Circular RNA circRNA_0082835 promotes progression and lymphatic metastasis of primary melanoma by sponging microRNA miRNA-429

Circular RNA Circ_0002762 promotes cell migration and invasion in cervical squamous cell carcinoma via activating RelA/nuclear factor kappa B (Nf-kB) signalling pathway

Cervical cancer is a leading cause of cancer-related deaths, with cervical squamous cell carcinoma (CSCC) accounting for a majority of cases. Circular RNAs (circRNAs) have been repeatedly suggested as crucial effectors in modulating the development of multiple malignancies. The expression of circ_0002762 was predicted to be high in CSCC tissues in GEO dataset, but the functional role and underlying regulatory mechanism of circ_0002762 in CSCC was unclear. By series of functional assays and mechanism assays, supported by bioinformatics analysis, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR) analysis and western blot assays, we identified that circ_0002762 aberrantly up-regulated in CSCC, promoting CSCC cell migration and invasion. Mechanically, circ_0002762 was transcriptionally activated by Fork head box A1 (FOXA1). Moreover, the involvement of nuclear factor kappa B (NF-kB) signalling in circ_0002762 regulation mechanism in CSCC cells was ascertained. Additionally, circ_0002762, predominantly accumulated in cell cytoplasm, was proved to recruit Mov10 RISC complex RNA helicase (MOV10) to enhance RelA mRNA stability, thus affecting CSCC cell migration and invasion. In summary, FOXA1-mediated circ_0002762 up-regulation could enhance the migratory and invasive abilities of CSCC cells via the MOV10/RelA/NF-kB pathway.

The Role of Non-coding RNAs in Tumorigenesis, Diagnosis/Prognosis, and Therapeutic Strategies for Cutaneous Melanoma

RNA is a substance with various biological functions. It serves as blueprint for proteins and shuttles information from the genes to the protein factories of the cells. However, these factories-the ribosomes-are also composed mainly of RNA, whose purpose is not storing information but enzymatic action. In addition, there is a cornucopia of RNA molecules within our cells that form a complex regulatory network, connected with all aspects of cellular development and maintenance. These non-coding RNAs can be used for diagnostics and therapeutic strategies in cancer. In this chapter we give an overview of recent developments in non-coding RNA-based diagnostics and therapies for cutaneous melanoma. It is not meant to be comprehensive; however, it describes examples based on some of the most recent publications in this field.

Hsa_circ_0007718 facilitates the progression of colorectal cancer by regulating the miR-1299/PSMC2 axis

Colorectal cancer (CRC) represents one of the most prevalent forms of malignant tumors, characterized by a notably high rate of mortality among affected individuals. The primary objective of this investigation is to delve into the functional role of Hsa_circ_0007718 in the context of colorectal cancer and to elucidate its impact on the progression of CRC by modulating the interaction between the miR-1299 microRNA and its target gene, PSMC2. To assess the expression levels of Hsa_circ_0007718, along with miR-1299 and PSMC2, real-time quantitative fluorescent PCR (qRT-PCR) assays were meticulously performed using both CRC cell lines and clinical samples derived from patients. A cellular model was established to investigate the interactions occurring between miR-1299 and Hsa_circ_0007718, as well as the connections to PSMC2, thereby providing a comprehensive understanding of these molecular interactions. The findings of this research revealed a significant upregulation of Hsa_circ_0007718 in both colorectal cancer cell lines and tissue samples. Importantly, the data indicated that the suppression of Hsa_circ_0007718 led to a marked decrease in the proliferation rates, migratory potential, and invasive capabilities of CRC cells. Furthermore, the study confirmed that Hsa_circ_0007718 acts as a downstream target of miR-1299, exerting its regulatory effects by inhibiting miR-1299 and thereby promoting the expression of PSMC2.

Liquid biopsy for diagnostic and prognostic evaluation of melanoma

Melanoma is the most aggressive form of skin cancer, and the majority of cases are associated with chronic or intermittent sun exposure. The incidence of melanoma has grown exponentially over the last 50 years, especially in populations of fairer skin, at lower altitudes and in geriatric populations. The gold standard for diagnosis of melanoma is performing an excisional biopsy with full resection or an incisional tissue biopsy. However, due to their invasiveness, conventional biopsy techniques are not suitable for continuous disease monitoring. Utilization of liquid biopsy techniques represent substantial promise in early detection of melanoma. Through this procedure, tumor-specific components shed into circulation can be analyzed for not only diagnosis but also treatment selection and risk assessment. Additionally, liquid biopsy is significantly less invasive than tissue biopsy and offers a novel way to monitor the treatment response and disease relapse, predicting metastasis.

Silencing Exosomal circ102927 Inhibits Foot Melanoma Metastasis via Regulating Invasiveness, Epithelial-Mesenchymal Transition and Apoptosis

Background

Exosomes contain abundant circular RNAs (circRNAs), playing an important role in intercellular communication. However, the function and underlying molecular mechanism of exosomal circRNAs in foot metastatic melanoma remain unclear.

Methods

Twelve differentially expressed exosomal circRNAs between patients with metastatic and primary foot melanoma were screened through high-throughput sequencing, and their expression levels were detected by the real-time reverse transcriptase-polymerase chain reaction (RT-qPCR). CircRNA102927 silencing and overexpression A2058 cell line was constructed, and the effects of circRNA102927 on cell proliferation, apoptosis, migration, invasion, and epithelial-mesenchymal transition (EMT) were assessed using cell counting kit-8 (CCK-8), flow cytometry, wound healing, Transwell, and Western blot assays, respectively.

Results

Twelve differentially expressed exosomal circRNAs were screened and ROC curve showed that six circRNAs could be used as the diagnostic biomarkers for metastatic melanoma. Melanoma-secreted exosomes induced the differentiation of CD4+ T cells into Treg cells. CircRNA102927 was highly expressed in metastatic melanomas. Functionally, circRNA102927 silencing inhibited proliferation, EMT, migration, and invasion in metastatic melanoma cells, while promoting apoptosis. Meanwhile, overexpression of circRNA102927 had the opposite effects.

Conclusion

Our investigation suggests that silencing exosomal circRNA102927 may suppress foot melanoma metastasis by inhibiting invasiveness, EMT and promoting apoptosis.

Circular RNAs in Cell Cycle Regulation of Cancers

Cancer has been one of the most problematic health issues globally. Typically, all cancers share a common characteristic or cancer hallmark, such as sustaining cell proliferation, evading growth suppressors, and enabling replicative immortality. Indeed, cell cycle regulation in cancer is often found to be dysregulated, leading to an increase in aggressiveness. These dysregulations are partly due to the aberrant cellular signaling pathway. In recent years, circular RNAs (circRNAs) have been widely studied and classified as one of the regulators in various cancers. Numerous studies have reported that circRNAs antagonize or promote cancer progression through the modulation of cell cycle regulators or their associated signaling pathways, directly or indirectly. Mostly, circRNAs are known to act as microRNA (miRNA) sponges. However, they also hold additional mechanisms for regulating cellular activity, including protein binding, RNA-binding protein (RBP) recruitment, and protein translation. This review will discuss the current knowledge of how circRNAs regulate cell cycle-related proteins through the abovementioned mechanisms in different cancers.

CircRTTN upregulates EPHA2 to aggravate the malignant process of melanoma via sponging miR-890

BACKGROUND

Malignant melanoma is a kind of tumor derived from melanocytes, which has the characteristics of drug resistance and distant metastasis. Accumulating evidence has demonstrated that circular RNAs (circRNAs) are involved in the pathogenesis of melanoma. Our current study aimed to investigate the role and mechanism of circRTTN in melanoma progression.

METHODS

The levels of circRTTN, microRNA-890 (miR-890) and EPH receptor A2 (EPHA2) were examined via quantitative real-time PCR (qRT-PCR) and Western blot. Cell Counting Kit-8 (CCK-8), colony formation, 5-Ethynyl-2'-deoxyuridine (EdU) staining, flow cytometry, transwell and tube formation assays were conducted to estimate the effects of circRTTN on growth, apoptosis, migration, invasion and angiogenesis of melanoma cells. Western blot was used to measure related marker protein levels. The interaction between miR-890 and circRTTN or EPHA2 was predicted by bioinformatics analysis and verified by dual-luciferase reporter and RNA Immunoprecipitation (RIP) assays. Xenograft assay was used to assess the effect of circRTTN in vivo.

RESULTS

CircRTTN and EPHA2 levels were up-regulated, while miR-890 was down-regulated in melanoma tissues and cells. CircRTTN knockdown restrained cell proliferation, migration, invasion and angiogenesis, but promoted cell apoptosis in vitro. CircRTTN was an effective molecular sponge for miR-890, and negatively regulated miR-890 expression. The suppressive role of circRTTN knockdown on cell growth, metastasis and angiogenesis in vitro was abated by blocking miR-890. MiR-890 directly targeted EPHA2. MiR-890 overexpression elicited a similar anti-tumor role in melanoma cells, which was abrogated by overexpression of EPHA2. In addition circRTTN knowdown markedly attenuated xenograft tumor growth in vivo.

CONCLUSION

Our findings demonstrated that circRTTN mediated melanoma progression via regulating the miR-890/ EPHA2 axis.

MicroRNA-128 acts as a suppressor in the progression of gastrointestinal stromal tumor by targeting B-lymphoma Mo-MLV insertion region 1

INTRODUCTION

The critical role of microRNA-128 (miR-128) in gastrointestinal-related diseases has been documented. In the current study, we tried to clarify the specific role miR-128 in gastrointestinal stromal tumor (GIST) and the underlying mechanism.

METHODS

Differentially expressed genes in GIST were identified following bioinformatics analysis. Then, expression patterns of miR-128 and B-lymphoma Mo-MLV insertion region 1 (BMI-1) in clinical tissue samples and cell lines were characterized, followed by validation of their correlation. GIST-T1 cells were selected and transfected with different mimic, inhibitor, or siRNA plasmids, after which the biological functions were assayed.

RESULTS

We identified low miR-128 and high BMI-1 expression in GIST tissues of 78 patients and 4 GIST cell lines. Ectopic expression of miR-128 or silencing of BMI-1 suppressed the malignant potentials of GIST-T1 cells. As a target of miR-128, BMI-1 re-expression could partly counteract the suppressive effect of miR-128 on the malignancy of GIST-T1 cells.

CONCLUSION

Our study provided evidence that miR-128-mediated silencing of BMI-1 could prevent malignant progression of GIST, highlighting a promising anti-tumor target for combating GIST.

Circ_PRDM5/miR-25-3p/ANKRD46 axis is associated with cell malignant behaviors in subjects with breast cancer evaluated by ultrasound

Circular RNAs (circRNAs) are key RNA molecules in cancer biology. CircRNA PR/SET domain 5 (circ_PRDM5, hsa_circ_0005654) was downregulated in breast cancer (BC) tissues. This study is designed to investigate the functional mechanism of circ_PRDM5 in BC. Ultrasound examinations were performed to evaluate BC patients and normal individuals. Circ_PRDM5, miR-25-3p, and Ankyrin repeat domain 46 (ANKRD46) level detection was carried out by reverse transcription-quantitative polymerase chain reaction. 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay was used for cell viability examination. Cell proliferation was evaluated by ethynyl-2'-deoxyuridine assay and colony formation assay. The protein levels were examined using western blot. Cell migration and invasion abilities were assessed via transwell assay. Target interaction was analyzed via dual-luciferase reporter assay. The role of circ_PRDM5 in vivo was explored via xenograft tumor assay. Circ_PRDM5 expression was downregulated in BC tissues and cells. Overexpression of circ_PRDM5 suppressed proliferation and motility but enhanced apoptosis of BC cells. Circ_PRDM5 served as a sponge of miR-25-3p. Circ_PRDM5 impeded BC cell malignant development via sponging miR-25-3p. Circ_PRDM5 induced ANKRD46 upregulation by targeting miR-25-3p. Inhibition of miR-25-3p retarded BC progression by increasing the ANKRD46 level. Circ_PRDM5 repressed BC tumorigenesis in vivo through mediating the miR-25-3p/ANKRD46 axis. This study evidenced that circ_PRDM5 inhibited cell progression and tumor growth in BC via interacting with mir-25-3p/ANKRD46 network.

HIF-1-Induced hsa-miR-429: Understanding Its Direct Targets as the Key to Developing Cancer Diagnostics and Therapies

MicroRNAs (miRNAs) play a critical role in the regulation of mRNA stability and translation. In spite of our present knowledge on the mechanisms of mRNA regulation by miRNAs, the utilization and translation of these ncRNAs into clinical applications have been problematic. Using hsa-miR-429 as an example, we discuss the limitations encountered in the development of efficient miRNA-related therapies and diagnostic approaches. The miR-200 family members, which include hsa-miR-429, have been shown to be dysregulated in different types of cancer. Although these miR-200 family members have been shown to function in suppressing epithelial-to-mesenchymal transition, tumor metastasis, and chemoresistance, the experimental results have often been contradictory. These complications involve not only the complex networks involving these noncoding RNAs, but also the problem of identifying false positives. To overcome these limitations, a more comprehensive research strategy is needed to increase our understanding of the mechanisms underlying their biological role in mRNA regulation. Here, we provide a literature analysis of the verified hsa-miR-429 targets in various human research models. A meta-analysis of this work is presented to provide better insights into the role of hsa-miR-429 in cancer diagnosis and any potential therapeutic approach.

Circ_0081054 facilitates melanoma development via sponging miR-637 and regulating RAB9A

BACKGROUND

Accumulating evidence announces that aberrantly expressed circRNAs were closely related to the development of human cancers. However, the role and mechanism of multiple circRNAs remain unclear. Our work aimed to disclose the functional role and mechanism of circ_0081054 in melanoma.

METHODS

Quantitative real-time polymerase chain reaction assay was utilized to detect circ_0081054, microRNA-637 (miR-637) and RAB9A (member RAS oncogene family) mRNA expression. Cell proliferative ability was evaluated via Cell Counting Kit-8 and colony formation assay. Cell invasion was assessed by using wound healing assay.

RESULTS

The significant upregulation of circ_0081054 was detected in melanoma tissues and cells. The proliferation, migration, glycolytic metabolism, and angiogenesis in melanoma cells were suppressed, while apoptosis was promoted following the silence of circ_0081054. In addition, circ_0081054 could target miR-637, and miR-637 inhibitor could reverse the effects of circ_0081054 deficiency. Furthermore, RAB9A was a target gene for miR-637 and RAB9A overexpression could reverse the effects of miR-637 overexpression. In addition, the deficiency of circ_0081054 hampered tumor growth in vivo. Moreover, circ_0081054 could regulate RAB9A expression by sponging miR-637.

CONCLUSION

All results indicated that circ_0081054 promoted the malignant behaviors of melanoma cells partly by regulating the miR-637/RAB9A molecular axis.

Circ_0082476 targets miR-138-5p to promote proliferation, invasion, migration and inflammation in IL-22-treated human keratinocytes by upregulating BRD4

BACKGROUND

Circular RNAs (circRNAs) are implicated in the disease progression via acting as sponges of microRNAs (miRNAs) to regulate gene expression. The purpose of this study was to analyze the involvement of circ_0082476 in Interleukin-22 (IL-22)-induced psoriasis.

METHODS

Expression detection for circ_0082476, microRNA-424-5p (miR-138-5p) or toll-like receptor (BRD4) was completed using reverse transcription-quantitative polymerase chain reaction assay. Cell Counting Kit-8 assay and EdU assay were used for analysis of cell viability and proliferation, respectively. Cell invasion and migration abilities were assessed through transwell assay and wound healing assay. The protein expression was examined via western blot. Inflammatory reaction was determined via Enzyme-linked immunosorbent assay. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were conducted for target binding research.

RESULTS

Circ_0082476 was significantly elevated in psoriasis patients and IL-22-treated keratinocytes (HaCaT). Knockdown of circ_0082476 reduced cell proliferation, invasion and migration in IL-22-treated HaCaT cells. Circ_0082476 induced sponge effect on miR-138-5p. Circ_0082476 regulated IL-22-induced cell injury through targeting miR-138-5p. BRD4 was confirmed as a target of miR-138-5p, and miR-138-5p relieved IL-22-induced cell dysfunction by the direct downregulation of BRD4. BRD4 was positively regulated by circ_0082476 via sponging miR-138-5p.

CONCLUSION

These findings disclosed that circ_0082476 facilitated the IL22-induced epidermis cell injury in psoriasis through the upregulation of BRD4 via binding to miR-138-5p.

circEZH2E2 /E3 is a dual suppressor of miR363/miR708 to promote EZH2 expression and prostate cancer progression

The histone methyltransferase enhancer of zeste homolog 2 (EZH2) is overexpressed in a variety of malignancies including prostate cancer (PCa) and may play important roles in tumor progression. Gene copy number gains, enhanced transcription, and a few circRNAs have been reported to upregulate EZH2. It was not known whether EZH2 itself generates circRNAs that promote its own expression. We here report the identification of circEZH2^E2/E3 that is derived from exons 2 and 3 of the EZH2 gene and overexpressed in PCa. We show that circEZH2^E2/E3 functions as a dual inhibitor for both miR363 and miR708 that target the EZH2 3'UTR and CDS, respectively, resulting in the upregulation of EZH2 expression and hence the downregulation of EZH2-repressed genes (e.g., CDH1 and DAB2IP), and enhancement of PCa cell proliferation, migration, invasion, and xenograft PCa growth. Overexpression of circEZH2^E2/E3 is significantly correlated with higher tumor grade, tumor progression, and unfavorable progression-free and disease-specific survival in PCa patients. These findings show a novel autoenhancing EZH2-circEZH2^E2/E3 -miR363/miR708-EZH2 regulatory loop, by which circEZH2^E2/E3 plays important roles in PCa tumorigenesis and progression by upregulating EZH2, and may have potential diagnostic, prognostic, and therapeutic uses in PCa management.

Non-coding RNAs in skin cancers:Biological roles and molecular mechanisms

Cutaneous malignancies, including basal cell carcinoma, cutaneous squamous cell carcinoma, and cutaneous melanoma, are common human tumors. The incidence of cutaneous malignancies is increasing worldwide, and the leading cause of death is malignant invasion and metastasis. The molecular biology of oncogenes has drawn researchers’ attention because of the potential for targeted therapies. Noncoding RNAs, including microRNAs, long noncoding RNAs, and circular RNAs, have been studied extensively in recent years. This review summarizes the aspects of noncoding RNAs related to the metastasis mechanism of skin malignancies. Continuous research may facilitate the identification of new therapeutic targets and help elucidate the mechanism of tumor metastasis, thus providing new opportunities to improve the survival rate of patients with skin malignancies.

Oxymatrine induces anti-tumor response in cervical cancer by modulating circ_0008460/miR-197-3p/ribonucleotide reductase subunit M2 (RRM2)

Oxymatrine (OMT) has exhibited an anti-cancer role in human cancers, including cervical cancer (CC). The dysregulated circular RNAs (circRNAs) are key regulators in cancer biology, and circ_0008460 was upregulated in CC. This study was performed to investigate the circRNA-based molecular mechanism for OMT in CC. RNA detection for circ_0008460, microRNA-197-3p (miR-197-3p), or ribonucleotide reductase subunit M2 (RRM2) was completed using reverse transcription-quantitative polymerase chain reaction assay. Cell behaviors were assessed by Cell Counting Kit-8 assay for cell viability, colony formation assay or Edu assay for cell proliferation, flow cytometry for cell apoptosis, and wound healing assay/transwell assay for migration/invasion. Protein expression examination was conducted using western blot. Dual-luciferase reporter assay and RNA pull-down assay were applied to confirm target binding. Tumor xenograft assay was performed for OMT research in vivo. OMT induced circ_0008460 downregulation in CC cells. OMT-induced inhibitory effects on cell growth, migration, and invasion but promoting effect on cell apoptosis were attenuated by circ_0008460. Circ_0008460 directly interacted with miR-197-3p, and OMT inhibited malignant behaviors of CC cells via mediating circ_0008460/miR-197-3p axis. RRM2 acted as a target for miR-197-3p and circ_0008460 affected the RRM2 level through absorbing miR-197-3p. OMT upregulated miR-197-3p to inhibit RRM2 expression to impede CC cell development. CC tumorigenesis was suppressed by OMT via targeting circ_0008460/miR-197-3p/RRM2 axis in vivo. These results suggested that OMT restrained CC cell progression in vitro and tumor growth in vivo by downregulating circ_0008460 to mediate miR-197-3p/RRM2 axis.

Circ_0003146 upregulates SCARB1 expression by acting as a miR-1272 sponge to promote malignant behaviors of clear cell renal cell carcinoma

Circular RNAs (circRNAs) exhibit essential regulation in the malignant development of clear cell renal cell carcinoma (ccRCC). The aims of this study were to investigate the role and mechanism of circ_0003146 in the biologic behaviors of ccRCC. RNA level analysis was performed through reverse transcription-quantitative PCR assay. Cell proliferation was measured by EdU assay and cell counting kit-8 assay. The protein expression was analyzed using a western blot. Flow cytometry and caspase 3 activity assay were used to assess cell apoptosis. Cell migration and invasion were evaluated via wound healing assay and transwell assay. Circ_0003146 function in vivo was determined by xenograft tumor assay. Dual-luciferase reporter assay was applied for target relation analysis. Circ_0003146 upregulation was detected in ccRCC tissues and cells. Downregulation of circ_0003146 induced inhibition of proliferation, migration, invasion and EMT but the promotion of apoptosis in ccRCC cells. Tumor growth in vivo was inhibited after knockdown of circ_0003146. Circ_0003146 directly interacted with miR-1272, and the miR-1272 sponging effect was responsible for the function of circ_0003146. Scavenger receptor class B type 1 (SCARB1) was a target of miR-1272, and circ_0003146 regulated SCARB1 level by absorbing miR-1272. The regulation of circ_0003146 in ccRCC progression was achieved by upregulating SCARB1 in part. The current findings demonstrated that circ_0003146 contributed to the malignant progression of ccRCC via inducing SCARB1 upregulation by targeting miR-1272.

Downregulation of sperm-associated antigen 5 inhibits melanoma progression by regulating forkhead box protein M1/A disintegrin and metalloproteinase 17/NOTCH1 signaling

Sperm-associated antigen 5 (SPAG5) has been identified as a driver in several type of cancers. In this study, we aimed to reveal the role of SPAG5 in melanoma and clarify whether FOXM1 (forkhead box protein M1) /ADAM17 (A disintegrin and metalloproteinase 17) /NOTCH1 signaling was involved. The expression of SPAG5 in malignant melanoma (MM) tissues and matched normal tissues was detected using qRT-PCR, immunohistochemistry and Western blotting. Cell viability was tested using CCK-8 (Cell Count Kit-8), colony formation and EdU staining. Cell migration and epithelial to mesenchymal transition (EMT) were measured using transwell chambers and immunofluorescent staining. Cell cycle distribution and tumorigenesis were assessed by flow cytometry and in vivo tumor-bearing experiments, respectively. The results demonstrated that the expression of SPAG5 was increased in MM tissues and cells. Downregulation of SPAG5 inhibited cell viability, migration, invasion and EMT, and induced a G1-phase arrest. In addition, downregulation of SPAG5 decreased the expression of FOXM1, thereafter inhibiting the expression of ADAM17, NOTCH1 and HES1. Furthermore, deletion of SPAG5 expression decreased the tumorigenesis of MM A375 cells. In conclusion, this study demonstrated that SPAG5 was overexpressed in MM. Downregulation of SPAG5 repressed MM cell growth and EMT, which might be induced by inactivation of the FOXM1/ADAM17/NOTCH1 signaling.

Circular RNA circRNA_0067934 promotes glioma development by modulating the microRNA miR-7/ Wnt/β-catenin axis

Glioma, one of the most prevalent malignant tumors, is well-known for its poor prognosis and low survival rate among patients. As a type of non-coding RNA, circular RNAs (circRNAs) play a significant role in tumor progression. However, the function and role of circRNAs in glioma development remain unclarified. In our experiments, the relative expression level of circRNA_0067934 and miR-7 in glioma tissue was detected by qRT-PCR, and specific gene knockdown was mediated by siRNA and miRNA-inhibitor. Dual-luciferase reporter assay was carried out to determine whether miR-7 successfully targeted circRNA_0067934. Also, CCK-8 and Transwell were performed to evaluate the malignant behaviors of glioma tissues. Western blotting and immunofluorescence were used to evaluate relative protein expression levels. The results of qRT-PCR indicated that circRNA_0067934 was over-expressed in glioma tissues, and down regulation of circRNA_0067934 reduced the tumor progression by inhibiting cell proliferation, invasion, and migration. The relative expression level of miR-7 was significantly reduced in glioma tissues, which showed a negative association with the expression of circRNA_0067934. CircRNA_0067934 could tagete the miR-7 to regulate progression of glioma cell. In addition, the Wnt/β-catenin signaling pathway might involve in down stream regulation of circRNA_0067934 and miR-7. In conclusion, our results revealed that circRNA_0067934 regulates glioma cells progression by targeting miR-7/ Wnt/β-catenin axis.

A novel circRNA-miRNA-mRNA network revealed exosomal circ-ATP10A as a biomarker for multiple myeloma angiogenesis

The importance of angiogenesis in multiple myeloma (MM) is unquestionable; however, to date, the success of antiangiogenic therapies has been fairly limited. Exosomal circular RNAs (circRNAs) have been proven to be pivotal players in angiogenesis in various cancers. Nevertheless, their role in MM remains unknown. Therefore, we aimed to identify differentially expressed circRNAs in peripheral blood exosomes from MM patients and explore their diagnostic and prognostic values. We screened 2,052 circRNAs with significant differential expression between MM patients and healthy controls via high-throughput sequencing. qRT-PCR confirmed that the expression of circ-ATP10A was significantly increased in MM patients. The bioinformatics analyses suggested that circ-ATP10A can act as a microRNA (miRNA) sponge and regulate the expression of downstream vascular endothelial growth factor-B (VEGFB), hypoxia-inducible factor-1alpha (HIF1A), platelet-derived growth factor subunit A (PDGFA), and fibroblast growth factor (FGF). The immunohistochemical results indicated that the circ-ATP10A level was positively correlated with the protein levels of VEGFB and marrow microvessel density (MVD) in MM patients, and the receiver operating characteristic (ROC) curve, area under the ROC curve (AUC) and Kaplan-Meier survival curve analyses confirmed it as a prognostic biomarker. Collectively, our study indicates that exosomal circ-ATP10A is a valuable prognostic biomarker in MM and may promote MM angiogenesis by targeting hsa-miR-6758-3p/hsa-miR-3977/hsa-miR-6804-3p/hsa-miR-1266-3p/hsa-miR-3620-3p and modulating their downstream mRNAs, such as VEGFB, HIF1A, PDGF, and FGF.

Sevoflurane inhibits progression of glioma via regulating the HMMR antisense RNA 1/microRNA-7/cyclin dependent kinase 4 axis

Sevoflurane (Sev) is a volatile anesthetic that can inhibit tumor malignancy. Glioma is a main brain problem, but the mechanism of Sev in glioma progression is largely unclear. This study aims to explore a potential regulatory network of long noncoding RNA (lncRNA)/microRNA (miRNA)/mRNA associated with the function of Sev in glioma progression. LncRNA HMMR antisense RNA 1 (HMMR-AS1), miR-7 and cyclin-dependent kinase 4 (CDK4) abundances were examined via quantitative reverse transcription polymerase chain reaction and western blot. Cell viability, invasion, and colony formation ability were analyzed via cell counting kit-8, transwell analysis, and colony formation. The target association was analyzed via dual-luciferase reporter analysis and RNA pull-down. The in vivo function of Sev was investigated by xenograft model. HMMR-AS1 abundance was increased in glioma tissues and cells, and reduced via Sev. Sev constrained cell viability, invasion, and colony formation ability via decreasing HMMR-AS1 in glioma cells. miR-7 expression was decreased in glioma, and was targeted via HMMR-AS1. HMMR-AS1 silence restrained cell viability, invasion, and colony formation ability by up-regulating miR-7 in glioma cells. Sev increases miR-7 abundance via decreasing HMMR-AS1. CDK4 was targeted via miR-7, and highly expressed in glioma. miR-7 overexpression inhibited cell viability, invasion, and colony formation ability via reducing CDK4 in glioma cells. CDK4 expression was reduced by Sev via HMMR-AS1/miR-7 axis. Sev suppressed cell growth in glioma by regulating HMMR-AS1. Sev represses glioma cell progression by regulating HMMR-AS1/miR-7/CDK4 axis.

Downregulated circular RNA hsa_circ_0005797 inhibits endometrial cancer by modulating microRNA-298/Catenin delta 1 signaling

Abnormal expression of circular RNA (circRNA) expression has been implicated in endometrial cancer (EC) progression. Thus, investigation of the mechanism of hsa_circ_0005797 during EC etiology may provide new insight into the treatment of EC. In the present study, we found that hsa_circ_0005797 expression was significantly increased in EC biological samples and cell lines, whereas its downregulation inhibited in vitro tumor cells proliferation and invasion phenotypes and suppressed tumor formation in nude mice. In mechanism, we characterized hsa_circ_0005797 as an miR-298 sponge, with CTNND1 identified as a target of miR-298. Our rescue assay data further revealed that hsa_circ_0005797 silencing inhibited EC cells proliferation and invasion via miR-298/CTNND1 signaling. In conclusion, our study confirmed hsa_circ_0005797 is a poor prognostic factor for EC and modulates EC phenotypes by regulating the hsa_circ_000579/miR-298/CTNND1 signaling, which provides potential treatment targets for EC

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 circCRKL inhibits the proliferation of acute myeloid leukemia cells via the miR-196a-5p/miR-196b-5p/p27 axis

As a new type of non-coding RNA, the role of circular RNA (circRNA) in various diseases and tumors has received considerable attention. Studies have shown that circRNAs play an important role in the progression of acute myeloid leukemia (AML) via different mechanisms. However, the specific underlying molecular mechanism of circRNAs in the proliferation of AML cells remians unclear. This study aimed to clarify the biological role and mechanism of circCRKL in AML. The results indicated low circCRKL expression in AML cell lines and samples. Moreover, the overexpression of circCRKL inhibited the proliferation and colony-forming ability of AML cells, while its silencing promoted them. In addition, bioinformatics tools and luciferase assays revealed that circCRKL could sponge miR-196a-5p and miR-196b-5p to promote the expression of p27. Furthermore, circCRKL inhibited AML cell proliferation via the miR-196a-5p/miR-196b-5p/p27 axis, suggesting a potential new target for AML therapy.