bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract A21: Increasing use of adjuvant radiation for parathyroid carcinoma is associated with improved survival outcomes: A population-based study
Authors: Cannon Richard B. , Carpenter Patrick S. , Buchmann Luke O. , Hunt Jason P. , Lloyd Shane , Hitchcock Ying , Monroe Marcus M.
Published: September 2020

Objectives: Parathyroid carcinoma is rare and treatment for these cancers varies between institutions. The primary purposes of this study were to use the Surveillance, Epidemiology, and End Results (SEER) database to evaluate current practice patterns in the use of adjuvant radiation for parathyroid cancers and to investigate the efficacy in a population-based setting.

Methods: There were 508 patients treated surgically for parathyroid cancer from 1973 to 2013 identified in the SEER database. Patients with metastatic disease and other prior malignancies were excluded. Three hundred and twenty-one patients (63%) had local disease, while 187 had regional lymph node involvement (37%). Of these patients, 78 (15%) were treated with adjuvant radiation. 5-year disease-specific survival (DSS) and overall survival (OS) were the primary outcomes.

Results: Treatment with adjuvant radiation therapy was significantly associated with improved 5-year DSS (94% versus 89%; p=0.045) and OS (81% versus 74%; p=0.036). Improved DSS and OS were significant after controlling for other known covariates on multivariate analysis (HR 0.59, 95% CI 0.44-0.87, p<0.001; HR 0.65, 95% CI 0.47-0.92, p<0.001). The percent utilization of adjuvant radiation for patients with parathyroid carcinoma has significantly increased through the study time period from 7% (1973 to 1986) to 11% (1987 to 2000) to 18% (2001 to 2013) (p=0.011).

Conclusion: Adjuvant radiation appears to provide a survival benefit for patients with parathyroid carcinoma. Utilization of adjuvant radiation is increasing over time for these patients.

Citation Format: Richard B. Cannon, Patrick S. Carpenter, Luke O. Buchmann, Jason P. Hunt, Shane Lloyd, Ying Hitchcock, Marcus M. Monroe. Increasing use of adjuvant radiation for parathyroid carcinoma is associated with improved survival outcomes: A population-based study [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A21.
Abstract A27: Differential protein-interactome of MYB-NF1B fusion in adenoid cystic carcinoma
Authors: Humtsoe Joseph O. , Kim Hyun-Su , Soucheray Margaret , Swaney Danielle , Ha Patrick K.
Published: September 2020

Chromosomal translocations occur frequently in adenoid cystic carcinomas (ACC). In salivary gland ACC, the commonly identified rearrangement occurs at chromosome t(6:9), resulting in the fusion of the transcription factor genes, MYB and NF1B. The gene fusion encoding a chimeric MYB-NF1B is a unique genetic feature, regarded as a hallmark in ACC carcinogenesis. Although MYB-NF1B may be involved in the deregulation of MYB expression and its downstream gene targets, the precise role of MYB-NF1B in the development and maintenance of ACC remains to be clearly defined. Here, we engineered an inducible system to express either MYB or MYB-NF1B in ACC-01 cells, which express low levels of endogenous MYB but not MYB-NF1B, to study the molecular and mechanistic role of MYB-NF1B. Immunoprecipitation and mass spectrometry analysis revealed the presence of previously unreported MYB- and MYB-NF1B-interacting partners, including vimentin and nuclear myosin (MYO1C). These interactions were positively validated in several patient-derived xenograft models of ACC. Interestingly, MYB and MYB-NF1B interaction with vimentin and MYO1C appeared to be differentially regulated, and altering vimentin expression reduces MYB levels, while maintaining relatively steady levels of MYB-NF1B. MYO1C is involved in transcriptional regulation, and altered MYB-NF1B binding activity with nuclear myosin may modulate downstream gene targets. While detailed further study is needed, these findings suggest a potential distinct function of MYB-NF1B that may play an important role in ACC pathogenesis.

Citation Format: Joseph O. Humtsoe, Hyun-Su Kim, Margaret Soucheray, Danielle Swaney, Patrick K. Ha. Differential protein-interactome of MYB-NF1B fusion in adenoid cystic carcinoma [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A27.
Abstract B02: Efficacy of EPA-enriched supplement compared with standard formula on body weight changes in malnourished head and neck cancer patients undergoing surgery: A randomized study
Authors: Jantharapattana Kitti , Orapipatpong Orachat
Published: September 2020

Background: Eicosapentaenoic acid (EPA) containing nutritional supplement can reverse weight loss and increase lean body mass in a perioperative period of head and neck cancer patients. There is no randomized study to clinically compare an EPA-enriched supplement over a conventional supplement in head and neck cancer patients. Thus the aim of this study was to compare an EPA-enriched supplement with a conventional supplement in malnourished head and neck cancer patients following surgery. The primary outcome of this study was defined as perioperative weight changes, with postoperative complications a secondary outcome.

Methods: The patients were stratified into 4 groups based on the extent of their surgery: primary tumor resection or neck dissection, primary tumor resection and neck dissection, primary tumor resection and flap reconstruction, and primary tumor resection and neck dissection and flap reconstruction. Pretreatment randomization was conducted in each stratified group for the selection of nutritional supplement, whether EPA-enriched or standard formula. The supplements were prescribed 7 days preoperative through 14 days postoperative. Body weight and composition including serum parameters were measured from 7 days preoperative until 4 months postoperative. The hospitalized courses were recorded.

Results: Thirty-one patients in each group consumed EPA-enriched and standard formula supplements. There were no significant body weight or composition changes perioperatively. From 7 days before surgery to 4 months after surgery, mean body weight reduced by 2.95 (SD 4.70) kg and 2.82 (SD 4.78) kg in the EPA-enriched and standard formula groups, respectively. The mean overall patient weight loss was 2.89 kg or 5% throughout the period of study. No significant differences in lean body mass and body composition changes from the beginning to the end of the study were observed between the groups. No significant differences in the hospitalized days and postoperative complications were observed.

Conclusions: Body weight changes in malnourished head and neck cancer patients following surgery were not influenced by EPA additives to perioperative nutritional supplements.

Citation Format: Kitti Jantharapattana, Orachat Orapipatpong. Efficacy of EPA-enriched supplement compared with standard formula on body weight changes in malnourished head and neck cancer patients undergoing surgery: A randomized study [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr B02.
Abstract B09: Inactivating the EGFR-Arf1 axis by HDAC-targeted therapy to suppress invasiveness of head and neck squamous cell carcinoma
Authors: He Leilei , Gao Lixia , Lang Liwei , Shay Chloe , Teng Yong
Published: September 2020

Histone deacetylase (HDAC)-targeted treatment has the great potential to treat head and neck squamous cell carcinoma (HNSCC). However, little has been reported regarding the beneficial role of HDAC inhibition in anti-HNSCC therapy and the underlying molecular mechanisms remain elusive. Here, we demonstrate that ADP-ribosylation factor 1 (Arf1), a small GTPase coordinating vesicle-mediated intracellular trafficking, can be inactivated by HDAC inhibitors TSA and PXD101, through histone acetylation-independent degradation of epidermal growth factor receptor (EGFR) in HNSCC cells. Mechanistically, activated Arf1 (GTP-Arf1) is maintained by binding to phosphorylated EGFR on the cancer cell plasma membrane. Decreased EGFR phosphorylation is associated with reduced EGFR protein levels in the presence of HDAC inhibitors, which inactivates Arf1 and eventually inhibits its dependent invasion in HNSCC cells. This novel finding represents the first example of modulating the EGFR-Arf1 complex in HNSCC by small-molecule agents. Our insights not only explore the critical role of the EGFR-Arf1 complex in driving HNSCC progression, but also shed light onto the molecular events accounting for HDAC-targeted therapy.

Citation Format: Leilei He, Lixia Gao, Liwei Lang, Chloe Shay, Yong Teng. Inactivating the EGFR-Arf1 axis by HDAC-targeted therapy to suppress invasiveness of head and neck squamous cell carcinoma [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr B09.
Abstract B29: Intraoperative identification of critical vascular landmarks of the lateral oropharynx and tongue base using transoral robotic ultrasound (TORUS)
Authors: Liu Wen P. , Holsinger F. Chris , Vendra Varun
Published: September 2020

Transoral robotic surgery (TORS) is an expanding domain of minimally invasive surgery, which has been employed since 2009 in the United States primarily for the management of upper aerodigestive tract tumors (1). Tongue base reduction is an emergent application of TORS in obstructive sleep apnea (2). The technique uses the da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA, USA) to deliver a camera and instruments on three robotic arms. Identification of large-caliber blood vessels emanating from the external carotid artery is a critical step in TORS for tongue base and lateral oropharynx disease. Specifically, control of the lingual artery and facial artery branches is necessary for safe surgical dissection (3). Previously, the use of ultrasound has been described in TORS for the intraoperative localization of retropharyngeal lymph nodes (4-6). One case series in the literature has described the use of a handheld ultrasound probe in TORS for pharyngeal and base of tongue tumors (7). We describe the use of a novel miniaturized ultrasound probe (Mindray North America, San Jose, CA, USA) capable of being manipulated by the da Vinci arm to allow intraoperative transoral robotic ultrasonography (TORUS). The ergonomics of this system was evaluated in human cadavers, followed by an efficacy trial in a porcine model. Two surgeons, one experienced (FCH) and one novice (VV), performed ultrasound-guided identification of the lingual and buccal arteries. Time to identification was measured. Mean time in seconds for the localization of the buccal artery was 53.0 for the experienced robotic surgeon versus 27.5 for the novice surgeon (p=0.10), and 55.0 versus 268.0, respectively, for the lingual arteries (p=0.003). Herein, we show the feasibility of TORUS to identify the large-caliber blood vessels of the oral cavity and oropharynx during TORS. This platform may allow for safer dissection, without a significant increase in operative time or need to interrupt the robotic setup. Future directions include human clinical trials, measurement of tumor volume, depth of invasion, and identification of additional surgical landmarks.

Citation Format: Wen P. Liu, F. Chris Holsinger, Varun Vendra. Intraoperative identification of critical vascular landmarks of the lateral oropharynx and tongue base using transoral robotic ultrasound (TORUS) [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr B29.
Abstract B32: Impact of cancer-associated fibroblasts on head and neck cancer stem cells
Authors: Neal Molly E. Heft , Owen John Henry J. , Spector Matthew E. , Carey Thomas E. , Prince Mark E.P. , Chinn Steven B.
Published: September 2020

Background: The tumor microenvironment (TME) is made up of epithelial cancer cells and mesenchymal stromal cells including tumor-infiltrating lymphocytes, cancer-associated fibroblasts (CAFs) and endothelial cells. Within the cancer cell population are cancer stem cells (CSC), a subpopulation of cells defined as having the capacity for self-renewal, tumorigenesis, and the ability to recapitulate a heterogeneous tumor. The interaction of the TME with cancer cells remains of interest. The focus of this study is to investigate the effect of patient-derived CAFs on head and neck CSC and tumor activity.

Methods: Patient-derived head and neck cancer cell lines and patient-derived fibroblasts lines have previously been established by our group. Tumor cells were grown alone or in combination with patient-matched fibroblasts in a coculture chamber system, allowing for mixture of media but not cells. Scratch tests were performed and closure rates were compared between the two conditions (tumor cells alone and coculture). Tumor cells were then grown alone or in direct contact with matched fibroblasts for one week. Cancer cells were selected for based on epithelial cell adhesion molecule (EpCAM) status and in vitro tumor growth and stem cells percentages (defined as proportion of CD44-high and ALDH-positive cells) were calculated.

Results: Patient-derived cancer cells cocultured with matched fibroblasts showed a significant increase in closure rates compared with tumor cells alone at three defined time points (p=0.03-0.002). Coculture conditions resulted in greater in vitro tumor growth after one week (6.4-fold vs. 3.7-fold increase) and an increased proportion of CD44-high tumor cells (9% vs. 5%). The effect of coculture on ALDH-positive percentages was variable.

Conclusion: CAFs have previously been shown to potentiate tumorigenesis and metastases. We validated these findings with matched patient derived tumor cells and CAFs. We were then able to demonstrate that CAFs increase the proportion of head and neck CSC, suggesting the mechanism for CAF-associated increased tumor activity may be mediated through CSC. Further studies investigating the relationship between CAFs and CSC are warranted.

Citation Format: Molly E. Heft Neal, John Henry J. Owen, Matthew E. Spector, Thomas E. Carey, Mark E.P. Prince, Steven B. Chinn. Impact of cancer-associated fibroblasts on head and neck cancer stem cells [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr B32.
Abstract B38: Identification of stage-wise miRNAs signature as potential biomarker in head and neck squamous cell carcinoma
Authors: Kumar Sugandh , Dixit Anshuman
Published: September 2020

The head and neck squamous cell carcinoma (HNSCC) is one of the predominant causes of cancer-related casualties globally. The high mortality rate of HNSCC is due to late diagnosis, and the overall survival rate is less than 50%. The early detection of a primary tumor and prevention of relapse are the major research challenges associated with various cancer including HNSCC. However, currently, not one molecular marker has been widely accepted for routine use in managing patients with HNSCC. Therefore, a study relating the association between clinical stages and different coding/noncoding expression profiles is very much required to identify the potential biomarker for early detection and therapeutics. In the current study, we have analyzed TCGA transcriptomics (i.e., miRNAs, mRNAs) profile to extract meaningful molecular signature in different TNM stages of HNSCC. Further, we used machine learning and other regression approaches to identify the signature miRNAs as a biomarker in various stages of cancer. The analysis revealed uncovered miRNAs with stage-dependent alterations in expression (has-miR-31, miR-143, miR-202, miR-135b, let-7, etc.) specifically expressed in early clinical stages whereas (miR-636, miR-1, miR-99a and miR-3934) specifically expressed in later stages. Kaplan-Meier survival analysis also revealed that some of the identified miRNA used as a potential prognostic biomarker. The top enriched regulatory genes involved in ECM degradation, Nicotine Degradation III, EMT, Integrin signaling and IL-10 in early stages were at later stage pathways, i.e., glucose metabolism. The combination of stage-specific miRNAs could be used for the target of oncogenesis and chemoresistance pathways. Initial stage biomarkers may prove to be essential tools in the timely diagnosis of the disease and improved overall survival outcome. We hope the current study for biomarker identification will open new opportunities for the development of effective diagnostic and therapeutic drug for HNSCC in the future.

Citation Format: Sugandh Kumar, Anshuman Dixit. Identification of stage-wise miRNAs signature as potential biomarker in head and neck squamous cell carcinoma [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr B38.
Abstract IA04: Novel approaches to study the tumor-stroma interaction and translate immune-directed therapies
Authors: Jimeno Antonio
Published: September 2020

Cancer research has long been hampered by the limitations of the current model systems. Both cultured cells and mouse xenografts grow in an environment highly dissimilar to that of their originating tumor, frequently resulting in promising treatments that are ultimately clinically ineffective. The development of highly immunodeficient mouse strains into which human immune systems can be engrafted can help bridge this gap. The need for more representative tools to investigate the human tumor microenvironment (TME) has led to the development of humanized mouse (HM) models. HM allow researchers to examine xenograft growth in the context of a human immune system and resultant tumor microenvironment, and recent studies have highlighted the increased similarities in attendant tumor structure, metastasis, and signaling to those features in cancer patients. This setting also facilitates the examination of investigational cancer therapies, including new immunotherapies.

We have developed an improved method for generating mismatched humanized mice (mHM), using a dual infusion of human hematopoietic stem and progenitor cells (HSPCs) and mesenchymal stem cells (MSCs), isolated from cord blood and expanded in vitro. Engraftment with both HSPCs and MSCs produces mice with almost twice the percentage of human immune cells in their bone marrow, compared to mice engrafted with HSPCs alone, and yields 9- to 38-fold higher levels of mature peripheral human immune cells. When head and neck squamous cell carcinoma (HNSCC) tumors are implanted on the flanks of HSPC-MSC engrafted mice, human T cells, B cells, and macrophages infiltrate the stroma of these tumors at 2- to 8-fold higher ratios. In dually HSPC-MSC engrafted mice we also more frequently observed additional types of immune cells, including regulatory T cells, cytotoxic T cells, and MDSCs. Higher humanization was associated with in vivo response to immune-directed therapy. The complex immune environment arising in tumors from dually HSPC-MSC engrafted mice better resembles that of the originating patient’s tumor, suggesting an enhanced capability to accurately recapitulate a human TME.

This review presentation also discusses other recent advancements in the generation and application of HM models, such as engineering mouse strains expressing human cytokines or HLA proteins, and implanting human bone, liver, and thymus tissue to facilitate immune cell maturation and trafficking. Finally, we discuss how these improvements may help direct future HM model cancer studies, and their potential in generating clinically relevant treatments.

Citation Format: Antonio Jimeno. Novel approaches to study the tumor-stroma interaction and translate immune-directed therapies [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr IA04.
Abstract IA14: Targeting the DNA damage response in head and neck cancers
Authors: Yap Timothy A.
Published: September 2020

The discovery that BRCA1/2 mutant cancer cells are exquisitely sensitive to inhibition of poly(ADP-ribose) polymerase (PARP) has ushered in a new era of research on biomarker-driven synthetic lethal treatment strategies for different cancers. The therapeutic landscape of antitumor agents targeting the DNA damage response (DDR) has rapidly expanded to include inhibitors of other key mediators of DNA repair and replication, such as ATM, ATR, CHK1 and CHK2, DNA-PK, and WEE1. Efforts to optimize these therapies are ongoing across a range of cancers, including head and neck cancer. These approaches have involved evaluation of molecular predictive biomarker of response beyond BRCA1/2 mutations, and the development of rational, tolerable combinations with novel molecularly targeted agents to create a BRCAness phenotype, other DDR inhibitors, and immune-checkpoint inhibitors.

Citation Format: Timothy A. Yap. Targeting the DNA damage response in head and neck cancers [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr IA14.
Abstract PR06: Tumor-infiltrating B cells colocalize with CD4 T effector cells within tertiary lymphoid structures to present antigen and educate the antitumor immune response in human primary tumors
Authors: Ruffin Ayana T. , Cillo Anthony R. , Kunning Sheryl , Ferris Robert L. , Vignali Dario A.A. , Bruno Tullia C.
Published: September 2020

Despite the success of checkpoint blockade immunotherapies, i.e., anti-PD1, only 20% of patients produce a durable response to these treatments. Thus, a need exists to develop additional therapeutic strategies to treat these patients, which includes evaluation of other tumor-infiltrating immune cells that could further augment the CD8+ and CD4+ T-cell response. Tumor-infiltrating B cells (TIL-B) represent a possible target for immunotherapy due to their predominance in the tumor microenvironment and crucial role in the immune response. In fact, current evidence suggests an antitumor role for TIL-Bs. Specifically, detection of TIL-Bs within tertiary lymphoid structures (TLS) correlates with both increased survival in patients with solid tumors and enhanced response to anti-PD1 immunotherapy. We hypothesize that TIL-Bs help generate potent, long-term immune responses against cancer by presenting tumor antigens to CD4 TILs within TLS. Utilizing single-cell RNAseq and high-level flow cytometry, we observed increased numbers of activated TIL-Bs in the primary tumors of head and neck squamous cell carcinoma (HNSCC) and non-small cell lung cancer (NSCLC) patients. We further assessed the location of TIL-Bs within the TME and determined that they predominantly sit adjacent to CD4+ tumor-infiltrating lymphocytes (TILs) within TLS. Thus, we generated an antigen presentation assay in vitro, and we observed increased CD4+ TIL responses when TIL-Bs presented autologous tumor antigens. Further, there was a differential impact on CD4+ TIL phenotype; specifically, if TIL-Bs were activated (CD27+), the CD4+ TILs were T helper (anti-tumor) CD4+ T cells and if the TIL-Bs were nonactivated (CD27-), the CD4+ TILs were T regulatory cells (protumor). These data suggest that TIL-Bs influence the phenotype and function of CD4+ TILs in patient tumors within TLS. Ultimately, results from this study will increase effective targeting of TIL-Bs within patient primary tumors.

Citation Format: Ayana T. Ruffin, Anthony R. Cillo, Sheryl Kunning, Robert L. Ferris, Dario A.A. Vignali, Tullia C. Bruno. Tumor-infiltrating B cells colocalize with CD4 T effector cells within tertiary lymphoid structures to present antigen and educate the antitumor immune response in human primary tumors [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr PR06.
Abstract A23: Ultrarapid total abdominal FLASH irradiation in a preclinical model of ovarian cancer
Authors: Levy Karen , Wang Jinghui , Eggold Joshua , Natarajan Suchitra , Maxim Peter , Loo Bill , Rankin Erinn
Published: September 2020

Introduction: Ultrahigh dose-rate irradiation (FLASH RT) is rapidly emerging as new strategy to enhance the therapeutic index of radiotherapy by protecting normal tissues from radiation-induced toxicity while maintaining tumor control. In mice, FLASH has been shown to protect the lung, skin, and brain against radiation-induced toxicity. A recent study has utilized FLASH radiotherapy in preclinical models of lung cancer to demonstrate that FLASH RT radiotherapy achieves similar tumor control to conventional RT. While these findings identify an important role for FLASH RT in the protection of multiple tissues, the role of FLASH in enhancing the therapeutic index of abdominal and pelvic tumors located near the highly radiosensitive intestine is not known. For this purpose, we have developed an experimental platform using a clinical linear accelerator that enables total abdominal FLASH RT where rapid delivery of a single fraction of high-dose radiotherapy is performed in less than one second (200 Gy/sec).

Methods: For the tumor model, ID8 cells were injected intraperitoneally into female mice. Radiation was delivered 10 days post-ID8 injection. Tumor burden was assessed at 28 days following tumor injection. Flow cytometry was used to profile infiltrating immune cells. Normal tissue toxicity was assessed through survival, total body weight, solid stool production, complete blood count, and histologic analysis.

Results: In ID8 tumor-bearing mice, 14 Gy FLASH promotes GI function with a 2-fold increase in solid stool production at 5 days post-TAI. Both modalities extended median overall survival in the ID8 model by 5 days and reduced tumor burden by 50% relative to unirradiated controls. Irradiated cohorts also demonstrated an increase in the number of proliferating CD8+ and CD4+ T cells present in the ascites.

Conclusion: We demonstrate that FLASH RT protects the gastrointestinal (GI) tract from lethal radiation-induced toxicity, improves epithelial integrity and GI function, enhances crypt survival, and provides efficient tumor control in a preclinical model of ovarian peritoneal metastasis. Here we present the first data supporting the potential for tumor control and GI protection using FLASH-TAI in a syngeneic orthotopic preclinical model of ovarian cancer.

Citation Format: Karen Levy, Jinghui Wang, Joshua Eggold, Suchitra Natarajan, Peter Maxim, Bill Loo, Erinn Rankin. Ultrarapid total abdominal FLASH irradiation in a preclinical model of ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A23.
Abstract A79: A novel small molecule, LLL12B, inhibits STAT3 Phosphorylation and sensitizes ovarian cancer cell to cisplatin and paclitaxel treatment
Authors: Zhang Ruijie , Yang Xiaozhi , Lin Jiayuh
Published: September 2020

Constitutive activation of signal transducer and activator of transcription 3 (STAT3) signaling plays an important role in many malignant progressions: cell viability, cell migration, cell growth, chemotherapy resistance, and so on. We developed a nonpeptide small molecule, LLL12B, though structure-based design, which targets STAT3 and was confirmed to inhibit STAT3 phosphorylation (tyrosine 705) and induce apoptosis as indicated by the increases of cleaved caspase-3 in human ovarian cancer cells. LLL12B, also inhibits the cell viability, cell migration, and cell growth in ovarian cancer cells. In addition, LLL12B combined treatment with paclitaxel or cisplatin exhibited greater inhibition of cell viability, cell migration, and cell growth than monotherapy in ovarian cancer cells. Furthermore, LLL12B and paclitaxel or cisplatin combination also showed greater inhibition of cell viability, cell migration, and cell colony than cisplatin and paclitaxel combinational treatment, which is a current ovarian cancer standard care therapy. Also, LLL12B combined with paclitaxel and cisplatin showed greater inhibition of cell viability and cell colony than each combinational treatment of two drugs. In summary, our results indicated that the novel small molecule LLL12B is a potent STAT3 inhibitor in ovarian cancer cells. Our results also indicate that the combinational treatment of LLL12B with cisplatin or/and paclitaxel exhibits potent inhibitory activity in ovarian cancer cells, supporting this drug combination as a potential therapeutic strategy for ovarian cancer.

Citation Format: Ruijie Zhang, Xiaozhi Yang, Jiayuh Lin. A novel small molecule, LLL12B, inhibits STAT3 Phosphorylation and sensitizes ovarian cancer cell to cisplatin and paclitaxel treatment [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A79.
Abstract A80: Targeting ovarian cancer stem cell by Dot1L inhibition
Authors: Zhang Yaqi , Wang Yinu , Zhao Guangyuan , Matei Daniela
Published: September 2020

Cancer stem cells (CSCs) are a specific population of cancer cells that are responsible for tumor initiation, chemoresistance, and metastasis. Previously, our lab has demonstrated ovarian cancer cells with high aldehyde dehydrogenase (ALDH) activities have multiple stem cell-like characteristics, including self-renewal, high clonogenicity, and chemoresistance. Here we identify that H3K79 methyltransferase DOT1L (disruptor of telomeric silencing-1-like) is a critical factor in self-renewal and tumor initiation capabilities of ovarian cancer stem cells (OCSCs). Firstly, we found that DOT1L have higher expression in ALDH(+)/CD133(+) OCSCs compared to double negative cells. Ovarian cancer cells with DOT1L-knockdown have reduced CSC fractions in flow cytometry analysis. Besides, knockdown of DOT1L expression impairs clonogenicity characteristics of CSCs, according to in vitro colony-forming assay and spheroid formation assay results. In order to effectively inhibit the enzymatic activity of DOT1L, we applied specific DOT1L inhibitor (DOT1Li) EPZ5676 to specifically target OCSCs and confirmed that the treatment of DOT1Li was able to block H3K79 methylation in ovarian cancer cells, and effectively represses the expression of stemness-associated transcriptional factors. Results from RNA-seq analysis and gene set enrichment assay have indicated that multiple stem-related pathways are repressed in DOT1Li-treated OCSCs. Furthermore, DOT1Li treatment not only shows inhibitory effects on colony forming in vitro but also delays tumor initiation in vivo compared to control treatment, which validates the effects of DOT1Li on CSCs inhibition. Based on our result, we infer that DOT1L is critical for self-renewal and tumor initiation abilities in ovarian cancer stem cells, and DOT1L inhibition by specific inhibitor provides a potential therapeutic strategy to target CSCs in ovarian cancer treatment.

Citation Format: Yaqi Zhang, Yinu Wang, Guangyuan Zhao, Daniela Matei. Targeting ovarian cancer stem cell by Dot1L inhibition [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A80.
Abstract B16: STAT3 promotes ovarian cancer spheroid growth and metastasis
Authors: Walker David F. , Lacroix Sarah J. , Giaccone Zachary T. , Frank David A. , Walker Sarah R.
Published: September 2020

High-grade serous ovarian cancer remains deadly for the majority of woman who are diagnosed every year. The high mortality rate necessitates new treatment options for physicians and patients to consider. To produce new therapies, different signaling pathways that are activated in ovarian cancer need to be identified. In order to mimic the growth of ovarian cancer in the body, 3D culturing systems were used to grow clusters of ovarian cells (spheroids). Comparing gene expression from cells grown in 2D and 3D, we identified the STAT3 signaling pathway as being highly enriched in ovarian spheroids. STAT3 is a transcription factor that is activated by tyrosine phosphorylation. Once phosphorylated, STAT3 dimerizes, translocates to the nucleus, and regulates the expression of many genes involved in cell survival and migration. To determine if STAT3 was activated in 3D growing cells, we analyzed protein from cells grown in 2D and 3D and determined that STAT3 was tyrosine phosphorylated in cells grown in 3D We have found that the increase in STAT3 phosphorylation in 3D grown cells was associated with increased expression of STAT3 target genes. Consistent with this, we found enhanced STAT3 DNA binding to regulatory regions of STAT3 target genes. Recognizing that STAT3 activation is upregulated in 3D, we wanted to know if STAT3 is necessary for growth in 3D. By using siRNA to reduce the expression of STAT3, we were able to hinder the ability for ovarian cancer to grow in 3D. Moreover, reducing the expression of various components in the STAT3 signaling pathway also reduced the growth of ovarian spheroids. One of the major steps in ovarian cancer metastasis is the clearance of mesothelial cells by the cancer cells. To assess the effects of enhanced STAT3 activity in spheroids, we performed a mesothelial clearance assay with spheroids containing and lacking STAT3 expression. We found that ovarian spheroids with reduced STAT3 expression had a decreased ability to metastasize. This suggests that the STAT3 signaling pathway is a critical pathway involved in the growth and metastasis of ovarian cancer spheroids. This raises the possibility of using STAT3 inhibitors by themselves or in conjunction with standard-of-care therapeutics in the treatment of advanced ovarian cancer. Thus, targeting signaling pathways important in 3D growth may be beneficial for the treatment of ovarian cancer.

Citation Format: David F. Walker, Sarah J. Lacroix, Zachary T. Giaccone, David A. Frank, Sarah R. Walker. STAT3 promotes ovarian cancer spheroid growth and metastasis [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B16.
Abstract B17: Modeling ovarian cancer in mice using in vivo electroporation and CRISPR-mediated genome editing
Authors: Harwalkar Keerthana , Teng Katie , Arceneau Jocelyn , Zhao Yifan , Farnell Dave , Ford Matt , Nu Tuyet Nhung Tun , Huntsman David , Yamanaka Yojiro
Published: September 2020

Ovarian cancer is the fifth largest cause of cancer-related deaths in women. The vast majority of ovarian cancers are epithelial ovarian cancers, and high-grade serous carcinoma (HGSC) is the most common and most lethal epithelial ovarian cancer. In the last 10 years, it has been recognized that the cell of origin of most HGSCs is within the fallopian tube epithelium, instead of the ovarian surface epithelium. However, the early events in disease progression still remain poorly defined, because HGSC is usually diagnosed at advanced stages and there is a lack of proper animal models recapitulating human disease progression. My group has recently developed a unique strategy for generating mouse ovarian cancer models, which is a combination of in vivo fallopian tube electroporation, Cre-mediated lineage tracing and CRISPR-mediated gene modifications. As proof of principle, we generated a highly metastatic HGSC model by targeting four tumor suppressor genes. The female mice targeted these four genes generated ovarian tumors within 5 months after electroporation and peritoneal metastasis within 6 months. After 6 months, ascites formation was observed in two third of those females. Interestingly, similar to human ovarian cancer patients, we observed two metastatic patterns, miliary and nonmiliary. Our unique strategy has several advantages over the current mouse cancer models: 1) high flexibility permitting many gene combinations/modifications and host genetic backgrounds to be tested; 2) control over the size and area of targeted cells (the low-frequency mosaic transfection pattern better recapitulates the sporadic nature of human tumorigenesis); 3) the ability to track genetically modified cells by fluorescent reporters, permitting analysis of tumor initiation and early metastasis; and 4) highly metastatic mouse models with immune competency.

Citation Format: Keerthana Harwalkar, Katie Teng, Jocelyn Arceneau, Yifan Zhao, Dave Farnell, Matt Ford, Tuyet Nhung Tun Nu, David Huntsman, Yojiro Yamanaka. Modeling ovarian cancer in mice using in vivo electroporation and CRISPR-mediated genome editing [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B17.
Abstract B23: CDK4/6 and MEK inhibitor combination in low-grade serous ovarian cancer cell lines
Authors: Hoenisch Joshua , Kim Hannah , Dawson Amy , Lam Nicole , Cheasley Dane A. , Gorringe Kylie , Campbell Ian , Huntsman David G. , DiMattia Gabriel , Kobel Martin , Fernandez Marta Llaurado , Carey Mark S.
Published: September 2020

Background: Low-grade serous ovarian cancer (LGSC) is a rare tumor type that requires effective therapies. CDKN2A/B (p16/p15) loss and oncogenic mutations in MAPK genes are common genetic aberrations found in these tumors. We aimed to evaluate CDK4/6 inhibitor (palbociclib) activity, with and without MEK inhibitor (trametinib) treatment, in LGSC cell lines.

Methods: Nine LGSC cell lines (from advanced/recurrent cases) were used to evaluate the effects of palbociclib treatment, with and without trametinib, on cell proliferation (Incucyte) and viability (MTS). Cell cycle gene and protein expression status (p16, CDK4, CDK6, Rb, p-Rb, CCDN1 and E2F) were characterized using whole-exome sequencing and Western blot analysis. CDKN2A and RB1 gene copy-number (CN) data and P16 immunohistochemistry staining were obtained from 70 LGSC FFPE tumors and correlated with patient overall survival (OS).

Results: Palbociclib treatment had cytotoxic effects on one LGSC cell line (11%). Presence of CDK4/CDK6 protein expression was observed in 100% of the lines. Absence of p16 and Rb1 expression was detected in 78% (7/9) and 44% (4/9) of lines, respectively, and did not correlate with gene copy number status. Interestingly, none of the lines had detectable mutations in the cell cycle genes screened. Trametinib-resistant lines expressed total and phosphorylated Rb1 but palbociclib treatment did not result in drug synergistic effects. CDKN2A and RB1 copy number loss was detected in 21% and 7% LGSC tumors (all stages), respectively. The prognostic value of CDKN2A/RB1 expression in LGSC tumors is under evaluation.

Conclusions: Palbociclib (with and without trametinib) showed poor activity in LGSC in vitro, and its activity did not correlate with either p16 or Rb1 expression. Our data suggest that other factors in addition to Rb-proficiency determine palbociclib efficacy in LGSC. Therefore, future translational research to define predictive biomarkers of palbociclib efficacy is needed.

Citation Format: Joshua Hoenisch, Hannah Kim, Amy Dawson, Nicole Lam, Dane A. Cheasley, Kylie Gorringe, Ian Campbell, David G. Huntsman, Gabriel DiMattia, Martin Kobel, Marta Llaurado Fernandez, Mark S. Carey. CDK4/6 and MEK inhibitor combination in low-grade serous ovarian cancer cell lines [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B23.
Abstract B26: The natural history of ovarian high-grade serous carcinoma from time effects of ovulation inhibition and progesterone clearance of p53-defective lesions
Authors: Chu Tang-Yuan , Wu Na-Yi Yuan , Wang Jing
Published: September 2020

High-grade serous carcinoma (HGSC) is the most common and devastating type of ovarian cancer; its etiology, mechanism of malignant transformation, and origin remain controversial. Recent studies have identified secretory cells at the fimbria of the fallopian tube as the cell of origin of HGSC, initiating TP53 mutation, evolving to tubal precursor lesions, including “p53 signature” and serous tubal intraepithelial carcinoma (STIC), and metastasizing to the ovary as clinically evident ovarian cancer. The etiologic mechanisms associated with the known epidemiologic risk factors, i.e., ovulation and retrograde menstruation, have also been unveiled. Mutagens and transforming growth factors, such as reactive oxygen species and IGF axis proteins, as well as the apoptosis-rescuing protein hemoglobin are abundantly present in the ovulatory follicular fluid and peritoneum fluid, which bathes the fimbrial epithelium, and induces malignant transformation after repeated exposure. Meanwhile, in accordance with the proposed therapeutic effect of progesterone from studies on oral contraceptive (OC) use or term pregnancy, our recent study indicated that the p53-null tubal epithelial cells are selectively cleared by progesterone depending on its progesterone receptor (PR). In this report, by analyzing different time-effects of OC use or pregnancy in the prevention of ovarian cancer and by aligning them with the carcinogenic and therapeutic clearance concepts of ovulation and P4, as well as the fact of progressive loss of PR during tubal transformation, we deduced the natural history of ovarian HGSC. The natural history begins at the first ovulation and spans more than 30 years, taking 10 years from the normal tubal epithelium to the “p53 signature” status, another 15 years to PR(-) STIC, and a final 5+ years to HGSC. The estimated natural history may help understand the pathogenesis of HGSC and defines the window for early detection and chemoprevention.

Citation Format: Tang-Yuan Chu, Na-Yi Yuan Wu, Jing Wang. The natural history of ovarian high-grade serous carcinoma from time effects of ovulation inhibition and progesterone clearance of p53-defective lesions [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B26.
Abstract B62: Integrating highly-multiplexed imaging with multi-omics data to uncover immunologic vulnerabilities in high-grade serous ovarian cancer
Authors: Kilkkila Miikka K. , Casado Julia , Jacobson Connor , Hakkinen Antti , Erkai Erdogan , Dai Jun , Zhan Kaiyang , Maliga Zoltan , Carpen Olli , Lehtonen Rainer , Hautaniemi Sampsa , Sorger Peter , Vaharautio Anna , Farkkila Anniina
Published: September 2020

A key event in cancer progression is the establishment of an immunosuppressive environment that prevents the immune system from effectively attacking the cancer cells. In this study we aim to characterize the cellular determinants and the spatial features of immune suppressive mechanisms in high-grade serous ovarian cancer (HGSOC) via integrating tissue Cyclic Immunofluorescence (tCycIF), a novel highly multiplexed single-cell spatial proteomics platform with multi-omics data, including state-of-the-art single-cell RNA sequencing. We have conducted a comprehensive analysis of a unique dataset consisting of 23 HGSOC samples, including 7 pairs of treatment-naïve and post-chemotherapy samples, using tCycIF, single-cell, and bulk RNA sequencing coupled with novel deconvolution algorithms and whole-genome sequencing. All samples were prospectively collected from patients treated at Turku University Hospital, Finland, as a part of the HERCULES consortium. Our preliminary findings suggest that tCycIF can reliably capture tumor microenvironment composition in HGSOC. Overall, there was a good correlation with tumor purity between all the methods used. In tCycIF, scRNAseq and bulk deconvolution macrophages were the most common immune cell type in the HGSOC microenvironment. However, specific immune subpopulations, such as CD8+T-cells, had a larger proportion in tCycIF compared to single-cell RNA sequencing and bulk-deconvoluted RNAseq data. Further, the immune profiling based on RNAseq deconvolution algorithm showed highly variable results based on the algorithm used. We are in the process of using our complete dataset to compare state-of-the-art methods and improve algorithms for HGSOC immunophenotyping. tCycIF’s spatial proteomic data in single-cell resolution allows us to gain new insights into the tumor microenvironment and discover the previously latent cell-to-cell interactions that make up the immunosuppressive milieus in HGSOC tumors. The improvement of novel reliable single-cell immunophenotyping methods is critical to develop more effective immunotherapies to improve the outcomes and survival of patients with HGSOC.

Citation Format: Miikka K. Kilkkila, Julia Casado, Connor Jacobson, Antti Hakkinen, Erdogan Erkai, Jun Dai, Kaiyang Zhan, Zoltan Maliga, Olli Carpen, Rainer Lehtonen, Sampsa Hautaniemi, Peter Sorger, Anna Vaharautio, Anniina Farkkila. Integrating highly-multiplexed imaging with multi-omics data to uncover immunologic vulnerabilities in high-grade serous ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr B62.