bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 81: E2F4/p107 complex regulates chemotherapy resistance in human colorectal cancer stem cells
Authors: Matsubara Junichi , Li Yong F. , Dalerba Piero , Sahoo Debashis , Isobe Taichi , Altman Russ B. , Clarke Michael F. 
Published: July 2017

Abstract
Most cancer patients experience disease progression despite one or multiple lines of treatment with cytotoxic chemotherapy. Evidence from human trials and in vivo experiments on patient-derived xenograft (PDX) tumor lines indicates that cancer stem cells (CSCs) can survive chemotherapy treatment. However, the mechanism of chemotherapy resistance in CSCs is not fully elucidated. To identify new mechanisms of the drug-resistance in colorectal cancer, we used gene-expression microarrays to examine the gene expression profile of CSCs and non-CSCs in four human PDX models of colorectal cancer, both before-and-after treatment with cytotoxic chemotherapy. The gene-expression data were analyzed using Independent Component Analysis (ICA) followed by Transcription Factor Target Genes (TFTG) enrichment analysis, which identified the transcription factor E2F4 as a candidate regulator of chemotherapy resistance in colorectal CSCs. E2F4 was predominantly expressed in the CSC-enriched cell population (CD44+/CD166+ human colorectal cancer cells). E2F4 knock-down sensitizes cancer cells to chemotherapy in three different PDX tumors as well as HT29 cells. Co-immunoprecipitation experiments showed that E2F4 forms a complex with p107 and DP-1, which also contributed to the chemotherapy resistance. Simultaneous knock-down of both E2F4 and p107 enhanced chemotherapy sensitivity more than E2F4 knock-down alone. In normal intestinal crypt cells E2F4 was dispensable for chemotherapy resistance. ChIP-seq and RNA-seq experiments revealed that LDHA is a key downstream target of E2F4. LDHA knock-down sensitizes cancer cells to chemotherapy. High LDHA expression in tumor tissues was an independent poor prognostic factor in colorectal cancer patients (n=466), as well as in non-small cell lung cancer (n=1,926) and breast cancer (n=3,554). Thus, the E2F4/p107-LDHA pathway represents a novel therapeutic target to overcome chemotherapy resistance in CSCs.
Citation Format: Junichi Matsubara, Yong F. Li, Piero Dalerba, Debashis Sahoo, Taichi Isobe, Russ B. Altman, Michael F. Clarke. E2F4/p107 complex regulates chemotherapy resistance in human colorectal cancer stem 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 81. doi:10.1158/1538-7445.AM2017-81
Abstract 827: Statistical analyses of stable housekeeping gene expression in cancer post-irradiation
Authors: Wang Albert R. , Iyer Gopal , Brennan Sean , Bourgeois Shay , Armstrong Eric , Shah Pari , Harari Paul M. 
Published: July 2017

Abstract
Ionizing radiation (IR) can induce DNA damage in human cells and result in changes in gene expression. The changes could also include some of the commonly used housekeeping genes (HKG), and thus making them unstable over the time period after being exposed to radiation. Normalization of housekeeping genes is critical for understanding gene expression post-irradiation. Toward the validation of stable HKGs, cancer cell lines from head and neck, non-small cell lung and pancreas were irradiated to 2, 4 and 6 Gy IR doses. Statistical analysis of RNA expression of fourteen HKGs measured at 5 min to 48hrs post-irradiation reveal tradition HKGs such as beta-actin (ACTB) and glucose-6-phosphate-dehydrogenase (G6PD) to be unstable, while TATA-Box Binding Protein (TBP) and Importin 8 (IPO8) was identified as stable HKGs in non-small lung and pancreas cell across all IR doses and time. Interestingly in head and neck cancer, TBP is also found stable across all IR doses and time. The statistical framework used for identification and validation of HKGs can serve as a reliable metric for quantifying gene expression post-irradiation.
Citation Format: Albert R. Wang, Gopal Iyer, Sean Brennan, Shay Bourgeois, Eric Armstrong, Pari Shah, Paul M. Harari. Statistical analyses of stable housekeeping gene expression in cancer post-irradiation [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 827. doi:10.1158/1538-7445.AM2017-827
Abstract 831: TGFβ controls the DNA damage response via miR-182 regulation of BRCA1 and ATM
Authors: Liu Qi , Martinez-Ruiz Haydeliz , Murnane John , Powell Simon N. , Barcellos-Hoff Mary Helen 
Published: July 2017

Abstract
Transforming growth factor β (TGFβ) is a well-documented tumor suppressor; a poorly studied aspect of TGFβ biology is its control of genomic stability. Our prior work showed that TGFβ compromises ATM (ataxia telangiectasia mutated) kinase activity, which mediates recognition and repair of DNA damage. Consequently, inhibiting TGFβ following ionizing radiation increases clonogenic death in vitro and tumor control in vivo in breast, brain, and lung cancer preclinical models. As yet unknown is how TGFβ controls ATM kinase. We recently determined that TGFβ regulates mammary lineage commitment by post-transcriptional control of BRCA1 mRNA and protein by its suppression of miR-182 (Martinez-Ruiz et al., Science Signaling, in press). miR-182-mediated downregulation of BRCA1 impacts DNA repair and sensitivity to PARP inhibitors in cancer cell lines (10.1016/j.molcel.2010.12.005) Here we used two cell culture models to investigate the effect of TGFβ regulation of BRCA1 and miR-182 on DNA damage response. Spontaneously immortalized Tgfb1 heterozygote and wild type fibroblasts from primary mammary epithelial preparations were synchronized in S-phase and exposed to UV radiation before fixation to detect unrepaired DNA damage by quantitative image analysis of 53BP1 foci. Consistent with compromised BRCA1 function, more than twice as many cells with 53BP1 foci were evident in Tgfb1 heterozygote fibroblasts compared to wild type cells (p&lt;0.01). The second model consisted of non-malignant human breast epithelial cell line, MCF10A, stably transduced with a scrambled or miR-182 antagomir, grown under serum free conditions and treated with a small molecule inhibitor of TGFβ type I receptor kinase, LY364937. FOXO3 is a target of miR-182 and thus also regulated by TGFβ. and FOXO3 association with ATM is required for its kinase activity (10.1038/ncb1709). As reported, FOXO3 and ATM co-immunoprecipitated, but was eliminated by TGFβ inhibition and this effect was lost in MCF10A cells expressing a miR-182 antagomir. The impaired DNA repair phenotype induced by TGFβ inhibition can be fully rescued by antagonizing miR-182. These studies support TGFβ as stringent regulator of the DNA damage response via suppression miR-182, which directly targets BRCA1 and indirectly affects ATM activity via FOXO3. We predict that cancers that have lost TGFβ signaling capacity will be genomically unstable due to defective DNA damage control, which is consistent with our studies showing that TGFβ inhibition sensitize cancers to radiation therapy.
Citation Format: Qi Liu, Haydeliz Martinez-Ruiz, John Murnane, Simon N. Powell, Mary Helen Barcellos-Hoff. TGFβ controls the DNA damage response via miR-182 regulation of BRCA1 and ATM [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 831. doi:10.1158/1538-7445.AM2017-831
Abstract 844: PPARD downregulation in cancer cells suppresses metastases by inhibiting tumor angiogenesis and EMT
Authors: Zuo Xiangsheng , Xu Weiguo , Xu Min , Tian Rui , Moussalli Micheline J. Moussalli J. , Mao Fei , Gagea Mihai , Wei Daoyan , Sood Anil K. , Shureiqi Imad 
Published: July 2017

Abstract
PPARD is upregulated in many major human cancers, but the role that its expression in cancer cells has in metastasis remains poorly understood. Here, we show that specific PPARD downregulation or genetic deletion of PPARD in cancer cells significantly repressed metastasis in various cancer models in vivo. Mechanistically, PPARD promoted angiogenesis via interleukin 8 in vivo and in vitro. Analysis of transcriptome profiling of HCT116 colon cancer cells with or without genetic deletion of PPARD and gene expression patterns in The Cancer Genome Atlas colorectal adenocarcinoma database identified novel pro-metastatic genes (GJA1, VIM, SPARC, STC1, SNCG) as PPARD targets. PPARD expression in cancer cells drastically affected epithelial-mesenchymal transition, migration, and invasion, further underscoring its necessity to metastasis. Clinically, high PPARD expression in various major human cancers (e.g., colorectal, lung, breast) was associated with significantly reduced metastasis-free survival. Our results demonstrate that PPARD, a druggable protein, is an important molecular target in metastatic cancer.
Citation Format: Xiangsheng Zuo, Weiguo Xu, Min Xu, Rui Tian, Micheline J. Moussalli J. Moussalli, Fei Mao, Mihai Gagea, Daoyan Wei, Anil K. Sood, Imad Shureiqi. PPARD downregulation in cancer cells suppresses metastases by inhibiting tumor angiogenesis and EMT [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 844. doi:10.1158/1538-7445.AM2017-844
Abstract 846: A novel high-throughput 3D screening system for EMT inhibitors
Authors: Arai Kazuya , Rahman M Mamunur , Itoh Manabu , Masuda Norio , Eguchi Takanori , Nakatsura Tetsuya , Calderwood Stuart K. 
Published: July 2017

Abstract
EMT (epithelial-mesenchymal transition) is a significant event in tumor metastasis and malignancy. Therefore, inhibition of EMT is considered to enable controlling of malignant transformation. In this study, we introduce an innovative three-dimensional (3D) high-throughput (HTS) system that leads to an identification of EMT inhibitors. At first, we established 3D-HTS EMT model with NanoCulture Plate (NCP) that provided a gel-free micro-patterned scaffold for cells forming spheroids naturally. In the NCP-based 3D cell culture system, A549 lung cancer cells migrated, gathered, and then formed multiple spheroids within 7 days. Live cell imaging experiments showed that an established EMT-inducer TGF-β promoted peripheral cells around the core of spheroids to acquire mesenchymal spindle shapes, loss of intercellular adhesion, and migration from the spheroids. Along with such morphological change, EMT-related gene expression signatures were altered, particularly alteration of mRNA levels of ECAD/CDH1, NCAD/CDH2, VIM and ZEB1/TCF8. These EMT-related phenotypic changes were blocked by SB431542, a TGF-βreceptor I (TGFβR1) inhibitor. Inside of the spheroids were highly hypoxic; in contrast, spheroid derived peripheral migrating cells were normoxic, revealed by visualization and quantification using Hypoxia Probe. Thus, TGF-β-triggered EMT caused spheroid hypoplasia and loss of hypoxia. Spheroid EMT inhibitory (SEMTIN) activity of SB431542 was calculated from fluorescence intensities of the Hypoxia Probe, and then was utilized in a drug screening of EMT-inhibitory small molecule compounds. In a pilot screening, 9 of 1,330 compounds were above the thresholds of the SEMTIN activity and cell viability. Finally, two compounds SB-525334 and SU9516 showed SEMTIN activities in a dose dependent manner. SB-525334 was a known TGFβR1 inhibitor. SU9516 was a cyclin-dependent kinase 2 (CDK2) inhibitor, which we showed also had an EMT-inhibitory activity. Taken together, it was shown that this 3D NCP-based HTS system was useful for screening of EMT-regulatory drugs.
Citation Format: Kazuya Arai, M Mamunur Rahman, Manabu Itoh, Norio Masuda, Takanori Eguchi, Tetsuya Nakatsura, Stuart K. Calderwood. A novel high-throughput 3D screening system for EMT inhibitors [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 846. doi:10.1158/1538-7445.AM2017-846
Abstract 848: Netropsin blocks EMT of murine BRAF mutated melanoma cells
Authors: Freitas Juliano , Leng Fenfei , Kos Lidia 
Published: July 2017

Abstract
Melanoma is the most aggressive and deadliest type of skin cancer due to its high propensity to metastasize. Despite current progress in the identification of promising drugs for treating melanoma, drug resistance has emerged as a serious issue indicating that novel therapeutic strategies may be required. It is well documented that the process of converting the epithelial tumorigenic cell to a mesenchymal phenotype, the epithelial-mesenchymal transition (EMT), is responsible for conferring an invasive phenotype to cancer cells. An EMT-like process has been shown to occur during melanoma progression. High-mobility-protein AT-hook 2 (HMGA2) is a multi-function transcription factor linked to oncogenesis and EMT in a variety of cancers. HMGA2 is a small DNA-binding protein with three “AT-hook” DNA-binding motifs that specifically recognize the minor groove of AT-rich DNA sequences. HMGA2 is significantly upregulated in human primary melanoma and metastases, including those with BRAF mutations. We accessed the potential application of netropsin, a potent inhibitor of HMGA2-DNA interactions, as an EMT blocking agent of BRAF mutated melanoma cells. Three murine melanoma cells lines that carry mutations in the BRAF gene and show resistance to vemurafenib (D4M, YUMM1.1, and YUMM1.7) were used. Cells were treated with EMT Inducing Media Supplement along with Netropsin and the expression of E-cadherin as well as their migratory behavior were evaluated. Netropsin treatment of EMT induced cells was not cytotoxic, prevented changes in cell morphology, maintained high levels of E-cadherin expression and decreased migratory behavior. All three cell lines express HMGA2 which continues to be expressed in the tumors resulting from subcutaneous injections in mice. YUMM1.1 cells showed the highest levels of expression of HMGA2 amongst the three cell lines. Interestingly, in our preliminary study only YUMM1.1-derived tumors generated overt metastasis in the lung 30 days after the injections. Altogether our data showed that Netropsin is capable of blocking EMT of murine BRAF mutated melanoma cells. The results of this study will contribute to the development of strategies to prevent EMT that may result in the implementation of more effective therapies to treat melanoma.
Citation Format: Juliano Freitas, Fenfei Leng, Lidia Kos. Netropsin blocks EMT of murine BRAF mutated melanoma 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 848. doi:10.1158/1538-7445.AM2017-848
Abstract 852: Bromodomain and extraterminal proteins regulate the epithelial-mesenchymal transition in breast cancer
Authors: Andrieu Guillaume , Denis Gerald V. 
Published: July 2017

Abstract
The epithelial-mesenchymal transition (EMT) is a developmental program that cancer cells often activate to acquire a highly plastic phenotype that promotes invasion, metastasis, but also chemoresistance and cancer stem cell generation. As readers of epigenetic marks, bromodomain and extra-terminal (BET) proteins BRD2, BRD3 and BRD4 participate in the regulation of multiple transcriptional programs implicated in cancer progression. We sought to unravel the roles of BET proteins in EMT in breast cancer.
Despite their homology, we report that BET proteins differentially regulate EMT. Based on an EMT PCR array, we identify a BRD2-specific transcriptional profile that promotes EMT, whereas BRD3 and BRD4 signatures repress this program. These individual signatures are unidentifiable upon pan-BET inhibition using JQ1, reinforcing the necessity to target each BET member separately to better understand their functions. Upon BRD2 depletion, basal-like breast cancer cells, which present a mesenchymal phenotype, exhibit a reduced expression of mesenchymal markers (N-cadherin, vimentin) and re-express epithelial markers (E-cadherin, cytokeratins). Moreover, a large panel of EMT master transcription factors is downregulated in BRD2-depleted cells, including the Snail and ZEB families or Twist. Interestingly, we found that BRD3 or BRD4 depletion leads to the opposite phenotype: an increase of mesenchymal marker expression and repression of the epithelial markers. In luminal A breast cancer cells which present an epithelial phenotype, BRD2 overexpression leads to the expression of mesenchymal markers. Similar results were obtained by depleting BRD3 or BRD4 in these cells, confirming the differential roles of BET proteins in EMT regulation.
Taken together, our results establish that BRD2 positively regulates EMT, whereas BRD3 and BRD4 repress this program. BET proteins possess separate and opposite biological functions, reinforcing the relevance of an individual targeting instead of a pan-BET inhibition using JQ1. We hypothesize that BET proteins modulate EMT through the regulation of its master transcription factors. We propose that the balance of BET proteins presence at the promoters of the EMT genes is a novel mechanism of regulation of this program in breast cancer cells.
Citation Format: Guillaume Andrieu, Gerald V. Denis. Bromodomain and extraterminal proteins regulate the epithelial-mesenchymal transition 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 852. doi:10.1158/1538-7445.AM2017-852
Abstract 862: Atypical protein kinase c inhibitors can repress epithelial to mesenchymal transition (type III) in malignant melanoma
Authors: Ratnayake Wishrawana Sarathi , Acevedo-Duncan Mildred 
Published: July 2017

Abstract
Melanoma is a type of cancer occurs in melanocytes. Approximately 90% of melanoma occurs in skin (cutaneous melanoma) but can rarely arise from the mucosal surfaces or areas which neural cells migrate. Examples are eye, intestine and mouth [Eur. J. Cancer, 69: 39-42 (2016)]. 76,380 of new cases and 10,130 number of deaths are expected in 2016 in the USA due to melanoma [http://seer.cancer.gov/statfacts/html/melan.html (11/05/2016)]. Atypical PKCs contains two structurally and functionally distinct isozymes in human which are PKC-ι (iota) and PKC-ζ (zeta). They are believed to be involved in cell cycle progression, tumorigenesis, cell survival and cell migration. We believe that atypical PKCs play an important role in cell motility of melanoma by involving the signaling pathways which induces EMT-type III (Epithelial to Mesenchymal Transition). In normal melanocytes, PKC-ζ was found in low levels and PKC-ι was not detected. But both proteins are detected in very high levels in malignant melanoma [Melenoma Res. 12:201-209 (2002)]. In the current study, we have investigated the effects of novel atypical PKC inhibitors [4-(5-amino-4-carbamoylimidazol-1-yl)-2, 3-dihydroxycyclopentyl] methyl dihydrogen phosphate (ICA-1) which is specific to PKC-ι and 8-hydroxy-1, 3, 6-naphthalenetrisulfonic acid (Compound-50) which is specific to PKC-ζ on the cell proliferation, apoptosis and cell migration of two malignant melanoma cell lines (SK-MEL-2 and MeWo) compared to a normal melanocyte cell line (PCS-200-013). We showed that both inhibitors can decrease the levels of total and phosphorylated levels of PKC-ζ and PKC-ι. Furthermore, both inhibitors increased the levels of E-cadherin and decreased the levels of Vimentin which is a mesenchymal marker associated with EMT. Treatments with inhibitors altered the levels of CD44, a cell-surface glycoprotein involved in cell-cell interactions, cell adhesion, migration and tumor cell homing during metastasis. These results suggest that both PKC-ι and PKC-ζ are involved in signaling pathways which upregulate EMT and which can be effectively suppress using ICA-1 and Compound-50. Furthermore we established that treatment with ICA-1/Compound-50 induced apoptosis as shown by increasing Caspase-3 levels and decreasing Bcl-2 levels.
Citation Format: Wishrawana Sarathi Ratnayake, Mildred Acevedo-Duncan. Atypical protein kinase c inhibitors can repress epithelial to mesenchymal transition (type III) in malignant melanoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 862. doi:10.1158/1538-7445.AM2017-862
Abstract 865: Cytoplasmic polyadenylation element binding protein 2 splice variants have opposing functions in the epithelial to mesenchymal transition pathway
Authors: DeLigio James T. , Chalfant Charles E. , Park Margaret A. 
Published: July 2017

Abstract
Alternative splicing of cytoplasmic polyadenylation element binding protein 2 (CPEB2) generates two isoforms, CPEB2B and CPEB2A, through inclusion/exclusion of exon 4, respectively, in mature mRNA. We previously reported that CPEB2B is essential to establish anoikis resistance (AnR), and promotes metastasis using in vivo orthotopic models. In contrast, CPEB2A decreases AnR and metastatic transformation. In the current studies, we examined the function of CPEB2 isoforms using next generation sequencing analysis of downstream signaling pathways. We found that CPEB2B expression upregulated AnR in breast cancer cells and induced key genes/proteins in the epithelial to mesenchymal transition (EMT) and hypoxic response (hypoxia inducible factor 1α (HIF1α)-dependent) pathways. Inhibition of either TWIST1 or HIF1α reduced the CPEB2B-mediated AnR in cells ectopically expressing CPEB2B, confirming a link between CPEB2 alternative splicing and the induction of the EMT/hypoxia pathways. We then extended our findings, and demonstrated that CPEB2 alternative splicing induced de novo translation of both HIF1α and TWIST1, whereas CPEB2A decreased translation of these factors. Furthermore, CPEB2 isoforms were found to modulate differential polyadenylation site selection of the TWIST1 3’UTR and competed for binding to HIF1α and TWIST1 3’UTR cytoplasmic polyadenylation element (CPE) site sequences. These results demonstrate that CPEB2A and CPEB2B modulate the translation of factors in the EMT/hypoxia pathways in an opposing fashion via differential polyadenylation site selection and subsequent translation.
Citation Format: James T. DeLigio, Charles E. Chalfant, Margaret A. Park. Cytoplasmic polyadenylation element binding protein 2 splice variants have opposing functions in the epithelial to mesenchymal transition pathway [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 865. doi:10.1158/1538-7445.AM2017-865