bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3313: Autophagic ovarian cancer cells exhibit substantially enhanced sensitivity to Crizotinib
Authors: Blessing Alicia M. , Wang Yan , Mao Weiqun , Pang Lan , Lu Zhen , Bast Robert C.
Published: July 2017

One of the major factors contributing to poor outcomes for patients with ovarian cancer is the persistence of dormant, drug resistant cancer cells after primary surgery and chemotherapy. Recurrent, progressively growing ovarian cancer metastases are generally well vascularized and may only have a small fraction of cancer cells undergoing autophagy. By contrast, the persistent, drug resistant, dormant cancer cells that remain on the peritoneal cavity after conventional treatment tend to be poorly vascularized. In this nutrient-poor, avascular microenvironment autophagy is widespread and can be found in more than 80% of cases. Drugs that regulate survival in autophagic cancer cells may be much more active when administered as maintenance therapy than when used to treat gross primary or recurrent disease. Using unbiased siRNA screens, we have identified target genes that regulate the survival of ovarian cancer cells that are undergoing autophagy that has been induced by the re-expression of DIRAS3 or by amino acid starvation. Knockdown of the anaplastic lymphoma kinase (ALK) significantly reduced survival of ovarian cancer cells that were undergoing autophagy. Importantly, the FDA-approved ALK inhibitor, Crizotinib, exhibited significantly greater toxicity after induction of autophagy by upregulation of DIRAS3 (ARHI) in OVCAR8, CAOV3, and SKOv3 ovarian cancer cells. Induction of autophagy by upregulation of DIRAS3 in SKOv3 ovarian cancer cells reduced the IC50 of Crizotinib from 7.44µM ± 0.04708 to 2.129µM ± 0.06152 (P<0.05). Conversely, siRNA knockdown of DIRAS3 in CAOV3 cells with endogenously high DIRAS3 expression and baseline autophagy increased the IC50 of Crizotinib from 204 nM ± 0.01265 to 267 nM ± 0.01715 (P<0.05). Our studies in cell culture suggest that Crizotinib might provide an effective agent to eliminate autophagic, dormant drug resistant ovarian cancer cells that remain after conventional cytoreductive surgery and combination chemotherapy. Subsequent studies will evaluate the effect of Crizotinib in xenograft models of DIRAS3-induced ovarian cancer dormancy.

Citation Format: Alicia M. Blessing, Yan Wang, Weiqun Mao, Lan Pang, Zhen Lu, Robert C. Bast. Autophagic ovarian cancer cells exhibit substantially enhanced sensitivity to Crizotinib [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 3313. doi:10.1158/1538-7445.AM2017-3313
Abstract 3323: Anticancer activity of medicinal plant and neuroglioma
Authors: Shivers Michael Quincy
Published: July 2017

Neuroglioma, also called gliocytoma, is one of the common malignant tumors in central nervous system at present. Neuroglioma can make aggressive growth around brain tissue, so complete radical treatment can be realized by single excision. Nutritional and botanical treatments have been found useful in treating neuroglioma and other types of cancers. Vernonia amygdalina (VA) is a valuable medicinal plant that is widespread in East and West Africa. It has been reported to have not only diverse therapeutic effects for many tropical diseases, but has recently been shown to possess anti-cancer properties. Therefore, the goal of this research was to determine the therapeutic mechanisms of VA leaf extracts in the management of brain tumor. To achieve this goal, Human H4 neuroglioma cells were treated with different concentrations of Vernonia Amygdalina for 24 hr. Cell survival was determined by MTs assay. The extent of oxidative cell/tissue damage was determined by measuring malondialdehyde (lipid peroxidation biomarker) concentrations by spectrophotometry. Cell apoptosis was measured by flow cytometry assessment (Annexin V/PI assay). Data obtained from the MTS assay indicated that VA significantly (p < 0.05) reduced the viability of in H4 cells in a concentration-dependent manner. We detected a significant (p < 0.05) increase in malondialdehyde (MDA) concentrations in VA-treated glioblastoma cells compared to the control. Flow cytometry data showed a strong concentration-response relationship between VA exposure annexin V/PI positive cells. Taken together, our finding indicates that VA induced cytotoxicity and apoptosis in H4 cells is associated with the formation of MDA, a by-product of lipid peroxidation and biomarker of oxidative stress. At therapeutic concentrations, VA-induced cytotoxic and apoptotic effects in H4 cells is mediated by oxidative stress.

Note: This abstract was not presented at the meeting.

Citation Format: Michael Quincy Shivers. Anticancer activity of medicinal plant and neuroglioma [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 3323. doi:10.1158/1538-7445.AM2017-3323
Abstract 3324: FATE1 promotes mitochondrial hyperfusion and supports maintenance of mitochondrial networks following apoptosis stimulation
Authors: Hamacher-Brady Anne , Lang Verena , Brady Nathan R.
Published: July 2017

FATE1 (fetal and adult testis expressed 1), also known as the cancer-testis antigen BJ-HCC-2, is expressed in testis and tumor tissues. FATE1 was recently described as a major survival factor in tumor cells of various origins, by mediating the degradation of the pro-apoptotic BH3-only protein Bik (Maxfield et al., in Nat Commun 2015 Nov 16;6:8840) and through ER-mitochondrial uncoupling (Doghman-Bouguerra et al., in EMBO Rep 2016 Sep;17(9):1264-80). Interestingly, FATE1 shares high sequence homology with the mitochondrial Drp1 receptor MFF (mitochondrial fission factor). We thus investigated a possible role of FATE1 impact on mitochondrial morphology following the stimulation of apoptosis in cancer cells. We found that, similar to MFF, FATE1 is localized to outer mitochondrial membranes and, unlike MFF, additionally localized to the endoplasmic reticulum. Importantly, in contrast to MFF, FATE1 overexpression does not recruit Drp1 to mitochondria, and instead promotes hyperfusion of mitochondrial networks. Co-immunoprecipitation experiments and reconstitution of Mfn2 or Mfn1 in double knockout mouse embryonic fibroblasts indicate a role for the mitochondrial fusion protein Mfn2, but not Mfn1. As FATE1 overexpressing cancer cells were more resistant to mitochondrial fragmentation in response to TNF and valinomycin treatments, we propose FATE1 as a novel regulator of mitochondrial morphology changes occurring during apoptosis, with possible implications in FATE1-mediated resistance of cancer cells to chemotherapy.

Citation Format: Anne Hamacher-Brady, Verena Lang, Nathan R. Brady. FATE1 promotes mitochondrial hyperfusion and supports maintenance of mitochondrial networks following apoptosis stimulation [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 3324. doi:10.1158/1538-7445.AM2017-3324
Abstract 3331: PID1, a candidate tumor suppressor in pediatric and adult brain tumors, is a novel interacting partner for a cell surface receptor
Authors: Erdreich-Epstein Anat , Ren Xiuhai
Published: July 2017

BACKGROUND: PID1 is higher in fat from obese patients and is an inhibitor of insulin receptor signaling. We reported that PID1 is a novel inhibitor of medulloblastoma and glioma cell growth, and its mRNA level is highly correlated with survival across multiple independent datasets of these tumors. PID1 harbors a phosphotyrosine binding domain and is predicted to interact with proteins harboring NPXY motifs. We therefore hypothesized that PID1 will interact with phosphotyrosine-binding (PTB) domain containing protein(s) that may be important in brain tumors, and will modulate its/their signaling. Here we report PID1 interactions with one of these proteins and determine its biological consequences.

METHODS: Experiments consisted of immunoprecipitations, transient transfections, and western blotting. Functionally, assays included cell culture, flow cytometry for proliferation using BrdU/7AAD and apoptosis using AnnexinV/7AAD. Plasmids were pCMV-AN-HA-PID1(2) or control or the protein of interest in pcDNA3.1. Cell lines used were glioblastoma, medulloblastoma, atypical teratoid rhabdoid (ATRT), HEK293, and cells deficient or intact in PID1.

RESULTS: We demonstrate co-immunoprecipitation of PID1 with a receptor that is considered important in cancer. Immunoprecipitation was both in HEK293T cells overexpressing both proteins and in native brain tumor cell lines with/without overexpression. While tyrosine in the NPXY motifs was not required for the interaction, mutating the kinase domain of the receptor or overall inhibition of tyrosine phosphorylation impaired the interaction with PID1. Different domains in PID1 differentially co-immunoprecipitated with the receptor. Interestingly, mouse embryo fibroblasts without PID1 showed increased growth factor-dependent tyrosine phosphorylation of this protein and increased growth factor-induced proliferation. Identity of the receptor will be disclosed at the meeting.

CONCLUSIONS: These data point to PID1 as a novel interacting partner and regulator of this receptor’s biological effects and signaling in brain tumors.

Note: This abstract was not presented at the meeting.

Citation Format: Anat Erdreich-Epstein, Xiuhai Ren. PID1, a candidate tumor suppressor in pediatric and adult brain tumors, is a novel interacting partner for a cell surface receptor [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 3331. doi:10.1158/1538-7445.AM2017-3331
Abstract 3334: The FGFR4-388Arg variant exerts pro-tumorogenic effects in lung cancer by inducing an EMT phenotype
Authors: Quintanal-Villalonga Álvaro , Suárez Rocío , Ojeda-Márquez Laura , Ponce-Aix Santiago , Carnero Amancio , Paz-Ares Luis , Ferrer Irene , Molina-Pinelo Sonia
Published: July 2017

The FGFR4-388Arg allele, where an arginine substitutes a glycine in the 388 codon of the FGFR4 gene, has been associated to poorer patient outcome in different tumor types. In lung cancer, the variant has been related to shorter overall survival in adenocarcinoma (ADC) patients, while no relationship with squamous cell carcinoma prognosis (SCC) has been reported. Mechanistically, the FGFR4-388Arg variant has been related to increased MAPK pathway activation and to EMT in prostate cancer in vitro models. Furthermore, the variant has been associated with higher STAT3 signaling in murine models of breast and lung cancer. However, so far the molecular biology for this FGFR4 variant in lung cancer patients has not been addressed.

We overexpressed the FGFR4-388Gly and FGFR4-388Arg variants in lung cancer cell lines from different histologic backgrounds and performed tumorogenicity surrogate assays and downstream signaling activation assessment. In the generated stable cell lines, we also determined the expression of EMT markers. Furthermore, we determined the FGFR4 variant and the FGFR4 and N-cadherin mRNA expression in a cohort of NSCLC patients (N=65) and correlated these data to patient outcome.

We reported that FGFR4-388Arg increases tumorogenicity in lung cancer cell lines. Mechanistically, these functional effects seem to be mediated by MAPK and STAT3 overactivation and by the induction of an EMT phenotype, which includes N-cadherin increased expression. In fact, this induction of N-cadherin protein expression by the FGFR4-388Arg variant seems to be responsible for the pro-oncogenic effects reported. In NSCLC patient tumor samples, the FGFR4-388Arg variant correlates with higher N-cadherin expression and with poorer survival.

In conclusion, the FGFR4-388Arg variant is a potential prognostic biomarker in NSCLC, including ADC and SCC patients. This variant increases tumorogenesis through the activation of MAPK and STAT3 signaling pathways and through the promotion of an EMT phenotype.

Citation Format: Álvaro Quintanal-Villalonga, Rocío Suárez, Laura Ojeda-Márquez, Santiago Ponce-Aix, Amancio Carnero, Luis Paz-Ares, Irene Ferrer, Sonia Molina-Pinelo. The FGFR4-388Arg variant exerts pro-tumorogenic effects in lung cancer by inducing an EMT phenotype [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 3334. doi:10.1158/1538-7445.AM2017-3334
Abstract 3338: A role for FGFR4 in growth and survival of Ewing sarcoma cells
Authors: Montoya Justin J. , Wai Daniel H. , Lee David W. , Azorsa Peter A. , Pepper Oliver B. , Arceci Robert J. , Azorsa David O.
Published: July 2017

Ewing sarcoma is the second most common cancer of bone and soft tissue arising in children and young adults. Although the survival rate has improved for patients treated for localized disease, the survival rate for patients with metastatic tumor remains lower than 30%. In order to identify novel therapeutic targets and to better understand the genes involved in growth and survival of Ewing sarcoma, we employed a functional genomics approach based on siRNA screening. Four Ewing sarcoma cell lines, TC-32, TC-71, SK-ES-1 and RD-ES, were transfected with a library of siRNA targeting 287 cancer-associated genes. The resulting siRNA screening data for each cell line were normalized and statistical cut-offs were determined. The results indicated that siRNAs targeting Fibroblast Growth Factor Receptor 4, FGFR4 were among the most effective in reducing cell viability in all four of the Ewing sarcoma cell lines. Validation of the siRNA screens showed that siRNAs to FGFR4, reduced viability much greater that those to FGFR1, FGFR2, or FGFR3. Furthermore, siRNA targeting FGFR4 were able to induce caspase 3 activity. FGFR4 protein is expressed on Ewing sarcoma cells as determined by western blot analysis, although expression levels were lower compared to FGFR4 expression on rhabdomyosarcoma cells. Targeting FGFR activity in Ewing sarcoma cells using a pan-FGFR inhibitors PD-173074 and BGJ-398 demonstrated that Ewing sarcoma cells were sensitive to FGFR inhibition. Furthermore, treatment of Ewing sarcoma cells with the selective FGFR4 inhibitor BLU9931 resulted in growth inhibition and decreased ERK signaling. These results indicate that FGFR4 may play an important role in growth and survival of Ewing sarcoma and could serve as a potential therapeutic target for this disease.

Citation Format: Justin J. Montoya, Daniel H. Wai, David W. Lee, Peter A. Azorsa, Oliver B. Pepper, Robert J. Arceci, David O. Azorsa. A role for FGFR4 in growth and survival of Ewing sarcoma 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 3338. doi:10.1158/1538-7445.AM2017-3338
Abstract 3343: RNA demethylase alkbh5 supports breast cancer growth and progression
Authors: Eedunuri Vijay Kumar , Subbarayalu Panneerdoss , Rajamanickam Subhapriya , Nourhan Abdelfattah , Onyeagucha Benjamin C. , Timilsina Santosh , Yadav Pooja , Rao Manjeet K.
Published: July 2017

N6-methyladenosine (m6A) is one of the most prevalent internal modifications in eukaryotic messenger RNA. This dynamic and reversible modification is installed by methyltransferase complex consisting of three subunits: Methyltransferase-like protein 3 (METTL3), Methyltransferase-like protein 14 (METTL14) and Wilms tumor 1-associating protein (WTAP), and erased by two independent demethylases, Fat mass and obesity associated protein (FTO) and AlkB homolog 5 (ALKBH5). RNA demthylase ALKBH5 has been reported to play vital roles in several biological processes. However, very little is known about the role of ALKBH5 in cancer in general and breast tumorigenesis in particular. In this study, we report that ALKBH5 promotes breast cancer growth and progression. Using in vitro and in vivo models, we show that silencing of ALKBH5 inhibits breast cancer growth and invasion. Importantly, our studies reveal that ALKBH5 mediates its pro-tumorigenic function by regulating several microtubule associated genes including KIF2C, PLK1, MAPRE1 and RCC2 that are critical for spindle formation or assembly during mitotic progression. Interestingly, ALKBH5 target genes KIF2C and MAPRE1 are highly expressed in breast cancer patients and their higher expression is strongly correlated with lower survival of breast cancer patients. We believe that an optimal level of RNA methylation of key target genes is critical for normal cell cycle progression and any alteration in the levels of RNA methylation may alter activity or expression of these genes resulting in unabated cell proliferation.

Citation Format: Vijay Kumar Eedunuri, Panneerdoss Subbarayalu, Subhapriya Rajamanickam, Abdelfattah Nourhan, Benjamin C. Onyeagucha, Santosh Timilsina, Pooja Yadav, Manjeet K. Rao. RNA demethylase alkbh5 supports breast cancer growth and progression [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 3343. doi:10.1158/1538-7445.AM2017-3343
Abstract 3344: AKT mediates transcriptional regulation of H3K4 demethylase in PTEN null prostate cancer
Authors: Khan Mohammad Imran , Rath Suvasmita , Khan Qateeb , Adhami Vaqar M. , Mukhtar Hasan
Published: July 2017

One of the common contributors to the pre-disposition of most human cancers is inappropriate activation of AKT due to loss of its negative regulator PTEN. Activated AKT regulates changes in metabolic processes such as acetyl-CoA production that impacts chromatin. AKT phosphorylates a wide variety of histone modulating enzymes including acetyltransferases and methyltransferases resulting in their hyperactivation or inhibition. Therefore, understanding the impact of AKT inhibition on global histone modification would be ideal to identify novel histone modifiers regulated by AKT. We performed unbiased and comprehensive profiling of histone modifications in prostate specific PTEN knockout mice treated with an AKT inhibitor (Perifosine, 10mg/kg body weight daily for 4 weeks) and observed that AKT inhibition significantly induces di and tri methylation of H3K4, concomitant with reduction acetylation of H3K9. Changes in other histone modifications such as H3K36 and H3K79 methylation and acetylation were not observed. Mechanistically, we observed that AKT inihibiton reduces the expression of H3K4 methylation related histone demethylases KDM5 family, especially KDM5B expression at transcriptional level. Similar observations were noted at translational level also. To further understand the transcriptional regulation of KDM5B by AKT we focused on miR-137 and miR-138 as these have been shown to transcriptionally regulate H3K4 demethylases. We observed that AKT activation negatively regulated miR-137 but not miR-138 levels, which further transcriptionally represses KDM5B expression. Overexpression of miR-137 significantly reduced KDM5B and increased H3K4 di and tri methylation levels but failed to change AKT phosphorylation. Genetic knockdown of AKT or inhibition of AKT phosphorylation increased miR137 and reduced both KDM5B levels. Overall, we observed that AKT transcriptionally regulates KDM5B mainly via repression of miR137. Our data identify a mechanism by which PI3K/AKT signaling modulates the prostate cancer epigenome through regulating H3K4 methylation and KDM5B expression. Additional studies that assess the impact of AKT inhibiton on genome occupancy of H3K4 methylation will help in the identification of targets and devise novel strategies to enhance the therapeutic efficacy of PI3K/AKT inhibitors that are currently in clinical development.

Citation Format: Mohammad Imran Khan, Suvasmita Rath, Qateeb Khan, Vaqar M. Adhami, Hasan Mukhtar. AKT mediates transcriptional regulation of H3K4 demethylase in PTEN null 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 3344. doi:10.1158/1538-7445.AM2017-3344
Abstract 3345: Selective killing of SMARCA2- and SMARCA4-deficient tumors by inhibition of EZH2: In vitro and in vivo preclinical models
Authors: Chan-Penebre Elayne , Armstrong Kelli , Drew Allison , Grassian Alexandra R. , Feldman Igor , Roche Maria , Ho Peter , Brach Dorothy , Raimondi Alejandra , Copeland Robert A. , Chesworth Richard , Smith Jesse J. , Ribich Scott A.
Published: July 2017

The histone methyltransferase EZH2 is the enzymatic subunit of the polycomb repressive complex 2 (PRC2) that catalyzes the methylation of H3K27 thereby repressing target gene transcription. EZH2 is amplified, overexpressed, or mutated in multiple cancer types, most notably Follicular Lymphoma (FL) and germinal center Diffuse Large B-cell Lymphoma (GCB-DLBCL). We previously reported that preclinical models of malignant rhabdoid tumors, which are deficient in the SWI/SNF core component INI1 (SNF5, SMARCB1), are selectively killed by potent and selective inhibitors of EZH2. Here we report another class of SWI/SNF-altered cancers named small cell carcinoma of the ovary hypercalcemic type (SCCOHT) that is dependent on EZH2 activity. SCCOHT is a very aggressive form of cancer that responds poorly to conventional therapy with a one-year overall survival rate of only 50%. Very few novel agents have been approved for this indication; thus there is a need for targeted therapeutics in SCCOHT. SMARCA4 and SMARCA2 are co-inactivated in this tumor type that has many rhabdoid features. We demonstrate that tazemetostat, an EZH2 inhibitor currently in phase 2 clinical trials, induces potent and selective killing in SMARCA2 and SMARCA4-deficient ovarian cell lines. In addition to small molecule inhibitor data, we conducted functional genomics studies with CRISPR pooled screening, and confirmed that SCCOHT is also sensitive to CRISPR-mediated EZH2 gene ablation. Dose-dependent anti-tumor effects were observed upon tazemetostat treatment in SCCOHT xenografts deficient in both SMARCA2 and SMARCA4. We also report on additional non-ovarian tumor types with dual SMARCA2/SMARCA4 loss including NSCLC that exhibit EZH2 dependence representing additional potential therapeutic indications for tazemetostat treatment.

Citation Format: Elayne Chan-Penebre, Kelli Armstrong, Allison Drew, Alexandra R. Grassian, Igor Feldman, Maria Roche, Peter Ho, Dorothy Brach, Alejandra Raimondi, Robert A. Copeland, Richard Chesworth, Jesse J. Smith, Scott A. Ribich. Selective killing of SMARCA2- and SMARCA4-deficient tumors by inhibition of EZH2: In vitro and in vivo preclinical models [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 3345. doi:10.1158/1538-7445.AM2017-3345
Abstract 3349: A regulatory circuit HP1 gamma/miR-451a/c-Myc promotes prostate cancer progression
Authors: Huang Ruimin , Chang Cunjie , Liu Jiakuan , Huang Xiaojing , Shen Lan , Zhang Dianzheng , Yan Jun
Published: July 2017

Heterochromatin protein 1 gamma (HP1 gamma), as a reader of the histone codes, is involved in the determination of higher order of chromatin structure. It has also been implicated in carcinogenesis of various cancer types. However, the role of HP1 gamma in prostate cancer (PCa) progression and the underlying molecular mechanisms remain largely unknown. Using the public microarray data from GEO and TCGA database, we found that HP1 gamma was upregulated in PCa, comparing with benign prostate tissues. PCa patients with higher level of HP1 gamma had shorter disease-free survival, indicating that HP1 gamma level can serve as prognostic marker in PCa patients (p = 0.016). In addition, depletion of HP1 gamma by shRNA in PCa cells not only repressed proliferation and induced apoptosis, but also impaired tumorigenicity in vitro and in vivo. We also found that c-Myc was capable of upregulating HP1 gamma by directly binding to the E-box element in the first exon of HP1 gamma gene, and the upregulated HP1 gamma, in turn, repressed the expression of miR-451a by enhancing H3K9 methylation at the promoter region of miR-451a. Furthermore, reduction of miR-451a significantly reversed HP1 gamma loss-induced PCa cell apoptosis, whereas miR-451a overexpression repressed cell survival by targeting and downregulating c-Myc. The association among mRNA and protein expression levels of c-Myc, HP1 gamma and miR-451a were further confirmed in human clinical samples using Spearman correlation analysis. Therefore, we propose that an HP1 gamma/miR-451a/c-Myc regulatory circuit exists in PCa cells and this circuit plays a crucial role in PCa progression.

Citation Format: Ruimin Huang, Cunjie Chang, Jiakuan Liu, Xiaojing Huang, Lan Shen, Dianzheng Zhang, Jun Yan. A regulatory circuit HP1 gamma/miR-451a/c-Myc promotes prostate cancer progression [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 3349. doi:10.1158/1538-7445.AM2017-3349
Abstract 3352: Genome-wide enhancer identify signature predictive of metastatic phenotypes in bladder cancers
Authors: Kim Sohyoung , Varticovski Lyuba , Lao Qizong , Baek Songjoon , Nickerson Michael L. , Sung Myong-Hee , Grontved Lars , Bethtrice Thompson , Theodorescu Dan , Agarwal Piyush K. , Dean Michael , Hager Gordon
Published: July 2017

In urothelial bladder cancer accurate identification of grade and stage is critical for optimal treatment to achieve robust disease control and long-term survival. However, among the initially superficial tumors, which are non-invasive and highly treatable, 20 to 25 % recur, progress to invasive tumors, and metastasize during the patients’ lifetime. Thus, the challenge is to provide risk stratification during the initial diagnosis in order to identify those patients who are unlikely to progress while offering radical therapy to those who are at risk. To address this issue, the field has heavily focused on the discovery of few mutations in potential driver genes. However, recent findings indicate that deregulation of enhancers can play a major role in cancer progression. In this study, we employed DNase-Seq to detect enhancer activities genome-wide in 16 bladder cancer cell lines (BLCs) that included three lineages (T24, UMUC3, 253J lineages) with different tumorigenic and metastatic potentials, and thus represent models of cancer progression and metastasis development. We analyzed the gain and loss of enhancer activity in each BLC lineages as well as in metastatic cell lines relative to non-metastatic cell lines. Our analysis in the T24 lineage revealed a striking feature, a dramatic loss of intronic and distal DHSs (DNase I Hypersensitive sites), during the initial transition to tumorigenic type. During metastatic progression, new enhancer classes emerged and there was an enrichment for association with target organ-specific genes. The analysis of differential DHSs between metastatic and non-metastatic BLCs identified an enhancer signature enriched with lost DHSs in metastatic BLCs where nearby genes were associated with cellular movement/invasion functions. Lost DHSs were also present near key factors such as PPARG, RXRA, FOXA1, TP63, and GATA3, which play a role in urothelial development and differentiation, and the transcription activity of those genes were correlated with the change of enhancer activity. This study identified a set of DHSs that are associated with cancer progression in bladder cancer, and provides a potential clinical application for developing prognostic markers to predict the risk of developing aggressive disease.

Citation Format: Sohyoung Kim, Lyuba Varticovski, Qizong Lao, Songjoon Baek, Michael L. Nickerson, Myong-Hee Sung, Lars Grontved, Thompson Bethtrice, Dan Theodorescu, Piyush K. Agarwal, Michael Dean, Gordon Hager. Genome-wide enhancer identify signature predictive of metastatic phenotypes in bladder cancers [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 3352. doi:10.1158/1538-7445.AM2017-3352
Abstract 3360: Targeted catalytic inhibition of EZH2 synergizes with low-dose HDACi in malignant rhabdoid tumors
Authors: Popovski Dean , Algar Elizabeth M. , Cochrane Catherine R. , Szczepny Anette , Jayasekara W. Samantha , Ashley David M. , Downie Peter , Watkins D. Neil , Cain Jason E.
Published: July 2017

Malignant Rhabdoid Tumor (MRT) is a rare pediatric cancer of the kidney and CNS that is resistant to current treatment protocols. MRT is genetically characterized by homozygous inactivation of SMARCB1, a critical subunit of the SWI/SNF chromatin-remodeling complex. Next-generation sequencing data suggests that inactivation of SMARCB1 is the primary driver mutation, implicating epigenetic deregulation in the pathogenesis of MRT. Recently, we showed that sustained treatment of MRT cell lines with low-dose Panobinostat (LBH589), inhibited tumor growth by driving multi-lineage differentiation in vitro and in vivo. Furthermore, re-expression of physiological levels of SMARCB1 in G401 MRT cells phenocopied the low-dose LBH589 treatment and led to growth inhibition, senescence and terminal differentiation in vitro and in vivo. Enhancer of Zeste homolog 2 (EZH2), a core subunit of the Polycomb Repressive Complex 2 (PRC2), confers transcriptional silencing via the addition of methyl groups to Lysine 27 of Histone 3 (H3K27me3), and is a transcriptional target of SMARCB1. EZH2 expression and H3K27me3 were drastically reduced following sustained low-dose LBH589 treatment and re-expression of SMARCB1 in G401 MRT cells. Sustained siRNA knockdown of EZH2 in G401 cells resulted in reduced cell growth and changes in mRNA expression similar to those observed following low-dose LBH589 treatment and SMARCB1 re-expression. Treatment of MRT cells with the EZH2-catalytic domain inhibitor, GSK-126, had no effect on EZH2 expression and only partially reduced H3K27me3 and cell growth at doses 1nM-10μM suggesting important non-catalytic EZH2 function. However, MRT cells treated in combination with low-dose LBH589 and GSK-126, lost EZH2 and H3K27me3 expression and exhibited significantly reduced cell growth in vitro compared to single agent controls, revealing a synergistic relationship. Similar effects were observed in an in vivo xenograft model, with low-dose LBH589 and GSK-126 treatment leading to a marked reduction in tumor growth, not observed with single agent treatment. This data suggests EZH2 is an important mediator of MRT proliferation and differentiation and provides evidence for dual therapeutic targeting of EZH2 with low-dose HDACi in MRT.

Citation Format: Dean Popovski, Elizabeth M. Algar, Catherine R. Cochrane, Anette Szczepny, W. Samantha Jayasekara, David M. Ashley, Peter Downie, D. Neil Watkins, Jason E. Cain. Targeted catalytic inhibition of EZH2 synergizes with low-dose HDACi in malignant rhabdoid tumors [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 3360. doi:10.1158/1538-7445.AM2017-3360
Abstract 3378: Whole exome sequencing identifies recurrent alterations of genes in malignant phyllodes tumors in nine Korean individuals
Authors: Yun Jihui , Moon Hyeong-Gon , Yoo Tae-Kyung , Lee Eunshin , Chae Jeesoo , Hur Sam , Lee Jiwoo , Kim Jong-Il , Noh Dong-Young
Published: July 2017

Phyllodes tumors of the breast are rare fibroepithelial neoplasms with variable clinical behavior accounting for about 1% of all breast neoplasms. Phyllodes tumors are classified into benign, borderline, and malignant grades on the basis of histological features. Among those categories, Malignant phyllodes tumor has a higher propensity for local recurrence and distant metastasis, however the malignant potential of phyllodes tumors is difficult to assess on initial pathologic examination. In previous studies, an important role of mediator complex subunit 12 (MED12) in phyllodes tumors has been frequently revealed. However, except that, genetic abnormalities that drive tumor initiation and progress in malignant phyllodes tumor remain still unclear. Here, by performing whole exome sequencing of 9 malignant phyllodes tumors with matching normal cases, we frequently observed mutations in MED12 (3/9, 33.34%). Additionally, non-silent mutations in p53(TP53) and epidermal growth factor receptor (EGFR) were recurrently identified. Whole-gene amplifications of EGFR were also found in six cases (6/9, 66.67%). We suggest that EGFR has an underlying role in malignant phyllodes tumors. This study identifies potential therapeutic targets in malignant phyllodes tumors, including EGFR.

Citation Format: Jihui Yun, Hyeong-Gon Moon, Tae-Kyung Yoo, Eunshin Lee, Jeesoo Chae, Sam Hur, Jiwoo Lee, Jong-Il Kim, Dong-Young Noh. Whole exome sequencing identifies recurrent alterations of genes in malignant phyllodes tumors in nine Korean individuals [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 3378. doi:10.1158/1538-7445.AM2017-3378
Abstract 3383: Exome sequencing in dedifferentiated ovarian mucinous carcinoma
Authors: Sanuki Kaori , Nakayama Kentaro , Nakamura Kohei , Ishikawa Masako , Ishibashi Tomoka , Yamashita Hitomi , Ono Ruriko , Minamoto Toshiko , Yoshihara Kosuke , Kyo Satoru
Published: July 2017

Mucinous ovarian tumor represent a distinct histotype of epithelial ovarian cancer and is thought to begin as a mucinous adenoma that progresses in a slow stepwise fashion. Dedifferentiated mucinous ovarian carcinoma is a rare type of carcinoma with a few reports and a progressive and poor prognosis. While the molecular genetic features of ovarian mucinous carcinoma is now well known, the pathogenesis of dedifferentiated mucinous carcinoma is largely unknown. In order to comprehensively analyse somatic mutations in dedifferentiated mucinous carcinoma, we applied exome sequencing to the DNA of a sample of affinity-purified, dedifferentiated mucinous carcinoma. Through comparative analyses of normal cells from the same patient, we identified several genes that were mutated in this tumor. P53, which encodes a well-known tumor suppressor protein, and KRAS, which encodes a well-known oncoprotein, had previously been implicated in ovarian mucinous carcinoma. The other mutated genes were previously unknown to be involved in mucinous carcinoma. CEP170 encodes a microtubule-binding protein that controls the targeting of the kinesin-13 depolymerase protein to the mitotic spindle, and kinesin-13 family influence the dynamics of microtubule growth and shrinkage. CEP170 gene mutation may be related to inability of a cell division properly. CEP170 mutations were identified with a prevalence of 33.3% in dedifferentiated mucinous ovarian carcinoma. Currently, CEP170 gene knock down assay and engineered expression of CEP170 assay in ovarian mucinous carcinoma is being performed whether morphologic change is observed. In summary, CEP170 may be one of the responsible gene in carcinogenesis of differentiated mucinous carcinoma.

Citation Format: Kaori Sanuki, Kentaro Nakayama, Kohei Nakamura, Masako Ishikawa, Tomoka Ishibashi, Hitomi Yamashita, Ruriko Ono, Toshiko Minamoto, Kosuke Yoshihara, Satoru Kyo. Exome sequencing in dedifferentiated ovarian mucinous 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 3383. doi:10.1158/1538-7445.AM2017-3383
Abstract 339: Identification of a novel isoform of WNT/planar cell polarity VANGL2 in breast cancer
Authors: Borg Jean-Paul , Walton Alexandra , Bailly Eric , Marchetto Sylvie , Audebert Stéphane
Published: July 2017

The WNT/PCP pathway is an evolutionarily conserved developmental process which is essential in embryogenesis and development of polarized structures in metazoans. Its importance in human diseases is best demonstrated in neural tube closure defects and cancer. WNT/PCP signaling involves a set of evolutionarily conserved WNT/PCP genes encoding WNT ligands, transmembrane (vangl2, frizzled, fat, dachsous) and cytoplasmic (scribble, prickle, dishevelled, diego) molecules triggering a genetically well-defined non-canonical WNT-JNK pathway. Recent work has linked defects of this pathway to breast cancer aggressiveness. We have shown that the non-canonical WNT/PCP transmembrane receptor VANGL2 is overexpressed in poor prognosis basal breast cancers and implicated in tumor growth. We also found that VANGL2 binds through its C-terminal sequence to Scribble and p62/SQSTM1 which are involved in cancer cell migration and growth. A recent in silico study has suggested the existence of an N-terminally extended VANGL2 isoform (VANGL2-Long), owing to the occurrence of an alternative non-AUG translation initiation site, upstream of the conventional start site. Translation initiation from this alternative site is expected to add an N-terminal extension of 48 amino acids. Accordingly, by analyzing VANGL2 immunoprecipitates by mass spectrometry, we identified a peptide mapping upstream of the first methionine supporting the existence of a longer isoform of VANGL2. While missing in Drosophila, this N-terminal extension is found in all vertebrate VANGL2 sequences that have been examined, suggesting a function for VANGL2-Long. We provide further experimental evidence in favor of the VANGL2-Long isoform, using polyclonal antibodies that have been raised against the predicted VANGL2 N-terminal extension. Using these tools, we characterized VANGL2-Long and showed that it dimerizes with VANGL2 and VANGL1, a close homologue, at the endogenous level in living cells. Our data depict a complex organization of VANGL1/VANGL2 molecules at the plasma membrane and improve the mechanistic understanding of VANGL2 in normal and cancer cells.

Citation Format: Jean-Paul Borg, Alexandra Walton, Eric Bailly, Sylvie Marchetto, Stéphane Audebert. Identification of a novel isoform of WNT/planar cell polarity VANGL2 in 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 339. doi:10.1158/1538-7445.AM2017-339
Abstract 3392: Genomic analysis of prostate cancer in Korean men
Authors: Jang Se Song , Kim Min Jung , Hong Dong Wan , Joung Jae Young , Kim Sung Han , Lee Kang Hyun , Park Weon Seo , Kim Jong-Il
Published: July 2017

Prostate cancer currently has the fifth highest incidence rate in Korean males, and is the most common cancer in western males. Prostate cancer is the second most common malignancy in men worldwide, and is responsible for approximately 250,000 cancer-related deaths annually. The search for accurate biomarkers and characterization of prostate cancer is critical for evolution of accurate management of prostate cancer. Previous studies have identified that several genomic alterations in prostate cancer including TMPRSS2-ERG fusion, PTEN deletion and SPOP single nucleotide variants (SNVs), the majority of which are from western population. In order to investigate the somatic mutations of Korean prostate cancers, we performed whole exome sequencing on 51 prostate cancer patient’s tumor tissues, and matched normal tissue. For the accurate detections of structural variations, we additionally performed whole genome sequencing on 9 matched pairs (tumor, normal). A total of 738 somatic non-silent variants affecting 692 distinct genes were identified. In addition to already known genes such as SPOP, FOXA1, TP53 and PTEN, we also found previously uncharacterized genes such as GRIN2A, LRP1, FNDC1 and LRP1B. Of the 40 mutated genes across multiple cases, missense SNVs of SPOP (10/60 cases, 16.7%) were the most frequent, followed by missense and splice-site SNVs of GRIN2A (5/60 cases, 8.3%). Mutations in low-density lipoprotein-related protein encoded by LRP1 and LRP1B affected considerable portion of all cases (7/60, 11.7%), describe the probable relation between lipid metabolism and prostate cancer. We found TMPRSS2-ERG fusion in 4 of 9 whole genome samples. Moreover, 5 samples had 8p whole arm deletion, which is found frequent in western prostate cancers. As a result, we describe the genomic patterns of genetic variations and structural variations involved in prostate cancer of Korean population.

Citation Format: Se Song Jang, Min Jung Kim, Dong Wan Hong, Jae Young Joung, Sung Han Kim, Kang Hyun Lee, Weon Seo Park, Jong-Il Kim. Genomic analysis of prostate cancer in Korean men [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 3392. doi:10.1158/1538-7445.AM2017-3392
Abstract 3398: The genomic and transcriptomic analysis of nine widely invasive follicular thyroid carcinomas (wiFTC) in Korean patients
Authors: Cho Angela Byuri , Yoo Seong-Keun , Sohn Min-Hwan , Shin Jong-Yeon , Kim Su-jin , Lee Eun Kyung , Park Young Joo , Seo Jeong-Sun
Published: July 2017

Widely invasive follicular thyroid carcinoma (wiFTC) can be characterized from minimally invasive follicular thyroid carcinoma (miFTC) as it exhibits poor prognosis with frequent distant metastasis. We have reported that miFTC shows similar mutational and transcriptional spectrum when compared to follicular adenoma (FA). Here, we performed whole-exome and transcriptome sequencing on wiFTC samples to define their aggressive biological features by comparing with 30 miFTCs and 26 FAs. Well-known miFTC and FA driver genes, NRAS (66.67%), HRAS (11.11%), and EIF1AX (11.11%), were identified in wiFTC. TERT mutation was found in all samples which can explain its aggressive feature. Chromosome 17p/q amplification was found in most wiFTC samples as well as 22q deletion that is frequently aberrant in H/K/NRAS mutated thyroid cancers. Most of wiFTCs were classified as RAS-like (66.67%) and a few were BRAF-like (22.22%) and NBNR (11.11%) molecular subtypes. From differentially expressed gene analysis, we found 1,832 and 1,384 up-regulated and down-regulated genes when wiFTC was compared to miFTC and FA together. wiFTC had many overlapped down-regulated genes as poorly differentiated and anaplastic thyroid carcinoma which also supports its aggressiveness. Through weighted correlation network analysis we have established gene expression networks, highly associated with wiFTC, that have SIRT6 and TGFBR2 as the central nodes. In this study, we demonstrated the distinctive mutational and transcriptional characteristics of wiFTC hence found the underlying molecular mechanism for its aggressiveness.

Citation Format: Angela Byuri Cho, Seong-Keun Yoo, Min-Hwan Sohn, Jong-Yeon Shin, Su-jin Kim, Eun Kyung Lee, Young Joo Park, Jeong-Sun Seo. The genomic and transcriptomic analysis of nine widely invasive follicular thyroid carcinomas (wiFTC) in Korean patients [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 3398. doi:10.1158/1538-7445.AM2017-3398
Abstract 3399: Genomic analysis of melanoma evolution following a 30 year disease-free interval
Authors: Miller Jerry J. , Lofgren Kristopher A. , Hughes Sarah R. , Cash Steven E. , Meier David R. , Kenny Paraic A.
Published: July 2017

The rate of ultra-late recurrence (beyond 10-15 years) of cutaneous melanoma has been estimated to be between 2.0-6.9% from large case series. Two major factors complicate the interpretation of these data. Firstly, the risk of second primary melanoma is approximately 5% creating uncertainty about whether at least some of these late onset tumors might be independent of the original lesion. Secondly, in the majority of cases, the original pathology specimen is no longer available for comparative analysis. Accordingly, putative late recurrences are difficult to unambiguously distinguish from a new primary melanoma. We identified a patient with a second melanoma diagnosed after a 30 year disease-free interval, and sought to determine if this new lesion was a recurrence of the original melanoma. We report the genomic sequence analysis of the exomes of two melanoma lesions isolated from the same individual in 1985 and 2015, and their comparison to each other and to the germline DNA of the patient. Identification of many shared somatic mutations between these lesions prove a lineal relationship spanning 30 years. Unlike prior reports of ultra-late melanoma recurrence, the availability of the original tumor and the use of comprehensive genomic analysis allowed us to confirm that the second lesion is truly a recurrence. We demonstrate the acquisition of numerous additional mutations during the three decade asymptomatic period. This is, to our knowledge, the longest disease-free interval that has been rigorously confirmed in melanoma or any other solid tumor type. These data highlight the low but very long-lasting risk of recurrence in this patient population.

Citation Format: Jerry J. Miller, Kristopher A. Lofgren, Sarah R. Hughes, Steven E. Cash, David R. Meier, Paraic A. Kenny. Genomic analysis of melanoma evolution following a 30 year disease-free interval [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 3399. doi:10.1158/1538-7445.AM2017-3399