bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract AP29: BRCA1 RING DOMAIN–DEFICIENT PROTEINS PROMOTE PARP INHIBITOR AND PLATINUM RESISTANCE
Authors: Wang Yifan , Krais John J. , Bernhardy Andrea J. , Nicolas Emmanuelle , Cai Kathy Q. , Harrell Maria I. , Kim Hyoung H. , George Erin , Swisher Elizabeth M. , Simpkins Fiona , Johnson Neil
Published: June 2017

Although cancers harboring BRCA1 mutations initially respond well to platinum and poly(ADP-ribose)-polymerase inhibitor (PARPi) therapy, resistance invariably arises and is a major clinical problem. The BRCA1185delAG allele is a common inherited mutation located close to the protein translation start site, thought to produce a short peptide devoid of function. In this study, we utilized the SUM1315MO2 cancer cell line that harbors a hemizygous BRCA1185delAG mutation to study PARPi and platinum resistance. SUM1315MO2 cells were initially PARPi and cisplatin sensitive but readily acquired resistance. PARPi and cisplatin resistant clones did not harbor secondary reversion mutations. Rather, increased expression of a RING domain-deficient BRCA1 protein (Rdd-BRCA1) was required for resistance. Translation initiation occurred downstream of the frameshift mutation, likely at the BRCA1-Met-297 codon. In contrast to full-length BRCA1, Rdd-BRCA1 did not require BARD1 interaction for stability. Functionally, Rdd-BRCA1 formed irradiation-induced foci and supported RAD51 foci-formation. Ectopic overexpression of Rdd-BRCA1 promoted partial PARPi and cisplatin resistance in vitro and in vivo. Furthermore, Rdd-BRCA1 protein expression was detectable in recurrent carcinomas from germline BRCA1185delAG mutation carriers. Taken together, these results indicate that RING-deficient BRCA1 proteins are hypomorphic, and when expressed at high enough levels are capable of contributing to PARPi and platinum resistance.

Citation Format: Yifan Wang, John J. Krais, Andrea J. Bernhardy, Emmanuelle Nicolas, Kathy Q. Cai, Maria I. Harrell, Hyoung H. Kim, Erin George, Elizabeth M. Swisher, Fiona Simpkins and Neil Johnson. BRCA1 RING DOMAIN–DEFICIENT PROTEINS PROMOTE PARP INHIBITOR AND PLATINUM RESISTANCE [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr AP29.
Abstract AP31: TARGETING PD–L1/PD1 PATHWAY THROUGH BET PROTEIN INHIBITION IN EPITHELIAL OVARIAN CANCER
Authors: Zhu Hengrui , Bengsch Fee , Svoronos Nikolaos , Rutkowski Melanie R. , Bitler Benjamin G. , Allegrezza Michael J. , Yokoyama Yuhki , Bradner James E. , Conejo-Garcia Jose R. , Zhang Rugang
Published: June 2017

BACKGROUND: Expression of programmed death ligand 1 (PD-L1) is up-regulated in many cancers and has been found to suppress antitumor immunity through binding to its receptor programmed death 1 (PD-1). Blockade of PD-1/PD-L1 signaling axis enhances antitumor immunity in many cancers including epithelial ovarian cancer (EOC). Despite the importance of PD-L1 in tumor immunity, the epigenetic regulation of PD-L1 expression remains poorly understood.

AIMS: To determine the roles of epigenetic components in regulating PD-L1 gene expression and modulating antitumor immunity.

METHODS: Toward this goal, I screened a small molecule library of epigenetic inhibitors and examined their inhibition on PD-L1 expression in EOC cells to identify the positive hits. To further confirm PD-L1 inhibition in vivo, C57BL/6 mice are injected with luciferase expressing mouse ovarian cancer ID8 cells and treated with or without epigenetic inhibitors, PD-L1 expression in both tumor cells and immune cells are examined, tumor growth and survival are also monitored.

RESULTS: BET inhibitors suppresses both constitutive and IFNγ induced PD-L1 expression in EOC cells through targeting BRD4. Further ChIP-seq and ChIP assay demonstrate that BRD4 directly binds to PD-L1 gene promoter and regulated its transcription. BET inhibitor JQ1 suppresses PD-L1 expression in both tumor cells and immune cells including dendritic cells and macrophages in mice bearing ID8 mouse ovarian cancer cells. Moreover, the BET inhibitor suppresses the tumor growth and improves the survival of EOC bearing mice through activating antitumor T cells.

CONCLUSION: Taken together, we demonstrated that BRD4 can directly regulate PD-L1 expression in EOC cells by binding to the promoter of PD-L1 encoding gene, suppressing PD-L1 expression with BET inhibitors blocks PD1/PD-L1 signaling and enhances antitumor immunity in vivo. These findings indicate that pharmacological inhibition of BET proteins represent a new therapeutic strategy for EOC by targeting PD-L1 expression.

Citation Format: Hengrui Zhu, Fee Bengsch, Nikolaos Svoronos, Melanie R. Rutkowski, Benjamin G. Bitler, Michael J. Allegrezza, Yuhki Yokoyama, James E. Bradner, Jose R. Conejo-Garcia, Rugang Zhang. TARGETING PD–L1/PD1 PATHWAY THROUGH BET PROTEIN INHIBITION IN EPITHELIAL OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr AP31.
Abstract DPOC-002: A NOVEL CELL LINE BASED IMMUNOHISTOCHEMICAL TP53 EXPRESSION PATTERN CONTROL PANEL
Authors: Syed Viqar , Hussain Imran , Johnson Jeptha , Malafronte Patrick , Wells Justin , Zhou Yaling , Xing Deyin , Andersen John D.
Published: June 2017

BACKGROUND: TP53 gene mutation status is known to be manifested through distinct p53 immunohistochemical staining patterns; diffuse, “wild-type” and null. This stratified staining pattern is commonly utilized in subtyping ovarian and endometrial cancer subtypes as well as distinguishing between ovarian low- and high-grade serous carcinoma.

EXPERIMENTAL PROCEDURES: Three ovarian cancer cell lines consistently demonstrating either diffuse, wild-type or null p53 staining were utilized in the construction of an immunohistochemical control panel slide that highlights each TP53 expression pattern. Cell lines were expanded, harvested and resuspended in agarose gel and subsequently sectioned onto a microscope slide (Figure 1A). Procured tissue specimens were submitted along with either standard control tissue or the TP53 cell line control panel to three pathologists of varying experience.

RESULTS: Interobserver variability was demonstrated to be similar with the use of the TP53 expression panel (Fleiss kappa= 0.79 vs 0.76) and there was a net decrease in categorization errors. The TP53 cell line expression pattern control panel sections demonstrated consistent clean and easily interpretable diffuse, wild-type and null p53 staining (Figure 1B).

CONCLUSIONS: We developed a novel cell line-based TP53 expression pattern control panel with refined quality assurance potential that would act, as a minimum, a model for antibody optimization. This study suggests the addition of a cell line TP53 control panel could potentially increase the accuracy of identification for ovarian and endometrial cancer subtypes as well as ovarian low grade versus high-grade serous carcinoma distinction. This control panel has the potential to be utilized in other disease states where TP53 expression pattern assists in diagnosis.

Citation Format: Viqar Syed PhD, Imran Hussain, BSc, Jeptha Johnson MD, Patrick Malafronte MD, Justin Wells MD, Yaling Zhou PhD, Deyin Xing MD PhD, John D. Andersen DO. A NOVEL CELL LINE BASED IMMUNOHISTOCHEMICAL TP53 EXPRESSION PATTERN CONTROL PANEL [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr DPOC-002.
Abstract DPOC-007: PROGESTERONE/PR ERADICATES p53–DEFECTIVE CELLS IN THE FALLOPIAN TUBE EPITHELIUM BY INDUCTION OF NECROPTOSIS
Authors: Chu Tang–Yuan
Published: June 2017

Cervical Cancer Prevention Center, Department of Research, Tzu Chi Medical Center, Hualien, Taiwan, Republic of China.

Institute of Medical Sciences, Tzu Chi University, Taiwan, Republic of China.

The fallopian tube (FT) fimbriae, which are regularly exposed to ovulatory carcinogens, have been identified as the origin of high–grade serous ovarian carcinoma (HGSOC), with loss of p53 determined to be a universal and the earliest step of carcinogenesis. In previous studies, we have identified ROS in ovarian follicle is highly mutagenic and toxic to the fallopian tube fimbria that bath in the ovulatory follicular fluid (FF) after ovulation. We also found that loss of p53 renders fimbrial epithelial cells less vulnerable to the ROS stress, and that hemoglobin in ovulated FF could rescue the ROS–stressed fimbrial epithelial cells from apoptosis. Given that both ovulation and retrograde menstruation, the two proven risk factors for HGSOC, are commonplace in menstrual cycles, and that occurrence of tubal p53 signature is frequent but HGSOC is rare, we hypothesize that luteal–phase progesterone (P4) is responsible for clearance of p53–defective epithelial lesions as a natural protection. Herein, we show that P4 and progesterone receptor (PR) induce necroptosis of tubal epithelial cells in p53–null mice and in immortalized p53–deficient human fimbria epithelial cells through the TNF–α/RIPK1/RIPK3/p–MLKL pathway. The clearance acts regularly in the luteal phase of the menstrual cycle, recovering shortly thereafter, and can be augmented with P4 supplementation. With the inhibition of PR, the oviduct epithelium of Trp53–null mice escapes the clearance and, upon repeated ovulation exposures, accumulates DNA double–strand breaks. Through the induction of necroptosis of p53–deficient epithelial cells, luteal phase P4 prevents the transformation of the FT epithelium after ovulation. This protection can be augmented with P4 supplementation.

Citation Format: Tang–Yuan Chu, MD, PhD. PROGESTERONE/PR ERADICATES p53–DEFECTIVE CELLS IN THE FALLOPIAN TUBE EPITHELIUM BY INDUCTION OF NECROPTOSIS [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr DPOC-007.
Abstract DPOC-008: LIFESTYLE AND REPRODUCTIVE RISK FACTORS AND OVARIAN CANCER RISK BY p53 AND MAPK EXPRESSION
Authors: Harris Holly R. , Rice Megan S. , Shafrir Amy L. , Poole Elizabeth M. , Hecht Jonathan L. , Terry Kathryn L. , Tworoger Shelley S.
Published: June 2017

BACKGROUND: One recent model of ovarian cancer development divides ovarian cancer into two types. Type II tumors are fast growing, potentially arising from the fallopian tubes, and characterized by tubal precursor lesions with p53 mutations. Type I tumors are slow–growing, arising from the ovary, and characterized by KRAS, BRAF, and PTEN mutations. The purpose of this study was to evaluate the association between selected lifestyle and reproductive risk factors and risk of ovarian cancer defined by expression of p53 (as a marker of Type II disease) and mitogen–activated protein kinase (MAPK), which is upregulated by KRAS and BRAF (as a marker of Type I disease).

METHODS: Epithelial ovarian cancer cases with available tumor blocks and cancer–free controls were identified from the Nurses' Health Study (NHS) and NHS II prospective cohorts, and from the population–based New England Case–Control (NECC) study of ovarian cancer. We performed immunohistochemical assays for p53 and MAPK expression. Age– and multivariable–adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for the association between each lifestyle or reproductive risk factor (e.g. parity, oral contraceptive use, tubal ligation, age at menarche, menopausal status, age at menopause, hormone therapy use, and family history of ovarian cancer) and ovarian cancer using polytomous logistic regression.

RESULTS: 249 cases and 1051 controls from the NHS/NHS II and 77 cases and 857 controls from the NECC study were included in the analyses. Overall there were few significant differences in lifestyle or reproductive risk factors by p53 or MAPK tumor expression. Increasing parity was associated with a greater decreased risk of p53 negative tumors (OR=0.40; 95% CI=0.26–0.62) than p53 positive tumors (OR=0.85; 95% CI=0.46–1.57) (pheterogeneity=0.03). Family history of ovarian cancer was associated with risk of developing MAPK negative (OR=1.87; 95% CI=1.28–2.74) but not MAPK positive tumors (OR=0.76; 95% CI=0.46–1.23) (pheterogeneity<0.01). When p53 and MAPK expression were cross–classified family history was most strongly associated p53+/MAPK– expression (OR=2.46; 95% CI=1.42–4.28).

CONCLUSIONS: These findings provide evidence that parity and family history may be associated with tumor subtypes defined by p53 and MAPK expression. However, in future studies other immunohistochemical markers that more clearly define these subtypes should be considered.

Citation Format: Holly R. Harris, Megan S. Rice, Amy L. Shafrir, Elizabeth M. Poole, Jonathan L. Hecht, Kathryn L. Terry, Shelley S. Tworoger. LIFESTYLE AND REPRODUCTIVE RISK FACTORS AND OVARIAN CANCER RISK BY p53 AND MAPK EXPRESSION [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr DPOC-008.
Abstract KP02: STARING DOWN THE BARREL OF A TUBE AT THE ORIGINS OF OVARIAN CANCER
Authors: Drapkin Ronny
Published: June 2017

There is an emerging consensus that a majority of high-grade serous carcinomas, the most common type of ovarian cancer, are derived from PAX8-expressing cells in the distal fallopian tube. Careful histologic examination of fallopian tubes from BRCA1/2 mutation carriers has led to the identification of a morphological continuum that begins with a benign secretory cell, transitions to identifiable precursor lesions, and culminates in serous carcinoma. We have previously demonstrated the biologic plausibility of this hypothesis by showing that dysregulation of BRCA1/2 and TP53 in PAX8-expressing mouse or human fallopian tube secretory epithelial cells (FTSECs) can induce tumors that are genomically and phenotypically identical to human high-grade serous ovarian cancers.

While PAX8 serves as the basis for many of the fallopian tube-based models we have developed, little is known about its role during neoplastic transformation. PAX8 is a lineage-defining transcription factor that directs the development of the Müllerian duct (the female reproductive tract). Its expression is retained by nearly all high-grade serous carcinomas but it remains unknown whether alterations in the PAX8 cistrome contribute to ovarian carcinomas. Using whole transcriptome shotgun sequencing (RNA-Seq) after PAX8 knockdown and ChIP-Seq, we show that FTSECs and high-grade serous carcinomas are distinguished by marked reprogramming of the PAX8 cistrome. Interestingly, the majority of PAX8 binding peaks are found in intronic and intergenic regions of the genome rather than promoters. Genes that are significantly altered between FTSECs and carcinoma lines are enriched near PAX8 binding sites. These sites are also near TEAD binding sites, and these transcriptional changes may be related to PAX8 interactions with the TEAD/YAP1 signaling pathway. These data suggest that transcriptional changes after transformation in ovarian cancer are closely related to epigenetic remodeling in lineage-specific transcription factors.

Citation Format: Ronny Drapkin. STARING DOWN THE BARREL OF A TUBE AT THE ORIGINS OF OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr KP02.
Abstract MIP-043: OVARIAN CARCINOMA CDK12 MUTATIONS IMPAIR GENE-SPECIFIC POL II ELONGATION AND FAITHFUL REPAIR OF DNA DOUBLE STRAND BREAKS
Authors: Ekumi Kingsley M. , Paculova Hana , Lenasi Tina , Pospichalova Vendula , Bösken Christian A. , Rybarikova Jana , Bryja Vitezslav , Geyer Matthias , Blazek Dalibor , Barboric Matjaz
Published: June 2017

The Cdk12/CycK complex is a novel transcription elongation-associated kinase that promotes expression of a subset of RNA polymerase II (Pol II) genes, including those of the DNA damage response (DDR) network. CDK12 is mutated in many cancers, particularly in high-grade serous ovarian carcinoma (HGS-OvCa), where it is one of only nine genes with statistically recurrent somatic mutations. However, the influence of these mutations on the kinase and their link to cancerogenesis remain ill-defined. Here, we show that most CDK12 mutations interfere with formation of the complex, rendering the kinase inactive. By examining the mutations within the Cdk12/CycK structure, we find that they likely provoke structural rearrangements detrimental to Cdk12 activation. Our mRNA expression analysis of the patient samples containing the CDK12 mutations identifies coordinated down-regulation of key DDR genes, particularly those of the homologous recombination (HR) repair pathway. Moreover, we note that production of nascent HR gene transcripts is compromised significantly upon CDK12 and CYCK knockdown. Indeed, Cdk12 occupies these genes and promotes phosphorylation of the Pol II's C-terminal domain (CTD) at Serine 2 (Ser2-P), the hallmark of effective transcription elongation, indicating that the down-regulated genes are directly controlled by Cdk12/CycK. Functionally, we demonstrate that the mutant Cdk12 proteins fail to stimulate the faithful repair of DNA double strand breaks via HR. In summary, we provide molecular basis of how mutated CDK12 ceases to function in ovarian carcinoma. We propose that CDK12 is a tumor suppressor of which the loss-of-function mutations could elicit defects in HR-mediated and possibly other DNA repair pathways, leading to genomic instability underlying the genesis of HGS-OvCa.

Citation Format: Kingsley M. Ekumi, Hana Paculova, Tina Lenasi, Vendula Pospichalova, Christian A. Bösken, Jana Rybarikova, Vitezslav Bryja, Matthias Geyer, Dalibor Blazek and Matjaz Barboric. OVARIAN CARCINOMA CDK12 MUTATIONS IMPAIR GENE-SPECIFIC POL II ELONGATION AND FAITHFUL REPAIR OF DNA DOUBLE STRAND BREAKS [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr MIP-043.
Abstract MIP-059: MITOCHONDRIAL DYNAMICS AND DYSFUNCTION IN OVARIAN CANCER
Authors: Shin Dong-Hui , Dier Usawadee , Timmins Patrick F. , Kesterson Joshua , Phaeton Rebecca , Hempel Nadine
Published: June 2017

Altered mitochondrial function remains a key feature of many tumor cells and drives pathways such gene expression, metabolic and stress responses, cell cycle progression and resistance to apoptosis. Many chemotherapeutics activate programmed cell death and it is thought that mitochondrial dysfunction may be one mechanism by which cancer cells evade killing by these compounds. Screening the metabolic profiles of ovarian cancer cell lines and patient ascites-derived tumor cells reveals that ovarian cancers fall into unique bioenergetic subgroups. For example, Ovarian Clear Cell Carcinomas (OCCC) display high oxygen consumption rate and glycolytic flux compared to the more common high grade serous adenocarcinoma (HGSA) subtype. In addition, we show that a portion of HGSAs have severe mitochondrial dysfunction, that is marked by a decrease in mitochondrial respiration, a lack of response to the uncoupler FCCP and a concomitant reliance on alternate metabolic pathways. Moreover, this is accompanied by enhanced chemoresistance to Cisplatin and Taxol. The cause of mitochondrial dysfunction has been attributed to a number of factors, including deregulation in mitochondrial fission/fusion dynamics. Moreover, fission is an integral component of apoptotic and authophagy pathways. Interestingly, the observed HGSA mitochondrial dysfunction correlates with aberrant fusion/fission dynamics and expression of a low molecular weight variant of the mitochondrial fission protein Drp1. The potential significance of Drp1 in ovarian cancer etiology is highlighted by TCGA data, where more than 15% of HGSA samples display significant increases in Drp1 mRNA levels, and associated amplification of the Drp1 gene DNM1L. Whether this represents the shorter, potentially dominant-negative Drp1 variant identified in our work is currently under active investigation. Our data suggest that compromised mitochondrial function and fission/fusion dynamics may be a hallmark of a previously unidentified subgroup of highly chemoresistant EOCs and that this is associated with aberrant expression of the fission protein Drp1. Studies are underway to identify the molecular identity and regulation of short Drp1, and the mechanistic links to alterations in fission, metabolic switching and chemoresistance.

Citation Format: Dong-Hui Shin, Usawadee Dier, Patrick F. Timmins, Joshua Kesterson, Rebecca Phaeton and Nadine Hempel. MITOCHONDRIAL DYNAMICS AND DYSFUNCTION IN OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr MIP-059.
Abstract MIP-060: EPIGENETIC DYSREGULATION OF A HISTONE MARK REVEALS A METABOLIC VULNERABILITY IN OVARIAN CANCER
Authors: Hood Jagmohan , Novak Marián , MacDuffie Emily , Lester Jenny , Parkash Vinita , Mills Gordon B. , Karlan Beth Y. , Oren Moshe , Drapkin Ronny
Published: June 2017

High-grade serous ovarian cancer (HGSOC) is frequently complicated by the inevitable development of therapeutic resistance, and thus remains an incurable disease. Recent insights supporting the fallopian tube epithelium (FTE) as the tissue of origin and serous tubal intraepithelial carcinomas (STICs) as the precursor lesion for the majority of HGSOCs provide a necessary context to study the mechanisms that drive the development and progression of HGSOC. Understanding these key molecular processes is essential to inform the development of next generation therapies. In this study we investigated the role of the ubiquitin ligase RNF20 and histone H2B monoubiquitylation (H2Bub1) in serous tumorigenesis. H2Bub1, catalyzed largely by RNF20, is an epigenetic mark with tumor suppressor properties. Conversely, the loss of RNF20/H2Bub1 has been linked with cancer progression. By analyzing the TCGA data we found that heterozygous loss of RNF20 defines the majority of HGSOC tumors. Our IHC results show that H2Bub1 is lost or downregulated in a large proportion of STICs and invasive HGSOC tumors, implicating RNF20/H2Bub1 loss as an early event in serous ovarian cancer tumorigenesis. Functionally, we demonstrated that shRNA-mediated RNF20 knockdown, with concomitant H2Bub1 downregulation, was sufficient to increase cell migration and clonogenic growth of immortalized tubal epithelial cells as well as cells derived from invasive HGSOC. Subsequent proteomic profiling (RPPA), of RNF20/H2Bub1-depleted cells revealed pronounced changes in the steady-state levels of a number of metabolic and signaling pathways. In particular, two of the top differentially expressed proteins were glutaminase (GLS) and glutamate dehydrogenase (GLUD1/2), key enzymes in the glutamine metabolism pathway. These changes are predicted to result in elevated levels of glutamate that can fuel the TCA cycle, amino acid biogenesis, and/or glutathione production. We hypothesize that loss of RNF20/H2Bub1 rewires glutamine metabolism in cancer cells and leads to an increase in transamination and glutathione production which fuels the progression of HGSOC. In conclusion, our study identifies that loss of H2Bub1 is an early epigenetic event in HGSOC progression, which rewires glutamine metabolism and may represent a unique therapeutic vulnerability.

Citation Format: Jagmohan Hood, Marián Novak, Emily MacDuffie, Jenny Lester, Vinita Parkash, Gordon B. Mills, Beth Y. Karlan, Moshe Oren, and Ronny Drapkin. EPIGENETIC DYSREGULATION OF A HISTONE MARK REVEALS A METABOLIC VULNERABILITY IN OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr MIP-060.
Abstract MIP-076: A RECURRENT BCAM-AKT2 FUSION GENE LEADS TO A CONSTITUTIVELY ACTIVATED AKT2 FUSION KINASE IN HIGH-GRADE SEROUS OVARIAN CARCINOMA
Authors: Kannan Kalpana , Coarfa Cristian , Chao Pei-Wen , Luo Liming , Wang Yan , Brinegar Amy E. , Hawkins Shannon M. , Milosavljevic Aleksandar , Matzuk Martin M. , Yen Laising
Published: June 2017

High-grade serous ovarian cancer (HGSC) is among the most lethal forms of cancer in women. Excessive genomic rearrangements, which are expected to create fusion oncogenes, are the hallmark of this cancer. Using high-throughput RNAseq, we identify a cancer-specific gene fusion between BCAM, a membrane adhesion molecule, and AKT2, a key kinase in the PI3K signaling pathway. This fusion is present in 7% of the 60 patient cancers tested, a significant frequency considering the highly heterogeneous nature of this malignancy. Further, we provide direct evidence that BCAM-AKT2 is translated into an in-frame fusion protein in the patient's tumor. The resulting AKT2 fusion kinase is membrane-associated, constitutively phosphorylated, and activated as a functional kinase in cells. Unlike endogenous AKT2, whose activity is tightly regulated by external stimuli, BCAM-AKT2 escapes the regulation from external stimuli. Moreover, a BCAM-AKT2 fusion gene generated via chromosomal translocation using the CRISPR/Cas9 system leads to focus formation in both OVCAR8 and HEK-293T cell lines, suggesting that BCAM-AKT2 is oncogenic. Together, the results indicate that BCAM-AKT2 expression is a new mechanism of AKT2 kinase activation in HGSC. BCAM-AKT2 is the only fusion gene in HGSC that is proven to translate an aberrant yet functional kinase fusion protein with oncogenic properties. This recurrent genomic alteration is a potential therapeutic target and marker of a clinically relevant subtype for tailored therapy of HGSC.

Citation Format: Kalpana Kannan, Cristian Coarfa, Pei-Wen Chao, Liming Luo, Yan Wang, Amy E. Brinegar, Shannon M. Hawkins, Aleksandar Milosavljevic, Martin M. Matzuk, and Laising Yen. A RECURRENT BCAM-AKT2 FUSION GENE LEADS TO A CONSTITUTIVELY ACTIVATED AKT2 FUSION KINASE IN HIGH-GRADE SEROUS OVARIAN CARCINOMA [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr MIP-076.
Abstract NTOC-093: SYNTHETIC LETHAL APPROACHES TO TARGET ARID1A DEFICIENT OVARIAN CANCERS
Authors: Khalique Saira , Williamson Chris T. , Pemberton Helen , Wai Patty T. , Menon Malini , Brough Rachel , Leonidou Andri , Peck Barrie , Banerjee Susana , Natrajan Rachael C. , Lord Christopher J.
Published: June 2017

Epithelial ovarian cancer (EOC) remains the most lethal gynaecological malignancy in the Western world. Ovarian clear cell carcinoma (OCCC), a distinct histological subtype, has a notably poor prognosis in the advanced setting compared to patients with high-grade serous ovarian cancer (HGSOC). Understanding why these patients have a poor outcome may be due to the underlying genetic drivers and their response to treatment. Dysregulation of the SWI/SNF complex is one of the most commonly occurring defects in solid cancers. Mutations in ARID1A (AT-rich interactive domain-containing protein 1A), a gene that encodes for BAF250A, forming part of the SWI/SNF chromatin remodeling complex, rarely occur in HGSOC but are common in ovarian clear cell carcinomas. The vast majority of these are loss of function frameshift or nonsense mutations, resulting in loss of protein function. In addition, loss of ARID1A expression in tumour specimens has been associated with a shorter progression free survival and chemoresistance in ovarian clear cell carcinoma (OCCC).

Despite the understanding that ARID1A defects are associated with tumourigenesis, targeted therapy approaches that exploit this deficiency have not as yet been developed. Our aims were to identify ways of targeting ARID1A deficient tumours by performing a large-scale functional genomics screen to identify actionable synthetic lethal effects. Using a high-throughput combination drug screen with a plate library of 80 compounds and a phase 1 compound, in isogenic ARID1A null and wild type HCT116 cells, we have identified candidate therapeutic approaches to targeting ARID1A mutant tumours that could be assessed in proof of concept clinical trials. We have undertaken subsequent high throughput drug screens in isogenic ARID1A null and wild type MCF10A cells that in we have identified a series of novel synthetic lethal effects. Assessment of this combinatorial approach in in vivo models of ARID1A mutant cancers is now underway. In conclusion, we have identified clinically actionable combinatorial approaches that may provide additional therapeutic benefit for ARID1A deficient patients.

Citation Format: Saira Khalique, Chris T. Williamson, Helen Pemberton, Patty T. Wai, Malini Menon, Rachel Brough, Andri Leonidou, Barrie Peck, Susana Banerjee, Rachael C. Natrajan and Christopher J. Lord,. SYNTHETIC LETHAL APPROACHES TO TARGET ARID1A DEFICIENT OVARIAN CANCERS [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr NTOC-093.
Abstract NTOC-104: BEYOND RECIST1.1 : THE NEED FOR ALTERNATIVE DISEASE MEASUREMENT CRITERIA FOR CLINICAL TRIALS IN OVARIAN CANCER
Authors: Pepke Shirley , Rucker Trudy
Published: June 2017

BACKGROUND AND PURPOSE: The majority of ovarian cancer patients respond initially to platinum combination chemo therapy, however at least 70% will relapse and eventually die from recurrent platinum-resistant disease. Thus upon relapse, there is a high degree of interest in participation in clinical trials of novel treatments. However, the pattern of presentation of recurrent disease skews toward “non-measurable” by RECIST solid tumor response criteria, with a majority of patients presenting with diffuse, non-nodular disease and hence being excluded from participating in most trials. Yet these excluded patients may be the ones who would see most benefit from the tested drugs since drug efficacy would not be confounded with issues of penetration into bulky tumors. In addition, in cases where patients present with apparently isolated tumors that are amenable to measurement, the patient is currently forced to choose between surgical excision of the tumor, which retrospective studies suggest extends survival in appropriately selected cases, and keeping the tumor as measurable disease required for entry into a clinical trial. Finally, the current rapid development of targeted therapies, immunotherapies, and combinations means there are potentially many more trial opportunities than can be filled by the relatively small number of ovarian cancer patients, potentially slowing the translation from preclinical findings to actual patient treatment. Here we review the salient facts demonstrating the need for greater clinical trial access for patients with non-RECIST tumor presentation, issues of measuring tumor response, as well as some potential solutions.

METHODS: We used a literature search and an online patient survey to assess the impact that the RECIST requirements have on clinical trial participation by ovarian cancer patients. We also reviewed the literature for potential alternative approaches to tumor assessment that would be novel to either solid tumor trials as a whole or ovarian cancer specifically.

CONCLUSIONS: Expanding clinical trial access to ovarian cancer patients whose tumors do not meet RECIST requirements should accelerate progress in a way that benefits all stakeholders: patients, pharmaceutical companies, and researchers. Viable alternatives exist and more are under development. Ovarian cancer patients are eager to see these put into practice and are willing to help move this effort forward by participating in relevant validation trials. Adapting clinical trial structure and response criteria to accommodate non-measurable disease in ovarian cancer should be a high priority.

Citation Format: Shirley Pepke and Trudy Rucker. BEYOND RECIST1.1 : THE NEED FOR ALTERNATIVE DISEASE MEASUREMENT CRITERIA FOR CLINICAL TRIALS IN OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr NTOC-104.
Abstract NTOC-106: FAK INHIBITION RE–SENSITIZES PLATINUM–RESISTANT SEROUS OVARIAN CANCER
Authors: Bean Lisa M. , Sulzmaier Florian J. , Anderson Kristen M. , Tancioni Isabelle , Butcher Cheyenne R. , Uryu Sean , Jean Christine , Lawson Christine , Chen Xiao Lei , Kleinschmidt Elizabeth G. , Kolev Vihren N. , Pachter Jonathan A. , Stupack Dwayne G. , Schlaepfer David D.
Published: June 2017

Most ovarian cancer patients respond well to surgical debulking and platinum-taxol chemotherapy. However, ~80% of patients with a complete response to therapy will exhibit tumor recurrence, and in time develop platinum and chemotherapy-resistant disease. It is hypothesized that recurrent disease emanates from the regrowth of microscopic clusters of chemotherapy-resistant tumor cells - also termed cancer stem cells (CSCs). Here, we find that cisplatin chemotherapy elevates focal adhesion (FAK) tyrosine kinase phosphorylation (Y397 FAK) in 3D ovarian tumor spheroids. Notably, FAK is not known as a DNA-damage sensing kinase. Instead, FAK is linked to integrin adhesion-, migration-, and CSC-promoting signaling pathways. In mouse tumors, CP-taxol chemotherapy increases FAK Y397 phosphorylation and aldehyde dehydrogenase (ALDH-1A1, a known markers of CSCs) in tumor areas not associated with necrosis. FAK Y397 phosphorylation is constitutively-elevated in CP-resistant ovarian cancer cells and nanomolar levels of FAK inhibitor (VS-4718) block 3D colony cell growth. Oral VS-4718 administration to mice reduces CP-resistant orthotopic tumor burden with a concomitant decrease in tumor-associated ALDH activity and secondary tumor-initiating capacity. CRISPR-mediated FAK knockout or VS-4718 treated ovarian carcinoma cells exhibit diminished ALDH-1A1 expression. Importantly, co-administration of VS-4718 enhances the anti-tumor effectiveness of CP-taxol chemotherapy in an orthotopic CP-resistant mouse tumor model. As CP activates FAK and FAK signaling sustains ovarian carcinoma CSC phenotypes, our results support the future testing of FAK inhibitors in combination with CP to prevent recurrent and chemo-resistant ovarian cancer.

Citation Format: Lisa M. Bean, Florian J. Sulzmaier, Kristen M. Anderson, Isabelle Tancioni, Cheyenne R. Butcher, Sean Uryu, Christine Jean, Christine Lawson, Xiao Lei Chen, Elizabeth G. Kleinschmidt, Vihren N. Kolev, Jonathan A. Pachter, Dwayne G. Stupack, and David D. Schlaepfer. FAK INHIBITION RE–SENSITIZES PLATINUM–RESISTANT SEROUS OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr NTOC-106.
Abstract TMEM-022: LYSOPHOSPHATIDIC ACID IN OVARIAN CANCER EPITHELIAL–TO–MESENCHYMAL TRANSITION
Authors: Dia Vermont P
Published: June 2017

Lysophosphatidic acid (LPA) is a bioactive phospholipid found in elevated concentrations in ovarian cancer (OVCA) patients. The objective of this study was to define the mechanism of action by which LPA contributes to ovarian carcinogenesis focusing on epithelial-to-mesenchymal transition (EMT) and role of human macrophages. THP-1 human macrophages and A27801AP human OVCA cells were used and treated with LPA up to 40 µM for 24 h. In THP-1 human macrophages, LPA treatment led to a dose-dependent increase in IL-1β secretion from 333.5 pg/mL (untreated) to 581.9, 661.8 and 1270.1 pg/mL for 10, 20 and 40 µM LPA treatment. We then used the conditioned medium (CM) from THP-1 macrophages to determine the effect on A27801AP OVCA cells. LPA-treated THP-1 CM increased the expression of EMT transcription factors p65, Slug and Snail as compared to non-LPA-treated THP-1 CM and resting OVCA cells. When A27801AP OVCA cells were treated with LPA alone, 20 µM LPA led to the same significant increase in the expression of EMT transcription factors p65, Slug and Snail. In addition, LPA treatment reduced the expression of the epithelial marker E-cadherin while increasing the expression of mesenchymal markers N-cadherin and vimentin which might be associated with increased phosphorylation of extracellular regulated kinase 1/2. The data show the role of LPA in modifying not only OVCA cells but also macrophages that can be found in the tumor microenvironment to promote progression of OVCA by promoting EMT.

Citation Format: Vermont P Dia, Ph D. LYSOPHOSPHATIDIC ACID IN OVARIAN CANCER EPITHELIAL–TO–MESENCHYMAL TRANSITION [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr TMEM-022.
Abstract TMEM-025: IMPACT OF MESOTHELIN EXPRESSION ON THE METASTATIC SUCCESS OF OVARIAN CANCER
Authors: Hilliard Tyvette , Iwamoto Kyle , Loughran Elizabeth , Asem Marwa , Liu Yueying , Yang Jing , Tarwater Laura , Klymenko Yuliya , Johnson Jeff , Shi Zonggao , Stack M. Sharon
Published: June 2017

Ovarian cancer is the most lethal gynecological cancer in U.S. women. Poor 5-year survival rates (<30%) are due to presentation of most women at diagnosis with advanced stage disease with widely disseminated intraperitoneal metastasis. However, when diagnosed before metastatic propagation the overall 5-year survival rate is >90%. Metastasizing tumor cells grow rapidly and aggressively attach to the mesothelium of all organs within the peritoneal cavity, including the parietal peritoneum and the omentum, producing secondary lesions. Mesothelin (MSLN), a 40kDa glycoprotein that is over expressed in many cancers including ovarian and mesotheliomas is suggested to play a role in cell survival, proliferation, tumor progression and adherence. However, the biological function of mesothelin is not fully understood as MSLN knockout mice do not present with an abnormal phenotype. Conversely, MSLN has been shown to bind to the ovarian cancer antigen, CA-125, and thought to play a role in the peritoneal diffusion of ovarian tumor cells. Taking into consideration the potential importance of MSLN/CA-125 binding in ovarian tumor metastasis within the peritoneum, MSLN wild type (WT) and knockout (KO) mice were used to explore the role of mesothelin on the susceptibility of ovarian tumor cells to adhere to the mesothelium of the organs in the peritoneal cavity. An ex vivo peritoneal assay, using CA-125 positive human ovarian tumor cells OVCAR8-GFP and peritoneal explants from MSLN WT and KO mice demonstrated a decrease in OVCAR8-GFP cell adhesion to peritoneal tissues from MSLN KO mice compared to MSLN WT mice. Furthermore, allograft tumor studies using MSLN WT and KO mice injected intraperitoneally with fluorescently-tagged syngeneic murine ovarian cancer cells (ID8-RFP) was performed. Disease progression was evaluated post injection by fluorescent in vivo imaging prior to end point dissection (~8 weeks). Abdominal organs were dissected, imaged ex vivo and organ-specific tumor burden was quantified by tumor area. Tumor burden was significantly decreased in the liver and omentum of MSLN KO mice compared to MSLN WT mice. Together, the results demonstrate a loss of mesothelial cell-ovarian tumor cell adhesion in the omentum and peritoneum of mice that do not express MSLN.

Citation Format: Tyvette Hilliard, Kyle Iwamoto, Elizabeth Loughran, Marwa Asem, Yueying Liu, Jing Yang, Laura Tarwater, Yuliya Klymenko, Jeff Johnson, Zonggao Shi, and M. Sharon Stack. IMPACT OF MESOTHELIN EXPRESSION ON THE METASTATIC SUCCESS OF OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr TMEM-025.
The Effects of Physical Activity and Body Fat Mass on Colorectal Polyp Recurrence in Patients with Previous Colorectal Cancer
Authors: Park Jihye , Kim Jae Hyun , Lee Hyun Jung , Park Soo Jung , Hong Sung Pil , Cheon Jae Hee , Kim Won Ho , Park Ji Soo , Jeon Justin Y. , Kim Tae Il
Published: June 2017

We aimed to identify the effects of physical activity and body composition on colorectal polyp recurrence in patients with previous colorectal cancer. A total of 300 patients were selected randomly from the colorectal cancer survivor cohort of Severance Hospital (Seoul, Korea). Patients reported various recreational physical activities and received surveillance colonoscopy. Body composition was measured with a body composition analyzer. We compared patients who exercised for at least 1 hour/week (active) with those who exercised less frequently or not at all (sedentary). The active exercise group (n = 203) had a lower recurrence of advanced adenoma than the sedentary group (n = 97; 6.4% vs. 14.4%, P = 0.023). The prevalence of advanced adenoma recurrence decreased in an exercise dose-dependent manner (Ptrend = 0.019). In multivariate logistic analysis, the independent factors associated with advanced polyp recurrence were body fat mass [OR, 7.601; 95% confidence interval (CI), 1.583–36.485; P = 0.011] and active exercise (OR, 0.340; 95% CI, 0.143–0.809; P = 0.015). In Cox proportional hazards models, body fat mass (HR, 5.315; 95% CI, 1.173–24.083; P = 0.030) and active exercise (HR, 0.367; 95% CI, 0.162–0.833; P = 0.017) were the independent factors associated with cumulative advanced adenoma recurrence. In conclusion, exercising for at least 1 hour/week and low body fat mass were found to be related to lower rates of colorectal polyp recurrence in the surveillance of colorectal cancer survivors. Cancer Prev Res; 10(8); 478–84. ©2017 AACR.
Quantification and Dosing of Renal Replacement Therapy in Acute Kidney Injury: A Reappraisal
Authors: Clark William R. , Leblanc Martine , Ricci Zaccaria , Ronco Claudio
Published: June 2017

Background/Aims: Delivered dialysis therapy is routinely measured in the management of patients with end-stage renal disease; yet, the quantification of renal replacement prescription and delivery in acute kidney injury (AKI) is less established. While continuous renal replacement therapy (CRRT) is widely understood to have greater solute clearance capabilities relative to intermittent therapies, neither urea nor any other solute is specifically employed for CRRT dose assessments in clinical practice at present. Instead, the normalized effluent rate is the gold standard for CRRT dosing, although this parameter does not provide an accurate estimation of actual solute clearance for different modalities. Methods: Because this situation has created confusion among clinicians, we reappraise dose prescription and delivery for CRRT. Results: A critical review of RRT quantification in AKI is provided. Conclusion: We propose an adaptation of a maintenance dialysis parameter (standard Kt/V) as a benchmark to supplement effluent-based dosing of CRRT. Video Journal Club “Cappuccino with Claudio Ronco” at http://www.karger.com/?doi=475457
Extraskeletal Chondroma of the Index Finger: A Case Report
Authors: Saito Masato , Nishimoto Kazumasa , Nakayama Robert , Kikuta Kazutaka , Nakamura Masaya , Matsumoto Morio , Morioka Hideo
Published: June 2017

Extraskeletal chondroma is defined as a rare, benign, cartilaginous tumor arising from soft tissues such as tendons, tendon sheath synovia, and joint capsules with no continuity to the periosteum or bone cortex. In histopathologic findings, the tumor exhibits many lobular structures and some parts similar to hyaline cartilage. Therefore, it is sometimes difficult to differentiate this tumor from low-grade chondrosarcoma because of their similar histopathologic findings. In order to prevent recurrence, it is necessary to remove the tumor as a whole, including the capsule, so as not to leave any remnants of the tumor. In this article, we report our treatment experience with a case of extraskeletal chondroma in the index finger of a 63-year-old patient.
Auswirkungen von Flohsamen (Psyllium) auf Parameter des Glukosestoffwechsels: Eine Übersicht
Authors: Granitzer Esther , Meier Beat , Drexel Heinz , Saely Christoph H.
Published: June 2017

Ziel dieser Literaturübersicht war es, den klinischen Stellenwert von Flohsamen (Psyllium) und deren Auswirkungen auf Parameter des Glukosestoffwechsels zu bewerten. Hierzu wurde in den Datenbanken CAMbase, CAM-QUEST, Cochrane Library, EMBASE und PubMed die Literatur zur glukosesenkenden Wirkung von Flohsamen herangezogen und letztmalig am 16. September 2015 systematisch erfasst. Von ursprünglich 107 als potenziell relevant identifizierten Veröffentlichungen erwiesen sich 11 als randomisierte, kontrollierte klinische Studien, in denen 417 Testpersonen Psyllium eingenommen hatten. Das Phytotherapeutikum zeigte in 2 Studien signifikante Senkungen der Nüchternglukose. In 1 Studie konnte durch die Einnahme von Flohsamen der Hämoglobin-A1c (HbA1c)-Wert signifikant um 1,6% gesenkt werden. Signifikant Auswirkungen von Psyllium auf den postprandialen Glukosewert konnten in 4 Studien gemessen werden. Ebenfalls reduzierte Psyllium in 4 Studien den Insulinspiegel nach Nahrungsaufnahme signifikant. Der Jadad-Score für die ausgewerteten Publikationen lag im Durchschnitt bei 3 Punkten, das Minimum bei 1 Punkt, das Maximum bei 5 Punkten. Gegenwärtig ist die Evidenz aus publizierten, randomisierten Studien für eine glukosesenkende Wirkung von Flohsamen für eine behördliche Empfehlung oder eine Aufnahme in therapeutische Richtlinien ungenügend. Da aber in einigen, teilweise kleineren Studien positive Auswirkungen des pflanzlichen Arzneimittels auf Parameter des Glukosestoffwechsels beobachtet wurden, erscheint die Prüfung der glukosesenkenden Wirkung von Flohsamen in größeren, methodisch einwandfreien Studien sinnvoll.
Modelagem e simulação de um sistema massa-mola com 2 graus de liberdade
Authors: Cancian Caio Garcia , Domingues Pietro Teruya
Published: June 2017

O presente texto tem como objetivo apresentar a resolução e uma discussão dos aspectos teóricos envolvidos no Exercício de Modelagem e Simulação Computacional 2 (EMSC 2) de 2015, que fez parte da disciplina PME 3200 - Mecânica II.