bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3400: Progression of epidermal growth factor receptor (EGFR)-independent colorectal cancer
Authors: Rojas Carolina Mantilla , Ming Yu , Threadgill David
Published: July 2017

When combined with standard of care treatment for colorectal cancer (CRC), the use of monoclonal antibodies or small molecule inhibitors against epidermal growth factor receptor (EGFR) show modest efficacy in the clinic. Early detection efforts and more effective therapies have reduced mortality, yet CRC remains the second mostly deadly cancer in the United States with approximately 50,000 deaths expected this year. Thus, it is imperative to better understand the mechanisms governing molecular progression of CRC. Primary and secondary resistance to anti-EGFR therapies occurs in approximately 80% of the patients with CRC. Mutations in Kras explain some non-responding CRCs, but even in cancers lacking Kras mutations, little is known about which cancers are likely to respond to EGFR targeted treatment, suggesting an alternative and EGFR-independent CRC progression mechanism. In this study, we used a conditional Egfr allele (Egfrf) within the ApcMin/+ mouse model and identified EGFR-independent tumors with faster growth rates than those developing in EGFR-wild type mice. To assess aggressiveness of EGFR-independent tumors, we used a metastatic CRC mouse model containing conditionally inactivated Apc alleles (Apcf/f) in combination with a conditionally active allele of Kras (KrasLSL-G12D). It has been reported that delivery of Cre recombinase-expressing adenovirus to the distal colon of these mice results in tumors that progress to carcinoma within 20 weeks, and liver metastases develop in approximately 20% of mice at 24 weeks. We discovered a 10% increase in the penetrance of tumors arising in the absence of EGFR (Egfrf/f, Apcf/f, KrasLSL-G12D/+). Endoscopic analysis suggests an increase in tumor multiplicity in EGFR-deficient tumors when compared with tumors developing in EGFR-wild-type mice. Biweekly colonoscopies confirmed that colonic tumors have a faster growth rate in the absence of EGFR. High-frequency abdominal ultrasound suggests liver metastasis at 16 weeks in 20% of mice lacking EGFR. These findings demonstrate the existence of an EGFR-independent mechanism by which CRC can arise and progress. Moreover, tumors lacking EGFR grow larger than those developing under normal EGFR activity and may be a more aggressive form of CRC. We also have evidence that ERBB3 and ERBB4, related EGFRs, mediate compensatory and alternative pathways, suggesting an important role for these receptors in the progression of EGFR-independent CRC. This study will advance our understanding of ERBB family biology during colonic tumorigenesis, ultimately contributing to better therapies for CRC.

Citation Format: Carolina Mantilla Rojas, Yu Ming, David Threadgill. Progression of epidermal growth factor receptor (EGFR)-independent colorectal 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 3400. doi:10.1158/1538-7445.AM2017-3400
Abstract 3406: Hereditary risks of male breast cancer in a multi-gene panel testing cohort
Authors: Chao Elizabeth C. , Pritzlaff Mary , Pia Summerour , McFarland Rachel , Li Shuwei , Dolinsky Jill , Goldgar David , Shimelis Hermela , Couch Fergus , Holly LaDuca
Published: July 2017

While the population-based risk for breast cancer in males remains relatively low (1:1000), inherited predisposition can significantly raise this to as high as 10%, in men who carry a mutation in the BRCA2 gene. Lifetime breast cancer risks of 1-2% have also been reported in men who carry a mutation in BRCA1. These risks, as well as elevated risks of prostate, pancreatic, and melanoma cancers, are important to discuss in families diagnosed with Hereditary Breast and Ovarian Cancer Syndrome, which is often viewed as being clinically relevant only to the women in an affected family. However, beyond the BRCA1/2 genes, limited data is available on hereditary predisposition to male breast cancer. We analyzed clinical histories and molecular results from multi-gene panel testing for hereditary cancer predisposition in a cohort of 715 men affected by breast cancer. A total of 708 male breast cancer patients were eligible for inclusion in the final analysis. Molecular testing included analysis of 5 to 59 genes for DNA coding sequence and copy number variants by next-generation sequencing and microarray. Genetic variants identified were classified according to a 5-tier system using previously validated algorithms1,2. Only those variants classified as pathogenic or likely pathogenic were included in the analyses as positive for a mutation. Overall, a mutation was detected in 18% of these men. Four subjects carried a mutation in two different breast cancer predisposition genes. BRCA2 and CHEK2 were the most frequently mutated genes. The risk of breast cancer was significantly elevated compared to public controls in individuals with a mutation in BRCA2 (odds ratio (OR)=13.9; p=1.92x10-16), CHEK2 (OR=3.8; p=6.24x10-24) and PALB2 (OR=6.6, p=0.01). Average age was similar amongst men with (63.5±2.7 years) and without (62.3±1.2 years) mutations, as were clinical and family histories of additional cancers. The high overall diagnostic yield suggests the utility of testing all male breast cancer patient regardless of age or family history by multigene panel testing, and provides data to support risk-based counseling and medical recommendations for screening and/or prevention in male mutation carriers.

1. 1. LaDuca et al. Genet Med. 2014 Nov;16(11):830-7 2. 2. Richards et al. Genet Med. 2015 May;17(5):405-24

Citation Format: Elizabeth C. Chao, Mary Pritzlaff, Summerour Pia, Rachel McFarland, Shuwei Li, Jill Dolinsky, David Goldgar, Hermela Shimelis, Fergus Couch, LaDuca Holly. Hereditary risks of male breast cancer in a multi-gene panel testing cohort [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 3406. doi:10.1158/1538-7445.AM2017-3406
Abstract 3407: Side effects of BRAF inhibitors mimic RASopathies
Authors: Sfecci Alicia , Dupuy Alain , Dinulescu Monica , Droitcourt Catherine , Adamski Henri , Hadj-Rabia Smail , Odent Sylvie , Galibert Marie-Dominique , Boussemart Lise
Published: July 2017

Recent advances in targeted anticancer therapies have substantially improved the prognosis of several cancers but they are not free of side effects. These side effects are, however, clearly distinct from those induced by classical cytotoxic chemotherapies, likely because targeted therapies are designed to interfere with specific oncogenic signaling pathways and not to inhibit cell proliferation in general. We, therefore, evaluated whether specific side effects of BRAF inhibitor therapies would resemble symptoms seen in patients with RASopathies, in which the MAPK pathway is affected and which includes Costello, Noonan and Cardio-Facio-Cutaneous syndromes. To this end, we collected a cohort of 18 patients with genetically confirmed RASopathies that were followed between 2012 and 2016 at the University Hospital of Rennes, France and that were evaluated based on their personal medical history and a clinical examination. Strikingly, RASopathy patients, particularly those with Cardio-Facio-Cutaneous syndrome, showed symptoms resembling those that we and others have previously seen in genetically characterized patients undergoing BRAF inhibitor treatment. These symptoms included keratosis pilaris, wavy hair, sparse eyelashes/eyebrows, poor hair growth, palmo-plantar hyperkeratosis in areas of pressure, verrucous papillomas, nevi efflorescence, and increased cancer risk. Nevertheless, BRAF-inhibitor treatment can also lead to side effects not typically found in patients with RASopathies, including acneiform dermatitis and vemurafenib-specific phototoxicity, which may even increase under a combined BRAF/MEK inhibition. These results suggest that the side effects of BRAF inhibition that are similar to symptoms in patients with RASopathies are due to direct targeting of the MAPK pathway in BRAF-non-mutated (wild type) cells while those that are dissimilar represent off-target effects that do not affect the MAPK pathway. We hope that this type of comparative analysis may lead to a better understanding of the multiple effects of targeted therapies and perhaps prompt modifications in the targeted therapy approach to minimize these side effects.

Citation Format: Alicia Sfecci, Alain Dupuy, Monica Dinulescu, Catherine Droitcourt, Henri Adamski, Smail Hadj-Rabia, Sylvie Odent, Marie-Dominique Galibert, Lise Boussemart. Side effects of BRAF inhibitors mimic RASopathies [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 3407. doi:10.1158/1538-7445.AM2017-3407
Abstract 3419: Uncovering the functional relevance of FBXW7 mutations in endometrial cancer
Authors: Urick Mary Ellen , Hong Bo , Rudd Meghan L. , Bell Daphne W.
Published: July 2017

The goal of this study is to elucidate the functional consequences of FBXW7 mutations in the context of endometrial carcinoma (EC). EC is a heterogeneous disease, consisting of multiple histological subtypes associated with distinct clinical outcomes. Endometrioid endometrial cancer is the most commonly diagnosed subtype and is associated with an overall favorable prognosis. Less common but more clinically aggressive subtypes that contribute disproportionately to patient deaths include clear cell and serous ECs. We previously reported that FBXW7 is somatically mutated in 10% of endometrioid, 13% of clear cell and 29% of serous ECs. FBXW7 functions as a substrate-recognition protein within a SKP/CUL1/F-Box ubiquitin ligase complex, which targets numerous proteins for ubiquitin-mediated proteosomal degradation. Although FBXW7 is a known tumor suppressor, the functional consequences of these mutations have not yet been fully elucidated in the context of EC. As a means to this end, we utilized shRNA and Western blotting to identify proteins that are upregulated following FBXW7 depletion in ARK1 serous EC cells. Among proteins that were consistently upregulated were cyclin E1 and cMYC. We treated EC cells harboring endogenous FBXW7 mutations and those with wildtype FBXW7 with a proteasome inhibitor to confirm that EC cells regulate cyclin E1 and cMYC through proteasome degradation. Furthermore, we identified three EC cell lines that harbor endogenous mutations in FBXW7 and show that these cell lines exhibit delayed degradation of these substrates compared to EC cells expressing wildtype FBXW7. Finally, we generated expression constructs for wildtype FBXW7α and six recurrent mutants found in EC. We show that transient exogenous overexpression of five out of six recurrent FBXW7 mutant constructs in two different serous EC cell lines resulted in increased levels of phosphorylated cMYC and cyclin E1 compared to wildtype FBXW7α. These results suggest that not all recurrent FBXW7 mutations are functionally equivalent. Our findings begin to reveal the molecular consequences of FBXW7 mutations in EC and ongoing studies are aimed at elucidating additional functional consequences of these aberrations in the context of EC.

Citation Format: Mary Ellen Urick, Bo Hong, Meghan L. Rudd, Daphne W. Bell. Uncovering the functional relevance of FBXW7 mutations in endometrial 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 3419. doi:10.1158/1538-7445.AM2017-3419
Abstract 342: WHSC1L1-mediated EGFR mono-methylation enhances the cytoplasmic and nuclear oncogenic activity of EGFR in head and neck cancer
Authors: Saloura Vassiliki , Vougiouklakis Theodore , Zewde Makda , Deng Xiaolan , Kiyotani Kazuma , Park Jae-Hyun , Matsuo Yo , Lingen Mark , Dohmae Naoshi , Suzuki Takehiro , Hamamoto Ryuji , Nakamura Yusuke
Published: July 2017

While multiple post-translational modifications have been reported to regulate the function of epidermal growth factor receptor (EGFR), the effect of protein methylation on its function has not been well characterized. In this study, we show that WHSC1L1 mono-methylates lysine 721 in the tyrosine kinase domain of EGFR, and that this methylation leads to enhanced activation of its downstream ERK cascade without EGF stimulation. We also show that EGFR K721 mono-methylation not only affects the function of cytoplasmic EGFR, but also that of nuclear EGFR. WHSC1L1-mediated methylation of EGFR in the nucleus enhanced its interaction with PCNA in squamous cell carcinoma of the head and neck (SCCHN) cells and resulted in enhanced DNA synthesis and cell cycle progression. Overall, our study demonstrates the multifaceted oncogenic function of the protein lysine methyltransferase WHSC1L1 in SCCHN, which is mediated through direct non-histone methylation of the EGFR protein with effects both in its cytoplasmic and nuclear functions.

Citation Format: Vassiliki Saloura, Theodore Vougiouklakis, Makda Zewde, Xiaolan Deng, Kazuma Kiyotani, Jae-Hyun Park, Yo Matsuo, Mark Lingen, Naoshi Dohmae, Takehiro Suzuki, Ryuji Hamamoto, Yusuke Nakamura. WHSC1L1-mediated EGFR mono-methylation enhances the cytoplasmic and nuclear oncogenic activity of EGFR in head and neck 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 342. doi:10.1158/1538-7445.AM2017-342
Abstract 3421: Pharmacological inhibition of histone methylation attenuates TGFβ induced EMT characteristics in pancreatic cancer
Authors: Mody Hardik R. , Govindarajan Rajgopal
Published: July 2017

Epithelial-to-Mesenchymal Transition (EMT) is a tumor cell remodeling process that drives progression of several epithelial solid tumors including pancreatic tumors. Transforming growth factor (TGF) β signaling is a key promoter of EMT pathway and remains an attractive target for curtailing tumor progression. Here we present a strategy for investigating inhibitors of TGFβ signaling in pancreatic cancer via reprograming of miRNAs. We find a carbocyclic adenosine analog and histone methyl transferase inhibitor, 3-deazaneplanocin A (DZNep) to significantly attenuate the TGFβ signaling induced EMT characteristics in pancreatic ductal adenocarcinoma (PDAC). Specifically, we find DZNep treatment to restore expression of selective epigenetically silenced miRNAs (mir-663a, miR-4787-5p, and miR-202) that inhibit endogenous TGFβ1 ligand and receptor expression via RNA interference. Consequently, DZNep significantly attenuated both exogenous and endogenous TGFβ-induced EMT response. Lentiviral overexpression of mir-663a, miR-4787-5p or miR-202 reduced tumor cellular proliferation and EMT phenotypic characteristics similar to DZNep in cultured pancreatic cancer cells, whereas locked nucleic acids inhibition of miRNAs abrogated such effects. In an orthotopic pancreatic cancer mouse model, DZNep and all three miRs reduced overall tumor burden in pancreas and metastatic load in liver, lungs and spleen. Together, these findings suggest epigenetic reprograming of miRNAs by synthetic histone methylation reversal agents as a potentially viable approach for attenuating TGFβ signaling pathway involved in pancreatic cancer progression.

Citation Format: Hardik R. Mody, Rajgopal Govindarajan. Pharmacological inhibition of histone methylation attenuates TGFβ induced EMT characteristics in pancreatic 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 3421. doi:10.1158/1538-7445.AM2017-3421
Abstract 3423: Elucidation of the role of miR-575 on tumorigenesis in glioblastoma
Authors: Gray Ashley N. , Cui Tiantian , Geurts Marjolein , Robe Pierre , McElroy Joseph , Bell Erica Hlavin , Chakravarti Arnab
Published: July 2017

Glioblastoma (GBM) patients currently face poor survival outcomes with an average survival rate less than 15 months, with only 3-5% of patients survive more than 36 months. Although the mechanisms of tumorigenesis are still being elucidated, miRNAs are promising candidates to explore as novel and prognostic biomarkers in GBM. MiRNAs are small regulatory molecules that play a crucial role in carcinogenesis via repression of oncogenes and tumor-suppressor genes either transcriptionally or post-transcriptionally. Our clinical data (n=268) shows that miR-575 is one of the top miRNAs associated with GBM overall survival (FDR: 0.0036, p-value: 5.77E-05) by univariate analysis (NanoString Technologies; Seattle, WA). This study was designed to investigate the expression and function of miR-575 in GBM. Basal expression of miR-575 was first detected in GBM cell lines prior to functional experimentation. Cell proliferation, colony formation, migration and invasion assays were performed to understand the role of miR-575 in GBM. We found that overexpression of miR-575 significantly increased cell proliferation and cell motility in LN229 and U251 cell lines. Additionally, BLID, a tumor-suppressor gene, was negatively regulated by miR-575 at the transcriptional level by qRT-PCR, which will be further investigated at the post-transcriptional level by western blot. Up-regulation of miR-575 in GBM cell lines suggests that it could be acting as an oncogene by degrading the mRNA of BLID. Luciferase assays also showed negative regulation of BLID expression by miR-575, supporting our hypothesis and findings in other cancers. In conclusion, miR-575 might act as an oncogene in GBM, and BLID may be a putative target gene of miR-575. This mechanism could potentially be useful as a novel prognostic biomarker for GBM patients after further in vitro and in vivo validation. Funding: 1R01CA169368 (PI: Houghton; Co-I:Chakravarti); 1R01CA11522358 Multiple-PI R01: Chakravarti (PI); Xia (PI); 1R01CA1145128 Baroukhim (PI); Chakravarti (Co-PI) 7/2015-6/2020; R01CA108633 (PI:Chakravarti); 1RC2CA148190 (Scientific PI: Chakravarti).

Citation Format: Ashley N. Gray, Tiantian Cui, Marjolein Geurts, Pierre Robe, Joseph McElroy, Erica Hlavin Bell, Arnab Chakravarti. Elucidation of the role of miR-575 on tumorigenesis in glioblastoma [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 3423. doi:10.1158/1538-7445.AM2017-3423
Abstract 3432: microRNA expression reflects site specificity of metastatic colorectal cancer
Authors: Fromm Bastian , Høye Eirik , Domanska Diana , Lund-Andersen Christin , Kristensen Annette Torgrund , Dagenborg Vegar J. , Boettger Paul H. , Abrahamsen Torveig W. , Solberg Steinar , Larsen Stein G. , Edwin Bjørn , Hovig Eivind , Lorenz Susanne , Flatmark Kjersti
Published: July 2017

Colorectal Cancer (CRC) is one of the leading causes of cancer related deaths in the western world, and metastatic progression is the dominating cause of mortality. The primary site of CRC metastasis is the liver, followed by the lungs and peritoneal cavity, and prognosis for patients with metastatic CRC (mCRC) is poor, with only 10 % five-year survival. Although much is known about progression and metastasis of CRC; how primary CRC (pCRC) differs from mCRC on the molecular level and potential differences between metastases located in different organs are incompletely understood. This is important for our understanding of the disease, but also could have significant implications with respect to treatment. MicroRNAs have been shown to be key elements in cancer progression, but recent reports on CRC failed to consistently identify microRNA signatures of metastatic progression. We have addressed this using a smallRNA sequencing approach to analyze primary tumors and a set of liver, lung and peritoneal metastases, including corresponding adjacent tissue (colon, liver, lung, peritoneum). Further, we use the highly curated and updated microRNA reference MirGeneDB.org, the novel pipeline MirAthon - including a correction-algorithm of benign tissue microRNA signatures for tumor or metastatic samples, and we compare pCRC and site specific metastases separately. We are able to show that microRNA profiles of mCRC are distinct to pCRC in a site-specific manner. We identify a small panel of differentially expressed microRNAs including isoforms (isomiRs) hidden under a layer of benign signatures that we confirmed in other available datasets, too. Our findings will help better understand metastatic progression and site-specificity in CRC and could be potential biomarkers for mCRC.

Our work identifies microRNA signatures of mCRC and suggest that microRNA signatures reflect mCRC site specificity. Furthermore, the results underline the importance of using a curated reference for microRNA studies, and to differentiate metastases based on their localization ab initio.

Citation Format: Bastian Fromm, Eirik Høye, Diana Domanska, Christin Lund-Andersen, Annette Torgrund Kristensen, Vegar J. Dagenborg, Paul H. Boettger, Torveig W. Abrahamsen, Steinar Solberg, Stein G. Larsen, Bjørn Edwin, Eivind Hovig, Susanne Lorenz, Kjersti Flatmark. microRNA expression reflects site specificity of metastatic colorectal 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 3432. doi:10.1158/1538-7445.AM2017-3432
Abstract 3433: Epigenetic silencing of miR-214-3p is associated with resistance to p53-induced apoptosis through up-regulation of gankyrin expression in hepatocellular carcinoma
Authors: Yasui Kohichiroh , Iwai Naoto , Terasaki Kei , Gen Yasuyuki , Itoh Yoshito
Published: July 2017

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression and can act as tumor suppressors or oncogenes. To identify miRNA involved in the development of HCC, a genome-wide miRNA gene expression analysis was performed using the human miRNA microarray (Agilent) in paired HCC tumors and non-tumorous liver tissues from patients with primary HCC. The array-based miRNA expression profiles were validated by quantitative PCR. We also screened for genes with promoter DNA hypermethylation using a genome-wide DNA methylation microarray analysis (the Illumina HumanMethylation27 BeadChip) in the same samples. We found that miR-214-3p were significantly down-regulated by aberrant promoter hypermethylation in HCC tumors compared to the non-tumorous liver tissues. We identified PSMD10, which encodes gankyrin, as a direct target of miR-214-3p using luciferase assay and immunoblotting. Gankyrin, an oncoprotein commonly overexpressed in HCC, binds to MDM2, a major E3 ubiquitin ligase for p53, and increases ubiquitylation and degradation of p53. Our experiments showed that reduced miR-214-3p expression was associated with resistance to p53-induced apoptosis through up-regulation of gankyrin expression in HCC cells. In conclusion, our results suggest that epigenetic silencing of tumor suppressor miR-214-3p is involved in hepatocarcinogenesis through up-regulation of gankyrin expression.

Citation Format: Kohichiroh Yasui, Naoto Iwai, Kei Terasaki, Yasuyuki Gen, Yoshito Itoh. Epigenetic silencing of miR-214-3p is associated with resistance to p53-induced apoptosis through up-regulation of gankyrin expression in hepatocellular carcinoma [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 3433. doi:10.1158/1538-7445.AM2017-3433
Abstract 3435: Profiling miRNAs in breast epithelial progenitor cells during branching morphogenesis and EMT in 3D culture
Authors: Briem Eirikur , Hilmarsdottir Bylgja , Budkova Zuzana , Ingthorsson Saevar , Magnusson Magnus K. , Gudjonsson Thorarinn
Published: July 2017

In this study we investigate the role of miRNA-203a in branching morphogenesis and epithelial to mesenchymal transition (EMT) in breast cell lines. D492 is a breast epithelial cell line with stem cell properties. D492 generates luminal- and myoepithelial cells and in 3D culture forms structures reminiscent of terminal duct lobular units of the breast. When cocultured with endothelial cells subset of D492 cells undergo EMT as evidenced by spindle shape morphology, E- to N cadherin switch and loss of keratin expression. We have established an endothelial-induced mesenchymal subline from D492 referred to as D492M. Here we use D492 and D492M as a model to investigate miRNA expression patterns during different stages of branching and in EMT. We performed small RNA-sequencing on D492 and D492M in 3D cultures. We were able to pinpoint miRNAs that are associated with epithelial integrity and suppressing EMT. We have recently shown that miRNA-200c-141 convert D492M back to the epithelial phenotype (Hilmarsdottir et al. G&D 2015). MiRNA-203a is also down-regulated in D492M. Here we overexpress miRNA-203a in D492 and D492M. Methylation analysis reveal that the promoter area of miRNA-203a is not methylated in D492M. When miRNA-203a is overexpressed in D492M, cells change phenotype from elongate, mesenchymal-like phenotype to more cuboidal epithelioid phenotype, show reduced cell proliferation, less ability to form colonies in low attachment cultures, less ability to migrate and reduced invasion capability. When D492MmiRNA-203a is co-cultured with endothelial cells in 3D culture they partially regain the ability to form branching structures similar to D492. D492MmiRNA-203a show reduced expression of EMT transcription factors SNAI2 and ZEB1. When cultured on transwell filters, D492M forms stratified squamous epithelial layer while D492MmiRNA-203a form single squamous layer. In conclusion, miRNA-203a induces partial epithelial phenotype in D492M as evidenced by morphology and marker expression. We also conclude that three dimensional cultures of D492 and D492M work well as a model system to investigate miRNA expression during branching morphogenesis and in EMT.

Citation Format: Eirikur Briem, Bylgja Hilmarsdottir, Zuzana Budkova, Saevar Ingthorsson, Magnus K. Magnusson, Thorarinn Gudjonsson. Profiling miRNAs in breast epithelial progenitor cells during branching morphogenesis and EMT in 3D culture [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 3435. doi:10.1158/1538-7445.AM2017-3435
Abstract 3454: Autophagy governs tumorigenic effects following mitotic slippage
Authors: Crasta Karen C. , Cheng Bing , Guo Ke
Published: July 2017

Antimitotic drugs are often administered as first-line chemotherapy in several malignancies. However, their clinical success is often limited by acquired chemoresistance and disease relapse. The anti-proliferative basis of these drugs is induction of mitotic arrest culminating in cell death. Mitotic slippage occurs when cells exit mitosis and “slip” into interphase without chromosome segregation and cytokinesis. Little is known about how cells post-slippage influence outcome of treatment. Here, we demonstrate that post-slippage cells exhibit paracrine pro-tumourigenic potential following senescence and senescence-associated secretory phenotype development. This occurs in an autophagy-p53 axis-dependent manner, with autophagic inhibition in post-slippage cells bypassing senescence and leading to cell death. Indeed, the autophagy inhibitor Chloroquine and microtubule poisons synergistically inhibited tumour growth in mice. Hence, regimens targeting the senescence phenotype could provide a potential effective combinatorial strategy with antimitotic drugs. Sensitivity to this combinatorial treatment was dependent on p53 status, an important factor to consider before treatment.

Citation Format: Karen C. Crasta, Bing Cheng, Ke Guo. Autophagy governs tumorigenic effects following mitotic slippage [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 3454. doi:10.1158/1538-7445.AM2017-3454
Abstract 3461: The Nek2 mitotic kinase drives centrosome amplification, mitotic dysfunction, and invasion in mammary epithelial and breast cancer cells
Authors: Rivera-Rivera Yainyrette , Marina Mihaela , Lee Miyoung , Saavedra Harold I.
Published: July 2017

Despite findings reported by The Cancer Genome Atlas (TCGA) that the most common human tumors have undergone at least one genomic doubling, the roles of polyploidy and chromosome instability (CIN) in cancer are poorly understood. Defective mitosis, and centrosome amplification (CA) are major sources of CIN, which generally associates with poor prognosis of patients. Prevalence of CA and CIN in hormone receptor negative (ER-PR-Her2- or ER-PR-Her2+) breast cancer patients, who have the poorest outcomes among all intrinsic subtypes, suggest that CA and CIN play major roles in the disease. CA in breast cancers correlates with poor survival, metastasis and high tumor grade, suggesting roles in tumor progression. Our laboratory, using an inducible K-RasG12D transgenic mouse that directed its expression to mammary epithelial cells, demonstrated CA appeared in precancerous mammary epithelial lesions, suggesting a role in tumor initiation. Despite these observations, the role of CA as cancer driver or promoter has not been tested experimentally. To understand that role, drivers of CA in cancer must be identified, and our laboratory showed that dysregulated E2F1, E2F2 and E2F3a, and their mitotic targets, including Nek2, TTK, and SgoI sustain CA and CIN in mammary epithelial and breast cancer cells. In fact, orthotopic models of breast cancer demonstrated that silencing of E2F3 leads to slow tumor growth that correlates with reduced mitosis, CA and Nek2 levels. We find that overexpression of the E2F target Nek2 in non-transformed mammary epithelial cells results in large acinar structures, CA, CIN, and changes in relevant EMT markers that include vimentin. Our findings indicate that deregulated E2F pathway contribute to mammary tumorigenesis in part by deregulating kinases that control mitosis, including Nek2, and in turn these affect mitotic progression, CIN, EMT and invasion. Thus, centrosome/kinases downstream of the E2F pathway may represent future targets for intervention in highly-malignant HR- breast cancers.

Citation Format: Yainyrette Rivera-Rivera, Mihaela Marina, Miyoung Lee, Harold I. Saavedra. The Nek2 mitotic kinase drives centrosome amplification, mitotic dysfunction, and invasion in mammary epithelial and breast 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 3461. doi:10.1158/1538-7445.AM2017-3461
Abstract 3478: Expression of the transcribed ultraconserved region Uc.63+ in prostate cancer
Authors: Sekino Yohei , Goto Keisuke , Honma Ririno , Shigematsu Yoshinori , Sakamoto Naoya , Sentani Kazuhiro , Oue Naohide , Teishima Jun , Matsubara Akio , Yasui Wataru
Published: July 2017

Prostate cancer (PCa) is the most prevalent cancer among men and the second leading cause of cancer related death in western world. Currently, there is a lack of effective treatment options for advanced PCa. Understanding the molecular mechanisms in prostate cancer development and progression would allow the identification of novel prognostic markers or therapeutic targets. The transcribed-ultraconserved regions (T-UCRs) are novel class of noncoding RNAs that are absolutely conserved (100%) between orthologous regions of the human, rat and mouse genomes. Some studies showed that T-UCRs exhibit distinct profiles in various human cancers. We examined the expression profile of representative 26 T-UCRs using qRT-PCR in 12 PCa tissues and 10 non-neoplastic prostate tissues, and found that the expression of Uc.63+ was higher in PCa tissues than that in non-neoplastic tissues. Further analysis revealed that the expression of Uc.63+ significantly correlated with higher PSA levels (p = 0.007) and higher Gleason score (p < 0.001). In order to verify biological function of Uc.63+ in PCa, we firstly transfected Uc.63+ expression vector into LNCaP cells expressing low level of Uc.63+. MTT assay and wound healing assay revealed that overexpression of Uc.63+ significantly increased the cell growth and migration. We also confirmed that downregulation of Uc.63+ using siRNA in DU145 and PC3 expressing high level of Uc.63+. Knockdown of Uc.63+ decreased the cell growth and migration. A recent report indicates that T-UCRs may act as endogenous competing RNA. miR-130b was found to have binding sites within the Uc.63+ using online software. We examined the expression of miR-130b by qRT-PCR in PCa tissues and non-neoplastic prostate tissues. We found a significant downregulation of miR-130b in PCa tissues compared with non-neoplastic prostate tissues, which figured out that there was a significant inverse correlation between Uc.63+ and miR-130b in PCa (p = 0.002). The expression of miR-130b in LNCaP was higher than that in DU145 and PC3. It has been shown that MMP2 is a direct target of miR-130b. Western blot analysis and qRT-PCR revealed that MMP2 expression was higher in LNCaP cells transfected with Uc.63+ expression than that in LNCaP cells transfected with empty vector. These results suggest that Uc.63+ may contribute to the progression of PC through miR-130b interaction.

Citation Format: Yohei Sekino, Keisuke Goto, Ririno Honma, Yoshinori Shigematsu, Naoya Sakamoto, Kazuhiro Sentani, Naohide Oue, Jun Teishima, Akio Matsubara, Wataru Yasui. Expression of the transcribed ultraconserved region Uc.63+ in prostate 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 3478. doi:10.1158/1538-7445.AM2017-3478
Abstract 3481: Leveraging protein coding gene expression profiles to accurately impute lncRNA transcriptome of cancer cells
Authors: Nath Aritro , Geeleher Paul , Huang R. Stephanie
Published: July 2017

Long noncoding RNAs (lncRNAs) represent a large, diverse and tissue-specific class of transcripts that are involved in gene regulation. Recent large-scale cancer sequencing efforts indicate that lncRNAs are an important component of the cancer transcriptome, and may play a critical role in carcinogenesis and drug sensitivity. Accurate profiling of lncRNAs however remains a challenge owing to significantly lower expression levels than mRNA, requiring deep paired-end total RNA sequencing, which can be prohibitively expensive. Additionally, previous generation microarrays that constitute a vast majority of GEO and ArrayExpress datasets do not provide comprehensive lncRNA coverage.

Here we propose a lncRNA expression imputation (LEXI) framework to reconstruct the lncRNA transcriptome of cancer cells using their mRNA expression profiles. Our goal is to provide a tool that enables the harnessing of enormous wealth of publicly available cancer mRNA datasets and discover novel lncRNAs associated with carcinogenesis and drug sensitivity. The LEXI approach is based on learning patterns of mRNA expression associated with each lncRNA across a diverse cohort of cancer cells and then predict lncRNA expression profile of uncharacterized cells.

We developed LEXI by evaluating the performance of various machine-learning algorithms benchmarked in a cross-validation study across a cohort of 675 cancer cell lines and 9755 pan-cancer tissues. We adapted the LEXI framework based on optimal performance and computation time and show that LEXI accurately predicts lncRNA expression profiles in both cell lines and tissues. To demonstrate the utility of LEXI, we reconstruct the lncRNA transcriptome of over 1000 cell lines and 2000 TCGA samples, and compare with RNAseq measured lncRNA levels in corresponding samples. We further show expression levels of MALAT1, HOTAIR, CCAT1 and other established cancer-associated lncRNAs are accurately predicted across cancer types, and can be used to discover novel associations in uncharacterized phenotypes. LEXI will be available as a free resource for researchers to easily obtain lncRNA profiles using their own mRNA data.

Citation Format: Aritro Nath, Paul Geeleher, R. Stephanie Huang. Leveraging protein coding gene expression profiles to accurately impute lncRNA transcriptome of 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 3481. doi:10.1158/1538-7445.AM2017-3481
Abstract 3491: A role for the long non-coding RNA GHRLOS in cancer
Authors: Shah Esha T. , Jeffery Penny , Thomas Patrick , Seim Inge , Chopin Lisa
Published: July 2017

Long non-coding RNA (lncRNA) genes are abundant in the human genome, and many are now recognized as oncogenes and/or tumor suppressors. We previously characterized the structure of GHRLOS, an antisense gene on the opposite strand of the multifunctional ghrelin gene (GHRL), however, its expression and function in disease has not been described.

To this end, using The Cancer Genome Atlas (TCGA) data set, we revealed that GHRLOS is differentially expressed in a number of cancers. In particular, expression was elevated in endometrial cancer (1.2 - fold; P = 7.1 x 10-3 Welch's two-sample t-test; n = 24 vs. n = 175) and prostate cancer (1.2-fold; P = 3.7 x 10-6; n = 52 vs. n = 498) compared to normal tissues. Using qRT-PCR (and commercial cDNA panels) we confirmed that GHRLOS expression was upregulated in endometrial cancer (1.96-fold, P = 0.005 Welch’s two-sample t-test, n = 5 vs. n = 17) and prostate cancer (2.46-fold, P = 0.0045 Welch’s two-sample t-test, n = 5 vs. n = 21) compared to normal tissues.

Initial studies, using siRNA designed to silence endogenous GHRLOS expression, significantly reduced cell migration in the PC3 prostate cancer cell line (0.47-fold change, P = 0.042 Kruskal-Wallis test, n = 2) conversely, preliminary data using forced GHRLOS overexpression increased migration and proliferation.

Taken together, we show that the long non-coding RNA GHRLOS is differentially expressed in tumor tissue and regulates cell migration and proliferation; possibly by modulating alternative splicing of the overlapping, multifunctional ghrelin gene locus. Targeting GHRLOS could provide a valuable and novel way to target the ghrelin axis in disease. Ongoing studies aim to validate in vitro functional results in complementary mouse xenograft models and identify genes and pathways regulated by this novel lncRNA.

Citation Format: Esha T. Shah, Penny Jeffery, Patrick Thomas, Inge Seim, Lisa Chopin. A role for the long non-coding RNA GHRLOS in 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 3491. doi:10.1158/1538-7445.AM2017-3491
Abstract 3499: Differentially expressed small noncoding RNAs in triple-negative breast cancer
Authors: Koduru Srinivas V. , Tiwari Amit K. , Leberfinger Ashley , Hazard Sprague W. , Kawasawa Yuka Imamura , Mahajan Milind , Ravnic Dino J.
Published: July 2017

Cancer is the second leading cause of death in the United States and is a major public health concern worldwide. Basic, clinical and epidemiological research is leading to improved cancer detection, prevention, and outcomes. Recent technological advances have allowed unbiased and comprehensive screening of genome-wide gene expression. Small non-coding RNAs (sncRNAs) have been shown to play an important role in biological processes and could serve as a diagnostic, prognostic and therapeutic biomarker for specific diseases. Recent findings have begun to reveal and enhance our understanding of the complex architecture of sncRNA expression including miRNAs, piRNAs, sn/snoRNAs and their relationships with biological systems. We used publicly available small RNA sequencing data that was derived from 24 triple negative breast cancers (TNBC) and 14 adjacent normal tissue samples to remap various types of sncRNAs. We found a total of 55 miRNAs were aberrantly expressed (p<0.005) in TNBC samples (8 miRNAs upregulated; 47 downregulated) compared to adjacent normal tissues whereas the original study reported only 25 novel miRs. In this study, we used pathway analysis of differentially expressed miRNAs which revealed TGF-beta signaling pathways to be profoundly affected in the TNBC samples. Furthermore, our comprehensive re-mapping strategy allowed us to discover a number of other differentially expressed sncRNAs including piRNAs, sn/snoRNAs, rRNAs, miscRNAs and nonsense-mediated decay RNAs. We believe that our sncRNA analysis workflow is extremely comprehensive and suitable for discovery of novel sncRNAs changes, which may lead to the development of innovative diagnostic and therapeutic tools for TNBC.

Citation Format: Srinivas V. Koduru, Amit K. Tiwari, Ashley Leberfinger, Sprague W. Hazard, Yuka Imamura Kawasawa, Milind Mahajan, Dino J. Ravnic. Differentially expressed small noncoding RNAs in triple-negative 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 3499. doi:10.1158/1538-7445.AM2017-3499
Abstract 3504: High expression of lncRNA-ATB and miR-21 as a biomarker in human hepatocellular carcinoma
Authors: Lee Eunhye , Kim Gyeonghwa , Jang Se Young , Choi Yong-Hun , Lee Yu Rim , Tak Won Young , Kweon Young Oh , Park Soo Young , Hur Keun
Published: July 2017

Non-coding RNAs (ncRNAs) including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) have emerged as novel gene-regulators. The aim of this study was to determine the clinical relevancies of 2 lncRNAs (lncRNA-ATB and MEG3) and 2 miRNAs (miR-21 and miR-31) in hepatocellular carcinoma (HCC). We analyzed clinical specimens from 100 pairs of HCC and matched normal liver (NL) tissues. MiRNAs and lncRNAs expression levels were evaluated by quantitative real-time PCR. In addition, we determined the clinical significance of the ncRNAs expression in matching tissue and serum exosome samples from HCC patients. MiR-21 significantly increased in HCC (P<0.01) compared to corresponding NL tissues. LncRNA-ATB was significantly up-regulated in HCC (P<0.05); however, lncRNA-MEG3 was down-regulated in HCC (P<0.05) tissues. In addition, expression of miR-21 and lncRNA-ATB was significantly associated with the tumor size and poor prognosis of HCC patients. More importantly, expression of serum exosomal lncRNA-ATB and miR-21 was more significantly associated with HCC progression and poor patients survival compared to its’ tissue expression. We conclude that non-coding RNAs (lncRNA-ATB and miR-21) expression has the potential to serve as biomarkers for prognosis and targeted therapy in HCC patients.

Citation Format: Eunhye Lee, Gyeonghwa Kim, Se Young Jang, Yong-Hun Choi, Yu Rim Lee, Won Young Tak, Young Oh Kweon, Soo Young Park, Keun Hur. High expression of lncRNA-ATB and miR-21 as a biomarker in human hepatocellular carcinoma [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 3504. doi:10.1158/1538-7445.AM2017-3504
Abstract 3510: A role for the Ewing’s sarcoma breakpoint protein EWS in ERG-induced prostate tumorigenesis
Authors: Kedage Vivekananda , Selvaraj Nagarathinam , Nicholas Taylor R. , Budka Justin A. , Jerde Travis J. , Hollenhorst Peter C.
Published: July 2017

The TMPRSS2-ERG gene fusion occurs in one-half of prostate tumors and results in expression of ERG, an ETS family transcription factor that promotes prostate tumorigenesis. Another 5-10% of prostate tumors have similar rearrangements that result in over-expression of other ETS family members such as ETV1, ETV4, and ETV5. However, not all ETS family members are oncogenic, and normal prostate cells express at least 15 of these other ETS factors. Therefore, it is important to understand mechanisms that differentiate oncogenic ETS factors from non-oncogenic ETS factors. We have recently discovered that ERG, ETV1, ETV4, and ETV5, and no other ETS factor can directly bind the protein EWS. This is striking, as EWS is fused to various ETS factors in the chromosomal rearrangements that cause Ewing’s sarcoma. We demonstrate that fusion of EWS to any ETS protein is sufficient for that protein to function like ERG in prostate cells. Furthermore, the EWS-ERG interaction is required for ERG to activate an oncogenic gene expression program and for ERG-mediated tumorigenesis. Therefore, these findings reveal a conserved oncogenic mechanism for prostate cancer and Ewing’s sarcoma. In prostate cancer, aberrant over-expression of an ETS factor that naturally interacts with EWS, brings EWS to ETS-bound regions. In Ewing’s sarcoma this interaction is forced by the presence of an EWS/ETS fusion protein. Therefore, this model predicts that treatments that target EWS function would be effective in both types of cancer.

Citation Format: Vivekananda Kedage, Nagarathinam Selvaraj, Taylor R. Nicholas, Justin A. Budka, Travis J. Jerde, Peter C. Hollenhorst. A role for the Ewing’s sarcoma breakpoint protein EWS in ERG-induced prostate tumorigenesis [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 3510. doi:10.1158/1538-7445.AM2017-3510