bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3111A: ADCT-401/MEDI3726, a novel pyrrolobenzodiazepine (PBD)-based antibody-drug conjugate (ADC) targeting PSMA-expressing prostate cancers
Authors: Zammarchi Francesca , Chivers Simon , Havenith Karin , Williams David G. , Adams Lauren , Mellinas-Gomez Maria , Corbett Simon , Tyrer Peter , D'Hooge Francois , Cho Song , Dimasi Nazzareno , Hinrichs Mary Jane , Howard Phil W. , Hartley John A. , Berkel Patrick H. van
Published: July 2017

Prostate-specific membrane antigen (PSMA) is an attractive target for an ADC approach as it is over-expressed by virtually all prostate cancers and its expression is highest in poorly-differentiated, metastatic and castration-resistant cases. PSMA has limited expression in non-prostatic tissues, it is not secreted or cleaved by PSMA-expressing cells, and it is constitutively internalized, a process that may be accelerated by specific antibody binding. ADCT-401/MEDI3726 is an ADC composed of a monoclonal antibody (J591), directed against human PSMA, site-specifically conjugated (drug-to-antibody ratio of 1.8) to a highly cytotoxic DNA cross-linking PBD dimer with a valine-alanine dipeptide linker. In vitro, ADCT-401/MEDI3726 demonstrated potent and specific cytotoxicity in a panel of PSMA-expressing prostate cancer cell lines, whereas its activity was greatly reduced in PSMA-negative cell lines. In vivo, ADCT-401/MEDI3726 showed strong antitumor activity against CWR22Rv1 and LNCaP human-derived prostate cancer xenograft models. In the CWR22Rv1 model, a tumor with low, heterogeneous PSMA expression, ADCT-401/MEDI3726 achieved dose-dependent antitumor activity when administered as single dose at either 0.33 or 1 mg/kg, which resulted in significant increase in survival compared to the vehicle-treated animals. Moreover, a single dose of ADCT-401/MEDI3726 showed remarkable superior antitumor activity compared to multiple doses of another PSMA-targeted ADC stochastically conjugated to the auristatin payload vcMMAE with a DAR of ~4. In the LNCaP model, ADCT-401/MEDI3726 resulted in dose-dependent antitumor activity when dosed once at 0.11, 0.33 or 1 mg/kg. In the PSMA-negative prostate cancer-derived PC3 xenograft model, ADCT-401/MEDI3726 and an isotope-control ADC showed limited tumor growth inhibition highlighting target-mediated antitumor activity. ADCT-401/MEDI3726 demonstrated potent and specific in vitro and in vivo antitumor activity in prostate cancer-derived models of differing levels of PSMA and this warrants further development of this ADC into the clinic.

Citation Format: Francesca Zammarchi, Simon Chivers, Karin Havenith, David G. Williams, Lauren Adams, Maria Mellinas-Gomez, Simon Corbett, Peter Tyrer, Francois D'Hooge, Song Cho, Nazzareno Dimasi, Mary Jane Hinrichs, Phil W. Howard, John A. Hartley, Patrick H. van Berkel. ADCT-401/MEDI3726, a novel pyrrolobenzodiazepine (PBD)-based antibody-drug conjugate (ADC) targeting PSMA-expressing prostate 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 3111A. doi:10.1158/1538-7445.AM2017-3111A
Abstract 3127: Roles of ERKs-RSK2 signaling in human cancers
Authors: Cho Yong Yeon
Published: July 2017

RSK2 is a member of p90RSK superfamily consisted with RSK1-4 and MSK1-2, and has suggested involving in many cellular processes including cell proliferation, differentiation, transformation and cancer development. Accumulating data obtained by our 16-year researches strongly demonstrated that RSK2 is a key player in cell transformation and cancer metastasis. We found that ectopic expression of RSK2 induced anchorage-independent cell transformation. Notably, knockdown of RSK2 strongly suppressed constitutive active-Ras (CA-Ras)-induced foci-formation, EGF-induced cell transformation and cancer cell growth in anchorage-independent condition. The results obtained from human skin cancer tissue array demonstrated that total protein levels and RSK2 activity were higher in cancer tissues than that of normal tissues. Molecular targeting of RSK2 or ERK1 and 2 with natural compounds demonstrated that ERKs-RSK2 signaling pathway plays a key role in cell transformation and cancer development. Moreover, inhibition of ERKs-RSK2 signaling suppressed NF-κB activity in JB6Cl41 cells. The EGF-induced NF-κB activity was abrogated up-regulation of COX-2 mRNA expression and COX-2 protein levels by inhibition of ERKs-RSK2 signaling pathway. Interestingly, magnolin, a specific inhibitor of ERK1 and ERK2, suppressed ERK-mediated MMP-2 and NF-κB-mediated MMP-9 expression. In addition, we found that the protein expression of N-cadherin involved in metastasis was markedly attenuated by inhibition of ERKs-RSK2 signaling pathway. Notably, magnolin suppressed the migration and invasion of lung cancer cells in a dose-dependent manner. Taken together, these results demonstrated that targeting of ERKs-RSK2 signaling is beneficial for the chemoprevention, and anti-invasion and -migration in cancer metastasis.

Key words: MAPK pathway, Transformation, Metastasis, Molecular targets

Citation Format: Yong Yeon Cho. Roles of ERKs-RSK2 signaling in human 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 3127. doi:10.1158/1538-7445.AM2017-3127
Abstract 3198: Using a genome-wide CRISPR-Cas9 knockout library to identify therapeutic combinations in oral cancer
Authors: Ludwig Megan , Birkeland Andrew , Nimmagadda Sai , Foltin Sue , Kulkarni Aditi , Jiang Hui , Carey Thomas , Brenner Chad
Published: July 2017

Oral squamous cell carcinoma (OSCC) has remained a disease with poor survival for decades with few novel treatment options. We anticipate great potential for personalized targeted therapies, facilitated by recent characterizations of the mutational landscape of OSCCs. Combinations of targeted therapies may have greater efficacy through inhibiting compensatory pathways. For example, targeting EGFR has had limited success. To identify synergistic combinations with EGFR-targeted therapy, we introduced Genome-scale CRISPR-Cas9 Knock-Out (GeCKO) libraries into OSCC cell lines. CRISPR-Cas9 generates individual genetic knockouts through targeted gene editing. We used a pool of CRISPRs targeting over 18,000 genes to perform genome-scale screening for drivers of sensitivity to EGFR-targeted therapy. Upon selection of the OSCC GeCKO pool, we identified gene knockouts in the FGFR pathway that increased sensitivity to the EGFR inhibitor gefitinib. Using resazurin viability assays we tested combinations of EGFR and FGFR inhibitors in 14 OSCC cell lines. Six/14 (43%) of the cell lines were responsive to the combination, indicating that the FGFR pathway is an alternate mechanism of resistance to EGFR-targeted therapy in some tumors. In complement, we again used CRISPR-Cas9 to generate a syngeneic EGFR knockout (KO) OSCC cell line. The parent OSCC cell line is responsive to the EGFR and FGFR dual inhibition, and the EGFR KO derivative retains sensitivity to FGFR-targeted monotherapies. We expect that this EGFR KO cell line will be a useful tool in further evaluating the compensatory mechanism of the FGFR pathway. OSCC remains a common and frequently lethal cancer with great potential for the development of personalized targeted therapies. Here, we describe the use of genome-wide CRISPR-Cas9 library to discover the synergistic combination of EGFR and FGFR inhibition. Further investigation suggests the FGFR pathway is a common compensatory mechanism to EGFR inhibition. We hope to use this approach to identify additional compensatory mechanisms of resistance to targeted therapies with the eventual goal of translating these findings to clinic.

Citation Format: Megan Ludwig, Andrew Birkeland, Sai Nimmagadda, Sue Foltin, Aditi Kulkarni, Hui Jiang, Thomas Carey, Chad Brenner. Using a genome-wide CRISPR-Cas9 knockout library to identify therapeutic combinations in oral 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 3198. doi:10.1158/1538-7445.AM2017-3198
Abstract 3498: Characterization of a novel metastatic lung cancer associated lncRNA
Authors: White Nicole M. , Rozycki Emily B. , Dang Ha X. , Maher Christopher A.
Published: July 2017

Lung cancer is the leading cause of death worldwide with the majority of patients presenting with metastasis and moreover, developing resistance to current treatments. One promising therapeutic area is the novel class of long noncoding RNAs (lncRNAs). While emerging evidence implicates them in cancer, lncRNA biology is still largely unexplored in tumor metastasis. To elucidate the function of lncRNAs in lung cancer, our lab used transcriptome sequencing (RNA-Seq) to discover 120 long non-coding RNAs (lncRNAs) that are enriched in metastatic tumors compared to their corresponding primary lung tumors, which we have named Metastasis Associated Lung cancer LncRNAs (MALLs). Notably, metastatic tumors were enriched for differentially expressed protein-coding genes targeted by Polycomb Repressive Complex 2 (PRC2). In lung cancer studies show that the catalytic subunit of PRC2, EZH2 (an H3K27 methylase), is overexpressed, associates with poor prognosis, promotes tumor progression, and epigenetically represses genes to promote metastasis. Specifically, we have found MALL-1 to be (i) highly up-regulated in lung cancer; (ii) promotes proliferation and migration/invasion, hallmarks of oncogenic phenotypes; (iii) binds to EZH2; and (iv) cooperatively represses well-known PRC2 target genes associated with metastasis in patients. Further, we found MALL-1 to be altered in multiple solid tumors thus suggesting a critical conserved oncogenic role of MALL-1 in solid tumor progression. We believe MALL-1 promotes aggressive disease through its interactions with, and recruitment of the PRC2 complex to chromatin, to epigenetically modify genes associated with metastasis.

Citation Format: Nicole M. White, Emily B. Rozycki, Ha X. Dang, Christopher A. Maher. Characterization of a novel metastatic lung cancer associated lncRNA [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 3498. doi:10.1158/1538-7445.AM2017-3498
Abstract 3589: A systematic approach toward gene annotation of the hallmarks of cancer
Authors: Kiefer Jeff , Nasser Sara , Graf John , Kodira Chinnappa , Ginty Fiona , Newberg Lee , Sood Anup , Berens Michael E.
Published: July 2017

The hallmarks of cancer consist of ten categories that serve as an organizing principle and framework for understanding neoplastic disease. The ten hallmarks include activating invasion and metastasis, avoiding immune destruction, deregulating cellular energetics, enabling replicative immortality, evading growth suppressors, genome instability and mutation, inducing angiogenesis, resisting cell death, sustaining proliferative signaling, and tumor-promoting inflammation. In order to facilitate the use of the hallmarks of cancer in genomic studies, we have undertaken a systematic methodology to map genes to each individual hallmark of cancer. Assignment of genes to the individual hallmarks was performed leveraging gene ontology (GO) annotations. Specifically, for each hallmark, a term list was generated by cancer research experts, with biological terms associated with each hallmark. This term list was used to search and identify matching GO terms. Matched terms were then mapped to the highest, most specific, representative, non-redundant GO term in the GO hierarchy. Genes for each term were restricted by selecting only human taxon, and high confidence experimental evidence codes. For specific GO terms, where present, the Regulation of ‘GO term’ category was included. The genes for each GO term for each hallmark were combined in a non-redundant list of genes for each hallmark. In the case of the evading growth suppressors category, a different strategy was employed. In this instance, genes were identified through ‘tumor suppressor’ gene/protein annotation in the DGIdb resource and UniProt. Additionally, text-mining methods on biomedical research literature were used to defined a high confidence list of genes for this hallmark. As an example use case of the hallmarks we applied them to the analysis of the TCGA Pan-Cancer RNAseq data set. Clustering across the individual hallmarks led to interesting differences within particular tumor tissue types, as well as shared hallmarks for other tumor types. For example, use of the genome instability and mutation hallmark for Pan-Cancer clustering, revealed a tight tissue-based cluster of low-grade gliomas and GBMs. This result suggests the importance of this hallmark expression in this tumor type. This high confidence mapping of genes to hallmarks of cancer provides a unique dataset to facilitate analyses of cancer genome data.

Citation Format: Jeff Kiefer, Sara Nasser, John Graf, Chinnappa Kodira, Fiona Ginty, Lee Newberg, Anup Sood, Michael E. Berens. A systematic approach toward gene annotation of the hallmarks of 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 3589. doi:10.1158/1538-7445.AM2017-3589
Abstract 3921: Detection of circulating tumor cells in osteosarcoma: A validation study using a translational model
Authors: Takada Marilia , Yang Ya-Ting , Piegols Hunter , Saavedra Paulo Vilar , Tang Cha-Mei , Amstutz Pete , Yuzbasiyan-Gurkan Vilma
Published: July 2017

Osteosarcoma (OS) is the most common primary bone cancer in humans, and most frequently seen in pediatric patients. Metastasis to distant organs via hematogenous route is the leading cause of mortality in OS. Current methods to detect metastasis and to monitor response to treatment largely depend on imaging systems with low sensitivity to micrometastases. The value of circulating tumor cells (CTCs) as prognostic marker has been demonstrated in several types of malignancies, including cancer of breast, prostate and colorectal. The objective of this study was to establish a protocol to quantify CTC in patients with OS, as a biomarker for the presence of micrometastases and early detection of tumor relapse. We used dogs with spontaneous OS as a unique translational model. OS occurs in dogs with a 15-fold higher incidence than in humans. Our experimental method consisted of the isolation of CTCs using the microfiltration system CellSieve™, and further enumeration of tumor cells by immunostaining. Normal blood cells were spiked with cultured OS cells and processed using the CellSieve™ system where the CTCs are captured on a microfilter and then incubated with an antibody mixture consisting of fluorescent dye-conjugated antibodies against Osteocalcin, Vimentin, and CD45R. We demonstrated that osteosarcoma tumor cells could be recovered from the blood and characterized by 4-channel immunofluorescence assay as Osteocalcin+ / Vimentin+ / DAPI + and CD45R-, where CD45 serves as a differential marker of normal blood cells. In addition, we were able to demonstrate that the system has a 98% yield of recovery of spiked tumor cells. When this protocol was applied to 7.5 ml of blood sample from a naïve large breed dog diagnosed with OS, we were able to detect one CTC with the predicted staining pattern. Ongoing studies evaluating CTC throughout the clinical course of dogs with OS will determine the value for prognosis as well as for evaluating response to therapy. In conclusion, the CellSieve™ microfiltration platform applied with a set of 4 immunofluorescent antibodies is an effective method for detection of CTCs in canine OS.

Citation Format: Marilia Takada, Ya-Ting Yang, Hunter Piegols, Paulo Vilar Saavedra, Cha-Mei Tang, Pete Amstutz, Vilma Yuzbasiyan-Gurkan. Detection of circulating tumor cells in osteosarcoma: A validation study using a translational model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3921. doi:10.1158/1538-7445.AM2017-3921
Abstract 4322: Exosomal delivery of stroma-derived miR-145 inhibits pancreatic cancer cell proliferation
Authors: Han Song , Belsare Sayali , Zhang DongYu , Beveridge Mark , Rinaldi Carlos , Trevino Jose G. , Schmittgen Thomas D. , Hughes Steven J.
Published: July 2017

We previously reported that within the pancreatic ductal adenocarcinoma (PDAC) microenvironment, miR-145 and miR-199a are exclusively expressed in tumor-associated stroma (TAS) cells, but these miRNAs are present in PDAC cells following co-culture with TAS cells. We hypothesized that miRNAs function as paracrine signals via exosomal exchange between TAS cells and adjacent PDAC cells.

Primary cultures of human TAS and PDAC cells were employed. Membrane-bound microparticles were isolated from TAS conditioned, serum-free culture media by sequential ultracentrifugation followed by ultrafiltration. Exosomes and microvesicles were then assayed for particle size distribution using nanoparticle tracking analysis and electronic microscopy. miRNA expression levels were determined using quantitative PCR. miRNA transfection was performed with RNAiMax reagents. Cell viability was measured by Alamar Blue. Statistics were performed using Prism 6 software.

Following transfection of human TAS cells with cel-miR-39, a nonhuman miRNA, we demonstrated that miRNA exchanges occurred between TAS cells and neighboring PDAC cells via a process that is not dependent upon cell-cell contact. We next confirmed the presence and enrichment of miR-145-5p in TAS-cell-derived exosomes (8-fold higher concentrations in exosomes than parental cells, p<0.05). Feeding of TAS-derived exosomes or transfection of miR-145-5p mimics into PDAC cells led to dose-dependent decreases in PDAC cell viability (p<0.05).

Taken together, our data suggest that stroma derived exosomes deliver miRNAs to adjacent PDAC cells and may function as tumor-suppressing paracrine signals in the case of miR-145. This finding provides a potential explanation for the observation that stroma depletion paradoxically accelerates PDAC progression in murine models.

Citation Format: Song Han, Sayali Belsare, DongYu Zhang, Mark Beveridge, Carlos Rinaldi, Jose G. Trevino, Thomas D. Schmittgen, Steven J. Hughes. Exosomal delivery of stroma-derived miR-145 inhibits pancreatic cancer cell proliferation [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 4322. doi:10.1158/1538-7445.AM2017-4322
Abstract 4574: Combinatorial strategies of folate receptor-targeted chemotherapy guided by improved understanding of tumor microenvironment and immunomodulation
Authors: Lu Yingjuan , Wheeler Leroy W. , Cross Vicky A. , Westrick Elaine M. , Lloyd Alex M. , Johnson Theresa P. , Parker Nikki L. , Leamon Christopher P.
Published: July 2017

Inflammation disorder is a major component of cancer progression and drug resistance. Tumor microenvironment due to its complex nature presents physical and physiological barriers to both chemotherapy and immunotherapy. On the other hand, the folate receptor (FR) family includes two cysteine-rich GPI-anchored membrane glycoproteins (FRα/β) that are capable of bringing folate-linked small-molecule drugs (SMDCs) into the cell cytosol via endocytosis. Consequently, both receptor isoforms have been considered promising therapeutic targets due to frequent overexpression of FRα by cancer cells of epithelial origins and FRβ by tumor-associated macrophages (TAMs). TAMs are strongly immunosuppressive and high TAM frequency has been correlated with poor patient prognosis and treatment outcome.

While a folate-targeted chemotherapy can be very powerful for sensitive tumor types, resistance does regularly occur in FR-positive tumors for reasons that are largely unknown. Moreover, there seems to be considerable disconnect between a drug candidate’s in-vitro activity and in-vivo efficacy. Using syngeneic mouse models that represent different tumor immune microenvironments (M109, Renca, 4T1-Cl2), we investigated the immunomodulatory properties of SMDCs and devised combinatorial strategies with standard-of-care (SOC) agents to break the tumor-induced immune tolerance. Our results indicated that a successful treatment goes beyond targeting the cancer cells themselves; instead, it requires a good match between our compound and a “sensitive” tumor microenvironment. We found that within “TAM-rich” solid tumors, an effective SMDC may be one with dual mechanisms of action that affect both FRα-positive tumor cells and FRβ-positive TAMs. Moreover, the process of choosing partner drugs, such as immune checkpoint inhibitors and inhibitors of myeloid-derived suppressor cells, should be guided by the immunomodulatory properties of both SMDCs and SOC agents to overcome the frequently observed chemo- and immuno-resistance.

Citation Format: Yingjuan Lu, Leroy W. Wheeler, Vicky A. Cross, Elaine M. Westrick, Alex M. Lloyd, Theresa P. Johnson, Nikki L. Parker, Christopher P. Leamon. Combinatorial strategies of folate receptor-targeted chemotherapy guided by improved understanding of tumor microenvironment and immunomodulation [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 4574. doi:10.1158/1538-7445.AM2017-4574
Abstract 4888: Human PGBD5 DNA transposase promotes site-specific oncogenic mutations in rhabdoid tumors
Authors: Henssen Anton G. , Koche Richard , Zhuang Jiali , Jiang Eileen , Reed Casie , Eisenberg Amy , Still Eric , Rodríguez-Fos Elias , Gonzalez Santiago , Puiggròs Montserrat , Blackford Andrew N. , Mason Christopher E. , Stanchina Elisa de , Gönen Mithat , Emde Anne-Katrin , Shah Minita , Arora Kanika , Reeves Catherine , Socci Nicholas D. , Perlman Elizabeth , Antonescu Cristina R. , Roberts Charles W. , Steen Hanno , Mullen Elizabeth , Jackson Stephen P. , Torrents David , Weng Zhiping , Armstrong Scott A. , Kentsis Alex
Published: July 2017

Genomic rearrangements are a hallmark of childhood solid tumors, but their mutational causes remain poorly understood. Here, we identify the piggyBac transposable element derived 5 (PGBD5) gene as an enzymatically active human DNA transposase expressed in the majority of rhabdoid tumors, a lethal childhood cancer. Using assembly-based whole-genome DNA sequencing, we observed previously unknown somatic genomic rearrangements in primary human rhabdoid tumors. These rearrangements were characterized by deletions and inversions involving PGBD5-specific signal (PSS) sequences at their breakpoints, with some recurrently targeting tumor suppressor genes, leading to their inactivation. PGBD5 was found to be physically associated with human genomic PSS sequences that were also sufficient to mediate PGBD5-induced DNA rearrangements in rhabdoid tumor cells. We found that ectopic expression of PGBD5 in primary human cells was sufficient to promote penetrant cell transformation in vitro and in immunodeficient mice in vivo. This activity required specific catalytic residues in the PGBD5 transposase domain, as well as end-joining DNA repair, and induced distinct structural rearrangements, involving PSS-associated breakpoints, similar to those found in primary human rhabdoid tumors. Thus, PGBD5 defines a distinct class of oncogenic mutators and induces site-specific somatic DNA rearrangements in human cancer.

Citation Format: Anton G. Henssen, Richard Koche, Jiali Zhuang, Eileen Jiang, Casie Reed, Amy Eisenberg, Eric Still, Elias Rodríguez-Fos, Santiago Gonzalez, Montserrat Puiggròs, Andrew N. Blackford, Christopher E. Mason, Elisa de Stanchina, Mithat Gönen, Anne-Katrin Emde, Minita Shah, Kanika Arora, Catherine Reeves, Nicholas D. Socci, Elizabeth Perlman, Cristina R. Antonescu, Charles W. Roberts, Hanno Steen, Elizabeth Mullen, Stephen P. Jackson, David Torrents, Zhiping Weng, Scott A. Armstrong, Alex Kentsis. Human PGBD5 DNA transposase promotes site-specific oncogenic mutations in 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 4888. doi:10.1158/1538-7445.AM2017-4888
Abstract 5079: Inhibition of HDAC2, but not HDAC1, abrogates triple negative breast cancer progression and metastasis
Authors: Burks Hope E. , Elliott Steven , Hoang Van T. , Matossian Margarite D. , Burow Bridgette Collins , Burow Matthew E.
Published: July 2017

Triple negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, with higher rates of metastasis and recurrence than other classified subtypes. The decreased survival rates seen in TNBC can be attributed in part to the lack of targeted therapeutics. HDAC inhibitors (HDACi) have emerged as a potential adjuvant therapy for patients with triple negative disease. Previously, our lab has identified Panobinostat, a pan-DAC inhibitor, as a successful therapy for the reversal of the metastatic phenotype in TNBC. However, this therapy lacks specificity and may have increased side effects as a result. In this study, we aim to dissect the necessary HDACs responsible for driving and maintaining the metastatic phenotype of TNBC, with the goal of informing specific HDAC targeted therapies. Here we show that Romidepsin, an HDAC 1 and 2 specific inhibitor, is capable of recapitulating aspects of Panobinostat treatment in TNBC both in vitro and in a patient derived xenograft model in vivo. To parse the necessity and role of HDAC1 and HDAC2 individually, we created knockdown cell lines and analyzed them for changes in gene expression changes and their respective associated biological processes, including proliferation, migration, mammosphere formation, tumor growth and metastasis. We found that HDAC2 knockdown was able to significantly repress migration and proliferation in TNBC cells and their associated gene expression signatures in vitro. Furthermore, HDAC2 knockdown resulted in decreased tumor growth and metastasis an in vivo mouse model. These results illustrate the efficacy of Romidepsin in inhibition of oncogenic processes and implicate HDAC2 as a potential target for therapeutic intervention in TNBC.

Citation Format: Hope E. Burks, Steven Elliott, Van T. Hoang, Margarite D. Matossian, Bridgette Collins Burow, Matthew E. Burow. Inhibition of HDAC2, but not HDAC1, abrogates triple negative breast cancer progression and metastasis [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 5079. doi:10.1158/1538-7445.AM2017-5079
Abstract 5797: Semaphorin 5A preserves epithelial phenotype in pancreatic cancer cells by regulating cross-talk between Wnt and TGF-β signaling
Authors: Saxena Sugandha , Purohit Abhilasha , Batra Surinder K. , Singh Rakesh K.
Published: July 2017

Pancreatic cancer (PC) is one of the deadliest forms of cancers. In spite of recent advances, minimal progress has been made in our understanding of PC progression, metastasis, and treatment of PC patients with advanced disease. Striking similarity between the process of cancer metastasis and guidance of neuronal cells to their target sites has generated interest in pharmacologically targeting guidance cue molecules for treatment of metastasis. Among the guidance cue family members, Semaphorin5A (SEMA5A), was found to be involved in organ-specific homing during PC metastasis. With an interest to delineate the function of SEMA5A in PC, we generated SEMA5A knockdown in metastatic PC cell lines. Knock down of SEMA5A expression resulted in loss of cellular differentiation and epithelial phenotype with higher motility as compared to vector control cells. This observation is in accordance with our previous finding that SEMA5A expression was higher in well-differentiated tumors in comparison with undifferentiated pancreatic tumors. Loss of SEMA5A increased TGF-β2 production, decreased expression of E-cadherin, and nuclear translocation of β-catenin. Furthermore, we observed higher Wnt activity and increased expression of the transcription factor SNAIL in SEMA5A knockdown cells in comparison with vector control cells. Higher Wnt signaling along with increased TGF-β2 production explains the loss of differentiation and epithelial markers. Moreover, we observed that non canonical TGF-β2/AKT mediated inhibition of GSK3-β is responsible for increased stability of β-catenin and SNAIL, thereby activating Wnt signaling in SEMA5A knockdown cells. Our observations demonstrate that SEMA5A has a potential role in maintaining the epithelial phenotype in PC cells by keeping cross-talk between Wnt and TGF-β signaling under check.

Citation Format: Sugandha Saxena, Abhilasha Purohit, Surinder K. Batra, Rakesh K. Singh. Semaphorin 5A preserves epithelial phenotype in pancreatic cancer cells by regulating cross-talk between Wnt and TGF-β signaling [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 5797. doi:10.1158/1538-7445.AM2017-5797
Abstract 5947: The NCI Best Practices for Biospecimen Resources: 2016 revised recommendations
Authors: Rao Abhi , Vaught Jim , Guan Ping , Weil Carol , Moore Helen M.
Published: July 2017

Improved biospecimen handling practices are increasingly important for cancer research as advanced molecular analysis becomes routine in clinical trials and more frequently available in standard of care medicine. Biospecimens and associated clinical data collected in a consistent, established fashion can greatly facilitate cancer biomarker validation and development and validation of clinical diagnostic assays. In order to establish a set of guidelines to improve the quality of biospecimen-related research, the NCI’s Biorepositories and Biospecimen Research Branch developed the NCI Best Practices for Biospecimen Resources which includes technical recommendations on biospecimen handling as well as ethical and regulatory best practices. The 3rd, 2016 revised version of these Best Practices focused on updating technical and operational best practices with recommendations based on more recent research, guidance and standards for collecting, processing and storing biospecimens; revised informatics best practices; and updated ethical, legal and policy sections describing new developments on return of research results, informed consent for genomics research, data sharing, and community engagement. These Best Practices aim to help patients by improving the reproducibility of cancer research data. The NCI Best Practices are also foundational to the NIH Precision Medicine Initiative, part of which aims to establish the world’s largest research biobank that will support studies that utilize biospecimens from a cohort of one million individuals in the United States.

Citation Format: Abhi Rao, Jim Vaught, Ping Guan, Carol Weil, Helen M. Moore. The NCI Best Practices for Biospecimen Resources: 2016 revised recommendations [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 5947. doi:10.1158/1538-7445.AM2017-5947
Abstract 936: Single cell analysis reveals cancer stem cell heterogeneities in hepatocellular carcinoma
Authors: Zheng Hongping , Pomyen Yotsawat , Hernandez Maria , Li Caiyi , Livak Ferenc , Greten Tim , Budhu Anuradha , Wang Xin
Published: July 2017

Tumor heterogeneity represents a major obstacle to effective cancer treatment and personalized medicine. Hepatocellular carcinoma (HCC) is clinically and biologically heterogeneous, which is partly attributed to the presence of hepatic cancer stem cells (CSCs). CSC surface makers can have overlapping expression or exclusive expression of different subpopulations of hepatic CSCs, and these cells may contain different oncogenic changes. The existence of various CSC surface-marked subpopulations might pose a problem for CSC targeted therapeutics. Little is known about whether there are shared or distinct pathways in different subpopulations. Moreover, it remains unknown whether heterogeneity exists within certain subpopulations. Thus, we propose to profile the global transcriptome of surface-marked CSCs (EpCAM+, CD133+ and CD24+) at the single-cell level using index flow cytometric sorting and single-cell RNA sequencing technology.

We statistically compared mRNA transcriptomes of individual single cells of triple positive (EpCAM+/ CD133+ /CD24+) CSCs and triple negative (EpCAM-/ CD133- /CD24-) cells. Further, we compared the triple positive and the triple negative cells at the single cell level in terms of their self-renew capability in both normoxic and hypoxic conditions. Our results show that at the single cell level, the transcriptomic profiles show a high-degree of heterogeneity in HCC cell lines, meanwhile, there is a dramatic difference between triple positive and triple negative cells in their transcriptomic profiles. There is a high-degree of intra-tumor and inter-tumor heterogeneity observed in single cell transcriptomes of HCC patients’ samples. Triple positive CSC single cells show continuous rather than discrete stemness-related gene expression patterns. In parallel, the self-renewal capability of triple positive cells also exhibits heterogeneity, while triple negative cells show little self-renewal capability. Thus, our single cell analysis study reveals molecular and biological heterogeneity of cancer stem cells in HCC, which may provide insight into the underlying mechanisms of how CSCs contribute to tumor heterogeneity and underscore key pathways and novel targets for hepatic CSC therapy.

Citation Format: Hongping Zheng, Yotsawat Pomyen, Maria Hernandez, Caiyi Li, Ferenc Livak, Tim Greten, Anuradha Budhu, Xin Wang. Single cell analysis reveals cancer stem cell heterogeneities 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 936. doi:10.1158/1538-7445.AM2017-936
Abstract LB-125: Snail determines the efficacy of mTOR-targeted therapies by transcriptional repression of 4E-BP1
Authors: Wang Jun , Ye Qing , Guo Yubin , Cao Yanan , Huang Xiuping , Mi Wenting , Liu Side , Wang Chi , Evers B. Mark , She Qing-Bai
Published: July 2017

The mTOR inhibitors, including the second generation of mTOR kinase inhibitors, for cancer treatment have been evaluated in clinical trials, but their overall activity as monotherapy is limited. The cap-dependent translation repressor, 4E-BP1, is an important effector of the mTOR kinase in controlling cell proliferation and tumor growth. Loss of 4E-BP1 expression in cancer has been linked to malignant progression and poor prognosis. However, the molecular mechanism(s) by which 4E-BP1 is downregulated in cancer remain largely unknown. Here, we identify Snail as a novel repressor of 4E-BP1 expression that can be exploited to alter mTOR-targeted therapies. We find that 4E-BP1 expression inversely correlates with Snail level in cancer cell lines and clinical specimens. Mechanistically, we show that Snail binds to three E-boxes present in the human 4E-BP1 promoter to repress transcription of 4E-BP1. Ectopic expression of Snail in cancer cell lines lacking Snail profoundly inhibits 4E-BP1 expression, and promotes cap-dependent translation and resistance to the anti-proliferative effect of mTOR kinase inhibitors. Conversely, genetic depletion of Snail restores 4E-BP1 expression and sensitizes cancer cells to mTOR inhibition by enhancing the translation-repressive function of 4E-BP1 on cell proliferation and tumor growth. Thus, our findings reveal a critical role for Snail in determining the therapeutic response to mTOR kinase inhibitors, and suggest that Snail may be a potential marker for predicting the efficacy of mTOR-target therapies in the clinic. Moreover, our work highlights the importance of combining Snail inhibition with mTOR kinase inhibitors for the treatment of tumors in which Snail overexpression occurs with reduced 4E-BP1 expression.

Citation Format: Jun Wang, Qing Ye, Yubin Guo, Yanan Cao, Xiuping Huang, Wenting Mi, Side Liu, Chi Wang, B. Mark Evers, Qing-Bai She. Snail determines the efficacy of mTOR-targeted therapies by transcriptional repression of 4E-BP1 [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 LB-125. doi:10.1158/1538-7445.AM2017-LB-125
Abstract LB-310: PYK2 as a therapeutic target for pancreatic cancer
Authors: Hu Jing , Gao Chenxi , Chen Guangming , Gao Xuan , Zhang Dennis H. , Kuan Shih-Fan
Published: July 2017

Since nearly 100% of pancreatic ductal adenocarcinoma (PDAC) carried mutational activation of KRAS, KRAS and its effectors are theoretically ideal candidates for PDAC therapeutic intervention. Unfortunately, attempts to directly inhibit oncogenic KRAS or known RAS effector pathways have been either unsuccessful or proven ineffective. As a result, there is significant interest in identifying novel downstream effectors of oncogenic KRAS signaling that could be amenable to pharmacologic intervention. Our results suggest that PYK2 (proline-rich tyrosine kinase 2, a non-receptor cytoplasmic tyrosine kinase) is a novel downstream mediator of mutant KRAS signaling and a new actionable therapeutic target for PDAC. Specifically, our studies revealed: (1) mutant KRAS activated PYK2 gene transcription in a YAP1 (Yes-associated protein 1)-dependent manner. Hippo pathway effector YAP1 is a transcription cofactor and a powerful downstream effector of mutant KRAS in PDAC. (2) PYK2 levels were drastically elevated in mouse PanINs (pancreatic intraepithelial neoplasia) and human PDAC tissues. (3) Functionally, Whole-body deletion of PYK2, even heterozygous deletion, remarkably suppressed PanIN formation and progression to PDAC in the Pdx1-Cre KRASG12D mice model. Further, knockdown of PYK2 abrogated tumor growth in a PDAC cell line xenograft model, indicating that PYK2 is required for PDAC maintenance. (4) Mechanistically, PYK2 directly phosphorylated β-catenin at tyrosine (Y) 654 to promote the Wnt/β-catenin pathway and increased RelA/p65 phosphorylation at serine (S) 536 to promote the NF-κB pathway in PDAC cells. Because both pathways are essential for PDAC development in mice, we propose that PYK2 contributes to PDAC through upregulating Wnt/β-catenin and NF-κB pathways. Overall, our study has revealed that PYK2 is a new actionable target for treating PDAC.

Citation Format: Jing Hu, Chenxi Gao, Guangming Chen, Xuan Gao, Dennis H. Zhang, Shih-Fan Kuan. PYK2 as a therapeutic target for 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 LB-310. doi:10.1158/1538-7445.AM2017-LB-310
Vasorelaxation to the Nitroxyl Donor Isopropylamine NONOate in Resistance Arteries Does Not Require Perivascular Calcitonin Gene–Related Peptide
Authors: Pinkney Alice M.H. , Lemmey Hamish A.L. , Dora Kim A. , Garland Christopher J.
Published: August 2017

Nitroxyl (HNO) donors offer considerable therapeutic potential for the treatment of hypertension-related cardiovascular disorders, particularly heart failure, as they combine an inotropic action with peripheral vasodilation. Angeli’s salt is the only HNO donor whose mechanism has been studied in depth, and recently, Angeli’s salt vasodilation was suggested to be indirect and caused by calcitonin gene–related peptide (CGRP) released from perivascular nerves after HNO activates TRPA1 (transient receptor potential cation channel subfamily A member 1) channels. We investigated resistance artery vasorelaxation to the HNO donor, isopropylamine NONOate (IPA/NO), one of the structures providing a template for therapeutic development. Wire myography in combination with measurements of smooth muscle membrane potential was used to characterize the effect of IPA/NO in mesenteric resistance arteries. Immunohistochemistry was assessed in pressurized arteries. IPA/NO concentration dependently hyperpolarized and relaxed arteries precontracted with the α
1
-adrenoreceptor agonist, phenylephrine. These effects were blocked by the soluble guanylyl cyclase inhibitor, ODQ (1
H
-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one) but not by the K
ATP
channel inhibitor, glibenclamide. Vasorelaxation persisted in the presence of raised [K
+
]
o
, used to block hyperpolarization, capsaicin to deplete perivascular CGRP, or HC030031 (2-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7
H
-purin-7-yl)-
N
-(4 isopropylphenyl) acetamide) to block TRPA1 receptors. Without preconstriction, hyperpolarization to IPA/NO was suppressed by glibenclamide, capsaicin, or HC030031. Hyperpolarization but not vasorelaxation to exogenous CGRP was inhibited with glibenclamide. Thus, vascular hyperpolarization is not necessary for vasorelaxation to the HNO donor IPA/NO, even though both effects are cGMP dependent. The reduced hyperpolarization after depletion of perivascular CGRP or block of TRPA1 receptors indicates some release of CGRP, but this does not contribute to HNO vasorelaxation. Therefore, HNO–TRPA1–CGRP signaling does not seem important for vasodilation to IPA/NO in resistance arteries.
Creature:Interactions: A Social Mixed-Reality Playspace
Authors: Bluff Andrew , Johnston Andrew
Published: August 2017

This paper discusses Creature:Interactions (2015), a large-scale mixed-reality artwork created by the authors that incorporates immersive 360° stereoscopic visuals, interactive technology, and live actor facilitation. The work uses physical simulations to promote an expressive full-bodied interaction as children explore the landscapes and creatures of Ethel C. Pedley’s ecologically focused children’s novel, Dot and the Kangaroo. The immersive visuals provide a social playspace for up to 90 people and have produced “phantom” sensations of temperature and touch in certain participants.
Molecular phylogenetic relationships among Anatolian-Hyrcanian brown frog taxa (Ranidae: Rana)
Authors: Najibzadeh Masoumeh , Veith Michael , Gharzi Ahmad , Rastegar-Pouyani Nasrullah , Rastegar-Pouyani Eskandar , Kieren Sarah , Pesarakloo Alireza
Published: August 2017

Although the phylogenetic relationship of Western Palearctic brown frogs has been repeatedly studied, the taxonomic status and phylogenetic relationship of Anatolian-Hyrcanian brown frogs is still not fully resolved. Here, we assess the phylogenetic status of these species among Western Palearctic brown frogs with special emphasize on Iranian populations based on two partial mitochondrial DNA sequences (16S rRNA and cytochromebgenes) and the application of a molecular clock. Our results clearly show that Western Palearctic brown frogs underwent a basal radiation in to two main monophyletic clades, the European brown frogs plus the AsianR. asiaticaand the Anatolian-Hyrcanian brown frogs, during Early Miocene ca. 20.2 mya. The Hyrcanian (R. pseudodalmatina) and the Anatolian lineage diverged approximately 16.6 mya. The further diverged into two subclades,R. tavasensisandR. macrocnemis, during the Middle Miocene, 14.5 mya. Our results suggest that diversification within these lineages may be closely linked to the formation of Neotethys and Paratethys and the subsequent uplift of the Turkish-Iranian plateau during the Early Miocene which led to restricted gene flow among brown frogs in these regions. Contrary to previous studies, we conclude that the Plio-Pleistocene epoch seems to be not associated to further significant speciation events within Anatolian-Hyrcanian brown frogs.
The Unbearable Lightness of the Image
Authors: Della Ratta Donatella
Published: August 2017

In this essay, I reflect on the aesthetic, political and material implications of filming as a continuous life activity since the beginning of the 2011 uprising in Syria. I argue that the blurry, shaky and pixelated aesthetics of Syrian user-generated videos serve to construct an ethical discourse (Ranciére 2009a; 2013) to address the genesis and the goal of the images produced, and to shape a political commitment to the evidence-image (Didi-Huberman 2008). However, while the unstable visuals of the handheld camera powerfully reconnect, both at a symbolic and aesthetic level, to the truthfulness of the moment of crisis in which they are generated, they fail to produce a clearer understanding of the situation and a counter-hegemonic narrative. In this article, I explore how new technologies have impacted this process of bearing witness and documenting events in real time, and how they have shaped a new understanding of the image as a networked, multiple object connected with the living archive of history, in a permanent dialogue with the seemingly endless flow of data nurtured by the web 2.0.
Seeing Syria
Authors: Crilley Rhys
Published: August 2017

The use of social media by groups such as the self-proclaimed Islamic State has been the focus of the press, politicians and scholars, but relatively little attention has been paid to how other actors involved in the Syrian conflict have been using social media platforms. In this article, I address this gap by analyzing how the National Coalition of Syrian Revolution and Opposition Forces has used Facebook. Specifically, I focus on the main narrative themes emerging in 1,174 posts uploaded to the Coalition’s English language Facebook page between November 2012 and March 2015. Recognizing that visual media play an important factor in communicating narratives of conflict, the paper also analyzes 280 sets of images of war posted during this time. I argue that these images construct a visuality focused on ‘the pain of others’ (Sontag 2004) that makes those affected, uprooted, injured, and killed by the conflict in Syria highly visible. In making this claim, I explore how this visuality of suffering has evolved over the course of the conflict.
Mythical State
Authors: Greenberg Nathaniel
Published: August 2017

In the summer of 2014, on the heels of the declaration of a ‘caliphate’ by the leader of the Islamic State in Iraq and Syria (ISIS), a wave of satirical production depicting the group flooded the Arab media landscape. Seemingly spontaneous in some instances and tightly measured in others, the Arab comedy offensive paralleled strategic efforts by the United States and its allies to ‘take back the Internet’ from ISIS propagandists. In this essay, I examine the role of aesthetics, broadly, and satire in particular, in the creation and execution of ‘counter-narratives’ in the war against ISIS. Drawing on the pioneering theories of Fred Forest and others, I argue that in the age of digital reproduction, truth-based messaging campaigns underestimate the power of myth in swaying hearts and minds. As a modus of expression conceived as an act of fabrication, satire is poised to counter myth with myth. But artists must balance a very fine line.