circ-MYBL2 Serves As A Sponge For miR-361-3p Promoting Cervical Cancer Cells Proliferation And Invasion

What is the role of circRNAs in the pathogenesis of cervical cancer? A systematic literature review

Cervical Cancer (CC) is one of the most prevalent neoplasms among women, considered the leading cause of gynecological death worldwide, and the fourth most common type of cancer. Regional metastasis is closely related to the low effectiveness of treatment, and validating biomarkers can optimize accuracy in diagnosis and prognosis. Among the potential biomarkers associated with disease metastasis are circular RNAs (circRNAs), whose altered expression has been linked to CC progression. In this context, this systematic review aims to compile information on the clinical-pathological significance and describe the biological function of circRNAs. Inclusion and exclusion criteria were used to include relevant literature, followed by in silico analysis. Additionally, we employed the UALCAN tools to search for host genes of circRNAs and expression data, miRTargetLink 2.0 to predict interactions of microRNA target genes and the Cytoscape software to predict possible interactions of microRNA target genes. According to the research, most circRNAs were found to be overexpressed and described as regulators of processes such as invasion, cell proliferation, apoptosis and migration. They were also implicated in clinical significance, including metastasis, TNM staging and microRNA interactions. CircRNAs may participate in critical processes in tumorigenesis; therefore, understanding the underlying molecular mechanisms of gene regulation in CC can contribute to the accuracy of diagnosis, prognosis and therapy.

Circular RNAs in EMT-driven metastasis regulation: modulation of cancer cell plasticity, tumorigenesis and therapy resistance

The non-coding RNAs comprise a large part of human genome lack of capacity in encoding functional proteins. Among various members of non-coding RNAs, the circular RNAs (circRNAs) have been of importance in the pathogenesis of human diseases, especially cancer. The circRNAs have a unique closed loop structure and due to their stability, they are potential diagnostic and prognostic factors in cancer. The increasing evidences have highlighted the role of circRNAs in the modulation of proliferation and metastasis of cancer cells. On the other hand, metastasis has been responsible for up to 90% of cancer-related deaths in patients, requiring more investigation regarding the underlying mechanisms modulating this mechanism. EMT enhances metastasis and invasion of tumor cells, and can trigger resistance to therapy. The cells demonstrate dynamic changes during EMT including transformation from epithelial phenotype into mesenchymal phenotype and increase in N-cadherin and vimentin levels. The process of EMT is reversible and its reprogramming can disrupt the progression of tumor cells. The aim of current review is to understanding the interaction of circRNAs and EMT in human cancers and such interaction is beyond the regulation of cancer metastasis and can affect the response of tumor cells to chemotherapy and radiotherapy. The onco-suppressor circRNAs inhibit EMT, while the tumor-promoting circRNAs mediate EMT for acceleration of carcinogenesis. Moreover, the EMT-inducing transcription factors can be controlled by circRNAs in different human tumors.

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.

Circ0060467 sponges miR-6805 to promote hepatocellular carcinoma progression through regulating AIFM2 and GPX4 expression

BACKGROUND

Circular RNAs (circRNAs) represent a subset of non-coding RNAs implicated in the regulation of diverse biological processes, including tumorigenesis. However, the expression and functional implications of circ0060467 in hepatocellular carcinoma (HCC) remain elusive. In this study, we aimed to elucidate the role of circ0060467 in modulating the progression of HCC.

METHODS

Differentially expressed circRNAs in HCC tissues were identified through circRNA microarray assays. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays revealed the upregulation of circ0060467 in both HCC cell lines and tissues. Various assays were conducted to investigate the roles of circ0060467 in HCC progression. Additionally, RNA immunoprecipitation (RIP) assays and luciferase assays were carried out to assess the interactions between circ0060467, microRNA-6085 (miR-6085), apoptosis-inducing factor mitochondria-associated 2 (AIFM2), and glutathione peroxidase 4 (GPX4) in HCC.

RESULTS

Microarray and qRT-PCR analyses demonstrated a marked elevation of circ0060467 in HCC tissues and cell lines. Knockdown of circ0060467 suppressed HCC cell proliferation. Luciferase reporter and RIP assays confirmed the binding of circ0060467, AIFM2, and GPX4 to miR-6805. Subsequent experiments revealed that circ0060467 competes with AIFM2 and GPX4, thereby inhibiting cancer cell ferroptosis by binding to miR-6085 and promoting hepatocellular carcinoma progression.

CONCLUSIONS

Collectively, circ0060467 modulates the levels of AIFM2 and GPX4, crucial regulators of tumor cell ferroptosis, by acting as a sponge for miR-6085 in HCC. Thus, circ0060467 may represent a novel diagnostic marker and therapeutic target for HCC.

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.

Hsa_circ_0060467 promotes breast cancer liver metastasis by complexing with eIF4A3 and sponging miR-1205

Breast cancer (BC) is the most common cancer and the top cause of female mortality worldwide. The prognosis for patients with breast cancer liver metastasis (BCLM) remains poor. Emerging studies suggest that circular RNAs (circRNAs) are associated with the progression of BC. Exploration of circRNAs presents a promising avenue for identifying metastasis-targeting agents and improving the prognosis of patients with BCLM. Microarray and bioinformatic analyses were used to analyze differentially expressed circRNAs between three pairs of BCLM and primary BC. The roles of hsa_circ_0060467 (circMYBL2) and its target gene E2F1 in BC cells were explored by multiple functional experiments. And xenograft mouse models and hepatic metastases of BC hemi-spleen models were used to illustrate the function of circMYBL2 in vivo. The intrinsic molecular mechanism involving circMYBL2 was confirmed by bioinformatics analyses, RIP assays, CHIRP assays, luciferase reporter assays, and rescue experiments. CircMYBL2 was overexpressed in BCLM tissues and BC cells. Functionally, circMYBL2 can facilitate the proliferation and liver metastasis of BC. Mechanistically, circMYBL2 upregulated the transcription factor E2F1 by sponging miR-1205 and complexing with eukaryotic translation initiation factor 4A3 (eIF4A3) and then facilitated the epithelial-mesenchymal transition (EMT) process in BC cells. Our findings showed that circMYBL2 promoted the tumorigenesis and aggressiveness of BC through the circMYBL2/miR-1205/E2F1 and circMYBL2/eIF4A3/E2F1 axes, which may provide a novel targeted therapy for patients with BCLM.

circPOLR1C Promotes the Development of Esophageal Cancer by Adsorbing miR-361-3p and Regulating Cancer Cell Apoptosis and Metastasis

Background

The effect of circular RNA-RNA polymerase I and III subunit C (circPOLR1C) on esophageal cancer (EC) has not been reported. Herein, this study is designed to unveil the effect and the regulatory mechanism of circPOLR1C on EC.

Methods

The expression of circPOLR1C in EC tissues and cells was detected by qRT-PCR. Circular structure, stability, and cell localization of circPOLR1C were confirmed by qRT-PCR, RNase R, actinomycin D, and fluorescence in situ hybridization (FISH) assay. Cell function experiments, nude mouse xenograft, lung transplant model, and HE staining were performed to evaluate the effects of CircPOLR1C on EC in vitro and in vivo. A regulatory relationship between miR-361-3p and circPOLR1C was confirmed by qRT-PCR, circRNA in vivo precipitation, RIP, FISH, CircInteractome database, dual-luciferase reporter assay, and immunohistochemistry. Rescue experiments were applied to assess the effects of miR-361-3p and circPOLR1C on EC cells and tissues. Apoptosis- and epithelial-mesenchymal transformation (EMT)-related gene expressions were quantified by qRT-PCR and Western blot.

Results

Highly expressed circPOLR1C in EC was related to tumor differentiation and invasion. circPOLR1C, which mainly exists in the cytoplasm, is a stable circular RNA. circPOLR1C silencing inhibited circPOLR1C expression and EC cell malignant function, while circPOLR1C overexpression promoted the growth of transplanted tumors and lung metastasis. The enrichment of miR-361-3p was higher than that of other targeted miRNAs. circPOLR1C adsorbed miR-361-3p to regulate apoptosis- and EMT-related genes and partially reversed the tumor suppressive effect of miR-361-3p, which was lowly expressed in EC tissues. Silencing the target genes of miR-361-3p also inhibited the malignant development of EC cells.

Conclusion

circPOLR1C adsorbs miR-361-3p and regulates apoptosis- and EMT-related gene expressions to promote the development of EC.

CircRNA circ-MYBL2 absorbs precursor miR-92b in the nucleus to suppress its role in enhancing gastric cancer cell proliferation

BACKGROUND

MM-associated circular RNA (Circ-MYBL2), a circular RNA (circRNA), participates in cancer biology. However, its role in gastric cancer (GC) is unclear. In this study, circ-MYBL2 was predicted to interact with precursor microRNA-92b (miR-92b). We then analyzed the role of circ-MYBL2 in GC and explored its crosstalk with miR-92b.

METHODS

In this research Circ-MYBL2 and miR-92b (mature and precursor) accumulation was determined using reverse transcription polymerase chain reaction (RT-qPCR). The involvement of circ-MYBL2 in the maturation of miR-92b was analyzed using overexpression assays. The subcellular location of circ-MYBL2 was determined using nuclear fractionation assay. The binding of precursor miR-92b to circ-MYBL2 was analyzed through RNA-RNA pulldown assay. The role of circ-MYBL2 and miR-92b in GC cell proliferation was studied with BrdU assay.

RESULTS

We found that GC tissues exhibited increased mature miR-92b levels but decreased precursor miR-92b and circ-MYBL2 levels. Circ-MYBL2 was detected in both the nucleus and cytoplasm in GC cells, and it directly interacted with precursor miR-92b. Moreover, circ-MYBL2 overexpression increased precursor miR-92b expression and decreased mature miR-92b level. Furthermore, miR-92b (mature) increased GC cell proliferation, and circ-MYBL2 decreased GC cell proliferation and suppressed the effect of miR-92b on GC cell proliferation.

CONCLUSIONS

Circ-MYBL2 may absorb precursor miR-92b in the nucleus to suppress its role in promoting gastric cancer cell proliferation.

Circ_0060551 promotes the migration and invasion of cervical cancer by Up-regulating TPD52

PROBLEM

Cervical cancer has been recognized as the second most common cancer in women worldwide. Previous studies have reported that some circular RNAs (circRNAs) can influence the progression of cervical cancer. However, more researches are still required to unveil the underlying mechanism of how circRNAs regulate the progression of such cancer. We aimed at unveiling the mechanism of how circ_0060551 effected the progression of cervical cancer.

METHOD OF STUDY

RT-qPCR and western blot assays were used to detect the expression and protein levels. Mechanism experiments were conducted to investigate the relationship among circ_0060551, TPD52, miR-520a-5p and ELAVL1. Rescue assays were mainly carried out to verify how circ_0060551 influenced the migration and invasion of cervical cancer cells.

RESULTS

According to the results, circ_0060551 was up-regulated in cervical cancer cells and could promote the migration and invasion of cells via TPD52. In addition, circ_0060551 could up-regulate TPD52 expression through a ceRNA model to target miR-520a-5p. Moreover, circ_0060551 could stabilize the mRNA expression of TPD52 via recruiting ELAVL1.

CONCLUSION

Our study proved that circ_0060551 could promote the migration and invasion of cervical cancer cells. This article is protected by copyright. All rights reserved.

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.

MM-associated circular RNA downregulates microRNA-19a through methylation to suppress proliferation of pancreatic adenocarcinoma cells

Opposite roles of circular RNA MM-associated circular RNA (circ-MYBL2) have been observed in different malignancies, and its role in pancreatic adenocarcinoma (PA) is unknown. Our preliminary sequencing data revealed its inverse correlation with microRNA-19a (miR-19a). This study was performed to explore the role of circ-MYBL2 in PA and its crosstalk with miR-19a. The accumulation of circ-MYBL2 and miR-19a in PA was detected by RT-qPCR. Participation of circ-MYBL2 in the regulation of miR-19a and its RNA gene methylation was studied with an overexpression assay, followed by RT-qPCR and MSP analyses. The role of miR-19a and circ-MYBL2 in PA cell proliferation and movement was evaluated using the BrdU assay and the Transwell assay, respectively. Downregulation of circ-MYBL2 and upregulation of miR-19a were observed in PA. In PA cells, circ-MYBL2 decreased the accumulation of miR-19a but increased its RNA gene methylation. Overexpression of circ-MYBL2 decreased PA cell proliferation and movement, while overexpression of miR-19a showed an opposite effect. In addition, circ-MYBL2 suppressed the role of miR-19a in cell proliferation, migration, and invasion. In conclusion, circ-MYBL2 was downregulated in PA and it downregulated miR-19a through methylation to suppress PA cell proliferation.

Circular RNA as a Novel Biomarker for Diagnosis and Prognosis and Potential Therapeutic Targets in Multiple Myeloma

Circular RNAs (circRNAs) are a novel type of covalently closed RNAs involved in several physiological and pathological processes. They display tissue-specific expression and are constant, abundant, and highly conserved, making them perfect markers for diagnosis and prognosis. Several studies have proposed that circRNAs are also differentially produced in malignancies where they have oncogenic effects. Furthermore, circRNAs affecting microRNAs modify the expression profile of several transcription factors which play essential roles in tumors. CircRNAs within the hematopoietic compartment were identified as modulators of mechanisms able to enhance or suppress tumor progression in blood malignancies. Moreover, several circRNAs were suggested to confer resistance to the conventional drugs employed in hematopoietic cancers. In this review, we highlight the growing role and the controlling mechanisms by which circRNAs modify multiple myeloma genesis. We propose that circRNAs can be considered as potential diagnostic and prognostic markers, can induce chemoresistance, and might represent novel therapeutic targets for multiple myeloma.

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.

The Role of the SOX9/lncRNA ANXA2P2/miR-361-3p/SOX9 Regulatory Loop in Cervical Cancer Cell Growth and Resistance to Cisplatin

Cervical cancer is a highly prevalent female malignancy. Presently, cisplatin (DDP) is a first-line agent for cervical cancer chemotherapy. However, its curative effect is limited because of chemo-resistance. It has been previously reported that SOX9 targeted and activated oncogenic genes, enhancing cervical cancer cell resistance to DDP. The effects of the SOX9/lncRNA ANXA2P2/miR-361-3p/SOX9 regulatory loop on cervical cancer cell growth and resistance to DDP have been demonstrated. miR-361-3p expression was decreased in DDP-resistant cervical cancer cells and tissues. Moreover, miR-361-3p overexpression inhibited the growth of resistant cervical cancer cells and the resistance to DDP, whereas miR-361-3p inhibition exerted opposite effects. miR-361-3p inhibited SOX9 expression through binding; the effects of miR-361-3p inhibition were partially reversed by SOX9 knockdown. LncRNA ANXA2P2 expression was elevated in DDP-resistant cervical cancer cells and tissues. LncRNA ANXA2P2 inhibited miR-361-3p expression by binding, thereby upregulating SOX9. LncRNA ANXA2P2 knockdown inhibited DDP-resistant cervical cancer cell growth and resistance to DDP, whereas the effects of lncRNA ANXA2P2 knockdown were partially reversed by miR-361-3p inhibition. SOX9 expression was elevated in DDP-resistant cervical cancer cells and tissues, and SOX9 activated lncRNA ANXA2P2 transcription by binding. Collectively, SOX9, lncRNA ANXA2P2, and miR-361-3p form a regulatory loop, modulating DDP-resistant cervical cancer cell growth and response to DDP treatment.

Circular RNA Circ_0000098 Elevates ALX4 Expression via Adsorbing miR-1204 to Inhibit the Progression of Hepatocellular Carcinoma

Background

Circular RNAs (CircRNAs) feature prominently in the progression of various cancers. However, the biological functions of many circRNAs in hepatocellular carcinoma (HCC) are far from fully clarified. This work is performed to decipher the function of circ_0000098 (circSLC30A7) in modulating the progression of HCC and its molecular mechanism.

Methods

Microarray data (GSE97332) were available from the Gene Expression Omnibus (GEO) database, and circRNA differentially expressed in HCC tissues was screened out by GEO2R tool. Circ_0000098, microRNA-1204 (miR-1204), and aristaless-like homeobox-4 (ALX4) mRNA expressions were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8), scratch wound healing, and Transwell assays were adopted to determine proliferation, migration, and invasion of HCC cells. ALX4 protein, E-cadherin, N-cadherin, and Vimentin expressions were evaluated by Western blot. In addition, the targeting relationship between miR-1204 and circ_0000098 or ALX4 was studied with dual-luciferase reporter assay and RIP assay.

Results

Circ_0000098 expression level was markedly declined in HCC tissues and cells, and its underexpression was associated with larger tumor size of HCC patients. Knocking down circ_0000098 observably promoted the multiplication, migration, invasion, and epithelial-mesenchymal transition (EMT) of Huh7 and SMMC-7721 cells. Additionally, circ_0000098 was mainly distributed in the cytoplasm of HCC cells, and up-regulated ALX4 expression through competitively decoying miR-1204.

Conclusion

Circ_0000098, as a competitive endogenous RNA (ceRNA) of miR-1204, upregulates ALX4 expression and suppresses the growth, migration, invasion, and EMT of HCC cells.

SKA3, negatively regulated by miR-128-3p, promotes the progression of non-small-cell lung cancer

Aim: To investigate the effects of SKA3 on cell proliferation and metastasis in non-small-cell lung cancer (NSCLC) and its underlying mechanism. Methods: Immunohistochemistry was employed to analyze the expression of SKA3 in NSCLC. CCK-8 assay, EdU assay, Transwell assay and flow cytometry analysis were employed to assess cell proliferation, metastatic potential and apoptosis in vitro, respectively. A lung metastasis model was used to evaluate metastasis of NSCLC cells in vivo. A luciferase reporter gene assay was conducted to verify the targeting relationship. Results: SKA3 exhibited high expression in NSCLC tissues and cells. Overexpression of SKA3 remarkably accelerated cell proliferation and metastasis and suppressed apoptosis of NSCLC cells and promoted lung metastasis in a mouse model. miR-128-3p repressed SKA3 expression by targeting it. Conclusion: miR-128-3p inhibited the progression of NSCLC through targeting SKA3.

Knockdown of LINC01123 inhibits cell viability, migration and invasion via miR-361-3p/TSPAN1 targeting in cervical cancer

Cervical cancer (CC) is a type of gynecological malignancy that poses a significant threat to females. The aim of the present study was to examine the role of long intergenic non-protein coding RNA 1123 (LINC01123) and its underlying molecular mechanism in the development of CC. mRNA expression levels of LINC01123 and microRNA (miR)-361-3p in CC tissue samples and cell lines were evaluated using reverse transcription-quantitative PCR. Cell viability, migration and invasion were detected using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, wound healing and Transwell assays. Moreover, a xenograft tumor model was established for elucidating the influence of LINC01123 knockdown on tumor growth in vivo. A dual-luciferase reporter assay was used to confirm the association between LINC01123 and miR-361-3p, and miR-361-3p and tetraspanin 1 (TSPAN1). Western blot analysis was used to determine TSPAN1 protein expression. LINC01123 expression was upregulated and miR-361-3p expression was reduced in CC tissue samples and cell lines. Knockdown of LINC01123 inhibited cell viability, migration and invasion in vitro, and suppressed tumor growth in vivo. Furthermore, LINC01123 targeted miR-361-3p and negatively regulated miR-361-3p expression. Overexpression of miR-361-3p inhibited cell viability, migration and invasion in HeLa and CaSki cells. Additionally, miR-361-3p targeted TSPAN1 and negatively regulated TSPAN1 expression. Inhibition of miR-361-3p and overexpression of TSPAN1 reversed the effect of LINC01123 knockdown on cell proliferation, migration and invasion in HeLa cells. Knockdown of LINC01123 inhibited cell proliferation, migration and invasion via miR-361-3p/TSPAN1 regulation in CC, which may present an effective target for treatment of CC.

A Cytoplasm-Enriched circRNA circ-MYBL2 is Downregulated in Non-Small Cell Lung Cancer and Sponges Oncogenic miR-28 to Regulate Cancer Cell Proliferation and Apoptosis

Background

Recent studies have reported different roles of circRNA circ-MYBL2 in different cancers. However, the involvement of circ-MYBL2 in non-small cell lung cancer (NSCLC) is unknown. This study was carried out to explore the role of circ-MYBL2 in NSCLC.

Methods

The expression of circ-MYBL2 and miR-28 was detected by RT-qPCR. A 5-year follow-up study was performed for survival analysis. Nuclear fractionation assay was used for subcellular localization analysis. RNA pull-down assay was performed to detect the interaction between circ-MYBL2 and miR-28. The role of circ-MYBL2 and miR-28 in regulating the expression of each other was evaluated by overexpression assay. BrdU incorporation assay and cell apoptosis assay were performed to investigate the role of circ-MYBL2 and miR-28 in cell proliferation and apoptosis.

Results

NSCLC tissues exhibited significantly higher expression levels of miR-28 and lower expression levels of circ-MYBL2. Close correlations between circ-MYBL2 and miR-28 and patients’ survival were observed. Circ-MYBL2, which was found to be mainly enriched in cytoplasm, directly interacted with miR-28. Although circ-MYBL2 and miR-28 showed no regulatory role in the expression of each other, circ-MYBL2 suppressed the effects of miR-28 on cell proliferation and apoptosis.

Conclusion

Circ-MYBL2 is enriched in cytoplasm, and it sponges oncogenic miR-28 to suppress cancer cell proliferation in NSCLC and promote cell apoptosis.

hsa_circ_0101119 facilitates the progression of cervical cancer via an interaction with EIF4A3 to inhibit TCEAL6 expression

Recently, circular RNAs (circRNAs/circs) have attracted increased attention due to their regulatory role in a variety of cancer types. However, the role and molecular mechanisms of circRNAs in cervical cancer (CC) remain unknown. The present study aimed to investigate the function of hsa_ circ_0101119 on CC and its potential mechanisms. The differentially expressed circRNAs associated with CC were screened out using R software, according to the database of Gene Expression Omnibus (GEO). The expression levels of hsa_circ_0101119, eukaryotic initiation factor 4A‑3 (EIF4A3) and transcription elongation factor A‑like 6 (TCEAL6) in CC cells were detected via reverse transcription‑quantitative (RT‑q)PCR, and their expression levels in CC tissues were analyzed based on the database of GEO and the Cancer Genome Atlas. Moreover, the accurate functions of hsa_circ_0101119 and TCEAL6 on the proliferation, apoptosis, migration and invasion of SiHa and HeLa cells was examined using colony formation assay, 5‑ethynyl‑20‑deoxyuridine incorporation assay, flow cytometry and Transwell assay. Next, the underlying mechanisms of hsa_circ_0101119 on CC progression were determined via bioinformatics analysis, RNA immunoprecipitation assay, RNA pull down assay, RT‑qPCR and western blotting. It was found that hsa_circ_0101119 was highly expressed in CC tissues and cells, while TCEAL6 was lowly expressed. Knockdown of hsa_circ_0101119 or TCEAL6 overexpression significantly inhibited the proliferation, migration and invasion of SiHa and HeLa cells, but facilitated apoptosis. It was also demonstrated that hsa_circ_0101119 could recruit EIF4A3 to inhibit TCEAL6 expression in CC. Furthermore, knockdown of TCEAL6 could reverse the effects of silencing hsa_circ_0101119 on the proliferation, apoptosis, migration and invasion of HeLa cells. In conclusion, the present study revealed that hsa_circ_0101119 could facilitate cell proliferation, migration and invasion, and suppress apoptosis in CC via an interaction with EIF4A3 to inhibit TCEAL6 expression, which may provide a potential therapeutic target for CC treatment.

Hsa_circ_0031787 promotes cell proliferation and invasion in colorectal cancer

OBJECTIVE

Circular RNA (circRNA) has been found to be involved in regulating tumor development. However, the roles and underlying mechanisms of circRNA in colorectal cancer (CRC) development remain unclear. In this study, we investigated the effects of hsa_circ_0031787 on CRC.a METHODS: Aberrant circRNA expression was explored by the Gene Expression Omnibus (GEO) database, and hsa_circ_0031787 was selected for further study. Hsa_circ_0031787 expression was determined in CRC tissues and cell lines by qRT-PCR. Cell proliferation was measured by Edu and colony formation assays. Cell invasion was tested by Transwell assays.

RESULTS

Hsa_circ_0031787 expression levels in CRC were significantly increased and correlated with advanced TNM stage and lymph node metastasis in CRC patients. Functional assays showed that hsa_circ_0031787 suppression reduced CRC cell proliferation and invasion in vitro and reduced tumor growth in vivo. Furthermore, hsa_circ_0031787 suppression reduced activation of the Wnt/β-catenin axis in CRC.

CONCLUSIONS

Our results showed that hsa_circ_0031787 may function as an oncogenic circRNA in CRC progression, thus providing a new potential therapeutic target.

CircMYBL2 regulates the resistance of cervical cancer cells to paclitaxel via miR-665-dependent regulation of EGFR

Circular RNAs are considered to be associated with cancer resistance. This study aims to investigate the function and mechanism of circMYBL2 in paclitaxel (PTX) resistance of cervical cancer (CC). The expression of circMYBL2, miR-665 and epidermal growth factor receptor (EGFR) was investigated using quantitative real-time polymerase chain reaction assay. Cell viability, cell colony number, cell proliferation, apoptosis and lactate dehydrogenase (LDH) were detected by 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, colony formation, 5-ethynyl-2'-deoxyuridine incorporation, flow cytometry and LDH release assays, respectively. The interaction between miR-665 and circMYBL2 or EGFR was confirmed by dual-luciferase reporter assay. The protein expression levels were quantified by western blot or immunohistochemistry assay. Mice xenograft models were constructed to investigate the effect of circMYBL2 on CC tumor growth. CircMYBL2 was upregulated in CC tissues and cells, especially in PTX-resistant CC tissues and cells, and it was a stable circRNA mainly distributed in the cytoplasm. CircMYBL2 could enhance the PTX resistance of CC cells in vitro and promote CC tumor growth in vivo. Mechanistically, circMYBL2 could inhibit the PTX sensitivity and promote cell malignant behaviors in PTX-sensitive and PTX-resistant CC cells via upregulating EGFR mediated by miR-665. CircMYBL2 played a positive role in the PTX resistance and malignant activities of PTX-sensitive and PTX-resistant CC cells by regulating the miR-665/EGFR network, providing a novel therapeutic strategy for the treatment of CC patients resistant to PTX.

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.

Long non-coding RNA ABHD11-AS1 boosts gastric cancer development by regulating miR-361-3p/PDPK1 signalling

Gastric cancer (GC) is one of the most common cancers in gastrointestinal malignant tumours. Long non-coding RNAs were widely reported to play a significant role in the regulation of occurrence or development of tumours. Bioinformatics analysis and a wide range of experiments were conducted to explore the expression status, specific function and molecular mechanism of long non-coding RNA ABHD11 antisense RNA 1 (ABHD11-AS1). ABHD11-AS1 knockdown repressed cell proliferation but enhanced cell apoptosis in function. We proved that miR-361-3p directly combines with the 3'wUTR of PDPK2 and ABHD11-AS1 cooperated with miR-361-3p to modulate PDPK2 mRNA and protein levels. Rescue assays confirmed that the miR-361-3p silence reversed the suppressive effect of ABHD11-AS1 deficiency. In summary, ABHD11-AS1 boosts GC development by regulating miR-361-3p/PDPK1 signalling.

Hypoxic colorectal cancer-derived extracellular vesicles deliver microRNA-361-3p to facilitate cell proliferation by targeting TRAF3 via the noncanonical NF-κB pathways

BACKGROUND

Hypoxic tumour microenvironment (TME) is a key regulator in cancer progression. However, the communications between hypoxic cells and other components in TME during colorectal cancer (CRC) progression via extracellular vesicles (EVs) remain unclear.

METHODS

High-throughput sequencing was employed to detect aberrantly expressed microRNAs (miRNAs) in hypoxic EVs. Quantitative real-time PCR was used to confirm and screen preliminarily candidate miRNAs. The effects of EVs derived from hypoxia (<1% O2 ) and miR-361-3p on CRC growth were assessed using CCK-8 assays, colony formation assays, EdU assays, flow cytometric assays and mouse xenograft. Then, the specific mechanisms of miR-361-3p were investigated by RNA immunoprecipitation, luciferase reporter assay, Western blot, chromatin immunoprecipitation, immunohistochemistry and rescue experiments.

RESULTS

The level of miR-361-3p expression was remarkably elevated in hypoxic EVs and can be transferred to CRC cells. Functional experiments exhibited that hypoxic EVs facilitated cell growth and suppressed cell apoptosis by transferring miR-361-3p of CRC. Hypoxia-inducible factor-1α induced the elevation of miR-361-3p levels in hypoxic EVs. Upregulated miR-361-3p in CRC inhibited cell apoptosis and facilitated cell growth by directly targeting TNF receptor-associated factor 3, which consequently activated the noncanonical NF-κB pathway. Moreover, the high expression of circulating exosomal miR-361-3p was correlated to worse prognosis of CRC patients.

CONCLUSIONS

Altogether, the abnormality of exosomal miR-361-3p derived from hypoxia acts vital roles in the regulation of CRC growth and apoptosis and can be an emerging prognostic biomarker and a therapeutic target for CRC patients.

circUBAP2 regulates osteosarcoma progression via the miR‑204‑3p/HMGA2 axis

Circular RNA (circRNA/circ)-ubiquitin associated protein 2 (UBAP2), a newly recognized circRNA, serves a functional role in several types of tumor, including ovarian cancer, colorectal cancer and osteosarcoma. However, the precise roles and molecular mechanism under-lying circUBAP2 in osteosarcoma (OS) are not completely understood. In the present study, the expression levels of circUBAP2, microRNA (miR)-204-3p and (HMGA2) were evaluated via reverse transcription-quantitative PCR in OS tissues and cells. OS cell proliferation, migration, invasion and apoptosis were assessed by performing Cell Counting Kit-8, Transwell and flow cytometry assays, respectively. HMGA2 protein expression levels were determined via western blot-ting. Dual-luciferase reporter assays were performed to verify the interaction between circUBAP2 and miR-204-3p, and between miR-204-3p and HMGA2. An RNA immunoprecipitation (RIP) assay was conducted to confirm the interaction between circUBAP2 and miR-204-3p. The results demonstrated that circUBAP2 expression was significantly upregulated in OS tissues and cell lines compared with para-cancerous tissues and hFOB1.19 cells, respectively. In addition, high circUBAP2 expression levels in patients with OS were associated with a lower survival rate compared with lower expression levels in patients with OS. The functional assays revealed that circUBAP2 knockdown significantly inhibited OS cell proliferation, migration and invasion, but increased OS cell apoptosis compared with the small interfering RNA-negative control (si-NC) group. The dual-luciferase reporter and RIP assay results confirmed that circUBAP2 bound to miR-204-3p. Moreover, miR-204-3p expression was significantly downregulated in OS tissues compared with paracancerous tissues, and miR-204-3p expression was negatively correlated with circUBAP2 expression in OS tissues. Collectively, the results demonstrated that miR-204-3p was associated with circUBAP2 knockdown-mediated inhibition of OS cell malignant behavior. Moreover, miR-204-3p was also identified as one of the direct targets of HMGA2. Collectively, the results indicated that compared with the si-NC group, circUBAP2 knockdown significantly inhibited OS cell malignant behavior by binding to miR-204-3p, which subsequently regulated HMGA2 expression. Therefore, the present study demonstrated that circUBAP2 expression was upregulated in OS, and circUBAP2 regulated OS cell malignant behavior via the miR-204-3p/HMGA2 axis.

circRNA circ-MYBL2 is a novel tumor suppressor and potential biomarker in multiple myeloma

Currently, multiple myeloma (MM) is still an incurable disease. Deciphering its pathogenesis will bring new targets for clinical diagnosis and treatment. In the present study, we identified a MM-associated circular RNA (circRNA), circ-MYBL2, which was dramatically decreased in MM tissue and serum samples in comparison to normal samples. Low circ-MYBL2 level was closely correlated with high clinical stage and unfavorable outcome, and serum circ-MYBL2 had excellent accuracy in diagnosing MM. Exogenous circ-MYBL2 expression notably repressed MM cell viability, DNA synthesis and cell cycle progression. Further exploration revealed that circ-MYBL2 exerted the tumor-inhibiting effect by affecting the phosphorylation level of its linear isoform, in which circ-MYBL2 facilitated the binding of Cyclin F to MYBL2, dampening MYBL2 phosphorylation and activation, thereby inhibiting the transcription of a number of well-known proliferation-related oncogenes. Importantly, overexpression of circ-MYBL2 significantly reduced the tumor size of subcutaneous xenografts in nude mice. Taken together, our data unveil a regulatory mechanism linking circ-MYBL2 and its host gene mediated by Cyclin F, providing a potential diagnostic, prognostic and therapeutic target for MM patients.

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.

Hsa_circ_0079480 promotes tumor progression in acute myeloid leukemia via miR-654-3p/HDGF axis

Circular RNAs (circRNAs) are newly-discovered endogenous non-coding RNAs that have vital functions in regulating gene expression in tumorigenesis. Nonetheless, the function of circRNAs in acute myeloid leukemia (AML) are not yet clarified. In this analysis, hsa_circ_0079480, a novel circRNA, has been identified as being highly expressed in AML. Loss-of-function assays showed that reduction of hsa_circ_0079480 decreased the growth and stimulated apoptosis of AML cells in vitro. Furthermore, miR-654-3p was sponged by hsa_circ_0079480, and hepatoma-derived growth factor (HDGF) was targeted by miR-654-3p with respect to the fundamental mechanism. Moreover, the influence on growth and apoptosis of AML cells stimulated by hsa_circ_0079480 inhibition can be rescued by miR-654-3p inhibitor or HDGF overexpression. In summary, hsa_circ_0079480 is highly expressed in AML and drives by tumor progression via regulation of hsa_circ_0079480/miR-654-3p/HDGF axis, indicating that hsa_circ_0079480 may function as a new treatment target for AML therapy.

The role of MYB proto-oncogene like 2 in tamoxifen resistance in breast cancer

Despite the efficacy of tamoxifen in preventing disease relapse, a large portion of breast cancer patients show intrinsic or acquired resistance to tamoxifen, leading to treatment failure and unfavorable clinical outcome. MYB proto-oncogene like 2 (MYBL2) is a transcription factor implicated in the initiation and progression of various human cancers. However, its role in tamoxifen resistance in breast cancer remained largely unknown. In the present study, by analyzing public transcriptome dataset, we found that MYBL2 is overexpressed in breast cancer and is associated with the poor prognosis of breast cancer patients. By establishing tamoxifen-resistant breast cancer cell lines, we also provided evidence that MYBL2 overexpression contributes to tamoxifen resistance by up-regulating its downstream transcriptional effectors involved in cell proliferation (PLK1, PRC1), survival (BIRC5) and metastasis (HMMR). In contrast, inhibiting those genes via MYBL2 depletion suppresses cancer progression, restores tamoxifen and eventually reduces the risk of disease recurrence. All these findings revealed a critical role of MYBL2 in promoting tamoxifen resistance and exacerbating the progression of breast cancer, which may serve as a novel therapeutic target to overcome drug resistance and improve the prognosis of breast cancer patients.

Markers of Angiogenesis, Lymphangiogenesis, and Epithelial-Mesenchymal Transition (Plasticity) in CIN and Early Invasive Carcinoma of the Cervix: Exploring Putative Molecular Mechanisms Involved in Early Tumor Invasion

The establishment of a proangiogenic phenotype and epithelial-to-mesenchymal transition (EMT) are considered as critical events that promote the induction of invasive growth in epithelial tumors, and stimulation of lymphangiogenesis is believed to confer the capacity for early dissemination to cancer cells. Recent research has revealed substantial interdependence between these processes at the molecular level as they rely on common signaling networks. Of great interest are the molecular mechanisms of (lymph-)angiogenesis and EMT associated with the earliest stages of transition from intraepithelial development to invasive growth, as they could provide the source of potentially valuable tools for targeting tumor metastasis. However, in the case of early-stage cervical cancer, the players of (lymph-)angiogenesis and EMT processes still remain substantially uncharacterized. In this study, we used RNA sequencing to compare transcriptomes of HPV(+) preinvasive neoplastic lesions and early-stage invasive carcinoma of the cervix and to identify (lymph-)angiogenesis- and EMT-related genes and pathways that may underlie early acquisition of invasive phenotype and metastatic properties by cervical cancer cells. Second, we applied flow cytometric analysis to evaluate the expression of three key lymphangiogenesis/EMT markers (VEGFR3, MET, and SLUG) in epithelial cells derived from enzymatically treated tissue specimens. Overall, among 201 differentially expressed genes, a considerable number of (lymph-)angiogenesis and EMT regulatory factors were identified, including genes encoding cytokines, growth factor receptors, transcription factors, and adhesion molecules. Pathway analysis confirmed enrichment for angiogenesis, epithelial differentiation, and cell guidance pathways at transition from intraepithelial neoplasia to invasive carcinoma and suggested immune-regulatory/inflammatory pathways to be implicated in initiation of invasive growth of cervical cancer. Flow cytometry showed cell phenotype-specific expression pattern for VEGFR3, MET, and SLUG and revealed correlation with the amount of tumor-infiltrating lymphocytes at the early stages of cervical cancer progression. Taken together, these results extend our understanding of driving forces of angiogenesis and metastasis in HPV-associated cervical cancer and may be useful for developing new treatments.

Circular RNA has_circ_0000034 accelerates retinoblastoma advancement through the miR-361-3p/ADAM19 axis

Retinoblastoma (RB) is an intraocular malignancy that mainly occurs in infants and young children under 5 years of age. Circular RNA hsa_circ_0000034 (circ_0000034) was reported to be upregulated in RB tissues. Nevertheless, the function and mechanism of circ_0000034 in RB are unclear. Expression of circ_0000034, microRNA-361-3p (miR-361-3p), and a disintegrin and metalloproteinase 19 (ADAM19) was examined via quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability, migration, invasion, and apoptosis were determined though Cell Counting Kit-8 (CCK-8), transwell, or flow cytometry assays. Caspase-3 activity was detected using a caspase-3 activity assay kit. Some protein levels were examined using Western blot analysis. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay, or RNA pull-down assay were performed to verify the relationship between circ_0000034 or ADAM19 and miR-361-3p. The function of circ_0000034 in vivo was confirmed via animal experiment. We verified that circ_0000034 expression was elevated in RB tissues and cells. Circ_0000034 silencing reduced RB growth in vivo, repressed viability, migration, invasion, and EMT, and induced apoptosis of RB cells in vitro. Circ_0000034 acted as a sponge for miR-361-3p, which targeted ADAM19 in RB cells. Furthermore, the inhibition of miR-361-3p restored circ_0000034 knockdown-mediated impacts on viability, migration, invasion, apoptosis, and EMT of RB cells. Moreover, ADAM19 overexpression abolished the influence of miR-361-3p mimic on viability, migration, invasion, apoptosis, and EMT of RB cells. Circ_0000034 expedited RB progression through upregulating ADAM19 via sponging miR-361-3p, which indicated that circ_0000034 might a target for RB therapy.

circ_0084927 promotes cervical carcinogenesis by sponging miR-1179 that suppresses CDK2, a cell cycle-related gene

Background

Cervical cancer (CC) is a malignant tumor found in the lowermost part of the womb. Evolving studies on CC have reported that circRNA plays a crucial role in CC progression. In this study, we investigated the main function of a novel circRNA, circ_0084927, and its regulatory network in CC development.

Methods

qRT-PCR was applied to evaluate the expression of circ_0084927, miR-1179, and CDK2 mRNA in CC tissues and cells. Dual-luciferase reporting experiments and RNA immunoprecipitation (RIP) assay were conducted to validate the target relationship of miR-1179 with circ_0084927 and CDK2 mRNA. CCK-8 and BrdU assays were also used to evaluate CC cell proliferation. The adhesion and apoptosis phenotypes of CC cells were measured using cell–matrix adhesion and caspase 3 activation assay. Flow cytometry was also employed to detect the CC cell cycle.

Results

Our results indicated that circ_0084927 was up-regulated in CC tissues and cells. Findings also revealed that circ_0084927 silence inhibited CC cell proliferation and adhesion while facilitating apoptosis and triggering cell cycle arrest. However, miR-1179 down-regulation appeared in CC tissues. Apart from observing that circ_0084927 abolished miR-1179’s inhibitory effects on cell proliferation and adhesion, it was found that CDK2 was up-regulated in CC tissues and was instrumental in cancer promotion. Also observed was that miR-1179 directly targeted CDK2, thereby inhibiting CDK2’s promotion on the malignant phenotypes of CC cells. Lastly, results indicated that circ_0084927 revoked the inhibitory effect of miR-1179 on CDK2 by sponging miR-1179.

Conclusion

circ_0084927 promoted cervical carcinogenesis by sequestering miR-1179, which directly targeted CDK2. Our results also provided novel candidate targets for CC treatment in that it revealed the circ_0084927/miR-1179/CDK2 regulatory network that strengthened CC aggressiveness.

High-Throughput MicroRNA Profiling of Vitreoretinal Lymphoma: Vitreous and Serum MicroRNA Profiles Distinct from Uveitis

Purpose: Vitreoretinal lymphoma (VRL) is a non-Hodgkin lymphoma of the diffuse large B cell type (DLBCL), which is an aggressive cancer causing central nervous system related mortality. The pathogenesis of VRL is largely unknown. The role of microRNAs (miRNAs) has recently acquired remarkable importance in the pathogenesis of many diseases including cancers. Furthermore, miRNAs have shown promise as diagnostic and prognostic markers of cancers. In this study, we aimed to identify differentially expressed miRNAs and pathways in the vitreous and serum of patients with VRL and to investigate the pathogenesis of the disease. Materials and Methods: Vitreous and serum samples were obtained from 14 patients with VRL and from controls comprising 40 patients with uveitis, 12 with macular hole, 14 with epiretinal membrane, 12 healthy individuals. The expression levels of 2565 miRNAs in serum and vitreous samples were analyzed. Results: Expression of the miRNAs correlated significantly with the extracellular matrix (ECM) ‒receptor interaction pathway in VRL. Analyses showed that miR-326 was a key driver of B-cell proliferation, and miR-6513-3p could discriminate VRL from uveitis. MiR-1236-3p correlated with vitreous interleukin (IL)-10 concentrations. Machine learning analysis identified miR-361-3p expression as a discriminator between VRL and uveitis. Conclusions: Our findings demonstrate that aberrant microRNA expression in VRL may affect the expression of genes in a variety of cancer-related pathways. The altered serum miRNAs may discriminate VRL from uveitis, and serum miR-6513-3p has the potential to serve as an auxiliary tool for the diagnosis of VRL.

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.

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.

Screening and Discovery of New Potential Biomarkers and Small Molecule Drugs for Cervical Cancer: A Bioinformatics Analysis

BACKGROUND

Cervical cancer (CC) is the second most common type of malignant tumor survival rate is low in advanced stage, metastatic, and recurrent CC patients. This study aimed at identifying potential genes and drugs for CC diagnosis and targeting therapies.

METHODS

Three GEO mRNA microarray datasets of CC tissues and non-cancerous tissues were analyzed for differentially expressed genes (DEGs) by limma package. GO (Gene Ontologies) and KEGG (Kyoto Encyclopedia of Genes and Genomes) were used to explore the relationships between the DEGs. Protein-protein interaction (PPI) of these genes was established by the STRING database. MCODE was used for screening significant modules in the PPI networks to select hub genes. Biochemical mechanisms of the hub genes were investigated with Metascape. GEPIA database was used for validating the core genes. According to these DEGs, molecular candidates for CC were recognized from the CMAP database.

RESULTS

We identified 309 overlapping DEGs in the 2 tissue-types. Pathway analysis revealed that the DEGs were involved in cell cycle, DNA replication, and p53 signaling. PPI networks between overlapping DEGs showed 68 high-connectivity DEGs that were chosen as hub genes. The GEPIA database showed that the expression levels of RRM2, CDC45, GINS2, HELLS, KNTC1, MCM2, MYBL2, PCNA, RAD54 L, RFC4, RFC5, TK1, TOP2A, and TYMS in CC tissues were significantly different from those in the healthy tissues and were significantly relevant to the OS of CC. We found 10 small molecules from the CMAP database that could change the trend of gene expression in CC tissues, including piperlongumine and chrysin.

CONCLUSIONS

The 14 DEGs identified in this study could serve as novel prognosis biomarkers for the detection and forecasting of CC. Small molecule drugs like piperlongumine and chrysin could be potential therapeutic drugs for CC treatment.