bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A05: BRCA1 promoter hypermethylation loss in recurrent high-grade serous carcinoma.
Authors: Bisogna Maria , Dao Fanny , Olvera Narciso , Bacares Ruben , Zhang Liying , Levine Douglas A.
Published: May 2016

Objective: BRCA1 germline mutations are associated with improved ovarian cancer survival, yet secondary revertant mutations that impair chemo-sensitivity can develop after platinum-based therapy. BRCA1 promoter hypermethylation, present in ~10% of all high-grade serous carcinomas (HGSCs), is associated with reduced gene and protein expression. We hypothesize that BRCA1 promoter hypermethylation decreases in recurrent HGSCs compared with matched primary samples.

Methods: Primary, untreated HGSCs with known BRCA1 promoter methylation status and matched recurrent samples were macrodissected from archival slides. After DNA was extracted and bisulfite treated, pyrosequencing was performed across 11 CpG sites within the BRCA1 promoter to quantify methylation using a CLIA-approved assay. The methylation percentage was calculated from allele frequencies and 10% or greater is considered hypermethylated. Validation data were obtained from The Cancer Genome Atlas (TCGA) substudy of paired primary and recurrent HGSCs.

Results: Eleven patients with matched primary and recurrent tumors were evaluated. Six patients had hypermethylated primary tumors, with methylation percentages ranging from 35-69%. We found that BRCA1 promoter methylation decreased 16-95% in five recurrent samples compared to their primary tumors. One patient with a demethylated recurrent tumor had platinum refractory disease clinically and died 12 months after diagnosis. In contrast, the only patient with an increase (74%) in promoter methylation between primary and recurrent specimens is a long-term survivor alive with disease 14 years after diagnosis. There was negligible change in promoter methylation between primary and recurrent cases for the five unmethylated samples. Three of 17 paired samples from the ovarian TCGA substudy had BRCA1 promoter hypermethylation and showed a 20-50% decrease between primary and recurrent samples with a corresponding increase in BRCA1 gene expression.

Conclusion: BRCA1 promoter hypermethylation generally decreases between primary and recurrent HGSCs and can be associated with remarkable clinical outcomes. BRCA1 promoter methylation may be a marker of platinum response in the recurrent disease setting and can be assessed in prospective clinical trials. In addition to BRCA1 somatic revertant mutations, loss of BRCA1 promoter methylation may be another mechanism to restore BRCA1 function in recurrent disease.

Citation Format: Maria Bisogna, Fanny Dao, Narciso Olvera, Ruben Bacares, Liying Zhang, Douglas A. Levine. BRCA1 promoter hypermethylation loss in recurrent high-grade serous carcinoma. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A05.
Abstract A39: FOXO1 is a key determinant of progesterone receptor isoform-specific senescence programming in ovarian cancer cells.
Authors: Diep Caroline H. , Knutson Todd P. , Mauro Laura J. , Lange Carol A.
Published: May 2016

Progesterone promotes proliferation and pro-survival in the breast, but inhibits growth in the reproductive tract and ovaries. Herein, using progesterone receptor (PR) isoform-specific ovarian cancer models, we show that PR-A and PR-B promote expression of distinct gene sets that differ from PR-driven genes in breast cancer cells. In ovarian cancer models, PR-A primarily regulates genes independently of progestin, while PR-B is the dominant ligand-dependent isoform. Notably, FOXO1 and the PR/FOXO1 target-gene p21 are repressed by PR-A, but induced by PR-B. In the presence of progestin, PR-B, but not PR-A, robustly induced cellular senescence via FOXO1-dependent induction of p21 and p15. ChIP assays performed on PR-isoform specific cells demonstrated that while each isoform is recruited to the same PRE-containing region of the p21 promoter in response to progestin, only PR-B elicits active chromatin. Overexpression of constitutively active FOXO1 (FOXO1-AAA) in PR-A-only expressing cells conferred robust ligand-dependent upregulation of the PR-B-target genes GZMA, IGFBP1, and p21, and induced cellular senescence. Similar results were observed when PR-A was titrated into PR-B-containing cells. PR isoform-specific regulation of the FOXO1/p21 axis recapitulated in human primary ovarian tumor explants treated with progestin. Our data indicate a key requirement for FOXO1 (a PR-B-induced, but PR-A-repressed gene) in progesterone signaling to cellular senescence in ovarian cancer cells and reveal a novel mechanism for PR-target gene (FOXO1) control of hormone sensitivity. Ultimately, harnessing PR isoform-specific gene regulation in hormone-driven cancers may provide a means to therapeutically induce the protective actions of progesterone while blocking unwanted proliferative and pro-survival effects.

Citation Format: Caroline H. Diep, Todd P. Knutson, Laura J. Mauro, Carol A. Lange. FOXO1 is a key determinant of progesterone receptor isoform-specific senescence programming in ovarian cancer cells. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A39.
Abstract A49: Investigating the expression of inhibitory surface molecules in ovarian cancer tumor-infiltrating lymphocytes.
Authors: Chacon Jessica , Yamamoto Tori , Garrabrant Thomas , Kari Gabor , Best Andrew , Ye Qunrui , Powell Daniel
Published: May 2016

Ovarian cancer causes more deaths than any other cancer of the female reproductive system. However, novel therapies, including immunotherapy are now being utilized to treat this cancer. In addition, efforts have been made to identify and evaluate the subsets of cells within the tumor environment that correspond with patient overall survival. Although the presence of intraepithelial CD3+ T cells and CD8+ T cells have been correlated with patient survival and CD137, a co-stimulatory molecule, has been identified as a biomarker for tumor-reactive cells, studies have not thoroughly investigated the phenotype of the T cells, specifically the CD4+, CD8+, and CD137+ subsets. In our study, we used a multi-parameter flow cytometry to measure inhibitory molecules, Th1 cytokines, and the effector phenotype in the T-cell subsets. We observed that the CD4+ and CD8+ T cells found within the tumor environment express inhibitory receptors, very limited Th1 cytokine producing cells and a decreased expression of Granzyme B within the CD8+ subset. The CD137+ population also expressed inhibitory molecules, but was still able to exhibit an effector phenotype and comprise Th1 cytokine producing cells. In conclusion, using multi-parameter flow cytometry enabled us to investigate the expression of inhibitory molecules on the CD4+, CD8+, and CD137+ subsets and measure their effector phenotype. We found that the T cells express many inhibitory receptors and this may hinder their ability to become optimal effector cells that maintain tumor control. However, future studies utilizing antibodies that block these inhibitory receptors may increase the T cells' ability to exhibit an increased effector phenotype and contain more Th1 cytokine producing cells.

Citation Format: Jessica Chacon, Tori Yamamoto, Thomas Garrabrant, Gabor Kari, Andrew Best, Qunrui Ye, Daniel Powell, Jr. Investigating the expression of inhibitory surface molecules in ovarian cancer tumor-infiltrating lymphocytes. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A49.
Abstract A53: Combining oncolytic virotherapy with immunotherapy for ovarian cancer treatment.
Authors: McGray AJ Robert , Eppolito Cheryl , Stephenson Kyle , Pol Jonathan , Lichty Brian , Odunsi Kunle
Published: May 2016

While spectacular responses have been observed in some patients following cancer immunotherapy, the majority of responses are short-lived with ultimate tumor relapse. Therefore, it is crucial to identify strategies that will effectively synergize with immunotherapies to improve clinical outcome. Oncolytic viruses (OV) are replication-competent viruses that can infect and kill tumor cells, while also acting as potent immune adjuvants. Additionally, as OV can be engineered to express tumor antigens, we are investigating the use of OV as vaccine vectors with the capacity to enhance immune responses to defined tumor antigen targets. Based on these unique attributes of OV, we hypothesized that OV could be effectively combined with multiple immunotherapeutic strategies currently in clinical testing as a means of enhancing anti-tumor immunity and improving tumor growth control/treatment outcome. Targeting a model tumor antigen in a pre-clinical ovarian cancer model, we observed that delivery of oncolytic Maraba virus (MRB) following vaccination enhanced tumor-specific CD8+ T cell expansion and trafficking to the tumor microenvironment, reduced intratumoral Tregs and MDSC frequencies, and resulted in improved survival compared to vaccination alone. Additionally, when MRB was combined with adoptive T cell transfer (ACT) of tumor-specific CD8+ T cells, this combination resulted in improved persistence of the transferred T cells and enhanced tumor control compared to treatment with MRB or ACT alone. Lastly, a dramatic improvement in treatment efficacy was observed when MRB was combined with checkpoint blockade (anti-PD-L1) compared to either monotherapy. These data suggest that OV can effectively synergize with multiple cancer immunotherapies currently being explored. Our current studies are focused on combining OV with either vaccines or ACT strategies that target clinically relevant ovarian cancer antigens (WT1, Sp17, and NY-ESO-1) using syngeneic and humanized mouse models. Additionally, we are exploring the transcriptional profile of tumors treated with immunotherapy + OV to identify gene signatures that correlate with improved therapeutic efficacy.

Citation Format: AJ Robert McGray, Cheryl Eppolito, Kyle Stephenson, Jonathan Pol, Brian Lichty, Kunle Odunsi. Combining oncolytic virotherapy with immunotherapy for ovarian cancer treatment. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A53.
Abstract A72: Dissecting the role of NF-kappaB signaling in ovarian cancer tumor-initiating cells.
Authors: House Carrie D. , Annunziata Christina M.
Published: May 2016

Ovarian cancer is the most lethal gynecological malignancy in the United States with high morbidity and mortality due to recurrence and chemoresistance. Our data suggest tumor-initiating cells (TICs) play an important role in disease biology. We previously showed that a subset of ovarian cancer cells depends on NF-kappaB signaling, and that expression of NF-kappaB proteins is associated with poor survival. To investigate this pathway in TICs, we designed a novel method to enrich for TICs from cell lines and patient samples by culturing non-adherent, floating cells in stem cell conditions. Preliminary data show these cells have higher stem cell marker expression, are chemoresistant, and are more tumorigenic in nude mice compared to their adherent counterparts. Given that NF-kappaB expression correlates with a poor outcome in ovarian cancer, and NF-kappaB activity supports drug resistance and tumorigenicity, we hypothesize that NF-kappaB supports a TIC program responsible for ovarian cancer relapse. Preliminary data show TIC-enriched culture conditions increased NF-kappaB expression and activity in TICs and stimulation of NF-kappaB signaling enhanced chemoresistance and stem cell marker expression. Current studies focus on dissecting the role of individual NF-kappaB proteins in TICs using inducible shRNAs to measure changes in spheroid formation, chemoresistance, tumorigenesis, and disease relapse following chemotherapy in a xenograft model. Future studies will measure system level changes induced by these shRNAs, and identify a gene signature specific to NF-kappaB in ovarian TICs. Clarifying the nuances of NF-kappaB signaling in TICs will increase our understanding of ovarian cancer recurrence and may lead to improved therapeutic strategies.

Citation Format: Carrie D. House, Christina M. Annunziata. Dissecting the role of NF-kappaB signaling in ovarian cancer tumor-initiating cells. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A72.
Abstract A77: Validation of the EORTC QLQ-OV28 instrument for the assessment of quality of life in women with ovarian carcinoma in Mexico.
Authors: Gallardo-Rincon Dolores , Munoz-Montano Wendy , Leon David Cantu de , Coronel-Martinez Jaime , Morales Flavia , Onate-Ocana. Luis F.
Published: May 2016

Objective: Health-related quality of life (HRQL) is an important outcome measurement in Oncology. Our aim was to validate the Mexican-Spanish version of the European Organization for Research and Treatment of Cancer (EORTC) QLQ-OV28 questionnaire to assess HRQL in patients with Ovarian cancer (OC).

Patients and Methods: The QLQ-C30 and QLQ-OV28 instruments were applied to Mexican patients with OC at a cancer referral centre. Reliability and validity tests were performed, and test-retest analysis was carried out in a subgroup of patients.

Results: Two hundred fifty-two women were included in this cohort. Questionnaire compliance rates were high and the instrument was well accepted; internal consistency tests demonstrated good convergent and divergent validity. Cronbach's α; coefficients of 8 of 9 multi-item scales of the QLQ-C30 and of 6 of 8 scales of the QLQ-OV28 instruments were >0.7 (range, 0.22 to 0.89). Scales of the QLQ-C30 and QLQ-OV28 instruments distinguished among clinically distinct groups of patients; some were highly sensitive to change over time after the use of induction chemotherapy, and some were associated to overall survival.

Conclusion: The Mexican-Spanish version of the QLQ-OV28 questionnaire is reliable and valid for the assessment of HRQL in patients with OC and can be broadly used in clinical trials.

Citation Format: Dolores Gallardo-Rincon, Wendy Munoz-Montano, David Cantu de Leon, Jaime Coronel-Martinez, Flavia Morales, Luis F. Onate-Ocana. Validation of the EORTC QLQ-OV28 instrument for the assessment of quality of life in women with ovarian carcinoma in Mexico. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr A77.
Abstract B02: Oxidized hemoglobin promotes survival of ROS-stressed and DNA damaged fallopian tube epithelial cells with p53 loss, resulting in a copy number variation phenotype of HGSC.
Authors: Huang Hsuan-Shun , Hsu Che-Fang , Chu Tang-Yuan
Published: May 2016

Purpose: Ovulation is a strong risk factor for high grade serous carcinoma (HGSC) of ovary known to largely originate from the fallopian tube fimbriae. Previously, we have showed ROS in the mature follicular fluid (FF) is mutagenic and cytotoxic to fimbria epithelial cells, and induces DNA double strand breaks (DSB) in the context of p53 loss. We hypothesized that hemoglobin (Hb) in FF accumulated in cul-de-sac (CDS) after ovulatory bleeding may protect the bathed fimbria from cell death and enhance cancer initiation.

Results: Peritoneal fluids collected from the CDS after ovulation contained high level of oxidized Hb and ROS, so did ovarian FFs retrieved from IVF patients. When treating E6/E7-immortalized fimbria secretory cells (FE25) with FFs with various ROS levels ranging from 100-1200 μM of H2O2 equivalence, a positive correlation of Hb levels (ranging from 100-1100 μg/ml) in FF and cell viability was observed. This was further confirmed in treating FE25 cells with H2O2 where Hb dose-dependently rescued cell death. As a consequence, FE25 cells treated with either Hb-high FF or with H2O2 plus Hb accumulated high level of DSB and showed an extensive DNA copy number variation compatible with the copy number variation (CNV) phenotype of HGSC. The resulted DNA aneuploidy rates were 50±5% and 65±7% in FE25 treated with 500 μM H2O2 supplemented with 100 μg/ml Hb or 3% Hb-hgih FF, respectively; as compared to 15±2% at baseline and 31±8% with H2O2 only. In the case of primary fimbria epithelial cells the figures were 2±0.3% and 1.3±0.2%, respectively. Finally, the p53 deficiency dependent rescuing effect of Hb on ROS-stressed tubal epithelial cells, and the consequent CNV phenotype were confirmed ex vivo with oviducts of wild type and Trp53-null mice.

Conclusion: While ROS in FF induces DNA damage and cytotoxicity of p53-deficient fimbria epithelial cells, oxidized Hb in peritoneal fluid rescues cells from death and results in a CNV phenotype, a major characteristic of HGSC.

Citation Format: Hsuan-Shun Huang, Che-Fang Hsu, Tang-Yuan Chu. Oxidized hemoglobin promotes survival of ROS-stressed and DNA damaged fallopian tube epithelial cells with p53 loss, resulting in a copy number variation phenotype of HGSC. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B02.
Abstract B08: Genomics analyses of less common epithelial ovarian cancer subtypes.
Authors: Gorringe Kylie L. , Wakefield Matthew , Hunter Sally M. , Ryland Georgina L. , Cheasley Dane , Anglesio Michael S. , Christie Michael , Sharma Raghwa , Yoland Antill , Rowley Simone M. , Li Jason , Gilks Blake , Allan Prue E. , Stephens Andrew N. , Ananda Sumi , Pyman Jan , Koebel Martin , McAlpine Jessica , Gourley Charlie , Huntsman David G. , deFazio Anna , Bowtell David DL , Campbell Ian G. , Scott Clare
Published: May 2016

While the genomics of high-grade serous carcinoma are well-studied in large international consortia, the less common subtypes have been neglected. We have sought to rectify this gap by analyzing international collections of low-grade serous and mucinous ovarian carcinomas and their putative benign and borderline precursors.

Exome sequencing and copy number analysis of low-grade serous carcinomas (n=9) and serous borderline tumours (n=13) and targeted sequencing and copy number analysis in additional carcinomas (n=10) and borderline tumours (n=44) identified recurrent mutations in novel drivers such as EIF1AX and USP9X, as well as the known drivers KRAS, BRAF and NRAS. Copy number changes including 9p and 1p losses were significantly associated with progression from borderline to carcinoma. Exome and targeted sequencing analysis of mucinous carcinomas (GAMuT study) found a surprisingly high proportion (~50%) with TP53 mutations, and mutations in new drivers like RNF43 and ELF3. Despite similarities in early RAS/RAF pathway oncogenic drivers and CDKN2A disruption, the genetics of these two subtypes are otherwise distinct, suggesting differing etiologies and selective pressures.

We also present here the first whole-genome sequencing analysis of a high-grade mucinous ovarian carcinoma collected from multiple sites at autopsy (CASCADE study). The patient, aged just 41 when diagnosed with Stage I mucinous ovarian carcinoma, had a 26-month progression-free interval, including normal CA125 and CA19-9 measurements at 21 months. The primary tumor was mostly borderline in appearance, with only a small focus of carcinoma. At autopsy, the carcinoma was widespread in the body, and whole-genome sequencing data was obtained from deposits in the omentum, iliac lymph node, para-aortic lymph node and upper diaphragm. These data were compared to the primary ovarian tumor and nine other sites sampled at autopsy.

Citation Format: Kylie L. Gorringe, Matthew Wakefield, Sally M. Hunter, Georgina L. Ryland, Dane Cheasley, Michael S. Anglesio, Michael Christie, Raghwa Sharma, Antill Yoland, Simone M. Rowley, Jason Li, Blake Gilks, Prue E. Allan, Andrew N. Stephens, Sumi Ananda, Jan Pyman, Martin Koebel, Jessica McAlpine, Charlie Gourley, David G. Huntsman, Anna deFazio, David DL Bowtell, Ian G. Campbell, Clare Scott. Genomics analyses of less common epithelial ovarian cancer subtypes. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B08.
Abstract B16: Synthetic lethality by targeting EZH2 methyltransferase activity in ARID1A-mutated ovarian cancers.
Authors: Bitler Benjamin , Shih Ie-Ming , Zhang Rugang
Published: May 2016

ARID1A, a chromatin remodeler, shows one of the highest mutation rates across many cancer types. Notably, ARID1A is mutated in ~50% of ovarian clear cell carcinomas and ~30% of ovarian endometrioid carcinomas. To date, clinically applicable targeted cancer therapy based on ARID1A mutational status has not been described. Here we show that inhibition of the EZH2 methyltransferase acts in a synthetic lethal manner in ARID1A mutated ovarian cancer cells. ARID1A mutational status correlates with response to the EZH2 inhibitor. We identified PIK3IP1 as a direct ARID1A/EZH2 target, which is upregulated by EZH2 inhibition and contributes to the observed synthetic lethality by inhibiting PI3K/AKT signaling. Significantly, EZH2 inhibition causes regression of ARID1A mutated, but not wild-type, ovarian tumors in vivo. Together, these data demonstrate for the first time a synthetic lethality between ARID1A mutation and EZH2 inhibition. They indicate that pharmacological inhibition of EZH2 represents an urgently needed, novel treatment strategy for ARID1A mutated ovarian cancers.

Citation Format: Benjamin Bitler, Ie-Ming Shih, Rugang Zhang. Synthetic lethality by targeting EZH2 methyltransferase activity in ARID1A-mutated ovarian cancers. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B16.
Abstract B31: Circulating periostin as a potential biomarker to predict platinum-resistant epithelial ovarian cancer.
Authors: Ryner Lisa , Noyes Amy , Nazzal Denise , Vu Paul , Guan Yinghui , Lu Shan , Morimoto Alyssa , Brignoli Sue , Wang Yulei
Published: May 2016

Roughly a third of ovarian cancer patients are intrinsically resistant to platinum-based treatment. However, predictive and therapeutic strategies are lacking to treat these patients due to a poor understanding of the underlying molecular mechanisms. We previously identified and validated a “reactive stroma” gene signature that is associated with primary chemoresistance in epithelial ovarian cancers (EOCs). In addition this signature was further validated in an independent dataset and high expression level of the signature genes predicts shorter progression free survival following front line chemotherapy. One of the key components of this gene signature is periostin (POSTN), an extracellular matrix protein known for its role in a variety of tissue remodeling conditions as well as overexpression in many types of cancers. Interestingly, POSTN is also involved in aspects of allergic inflammation and is used as a circulating biomarker for TH2-driven asthma. To investigate whether circulating POSTN could be used to predict chemoresistance in EOC, we developed an ELISA assay for detecting circulating POSTN in serum and plasma. Serum POSTN levels were measured in panels of serum samples from 143 EOC patients, 102 normal healthy subjects (NHS) and from 126 patients with other cancers. The serum POSTN ELISA was sensitive down to 1.88ng/mL and POSTN was detected in the serum of all patients and NHS. Although the range of POSTN expression in the EOC patients was highly overlapping with that of normal healthy subjects, a positive correlation was observed with the stage of disease. Retrospective and prospective studies are underway to determine whether baseline serum-POSTN levels can predict chemoresistance in EOC patients. Our study may lead to the development of a novel diagnostic strategy for predicting response to chemotherapy in ovarian cancer.

Citation Format: Lisa Ryner, Amy Noyes, Denise Nazzal, Paul Vu, Yinghui Guan, Shan Lu, Alyssa Morimoto, Sue Brignoli, Yulei Wang. Circulating periostin as a potential biomarker to predict platinum-resistant epithelial ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B31.
Abstract B67: The impact of parity on the metastatic success of ovarian cancer.
Authors: Loughran Elizabeth A. , Phan Ryan , Leonard Annemarie K. , Tarwater Laura , Asem Marwa , Klymenko Yuliya , Liu Yueying , Yang Jing , Johnson Jeff , Ravosa Matthew , Stack. M. Sharon
Published: May 2016

Ovarian cancer is the most fatal gynecological cancer. Epithelial ovarian cancer (OvCa), the most common subtype, usually goes undetected until metastatic and often fatal stages of the disease. OvCa follows a unique form of metastasis, spreading through the peritoneal cavity and forming metastatic sites on the peritoneum. Epidemiologic data suggest that child-bearing, or parity, reduces a woman's risk of developing ovarian cancer, with more births providing greater protection. Despite the association of parity with a decreased incidence of ovarian cancer, very few studies have explored the relationship between parity and metastatic success. A recent study compared metastatic success to the omentum in 12-month-old C57Bl/6 retired breeders and 5-month-old virgin mice, reporting that parous mice are less susceptible to metastasis due to the parity-associated differences in the immune compositional profile in the omental fat band (Cohen et al. 2013). This tumor study compared mice of different ages and did not report specific numbers of pregnancies. To further investigate the role of parity number in OvCa metastasis, we designed a study that controls for age and compares mice with specific parity number. Three age-matched C57Bl/6 groups were evaluated: nulliparous (V), parous 1 (P1), and parous 3 (P3) mice. We tested the effect of parity on metastatic success in vivo with an allograft study using the C57Bl/6 syngeneic ID8 mouse ovarian surface epithelial cell line. ID8 ovarian cancer cells (106) were injected into the peritoneal cavity of V, P1 and P3 mice. In contrast to the results of Cohen at al. that utilized a different syngeneic ovarian cancer cell line, we found no significant difference in metastasis to the omentum in the parous animals, but significantly reduced metastasis to the fat-enveloped ovaries and visceral fat pads in the P3 mice. This suggests that the visceral fat adjacent to the uterus and ovaries in multi-parous animals is a unique environment, resilient to metastasis. Factors in fat tissue responsible for this phenomenon are being investigated.

Citation Format: Elizabeth A. Loughran, Ryan Phan, Annemarie K. Leonard, Laura Tarwater, Marwa Asem, Yuliya Klymenko, Yueying Liu, Jing Yang, Jeff Johnson, Matthew Ravosa, M. Sharon Stack. The impact of parity on the metastatic success of ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B67.
Abstract B70: Targeted activation of macrophages to limit ovarian cancer progression.
Authors: Barham Whitney , Wilson Andrew , Ortega Ryan , Saskowski Jeanette , Tikhomirov Oleg , Giorgio Todd , Khabele Dineo , Yull Fiona E.
Published: May 2016

Macrophages are a major population in the ovarian tumor microenvironment and are capable of exhibiting either pro- or anti-tumor effects. The overall outcome of macrophage interactions with tumor cells is a balance between anti-tumor immune responses and the pro-tumor effects of re-educated tumor associated macrophages (TAMs). Our goal is to develop a treatment that will shift the balance of responses from pro- to anti-tumor resulting in significant clinical benefit. Using macrophage-specific doxycycline-inducible transgenics, IkappaBalpha -/- and wild type bone marrow derived macrophages (BMDMs), and tumor-associated macrophages (TAMs) we have generated convincing evidence both in vitro and in vivo that activating nuclear factor-kappaB (NF-κB) signaling specifically in macrophages induces anti-tumor effects by direct and indirect mechanisms. We are testing two strategies to translate this important finding into clinical usage. The first is delivery of MTP-PE via liposomes that are taken up by macrophages resulting in increased NF-κB activity. This strategy has the advantage that a similar approach is in current clinical usage for osteosarcoma therapy. However, it may prove to have some limitations based on the relatively non-specific activation of macrophages that would be induced. Therefore, our second strategy, designed to increase the specificity of response, is the development of mannosylated nanoparticles that mediate delivery of siRNA specifically to a subset of macrophages, namely the mannose receptor expressing TAMs. We have investigated multiple siRNAs capable of modulating the NF-κB signaling pathways and have evidence that delivery of IκBα siRNA results in beneficial changes in the expression of target genes in macrophages to generate antitumor outcomes. We have promising data using a model of ovarian cancer progression in which ID8 tumor cells are introduced into the peritoneal cavity that supports our therapeutic concept. While further optimization will be necessary, we believe that these treatments have the potential to be used alone or, due to the induction of both direct tumor cytotoxic and immune stimulatory effects, could be used in combination with standard chemotherapy to improve responses of treatment resistant tumors or with T cell mediated therapy to improve outcomes via increased recruitment of T cells.

Citation Format: Whitney Barham, Andrew Wilson, Ryan Ortega, Jeanette Saskowski, Oleg Tikhomirov, Todd Giorgio, Dineo Khabele, Fiona E. Yull. Targeted activation of macrophages to limit ovarian cancer progression. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B70.
Abstract B76: Involuntary weight loss is an independent prognostic factor for overall survival and predicts better response to chemotherapy in high-grade serous ovarian cancer patients.
Authors: Sznurkowski J. Jan , Pawlowski Maciej , Kabata Pawel
Published: May 2016

High-grade serous ovarian cancer (HGSOC) is the most common and very aggressive histological type of this neoplasm. Most of the patients require platinum-based chemotherapy following primary surgical treatment.

Aim: to assess the prognostic value of involuntary weight loss between surgery and first cycle of chemotherapy.

Material and methods: Out of 73 patients surgically treated for HGSOC, 64 received adjuvant chemotherapy. Prognostic value of several clinico-pathological features was assessed, including change of body weight between the day of primary debulking surgery and 1st cycle of chemotherapy. Survival analyses included the Kaplan–Meier method, log-rank test and Cox proportional hazards model.

Results: The median follow-up was 47.25 months (range 17–79 months). Median change of body weight in the group of 64 patients who received chemotherapy was -3.5 kg (range from -33kg to +5kg). Higher weight loss values (median -5 kg, range: -1 to -33 kg) were observed in platinum-resistant patients (n=21) compared to platinum-sensitive ones (n=43) (median -3.5 kg, range: -5 to -14 kg) (p= 0.03). Weight loss between primary surgery and first cycle of chemotherapy was found to be independent prognostic factor for decreased OS (HR=3.8, CI 95%= 1.15-12.53, p=0.0285) and PFS (HR= 3.07; CI 95%= 1.28-7.38; p= 0.0123).

Conclusions: Prevention of weight loss and nutritional wasting in HGSOC patients planned for adjuvant chemotherapy might improve results of treatment. Further prospective trials on nutrition of this group of patients are needed.

Citation Format: J. Jan Sznurkowski, Maciej Pawlowski, Pawel Kabata. Involuntary weight loss is an independent prognostic factor for overall survival and predicts better response to chemotherapy in high-grade serous ovarian cancer patients. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr B76.
Abstract IA06: Regulation of BRCA1- and BRCA2-dependent DNA repair.
Authors: Durocher Daniel
Published: May 2016

High-grade serous epithelial ovarian cancers are strongly associated with defective homologous recombination (HR), a DNA repair pathway involved in the mending of DNA double-strand breaks (DSB) and in which the BRCA1, PALB2 and BRCA2 tumor suppressors play key roles. In late December last year, the first poly(ADP-ribose) polymerase (PARP) inhibitor, lynparza or olaparib as it is widely known was approved in Europe and in the US for the treatment of ovarian cancer in tumors with deleterious mutations in the BRCA1 and BRCA2 genes. The approval of olaparib marks a milestone in the development of targeted cancer therapies, as it is the first approved drug that is based on the concept of synthetic lethality. In my presentation, I will report the identification of a system that licenses the assembly of a BRCA1-PALB2-BRCA2 complex in the S and G2 phases of the cell cycle. This system plays a major role in restricting the activation of DNA repair by HR to these cell cycle phases and I will discuss the implication of this newly discovered regulatory pathway to our understanding of genome maintenance and PARP inhibitor therapy.

Citation Format: Daniel Durocher. Regulation of BRCA1- and BRCA2-dependent DNA repair. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr IA06.
Abstract IA12: Determinants of resistance and response in high-grade serous ovarian cancer.
Authors: Bowtell David D. L.
Published: May 2016

In contrast to other solid cancers, overall survival for patients with high-grade serous ovarian cancer (HGSC) is little changed over the last 30 years and it has been difficult to advance beyond platinum-based combination chemotherapy. As HGSC are driven by genomic copy number change rather than recurrent point mutation, we undertook whole genome sequence (WGS) analysis of a large HGSC cohort in order to survey structural variation at high resolution. Utilizing 114 tumors from 92 patients, we performed transcriptome, methylation, and miRNA expression analyses to support the WGS data, and compared resistant, refractory, and sensitive primary disease. We evaluated tumor and normal DNA samples from patients with primary refractory, primary resistant or primary sensitive disease to better understand the drivers of these clinical phenotypes. We also characterized paired pre-treatment chemosensitive and post-resistance samples, and end-stage HGSC obtained from patients who underwent a research autopsy. We found that gene breakage involving tumor suppressors such as NF1 and RB1 is a common form of inactivation in HGSC and in other circumstances contributes to acquired chemotherapy resistance in some patients. We found evidence of a chemotherapy footprint in the genome of recurrent tumor samples. We observed a striking degree of diversity of other mechanisms of acquired resistance, including multiple independent germline BRCA1 or BRCA2 reversion events in individual patients, loss of BRCA1 promoter methylation, a shift in molecular subtype to a desmoplastic phenotype, and a recurrent promoter fusion associated with overexpression of a driver of drug resistance, validated in an independent dataset. Collectively these findings underscore the plasticity of the HGSC genome and indicate that pre-empting resistance by modifying current first line therapy or countering it when it emerges will require a diversity of approaches.

Citation Format: David D. L. Bowtell. Determinants of resistance and response in high-grade serous ovarian cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr IA12.
Abstract IA21: Mutant p53 activities in tumor development.
Authors: Lozano Guillermina
Published: May 2016

Alterations in the p53 tumor suppressor gene stand out as the most common alteration in many cancers including 96% of ovarian serous carcinoma. The fact that most p53 alterations in tumors are missense mutations suggests that cells expressing mutant p53 have an inherent biologic advantage (often termed gain of function (GOF)) over tumors lacking p53. Mouse models directly examined the role of p53 mutants in tumorigenesis and show an increased invasiveness and aggressive nature of mutant p53 tumors as opposed to those lacking p53. An additional prerequisite for GOF is the stabilization of mutant p53 proteins by various signaling pathways. The emerging themes by which mutant p53 exhibits its gain of function are 1) through formation of mutant p53 complexes with other proteins that modify their activities (p63 and p73, for example), and 2) by interaction of mutant p53 with other transcription factors (SREBP and Ets2, for example) that bring a potent transcriptional activation domain to promoters not normally regulated by wild type p53. An understanding of the mechanisms that drive mutant p53 activities in ovarian serous carcinoma is needed.

Citation Format: Guillermina Lozano. Mutant p53 activities in tumor development. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr IA21.
Abstract PR07: Synchronous ovarian and endometrial carcinomas: The case for pseudo-metastasis.
Authors: Anglesio Michael S. , Wang Yi Kan , Maassen Madlen , Horlings Hugo M. , Bashashati Ali , Gilks Blake , Kommoss Stefan , Huntsman David G.
Published: May 2016

Background: Almost half of ovarian endometrioid histotype carcinomas present with concurrent endometrial carcinoma or pre-cancerous lesions. These “synchronous” ovarian and endometrial (SEO) tumors, when organ-confined and low-grade, consistently behave as two independent primary tumors, rather than a tumor-metastasis pair typical of advanced-stage carcinoma. Our study aims to investigate the ancestral relationship between ovarian and endometrial components of SEOs.

Methods: We identified a cohort of SEOs and performed targeted, with the Illumina Truseq Custom Amplicon assay, and exome-level, with Nugen Ovation Library System and Agilent SureSelect XT2 capture, library construction followed by massively parallel sequencing on illumina MiSeq or HiSeq.

Results: Despite complexities introduced as a result of sampling formalin fixed and paraffin embedded archival specimens we were able to confirm shared identical mutations, and thus a clonal relationship, between ovarian and endometrial tumors in all but one case.

Discussion: In simultaneous presentation of cancer of the endometrium and ovary from our series we observed strong evidence of a primary tumor and metastasis relationship. However, the clinical behavior of this series, and SEOs in general, defies the basic tenant of cancer metastasis as a dire prognosis. Curiously similar anomalies, where there is advanced stage yet favorable outcome, occur in other organ systems. We therefore suggest a generalizable process “pseudo-metastasis” through which cells can spread to microenvironment-compatible and physically accessible sites. This restricted metastatic process can occur in cells that lack the full complement of cancer-associated transformation hallmarks required for tissue invasion and hematogenous or lymphatic metastasis. This phenomenon may be an important early step in dissemination of apparent multi-focal benign lesions, pre-malignant lesions, and low-grade carcinomas.

This abstract is also presented as Poster B07.

Citation Format: Michael S. Anglesio, Yi Kan Wang, Madlen Maassen, Hugo M. Horlings, Ali Bashashati, Blake Gilks, Stefan Kommoss, David G. Huntsman. Synchronous ovarian and endometrial carcinomas: The case for pseudo-metastasis. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research: Exploiting Vulnerabilities; Oct 17-20, 2015; Orlando, FL. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(2 Suppl):Abstract nr PR07.
Abstract 07: Using copy number alterations to identify targeted therapies in a preclinical model of osteosarcoma
Authors: Breese Marcus R. , Sayles Leanne C. , Sweet-Cordero Alejandro
Published: May 2016

Osteosarcoma (OS) is an aggressive bone malignancy affecting approximately 400 pediatric patients in the United States annually. Compared with other pediatric cancers, OS has a low 5-year overall survival rate. There are few treatment options for patients that progress on standard therapy, making it important to identify new therapeutic targets for these high-risk patients. At the genomic level, OS is characterized by significant genomic instability, resulting in numerous copy number alterations (CNA) and structural variations (SV). Unfortunately, many of the CNAs and SV events are non-recurrent, making each disease highly patient-specific. We hypothesized that CNAs may be drivers of OS and that we could use patient-specific CNA profiles to identify actionable targets in OS. In order to test this in a preclinical setting, we have developed a robust program for generating and maintaining patient-derived xenografts (PDX) from patients with OS. In a pilot study of 3 patients, we used a combination of tumor/normal whole-genome sequencing (WGS) and commercial gene panel testing to identify potentially druggable targets using CNA. For samples tested with WGS, gene-level CNA was assessed for a number of clinically actionable genes. For each gene, CNA was determined using the normalized ratio of sequencing reads mapped to the gene in the tumor versus the normal sample. The degree of CNA was used to help prioritize potential targets. For the commercially tested samples, genes were either reported as amplified or not. Using these results to inform target selection, we treated each PDX with a drug matched to its corresponding CNA predicted target. In each sample, we saw a significant reduction in the growth rate of the PDX compared to vehicle or a non-matched drug. This suggests that using the patient-specific CNAs to identify drug targets may be an effective strategy in the treatment of OS.

Citation Format: Marcus R. Breese, Leanne C. Sayles, Alejandro Sweet-Cordero. Using copy number alterations to identify targeted therapies in a preclinical model of osteosarcoma. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Integrating Clinical Genomics and Cancer Therapy; Jun 13-16, 2015; Salt Lake City, UT. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(1_Suppl):Abstract nr 07.
Abstract 29: Concordance of somatic mutations found in primary tumors and plasma circulating-free DNA from early and late-stage colorectal cancer patients
Authors: Bray Steven M. , Ebert Philip J. , Calley John N. , Higgs Richard E. , Wulur Isabella H. , Wong Swee Seong , Horn Candice L. , Martinez Ricardo , Reinhard Christoph
Published: May 2016

Circulating-free DNA (cfDNA) holds great potential for non-invasive somatic mutation detection in cancer patients as a so-called “liquid biopsy”. A liquid biopsy is especially valuable when tumor tissue is not available and for longitudinal monitoring of tumor burden or emerging resistance. In such cases, tumor-specific mutations are not known a priori and in order to detect tumor-derived somatic mutations it is best to interrogate a broad panel of cancer genes. The primary obstacle to sequencing cfDNA with broad mutation panels is achieving the necessary limit of detection to identify small amounts of tumor-derived cfDNA relative to the predominant wild-type cfDNA in the plasma of cancer patients. Tumor-derived cfDNA levels correlate with tumor stage, also making it an important consideration when investigating the sensitivity of this approach. We demonstrate the detection of somatic variants in several cancer genes in the plasma of early and late-stage colorectal cancer (CRC) patients by deep sequencing (> 8,000X) the cfDNA and matched normal DNA of N=33 CRC patients using the AmpliSeq cancer panel. The AmpliSeq panel requires less than 10ng of input DNA and amplifies hotspot loci of 50 known cancer genes for next-generation sequencing (NGS). We observe at least one somatic mutation with greater than 0.1% variant allele frequency in the cfDNA of all 33 CRC patients. We also show the sensitivity of detecting tumor-derived somatic mutations in cfDNA by exome sequencing of the primary tumor tissue. We find higher sensitivity for tumor mutations in cfDNA of late-stage patients compared to early-stage patients. Overall, we demonstrate the feasibility of using NGS on a small sized cancer panel for identifying somatic mutations, including those with low variant allele frequency, in cfDNA of early and late-stage CRC patients. Although a cfDNA approach holds promise as a tool to aid in pre-clinical and clinical research, more work is needed to understand its performance under different assay and disease conditions.

Citation Format: Steven M. Bray, Philip J. Ebert, John N. Calley, Richard E. Higgs, Isabella H. Wulur, Swee Seong Wong, Candice L. Horn, Ricardo Martinez, Christoph Reinhard. Concordance of somatic mutations found in primary tumors and plasma circulating-free DNA from early and late-stage colorectal cancer patients. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Integrating Clinical Genomics and Cancer Therapy; Jun 13-16, 2015; Salt Lake City, UT. Philadelphia (PA): AACR; Clin Cancer Res 2016;22(1_Suppl):Abstract nr 29.