bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3019: The role of TACC3 in the progression from ductal carcinoma in situ to invasive breast cancer
Authors: Campo Loredana , Mathew Maya , breuer Eun-Kyoung , Small William
Published: July 2017

Ductal carcinoma in situ (DCIS) is a non-invasive breast cancer with the potential to become invasive/metastatic. The development of DCIS to invasive breast cancer is an important aspect of breast tumor aggressiveness, however, little is known about the genetic and molecular alterations involved in this progression. Also, analysis of molecular markers and genetic signatures of DCIS and invasive breast cancer have failed to identify transition-specific biomarkers or pathways. Hence, identifying the molecular mechanisms by which DCIS progresses to invasive breast cancer is critical for the success of diagnosis, prognosis and therapy of breast cancer. Members of the transforming acidic coiled-coil (TACC) protein family are key players in the maintenance of centrosome integrity, the regulation of microtubule assembly, and spindle stability during mitosis. TACC3 has been shown to be involved in the regulation of centrosome-microtubule dynamic networks, cell growth and differentiation, and transcription/gene expression through interactions with other molecules. Mounting evidence indicates that high levels of TACC3 may contribute to breast cancer development. Here, we investigated the significance of TACC3 in the transition of DCIS to invasive breast cancer. First, we examined the expression of TACC3 in non-tumorigenic human mammary epithelial MCF10A cells and MCF10DCIS.COM cells, which are known to form DCIS-like lesions in mice and to progress to invasive cancer, and found that the expression of TACC3 is elevated in MCF10DCIS.COM cells compared to MCF10A cells. By analyzing tissue microarray data, we found that expression of TACC3 gradually increased from normal breast to DCIS, and further increased in invasive breast cancer. In addition, ectopic expression of TACC3 in MCF10DCIS.COM cells promoted cell proliferation, migratory and invasive capabilities as well as the epithelial-mesenchymal transition (EMT)-like phenotype. Moreover, MCF10DCIS.COM cells stably expressing TACC3 exhibited increased expression of stemness markers. Interestingly, a small molecule inhibitor of TACC3, KHS101 treatment in MCF10DCIS.COM cells significantly suppressed cell proliferation and the PI3K/AKT signaling pathway while having little effect on MCF10A cells. Our findings, therefore, suggest that TACC3 may play an important role in the progression from DCIS to invasive breast cancer and that targeting TACC3 could be a promising new therapeutic strategy for DCIS patients.

Citation Format: Loredana Campo, Maya Mathew, Eun-Kyoung breuer, William Small. The role of TACC3 in the progression from ductal carcinoma in situ to invasive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3019. doi:10.1158/1538-7445.AM2017-3019
Abstract 303: Oncogenic activity of amplified miniature chromosome maintenance 8 in human malignancies
Authors: Luo Jian-Hua , He Dong-Mei , Ren Baoguo , Yu Yan
Published: July 2017

Miniature chromosome maintenance (MCM) proteins play critical roles in DNA replication licensing, initiation and elongation. MCM8, one of the MCM proteins playing critical role in DNA repairing and recombination, was found to have over-expression and increased DNA copy number in a variety of human malignancies. The gain of MCM8 is associated with aggressive clinical features of several human cancers. Increased expression of MCM8 in prostate cancer is associated with cancer recurrence. Forced expression of MCM8 in RWPE1 cells, the immortalized but non-transformed prostate epithelial cell line, exhibited fast cell growth and transformation, while knocked down of MCM8 in PC3, DU145 and LNCaP cells induced cell growth arrest, and decreased tumor volumes and mortality of severe combined immunodeficiency mice xenografted with PC3 and DU145 cells. MCM8 bound cyclin D1 and activated Rb protein phosphorylation by cyclin-dependent kinase 4 in vitro and in vivo. The cyclin D1/MCM8 interaction is required for Rb phosphorylation and for S phase entry in cancer cells. As a result, our study showed that copy number increase and overexpression of MCM8 may play critical roles in human cancer development.

Note: This abstract was not presented at the meeting.

Citation Format: Jian-Hua Luo, Dong-Mei He, Baoguo Ren, Yan Yu. Oncogenic activity of amplified miniature chromosome maintenance 8 in human malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 303. doi:10.1158/1538-7445.AM2017-303
Abstract 3030: Mutant p53-driven metastasis explored utilizing a traceable, conditional osteosarcoma model
Authors: Pourebrahimabadi Rasoul , Zhang Yun , McArthur Mark J. , Lozano Guillermina
Published: July 2017

TP53 is the most frequently mutated gene in cancer and missense mutations in particular account for the majority of mutations. Mutant p53 proteins exert oncogenic Gain-of-Function (GOF) properties that contribute to increased migration and invasion in culture and metastasis in vivo. To elucidate how mutant p53 drives metastasis, we developed a traceable somatic osteosarcoma model that initiates with a single p53 mutation (p53R172H or p53R245W), or p53 loss specifically in osteoblasts using Osx-cre. To mark tumor cells, we utilized the mTmG allele which expresses membrane-targeted Tomato (mT) prior to Cre-mediated excision and membrane-targeted green fluorescent protein (mG) after excision so the tumor cells become GFP+ and the stromal cells remain RFP+. In this high penetrant, short latency mouse model, tumor micro-metastasis can be detected by GFP expression in the context of a normal stroma and immune system. The cohort has developed osteosarcoma with complete penetrance and an average survival of 304± 65 day. We observed metastasis in 55% of p53 mutant osteosarcomas which was significantly higher than 26% metastasis observed in p53 null tumors (p<0.01). In p53 mutant osteosarcomas, the metastasis rate was found significantly associated with low p53 copy number. Spectral karyotyping (SKY) on early passage cells derived from somatic p53 mutant tumors exhibited marked aneuploidy with modal chromosome numbers near tetraploid. To characterize the transcriptional profile associated with mutant p53 GOF, we analyzed and compared the RNA-Seq transcriptomes of eight tumors derived from p53R172H mutant mice with eight p53 null tumors. Comparative analysis of gene expression identified a signature of snRNA genes to be strongly associated with mutant p53 gain of function. Functional annotation of upregulated genes in mutant tumors was also highly enriched for chromatin modifying enzymes. These findings contribute to our understanding of the role of mutant p53 GOF in metastasis. Our long term goal is to study how tumor-stromal interactions affect tumor development and metastasis. This understanding will have broad translational significance in diagnosis and treatment of tumors with mutant p53.

Citation Format: Rasoul Pourebrahimabadi, Yun Zhang, Mark J. McArthur, Guillermina Lozano. Mutant p53-driven metastasis explored utilizing a traceable, conditional osteosarcoma model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3030. doi:10.1158/1538-7445.AM2017-3030
Abstract 3033: The PRL family of tyrosine phosphatases as a novel drug targets in acute lymphoblastic leukemia
Authors: Blackburn Jessica S.
Published: July 2017

The aggressive and unpredictable behavior of acute lymphoblastic leukemia (ALL) presents a major clinical challenge in both the pediatric and adult setting. The development of new and better chemotherapies for this disease requires a detailed understanding of the genes and pathways that drive ALL malignancy. Phosphatases are emerging as new drug targets with important roles in leukemia progression. To determine the extent to which phosphatases play a role in ALL malignancy, we used CRISPR/Cas9 to knock out expression of 255 individual phosphatases in human T-cell acute lymphoblastic leukemia cell lines and screened for deleterious effects on cell viability. Top hits from this screen included the protein tyrosine phosphatase type IVa family, also known as the PRLs. PRL3 is genomically amplified in a subset of human T-ALL, and more than 50% of human ALL patients have significantly higher expression of PRL2 and/or PRL3, compared to normal lymphocytes, suggesting that these PRLs may play an important role in ALL malignancy. Transgenic Myc-induced ALL models in zebrafish showed that overexpression of PRL2 and PRL3 significantly shortened latency of primary and relapse ALL, enhanced leukemia stem cell self-renewal (PRL2) and prevented apoptosis after standard chemotherapy treatment (PRL3). Finally, a specific PRL inhibitor strongly induced apoptosis of PRL-expressing ALL cells in a dose-dependent manner, in both zebrafish models in vivo and human cell lines in vitro. We have identified several FDA-approved, general phosphatase inhibitors that have potent anti-PRL activity and are capable of killing ALL cells in vitro. Current work is focused on moving these inhibitors into pre-clinical testing using patient-derived xenografts. Pull-down approaches are also being used to identify the substrates of PRL phosphatase activity that are critical to ALL survival and may represent new, tractable drug targets for the treatment of ALL.

Citation Format: Jessica S. Blackburn. The PRL family of tyrosine phosphatases as a novel drug targets in acute lymphoblastic leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3033. doi:10.1158/1538-7445.AM2017-3033
Abstract 3035: Decomposing oncogenic transcriptional signatures to generate maps of divergent cellular states
Authors: Kim William J. , Hahn William C. , Mesirov Jill , Tamayo Pablo
Published: July 2017

The systematic sequencing of the cancer genome has provided a powerful framework for identifying genetic alterations in cancer. However, a deeper understanding of the functional consequences of these alterations is necessary to guide appropriate therapeutic strategies. Here, we describe Onco-GPS (OncoGenic Positioning System), a data-driven analysis framework, and associated experimental and computational methodology, to organize individual tumor samples with shared oncogenic alterations onto a reference map defined by their underlying cellular states. Using this approach, we generated series of RAS/MAPK sub-signatures that reflect known and novel downstream pathways. These sub-signatures were then used to classify KRAS and BRAF mutant cancers into sub groups or cell states, as represented in the novel visual paradigm “OncoGPS map”. OncoGPS approach was first applied to cancers with BRAF mutations. The approach not only accurately classified three groups of BRAF mutant cancers that aligned with sensitivity to BRAF inhibitors, but also identified resistance mechanisms associated with each state, validating the overall approach. OncoGPS also identified four major cell states associated with KRAS mutant cancers. Further characterization of the four cell states showed that multiple molecular features representing epithelial-EMT states and activation of NF-κB pathway delineated two major “axes” of KRAS mutant cancers. In addition to the pathways and cell states defined in each group, the OncoGPS approach is able to identify effective drug combinations which was experimentally tested and confirmed. These results show that the Onco-GPS is an effective analytic framework to explore the complex landscape of oncogenic cellular states across cancers, and a powerful framework to summarize knowledge, establish relationships, and generate more effective disease models for research or as part of individualized precision medicine paradigms.

Citation Format: William J. Kim, William C. Hahn, Jill Mesirov, Pablo Tamayo. Decomposing oncogenic transcriptional signatures to generate maps of divergent cellular states [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3035. doi:10.1158/1538-7445.AM2017-3035
Abstract 306: Antitumor effect of Wee1 inhibitor in gastric cancer cells
Authors: Kim Seongyeong , Min Ahrum , Kim So Hyeon , Ha Dong Hyeon , Jang Hyemin , Kim Yu JIn , Kim Hee Jun , Lee Kyung-Hun , Kim Tae-Yong , Oh Do-Youn , Bang Yung-Jue , Im Seock-Ah
Published: July 2017

Background: A cell cycle checkpoint is a key step to watch any damages and, it is needed to maintain genomic stability. Thus, to jeopardize cell cycle checkpoint is an attractive strategy for cancer treatment. Wee1 is a G2 cell cycle regulator that phosphorylate cdc2 on tyrosine 15 for inhibiting its activity. The activation of Wee1 can delay G2 phase progression and cells can have a chance to repair DNA damages. Therefore, to inhibit wee1 can accelerate DNA damage accumulation in the cell. AZD1775 is a first-in-class wee1 inhibitor. So far, previous studies showed the antitumor effect of AZD1775 as a mono-therapeutic agent or combination treatment with other chemo-agents. However, the activity of wee1 in gastric cancer (GC) cells is not yet fully understood. Thus, we would like to study whether AZD1775 has an antitumor effect against GC or not.

Materials and methods: We determined the antitumor effects of AZD1775 on GC cells using a cytotoxicity assay, cell cycle analysis, immunofluorescence assay and western blotting by AZD1775 treatment.

Results: AZD1775 effectively inhibit GC cell proliferation. The TP53 gene status or p-Wee1 expression levels were not associated with AZD1775 sensitivity. AZD1775 effectively down-regulated p-Wee1 and p-cdc2 expressions in SNU-601, a sensitive cell line. However, these effects were not significant in KATO-III cells, which is less sensitive to AZD1775. Cell cycle analysis revealed that the cells had different responses by AZD1775 treatment. SNU-601 cells were enriched in S phase when we decide cell cycle only by its DNA contents. However, KATO-III cells were arrested in G2/M phase. The sub-G1 population was dramatically increased only in SNU-601 cells. A population of BrdU-positive and p-HH3 positive cells was significantly increased in the SNU-601 cells which indicate that premature mitosis was increased. However, no differences were observed in KATO-III cells. Moreover, due to premature mitotic entry, multi-nucleated cells were observed only in SNU-601 cells.

Conclusion: AZD1775 effectively inhibited the growth of GC cell lines. The inhibition of cdc2 by AZD1775 was observed only in a sensitive cell line. Moreover, early mitotic entry was induced by AZD1775, and it led the induction of mitotic catastrophe. This result indicates that AZD1775 have an antitumor effect on GC and the possibility of adoption to the clinical trial design.

Citation Format: Seongyeong Kim, Ahrum Min, So Hyeon Kim, Dong Hyeon Ha, Hyemin Jang, Yu JIn Kim, Hee Jun Kim, Kyung-Hun Lee, Tae-Yong Kim, Do-Youn Oh, Yung-Jue Bang, Seock-Ah Im. Antitumor effect of Wee1 inhibitor in gastric cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 306. doi:10.1158/1538-7445.AM2017-306
Abstract 3064: Retinoic acid: An effective therapy for basal-like breast cancer
Authors: Coyle Krysta Mila , Dean Cheryl A. , Vidovic Dejan , Weaver Ian C. , Giacomantonio Carman A. , Marcato Paola
Published: July 2017

We have identified a novel strategy to identify breast cancer patients who will benefit from an existing anti-cancer agent, retinoic acid (RA). While RA has not yet achieved success in the treatment of breast cancers, we hypothesized that it can be an effective therapy for a subset of triple-negative breast cancer (TNBC) patients. TNBC is among the most aggressive breast cancers, and lacks targeted therapies. TNBCs can be further subtyped into basal-like and claudin-low, which differ in gene expression and drug sensitivities. Understanding the molecular basis of these subtypes will lead to the development of more effective treatment options for TNBC. To test this hypothesis, we performed tumor growth assays on TNBC cell lines and patient-derived xenografts (PDXs). We found that RA treatment decreased the tumor growth of four basal-like TNBC cell lines (MDA-MB-468, HCC70, SUM149, HCC1937). In contrast, RA increased the tumor growth of two claudin-low TNBC cell lines (MDA-MB-231, MDA-MB-436). Gene expression and methylation analysis of these affected cell lines revealed subtype-specific expression of RA-inducible genes due to silencing by DNA methylation, e.g. of the RA-inducible tumor-suppressor gene RARRES1. RARRES1 is silenced by methylation in claudin-low cell lines, but is hypomethylated and expressed in basal-like cells. Use of the subtype-specific expression and methylation profiles allowed us to accurately predict the response of 4 PDXs to RA treatment. Continued classification of TNBCs into these two subtypes will enable clinical use of RA, in part due to the subtype-specific hypomethylation of RA-inducible tumor suppressor genes including RARRES1. We have identified additional subtype-specific biomarkers which can predict the response of patient tumors to RA treatment, thus identifying a novel targeted therapy strategy for TNBCs.

Citation Format: Krysta Mila Coyle, Cheryl A. Dean, Dejan Vidovic, Ian C. Weaver, Carman A. Giacomantonio, Paola Marcato. Retinoic acid: An effective therapy for basal-like breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3064. doi:10.1158/1538-7445.AM2017-3064
Abstract 3067: Galectin-3, a target for KRAS-addicted lung cancer
Authors: Seguin Laetitia , Camargo Maria F. , Wettersten Hiromi I. , Kato Shumei , Schalscha Tami von , Elliott Kathryn C. , Weis Sara M. , Cheresh David A.
Published: July 2017

KRAS-mutant cancers are notoriously therapy-resistant. While responsible for oncogenesis, mutant KRAS or the sustained activation of KRAS-driven effectors may or may not be required throughout the course of cancer progression. Thus, understanding which tumors remain dependent on oncogenic KRAS could lead to the identification of unique vulnerabilities and opportunities to treat them. We previously discovered that the carbohydrate-binding Galectin-3 (Gal-3) brings together KRAS with integrin αvβ3 at the cell membrane in epithelial cancer cells to promote tumor progression. Here, we show that by directly binding to the cell surface receptor integrin αvβ3, Gal-3 drives addiction to oncogenic KRAS by enhancing macropinocytosis and reducing mitochondrial reactive oxygen species (ROS). This pathway drives increased expression of SOD2, a superoxide dismutase that clears mitochondrial ROS to protect against cell death. Targeting Gal-3 with a clinically active drug decreases macropinocytosis and increases ROS to eradicate KRAS-addicted lung cancer in patient-derived xenografts and spontaneous KRAS-driven lung cancer in mice. Our work reveals Gal-3 as a druggable target for KRAS-addicted lung cancer, and indicates integrin αvβ3 as a biomarker to identify this dependence.

Citation Format: Laetitia Seguin, Maria F. Camargo, Hiromi I. Wettersten, Shumei Kato, Tami von Schalscha, Kathryn C. Elliott, Sara M. Weis, David A. Cheresh. Galectin-3, a target for KRAS-addicted lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3067. doi:10.1158/1538-7445.AM2017-3067
Abstract 307: TRIB3 regulates cell cycle progression and programmed cell death in non-small cell lung cancer
Authors: Almiman Abeer , Nie Daotai , Adom Jamila
Published: July 2017

Introduction: The pseudokinase Tribbles pseudokinase 3 (TRIB3) is known as a regulator in cellular responses to a variety of stresses such as glucose insufficiency and (ER) stress. TRIB3 has been described in some studies as a tumor suppressor due to its effect on inactivating PI3K/Akt pathway, but other studies suggest TRIB3 as a stimulator of tumor progression. In this study, we aimed to define the functions of TRIB3 in in non-small cell lung cancer.

Methods: TRIB3 expression was altered using a lentiviral vector to overexpress TRIB3 in non-small cell lung cancer. A CRISPR-CAS9 construct with guiding sequence matching to TRIB3 gene was used to knock out its expression. Cell proliferation was evaluated using MTS and trypan blue assays. Boyden chamber assay was used to assess the cell migration while cell cycle phases were determined using flow cytometry. Heatmap analysis was performed to assess the changes in the expressions of genes in cell cycle progression and apoptosis.

Results: TRIB3 overexpression led to reduced cell proliferation and migration. Moreover, it contributed to the increased of cell cycle arrest at G0/G1 phase. QPCR analyses of cell cycle related genes showed an upregulation of CDK inhibitors in (NCI-H358) TRIB3 overexpression cells, while depletion of TRIB3 led to the down-regulation of CDK inhibitors. TRIB3 overexpression led to downregulation of LC3B and other autophagy markers while increasing the expression of apoptotic genes.

Conclusion: Increased TRIB3 expression in non-small cell lung cancer cells inhibited proliferation by blocking cell cycle progression through the upregulation of CDK inhibitors, led to activation of cell death through apoptosis. Our study reveals a significant role of TRIB3 in regulating cell cycle progression, apoptosis and autophagy.

Citation Format: Abeer Almiman, Daotai Nie, Jamila Adom. TRIB3 regulates cell cycle progression and programmed cell death in non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 307. doi:10.1158/1538-7445.AM2017-307
Abstract 3074: Selective lethality of cisplatin in pancreatic cancer is dependent on mitotic functions of BRCA2
Authors: Orelli Barbara , Maurer Hans C. , Palermo Carmine , Sastra Steven A. , Olive Kenneth P.
Published: July 2017

Pancreatic ductal adenocarcinoma (PDA) is an aggressive malignancy with a 5-year survival rate of just 8%. Mutations in BRCA2 are among the most common known germline alterations that predispose to PDA. While the sensitivity of BRCA2-mutant breast and ovarian tumors to platinum compounds has long been recognized, the recent approval a PARP inhibitor in BRCA2-mutant ovarian cancer confers hope that such tumors might be targeted with greatly reduced toxicity. To test whether PDA exhibits a similar genetic susceptibility to these agents, we carried out preclinical intervention studies in Kras/p53-mutant genetically engineered mouse models (KPC mice) with or without the additional mutation of BRCA2 (KPCB2 mice). Mice were enrolled based on 3D ultrasound imaging criteria to assure similar initial tumor burden, and tumor growth was monitored longitudinally by ultrasound. To our surprise, loss of Brca2 failed to sensitize pancreatic tumors to Parp inhibition and did not provide additional benefit in combination with cisplatin treatment. By contrast, cisplatin induced substantial regressions in most KPCB2 tumors, leading to a >3-fold increase in overall survival, while having no effect on the growth or survival of mice with wild-type BRCA2. More surprisingly, the efficacy of cisplatin was not shared with oxaliplatin, even at higher doses.

While BRCA2 is primarily known for its role in homology-directed repair, a network biology analysis of the function of BRCA2 in human pancreatic cancer led us to investigate the role of BRCA2 in mitosis. Wild type BRCA2 protein localizes to the midbody- a structure formed during the final stages of telophase- and plays and poorly understood role in the final abscission of cytoplasm between two dividing cells. Timelapse video microscopy of KPCB2 tumor cells treated once weekly for 2 hours with cisplatin revealed the frequent induction of endoreduplication and eventual formation of polyploid giant cells subsequent death. Similar cells were found throughout KPCB2 tumors during regression in response to cisplatin treatment, but were largely absent from tumors in other treatment arms. Mechanism studies found that BRCA2 deficient PDA cells are susceptible to replicative stress following cisplatin treatment that selectively leads to the formation of radial chromosomes that cannot be resolved during mitosis. These studies argue for the consideration of cisplatin-based (rather than oxaliplatin-based) regimens for the treatment of BRCA2-mutant pancreatic tumors.

Citation Format: Barbara Orelli, Hans C. Maurer, Carmine Palermo, Steven A. Sastra, Kenneth P. Olive. Selective lethality of cisplatin in pancreatic cancer is dependent on mitotic functions of BRCA2 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3074. doi:10.1158/1538-7445.AM2017-3074
Abstract 3078: The role of extracellular vesicles in chemotherapy resistance in gastric cancer
Authors: Cassinela Edson , Landemberger Michele C. , Oliveira Gabriela P. de , Martins Vilma Regina
Published: July 2017

Gastric adenocarcinoma (GAd) is the fourth most common cancer and the second cause of cancer death in the world. Chemotherapy has been largely used to treat this disease however acquired drug resistance is a common event and is associated to the development of new more aggressive clones of tumor cells. Herein, a gastric adenocarcinoma cell line (AGS) resistant to the 5-fluorouracil (rAGS-FU) was generated in order to establish mechanisms associated to acquire drug resistance. In the presence of 5-FU (10μM) resistant cells show a 2-3 times higher proliferation ratio than parental cells, a plating efficiency of 38% compared to 1% of parental cells and a higher invasive phenotype. Remarkable, when compared to parental cells, rAGS-FU resistant cells secreted 2-3 times more extracellular vesicles, EVs (85-175nm). When parental cells were treated with EVs from rAGS-5-FU resistant cells they acquired the same phenotype of the latter cells regarding higher proliferation, plating efficiency and invasion. The proteomic analysis of parental and rAGS-FU cells showed 306 differentially expressed proteins, while 66 differentially expressed proteins were found when EVs secreted from these cells were compared. Our data suggest that cells resistant to chemotherapy have a more aggressive phenotype and are able to transfer these characteristics to non-resistant cells. These findings point to mechanisms of chemoresistance mediated by components that are carried from cell to cell by EVs, what may indicate novel approaches that can be addressed to impair drug resistance and improve treatment response.

Supported by FAPESP

Citation Format: Edson Cassinela, Michele C. Landemberger, Gabriela P. de Oliveira, Vilma Regina Martins. The role of extracellular vesicles in chemotherapy resistance in gastric cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3078. doi:10.1158/1538-7445.AM2017-3078
Abstract 3082: Deficient NOXA in HER2-amplified breast cancer drives kinase inhibitor resistance
Authors: Floros Konstantinos V. , Song Kyung-A , Lochmann Timothy L. , Hughes Mark T. , Heisey Daniel A. , Harada Hisashi , Hu Bin , Koblinski Jennifer , Souers Andrew J. , Leverson Joel D. , Faber Anthony C.
Published: July 2017

The purpose of this study is the development of a novel combination therapy that targets HER2-amplified breast cancer. About one quarter of breast cancers harbor amplification of HER2. HER2 is a transmembrane receptor tyrosine kinase (RTK) belonging to the ERBB family of receptors (ERBB1-4). Upon hetero- and homo-dimerization, HER2 activates several key intracellular pathways, regulating many cellular functions including proliferation and survival. HER2 inhibitors (HER2i) (e.g. the receptor tyrosine kinase (RTK) inhibitor, lapatinib) are now part of standard care for treating HER2-amplified breast cancers. However, despite their anti-cancer benefit, these drugs have limited efficacy as monotherapies, which contrasts to other RTK inhibitors in other RTK-driven cancers. To better understand this apparent dichotomy, in the present study, we evaluated potential modifiers of HER2i therapy. Here, we found that the pro-apoptotic NOXA, a member of the B-cell CLL/lymphoma 2 (BCL2) family which acts mainly via inhibitory binding of the pro-survival MCL-1, was markedly down-regulated in breast cancers compared to other cancers, and this was largely attributed to the HER2-amplified subset. Experimentally, overexpressing NOXA or silencing MCL-1 dramatically sensitizes HER2 amplified breast cancer cell lines to lapatinib via apoptosis. Consistently, pharmaceutical inhibition of MCL-1 sensitizes HER2-amplified breast cancers to lapatinib in vitro and in vivo. Mechanistically, disruption of MCL-1:BIM complexes and MCL-1:BAK underlie dual HER2i/MCL-1i therapy. Therefore, deficient NOXA expression constitutes a bonafide apoptotic block in HER2 amplified breast cancers, contributes to mitigated HER2i responses, and presents a rational combination therapy that may improve HER2i responses.

Citation Format: Konstantinos V. Floros, Kyung-A Song, Timothy L. Lochmann, Mark T. Hughes, Daniel A. Heisey, Hisashi Harada, Bin Hu, Jennifer Koblinski, Andrew J. Souers, Joel D. Leverson, Anthony C. Faber. Deficient NOXA in HER2-amplified breast cancer drives kinase inhibitor resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3082. doi:10.1158/1538-7445.AM2017-3082
Abstract 3084: Therapeutic implications of sex hormone signaling in melanoma
Authors: Natale Christopher , Zhang Junqian , Dahal Ankit , Ridky Todd
Published: July 2017

Female gender, early age of first birth, and multiparity are associated with less aggressive melanoma; however, the mechanisms underlying the apparent clinical benefit are undefined. Previously we reported that 17β-estradiol drives melanocyte differentiation through G-protein coupled estrogen receptor (GPER), a nonclassical sex hormone receptor. Here, we use genetically-defined human skin xenograft melanoma to show that pregnancy antagonizes oncogenic BRAF and inhibits melanomagenesis. Transient GPER activation drives stable melanocyte differentiation that persists after removal of the activating ligand. Consistent with this, brief exposure of melanoma cells to GPER agonists prior to xenografting inhibited subsequent tumor growth. Systemic treatment with GPER agonists cooperated with PD-1 blockade in melanoma bearing mice to greatly prolong survival longer than that observed with either agent alone. The combination of differentiation-based therapies with immunotherapy may have significant therapeutic benefit for melanoma.

Citation Format: Christopher Natale, Junqian Zhang, Ankit Dahal, Todd Ridky. Therapeutic implications of sex hormone signaling in melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3084. doi:10.1158/1538-7445.AM2017-3084
Abstract 310: Enhanced stability of D-type cyclins correlates with glioblastoma resistance to ionizing radiation
Authors: Guessous Fadila , Benamar Mouadh , Zhong Hui , Abbas Tarek
Published: July 2017

Transition from G1 to S phase of the cell cycle is promoted by D-type cyclins (D1, D2 and D3), regulatory subunits critical for the activation of cyclin dependent kinases 4 and 6 (CDK4/6), which phosphorylate and inactivate the retinoblastoma protein (pRb) and activate the transcription factor E2F1 to promote the expression of genes essential for DNA synthesis. Deregulated expression of D-type cyclins is frequently observed in human malignancies and correlates with increased proliferation. Cyclin Ds overexpression is also associated with radioresistance, leading to radiotherapy failure and disease recurrence. Cyclin D1 undergoes ubiquitin-dependent degradation following the exposure of cancer cells to ionizing radiation (IR), and this has been shown to be critical for IR-induced G1 growth arrest and sensitivity of cancer cells to IR. While the role of cyclin D1 overexpression in drug resistance is already well documented, less is known about the role of cyclins D2 and D3 in radio-resistance in human cancer cells, particularly in brain neoplasms. In the present study, we investigated the effect of IR on different D-type cyclins (D1, D2, D3) in human glioblastoma cell lines as well as in tumor-derived mouse oligodendrocytes progenitor cells (OPCs). Here, we show that exposure of human astrocytes to increasing levels of IR led to a rapid proteasomal degradation of all three D-type cyclins. On the other hand, IR failed to induce significant cyclin Ds degradation in a number of human glioblastoma cells (U87, A172, U251, Snb19). Analysis of cell cycle profile of all glioblastoma cells tested and exposed to IR showed prominent cell cycle arrest in G1 starting at 24 hours following exposure. Furthermore, we show that the steady-state levels of D-type cyclin is higher in OPCs compared to mouse NIH3T3 cells and fail to undergo proteasomal degradation following IR exposure. Collectively, these results suggest that the degradation of D-type cyclins is not critical for IR-induced G1 cell cycle arrest in GMB and may underlie their resistance to IR. Understanding the role of cyclin Ds in promoting radioresistance may lead to a useful pharmacological strategy to enhance radiotherapy outcome and help implement a more effective treatment modality.

Citation Format: Fadila Guessous, Mouadh Benamar, Hui Zhong, Tarek Abbas. Enhanced stability of D-type cyclins correlates with glioblastoma resistance to ionizing radiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 310. doi:10.1158/1538-7445.AM2017-310
Abstract 3106: Targeted delivery via Elastin Like Polypeptide: Biodistribution of a doxorubicin derivative in MDA-MB231 human breast cancer xenografts in mice
Authors: Dragojevic Sonja , Ryu Jung Su , Kratz Felix , Raucher Drazen
Published: July 2017

The anticancer agent doxorubicin has been widely used in the treatment of a variety of hematological malignancies and solid tumors. Despite doxorubicin’s efficiency in eradicating tumor cells, severe damage to healthy tissues, along with cardiotoxicity, limits its use in clinics. To overcome adverse side effects, improve patient safety, and enhance therapeutic efficacy, we have designed a thermally responsive biopolymer doxorubicin carrier that can be specifically targeted to tumor tissue by locally applying mild hyperthermia (41 degrees C).

The developed drug vehicle is composed of: a cell penetrating peptide (SynB1) to promote tumor and cellular uptake; thermally responsive Elastin like polypeptide (ELP); and the (6-maleimidocaproyl) hydrazone derivative of doxorubicin (DOXO-EMCH) containing a pH-sensitive hydrazine linker that releases dox in the acidic tumor environment. We used the in vivo imaging system, IVIS, to determine the biodistribution of doxorubicin-delivered ELP in MDA-MB231 triple negative human breast cancer cell line xenografts in nude mice. Tumor bearing mice were treated with a single IV injection of 10 mg/kg doxorubicin equivalent dose with free doxorubicin, thermally responsive SynB1 ELP 1-DOXO, and a thermally nonresponsive control biopolymer, SynB1 ELP 2-DOXO. Following a 2 hour treatment with hyperthermia, tumors showed a 2-fold higher uptake when treated with SynB1 ELP 1-DOXO compared to free doxorubicin. Accumulation of the thermally non-responsive control SynB1 ELP2 -DOXO was comparable to free doxorubicin, indicating that an increase in dox accumulation with ELP is due to aggregation in response to thermal targeting. Higher levels of SynB1 ELP1 -DOXO and SynB1 ELP2 -DOXO with respect to free doxorubicin were observed in kidneys. Fluorescence intensity from hearts of animals treated with SynB1 ELP1 - DOXO show a 5-fold lower accumulation of doxorubicin than the same dose of free doxorubicin. SynB1-ELP1-DOXO biopolymers demonstrated a 6-fold increase in tumor/heart ratio in comparison to free doxorubicin, indicating preferential accumulation of the drug carrier in tumors.

Overall, thermally targeted polymers are a promising therapy to enhance tumor targeting and uptake of anticancer drugs and to minimize free drug toxicity in healthy tissues, representing a great potential for clinical application.

Citation Format: Sonja Dragojevic, Jung Su Ryu, Felix Kratz, Drazen Raucher. Targeted delivery via Elastin Like Polypeptide: Biodistribution of a doxorubicin derivative in MDA-MB231 human breast cancer xenografts in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3106. doi:10.1158/1538-7445.AM2017-3106
Abstract 3111: Validated antibody Database: A curated database of antibodies cited in formal publications
Authors: Xie Hanqing
Published: July 2017

Currently research antibodies have a serious quality problem, which is one of the major contributing factors to the irreproducibility of published reports. Labome organizes antibody applications cited in formal publications and has developed Validated Antibody Database (VAD). VAD, a manually curated database, compiles commercial and non-commercial antibodies whose specificities and applications have been independently reported in published results from formal articles. Labome prioritizes the curation of articles with knockout studies and monoclonal antibodies. One of the benefits of our curation effort is the identification of cross-reactive species and novel applications for antibodies, which are often developed for human/mouse proteins and tested by suppliers for a limited number of applications. Labome registers many antibodies having cross-reactivities with model organisms such as flies, worms, zebrafish, and frogs and with novel applications from the literature. The current version released in September 2016 is based on over 50000 formal publications and is freely accessible for online browsing.

Citation Format: Hanqing Xie. Validated antibody Database: A curated database of antibodies cited in formal publications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3111. doi:10.1158/1538-7445.AM2017-3111
Abstract 3114: The role of prostaglandin signaling in human glioblastoma cell activities and growth in vitro and in vivo
Authors: Qiu Jiange , Du Yifeng , Li Qianqian , Shi Zhi , Jiang Jianxiong
Published: July 2017

Glioblastoma multiforme (GBM) constitutes the most frequent and aggressive form of malignant brain primary tumors. Despite current combined treatment involving surgery, chemotherapy and radiation therapy, the median survival of GBM patients is only about one year, with less than 3-5% of patients surviving over 5 years. Cyclooxygenase-2 (COX-2) is overexpressed in glioblastoma, and its expression level is highly positively correlated with the tumor grade. As a major enzymatic product of COX-2, prostaglandin E2 (PGE2) mediates inflammatory processes within the brain and facilitates progression of many chronic inflammation-associated neurological diseases via its four downstream receptors - EP1-EP4. We hypothesize that selectively targeting these receptors might provide an alternative therapeutic strategy for GBM with more specificity than generic blockade of the entire COX-2 cascade. In this study, two engineered human GBM cells with or without activated COX-2 were used to explore the PGE2 signaling involved in the development and progression of GBM. COX-2 activation by LPS or its overexpression facilitated migration, invasion, and transformation of these GBM cells in vitro. Moreover, the COX-2-mediated GBM cell activities were substantially suppressed by selective antagonists of PGE2 receptors that are highly expressed in these cells. Furthermore, the tested PGE2 receptor selective antagonists also suppressed the growth of GBM cells in vivo. In sum, our results suggested the inflammatory PGE2 signaling is involved in human GBM cell inflammation, migration, invasion and transformation through its downstream receptors, and should be explored as alternative molecular targets for novel GBM therapies.

Citation Format: Jiange Qiu, Yifeng Du, Qianqian Li, Zhi Shi, Jianxiong Jiang. The role of prostaglandin signaling in human glioblastoma cell activities and growth in vitro and in vivo [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3114. doi:10.1158/1538-7445.AM2017-3114
Abstract 312: Anti-proliferative effects of cinnamon extract in colon cancer
Authors: Carriere Patrick P. , Mir Hina , Kapur Neeraj , Clark Clarence E. , Singh Shailesh
Published: July 2017

Colon cancer is the third most lethal cancer worldwide, and is estimated to cause 49,190 cancer-related deaths in the U.S. in 2016 alone. Current treatments for colon cancer are limited in their capacity to target tumor cells employing adaptive mechanisms necessary for survival and proliferation, often resulting in poor prognosis. Therefore, it is critical to develop novel target-specific therapeutic approaches with minimal cytotoxicity to normal cells, in order to mitigate potential side effects. Proanthocyanidins represent a subclass of flavonoids, which have been widely investigated for their chemopreventive and therapeutic potential. Cinnamtannin B-1 (CTB-1) is a proanthocyanidin shown to have anti-cancer effects in several cancers, but its anti-cancer potential in colon cancer has not been tested. Hence, the focus of this study was to determine the anticancer effects of CTB-1 in colon cancer. Our results show that CTB-1 treatment significantly decreases the cell viability and proliferation of DLD-1 and COLO 201 human colon cancer cells in a time and dose-dependent manner. In addition, CTB-1 treatment modulated the cell cycle progression of colon cancer cells via G2/M arrest, coupled with a reduction of cells in the S phase. The expression and/or phosphorylation of key molecules involved in apoptosis and cell cycle progression were also modulated in response to CTB-1 treatment. Collectively, these findings, for the first time, shed light on the anti-proliferative effects of CTB-1 in colon cancer, and further demonstrate its potential as a novel therapeutic/preventive agent.

Citation Format: Patrick P. Carriere, Hina Mir, Neeraj Kapur, Clarence E. Clark, Shailesh Singh. Anti-proliferative effects of cinnamon extract in colon cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 312. doi:10.1158/1538-7445.AM2017-312
Abstract 3123: Identification of TIFA as a novel therapeutic target in acute myeloid leukemia
Authors: Wu Pei-Yu , Wei Tong-You Wade , Wu Ting-Jung , Tsai Ming-Daw
Published: July 2017

Aurora A-dependent NF-κB signaling portends poor prognosis of cancers including acute myeloid leukemia (AML). Our previous study demonstrated that phosphorylation-dependent oligomerization of TRAF-interacting protein with FHA domain (TIFA) triggers the activation of NF-κB. The present study identifies that Aurora A is an essential kinase for the Thr9 phosphorylation of TIFA, and that TIFA functionally mediates the Aurora A-driven NF-κB survival pathway in AML. Overexpression of TIFA occurred concurrently with Aurora A and NF-κB signaling factors in de novo AML patients but not healthy individuals, and also correlated with poor prognosis. Silencing of TIFA specifically attenuated leukemic cell growth and enhanced chemosensitivity of AML cells via down-regulation of pro-survival factors Bcl-2 and Bcl-XL that support NF-κB-dependent anti-apoptotic events. In addition, molecular targeting of TIFA perturbed leukemic cytokine secretion and significantly lowered the IC50 of chemotherapeutic drugs to treat AML cells. Furthermore, in vivo delivery of TIFA-inhibitory fragments potentiates the clearance of leukemic myeloblasts in the bone marrow of xenograft-recipient mice via enhanced chemotoxicity, similar to the effect of anti-inflammatory drug treatments. Collectively, we proposed that TIFA functionally supports the positive feedback between TNF-α, Aurora A, and NF-κB to facilitate AML survival signaling, and impairment in this pathway can enhance the efficacy of AML treatments.

Citation Format: Pei-Yu Wu, Tong-You Wade Wei, Ting-Jung Wu, Ming-Daw Tsai. Identification of TIFA as a novel therapeutic target in acute myeloid leukemia [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3123. doi:10.1158/1538-7445.AM2017-3123