tbuckley/cabot-search huggingface dataset:
Abstract A110: Targeting methionine metabolism inhibits ovarian cancer stem cells
Authors: Shu Zhang, Tara X. Metcalfe, Christiane A. Hassel, Heather M. O'Hagan, Kenneth P. Nephew
Journal: Cancer Research (2024)

Abstract Ovarian cancer (OC) is the leading cause of gynecologic cancer death. Platinum (Pt)- based chemotherapy can reprogram cancer cells to ovarian cancer stem cells (OCSCs) and contribute to disease recurrence. In the current study, we demonstrated that platinum drugs can enrich for OCSCs. In high grade serous ovarian cancer (HGSOC) cell lines, cisplatin treatment (IC50 for 16hrs) increased the percentage of cells with high aldehyde dehydrogenase (ALDH+) activity, a known OCSCs marker, and altered methionine (Met) metabolism. Extracellular Met uptake is converted to S-adenosyl-methionine (SAM) by methionine adenosyltransferase 2A (MAT2A), the rate-limiting enzyme of Met utilization. Short-term cisplatin treatment decreased SAM level and increased expression of MAT2A. It has been reported that CSCs have a high-flux metabolic state and are dependent on Met metabolism. We observed higher MAT2A expression in ALDH+ cells compared to the whole cell population, and Met depletion blocked the cisplatin-induced increase in %ALDH+ cells and spheroid formation ability. Furthermore, both MAT2A siRNA knockdown and the MAT2A inhibitor FIDAS-5 prevented cisplatin-induced increase in %ALDH+ cells, suggesting that blocking Met metabolism phenotypically inhibited the platinum enrichment of OCSCs. MAT2A inhibition also downregulated Cyclin E and arrested HGSOC cells in G1/S phase, indicating that a lower level of Met utilization re-established G1/S checkpoint in p53-mutant OC. As SAM is the universal methyl-group donor, it was of interest to examine whether the observed cisplatin-induced alterations in SAM level resulted in changes in DNA methylation. Methylation specific-PCR analysis demonstrated that siMAT2A or FIDAS-5 treatment of HGSOC cells inhibited cisplatin-induced hypermethylation of CpG islands of BRCA1 and ALDH1L1, a folate metabolic enzyme of which promoter hypermethylation is associated to tumor progression. Collectively, these results demonstrated a crucial role of Met metabolism in cisplatin-induced OCSCs enrichment. MAT2A has been recognized as a therapeutic target for the treatment of solid tumors and Met inhibition by targeting MAT2A could represent a therapeutic approach for inhibiting CSC in ovarian cancer. Citation Format: Shu Zhang, Tara X. Metcalfe, Christiane A. Hassel, Heather M. O'Hagan, Kenneth P. Nephew. Targeting methionine metabolism inhibits ovarian cancer stem cells [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 A110.
Abstract A111: Development and analytical validation of a multiplexed targeted mass spectrometry assay to detect ovarian cancer protein biomarkers in sera
Authors: Joohyun Ryu, Kristin L. M. Boylan, Carly A. I. Twigg, Richard Evans, Amy P. N. Skubitz, Stefani N. Thomas
Journal: Cancer Research (2024)

Abstract Background: Ovarian cancer is the most lethal gynecologic malignancy in women, and high-grade serous ovarian cancer (HGSOC) is the most common subtype. Currently, no clinical test has been approved by the FDA for the detection of ovarian cancer in the general population. This underscores the critical need for the development of a robust methodology combined with novel technology to detect diagnostic biomarkers for HGSOC in the sera of women. Targeted mass spectrometry (MS) can be used to identify and quantify specific peptides/proteins in complex biological samples with high accuracy, sensitivity, and reproducibility. In this study, we developed and conducted analytical validation of a multiplexed Tier 2 targeted MS parallel reaction monitoring (PRM) assay for the relative quantification of 23 ovarian cancer protein biomarker candidates in sera. Methods: To develop a PRM method for our target peptides, we followed nationally recognized consensus guidelines for validating fit-for-purpose Tier 2 targeted mass spectrometry (MS) assays. The endogenous target peptide concentrations were calculated using the calibration curves for each target peptide. Receiver operating characteristic (ROC) curves were analyzed to evaluate the diagnostic performance of the biomarker candidates. Results: We describe the development and analytical validation of a multiplexed Tier 2 targeted MS PRM assay to quantify ovarian cancer protein biomarker candidates in sera. Among the 64 peptides corresponding to 23 proteins in our PRM assay, 24 peptides corresponding to 16 proteins passed the assay validation acceptability criteria. Six of these peptides from insulin-like growth factor-binding protein 2 (IBP2), sex hormone-binding globulin (SHBG), and TIMP metalloproteinase inhibitor 1 (TIMP1) were quantified in sera from a cohort of 69 patients with early-stage HGSOC, late-stage HGSOC, benign ovarian conditions, and healthy (non-cancer) controls. IBP2 was identified as a diagnostic biomarker candidate based on its significantly increased abundance in the late-stage HGSOC patient sera compared to the healthy controls and patients with benign ovarian conditions. Conclusions: This study developed and validated a multiplexed targeted MS PRM assay for diagnostic biomarker analysis in HGSOC. To evaluate the clinical utility of IBP2 for HGSOC detection, further studies need to be performed using a larger patient cohort. Citation Format: Joohyun Ryu, Kristin L. M. Boylan, Carly A. I. Twigg, Richard Evans, Amy P. N. Skubitz, Stefani N. Thomas. Development and analytical validation of a multiplexed targeted mass spectrometry assay to detect ovarian cancer protein biomarkers in sera [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 A111.
Abstract B003: A multi-omic analysis to identify epigenetic drivers of platinum-resistance in high-grade serous ovarian carcinoma models
Authors: Kristin Adams, Ryan Moreno, Jae-Rim Wendt, Josie Wood, Avtar Roopra, Jessica D. Lang
Journal: Cancer Research (2024)

Abstract Despite being rare cancers, ovarian cancer rank as the fifth leading cause of cancer mortalities in women in the United States. Most patients are detected late, with most patients diagnosed in Stages 3 and 4. While patients often initially respond to standard of care chemotherapy, which includes platinum-based chemotherapy such as cisplatin and carboplatin, they recur with resistant phenotypes. While a large effort has characterized mechanisms of resistance to platinum-based chemotherapy, it is still challenging to identify these patients and identify more promising therapies. While the field understands that a quiescent, stem cell-like state can serve as an intermediate from which chemoresistant recurrences can arise, the epigenetics of this state are less well understood. In fact, we do know that embryonic and pluripotent stem cells differ significantly in enhancers and other epigenetic features that contribute significantly to their phenotypes. We performed histone post-translational modifications by CUT&amp;Tag, as well as ATACseq and RNA-seq, on four isogenic cell line models of cisplatin resistance. We show that these models are resistant to both cisplatin and carboplatin. While we see paradoxical quiescent cell markers in these isogenic lines, we have characterized differential features of their epigenetics that may contribute to the resistant phenotype. We are continuing to explore transcription factors that may drive this resistance. We are also examining super-enhancers that are altered between chemo-sensitive and -resistant cell lines. Similarly, we have examined whether inhibitors of components of super-enhancers may be a viable therapeutic option for platinum-resistant high-grade serous ovarian cancer patients. We see moderate synergy between triptolide (targets TFIIH subunit XPB1) and JQ-1 (targets BRD4) with cisplatin in resistant models. Together, we hope our studies can contribute to the knowledge of how epigenetic features might contribute and be targets for chemoresistance in ovarian cancer. Citation Format: Kristin Adams, Ryan Moreno, Jae-Rim Wendt, Josie Wood, Avtar Roopra, Jessica D. Lang. A multi-omic analysis to identify epigenetic drivers of platinum-resistance in high-grade serous ovarian carcinoma models [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 B003.
Abstract B028: Unraveling the role of matrix metalloproteinase 3 (mmp3) in cisplatin resistance of ovarian cancer
Authors: Mariela Rivera-Serrano, Pablo E. Vivas-Mejía
Journal: Cancer Research (2024)

Abstract Seventy percent of women with ovarian cancer will develop chemotherapy-resistance to cisplatin. Regardless of the advancements in technology, mortality rates for ovarian cancer have declined only slightly in the last forty years. Therefore, novel and effective second-line therapies for women with ovarian cancer are urgently needed. Previously we showed that Matrix Metalloproteinase 3 (MMP3) expression is upregulated in cisplatin resistant when compared with cisplatin sensitive cells. However, the contribution of MMP3 to cisplatin resistance have not been studied previously. Western blots, ELISAs, and real-time RT-PCR confirmed that the protein and mRNA levels are higher in cisplatin resistant as compared with cisplatin sensitive cells. MMP3 expression levels were also increased by cisplatin treatment of cisplatin resistant cells. Additionally, interrogation of the Kaplan-Meier plotter database showed that ovarian cancer patients with low MMP3 levels live longer than patients with higher MMP3 levels. To understand the impact of targeting MMP3, we employed commercially available chemical inhibitors and small-interference RNA (siRNA) in cell viability, colony formation, invasion, and RNAseq experiments. Notably, MMP3-targeted siRNA significantly reduced cell viability, proliferation, and invasion, particularly when combined with cisplatin treatment. However, the MMP3 chemical inhibitor did not exhibit significant biological effects. RNAseq analysis revealed 415 differentially expressed genes (DEGs) between MMP3-siRNA and negative control (NC)-siRNA groups, as well as 440 DEGs between MMP3-siRNA + cisplatin and NC-siRNA + cisplatin groups. Functional enrichment analysis using Metascape via Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) identified genes associated with potassium and aquaporin mediated transport, clathryn-mediated endocytosis, cell cycle, metabolic processes, cellular response to stress, and extracellular matrix organization. These findings highlight the role of MMP3 upregulation in promoting cisplatin resistance. Citation Format: Mariela Rivera-Serrano, Pablo E. Vivas-Mejía. Unraveling the role of matrix metalloproteinase 3 (mmp3) in cisplatin resistance 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 B028.
Abstract B018: Enhanced transfection efficiency with folic acid conjugated synthetic polymer nanoparticles for high grade serous ovarian cancer
Authors: Chaebin Lee, Kevin Elias
Journal: Cancer Research (2024)

Abstract Objective High grade serous ovarian cancer (HGSOC) represents the predominant subtype of epithelial ovarian cancer. Developing targeted therapies for HGSOC presents challenges due to its distinctive characteristic of copy number variation rather than recurrent somatic mutation. In our recent study, we proposed a novel approach for treating ovarian cancer by combining a gene editing system and nanotechnology, utilizing a cationic synthetic biopolymer, poly (γ-propargyl L-glutamine) (PPLQ). While our findings demonstrated promising results, we identified the presence of a negatively charged polymer layer, required for systematic delivery in vivo, significantly reduced both transfection efficiency and therapeutic efficacy. Therefore, an innovative approach to enhance transfection efficiency is desired to achieve improved treatment outcomes. Folate receptor alpha (FRα) is highly overexpressed in various epithelial cancers, including breast, lung, and ovarian cancer. Previous studies have revealed that FRα exhibits high tumor specificity, with epithelial ovarian cancers demonstrating 10 to 100-fold higher FRα expression levels compared to kidney, lung, and breast epithelial cells. Therefore, FRα is an attractive candidate for targeted therapy for ovarian cancer. Method In this study, we conjugated folic acid (FA), which has high affinity for FRα, to PPLQ to enhance gene delivery efficiency. Polyplexes were synthesized using FA conjugated PPLQ (FA-PPLQ) with pGL3 luciferase reporter vector. The particle size and the zeta potential were analyzed by Zetasizer, and transfection efficiency was evaluated by a luminescence assay. Result Compared to the positively charged PPLQ polyplexes, +55.5 mV, the FA-PPLQ polyplexes showed highly negative surface charges of -43.8 mV. The particle size was slightly increased from 35.07 ± 0.5422 for the PPLQ polyplexes to 48.63 ± 0.4239 for the FA-PPLQ polyplexes. The luminescence assay using a pGL3 luciferase reporter vector demonstrated a 74.4% improvement in transfection efficiency with FA conjugation compared to the negatively charged polymer layer. Conclusion Through the conjugation of folic acid to a cationic biopolymer, we successfully achieved enhanced transfection efficiency compared to a negatively charged polymer layer. Notably, the FA-PPLQ polyplexes exhibited a negative surface charge, which is advantageous for in vivo delivery. The results suggest that folic acid conjugation on the surface of polyplexes has a great promise as an effective approach for targeted gene therapy in HGSOC. Citation Format: Chaebin Lee, Kevin Elias. Enhanced transfection efficiency with folic acid conjugated synthetic polymer nanoparticles for high grade serous 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 B018.
Abstract A102: ROR2/Wnt5a signaling regulates directional cell migration and early tumor cell invasion in ovarian cancer
Authors: Whitney R. Grither, Breanna Baker, Vasilios A. Morikis, Katherine C. Fuh, Gregoery D Longmore
Journal: Cancer Research (2024)

Abstract Adhesion to and clearance of the mesothelial monolayer are key events in the early metastatic seeding of ovarian cancer. To identify mediators of ovarian cancer cell adhesion and invasion, we developed and conducted a cellular, high-throughput genetic screen using a human kinome siRNA library. Through this screen, we identified ROR2 as a driver of ovarian cancer adhesion and invasion. ROR2 is a receptor tyrosine kinase that interacts with Wnt5a ligand to activate non-canonical Wnt signaling and has been previously shown to be upregulated in ovarian cancer tissue. However, no prior study has evaluated the mechanistic role of ROR2 in ovarian cancer. Using in vitro adhesion and mesothelial clearance assays, we show that ROR2 promotes ovarian cancer cell adhesion and clearance of the mesothelial monolayer, key early steps in ovarian cancer metastasis. Further, we show that depletion of ROR2 reduces metastatic tumor burden in a syngeneic mouse model of ovarian cancer. Additionally, using a microfluidic device capable of producing stable fluid gradients, we demonstrate that ROR2 expression in ovarian cancer cells serves to drive directed cell migration of tumor cells, preferentially to areas of high Wnt5a ligand. As Wnt5a has been previously shown to be produced and upregulated in the mesothelial cells of the ovarian cancer microenvironment, these findings represent a novel role for ROR2 to promote the homing of ovarian tumor cells to the mesothelial lined metastatic niche by using Wnt5a as a chemotactic cue. These findings support the role of ROR2 as a critical factor contributing to the steps of ovarian cancer metastasis. Therapeutic targeting of the ROR2/Wnt5a signaling axis could provide a means of improving treatment for patients with advanced ovarian cancer. Citation Format: Whitney R. Grither, Breanna Baker, Vasilios A. Morikis, Katherine C. Fuh, Gregoery D Longmore. ROR2/Wnt5a signaling regulates directional cell migration and early tumor cell invasion in 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 A102.
Abstract B024: Maintenance therapy inhibition of ptk2 yields decreased disease in preclinical HRP/HRD models of recurrent HGSOC
Authors: Breana Hill, Ioana Bondre, H Meryem Soylu, Juliette Antoine, Xiao Lei Chen, Elise Tahon, Yichi Zhang, Marjaana Olajill, Sarah Kinkel, Terrie-Anne Cock, Pratibha Binder, Chris Burns, David Schlaepfer, Michael McHale T. McHale, Dwayne G Stupack
Journal: Cancer Research (2024)

Abstract High grade serous ovarian cancer remains the most lethal of the gynecologic malignancies, in part, because of the high incidence of recalcitrant and rapidly recurring disease. Disease recurrence is now better controlled due to maintenance therapy with PARP inhibitors, particularly in homologous repair deficient tumors. Efficacy in homologous repair proficient tumors represents an unmet need. We previously demonstrated that inhibitors of protein tyrosine kinase 2 (ptk2), a gene that is frequently gained in HGSOC, compromises the expression of tumor repair genes, decreases stemness, and limits immune evasion. The low toxicity of ptk2 inhibitors appears to be well suited for a maintenance role. Here, we tested the effect of six weeks of ptk2 inhibitor maintenance treatment, post-chemotherapy, in two preclinical models. In a homologous repair proficient model (KMF), and in a PARP inhibitor-resistant model (HGS2), ptk2 inhibitor treatment yielded lower tumor burden, fewer solid tumors, and decreased bloody ascites accumulation relative to treatment with Niraparib. The low toxicity and overall efficacy provide strong support for future clinical trials with ptk2 inhibitors in the maintenance role, for patients with HGSOC. Citation Format: Breana Hill, Ioana Bondre, H Meryem Soylu, Juliette Antoine, Xiao Lei Chen, Elise Tahon, Yichi Zhang, Marjaana Olajill, Sarah Kinkel, Terrie-Anne Cock, Pratibha Binder, Chris Burns, David Schlaepfer, Michael McHale T. McHale, Dwayne G Stupack. Maintenance therapy inhibition of ptk2 yields decreased disease in preclinical HRP/HRD models of recurrent HGSOC [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 B024.
Abstract B031: The PLK1 inhibitor Volasertib as a treatment for HSF1 and MYC coamplified ovarian cancer
Authors: Matthew O'Malley, Imade W. Williams, Bobby Walker, Haimanti Ray, Kenneth P. Nephew, Richard Carpenter
Journal: Cancer Research (2024)

Abstract Ovarian cancer is a disease that afflicts 1 in 78 women. This disease only has a 5-year relative survival rate of 49% due to the fact that the first line chemotherapy for this disease, platinum-based chemotherapy with taxanes, has an 80% recurrence rate. To improve the treatment for this disease, it would be wise to find biomarkers of sensitivity to other drugs. Using publicly available data from The Cancer Genome Project, our lab has shown that 36% of High Grade Serous Ovarian Cancers (HGSOC) have gene amplifications for both Cellular Myelocytomatosis (MYC) and Heat Shock Factor 1 (HSF1) genes. These genes encode for transcription factors and are known to contribute to malignant disease in multiple cancer types, including ovarian cancer. Evidence indicates that MYC and HSF1 are both essential to HGSOC cells with co-amplification of these genes, that MYC and HSF1 transcriptional activities are highly correlated in patient tumors, and the two transcription factors have a protein-protein interaction, all suggesting these two transcription factors cooperate to drive this subset of HGSOC tumors. Many drugs have been developed to inhibit MYC or HSF1 though they have not shown success in clinical development. We aimed to decrease the activity of these proteins by targeting polo-like kinase 1 (PLK1), a kinase that phosphorylates and regulates both MYC and HSF1 proteins. Active PLK1 levels were highly correlated with MYC and HSF1 protein levels and inhibition of PLK1 with volasertib reduced MYC and HSF1 protein levels and transcriptional activity. Furthermore, volasertib was found to have 155-fold greater potency in HGSOC cells with MYC-HSF1 co-amplification compared to cells without these genes amplified. The increased potency of volasertib in MYC-HSF1 co-amplified cells were also observed in clonogenic growth and spheroid models. Together, these data indicate that MYC and HSF1 cooperate in HGSOC when these genes are amplified and targeting a common kinase between them in PLK1 disrupts this cooperation. Furthermore, MYC and HSF1 co-amplification may serve as a biomarker for volasertib through a personalized medicine approach to treat HGSOC patients. Citation Format: Matthew O'Malley, Imade W. Williams, Bobby Walker, Haimanti Ray, Kenneth P. Nephew, Richard Carpenter. The PLK1 inhibitor Volasertib as a treatment for HSF1 and MYC coamplified 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 B031.