Invasion Of Ovarian Cancer Cells Research Articles

Dual‑regulated oncolytic adenovirus carrying ERCC1‑siRNA gene possesses potent antitumor effect on ovarian cancer cells.

Ovarian cancer is a multifactorial and deadly disease. Despite significant advancements in ovarian cancer therapy, its incidence is on the rise and the molecular mechanisms underlying ovarian cancer invasiveness, metastasis and drug resistance remain largely elusive, resulting in poor prognosis. Oncolytic viruses armed with therapeutic transgenes of interest offer an attractive alternative to chemical drugs, which often face innate and acquired drug resistance. The present study constructed a novel oncolytic adenovirus carrying ERCC1 short interfering (si)RNA, regulated by hTERT and HIF promoters, termed Ad‑siERCC1. The findings demonstrated that this oncolytic adenovirus effectively inhibits the proliferation, migration and invasion of ovarian cancer cells. Furthermore, the downregulation of ERCC1 expression by siRNA ameliorates drug resistance to cisplatin (DDP) chemotherapy. It was found that Ad‑siERCC1 blocks the cell cycle in the G1 phase and enhances apoptosis through the PI3K/AKT‑caspase‑3 signaling pathways in SKOV3 cells. The results of the present study highlighted the critical effect of oncolytic virus Ad‑siERCC1 in inhibiting the survival of ovarian cancer cells and increasing chemotherapy sensitivity to DDP. These findings underscore the potent antitumor effect of Ad‑siERCC1 on ovarian cancers in vivo.

IL-6 regulates epithelial ovarian cancer EMT, invasion, and metastasis by modulating Let-7c and miR-200c through the STAT3/HIF-1α pathway.

Interleukin-6 (IL-6) and hypoxia-inducible factor-1α (HIF-1α) play important roles in epithelial-mesenchymal transformation (EMT) and tumor development. Previous studies have demonstrated that IL-6 promotes EMT, invasion, and metastasis in epithelial ovarian cancer (EOC) cells by activating the STAT3/HIF-1α pathway. MicroRNA (miRNA) is non-coding small RNAs that also play an important role in tumor development. Notably, Let-7 and miR-200 families are prominently altered in EOC. However, whether IL-6 regulates the expression of Let-7 and miR-200 families through the STAT3/HIF-1α signaling to induce EMT in EOC remains poorly understood. In this study, we conducted in vitro and in vivo investigations using two EOC cell lines, SKOV3, and OVCAR3 cells. Our findings demonstrate that IL-6 down-regulates the mRNA levels of Let-7c and miR-200c while up-regulating their target genes HMGA2 and ZEB1 through the STAT3/HIF-1α signaling in EOC cells and in vivo. Additionally, to explore the regulatory role of HIF-1α on miRNAs, both exogenous HIF blockers YC-1 and endogenous high expression or inhibition of HIF-1α can be utilized. Both approaches can confirm that the downstream molecule HIF-1α inhibits the expression and function of Let-7c and miR-200c. Further mechanistic research revealed that the overexpression of Let-7c or miR-200c can reverse the malignant evolution of EOC cells induced by IL-6, including EMT, invasion, and metastasis. Consequently, our results suggest that IL-6 regulates the expression of Let-7c and miR-200c through the STAT3/HIF-1α pathway, thereby promoting EMT, invasion, and metastasis in EOC cells.

EMP1 correlated with cancer progression and immune characteristics in pan-cancer and ovarian cancer.

This study examines the prognostic role and immunological relevance of EMP1 (epithelial membrane protein-1) in a pan-cancer analysis, with a focus on ovarian cancer. Utilizing data from TCGA, CCLE, and GTEx databases, we assessed EMP1 mRNA expression and its correlation with tumor progression, prognosis, and immune microenvironment across various cancers. Our results indicate that EMP1 expression is significantly associated with poor prognosis in multiple cancer types, including ovarian, bladder, testicular, pancreatic, breast, brain, and uveal melanoma. Immune-related analyses reveal a positive correlation between EMP1 and immune cell infiltration, particularly neutrophils, macrophages, and dendritic cells, as well as high expression of immune checkpoint such as CD274, HAVCR2, IL10, PDCD1LG2, and TGFB1 in most tumors. In vivo experiments confirm that EMP1 promotes ovarian cancer cell proliferation, metastasis, and invasion. In conclusion, EMP1 emerges as a potential prognostic biomarker and therapeutic target in various cancers, particularly ovarian cancer, due to its influence on tumor progression and immune cell dynamics. Further research is warranted to elucidate the precise mechanisms of EMP1 in cancer biology and to translate these findings into clinical applications.

ATP6V1B1 regulates ovarian cancer progression and cisplatin sensitivity through the mTOR/autophagy pathway.

Early detection and effective chemotherapy for ovarian cancer, a serious gynecological malignancy, require further progress. This study aimed to investigate the molecular mechanism of ATPase H+-Transporting V1 Subunit B1 (ATP6V1B1) in ovarian cancer development and chemoresistance. Our data show that ATP6V1B1 is upregulated in ovarian cancer and correlated with decreased progression-free survival. Gain- and loss-of-function experiments demonstrated that ATP6V1B1 promotes the proliferation, migration, and invasion of ovarian cancer cells in vitro, while ATP6V1B1 knockout inhibits tumor growth in vivo. In addition, knocking down ATP6V1B1 increases the sensitivity of ovarian cancer cells to cisplatin. Mechanistic studies showed that ATP6V1B1 regulates the activation of the mTOR/autophagy pathway. Overall, our study confirmed the oncogenic role of ATP6V1B1 in ovarian cancer and revealed that ATP6V1B1 promotes ovarian cancer progression via the mTOR/autophagy axis.

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.

Knockdown of CENPM activates cGAS-STING pathway to inhibit ovarian cancer by promoting pyroptosis.

We aimed to screen novel gene signatures for ovarian cancer (OC) and explore the role of biomarkers in OC via regulating pyroptosis using bioinformatics analysis. Differentially expressed genes (DEGs) of OC were screened from GSE12470 and GSE16709 datasets. Hub genes were determined from protein-protein interaction networks after bioinformatics analysis. The role of Centromeric protein M (CENPM) in OC was assessed by subcutaneous tumor experiment using hematoxylin-eosin and immunohistochemical staining. Tumor metastasis was evaluated by detecting epithelial-mesenchymal transition-related proteins. The proliferation, migration, and invasion were determined using cell counting kit and transwell assay. Enzyme-linked immunosorbent assay was applied to measure inflammatory factors. The mRNA and protein expression were detected using real-time quantitative PCR and western blot. We determined 9 hub genes (KIFC1, PCLAF, CDCA5, KNTC1, MCM3, OIP5, CENPM, KIF15, and ASF1B) with high prediction value for OC. In SKOV3 and A2780 cells, the expression levels of hub genes were significantly up-regulated, compared with normal ovarian cells. CENPM was selected as a key gene. Knockdown of CENPM suppressed proliferation, migration, and invasion of OC cells. Subcutaneous tumor experiment revealed that CENPM knockdown significantly suppressed tumor growth and metastasis. Additionally, pyroptosis was promoted in OC cells and xenograft tumors after CENPM knockdown. Furthermore, CENPM knockdown activated cGAS-STING pathway and the pathway inhibitor reversed the inhibitory effect of CENPM knockdown on viability, migration, and invasion of OC cells. CENPM was a novel biomarker of OC, and knockdown of CENPM inhibited OC progression by promoting pyroptosis and activating cGAS-STING pathway.

Retracted] MicroRNA‑19b promotes the migration and invasion of ovarian cancer cells by inhibiting the PTEN/AKT signaling pathway.

[This retracts the article DOI: 10.3892/ol.2018.8695.].

Tumour-derived exosome SNHG17 induced by oestrogen contributes to ovarian cancer progression via the CCL13-CCR2-M2 macrophage axis.

Oestrogen is known to be strongly associated with ovarian cancer. There was much work to show the importance of lncRNA SNHG17 in ovarian cancer. However, no study has revealed the molecular regulatory mechanism and functional effects between oestrogen and SNHG17 in the development and metastasis of ovarian cancer. In this study, we found that SNHG17 expression was significantly increased in ovarian cancer and positively correlated with oestrogen treatment. Oestrogen could promote M2 macrophage polarization as well as ovarian cancer cells SKOV3 and ES2 cell exosomal SNHG17 expression. When exposure to oestrogen, exosomal SNHG17 promoted ovarian cancer cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) invitro, and tumour growth and lung metastasis invivo by accelerating M2-like phenotype of macrophages. Mechanically, exosomal SNHG17 could facilitate the release of CCL13 from M2 macrophage via the PI3K-Akt signalling pathway. Moreover, CCL13-CCR2 axis was identified to be involved in ovarian cancer tumour behaviours driven by oestrogen. There results demonstrate a novel mechanism that exosomal SNHG17 exerts an oncogenic effect on ovarian cancer via the CCL13-CCR2-M2 macrophage axis upon oestrogen treatment, of which SNHG17 may be a potential biomarker and therapeutic target for ovarian cancer responded to oestrogen.

Retracted] LINC01094 promotes the invasion of ovarian cancer cells and regulates the Wnt/β‑catenin signaling pathway by targeting miR‑532‑3p.

[This retracts the article DOI: 10.3892/etm.2021.10662.].

Patient-Derived Exosomes as siRNA Carriers in Ovarian Cancer Treatment.

RNA interference is a powerful gene-silencing tool with potential clinical applications. However, its therapeutic use is challenging because suitable carriers are unavailable. Exosomes are stable small endogenous vesicles that can transport functional molecules to target cells, making them ideal small interfering RNA (siRNA) carriers. Herein, we elucidated the therapeutic potential of patient-derived exosomes as an siRNA carrier for ovarian cancer (OC) treatment. The exosomes were extracted from the culture medium of primary fibroblasts collected from the omentum of patients with OC during surgery. MET proto-oncogene, receptor tyrosine kinase (MET) was selected for gene silencing, c-Met siRNAs were synthesized and loaded into the exosomes (Met-siExosomes) via electroporation, and the treatment effect of the Met-siExosomes was assessed in vitro and in vivo. The Met-siExosomes downregulated the c-Met protein levels and inhibited OC cell proliferation, migration, and invasion. In xenograft experiments using SKOV3-13 and ES-2 cells, Met-siExosomes were selectively extracted from peritoneally disseminated tumors. Intraperitoneal treatment suppressed the c-Met downstream targets in cancer cells and prolonged mouse survival. The synthesized siRNAs were successfully and selectively delivered via the exosomes to intraperitoneally disseminated tumors. As patients with OC routinely undergo omentectomy and abundant fibroblasts can be easily collected from the omentum, patient-derived exosomes may represent a promising therapeutic siRNA carrier to treat OC.

Ginger inhibits the invasion of ovarian cancer cells SKOV3 through CLDN7, CLDN11 and CD274 m6A methylation modifications

BackgroundGinger is a common aromatic vegetable with a wide range of functional ingredients and considerable medicinal and nutritional properties. Numerous studies have shown that ginger and its active ingredients have suppressive effects on manifold tumours, including ovarian cancer (OC). However, the molecular mechanism by which ginger inhibits OC is not clear. The aim of this study was to investigate the function and mechanism of ginger in OC.MethodsThe estimation of n6-methyladenosine (m6A) levels was performed using the m6A RNA Methylation Quantification Kit, and RT-qPCR was used to determine the expression of m6A-related genes and proteins. The m6A methylationome was detected by MeRIP-seq, following analysis of the data. Differential methylation of genes was assessed utilizing RT-qPCR and Western Blotting. The effect of ginger on SKOV3 invasion in ovarian cancer cells was investigated using the wound healing assay and transwell assays.ResultsGinger significantly reduced the m6A level of OC cells SKOV3. The 3’UTR region is the major site of modification for m6A methylation, and its key molecular activities include Cell Adhesion Molecules, according to meRIP-seq results. Moreover, it was observed that Ginger aids significantly in downregulating the CLDN7, CLDN11 mRNA, and protein expression. The results of wound healing assay and transwell assay showed that ginger significantly inhibited the invasion of OC cells SKOV3.ConclusionsGinger inhibits ovarian cancer cells’ SKOV3 invasion by regulating m6A methylation through CLDN7, CLDN11, and CD274.

Effects of silencing hsa_circ_0015326 on proliferation, migration, invasion, and apoptosis of epithelial ovarian cancer cells.

Although the treatment of ovarian cancer has made great progress, there are still many patients who are not timely detected and given targeted therapy due to unknown pathogenesis. Recent studies have found that hsa_circ_0015326 is upregulated in ovarian cancer and is involved in the proliferation, invasion, and migration of ovarian cancer cells. However, whether hsa_circ_0015326 can be used as a new target of ovarian cancer needs further investigation. Therefore, the effect of hsa_circ_0015326 on epithelial ovarian cancer was investigated in this study. At first, si-hsa_circ_0015326 lentivirus was transfected into epithelial ovarian cancer cells. Then real-time fluorescence quantitative PCR (qRT-PCR) was used to detect hsa_circ_0015326 level. The proliferation of ovarian cancer cells was detected by CCK-8 assay. The horizontal and vertical migration abilities of the cells were detected by wound-healing assay and Transwell assay, respectively. Transwell assay was also used to determine the invasion rate. As for the apoptosis rate, it was assessed by flow cytometry. As a result, the expression level of hsa_circ_0015326 in A2780 and SKOV3 was found to be higher than that in IOSE-80. However, after transfecting si-hsa_circ_0015326 and si-NC into the cells, the proliferation, migration, and invasion abilities of A2780 and SKOV3 cells in the si-hsa_circ_0015326 group were significantly reduced in comparison to those in the si-NC and mock groups, while their apoptosis rates were elevated. Collectively, silencing hsa_circ_0015326 bears the capability of inhibiting the proliferation, migration, and invasion of ovarian cancer cells while increasing apoptosis rate. It can be concluded that hsa_circ_0015326 promotes the malignant biological activities of epithelial ovarian cancer cells.

Contribution of sphingomyelin phosphodiesterase acid-like 3B to the proliferation, migration, and invasion of ovarian cancer cells.

Cancer has the highest mortality rate among gynecological cancers and poses a serious threat to women's lives. However, the treatment options for ovarian cancer are still limited, and exploring effective targeted biomarkers is particularly important for predicting and treating ovarian cancer. Therefore, it is necessary to explore the molecular mechanisms of the occurrence and development of ovarian cancer. This investigation encompassed the analysis of gene expression profiles, measurement of transcription levels of potential target genes in peripheral blood samples from ovarian cancer patients and characterization of the ovarian cancer-related secretory protein sphingomyelin phosphodiesterase acid-like 3B (SMPDL3B). Through bioinformatics analysis, potential target genes were identified, and their association with overall survival (OS) and progression-free survival (PFS) in ovarian cancer patients was assessed utilizing relevant databases. Subsequently, differences in target gene expression in ovarian cancer tissue samples were validated through protein blotting and quantitative real-time PCR (qRT-qPCR). Cell proliferation assays using the cell count kit-8 (CCK-8) method, as well as transwell chamber assay and pre coated matrix gel chamber assay were employed to elucidate the role of SMPDL3B in ovarian cancer cell migration and invasion. This study revealed a substantial upregulation of SMPDL3B in the serum of ovarian cancer patients, correlating with an unfavorable prognosis. High SMPDL3B expression was linked not only to increased proliferation of ovarian cancer cells, but also enhanced migration and invasion. Remarkably, the knockdown the human alkaline ceramidase 2 (ACER2) gene in cancer cells with heightened SMPDL3B expression significantly inhibited cell proliferation, migration, and invasion induced by SMPDL3B activation (P<0.05), highlighting the functional interplay between ACER2 and SMPDL3B in ovarian cancer. In summary, this study proposes SMPDL3B as a prognostic marker for ovarian cancer, with implications for potential therapeutic intervention targeting the ACER2-SMPDL3B axis.

Expression of concern: LncRNA TUG1 facilitates proliferation, invasion and stemness of ovarian cancer cell via miR-186-5p/ZEB1 axis.

Expression of concern: LncRNA TUG1 facilitates proliferation, invasion and stemness of ovarian cancer cell via miR-186-5p/ZEB1 axis.

CDCA5 promoted cell invasion and migration by activating TGF-β1 pathway in human ovarian cancer cells

BackgroundThe gene cell division cycle associated 5 (CDCA5), also called sororin, has oncogenic characteristics and is upregulated in various carcinomas. Nevertheless, the involvement of CDCA5 in ovarian cancer (OC), a highly aggressive form of cancer, and the underlying mechanism of metastasis remain inadequately investigated.ResultsThe bioinformatics data revealed a negative correlation between the patient’s survival and CDCA5 expression, which was overexpressed in OC. Functional assays also confirmed high expression levels of CDCA5 in OC tissues and cells. This suggests that CDCA5 may potentially enhance the motility, migration, and proliferation of OC cells invitro. It impedes DNA damage and apoptosis in OC cells, inhibiting xenograft development in nude mice. The RNA sequencing results suggest CDCA5 is majorly associated with biological functions related to the extracellular matrix (ECM) and influences the transforming growth factor (TGF) signaling pathway. Moreover, subsequent functional investigations elucidated that CDCA5 facilitated the migration and invasion of OC cells viathe TGF-β1/Smad2/3 signaling pathway activation.ConclusionsCDCA5 may be a strong potential therapeutic target for the treatment and management of OC.

Abstract 7557: Hypoxia-induced downregulation of MUC16: A key player in bispecific T-cell engager resistance in ovarian cancer

Abstract Background: Ovarian cancer (OC) is a lethal disease due to limited treatment options and the development of multidrug resistance. Bispecific T-cell engager (BiTE) therapy represents a promising immunotherapeutic approach to OC. Our previous findings suggest that resistance to BiTE therapy in OC is a complex interplay of factors including loss of tumor-associated antigens and epithelial-mesenchymal transition (EMT). Since the peritoneum is a relatively hypoxic (HX) tumor microenvironment, we hypothesized that HX plays a role in the modulation of MUC16 and potential resistance to BiTE therapy. Methods: After informed consent, samples were collected from patients with recurrent OC undergoing treatment with MUC16 BiTEs. For HX studies, we used OVCAR3 tumor cell lines which express full-length MUC16. Tumor cells were cultured under normoxic (NX) or HX conditions. The effect of HX on cell death was analyzed using an apoptosis assay. Cells were evaluated for changes in cell surface MUC16 expression by flow cytometry. MUC16 protein expression and EMT markers were analyzed by western blot. Proteasome inhibitors were used to stabilize MUC16 expression under HX conditions. Antibody internalization assays were conducted to assess MUC16 endocytosis and recycling. Results: In patients who progressed on MUC16 BiTEs, we found decreased MUC16 expression on tumor samples isolated from ascites samples. Using OVCAR3 cells, we found significantly decreased MUC16 expression on ovarian cancer cells grown under HX conditions (Fold change: 0.4 vs NX, p&amp;lt;0.001). Flow cytometry analysis revealed a time-dependent loss of MUC16 expression on the cell surface under HX (64.22% after 9 days HX vs 88.26% NX), highlighting the susceptibility of MUC16 to HX-induced downregulation. Treatment with proteasome inhibitors partially rescued MUC16 expression under HX conditions (Fold change: 1.4 vs NX, p&amp;lt;0.001). Notably, HX did not induce necrotic cell death in these tumor cells. In addition to the loss of MUC16, tumor cells under HX conditions showed alterations in EMT markers. E-cadherin was downregulated with prolonged HX exposure (Fold change: 0.3 vs NX, p &amp;lt; 0.001), while Vimentin (Fold change: 7.1 vs NX, p &amp;lt; 0.001) and Snail (Fold change: 2.8 vs NX, p &amp;lt; 0.001) were upregulated, indicating a potential shift towards a more aggressive phenotype. Epidermal growth factor receptor (EGFR) was also upregulated (Fold change: 4.9 vs NX, p &amp;lt; 0.001), potentially contributing to enhanced survival and invasion of OC cells under HX stress. Finally, under HX conditions, MUC16 internalization was slower in response to antibody binding over time due to reduced cell antigen expression, corroborating the observed MUC16 loss. Conclusion: Understanding hypoxia-induced MUC16 downregulation and its downstream effects on EMT markers and CA125 expression provides crucial insight into the mechanisms of BiTE therapy resistance in ovarian cancer. Citation Format: Mengyao Xu, Syem K. Barakzai, Artem Kononenko, Raj Kumar, Irva Veillard, Eugene Kim, Timothy S. Bond, David R. Spriggs, Bo R. Rueda, Oladapo Yeku. Hypoxia-induced downregulation of MUC16: A key player in bispecific T-cell engager resistance 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 7557.

Abstract 2744: Exploring the role of the MSLN/MUC16 interaction in cancer progression via the in situ proximity ligation technique

Abstract Introduction: Mesothelin (MSLN) is a glycoprotein present on the surface of mesothelial cells, sometimes used as a tumor marker. Its overexpression in various cancers, including mesothelioma, ovarian, pancreatic, and lung, is linked to increased tumor aggressiveness, evasion of apoptosis, metastasis, and resistance to treatments. Mucin16 (MUC16) belongs to a family of proteins that play a crucial role in cell adhesion, signaling, and immune responses. In cancer, alterations in mucin expression and structure may contribute to tumor progression and metastasis by enhancing cell survival and immune evasion. Mesothelin is known to interact with mucins, influencing tumor cell behavior and metastatic potential. More specifically, the MSLN/MUC16 interaction facilitates tumor cell invasion and peritoneal spread in ovarian cancer. However, reliable molecular tools to study protein interactions have been scarce. Here, we relied on the Naveni® in situ proximity ligation technology to identify MSLN/MUC16 in various cancer samples. The method detects proteins located within interaction range (&amp;lt;40 nm) by means of antibodies conjugated to oligonucleotides that create amplified fluorescent signal. Since the technique does not compromise the structural integrity of tissues, communication between proteins can be studied in their native environment. Materials &amp; Methods: Human FFPE tissue microarrays (TMA) with ovarian primary carcinoma and matched metastatic cancer (80 cores) and ovarian cancer tissue with normal tissue (100 cores) were deparaffinized and subjected to standard heat-induced antigen retrieval and blocking. Staining against the MSLN/MUC16 interaction was performed with the NaveniFlex Tissue MR Atto647N kit (Navinci Diagnostics). Co-staining antibodies against pan-Cytokeratin and Ki67 were included in the detection mix. Immunofluorescence (IF), using the same MSLN and MUC1 primary antibodies, was completed on an additional slide of each TMA, and then secondary antibodies conjugated to Alexa Fluor™ 488 and 594 were used for detection. Imaging was performed on an Olympus scanner VS200. Results &amp; Discussion: In this study, we showed that the interaction is abundant in ovarian cancer, with a distinguishable difference in the signal presence between cancerous and normal adjacent tissue. Furthermore, the additional tumor marker co-stainings give insights into the tumor invasion and growth. When comparing the Naveni® signal of MSLN/MUC16 against IF staining of each, the Naveni® signal shows true interactions, as opposed to expression patterns. Understanding the roles of mesothelin and mucin in cancer, both individually and in interaction, is crucial for developing targeted therapies and diagnostic tools. Further research on their interaction and specific molecular pathways triggered by it is essential for devising effective strategies to combat cancer progression. Citation Format: Sara Bodbin, Doroteya Raykova, Agata Zieba-Wicher. Exploring the role of the MSLN/MUC16 interaction in cancer progression via the in situ proximity ligation technique [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 2744.

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.

Cancer-associated fibroblast-secreted FGF7 as an ovarian cancer progression promoter.

Ovarian cancer (OC) is distinguished by its aggressive nature and the limited efficacy of current treatment strategies. Recent studies have emphasized the significant role of cancer-associated fibroblasts (CAFs) in OC development and progression. Employing sophisticated machine learning techniques on bulk transcriptomic datasets, we identified fibroblast growth factor 7 (FGF7), derived from CAFs, as a potential oncogenic factor. We investigated the relationship between FGF7 expression and various clinical parameters. A series of in vitro experiments were undertaken to evaluate the effect of CAFs-derived FGF7 on OC cell activities, such as proliferation, migration, and invasion. Single-cell transcriptomic analysis was also conducted to elucidate the interaction between FGF7 and its receptor. Detailed mechanistic investigations sought to clarify the pathways through which FGF7 fosters OC progression. Our findings indicate that higher FGF7 levels correlate with advanced tumor stages, increased vascular invasion, and poorer prognosis. CAFs-derived FGF7 significantly enhanced OC cell proliferation, migration, and invasion. Single-cell analysis and in vitro studies revealed that CAFs-derived FGF7 inhibits the ubiquitination and degradation of hypoxia-inducible factor 1 alpha (HIF-1α) via FGFR2 interaction. Activation of the FGF7/HIF-1α pathway resulted in the upregulation of mesenchymal markers and downregulation of epithelial markers. Importantly, in vivo treatment with neutralizing antibodies targeting CAFs-derived FGF7 substantially reduced tumor growth. Neutralizing FGF7 in the medium or inhibiting HIF-1α signaling reversed the effects of FGF7-mediated EMT, emphasizing the dependence of FGF7-mediated EMT on HIF-1α activation. These findings suggest that targeting the FGF7/HIF-1α/EMT axis may offer new therapeutic opportunities to intervene in OC progression.

ST14 interacts with TMEFF1 and is a predictor of poor prognosis in ovarian cancer

TMEFF1 is a new protein involved in the physiological functions of the central nervous system, and we previously reported TMEFF1 can promote ovarian cancer. ST14 was determined to be involved in the processes of epidermal differentiation, epithelial cell integrity, and vascular endothelial cell migration, etc. The relationship between ST14 and TMEFF1 in the ovary remains unknown. In this study, we detected the expression of ST14 and TMEFF1 in 130 different ovarian cancer tissues through immunohistochemistry. We determined ST14 and TMEFF1 were highly expressed in ovarian cancer, indicating a higher degree of tumor malignancy and a worse prognosis. Tissues significantly expressing ST14 also highly expressed TMEFF1, and the expression of the two proteins was positively correlated. Consistently, immunofluorescence double staining demonstrated the co-localization of ST14 and TMEFF1 in the same region, and immunoprecipitation confirmed the interaction between ST14 and TMEFF1. TMEFF1 expression was also reduced after knocking down ST14 through Western blot. MTT, wound healing and Transwell assays results determined that knockdown of ST14 inhibited proliferation, migration and invasion of ovarian cancer cells in vitro, but the inhibitory effect was restored after adding TMEFF1 exogenous protein. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways analysis showed that ST14 and its related genes were enriched in the processes of epithelial formation, intercellular adhesion, protein localization, and mitosis regulation. We also clarified the kinase, microRNA, and transcription factor target networks and the impact of genetic mutations on prognosis. Overall, high expression of ST14 and TMEFF1 in ovarian cancer predicts higher tumor malignancy and a worse prognosis. ST14 and TMEFF1 co-localize and interact with each other in ovarian cancer. ST14 can regulate TMEFF1 expression to promote proliferation, migration and invasion of ovarian cancer cells. We speculate that the relationship between ST14 and TMEFF1 in ovarian cancer could become a potential target for anti-cancer therapy.