Overexpressed circ_0067934 acts as an oncogene to facilitate cervical cancer progression via the miR-545/EIF3C axis

Circular RNAs were recently identified as a novel type of noncoding RNAs. An increasing number of reports have demonstrated their essential regulatory roles in various biological processes and human diseases, including cancer. However, the role of circRNA in cervical cancer (CC) remains largely unknown. In the current study, we investigated the physiological functions of circ_0067934 during CC development and progression. We found that circ_0067934 was overexpressed in CC tissues and cell lines. Circ_0067934 upregulation was associated with advanced stage, lymph node metastasis, and poor prognosis in CC patients. Knockdown of circ_0067934 suppressed the proliferation, colony formation, migration, invasion, and epithelial-mesenchymal transition of CC cells in vitro. Circ_0067934 loss also inhibited CC tumor growth in vivo. Mechanistically, silencing circ_0067934 increased miR-545 expression. MiR-545 repressed EIF3C expression through targeting its 3′-untranslated region. MiR-545 suppressed the proliferation, migration, and invasion of CC cells, whereas restoration of EIF3C could rescue the effects of circ_0067934 knockdown. Taken together, our findings revealed that circ_0067934 promotes CC progression via miR-545/EIF3C axis. Our study may provide a new insight into the pathogenesis of CC.     

miR-224-5p inhibits proliferation,migration, and invasion by targeting PIK3R3/AKT3 in uveal melanoma

Uveal melanoma (UM) is the most common primary intraocular malignancy in adults. Accumulating investigations have identified the aberrant expression of miRNAs (microRNAs) in UM, such as miR-181, miR-20a, miR-144, miR-146a. The purpose of this study is to investigate the biological function of miR-224-5p in UM. The expression of miR-224-5p, PIK3R3, and AKT3 in 30 tumor tissues and paired adjacent noncancerous tissues were analyzed using Western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR) assays. Cell proliferation assay, transwell assay, and wound healing assay were used to measure the effects of miR-224-5p on the motility of UM in vitro. Western blot analysis and luciferase assays were used to detect the expression of PIK3R3 and AKT3 as miR-224-5p downstream targets. The results of Western blot analysis and qRT-PCR assays indicated that the expression of miR-224-5p was lower in UM tissues compared to normal tissue, while the expression of PIK3R3 and AKT3 were simultaneously increased. Upregulation of miR-224-5p significantly inhibited capacities of proliferation, invasion, and migration of OCM-1A cells and decreased expression of PIK3R3 and AKT3. Luciferase assay demonstrated PIK3R3 and AKT3 as downstream targets of miR-224-5p. Moreover, upregulating PIK3R3 and AKT3 restrained miR-224-5p-induced inhibition of the motility of OCM-1A cells. Thus, our study proved that miR-224-5p was involved in proliferation, invasion, and migration of UM cells via regulation the expression of PIK3R3 and AKT3. And the results also established a miR-224-5p/PIK3R3/PI3K/AKT axis in the regulation of UM progression, providing an experimental basis for further exploring the miR-224-5p as a therapeutic and diagnosis target for patients with UM.     

Upregulation of miR-582-5p regulates cell proliferation and apoptosis by targeting AKT3 in human endometrial carcinoma

The human endometrial carcinoma is one of the most common female malignancies, and there is an urgent requirement to explore new therapeutic strategies. There is accumulating evidence that microRNAs (miRNAs) can serve as potential diagnostic and prognostic biomarkers for various types of cancer, but the significance of miR-582-5p still remains largely unknown in the endometrial carcinoma. The aims of this study were to understand and identify the influence of miR-582-5p on the proliferation and apoptosis of human endometrial carcinoma and its relevant mechanism. First, quantitative real-time PCR (qRT-PCR) was used to detect miR-582-5p and AKT3 expression in human tissue samples and cells. Then, CyQuant assay and 2D colony assay were employed to evaluate cell proliferation. Western blotting was used to determine protein expression. Subsequently, the luciferase reporter assay was used to identify the target of miR-582-5p. Finally, Annexin V assay was used to detect cell apoptosis. We found that miR-582-5p expression was significantly decreased in human endometrial carcinoma tissues, and miR-582-5p upregulation in human endometrial carcinoma cells inhibit cell proliferation and promote apoptosis. Moreover, AKT3 was validated as a target of miR-582-5p and AKT3 expression was inversely correlated with miR-582-5p expression. Besides, AKT3 upregulation efficiently abrogates the effect of miR-582-5p on the cells. These results demonstrated that miR-582-5p regulates cell proliferation and apoptosis in human endometrial carcinoma via AKT3. Thus, miR-582-5p represents a potential therapeutic target in human endometrial carcinoma meriting further investigation.     

Circular RNA hsa_circ_0011385 contributes to cervical cancer progression through sequestering miR-149–5p and increasing PRDX6 expression

Cervical cancer (CC) is a common tumor in the female reproductive tract. Circular RNA hsa_circ_0011385 has been reported to be up-regulated in CC tissues. Nevertheless, the role and regulatory mechanism of hsa_circ_0011385 in CC are still being further verified. The levels of hsa_circ_0011385, microRNA (miR)? 149–5p, and peroxiredoxin 6 (PRDX6) mRNA in CC samples and cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Loss-of-function experiments were performed to survey the impacts of hsa_circ_0011385 inhibition on CC cell proliferation, colony formation, cycle progression, apoptosis, metastasis, invasion, and angiogenesis. Protein levels were detected by western blotting. The relationship between hsa_circ_0011385 or PRDX6 and miR-149–5p was verified by dual-luciferase reporter, RNA immunoprecipitation (RIP), and/or RNA pull-down assays. The tumorigenesis role of hsa_circ_0011385 in CC was confirmed by xenograft assay. We observed that hsa_circ_0011385 and PRDX6 were up-regulated while miR-149–5p was down-regulated in CC samples and cell lines. CC patients with high hsa_circ_0011385 expression possessed a shorter overall survival. Hsa_circ_0011385 knockdown reduced tumor growth in vivo and facilitated apoptosis, cell cycle arrest, impeded proliferation, metastasis, invasion, and angiogenesis of CC cells in vitro. Hsa_circ_0011385 could mediate PRDX6 expression through binding to miR-149–5p. MiR-149–5p silencing reversed hsa_circ_0011385 knockdown-mediated effects on CC cell angiogenesis and malignancy. PRDX6 overexpression overturned the inhibitory effects of miR-149–5p overexpression on angiogenesis and malignant behaviors of CC cells. In conclusion, hsa_circ_0011385 accelerated angiogenesis and malignant behaviors of CC cells by regulating the miR-149–5p/PRDX6 axis, manifesting that hsa_circ_0011385 might be a therapeutic target for CC.     

miR-4510 acts as a tumor suppressor in gastrointestinal stromal tumor by targeting APOC2

Dysregulation of microRNAs (miRNAs) expression has been demonstrated in gastrointestinal stromal tumor (GIST). In this study, we aimed to determine the differential miRNAs expression in GISTs and explore the functional mechanism of differential miRNAs in GIST cells. We measured differential miRNAs in six pairs of GIST tissues and matched adjacent tissues through a high-throughput sequencing, which was confirmed in 64 pairs of GIST tissues and adjacent tissues by real-time polymerase chain reaction. We found that miR-4510 expression was significantly downregulated in GIST tissues compared to matched control tissues. Luciferase reporter assay identified apolipoprotein C-II (APOC2) as a direct target of miR-4510. Overexpression of miR-4510 inhibited the mRNA and protein expression of APOC2. In addition, overexpression of miR-4510 suppressed GIST cell proliferation, migration, and invasion. Overexpression of miR-4510 also inhibited the phosphorylation of AKT and ERK1/2, reduced the expression of matrix metallopeptidase 2 (MMP2) and MMP9. APOC2 knockdown mimicked the effect of miR-4510 overexpression. Further investigation confirmed that APOC2 was notably upregulated in GIST tissues compared to adjacent control tissues. These results suggested that miR-4510 downregulation could promote GIST progression, including growth, invasion, and metastasis, through increasing APOC2 expression.     

MicroRNA-144 inhibits hepatocellular carcinoma cell proliferation,invasion and migration by targeting ZFX

MicroRNA 144 (miR-144), a small non-coding RNA, is frequently dysregulated in human several tumour progression, but its role and the underlying mechanisms in hepatocellular carcinoma (HCC) is poorly investigated. In the present study, the expression of miR-144 was firstly analysed in datasets derived from GSE21362 and TCGA, and then detected in HCC tissues and cell lines by quantitative RT-PCR (qRT-PCR) analysis. MiR-144 was shown to be significantly down-regulated in HCC tissues and cell lines. Subsequently, overexpression of miR-144 was transfected into HCC cell lines so as to investigate its biological function, including MTT, colony formation, and transwell assays. Gain of function assay revealed miR-144 remarkably inhibited cell proliferation, migration and invasion. In addition, bioinformatical analysis and luciferase reporter assay identified ZFX as a novel target of miR-144 in HCC cells, as confirmed by qRT-PCR and Western blot. Furthermore, ZFX was found to be significantly up-regulated using Oncomine database analysis. Loss of function assay further indicated knockdown of ZFX had similar effects of miR-144-mediated HCC cell proliferation and invasion. Therefore, miR-144 has been demonstrated to act as a tumour suppressor in HCC cell growth and motility by directly targeting ZFX, which implicates its potential applications in the development of HCC treatment.     

Hsa_circ_0001495 contributes to cervical cancer progression by targeting miR-526b-3p/TMBIM6/mTOR axis

Cervical cancer (CC) is a common gynecological malignant tumor, causing poor survival rate. Circular RNAs (circRNAs) are abundantly expressed in CC with their stable loop structure. However, the underlying mechanism and biological function of circRNAs remained unclear. Using quantitative real-time polymerase chain reaction (qRT-PCR) or western blot assay, we measured the expression of hsa_circ_0001495, miR-526b-3p, and transmembrane Bax inhibitor motif containing 6 (TMBIM6) in CC tissues and cells. The relationship between miR-526b-3p and hsa_circ_0001495 or TMBIM6 was investigated by bioinformatics analysis, dual-luciferase and RIP analysis. Enzyme linked immunosorbent assay (ELISA) was conducted to evaluate glucose consumption and lactate production. 5-ethynyl-2′-deoxyuridine (EDU) assay were used to test cell proliferation. Cell apoptosis was analyzed by using flow cytometry assay. Transwell and wound-healing assays were used to measure cell invasion and migration. The expression of proteins was examined by western blot. Xenograft assay was applied to detect the effect of hsa_circ_0001495 in vivo. Our finding showed that hsa_circ_0001495 and TMBIM6 expression were upregulated, while miR-526b-3p was downregulated in CC tissues and cell lines. Hsa_circ_0001495 knockdown or TMBIM6 knockdown suppressed cell proliferation, migration, glycolysis, while promoted cell apoptosis in vitro, and hsa_circ_0001495 silence curbed tumor growth in vivo. Beside, hsa_circ_0001495 exerted its function in CC by positively regulating TMBIM6. Furthermore, hsa_circ_0001495 acted as a sponge for miR-526b-3p to regulate TMBIM6 expression. Hsa_circ_0001495/miR-526b-3p/TMBIM6 axis also regulated the phosphorylation of mammalian target of rapamycin (mTOR) in CC cells. In summary, hsa_circ_0001495 regulated the progression of CC by regulating miR-526b-3p/TMBIM6/mTOR pathway.     

MicroRNA-137 Contributes to Dampened Tumorigenesis in Human Gastric Cancer by Targeting AKT2

MiRNAs play important roles in tumorigenesis. This study focused on exploring the effects and regulation mechanism of miRNA-137 on the biological behaviors of gastric cancer. Total RNA was extracted from tissues of 100 patients with gastric cancer and from four gastric cancer cell lines. Expression of miR-137 was detected by real-time PCR from 100 patients. The effects of miR-137 overexpression on gastric cancer cells’ proliferation, apoptosis, migration and invasion ability were investigated in vitro and in vivo. The target gene of miR-137 was predicted by Targetscan on line software, screened by dual luciferase reporter gene assay and demonstrated by western blot. As a result, the expression of miR-137 was significant reduced in gastric cancer cell line HGC-27, HGC-803, SGC-7901 and MKN-45 as well as in gastric cancer tissues compared with GES-1 cell or matched adjacent non-neoplastic tissues (p<0.001). The re-introduction of miR-137 into gastric cancer cells was able to inhibit cell proliferation, migration and invasion. The in vivo experiments demonstrated that the miR-137 overexpression can reduce the gastric cancer cell proliferation and metastasis. Bioinformatic and western blot analysis indicated that the miR-137 acted as tumor suppressor roles on gastric cancer cells through targeting AKT2 and further affecting the Bad and GSK-3β. In conclusion, the miR-137 which is frequently down-regulated in gastric cancer is potentially involved in gastric cancer tumorigenesis and metastasis by regulating AKT2 related signal pathways.     

lncRNA MIR503HG functioned as a tumor suppressor and inhibited cell proliferation,metastasis and epithelial-mesenchymal transition in bladder cancer

Bladder cancer is the most common malignancy with high recurrence. Currently, the long noncoding RNAs (lncRNAs) have been suggested to play vital roles in the pathogenesis of bladder cancer. The present study investigated the role of lncRNA MIR503 host gene (MIR503HG) in the pathogenesis of bladder cancer by using both in vitro and in vivo functional assays. The expression of MIR503HG was downregulated in bladder cancer tissues and cell lines. Low expression of MIR503HG was associated with advanced tumor stage, advanced histological grade, and lymph node metastasis. Ectopic expression of MIR503HG inhibited cell proliferation, cell growth, cell invasion, and migration, and also promoted cell apoptosis and inhibited cell cycle progression in SW780 cells. In parallel, T24 cells were used for loss-of-function studies. Knockdown of MIR503HG promoted the cancer cell proliferation and increased the migration and invasion abilities of T24 cells. In addition, knockdown of MIR503HG reduced the cell apoptotic rate in cancer cells and promoted cell cycle progression. Furthermore, MIR503HG overexpression decreased the epithelial-mesenchymal transition-related mRNA and protein levels of ZEB1, Snail, N-cadherin, and vimentin, with an increase in E-cadherin level. Consistently, knockdown of MIR503HG showed the opposite effects. In vivo xenograft, nude mice results showed that overexpression of MIR503HG suppressed the tumor growth and tumor metastasis. In conclusion, our results identified a novel lncRNA MIR503HG that exhibited significant antiproliferation, antimigration/invasion effects on bladder cancer cells both in vitro and in vivo, which may hold a therapeutic promise to treat bladder cancer.     

Circ_0005615 promotes cervical cancer cell growth and metastasis by modulating the miR-138-5p/KDM2A axis

Cervical cancer (CC) is a highly fatal gynecological malignancy due to its high metastasis and recurrence rate. Circular RNA (circRNA) has been regarded as a regulator of CC. However, the underlying molecular mechanism of circ_0005615 in CC remains unclear. The levels of circ_0005615, miR-138-5p, and lysine demethylase 2A (KDM2A) were measured using qRT-PCR or western blot. Cell proliferation was assessed by Cell Counting Kit-8, 5-ethynyl-2′-deoxyuridine, and colony formation experiments. Cell invasion and migration were tested by transwell assay and wound healing assay. Flow cytometry and Caspase-Glo 3/7 Assay kit were used to analyze cell apoptosis. The expression of proliferation-related and apoptosis-related markers was detected by western blot. The binding relationships among circ_0005615, miR-138-5p, and KDM2A were verified by dual-luciferase reporter assay or RNA immunoprecipitation assay. Xenograft assay was applied to detect the effect of circ_0005615 in vivo. Circ_0005615 and KDM2A were upregulated, while miR-138-5p was downregulated in CC tissues and cells. Circ_0005615 knockdown retarded cell proliferation, migration, and invasion, while promoting apoptosis. Besides, circ_0005615 sponged miR-138-5p, and miR-138-5p could target KDM2A. miR-138-5p inhibitor reversed the regulation of circ_0005615 knockdown on CC cell growth and metastasis, and KDM2A overexpression also abolished the inhibitory effect of miR-138-5p on CC cell growth and metastasis. In addition, we also discovered that circ_0005615 silencing inhibited CC tumor growth in vivo. Circ_0005615 acted as a tumor promoter in CC by regulating the miR-138-5p/KDM2A pathway.     

Circ_0004015 silencing represses cisplatin chemoresistance and tumor progression by reducing KLF8 in a miR-198-dependent manner in non-small cell lung cancer

Circular RNA (circRNA) plays vital roles in diverse cancer progression, including non-small cell lung cancer (NSCLC). Herein, the role of circ_0004015 in regulating the sensitivity of NSCLC to cisplatin (DDP) is revealed. The RNA expression of circ_0004015, microRNA-198 (miR-198) and kruppel like factor 8 (KLF8) was detected by quantitative real-time polymerase chain reaction. Protein expression was checked by western blot. The half maximal inhibitory concentration of DDP and cell proliferation were determined by cell counting kit-8 assay. Cell colony formation ability, migration, invasion and apoptosis were investigated by colony-forming assay, transwell assay and flow cytometry analysis, respectively. The effect of circ_0004015 knockdown on DDP sensitivity in vivo was demonstrated by mouse model assay. The interactions among circ_0004015, miR-198 and KLF8 were predicted by bioinformatics methods, and identified by mechanism assays. The expression of circ_0004015 and KLF8 was apparently upregulated, while miR-198 expression was downregulated in DDP-resistant NSCLC tissues and cells compared with control groups. Additionally, circ_0004015 silencing repressed DDP resistance, cell proliferation, migration and invasion, but induced cell apoptosis in DDP-resistant NSCLC cells. Circ_0004015 knockdown promoted the effect of DDP on tumor formation in vivo. Also, miR-198 inhibitors attenuated circ_0004015 depletion-mediated action though associating with circ_0004015. MiR-198 regulated DDP sensitivity and NSCLC progression by targeting KLF8. Furthermore, circ_0004015 modulated KLF8 expression through interaction with miR-198. Circ_0004015 conferred DDP resistance and promoted NSCLC progression by miR-198/KLF8 pathway, proving a potential target for studying DDP-mediated treatment of NSCLC.     

miR-141 suppresses proliferation and motility of gastric cancer cells by targeting HDGF

miR-141 belongs to the miR-200 family, and has been found to be associated with numerous human malignancies; however, its role in gastric cancer (GC) has not been examined in detail. Here, we validated that miR-141 was decreased in GC tissues and cell lines. Forced expression of miR-141 significantly repressed GC cell proliferation and colony formation. Furthermore, miR-141 suppressed in vitro migration and invasion of GC cells. Hepatoma-derived growth factor (HDGF) was confirmed to be a direct target of miR-141 in GC cells. The suppressive effects of miR-141 on GC cell proliferation, colony formation, in vitro migration, and invasion were partially mediated by suppressing HDGF expression. Moreover, the expression of HDGF was negatively correlated with miR-141 in GC tissues. Our data suggest that miR-141 might be associated and plays essential role in GC progression.     

miR-760 exerts an antioncogenic effect in esophageal squamous cell carcinoma by negatively driving fat metabolism via targeting c-Myc

miR-760 is downregulated in various human tumors, and fat metabolism disorder correlates with tumor progression, especially anomalism of key fat metabolic enzymes that are positively modulated by c-Myc. The aim of our study is to elucidate the presumptive molecular mechanisms of miR-760-mediated esophageal squamous cell carcinoma (ESCC) cell function and to assess the therapeutic significance of miR-760 in ESCC patients. Quantitative real-time PCR (RT-qPCR) analysis indicated that miR-760 was significantly downexpressed in ESCC tissues and cell lines. Cell counting kit-8 (CCK-8) assay, colony formation assay, transwell assay, and flow cytometry denoted that induced ectopic overexpression of miR-760 dramatically inhibited ESCC cells proliferation, attenuated migration, and invasion facilitated apoptosis in vitro. Mechanistically, c-Myc predicted using bioinformatics was identified as a potential target gene of miR-760 by luciferase reporter assay. Furthermore, mRNA and protein expression levels of c-Myc and key fat metabolic enzymes were downregulated with miR-760 mimics. The above investigation results, responsible for the antineoplastic properties of miR-760 in ESCC, preliminarily highlighted that the hypothetical signal amongst miR-760, c-Myc, and key fat metabolic enzymes may develop a novel diagnostic marker, therapeutic target, and independent prognostic indicator.     

The novel circ_0084904/miR-802/MAL2 axis promotes the development of cervical cancer

Circular RNAs (circRNAs) have been identified as critical regulators in human cancers, including cervical cancer (CC). However, the precise action of circ_0084904 in cervical carcinogenesis remains to be elucidated. The levels of circ_0084904, microRNA (miR)-802, and Mal, T cell differentiation protein 2 (MAL2) were checked by quantitative real-time PCR (qRT-PCR) or western blot. Ribonuclease R (RNase R) and subcellular localization assays were used to detect the stability and localization of circ_0084904, respectively. Cell colony formation ability was assessed by colony formation assay. Cell cycle and apoptosis were detected by flow cytometry. Cell migration and invasion abilities were gauged by transwell assay. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were applied to determine the direct relationship between miR-802 and circ_0084904 or MAL2. The xenograft experiments were performed to evaluate the role of circ_0084904 in tumor growth in vivo. Circ_0084904 was markedly up-regulated in CC tissues and cell lines. Silencing endogenous circ_0084904 impeded cell colony formation, cell cycle progression, migration, invasion, epithelial-mesenchymal transition (EMT), and promoted apoptosis in vitro, as well as diminished tumor growth in vivo. Mechanistically, circ_0084904 targeted miR-802, and the effects of circ_0084904 silencing were mediated by miR-802. MAL2 was directly targeted and inhibited by miR-802, and MAL2 was a functional target of miR-802. Moreover, circ_0084904 modulated MAL2 expression via miR-802. Our study identified circ_0084904 as a novel oncogenic driver in CC depending on the modulation of the miR-802/MAL2 axis, establishing the notion that silencing of circ_0084904 might represent a promising targeted therapy for CC.