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846 citation(s) found for "Russell, C F J".

Abstract 19131: Stent-Based Vascular Cell Delivery for Therapeutic VEGF-Induced Angiogenesis
Doyle, Brendan, Martin, Kenneth, Ali, Mohammed T. , Skelding, Kimberley A, Gleeson, Birgitta , Ritman, Erik L., Caplice, Noel M. , Kumar, Arun , Skelding, Kimberley, Wang, Shaohua , Russell, Stephen J

Circulation | April 23, 2024 | Volume: 128 | Issue: suppl_22 | Pages: No page available

10.1161/circ.128.suppl_22.a19131 Get It

Site specific targeting remains an elusive goal for stem cell and gene therapies in the cardiovascular field. One promising option involves use of modified 3D stent designs that deliver larger cell/gene payloads to specific disease sites using the versatility of percutaneous vascular access. Here, we engineered smooth muscle cells (SMCs) placed in a 3D metallic stent scaffold to deliver high local concentrations of an angiogenic gene (VEGF165) in a porcine model of chronic total occlusion involving ameroid placement on the proximal left circumflex (LCx) artery(n≥8 per group). Engineered SMCs were retained within the mesh stent structure (479 ± 47.4 SMC/mm2) and were competent for VEGF production in vitro (8.8 ± 1.8 ng/ml in media). Following implantation, micro CT analyses revealed that stents loaded with VEGF producing SMCs significantly enhanced vasa vasora microvessel density (5.43 ± 0.46 vs 2.14 ± 0.19 vessels/mm2, p<0.001) with a concomitant increase in tissue VEGF protein levels (277.9 ± 85.7 vs 18.8 ± 4.4 pg/mg protein, p<0.0001). Formation of endothelial cell colonies from peripheral blood mononuclear cells was significantly increased with the implantation of VEGF-secreting cells suggesting increased angiogenic potential (7.0 ± 2.0 versus 41.6 ± 4.5, EC:CFU p<0.0001). VEGF secreting mesh stent placement enhanced regional blood flow analyses determined by microsphere analyses as well as improving regional wall motion in the LCx-related territory (p<0.05) as well as left ventricular function assessed in terms of ejection fraction (34.2 ± 6.7% vs 61.2 ± 5.2% P<0.001) and dp/dt (p<0.001) Our data indicate robust clinically relevant angiogenesis can be achieved in a human scale porcine chronic vascular occlusion model following stent based delivery of angiogenic cells. This may have implications for percutaneous delivery of stem cells, genes and secreted therapeutic factors in cardiovascular disease in general and in creation of percutaneous microvascular bypass networks in the setting of chronic vaso-occlusive disease in particular.
Abstract 13545: ST2 in Heart Failure With Preserved Ejection Fraction
Stevens, Susanna R., Chen, Horng H. , Redfield, Margaret M. , AbouEzzeddine, Omar F. , McKie, Paul M. , Dunlay, Shannon M. , Felker, G. Michael , Borlaug, Barry A. , Tracy, Russell P. , Braunwald, Eugene

Circulation | April 23, 2024 | Volume: 132 | Issue: suppl_3 | Pages: No page available

10.1161/circ.132.suppl_3.13545 Get It

Introduction: In vitro, ST2 is a marker of myocyte stress and inflammation but in vivo, there is no trans-cardiac ST2 concentration step-up to support cardiac ST2 activation in human heart failure (HF) calling into question the source of ST2 in HF. While ST2 is predictive of adverse outcomes in HF, the relationship between ST2 and key pathophysiologic domains in HF with preserved ejection fraction (HFpEF) is not well characterized. Hypothesis: ST2 levels increase in proportion to the severity of left ventricular (LV) remodeling and dysfunction in HFpEF. Methods: At enrollment, patients (n=174) from the RELAX trial testing sildenafil in HFpEF had serum ST2 levels measured and underwent assessment of pathophysiologic domains including congestion, cardiac structure and function, exercise performance (peak oxygen consumption (VO2)) and biomarkers of neurohumoral activation (NT-proBNP, aldosterone, endothelin-1), renal dysfunction (cystatin-C), fibrosis (pro-collagen III N-terminal peptide [NTP], C-telopeptide for type I collagen [CITP]), inflammation (high-sensitivity CRP [hsCRP]) and myocardial necrosis (high-sensitivity troponin-I [hsTnI]). Analysis adjusted for sex, a covariate associated with ST2 levels in normal persons. Results: See table. ST2 was associated with greater congestion, worse right ventricular (RV) pressure overload and dysfunction, lower peak VO2 and biomarkers of neurohumoral activation, renal dysfunction, fibrosis and myocardial necrosis and tended to be associated with systemic inflammation (hsCRP). ST2 was not associated with LV structure or LV systolic or diastolic function. Conclusions: In HFpEF, ST2 was associated with measures of right sided congestion, RV overload and dysfunction, exercise intolerance and other systemic markers of more advanced HF but not with LV structure or LV systolic or diastolic function. These data suggest that mechanisms distinct from LV stress stimulate ST2 activation in HFpEF.
Placental senescence pathophysiology is shared between peripartum cardiomyopathy and preeclampsia in mouse and human
Roh, Jason D. , Castro, Claire , Yu, Andy, Rana, Sarosh , Shahul, Sajid , Gray, Kathryn J. , Honigberg, Michael C. , Ricke‐Hoch, Melanie , Iwamoto, Yoshiko , Yeri, Ashish, Guerra, Justin Ralph Baldovino , Hobson, Ryan , Chaudhari, Vinita , Chang, Bliss , Sarma, Amy , Lerchenmüller, Carolin , Sayed, Zeina R. Al , Verdugo, Carmen Diaz , Xia, Peng , Skarbianskis, Niv, Zeisel, Amit , Kirkland, James L. , Gorcsan, John , Damp, Julie B., Hanley‐Yanez, Karen , McNamara, Dennis M. , Investigators, for the IPAC, Rosenzweig, Anthony , Fett, James D., Pisarcik, Jessica, McTiernan, Charles F. , Alharethi, Rami , Rasmusson, Kismet, Brunisholz, Kim , Butler, Amy L., Budge, D., Kfoury, Abdallah G., Horne, Benjamin D. , Tuinei, Joe, Brown, Heather , Naftilan, Allen J., Russell, Jill , Freehardt, Darla, Hsich, Eileen , Oblak, Cynthia, Ewald, Greg, Whitehead, Donna, Flanagan, Jean, Platts, Anne, Mullin, Stephanie, Givertz, Michael M. , Anello, Mary Susan, Booth, David R. , Sandlin, Tiffany, Wijesiri, Wendy, Blauwet, Lori A., Brunner, Joann, Phelps, Mary, Kempf, Ruth, Modi, Kalgi , Norwood, Tracy, Griza, Decebal Sorin, Adams, Patricia L., Thohan, Vinay , Wesley-Farrington, Deborah, Soots, Sandra, Sheppard, Richard , Lapointe, Nathalie, Nathaniel, Heather, Kealey, Angela, Semigran, Marc J., Daher, Maureen, Silber, David, Popjes, Eric , Frey, Patricia, Nicklas, Todd, Alexis, Jeffrey D. , Caufield, Lori, Thornton, John W., Gentry, Mindy, Robinson, V.J. , Sharma, Gyanendra K. , Holloway, Joan, Powell, Maria, Markham, David W. , Fernandez, Lynn, Gimovsky, Martin L., Hochbaum, Natalia, Patel, Bharati Kadamb , Adams, Laura , Ramani, Gautam , Robinson, Shawn , Fisher, Stacy D. , Marshall, Joanne, Haythe, Jennifer , Mancini, Donna , Bijou, Rachel, Marks, Marybeth, Arango, Henry, Bolos, Mariana, Mather, Paul , Rubin, Sharon, Bonita, Raphael , Eberwine, Susan, Skopicki, Hal A. , Stergiopoulos, Kathleen , McCathy-Santoro, Ellen, Intravaia, Jennifer, Maas, Elizabeth W., Safirstein, Jordan, Martinez, Nancy , Corpoin, Christine, Hesari, Donna, Chaparro, Sandra , Hudson, Laura J., Ghali, Jalal K. , Injic, Zora, Wittstein, Ilan S. , Kitchen, Robert , Guerra, Justin Baldovino , Chaudhari, Vinita , Chang, Bliss , Sarma, Amy , Al Sayed, Zeina R , Diaz Verdugo, Carmen , Xia, Peng , Zeisel, Amit , Bauersachs, Johann , Kirkland, James L , Karumanchi, S Ananth , Gorcsan, John , Sugahara, Masataka , Hanley-Yanez, Karen , Ellinor, Patrick T , Arany, Zoltan Pierre , McNamara, Dennis M , Rosenzweig, Anthony , Honigberg, Michael C , Castro, Claire , Karumanchi, S. Ananth , Ellinor, Patrick T. , Investigators, for the IPAC, Hilfiker‐Kleiner, Denise , Schelbert, Erik B. , Butler, Amy, Elkayam, Uri , Caro, Jorge , Rajagopalan, Navin , Booth, David, Cooper, Leslie T. , Briller, Joan Ellen , Felker, G. Michael , Kociol, Robb D. , Adams, Patricia, Wells, Gretchen , Michel, Caroline, Boehmer, John , Holloway, Joan, Powell, Maria, Drazner, Mark H. , Zucker, Mark Jay , Baran, David A. , Patel, Bharati, Gottlieb, Stephen S. , Farr, Maryjane , Bozkurt, Biykem , Maas, Elizabeth, Kleet, Audrey

Science Translational Medicine | April 17, 2024 | Volume: 16 | Issue: 743 | Pages: No page available

10.1126/scitranslmed.adi0077 | PMID 38630848 Get It

Peripartum cardiomyopathy (PPCM) is an idiopathic form of pregnancy-induced heart failure associated with preeclampsia. Circulating factors in late pregnancy are thought to contribute to both diseases, suggesting a common underlying pathophysiological process. However, what drives this process remains unclear. Using serum proteomics, we identified the senescence-associated secretory phenotype (SASP), a marker of cellular senescence associated with biological aging, as the most highly up-regulated pathway in young women with PPCM or preeclampsia. Placentas from women with preeclampsia displayed multiple markers of amplified senescence and tissue aging, as well as overall increased gene expression of 28 circulating proteins that contributed to SASP pathway enrichment in serum samples from patients with preeclampsia or PPCM. The most highly expressed placental SASP factor, activin A, was associated with cardiac dysfunction or heart failure severity in women with preeclampsia or PPCM. In a murine model of PPCM induced by cardiomyocyte-specific deletion of the gene encoding peroxisome proliferator–activated receptor γ coactivator-1α, inhibiting activin A signaling in the early postpartum period with a monoclonal antibody to the activin type II receptor improved heart function. In addition, attenuating placental senescence with the senolytic compound fisetin in late pregnancy improved cardiac function in these animals. These findings link senescence biology to cardiac dysfunction in pregnancy and help to elucidate the pathogenesis underlying cardiovascular diseases of pregnancy.
Prostate Cancer, Version 3.2024
Schaeffer, Edward M. , Srinivas, Sandy, An, Yi , Bitting, Rhonda L. , Chapin, Brian F. , D’Amico, Anthony V. , Desai, Neil , Dorff, Tanya B. , Eastham, James A., Farrington, Thomas A., Gupta, Shilpa , Guzzo, Thomas, Karnes, R. Jeffrey , Kuettel, Michael, McKay, Rana R. , Morgan, Todd M. , Pow‐Sang, Julio M. , Reiter, Robert E. , Roach, Mack , Rosenfeld, Stan, Shabsigh, Ahmad , Valicenti, Richard K., Wong, J.K. , Snedeker, Jenna, Freedman-Cass, Deborah A., Morgan, Todd M , Robin, Tyler P. , Adra, Nabil , Cheng, Heather H. , Gao, Xin Yuan , Ippolito, Joseph E. , Lang, Joshua M. , Lotan, Tamara Levin , Spratt, Daniel E. , Szmulewitz, Russell Z , Teply, Benjamin A. , Tward, Jonathan D.

Journal of the National Comprehensive Cancer Network | April 16, 2024 | Volume: 22 | Issue: 3 | Pages: 140-150

10.6004/jnccn.2024.0019 | PMID 38626801 Get It

The NCCN Guidelines for Prostate Cancer include recommendations for staging and risk assessment after a prostate cancer diagnosis and for the care of patients with localized, regional, recurrent, and metastatic disease. These NCCN Guidelines Insights summarize the panel's discussions for the 2024 update to the guidelines with regard to initial risk stratification, initial management of very-low-risk disease, and the treatment of nonmetastatic recurrence.
Adult-onset Leigh Syndrome: An analysis of the North American Mitochondrial Disease Consortium Database (P3-11.017)
Kroopnick, Adam, Houck, Alexander, Thakur, Kiran T. , Dugue, Rachelle , Goldstein, Amy , Gavrilova, Ralitza H. , Hove, Johan Van, Saneto, Russell P. , Buchsbaum, Richard , Thompson, John L.P. , Barca, Emanuele , Zolkipli‐Cunningham, Zarazuela , Falk, Marni J. , Demczko, Matthew M. , Larson, Austin , Hirano, Michio

Neurology | April 9, 2024 | Volume: 102 | Issue: 7_supplement_1 | Pages: No page available

10.1212/wnl.0000000000206383 Get It

Large-scale network analysis of the cerebrospinal fluid proteome identifies molecular signatures of frontotemporal lobar degeneration
Saloner, Rowan , Staffaroni, Adam M. , Dammer, Eric B. , Johnson, Erik C. B. , Wise, Amy B. , Heuer, Hilary W. , Forsberg, Leah K. , Lago, Argentina Lario , Webb, Julia D, Kramer, Joel H. , Li, Jingyao , Sivasankaran, Rajeev , Seyfried, Nicholas T. , Yokoyama, Jennifer S. , Grinberg, Lea T. , Ljubenkov, Peter A. , Brushaber, Danielle , Considine, Ciaran , Day, Gregory S. , Faber, Kelley , Geschwind, Daniel H. , Ghoshal, Nupur , Graff‐Radford, Neill R. , Hales, Chadwick M. , Huey, Edward D. , Kornak, John , Lee, Suzee, Mendez, Mario F. , Miyagawa, Toji , Pascual, Belén , Paulson, Henry L. , Petrucelli, Leonard , Ramos, Eliana Marisa , Rascovsky, Katya, Savica, Rodolfo , Snyder, Allison , Sullivan, A. Campbell , Vandebergh, Marijne , Rosen, Howie, Boxer, Adam L. , Casaletto, Kaitlin B. , Staffaroni, Adam M , Hansson, Oskar , Sivasankaran, Rajeev , Yokoyama, Jennifer , Spina, Salvatore , Grinberg, Lea , VandeVrede, Lawren , Brushaber, Danielle , Day, Gregory S , Dickerson, Bradford Clark , Domoto-Reilly, Kimiko , Galasko, Douglas , Geschwind, Daniel , Ghoshal, Nupur , Honig, Lawrence S. , Hsiung, Gink-Yuek , Lapid, Maria I. , Litvan, Irene , Mendez, Mario , Pascual, Belen , Roberson, Erik , Snyder, Allison , Tartaglia, Maria Carmela , Vandebergh, Marijne , Boeve, Brad , Paulson, Henry L , Dammer, Eric B

No container title available | March 28, 2024 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.21203/rs.3.rs-4103685/v1 | PMID 38585969 Get It

Abstract The pathophysiological mechanisms driving disease progression of frontotemporal lobar degeneration (FTLD) and corresponding biomarkers are not fully understood. We leveraged aptamer-based proteomics (> 4,000 proteins) to identify dysregulated communities of co-expressed cerebrospinal fluid proteins in 116 adults carrying autosomal dominant FTLD mutations (C9orf72, GRN, MAPT) compared to 39 noncarrier controls. Network analysis identified 31 protein co-expression modules. Proteomic signatures of genetic FTLD clinical severity included increased abundance of RNA splicing (particularly in C9orf72 and GRN) and extracellular matrix (particularly in MAPT) modules, as well as decreased abundance of synaptic/neuronal and autophagy modules. The generalizability of genetic FTLD proteomic signatures was tested and confirmed in independent cohorts of 1) sporadic progressive supranuclear palsy-Richardson syndrome and 2) frontotemporal dementia spectrum syndromes. Network-based proteomics hold promise for identifying replicable molecular pathways in adults living with FTLD. ‘Hub’ proteins driving co-expression of affected modules warrant further attention as candidate biomarkers and therapeutic targets.
Factors underlying scalp‐EEG interictal epileptiform discharges in intractable frontal lobe epilepsy
So, Elson L., Mosewich, Russell K., Cascino, Gregory D. , Meyer, Fredric B. , Lesnick, Timothy G. , Vadlamudi, Lata , Worrell, Gregory A.

Epileptic Disorders | March 27, 2024 | Volume: 6 | Issue: 2 | Pages: 89-95

10.1684/j.1950-6945.2004.tb00056.x Get It

ABSTRACT Aims Scalp‐EEG interictal epileptiform discharges (IEDs) may be less predictive of the outcome of frontal lobe epilepsy surgery than of temporal lobe epilepsy surgery. We identified factors associated with the location of scalp‐EEG IEDs in intractable frontal lobe epilepsy. Methods Ten factors were assessed in a retrospective review of 53 patients with either concordant (frontal lobe seizure focus) or discordant (generalized or outside frontal seizure focus) IED or both, who had excellent surgical outcomes. The Fisher exact test and the Wilcoxon rank sum test determined statistically significant associations. Results Thirty‐six patients (68%) had concordant IED, 24 (45%) discordant IED, and 17 (32%) both. Younger age at onset was significantly associated with discordant IED (mean, 7.5 years versus 17 years for patients without discordant IED; P < 0.01), whereas duration of epilepsy was not. Seizure foci at the frontal convexity were associated with concordant IED. About 72% of patients with a convexity seizure focus had concordant IED, compared with only 33% of patients with mesial frontal foci having concordant IED ( P = 0.06). Conclusions Early seizure onset in intractable frontal lobe epilepsy is associated with IEDs discordant with seizure focus. Frontal convexity seizure foci are more likely than mesial frontal seizure foci to be associated with concordant discharges.
Abstract 983: Epigenomic analysis of plasma cell-free DNA identifies stemness features associated with worse prognosis in AR-altered lethal metastatic castration resistant prostate cancer
Mueller, Ryan , Shiang, Alexander L. , Dang, Ha X. , Saha, Debanjan , Babbra, Ramandeep K. , Feng, Wenjia , Qaium, Faridi , Caputo, Sydney , Sartor, Oliver A., Maher, Christopher A. , Chaudhuri, Aadel A. , Chauhan, Pradeep S. , Alahi, Irfan , Sinha, Savar , Webster, Jace , Saha, Debanjan, Greiner, Lilli , Yang, Breanna , Ledet, Elisa M. , Harris, Peter K , Jaeger, Ellen , Miller, Patrick J., Pachynski, Russell K.

Cancer Research | March 22, 2024 | Volume: 84 | Issue: 6_Supplement | Pages: 983-983

10.1158/1538-7445.am2024-983 Get It

Abstract Background: Metastatic castration-resistant prostate cancer (mCRPC) resistant to androgen receptor (AR)-targeted agents is often lethal. Unfortunately, biomarkers for this deadly disease remain under investigation, and underpinning mechanisms are ill-understood. Here, we applied epigenomic approaches to identify cell-free (cf) DNA features associated with these lethal AR-resistant mCRPC patients. Methods: Plasma from 99 mCRPC patients was collected from two independent institutions, either prior to first-line AR-targeted therapy (n = 63) or during treatment (n = 36). We applied EnhanceAR-Seq to detect alterations in the AR locus including the upstream enhancer. We then applied genome-wide cfDNA epigenomics to 43 pre-treatment plasma samples and performed both fragmentomics and methylation sequencing to delineate the biology of AR/enhancer-altered lethal mCRPC. Finally, we identified stemness genes by applying CytoTRACE to external single-cell RNA-seq data from mCRPC, and applied these to cfDNA via promoter-level methylation analysis. We then assessed these stem-associated genes in tumor bulk RNA-seq data from an independent mCRPC cohort. Results: AR/enhancer alterations were detected in 44% of pre-treatment cfDNA samples and correlated with significantly worse progression-free survival (PFS) (HR = 2.12, P = 0.01) and overall survival (OS) (HR = 2.48; P = 0.02). AR/enhancer alterations were detected in 19% of on-treatment cfDNA samples and were also associated with profoundly worse PFS (HR = 15.38, P = 0.0003) and OS (HR = 15.53, P = 0.002). Further, genome-wide cfDNA fragmentomic analysis revealed that binding sites for developmentally relevant transcription factors such as FOXA1, NKX-3 and HOXB13 were significantly more accessible in AR/enhancer-altered lethal mCRPC patients. Gene set enrichment analysis of the 20 most accessible transcription factors revealed several pathways associated with stem cell development. Interestingly, the 10 most stem-associated genes obtained using CytoTRACE applied to an external cohort of single-cell RNA-seq data from mCRPC (He et al. 2021) were promoter-hypomethylated in the plasma cfDNA of AR/enhancer-altered lethal mCRPC patients (P = 0.005). Further, metagene analysis of these stem-associated genes revealed worse PFS by Kaplan-Meier analysis (P = 0.04), which was confirmed by multivariate cox proportional hazards modeling. Our stemness metagene further stratified overall survival (P = 0.03) when applied to an external cohort of 80 mCRPC patients from Abida et al. 2019. Conclusions: Alterations in AR including the upstream enhancer are remarkably prognostic in mCRPC with pre-treatment predictive potential. The mechanism can be inferred via cfDNA epigenomic analysis and appears to involve increased tumor cell stemness in AR-altered lethal mCRPC. Citation Format: Pradeep Singh Chauhan, Irfan Alahi, Savar Sinha, Ryan Mueller, Alexander L. Shiang, Jace Webster, Ha X. Dang, Debanjan Saha, Lilli Greiner, Breanna Yang, Elisa M. Ledet, Ramandeep K. Babbra, Wenjia Feng, Peter K. Harris, Faridi Qaium, Ellen B. Jaeger, Patrick J. Miller, Sydney A. Caputo, Oliver A. Sartor, Russell K. Pachynski, Christopher A. Maher, Aadel A. Chaudhuri. Epigenomic analysis of plasma cell-free DNA identifies stemness features associated with worse prognosis in AR-altered lethal metastatic castration resistant prostate cancer [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 983.
Abstract 1878: CTPS1: An unexplored vulnerability in breast and ovarian cancer
Wang, Xiyin , Emch, Michael J. , Voll, Lauren, Russell, Rebecca A , Rodman, Esther , Pearson, Nicole A, Hou, Xiaonan , Weroha, Saravut J., Hawse, John R. , Russell, Rebecca, Kaufmann, Scott H. , Beer, Philip

Cancer Research | March 22, 2024 | Volume: 84 | Issue: 6_Supplement | Pages: 1878-1878

10.1158/1538-7445.am2024-1878 Get It

Abstract Breast and ovarian cancer represent the most common cancer types in women worldwide and are among the top fatal cancers. Despite the use of cytotoxic chemotherapy and targeted agents, recurrence is frequent and survival rates for patients with advanced metastatic disease are dismal. These realities highlight the need to identify novel biomarkers and therapeutic vulnerabilities in such tumors and to develop alternative treatment strategies. We took an unbiased approach to tackle this problem in which we leveraged publically available (DepMap) and in-house generated genome-wide CRISPR screens conducted in over 1000 cancer cell lines. We initially focused on the identification of essential genes that were unique to triple-negative breast cancer (TNBC) cells and whose expression levels were associated with worse patient outcomes. This interrogation revealed six genes (CTPS1, RHOA, PRKRA, RAD9A, HUS1, and RAD1) meeting these initial criteria. The essentiality of these genes was validated using gene-specific siRNAs in a panel of TNBC cells and knockdown of CTPS1 was shown to elicit the most inhibitory effect. CTPS1 depletion resulted in a rapid S-phase cell cycle arrest followed by apoptosis, not only in TNBC cells but also in highly aggressive ovarian cancer cells which share many molecular features with TNBC. CTPS1 converts uridine triphosphate to cytidine triphosphate, forming an essential nucleic acid required for multiple cellular processes. CTPS1 mRNA expression was substantially elevated in tumor vs. normal tissue, for both breast and ovarian cancer. Using over 40 breast and ovarian cancer cell lines, RT-PCR analyses confirmed increased expression of CTPS1 in TNBC and most ovarian cancer cell lines compared to other disease sub-types and “normal” cell line/tissue controls. Interestingly, chemoresistant and PARP inhibitor-resistant models exhibited the highest levels of CTPS1 among all cells analyzed. We subsequently identified and acquired STP938, a first-in-class highly selective CTPS1 inhibitor being developed by Step-Pharma. STP938 was found to elicit potent anti-cancer effects at nM concentrations across many cell line and patient-derived models, in both 2D and 3D culture systems. RNAseq analysis in aggressive cell line models following STP938 treatment or CTPS1 knockdown revealed significant regulation of genes related to DNA replication and the cell cycle pathways suggesting that combinatorial/sequential treatments of STP938 with replication stress/DNA damage response related drugs may be synergistic. STP938 is currently being developed for the treatment of lymphoma, and our findings support the repurposing of STP938 for breast and ovarian cancer, an avenue that we are currently developing. Citation Format: Xiyin Wang, Michael Emch, Lauren Voll, Rebecca Russell, Esther Rodman, Nicole Pearson, Xiaonan Hou, Scott Kaufmann, Saravut Weroha, Philip Beer, John Hawse. CTPS1: An unexplored vulnerability in breast and ovarian cancer [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 1878.