bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract A25: Tissue transglutaminase interacts with Frizzled 7 in ovarian cancer stem cells
Authors: Condello Salvatore , Sima Livia , Ivan Cristina , Cardenas Horacio , Schiltz Gary , Mishra Rama K , Matei Daniela 
Published: August 2018

Abstract
Increasing evidence correlates the metastatic progression and post-chemotherapy recurrence of ovarian cancer (OC) to a small population of cancer stem cells (CSCs), resistant to traditional chemotherapy and responsible for tumor relapse. Tissue transglutaminase (TG2) is a multifunctional protein, with enzymatic and scaffold functions, overexpressed in ovarian carcinomas, where it promotes metastasis. Independently of its enzymatic function, TG2 can be secreted in the extracellular compartment where it increases cell adhesion to the fibronectin (FN) matrix by regulating integrins clustering and matrix reorganization. We hypothesized that by binding to the integrins and FN, TG2 promotes survival of CSCs and supports OC spheroid formation. Our data demonstrate that TG2, β1 integrin, and FN1 expression are markedly increased in OC spheroids compared with monolayers and are enriched in successive sphere generations. Immunofluorescence (IF) staining supports that TG2 forms abundant complexes with β1 integrin and FN in cells grown as spheroids. TG2 expression is strongly correlated with β1 integrin (ITGB1) (R=0.23, P&lt;0.0001) and with FN1 (R=0.39, P&lt;0.0001) in the TCGA ovarian cancer database, which houses gene expression data of 560 clinically annotated HGSOC tumors. Patients with high TG2 and ITGB1 expression levels had an increased estimated risk of death when compared to those with low TG2 and ITGB1 expression levels (P=0.00652). Use of function-inhibiting antibody against the FN-binding domain of TG2 (4G3) dramatically suppressed TG2/FN/β1 integrin complex formation, spheroid proliferation, and tumor growth in a xenograft model. Furthermore, disruption of TG2/FN complex formation altered key oncogenic signaling pathways, and in particular blocked the canonical Wnt/β-catenin signaling pathway essential to sustaining cancer cell stemness. The Wnt receptor Frizzled genes (Fzd1, Fzd7 and Fzd8) showed the greatest difference in gene expression, indicating a direct correlation between TG2/FN complex and Wnt pathway activation. By co-immunoprecipitation and IF staining we demonstrated that TG2 colocalizes and directly binds to Fzd7 receptor. In conclusion, our data support that TG2/FN/β1 integrin complex formation is essential to promoting ovarian CSCs survival by acting as coreceptor complex with Fzd7 in regulating β-catenin signaling and represents a new target to eradicate chemotherapy-resistant tumors.
Citation Format: Salvatore Condello, Livia Sima, Cristina Ivan, Horacio Cardenas, Gary Schiltz, Rama K Mishra, Daniela Matei. Tissue transglutaminase interacts with Frizzled 7 in ovarian cancer stem cells. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr A25.
Abstract A28: Beta-escin inhibits ovarian cancer metastasis by targeting the tumor microenvironment
Authors: Kenny Hilary A. , Lal Madhu , Shen Min , Kara Betul , Chiang Chun-Yi , Watters Karen , Hart Peter , Ferrer Marc , Lengyel Ernst 
Published: August 2018

Abstract
The high mortality rate that results from ovarian cancer (OvCa) is caused by the wide dissemination of cancer cells within the abdominal cavity. OvCa cells metastasize to the peritoneum, which is covered by a single layer of mesothelial cells, and invade into the underlying stroma, composed of extracellular matrices including fibronectin (FN) and stromal cells such as fibroblasts. Using a three-dimensional organotypic quantitative high-throughput screening platform (3D-qHTS) modeling the peritoneum, we discovered that beta-escin inhibited OvCa adhesion and invasion to the peritoneum. Beta-escin is a natural triterpenoid saponin from Chinese horse chestnut seeds and has a variety of known pharmacologic effects. We hypothesize that beta-escin targets both the cancer cells and the stromal cells to inhibit the metastatic niche. The therapeutic effects of beta-escin and horse chestnut seed extract were tested in vivo using xenograft and syngeneic models of OvCa prevention and intervention. The mechanisms of beta-escin action in cancer cells and microenvironmental cells was explored in vitro using OvCa cell lines and primary human mesothelial cells and fibroblasts, and in vivo using different mouse models of metastasis. Moreover, a collection of 160 analogs of beta-escin were gathered and screened using our 3D-qHTS platform for inhibitory activity in OvCa cell adhesion/invasion. Our results reveal that beta-escin and horse chestnut extract taken orally inhibit metastasis in both OvCa prevention and intervention models. In addition, beta-escin mechanistically depresses the pluripotent stem cell population, inflammatory cytokine secretion, HIF-1alpha expression, and fibronectin production, while it increases autophagy in the tumor microenvironment. Furthermore, three distant analogs of beta-escin inhibited OvCa metastasis, and all three are cardiac glycosides. Taken together, we reveal a potential therapeutic value for beta-escin and/or analogs of beta-escin in preventing and treating OvCa dissemination.
Citation Format: Hilary A. Kenny, Madhu Lal, Min Shen, Betul Kara, Chun-Yi Chiang, Karen Watters, Peter Hart, Marc Ferrer, Ernst Lengyel. Beta-escin inhibits ovarian cancer metastasis by targeting the tumor microenvironment. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr A28.
Abstract A52: Potassium channel activator minoxidil (Rogaine) as a novel single-agent or combination therapy in ovarian cancer
Authors: Fukushiro-Lopes Daniela , Jain Megan , Khalid Maryam , Hegel Alexandra , Gentile Saverio 
Published: August 2018

Abstract
Recent advances in cancer therapy treatments for ovarian cancer have been severely hindered by limited drug availability, excessive side effects, and drug resistance and the difficulty in finding and targeting proteins governing important events in ovarian cancer cells. Novel therapeutic agents targeting specific molecular pathways involved in ovarian cancer are urgently needed.
During our investigation to identify new and critical targets in cancer, we found a novel role for the potassium ion channel Kir6.2 in ovarian cancer cells. Our bioinformatics investigation showed that Kir6.2 is expressed in ovarian cancers. We discovered that stimulation of the Kir6.2 channel activity with the small molecule minoxidil (Rogaine®) produces a strong inhibition on ovarian cancer cells’ growth. However, minoxidil had no significant effects on cells that do not express Kir6.2.
We describe a biochemical signaling linking activation of Kir6.2 potassium channel to the tumor suppressor mechanism, which includes a Ca2+-dependent production of superoxide species (ROS), which leads to a significant increase of DNA damage. Consequently, cells die upon activation of apoptosis via caspase-3. Minoxidil is an FDA-approved drug that presents very limited side effects. Therefore, our data are important because for the first time they reveal that use of the Kir6.2 potassium channel activator, e.g., Rogaine®, could be considered as a potential single-agent novel treatment for ovarian cancer.
Clinicians’ approaches for treating advanced ovarian cancer patients are strongly limited by the concern that current chemotherapeutic agent will raise toxicity. For example, although genotoxic chemotherapeutic agents such as doxorubicin or platinum-containing molecules of carboplatin are among the most effective drug classes in ovarian cancer, dose-dependent toxicity of these agents is often the cause for interrupting the treatment.
Our experiments demonstrated that the Kir6.2 activator minoxidil potentiates the antineoplastic effects of doxorubicin as well as of carboplatin by exacerbating their DNA-damaging effects. This discovery is important because it offers the opportunity to design a clinically effective therapeutic strategy in which minoxidil could be administered in combination with genotoxic agents to limit their toxicity in ovarian cancer patients.
Citation Format: Daniela Fukushiro-Lopes, Megan Jain, Maryam Khalid, Alexandra Hegel, Saverio Gentile. Potassium channel activator minoxidil (Rogaine) as a novel single-agent or combination therapy in ovarian cancer. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr A52.
Abstract A66: The tissue transglutaminase 2–fibronectin protein complex: A new target in ovarian cancer
Authors: Sima Livia Elena , Yakubov Bakhtiyor , Condello Salvatore , Cardenas Horacio , Zhang Zhong Yin , Chen Lan , Matei Daniela Elena 
Published: August 2018

Abstract
Here we describe a small-molecule inhibitor (SMI) that disrupts the tissue transglutaminase 2 (TG2)-fibronectin (FN) interaction. TG2 is a multifunctional protein, with enzymatic (transglutaminase, isopeptidase, protein disulfide isomerase), GTPase, and extracellular matrix (ECM) scaffold activities. TG2 directly interacts with FN through its N-terminus domain, playing an important role in stabilizing ternary TG2/FN/integrin complexes, which regulate cell adhesion to the matrix. Our group has previously shown that TG2 overexpressed in ovarian cancer (OC) promotes epithelial-to-mesenchymal transition (EMT) contributing to OC cell invasiveness and metastatic behavior. We showed that the interaction with FN is critical to these functions. Proximity ligation assay was used to measure TG2/integrin beta 1 interaction in OC tumors and identified TG2/integrin beta 1 complex in &gt;50% of ovarian tumors, irrespective of histologic type. Based on those findings, we conducted the high-throughput screening and identified TG53 as the lead TG2/FN inhibitory compound. Structure-activity relationship-based approach was used to optimize the physicochemical properties of TG53, leading to design and chemical synthesis of 6 analogues (MT1-6). All analogues blocked TG2/FN interaction, as measured by an ELISA assay, and OC cell adhesion to FN, as measured by a solid phase assay, MT4 being the most potent inhibitor. MT4 downregulates integrin-initiated signaling in OC cells, leading to downstream inhibition of FAK and ERK. Immunofluorescence staining demonstrated that the actin cytoskeleton adopts a cortical localization pattern in MT4-treated cells. MT4 caused membrane ruffling delaying the formation of stable focal contacts and mature adhesions points. Pretreatment with MT4 sensitized OC cells to paclitaxel, as measured by colony-forming assay. In an intraperitoneal OC mouse model, MT4 caused decreased OC cell adhesion to the peritoneum, inhibiting peritoneal dissemination. Hence, MT4 is a potential candidate to be developed and used in combination with current chemotherapeutics to target OC tumor progression. Further studies will continue to optimize this new class of TG2/FN SMIs for potential clinical use in OC.
Citation Format: Livia Elena Sima, Bakhtiyor Yakubov, Salvatore Condello, Horacio Cardenas, Zhong Yin Zhang, Lan Chen, Daniela Elena Matei. The tissue transglutaminase 2–fibronectin protein complex: A new target in ovarian cancer. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr A66.
Abstract B23: The evolution of estrogen receptor signaling in the progression of endometriosis to endometriosis-associated ovarian cancer
Authors: Boisen Michelle , Andersen Courtney , Sikora Matt , Ma Tianzhou , Tseng George , Vlad Anda , Elishaev Esther , Chandran Uma , Edwards Robert , Oesterreich Steffi 
Published: August 2018

Abstract
Objectives: To investigate changes in estrogen receptor–alpha (ERα) signaling during the progression of endometriosis to endometriosis-associated ovarian cancer (EAOC) as a putative driver of malignant transformation.
Methods: We procured tissue samples of normal endometrium (n=23), endometriosis (benign, n=19; atypical, n=11; concurrent with EAOC, n=9), and EAOC (n=21). In this cohort, we evaluated expression of a 236-gene signature of estrogen signaling. ANOVA and unsupervised clustering were used to identify distinct gene expression profiles across disease states. These profiles were compared to public profiles of estrogen regulation in preclinical cancer models from the Gene Expression Omnibus (GEO). Gene set enrichment analysis (GSEA) was performed to determine whether gene expression in EAOC was consistent with ERα activity.
Results: ANOVA revealed 158 differentially expressed genes (q&lt;0.05) and unsupervised clustering identified 4 distinct gene clusters. Cluster 1 comprises genes with increasing expression from benign endometriosis to EAOC (e.g. FGF18, ESR2). Clusters 2 and 3 include genes that are overexpressed or downregulated in EAOC compared to benign endometriosis, respectively (e.g., NRIP1, IGFBP3). Cluster 4 consists of genes with an incremental decrease in expression from benign endometriosis to EAOC (e.g., ESR1, PGR, and GREB1). The estrogen signaling profile of EAOC was not consistent with activated ERα in the preclinical models. Further, GSEA did not identify signatures of activated ERα in EAOC but instead identified expression patterns consistent with loss of ERα function and development of endocrine resistance.
Conclusions: Gene expression data suggest that classical ERα signaling becomes inactivated throughout the progression of endometriosis to EAOC. Rather, the gene expression pattern in EAOC is more consistent with profiles of endocrine resistance. De-repression of ERα target genes such as FGF18 may contribute to evolution of endometriosis into EAOC.
Citation Format: Michelle Boisen, Courtney Andersen, Matt Sikora, Tianzhou Ma, George Tseng, Anda Vlad, Esther Elishaev, Uma Chandran, Robert Edwards, Steffi Oesterreich. The evolution of estrogen receptor signaling in the progression of endometriosis to endometriosis-associated ovarian cancer. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr B23.
Abstract B64: The novel ZIP4 regulation and its role in cancer stem cell-related activities in ovarian cancer
Authors: Xu Yan , Fan Qipeng , Cai Qingchun , Nephew Kenneth P. 
Published: August 2018

Abstract
The role and regulation of ZIP4, a zinc (Zn) transporter, have been studied in the context of extracellular Zn transporting. Factors other than Zn with ZIP4 regulatory effects are essentially unknown. In addition, its role in cancer stem cell (CSC) has not been reported in any type of cancer. RNA-seq analyses were conducted to compare genes differentially expressed in less and more aggressive epithelial ovarian cancer (EOC) cells. ZIP4 expression and its regulation was assessed by immunoblotting, quantitative PCR, or immunofluorescence staining in human ovarian tissues. CSC-related activities were examined to evaluate the role of ZIP4 in human high-grade serous ovarian cancer (HGSOC) cells. RNAi and CRISPR techniques were used to knock down or knock out ZIP4 and related genes. EOC tumors overexpressed ZIP4 when compared with normal and benign tissues. ZIP4 knockout significantly reduced several CSC-related activities in EOC cells, including proliferation, anoikis resistance, colony formation, spheroid formation, drug resistance, and side-population (SP). Only ZIP4-expressing SP highly expressed known CSC markers ALDH1 and OCT4. ZIP4 knockout dramatically reduced tumorigenesis and ZIP4 overexpression increased tumorigenesis in vivo. In addition, the ZIP4-expressing SP population had the tumor initiating activity. Moreover, the oncolipid lysophosphatic acid (LPA) effectively upregulated ZIP4 expression via the nuclear receptor peroxisome proliferator-activated receptor gamma, and LPA’s promoting effects in CSC-related activities in HGSOC cells was at least partially mediated by ZIP4 in an extracellular Zn-independent manner. Our critical data imply that ZIP4 is a new and important cancer stem cell regulator in EOC. Our data also provide an innovative interpretation for the apparent disconnection between low levels of zinc and upregulation of ZIP4 in EOC tissues.
Citation Format: Yan Xu, Qipeng Fan, Qingchun Cai, Kenneth P. Nephew. The novel ZIP4 regulation and its role in cancer stem cell-related activities in ovarian cancer. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr B64.
Abstract B67: Antitumor effect of black tea pigments, theaflavin-3/3’-gallate, against cisplatin-resistant ovarian cancer cells
Authors: Chen Yi Charlie 
Published: August 2018

Abstract
Ovarian cancer ranks fifth in cancer deaths among women in the United States, accounting for approximately 5% of all cancer deaths. Acquired resistance to conventional platinum-based chemotherapy drives the development of more selective anticancer drugs. Theaflavin-3-gallate (TF2a) and theaflavin-3’-gallate (TF2b) are the major bioactive components in black tea. In this study, we evaluated TF2a and TF2b as potential anticancer agents using human ovarian cancer cells. The cells were cultured in RPMI-1640 medium supplemented with 10% fetal bovine serum at 37˚C in a humidified incubator with 5% CO2. The [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay, flow cytometry, and Western blot analysis were used to confirm that TF2a and TF2b exhibited a potent growth-inhibitory effect against cisplatin-resistant ovarian cancer A2780/CP70 cells. Treatment with TF2a and TF2b (10-40 μM) significantly decreased A2780/CP70 cell viability (p&lt; 0.05). Treatment with TF2a and TF2b (5, 10 and 20 μM) increased the percentage of apoptotic cells in a concentration-dependent manner. Western blot analysis was used to evaluate the expression of proteins related to apoptosis in A2780/CP70 cells treated with designated concentrations (0, 5, 10, and 20 μM) of TF2a and TF2b for 24 h. The protein levels of procaspase-3/7 for TF2a-treated cells and procaspase 3 for TF2b-treated cells decreased significantly in A2780/CP70 cells (p&lt; 0.05). Treatment with TF2a or TF2b significantly increased the protein levels of cleaved caspase-3/7, full-length PARP, and cleaved PARP in A2780/CP70 cells. Our study demonstrated that TF2a and TF2b are potential agents for treating platinum-resistant ovarian cancer by inducing apoptosis.
Note: This abstract was not presented at the conference.
Citation Format: Yi Charlie Chen. Antitumor effect of black tea pigments, theaflavin-3/3’-gallate, against cisplatin-resistant ovarian cancer cells. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr B67.
Abstract IA04: Mitotic progression connects DNA damage to activation of antitumor immune responses
Authors: Greenberg Roger A. 
Published: August 2018

Abstract
Inflammatory gene expression following genotoxic cancer therapy is well documented, yet the events underlying its induction remain poorly understood. Inflammatory cytokines modify the tumor microenvironment by recruiting immune cells and are critical for both local and systemic (abscopal) tumor responses to radiotherapy. An enigmatic feature of this phenomenon is its delayed onset (days), in contrast to the acute DNA damage responses that occur in minutes to hours. Such dichotomous kinetics implicate additional rate limiting steps that are essential for DNA-damage induced inflammation. Here, we show that cell cycle progression through mitosis following DNA double-strand breaks (DSBs) leads to the formation of micronuclei, which precede activation of inflammatory signaling and are a repository for the pattern recognition receptor cGAS. Inhibiting progression through mitosis or loss of pattern recognition by cGAS-STING impaired interferon signaling and prevented the regression of abscopal tumors in the context of ionizing radiation and immune checkpoint blockade in vivo. These findings implicate temporal modulation of the cell cycle as an important consideration in the context of therapeutic strategies that combine genotoxic agents with immune checkpoint blockade.
Citation Format: Roger A. Greenberg. Mitotic progression connects DNA damage to activation of antitumor immune responses. [abstract]. In: Proceedings of the AACR Conference: Addressing Critical Questions in Ovarian Cancer Research and Treatment; Oct 1-4, 2017; Pittsburgh, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(15_Suppl):Abstract nr IA04.
Abstract A02: Succinate dehydrogenase deficiency in a PDGFRA mutated gastrointestinal stromal tumor
Authors: Belinsky Martin G. , Rink Lori , Cai Kathy K. , Luo Biao , Zhou Yan , Mehren Margaret von 
Published: August 2018

Abstract
Most gastrointestinal stromal tumors harbor mutually exclusive gain-of-function mutations in the receptor tyrosine kinase (RTK) KIT (70-80%) or in the related receptor PDGFRA (~10%). Mutations in PDGFRA are most commonly found in the TK domain encoded by exon 18, conferring resistance to approved tyrosine kinase inhibitors (TKI). A more recently defined subset of GIST exhibit deficiencies in the succinate dehydrogenase (SDH) enzyme complex as a result of genetic or epigenetic inactivation of one of the four SDH subunit genes (SDHA-D). SDH-deficient GISTs generally lack mutations in KIT and PDGFRA and do not respond to imatinib (IM), although these GISTs may respond to TKIs targeting VEGFR, such as sunitinib and regorafenib. Whole-exome sequencing (WES) of two GISTs from a single case carrying the IM-resistant exon 18 PDGFRA mutation D842V was carried out to identify additional potential targets for therapy. Surprisingly, a somatic mutation in exon 4 of the SDHB subunit gene (c.291_292delCT, p.I97Mfs*21) was identified in both tumors. Sanger sequencing confirmed the presence of this inactivating mutation, and immunohistochemistry for the SDHB subunit demonstrated that these tumors were in fact SDH deficient. IHC for the SDHB subunit across a panel of ~100 GIST cases failed to detect SDH deficiency in other GISTs with RTK mutations. To our knowledge this is the first reported case of an SDH-deficient GIST harboring a gain-of-function mutation in the PDGFRA receptor, and this finding has implications for the molecular-based classification and treatment of GIST.
Citation Format: Martin G. Belinsky, Lori Rink, Kathy K. Cai, Biao Luo, Yan Zhou, Margaret von Mehren. Succinate dehydrogenase deficiency in a PDGFRA mutated gastrointestinal stromal tumor [abstract]. In: Proceedings of the AACR Conference on Advances in Sarcomas: From Basic Science to Clinical Translation; May 16-19, 2017; Philadelphia, PA. Philadelphia (PA): AACR; Clin Cancer Res 2018;24(2_Suppl):Abstract nr A02.