therapy compared to other types of lung cancer, cure is difficult because of frequent recurrence. Molecular alterations in SCLC include inactivation of TP53 and RB1, high copy number of Myc family, and amplifications of FGFR1 and SOX2. Additionally, achaete-scute homolog 1 (ASCL1), a transcription factor for development of pulmonary neuroendocrine cells, is a lineage-dependent oncogene for SCLC. New drugs and molecular targets need to be identified. Previously, we reported nelfinavir (NFV), a HIV protease inhibitor, inhibited proliferation of non-small cell lung cancer (NSCLC) cells in vitro and human NSCLC xenograft tumors through induction of the unfolded protein response (UPR). Here we demonstrate that the effect of NFV in SCLC cells and preclinical treatment studies using SCLC patient-derived xenograft (PDX) mouse models. NFV inhibited SCLC cell proliferation and induced cell death in vitro. Activating transcription factor 4 (ATF4), a marker of the UPR, was rapidly increased, whereas Myc was decreased after 4 hr treatment with NFV. AMP-activated protein kinase (AMPK), which plays a role in cellular energy homeostasis, was activated in the early phase of NFV treatment, whereas the mammalian target of rapamycin (mTOR) that is a serine/threonine kinase that regulates cell growth, was inactivated. NFV inhibited the expression of SOX2, ASCL1 and Aurora B in a cell line- and time-dependent manner. Taken together, NFV had pleiotropic effects against multiple targets during the inhibition of SCLC cell proliferation. In vivo, NFV inhibited growth of SCLC PDX tumors, which correlated with induction of the UPR and decreased expression of ASCL1 and Aurora B. Collectively, these findings show that NFV is highly effective in SCLC in vitro and in vivo, suggesting possible value of incorporating NFV into clinical trials for patients with SCLC.

Citation Format: Shigeru Kawabata, Nick Connis, Chunyu Zhang, Joell J. Gills, Christine L. Hann, Phillip A. Dennis. Nelfinavir inhibits the growth of small cell lung cancer cells and patient-derived xenograft tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 684. doi:10.1158/1538-7445.AM2015-684
Abstract 689: Characterization of two novel oncogenic FGFR2 fusions sensitive to the FGFR-selective inhibitor Debio 1347 in cholangiocarcinoma
Authors: Vaslin Anne , Rigotti Stefania , Lembrez Nathalie , Vuagniaux Grégoire , Moulon Corinne , Tanaka Hiroaki
Published: August 2015

Dysregulation of the fibroblast growth factor receptor (FGFR) signaling pathway due to receptor overexpression, gene amplification, point mutations or fusions/chromosomal translocations is associated with cancer development and progression. FGFR gene fusions have recently been discovered in several indications including bladder cancer, glioblastoma, lung squamous cell cancer and cholangiocarcinoma. Predominant gene fusions have been identified in some indications such as FGFR3-TACC3 (with different genomic variations in the two genes) for bladder cancer whereas for other indications the genomic-altered landscape is a lot more heterogeneous, as seen in cholangiocarcinoma where at least ten FGFR2 fusions each with a different fusion partner have been identified.

We herein report for the first time the discovery of two novel FGFR fusions in intra hepatic cholangiocarcinoma patient samples. These new fusions contain an intact FGFR2 tyrosine kinase domain and fused partner harbor oligomerization domains that suggest similar mechanism of constitutive kinase activation.

Both fusions display oncogenic activities when introduced into Rat 2 cells in in vitro colony formation assays as compared to parental cells. The two fusions are also tumorigenic in vivo when implanted subcutaneously in NMRI nude mice, whereas parental cell do not grow in vivo. FGFR inhibition by the FGFR selective inhibitor Debio 1347 (CH5183284) reduced cell proliferation in vitro. In vivo sensitivity to FGFR inhibition could also be demonstrated for the two fusions.

Altogether, these results suggest that these two novel oncogenic fusions are actionable targets in cholangiocarcinoma and that patients harboring these fusions could benefit from targeted FGFR inhibition, such as Debio 1347, currently investigated in a Phase I trial in selected patients harboring FGFR genetic alterations (NCT01948297).

Citation Format: Anne Vaslin, Stefania Rigotti, Nathalie Lembrez, Grégoire Vuagniaux, Corinne Moulon, Hiroaki Tanaka. Characterization of two novel oncogenic FGFR2 fusions sensitive to the FGFR-selective inhibitor Debio 1347 in cholangiocarcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 689. doi:10.1158/1538-7445.AM2015-689
Abstract 716: Targeting Mek-Erk pathway abrogates hypoxia-mediated lapatinib resistance in ErbB2-positive breast cancer cells
Authors: Karakashev Sergey , Reginato Mauricio
Published: August 2015

Overexpression/amplification of the tyrosine kinase ErbB2 is often observed in breast cancers. ErbB2 expression activates EGFR signaling pathway promoting tumorigenesis. Breast cancer ErbB2-positive patients are treated with lapatinib, a dual EGFR/ERBB2 inhibitor. Despite lapatinib clinical efficacy, acquired resistance has been reported and its mechanism is poorly understood. Another factor that is associated with mammary tumors is hypoxia. Hypoxia stabilizes hypoxia inducible factor 1 (HIF-1), a transcription factor that regulates cell growth, proliferation and survival. As a result, hypoxic tumors are often chemoresistant.

Here, we show that hypoxia decreases lapatinib-mediated growth inhibition and apoptosis in three-dimensional cultures. In agreement with this data, hypoxia also promotes activation of signaling pathways downstream from ErbB2/EGFR including AKT and ERK in the presence of lapatinib. This protective effect depends on HIF-1 and can be abrogated by HIF-1 RNAi. Moreover stable overexpression HIF-1 in ErbB2-expressing cells under normoxic conditions is sufficient to rescue cell proliferation and survival and maintain ERK and AKT signaling in the presence of lapatinib. We also show that activation of ERK signaling is required for hypoxia-mediated lapatinib resistance and inhibition of MEK (a kinase upstream of Erk) reverses hypoxia protective effect on ErbB2-expressing cells. One potential mechanism of how hypoxia/HIF-1 may lead to activation of ERK pathway is via regulation of dual-specificity phosphatase 2 (DUSP2). DUSP2 is a negative regulator of ERK pathway. Here we demonstrate that cells exposed to hypoxia have decreased levels of DUSP2 and it correlate with increased activation of Erk signaling. Moreover, reducing DUSP2 expression alone in ErbB2-positive breast cancer cells is sufficient to reduce lapatinib-mediated effects. And DUSP2 overexpression abrogates hypoxia-mediated protective effect on ErbB2-expressing cells treated with lapatinib.

All these data suggests that targeting MEK-Erk signaling pathway may reverse hypoxia mediated lapatinib resistance and might be a viable option for lapatinib resistant ErbB2-posive tumors. Indeed, a combination of lapatinib and an FDA approved MEK inhibitor trametinib abrogates hypoxia protective effect on cell growth inhibition and apoptosis in three dimensional (3D) cultures. Thus targeting MEK/ERK pathway in hypoxic breast cancer may improve an anti-ErbB2 therapy in breast cancer.

Citation Format: Sergey Karakashev, Mauricio Reginato. Targeting Mek-Erk pathway abrogates hypoxia-mediated lapatinib resistance in ErbB2-positive breast cancer cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 716. doi:10.1158/1538-7445.AM2015-716
Abstract 73: Targeting KDR mutations in lung adenocarcinoma
Authors: Mockus Susan M. , Potter Christopher S. , Stafford Grace A. , Ananda Guruprasad , Hinerfeld Douglas , Tsongalis Gregory J.
Published: August 2015

KDR, also known as VEGFR2, is a target of several VEGFR inhibitors, however, only bevacizumab, which targets the VEGF ligand, is FDA approved for lung cancer. Since an activating mutation in KDR was identified in 70% of lung adenocarcinoma patients we sought to identify the number of available clinical trials targeting KDR in lung adenocarcinomas and/or solid tumors, thereby increasing therapeutic options and treatment accessibility for these patients.

DNA from thirteen lung cancer FFPE samples was sequenced on Illumina HiSeq 2500 or MiSeq sequencers using a CLIA-certified 358-gene targeted sequencing assay. FASTQ files generated from Illumina's CASAVA software were submitted to a Clinical Genome Analytics (CGA) data analysis pipeline to perform automated read quality assessment, alignment, and variant calling. Clinical reports were written for each sample through extensive literature and clinicaltrials.gov searches.

Thirteen lung biopsies were obtained and subdivided based on pathology reports, into 10 lung adenocarcinomas, 1 mixed NSCLC/SCLC, 1 small cell carcinoma, and 1 squamous carcinoma. KDR Q472H was identified in 7/10 lung adenocarcinomas and 1/1 mixed NSCLC/SCLC, but not in the small or squamous cell carcinomas. KDR encodes Vegfr-2, a receptor tyrosine kinase overexpressed in a variety of solid tumors. KDR Q472H is an activating missense mutation, which increases phosphorylation and activation of Vegfr-2, thereby promoting increased microvessel density in lung tumor tissues. At the time of clinical report writing, there were a total of 47 actively recruiting clinical trials targeting KDR and 4 trials requiring the patient to have a molecular alteration of KDR. Further breakdown of these trials identified the use of 33 off-label VEGFR inhibitors, 5 investigational pan-VEGFR inhibitors, and 5 investigational specific KDR (VEGFR2) inhibitors.

Next-generation sequencing of 358 genes from lung cancer biopsies identified a common KDR activating mutation, Q472H, in 70% of lung adenocarcinomas. Searching clincialtrials.gov by pan-VEGFR and specific KDR inhibitors identified 47 actively recruiting trials, thus increasing the accessible repertoire of treatment options for lung adenocarcinoma patients.

Citation Format: Susan M. Mockus, Christopher S. Potter, Grace A. Stafford, Guruprasad Ananda, Douglas Hinerfeld, Gregory J. Tsongalis. Targeting KDR mutations in lung adenocarcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 73. doi:10.1158/1538-7445.AM2015-73
Abstract 735: Honokiol enhances the anticancer effects of doxorubicin by regulating Mucin 1 and Multidrug resistance-associated protein 1 (MRP1) in mammary carcinoma MDA-MB-231 cells
Authors: Thulasiraman Padmamalini , Alshareedah Saad
Published: August 2015

Although great progress has been made in the treatment of breast cancer, resistance to chemotherapeutic drugs is a problem facing current cancer research, promoting the need to understand the molecular mechanisms involved in breast cancer and identify future targeted therapy. One of the mechanisms by which chemoresistance is attained in cancer cells is mediated through the expression of MDR-related proteins (MRPs). These transmembrane proteins efflux drugs across the plasma membrane, conferring resistance of cancer cells to anticancer drugs. Acquiring drug resistance has been correlated to the emergence of metastasis, accounting for two factors that may be related to progression of the disease. One of the diagnostic markers of metastatic progression is Mucin 1 (MUC1), an oncoprotein which has been implicated in reduced survival rate. Interaction of MUC1 with MRP-1 promotes resistance to conventional chemotherapeutic drugs. While several inhibitors have been identified and characterized to overcome drug resistance, thus far none of these have led to effectively managing acquired drug resistance. Along with existing drug treatments for breast cancer, the focus of clinicians and researchers have shifted towards exploring natural products to treat alone or in combination with chemotherapeutic agents to enhance the efficacy of these drugs in cancer. One such compound is honokiol, a natural phenolic compound extracted from Magnolia grandiflora that suppresses breast carcinogenesis in vitro and in vivo. The purpose of the current study is to determine whether honokiol regulates MUC1 and MRP1 in mammary carcinoma cells, MDA-MB-231, and the role of honokiol to enhance the efficacy of chemotherapeutic agent, doxorubicin. We investigated the effects of honokiol on the expression of MUC1 and MRP1 in MDA-MB-231 cells by RT-PCR and Immunoblotting. Cell proliferation assays (MTT-(3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) were used to study the effect of honokiol on doxorubicin-mediated growth suppression. Honokiol suppressed mRNA and protein expression levels of MUC1 and MRP1 in MDA-MB-231 cells. In addition, honokiol suppressed the growth of mammary carcinoma MDA-MB-231 cells, and enhanced the efficacy of doxorubicin-mediated mammary carcinoma growth suppression. Taken together, suppressing the expression level of MUC1 and MRP1 by honokiol enhances the effect of conventional chemotherapeutic drugs.

Citation Format: Padmamalini Thulasiraman, Saad Alshareedah. Honokiol enhances the anticancer effects of doxorubicin by regulating Mucin 1 and Multidrug resistance-associated protein 1 (MRP1) in mammary carcinoma MDA-MB-231 cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 735. doi:10.1158/1538-7445.AM2015-735
Abstract 736: Combining PD1- and CTLA4-inhibiting antibodies with cisplatin or PARP inhibition in an attempt to eradicate BRCA1-deficient mouse mammary tumors
Authors: Blatter Sohvi , Guyader Charlotte , Küçükosmanoğlu Aslı , Freriks Stephan , de Visser Karin , Borst Piet , Rottenberg Sven
Published: August 2015

Solid tumors are usually not eradicated by conventional chemotherapy resulting in disease relapse and mortality. An intriguing example is BRCA-associated breast cancer. A genetically engineered mouse model for BRCA1-associated breast cancer (K14Cre;Brca1F/F;p53F/F), which highly resembles disease in human patients, can be used to study therapy escape and residual disease in BRCA-deficient tumors. Due to the BRCA inactivation, the tumors that arise in this model lack homologous recombination-directed DNA repair, an Achilles heel that has provided a therapeutic opportunity to eradicate tumors with DNA damage-inducing agents. Despite repeated sensitivity some residual cancer cells escape the deadly effect of anticancer therapy and lead to disease relapse. A special histopathological feature of BRCA1-mutated tumors in both humans and mice is the presence of infiltrating lymphocytes. This may be explained by the high frequency of genomic alterations of BRCA1-mutated tumors resulting in the generation of many neo-antigens. Our hypothesis is that blocking inhibitory T-cell signaling, using antibodies directed against CTLA4 and PD1, may increase the activity of the T-cell compartment towards a diverse pool of antigens, and successfully eliminate residual tumor cells in combination with DNA damage-inducing drugs. In particular, we will present data of combining CTLA4- and PD1- targeting antibodies with PARP inhibition or cisplatin to eliminate residual tumor cells in this mouse model for BRCA1-mutated breast cancer.

Citation Format: Sohvi Blatter, Charlotte Guyader, Aslı Küçükosmanoğlu, Stephan Freriks, Karin de Visser, Piet Borst, Sven Rottenberg. Combining PD1- and CTLA4-inhibiting antibodies with cisplatin or PARP inhibition in an attempt to eradicate BRCA1-deficient mouse mammary tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 736. doi:10.1158/1538-7445.AM2015-736
Abstract 756: Inhibition of ABCB1 overcomes cancer stem cell-like properties and acquired resistance to MET inhibitor in non-small cell lung cancer
Authors: Sugano Teppei , Seike Masahiro , Noro Rintaro , Soeno Chie , Nakamichi Shinji , Nishijima Nobuhiko , Matsumoto Masaru , Takeuchi Susumu , Miyanaga Akihiko , Kubota Kaoru , Gemma Akihiko
Published: August 2015

Non-small cell lung cancer (NSCLC) patients with EGFR mutations have shown a dramatic response to EGFR inhibitors (EGFR-TKI). EGFR T790M mutation and MET amplification have been recognized as mechanisms of acquired resistance to EGFR-TKI. Recently, MET inhibitors have been used in NSCLC patients for clinical trials. In this study, we tried to identify the mechanisms of acquired resistant to MET inhibitor. We analyzed the antitumor effects of two MET inhibitors; PHA-665752 and crizotinib, in 10 NSCLC cell lines. EBC1 cells with MET amplification were only sensitive cells to both of MET inhibitors. We have established PHA-665752 resistant cells; namely EBC1-R cells. EBC1-R cells showed high expression levels of ATP-binding Cassette Sub-family B Member 1 (ABCB1) as wells as phosphorylation MET (p-MET). EBC1-R cells grew as cell sphere that exhibited cancer stem cell-like (CSC) properties and epithelial mesenchymal transition (EMT) feature. Two miRNAs, miR-374a and miR-138 which targeted ABCB1, were decreased in EBC1-R cells. ABCB1 inhibitor elacridar could suppress sphere numbers and EMT phenomenon and restore to the resistance to PHA-665752 in EBC1-R cells. Our study demonstrated that ABCB1 overexpression associated with CSC properties and EMT may be critical for acquire resistance for MET inhibitor. ABCB1 inhibition might be a novel therapeutic strategy for resistance to MET inhibitor in NSCLC cells.

Citation Format: Teppei Sugano, Masahiro Seike, Rintaro Noro, Chie Soeno, Shinji Nakamichi, Nobuhiko Nishijima, Masaru Matsumoto, Susumu Takeuchi, Akihiko Miyanaga, Kaoru Kubota, Akihiko Gemma. Inhibition of ABCB1 overcomes cancer stem cell-like properties and acquired resistance to MET inhibitor in non-small cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 756. doi:10.1158/1538-7445.AM2015-756
Abstract 783: Ponatinib demonstrates antitumor activity in RET- and FGFR-driven patient-derived xenografts
Authors: Gozgit Joseph M. , Song Youngchul , Rivera Victor M.
Published: August 2015

Background: Ponatinib is a potent pan-BCR-ABL tyrosine kinase inhibitor (TKI) approved for patients (pts) with refractory or T315I+ chronic myeloid leukemia or Ph+ acute lymphoblastic leukemia. We have previously shown that ponatinib also inhibits oncogenic variants of KIT, RET, and FGFR in vitro. Moreover, ponatinib induced complete regression of KIT-mutant tumors in a gastrointestinal stromal tumor (GIST) patient-derived xenograft (PDX), a finding consistent with the preliminary evidence of efficacy observed in pts with refractory GIST (NCT01874665). In this study, we evaluated ponatinib in a panel of PDXs harboring oncogenic variants of RET and FGFR.

Methods: The efficacy of ponatinib (20 mg/kg once-daily oral dosing) was compared to that of vehicle in 10 PDXs derived from a variety of tumor types containing oncogenic RET or FGFR fusions, high-level FGFR amplification (amp), or no known oncogenic drivers (WT; Table 1). Chemotherapeutic comparators (cisplatin or 5-fluorouracil) were included in 6 models. To confirm target modulation, levels of RET or FGFR phosphorylation in tumors were analyzed 6 hrs post dosing.

Results: Ponatinib induced tumor regression or ∼80% tumor growth inhibition (TGI) in the 4 RET fusion PDXs, and 62-98% TGI in the 3 FGFR PDXs (Table 1). Complete abrogation of target phosphorylation due to ponatinib treatment was verified in the 3 models examined. The efficacy of ponatinib exceeded that of the chemotherapy comparator in RET-driven but not WT PDXs, further suggesting this efficacy was driven primarily through inhibition of the driver oncogene.

Conclusion: Ponatinib demonstrates marked efficacy across several PDX models with either RET fusion-, FGFR2/3 fusion-, or FGFR2 amp-driven cancers, in a target dependent manner. These results provide additional support for evaluating ponatinib in pts with cancers positive for these aberrations; such trials are planned or ongoing (NCT01813734, NCT02265341, NCT01935336, and NCT02272998).

Table 1: Ponatinib's efficacy in PDX tumor modelsCancer TypeTargetTumor growth inhibition (%)Tumor regression (%)CRCCCDC6-RET-78CRCNCOA4-RET79-NSCLCKIF5B-RET80-NSCLCKIF5B-RET-12NSCLCMCU-FGFR290-GliomaTACC3-FGFR362-GastricFGFR2 amp98-CRCWT (control)41-CRCWT (control)24-NSCLCWT (control)51-

Citation Format: Joseph M. Gozgit, Youngchul Song, Victor M. Rivera. Ponatinib demonstrates antitumor activity in RET- and FGFR-driven patient-derived xenografts. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 783. doi:10.1158/1538-7445.AM2015-783
Abstract 797: Discovery of a highly selective and potent small molecule inhibitor against c-MET for cancer therapy
Authors: Bao Rudi , Pan Zhongzong , Zhao Zhiming , Yu Hongping , Xu Yaochang
Published: August 2015

c-MET is a receptor tyrosine kinase that is dysregulated in several types of maliganacies, including gastric, liver and lung cancers. Abnormal activation of c-MET could be caused by gene amplification, overexpression, or HGF aberrant expression. Activation of c-MET is involved in several cellular processes, including cell proliferation, cell migration, and angiogenesis. To explore c-MET targeted therapy, we discovered a small molecule that selectively inhibits c-MET activity with an IC50 of single digit nanomolar concentration across several cell lines. In xenograft tumor models from cell lines harboring cMET amplification including liver, gastric and lung cancer, tumor growth was significantly inhibited by this compound in a dose dependent manner. In addition, PD studies showed that c-MET and down-stream signaling pathways were blocked by the compound in the cMET amplified tumors. The compound also showed desirable PK and safety profiles. These data warrants further development of this compound for cancer therapy in cMET dysregulated cancers.

Citation Format: Rudi Bao, Zhongzong Pan, Zhiming Zhao, Hongping Yu, Yaochang Xu. Discovery of a highly selective and potent small molecule inhibitor against c-MET for cancer therapy. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 797. doi:10.1158/1538-7445.AM2015-797
Abstract 814: Truncated HBx-dependent silencing of growth arrest-specific 2 promotes hepatocarcinogenesis through inhibition of p53-mediated apoptosis
Authors: Cheng Alfred S. L. , Zhu Ranxu , Mok Myth T.S. , Kang Wai , To Ka-Fai , Sung Joseph J.Y. , Chan Henry L.Y.
Published: August 2015

Hepatocellular carcinoma (HCC) is a worldwide threat to public health, especially in China where chronic hepatitis B virus (HBV) infection is found in 80-90% of all HCCs. The HBV encoded X antigen (HBx) is a trans-regulatory protein involved in the virus-induced hepatocarcinogenesis. Although the carboxyl-terminus truncated HBx, rather than the full-length counterpart, is frequently overexpressed in human HCCs, its functional mechanisms have yet been fully defined. In this study, we investigated the molecular pathogenesis of a naturally-occurring HBx variant which has 35 amino acids deleted at C-terminus (HBxΔ35). By performing genome-wide scanning analysis and PCR validation, we identified growth arrest-specific 2 (GAS2) as a direct target of HBxΔ35 at transcriptional level in human immortalized liver cells. HBxΔ35 was found to bind the promoter region of GAS2 and suppress its expression to promote hepatocellular proliferation and tumorigenicity. Further functional assays showed that overexpression of GAS2 inhibited tumor growth both in vitro and in vivo by inducing p53-dependent apoptosis. Conversely, siRNA-mediated knockdown of GAS2 in hepatocytes attenuated apoptotic response and reduced cell susceptibility to etoposide-induced apoptosis. Notably, GAS2 expression was significantly down-regulated in truncated HBx-expressing HCCs compared with the corresponding normal tissues. In conclusion, our integrated study uncovered a novel viral mechanism in hepatocarcinogenesis, wherein HBxΔ35 ablates p53-driven apoptosis via direct silencing of GAS2, and thereby provides survival advantage for pre-neoplastic hepatocytes to facilitate cancer development.

Citation Format: Alfred S. L. Cheng, Ranxu Zhu, Myth T.S. Mok, Wai Kang, Ka-Fai To, Joseph J.Y. Sung, Henry L.Y. Chan. Truncated HBx-dependent silencing of growth arrest-specific 2 promotes hepatocarcinogenesis through inhibition of p53-mediated apoptosis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 814. doi:10.1158/1538-7445.AM2015-814