Down-regulation of circ-PRKCI inhibits cell migration and proliferation in Hirschsprung disease by suppressing the expression of miR-1324 target PLCB1

The roles of non-coding RNAs in Hirschsprung's disease

Hirschsprung's disease (HSCR) is a congenital disorder characterized by the absence of ganglion cells in the colon, leading to various intestinal complications. The etiology of HSCR stems from complex genetic and environmental interactions, of which the intricate roles of non-coding RNAs (ncRNAs) are a key area of research. However, the roles of ncRNAs in the pathogenesis of HSCR have not been fully elucidated. In order to understand the variety of symptoms caused by HSCR and develop new therapeutic approaches, it is essential to understand the underlying biological genetic basis of HSCR. This review presents a comprehensive overview of the current understanding regarding the involvement of ncRNAs in HSCR, including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs). Additionally, it provides a summary of the molecular mechanisms through which ncRNAs regulate the expression of genes related to the proliferation, migration, and differentiation of intestinal neural crest cells, thereby contributing to the advancement of HSCR research.

Sequencing Reveals miRNAs Enriched in the Developing Mouse Enteric Nervous System

The enteric nervous system (ENS) is an essential network of neurons and glia in the bowel wall. Defects in ENS development can result in Hirschsprung disease (HSCR), a life-threatening condition characterized by severe constipation, abdominal distention, bilious vomiting, and failure to thrive. A growing body of literature connects HSCR to alterations in miRNA expression, but there are limited data on the normal miRNA landscape in the developing ENS. We sequenced small RNAs (smRNA-seq) and messenger RNAs (mRNA-seq) from ENS precursor cells of mid-gestation Ednrb-EGFP mice and compared them to aggregated RNA from all other cells in the developing bowel. Our smRNA-seq results identified 73 miRNAs that were significantly enriched and highly expressed in the developing ENS, with miR-9, miR-27b, miR-124, miR-137, and miR-488 as our top 5 miRNAs that are conserved in humans. However, contrary to prior reports, our follow-up analyses of miR-137 showed that loss of Mir137 in Nestin-cre, Wnt1-cre, Sox10-cre, or Baf53b-cre lineage cells had no effect on mouse survival or ENS development. Our data provide important context for future studies of miRNAs in HSCR and other ENS diseases and highlight open questions about facility-specific factors in development.

Circular RNA MTCL1 targets SMAD3 by sponging miR-145-5p for regulation of cell proliferation and migration in Hirschsprung's disease

BACKGROUND

Hirschsprung's disease (HSCR) is a congenital disorder resulting from abnormal development of the enteric nervous system (ENS). Given the complexity of its pathogenesis, it is important to investigate the role of epigenetic inheritance in its development. As Circ-MTCL1 is abundant in brain tissue and colon tissue, whether it has a significant part in the development of ENS is worth exploring. This study clarifies its role in HSCR and identifies the specific molecular mechanisms involved.

METHODS

Diseased and dilated segment colon tissues diagnosed as HSCR were collected for the assessment of gene expression levels using RT-PCR. EdU and CCK-8 assays were adopted to evaluate cell proliferation, and Transwell assay was adopted to assess cell migration. The interaction between Circ-MTCL1, miR-145-5p and SMAD3 was confirmed by dual luciferase reporter gene analysis, RT-PCR and Western blotting.

RESULTS

Circ-MTCL1 was down-regulated in the aganglionic colon tissues. The decreased expression of Circ-MTCL1 associated with a reduction in cell migration and proliferation. Bioinformatics analysis and cellular experiments confirmed its role might have been associated with the inhibition of miR-145-5p. MiR-145-5p was up-regulated in HSCR diseased segment colon tissues, exhibiting a negative correlation with Circ-MTCL1. Overexpression of miR-145-5p reversed the inhibition of cell migration and proliferation associated with Circ-MTCL1 down-regulation. The expression of SMAD3 was inhibited by miR-145-5p. The overexpression of SMAD3 eliminated the miR-145-5p-associated inhibition of cell migration and proliferation. Overexpression of miR-145-5p reversed the inhibitory effects of Circ-MTCL1 down-regulation-associated inhibition of cell migration and proliferation, while suppressing SMAD3 expression. Conversely, overexpression of SMAD3 counteracted the miR-145-5p-associated inhibition of cell migration and proliferation.

CONCLUSIONS

Circ-MTCL1 may function as a miR-145-5p sponge, regulating the expression of SMAD3 and influencing cell migration and proliferation, thus participating in the development of HSCR.

Circ-ITCH overexpression promoted cell proliferation and migration in Hirschsprung disease through miR-146b-5p/RET axis

BACKGROUND

Hirschsprung disease (HSCR) is a congenital intestinal disease caused by the abnormal proliferation and migration of enteric nerve cells (ENCC). Research suggested critical roles for circular RNA (circRNA) itchy E3 ubiquitin protein ligase (ITCH) in gastrointestinal malignancies progression. However, the function of circ-ITCH in HSCR remains poorly defined.

METHODS

The related genes expression in 30 HSCR patients and 30 controls without HSCR were detected using qRT-PCR. Cell proliferation was assessed by CCK-8 assay and EdU assay. Cell migration was detected with wound-healing assay and transwell assay. The interactions among circ-ITCH, miR-146b-5p, and RET were confirmed by Dual luciferase reporter assay.

RESULTS

Circ-ITCH and RET expressions were downregulated in HSCR patients and cells, while the miR-146b-5p expression was upregulated. Circ-ITCH overexpression facilitated cell proliferation, migration, and activated MAPK pathway, which were reversed by circRNA-ITCH knockdown. Circ-ITCH negatively regulated miR-146b-5p expression. MiR-146b-5p overexpression abolished the promoting effects of circ-ITCH overexpression on cell proliferation and migration. MiR-146b-5p inhibited RET expression. RET overexpression eliminated the inhibitory effects of miR-146b-5p overexpression on cell proliferation and migration.

CONCLUSION

Circ-ITCH overexpression facilitated cell proliferation and migration in HSCR by regulating miR-146b-5p/RET/MAPK axis.

IMPACT

The expressions of Circ-ITCH and RET were markedly reduced in HSCR, while miR-146b-5p expression was increased in HSCR. Circ-ITCH overexpression enhanced the proliferative and migratory abilities of SH-SY5Y and 293T cells. Circ-ITCH negatively regulated miR-146b-5p expression.

MicroRNA-1297 participates in the repair of intestinal barrier injury in patients with HIV/AIDS via negative regulation of PLCβ1

To explore the role of the miRNA-1297/phospholipase Cβ1 (PLCβ1) axis in intestinal barrier injury. Abnormally expressed miR-1297 and its target gene PLCβ1 as well as their transcriptome sequencing were confirmed by bioinformatics analysis. Next, the intestinal barrier injury was induced by lipopolysaccharide (LPS) in the CCCHIE-2 cells. Subsequently, the impacts of miR-1297 and PLCβ1 on the transcriptome were estimated. QRT-PCR and Western blotting were conducted to detect the relative mRNA and protein expressions, respectively. The cell viability and permeability were analyzed by MTT assay and fluorescent yellow detection. miR-1297 was significantly upregulated in patients with human immunodeficiency virus/acquired immunodeficiency syndrome and targeted PLCβ1. Moreover, overexpressed PLCβ1 was mainly enriched in the transforming growth factor-beta signaling pathway, while the knockdown of miR-1297 was focused on the arginine biosynthesis pathway. The overexpression of miR-1297 could reduce the PLCβ1 expression and inhibit the viability of CCCHIE-2 cells injured by LPS, while the effect of the downregulation of miR-1297 was on the opposite. Western blotting and cell fluorescence localization experiments revealed that the inhibition of miR-1297 increased the expressions of PLCβ1 and ZO-1. In addition, the upregulation of miR-1297 strengthened the permeability in cells injured by LPS, as did the knockdown of PLCβ1. miR-1297 could restrain the repair of intestinal barrier injury via negatively regulating PLCβ1 and its tight junction downstream protein ZO-1 in CCC-HIE-2 cells injured by LPS, which indicated that PLCβ1 and miR-1297 might be important targets for the repair of intestinal barrier injury.

Systematic screen of potential circular RNA biomarkers of Hirschsprung's disease

BACKGROUND

Hirschsprung's disease (HSCR) is a developmental disorder of the enteric nervous system in which enteric ganglia are missing along a portion of the intestine. Aberrant expression of several circular RNAs (circRNAs) has been identified in the disease, but the full range of dysregulated circRNAs and their potential roles in its pathogenesis remain unclear. We used microarray profiling to systematically screen for circRNAs that were differentially expressed in HSCR, and we comprehensively analyzed the potential circRNA-miRNA-mRNA regulatory network to identify molecular mechanisms involved in the disorder.

METHODS

We identified circRNAs that were differentially expressed between diseased tissue and paired normal intestinal tissues from patients with HSCR. The most strongly upregulated circRNAs were then validated by quantitative reverse-transcription-PCR (RT-PCR). We also constructed a circRNA-miRNA-mRNA interaction network to determine functional interactions between miRNAs and mRNAs.

RESULTS

We identified 17 circRNAs that were upregulated and 10 that were downregulated in HSCR tissue compared with normal tissues. The five circRNAs that showed the greatest upregulation were verified by RT-PCR: hsa_circRNA_092493, hsa_circRNA_101965, hsa_circRNA_103118, hsa_circRNA_103279, and hsa_circRNA_104214. These five circRNAs were successfully adopted to diagnose HSCR based on receiver operating characteristic curves, and they were used to generate a circRNA-miRNA-mRNA network. The network revealed a potential function of the circRNAs as molecular sponges targeting miRNAs and mRNAs in HSCR.

CONCLUSIONS

This first-ever systematic dissection of the circRNA profile in HSCR may provide useful insights into improving diagnosis and therapy.

Genome-Wide RNA-Sequencing Reveals Massive Circular RNA Expression Changes of the Neurotransmission Genes in the Rat Brain after Ischemia-Reperfusion

Ischemic brain stroke is one of the most serious and socially significant diseases. In addition to messenger RNAs (mRNAs), encoding protein, the study of regulatory RNAs in ischemic has exceptional importance for the development of new strategies for neuroprotection. Circular RNAs (circRNAs) have a closed structure, predominantly brain-specific expression, and remain highly promising targets of research. They can interact with microRNAs (miRNAs), diminish their activity and thereby inhibit miRNA-mediated repression of mRNA. Genome-wide RNA-Seq analysis of the subcortical structures of the rat brain containing an ischemic damage focus and penumbra area revealed 395 circRNAs changed their expression significantly at 24 h after transient middle cerebral artery occlusion model (tMCAO) conditions. Furthermore, functional annotation revealed their association with neuroactive signaling pathways. It was found that about a third of the differentially expressed circRNAs (DECs) originate from genes whose mRNA levels also changed at 24 h after tMCAO. The other DECs originate from genes encoding non-regulated mRNAs under tMCAO conditions. In addition, bioinformatic analysis predicted a circRNA–miRNA–mRNA network which was associated with the neurotransmission signaling regulation. Our results show that such circRNAs can persist as potential miRNA sponges for the protection of mRNAs of neurotransmitter genes. The results expanded our views about the neurotransmission regulation in the rat brain after ischemia–reperfusion with circRNA action.

RNA-Seq Profiling of Circular RNAs During Development of Hindgut in Rat Embryos With Ethylenethiourea-Induced Anorectal Malformations

Anorectal malformations (ARMs) are among the most common congenital terminal digestive tract malformations. Circular RNAs (circRNAs), a novel type of endogenous non-coding RNAs, play roles in the development of the digestive system; however, their contributions to the pathogenesis of ARMs are not well-established. In this study, we explored the mechanism underlying ethylenethiourea (ETU)-induced ARMs by profiling circRNA expression via RNA-seq and constructing a regulatory circRNA-miRNA-mRNA network. Nine pregnant rats were gavage-fed a single dose of 125 mg/kg 1% ETU (ARM group) on gestational day 10 (GD10), and another 9 pregnant rats received a similar dose of saline (normal group) as a control. Embryos were obtained by cesarean section on the key time-points of anorectal development (GD14, GD15, and GD16). Hindgut samples isolated from the fetuses were evaluated by high-throughput sequencing and differentially expressed circRNAs were validated by reverse transcription-quantitative polymerase chain reaction, agarose gel electrophoresis, and Sanger cloning and sequencing. A total of 18295 circRNAs were identified in the normal and ARM groups. Based on the 425 differentially expressed circRNAs (|Fc| > 2, p < 0.05), circRNA-miRNA and miRNA-mRNA pairs were predicted using miREAP, miRanda, and TargetScan. A total of 55 circRNAs (14 up- and 41 downregulated in the ARM group compared to the normal group) were predicted to bind to 195 miRNAs and 947 mRNAs. Competing endogenous RNA networks and a Kyoto Encyclopedia of Genes and Genomes analysis revealed that novel_circ_001042 had the greatest connectivity and was closely related to ARM-associated signaling pathways, such as the Wingless Type MMTV integration site family, mitogen-activated protein kinase, and transforming growth factor-β pathways. These results provide original insight into the roles of circRNAs in ARMs and provide a valuable resource for further analyses of molecular mechanisms and signaling networks.

The Biogenesis and Functions of circRNAs and Their Roles in Breast Cancer

Recent statistics show that breast cancer is among the most frequent cancers in clinical practice. It is also the second-leading cause of cancer-related deaths among women worldwide. CircRNAs are a new class of endogenous regulatory RNA molecules whose 5’ end and 3’ end are connected together to form a covalently closed single-stranded loop by back-splicing. CircRNAs present the advantages of disease-specific expression and excellent expression stability, and they can modulate gene expression at posttranscriptional and transcriptional levels. CircRNAs are abnormally expressed in multiple cancers, such as breast cancer, and drive the initiation and progression of cancer. In this review, we describe current knowledge about the functions of circRNAs and generalize their roles in various aspects of breast cancer, including cell proliferation, cell cycle, apoptosis, invasion and metastasis, autophagy, angiogenesis, drug resistance, and tumor immunity, and their prognostic and diagnostic value. This may add to a better understanding of the functions and roles of circRNAs in breast cancer, which may become new diagnostic and predictive biomarkers of breast cancer.

CircAgtpbp1 Acts as a Molecular Sponge of miR-543-5p to Regulate the Secretion of GH in Rat Pituitary Cells

CircRNAs have been identified to be expressed differently and stably in numerous species and tissues, but their functions in growth hormone (GH) secretion are still largely unknown. In summary, we have revealed a circRNA-miRNA-mRNA network that may play a biological role in the rat pituitary gland. First, we verified the chromosome location information of circAgtpbp1 according to sequencing analysis. The circAgtpbp1 characteristics were authenticated through PCR, qRT-PCR, treating with RNase and fluorescent in situ hybridization (FISH). Second, we detected the expression pattern of circAgtpbp1 in the rat anterior pituitary by qRT-PCR. We also designed circAgtpbp1 siRNA and constructed overexpression plasmid to evaluate the effect of circAgtpbp1 function on GH secretion by qRT-PCR, ELISA and Western blot. CircAgtpbp1 is a stable, truly circular molecule. We found that circAgtpbp1 interacted with miR-543-5p and can regulate GH secretion in pituitary cells through a circAgtpbp1-miR-543-5p-GH axis. Overall, the evidence generated by our study suggests that circAgtpbp1 can act as a sponge of miR-543-5p to reduce the inhibitory effect of miR-543-5p on Gh1 and further promote GH secretion. These findings expand our existing knowledge on the mechanisms of hormone regulation in the pituitary gland.

Circular RNA PRKCI and microRNA-545 relate to sepsis risk, disease severity and 28-day mortality

This study aimed to explore the clinical values of circular RNA protein kinase C iota (circ-PRKCI) and its target microRNA-545 (miR-545) in sepsis patients. Plasma samples of 121 sepsis patients and 60 healthy controls (HCs) were collected, then circ-PRKCI and miR-545 expressions were detected using RT-qPCR. Sepsis patients' demographics, biochemical indexes, medical histories, infection information were recorded. Besides, comprehensive disease scores (APACHE II score and SOFA score) were assessed within 24 h after admission. According to the survival status, 28-day mortality was calculated. Decreased circ-PRKCI expression and increased miR-545 expression were observed in sepsis patients compared to HCs, both of which had close correlations with sepsis risk. Besides, circ-PRKCI was negatively correlated with miR-545 in sepsis patients and HCs, respectively. Circ-PRKCI was negatively correlated with serum creatinine, white blood cell, C-reactive protein, APACHE II score, SOFA score, but positively correlated with albumin, which also related to blood stream infection (as primary infection site) and anaerobes infection in sepsis patients. Whereas the miR-545 showed a roughly opposite tendency. Decreased circ-PRKCI and increased miR-545 expressions were discovered in deaths compared to survivors, and both of them had values for predicting 28-day mortality risk in sepsis patients, which were slightly lower than the predictive values of APACHE II score and SOFA score for predicting 28-day mortality risk. Multivariate logistic analyses displayed circ-PRKCI as an independent factor predicting decreased 28-day mortality risk. In conclusion, circ-PRCKI insufficiency and miR-545 sufficiency were related to sepsis risk, clinical disease severity and 28-day mortality risk.

miR-100 rs1834306 A>G Increases the Risk of Hirschsprung Disease in Southern Chinese Children

Background

Hirschsprung disease (HSCR) is a rare congenital gastrointestinal disease characterized by the absence of intestinal submucosal and myometrial ganglion cells. Recently, researches indicated that miR-100 regulated the growth, differentiation and apoptosis of neurons, and affected the functions of HSCR-associated pathways. While miR-100 rs1834306 A>G polymorphism was shown to modify the susceptibility to tumors, the association between this polymorphism and HSCR susceptibility is still unknown.

Methods

This was a case-control study consisting of 1470 HSCR cases and 1473 controls from southern China. DNA was genotyped by TaqMan real-time PCR. Odds ratios (ORs) and 95% confidence intervals (CIs) were used as statistical indicators.

Results

We found that miR-100 rs1834306 G allele and GG genotype significantly increased HSCR susceptibility (GG vs AA: adjusted OR=1.31, 95% CI=1.04-1.64, P=0.020; G vs A: adjusted OR=1.12, 95% CI=1.01-1.25, P=0.041; GG vs AA/AG: adjusted OR=1.30, 95% CI=1.07-1.59, P=0.010). In the stratified analysis, miR-100 rs1834306 GG genotype carriers had higher risk to develop HSCR in all clinical subtypes when compared with those with AA/AG genotypes, and OR was rising with HSCR aggravation (SHSCR: adjusted OR=1.28, 95% CI=1.03-1.59, P=0.029; LHSCR: adjusted OR=1.48, 95% CI=1.06-2.07, P=0.020; TCA: adjusted OR=2.12, 95% CI=1.22-3.69, P=0.008).

Conclusion

Our findings suggested that miR-100 rs1834306 A>G polymorphism was associated with increased HSCR susceptibility in southern Chinese children. Furthermore, miR-100 rs1834306 GG genotype had a greater genetic pathopoiesis in severe HSCR.

CircPRKCI relieves lipopolysaccharide-induced HK2 cell injury by upregulating the expression of miR-545 target gene ZEB2

The aim of this study was to investigate the possible influences of circPRKCI abnormal expression on lipopolysaccharide (LPS)-induced HK2 cell injury and its mechanism. The circPRKCI level was identified in serum samples from patients with urosepsis and healthy subjects, as well as LPS-treated HK2 cells by qRT-PCR. Cell viability, apoptosis, expression of proteins associated with apoptosis, and expression of pro-inflammatory cytokines in LPS-treated HK2 cells were measured. Effects of circPRKCI abnormal expression on LPS-induced HK2 cell injury were then evaluated. Afterward, the binding miRNA of circPRKCI and target gene of miRNA were identified, and the involvements of NF-kB pathway signaling pathway with the effects of circPRKCI were finally studied. CircPRKCI was significantly down-regulated in serum samples from patients with urosepsis and LPS-treated HK2 cells. LPS-induced decrease of cell viability, increase of cell apoptosis, as well as elevated productions of tumor necrosis factor (TNF)-α, interleukins (IL)-1β, IL-6, and IL-8 in HK2 cells were attenuated by overexpressed circPRKCI. In addition, circPRKCI negatively regulated the expression of miR-545, and miR-545 up-regulation reversed the inhibiting effects of circPRKCI overexpression on LPS-induced HK2 cell injury. Moreover, zinc finger E-box-binding homeobox 2 (ZEB2) was identified as a target gene of miR-545, and ZEB2 overexpression partly reversed the effects of miR-545 up-regulation on LPS-induced HK2 cell injury. Furthermore, NF-kB pathway was revealed to be associated to the effects of circPRKCI on LPS-induced HK2 cell injury. This research indicated that the highly expressed circPRKCI relieved inflammatory injury induced by LPS in HK2 cells by suppressing miR-545/ZEBs and depressing the briskness of NF-kB pathway.

Molecular function predictions and diagnostic value analysis of plasma exosomal miRNAs in Hirschsprung's disease

Aim: To discover the potential roles of plasma exosomal miRNAs in Hirschsprung's disease (HSCR) and identify potential noninvasive biomarkers for early diagnosis of HSCR. Materials & methods: Plasma samples were collected from HSCR patients and matched controls. Exosomes were isolated before high-throughput Illumina sequencing was utilized to gain a profile of dysregulated exosomal miRNAs, followed with further verification in two separate cohorts. Bioinformatics analyses were also adopted to explore the molecular functions of dysregulated miRNAs in Hirschsprung's disease. Results & conclusion: 31 dysregulated miRNAs were identified with five considered as promising HSCR signatures. Gene enrichment analysis disclosed that the upregulated miRNAs were most likely to participate in 'extracellular matrix-receptor interaction' and contribute to HSCR through interfering in cell junctions.

miR-423-5p inhibits the proliferation and metastasis of glioblastoma cells by targeting phospholipase C beta 1

Glioma is a common brain tumor which is highly invasive, responds poorly to therapy, and has a poor prognosis. There is growing evidence that an abnormal expression of many genes is related to glioma and leads to glioma cell growth and metastasis. Phospholipase C beta 1 (PLCB1) plays critical roles in intracellular transduction and regulating signal activation, which are important to tumorigenesis. Therefore, it could bind to miRNA as a target gene. The purpose of our study was to confirm that PLCB1 plays a critical role in suppressing glioma progression. We found that the expression of miR-423-5p was reduced, but the expression of PLCB1 was increased, in glioma tissues and cells. To explore whether miR-423-5p affects PLCB1, a bioinformatics approach suggested that miR-423-5p can directly target PLCB1. Moreover, we observed, using luciferase reporter assays, that miR-423-5p could target PLCB1 3'-UTR. Functionally, the overexpression of miR-423-5p could attenuate the proliferation, invasion, and migration and promote the apoptosis of glioma cells. Furthermore, we found that miR-423-5p could enhance p-ERK expression in glioma cells. Taken together, we deduced that miR-423-5p inhibited proliferation and metastasis by targeting PLCB1, and it also promotes apoptosis in glioma cells. These results suggest that miR-423-5p directly targets PLCB1 3'-UTR and could inhibit cell invasion and migration through the ERK-dependent pathway in glioma, and the miR-423-5p/PLCB1 axis may be a potential target for new potential therapeutic strategies to treat glioma.

Epigenetic Mechanisms in Hirschsprung Disease

Hirschsprung disease (HSCR, OMIM 142623) is due to a failure of enteric precursor cells derived from neural crest (EPCs) to proliferate, migrate, survive or differentiate during Enteric Nervous System (ENS) formation. This is a complex process which requires a strict regulation that results in an ENS specific gene expression pattern. Alterations at this level lead to the onset of neurocristopathies such as HSCR. Gene expression is regulated by different mechanisms, such as DNA modifications (at the epigenetic level), transcriptional mechanisms (transcription factors, silencers, enhancers and repressors), postranscriptional mechanisms (3′UTR and ncRNA) and regulation of translation. All these mechanisms are finally implicated in cell signaling to determine the migration, proliferation, differentiation and survival processes for correct ENS development. In this review, we have performed an overview on the role of epigenetic mechanisms at transcriptional and posttranscriptional levels on these cellular events in neural crest cells (NCCs), ENS development, as well as in HSCR.

Role and mechanism of circ-PRKCI in hepatocellular carcinoma

BACKGROUND

The circular RNA circ-PRKCI is an endogenous non-coding RNA that forms a covalently closed ring after reverse splicing, which plays a key role in the occurrence and development of multiple digestive system tumors.

AIM

To investigate the role and mechanism of circ-PRKCI in the occurrence and development of hepatocellular carcinoma (HCC).

METHODS

This study used real-time polymerase chain reaction to detect the expression of circ-PRKCI in tumor tissues, tumor adjacent tissues, and blood in patients with HCC and other digestive system tumor cells. A series of functional tests were performed to explore whether circ-PRKCI affects the growth of HCC cells and what is its mechanism in HCC. Meanwhile, fluorescence in situ hybridization was used to detect the subcellular localization of circ-PRKCI. Survival analysis was performed to predict the correlation between circ-PRKCI and the prognosis of HCC. Chi-square test and t-test were performed for statistical analyses.

RESULTS

The level of circ-PRKCI was significantly higher in HCC tissues than in tumor adjacent tissues, and in HCC cell lines than in cells lines of esophageal, liver, stomach, and colon cancers. A series of functional tests showed that circ-PRKCI substantially inhibited cell apoptosis and promoted cell invasion. It was found that circ-PRKCI can act as the sponge of miRNA-545 to reduce the expression of AKT3 protein. Moreover, the result of survival analysis showed that circ-PRKCI target gene E2F7 can reduce liver cancer patients’ survival rate. And clinical data suggested that the distribution of circ-PRKCI rose with the depth of invasion, lymph node metastasis, distant metastasis, and TNM stage, indicating that circ-PRKCI may affect the survival and prognosis of patients with HCC by regulating E2E7.

CONCLUSION

This study explores the role and mechanism of circ-PRKCI in HCC, which provides a new research direction and theoretical basis for the treatment of HCC.

Circular RNA circ-PRKCI functions as a competitive endogenous RNA to regulate AKT3 expression by sponging miR-3680-3p in esophageal squamous cell carcinoma

Circular RNA (circRNA) is a new noncoding RNAs and plays an important role in many pathological processes. Recently, studies have shown that circular RNA_PRKCI (circ-PRKCI) regulates cell proliferation and cell migration of tumor cells. Esophageal carcinoma is a highly malignant digestive tract tumor, which is divided into esophageal adenocarcinoma and esophageal squamous cell carcinoma. In this study, we studied whether circ-PRKCI might influence cell proliferation and cell migration in esophageal squamous cell carcinoma. Quantitative reverse transcription PCR was performed to detect the relative expression of circ-PRKCI in five cases of esophageal squamous cell carcinoma and five cases of paired adjacent normal tissues. RNA immunoprecipitation assay and Luciferase assay confirm the direct interaction between miR-3680-3p and AKT3 or circ-PRKCI. Ethynyldeoxyuridine assays and cell counting Kit-8 were performed to evaluate the effect of miR-3680-3p or circ-PRKCI on cell proliferation, transwell assays were also performed to detect migration in vitro. We found circ-PRKCI is obviously upregulated in esophageal squamous cell carcinoma and upregulation of circ-PRKCI stimulated cell migration and proliferation of ESCC cells. In the mechanism, we confirm that circ-PRKCI, as a molecular sponge of miR-3680-3p, upregulates the expression of AKT. In conclusion, our current studies have been revealing that circ-PRKCI/miR-3680-3p/AKT3 regulatory network plays an important role in esophageal squamous cell carcinoma and that provide new insights into the pathogenesis of esophageal squamous cell carcinoma.

Circular RNA CCDC66 targets DCX to regulate cell proliferation and migration by sponging miR-488-3p in Hirschsprung's disease

It has been suggested that circular RNAs play critical roles in natural growth and disease development. Nevertheless, whether the circular RNAs were related in Hirschsprung's disease (HSCR) remains unknown. Thus, we discovered the cir-CCDC66 was downregulated in HSCR compared with the normal gut tissues. The cir-CCDC66 reduction might inhibit cells' proliferation and migration in vitro. Then, we found that DCX transcript was putative cir-CCDC66 competing endogenous RNA. Furthermore, the function of cir-CCDC66 as a sponge for miR-488-3p to regulate DCX RNA expression was demonstrated by immunoprecipitation and luciferase reporter assays. In conclusion, this is the first report revealing that cir-CCDC66 modulates DCX expression through sponging miR-488-3p and thus participates in the onset of HSCR.