scholarly journals Silencing of ANKRD12 circRNA induces molecular and functional changes associated with invasive phenotypes

2018 ◽  
Author(s):  
Thasni Karedath ◽  
Ikhlak Ahmed ◽  
Wafa Al Ameri ◽  
Fatima M. Al-Dasim ◽  
Simeon S. Andrews ◽  
...  

ABSTRACTCircular RNAs (circRNA) that form through non-canonical backsplicing events of pre-mRNA transcripts are evolutionarily conserved and abundantly expressed across species. However, the functional relevance of circRNAs remains a topic of debate. In this study, we identified and characterized a circular RNA derived from Exon 2 and Exon 8 of the ANKRD12 gene, termed here as circANKRD12. We show that this circRNA is abundantly expressed in breast and ovarian cancers. The circANKRD12 is RNase R resistant and predominantly localized in the cytoplasm in contrast to its source gene mRNA. We confirmed the expression of this circRNA across a variety of cancer cell lines and provide evidence for its functional relevance through downstream regulation of several tumor invasion genes. We show that silencing of circANKRD12 induces a phenotypic change by significantly regulating cell cycle, increasing invasion and migration, altering the metabolism in cancer cells. These results reveal the functional significance of circANKRD12 and provide evidence of a regulatory role for this circRNA in cancer progression.

Author(s):  
Tong Li ◽  
Jianguo Xu ◽  
Yi Liu

An increasing number of studies have indicated that circular RNAs (circRNAs) participate in the progression of numerous tumors. However, the functions of circRNAs in glioblastoma (GBM) remain largely unknown. In this study, we focused on a novel circRNA (hsa_circRFX3_003) that was spliced from RFX3, which we named circRFX3. We confirmed that the expression of circRFX3 was substantially increased in GBM cell lines and clinical GBM tissues. The results of a series of overexpression and knockdown assays indicated that circRFX3 could boost the proliferation, invasion, and migration of GBM cells. By performing dual-luciferase reporter gene and RNA pull-down assays, we verified that circRFX3 could sponge microRNA-587 (miR-587) to exercise its function as a competing endogenous RNA (ceRNA) in the development of GBM. In addition, PDIA3 was proven to be a downstream target of miR-587 and to regulate the Wnt/β-catenin pathway. In conclusion, circRFX3 could act as a cancer-promoting circRNA to boost the development of GBM and regulate the miR-587/PDIA3/β-catenin axis. This study might provide a novel target for the treatment of GBM with molecular therapy.


Author(s):  
Haifeng Jin ◽  
Zheng Wu ◽  
Bibo Tan ◽  
Zhen Liu ◽  
Binqian Zhang

In recent years, there have been reports about the involvement of circular RNAs (circRNAs) in the pathogenesis of gastric cancer (GC), but the molecular mechanism in cell proliferation, invasion, and migration is still unclear. Based on The Cancer Genome Atlas (TCGA) database, we analyzed differentially expressed circRNAs between GC and non-tumor tissues. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis were used to clarify the functional role in GC. Here, we showed that circITGA7 was lowly expressed in GC tissues based on the TCGA database. In vitro, silencing the expression of circITGA7 increased cell proliferation and metastasis, whereas overexpression did the opposite. Mechanistically, miR-1471 has circITGA7 as a sponge, and miR-1471 has metadherin (MTDH) as a target gene. Consequently, functional analysis showed that the tumor suppressor effect of circITGA7 was the result of regulating the miR-1471/MTDH axis. Overall, the circITGA7/miR-1471/MTDH signaling pathway may play a crucial role in GC, providing a new potential mechanism involved in GC progression.


Author(s):  
Xianxiong Ma ◽  
Hengyu Chen ◽  
Lei Li ◽  
Feng Yang ◽  
Chuanqing Wu ◽  
...  

Abstract Background Circular RNAs (circRNAs) are a class of non-coding RNA that play critical roles in the development and pathogenesis of various cancers. The circRNA circGSK3B (hsa_circ_0003763) has been shown to enhance cell proliferation, migration, and invasion in hepatocellular carcinoma. However, the specific functions and underlying mechanistic involvement of circGSK3B in gastric cancer (GC) have not yet been explored. Our study aimed to investigate the effect of circGSK3B on the progression of GC and to identify any potential mechanisms underlying this process. Methods CircRNA datasets associated with GC were obtained from the PubMed, GEO, and ArrayExpress databases, and circRNAs were validated via RT-qPCR and Sanger sequencing. Biotin-labeled RNA pull-down, mass spectrometry, RNA immunoprecipitation, and in vitro binding assays were employed to determine proteins demonstrating interactions with circGSK3B. Gene expression regulation was assessed through RT-qPCR, chromatin immunoprecipitation, and western blot assays. Gain- and loss-of-function assays were used to analyze any effects of circGSK3B and its partner regulatory molecule (EZH2) on the proliferation, invasion, and migration abilities of GC cells both in vitro and in vivo. Results CircGSK3B was mainly identified in the nucleus. This circRNA was present at a reduced concentration in GC tissues and cell lines. Overexpression of circGSK3B was shown to inhibit the growth, invasion, and metastasis of GC cells both in vitro and in vivo. Mechanistically, circGSK3B directly interacted with EZH2, acting to suppress the binding of EZH2 and H3K27me3 to the RORA promoter, and leading to an elevation in RORA expression and ultimately the suppression of GC progression. Conclusions CircGSK3B acts as a tumor suppressor, reducing EZH2 trans-inhibition and GC progression. This demonstrates the potential use of this RNA as a therapeutic target for GC.


2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Haitian Chen ◽  
Shaofeng Zhang ◽  
Yanxin Wu ◽  
Zhuyu Li ◽  
Dongyu Wang ◽  
...  

Abstract Background Circular RNAs (circRNAs) has emerged as vital regulator involved in various diseases. In this study, we identified and investigated the potential circRNAs involved in gestational diabetes mellitus (GDM). Methods High-throughput sequencing was used to collect the plasma circRNAs expression profiles of GDM patients. Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was used to measure the expressions of circ_0008285 and circ_0001173 in the plasma specimens. The Pearson’s correlation test was employed to assess the correlation between 2 circRNAs expression and the clinicopathologic data. Two circRNAs expression was verified in high glucose (HG)-induced HTR-8/SVneo cells. MTS, transwell assay was used to evaluate the effects of circ_0008285 expression on HG-induced HTR-8/SVneo cells. The network of circ_0008285 was constructed using cytocape. Results In GDM patients, the expression of circ_0008285 was significantly upregulated, while that of circ_0001173 was decreased. Circ_0008285 was significantly correlated with the total cholesterol and LDL-C levels. Circ_0001173 was significantly correlated with glycated hemoglobin. HG promoted the proliferation, invasion, and migration in HTR-8/SVneo cells, while the knockdown of circ_0008285 exerted reverse effects. In addition, network construction exhibited that circ_0008285 had 45 miRNA binding sites, which correlated with 444 mRNA. Conclusions circ_0008285 plays an important role and provides a clue for the usage of therapeutic targets in the development of GDM.


2021 ◽  
Vol 22 (13) ◽  
pp. 7226
Author(s):  
Violeta Stojanovska ◽  
Aneri Shah ◽  
Katja Woidacki ◽  
Florence Fischer ◽  
Mario Bauer ◽  
...  

Cold shock Y-box binding protein-1 (YB-1) coordinates several molecular processes between the nucleus and the cytoplasm and plays a crucial role in cell function. Moreover, it is involved in cancer progression, invasion, and metastasis. As trophoblast cells share similar characteristics with cancer cells, we hypothesized that YB-1 might also be necessary for trophoblast functionality. In samples of patients with intrauterine growth restriction, YB-1 mRNA levels were decreased, while they were increased in preeclampsia and unchanged in spontaneous abortions when compared to normal pregnant controls. Studies with overexpression and downregulation of YB-1 were performed to assess the key trophoblast processes in two trophoblast cell lines HTR8/SVneo and JEG3. Overexpression of YB-1 or exposure of trophoblast cells to recombinant YB-1 caused enhanced proliferation, while knockdown of YB-1 lead to proliferative disadvantage in JEG3 or HTR8/SVneo cells. The invasion and migration properties were affected at different degrees among the trophoblast cell lines. Trophoblast expression of genes mediating migration, invasion, apoptosis, and inflammation was altered upon YB-1 downregulation. Moreover, IL-6 secretion was excessively increased in HTR8/SVneo. Ultimately, YB-1 directly binds to NF-κB enhancer mark in HTR8/SVneo cells. Our data show that YB-1 protein is important for trophoblast cell functioning and, when downregulated, leads to trophoblast disadvantage that at least in part is mediated by NF-κB.


Author(s):  
Mingyi Zhou ◽  
Zhuo Yang ◽  
Danbo Wang ◽  
Peng Chen ◽  
Yong Zhang

Abstract Background As a novel type of non-coding RNA, circular RNAs (circRNAs) play a critical role in the initiation and development of various diseases, including cancer. However, the exact function of circRNAs in human cervical cancer remains largely unknown. Methods We identified the circRNA signature of upregulated circRNAs between cervical cancer and paired adjacent normal tissues. Using two different cohorts and GEO database, a total of six upregulated circRNAs were identified with a fold change > 2, and P < 0.05. Among these six circRNAs, hsa_circ_0072088 (circZFR) was the only exonic circRNA significantly overexpressed in cervical cancer. Functional experiments were performed to investigate the biological function of circZFR. CircRNA pull-down, circRNA immunoprecipitation (circRIP) and Co-immunoprecipitation (Co-IP) assays were executed to investigate the molecular mechanism underlying the function of circZFR. Results Functionally, circZFR knockdown represses the proliferation, invasion, and tumor growth. Furthermore, circRNA pull-down experiments combined with mass spectrometry unveil the interactions of circZFR with Single-Stranded DNA Binding Protein 1 (SSBP1). Mechanistically, circZFR bound with SSBP1, thereby promoting the assembly of CDK2/cyclin E1 complexes. The activation of CDK2/cyclin E1 complexes induced p-Rb phosphorylation, thus releasing activated E2F1 leading to cell cycle progression and cell proliferation. Conclusion Our findings provide the first evidence that circZFR is a novel onco-circRNA and might be a potential biomarker and therapeutic target for cervical cancer patients.


2020 ◽  
Author(s):  
Nan Zhang ◽  
Yue Jin ◽  
Qiubo Hu ◽  
Shanshan Cheng ◽  
Chao Wang ◽  
...  

Abstract Background: Increasing researches have demonstrated the critical functions of circular RNAs (circRNAs) in the progression of malignant tumors, including ovarian cancer. In this study, we aim to investigate abnormally expression of hsa_circ_0078607 and the role of hsa_circ_0078607 during ovarian cancer pathogenesis.Methods: RT-PCR were used to detect the expression of circ_0078607 in ovarian cancer tissues. To determine the functional roles of circ_0078607 in ovarian cancer, cell proliferation and cell invasion assays were performed. Bioinformatics and luciferase reporter analysis were used to predict the target of circ_0078607.Results: In the present study, we first found that circ_0078607 was downregulated in ovarian cancer. Forced circ_0078607 expression significantly suppressed proliferation and promotes apoptosis of ovarian cancer cells. Mechanically, bioinformatics and luciferase reporter analysis identified that miR-518a-5p as a direct target of circ_0078607, while Fas as a direct target of miR-518a-5p. MiR-518a-5p negatively regulates Fas in ovarian cancer cells, while overexpression of circ_0078607 could increase the expression of Fas inhibited by miR-518a-5p. Furthermore, overexpression of circ_0078607 could inhibit the proliferation and invasion of ovarian cancer cells caused by miR-518a-5p mimic.Conclusion: The results of the present study revealed that circ_0078607 suppresses ovarian cancer progression by sponging oncogenic miR-518a-5p to induce Fas expression, which may provide new therapeutic approach for ovarian cancer.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Qinchen Cao ◽  
Yonggang Shi ◽  
Xinxin Wang ◽  
Jing Yang ◽  
Yin Mi ◽  
...  

AbstractCircular RNAs (circRNAs) are a newly identifed non-coding RNA in many cellular processes and tumours. This study aimed to investigate the role of hsa_circ_0037251, one circRNA generated from several exons of the gene termed METRN, in glioma progression. Through in vitro experiments, we discovered that high expression of hsa_circ_0037251 was related to low expression of the microRNA miR-1229-3p and high expression of mTOR. The over-expressed hsa_circ_0037251 promoted cell proliferation, invasion and migration in glioma, while knockdown of hsa_circ_00037251 promoted cell apoptosis and induced G1 phase arrest. Then, hsa_circ_0037251 was observed to directly sponge miR-1229-3p, and mTOR was identified as a direct target of miR-1229-3p. In addition, knockdown of hsa_circ_0037251 up-regulated the expression of miR-1229-3p and inhibited the expression of mTOR. And overexpression of miR-1229-3p or low-expressed mTOR inhibited the glioma cell progression. Furthermore, transfection with mTOR overexpression vectors can restore the abilities of glioma cell progression even if hsa_circ_00037251 was knocked down using siRNAs. In vivo experiments revealed that hsa_circ_00037251 promoted the growth of xenografted tumours and shortened the survival period. These results indicated that hsa_circ_0037251 may act as a tumour promoter by a hsa_circ_0037251/miR-1229-3p/mTOR axis, and these potential biomarkers may be therapeutic targets for glioma.


Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1406 ◽  
Author(s):  
Sun Tae Hwang ◽  
Min Hee Yang ◽  
Alan Prem Kumar ◽  
Gautam Sethi ◽  
Kwang Seok Ahn

Corilagin (CLG), a major component of several medicinal plants, can exhibit diverse pharmacological properties including those of anti-cancer, anti-inflammatory, and hepatoprotective qualities. However, there are no prior studies on its potential impact on the epithelial-to-mesenchymal transition (EMT) process. EMT can lead to dissemination of tumor cells into other organs and promote cancer progression. Hence, we aimed to investigate the effect of CLG on EMT and its mechanism(s) of action in tumor cells. We noted that CLG reduced the expression of various epithelial markers and up-regulated the expression of Occludin and E-cadherin in both basal and TGFβ-stimulated tumor cells. CLG treatment also abrogated cellular invasion and migration in colon and prostate carcinoma cells. In addition, CLG effectively attenuated the Wnt/β-catenin signaling cascade in TGFβ-stimulated cells. Overall, our study suggests that CLG may function as and effective modulator of EMT and metastasis in neoplastic cells.


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