Upregulated circ_0005576 facilitates cervical cancer progression via the miR-153/KIF20A axis

Role of microRNAs in tumor progression by regulation of kinesin motor proteins

Aberrant cell proliferation is one of the main characteristics of tumor cells that can be affected by many cellular processes and signaling pathways. Kinesin superfamily proteins (KIFs) are motor proteins that are involved in cytoplasmic transportations and chromosomal segregation during cell proliferation. Therefore, regulation of the KIF functions as vital factors in chromosomal stability is necessary to maintain normal cellular homeostasis and proliferation. KIF deregulations have been reported in various cancers. MicroRNAs (miRNAs) and signaling pathways are important regulators of KIF proteins. MiRNAs have key roles in regulation of the cell proliferation, migration, and apoptosis. In the present review, we discussed the role of miRNAs in tumor biology through the regulation of KIF proteins. It has been shown that miRNAs have mainly a tumor suppressor function via the KIF targeting. This review can be an effective step to introduce the miRNAs/KIFs axis as a probable therapeutic target in tumor cells.

Circular RNA in cervical cancer: Fundamental mechanism and clinical potential

CC (CC) remains a significant global health concern, imposing a substantial health burden on women worldwide due to its high incidence and mortality rates. To address this issue, there is a need for ongoing research to uncover the underlying molecular mechanisms of CC and to discover novel diagnostic and therapeutic strategies. Recent progress in non-coding RNAs (ncRNAs) has opened new avenues for investigation, and circular RNAs (circRNAs) have emerged as molecules with diverse roles in various cellular processes. These circRNAs are distinct in structure, forming a closed loop, setting them apart from their linear counterparts. They are intricately involved in regulating different aspects of cellular functions, particularly in cell growth and development. Remarkably, circRNAs can have varying functions, either promoting or inhibiting oncogenic processes, depending on the specific cellular context. Recent studies have identified abnormal circRNAs expression patterns associated with CC, indicating their significant involvement in disease development. The differing circRNAs profiles linked to CC present promising opportunities for early detection, precise prognosis evaluation, and personalized treatment strategies. In this comprehensive review, we embark on a detailed exploration of CC-related circRNAs, elucidating their distinct roles and providing insights into the intricate molecular mechanisms governing CC's onset and progression. A growing body of evidence strongly suggests that circRNAs can serve as valuable biomarkers for early CC detection and hold potential as therapeutic targets for intervention. By delving into the complex interplay between circRNAs and CC, we are paving the way for innovative, individualized approaches to combat this serious disease, with the goal of reducing its impact on women's health globally and improving patient outcomes. As our understanding of circRNAs in the context of CC continues to deepen, the outlook for breakthroughs in diagnosis and treatment becomes increasingly promising.

Circular RNAs and cervical cancer: friends or foes? A landscape on circRNA-mediated regulation of key signaling pathways involved in the onset and progression of HPV-related cervical neoplasms

Cervical cancer (CC) is a common gynecologic malignancy, accounting for a significant proportion of women death worldwide. Human papillomavirus (HPV) infection is one of the major etiological causes leading to CC onset; however, genetic, and epigenetic factors are also responsible for disease expansion. Circular RNAs (circRNAs), which are known as a particular subset of non-coding RNA (ncRNA) superfamily, with covalently closed loop structures, have been reported to be involved in the progression of diverse diseases, especially neoplasms. In this framework, abnormally expressed circRNAs are in strong correlation with CC pathogenesis through regulating substantial signaling pathways. Also, these RNA molecules can be considered as promising biomarkers and therapeutic targets for CC diagnosis/prognosis and treatment, respectively. Herein, we first review key molecular mechanisms, including Wnt/β-catenin, MAPK, and PI3K/Akt/mTOR signaling pathways, as well as angiogenesis and metastasis, by which circRNAs interfere with CC development. Then, diagnostic, prognostic, and therapeutic potentials of these ncRNA molecules will be highlighted in depth.

Hsa_circ_0084912 Drives the Progression of Cervical Cancer Via Regulating miR-429/SOX2 Pathway

We focus on hsa_circ_0084912's role in Cervical cancer (CC) and its molecular pathways. In order to determine the expression of Hsa_circ_0084912, miR-429, and SOX2 in CC tissues and cells, Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were utilized. Cell counting kit 8 (CCK-8), colony formation and Transwell assays were respectively to analyze CC cell proliferation viability, clone formation ability and migration. RNA immunoprecipitation (RIP) assay and dual-luciferase assay were used to assure the targeting correlation among hsa_circ_0084912/SOX2 and miR-429. By using a xenograft tumor model, the hsa_circ_0084912 impact on CC cell proliferation in vivo was confirmed. Hsa_circ_0084912 and SOX2 expressions were aggrandized, however, miR-429 expression was descended in CC tissues and cells. Silencing hsa_circ_0084912 inhibited cell proliferation, colony formation and migration in vitro of CC, meanwhile reducing growth of tumor in vivo. MiR-429 might be sponged by Hsa_circ_0084912 to control SOX2 expression. Hsa_circ_0084912 knockdown impact on the malignant phenotypes of CC cells was restored by miR-429 inhibitor. Moreover, SOX2 silencing eliminated the promotive effects of miR-429 inhibitors on CC cell malignancies. By raising SOX2 expression by targeting miR-429, hsa_circ_0084912 accelerated the development of CC, offering fresh proof that it is a viable target for CC treatment.

In-silico analysis reveals Quinic acid as a multitargeted inhibitor against Cervical Cancer

The cervix is the lowermost part of the uterus that connects to the vagina, and cervical cancer is a malignant cervix tumour. One of this cancer's most important risk factors is HPV infection. In the approach to finding an effective treatment for this disease, various works have been done around genomics and drug discovery. Finding the major altered genes was one of the most significant studies completed in the field of cervical cancer by TCGA (The Cancer Genome Atlas), and these genes are TGFBR2, MED1, ERBB3, CASP8, and HLA-A. The greatest genomic alterations were found in the PI3K/MAPK and TGF-Beta signalling pathways, suggesting that numerous therapeutic targets may come from these pathways in the future. We, therefore, conducted a combined enrichment analysis of genes gathered from various works of literature for this study. The final six key genes from the list were obtained after enrichment analysis using GO, KEGG, and Reactome methods. The six proteins against the identified genes were then subjected to a docking-based screening against a library of 6,87,843 prepared natural compounds from the ZINC15 database. The most stable compound was subsequently discovered through virtual screening to be the natural substance Quinic acid, which also had the highest binding affinity for all six proteins and a better docking score. To examine their stability, the study was extended to MM/GBSA and MD simulations on the six docked proteins, and comparative docking-based calculations led us to identify the Quinic Acid as a multitargeted compound. The overall deviation of the compound was less than 2 Å for all the complexes considered best for the biological molecules, and the simulation interaction analysis reveals a huge web of interaction during the simulation.Communicated by Ramaswamy H. Sarma.

MicroRNAs, long non-coding RNAs, and circular RNAs and gynecological cancers: focus on metastasis

Gynecologic cancer is a significant cause of death in women worldwide, with cervical cancer, ovarian cancer, and endometrial cancer being among the most well-known types. The initiation and progression of gynecologic cancers involve a variety of biological functions, including angiogenesis and metastasis-given that death mostly occurs from metastatic tumors that have invaded the surrounding tissues. Therefore, understanding the molecular pathways underlying gynecologic cancer metastasis is critical for enhancing patient survival and outcomes. Recent research has revealed the contribution of numerous non-coding RNAs (ncRNAs) to metastasis and invasion of gynecologic cancer by affecting specific cellular pathways. This review focuses on three types of gynecologic cancer (ovarian, endometrial, and cervical) and three kinds of ncRNAs (long non-coding RNAs, microRNAs, and circular RNAs). We summarize the detailed role of non-coding RNAs in the different pathways and molecular interactions involved in the invasion and metastasis of these cancers.

Value of non-coding RNAs to assess lymph node status in cervical cancer

Cervical cancer (CC) is the fourth cancer in women and is the leading cause of cancer death in 42 countries. Lymph node metastasis is a determinant prognostic factor, as underlined in the latest FIGO classification. However, assessment of lymph node status remains difficult, despite the progress of imaging such as PET-CT and MRI. In the specific setting of CC, all data underlined the need for new biomarkers easily available to assess lymph node status. Previous studies have underlined the potential value of ncRNA expression in gynecological cancers. In this review, we aimed to evaluate the contribution of ncRNAs in tissue and biofluid samples to determine lymph node status in CC with potential impact on both surgical and adjuvant therapies. In tissue samples, our analysis found that there are arguments to support the role of ncRNAs in physiopathology, differential diagnosis from normal tissue, preinvasive and invasive tumors. In biofluids, despite small studies especially concerning miRNAs expression, promising data opens up new avenue to establish a non-invasive signature for lymph node status as well as a tool to predict response to neo- and adjuvant therapies, thus improving management algorithm of patients with CC.

Discovery of BAR502, as potent steroidal antagonist of leukemia inhibitory factor receptor for the treatment of pancreatic adenocarcinoma

Introduction

The leukemia inhibitory factor (LIF), is a cytokine belonging to IL-6 family, whose overexpression correlate with poor prognosis in cancer patients, including pancreatic ductal adenocarcinoma (PDAC). LIF signaling is mediate by its binding to the heterodimeric LIF receptor (LIFR) complex formed by the LIFR receptor and Gp130, leading to JAK1/STAT3 activation. Bile acids are steroid that modulates the expression/activity of membrane and nuclear receptors, including the Farnesoid-X-Receptor (FXR) and G Protein Bile Acid Activated Receptor (GPBAR1).

Methods

Herein we have investigated whether ligands to FXR and GPBAR1 modulate LIF/LIFR pathway in PDAC cells and whether these receptors are expressed in human neoplastic tissues.

Results

The transcriptome analysis of a cohort of PDCA patients revealed that expression of LIF and LIFR is increased in the neoplastic tissue in comparison to paired non-neoplastic tissues. By in vitro assay we found that both primary and secondary bile acids exert a weak antagonistic effect on LIF/LIFR signaling. In contrast, BAR502 a non-bile acid steroidal dual FXR and GPBAR1 ligand, potently inhibits binding of LIF to LIFR with an IC50 of 3.8 µM.

Discussion

BAR502 reverses the pattern LIF-induced in a FXR and GPBAR1 independent manner, suggesting a potential role for BAR502 in the treatment of LIFR overexpressing-PDAC.

Propofol-mediated circ_0000735 downregulation restrains tumor growth by decreasing integrin-β1 expression in non-small cell lung cancer

Propofol, an intravenous anesthetic agent, exerts an anti-tumor peculiarity in multifarious tumors. Circular RNA hsa_circ_0000735 (circ_0000735) is involved in non-small cell lung cancer (NSCLC) progression. The purpose of this study is to investigate whether propofol can curb NSCLC progression via regulating circ_0000735 expression. Cell viability, proliferation, apoptosis, and invasion were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, 5-ethynyl-2'-deoxyuridine, flow cytometry, and transwell assays. Evaluation of protein levels was performed using western blotting or immunohistochemistry. Detection of circ_0000735 in tissue samples and cells was carried out using a real-time quantitative polymerase chain reaction. The molecular mechanisms associated with circ_0000735 were predicted by bioinformatics analysis and verified by dual-luciferase reporter assays. The relationship between propofol and circ_0000735 in vivo was verified by xenograft models. The results showed that circ_0000735 was overexpressed in NSCLC samples and cells. Propofol treatment overtly decreased circ_0000735 expression in NSCLC cells and repressed NSCLC cell viability, proliferation, invasion, and facilitated NSCLC cell apoptosis, but these effects mediated by propofol were counteracted by circ_0000735 overexpression. Circ_0000735 functioned as a miR-153-3p sponge and regulated integrin-β1 (ITGB1) expression via adsorbing miR-153-3p. ITGB1 overexpression reversed circ_0000735 silencing-mediated effects on NSCLC cell viability, proliferation, invasion, and apoptosis. In conclusion, propofol restrained NSCLC growth by downregulating circ_0000735, which functioned as a miR-153-3p sponge and regulated ITGB1 expression via adsorbing miR-153-3p. This study provides evidence to support that propofol curbs NSCLC progression by regulating circRNA expression.

Expression, regulating mechanism and therapeutic target of KIF20A in multiple cancer

Kinesin family member 20A (KIF20A) is a member of the kinesin family. It transports chromosomes during mitosis, plays a key role in cell division. Recently, studies proved that KIF20A was highly expressed in cancer. High expression of KIF20A was correlated with poor overall survival (OS). In this review, we summarized all the cancer that highly expressed KIF20A, described the role of KIF20A in cancer. We also organized phase I and phase II clinical trials of KIF20A peptides vaccine. All results indicated that KIF20A was a promising therapeutic target for multiple cancer.

A comprehensive review on miR-153: Mechanistic and controversial roles of miR-153 in tumorigenicity of cancer cells

miRNAs play a crucial role in regulating genes involved in cancer progression. Recently, miR-153 has been mainly well-known as a tumor suppressive miRNA modulating genes in proliferation, metastasis, EMT, angiogenesis and drug resistance ability of a variety types of cancer. Mechanistic activity of miR-153 in tumorigenicity has not been fully reviewed. This manuscript presents a comprehensive review on the tumor suppressive activity of miR-153 as well as introducing the controversial role of miR-153 as an oncogenic miRNA in cancer. Furthermore, it summarizes all potential non-coding RNAs such as long non-coding RNAs (LncRNAs), transcribed ultra-conserved regions (T-UCRs) and circular RNAs (CircRNAs) targeting and sponging miR-153. Understanding the critical role of miR-153 in cell growth, metastasis, angiogenesis and drug resistance ability of cancer cells, suggests miR-153 as a potential prognostic biomarker for detecting cancer as well as providing a novel treatment strategy to combat with several types of cancer.

Circular RNA circMTO1 suppressed the progression of renal cell carcinoma progression by sponging miR-211 and miR-204

Despite considerable improvements in renal cell carcinoma (RCC) diagnostic and therapeutic strategy, the clinical prognosis of patients is far from satisfactory due to its recurrence and metastasis. Here, we attempted to explore the role of circMTO1 in RCC progression, and the underlying mechanism was further elucidated. We first detected the expression of circMTO1 in 90 pairs of RCC tissues and adjacent normal tissues using qRT-PCR. Besides, circMTO1, miR-211, miR-204 and KLF6 expression levels in RCC cells were also measured using qRT-PCR. MTT assay, cell migration, flow cytometry analysis, qRT-PCR and western blotting analysis were applied to evaluating the effect of circMTO1 in RCC cells. The bioinformatics analysis and the rescue experiment were devoted to the underlying mechanism. The results demonstrated CircMTO1 expression was significantly down-regulated in RCC tissues and cell lines. Besides, CircMTO1 inhibited cell proliferation, migration and invasion, induced apoptosis in RCC cells. In addition, CircMTO1 serves as a sponge for miR-211 and miR-204, KLF6 is a direct target of miR-211 and miR-204. Furthermore, circMTO1 and KLF6 overexpression rescued the suppression of miR-211/204 in RCC cell proliferation. In short, circMTO1 repressed RCC progression by regulating KLF6 via sponging miR-211 and miR-204, which may provide new idea of diagnosis and treatment in renal cell carcinoma.

Systematic analyses of a novel circRNA-related miRNAs prognostic signature for Cervical Cancer

Accumulating evidences shed light on the important roles of Circular RNAs (circRNAs) acting as competing endogenous RNAs (ceRNAs) in cervical cancer (CC) biology. The present study aimed to identify a novel circRNA-related prognostic signature for CC. The expression data and clinical information of CC were downloaded from the Gene Expression Omnibus (GEO) datasets to identify the differential circRNAs expression. Based on the targeted miRNA prediction, circRNA-related miRNAs were detected in training group and validation group of The Cancer Genome Atlas (TCGA) dataset to construct the novel prognostic signature of CC with least absolute shrinkage and selection operator (LASSO). Moreover, the Kaplan-Meier (K-M) analysis was applied to test the model. In the present study, three differentially expressed circRNAs (hsa_circ_0001498, hsa_circ_0066147, and hsa_circ_0006948) were identified in GSE102686 and GSE107472. Then, with the criteria 25 predicted miRNAs were analyzed in TCGA datasets to calculate the prognostic signature. Furthermore, we developed a six-miRNA signature (hsa-miR-217, hsa-miR-30b-3p, hsa-miR-136-5p, hsa-miR-185-3p, hsa-miR-501-5p and hsa-miR-658) based on their expression level and coefficients. We performed a Pearson correlation analysis to screen 47 mRNAs which are negatively regulated by these six miRNAs. Functional enrichment analysis indicated these mRNAs were mainly enriched in cancer-related biology, such as regulation of transcription, signal transduction, and cell cycle. The present study provides novel insight for better understanding of circRNA-related ceRNA network in CC and facilitates the identification of potential biomarkers for prognosis.

Novel Insight of CircRNAs in Cervical Cancer: Potential Biomarkers and Therapeutic Target

Cervical cancer (CC) is a prominent cancer around the globe, with a high incidence, and fatality rate. Numerous recent investigations have shown that various non-coding RNAs are associated with the progression of CC. Circular RNAs, a novel class of non-coding RNAs, have a single chain covalent closed-loop structure and are involved in cell growth and other physiological processes. These dysregulated circRNAs seem to have environment-specific functions. They have been demonstrated in certain studies to have a dual involvement in oncogene production and tumor inhibition in different cell settings. Simultaneously, some evidence indicates that circRNAs are abnormally expressed in CC and contributes to its progression. Thus, the distinctive expression profile of circRNAs is associated with the diagnosis, prognosis, and treatment outcomes of CC. We summarized numerous CC-specific circles and their function in revealing the molecular processes of carcinogenesis and progression in CC in this review. Taken together, these data suggest that circRNA may be used as an early detection biomarker and potential therapeutic target in patients with CC.

Circular RNAs as emerging players in cervical cancer tumorigenesis; A review to roles and biomarker potentials

Cervical cancer is the most lethal gynecological cancer among women worldwide. Most of the patients are diagnosed at the advanced stages due to late diagnosis and lack of accessible and valuable approaches for early detection of the disease. Circular RNAs (circRNAs) are a distinguishable class of non-coding RNAs with characteristic loop structures. Although their function has not been completely elucidated; however, recent evidence has suggested regulatory functions for circRNAs on gene expression controlling various biological functions like cell growth and apoptosis, development, embryogenesis, and pathogenesis of human diseases particularly cancers. Studies show the role of dysregulated circRNAs in biological processes including cell proliferation, migration, invasion, apoptosis, angiogenesis, and chemoresistance contributing to affect tumorigenesis in ovarian cancer cells, animal, and clinical studies. These effects can be defined as consistent with several tumorigenesis characteristics, which are defined as "hallmarks of cancer". Additionally, dysregulated circRNAs exhibit prognostic, and diagnostic potentials both in the prediction of prognosis in ovarian cancer patients, and also their discrimination from healthy individuals. Furthermore, targeting circRNAs has shown positive results in the suppression of malignant features of cancer cells, and also in overcoming chemoresistance. In this review, I have gathered the majority of studies evaluating the role of circRNAs in the development, and progression of cervical cancer, and also have discussed prognostic, diagnostic, and therapeutic potentials of circRNAs for clinical applications in cervical cancer patients.

CircCDK17 knockdown inhibits tumor progression and cell glycolysis by downregulaing YWHAZ expression through sponging miR-1294 in cervical cancer

BACKGROUND

Cervical cancer (CC) is the fourth aggressive tumor affecting women worldwide. Circular RNA (circRNA) is enrolled in CC process. This study aims to unveil the profiles of circ_101119 (circCDK17) in cell proliferation, migration, invasion, apoptosis and glycolysis in CC.

METHODS

The expression levels of circCDK17, microRNA-1294 (miR-1294) and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ) mRNA were detected by quantitative real time polymerase chain reaction (qRT-PCR). The protein expression levels of YWHAZ, recombinant glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) were determined by western blot. Cell proliferation, migratory and invasive abilities and apoptosis were illustrated by cell counting kit-8 (CCK-8) assay, transwell assay and flow cytometry analysis, respectively. Cell lactate production, glucose uptake and adenosine 5'-triphosphate (ATP) level were severally elucidated by lactate assay kit, glucose assay kit and ATP detection kit.

RESULTS

CircCDK17 expression and the mRNA and protein expression levels of YWHAZ were dramatically upregulated, while miR-1294 expression was obviously downregulated in CC tissues or cells compared with control groups. CircCDK17 silencing suppressed cell proliferation, migration, invasion and glycolysis, and induced cell apoptosis in CC; however, miR-1294 inhibitor restrained these effects. Additionally, circCDK17 was a sponge of miR-1294 and miR-1294 bound to YWHAZ. Furthermore, circCDK17 knockdown inhibited tumor formation in vivo.

CONCLUSION

CircCDK17 knockdown repressed cell proliferation, migration, invasion and glycolysis, and promoted cell apoptosis via miR-1294/YWHAZ axis in CC. This finding provides a theoretical basis in studying circRNA-mediated therapy in CC.

CircRNF121 knockdown suppresses the progression of cervical cancer by regulating miR-153-3p/ATF2 axis and wnt/β-catenin pathway

Cervical cancer (CC) is a common malignancy in gynecology. Emerging evidence has demonstrated that circular RNAs (circRNAs) act as vital mediators in CC. However, the roles of circRNA ring finger protein 121 (circRNF121) in CC are largely unknown. Herein, we focused on the exact function and underlying mechanism of circRNF121 in CC development. Our results showed that circRNF121 was highly expressed in CC tissues and cells. Knockdown of circRNF121 suppressed cell growth, metastasis, epithelial-mesenchymal transition (EMT), autophagy, and wnt/β-catenin pathway in CC cells in vitro and blocked tumor formation in vivo. For mechanism investigation, circRNF121 could affect activating transcription factor 2 (ATF2) expression by decoying miR-153-3p, thereby accelerating CC cell development. In conclusion, circRNF121 exerted the tumor-suppressive role in CC progression by altering miR-153-3p/ATF2 axis. These results suggested that circRNF121 might be a possible circ-targeted therapy for patients with CC.

Hsa_circ_0005576 promotes osimertinib resistance through the miR-512-5p/IGF1R axis in lung adenocarcinoma cells

Osimertinib is a third‐generation epidermal growth factor receptor tyrosine kinase inhibitor (EGFR‐TKI) for lung adenocarcinoma (LUAD) harboring activating mutations, but patients ultimately develop acquired resistance. Circular RNAs are involved in EGFR‐TKI resistance, while the role of hsa_circ_0005576 in the osimertinib resistance of LUAD remains unknown. In this study, we demonstrated that hsa_circ_0005576 could facilitate osimertinib‐resistant LUAD cells. Briefly, knockdown of hsa_circ_0005576 not only suppressed the proliferation and promoted the apoptosis of resistant LUAD cells, but also increased their sensitivity to osimertinib. Mechanistically, hsa_circ_0005576, serving as an miRNA sponge, could directly interact with miR‐512‐5p and subsequently upregulate the miR‐512‐5p‐targeted insulin‐like growth factor 1 receptor. Rescue assays indicated that miR‐512‐5p inhibition could reverse the effects of hsa_circ_0005576 knockdown in LUAD cells resistant to osimertinib. Overall, our study revealed that hsa_circ_0005576 regulates proliferation and apoptosis through miR‐512‐5p/IGF1R signaling, which contributes further to the resistance of LUAD cells to osimertinib. In addition, this study provides a novel insight into the mechanisms underlying osimertinib resistance of LUAD.

Identification of Biomarkers for Cervical Cancer Radiotherapy Resistance Based on RNA Sequencing Data

Cervical cancer as a common gynecological malignancy threatens the health and lives of women. Resistance to radiotherapy is the primary cause of treatment failure and is mainly related to difference in the inherent vulnerability of tumors after radiotherapy. Here, we investigated signature genes associated with poor response to radiotherapy by analyzing an independent cervical cancer dataset from the Gene Expression Omnibus, including pre-irradiation and mid-irradiation information. A total of 316 differentially expressed genes were significantly identified. The correlations between these genes were investigated through the Pearson correlation analysis. Subsequently, random forest model was used in determining cancer-related genes, and all genes were ranked by random forest scoring. The top 30 candidate genes were selected for uncovering their biological functions. Functional enrichment analysis revealed that the biological functions chiefly enriched in tumor immune responses, such as cellular defense response, negative regulation of immune system process, T cell activation, neutrophil activation involved in immune response, regulation of antigen processing and presentation, and peptidyl-tyrosine autophosphorylation. Finally, the top 30 genes were screened and analyzed through literature verification. After validation, 10 genes (KLRK1, LCK, KIF20A, CD247, FASLG, CD163, ZAP70, CD8B, ZNF683, and F10) were to our objective. Overall, the present research confirmed that integrated bioinformatics methods can contribute to the understanding of the molecular mechanisms and potential therapeutic targets underlying radiotherapy resistance in cervical cancer.

Role of Virus-Induced Host Cell Epigenetic Changes in Cancer

The tumor viruses human T-lymphotropic virus 1 (HTLV-1), hepatitis C virus (HCV), Merkel cell polyomavirus (MCPyV), high-risk human papillomaviruses (HR-HPVs), Epstein-Barr virus (EBV), Kaposi’s sarcoma-associated herpes virus (KSHV) and hepatitis B virus (HBV) account for approximately 15% of all human cancers. Although the oncoproteins of these tumor viruses display no sequence similarity to one another, they use the same mechanisms to convey cancer hallmarks on the infected cell. Perturbed gene expression is one of the underlying mechanisms to induce cancer hallmarks. Epigenetic processes, including DNA methylation, histone modification and chromatin remodeling, microRNA, long noncoding RNA, and circular RNA affect gene expression without introducing changes in the DNA sequence. Increasing evidence demonstrates that oncoviruses cause epigenetic modifications, which play a pivotal role in carcinogenesis. In this review, recent advances in the role of host cell epigenetic changes in virus-induced cancers are summarized.

Hsa_circ_0000520 overexpression increases CDK2 expression via miR-1296 to facilitate cervical cancer cell proliferation

Background

Circular RNA (circRNA) has been demonstrated to participate in cervical cancer development. In this study, we analyzed the role of hsa_circ_0000520 in cervical cancer.

Methods

Fifty-two pairs of cervical cancer and adjacent normal tissue samples were collected, and five human cervical cancer cell lines were obtained followed by the detection of hsa_circ_0000520 expression. Nuclear-cytoplasmic isolation and fluorescence in situ hybridization were performed to analyze the subcellular localization of hsa_circ_0000520 while linear RNA was digested by RNase R. Gain- or loss-of function experiments on hsa_circ_0000520 were performed, followed by detection of cell proliferation and cell cycle by EdU, Cell Counting Kit-8, colony formation assay, and flow cytometry respectively.

Results

Hsa_circ_0000520 and cyclin-dependent kinase 2 (CDK2) were highly expressed in cervical cancer tissues. Binding sites between microRNA-1296 (miR-1296) and hsa_circ_0000520 or CDK2 were verified. Antibody to Argonaute 2 (Ago2) could precipitate hsa_circ_0000520, indicating that hsa_circ_0000520 could competitively bind to miR-1296 via Ago2. Silencing hsa_circ_0000520 inhibited cervical cancer cell proliferation and promoted the inhibitory effects of miR-1296 on CDK2, thereby blocking cell cycle progression and promoting apoptosis.

Conclusion

These results support the premise that targeting hsa_circ_0000520 can be a potential approach to combat cervical cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-02953-9.

Circular RNA Circ_0003221 Promotes Cervical Cancer Progression by Regulating miR-758-3p/CPEB4 Axis

BACKGROUND

Circular RNAs (circRNAs) play crucial roles in the development and progression of various cancers, including cervical cancer. However, the role and regulatory mechanism of circ_0003221 in cervical cancer are still unclear.

METHODS

The expression of circ_0003221, microRNA-758-3p (miR-758-3p), cytoplasmic polyadenylation element-binding protein 4 (CPEB4) was detected by quantitative real-time PCR (qRT-PCR). Cell Counting Kit-8 (CCK-8), colony formation, and 5-Ethynyl-2'-deoxyuridine (Edu) assays were utilized to determine cell proliferation. Cell cycle distribution was analyzed by flow cytometry. Cell migration and invasion were detected by transwell assay. All protein levels were detected by Western blot assay. The interaction between miR-758-3p and circ_0003221 or CPEB4 was confirmed by dual-luciferase reporter, RNA immunoprecipitation (RIP) and RNA pull-down assays. Mice xenograft model of cervical cancer was established to verify the function of circ_0003221 in vivo.

RESULTS

Circ_0003221 was upregulated in cervical cancer tissues and cells. Knockdown of circ_0003221 suppressed cell proliferation, migration, invasion, and EMT and induced cell cycle arrest in cervical cancer cells. MiR-758-3p was a direct target of circ_0003221, and miR-758-3p inhibition reversed the effects of circ_0003221 knockdown in cervical cancer cells. Moreover, CPEB4 was identified as a direct target of miR-758-3p, and miR-758-3p exerted its anti-cancer role by targeting CPEB4. Furthermore, circ_0003221 acted as a sponge of miR-758-3p to upregulate CPEB4 expression. In addition, circ_0003221 silence also suppressed tumor growth and EMT in vivo.

CONCLUSION

Circ_0003221 knockdown inhibited cervical cancer progression via modulating miR-758-3p/CPEB4 axis, which might suggest a new insight into the pathogenesis of cervical cancer.

Circ_0001806 Promotes the Proliferation, Migration and Invasion of NSCLC Cells Through miR-1182/NOVA2 Axis

Background

Circular RNAs (circRNAs) are non-coding RNAs with a covalently closed loop. circRNAs affect the progression of diverse cancers. Nonetheless, circ_0001806 expression and function in non-small cell lung cancer (NSCLC) are undefined.

Methods

qRT-PCR was executed to examine circ_0001806, miR-1182 and NOVA2 mRNA expression levels in NSCLC tissues and cells. CCK-8, EdU, cell scratch test and Transwell assay were conducted to examine the viability, multiplication, migration and invasion of NSCLC cell lines H1650 and HCC827. The binding sites between circ_0001806 and miR-1182, miR-1182 and NOVA2 mRNA were predicted by the circular RNA Interactome and TargetScan databases, and the dual-luciferase reporter gene experiment was employed for verification. Western blot was implemented to examine NOVA2 expression.

Results

Circ_0001806 expression in NSCLC tissues and cell lines was substantially augmented, while miR-1182 expression was markedly decreased. Circ_0001806 facilitated the multiplication, migration and invasion of H1650 and HCC827 cells, while miR-1182 exerted the opposite effect. Circ_0001806 indirectly enhanced NOVA2 expression by specifically down-modulating miR-1182.

Conclusion

Circ_0001806 augments NOVA2 expression by targeting miR-1182 to enhance the multiplication, migration and invasion of NSCLC cells.

The Potential of circRNA as a Novel Diagnostic Biomarker in Cervical Cancer

Cervical cancer is the fourth most common cancer among females worldwide. In spite of advances in detection and treatment, it is still one of the most dangerous gynecological malignancies in the world, especially in developing countries, and seriously threatens human health. Circular RNA (circRNA) is a special new type of endogenous noncoding RNA discovered recently. They form a covalently closed continuous loop and are specifically expressed in the eukaryotic transcriptome. With further understanding of circular RNA, a large number of studies have determined the key regulatory role of circRNA in a variety of diseases, especially cancer (including cervical cancer, liver cancer, and lung cancer). In addition, it has also been found that the abnormal expression of circRNA is related to its pathological characteristics in cervical cancer tissue, which can be used as a potential indicator for early screening and diagnosis of cervical cancer, targeted therapy, and prognosis prediction. This article summarizes the recent research achievements of circRNAs in cervical cancer. We briefly described the abnormal expression of circRNA in cervical cancer and discussed the involvement of circRNA in the occurrence process of cervical cancer by regulating cell proliferation, migration, invasion, and apoptosis. We believe that circRNA has potential value as a biomarker in the diagnosis and prognosis of cervical cancer.

Investigating the Underlying Mechanisms of Circular RNAs and Their Application in Clinical Research of Cervical Cancer

Circular RNAs (circRNAs) are non-coding RNA molecules, and these are differentially expressed in various diseases, including cancer, suggesting that circRNAs can regulate certain diseases. CircRNAs can act as miRNAs sponges, RNA-binding protein (RBP) sponges, and translation regulators, and they can become an important part of the regulation of gene expression. Furthermore, because of their biomedical features in body fluids, such as high abundance, conservation, and stability, circRNAs are seen as potential biomarkers for various cancers. Cervical cancer (CC) is one of the main causes of cancer-related death in women, and there have been a large number of studies that analyze circRNAs as a new object to be evaluated in CC. Therefore, this review, by understanding the role of circRNAs in CC, may create innovative strategies in the future clinical diagnosis, treatment, and prognosis of CC and promote the development of personalized and highly accurate cancer therapy.

MicroRNA‑153 attenuates hypoxia‑induced excessive proliferation and migration of pulmonary arterial smooth muscle cells by targeting ROCK1 and NFATc3

The aim of the present study was to explore the effect of microRNA (miR)‑153 on the proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) in a hypoxic condition by targeting ρ‑associated, coiled‑coil‑containing protein kinase 1 (ROCK1) and nuclear factor of activated T cells cytoplasmic 3 (NFATc3). The right ventricular systolic pressure, right ventricular hypertrophy index, medial wall thickness and medial wall area were studied at different time‑points after rats were exposed to hypoxia. Western blot analysis was used to detect ROCK1 and NFATc3 protein levels. In addition, reverse transcription‑quantitative (RT‑q) PCR was performed to confirm the mRNA levels of miR‑153, ROCK1 and NFATc3 in human (H)PASMCs under hypoxic conditions. Transfected cells were then used to evaluate the effect of miR‑153 on cell proliferation and migration abilities. The association between miR‑153 and ROCK1 or NFATc3 was identified through double luciferase assays. Hypoxia induced pulmonary vascular remodeling and pulmonary arterial hypertension, which resulted from the abnormal proliferation of HPASMCs. ROCK1 and NFATc3 were the target genes of miR‑153 and miR‑153 mimic inhibited the protein expressions of ROCK1 and NFATc3 in HPASMCs and further inhibited cell proliferation and migration under hypoxic conditions. By contrast, the miR‑153 inhibitor promoted the proliferation and migration of HPASMCs. miR‑153 regulated the proliferation and migration of HPASMCs under hypoxia by targeting ROCK1 and NFATc3.

Circular RNA hsa_circ_0001829 promotes gastric cancer progression through miR-155-5p/SMAD2 axis

Background

Accumulating evidences have shown that circular RNAs (circRNAs) play important roles in regulating the pathogenesis of cancer. However, the role of circRNAs in gastric cancer (GC) remains largely unclear.

Methods

In this study, we identified a novel upregulated circRNA, hsa_circ_0001829, in chemically induced malignant transformed human gastric epithelial cells using RNA-seq. Subsequent qRT-PCR and ISH assays were performed to detect the expression level of hsa_circ_0001829 in GC cell lines and tissues. Functional roles of hsa_circ_0001829 in GC were then explored by loss- and gain-of- function assays. Bioinformatic prediction and luciferase assay were used to investigate potential mechanisms of hsa_circ_0001829. Finally, the mice xenograft and metastasis models were constructed to assess the function of hsa_circ_0001829 in vivo.

Results

We found that hsa_circ_0001829 was significantly upregulated in GC tissues and cell lines. Loss- and gain-of- function assays showed that hsa_circ_0001829 promotes GC cells proliferation, migration and invasion, and the affected cell cycle progression and apoptosis rates may account for the effect of hsa_circ_0001829 on GC proliferation. In addition, bioinformatic prediction and luciferase assay showed that hsa_circ_0001829 acts as a molecular sponge for miR-155-5p and that SMAD2 was a target gene of miR-155-5p; moreover, hsa_circ_0001829 sponges miR-155-5p to regulate SMAD2 expression and hsa_circ_0001829 promotes GC progression through the miR-155-5p–SMAD2 pathway. Finally, suppression of hsa_circ_0001829 expression inhibited tumor growth and aggressiveness in vivo.

Conclusion

Taken together, our findings firstly demonstrated a novel oncogenic role of hsa_circ_0001829 in GC progression through miR-155-5p–SMAD2 axis, and our study may offer novel biomarkers and therapeutic targets for GC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-020-01790-w.

Hsa_circ_0102171 aggravates the progression of cervical cancer through targeting miR-4465/CREBRF axis

Cervical cancer (CC) has caused numerous cancer-related deaths in women. Recent years, circular RNAs have been reported as vital factors in CC tumorigenesis. Our current study focused on the role of hsa_circ_0102171 (called circ_0102171 subsequently) in CC. At first, we applied reverse transcription polymerase chain reaction to detect the expression of circ_0102171 in CC tissues and cells. Subsequently, we silenced circ_0102171 to conduct loss-of-function assays, including cell counting kit-8 assay, 5-ethynyl-2'-deoxyuridine staining, Transwell assay, and flow cytometry analysis. Interestingly, we discovered that circ_0102171 expressed at a high level in CC tissues and cells. Functionally, silencing circ_0102171 prohibited cell proliferation, migration and invasion, and strengthened cell apoptosis in CC in vitro. Mechanistic investigations revealed that circ_0102171 could act as a sponge for miR-4465. Gain-of-function assays demonstrated that miR-4465 hindered the growth and migration of CC cells. Moreover, circ_0102171 enhanced the level of CREB3 regulatory factor (CREBRF) which was the downstream target of miR-4465. Rescue assays suggested that CREBRF and miR-4465 could involve in circ_0102171-mediated CC progression. Finally, in vivo data supported that silencing circ_0102171 hindered CC cell growth. In conclusion, circ_0102171 aggravates CC progression via targeting miR-4465/CREBRF axis.

Gynecologic cancers and non-coding RNAs: Epigenetic regulators with emerging roles

Gynecologic cancers involve the female genital organs, such as the vulva, vagina, cervix, endometrium, ovaries, and fallopian tubes. The occurrence and frequency of gynecologic cancer depends on personal lifestyle, history of exposure to viruses or carcinogens, genetics, body shape, and geographical habitat. For a long time, research into the molecular biology of cancer was broadly restricted to protein-coding genes. Recently it has been realized that non-coding RNAs (ncRNA), including long noncoding RNAs (LncRNAs), microRNAs, circular RNAs and piRNAs (PIWI-interacting RNAs), can all play a role in the regulation of cellular function within gynecological cancer. It is now known that ncRNAs are able to play dual roles, i.e. can exert both oncogenic or tumor suppressive functions in gynecological cancer. Moreover, several clinical trials are underway looking at the biomarker and therapeutic roles of ncRNAs. These efforts may provide a new horizon for the diagnosis and treatment of gynecological cancer. Herein, we summarize some of the ncRNAs that have been shown to be important in gynecological cancers.

CircPVT1 Promoted the Progression of Breast Cancer by Regulating MiR-29a-3p-Mediated AGR2-HIF-1α Pathway

Background

Breast cancer (BC) is a great contributor to cancer-related death. Mounting studies have identified that circular RNAs (circRNAs) play vital roles in cancer cell proliferation, apoptosis and invasion. Here, we explored the effect of circPVT1 on BC development as well as its downstream mechanisms.

Methods

qRT-PCR was used to determine the relative expression levels of circPVT1 and miR-29a-3p in BC tissue samples and cell lines. We also analyzed the relevance between pathological indexes and circPVT1 expression level. Human breast cancer cell lines MCF-7 and MDA-MB-231 were taken as cell models. Gain- or loss-of-functional assays of circPVT1 and miR-29a-3p were conducted in BC cell lines to investigate their effects on the cell proliferation, apoptosis, migration and invasion. The protein levels of AGR2, HIF-1α, Bax, Bcl2 and Caspase3 were determined by Western blot. Furthermore, dual-luciferase reporter assay and RNA fluorescence in situ hybridization (FISH) were used to confirm the targeted relationships between circPVT1 and miR-29a-3p, miR-29a-3p and anterior gradient 2 (AGR2).

Results

CircPVT1 was highly expressed while miR-29a-3p was lowly expressed in BC tissues and cell lines. Inhibition of circPVT1 or overexpression of miR-29a-3p remarkably suppressed BC cell proliferation, invasion and migration while promoted cell apoptosis. By contrast, circPVT1 upregulation or miR-29a-3p inhibition led to mitigate malignant behaviours of BC cells. Functionally, circPVT1 bound to miR-29a-3p, and AGR2 was a target gene of miR-29a-3p. Overexpressed circPVT1 promoted AGR2 and HIF-1α expression by repressing miR-29a-3p. More importantly, overexpressing AGR2 enhances HIF-1α expression, accompanied with accelerated proliferation, invasion and migration of BC cells.

Conclusion

CircPVT1 acts as an oncogene in BC via promoting the growth, invasion, migration and inhibiting apoptosis through miR-29a-3p-mediated AGR2-HIF-1α axis.

Circular RNAs: Novel biomarkers for cervical, ovarian and endometrial cancer (Review)

Cervical, ovarian and endometrial cancer are the three most common types of malignant tumor and the leading causes of cancer-associated death in women. Tumor debulking surgery followed by platinum and paclitaxel chemotherapy is the current treatment regime of choice. However, as a result of late diagnosis and chemoresistance, the survival rates of patients with advanced gynecological cancers remains unsatisfactory. Circular RNAs (circRNAs) are stable noncoding RNAs that are present in a wide variety of tissue and cell types. With the enhancement of RNA sequencing methods, increasing numbers of circRNAs have been identified, and their functions are gradually being revealed. In recent years, circRNAs have received increasing attention for their regulatory roles in cervical, ovarian and endometrial cancer. The aim of the present review was to summarize the possible mechanisms of recently identified circRNAs; we hypothesize that a novel diagnostic and therapeutic biomarker may be identified to prolong the survival time of patients with gynecological malignancies.

Circ_0005576 Promotes Malignant Progression Through miR-874/CDK8 Axis in Colorectal Cancer

PURPOSE

To investigate the function of circ_0005576 in colorectal cancer (CRC) progression.

PATIENTS AND METHODS

Circ_0005576 expression in CRC patients was detected by quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization (ISH). CRC cells were transfected using Lipofectamine 2000 reagent. CRC cell proliferation was researched by Cell Counting Kit-8 (CCK-8) assay and 5-ethynyl-2-deoxy-uridine (EdU) incorporation experiment. Cell cycle and apoptosis were determined by flow cytometry analysis. Luciferase reporter assay was used to explore the relationship between circ_0005576 and miR-874 or between miR-874 and CDK8. qRT-PCR and Western blot were used to detect circ_0005576, miR-874, and CDK8 expression. In vivo experiments were performed using nude mice. CDK8 and Ki67 expression in xenograft tumors was investigated by immunohistochemistry. Tunel assay was conducted to analyze the apoptosis of xenograft tumors.

RESULTS

Circ_0005576 expression was up-regulated in CRC, which was associated with tumor progression (P < 0.05 or P < 0.01). Circ_0005576 knockdown in CRC cells reduced proliferation, induced apoptosis, increased cells in the G1 phase, and decreased cells in the S phase (P < 0.01 or P < 0.001). Circ_0005576 promoted CDK8 expression via sponging miR-874. miR-874 knockdown and CDK8 overexpression significantly reversed the inhibitory effect of circ_0005576 knockdown on CRC cells malignant phenotype (P < 0.05 or P < 0.01). Circ_0005576 knockdown inhibited tumor growth in vivo (P < 0.01). Circ_0005576 knockdown reduced CDK8, Ki67 expression, and enhanced apoptosis in xenograft tumors.

CONCLUSION

Circ_0005576 promoted malignant progression through the miR-874/CDK8 axis in CRC.

The Expression, Functions and Mechanisms of Circular RNAs in Gynecological Cancers

Circular RNAs (circRNAs) are covalently closed, endogenous non-coding RNAs and certain circRNAs are linked to human tumors. Owing to their circular form, circRNAs are protected from degradation by exonucleases, and therefore, they are more stable than linear RNAs. Many circRNAs have been shown to sponge microRNAs, interact with RNA-binding proteins, regulate gene transcription, and be translated into proteins. Mounting evidence suggests that circRNAs are dysregulated in cancer tissues and can mediate various signaling pathways, thus affecting tumorigenesis, metastasis, and remodeling of the tumor microenvironment. First, we review the characteristics, biogenesis, and biological functions of circRNAs, and describe various mechanistic models of circRNAs. Then, we provide a systematic overview of the functional roles of circRNAs in gynecological cancers. Finally, we describe the potential future applications of circRNAs as biomarkers for prognostic stratification and as therapeutic targets in gynecological cancers. Although the function of most circRNAs remains elusive, some individual circRNAs have biologically relevant functions in cervical cancer, ovarian cancer, and endometrial cancer. Certain circRNAs have the potential to serve as biomarkers and therapeutic targets in gynecological cancers.

Beyond MicroRNAs: Emerging Role of Other Non-Coding RNAs in HPV-Driven Cancers

Persistent infection with high-risk Human Papilloma Virus (HPV) leads to the development of several tumors, including cervical, oropharyngeal, and anogenital squamous cell carcinoma. In the last years, the use of high-throughput sequencing technologies has revealed a number of non-coding RNA (ncRNAs), distinct from micro RNAs (miRNAs), that are deregulated in HPV-driven cancers, thus suggesting that HPV infection may affect their expression. However, since the knowledge of ncRNAs is still limited, a better understanding of ncRNAs biology, biogenesis, and function may be challenging for improving the diagnosis of HPV infection or progression, and for monitoring the response to therapy of patients affected by HPV-driven tumors. In addition, to establish a ncRNAs expression profile may be instrumental for developing more effective therapeutic strategies for the treatment of HPV-associated lesions and cancers. Therefore, this review will address novel classes of ncRNAs that have recently started to draw increasing attention in HPV-driven tumors, with a particular focus on ncRNAs that have been identified as a direct target of HPV oncoproteins.

Circ_100565 promotes proliferation, migration and invasion in non-small cell lung cancer through upregulating HMGA2 via sponging miR-506-3p

Background

Circular RNAs (circRNAs) play a vital role in the development of various cancers. Circ_100565 was found to be a highly expressed circRNA in non-small cell lung cancer (NSCLC) tissues screened by microarray profiles of circRNAs. However, the role of circ_100565 in NSCLC still remains unknown.

Methods

Microarray analysis was used to screen for differentially expressed circRNAs in NSCLC tissues. The expression levels of circ_100565, microRNA-506-3p (miR-506-3p) and high mobility group AT-hook 2 (HMGA2) were measured by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was detected by cell counting kit-8 (CCK-8) and colony formation assays. Transwell assay was used to determine the migration and invasion of cells. Besides, Western blot (WB) analysis was performed to assess the levels of proliferation and metastasis-related proteins and HMGA2 protein. Moreover, animal experiments were used to confirm the effect of circ_100565 on NSCLC tumor growth in vivo. In addition, the interaction between miR-506-3p and circ_100565 or HMGA2 was confirmed by dual-luciferase reporter, RNA immunoprecipitation (RIP) assay or biotin-labeled pull-down assay.

Results

Circ_100565 was upregulated in NSCLC, and its high expression was positively associated with the poor overall survival of NSCLC patients. Silencing of circ_100565 suppressed the proliferation, migration and invasion of NSCLC cells in vitro and reduced the tumor growth of NSCLC in vivo. Circ_100565 could sponge miR-506-3p, and miR-506-3p could target HMGA2. Moreover, miR-506-3p inhibitor or HMGA2 overexpression could reverse the inhibition effect of circ_100565 knockdown on NSCLC progression.

Conclusion

Circ_100565 increased HMGA2 expression to promote proliferation, migration and invasion in NSCLC via absorbing miR-506-3p. Our findings provided a new biomarker for NSCLC therapy.

CircularRNA-9119 promotes the proliferation of cervical cancer cells by sponging miR-126/MDM4

The aim of this study was to investigate the role of circular RNA-9119 (circ9119) in cervical cancer (CC) and the microRNA-126-3p (miR-126)-based molecular mechanism underlying CC. circ9119 and MDM4 were initially overexpressed, and miR-126 expression was found to be reduced in CC cells and tissues. A series of mimics, inhibitors, overexpressing plasmids or siRNAs were introduced into CC cells to alter the circ9119, miR-126, and MDM4 expressions. Cell-based experiments showed that silencing of circ9119 or the upregulation of miR-126 resulted in suppressed proliferation, accompanied by the induced apoptosis of CC cells. The dual-luciferase reporter assay highlighted that circ9119 functioned as an miR-126 ceRNA to increase MDM4 expression. In vivo experiments further confirmed the suppressed tumor growth caused by circ9119 silencing. Our findings demonstrated that circ9119 acts as an oncogene in CC. Our study provides evidence for targeting circ9119 for the treatment of CC.

A potential disease monitoring and prognostic biomarker in cervical cancer patients: The clinical application of circular RNA_0018289

OBJECTIVE

This study aimed to investigate the tumor circular RNA_0018289 (circ_0018289) expression and its correlation with clinical characteristics as well as survival profiles in cervical cancer patients.

METHODS

A hundred and ninety-two cervical cancer patients who received surgical resection were recruited in this prospective study. Tumor tissue and paired adjacent tissue were obtained during the surgery, in which circ_0018289 expression was detected by reverse transcription quantitative polymerase chain reaction. Disease-free survival (DFS) and overall survival (OS) were recorded.

RESULTS

Circ_0018289 expression was upregulated in tumor tissue compared with paired adjacent tissue (P < .001), and receiver operative characteristic curve disclosed its good value for separating tumor tissue from adjacent tissue with an area under curve of 0.907 (95% CI: 0.879-0.935). Additionally, tumor circ_0018289 expression was positively associated with tumor size (P = .009), lymph node metastasis (P = .005) and Federation International of Gynecology and Obstetrics stage (P = .005). The DFS (P = .005) and OS (P = .015) were both worse in patients with circ_0018289 high expression compared to patients with circ_0018289 low expression. Meanwhile, in patients with circ_0018289 high expression, DFS and OS were the longest in patients with high+ expression followed by patients with high++ expression, and the shortest in patients with high+++ expression. Moreover, circ_0018289 high expression could independently predict worse DFS in the total cervical cancer patients (P = .042).

CONCLUSION

Circ_0018289 could serve as a potential disease monitoring and prognostic biomarker in cervical cancer patients.

Upregulation of hsa_circ_0007874 suppresses the progression of ovarian cancer by regulating the miR-760/SOCS3 pathway

Ovarian cancer (OVA) is a fatal and common malignancy in women worldwide. Circular RNAs (circRNAs) consist of a family of circular endogenous RNAs generated by selective splicing, and they are involved in many diseases. Previous studies reported that hsa_circ_0007874 is aberrantly expressed in cancer and functions in tumorigenesis. While the hsa_circ_0007874 role in OVA is unclear. Here, we detected the hsa_circ_0007874 expression in OVA cell lines using Rt‐qPCR. Hsa_circ_0007874 subcellular localization was confirmed by fluorescence in situ hybridization. The relationship between hsa_circ_0007874, microRNAs (miRNAs), and relative protein levels was assessed using the luciferase reporter assays. Results verified that hsa_circ_0007874 is downregulated in OVA cell lines. hsa_circ_0007874 overexpression decreased the OVA cell migration and proliferation in vitro and in vivo. Bioinformatics and luciferase reporter assays confirmed that miR‐760 and SOCS3 are the downstream targets of hsa_circ_0007874. Downregulation of SOCS3 or miR‐760 overexpression restored the migration and proliferation ability of SKOV3 or A2780 cells overexpressing hsa_circ_0007874. Downregulation of SOCS3 restored the proliferation and migration in miR‐760 knockdown SKOV3 and A2780 cells. In summary, the data suggest that hsa_circ_0007874 acts as a tumor suppressor by regulating the miR‐760/SOCS3 axis, highlighting its potential as an effective therapeutic target for OVA.

Overexpression of circRNA_100290 promotes the progression of laryngeal squamous cell carcinoma through the miR-136-5p/RAP2C axis

Circular RNAs (circRNAs) exert critical functions in tumorigenesis and tumor development, but whether and how circRNAs contribute to laryngeal squamous cell carcinoma (LSCC) is unclear. In this study, we explored the function and mechanisms of circRNA_100290 in LSCC. Tissue samples were obtained from 40 patients with LSCC. The expression of circRNA_100290 and other targets was measured through quantitative reverse transcription-polymerase chain reaction and western blot analysis. Cell proliferation, colony-forming ability, and apoptosis were tested using CCK-8 assay and EdU assay, colony formation assay, and flow cytometry, respectively. Cell migration and invasion were detected by Transwell assay. Moreover, the interactions between circRNA_100290, miR-136-5p, and RAP2C were analyzed by bioinformatics, and verified by dual-luciferase reporter assays. Here, we found that circRNA_100290 expression was significantly upregulated in LSCC tissues and cell lines compared with the normal controls. Expression of circRNA_100290 positively correlated with advanced TNM stage and lymph node metastasis in LSCC patients. In cell culture, upregulation of circRNA_100290 promoted LSCC cell proliferation, migration, and invasion, while it inhibited cell apoptosis; downregulating circRNA_100290 exerted the opposite effects. In vivo, circRNA_100290 overexpression dramatically promoted tumor growth. Mechanistically, circRNA_100290 may act as a sponge of miR-136-5p, and inhibiting miR-136-5p in LSCC cells indeed reversed the effects of circRNA_100290 downregulation. The RAS oncogene RAP2C was predicted to be a target of miR-136-5p, and downregulating RAP2C in LSCC cells partially reversed the oncogenic effects of circRNA_100290 overexpression or miR-136-5p decrease. Our findings suggest that circRNA_100290 promotes LSCC progression by targeting the miR-136-5p/RAP2C axis, which may lead to the identification of potential therapeutic targets.

Circular RNA circSLC26A4 Accelerates Cervical Cancer Progression via miR-1287-5p/HOXA7 Axis

Circular RNAs (circRNAs) are group of noncoding RNAs derived from back-splicing events. Accumulating evidence certifies the critical roles of circRNAs in human tumorigenesis. However, the role and biogenesis of circRNAs in cervical cancer are still unclear. Here, a novel identified circRNA, circSLC26A4, was found to be upregulated in cervical cancer tissue and cells. Clinically, the high expression of circSLC26A4 was related to the poor survival of cervical cancer patients. Functionally, cellular experiments indicated that circSLC26A4 knockdown repressed the proliferation, invasion, and tumor growth in vitro and in vivo. Furthermore, circSLC26A4 acted as the sponge of miR-1287-5p; moreover, miR-1287-5p targeted the 3′ UTR of HOXA7 mRNA. Mechanistically, RNA binding protein (RBP) quaking (QKI) was identified to interact with the QKI response elements (QREs) in SLC26A4 gene introns, thereby promoting circSLC26A4 biogenesis. In conclusion, these findings demonstrate that circSLC26A4 facilitates cervical cancer progression through the QKI/circSLC26A4/miR-1287-5p/HOXA7 axis, which might bring novel therapeutic strategies for cervical cancer.