bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract IA04: Novel approaches to study the tumor-stroma interaction and translate immune-directed therapies
Authors: Jimeno Antonio 
Published: September 2020

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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

Abstract
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.