CircSETDB1 knockdown inhibits the malignant progression of serous ovarian cancer through miR-129-3p-dependent regulation of MAP3K3

SETDB1, an H3K9-specific methyltransferase: An attractive epigenetic target to combat cancer

SET domain bifurcated histone lysine methyltransferase 1 (SETDB1) is an important epigenetic regulator catalyzing histone H3 lysine 9 (H3K9) methylation, specifically di-/tri-methylation. This regulation promotes gene silencing through heterochromatin formation. Aberrant SETDB1 expression, and its oncogenic role is evident in many cancers. Thus, SETDB1 is a valid target with novel therapeutic benefits. In this review, we explore the structural and biochemical features of SETDB1, its regulatory mechanisms, and its role in various cancers. We also discuss recent discoveries in small molecules targeting SETDB1 and provide suggestions for future research.

Deregulated circRNAs in Epithelial Ovarian Cancer With Activity in Preclinical In Vivo Models: Identification of Targets and New Modalities for Therapeutic Intervention

Epithelial ovarian cancer (EOC) is associated with a dismal prognosis due to development of resistance to chemotherapy and metastasis in the peritoneal cavity and distant organs. In order to identify new targets and treatment modalities we searched the literature for up- and and down-regulated circRNAs with efficacy in preclinical EOC-related in vivo systems. Our search yielded circRNAs falling into the following categories: cisplatin and paclitaxel resistance, transmembrane receptors, secreted factors, transcription factors, RNA splicing and processing factors, RAS pathway-related components, proteolysis and cell-cycle regulation, signaling-related proteins, and circRNAs regulating proteins in additional categories. These findings can be potentially translated by validation and manipulation of the corresponding targets, inhibition of circRNAs with antisense oligonucleotides (ASO), small interfering RNAs (siRNA) or small hairpin RNA (shRNA) or by reconstituting their activity.

SETDB1: Progress and prospects in cancer treatment potential and inhibitor research

SET domain bifurcated methyltransferase 1 (SETDB1) serves as a histone lysine methyltransferase, catalyzing the di- and tri-methylation of histone H3K9. Mounting evidence indicates that the abnormal expression or activity of SETDB1, either through amplification or mutation, plays a crucial role in tumorigenesis and progression. This is particularly evident in the context of tumor immune evasion and resistance to immune checkpoint blockade therapy. Furthermore, there is a robust association between SETDB1 dysregulation and an unfavorable prognosis across various types of tumors. The oncogenic role of SETDB1 primarily arises from its methyltransferase function, which contributes to the establishment of a condensed and transcriptionally inactive heterochromatin state. This results in the inactivation of genes that typically hinder cancer development and silencing of retrotransposons that could potentially trigger an immune response. These findings underscore the substantial potential for SETDB1 as an anti-tumor therapeutic target. Nevertheless, despite significant strides in recent years in tumor biology research, challenges persist in SETDB1-targeted therapy. To better facilitate the development of anti-tumor therapy targeting SETDB1, we have conducted a comprehensive review of SETDB1 in this account. We present the structure and function of SETDB1, its role in various tumors and immune regulation, as well as the advancements made in SETDB1 antagonists. Furthermore, we discuss the challenges encountered and provide perspectives for the development of SETDB1-targeted anti-tumor therapy.

SETDB1 promotes progression through upregulation of SF3B4 expression and regulates the immunity in ovarian cancer

BACKGROUND

Ovarian cancer (OC) is the most lethal gynecologic malignant tumour. The mechanism promoting OC initiation and progression remains unclear. SET domain bifurcated histone lysine methyltransferase 1(SETDB1) acts as an oncogene in a variety of tumours. This study aims to explore the role of SETDB1 in OC.

METHODS

GEO, TCGA, CSIOVDB and CPTAC databases jointly analysed SETDB1 mRNA and protein expression. Effect of SETDB1 expression on the clinical prognosis of OC patients was analysed through online Kaplan‒Meier plotter and CSIOVDB database. Then, the effect of SETDB1 in OC cells progression and mobility was examined using MTT, EdU, colony formation and transwell assay. Additionally, Cistrome DB database was used to visualize the binding of SETDB1 protein and splicing factor 3b subunit 4 (SF3B4) promoter, and dual-luciferase reporter gene assay was performed to confirm the interaction. Finally, bioinformatics analysis was employed to reveal the relationship between SETDB1 and the microenvironment of OC.

RESULTS

In the present study, we found that SETDB1 was obviously upregulated in OC and its overexpression predicted poor prognosis of OC patients. Then, we verified that SETDB1 promoted the progression and motility of OC cells in vitro. Knockdown of SETDB1 had the opposite effect. Further research showed that SETDB1 acted as a transcription factor to activate SF3B4 expression. SF3B4 knockdown impaired the effect of SETDB1 to promote the proliferative capacity and motility of OC cells. Finally, the results of bioinformatics analysis confirmed that SETDB1 regulated the immune microenvironment of ovarian cancer.

CONCLUSION

SETDB1 promoted ovarian cancer progression by upregulating the expression of SF3B4 and inhibiting the tumour immunity. SETDB1 may be a promising prognostic and therapeutic marker for OC.

The role of circRNAs in regulation of drug resistance in ovarian cancer

Ovarian cancer is one of the female reproductive system tumors. Chemotherapy is used for advanced ovarian cancer patients; however, drug resistance is a pivotal cause of chemotherapeutic failure. Hence, it is critical to explore the molecular mechanisms of drug resistance of ovarian cancer cells and to ameliorate chemoresistance. Noncoding RNAs (ncRNAs) have been identified to critically participate in drug sensitivity in a variety of human cancers, including ovarian cancer. Among ncRNAs, circRNAs sponge miRNAs and prevent miRNAs from regulation of their target mRNAs. CircRNAs can interact with DNA or proteins to modulate gene expression. In this review, we briefly describe the biological functions of circRNAs in the development and progression of ovarian cancer. Moreover, we discuss the underneath regulatory molecular mechanisms of circRNAs on governing drug resistance in ovarian cancer. Furthermore, we mention the novel strategies to overcome drug resistance via targeting circRNAs in ovarian cancer. Due to that circRNAs play a key role in modulation of drug resistance in ovarian cancer, targeting circRNAs could be a novel approach for attenuation of chemoresistance in ovarian cancer.

ncRNA-mediated low expression of P2RY14 correlates with poor prognosis and tumor immune infiltration in ovarian carcinoma

Background

Ovarian cancer (OV) has been puzzling clinicians because of its poor prognosis. More and more evidence show that the G protein coupled receptor P2RY14 plays a key role in the initiation and progression of various types of human cancer. The purpose of our study is to explore the correlation between P2RY14 and the prognosis of ovarian cancer patients and the relevant mechanism.

Methods

First, the differentially expressed gene P2RY14 was screened from The Cancer Genome Atlas (TCGA) database. Explored possible P2RY14 related miRNAs and lncRNAs through multiple public databases, predicted and analyzed the expression level of candidate miRNAs and candidate lncRNAs that can bind to candidate miRNAs in OV through StarBase database. The TIMER database was used to comprehensively analyze the expression of tumor infiltrating immune cells, and to analyze the correlation between the expression level of P2RY14 and the level of immune cell infiltration in OV or the expression level of immune checkpoints.

Results

Patients with P2RY14 overexpression had better overall survival (OS) and progression-free interval (PFI). In the Targetscan database, 22 upstream miRNAs that may bind to P2RY14 were predicted. According to the regulatory network constructed by the Cytoscape software, correlation analysis and the role of miRNAs in the prognosis of OV, we first determined that the candidate miRNAs were miR-34c-5p. Then, we predicted the upstream lncRNAs of miR-34c-5p in the StarBase database, the expression level of these lncRNAs in OV in the Gene Expression Profiling Interactive Analysis (GEPIA) database, and the role in prognosis. We determined that LINC00665 is the most potential lncRNA upstream of ovarian cancer miRNA (hsa-miR-34c-5p)-P2RY14. Then, we analyzed the results in the Timer database, suggesting that P2RY14 expression was positively correlated with CD8⁺T Cell, CD4⁺T Cell, Macrophage, Neutral and Dendritic cells, and negatively correlated with B cells. Meanwhile, P2RY14 was positively correlated with CD274 and PDCD1.

Conclusions

P2RY14 can be used as a new predictive biomarker of ovarian cancer. Intervention of P2RY14 can affect the prognosis of ovarian cancer by affecting LINC00665-miR-34c-5p-P2RY14 axis. These findings provide a potential target for the development of anti-cancer strategies for ovarian cancer.

Circular RNAs in Epithelial Ovarian Cancer: From Biomarkers to Therapeutic Targets

Epithelial ovarian cancer (EOC) is the most lethal gynecological cancer, and more than 70% of patients are diagnosed at advanced stages. Despite the application of surgery and chemotherapy, the prognosis remains poor due to the high relapse rate. It is urgent to identify novel biomarkers and develop novel therapeutic strategies for EOC. Circular RNAs (circRNAs) are a class of noncoding RNAs generated from the "back-splicing" of precursor mRNA. CircRNAs exert their functions via several mechanisms, including acting as miRNA sponges, interacting with proteins, regulating transcription, and encoding functional proteins. Recent studies have identified many circRNAs that are dysregulated in EOC and may be used as diagnostic and prognostic markers. Increasing evidence has revealed that circRNAs play a critical role in ovarian cancer progression by regulating various cellular processes, including proliferation, apoptosis, metastasis, and chemosensitivity. The circRNA-based therapy may be a novel strategy that is worth exploring in the future. Here, we provide an overview of EOC and circRNA biogenesis and functions. We then discuss the dysregulations of circRNAs in EOC and the possibility of using them as diagnostic/prognostic markers. We also summarize the role of circRNAs in regulating ovarian cancer development and speculate their potential as therapeutic targets.

MiR-129-3p regulates ferroptosis in the liver of Selenium-deficient broilers by targeting SLC7A11

Selenium (Se) has been proven to be an essential trace element for organism. Se deficiency in poultry can cause widespread damage, such as exudative diathesis. The liver is not only the main organ of metabolism, but also one of the organs with high Se content in organism. Recent studies have shown that solute carrier family 7 member 11 (SLC7A11) plays a key role in the negative regulation of ferroptosis. In order to explore the mechanism of Se deficiency induces liver ferroptosis in broilers, and the role of microRNAs (miRNAs) in this process, we divided broilers into 2 groups: control group (0.2 mg/kg Se) and Se deficiency group (0.03 mg/kg Se). Hematoxylin-Eosin staining detected liver tissue damage in broilers. Predicted and verified the targeting relationship between miR-129-3p and SLC7A11 through miRDB and dual luciferase report experiments. The genes related to ferroptosis were detected by qRT-PCR and Western Blot. The results showed that the expression level of miR-129-3p mRNA in Se-deficient liver was significantly increased. To understand whether the miR-129-3p/SLC7A11 axis could involve in the process of ferroptosis, our further research showed that overexpression of miR-129-3p could reduce the expression of SLC7A11 and its downstream GCL, GSS, and GPX4, thereby inducing ferroptosis. These data indicates that miR-129-3p affected ferroptosis under Se deficiency conditions through the SLC7A11 pathway. Our research provides a new perspective for the mechanism of Se deficiency on the liver damage.

The emerging roles and potential applications of circular RNAs in ovarian cancer: a comprehensive review

Ovarian cancer (OC) is among the most common human malignancies and the first cause of deaths among gynecologic cancers. Early diagnosis can help improving prognosis in those patients, and accordingly exploring novel molecular mechanisms may lead to find therapeutic targets. Circular RNAs (circRNAs) comprise a group of non-coding RNAs in multicellular organisms, which are identified with characteristic circular structure. CircRNAs have been found with substantial functions in regulating gene expression through interacting with RNA-binding proteins, targeting microRNAs, and transcriptional regulation. They have been found to be involved in regulating several critical processes such as cell growth, and death, organ development, signal transduction, and tumorigenesis. Accordingly, circRNAs have been implicated in a number of human diseases including malignancies. They are particularly reported to contribute to several hallmarks of cancer leading to cancer development and progression, although a number also are described with tumor-suppressor function. In OC, circRNAs are linked to regulation of cell growth, invasiveness, metastasis, angiogenesis, and chemoresistance. Notably, clinical studies also have shown potentials in diagnosis, prediction of prognosis, and therapeutic targets for OC. In this review, I have an overview to the putative mechanisms, and functions of circRNAs in regulating OC pathogenesis in addition to their clinical potentials.