The Sponge Interaction Between Circular RNA and microRNA Serves as a Fast-Evolving Mechanism That Suppresses Non-small Cell Lung Cancer (NSCLC) in Humans.

Non-small cell lung cancer (NSCLC) is one of the most lethal cancer types in the world. Currently, the molecular mechanisms and pathways underlying NSCLC oncogenesis are poorly understood. Using multiple Omics data, we systematically explored the differentially expressed circular RNAs (circRNAs) in NSCLC. We also investigated potential microRNA sponges (that absorb circRNAs) in NSCLC and downstream target genes with experimental verifications. hsa_circ_0003497 was down-regulated in NSCLC and played an inhibitory role in tumorigenesis. In contrast, miR-197-3p was up-regulated in NSCLC. hsa_circ_0003497 directly interacts with miR-197-3p and releases a target gene of miR-197-3p termed CTNND1 (a known tumor suppressor gene). Evolutionary analysis reveals fast evolution of this hsa_circ_0003497-miR-197-3p-CTNND1-NSCLC axis in mammals. This work clarified the biological functions and molecular mechanisms of how hsa_circ_0003497 suppresses NSCLC through miR-197-3p and CTNND1. We discovered molecular markers for the prognosis of NSCLC and provided potential intervention targets for its treatment.

Circ_0014130 is involved in the drug sensitivity of colorectal cancer through miR-197-3p/PFKFB3 axis.

BACKGROUND AND AIM: Colorectal cancer (CRC) is one of the most deadly cancers in the world, with few treatments and a poor prognosis. In recent years, many circular RNAs have been studied in CRC, but the role of circ_0014130 in CRC has not been investigated. Therefore, this research is designed to investigate the impact of circ_0014130 on the resistance of 5-fluorouracil (5-FU) in CRC. METHODS: Quantitative real-time polymerase chain reaction was conducted to assess the expression of circ_0014130, microRNA-197-3p (miR-197-3p), and 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase 3 (PFKFB3). The expression of PFKFB3 protein was detected by Western blot. The effect of cric_0014130 on drug resistance in CRC was verified by Cell Counting Kit-8 assay, clone formation assay, Transwell, and flow cytometry. The effect of circ_0014130 on tumor growth was evaluated by xenograft tumor model in vivo. RESULTS: Circ_0014130 and PFKFB3 were increased, while miR-197-3p was reversed in CRC tissues and cells. Knocking down circ_0014130 can promote cell apoptosis, inhibit the proliferation of CRC cells, and reduced the IC50 of 5-FU. In addition, miR-197-3p inhibitors reversed the effect of si-circ_0014130 on CRC cells. Similarly, overexpression of PFKFB3 can regulate CRC cell behavior and 5-FU resistance caused by miR-197-3p. Finally, decrease of circ_0014130 was demonstrated to enhance the resistance of 5-FU in CRC tissues in vivo. CONCLUSION: Circ_0014130 modulates 5-FU resistance in CRC by modulating the miR-197-3p/PFKFB3 axis, which is helpful for drug chemotherapy in CRC.

Hsa_circ_001988 attenuates GC progression in vitro and in vivo via sponging miR-197-3p.

Hsa_circ_001988 has been identified as a tumor suppressor gene in several carcinomas. However, its expression pattern and role in gastric cancer (GC) have still remained elusive. This study aimed to explore the functions of hsa_circ_001988 in GC. Quantitative reverse transcription polymerase chain reaction assay was performed to assess the expressions of hsa_circ_001988, miR-197-3p, FBXW7, CCDC6, and U2AF65 in GC tissues. The correlation analysis was undertaken to find out the relationship between hsa_circ_001988 expression and clinicopathological factors. A series of cellular experiments were carried out to describe the effects of hsa_circ_001988 on GC in vivo and in vitro. Besides, RNA immunoprecipitation (RIP) assay was performed to verify the relationship among EIF4A3, U2AF65, and hsa_circ_001988. We first found that the expression of hsa_circ_001988 was decreased in 341 GC patients that was related to World Health Organization histological types, Lauren types, and tumor invasion depth (p < .05). Silencing of hsa_circ_001988 facilitated proliferation, colony formation, migration, and invasion of GC cells, while overexpression of hsa_circ_001988 reversed the effect on GC progression in vitro. Additionally, the results of subcutaneous xenotransplanted tumor model demonstrated that overexpressing hsa_circ_001988 significantly suppressed the subcutaneous tumor growth in vivo. Mechanistically, hsa_circ_001988 attenuated the miR-197-3p expression possibly due to its molecular sponge effect, and then, positively promoted FBXW7 expression. Afterwards, FBXW7 regulated the expressions of yes-associated protein 1, cyclinD1, CCDC6, and EMT-related proteins. Notably, RIP assay showed the enrichment relationship among EIF4A3, U2AF65, and hsa_circ_001988. Additionally, EIF4A3 or U2AF65 promoted cyclization of hsa_circ_001988 in GC. Hsa_circ_001988 inhibits the proliferation and metastasis of GC via modulating EIF4A3/U2AF65-mediated hsa_circ_001988/miR-197-3p/FBXW7 axis.

MicroRNA-197-3p mediates damage to human coronary artery endothelial cells via targeting TIMP3 in Kawasaki disease.

Kawasaki disease (KD) causes cardiovascular system injury in children. However, the pathogenic mechanisms of KD have not been well defined. Recently, strong correlation between aberrant microRNAs and KD nosogenesis has been revealed. A role of microRNA-197-3p (miR-197-3p) in the pathogenesis of KD is identified in the present study. Cell proliferation assay showed human coronary artery endothelial cells (HCAECs) were suppressed by serum from KD patients, which was correlated with high levels of miR-197-3p in both KD serum and HCAECs cultured with KD serum. The inhibition of HCAECs by miR-197-3p was confirmed by cells expressing miR-197-3p mimic and miR-197-3p inhibitor. Comparative proteomics analysis and Ingenuity Pathway Analysis (IPA) revealed TIMP3 as a potential target of miR-197-3p, which was demonstrated by western blot and dual-luciferase reporter assays. Subsequently, by detecting the endothelium damage markers THBS1, VWF, and HSPG2, the role of miR-197-3p/TIMP3 in KD-induced damage to HCAECs was confirmed, which was further validated by a KD mouse model in vivo. The expressions of miR-197-3p and its target, TIMP3, are dramatically variational in KD serum and HCAECs cultured with KD serum. Increased miR-197-3p induces HCAECs abnormal by restraining TIMP3 expression directly. Hence, dysregulation of miR-197-3p/TIMP3 expression in HCAECs may be an important mechanism in cardiovascular endothelium injury in KD patients, which offers a feasible therapeutic target for KD treatment.

Effects of single bouts of different endurance exercises with different intensities on microRNA biomarkers with and without blood flow restriction: a three-arm, randomized crossover trial.

PURPOSE: Physical activity is associated with altered levels of circulating microRNAs (ci-miRNAs). Changes in miRNA expression have great potential to modulate biological pathways of skeletal muscle hypertrophy and metabolism. This study was designed to determine whether the profile of ci-miRNAs is altered after different approaches of endurance exercise. METHODS: Eighteen healthy volunteers (aged 24 ± 3 years) participated this three-arm, randomized-balanced crossover study. Each arm was a single bout of treadmill-based acute endurance exercise at (1) 100% of the individual anaerobic threshold (IANS), (2) at 80% of the IANS and (3) at 80% of the IANS with blood flow restriction (BFR). Load-associated outcomes (fatigue, feeling, heart rate, and exhaustion) as well as acute effects (circulating miRNA patterns and lactate) were determined. RESULTS: All training interventions increased the lactate concentration (LC) and heart rate (HR) (p < 0.001). The high-intensity intervention (HI) resulted in a higher LC than both lower intensity protocols (p < 0.001). The low-intensity blood flow restriction (LI-BFR) protocol led to a higher HR and higher LC than the low-intensity (LI) protocol without BFR (p = 0.037 and p = 0.003). The level of miR-142-5p and miR-197-3p were up-regulated in both interventions without BFR (p < 0.05). After LI exercise, the expression of miR-342-3p was up-regulated (p = 0.038). In LI-BFR, the level of miR-342-3p and miR-424-5p was confirmed to be up-regulated (p < 0.05). Three miRNAs and LC show a significant negative correlation (miR-99a-5p, p = 0.011, r = - 0.343/miR-199a-3p, p = 0.045, r = - 0.274/miR-125b-5p, p = 0.026, r = - 0.302). Two partial correlations (intervention partialized) showed a systematic impact of the type of exercise (LI-BFR vs. HI) (miR-99a-59: r = - 0.280/miR-199a-3p: r = - 0.293). CONCLUSION: MiRNA expression patterns differ according to type of activity. We concluded that not only the intensity of the exercise (LC) is decisive for the release of circulating miRNAs-as essential is the type of training and the oxygen supply.

Hsa_circ_0025202 suppresses cell tumorigenesis and tamoxifen resistance via miR-197-3p/HIPK3 axis in breast cancer.

BACKGROUND: The involvement of circular RNAs (circRNAs) in tamoxifen (TAM) resistance has been identified. Herein, we aimed to identify the role and novel mechanisms of hsa_circ_0025202 in tamoxifen resistance in breast cancer (BC). METHODS: The levels of hsa_circ_0025202, microRNA (miR)-197-3p, and homeodomain-interacting protein kinase 3 (HIPK3) were tested using quantitative real-time polymerase chain reaction and western blot. IC50 value of TAM, cell proliferation, cell cycle, cell invasion, migration, apoptosis, western blot, and mouse xenograft assays was used to demonstrate the effects of hsa_circ_0025202, miR-197-3p, and HIPK3 on BC cell tumorigenesis and TAM resistance. Dual-luciferase report and RNA immunoprecipitation assays were applied to explore the potential interaction between miR-197-3p and hsa_circ_0025202 or HIPK3. RESULTS: Hsa_circ_0025202 was decreased in BC tissues and TAM resistant BC cells, and knockdown of hsa_circ_0025202 elevated the IC50 value of cells to TAM, led to the promotion of cell proliferation, invasion and migration, mediated cell cycle progression, and inhibited cell apoptosis in BC in vitro. Besides, the upregulation of hsa_circ_0025202 hindered tumor growth and promoted TAM sensitivity in vivo. In a mechanical study, hsa_circ_0025202 targeted miR-197-3p, and silencing of miR-197-3p reversed the regulatory effects of hsa_circ_0025202 knockdown on TAM resistance and malignant phenotypes. Additionally, HIPK3 was a target of miR-197-3p, and miR-197-3p overexpression enhanced TAM resistance and promoted cell malignant biological behaviors in BC by targeting HIPK3. CONCLUSION: Hsa_circ_0025202 repressed cell tumorigenesis and TAM resistance via miR-197-3p/HIPK3 axis in BC, suggesting a potential therapeutic strategy to overcome chemoresistance in BC patients.

Restoration of microRNA-197 expression suppresses oncogenicity in fibrosarcoma through negative regulation of RAN.

MicroRNAs (miRNAs) act as crucial regulators of biological pathways/processes by reinforcing transcriptional programs and moderating transcripts. Emerging evidences have shown the involvement of dysregulated miRNAs in pathophysiology of human diseases including several cancer types. Recently, miR-197-3p has been reported to play different roles in different cancers; however, its role in fibrosarcoma, a highly aggressive and malignant soft tissue sarcoma originated from the mesenchymal tissues, has not yet been studied. Therefore, this study aims to investigate the possible regulatory roles of miR-197-3p in the oncogenicity of fibrosarcoma. For this, we initially performed qRT-PCR of miR-197-3p, which we found to be downregulated in HT1080 human fibrosarcoma cells compared with IMR90-tert normal fibroblast cells. Subsequently, we performed gain-of-function study by employing several methods such as MTT assay, clonogenic assay, wound healing, flow cytometry cell cycle analysis, and acridine orange staining after transfecting HT1080 cells with miR-197-3p mimic. From these assays, we observed that miR-197-3p significantly inhibits viability, colony forming, and migration ability as well as triggers G2/M phase cell cycle arrest and autophagy in fibrosarcoma cells. To understand the mechanism through which miRNA performs these functions, we predicted its targets using TargetScan and performed pathway enrichment analysis after screening them by their expression in fibrosarcoma. Among the enriched targets, we found RAN (ras-related nuclear protein) to be a crucial target through which miR-197-3p represses tumorigenesis by binding to its 3´ UTR, validated by luciferase reporter assay. The tumor suppressive role of the miRNA was further confirmed by transfecting its mimic in RAN-overexpressed cells which showed significant attenuation in tumorigenic effect of RAN in fibrosarcoma as seen in different assays. Taken together, our study unveiled that miR-197-3p acts as an oncosuppressor in fibrosarcoma through G2/M phase arrest and induction of autophagy, and raises the possibility to act as a novel therapeutic intervention for the malignancy.

LINC00312 inhibits the migration and invasion of bladder cancer cells by targeting miR-197-3p.

To investigate the influence of the long non-coding RNA LINC00312 on bladder cancer (BC) cell invasion and metastasis by targeting miR-197-3p. BC and corresponding adjacent tissues were collected. LINC00312 and miR-197-3p were measured, and their correlation was detected through quantitative real-time PCR (qRT-PCR). BC cell line T24 was transfected and grouped (five groups) according to different transfection conditions. A scratch test was applied to analyze cell migration, and a Transwell assay was used to test cell invasion ability. Western blotting was to measure matrix metalloproteinase (MMP)-2, MMP-9, and the tissue inhibitor of metalloproteinase 2 (TIMP2) protein levels. qRT-PCR indicated that LINC00312 expression was lower but miR-197-3p expression was higher in BC tissues compared with adjacent tissues; LINC00312 was negatively correlated with miR-197-3p. The migration test revealed that the downregulation of miR-197-3p and overexpression of LINC00312 inhibited cell migration and invasion abilities, while the overexpression of miR-197-3p and the upregulation of LINC00312 promoted cell migration and invasion. BC cells with downregulated miR-197-3p or upregulated LINC00312 had low MMP-2 and MMP-9 levels but high TIMP2. LINC00312 inhibited BC cell invasion and metastasis through mediating miR-197-3p.

WTAP mediated m6A-modified circ_0056856 contributes to the proliferation, migration, and invasion of IL-22-stimulated human keratinocyte by miR-197-3p/CDK1 axis.

BACKGROUND: Psoriasis is a chronic inflammation-associated skin disorder, and interleukin-22 (IL-22) is involved in psoriasis pathogenesis by boosting the proliferation and migration of keratinocytes. Mounting evidence has shown that circRNAs might play an important role in several aspects of psoriasis. This study is designed to explore the role and mechanism of circ_0056856 in regulating the phenotypes of IL-22-induced keratinocytes (HaCaT cells). METHODS: Circ_0056856, microRNA-197-3p (miR-197-3p), Cyclin-dependent kinase 1 (CDK1), and Wilms tumor 1-associated protein (WTAP) levels were detected using real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability, proliferation, migration, and invasion were analyzed using 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Wound scratch, and Transwell assays. After being predicted by Circinteractome or TargetScan, binding between miR-197-3p and circ_0056856 or CDK1 was verified by a dual-luciferase reporter assay. CDK1 and WTAP protein levels were determined using Western blot. Interaction between WTAP and circ_0056856 was assessed using methylated RNA immunoprecipitation (MeRIP) assay. RESULTS: Increased circ_0056856, CDK1, and WTAP were observed in psoriasis patients and IL-22-treated HaCaT cells. Moreover, circ_0056856 knockdown might repress IL-22-induced HaCaT cell proliferation, migration, and invasion in vitro. In mechanism, circ_0056856 might function as a sponge of miR-197-3p to modulate CDK1 expression, and WTAP improved circ_0056856 expression via m6A methylation. CONCLUSION: WTAP-guided m6A modified circ_0056856 facilitates IL-22-stimulated HaCaT cell damage through the miR-197-3p/CDK1 axis, which could provide novel insights into psoriasis treatment.

Circular RNA_0003800 exacerbates IL-1ß-induced chondrocyte injury via miR-197-3p/SOX5 axis.

BACKGROUND: Osteoarthritis (OA) is a serious degenerative disease of articular cartilage, which has a great impact on the quality of life of patients. Circular RNA (circRNA) plays an important role in OA progression. Our study aims to explore the role and mechanism of circ_0003800 in OA. METHODS: Circ_0003800, microRNA-197-3p (miR-197-3p) and SRY-box transcription factor 5 (SOX5) contents were measured by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Cell Counting Kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, western blot and enzyme-linked immunosorbent assay (ELISA) were deployed to evaluate cell proliferation, apoptosis, extracellular matrix (ECM) degradation, inflammatory response and oxidative stress. Interaction of miR-197-3p and circ_0003800 or SOX5 was evidenced by dual-luciferase reporter system, RNA immunoprecipitation (RIP) and RNA pull down assays. RESULTS: OA tissues and model cells had higher abundance of circ_0003800 and SOX5, while miR-197-3p content was lower. Functionally, circ_0003800 knockdown alleviated IL-1ß-mediated injury in C28/I2 cells. Mechanistically, circ_0003800 could sponge miR-197-3p, and miR-197-3p could target SOX5. Besides, in-miR-197-3p reversed the suppressive effect of circ_0003800 downregulation on IL-1ß-induced C28/I2 cell injury, and SOX5 overexpression could also diminish the inhibitory effect of miR-197-3p on IL-1ß-induced C28/I2 cell injury. CONCLUSION: Circ_0003800 exacerbates IL-1ß-induced chondrocyte injury via miR-197-3p/SOX5 axis.

Circ_103809 Aggravates the Malignant Phenotype of Pancreatic Cancer Through Modulating miR-197-3p/TSPAN3 Axis.

Pancreatic cancer (PC) is a malignant tumor with insidious clinical manifestations and dismal prognosis. Emerging reports have demonstrated that circRNAs exert pivotal biological function in PC. Here, we investigated the crucial biological role and underlying regulatory mechanisms of differentially expressed circ_103809 in PC. In this study, hsa_circ_103809 (hsa_circ_0072088) was identified as the research object via analyzing and screening the aberrantly expressed circRNAs in PC by GSE69362 dataset. The levels of circ_103809 in PC tissues and cells were assessed via qRT-PCR. Functional assays were conducted to monitor the impacts of circ_103809 on PC cells. Additionally, the downstream molecular targets and regulatory networks of circ_103809 were predicted by bioinformatics and validated using luciferase assays and rescue experiments. We found that circ_103809 was substantially upregulated in PC tissues and cells. Silencing circ_103809 restrained the growth viability, clonogenic rate, migration, and invasion capabilities of PC cells. Further mechanistic exploration disclosed that miR-197-3p was the downstream gene of circ_103809, while Tetraspanin-3 (TSPAN3) was a direct target of miR-197-3p. The suppressive effect of circ_103809 knockdown on malignant processes of PC cells was eliminated by miR-197-3p downregulation or TSPAN3 upregulation. Our study demonstrated that circ_103809 served as an innovative positive regulator in the growth and metastasis of PC cells. Furthermore, circ_103809 mediated the miR-197-3p/TSPAN3 axis to modulate the malignant progression of PC cells, which was prospected to be a probable biomarker and an efficient therapeutic target for PC.

miR-197-3p Promotes Osteosarcoma Stemness and Chemoresistance by Inhibiting SPOPL.

First-line treatment for osteosarcoma includes chemotherapy and surgery. However, the five-year survival rate of refractory osteosarcoma remains unsatisfactory. Osteosarcoma cancer stem cells, possessing stemness and chemoresistance, are one of the critical causes of poor response to chemotherapy. Elucidating regulatory signaling pathways of osteosarcoma cancer stem cells may provide a rationale for improving regimens against chemoresistant osteosarcoma. Methotrexate (MTX)-resistant osteosarcoma cells were established. microRNA expression profiles were used for detecting differentially expressed microRNA in resistant clones and the parental cells. microRNA target databases were employed to predict potential microRNA and mRNA interactions. Flow cytometry was performed to measure stem cell marker Prominin-1 (CD133)-positive cells. Immunofluorescence staining was applied to detect CD133 expression. miR-197-3p mimic or anti-miR-197-3p stably transfected cells were used to generate xenograft models. In the study, we found that miR-197-3p was increased in MTX-resistant cell lines. Overexpression of miR-197-3p enhanced the expression of cancer stem cell markers CD133, Octamer-binding protein 4 (OCT4), Transcription factor SOX-2 (SOX2), and Homeobox protein NANOG (NANOG), as well as chemoresistance-associated genes ATP-dependent translocase ABCB1 (ABCB1) and Broad substrate specificity ATP-binding cassette transporter ABCG2 (ABCG2), whereas miR-197-3p knockdown inhibited stemness and recovered sensitivity to MTX. We also classified the tumor suppressor Speckle-type POZ protein-like (SPOPL) as a target of miR-197-3p. The miR-197-3p mutation that could not combine SPOPL promoter regions was unable to sustain stemness or chemoresistance. Collectively, we discovered miR-197-3p conferred osteosarcoma stemness and chemotherapy resistance by targeting SPOPL, prompting promising therapeutic candidates for refractory osteosarcoma treatment.

Circ_0060055 Promotes the Growth, Invasion, and Radioresistance of Glioblastoma by Targeting MiR-197-3p/API5 Axis.

Circular RNA (circRNA) has been shown to be involved in the regulation of human disease progression. Our study aims to reveal the role of circ_0060055 in the progression of glioblastoma (GBM) and its potential molecular mechanism. The expression of circ_0060055, microRNA (miR)-197-3p, and apoptosis inhibitor 5 (API5) was determined by quantitative real-time PCR. GBM cell proliferation, apoptosis, and invasion were assessed using cell counting kit 8 assay, colony formation assay, EdU assay, flow cytometry, and transwell assay. Besides, the radiosensitivity of cells also was assessed using colony formation assay. The interaction between miR-197-3p and circ_0060055 or API5 was analyzed by dual-luciferase reporter assay and RNA pull-down assay. Animal experiments were conducted to measure the effect of circ_0060055 on GBM tumor growth and radiosensitivity in vivo. Circ_0060055 was overexpressed in GBM tumor tissues and cells, and its silencing suppressed GBM cell proliferation and invasion, while promoted apoptosis and radiosensitivity. In terms of mechanism, circ_0060055 could interact with miR-197-3p, and miR-197-3p could target API5. API5 expression also could be positively regulated by circ_0060055. Function experiments suggested that miR-197-3p inhibitor abolished the effect of circ_0060055 knockdown on GBM cell growth, invasion, and radiosensitivity. MiR-197-3p repressed GBM cell progression and improved radiosensitivity, and this effect was eliminated by API5 upregulation. In vivo experiments confirmed that circ_0060055 knockdown reduced GBM tumor growth and enhanced the radiosensitivity of tumors. This study revealed that circ_0060055 contributed to GBM progression and radioresistance through miR-197-3p/API5 pathway, providing a potential target for GBM treatment.

Circ-CCS enhances autophagy during imatinib resistance of gastrointestinal stromal tumor by regulating miR-197-3p/ATG10 signaling.

Context: Drug resistance in gastrointestinal stromal tumors (GISTs) is connected with autophagy activation. Accumulating data demonstrates the critical role of circular RNAs (circRNAs) dysregulation in this development. Aim: To explore the possible function of hsa_circ_0092306 (circ-CCS) in GIST imatinib resistance. Materials and Methods: Quantitative real-time reverse transcription PCR (RT-qPCR) was used to determine the expression levels of circ-CCS and miR-197-3p. The vitality and apoptosis of cells were determined using the Cell Counting Kit-8 and TUNEL assays, respectively. Western blot analysis was used to evaluate the relative protein expression. A dual-luciferase reporter assay was used to validate the link between circ-CCS, miR-197-3p, and ATG10. Statistical Analysis Used: Comparisons of two groups were analyzed using Student's t tests, and analysis of variance (ANOVA) with Tukey's post hoc test was used to compare three or more groups. Results: Circulating-CCS expression was considerably increased in the serum of imatinib-resistant GIST patients (P < 0.001). Circulating-CCS deficiency decreased cell proliferation and autophagy in GIST-882 and GIST-T1 cells, but promoted apoptosis (P < 0.05). Additionally, circ-CCS was predominantly found in the cytoplasm. Mechanically, circ-CCS targeted miR-197-3p, which may influence autophagy by downregulating ATG10, in order to modulate GIST cells' malignant tendencies. Moreover, silencing miR-197-3p reversed the effect of circ-CCS knockdown on apoptosis and autophagy in GIST cells. Conclusions: By modulating the miR-197-3p/ATG10 axis, circ-CCS increased imatinib resistance in GIST cells, establishing a potential target for reversing medication resistance in such patients.

Silencing circular RNA-friend leukemia virus integration 1 restrained malignancy of CC cells and oxaliplatin resistance by disturbing dyskeratosis congenita 1.

Circular-RNA friend leukemia virus integration 1 (circ-FLI1; hsa_circ_0000370) is a noninvasive biomarker for the diagnosis of colon carcinoma (CC). Herein, we intended to investigate its functions and competing endogenous RNA (ceRNA) mechanisms in CC cells. In terms of expression status, circ-FLI1 was abnormally upregulated in CC patients' tumors and cells, paralleled with DKC1 upregulation and miR-197-3p downregulation. Most strikingly, there was a direct target relationship between miR-197-3p and circ-FLI1 or DKC1 based on the starbase database, dual-luciferase reporter assay, and RNA immunoprecipitation. Functionally, the colony formation assay, MTS method, fluorescence-activated cell sorting method, cell cycle and apoptosis assays, and transwell assays were performed, and the results revealed that interfering circ-FLI1 and re-expressing miR-197-3p could restrict colony formation, cell viability, cell cycle progression, and migration/invasion of CC cells with apoptosis rate elevation; besides, they promoted oxaliplatin (L-OHP)-induced cell viability inhibition. Furthermore, there were counteractive effects between circ-FLI1 silencing and miR-197-3p depletion, miR-197-3p overexpression and DKC1 restoration on regulating CC cell functions and L-OHP resistance. With a xenograft tumor model, the anti-growth role of circ-FLI1 silencing was also found in vivo with or without L-OHP treatment. Collectively, we demonstrated that circ-FLI1 might confer L-OHP resistance and malignant progression of CC presumably through the circ-FLI1/miR-197-3p/DKC1 ceRNA axis.

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.

CircMMD_007 promotes oncogenic effects in the progression of lung adenocarcinoma through microRNA-197-3p/protein tyrosine phosphatase non-receptor type 9 axis.

Circular RNAs play important roles in cancer biology. In this research, we explored the underlying function and mechanism of cirMMD_007 in lung adenocarcinoma (LC). Clinical lung adenocarcinoma samples were obtained from surgery. Bioinformatic databases were used to predict miRNAs that can potentially target circRNAs and miRNA target genes. hsa_circMMD_007, miR-197-3p, and PTPN9 mRNA expressions were investigated by qRT-PCR. Protein expressions were examined using Western blot. The proliferation abilities were assessed by Cell Counting Kit-8 assays. Wound healing cell migration assay was applied to evaluate cell migration ability. Luciferase reporter assay and rescue experiments were then performed to elucidate the underlying mechanism. We found that the expression of circMMD_007 was abnormally increased in LC. The expression of circMMD_007 was higher in advanced stages. Knockout of circMMD_007 hindered the tumorigenesis of LC in vivo and in vitro. circMMD_007 could negatively regulate the expression of miR-197-3p. PTPN9 behaved to be a molecular target of miR-197-3p. In summary, this research demonstrated that circular RNA circMMD_007 could promote the oncogenic effects in the progression of LC through miR-197-3p/PTPN9 axis.

MiR-197-3p reduces bortezomib resistance in multiple myeloma by inhibiting IL-6 expression in a MEAF6-dependent manner.

OBJECTIVE: This study investigated the mechanism by which miR-197-3p regulated IL-6 expression and reduced bortezomib (BTZ) resistance in multiple myeloma (MM). METHODS: The expression of miR-197-3p, MEAF6 and IL-6 in BTZ-resistant MM cells was measured. The effects of miR-197-3p/IL-6 axis on drug resistance and cell apoptosis were evaluated in BTZ-resistant MM cells. The expression of JAK/STAT3 proteins was detected by Western blotting. The binding of miR-197-3p to MEAF6 mRNA was verified using molecular biology techniques. Chromatin immunoprecipitation was used to assess histone acetylation in IL-6 promoter. The effect of miR-197-3p on MM growth was investigated in a mouse model. RESULTS: MiR-197-3p was lowly expressed, and MEAF6 and IL-6 were highly expressed in BTZ-resistant MM cells. Overexpression of miR-197-3p increased drug sensitivity in BTZ-resistant MM cells, which was counteracted by overexpression of IL-6. Overexpression of miR-197-3p also inhibited MM growth in vivo. Mechanistically, miR-197-3p suppressed the expression of IL-6 by inhibiting MEAF6-mediated histone H3 acetylation in IL-6 promoter. The miR-197-3p/IL-6 axis also inhibited the activation of JAK/STAT3 signaling pathway. CONCLUSION: miR-197-3p reduces BTZ resistance in MM by inhibiting acetylation-mediated expression of IL-6 and by inactivating JAK/STAT3 signaling pathway.

MiR-197-3p affects angiogenesis and inflammation of endothelial cells by targeting CXCR2/COX2 axis.

BACKGROUND: Decreased circulating miR-197-3p was found in patients with recurrent deep vein thrombosis (DVT), but the specific role of miR-197-3p needs further exploration. MATERIALS AND METHODS: Venous blood samples were collected from DVT patients and healthy controls, and peripheral blood mononuclear cells (PBMCs) were isolated to examine the expression patterns of miR-197-3p, CXCR2 and COX2 by qRT-PCR. Human umbilical vein endothelial cells (HUVECs) were further used as a cellular model to investigate the role of the miR-197-3p/CXCR2/COX2 axis in regulating cell viability, angiogenesis, and inflammation, which were determined by MTT assay, Matrigel-based tube formation assay, and enzyme-linked immunosorbent assay, respectively. Dual-luciferase reporter assay was used to examine the interactions between miR-198-3p and CXCR2. Expression of NF-κB p65 was examined by western blot to investigate whether the NF-κB pathway was involved in the regulatory effect of miR-197-3p on DVT. RESULTS: miR-197-3p was decreased in PBMCs of patients with DVT, while CXCR2 and COX2 were increased compared to the healthy controls. In HUVECs, overexpression of miR-197-3p reduced CXCR2 levels and inhibited cell viability, angiogenesis, and release of inflammatory cytokines including TNF-α, IL-1ß, and IL-6, which were reversed by miR-197-3p inhibition. Dual-luciferase reporter assay indicated miR-197-3p directly bound to CXCR2. CXCR2 further upregulated the expression of COX2 and activated the NF-κB pathway, promoting cell viability, angiogenesis and release of inflammatory cytokines in HUVECs. The effect of miR-197-3p inhibition on cell viability, angiogenesis and inflammation of HUVECs could be reversed by CXCR2 silencing. CONCLUSION: MiR-197-3p affected viability, angiogenesis and inflammation of endothelial cells by targeting CXCR2/COX2 axis in vitro. Our findings provided a novel theoretical basis to investigate more effective therapies for DVT.

MiR-193-3p inhibits the malignant progression of atherosclerosis by targeting WDR5.

BACKGROUND: The aberrantly increased proliferation and migration of vascular smooth muscle cells (VSMCs) was critically associated with atherosclerosis (AS) progression. MiR-197-3p has been confirmed to regulate various biological processes, such as tumorigenesis; however, whether miR-197-3p is involved with the pathological development of AS remains largely unknown. METHODS: The serum levels of miR-197-3p in AS patients and healthy donors were determined by polymerase chain reaction (PCR) assay. The transfection efficacies of miR-197-3p mimic or inhibitor in VSMCs were evaluated by PCR assay. The effects of miR-197-3p on VSMC proliferation and migration were determined by EdU cell proliferation and Traswell migration assays. Western blotting was conducted to evaluate the effect of miR-197-3p on WDR5 expression in VSMCs. RESULTS: In the present study, we found that the expression of miR-197-3p was decreased in the serum of AS patients compared to healthy donors. Overexpression of miR-197-3p inhibited the proliferation and migration of VSMCs, while silencing miR-197-3p showed opposite effects. Mechanistical study revealed that WD Repeat Domain 5 (WDR5) was a target of miR-197-3p. Moreover, miR-197-3p was downregulated in VSMCs upon IL6 treatment and inhibited IL6-induced proliferation and migration in VSMCs. CONCLUSIONS: These findings indicate that miR-197-3p could serve as a promising diagnostic marker for AS and that targeting IL6/miR-197-3p/WDR5 axis might be a potential approach to treat AS.