Growth Of Ovarian Cancer Cells Research Articles

Nucleolar Localization of the RNA Helicase DDX21 Predicts Survival Outcomes in Gynecological Cancers.

Cancer cells with DNA repair defects (e.g., BRCA1/2 mutant cells) are vulnerable to PARP inhibitors (PARPi) due to induction of synthetic lethality. However, recent clinical evidence has shown that PARPi can prevent the growth of some cancers irrespective of their BRCA1/2 status, suggesting alternative mechanisms of action. We previously discovered one such mechanism in breast cancer involving DDX21, an RNA helicase that localizes to the nucleoli of cells and is a target of PARP1. We have now extended this observation in endometrial and ovarian cancers and provided links to patient outcomes. When PARP1-mediated ADPRylation of DDX21 is inhibited by niraparib, DDX21 is mislocalized to the nucleoplasm resulting in decreased rDNA transcription, which leads to a reduction in ribosome biogenesis, protein translation, and ultimately endometrial and ovarian cancer cell growth. High PARP1 expression was associated with high nucleolar localization of DDX21 in both cancers. High nucleolar DDX21 negatively correlated with calculated IC50s for niraparib. By studying endometrial cancer patient samples, we were able to show that high DDX21 nucleolar localization was significantly associated with decreased survival. Our study suggests that the use of PARP inhibitors as a cancer therapeutic can be expanded to further types of cancers and that DDX21 localization can potentially be used as a prognostic factor and as a biomarker for response to PARPi.

Naringin Regulates the Growth and Apoptosis of Ovarian Cancer Cells via the TGF-β Signaling Pathway: A Prospective Laboratory Based Study

Naringin Regulates the Growth and Apoptosis of Ovarian Cancer Cells via the TGF-β Signaling Pathway: A Prospective Laboratory Based Study

Cell-cycle related centromere protein F deficiency suppresses ovarian cancer cells growth by inducing ferroptosis.

This study aimed to investigate the involvement of the cell cycle-related protein centriole protein F (CENPF) in the development of ovarian cancer (OC) and explored its relationship with ferroptosis. The databases were analyzed to identify differential expression of cell cycle-related proteins between individuals with ovarian cancer and normal individuals. Immunohistochemistry and statistical analysis were conducted on ovarian tissues obtained from 40 patients with epithelial ovarian cancer and 20 normal individuals. In vitro experiments were performed using SKOV3 and HEY epithelial ovarian cancer cell lines. The mRNA microarray data set, consisting of GSE14001, GSE54388, GSE40595, and GSE14407, was downloaded from the Gene Expression Omnibus (GEO) database to investigate the genes associated with cell cycle regulation in ovarian cancer cells. CENPF was selected as the subject of study through differential analysis. Assessed the expression of CENPF in both ovarian cancer (OC) patients and normal ovarian tissues using immunohistochemistry. Lentivirus infection was employed to downregulate CENPF expression, and subsequent experiments including Cell Counting Kit-8 (CCK-8) assay, cell cycle analysis, transwell assay, and wound-healing assay were conducted to investigate the effects of CENPF on proliferation, invasion, migration, and cell cycle regulation in OC cells. The Reactive oxygen species (ROS) and the malondialdehyde (MDA) assays were performed to assess the involvement of CENPF in cellular redox reactions. Western blot analysis was conducted to examine the expression levels of ferroptosis-related proteins (GPX4, SLC7A11, DMT1, and P53). By querying and integrating cell cycle-related genes from the GEO database, in silico analyses using The Cancer Genome Atlas (TCGA) database combined with immunohistochemical studies, we discovered that CENPF is upregulated in ovarian cancer tissues and is related to survival. Downregulation of CENPF inhibited biological function of OC cells, increased intracellular ROS and MDA levels, and downregulated the GPX4 protein and the SLC7A11/xCT protein, but upregulated the DMT1 protein and the tumor protein 53(P53) protein expression to induce ferroptosis. This study did not investigate ferroptosis-related studies following CENPF overexpression, and the findings have not been validated in animal studies. Our findings demonstrated that the deficiency of CENPF played a crucial anti-oncogenic role in the progression of OC through the mechanism of ferroptosis.

ANGPTL3 diminishes the resistance of ovarian cancer to paclitaxel by blocking the PI3K-AKT-mTOR signaling pathway

Angiopoietin-like protein 3 (ANGPTL3) is key in ovarian cancer (OC) cell growth and metastasis, notably by enhancing natural killer cells' capacity for inducing cell toxicity and apoptosis. However, its role in influencing chemotherapy resistance in OC remains ambiguous. In this study, we discovered a correlation between reduced ANGPTL3 levels and a less favorable outcome in OC patients using the Kaplan-Meier Plotter database. Lower levels of ANGPTL3 were detected in paclitaxel (PTX)-resistant OC tissues and cell lines via western blotting and immunohistochemistry. To investigate ANGPTL3's effects, we established SKOV3/PTX and 2780/PTX as PTX-resistant OC cell lines by incrementally increasing PTX exposure and then transfecting them with overexpress ANGPTL3 (OE-ANGPTL3) lentivirus. We conducted various assays such as CCK-8, colony formation, Edu staining, flow cytometry, and transwell to investigate the impact of ANGPTL3 on PTX resistance. Additionally, this effect was examined in a mouse subcutaneous xenograft model. Both in vitro and in vivo experiments demonstrated that ANGPTL3 overexpression mitigated PTX resistance in OC cells by inactivating the PI3K-AKT-mTOR pathway. In summary, our research reveals that ANGPTL3 enhances PTX sensitivity in OC by downregulating the PI3K-AKT-mTOR pathway. The study of this study suggest that ANGPTL3 could serve as a valuable therapeutic target for OC, signifying its clinical relevance in OC management.

Circular RNA circMAN1A2 promotes ovarian cancer progression through the microRNA-135a-3p/IL1RAP/TAK1 pathway.

Ovarian cancer (OC) is the most lethal malignancy in women owing to its diagnosis only at the advanced stage. Elucidation of its molecular pathogenesis may help identify new tumor markers and targets for therapy. Circular RNAs (circRNAs) are stable, conserved, and functional biomolecules that can be used as effective biomarkers for various cancers. In this study, a potential circRNA related to early diagnosis of OC, circMAN1A2, was analyzed. Overexpression/knockdown of circMAN1A2 in OC cells was used to decipher its effects on cell proliferation with a Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine (EdU), cell cycle, clone formation, and wound healing assay. RNA pull-down and Dual luciferase assay were used to explain the underlying mechanism by which circMAN1A2 regulates OC cell proliferation. In vivo, the effect of circMAN1A2 in OC was evaluated using nude mouse xenograft experiments. CircMAN1A2 was highly expressed in OC and promoted proliferation, clone formation, and tumorigenicity of OC cells. In addition, we found that circMAN1A2 acted as a sponge for microRNA (miR)-135a-3p; miR-135a-3p directly targeted the 3' untranslated region of interleukin 1 receptor accessory protein (IL1RAP) in OC cells, thereby regulating the phosphorylation of transforming growth factor-beta activated kinase 1 (TAK1), which resulted in promotion of OC cell growth. CircMAN1A2 promotes OC cell proliferation by inhibiting the miR-135a-3p/IL1RAP/TAK1 axis. In conclusion, circMAN1A2 may be a biomarker for early detection of OC and a target for subsequent therapy.

A Novel Synthesized Cyclohexane-Hydroxytyrosol Derivative Suppresses Ovarian Cancer Cell Growth Through Inducing Reactive Oxidative Species and Blocking Autophagic Flux.

Aims: Drug resistance in ovarian cancer (OC) cells often leads to recurrence, metastasis, and high mortality rates among OC patients. Hydroxytyrosol (HT) has been reported to inhibit the proliferation of ovarian and other types of cancer cells. Here we synthesized a novel cyclohexane-hydroxytyrosol derivative (Chx-HT) for enhanced anticaner efficacy. We examined the growth-suppressing effect of Chx-HT on OC cells in vitro and in a xenograft mouse model and investigated the underlying mechanism. Results: We demonstrated that Chx-HT inhibits proliferation, promotes apoptosis, and remodels glucose and lipid metabolism by reducing fatty acid β-oxidation while increasing glycolysis, de novo fatty acid synthesis (FAS), and lipid droplet (LD) accumulation, impairs mitochondrial respiration, and induces oxidative stress both in vitro and in vivo. In addition, Chx-HT blocks autophagic flux by obstructing the maturation of lysosomal cathepsins in the late stage, but also activates autophagy through the p-AMPK/p-mTOR/p-ULK1 pathway in response to energy deficit. Innovation and Conclusion: Reactive oxidative species (ROS) play a critical role in mediating the effects of Chx-HT on proliferation, apoptosis, autophagy, tricarboxylic acid (TCA) cycle, fatty acid β-oxidation, and mitochondrial respiration, and the autophagic activation underlies the effects of Chx-HT on glycolysis, de novo FAS, and LD accumulation in OC cells. Cotreating OC cells with Chx-HT and autophagic inhibitor or glycolytic inhibitor results in an additive inhibition of proliferation. Our study indicates that Chx-HT stands for a promising OC therapeutic by ROS and autophagy blockade-mediated metabolic remodeling.

Abstract 1224: 3D models of chemotherapy- and PARPi-resistant ovarian cancer indicate essential roles for JAK/STAT signaling in mediating drug resistance

Abstract Ovarian cancer is the deadliest gynecological cancer with a low 5-year overall survival rate that affects over 300,000 women globally each year. Given lack of routine screening procedures, ovarian cancer patients are frequently diagnosed with late-stage disease that rapidly progress despite initial responses to front line therapy. PARPi and VEGFi targeted therapies have improved progression free survival in small subsets of patients but have largely failed to improve overall survival. Since the robust uptake of PARPis in the front line setting, resistance to this class of drugs is a growing problem. The literature is filled with many novel treatment approaches, but the vast majority fail to gain traction in pre-clinical models and early phase trials. A contributing factor to these disappointments relates to the prevalent use of 2D monoculture model systems that do not recapitulate the tumor microenvironment. To address this issue, we utilized the Rastrum 3D cell printer to grow ovarian cancer cells and PDX models in bio-functional matrices which provide optimal stiffness and extracellular matrix components specific to the ovarian tumor microenvironment. We found that ovarian cancer cells grown under these conditions exhibit dramatic up-regulation of the JAK/STAT signaling pathway, including autocrine/paracrine signaling factors, which correlated with increased sensitivity to JAK/STAT inhibitors. This affect was lost when STAT1 and STAT3 knockout cell lines were grown in this 3D environment. Ovarian tumors are known to be rich in cancer-associated fibroblasts (CAFs) and tumor-associated macrophages (TAMs). We incorporated primary CAFs into this 3D culture system and found they could promote ovarian cancer cell growth only in cancer cells with intact JAK/STAT signaling further indicating the essential role of this pathway in mediating tumor progression. Co-culture with M2 macrophages was also found to induce ovarian cancer cell growth, particularly in resistant models. Conversely, co-culture with M1 macrophages inhibited treatment naïve ovarian cancer cell growth but not resistant cell line growth. Single-cell RNAseq of the complex 3D cultures elucidated profound differences in the cross-talk between these cell types that is dependent on cancer cell sensitivity to standard-of-care agents. Finally, the addition of JAK/STAT inhibitors was found to substantially alter this cross-talk between cell types and inhibit cancer cell viability. These data further implicate the importance of JAK/STAT signaling, specifically in clinically relevant 3D models, in supporting ovarian cancer progression and response to chemotherapy and PARPi treatment. Ongoing studies are aimed at confirming these findings in pre-clinical mouse models and to elucidate the most effective JAK/STAT inhibitors in vivo with the goal of informing the design of future clinical trials. Citation Format: Esther Rodman, Xiyin Wang, Hannah Smith, Xiaonan Hou, Scott Kaufmann, John Weroha, John Hawse. 3D models of chemotherapy- and PARPi-resistant ovarian cancer indicate essential roles for JAK/STAT signaling in mediating drug resistance [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 1224.

Abstract 4318: CD24 enhances cisplatin resistance in ovarian cancer by suppressing autophagy

Abstract Ovarian cancer is one of the most common gynecological cancers with the highest mortality rate. Most patients are diagnosed with advanced disease and will relapse due to chemoresistance. CD24, a highly glycosylated GPI-anchored membrane protein. Recent studies have shown that CD24 expression is significantly up-regulated in ovarian cancer and is associated with chemotherapy resistance, and CD24 also plays an inhibitory role in tumor immunity by binding to Siglec-10 on macrophages. However, the molecular mechanisms of how CD24 affects chemotherapy resistance in ovarian cancer remain unclear. In this study, we used shRNAs to knockdown CD24 and explore the impact and mechanism of CD24 on the chemotherapy resistance of ovarian cancer cells. The results showed that knockdown of CD24 in ovarian cancer cells SKOV3 and TOV21G significantly reduced cell proliferation and arrested the cell cycle in S phase. Knockdown of CD24 also significantly increased the sensitivity of ovarian cancer cells to cisplatin but had no effect on paclitaxol treatment. Further experiments showed that knockdown of CD24 increased cisplatin sensitivity by promoting autophagy-induced cell death. In addition, Gene Set Enrichment Analysis (GSEA) was used to analyze the correlation between the expression of CD24 and its biological functions in the TCGA ovarian cancer dataset. The results showed that CD24 is mostly correlated to cell proliferation and autophagy-related pathways in ovarian cancers. Further mouse xenograft tumor transplantation experiments also confirmed that knockdown of CD24 reduced tumor size and increased sensitivity to cisplatin treatment by increasing cell autophagy. Taken together, these results indicate that CD24 regulates cell growth and chemoresistance in ovarian cancer cells and that inhibition of CD24 may be helpful in the treatment of ovarian cancer. Citation Format: Yuh-Ling Chen, Tse-Ming Hong, Yu-Yi Wen. CD24 enhances cisplatin resistance in ovarian cancer by suppressing autophagy [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 4318.

Abstract 575: Identification of SORL1 as a key regulator of chemoresistance in ovarian cancer

Abstract This study aimed to understand the molecular mechanism of platinum chemoresistance in recurrent ovarian tumors with a focus on the SORL1-regulated pathways. SORL1 is an intracellular sorting receptor that binds to HER2 in breast cancer; this promotes HER2 recycling to the cell surface, which ultimately impacts the progression and treatment of breast cancer. The role of SORL1 in ovarian cancer has not been extensively studied. Method: RNA was extracted from 15 pairs of matched primary and recurrent high grade serous ovarian tumors collected from patients. Human transcriptomic microarray was used to identify the differentially expressed genes. The identified genes were validated by RT-QPCR and western blot in five ovarian cancer cell lines that were treated or untreated with carboplatin. To study the effects of identified target gene SORL1, overexpression and knockdown in ovarian cancer cell lines were established using SORL1 plasmid and shRNA. Proliferation and response to carboplatin were analyzed using celltiter Glo and caspase-3/7 activity assays respectively. EGFR and FGFR4 were identified as the interacting proteins of SORL1 in ovarian cancer cells through FGF1 and EGF1 treatment and co-immunoprecipitation. A proximity ligation assay was performed to validate their interactions. Finally, a xenograft mouse model was used to compare the tumor forming abilities and the response to carboplatin of SORL1-knockdown ovarian cancer cells and the control cancer cells in vivo. Protein expression of SORL1, EGFR, and FGFR4 in the collected tumors was determined via western blot. Result: Transcriptomic analysis of matched human primary and recurrent ovarian tumors identified SORL1 as an upregulated gene in recurrent tumors compared to primary samples. SORL1 expression was also upregulated in ovarian cancer cells surviving carboplatin treatment. Proliferation assays demonstrated that SORL1-overexpressing and knockdown cell lines had increased and inhibited proliferative capabilities respectively. Caspase-3 activity assays showed that SORL1-overexpressing and knockdown cell lines had reduced and increased sensitivity to carboplatin treatment respectively. SORL1 was found to bind to and promote the expression of EGFR and FGFR4. When injected subcutaneously into nude mice, SORL1-knockdown cells had reduced tumor forming capabilities and increased sensitivity to carboplatin. SORL1-knockdown caused the tumors to express lower levels of SORL1, EGFR, and FGFR4 proteins in comparison with the control tumors. Conclusion: This study demonstrates that SORL1 regulates the EGFR and FGF4 pathways to promote the growth and carboplatin resistance of ovarian cancer cells. Targeting this pathway has potential to aid in the treatment of platinum-resistant ovarian cancer. Citation Format: Miranda Mansolf, Ziyan Jian, Fangfang Bi, Tobias M. Hartwich, Yang Yang-Hartwich. Identification of SORL1 as a key regulator of chemoresistance in 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 575.

Abstract 4473: Targeting matrix metalloproteinase-3 (MMP-3) in high-grade serous ovarian cancer

Abstract High-Grade Serous Ovarian Cancer (HGSOC) is the most aggressive and lethal gynecological malignancy. Surgery and chemotherapy (with platinum compounds) are the main treatments. Many patients relapse and develop chemotherapy resistance, limiting the therapeutic utility of these therapies. This persistent resistance makes HGSOC treatment difficult. Cisplatin-resistant ovarian cancer cells upregulate Matrix Metalloproteinase-3. MMP3 is an enzyme involved in active tissue remodeling and extracellular matrix protein breakdown during dynamic physiological processes. The structure of MMP3 includes the prodomain, the catalytic domain and the hemopexin domain. We showed that MMP3 protein levels are higher in cisplatin resistant as compared with cisplatin sensitive HGSOC cells. Our research team showed that small interference RNA (siRNA)-mediated MMP3 knockdown reduced cisplatin-resistant ovarian cancer cell growth and invasion. This data indicates that MMP3 may be a promising HGSOC treatment target. Targeting MMP3 with small chemical inhibitors (SCI) could represent a better option than siRNA because SCI are more stable and easier to deliver. The purpose of this project is to design SCI of MMP3 in the propeptide, catalytic, and hemopexin domains of MMP3. We used in silico methods to identify MMP3 inhibitors in these domains. The ZINC20 database of commercially compounds was used for virtual screening using Python Prescription (PyRx) software. We identified 25 ligands out of 370,000 with the greatest affinity for each MMP3 functional domains. SwissADME was then used to evaluate in silico absorption, distribution, metabolism, pharmacokinetics, drug-likeliness, and medicinal chemistry. This research lays the groundwork for HGSOC therapeutic strategies to improve treatment efficacy, especially for chemotherapy-resistant patients. Citation Format: Víctor G. Reyes-Burgos, Eliud Hernández-O'Farrill, Luis E. Vazquez Quiñones, Marienid Flores-Colón, Fatima Valiyeva, Pablo E. Vivas-Mejía. Targeting matrix metalloproteinase-3 (MMP-3) in high-grade serous 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 4473.

A novel SIK2 inhibitor SIC-19 exhibits synthetic lethality with PARP inhibitors in ovarian cancer

PurposeOvarian cancer patients with HR proficiency (HRP) have had limited benefits from PARP inhibitor treatment, highlighting the need for improved therapeutic strategies. In this study, we developed a novel SIK2 inhibitor, SIC-19, and investigated its potential to enhance the sensitivity and expand the clinical utility of PARP inhibitors in ovarian cancer. MethodsThe SIK2 protein was modeled using a Molecular Operating Environment (MOE), and the most favorable model was selected based on a GBVI/WSA dG scoring function. The Chembridge Compound Library was screened, and the top 20 candidate compounds were tested for their interaction with SIK2 and downstream substrates, AKT-pS473 and MYLK-pS343. SIC-19 emerged as the most promising drug candidate and was further evaluated using multiple assays. ResultsSIC-19 exhibited selective and potent inhibition of SIK2, leading to its degradation through the ubiquitination pathway. The IC50 of SIC-19 correlated inversely with endogenous SIK2 expression in ovarian cancer cell lines. Treatment with SIC-19 significantly inhibited cancer cell growth and sensitized cells to PARP inhibitors in vitro, as well as in ovarian cancer organoids and xenograft models. Mechanistically, SIK2 knockdown and SIC-19 treatment reduced RAD50 phosphorylation at Ser635, prevented nuclear translocation of RAD50, disrupted nuclear filament assembly, and impaired DNA homologous recombination repair, ultimately inducing apoptosis. These findings highlight the crucial role of SIK2 in the DNA HR repair pathway and demonstrate the significant PARP inhibitor sensitization achieved by SIC-19 in ovarian cancer. ConclusionsSIC-19, a novel SIK2 inhibitor, effectively inhibits tumor cell growth in ovarian cancer by interfering with RAD50-mediated DNA HR repair. Furthermore, SIC-19 enhances the efficacy of PARP inhibitors, providing a promising therapeutic strategy to improve outcomes for ovarian cancer patients.

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, >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.

Pharmacological Mechanisms of Kirenol against Ovarian Carcinoma: A Network Pharmacology and Experimental Validation Study In Vitro.

Ovarian carcinoma is an aggressive gynecological malignancy. Kirenol, a diterpene compound, has recently gained attention for its potential anticancer properties. However, its exact anti-tumor mechanism remains largely unexplored. In this study, we explored the inhibitory effects of Kirenol on ovarian cancer using network pharmacology and in vitro experiments and elucidated its underlying mechanisms. Through the utilization of molecular docking, we established a network of proteinprotein interactions (PPI), which unveiled CDK4 as an essential target. Additionally, gene enrichment and pathway analysis highlighted the significance of the PI3K/AKT pathway. The viability of ovarian cancer cells and normal ovarian epithelial cells was evaluated using CCK8 assays to determine the effect of Kirenol. Following in vitro tests, cell colony formation, wound healing, flow cytometry, and Western blotting were conducted to assess its impact on cell proliferation, metastasis, apoptosis, and the cell cycle. Kirenol significantly reduced the viability of ovarian cancer cells (SKOV3 and A2780) compared to normal ovarian epithelial cells (IOSE-80). Moreover, Kirenol efficiently suppressed the growth and movement, caused a cell cycle halt, and stimulated programmed cell death in SKOV3 and A2780 cells. Through molecular analysis, it was observed that Kirenol increased the expression of Bax while decreasing the expression of MMP2, MMP9, and Bcl-2. It also attenuated the phosphorylation of PI3K, AKT, and RB and downregulated CDK4 and CCND1 expression. Notably, co-treatment with the PI3K pathway inhibitor LY294002 enhanced the inhibitory effect of Kirenol on ovarian cancer cells. In summary, the combined results of our network pharmacology analysis and in vitro tests emphasized that Kirenol hinders the growth of ovarian cancer cells, causes cell cycle arrest, enhances apoptosis, and hampers migration, possibly by regulating the PI3K/AKT/CDK4 signaling pathway.

Tripartite-motif 3 represses ovarian cancer progression by downregulating lactate dehydrogenase A and inhibiting AKT signaling.

The E3 ubiquitin ligase Tripartite-motif 3 (TRIM3) is known to play a crucial role in tumor suppression in various tumors through different mechanisms. However, its function and mechanism in ovarian cancer have yet to be elucidated. Our study aims to investigate the expression of TRIM3 in ovarian cancer and evaluate its role in the development of the disease. Our findings revealed a significant decrease in TRIM3 mRNA and protein levels in ovarian cancer tissues and cells when compared to normal ovarian epithelial tissues and cells. Furthermore, we observed a negative correlation between the protein level of TRIM3 and the FIGO stage, as well as a positive correlation with the survival of ovarian cancer patients. Using gain and loss of function experiments, we demonstrated that TRIM3 can inhibit cell proliferation, migration and invasion of the ovarian cancer cells in vitro, as well as suppress tumor growth in vivo. Mechanistic studies showed that TRIM3 interacts with lactate dehydrogenase A, a key enzyme in the glycolytic pathway, through its B-box and coiled-coil domains and induces its ubiquitination and proteasomal degradation, leading to the inhibition of glycolytic ability in ovarian cancer cells. RNA-sequencing analysis revealed significant alterations in the phosphatidylinositol signaling pathways upon TRIM3 overexpression. Additionally, overexpression of TRIM3 inhibited the phosphorylation of AKT. In conclusion, our study demonstrated that TRIM3 exerts a tumor-suppressive effect in ovarian cancer, at least partially, by downregulating LDHA and inhibiting the AKT signaling pathway, and thus leading to the inhibition of glycolysis and limiting the growth of ovarian cancer cells.

LRP8 promotes tumorigenesis in ovarian cancer through inhibiting p53 signaling.

Ovarian cancer (OC) is the most lethal gynecological malignancy with a high mortality rate. Low-density lipoprotein (LDL) receptor-related protein 8 (LRP8) is a cell membrane receptor belonging LDL receptor family and is involved in several tumor progressions. However, there is limited understanding of how LRP8 mediates OC development. LRP8 expression level was identified in human OC tissues and cells using immunohistochemical staining and quantitative polymerase chain reaction assays, respectively. Functions of LRP8 in OC progression were evaluated by Celigo cell counting, wound healing, transwell and flow cytometry assays, and the xenograft models. The human phospho-kinase array analysis was used for screening potential signaling involved in OC development. We observed that LRP8 was overexpressed in OC tissues, and high expression of LRP8 was associated with poor prognosis of OC patients. Functionally, LRP8 knockdown remarkably reduced proliferation and migration of OC cells, and induced apoptosis and S phase cycle arrest. LRP8 deficiency attenuated in vivo tumor growth of OC cells. Moreover, the addition of p53 inhibitor partially reversed the effects of LRP8 knockdown on OC cell proliferation and apoptosis, indicating the involvement of p53 signaling in LRP8-mediated OC progression. This study confirmed that LRP8/p53 axis contributed to OC progression, which might serve as a novel potential therapeutic target for OC patients.

Targeting endogenous fatty acid synthesis stimulates the migration of ovarian cancer cells to adipocytes and promotes the transport of fatty acids from adipocytes to cancer cells.

Despite significant advances in oncology, 1 of 108 female patients succumb to ovarian cancer (OC) each year. Improved novel treatments against this aggressive disease would be a major improvement. The growth of OC cells has been demonstrated to be highly dependent on lipids. OC cells are abundantly present in the abdominal cavity and omentum, the main sites of OC expansion. Accordingly, it has been attempted not only to block the hyperactive synthesis of fatty acids (FAs) in cancer cells, but also to disrupt lipid supply. While either strategy has yielded promising results as monotherapy, the induction of resistance pathways diminishing the anticancer effects is yet conceivable. The endogenous regulation of lipid biosynthesis in OC has been extensively studied. However, the role of stromal cells in the modulation of the effects of anti‑lipogenic drugs has not yet been well documented. The present study thus examined the interaction between OC cells and associated stromal cells, when denovo FA synthesis was blocked. It has recently been revealed by the authors that when FA are provided to OC cells in monoculture, the lipid deficiency induced by pharmacological inhibition of FA synthase (FASN), the key enzyme of endogenous FA synthesis, cannot be compensated through an increased FA uptake by OC cells. In the present study, OC cells were co‑cultured with adipocytes preloaded with fluorescent FA and the effects of FASN‑inhibition on OC homing to adipocytes and the transcellular delivery of fluorescent FA from adipocytes to OC cells were examined. The FASN inhibitors, G28UCM and Fasnall, stimulated the spontaneous migration of A2780 OC cells in a concentration‑dependent manner and stimulated the transfer of FA from adipocytes to OC cells. Similar effects were observed with all types of adipocytes tested. The models applied in the present study demonstrated that co‑cultured cancer‑associated adipocytes may attenuate the anticancer effects of FASN inhibitors by attracting tumor cells and by supplying the cells with FA. This lipid‑mediated dependency may provide a rationale for the design of new treatment approaches for the treatment of OC.

HERC4 modulates ovarian cancer cell proliferation by regulating SMO-elicited hedgehog signaling

BackgroundHERC4 has been reported to have functions in several types of tumors, but its roles in ovarian cancer have not been studied yet. MethodsPrimary tissues from ovarian cancer patients and cell lines were collected for real-time PCR. Kaplan-Meier Plotter was used to predict the prognosis of ovarian cancer patients. HERC4 was overexpressed in cells by lentivirus, and CCK-8 assay was performed to evaluate cell viability. Real-time PCR and Western blot were carried out to analyze the mRNA and protein expression, respectively. Xenograft tumor models were established to analyze HERC4 function in vivo. ResultsFirstly, we found that HERC4 was significantly downregulated in ovarian cancer. We then found that ovarian cancer patients with high HERC4 expression had significantly higher overall survival and progression-free survival rates compared with patients with low expression. Then, HERC4 was overexpressed in ovarian cancer cells, and we found that overexpression of HERC4 significantly inhibited ovarian cancer cell growth, as well as the expression of the target protein SMO, and the key proteins in the downstream hedgehog signaling pathway. Finally, the xenograft tumor models revealed that overexpression of HERC4 significantly inhibited tumor growth in vivo. ConclusionsOverall, these results indicate that overexpression of HERC4 inhibits cell proliferation of ovarian cancer in vitro and in vivo, suggesting that HERC4 may serve as an effective target for the treatment of ovarian cancer.

PFKFB3 regulated the growth and migration of ovarian cancer cells

PFKFB3 regulated the growth and migration of ovarian cancer cells

RIPK4 Promotes Cell Invasion and the Epithelial-Mesenchymal Transition in Ovarian Cancer.

To investigate the clinical role and biological function of receptor-interacting protein kinase 4 (RIPK4) in ovarian cancer (OC). We conducted a comprehensive analysis of the expression and prognostic role of RIPK4 in OC using various public databases including The Cancer Genome Atlas, Oncomine, and Kaplan-Meier plotter. In vitro studies included wound healing, cell migration and invasion, cell proliferation, and cell apoptosis assays as well as vascular mimicry experiments. In vivo studies were conducted using subcutaneous and intraperitoneal xenografts. Our findings revealed that RIPK4 was significantly overexpressed in OC tissue compared to normal ovarian tissue. Moreover, the overexpression of RIPK4 was associated with advanced-stage disease and a poor prognosis in OC patients. RIPK4 silencing resulted in significant inhibition of intraperitoneal tumor growth, invasion, and vascular mimicry in OC cells. Furthermore, downregulation of RIPK4 inhibited the epithelial-mesenchymal transition of OC cells both in vitro and in vivo by promoting the expression of E-cadherin and inhibiting the expression of N-cadherin. The results of this study suggest that RIPK4 may function as an oncogene in the development and prognosis of OC.

Epigallocatechin gallate inhibits ovarian cancer cell growth and induces cell apoptosis via activation of FOXO3A.

Epigallocatechin gallate (EGCG), a bioactive component in tea, displays broad anti-cancer effects. Our study was designed to evaluate the anti-cancer effects of EGCG on ovarian cancer and explored the underlying molecular mechanisms. To evaluate the in vitro inhibitory effects of EGCG against ovarian cancer, MTT assay, colony formation assay, apoptosis assay, and wound healing assay, were performed. Besides, the inhibitory effects of EGCG on tumor growth in the xenograft animal model were evaluated by measuring tumor volume and tumor weight. Moreover, Western blotting and qPCR were used to evaluate the levels of target genes and proteins. Treatment with EGCG inhibited cell migration and cell survival, and promoted cell apoptosis in A2780 and SKOV3 cells. Interestingly, treatment with EGCG inhibited the tumor growth in the xenograft animal model. The mechanistic study revealed that treatment with EGCG induced the activation of FOXO3A and suppressed the expression of c-Myc both in vitro and in vivo. Our findings demonstrate that EGCG suppress ovarian cancer cell growth, which may be due to its regulation on FOXO3A and c-Myc.