Ongoing Studies Research Articles

Abstract PO2-24-07: Investigation into potential Estrogen Receptor (ER)-mediated regulation of Phosphoserine Aminotransferase (PSAT1)

Abstract Breast cancer is one of the leading causes of death among women. Expression of different proteins, such as hormone receptors (HR), are used to classify different types of breast cancer (i.e., HR+BC or triple negative breast cancer (TNBC)). While activation of the estrogen receptor (ER) in HR+BC is known to regulate a vast number of downstream targets in promoting breast cancer, there may be additional ER-regulated processes that are still unknown. The serine synthetic pathway has been demonstrated to be crucial in the proliferation and survival of select subtypes of breast cancer and phosphoserine aminotransferase 1 (PSAT1) is a key regulatory step. Previous studies have demonstrated higher PSAT1 levels in cells lacking ER and we now show a negative correlation between ERα protein levels and PSAT1 transcripts in human patient samples. This indicates that ER may potentially regulate PSAT1 expression. To initially investigate this potential relationship, either WT or constitutively active mutant ERα was expressed in TNBC cells (MDA-MB-231), which have high endogenous PSAT1 expression and no ER. Immunoblot was used to verify ERα levels and to assess effects on PSAT1. We observed a qualitative trend in decreasing PSAT1 levels with re-expression of ERα in the TNBC cells. While the variabilities in these results preclude any conclusion of a ERα:PSAT1 regulatory axis, the lack of a quantifiable effect on PSAT1 levels is postulated to be due to the transient nature of ERα expression/suppression in these systems. A more profound effect would be expected under durable changes in ERα levels and is a focus on-going studies. Citation Format: Mary Sumlut, James Wittliff, Brian Clem. Investigation into potential Estrogen Receptor (ER)-mediated regulation of Phosphoserine Aminotransferase (PSAT1) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-24-07.

Study design of BI 1015550 for idiopathic pulmonary fibrosis and progressive pulmonary fibrosis: a plain language summary

What is this summary about? Two ongoing clinical studies are part of a programme called FIBRONEER. The FIBRONEER studies are testing the drug BI 1015550 as a treatment for people with idiopathic pulmonary fibrosis (IPF) and people with progressive pulmonary fibrosis (PPF). IPF is a severe lung disease where scar tissue builds up in the lungs. The ‘idiopathic’ part means that doctors do not know the cause of the lung scarring. PPF is a general term to describe the worsening of lung scarring in any disease where scar tissue forms in the lungs, both from known causes such as other underlying diseases and for unknown reasons. While IPF can be considered to be a typical form of worsening lung scarring, in clinical studies, IPF and PPF are usually considered separately. In both IPF and PPF, scar tissue builds up in the lungs, making them smaller and no longer able to take in oxygen well. This leads to difficulty in breathing and getting oxygen to the tissues, making it difficult to perform daily activities and reducing the patient's quality of life. The symptoms and outcomes of PPF are often similar to IPF. What study drug is being investigated? BI 1015550 is a new study drug being developed to reduce scarring in the lungs in IPF and PPF. In the FIBRONEER studies, some participants are taking BI 1015550 and others are taking placebo. The placebo looks identical to BI 1015550 but does not contain any medicine. Researchers will compare the study drug to placebo to find out how well the study drug works. Participants may also take another approved medicine to treat their lung scarring. The FIBRONEER studies are investigating the effects of BI 1015550 alone and in combination with any existing medicines the participants are taking. The goal is to see whether BI 1015550 can slow down or stop a decline in lung function in people with IPF and PPF, and how well it is tolerated.

Abstract 2416: Personalized minimal residual disease detection using tumor-derived structural variants in cell-free DNA

Abstract We demonstrate development and technical validation of a novel approach for analysis of plasma circulating-tumor DNA (ctDNA) for residual disease detection and monitoring that offers improvements over existing technologies. ctDNA in blood can be leveraged to monitor treatment response, detect cancer recurrence, and inform treatment decisions for cancer patients. However, accurate detection and quantification of ctDNA is technically challenging due to low concentration of plasma DNA, especially in the adjuvant setting. Most current assays rely on interrogating multiple patient-specific point mutations to achieve exquisite limits of detection but struggle with polymerase errors, sequencing artifacts and limited conversion of input DNA. To overcome these challenges, we developed an approach called Structural Variant Enrichment and Normalization (SVEN) that targets patient-specific genomic rearrangements to achieve sensitive detection and quantification of plasma ctDNA. This method leverages intrinsic features of tumor-derived structural variants (SVs) to improve enrichment and confidence of detection at low tumor fraction through multiplexed PCR and amplicon-based next generation sequencing. To evaluate the assay, we performed whole genome sequencing of DNA from two breast cancer cell lines, as well as matched FFPE tumor and buffy coat samples from 21 early-stage breast cancer patients. We identified consensus SVs, and designed multiplexed SV-specific primers for each subject. We then conducted PCR amplification of cell-free DNA followed by sequencing, amplicon identification, and quantification. Analytical validation was conducted using 284 replicates of cell line dilutions from 1% to 0.003%, and 5 to 40 ng of input. We developed multiplexed assays targeting 25 and 32 SVs across two cell lines, and 3 - 43 SVs across breast cancer patients (median 23 per patient). 91% and 42% of PCR targets were successfully validated for cell lines and FFPE samples respectively. Cell line dilutions demonstrated a sensitivity of 89% at 0.003% tumor fraction with 10 ng input or more. Tumor fractions measured using SVEN agreed with known values (R2 = 0.989). Application of validated panels to patient plasma samples and tumor/germline dilutions is ongoing. SVEN is a novel approach for tumor-guided ctDNA detection and quantification with potential relevance for residual disease detection. On-going studies are investigating the performance of this approach for ctDNA detection in patients with early and locally advanced breast cancer treated with neoadjuvant therapy. Citation Format: Bradon R. McDonald, Kirsten L. Dennison, Amanda L. Schussman, Stephanie M. McGregor, Barbara A. Pockaj, Muhammed Murtaza. Personalized minimal residual disease detection using tumor-derived structural variants in cell-free DNA [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2416.

Abstract 607: Development of a novel, selective, and potent inhibitor of RON kinase

Abstract Purpose: Receptor d’origine nantais (RON) is a highly conserved transmembrane protein expressed at low levels in healthy adult tissues of epithelial origin and at various levels in immune cells such as macrophages. Aberrant activation of RON has been described in many solid tumors, and it contributes to tumorigenesis by modulating the immune tumor microenvironment, activating numerous oncogenic signaling pathways, and protecting tumor cells under stress. The overexpression of RON protein and the subsequent generation of oncogenic variants are mainly responsible for the persistent activation of downstream signaling pathways. In breast cancer, more than 80% of primary cancer samples are positive for RON expression, with overexpression reported in approximately 50% of cases. Importantly, tumoral RON expression correlates with increased breast cancer progression, metastasis, and poor prognosis independent of molecular subtype. We hypothesize that a small molecule inhibitor of RON that can target both full-length and truncated isoforms will promote anti-tumor immunity within the tumor microenvironment and block pro-metastatic signaling pathways. Herein, we report the development of a novel, orally bioavailable, selective, and potent inhibitor of RON kinase. Methods: With structure-guided and iterative medicinal chemistry approaches, we identified a novel chemical entity that potently inhibited RON kinase activity. Further optimization resulted in the identification of ZB-60 with improved potency, selectivity, and desirable drug-like properties. In vitro kinase assays were performed using ADP-Glo RON kinase assay kit (Promega). Changes in phosphorylation of RON was demonstrated by Western blotting. Plasma pharmacokinetics (PK) was conducted in mice to measure exposures and to determine the oral bioavailability of ZB-60. In vivo efficacy of ZB-60 was evaluated in syngeneic mouse models of breast (EMT6) and colorectal (CT26) cancer. Results: ZB-60 inhibited RON kinase activity with an IC50 of 56 nM and showed greater than 40-fold selectivity against MET and other closest members of the tyrosine kinase family. In ZB-60 treated breast cancer cells, there was a dose dependent reduction of RON phosphorylation and downstream signaling. PK analysis showed a high oral bioavailability with low clearance. In vivo evaluation of ZB-60 showed inhibition of tumor growth in EMT6 and CT26 models. Ongoing studies are focused on testing ZB-60 in combination with checkpoint inhibitors. The results from these studies along with ADME-TOX and pharmacokinetics will be presented. Conclusion: ZB-60 has target specific activity and exhibits favorable drug-like properties. Citation Format: Mohan Rao Kaadige, Trason Thode, Jaime Fornetti, Alexis Weston, Serina Ng, Tithi Ghosh-Halder, Taylor Bargenquast, Brian Durbin, Srinivas Kasibhatla, Raffaella Soldi, Alana Welm, Sunil Sharma. Development of a novel, selective, and potent inhibitor of RON kinase [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 607.

Abstract 1027: Immunohistochemistry (IHC) to assess tumor cell-associated OX40 expression in lymphoma PDXs

Abstract Background. Tumor necrosis factor receptor superfamily member 4, or OX40, is an immunostimulatory receptor usually expressed in activated T-cells. The OX40-OX40L (ligand of OX40) interaction plays a crucial role in the enhancement of T-cell proliferation, survival, and cytokine production, including those in tumor microenvironment (TME) leading to increased anti-tumor immunity1. OX40 agonist antibodies have been widely tested for immunotherapy for solid tumors2,3. Interestingly, in the treatment of lymphoma, the situation may become more complicate, where OX40 could also be found to be expressed on lymphoma cells, in addition to TME. This phenomenon might or might not impact OX40 agonist therapy. This report aims at developing an immunohistochemistry (IHC) assay to assess tumor-associated OX40 by utilizing morphology approach to understand OX40 expression in lymphoma cells, as opposed on tumor-infiltrate T-lymphocytes (TILs) present in TME. FFPE samples from patient-derived xenografts (PDXs), recapitulating the main pathological features of the original tumors, but exclusive of human TILs, were used as the first stage of the assay development, avoiding TIL interference prior to human sample testing. Methods. Ninety leukemia and lymphoma PDXs are comprehensively annotated, including RNAseq and histopathology (HuBaseTM: https://hubase.crownbio.com). IHC staining of PDX FFPE slides or TMA (tissue microarray) of various cancers was performed using a commercial OX40 antibody (CST, #61637) and Bond RX Automated IHC/ISH Staining System (Leica Biosystems), followed by whole slide imaging by NanoZoomer NDP2.0-HT Digital Slide System (Hamamatsu) and quantitative analysis by HALOTM image analysis software (Indica labs). OX40 IHC scores were also compared to the RNA expression determined by RNAseq. Results. A total of 90 leukemia and lymphoma PDXs were comprehensively evaluated. RNASeq data (human mRNA) indeed revealed OX40 gene expression (cutoff as Log2 (FPKM)>3) in 8.9% of models (8/90 models); on the other hand, IHC data also confirmed these OX40 protein expression; and the IHC scores largely correlated with the RNA data. Together, our data firmly confirmed the expression of OX40 in certain hematological cancers, beyond just in TME. The ongoing studies is investigating the characteristics of the OX40 positive lymphoma/leukemia, and the preliminary data will be presented in the annual conference. Furthermore, we are also using the same assay to explore other cancer types beyond hematological cancers. Conclusion. A tumor associated OX40 expression IHC workflow was preliminarily established and validated to facility the OX40 immunotherapy development. Citation Format: Jie Lin, Xiaolong Tu, Likun Zhang, Hongjiang Yu, Cheng JIang, Tao Yang, Henry Qixiang Li. Immunohistochemistry (IHC) to assess tumor cell-associated OX40 expression in lymphoma PDXs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1027.

Effects of Interventions for Menstrual Health and Hygiene Management for Adolescent Girls: A Systematic Review and Meta-analysis

Menstruation relates to women’s well-being, and menstrual health and hygiene are important. However, the effects of menstrual health and hygiene interventions remain unclear. This systematic review assessed the effects of menstrual health and hygiene interventions on adolescent girls and young women. Structured systematic searches were conducted using five databases from 5 August to 30 September 2022 with no restriction. We included individual-, cluster- and quasi-randomized controlled trials that assessedthe effects of menstrual health and hygiene interventions on the quality of life and social outcomes. Two researchers independently completed the screening process and assessed the risk of bias using the second version of the Cochrane risk of bias tool for randomized trials.Ten studies were described in 12 reports, and three ongoing studies were included. Five studies evaluated education interventions, one evaluated the distribution of menstrual products, and four assessed both. No study reported the quality of life. A small but non-significant positive impact on school attendance was found from the meta-analysis of four studies evaluating the distribution of sanitary products compared with no intervention (SMD = 0.23, 95%CI [-0.03, 0.48]). Although this study’s result should be used cautiously, menstrual health and hygiene interventions offer positive outcomes. Quality of life should be assessed as well. Morecomprehensive and innovative interventions and a rigorous research design are required, and nurses have an important role in education, practice and further research on this topic.

Impact of cryopreservation on elastomuscular artery mechanics

Low temperatures slow or halt undesired biological and chemical processes, protecting cells, tissues, and organs during storage. Cryopreservation techniques, including controlled media exchange and regulated freezing conditions, aim to mitigate the physical consequences of freezing. Dimethyl sulfoxide (DMSO), for example, is a penetrating cryoprotecting agent (CPA) that minimizes ice crystal growth by replacing intracellular water, while polyvinyl alcohol (PVA) is a nonpenetrating CPA that prevents recrystallization during thawing. Since proteins and ground substance dominate the passive properties of soft biological tissues, we studied how different freezing rates, storage temperatures, storage durations, and the presence of cryoprotecting agents (5% [v/v] DMSO + 1 mg/mL PVA) impact the histomechanical properties of the internal thoracic artery (ITA), a clinically relevant blood vessel with both elastic and muscular characteristics. Remarkably, biaxial mechanical analyses failed to reveal significant differences among the ten groups tested, suggesting that mechanical properties are virtually independent of the cryopreservation technique. Scanning electron microscopy revealed minor CPA-independent delamination in rapidly frozen samples, while cryoprotected ITAs had better post-thaw viability than their unprotected counterparts using methyl thiazole-tetrazolium (MTT) metabolic assays, especially when frozen at a controlled rate. These results can be used to inform ongoing and future studies in vascular engineering, physiology, and mechanics.

HER2-Positive Early Breast Cancer: Time for Ultimate De-Escalation?

De-escalation is currently taking place in both the surgical and systemic treatment of breast cancer. The introduction of trastuzumab, the first monoclonal antibody against the HER2 receptor, over 20 years ago was a milestone in the treatment of HER2-positive breast cancer and marked the beginning of a new era in targeted tumor therapy. In the sense of de-escalation, omitting non-targeted cytotoxic chemotherapy altogether is often hailed as the ultimate goal of oncological research. Especially in cases of small, node-negative, HER2-positive early breast cancer, it remains a challenge for clinicians to establish the safest and most efficient treatment plan while considering the significant potential for toxic side effects associated with chemotherapy and HER2-targeted therapy, and the generally excellent prognosis. In this context, several ongoing studies are currently assessing chemotherapy-free regimens as part of strategies aimed at de-escalating therapy in the field of HER2-positive early breast cancer. Despite the promising early results of these studies, the combination of anti-HER2 treatment with a chemotherapy backbone remains the standard of care.

COVID-19, a self-limiting disease – A case report of a severe COVID-19 pneumonia patient with multiple comorbidities successfully treated without antivirals

COVID-19 pneumonia is a communicable disease with no definite therapy. Therapeutic recommendations are still evolving based on ongoing studies and clinical trials. Patients with comorbidities, such as obesity and diabetes, are at risk for developing more severe diseases with higher mortality rates. A number of antivirals, such as oseltamivir, favipiravir, and remdesivir, have been proposed as a treatment for COVID-19, especially in severe diseases. However, the World Health Organization (WHO) initially does not recommend any antiviral therapy.

Benefits, Risk Factors and Cognitive Insights for Improving the Well-being of Minors in Greek Foster Care.

This research paper presents a holistic analysis of the foster care system in Greece, exploring its historical evolution, legal nuances, practical concerns, and the recent legislative reforms aimed at improving the well-being of minors in foster care. The study examines various types of foster care arrangements—kinship, non-relative, and professional fostering—highlighting their impact on the psychological, social, and cognitive development of children. It underscores the crucial role of foster families and social workers in providing a conducive family environment, while also cataloging the potential drawbacks of the system, including professional intervention challenges, emotional and social strain on the children, and gaps in the fostering infrastructure. By comparing the Greek fostering institution with systems in France, Germany, Denmark, Italy, and Ireland, the paper identifies unique challenges and best practices, contributing to an understanding of international foster care dynamics. The research also delves into the intricacies of adoption versus fostering, detailing the emotional and legal commitments involved. Furthermore, the paper integrates insights from related studies on trauma, mental health, and educational neuroscience, providing a multidisciplinary perspective on the needs of foster children. It illustrates the promising strides made by initiatives like the Child Guarantee program to fight poverty and exclusion, emphasizing the need for targeted policies and legislative action. Toward its conclusion, the research accentuates the call for ongoing interdisciplinary studies, policy refinements, and improved professional training within Greek child welfare systems. It presents a compelling case for robust, trauma-informed care frameworks and legislation designed to secure the best outcomes for vulnerable children in foster care.

Zinc oxide‐cadmium(II) sulfide heterostructure as a potential photocatalyst for preparing substituted chromenes and its anti‐liver cancer activity

There are ongoing studies on the potential use of chromene derivatives in liver cancer therapy. They have shown promising results in preclinical studies for liver cancer, including inhibiting tumor growth and inducing apoptosis. Herein, the nanosized hybrid material zinc oxide (ZnO)–cadmium sulfide (CdS) is prepared using a green and ecofriendly procedure. The nanomaterial was characterized by FE‐SEM, transmission electron microscopy, energy dispersive X‐ray, DRS, X‐ray diffraction, and Fourier transform infrared spectroscopy. The photocatalytic proficiency of ZnO–CdS was then scrutinized in the fabrication of some 4H‐chromenes in a mild condition. The outcomes of this study revealed that the nanophotocatalyst has high photocatalytic reactivity and acceptable reusability in the desired condensation reaction. Furthermore, a preliminary in vitro cellular toxicity assay was performed on ZnO–CdS nanoparticles using HepG2 cancer cell line through MTT assay.

Admission avoidance hospital at home.

Admission avoidance hospital at home provides active treatment by healthcare professionals in the patient's home for a condition that would otherwise require acute hospital inpatient care, and always for a limited time period. This is the fourth update of this review. To determine the effectiveness and cost of managing patients with admission avoidance hospital at home compared with inpatient hospital care. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and CINAHL on 24 February 2022, and checked the reference lists of eligible articles. We sought ongoing and unpublished studies by searching ClinicalTrials.gov and WHO ICTRP, and by contacting providers and researchers involved in the field. Randomised controlled trials recruiting participants aged 18 years and over. Studies comparing admission avoidance hospital at home with acute hospital inpatient care. We followed the standard methodological procedures expected by Cochrane and the Effective Practice and Organisation of Care (EPOC) Group. We performed meta-analysis for trials that compared similar interventions, reported comparable outcomes with sufficient data, and used individual patient data when available. We used the GRADE approach to assess the certainty of the body of evidence for the most important outcomes. We included 20 randomised controlled trials with a total of 3100 participants; four trials recruited participants with chronic obstructive pulmonary disease; two trials recruited participants recovering from a stroke; seven trials recruited participants with an acute medical condition who were mainly older; and the remaining trials recruited participants with a mix of conditions. We assessed the majority of the included studies as at low risk of selection, detection, and attrition bias, and unclear for selective reporting and performance bias. For an older population, admission avoidance hospital at home probably makes little or no difference on mortality at six months' follow-up (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.68 to 1.13; P = 0.30; I2 = 0%; 5 trials, 1502 participants; moderate-certainty evidence); little or no difference on the likelihood of being readmitted to hospital after discharge from hospital at home or inpatient care within 3 to 12 months' follow-up (RR 1.14, 95% CI 0.97 to 1.34; P = 0.11; I2 = 41%; 8 trials, 1757 participants; moderate-certainty evidence); and probably reduces the likelihood of living in residential care at six months' follow-up (RR 0.53, 95% CI 0.41 to 0.69; P < 0.001; I2 = 67%; 4 trials, 1271 participants; moderate-certainty evidence). Hospital at home probably results in little to no difference in patient's self-reported health status (2006 patients; moderate-certainty evidence). Satisfaction with health care received may be improved with admission avoidance hospital at home (1812 participants; low-certainty evidence); few studies reported the effect on caregivers. Hospital at home reduced the initial average hospital length of stay (2036 participants; low-certainty evidence), which ranged from 4.1 to 18.5 days in the hospital group and 1.2 to 5.1 days in the hospital at home group. Hospital at home length of stay ranged from an average of 3 to 20.7 days (hospital at home group only). Admission avoidance hospital at home probably reduces costs to the health service compared with hospital admission (2148 participants; moderate-certainty evidence), though by a range of different amounts and using different methods to cost resource use, and there is some evidence that it decreases overall societal costs to six months' follow-up. Admission avoidance hospital at home, with the option of transfer to hospital, may provide an effective alternative to inpatient care for a select group of older people who have been referred for hospital admission. The intervention probably makes little or no difference to patient health outcomes; may improve satisfaction; probably reduces the likelihood of relocating to residential care; and probably decreases costs.

Mimetic desire in Augustine’s Confessiones as a model for natural theology and virtue ethics

This article examined the concept and notability of mimetic desire in Augustine’s autobiographical work Confessiones. Mimetic desire is based primarily on the knowledge that there is a Perfect Being, viz. God, ideal forms (in Platonic idiom), which may be known and imitated by humans. Mimesis demonstrates that humans have a natural capacity and tendency to imitate and possess what others have. Despite this, in popular culture, mimesis has the connotation of feyness and is discouraged in place of inventiveness. The culture and spirit of our day promote originality and inventiveness without an understanding of the human nature and its inherent mimetic desires. The concept of mimetic desire is rooted in Rene Girard’s theory of anthropology but can be traced back as far as Plato’s Republic. Therefore, this interdisciplinary concept has been explored through Augustine’s narratological composition of Confessiones. The introspective tone and cultural forming narratives that make up Confessiones were succinctly examined in the context of mimetic theory. The triangular structure of mimetic desire was further explored to gain a better understanding of how Augustine relied on mimesis in his conversion to Christianity. The choice of imitating authentic models led to Augustine’s moral renewal, and likewise such implications are relevant to modern-day Christians. Moreover, this article aims to promote the concept of mimesis as an ideal practise concerning human nature and conditioning, towards a virtuous and morally acceptable society. The results of this article underline the importance of narrative theory and friendship in developing positive cultures through mimesis. Through contrasting Augustine’s earlier Manichaean life and his later Christian life, an illustration of mimetic desire can be drawn, and for Augustine, this could only mean Christ.Contribution: This article contributes to the ongoing interdisciplinary studies of ontology, anthropology, theology, and sociology. By interpreting or reading Augustine’s Confessiones through the lens of mimetic desire, this article offers an alternative perspective on Augustine’s natural theology and virtue ethics. It further presents the conceptual framework of mimesis on Christian and Platonist praxis of the ideal forms. Moreover, the article of the narratological composition of Confessiones expounds the importance of interpersonal relationships in our spiritual growth. The triangular structure of mimesis was further expounded in the context of interior life, viz. interior homo [inner man] as the ultimate model.

Abstract B053: Lipid metabolism and lipidomics of ovarian clear cell carcinoma: a comprehensive analysis

Abstract Ovarian clear cell carcinoma (OCCC) is a chemoresistant subtype of ovarian cancer accounting for 5-12% of all epithelial ovarian cancer cases. Lipid metabolism has been reported to be involved in platinum resistance and resistance to ferroptosis induction in various cancer types. However, the metabolomic and lipidomic landscape of OCCC has not been characterized. To explore the metabolic processes driving the aggressive nature of advanced OCCC, we carried out global metabolomic and lipidomic profiling on 64 early and advanced ovarian cancer samples, including tumors with corresponding metastases. Snap frozen tissue from 29 OCCC, 22 high-grade serous carcinoma (HGSOC), and 13 endometrioid ovarian carcinoma (EnOC) cases were included. Hydrophilic interaction liquid chromatography (HILIC)-mass spectrometry was performed to quantify the relative steady-state level of 318 unique metabolites. Principal component analysis (PCA) showed a distinct separation between OCCC and HGSOC/EnOC samples, mainly driven by short and medium chain acylcarnitine and hydroxylated acylcarnitine esters that were significantly more abundant in OCCC. Acylcarnitines are intermediaries of fatty acid beta-oxidation (FAO), and their enrichment in OCCC patient samples might indicate a difference in fatty acid utilization and lipid metabolism compared to OCCC and HGSOC/EnOC. FAO has been linked to redox homeostasis in cancer cells, acting as a protective factor against lipid peroxidation through selective depletion of certain lipid species. To explore whether deeper lipidomic changes in OCCC accompany increased acylcarnitine production, we performed global complex lipid detection on 7 OCCCs and 3 HGSOC tissue samples using reverse phase liquid chromatography and mass spectrometry. Six-hundred and fifty-seven unique lipid species were successfully identified. A comparison of lipid class abundances between OCCC and HGSOC uncovered increased levels of medium chain acylcarnitines in OCCC, corroborating the HILIC findings. Moreover, the levels of cholesterol esters and ceramides with polyunsaturated fatty acid chains were also more abundant in OCCC. Conversely, choline plasmalogens, a lipid class known to induce lipid peroxidation and ferroptosis cell death exhibited significantly lower abundance in OCCC. Additionally, saturated ethanolamine plasmalogens and ceramides containing saturated fatty acids were decreased in OCCC. In summary, our study reports significant differences in the lipid metabolism of OCCC compared to other major ovarian cancer subtypes. The observed decrease in peroxidation-prone lipid species might indicate the involvement of FAO in OCCC’s redox homeostasis and highlights FAO as a potential novel mechanism of platinum resistance in OCCC. Ongoing studies, presented at the meeting include the metabolomic and lipidomic profiling of a large panel of ovarian cancer cell lines to identify those that best model patient sample metabolism. These models will subsequently be used for in vitro and in vivo studies to evaluate FAO as a potential therapeutic target in OCCC. Citation Format: Agnes J. Bilecz, Roya AminiTabrizi, Hardik Shah, Ernst Lengyel. Lipid metabolism and lipidomics of ovarian clear cell carcinoma: a comprehensive analysis [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr B053.

Abstract B002: Exploiting JAK/STAT signaling to inhibit highly advanced and resistant forms of ovarian cancer

Abstract Ovarian cancer is the most fatal of all female reproductive cancers due to its late detection, aggressive nature, and propensity to develop resistance to current standards of care. Despite initial responses to first line platinum- and paclitaxel-based chemotherapies, &amp;gt;70% of ovarian cancers recur with increasingly resistant disease. Targeted therapies, including PARP-inhibitors (PARPi) and VEGF-inhibitors, are being included in the front-line setting; and while they have improved progression-free survival in a subset of patients, they have thus far failed to improve overall survival in patients without specific genetic signatures. With the broad uptake of PARPi, PARPi-resistance is becoming common. Once resistance develops, nearly all patients die of their disease and there is an obvious need to elucidate the basis for chemotherapy- and PARPi-resistance and devise novel approaches to overcome resistance. Using a small molecule drug screen, we identified lestaurtinib, a known tyrosine kinase inhibitor as a potent inhibitor of treatment naive and highly advanced models of ovarian cancer. Lestaurtinib was originally developed to target FLT3, a protein not expressed in any ovarian cancer models we’ve tested. To identify lestaurtinib targets, we preformed phospho-proteomics in parallel with RNAseq and discovered the JAK/STAT signally pathway as a top hit. We confirmed that essential components of JAK/STAT signaling are constitutively activated in chemotherapy- and PARPi-resistant cells, suggesting that induction of this pathway may drive resistance. Importantly, we found that lestaurtinib-sensitive patient-derived-xenografts (PDXs) exhibited higher expression of multiple JAK/STAT signaling pathway members compared to PDXs that did not respond to lestaurtinib. Genetic knockdown of STAT1 and STAT3 via siRNA, or knockout via CRISPR/Cas9, resulted in significant growth inhibition of sensitive and resistant models, confirming their importance in maintaining cell viability and progression. Combining lestuartinib with standard-of-care cisplatin or olaparib, a PARPi, was shown to be synergistic in multiple models, indicating that pharmacological inhibition of JAK/STAT signaling has the potential to alleviate drug resistance. Finally, we assessed a panel of JAK/STAT inhibitors that interfere at various levels of the pathway and found profound differences in their ability to block STAT-phosphorylation and inhibit cell proliferation. Thus, it is critical to further define the mechanisms by which these drugs function to selectively suppress JAK/STAT signaling in order to elucidate specific nodes of the pathway that drive ovarian cancer progression. Ongoing studies are aimed at identifying the unique roles of STAT1 and STAT3, the specific contributions of their tyrosine and serine phosphorylation, and the relevance of up-/down-stream mediators of the JAK/STAT pathway on ovarian cancer cell growth with the goal of informing future clinical trials. Citation Format: Esther Rodman, Michael Emch, Archit Bajaj, Xiaojia Tang, Xiaonan Hou, Scott Kaufmann, Krishna Kalari, John Weroha, John Hawse. Exploiting JAK/STAT signaling to inhibit highly advanced and resistant forms of ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr B002.

Resistant hypertension.

Resistant hypertension (RH) is characterized by persistently elevated blood pressure despite the concurrent use of three antihypertensive medications, including a diuretic, at optimal doses. This clinical phenomenon poses a significant burden on healthcare systems worldwide due to its association with increased cardiovascular disease morbidity and mortality. Ongoing studies on device-based treatment of RH, with aim to reduce sympathetic nervous system outflow, have shown promising evidence in management of RH which may in turn decrease the incidence of composite cardiovascular outcome faced by the affected population. This paper aims to provide a comprehensive overview of RH, and review some of the diagnostic and therapeutic approaches in management of RH.

Abstract P18: Splicing polymorphism rs12459419 modulates antibody-bound internalization of CD33 isoforms

Abstract P18: Splicing polymorphism rs12459419 modulates antibody-bound internalization of CD33 isoforms

Myeloid-Derived Suppressor Cells: Therapeutic Target for Gastrointestinal Cancers.

Gastrointestinal cancers represent one of the more challenging cancers to treat. Current strategies to cure and control gastrointestinal (GI) cancers like surgery, radiation, chemotherapy, and immunotherapy have met with limited success, and research has turned towards further characterizing the tumor microenvironment to develop novel therapeutics. Myeloid-derived suppressor cells (MDSCs) have emerged as crucial drivers of pathogenesis and progression within the tumor microenvironment in GI malignancies. Many MDSCs clinical targets have been defined in preclinical models, that potentially play an integral role in blocking recruitment and expansion, promoting MDSC differentiation into mature myeloid cells, depleting existing MDSCs, altering MDSC metabolic pathways, and directly inhibiting MDSC function. This review article analyzes the role of MDSCs in GI cancers as viable therapeutic targets for gastrointestinal malignancies and reviews the existing clinical trial landscape of recently completed and ongoing clinical studies testing novel therapeutics in GI cancers.

Abstract IA003: Advancing novel therapeutics through reverse translation

Abstract Background: The established paradigm for cancer drug development was designed to advance cytotoxic agents targeting tumor cells. An increased appreciation of the role of the tumor microenvironment in treatment efficacy and disease outcomes has identified tumor-extrinsic therapeutic targets. The different mechanisms of action employed by anti-angiogenic drugs or immunotherapeutics highlight the need for updated study endpoints to identify the maximally effective dose for clinical applications. These advances, and the translation of novel therapeutics, can be accelerated through reverse translation, a term used to describe research using patient samples to inform mechanistic studies – going from bedside-to-bench. Objective: To present an example of reverse translation in the development of an immune therapy combination for ovarian cancer. Preclinical studies demonstrated therapeutic synergy of CTLA4 immune checkpoint blockade and poly(ADP ribose) polymerase (PARP) inhibition in high grade serous ovarian cancer models. These results were translated to two clinical trials for the treatment of recurrent ovarian cancer. Tumor samples from study subjects have been collected to support ongoing mechanistic investigations and exploratory biomarker studies. Both targeted and unbiased approaches identified candidate biomarkers of response to treatment for further development. Ongoing mechanistic studies are examining the significance of top prognostic markers. Conclusions: Strategies are needed to support the integration of translational studies with clinical research to inform next generation trials and to optimize clinical applications of novel therapeutics. Citation Format: Sarah F. Adams. Advancing novel therapeutics through reverse translation [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr IA003.

108 Discriminating highly resilient spermatozoa during long-term chilled storage

Abstract Artificial insemination (AI) is the most important assisted reproductive technique devised to enhance the genetic potential of animals by enabling widespread utilization of elite males. In the swine industry, AI with extended semen is highly effective, with several extenders developed for long-term storage. Regardless, the gradual decline of sperm quality during storage remains a major concern for rapid genetic dissemination. We hypothesized that existing sire-to-sire variations could reflect on sperm survival during prolonged storage. Therefore, this study examined boar sperm motility and morphology profiles to determine potential disparities during long-term storage within a commercial extender. Freshly collected Duroc boar semen samples (n = 58 boars) were extended at a commercial boar stud (Prestage Farms, MS), and sample doses (n = 29) were appropriately transported to the laboratory for experiments. Semen samples were aliquoted in tubes (filled to the top) and immediately stored in an incubator set at 17°C for up to 10 d post-collection. Daily, samples were assessed for total motility (TM), progressive motility (PM), velocities [average path velocity (VAP), curvilinear velocity (VCL), and straight-line velocity (VSL)], and normal morphology (NM) using the computer-assisted sperm analyzer (CASA, CEROS II). The deviations of TM means were used for survival discrimination between so-called “good” and “bad” semen. Data were log-transformed and analyzed (repeated ANOVA and Bonferroni adjustment) to determine the effect of time during storage. Results are expressed as mean ± SEM and P &amp;lt; 0.05 indicates significant differences. As expected, all data demonstrated a consistent and significant decline over time (P &amp;lt; 0.05), from day-0 to day-10 (TM: 78.2 ± 1.0% to 42.8 ± 4.3%; PM: 46.1 ± 1.8% to 16.2 ±2.3%, and NM: 85.1 ± 1.0% to 76.1 ± 1.9%). Notably, velocity parameters (VAP, VSL, and VCL) remained relatively stable during the storage period, while the distal droplets contributed the most to morphological defects (54.1±1.5% vs. 28.3±1.5%, 18.3±0.5%, and 2.4±0.2% for the proximal droplets, bent and coiled tailed, respectively; P&amp;lt; 0.05). Survival discrimination indicated the highest deviations from the overall averages on day-7.Consequently, good (n = 8) and bad (n = 7) semen samples had significantly different (P &amp;lt; 0.05) in TM (80.2 ± 1.4% and 21.7 ± 4.6%, respectively), PM (39.7 ± 2.7% and 4.7 ± 1.7%, respectively), and NM (87.9 ± 1.9 and 66.4 ± 2.6%, respectively).Similarly, the velocity parameters were significantly different (P &amp;lt; 0.05) between both sample groups, including VAP (74.9 ± 2.6 µm/s vs. 40.4 ± 8.7 µm/s), VCL (135.2 ± 6.0µm/s vs. 81.9 ± 17.3 µm/s), and VSL (59.0 ± 1.8 µm/s vs. 31.3 ± 6.8 µm/s). These findings indicate that specific subsets of boar semen may be well-suited for survival during long-term chilled preservation. The development of tools for early discrimination of semen doses, immediately following collection, could significantly enhance their management and facilitate appropriate shipments to remote areas or during adverse weather conditions. Ongoing studies are dedicated to unraveling the cellular mechanisms underlying the resilience of such spermatozoa. - Research funded by USDA-ARS, grant#58-6066-3-038.