Hsa_circ_0069094 accelerates cell malignancy and glycolysis through regulating the miR-591/HK2 axis in breast cancer

Plasma Circular RNAs as Biomarkers for Breast Cancer

Breast cancer (BC) is currently the most common neoplasm, the second leading cause of cancer death in women worldwide, and is a major health problem. The discovery of new biomarkers is crucial to improve our knowledge of breast cancer and strengthen our clinical approaches to diagnosis, prognosis, and follow-up. In recent decades, there has been increasing interest in circulating RNA (circRNA) as modulators of gene expression involved in tumor development and progression. The study of circulating circRNAs (ccircRNAs) in plasma may provide new non-invasive diagnostic, prognostic, and predictive biomarkers for BC. This review describes the latest findings on BC-associated ccircRNAs in plasma and their clinical utility. Several ccircRNAs in plasma have shown great potential as BC biomarkers, especially from a diagnostic point of view. Mechanistically, most of the reported BC-associated ccircRNAs are involved in the regulation of cell survival, proliferation, and invasion, mainly via MAPK/AKT signaling pathways. However, the study of circRNAs is a relatively new area of research, and a larger number of studies will be crucial to confirm their potential as plasma biomarkers and to understand their involvement in BC.

Circular RNA-mediated miRNA sponge & RNA binding protein in biological modulation of breast cancer

Circular RNAs (circRNAs) and small non-coding RNAs of the head-to-junction circle in the construct play critical roles in gene regulation and are significantly associated with breast cancer (BC). Numerous circRNAs are potential cancer biomarkers that may be used for diagnosis and prognosis. Widespread expression of circRNAs is regarded as a feature of gene expression in highly diverged eukaryotes. Recent studies show that circRNAs have two main biological modulation models: sponging and RNA-binding. This review explained the biogenesis of circRNAs and assessed emerging findings on their sponge function and role as RNA-binding proteins (RBPs) to better understand how their interaction alters cellular function in BC. We focused on how sponges significantly affect the phenotype and progression of BC. We described how circRNAs exercise the translation functions in ribosomes. Furthermore, we reviewed recent studies on RBPs, and post-protein modifications influencing BC and provided a perspective on future research directions for treating BC.

Circular RNA and its potential diagnostic and therapeutic values in breast cancer

Breast cancer (BC) is one of the most common malignant tumors in women and still poses a significant threat to women worldwide. Recurrence of BC in situ, metastasis to distant organs, and resistance to chemotherapy are all attached to high mortality in patients with BC. Non-coding RNA (ncRNA) of the type known as "circRNA" links together from one end to another to create a covalently closed, single-stranded circular molecule. With characteristics including plurality, evolutionary conservation, stability, and particularity, they are extensively prevalent in various species and a range of human cells. CircRNAs are new and significant contributors to several kinds of disorders, including cardiovascular disease, multiple organ inflammatory responses and malignancies. Recent studies have shown that circRNAs play crucial roles in the occurrence of breast cancer by interacting with miRNAs to regulate gene expression at the transcriptional or post-transcriptional levels. CircRNAs offer the potential to be therapeutic targets for breast cancer treatment as well as prospective biomarkers for early diagnosis and prognosis of BC. Here, we are about to present an overview of the functions of circRNAs in the proliferation, invasion, migration, and resistance to medicines of breast cancer cells and serve as a promising resource for future investigations on the pathogenesis and therapeutic strategies.

The emerging regulatory roles of non-coding RNAs associated with glucose metabolism in breast cancer

Altered energy metabolism is one of the hallmarks of tumorigenesis and essential for fulfilling the high demand for metabolic energy in a tumor through accelerating glycolysis and reprogramming the glycolysis metabolism through the Warburg effect. The dysregulated glucose metabolic pathways are coordinated not only by proteins coding genes but also by non-coding RNAs (ncRNAs) during the initiation and cancer progression. The ncRNAs are responsible for regulating numerous cellular processes under developmental and pathological conditions. Recent studies have shown that various ncRNAs such as microRNAs, circular RNAs, and long noncoding RNAs are extensively involved in rewriting glucose metabolism in human cancers. In this review, we demonstrated the role of ncRNAs in the progression of breast cancer with a focus on outlining the aberrant expression of glucose metabolic pathways. Moreover, we have discussed the existing and probable future applications of ncRNAs to regulate energy pathways along with their importance in the prognosis, diagnosis, and future therapeutics for human breast carcinoma.

Non-coding RNAs in breast cancer: with a focus on glucose metabolism reprogramming

Breast cancer is the tumor with the highest incidence in women worldwide. According to research, the poor prognosis of breast cancer is closely related to abnormal glucose metabolism in tumor cells. Changes in glucose metabolism in tumor cells are an important feature. When sufficient oxygen is available, cancer cells tend to undergo glycolysis rather than oxidative phosphorylation, which promotes rapid proliferation and invasion of tumor cells. As research deepens, targeting the glucose metabolism pathway of tumor cells is seen as a promising treatment. Non-coding RNAs (ncRNAs), a recent focus of research, are involved in the regulation of enzymes of glucose metabolism and related cancer signaling pathways in breast cancer cells. This article reviews the regulatory effect and mechanism of ncRNAs on glucose metabolism in breast cancer cells and provides new ideas for the treatment of breast cancer.

Circ_0069094 regulates malignant phenotype and paclitaxel resistance in breast cancer cells via targeting the miR-136-5p/YWHAZ axis

BACKGROUND

Breast cancer is one of the most malignant cancers. Increasing evidence suggests that circular RNAs (circRNAs) are involved in breast cancer progression through sponging microRNA (miRNA). However, the underlying molecular mechanisms of circ_0069094 in breast cancer are unclear. This study aimed to reveal the effect of the circ_0069094/miR-136-5p/tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ) pathway on the malignant progression of breast cancer.

METHODS

The quantitative real-time polymerase chain reaction and western blot were used to assess the expression of circRNA/miRNA/mRNA. The functional effects of circ_0069094 on the cell processes of breast cancer were investigated by cell counting kit-8, colony-forming assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, and transwell invasion assay. The interactions among circ_0069094, miR-136-5p, and YWHAZ were assessed by dual-luciferase reporter assay. A xenograft experiment was performed to determine the effects of circ_0069094 on tumor formation.

RESULTS

Circ_0069094 was overexpressed in paclitaxel (PTX)-resistant breast cancer tissues and cells, and the silencing of circ_0069094 decreased tumor growth, cell proliferation and cell invasion while increasing PTX sensitivity and cell apoptosis in PTX-resistant cells. In addition, miR-136-5p was a target of circ_0069094, and miR-136-5p inhibition abolished circ_0069094 knockdown-induced effects in PTX-resistant cells. MiR-136-5p expression was decreased in PTX-resistant breast cancer tissues and cells, and the overexpression of miR-136-5p suppressed the malignant behaviors of breast cancer cells by targeting YWHAZ. Importantly, circ_0069094 regulated YWHAZ expression in breast cancer by targeting miR-136-5p.

CONCLUSION

Circ_0069094 silencing improved PTX sensitivity in breast cancer progression through competitively sponging miR-136-5p.

Circular RNAs: Emerging regulators of glucose metabolism in cancer

Aberrant glucose metabolism is one of the most striking characteristics of metabolic reprogramming in cancer. Thus, clarifying the regulatory mechanism of glucose metabolism is crucial to understanding tumor progression and developing novel therapeutic strategies for cancer patients. Recent developments in circular RNAs have explained the regulatory mechanism of glucose metabolism from a new dimension. In this review, we briefly summarize the recent advances in circRNA research on cancer glucose metabolism and emphasize the different regulatory mechanisms, including acting as miRNA sponges, interacting with proteins and being translated into proteins. Additionally, we discuss the future research directions of circular RNAs in the field of glucose metabolism.

Metabolic Pathways in Breast Cancer Reprograming: An Insight to Non-Coding RNAs

Cancer cells reprogram their metabolisms to achieve high energetic requirements and produce precursors that facilitate uncontrolled cell proliferation. Metabolic reprograming involves not only the dysregulation in glucose-metabolizing regulatory enzymes, but also the enzymes engaging in the lipid and amino acid metabolisms. Nevertheless, the underlying regulatory mechanisms of reprograming are not fully understood. Non-coding RNAs (ncRNAs) as functional RNA molecules cannot translate into proteins, but they do play a regulatory role in gene expression. Moreover, ncRNAs have been demonstrated to be implicated in the metabolic modulations in breast cancer (BC) by regulating the metabolic-related enzymes. Here, we will focus on the regulatory involvement of ncRNAs (microRNA, circular RNA and long ncRNA) in BC metabolism, including glucose, lipid and glutamine metabolism. Investigation of this aspect may not only alter the approaches of BC diagnosis and prognosis, but may also open a new avenue in using ncRNA-based therapeutics for BC treatment by targeting different metabolic pathways.

circ_0089153 exacerbates breast cancer cells proliferation and metastasis via sponging miR-2467-3p/E2F6

The role of circ_0089153 in breast cancer (BCa) malignancy development was explored. circ_0089153 expression in BCa was analyzed by Gene Expression Omnibus database. Clinical tissues were obtained from 90 BCa patients. Cell counting kit-8 assay, 5-ethnyl-2 deoxyuridine assay and colony formation experiment were applied for proliferation detection. Wound healing assay and Transwell experiment were used for migration and invasion detection. Dual luciferase reporter gene assay, RNA immunoprecipitation assay and RNA pull-down assay were conducted. In vivo growth and metastasis of BCa cells were performed. Quantitative real-time polymerase chain reaction, Western blot and immunohistochemistry were applied for RNAs and proteins expression. The up-modulated circ_0089153 indicated an unfavorable survival of BCa patients. circ_0089153 knockdown attenuated BCa cells proliferation, migration, invasion and epithelial-mesenchymal transition (EMT) (P < .01). circ_0089153 was miR-2467-3p sponge. Low miR-2467-3p expression indicated a worse survival of BCa patients. miR-2467-3p overexpression reduced BCa cells proliferation, migration, invasion and EMT (P < .05). circ_0089153 enhanced BCa cells proliferation, migration, invasion and EMT by sponging miR-2467-3p (P < .05). E2F6 was directly suppressed by miR-2467-3p. E2F6 high expression in BCa patients associated with worse survival. circ_0089153 knockdown suppressed in vivo BCa cells growth and lung metastasis (P < .01). circ_0089153 was an oncogene in breast cancer, which enhanced proliferation and metastasis through sponging miR-2467-3p/E2F6. circ_0089153 was suggested to be a potential target for BCa target treatment.

Construction of a circRNA-miRNA-mRNA Regulatory Network for Coronary Artery Disease by Bioinformatics Analysis

Background. Circular RNAs (circRNAs) were known to be related to the pathogenesis of many diseases through competing endogenous RNA (ceRNA) regulatory mechanisms. However, the function of circRNA in coronary artery disease (CAD) remains unclear. In this study, we aim to construct a circRNA-related competing endogenous RNA (ceRNA) network in CAD. Methods. The gene expression profiles of CAD were obtained from Gene Expression Omnibus datasets. Bioinformatics analysis was performed to construct a ceRNA regulatory network, from which the hub genes involved were identified through protein-protein interaction (PPI) networks leading to the identification of the circRNA-miRNA-hub gene subnetwork. In addition, function enrichment analysis was performed to detect the potential biological mechanism in which circRNA might be involved. Results. A total of 115 DEcircRNAs (differentially expressed circRNAs), 17 DEmiRNAs (differentially expressed microRNAs), and 790 DEmRNAs (differentially expressed mRNAs) were identified between CAD and control groups from microarray datasets. Functional enrichment analysis showed that DEmRNAs were significantly involved in inflammation-related pathways and ubiquitin-protein ligase binding. After identifying 20 DEcircRNA-DEmiRNA pairs and 561 DEmiRNA-DEmRNA pairs, we obtained a circRNA-miRNA-mRNA regulatory network. PPI network analysis showed that eight hub genes were closely related to CAD, leading to the identification of a circRNA-miRNA-hub gene subnetwork consisting of nine circRNAs (hsa_circ_0020275, hsa_circ_0020387, hsa_circ_0020417, hsa_circ_0045512, hsa_circ_0047336, hsa_circ_0069094, hsa_circ_0071326, hsa_circ_0071330, and hsa_circ_0085340), four miRNAs (hsa-miR-136-5p, hsa-miR-376c-3p, hsa-miR-411-5p, and hsa-miR-654-5p), and eight mRNAs (MKRN1, UBE2H, UBE2W, UBE2D1, UBE2F, BE2J1, ZNRF1, and SIAH2). In addition, we discovered these hub genes were enriched in the ubiquitin-mediated proteolysis pathway, suggesting circRNAs may be involved in the pathogenesis of CAD through this pathway. Conclusions. This study may deepen our understanding of the potential role of circRNA-miRNA-mRNA regulation network in CAD and suggest novel diagnostic biomarkers and therapeutic targets for CAD.

circRNA-miRNA-mRNA in breast cancer

Among cancers, breast cancer has the highest incidence rate among women and poses a tremendous threat to women's health. Messenger RNA (mRNA), microRNA (miRNA) and circular RNA (circRNA) play vital roles in the progression of breast cancer through a variety of biological effects and mechanisms. Recently, the regulatory network formed by circRNAs, miRNAs and mRNAs has piqued attention and garnered interest. CircRNAs bind to miRNAs through a regulatory mechanism in which endogenous RNAs compete to indirectly regulate the expression of mRNA corresponding to downstream target genes of miRNAs, contributing to the progression of breast cancer. The circRNA-miRNA-mRNA axis may be a marker for the early diagnosis and prognosis of breast cancer and a potential breast cancer treatment target, providing unlimited possibilities for the development of breast cancer biomarkers and therapeutic strategies. This article reviews recent research progress on the circRNA-miRNA-mRNA axis as a regulatory network of competing endogenous RNAs in breast cancer. Herein, we focus on the mechanism and function of the circRNA-miRNA-mRNA axis in the occurrence and metastasis of breast cancer, and resistance to chemotherapy.

Circular RNAs Regulate Glucose Metabolism in Cancer Cells

Circular RNAs (circRNAs) were originally thought to result from RNA splicing errors. However, it has been shown that circRNAs can regulate cancer onset and progression in various ways. They can regulate cancer cell proliferation, differentiation, invasion, and metastasis. Moreover, they modulate glucose metabolism in cancer cells through different mechanisms such as directly regulating glycolytic enzymes and glucose transporter (GLUT) or indirectly regulating signal transduction pathways. In this review, we elucidate on the role of circRNAs in regulating glucose metabolism in cancer cells, which partly explains the pathogenesis of malignant tumors, and provides new therapeutic targets or new diagnostic and prognostic markers for human cancers.

Emerging role of circular RNAs in breast cancer

Circular RNAs (cirRNAs) are generally considered as non-coding RNAs which can act as molecular sponges for miRNAs, exert regulatory roles in transcription or splicing, and interplay with RNA binding proteins. These single-stranded transcripts can affect tumor growth, the metastatic ability of cancer cells, stemness properties, and resistance to therapeutic options. Recent investigations have shown the crucial effects of circrNAs in the evolution of breast cancer. Signature of circRNAs in breast cancer samples has been mostly assessed through microarray-based methods revealing up-regulation of some circRNAs such as circ-TFF1, circACAP2, circ-TFCP2L1, hsa_circ_0000519, circDENND4C, circPLK1 and circRNA_069718, while down-regulation of other circRNAs such as hsa_circ_0000375, circYap, hsa_circ_0025202, circTADA2A-E6, circASS1 and circRNA_BARD1 in breast cancer samples. Mechanistically, these transcripts mainly affect breast cancer tumorigenesis via serving as sponges for miRNAs. In the current manuscript, we explore the results of researches that appraised the role of circRNAs in breast cancer.

Knockdown of Circ_SLC39A8 protects against the progression of osteoarthritis by regulating miR-591/IRAK3 axis

BACKGROUND

The dysregulation of circular RNAs (circRNAs) has been identified in various human diseases, including osteoarthritis (OA). The purpose of this study was to identify the role and mechanism of circ_SLC39A8 in regulating the progression of OA.

METHODS

The expression levels of circ_SLC39A8, miR-591, and its potential target gene, interleukin-1-receptor-associated kinase 3 (IRAK3), were identified by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were determined by Cell Counting Kit-8 (CCK-8) assay and flow cytometry, respectively. The relationship between miR-591 and circ_SLC39A8 or IRAK3 was predicted by bioinformatics tools and verified by dual-luciferase reporter.

RESULTS

Circ_SLC39A8 and IRAK3 were upregulated and miR-591 was downregulated in OA cartilage tissues. Knockdown of circ_SLC39A8 inhibited apoptosis and inflammation in OA chondrocytes, while these effects were reversed by downregulating miR-591. Promotion cell viability effects of miR-591 were partially reversed by IRAK3 overexpression.

CONCLUSION

Our findings indicated that knockdown of circ_SLC39A8 delayed the progression of OA via modulating the miR-591-IRAK3 axis, providing new insight into the molecular mechanisms of OA pathogenesis.