bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibitory Effects of Cytosolic Ca2+Concentration by Ginsenoside Ro Are Dependent on Phosphorylation of IP3RI and Dephosphorylation of ERK in Human Platelets
Authors: Kwon Hyuk-Woo , Shin Jung-Hae , Lee Dong-Ha , Park Hwa-Jin
Published: August 2015

Intracellular Ca2+([Ca2+]i) is platelet aggregation-inducing molecule and is involved in activation of aggregation associated molecules. This study was carried out to understand the Ca2+-antagonistic effect of ginsenoside Ro (G-Ro), an oleanane-type saponin inPanax ginseng. G-Ro, without affecting leakage of lactate dehydrogenase, dose-dependently inhibited thrombin-induced platelet aggregation, and the half maximal inhibitory concentration was approximately 155 μM. G-Ro inhibited strongly thrombin-elevated[Ca2+]i, which was strongly increased by A-kinase inhibitor Rp-8-Br-cAMPS compared to G-kinase inhibitor Rp-8-Br-cGMPS. G-Ro increased the level of cAMP and subsequently elevated the phosphorylation of inositol 1, 4, 5-triphosphate receptor I (IP3RI) (Ser1756) to inhibit[Ca2+]imobilization in thrombin-induced platelet aggregation. Phosphorylation of IP3RI (Ser1756) by G-Ro was decreased by PKA inhibitor Rp-8-Br-cAMPS. In addition, G-Ro inhibited thrombin-induced phosphorylation of ERK 2 (42 kDa), indicating inhibition of Ca2+influx across plasma membrane. We demonstrate that G-Ro upregulates cAMP-dependent IP3RI (Ser1756) phosphorylation and downregulates phosphorylation of ERK 2 (42 kDa) to decrease thrombin-elevated[Ca2+]i, which contributes to inhibition of ATP and serotonin release, and p-selectin expression. These results indicate that G-Ro inPanax ginsengis a beneficial novel Ca2+-antagonistic compound and may prevent platelet aggregation-mediated thrombotic disease.
One-Step Synthesis of Spherical γ-Fe2O3 Nanopowders and the Evaluation of Their Photocatalytic Activity for Orange I Degradation
Authors: Liang Chunhua , Liu Hui , Zhou Jianmin , Peng Xiaochun , Zhang Haizhou
Published: August 2015

Maghemite (γ-Fe2O3) nanopowders were synthesized under aeration (oxidizing) conditions by aqueous synthesis in this study. The microstructures of the prepared powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET-BJH. The XRD analysis and the chemical experiments showed that well-crystallized γ-Fe2O3 nanoparticles were successfully obtained with a mean particle size of approximately 17 nm. The prepared γ-Fe2O3 was spherical with a BET surface area of 14.357 m2/g and a total pore volume of 0.050 cm3/g. Varying the reaction conditions, such as pH, temperature, and reaction time, we obtained crystallized γ-Fe2O3 powders with different crystallization extent and different particle sizes. When the pH of the reaction suspension was increased, the reaction time was prolonged, and the reaction temperature was increased, the γ-Fe2O3 powders underwent superior crystallization and had larger particle sizes. All the obtained γ-Fe2O3 powders had significant photocatalytic activities under both UV and visible light irradiation for Orange I degradation, and the powders with better crystallization and larger particle size had relatively lower activities for Orange I photocatalytic degradation. The one-step aqueous synthesis method presented in this paper may provide an advantageous pathway to synthesize large quantities of this important iron oxide.
New Topological Configurations in the Continuous Heisenberg Spin Chain: Lower Bound for the Energy
Authors: Dandoloff Rossen
Published: August 2015

In order to study the spin configurations of the classical one-dimensional Heisenberg model, we map the normalized unit vector, representing the spin, on a space curve. We show that the total chirality of the configuration is a conserved quantity. If, for example, one end of the space curve is rotated by an angle of 2πrelative to the other, the Frenet frame traces out a noncontractible loop inSO(3)and this defines a new class of topological spin configurations for the Heisenberg model.
Relationship between Complete Pathologic Response to Neoadjuvant Chemotherapy and Survival in Triple-Negative Breast Cancer
Authors: Hatzis Christos , Symmans W. Fraser , Zhang Ya , Gould Rebekah E. , Moulder Stacy L. , Hunt Kelly K. , Abu-Khalaf Maysa , Hofstatter Erin W. , Lannin Donald , Chagpar Anees B. , Pusztai Lajos
Published: August 2015

Purpose: Pathologic complete response (pCR) to neoadjuvant chemotherapy reflects the cytotoxic efficacy of a drug, but patient survival is influenced by many other factors. The purpose of this study was to assess the relationship between increased pCR rate and trial-level survival benefit in triple-negative breast cancer (TNBC).

Experimental Design: We used bootstrap resampling from a neoadjuvant trial to simulate trials with different pCR rates. We used estimates from Adjuvant!Online to simulate trial populations with different baseline prognosis and estimated survival improvements associated with changes in pCR rate.

Results: Assuming that survival is similar for patients with pCR regardless of treatment arm, a linear relationship exists between increasing pCR rate and increasing recurrence-free survival (RFS). The slope is equal to the difference in survival between those with pCR and residual disease, which in turn is influenced by (i) the baseline prognosis of the trial population, (ii) interactions between prognostic variables and pCR, and (iii) the efficacy of the postneoadjuvant therapies. For example, if the pCR rates are 30% and 60% (OR = 3.5) and the 10-year RFS of the control arm is 0.74, the trial would require 3,550 patients per arm, whereas if the RFS is 0.54, the trial would require only 425 patients per arm to detect significant survival benefit.

Conclusions: We provide a framework for understanding the relationship between pCR and overall survival benefit that can help inform the design of neoadjuvant trials aiming to demonstrate improved survival from a regimen that results in higher pCR rate. Clin Cancer Res; 22(1); 26–33. ©2015 AACR.

See related commentary by Berry, p. 3
Low Socioeconomic Status, Adverse Gene Expression Profiles, and Clinical Outcomes in Hematopoietic Stem Cell Transplant Recipients
Authors: Knight Jennifer M. , Rizzo J. Douglas , Logan Brent R. , Wang Tao , Arevalo Jesusa M.G. , Ma Jeffrey , Cole Steve W.
Published: August 2015

Purpose: Low socioeconomic status (SES) is associated with adverse outcomes among unrelated donor hematopoietic stem cell transplant (HCT) recipients, but the biologic mechanisms contributing to this health disparity are poorly understood. Therefore, we examined whether social environment affects expression of a stress-related gene expression profile known as the conserved transcriptional response to adversity (CTRA), which involves upregulation of proinflammatory genes and downregulation of genes involved in type I IFN response and antibody synthesis.

Experimental Design: We compared pretransplant leukocyte CTRA gene expression between a group of 78 high versus low SES recipients of unrelated donor HCT for acute myelogenous leukemia in first remission. Post hoc exploratory analyses also evaluated whether CTRA gene expression was associated with poor clinical outcomes.

Results: Peripheral blood mononuclear cells collected pre-HCT from low SES individuals demonstrated significant CTRA upregulation compared with matched HCT recipients of high SES. Promoter-based bioinformatics implicated distinct patterns of transcription factor activity, including increased CREB signaling and decreased IRF and GR signaling. High expression of the CTRA gene profile was also associated with increased relapse risk and decreased leukemia-free survival.

Conclusions: Low SES is associated with increased expression of the CTRA gene profile, and CTRA gene expression is associated with adverse HCT clinical outcomes. These findings provide a biologic framework within which to understand how social environmental conditions may influence immune function and clinical outcomes in allogeneic HCT. Clin Cancer Res; 22(1); 69–78. ©2015 AACR.

See related commentary by Turcotte and Verneris, p. 6
Abstract AS20: DNA-PKcs is amplified in high grade serous ovarian cancer (HGSC), correlates with poor outcome and drives resistance to platinum therapy via the AKT signaling pathway
Authors: Curry E , Cheraghchi-Bashi-Astaneh A , Chen M , Cunnea P , De Sousa C , Maginn E , Dai Y , Liu E , Wasan H , Mills G , Bowtell D , Gabra H , Stronach EA
Published: August 2015

High grade serous ovarian cancer is typified by p53 mutation, high degrees of genomic instability and the development of chemo-resistance. Genomic translocations result from incorrectly repaired DNA double strand breaks (DSBs). DNA-PKcs is a central catalytic component of the error prone non-homologous end joining (NHEJ) DSB repair mechanism. We report here that DNA-PKcs is frequently amplified in copy number in HGSC and that amplification correlates with higher DNA-PKcs gene expression and poorer patient outcome (PFS/OS) using both in-house and publicly available datasets (TCGA). Targeting DNA-PKcs, pharmacologically or by RNAi, enhances apoptosis in response to platinum treatment in platinum resistant cell lines and primary models. Furthermore we report that inhibition of DNA-PK restores response to cisplatin in chemoresistant ovarian cancer cells in vivo. SKOV-3 tumor xenografts were implanted subcutaneously into Balb/c Nu/Nu mice and treated with DNA-PKcs inhibitor NU7441 for 2 weeks alone or in combination with cisplatin. DNA-PK inhibition or cisplatin treatment alone were ineffective however in combination they decreased tumor growth at 14 days by 90%, relative to platinum only treatment. On investigating the mechanism of DNA-PKcs mediated chemoresistance we revealed that, in response to DNA damage, DNA-PKcs phosphorylates AKT on serine residue 473 in the nucleus of platinum resistant ovarian tumor cells, but not sensitive cells from the same patient. Phosphorylation at AKT threonine 308 is unaffected and DNA-PK inhibition does not interfere with insulin-mediated phosphorylation of AKT S473. DNA-PK mediated AKT activation in chemoresistant cells results in inhibitory phosphorylation of the pro-apoptotic protein BAD and stabilisation of the anti-apoptotic Bcl-2 protein resulting in the observed attenuation of apoptotic response to platinum treatment. DNA-PK inhibition is an attractive therapeutic strategy for resensitising resistant tumors to platinum based therapy, directly linking the DNA damage caused by platinum to the pro-survival AKT pathway, without interfering with normal physiological roles of AKT.

Citation Format: Curry E, Cheraghchi-Bashi-Astaneh A, Chen M, Cunnea P, De Sousa C, Maginn E, Dai Y, Liu E, Wasan H, Mills G, Bowtell D, Gabra H & Stronach EA. DNA-PKcs is amplified in high grade serous ovarian cancer (HGSC), correlates with poor outcome and drives resistance to platinum therapy via the AKT signaling pathway [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr AS20.
Abstract AS23: Microenvironment mediated downregulation of miR-193b promotes ovarian cancer metastasis
Authors: Mitra AK , Chiang CY , Tiwari P , Peter ME , Lengyel E
Published: August 2015

The cross-talk between ovarian cancer cells with the microenvironment of the site of metastasis is an essential determinant of successful metastatic colonization. microRNAs have been well established to play critical roles in various stages of cancer progression, including metastasis. However, the role of the signals from the microenvironment in regulating key microRNAs in metastasizing cancer cells has not been studied. Using a 3D culture model mimicking the human omentum, one of the principal sites of ovarian cancer metastasis, we have identified the microenvironment-induced downregulation of a tumor suppressor microRNA miR-193b in the metastasizing ovarian cancer cells. The direct interaction of the ovarian cancer cells with the mesothelial cells covering the surface of the omentum caused DNA methyltransferase 1 (DNMT1) mediated methylation and decreased expression of miR-193b. The reduction in miR-193b enabled the metastasizing cancer cells to invade and proliferate in the omentum both in vitro and in a mouse xenograft model of ovarian cancer metastasis. The functional effects of miR-193b were mediated at least partly through the concomitant increased expression of its target urokinase-type plasminogen activator (uPA). Our findings link paracrine signals from the microenvironment with the regulation of a key microRNA in cancer cells that is essential for the initial steps of ovarian cancer metastatic colonization. Targeting miR-193b would be a promising approach to treat ovarian cancer metastasis.

Citation Format: AK Mitra, CY Chiang, P Tiwari, ME Peter, E Lengyel. Microenvironment mediated downregulation of miR-193b promotes ovarian cancer metastasis [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr AS23.
Abstract AS30: BRCA1-IRIS inactivation sensitizes ovarian tumors to cisplatin
Authors: Paul Bibbin T. , Blanchard Zannel , Ridgway Mildred , ElShamy Wael M.
Published: August 2015

Ovarian cancer is the first in mortalities among gynecological cancers in the USA, often due to late diagnosis and/or acquired platinum-resistant recurrences. This study investigates whether BRCA1-IRIS is a novel treatment target for ovarian cancers and their platinum-resistant recurrences. Here we show that more than half of ovarian cancer samples analyzed showed BRCA1-IRIS and survivin overexpression and lacked nuclear FOXO3a expression. Normal ovarian epithelial cells overexpressing BRCA1-IRIS formed metastasis in mice when injected in the peritoneal cavity, whereas aggressive ovarian cancer cell lines failed to form tumors or metastases in mice when BRCA1-IRIS was silenced in them. We show that BRCA1-IRIS activates two autocrine signaling loops, BDNF/TrkB and NRG1/ErbB2. These loops are involved in anoikis resistance and metastasis promotion. These loops operate in several ovarian cancer cell lines and BRCA1-IRIS silencing or inactivation using a novel inhibitory peptide renders both non-functional and promoted cell death. In a mouse xenograft model BRCA1-IRIS inactivation using this novel inhibitory peptide resulted in significant reduction in ovarian tumor growth. More importantly, this treatment sensitized ovarian tumors to low Cisplatin concentrations. Taken together, these data strongly suggest that BRCA1-IRIS and/or BDNF/TrkB and NRG1/ErbB2 could serve as rational therapeutic targets for advanced ovarian cancers.

Citation Format: Bibbin T. Paul, Zannel Blanchard, Mildred Ridgway, Wael M. ElShamy. BRCA1-IRIS inactivation sensitizes ovarian tumors to cisplatin [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr AS30.
Abstract KP02: Functional genomics, cancer biology and targets
Authors: Hahn William C.
Published: August 2015

Recent advances in genomics now make it possible to consider enumerating all of the genetic lesions in specific cancers. These approaches will yield critical information regarding the identification, number, and types of alterations found in human tumors and are increasingly being applied prospectively to patient samples in the clinic. At the same time, complementary approach to decipher the molecular basis of malignant transformation depends upon the application of genome scale tools to annotate the function of genes involved in cancer initiation and progression. Over the past several years, we have developed genome scale loss-of-function libraries and open reading frame expression libraries that permit a systematic evaluation of genes involved in cancer initiation and maintenance. Using these libraries, we have now performed screens in a panel of human ovarian cancer cell lines to systematically identify cancer vulnerabilities. By combining these functional approaches with information derived from mapping the structural abnormalities present in cancer genomes, we have identified several new oncogenes that contribute to cancer development. The ability to systematically manipulate gene expression at genome scale now provides opportunities to investigate the function of genes involved in cancer initiation and maintenance, which will provide a framework for therapeutic strategies.

Citation Format: William C. Hahn. Functional genomics, cancer biology and targets [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr KP02.
Abstract POSTER-BIOL-1309: Beta-catenin regulated ALDH1A1 is a target in ovarian cancer stem cells
Authors: Condello Salvatore , Nagdas Sarbajeet , Morgan Cynthia , Turek John , Hurley Thomas , Matei Daniela
Published: August 2015

Spheroids are 3D multi-cell aggregates formed in non-adherent culture conditions. In ovarian cancer (OC), they serve as a vehicle for cancer cell dissemination in the peritoneal cavity and protect cells from extracellular stress-induced anoikis. We hypothesized that spheroids are enriched in cancer stem cells and investigated pathways activated under these conditions. Affymetrix-based gene expression profiling of OC cells grown as spheroids vs. monolayers identified β-catenin pathway being upregulated in 3D cultures. Increased expression of β-catenin and target genes (cyclin D1, c-myc) was demonstrated in spheroids vs. monolayers and in successive spheroid generations using OC cell lines and primary cultures. B-catenin function measured as TCF/LEF1 reporter activity was augmented in spheroids vs. monolayers and siRNA mediated β-catenin knock down decreased the number of spheroids (p<0.001). Along with β-catenin, the expression level of ALDH1A1, an OC stem cell marker, was increased in successive spheroid generations. The percentage of ALDH+ cells was significantly higher in spheroids vs. monolayers in IGROV1, A2780, SKOV3, and primary OC cells. B-catenin knock-down decreased ALDH1A1 expression, suggesting that it is a β-catenin target. The percentage of ALDH+ cells and the number of spheroids formed were increased in the cell population dissociated from OC xenografts treated with carboplatin compared to control (44% vs. 2.3%), supporting that ALDH1A1 is a stem cell marker. A37 is a novel ALDH1A1 enzymatic inhibitor (Ki of 5nM). A37 decreased cell viability and spheroid formation by IGROV1 cells (p<0.001). A37 also decreased the percentage of ALDH+ cells under 3D culture conditions. These data support the role of β-catenin regulated ALDH1A1 in the maintenance of OC spheroids and of a stem cell phenotype and propose new ALDH1A1 inhibitors targeting this cell population.

(Funding: US Department of Veterans Affairs and Ovarian Cancer Research Fund)

Citation Format: Salvatore Condello, Sarbajeet Nagdas, Cynthia Morgan, John Turek, Thomas Hurley, Daniela Matei. Beta-catenin regulated ALDH1A1 is a target in ovarian cancer stem cells [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1309.
Abstract POSTER-BIOL-1318: Claudin 4 controls the receptor tyrosine kinase EphA2 pro-oncogenic switch through β-catenin
Authors: Shang Xiying , Lin Xinjian , Howell Stephen B.
Published: August 2015

EphA2, which is expressed in ovarian cancer, is activated by two different mechanisms. Activation by engagement with one of its ephrin ligands is anti-oncogenic whereas activation by phosphorylation of S897 by AKT increases migration, invasion and metastasis. Down-regulation of claudin-4 (CLDN4) produces a loss of E-cadherin and increased β-catenin signaling and a phenotype similar to that produced by oncogenic activation of EphA2. We found that constitutive knockdown of CLDN4 was associated with a 4.5-fold increase in EphA2 mRNA and a 2.5-fold increase in EphA2 protein which was reversed by re-expression of CLDN4. Knockdown of EphA2 blocked the migratory phenotype induced by loss of CLDN4. Knockdown of CLDN4 resulted in a 5.8-fold increase in pEphA(S897), the oncogenic form of the receptor, as well as mislocalization of EphA2 to the interior of the cell. Forced expression of E-cadherin did not reduce total EphA2 or pEphA(S897) whereas re-expression of CLDN4 restored localization and reduced EphA2 and pEphA(S897) even in cells not expressing E-cadherin. Transient siRNA-mediated knockdown of EphA2 and β-catenin, and inhibition of PI3K by LY294002, demonstrated that increased pEphA(S897) in the CLDN4 knockdown cells was attributable to an increase in the level of active dephospho- β-catenin upstream of PI3K and AKT. We conclude that CLDN4 serves to restrain pro-oncogenic signaling from EphA2 by limiting the activity of β-catenin and PI3K and preventing phosphorylation of EphA2 on S897 by AKT. This suggests that interventions directed at enhancing the level or functional activity of CLDN4 may be of therapeutic interest.

Citation Format: Xiying Shang, MD, PhD, Xinjian Lin, MD, Stephen B. Howell, MD. Claudin 4 controls the receptor tyrosine kinase EphA2 pro-oncogenic switch through β-catenin [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1318.
Abstract POSTER-BIOL-1322: Natural anti-glycan IgM recognize P1 glycosphingolipid expressed on ovarian cancer cells
Authors: Jacob Francis , Anugraham Merrina , Pochechueva Tatiana , Tse Brian Wan-Chi , Alam Shahidul , Guertler Rea , Bovin Nicolai V. , Fedier André , Hacker Neville F. , Huflejt Margaret E. , Packer Nicolle , Heinzelmann-Schwarz Viola A.
Published: August 2015

Recent research strongly suggests a role of plasma-derived anti-P1 antibodies (AGA) in ovarian cancer, as demonstrated by three independent glycan-based immunoassays. The level of these antibodies was lower in ovarian cancer patients and therefore discriminate cancer patients from healthy women. Here we investigate in a separate Australian cohort (n=155) whether IgM or IgG to P1 accounts for this discrimination and whether plasma matched ascites samples contain AGA. We also aimed to identify the P1 antigen in cancer tissue and cultured cells that are recognized by naturally occurring anti-P1 IgM and to investigate the potential function in respect to cell migration.

Our results demonstrated that the IgM to P1 discriminates patients with ovarian cancer from healthy controls (p=0.0002) and that lower anti-P1 antibody levels are associated with a slightly higher risk for early relapse. Mass spectrometry identified P1 and structurally related epitopes in fresh tissue specimens and cultured cells. Ovarian cancer cell line IGROV1 was identified to be P1-positive while others (n=7) including human ovarian surface epithelial cells were negative determined by comprehensive flow cytometry. Epitope-mapped and characterized affinity purified anti-P1 antibodies from ascites were shown to bind P1-expressing cancer cells. IGROV1 was cell-sorted into two subpopulations, P1–high (66.1%) and P1-low (33.3%) and we found a significantly higher migration rate in P1-high expressing cells.

Plasma-and ascites-derived natural anti-P1 IgM bind to the corresponding selfantigen expressed on the ovarian cancer cell surface. These findings are in concordance with the literature on natural IgM as part of the innate immune system recognizing carbo-neo-epitopes. These results deliver the first evidence that P1 may also be involved in cell migration and therefore may have a role in metastasis.

Citation Format: Francis Jacob, Merrina Anugraham, Tatiana Pochechueva, Brian Wan-Chi Tse, Shahidul Alam, Rea Guertler, Nicolai V. Bovin, André Fedier, Neville F. Hacker, Margaret E. Huflejt, Nicolle Packer, Viola A. Heinzelmann-Schwarz. Natural anti-glycan IgM recognize P1 glycosphingolipid expressed on ovarian cancer cells [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1322.
Abstract POSTER-BIOL-1323: Elevated MGAT3 expression in ovarian cancer cells is epigenetically regulated and correlates with expression of bisecting GlcNAc-modified proteins
Authors: Jacob Francis , Anugraham Merrina , Kohler Reto , Nixdorf Sheri , Everest-Dass Arun Vijay , Fedier André , Heinzelmann-Schwarz Viola , Packer Nicolle H.
Published: August 2015

Changes in the glycosylation of membrane proteins are a common feature of malignant transformation including ovarian cancer development. Of particular interest are N-linked glycans because these cell surface glycans mediate various cellular functions in cell-cell communication, cell adhesion, and cell motility. However the nature of these changes, their underlying molecular mechanisms, and the biological function of these glycans are poorly understood. In the present study, N-glycans were released from extracted membrane glycoproteins from ovarian cancer and normal ovarian epithelial cell lines and analysed using electrospray ionisation mass spectrometry; RT-qPCR measured gene expression of related glycosyltransferases; bisulfite sequencing analysed DNA methylation of the corresponding genes.

We identified characteristic glycan features unique to membrane proteins of ovarian cancer cells. Among those ovarian cancer specific N-glycans were the ‘bisecting N-acetyl-glucosamine (GlcNAc)’ type. The bisecting GlcNAc is the product of the enzyme MGAT3 (beta-1,4-N-acetylglucosaminyltransferase 3) and the expression of the MGAT3 gene was elevated in ovarian cancer cell lines (SKOV3, IGROV1, A2780, OVCAR3) as compared to normal ovary surface epithelial (HOSE) cells. This elevated MGAT3 expression in ovarian cancer cells correlated with DNA hypomethylation at the transcription start site (TSS) of the MGAT3 promotor, which contains a large CpG island with 204 CpG dinucleotides located -600/+800bp relative to the TSS. This finding suggests that MGAT3 expression is epigenetically regulated. This was validated by the finding that the treatment of HOSE cells with the DNA-methyltransferase inhibitor 5-Aza increased MGAT3 expression and corresponded to a reduction in DNA methylation at the TSS.

Taken together, we conclude that the elevated MGAT3 expression in ovarian cancer cells correlates with the presence of the resultant specific N-glycan substructures and with the epigenetic regulation of the associated enzymes by DNA methylation. These findings may stimulate the development of novel anti-glycan targeted drugs and clinical diagnostic tools for ovarian cancer

Citation Format: Francis Jacob, Merrina Anugraham, Reto Kohler, Sheri Nixdorf, Arun Vijay Everest-Dass, André Fedier, Viola Heinzelmann-Schwarz, Nicolle H. Packer. Elevated MGAT3 expression in ovarian cancer cells is epigenetically regulated and correlates with expression of bisecting GlcNAc-modified proteins [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1323.
Abstract POSTER-BIOL-1325: Ovarian cancer-associated CDK12 mutations disable its kinase activity and cause defects in homologous recombination
Authors: Joshi Poorval M. , Sutor Shari L. , Huntoon Catherine J. , Karnitz Larry M.
Published: August 2015

PURPOSE: The purpose of this study was to determine whether a) high-grade serous ovarian cancer-associated CDK12 kinase domain mutations affect catalytic activity, b) loss of CDK12 affects BRCA1 expression levels and Homologous Recombination (HR) in ovarian cancer, c) tumor-associated CDK12 mutations cause HR defects in ovarian cancer, and d) loss of CDK12 sensitizes ovarian cancer to chemotherapy and Poly(ADP-ribose) Polymerase [PARP] inhibitors.

EXPERIMENTAL PROCEDURES: We compared the kinase activities of wild-type CDK12 and tumor-associated CDK12 kinase domain mutants using in-vitro kinase assays. To determine the impact of CDK12 activity on HR, we assessed RAD51 foci formation and HR using a DR-GFP construct. To analyze the effect of tumor-associated CDK12 mutations on HR, CDK12-depleted OVCAR-8 cells were reconstituted with either wild-type CDK12 or the tumor-associated CDK12 mutant (G909R), irradiated and stained for RAD51 foci. We performed clonogenic assays using ovarian cancer cell lines (OVCAR-8, OVCAR-5 and OVCAR-3) to measure sensitivity to DNA cross-linking agents (melphalan and cisplatin) and the PARP inhibitor, veliparib, in the presence or absence of CDK12 activity. CDK12 depletion was carried out using at least two independent short-interfering RNAs (siRNAs).

RESULTS: We showed that many, but not all, ovarian cancer-associated CDK12 kinase domain mutations severely disrupted kinase activity. Moreover, we found that disabling CDK12 activity in ovarian cancer cells decreased BRCA1 levels and disrupted HR. Additionally, the tumor-associated CDK12 G909R mutant did not restore impaired RAD51 foci formation in CDK12-depleted OVCAR-8 cells. Finally we show that CDK12 depletion sensitized multiple ovarian cancer cells to the DNA cross-linking agents melphalan and cisplatin and to the PARP inhibitor veliparib.

CONCLUSION: Ovarian cancer-associated CDK12 mutations disrupt kinase activity and cause defects in HR, suggesting that ovarian tumors harboring deleterious CDK12 mutations may predict sensitivity to chemotherapeutic agents, including PARP inhibitors.

Citation Format: Poorval M. Joshi, Shari L. Sutor, Catherine J. Huntoon, Larry M. Karnitz. Ovarian cancer-associated CDK12 mutations disable its kinase activity and cause defects in homologous recombination [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1325.
Abstract POSTER-BIOL-1329: The ovary is an alternative site of origin for high-grade serous ovarian cancer in mice
Authors: Kim Jaeyeon , Coffey Donna M. , Ma Lang , Matzuk Martin M.
Published: August 2015

The tumor suppressor p53 is the most frequently mutated gene in high-grade serous carcinoma (HGSC), the most common and deadliest ovarian cancer. It remains unknown, however, whether p53 mutation can cause HGSC. To address this, we have incorporated a p53 activating mutation, p53R172H, into conditional Dicer-Pten double-knockout (DKO) mice, generating triple-mutant (TKO) mice. Like DKO mice, TKO mice develop metastatic HGSCs originating from the fallopian tube. Besides, even when fallopian tubes are removed in TKO mice, ovaries alone can spur their own metastatic HGSCs, indicating that p53 mutation can drive HGSC arising from the ovary. To further confirm the ability of p53 mutation to induce ovarian HGSC, we have generated p53R172H-Pten double-mutant (DMu) mice, one genetic control line for TKO mice. As anticipated, these DMu mice develop metastatic HGSCs from the ovary, which spread to the abdominal cavity before killing the mice, just like fallopian tube-deficient TKO mice. Our study therefore shows that the ovary, as well as the fallopian tube, can be a source of high-grade serous ovarian cancer.

(Grant support: Marsha Rivkin Ovarian Cancer Challenge Grant; Ovarian Cancer Research Fund (OCRF); F32 NCI National Research Service Award (NRSA); and K99/R00 NCI Pathway to Independence Award)

Citation Format: Jaeyeon Kim, Donna M. Coffey, Lang Ma, Martin M. Matzuk. The ovary is an alternative site of origin for high-grade serous ovarian cancer in mice [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1329.
Abstract POSTER-BIOL-1332: Molecular, cellular and clinical interaction between MDSC and ovarian cancer stemness
Authors: Kryczek Ilona , Cui Tracy X. , Zhao Lili , Vatan Linda , Szeliga Wojciech , Liu Rebecca , Zou Weiping
Published: August 2015

Myeloid derived suppressor cells (MDSCs) and cancer stem cells (CSCs) are important cellular components in the cancer microenvironment, and may affect cancer phenotype and patient outcome. The nature of MDSCs and their interaction with CSCs in ovarian carcinoma are unclear. We examined the interaction between MDSCs and CSCs in patients with ovarian carcinoma. We demonstrate that MDSCs inhibit T cell activation, enhance CSC gene expression, sphere formation and cancer metastasis. MDSCs trigger microRNA101 expression in cancer cells; microRNA101 subsequently represses the co-repressor gene C-terminal binding protein-2 (CtBP2), and CtBP2 directly targets stem cell core genes resulting in increased cancer cell stemness, and increasing metastatic and tumorigenic potential. Increased MDSC density and tumor microRNA101 levels, and decreased tumor CtBP2 expression independently predict poor survival. Collectively, the work identifies a novel immune associated cellular, molecular and clinical network involving MDSCs/microRNA101/CtBP2/stem cell core genes, which extrinsically controls cancer stemness and impacts patient outcome.

Citation Format: Ilona Kryczek, Tracy X. Cui, Lili Zhao, Linda Vatan, Wojciech Szeliga, Rebecca Liu, Weiping Zou. Molecular, cellular and clinical interaction between MDSC and ovarian cancer stemness [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1332.
Abstract POSTER-BIOL-1336: Investigating the role of phosphodiesterase 10A as a novel target in ovarian cancer
Authors: Silva Luciana Madeira da , Lee Kevin , Piazza Gary A. , Bachaboina Lavanya , Rocconi Rodney P. , Scalici Jennifer
Published: August 2015

Cyclic nucleotide phosphodiesterases (PDEs) play major roles regulating cell signaling by hydrolyzing the second messengers cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Phosphodiesterase 10A (PDE10A) is one of 21 PDEs encoded in the human genome. Its predominant expression in the brain striatum has guided intensive investigations on the therapeutic potential of PDE10A in psychiatric and neurological disorders, leading to several PDE10A inhibitors in clinical trials for schizophrenia and Hungtington's disease. Recently, we described for the first time an oncogenic role for PDE10A in colorectal cancer (N. Li et al. 2014 Oncogene 1-11). Our published data showed that PDE10A is overexpressed in colon tumor cells when compared to normal colonocytes, and that pharmacological inhibition or genetic knockdown of PDE10A suppresses colon tumor growth. Here, we are investigating the role of PDE10A in ovarian cancer and its potential as a novel therapeutic target. We detected expression of PDE10A in several ovarian cancer cell lines (SKOV3, SKOV3ip1, A2780, A2780-CP70, OV-90, ES-2 and TOV112D) by western-blotting and quantitative RT-PCR. In addition, our preliminary analysis revealed PDE10A expression in tumors and matched normal tissues from eight patients of ovarian cancer. Finally, we developed novel small molecule compounds targeting PDE10A which potently inhibit growth of all these ovarian cancer cell lines at low micromolar or sub-micromolar concentrations. Future work will focus on i) expanding the cohort of ovarian cancer patient tissues to analyze expression levels of PDE10A by western-blotting, quantitative RT-PCR and immunohistochemistry; ii) genetic silencing of PDE10A by siRNA/shRNA to investigate its role regulating cell proliferation, apoptosis, and cGMP/cAMP cell signaling in ovarian cancer; iii) investigate the signaling pathways suppressed by our novel PDE10A inhibitors. Our studies will determine the potential of using PDE10A as a novel therapeutic target for the treatment and chemoprevention of ovarian cancer.

Citation Format: Luciana Madeira da Silva, Kevin Lee, Gary A. Piazza, Lavanya Bachaboina, Rodney P. Rocconi, Jennifer Scalici. Investigating the role of phosphodiesterase 10A as a novel target in ovarian cancer [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1336.
Abstract POSTER-CTRL-1206: The mutational landscape of fallopian tube carcinoma
Authors: Harrell M.I. , Walshb T. , Agnew K.J. , Norquist B. , Lee M.K. , Bernards S. , Pennington K.P. , Swisher E.M.
Published: August 2015

Fallopian tube (FT) carcinoma is a rare gynecological malignancy, whose incidence is most likely underestimated due to misdiagnoses as ovarian cancer. Recent advances in pathology with more thorough serial sectioning techniques have led to better identification. We undertook to define germline and somatic mutations in 98 FT carcinoma cases enrolled at diagnosis in IRB-approved studies at the University of Washington, excluding cases with carcinoma identified at the time of risk-reducing surgery. We sequenced DNA from blood and neoplastic tissue using BROCA, a targeted capture and massively parallel genomic sequencing approach that detects all classes of mutation in 64 genes. The fraction of all primary ovarian, peritoneal and FT carcinoma defined as a FT primary increased over time in our tissue bank: FT diagnoses accounted for 23% of cases in the past five years compared to 5% in the previous 10 years (p=0.002). Of 98 subjects with FT carcinoma, 32 (33%) had loss of function germline mutations in 9 genes. Mutations in BRCA1 were identified in 18 (19%), making up the largest number of germline mutations, and in BRCA2 in 4 (4%). Germline mutations were also identified in 6 other known breast and/or ovarian cancer susceptibility genes including 2 in BRIP1 (2%), 2 in CHECK2 (2%), and 1 each in BARD1, BLM, MRE11A, and ATM (1%). One mutation was found in the FA gene FANCL. Additionally, we found 1 mosaic mutations in TP53 (1%) and 2 in PPM1D (2%). Together germline and mosaic mutations were identified in 34 (35%) of cases. We sequenced neoplastic DNA with BROCA in 30 FT carcinomas and found 27 somatic mutations in TP53 (90%), 1 in PTEN (3%) and 1 in CHEK2 (3%). The germline mutation rate was higher in FT carcinoma compared to our previous studies in ovarian carcinoma (35% versus 22%), though the identified genes were similar. Recently identified ovarian cancer susceptibility genes such as BRIP1, BARD1, and PPM1D are also associated with hereditary fallopian tube cancer. Known breast cancer genes (i.e. CHEK2, MRE11A, ATM) and other cancer associated genes (BLM, FANCL) require further study to prove their association with FT or ovarian cancer risk. An increased pathological recognition of the FT as a primary site of disease is changing the relative distribution of FT, ovarian, and peritoneal carcinoma in some centers.

Citation Format: M.I. Harrell, T. Walshb, K.J. Agnew, B. Norquist, M.K. Lee, S. Bernards, K.P. Pennington, E.M. Swisher. The mutational landscape of fallopian tube carcinoma [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-CTRL-1206.
Abstract POSTER-CTRL-1214: Systematic identification of high risk women for genetic counseling and surgical prevention of ovarian cancer
Authors: Resta Robert , Drescher Charles W. , Beatty David , Andersen M Robyn , Watabayashi Kate , Thorpe Jason , Purkey Hannah , Chubak Jessica , Hanson Nancy , Buist Diana S.M. , Urban Nicole
Published: August 2015

Objectives: Information technology provides an opportunity for systematic identification of high-risk patients for appropriate referral. We conducted a randomized controlled trial to test whether routine identification of women at high risk for epithelial ovarian cancer using an electronic database and subsequent referral to genetic counseling would promote genetic testing and prophylactic surgery.

Methods: Electronic data in a mammography reporting system from a large community hospital in Seattle was used to identify women at increased risk for ovarian cancer based on personal and family cancer history. Following secondary confirmation of eligibility and consent, women were randomly assigned to an intervention consisting of a genetic counseling referral, or to standard clinical care.

Results: A total of 458 women were enrolled. Compared to standard clinical care systemic identification and referral of high risk women to genetic counseling increased the number of women who elect to undergo genetic testing (75 vs 20, p<0.005) and prophylactic surgery (OR: 3.5, p=0.05).

Conclusions: Our results demonstrated that systematic identification of high-risk women for referral to genetic counseling is feasible and increases utilization of risk-appropriate prevention strategies.

Citation Format: Robert Resta, MS CGC; Charles W. Drescher, MD; David Beatty, MD; M Robyn Andersen, PhD; Kate Watabayashi, BA; Jason Thorpe, MSc; Hannah Purkey, BS; Jessica Chubak, PhD; Nancy Hanson, MS CGC; Diana S.M. Buist, MPH PhD; Nicole Urban, ScD. Systematic identification of high risk women for genetic counseling and surgical prevention of ovarian cancer [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-CTRL-1214.
Abstract POSTER-CTRL-1216: Profile of BRCA testing in ovarian cancer patients in the US and EU
Authors: Tyczynski JE , Moss S , De Richter P
Published: August 2015

Purpose: Around 13% of patients with ovarian cancer harbor mutations in the BRCA genes. Their disease has distinct characteristics which may impact treatment pathways. However, currently only a selected subset of ovarian cancer patients are offered testing for BRCA mutation, based largely upon family history of BRCA-related tumors. Frequencies of, and barriers to testing are not well characterized; therefore, our objective was to describe the current BRCA testing practices among women diagnosed with ovarian cancer.

Methods: A survey of 465 oncologists, 513 pathologists and 97 laboratory directors, including detailed questionnaires for 435 ovarian cancer patients, across the US, UK, France, Germany, Italy and Spain was conducted during 2013 by Ipsos Healthcare syndicated MDx Monitor.

Results: Physician awareness of BRCA testing in ovarian cancer patients varies: 61–86% in EU and over 90% in US. 50–67% of oncologists in EU, compared with over 80% in US, claim to have used BRCA testing within 6 months from diagnosis. On average, between 24% (US) to 7% (UK) of ovarian cancer patients were tested for BRCA post-diagnosis with large variations between physicians. Guidelines and patient requests were drivers for testing; barriers included perceived lack of clinical utility/targeted therapies (~35%), lack of BRCA risk factors (~5–70% depending on country), patient refusal (~5%), and reimbursement/cost (~15%). In all markets, both germline and somatic BRCA testing were common. Testing was generally performed in remote laboratories for efficiency. In US, most testing was conducted by Myriad; in EU several different tests, including 5% that were developed locally (by individual laboratories), were used.

Conclusions: While there is broad knowledge and use of BRCA testing, the survey has highlighted significant barriers which may prevent ovarian cancer patients from being offered the test. Ongoing research aims to demonstrate the value of testing a broader cohort of patients, to identify individuals who may benefit from more personalized treatment approaches.

Citation Format: Tyczynski JE, Moss S, De Richter P. Profile of BRCA testing in ovarian cancer patients in the US and EU [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-CTRL-1216.
Abstract POSTER-TECH-1119: Phylogenetic portraits of high grade serous ovarian cancer
Authors: McPherson Andrew , Roth Andrew , Huntsman David , McAlpine Jessica , Shah Sohrab
Published: August 2015

High Grade Serous Ovarian Cancer (HGSOvCa) is characterized by genomic instability resulting from deficient DNA repair processes primarily due to TP53 mutation and BRCA abnormalities. Genomic instability has been shown to result in significant intratumoral heterogeneity, with temporally and spatially separated tumours exhibiting unique mutational profiles. A key unanswered question is whether genomic instability produces functionally relevant driver mutations, or whether the tumours complement of driver mutations predates the emergence of instability.

We sought to reconstruct the evolutionary histories of the tumours of 8 HGSOvCa patients using spatial and temporal profiling of somatic mutations. For each patient, we collected multiple tumour biopsies resected from primary and metastatic sites at the time of surgery. We then used whole genome shotgun sequencing to identify somatic point mutation, rearrangement and copy number changes present at each site. We used novel computational techniques to unmix the signal produced by sequencing of a mixture of tumour cells, and infer the genomic architecture of clonal populations in each tumour sample. Additionally, we used phylogenetic inference techniques to reconstruct the ancestral relationships between the genomically distinct clones identified in each patient. We classified mutations as occurring ancestrally (before clonal divergence) or occurring on a descendent lineage.

We identified multiple well known driver mutations occurring in descendent lineages of the tumour phylogeny, including mutations in CDKN2A, BCL6 and ERBB2. Aberrant site specific expression patterns were concomitant with genomic changes. Furthermore, we identified instances of convergent evolution, including independent deletion of wild type RAD51B in a patient with a germline RAD51B mutation. Reconstruction of clonal phylogenies enabled inference of metastatic spread. In one patient, a minor subclone of a right ovary tumour acquired an ERBB2 amplification, then subsequently populated all other metastatic sites sampled by the experiment. Finally, from our analyses we concluded that in many HGSOvCa, genomic instability and associated copy number changes result in the deletion of a significant number of point mutations, with implications for phylogenetic reconstruction using traditional techniques.

Citation Format: Andrew McPherson, Andrew Roth, David Huntsman, Jessica McAlpine, Sohrab Shah. Phylogenetic portraits of high grade serous ovarian cancer [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-TECH-1119.