Circular RNA hsa_circ_0000034 promotes the progression of retinoblastoma via sponging microRNA-361-3p

EIF4A3-induced hsa_circ_0078136 inhibits the tumorigenesis of retinoblastoma via IL-17 signaling pathway

PURPOSE

Retinoblastoma (RB) is one of the most common intraocular cancers, with the highest prevalence among infants and young children under the age five. Numerous findings across the literature illustrate the involvement and significance of circular RNAs (circRNAs) in human malignancies, including RB. The current investigation attempted to decipher the exact roles and underlying mechanisms of a novel circRNA, hsa_circ_0078136, in RB progression.

METHODS

The hsa_circ_0078136 expression was evaluated in RB tumors and cell lines via qRT-PCR. The significance of hsa_circ_0078136 in RB was examined by performing CCK8 assay, transwell assays, western blotting of apoptotic and IL-17 signaling ligand molecules, and a subcutaneous xenograft tumor model. In addition, the interaction of circRNA and eukaryotic translation initiation factor 4A3 (EIF4A3) was determined with bioinformatics, western blot, and RIP assay.

RESULTS

The hsa_circ_0078136 expression was reduced in RB tumor samples and cells. Additionally, its overexpression restricted the oncogenic properties of RB cells in vitro. Moreover, hsa_circ_0078136 overexpression lowered the protein levels of cytokine ligand molecules of IL-17 signaling pathway in RB cell lines. In vivo, hsa_circ_0078136 overexpression in subcutaneous tumor xenografts reduced tumor growth. We also observed that EIF4A3 binds to the downstream flanking sequence of hsa_circ_0078136 in the SHRPH pre-mRNA transcript, and EIF4A3 overexpression reduced hsa_circ_0078136 expression, suggesting that EIF4A3 inhibited hsa_circ_0078136 formation.

CONCLUSIONS

Our results demonstrate that hsa_circ_0078136 is regulated by EIF4A3 and functions as a tumor suppressor via the IL-17 signaling pathway in RB.

Plasma Circular RNAs as Biomarkers for Breast Cancer

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

The functional role of circular RNAs in the pathogenesis of retinoblastoma: a new potential biomarker and therapeutic target?

Retinoblastoma (RB) is a common cancer in infants and children. It is a curable disease; however, a delayed diagnosis or treatment makes the treatment difficult. Genetic mutations have a central role in the pathogenesis of RB. Genetic materials such as RNAs (coding and non-coding RNAs) are also involved in the progression of the tumor. Circular RNA (circRNA) is the most recently identified RNA and is involved in regulating gene expression mainly through "microRNA sponges". The dysregulation of circRNAs has been observed in several diseases and tumors. Also, various studies have shown that circRNAs expression is changed in RB tissues. Due to their role in the pathogenesis of the disease, circRNAs might be helpful as a diagnostic or prognostic biomarker in patients with RB. In addition, circRNAs could be a suitable therapeutic target to treat RB in a targeted therapy approach.

The impact of non-coding RNAs in the pathobiology of eye disorders

Eye disorders are common disorders with significant effects on personal, economic, and social aspects of life. These disorders have a genetic background and are associated with dysregulation of non-coding RNAs. Three classes of these transcripts, namely long non-coding RNAs (lncRNAs), circular RNAs (circRNAs) and microRNAs (miRNAs) have established roles in the regulation of gene expression and pathoetiology of ocular disorders. H19, MEG3, BANCR, UCA1, HOTAIR, ANRIL, XIST and MIAT are among important lncRNAs in ocular disorders. CircRNAs from ZBTB44, HIPK3, circ-PSEN1, COL1A2, ZNF532 and FAM158A loci have also been found to affect pathoetiology of ocular disorders. Both lncRNAs and circRNAs can serve as molecular sponges for miRNAs. In this review, we searched PubMed and Google Scholar databases to find the research articles summarizing the impact of non-coding RNAs in ocular disorders. The results of these studies would help in identification of suitable targets for treatment of ocular disorders.

Role of non-coding RNAs and exosomal non-coding RNAs in retinoblastoma progression

Retinoblastoma (RB) is a rare aggressive intraocular malignancy of childhood that has the potential to affect vision, and can even be fatal in some children. While the tumor can be controlled efficiently at early stages, metastatic tumors lead to high mortality. Non-coding RNAs (ncRNAs) are implicated in a number of physiological cellular process, including differentiation, proliferation, migration, and invasion, The deregulation of ncRNAs is correlated with several diseases, particularly cancer. ncRNAs are categorized into two main groups based on their length, i.e. short and long ncRNAs. Moreover, ncRNA deregulation has been demonstrated to play a role in the pathogenesis and development of RB. Several ncRNAs, such as miR-491-3p, miR-613,and SUSD2 have been found to act as tumor suppressor genes in RB, but other ncRNAs, such as circ-E2F3, NEAT1, and TUG1 act as tumor promoter genes. Understanding the regulatory mechanisms of ncRNAs can provide new opportunities for RB therapy. In the present review, we discuss the functional roles of the most important ncRNAs in RB, their interaction with the genes responsible for RB initiation and progression, and possible future clinical applications as diagnostic and prognostic tools or as therapeutic targets.

Role of circular RNAs in retinoblastoma

Retinoblastoma (RB), the most common malignant retinal tumor among children under 3 years old, is lethal if left untreated. Early diagnosis, together with timely and effective treatment, is important to improve retinoblastoma-related outcomes. Circular RNAs (circRNAs), a new class of non-coding RNAs with the capacity to regulate cellular activities, have great potential in retinoblastoma diagnosis and treatment. Recent studies have identified circular RNAs that regulate multiple cellular processes involved in retinoblastoma, including cell viability, proliferation, apoptosis, autophagy, migration, and invasion. Six circular RNAs (circ-FAM158A, circ-DHDDS, circ-E2F3, circ-TRHDE, circ-E2F5, and circ-RNF20) promote disease progression and metastasis in retinoblastoma and function as oncogenic factors. Other circular RNAs, such as circ-TET1, circ-SHPRH, circ-MKLN1, and circ-CUL2, play tumor suppressive roles in retinoblastoma. At present, the studies on the regulatory mechanism of circular RNAs in retinoblastoma are not very clear. The purpose of this review is to summarize recent studies on the functional roles and molecular mechanisms of circular RNAs in retinoblastoma and highlight novel strategies for retinoblastoma diagnosis, prognosis, and treatment.

Nucleic acid therapy in pediatric cancer

The overall survival, progress free survival, and life quality of cancer patients have improved due to the advance in minimally invasive surgery, precision radiotherapy, and various combined chemotherapy in the last decade. Furthermore, the discovery of new types of therapeutics, such as immune checkpoint inhibitors and immune cell therapies have facilitated both patients and doctors to fight with cancers. Moreover, in the context of the development in biocompatible and cell type targeting nano-carriers as well as nucleic acid-based drugs for initiating and enhancing the anti-tumor response have come to the age. The treatment paradigms utilization of nucleic acids, including short interfering RNA (siRNA), antisense oligonucleotides (ASO), and messenger RNA (mRNA), can target specific protein expression to achieve the therapeutic effects. Over ten nucleic acid therapeutics have been approved by the FDA and EMA in rare diseases and genetic diseases as well as dozens of registered clinical trails for varies cancers. Though generally less dangerous of pediatric cancers than adult cancers was observed during the past decades, yet pediatric cancers accounted for a significant proportion of child deaths which hurt those family very deeply. Therefore, it is necessary to pay more attention for improving the treatment of pediatric cancer and discovering new nucleic acid therapeutics which may help to improve the therapeutic effect and prognoses in turns to ameliorate the survival period and quality of life for children patient. In this review, we focus on the nucleic acid therapy in pediatric cancers.

CircRNA-Associated CeRNAs Regulatory Axes in Retinoblastoma: A Systematic Scoping Review

Retinoblastoma (RB) is one of the most common childhood cancers caused by RB gene mutations (tumor suppressor gene in various patients). A better understanding of molecular pathways and the development of new diagnostic approaches may lead to better treatment for RB patients. The number of studies on ceRNA axes is increasing, emphasizing the significance of these axes in RB. Circular RNAs (circRNAs) play a vital role in competing endogenous RNA (ceRNA) regulatory axes by sponging microRNAs and regulating gene expression. Because of the broadness of ceRNA interaction networks, they may assist in investigating treatment targets in RB. This study conducted a systematic scoping review to evaluate verified loops of ceRNA in RB, focusing on the ceRNA axis and its relationship to circRNAs. This scoping review was carried out using a six-step strategy and the Prisma guideline, and it involved systematically searching the publications of seven databases. Out of 363 records, sixteen articles were entirely consistent with the defined inclusion criteria and were summarized in the relevant table. The majority of the studies focused on the circRNAs circ_0000527, circ_0000034, and circTET1, with approximately two-fifths of the studies focusing on a single circRNA. Understanding the many features of this regulatory structure may help elucidate RB’s unknown causative factors and provide novel molecular potential therapeutic targets and medical fields.

CircRNA hsa_circ_0070659 predicts poor prognosis and promotes non-small cell lung cancer (NSCLC) progression via microRNA-377 (miR-377) / Ras-Associated Binding Protein 3C (RAB3C) pathway

A large number of circular RNAs (circRNAs) are dysregulated in lung cancer and affect the progression and prognosis of lung disease. Herein, this study selected specific circular RNA (circ_0070659) by bioinformatics analysis and aimed to investigate the role of circ_0070659 in non-small cell lung cancer (NSCLC). The differentially expressed circRNA (hsa_circ_0070659) in NSCLC was screened from public databases (GEO), and real-time quantitative polymerase chain reaction (RT-qPCR) was carried out to identify the circ_0070659 levels in cancer tissues and cells. NSCLC cell proliferation, migration, and invasion abilities after circ_0070659 silencing was detected by colony formation assay, Cell Counting Kit-8 (CCK-8) assay and Transwell assay. Targeted binding between microRNA-377 (miR-377) and circ_0070659 or Ras-Associated Binding Protein 3C (RAB3C) was verified by western blot, dual-luciferase reporter assay, and RNA pull-down assay. Our experimental results showed that circ_0070659 levels were largely increased in tumor tissues and cells. Biologically, knockdown of circ_0070659 obviously inhibited proliferation, migration, and invasion of NSCLC cells. Mechanistically, circ_0070659 promoted RAB3C-mediated proliferation and invasion through sponging miR-377. Furthermore, miR-377 inhibitor reversed the inhibitory ability of circ_0070659 silencing on malignant biological behavior of NSCLC cells. Our study revealed a novel signaling pathway that circ_0070659/miR-377/RAB3C axis regulates tumor progression, and it may become a new therapeutic target for NSCLC.

Circ_0075804 regulates the expression of LASP1 by Targeting miR-1287-5p and thus affects the biological process of retinoblastoma

BACKGROUND

Increasing evidence reveals that circular RNA (circRNA) dysregulation is involved in retinoblastoma (RB) pathogenesis. To further realize the development of RB, we investigated the role and regulatory mechanism of circ_0075804 in RB.

METHODS

Real-time quantitative PCR (RT-qPCR) and western blot were employed for expression analysis. CCK-8 assay, EdU assay, colony formation assay, flow cytometry assay and transwell assay were performed to monitor cell phenotypes. Xenograft models were established to monitor the role of circ_0075804 on tumor growth. Tumor growth was assessed by the expression of Ki67, N-cadherin, MMP2 and MMP9 via IHC assay. The predicted binding sites between miR-1287-5p and circ_0075804 or LIM and SH3 protein 1 (LASP1) were validated by dual-luciferase reporter assay.

RESULTS

Upregulation of circ_0075804 and LASP1, and downregulation of miR-1287-5p were shown in RB tissues and cells. Circ_0075804 knockdown repressed RB cell growth, invasion and survival, and hindered tumor development in vivo. MiR-1287-5p was targeted by circ_0075804, and its repression largely reversed the functional effects of circ_0075804 knockdown. LASP1 was a functional target of miR-1287-5p. The inhibition of miR-1287-5p upregulation on RB cell proliferation, survival and invasion was reversed by LASP1 overexpression. Moreover, circ_0075804 knockdown weakened LASP1 expression via increasing miR-1287-5p.

CONCLUSION

Circ_0075804 promotes LASP1 expression by targeting miR-1287-5p, thus acting as a contributor to RB carcinogenesis.Highlights:Circ_0075804 is overexpressed in RB.Circ_0075804 knockdown inhibits RB cell malignant phenotypes and tumor growth in vivo.Circ_0075804 regulates RB cell behaviors by targeting miR-1287-5p.MiR-1287-5p affects RB cell behaviors by binding to LASP1.Circ_0075804 regulates LASP1 expression via targeting miR-1287-5p.

LncRNA nuclear receptor subfamily 2 group F member 1 antisense RNA 1 (NR2F1-AS1) aggravates nucleus pulposus cell apoptosis and extracellular matrix degradation

Emerging reports uncover that long noncoding RNAs (lncRNAs) help regulate intervertebral disc degeneration (IVDD). Here, we probe the function of lncRNA nuclear receptor subfamily 2 group F member 1 antisense RNA 1 (NR2F1-AS1) in IVDD. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was applied to verify the expression of NR2F1-AS1 and miR-145-5p in nucleus pulposus (NP) tissues from IVDD patients or NP cells dealt with IL-1β or TNF-α. Flow cytometry or the TdT-mediated dUTP nick end labeling (TUNEL) assay was performed to validate the apoptosis of NP cells with selective regulation of NR2F1-AS1 and miR-145-5p. ECM-related genes, FOXO1, Bax, and Bcl2 were evaluated by qRT-PCR or Western blot (WB). The targeted relationships between NR2F1-AS1 and miR-145-5p, miR-145-5p and FOXO1 were testified by the dual-luciferase reporter assay and the RNA immunoprecipitation (RIP) assay. Our outcomes substantiated that NR2F1-AS1 was up-regulated, while miR-145-5p was down-regulated in intervertebral disc tissues of IVDD patients or NP cells treated with IL-1β or TNF-α. Besides, overexpressing NR2F1-AS1 intensified ECM degradation and NP cell apoptosis induced by IL-1β, while knocking down NR2F1-AS1 or up-regulating miR-145-5p reversed IL-1β-mediated effects in NP cells. Meanwhile, NR2F1-AS1 choked miR-145-5p and abated its effects in NP cells. This study confirms that NR2F1-AS1 modulates IVDD progression by up-regulating the FOXO1 pathway through the sponge of miR-145-5p as a competitive endogenous RNA (ceRNA).

Hsa_circ_0000527 Downregulation Suppresses the Development of Retinoblastoma by Modulating the miR-27a-3p/HDAC9 Pathway

BACKGROUND

Accumulating evidence indicates that the progression of retinoblastoma (RB) may involve circRNA dysfunction. We aimed to disclose the role of hsa_circ_0000527 and its potential functional mechanism in RB.

METHODS

The expression of hsa_circ_0000527, miR-27a-3p and histone deacetylase 9 (HDAC9) mRNA was monitored using quantitative real-time polymerase chain reaction (qPCR). Functional assays, including cell proliferation and apoptosis, were investigated using cell counting kit-8 (CCK-8) assay, colony formation assay and flow cytometry assay. The expression of apoptosis-associated proteins and HDAC9 protein was detected by western blot. The targeting relationship between miR-27a-3p and hsa_circ_0000527 or HDAC9 was verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. Besides, Xenograft models were constructed to confirm the effect of hsa_circ_0000527 in vivo.

RESULTS

Hsa_circ_0000527 and HDAC9 were upregulated, while miR-27a-3p was downregulated in RB tissues and cells. Hsa_circ_0000527 downregulation repressed RB cell proliferation and induced RB cell apoptosis. MiR-27a-3p was a target of hsa_circ_0000527, and hsa_circ_0000527 suppressed the expression of miR-27a-3p. MiR-27a-3p inhibition reversed the role of hsa_circ_0000527 downregulation. In addition, HDAC9 was a target of miR-27a-3p, and hsa_circ_0000527 indirectly regulated HDAC9 expression by targeting miR-27a-3p. MiR-27a-3p restoration inhibited RB cell proliferation and promoted apoptosis, which was reversed by HDAC9 overexpression. Hsa_circ_0000527 downregulation could inactivate the PI3K/AKT pathway. Moreover, hsa_circ_0000527 downregulation blocked tumor growth rate in vivo.

CONCLUSION

hsa_circ_0000527 downregulation blocked the progression of RB by regulating the miR-27a-3p/HDAC9 pathway, which might be associated with the inactivation of the PI3K/AKT pathway.

Insulin-like growth factor 2 mRNA binding protein 2 regulates proliferation, migration, and angiogenesis of keratinocytes by modulating heparanase stability

Wound healing is related to proliferation, migration, and angiogenesis of keratinocytes. Insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) is an important N6-methyladenosine (m6A) reader, which is involved in multiple processes, including wound healing. However, the function and mechanism of IGF2BP2 in keratinocyte processes are largely uncertain. In the present study, expression levels of IGF2BP2 and heparanase (HPSE) were detected by quantitative reverse transcription polymerase chain reaction and western blotting assays. Cell proliferation was investigated by cell counting kit-8 (CCK-8) analysis. Cell migration was determined through wound healing assay. Angiogenesis was measured by tube formation assay and vascular endothelial growth factor (VEGF) level using enzyme linked immunosorbent assay (ELISA). The interaction between IGF2BP2 and HPSE was analyzed by RNA immunoprecipitation, pull-down and luciferase reporter analyses. The results showed that IGF2BP2 expression was enhanced in wound healing. IGF2BP2 downregulation constrained HaCaT cell proliferation, migration, and angiogenesis. IGF2BP2 knockdown decreased HPSE expression. IGF2BP2 could regulate HPSE stability by binding with 3ʹ untranslated region (UTR) of HPSE. HPSE upregulation attenuated silencing IGF2BP2-mediated suppression of proliferation, migration, and angiogenesis. As a conclusion, IGF2BP2 knockdown repressed proliferation, migration, and angiogenesis of HaCaT cells by decreasing HPSE stability.

Circular RNA hsa_circ_0075542 acts as a sponge for microRNA-1197 to suppress malignant characteristics and promote apoptosis in prostate cancer cells

Numerous differentially expressed circular RNAs (circRNAs) have been identified; however, their roles have not been fully elucidated. Since dysregulated circRNAs may have clinical applications, it is vital to study their expression characteristics, function, and mechanism in prostate cancer cells. The role, regulatory mechanism, and expression of hsa_circ_0075542 were analyzed using quantitative reverse transcription polymerase chain reaction. The results indicated that the expression of hsa_circ_0075542 was downregulated in prostate tumor tissues. The functions of prostate cancer cell lines LNCaP and PC3 cells were assessed using cell counting kit-8 and transwell assays and flow cytometry analysis. The results of the functional experiments showed that overexpression of hsa_circ_0075542 suppressed cell proliferation, reduced migration and invasiveness capabilities, and promoted apoptosis. Moreover, hsa_circ_0075542 targeted the microRNA-1197 (miR-1197) homeobox C11 (HOXC11) axis by sponging miR-1197. Overexpression of miR-1197 played a tumor-promoting role. Overexpression of hsa_circ_0075542 alleviated the tumor-promoting effect of miR-1197 overexpression In conclusion, hsa_circ_0075542 suppressed malignant characteristics and promoted apoptosis in LNCaP and PC3 cells by acting as a competing endogenous RNA of miR-1197. The hsa_circ_0075542/miR-1197 axis might play a role via HOXC11.

Long non-coding RNA ARAP1-AS1 contributes to cell proliferation and migration in clear cell renal cell carcinoma via the miR-361-3p/placental growth factor axis

Clear cell renal cell carcinoma (ccRCC) is an aggressive malignancy with a poor prognosis. Therefore, investigating the molecular mechanism of ccRCC is important for ccRCC treatment. Here, we aimed to explore the effect of the long non-coding RNA ARAP1-AS1/miR-361-3p/PGF axis on ccRCC. The expression of lncRNA ARAP1-AS1, miR-361-3p, and placental growth factor (PGF) in ccRCC cells was verified by real-time quantitative PCR (RT-qPCR). The influence of the ARAP1-AS1/miR-361-3p/PGF axis on ccRCC cells was identified using the Cell Counting Kit-8 (CCK-8) assay, colony formation assay, flow cytometry, and wound healing assay. The interaction between ARAP1-AS1, miR-361-3p, and PGF was confirmed by bioinformatics analysis and luciferase assay. The results showed that the levels of ARAP1-AS1 and PGF increased in ccRCC cells, while miR-361-3p expression decreased. Cell functional experiments showed that cell proliferation and migration were inhibited by silencing ARAP1-AS1 or PGF, while miR-361-3p inhibitor or PGF overexpression could relieve the inhibitory effect of silencing ARAP1-AS1 on ccRCC cells. Moreover, ARAP1-AS1 sponges miR-361-3p to increase PGF expression. In conclusion, our study revealed that ARAP1-AS1 enhanced the malignancy of ccRCC cells by regulating the miR-361-3p/PGF axis.

Centromere protein E as a novel biomarker and potential therapeutic target for retinoblastoma

Retinoblastoma is the most common intraocular malignancy during childhood. Currently, there is no effective treatment for metastatic retinoblastoma. We investigated potential biomarkers of retinoblastoma by utilizing three datasets from a public database. Functional enrichment analysis, including gene ontology, Kyoto encyclopedia of genes and genomes, gene set enrichment analysis and variation analysis, suggested that differentially expressed genes in retinoblastoma were enriched in accelerated cell cycle events. Protein-protein interaction analysis constructed a network consisting of six hub genes, including benzimidazoles 1 (BUB1), cyclin dependent kinase 1 (CDK1), centromere protein E (CENPE), kinesin family member 20A (KIF20A), PDZ binding kinase (PBK), and targeting protein for xklp2 (TPX2). Drug sensitivity analysis showed that nelarabine was positively correlated with five hub genes. All six genes were expressed differently in six immune subtypes and were positively correlated with stemness indices in most human cancer types. Since CENPE is the least known hub gene in retinoblastoma, we further analyzed the potential non-coding RNAs and transcription factors that regulate CENPE and built interaction networks of competing endogenous RNA and transcription factors. Immune cell infiltration, especially by plasma and B cells, was enhanced in samples with high CENPE expression. Pan-cancer analysis illustrated that CENPE was highly expressed in a wide range of human tumors. In vitro validation revealed that CENPE was significantly upregulated at both the mRNA and protein levels in retinoblastoma cells. In conclusion, CENPE, along with other hub genes, could serve as a potential biomarker and intervention target for retinoblastoma.

Whole-transcriptome analysis of rat cavernosum and identification of circRNA-miRNA-mRNA networks to investigate nerve injury erectile dysfunction pathogenesis

There is growing evidence that circular RNAs (circRNAs) play a vital role in many kinds of diseases, including erectile dysfunction (ED). Nevertheless, the role of circRNAs in cavernous nerve-damaging ED (CNI-ED) is unknown. Here, we aimed to discover novel circRNAs, probed their potential role in the CNI-ED, and construct a ceRNA network of circRNAs. Twelve male Sprague Dawley rats were randomly divided into 2 groups by us: bilateral cavernous nerve crush (BCNC) and control groups. Four weeks after surgery, the spongy smooth muscle tissue of the rat penis was sequenced using high-throughput full transcriptome sequencing. We analyzed the expression of circRNAs, miRNAs, and mRNAs in the two groups. Twenty circRNAs with significantly different expressions were selected for RT-qPCR. CeRNA network of circRNAs was established using Cytoscape. GO and KEGG analysis was done by R package. Sequencing showed that 4,587 circRNAs, 762 miRNAs, and 21,661 mRNAs were dysregulated in the BCNC group. The top 20 differentially expressed circRNAs were further verified via RT-qPCR. The ceRNA network contained ten circRNAs, six miRNAs, and 227 mRNAs, including 23 circRNA-miRNA pairs and 227 miRNA-mRNA pairs. GO and KEGG analysis suggested that these ten circRNAs could main regulate energy metabolism processes. A protein‐protein interaction network was constructed with the mRNAs in ceRNA network, and five hub genes were identified. Our study revealed a potential link between circRNAs, miRNAs, and mRNAs in CNI-ED, suggesting that circRNAs may contribute to the occurrence of ED by regulating the cellular energy metabolism in CNI-ED.

Circ_0072995 Promotes Proliferation and Invasion via Regulating miR-1253/EIF4A3 Signaling in HCC

Background

Hepatocellular carcinoma (HCC) is a major threat for human health. This work aimed to determine the potential function of circ_0072995 in HCC progression and its molecular mechanism.

Methods

qRT-PCR was conducted to analyze circ_0072995 expression. CCK8 and colony formation assays were utilized to detect cell proliferation. Transwell assay was performed to determine migration and invasion. Interactions among circ_0072995, miR-1253 and EIF4A3 (Eukaryotic Translation Initiation Factor 4A3) were predicted through bioinformatics methods and confirmed via luciferase reporter assay and RNA pulldown assay.

Results

circ_0072995 expression was upregulated in HCC tissues. Circ_0072995 high level was associated with poor prognosis. Circ_0072995 knockdown impaired proliferation, migration, invasion and survival. MiR-1253 was sponged by circ_0072995 and targeted EIF4A3 directly. Circ_0072995 inhibited miR-1253 to upregulate EIF4A3 level.

Conclusion

Circ_0072995 exerted tumorigenic roles to enhance HCC progression through activating EIF4A3 by sponging miR-1253.

CircMKLN1 Suppresses the Progression of Human Retinoblastoma by Modulation of miR-425-5p/PDCD4 Axis

Purpose: Circular RNAs (circRNAs) are essential regulators in tumorigenesis and development. In this study, we focused on the functions of circRNA muskelin 1 (circMKLN1) in retinoblastoma (RB) progression.Materials and Methods: Quantitative real-time polymerase chain reaction (qRT-PCR) assay was conducted to determine the levels of circMKLN1, microRNA-425-5p (miR-425-5p) and programmed cell death 4 (PDCD4). The characteristic of circMKLN1 was analyzed using RNase R assay. Cell Counting Kit-8 (CCK-8) assay and colony formation assay were employed to explore cell proliferation ability. The transwell assay was utilized for cell migration and invasion. A Western blot assay was performed for protein levels. The dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted to demonstrate the relationships among circMKLN1, miR-425-5p and PDCD4. Murine xenograft model assay was adopted to investigate the role of circMKLN1 in vivo.Results: CircMKLN1 was downregulated in RB tissues and cells. High levels of circMKLN1 were related to a favorable outcome of RB patients. CircMKLN1 was resistant to RNase R digestion and circMKLN1 overexpression repressed RB cell proliferation, migration and invasion in vitro. MiR-425-5p was identified as the target of circMKLN1 and miR-425-5p elevation reversed the effects of circMKLN1 overexpression on RB cell malignant behaviors. Furthermore, as the target gene of miR-425-5p, PDCD4 silencing could ameliorate the suppressive roles of circMKLN1 in RB cell growth and metastasis. Additionally, circMKLN1 overexpression hampered tumor growth in vivo.Conclusions: CircMKLN1 overexpression decelerated the progression of RB through sponging miR-425-5p and elevating PDCD4.