Poor Prognosis In Ovarian Cancer Research Articles

The oncogenic roles of GPR176 in ovarian cancer: a molecular target for aggressiveness and gene therapy

Background At present, the discovery of new biomarkers is of great significance for the early diagnosis, treatment and prognosis assessment of ovarian cancer. Previous findings indicated that aberrant G-protein-coupled receptor 176 (GPR176) expression might contribute to tumorigenesis and subsequent progression. However, the expression of GPR176 and the molecular mechanisms in ovarian cancer had not been investigated. Methods GPR176 expression was compared with clinicopathological features of ovarian cancer using immunohistochemical and bioinformatics analyses. GPR176-related genes and pathways were analysed using bioinformatics analysis. Additionally, the effects of GPR176 on ovarian cancer cell phenotypes were investigated. Results GPR176 expression positively correlated with elder age, clinicopathological staging, tumour residual status, and unfavourable survival of ovarian cancer, but negatively with purity loss, infiltration of B cells, and CD8+ T cells. Gene Set Enrichment Analysis showed that differential expression of GPR176 was involved in focal adhesion, ECM-receptor interaction, cell adhesion molecules and so on. STRING and Cytoscape were used to determine the top 10 nodes. Kyoto Encyclopaedia of Genes and Genomes analysis indicated that GPR176-related genes were involved in the ECM structural constituent and organisation and so on. GPR176 overexpression promoted the proliferation, anti-apoptosis, anti-pyroptosis, migration and invasion of ovarian cancer cells with overexpression of N-cadherin, Zeb1, Snail, Twist1, and under-expression of gasdermin D, caspase 1, and E-cadherin. Conclusion GPR176 might be involved in the progression of ovarian cancer. It might be used as a biomarker to indicate the aggressive behaviour and poor prognosis of ovarian cancer and a target of genetic therapy.

TCEB3 initiates ovarian cancer apoptosis by mediating ubiquitination and degradation of MCL-1.

Platinum resistance remains a major contributor to the poor prognosis of ovarian cancer. Anti-apoptotic protein myeloid cell leukemia-1 (MCL-1) has emerged as a promising target for overcoming drug resistance, but different cancer cells utilize distinct protein degradation pathways to alter MCL-1 level. We systematically investigated E3 ligases to identify novel candidates that mediate platinum resistance in ovarian cancer. Transcription Elongation Factor B (TCEB3) has been identified as a novel E3 ligase recognition subunit that targets MCL-1 in the cytoplasm during platinum treatment other than its traditional function of targeting the Pol II in the nuclear compartment. TCEB3 expression is downregulated in platinum-resistant cell lines and this low expression is associated with poor prognosis. The ubiquitination of MCL-1 induced by TCEB3 leads to cell death in ovarian cancer. Moreover, platinum treatment increased the cytoplasm proportion of TCEB3, and the cytoplasm localization of TCEB3 is important for its targeting of MCL-1. This study emphasizes the dual function of TCEB3 in homeostasis maintenance and in cell fate determination under different conditions, and provides a new insight into drug resistance in ovarian cancer.

Identification of potentially actionable genetic variants in epithelial ovarian cancer: a retrospective cohort study

Ovarian cancer is the most lethal gynecologic malignancy, mainly due to late-stage diagnosis, frequent recurrences, and eventually therapy resistance. To identify potentially actionable genetic variants, sequencing data of 351 Belgian ovarian cancer patients were retrospectively captured from electronic health records. The cohort included 286 (81%) patients with high-grade serous ovarian cancer, 17 (5%) with low-grade serous ovarian cancer, and 48 (14%) with other histotypes. Firstly, an overview of the prevalence and spectrum of the BRCA1/2 variants highlighted germline variants in 4% (11/250) and somatic variants in 11% (37/348) of patients. Secondly, application of a multi-gene panel in 168 tumors revealed a total of 214 variants in 28 genes beyond BRCA1/2 with a median of 1 (IQR, 1–2) genetic variant per patient. The ten most often altered genes were (in descending order): TP53, BRCA1, PIK3CA, BRCA2, KRAS, ERBB2 (HER2), TERT promotor, RB1, PIK3R1 and PTEN. Of note, the genetic landscape vastly differed between the studied histotypes. Finally, using ESCAT the clinical evidence of utility for every genetic variant was scored. Only BRCA1/2 pathogenic variants were classified as tier-I. Nearly all patients (151/168; 90%) had an ESCAT tier-II variant, most frequently in TP53 (74%), PIK3CA (9%) and KRAS (7%). In conclusion, our findings imply that although only a small proportion of genetic variants currently have direct impact on ovarian cancer treatment decisions, other variants could help to identify novel (personalized) treatment options to address the poor prognosis of ovarian cancer, particularly in rare histotypes.

Abstract 5329: Ovarian cancer predisposes neutrophils to form neutrophil extracellular traps(NETs)

Abstract Objective: Neutrophil extracellular trap (NETs) are neutrophil-derived extracellular DNA released in response to inflammation. In contrast to their primary host-defensive role, NETs have been recently reported to promote cancer progression. The aim of this study is to investigate the role of NETs in ovarian cancer progression. Method: The clinical data of ovarian cancer patients who underwent primary surgery at Osaka University Medical Hospital were retrospectively reviewed (n=340). The relationship between neutrophilia, peritoneal dissemination and prognosis were analyzed. Prior to initial treatment, peripheral blood was obtained from newly diagnosed ovarian cancer patients and examined for CBC and granulocyte-colony stimulating factor (G-CSF) concentration by ELISA. To evaluate NETs formation capacity, isolated neutrophils were stimulated with G-CSF and incubated in vitro to monitor NETs formation. The ascites was collected at the initial surgery and assessed for G-CSF concentration and for neutrophils population using flow cytometry. The omental tissues were pathologically examined for NETs using H&E-staining and immunostaining with anti-Citrullinated Histon3 (CitH3) antibody. To test NETs induction capacity, we treated human peripheral blood neutrophils with the conditioned media from 20 ovarian cancer cell lines and the serum from ovarian cancer patients. Then human ovarian cancer OVCAR8 cells were co-cultured with NETs to evaluate the effect of NETs on cancer cell adhesion. Results: Neutrophilia (neutrophils>7000/µl) was found in 39 patients (39/340,11.5%). Patients with neutrophilia were associated with advanced disease accompanied by peritoneal dissemination and compromised survival compared to patients without neutrophilia (5-year PFS 40.0 vs 59.9 %, p 0.0027). In these patients, serum G-CSF was upregulated. Neutrophils from ovarian cancer patients formed NETs significantly earlier than those from benign tumor patients. Ovarian cancer patients with neutrophilia showed elevated G-CSF concentration and increased neutrophils proportion in their ascites. Omental tissues from patients with neutrophilia showed NETs foci close to the disseminated lesions. G-CSF strongly induced neutrophils to form NETs in vitro, which was observed in some conditioned media from ovarian cancer cell lines and serum from ovarian cancer patients as well. The adhesion of ovarian cancer cell was increased by co-incubation with NETs. Conclusion: Neutrophilia is associated with peritoneal dissemination and poor prognosis in ovarian cancer. One of the underlying mechanism of neutrophilia is upregulated G-CSF, which stimulate neutrophils to form NETs. NETs may have a causative effect on ovarian cancer dissemination. Citation Format: Gaku Yamamoto, Mahiru Kawano, Michiko Bun, Koutaro Shimura, Aska Toda, Koji Nakamura, Yasuto Kinose, Michiko Kodama, Kae Hashimoto, Kenjiro Sawada, Tadashi Kimura. Ovarian cancer predisposes neutrophils to form neutrophil extracellular traps(NETs) [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 5329.

Abstract 4742: Targeting the RNA-binding protein LARP1 overcomes therapeutic resistance in ovarian cancer

Abstract La-related protein 1 (LARP1) is an RNA-binding protein that plays a pivotal role in regulating mRNA on a post-transcriptional level. Overexpression of LARP1 has been detected in multiple cancers substantiating the critical role of LARP1 as a driver for cancer progression. This study aims to investigate the downstream target pathways regulated by LARP1 and to determine the impact of LARP1 targeting on the resistance to cisplatin and olaparib therapy in ovarian cancer (OC). Analysis of The Cancer Genome Atlas OC dataset, reverse phase protein array, in vitro functional and mechanistic experiments, and a xenograft OC mouse model using OVCAR8 cell line were executed. Our results revealed that overexpression of LARP1 is negatively correlated with progression-free survival in OC patients. Furthermore, LARP1 knockdown using two independent small interfering RNAs (siRNAs) suppressed cell growth, invasion, and migration, and ameliorated cisplatin resistance in vitro. Mechanistic analyses identified AXL as a target of LARP1 and this finding was further supported clinically in which co-overexpression of LARP1 and AXL is associated with poor prognosis in OC. Furthermore, LARP1 knockdown resulted in reduced phosphorylation of mTOR, AKT, and SRC with no significant effect on FAK. In vivo, administration of 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) nanoparticles loaded with LARP1-siRNA suppressed tumor growth and improved the response to cisplatin and olaparib in a xenograft OC mouse model. In conclusion, LARP1 acts as an oncogenic RNA-binding protein in OC, and targeting LARP1 may represent an innovative therapeutic approach for ameliorating resistance to chemotherapy and targeted therapy in OC. Keywords: RNA-binding proteins; cisplatin resistance; olaparib resistance; chemotherapy resistance; LARP1; ovarian cancer. Citation Format: Abdelrahman M. Elsayed, Paola Amero, Emine Bayraktar, Anil K. Sood, Gabriel Lopez-Berestein, Cristian Rodriguez-Aguayo. Targeting the RNA-binding protein LARP1 overcomes therapeutic 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 4742.

XTP8 Promotes Ovarian Cancer Progression by Activating AKT/AMPK/mTOR Pathway to Regulate EMT.

Ovarian cancer (OC) ranks as the fifth leading cause of cancer-related death in women. The main contributors to the poor prognosis of ovarian cancer are the high rates of recurrence and metastasis. Studies have indicated a crucial role for hepatitis B virus X Ag-Transactivated Protein 8 (XTP8), a protein containing the DEP domain, in various cellular processes, including cell growth, movement, and differentiation, across several types of cancers. However, the role of XTP8 in ovarian cancer remains unclear. We observed elevated expression of XTP8 in ovarian cancer. Silencing XTP8 inhibited cell proliferation, promoted apoptosis, and yielded contrasting results in cells overexpressing XTP8. Furthermore, XTP8 facilitated ovarian cancer invasion and migration, triggering epithelial-mesenchymal transition (EMT). Mechanistically, XTP8 silencing led to reduced phosphorylation levels of AKT, increased p-AMPK levels, and decreased p-mTOR levels, while XTP8 overexpression exerted the opposite effects. Additionally, the activation of p-AMPK rescued the promoting effect of XTP8 on EMT in ovarian cancer cell lines, indicating that XTP8 acts as an oncogene by modulating the AKT/AMPK/mTOR pathway. Through transcriptome sequencing to identify downstream targets of XTP8, we found that XTP8 influences the expression of Caldesmon (CALD1) at both transcriptional and translational levels. CALD1 can be considered a downstream target of XTP8. The collaborative action of XTP8 and CALD1 activates the AKT/AMPK/mTOR pathway, regulating EMT to promote ovarian cancer progression. Inhibiting this signaling axis might represent a potential therapeutic target for ovarian cancer.

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.

Comprehensive single-cell analysis reveals heterogeneity of fibroblast subpopulations in ovarian cancer tissue microenvironment

BackgroundOvarian cancer, as a highly malignant tumor, features the critical involvement of tumor-associated fibroblasts in the ovarian cancer tissue microenvironment. However, due to the apparent heterogeneity within fibroblast subpopulations, the specific functions of these subpopulations in the ovarian cancer tissue microenvironment remain insufficiently elucidated. MethodsIn this study, we integrated single-cell sequencing data from 32 ovarian cancer samples derived from four distinct cohorts and 3226 bulk RNA-seq data from GEO and TCGA-OV cohorts. Utilizing computational frameworks such as Seurat, Monocle 2, Cellchat, and others, we analyzed the characteristics of the ovarian cancer tissue microenvironment, focusing particularly on fibroblast subpopulations and their differentiation trajectories. Employing the CIBERSORTX computational framework, we assessed various cellular components within the ovarian cancer tissue microenvironment and evaluated their associations with ovarian cancer prognosis. Additionally, we conducted Mendelian randomization analysis based on cis-eQTL to investigate causal relationships between gene expression and ovarian cancer. ResultsThrough integrative analysis, we identified 13 major cell types present in ovarian cancer tissues, including CD8+ T cells, malignant cells, and fibroblasts. Analysis of the tumor microenvironment (TME) cell proportions revealed a significant increase in the proportion of CD8+ T cells and CD4+ T cells in tumor tissues compared to normal tissues, while fibroblasts predominated in normal tissues. Further subgroup analysis of fibroblasts identified seven subgroups, with the MMP11+Fib subgroup showing the highest activity in the TGFβ signaling pathway. Single-cell analysis suggested that oxidative phosphorylation could be a key pathway driving fibroblast differentiation, and the ATRNL1+KCN + Fib subgroup exhibited chromosomal copy number variations. Prognostic analysis using a large sample size indicated that high infiltration of MMP11+ fibroblasts was associated with poor prognosis in ovarian cancer. SMR analysis identified 132 fibroblast differentiation-related genes, which were linked to pathways such as platinum drug resistance. ConclusionsIn the context of ovarian cancer, fibroblasts expressing MMP11 emerge as the primary drivers of the TGF-beta signaling pathway. Their presence correlates with an increased risk of adverse ovarian prognoses. Additionally, the genetic regulation governing the differentiation of fibroblasts associated with ovarian cancer correlates with the emergence of drug resistance.

Loss of phosphatase and tensin homolog (PTEN) increases Lysyl oxidase-like 2 (LOXL2) expression enhancing the growth of fallopian tube epithelial cells as three-dimensional spheroids

BackgroundHigh-grade serous ovarian cancer (HGSOC) accounts for 70–80% of all ovarian cancer-related deaths. Multiple studies have suggested that the fallopian tube epithelium (FTE) serves as the cell of origin of HGSOC. Phosphatase and tensin homolog (PTEN) is a tumor suppressor and its loss is sufficient to induce numerous tumorigenic changes in FTE, including increased migration, formation of multicellular tumor spheroids (MTSs), and ovarian colonization. In murine oviductal epithelial (MOE) cells (the equivalent of human FTE) loss of PTEN results in the upregulation of transcripts associated with the extracellular matrix, with a specific focus on the elevation of lysyl oxidase-like 2 (LOXL2). Although LOXL2 is known to drive transformation and invasion in solid tumors and is associated with a poor prognosis in ovarian cancer, its specific role in the tumorigenesis of ovarian cancer originating from FTE remains unclear. Therefore, we aim to investigate whether LOXL2 mediates tumorigenesis from the fallopian tube epithelium. MethodsIn this study, we utilized clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (CAS9) technology to delete LOXL2 in PTEN-deficient MOE cells to understand its role in mediating the oncogenic effects of PTEN loss. In addition, CRISPR-CAS9 was used to delete LOXL2 in OVCAR8 ovarian cancer cells. We monitored the changes in tumorigenic properties, such as migration, invasion, and growth of three-dimensional (3D) spheroids, to assess whether the loss of LOXL2 resulted in any changes. ResultsWe found that a reduction in LOXL2 expression did not significantly change the migration or invasive capabilities of PTEN-depleted MOE or human ovarian cancer cells. However, we found that a reduction in LOXL2 expression resulted in a significant reduction in 3D MTS formation and survival in both lines. ConclusionsThese results reveal for the first time that PTEN loss in FTE cells increases LOXL2 expression through downregulation of Pax2, and LOXL2 deletion blocks 3D spheroid formation.

Low FHL1 expression indicates a good prognosis and drug sensitivity in ovarian cancer.

Chemotherapy resistance is the main reason for the poor prognosis of ovarian cancer (OC). FHL1 is an important tumour regulator, but its relationship with the prognosis, drug resistance, and tumour microenvironment of OC is unknown. Immunohistochemistry was used to determine FHL1 expression in OC. Kaplan‒Meier plotter was used for survival analysis. The value of gene expression in predicting drug resistance was estimated using the area under the curve (AUC). Bivariate correlation was used to determine the coexpression of two genes. Functional cluster and pathway enrichment were used to uncover hidden signalling pathways. The relationship between gene levels and the tumour microenvironment was visualised through the ggstatsplot and pheatmap packages. The mRNA and protein levels of FHL1 were downregulated in 426 and 100 OC tissues, respectively. Low FHL1 expression was correlated with good progression-free survival (PFS), postprogression survival, and overall survival (OS) in 1815 OC patients,and was further confirmed to be associated with good OS by immunohistochemistry in 152 OC tissues. Furthermore, FHL1 was downregulated in drug-sensitive tissues, while its high expression predicted drug resistance (AUC > 0.65). Mechanistically, FHL1 was coexpressed with FLNC, CAV1, PPP1R12B, and FLNA at the mRNA and protein levels in 558 and 174 OC tissues, respectively, and their expression was downregulated in OC. Additionally, very strong coexpression of FHL1 with the four genes was identified in at least 23 different tumours. Low expression of the four genes was associated with good PFS, and the combination of FHL1 with the four genes provided better prognostic power. Meanwhile, the expression of all five genes was strongly and positively associated with the abundance of macrophages. Low FHL1 expression acts as a favourable factor in OC, probably via positive coexpression with FLNC, CAV1, PPP1R12B, and FLNA.

Targeting LTA4H facilitates the reshaping of the immune microenvironment mediated by CCL5 and sensitizes ovarian cancer to Cisplatin.

Ovarian cancer is the most lethal and aggressive gynecological cancer with a high recurrence rate and is often diagnosed late. In ovarian cancer, multiple metabolic enzymes of lipid metabolism are abnormally expressed, resulting in metabolism disorder. As a characteristic pathway in polyunsaturated fatty acid (PUFA) metabolism, arachidonic acid (AA) metabolism is disturbed in ovarian cancer. Therefore, we established a 10-gene signature model to evaluate the prognostic risk of PUFA-related genes. This 10-gene signature has strong robustness and can play a stable predictive role in datasets of various platforms (TCGA, ICGC, and GSE17260). The high association between the risk subgroups and clinical characteristics indicated a good performance of the model. Our data further indicated that the high expression of LTA4H was positively correlated with poor prognosis in ovarian cancer. Deficiency of LTA4H enhanced sensitivity to Cisplatin and modified the characteristics of immune cell infiltration in ovarian cancer. Additionally, our results indicate that CCL5 was involved in the aberrant metabolism of the AA/LTA4H axis, which contributes to the reduction of tumor-infiltrating CD8+ T cells and immune escape in ovarian cancer. These findings provide new insights into the prognosis and potential target of LTA4H/CCL5 in treating ovarian cancer.

Copine 1 predicts poor clinical outcomes by promoting M2 macrophage activation in ovarian cancer.

Copine 1 (CPNE1), a membrane-binding protein, influences the prognosis of various cancers. According to cBioPortal, CPNE1 amplification is a prevalent genetic mutation in ovarian cancer but with unknown oncogenic mechanism. This study analysed the CPNE1 expression in ovarian cancer using online datasets, as validated by immunohistochemistry (IHC), quantitative polymerase chain reaction (qPCR) and western blotting. Concurrently, the prognostic value of CPNE1 was accessed. Cell Counting Kit-8, colony formation, transwells and xenograft experiments were performed to evaluate the functions of CPNE1 during ovarian cancer carcinogenesis. CPNE1 and its related genes were analysed by g:Profiler and Tumour Immune Estimation Resource. Furthermore, human monocytic THP-1 cells were co-cultured with ES2 cells to investigate the effect of CPNE1 on macrophage polarization. The results of bioinformatic analysis, IHC, qPCR and western blotting indicated a higher CPNE1 in ovarian cancer. CPNE1 overexpression demonstrated an association with a poor prognosis of ovarian cancer. Functionally, CPNE1 overexpression increased ES2 and SKOV3 cell proliferation, invasion and migration in vitro and promoted ovarian tumour xenograft growth in vivo, while CPNE1 knockdown led to opposite effects. Additionally, CPNE1 expression demonstrated an association with immune cell infiltration in ovarian cancer, especially macrophage. CPNE1 promoted protumour M2 macrophage polarization by upregulating cluster of differentiation 163 (CD163), CD206 and interleukin-10. Our study revealed that CPNE1 mediated M2 macrophage polarization and provided a therapeutic target for ovarian cancer.

Transcriptome analyses reveal new insights on key determinants of perineural invasion in high-grade serous ovarian cancer.

Perineural invasion (PNI) is a pathological feature of many cancers associated with poor outcomes, metastases, and recurrence. In relation to ovarian cancer (OC), there is no information about PNI's role and mechanisms. Our study found that patients with PNI-positive symptoms had significantly shorter overall survival (OS) time than patients with PNI-negative symptoms. Multivariate analyses demonstrated that PNI represented a substantial independent prognostic factor in OC patients. At the transcriptome level, it is noteworthy that PNI positivity was negatively correlated with the degree of infiltration of immune killer cells in OC tumor tissues, including macrophage, central memory CD4 T-cell, natural killer cells, monocyte, and central memory CD4 T-cell. The results of this study revealed that TAS2Rs proteins were markedly upregulated in PNI-positive OC tissues and predicted poor prognoses. Moreover, Immunohistochemical analysis demonstrated that the TAS2R10 protein was associated with poor prognoses and PNI in OC. Consequently, we found for the first time that PNI was a powerful predictor of poor prognosis in OC and analyzed its expression pattern and some preliminary biochemical characterization, providing new clues for guiding clinical prevention and treatment of OC.

High BMP7 expression is associated with poor prognosis in ovarian cancer.

Bone Morphogenetic Protein 7 (BMP7) is an extracellular signalling protein that belongs to the transforming growth factor-β (TGF- β) superfamily. Previous transcriptomic data suggested that BMP7 expression may be disrupted in ovarian carcinoma and may play an important role in the aggressiveness of the disease. However, the protein expression in patient tumours has not been well studied. The current study aimed to assess BMP7 protein expression in a large cohort of ovarian carcinoma patient tumour samples to establish its associations with different clinical endpoints. Ovarian carcinoma tissue samples from 575 patients who underwent surgery for different subtypes of ovarian cancer were used. BMP7 protein expression was analysed by immunohistochemistry using tissue microarray and full face tumour sections. High BMP7 expression is associated with aggressive ovarian cancer clinicopathological variables including advanced FIGO stage, high grade, residual disease and poor overall survival. Elevated cytoplasmic and nuclear BMP7 expression was significantly associated with advanced FIGO stage, high tumour grade, presence of residual tumours and high-grade serous carcinomas (p = 0.001, 0.005, 0.004, <0.001 and p < 0.001, <0.001, 0.002, 0.001 respectively). Increased cytoplasmic and nuclear BMP7 expression was also significantly associated with an adverse overall survival (p = 0.001 and 0.046 respectively). The study highlights the potential of BMP7 as a prognostic tool and as a potential novel target for ovarian cancer therapies to limit disease progression.

Single-cell transcriptomics identify TNFRSF1B as a novel T-cell exhaustion marker for ovarian cancer.

Ovarian cancer (OC) patients routinely show poor immunotherapeutic response due to the complex tumour microenvironment (TME). It is urgent to explore new immunotherapeutic markers. Through the single-cell RNA sequencing (scRNA-seq) analyses on high-grade serous OC (HGSOC), moderate severity borderline tumour and matched normal ovary, we identified a novel exhausted T cells subpopulation that related to poor prognosis in OC. Histological staining, multiple immunofluorescences, and flow cytometry were applied to validate some results from scRNA-seq. Furthermore, a tumour-bearing mice model was constructed to investigate the effects of TNFRSF1B treatment on tumour growth in vivo. Highly immunosuppressive TME in HGSOC is displayed compared to moderate severity borderline tumour and matched normal ovary. Subsequently, a novel exhausted subpopulation of CD8+ TNFRSF1B+ T cells is identified, which is associated with poor survival. In vitro experiments demonstrate that TNFRSF1B is specifically upregulated on activated CD8+ T cells and suppressed interferon-γ secretion. The expression of TNFRSF1B on CD8+ T cells is closely related to OC clinical malignancy and is a marker of poor prognosis through 140 OC patients' verification. In addition, the blockade of TNFRSF1B inhibits tumour growth via profoundly remodeling the immune microenvironment in the OC mouse model. Our transcriptomic results analyzed by scRNA-seq delineate a high-resolution snapshot of the entire tumour ecosystem of OC TME. The major applications of our findings were an exhausted subpopulation of CD8+ TNFRSF1B+ T cells for predicting OC patient prognosis and the potential therapeutic value of TNFRSF1B. These findings demonstrated the clinical value of TNFRSF1B as a potential immunotherapy target and extended our understanding of factors contributing to immunotherapy failure in OC.

PAXIP1-AS1 is associated with immune infiltration and predicts poor prognosis in ovarian cancer.

The long non-coding RNA (LncRNA) PAXIP1 antisense RNA 1 (PAXIP1-AS1) was found to promote proliferation, migration, EMT, and apoptosis of ovarian cancer (OC) cells in OC cell lines, but the relationship between PAXIP1-AS1 expression and clinical characteristics, prognosis, and immune infiltration of OC patients and its regulatory network are unclear. 379 OC tissues were collected from The Cancer Genome Atlas (TCGA) database. 427 OC tissues and 88 normal ovarian tissues were collected from GTEx combined TCGA database. 130 OC samples were collected from GSE138866. Kruskal-Wallis test, Wilcoxon sign-rank test, logistic regression, Kaplan-Meier method, Cox regression analysis, Gene set enrichment analysis (GSEA), and immuno-infiltration analysis were used to evaluate the relationship between clinical characteristics and PAXIP1-AS1 expression, prognostic factors, and determine the significant involvement of PAXIP1-AS1 in function. QRT-PCR was used to validate the expression of PAXIP1-AS1 in OC cell lines. Low PAXIP1-AS1 expression in OC was associated with age (P = 0.045), histological grade (P = 0.011), and lymphatic invasion (P = 0.004). Low PAXIP1-AS1 expression predicted a poorer overall survival (OS) (HR: 0.71; 95% CI: 0.55-0.92; P = 0.009), progression free interval (PFS) (HR: 1.776; 95% CI: 1.067-2.955; P = 0.001) and disease specific survival (DSS) (HR: 0.67; 95% CI: 0.51-0.89; P = 0.006). PAXIP1-AS1 expression (HR: 0.711; 95% CI: 0.542-0.934; P = 0.014) was independently correlated with PFS in OC patients. GSEA demonstrated that neutrophil degranulation, signaling by Interleukins, GPCR-ligand binding, G alpha I signaling events, VEGFAVEGFR-2 signaling pathway, naba secreted factors, Class A 1 Rhodopsin-Like Receptors, PI3K-Akt signaling pathway, and Focal Adhesion-PI3K-Akt-mTOR-signaling pathway were differentially enriched in PAXIP1-AS1 high expression phenotype. PAXIP1-AS1 was significantly downregulated in OC cell lines compared with IOSE29 cell line. The expression of PAXIP1-AS1 was associated with immune infiltration. low expression of PAXIP1-AS1 was correlated with poor OS (HR: 0.52; 95% CI: 0.34-0.80; P = 0.003) from GSE138866. There were some genomic variations between the PAXIP1-AS1 high and low expression groups. Low expression of PAXIP1-AS1 was significantly associated with poor survival and immune infiltration in OC. PAXIP1-AS1 could be a promising prognosis biomarker and response to immunotherapy for OC.

The splicing factor SNRPB promotes ovarian cancer progression through regulating aberrant exon skipping of POLA1 and BRCA2.

Splicing factors play a crucial role in the initiation and development of various human cancers. SNRPB, a core spliceosome component, regulates pre-mRNA alternative splicing. However, its function and underlying mechanism in ovarian cancer remain unclear. This study identified SNRPB as a critical driver of ovarian cancer through TCGA and CPTAC database analysis. SNRPB was highly upregulated in fresh frozen ovarian cancer tissues compared with normal fallopian tubes. Immunohistochemistry revealed that SNRPB expression was increased in formalin-fixed, paraffin-embedded ovarian cancer sections and was positively correlated with a poor prognosis for ovarian cancer. Functionally, SNRPB knockdown suppressed ovarian cancer cell proliferation and invasion, and overexpression exerted opposite effects. SNRPB expression increased after cisplatin treatment, and silencing SNRPB sensitized ovarian cancer cells to cisplatin. KEGG pathway analysis revealed that the differentially expressed genes (DEGs) were mainly enriched in DNA replication and homologous recombination, and almost all DEGs related to DNA replication and homologous recombination were downregulated after SNRPB knockdown according to RNA-seq. Exon 3 skipping of the DEGs DNA polymerase alpha 1 (POLA1) and BRCA2 was induced by SNRPB silencing. Exon 3 skipping of POLA1 yielded premature termination codons and led to nonsense-mediated RNA decay (NMD); exon 3 skipping of BRCA2 led to loss of the PALB2 binding domain, which is necessary for homologous recombination, and increased ovarian cancer cell cisplatin sensitivity. POLA1 or BRCA2 knockdown partially impaired the increased malignancy of SNRPB-overexpressing ovarian cancer cells. Moreover, miR-654-5p was found to reduce SNRPB mRNA expression by directly binding to the SNRPB 3'-UTR. Overall, SNRPB was identified as an important oncogenic driver that promotes ovarian cancer progression by repressing exon 3 skipping of POLA1 and BRCA2. Thus, SNRPB is a potential treatment target and prognostic marker for ovarian cancer.

MOB kinase activator 1A acts as an oncogene by targeting PI3K/AKT/mTOR in ovarian cancer

BackgroundTo illuminate the precise roles of MOB Kinase Activator 1 A (MOB1A) in the development of ovarian cancer (OC).MethodsMOB1A expression and clinical data of OC were obtained from the public database on gene expression and proteomics. Meanwhile, verification of expression was carried out in Gene Expression Omnibus, the Human Protein Atlas, and OC cell lines. The prognosis of MOB1A was explored in the Kaplan-Meier plotter. RNA interference and lentivirus vectors were applied to construct knockdown and overexpressed cell models. Changes in the malignant behaviors of OC cells were detected by cholecystokinin octopeptide cell counting kit, wound healing, colony formation assay, transwell, flow cytometry assays, and in vivo experiments. Changes in proteins in the PI3K and autophagy-related makers were detected by western blot analysis.ResultsThe expression of MOB1A was significantly upregulated and accompanied by an inferior survival rate in OC. Knockdown of MOB1A inhibited the proliferation, invasion, migration, and cell cycle of OC cells, whereas induced cell autophagy. MOB1A upregulation had the opposite effects. In addition, bioinformatics analysis and western blot experiments showed that MOB1A plays an important role in the PI3K/AKT/mTOR pathway.ConclusionsOur findings indicated that MOB1A is highly expressed and related to poor prognosis in OC. MOB1A plays a role in promoting the malignant biological behavior of tumor cells through PI3K/AKT/mTOR signaling pathway.

Inhibit ALDH3A2 reduce ovarian cancer cells survival via elevating ferroptosis sensitivity

Ovarian cancer (OC) is a malignant gynecologic tumor with high morbidity and mortality. As a newly discovered mode of programmed cell death, ferroptosis has been involved in various pathological processes of kinds of tumors in recent years. Aldehyde dehydrogenase 3 family member A2 (ALDH3A2) catalyzes the oxidation of long-chain aliphatic aldehydes to fatty acid. ALDH3A2 has been shown to be associated with ferroptosis in acute myeloid leukemia (AML), but the mechanism remains unclear. In this study, we analyzed the TCGA and GTEx databases and showed that high ALDH3A2 expression predicted poor prognosis in ovarian cancer. Further studies found that knockout or overexpression of ALDH3A2 correspondingly increased or attenuated the ferroptosis sensitivity of ovarian cancer cells. And sequencing revealed that ALDH3A2 knockout led to the activation of lipid metabolic, GSH metabolic, phospholipid metabolic, and aldehyde metabolic pathways, suggesting that ALDH3A2 induced changes in the sensitivity of ovarian cancer cells to ferroptosis by affecting these metabolic processes. Our results provide a new promising therapeutic strategy for the treatment of OC.

Pharmacological inhibition of EZH2 using a covalent inhibitor suppresses human ovarian cancer cell migration and invasion.

Metastasis is the cause of poor prognosis in ovarian cancer (OC). Enhancer of Zeste homolog 2 (EZH2), a histone-lysine N-methyltransferase enzyme, promotes OC cell migration and invasion by regulating the expression of tissue inhibitor of metalloproteinase-2 (TIMP2) and matrix metalloproteinases-9 (MMP9). Hence, we speculated that EZH2-targeting therapy might suppress OC migration and invasion. In this study, the expression of EZH2, TIMP2, and MMP9 in OC tissues and cell lines was analyzed using The Cancer Genome Atlas (TCGA) database and western blotting, respectively. The effects of SKLB-03220, an EZH2 covalent inhibitor, on OC cell migration and invasion were investigated using wound-healing assays, Transwell assays, and immunohistochemistry. TCGA database analysis confirmed that the EZH2 and MMP9 mRNA expression was significantly higher in OC tissues, whereas TIMP2 expression was significantly lower than that in normal ovarian tissues. Moreover, EZH2 negatively correlated with TIMP2 and positively correlated with MMP9 expression. In addition to the anti-tumor activity of SKLB-03220 in a PA-1 xenograft model, immunohistochemistry results showed that SKLB-03220 markedly increased the expression of TIMP2 and decreased the expression of MMP9. Additionally, wound-healing and Transwell assays showed that SKLB-03220 significantly inhibited the migration and invasion of both A2780 and PA-1 cells in a concentration-dependent manner. SKLB-03220 inhibited H3K27me3 and MMP9 expression and increased TIMP2 expression in PA-1 cells. Taken together, these results indicate that the EZH2 covalent inhibitor SKLB-03220 inhibits metastasis of OC cells by upregulating TIMP2 and downregulating MMP9, and could thus serve as a therapeutic agent for OC.