bluuebunny/crossref_metadata_2025_split huggingface dataset:
Abstract 891: Therapeutic targeting of ovarian cancer stem cells using estrogen receptor beta agonist
Authors: He Yi , Alejo Salvador , Venkata Prabhakar P. , Johnson Jessica D. , Loeffel Ilanna , Martel Julie Ann , Pratap Uday P. , Viswanadhapalli Suryavathi , Tekmal Rajeshwar R. , Vadlamudi Ratna K. , Kost Edward , Sareddy Gangadhara R. 
Published: June 2022

Abstract
Background: Ovarian cancer (OCa) is the deadliest gynecologic cancer. Emerging studies suggest that ovarian cancer stem cells (OCSCs) contribute to tumor relapse and chemotherapy resistance. Recent studies demonstrate that OCa cells express estrogen receptor beta (ERβ), which functions as a tumor suppressor. However, the status of ERβ expression in OCSCs and the therapeutic utility of ERβ agonist LY500307 for targeting OCSCs remain unknown. In this study, we tested the hypothesis that OCSCs express ERβ and that treatment with ERβ agonist reduces stemness and promotes apoptosis of OCSCs.
Methods: We isolated subpopulations of OCSCs from SKOV3, A2780, and patient-derived ascites cells using ALDEFLUOR kit and examined the expression of ERβ in OCSCs using RT-qPCR. The effect of ERβ agonist LY500307 on OCSCs was examined utilizing cell viability, cell cycle, sphere formation, self-renewal, and apoptosis assays. Mechanistic studies were conducted using RNA-seq, RT-qPCR, and Western blot analysis. The efficacy of LY500307 on the tumor-initiating capacity of OCSCs was determined via in vivo limiting dilution assay studies using orthotopic intrabursal xenograft murine models.
Results: RT-qPCR assay showed that ERβ, particularly ERβ isoform 1, is highly expressed in OCSCs compared to non-OCSCs. ERβ agonist LY500307 significantly reduced the viability of OCSCs compared to non-OCSCs. Treatment of OCSCs with LY500307 significantly reduced the sphere formation and self-renewal of OCSCs. Further, LY500307 treatment resulted in G2/M cell cycle arrest and promoted the apoptosis of OCSCs. Mechanistic studies using RNA-seq analysis demonstrated that ERβ agonist treatment resulted in the modulation of pathways related to cell cycle and apoptosis. Western blots and RT-qPCR assays confirmed the upregulation of genes involved in apoptosis and cell cycle arrest, such as FDXR and CDKN1A. Importantly, treatment of LY500307 significantly attenuated the tumor-initiating capacity of OCSCs in orthotopically implanted OCa murine models.
Conclusions: Our results demonstrate that ERβ agonist LY500307 is highly efficacious in reducing the stemness and promoting apoptosis of OCSCs and may serve as a novel therapeutic agent in treating OCa
Citation Format: Yi He, Salvador Alejo, Prabhakar P. Venkata, Jessica D. Johnson, Ilanna Loeffel, Julie Ann Martel, Uday P. Pratap, Suryavathi Viswanadhapalli, Rajeshwar R. Tekmal, Ratna K. Vadlamudi, Edward Kost, Gangadhara R. Sareddy. Therapeutic targeting of ovarian cancer stem cells using estrogen receptor beta agonist [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 891.
Abstract 942: Development of customizable bladder cancer mouse model using CRISPR
Authors: Valentine Henkel L. , Satyal Uttam , Abbosh Philip H. 
Published: June 2022

Abstract
Introduction: In forward genetics, a phenotype (sensitivity to therapy) is attributed to a genotype (mutation in relevant gene) based on findings in anecdotal cases (e.g., extreme responders) with little systematic/experimental study. Although powerful, this approach is not widely applicable due to the limited availability of clinical materials and throughput thus limiting the number and type of hypotheses that can be rigorously tested. However, a genotype-therapy sensitivity relationship could be measured in isogenic systems using reverse genetics, whereby mutations in relevant genes are introduced followed by evaluation of a phenotype in wild-type and mutant contexts. Since no such pre-clinical system exists for bladder cancer, we developed an immunocompetent mouse model to induce customizable isogenic tumor formation in bladder urothelium using CRISPR.
Methods: Bladder urothelium was harvested from transgenic mice harboring LSL-Cas9/GFP in Rosa26 locus (as described by Platt et al) and grown as organoids. These organoids had a basal phenotype. AAV harboring Cre and sgRNA(s) were used to induce Cas9 and engineer mutations. Based on their frequent somatic alteration pathway in TCGA-BLCA, Tp53 and Rb1 were chosen for knockout first to establish ‘base organoids’. Additional genes related to PI3K/AKT/mTOR pathway were edited in base organoids to develop a series of organoids with different genotypes predicted to activate this signaling pathway. Sanger sequencing and western blot were used to confirm knockout. Kinase inhibitors targeting the mTOR pathway at different levels were assessed in organoids with different genotypes. The edited urothelial cells were grafted in mouse bladder to develop isogenic tumor to assess in vivo therapeutic vulnerability of in-vitro-prioritized kinase inhibitors matching the genotype of the allografted tumor.
Results: Rb1, Tp53, and Pten were successfully knocked out in urothelial organoids. When treated with Ipataseritib, an AKT inhibitor, the triple knockout organoid was found to be 9X more sensitive than Trp53/Rb1 knockout organoids. In contrast, triple knockout organoids were 15X less sensitive to Gefitinib, an EGFR inhibitor, than Trp53/Rb1 knockout organoids, in line with published data. Edited organoids generate a neo-urothelium in murine bladder in short term assays.
Conclusions: We developed a flexible bladder cancer mouse model to study mutation-therapy relationship using reverse genetics. This system is a plausible way to uncover unappreciated therapeutic vulnerabilities that probably exist in bladder cancer.
Citation Format: Henkel L. Valentine, Uttam Satyal, Philip H. Abbosh. Development of customizable bladder cancer mouse model using CRISPR [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 942.
Abstract 976: Interrogating the pre-metastastic gene signature to block brain metastases
Authors: Kieliszek Agata , Bassey-Archibong Blessing , Venugopal Chitra , Singh Sheila 
Published: June 2022

Abstract
BACKGROUND: The incidence of brain metastases (BM) is tenfold higher than that of primary brain tumors. BM predominantly originate from primary lung, breast, and melanoma tumors with a 90% mortality rate within one year of diagnosis, posing a large unmet clinical need to identify novel therapies against BM. The goal of this work is to uncover the molecular factors that drive the formation of BM and investigate whether we can slow down and ultimately block BM formation.
METHODS: The Singh lab has generated a large in-house biobank of patient-derived BM cell lines that are established from BM patient tumor samples. We use these BM cell lines to generate murine orthotopic xenograft models of BM and interrogate the biological processes that lead to BM. These models have successfully recapitulated all the stages of their respective BM cascades and additionally captured a “pre-metastatic” population of BM cells that have just seeded the brains of mice before forming mature, clinically detectable tumors. Pre-metastatic cell populations are impossible to detect in human patients but represent a therapeutic window wherein metastasizing cells can be targeted and eradicated before establishing clinically detectable and difficult to treat brain tumors.
RESULTS: RNA sequencing of pre-metastatic BM cells revealed a unique deregulated transcriptomic profile that is specific to pre-metastatic cells despite the tumor of origin. Subsequent Connectivity Map analysis revealed compounds that we biologically characterized in vitro for selective anti-BMIC phenotypes. This effort led to a lead compound that exhibits anti-BM activity in vitro, while remaining ineffective against normal brain cell controls. Preliminary in vivo work has shown that following both orthotopic and intracardiac injection of BM cells, treatment with this lead compound reduces the tumor burden compared to mice being treated by a vehicle control, while providing a significant survival advantage. Ongoing mechanistic investigations aim to delineate the protein target of this compound in the context of the observed selective anti-BM phenotype.
CONCLUSION: Identification of novel small molecules that target premetastatic BM cells could slow or prevent the formation of BM and dramatically improve the prognosis of at-risk cancer patients.
Citation Format: Agata Kieliszek, Blessing Bassey-Archibong, Chitra Venugopal, Sheila Singh. Interrogating the pre-metastastic gene signature to block brain metastases [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 976.
Abstract 98: The role of HORMAD1 in transformation of keratinocytes following vemurafenib treatment
Authors: Gantchev Jennifer , Villarreal Amelia Martinez , Ramchatesingh Brandon , Litvinov Ivan V. 
Published: June 2022

Abstract
BRAF inhibitor (BRAFi) therapies are highly effective treatments for metastatic melanoma. However, BRAFi monotherapies are associated with a significant risk of squamous cell carcinoma (SCC) development in melanoma patients. Consequently, BRAF inhibition results in an unanticipated activation of the MAPK pathway in surrounding cells that harbour wildtype BRAF. Fortunately, a combination approach with both a BRAFi and the selective MAPK inhibitor (MEKi), trametinib, attenuates BRAFi-induced risk of SCCs. Despite the fact that this combination therapy is widely used in clinical practice, the mechanisms associated with SCC induction and why this effect is attenuated with a MEK inhibitor remain poorly understood. HORMAD1, a meiosis specific gene, has been shown to have an impact on genomic instability and proliferation in the development of SCCs. Moreover, recent work in our lab has demonstrated that the MAPK pathway regulates HORMAD1 expression in SCC cell lines. Therefore, we sought to investigate a potential role of HORMAD1 in the risk and development of SCCs as a mechanism of BRAFi that is attenuated with the co-administration of the MEKi, trametinib. Using the BRAFi, vemurafenib, we inhibited the kinase activity of activated BRAF (V600E) and the MEKi, trametinib to evaluate the expression of HORMAD1 in melanoma and normal keratinocyte cell lines. To determine the effects of these two inhibitors, a cell proliferation assay was conducted followed by the evaluation of various components of cell cycle regulation and genomic instability. We found that HORMAD1 protein expression levels increased following treatment with the BRAFi, vemurafenib, in the normal keratinocyte cell line, HaCaT, but not in the melanoma cell line, A375. In contrast, HORMAD1 expression decreased following treatment with the MEKi, trametinib in both HaCaT and A375. Cell proliferation assays depict a vulnerability to both vemurafenib and trametinib in both normal and melanoma cell lines, however, HaCaT cells appear to be more susceptible to increased levels of genomic instability following treatment with vemurafenib when compared to A375. Our results suggest that HORMAD1 likely plays a key role in the development of SCCs by increasing genomic instability and proliferation in normal keratinocytes following BRAFi monotreatment. The increased risk of SCC formation is attenuated by dampening HORMAD1 levels with the co-administration of the MEKi, trametinib.
Citation Format: Jennifer Gantchev, Amelia Martinez Villarreal, Brandon Ramchatesingh, Ivan V. Litvinov. The role of HORMAD1 in transformation of keratinocytes following vemurafenib treatment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 98.
Abstract 988: Epigenetic upregulation of neuropilin-1 promotes osteosarcoma progression and metastasis
Authors: Nerlakanti Niveditha , Mcguire Jeremy , Yu Diana , Reed Damon , Lynch Conor C. 
Published: June 2022

Abstract
Background: Osteosarcoma (OS) frequently metastasizes to lung and the prognosis for these patients is grim with 5-year overall survival rates as low as 30%. There has been little change in the treatment paradigm for this disease and new targeted therapies are an urgent and unmet clinical need. Previously, we showed that the epigenetic regulators, histone deacetylase 1 and 2 (HDAC1 and 2) are key mediators of OS progression and lung metastasis and that the HDAC1/2 selective inhibitor (romidepsin) significantly prevented OS lung metastasis in vivo. Yet, inhibition of HDACs by romidepsin has noted toxicities in humans and here we define the potential mechanisms through which HDAC1/2 mediate their effects in a bid to identify additional therapeutic targets.
Methods: Human OS cell lines were treated with vehicle or romidepsin for 24h before undergoing RNA/protein isolation for microarray/proteomics to identify differentially regulated genes. Standard siRNA, proliferation, migration and molecular analyses were preformed to investigate the role of candidate genes in OS malignant behavior.
Results: Microarray/proteomics analyses on romidepsin treated OS cells identified neuropilin-1 (NRP1), a membrane bound co-receptor for vascular endothelial growth factor, to be highly downregulated in response to romidepsin; (&lt;70% compared to vehicle in multiple OS cell lines). NRP1 knockdown (siRNA) led to reduced cell proliferation and interestingly, increased cell migration. Further, a phosphokinase array revealed increased phosphorylation in eNOS, ERK 1/2 and β-catenin in NRP1 knockdown cells that is consistent with a role for NRP1 in regulating OS migration. Based on this data, we hypothesize that NRP1 is a significant regulator of OS proliferation and migration. Our next steps will be to dissect the role of NRP1 silencing in OS invasion and metastasisin vivo and the potential role of NRP1 in OS differentiation.
Conclusions: HDAC1/2 contributes to OS growth potentially via the upregulation of NRP1, a therapeutically actionable target.
Citation Format: Niveditha Nerlakanti, Jeremy Mcguire, Diana Yu, Damon Reed, Conor C. Lynch. Epigenetic upregulation of neuropilin-1 promotes osteosarcoma progression and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 988.
Abstract CT245: First in human CD200 activation receptor ligand and tumor lysate vaccine immunotherapy for recurrent glioblastoma in adults
Authors: Olin Michael R. , Neil Elizabeth C. , Eaton Anne , Lunn Shannon , Moertel Christopher L. 
Published: June 2022

Abstract
Background: Immunotherapy has revolutionized clinical management of malignancies rendering cancers that previously had a dismal prognosis more manageable. Unfortunately, these therapies can cause serious immune-related adverse events, including death. In CNS cancers, currently available immunotherapies have limited to no efficacy. Our work in glioblastoma (GBM), which is considered one of the most aggressive cancers as well as being universally fatal, is focused on the CD200 immune checkpoint that modulates the immune system through the inhibitory receptor (CD200R1) and activation receptor (CD200AR). The peptide checkpoint ligand (CD200AR-L) was developed to target the CD200AR that downregulates the inhibitory PD-1/PD-L1, CTLA4 and CD200R immune checkpoints, permitting immune system activation that is less hampered by the inhibitory effects of GBM. Following a positive clinical trial in dogs that spontaneously developed high-grade gliomas, we initiated a first-in-human Phase 1 Study of the CD200 Activation Receptor Ligand (CD200AR-L) and Allogeneic Tumor Lysate Vaccine (GBM6-AD) immunotherapy for Recurrent Glioblastoma (NCT04642937).
Methods: This is a single-center, first-in-human, dose-escalation Phase 1 clinical trial utilizing a 3+3 design at three dose levels; 3.75micrograms/kg, 5micrograms/kg, and 7.25micrograms/kg. Adults 18 years and old with recurrent GBM and no pre-exiting immune-related condition plus adequate performance score were eligible. Accrual started in December 2020 at dose level 1 with a second cohort having received treatment on dose level 2. CD200AR-L is administered on days 1 and 2 by suprascapular intradermal injection following the application of topical imiquimod. On day 2, a fixed dose of the allogeneic vaccine is injected intradermally at the same site. The “Induction Phase” consists of this injection series weekly for 4 weeks with monitoring for dose-limiting toxicity through Day28. The “Maintenance Phase” doses the vaccine series monthly for 2 months, then the “Booster Phase” doses every eight weeks for 24 months or until end of treatment. Patients are monitored for adverse events, including immune-mediated intracranial edema and other immune-related complications, and their neurological function is scored per NANO criteria. Correlative studies include immune monitoring (including expression of CD200R1, PD1/PD-L1, and CTLA-4) and MRI imaging assessment per iRANO criteria.
Citation Format: Michael R. Olin, Elizabeth C. Neil, Anne Eaton, Shannon Lunn, Christopher L. Moertel. First in human CD200 activation receptor ligand and tumor lysate vaccine immunotherapy for recurrent glioblastoma in adults [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT245.
Abstract CT534: Magnesium treatment on the demethylation of chemokine (C-X-C motif) ligand 9 (CXCL9) gene, results from the personalized prevention of colorectal cancer trial
Authors: Zhu Xiangzhu , Huang Xiang , Zheng Yinan , Zhang Wei , Shu Lihua , Ness Reid , Murff Harvey J , Yu Chang , Shrubsole Martha J , Hou Lifang , Dai Qi 
Published: June 2022

Abstract
Background: Chemokine ligand 9 (CXCL9), a T-cell chemoattractant, plays a critical role in regulating antitumor immunity in cancer immunotherapy, i.e., clinical responses to anti-PD(L)-1 treatment. Very recently, CXCL9 was identified as the strongest contributor to the “inflammatory clock of aging”, linked to age-related chronic inflammation. Due to the critical role of magnesium (Mg) in regulating inflammatory responses, this study aims to investigate the effect of Mg treatment on DNA methylation changes in CXCL9.
Methods: The Personalized Prevention of Colorectal Cancer Trial conducted at Vanderbilt University Medical Center was a double-blind 2 × 2 factorial randomized controlled trial of 240 participants who completed the study. Participants aged from 40 to 85 years, had a daily calcium intake 700-2000 mg and calcium:magnesium intake ratio ≥2.6 based on the average of the two baseline 24-hour dietary recalls.
Results: Among three CpG sites, a 12-week personalized dose of Mg supplementation marginally increased the 5-hydroxymethylcytosine methylation, a measure of active demethylation, at CpG site 04038163 (3'UTR of CXCL9 gene) by 7.0% compared to the placebo group (p=0.07). Although the overall effect was not significant or of borderline significance, Mg treatment significantly reduced the levels of 5-hydroxymethylcytosine by 3.7% at the CpG site 12793812 (body of CXCL9 gene) among those with aged 60 years or above (p=0.03).
Conclusions: These findings indicate that Mg treatment modified the demethylation process in the CXCL9 gene, a critical regulator of immune responses and inflammation. Future studies are needed to examine if Mg treatment also changes the circulating levels of CXCL9.
Citation Format: Xiangzhu Zhu, Xiang Huang, Yinan Zheng, Wei Zhang, Lihua Shu, Reid Ness, Harvey J Murff, Chang Yu, Martha J Shrubsole, Lifang Hou, Qi Dai. Magnesium treatment on the demethylation of chemokine (C-X-C motif) ligand 9 (CXCL9) gene, results from the personalized prevention of colorectal cancer trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT534.
Abstract LB039: VHL-deficient renal cell carcinoma displays defective ATM activation and sensitivity to ATR inhibition
Authors: Pilie Patrick G. , Zhou Lijun , Zhang Yan-Ting , Peterson Christine , McGrail Daniel , Peng Yang , Peng Guang , Liu Xiande , Zhang Xuesong , Jonasch Eric 
Published: June 2022

Abstract
Introduction: Clear cell renal cell carcinoma (ccRCC) displays genomic instability, but lacks mutations in canonical DNA damage response (DDR) genes. Bi-allelic loss of VHL is a near ubiquitous, truncal event in ccRCC development. Herein, we performed preclinical and clinical analysis to understand how VHL loss impacts DDR pathway activity and how specific DDR deficiencies (DDR-D) may be targeted in ccRCC.
Methods: We performed DNA whole exome sequencing (WES) and reverse phase protein array (RPPA) early stage ccRCC tumors. All patients were consented under an IRB-approved protocol for the use of tissue. Transcriptomic and protein analyses of select DDR pathways was performed on in silico data (TCGA). DDR functional assays and ATR inhibitor treatment were performed on preclinical cell line models, and in vivo ATR inhibitor treatment in ccRCC xenografts with varying VHL status.
Results: Bi-allelic loss of VHL via mutation in one allele and copy number loss of chromosome 3p was observed in 13/13 patient tumors. Mutations in other genes associated with ccRCC and/or canonical DDR genes were not observed. Despite VHL loss being the only driver mutation, these early stage tumors displayed tumor mutational burden (TMB) similar to ccRCC across all tumor stages (1.1 ± 0.5 mut/Mb). Proteomic analysis of patient tumor versus normal tissue (N=12) revealed significantly different (P&lt;0.05) mean expression level of 218 proteins, including significantly lower phospho-ATM at the autophosphorylated S1981 site and lower phospho-CHK2 at the downstream T68 site. VHL-/- cells display defective binding to and repressed activation of Tip60 (KAT5), a key acetyltransferase that activates ATM kinase and aids in the selection of DNA repair pathways following damage. Lastly, treatment with ATRi (VE-822) of 786-O and 786-VHL overexpressing tumor xenografts showed ATRi was safe and significantly inhibited tumor growth preferentially in the 786-O VHL null model.
Conclusions: Here we show in patient tissue and preclinical models that VHL biallelic loss results in genomic instability and functional impairment of ATM kinase activity; furthermore, we provide preclinical evidence for selectively targeting the ATR signaling cascade in patients with VHL-deficient kidney cancer. Clinical trials of ATR inhibitor based therapy in patients with advanced cancer, including ccRCC, are underway (e.g. NCT04266912).
Citation Format: Patrick G. Pilie, Lijun Zhou, Yan-Ting Zhang, Christine Peterson, Daniel McGrail, Yang Peng, Guang Peng, Xiande Liu, Xuesong Zhang, Eric Jonasch. VHL-deficient renal cell carcinoma displays defective ATM activation and sensitivity to ATR inhibition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB039.