Knockdown of circ_0067934 inhibits gastric cancer cell proliferation, migration and invasion via the miR‑1301‑3p/KIF23 axis

Role of microRNAs in tumor progression by regulation of kinesin motor proteins

Aberrant cell proliferation is one of the main characteristics of tumor cells that can be affected by many cellular processes and signaling pathways. Kinesin superfamily proteins (KIFs) are motor proteins that are involved in cytoplasmic transportations and chromosomal segregation during cell proliferation. Therefore, regulation of the KIF functions as vital factors in chromosomal stability is necessary to maintain normal cellular homeostasis and proliferation. KIF deregulations have been reported in various cancers. MicroRNAs (miRNAs) and signaling pathways are important regulators of KIF proteins. MiRNAs have key roles in regulation of the cell proliferation, migration, and apoptosis. In the present review, we discussed the role of miRNAs in tumor biology through the regulation of KIF proteins. It has been shown that miRNAs have mainly a tumor suppressor function via the KIF targeting. This review can be an effective step to introduce the miRNAs/KIFs axis as a probable therapeutic target in tumor cells.

The role of circRNAs in regulation of drug resistance in ovarian cancer

Ovarian cancer is one of the female reproductive system tumors. Chemotherapy is used for advanced ovarian cancer patients; however, drug resistance is a pivotal cause of chemotherapeutic failure. Hence, it is critical to explore the molecular mechanisms of drug resistance of ovarian cancer cells and to ameliorate chemoresistance. Noncoding RNAs (ncRNAs) have been identified to critically participate in drug sensitivity in a variety of human cancers, including ovarian cancer. Among ncRNAs, circRNAs sponge miRNAs and prevent miRNAs from regulation of their target mRNAs. CircRNAs can interact with DNA or proteins to modulate gene expression. In this review, we briefly describe the biological functions of circRNAs in the development and progression of ovarian cancer. Moreover, we discuss the underneath regulatory molecular mechanisms of circRNAs on governing drug resistance in ovarian cancer. Furthermore, we mention the novel strategies to overcome drug resistance via targeting circRNAs in ovarian cancer. Due to that circRNAs play a key role in modulation of drug resistance in ovarian cancer, targeting circRNAs could be a novel approach for attenuation of chemoresistance in ovarian cancer.

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.

Circ_0067934: a circular RNA with roles in human cancer

A circular RNA (circRNA) is a non-coding RNA (ncRNA) derived from reverse splicing from pre-mRNA and is characterized by the absence of a cap structure at the 5' end and a poly-adenylated tail at the 3' end. Owing to the development of RNA sequencing and bioinformatics approaches in recent years, the important clinical value of circRNAs has been increasingly revealed. Circ_0067934 is an RNA molecule of 170 nucleotides located on chromosome 3q26.2. Circ_0067934 is formed via the reverse splicing of exons 15 and 16 in PRKCI (protein kinase C Iota). Recent studies revealed the upregulation or downregulation of circ_0067934 in various tumors. The expression of circ_0067934 was found to be correlated with tumor size, TNM stage, and poor prognosis. Based on experiments with cancer cells, circ_0067934 promotes cancer cell proliferation, migratory activity, and invasion when overexpressed or downregulated. The potential mechanism involves the binding of circ_0067934 to microRNAs (miRNAs; miR-545, miR-1304, miR-1301-3p, miR-1182, miR-7, and miR-1324) to regulate the post-transcriptional expression of genes. Other mechanisms include inhibition of the Wnt/β-catenin and PI3K/AKT signaling pathways. Here, we summarized the biological functions and possible mechanisms of circ_0067934 in different tumors to enable further exploration of its translational applications in clinical diagnosis, therapy, and prognostic assessments.

Circ_0067934 as a novel therapeutic target in cancer: From mechanistic to clinical perspectives

Circular RNAs, as a type of non-coding RNAs, are identified in a various cell. Circular RNAs have stable structures, conserved sequence, and tissue and cell-specific level. High throughput technologies have proposed that circular RNAs act via various mechanisms like sponging microRNAs and proteins, regulating transcription factors, and scaffolding mediators. Cancer is one of the major threat for human health. Emerging data have proposed that circular RNAs are dysregulated in cancers as well as are associated with aggressive behaviors of cancer -related behaviors like cell cycle, proliferation, apoptosis, invasion, migration, and epithelial-mesenchymal transition (EMT). Among them, circ_0067934 was shown to act as an oncogene in cancers to enhance migration, invasion, proliferation, cell cycle, EMT, and inhibit cell apoptosis. In addition, these studies have proposed that it could be a promising diagnostic and prognostic biomarker in cancer. This study aimed to review the expression and molecular mechanism of circ_0067934 in modulating the malignant behaviors of cancers as well as to explore its potential as a target in cancer chemotherapy, diagnosis, prognosis and treatment.

Identification of m7G Methylation-Related miRNA Signature Associated with Survival and Immune Microenvironment Regulation in Uterine Corpus Endometrial Carcinoma

Background. N7-methylguanosine (m7G) has been implicated in the development of cancer. The role of m7G-related miRNAs in the survival prediction of UCEC patients has not been investigated. Current research was the first to construct an m7G-related miRNA model to accurately predict the survival of patients with uterine corpus endometrial carcinoma (UCEC) and to explore immune cell infiltration and immune activity in the tumor microenvironment. Methods. RNA-seq data and clinical information of UCEC patients were derived from The Cancer Genome Atlas (TCGA) database. Using the TargetScan online database, we predicted miRNAs linked to the m7G-related genes and identified miRNAs which were significantly associated with the survival in UCEC patients and constructed a risk scoring model. The TCGA-UCEC cases were scored according to the risk model, and the high- and low-risk groups were divided by the median risk value. Gene enrichment analysis and immune cell infiltration and immune function analysis were performed using “clusterProfiler” and “GSVA” packages in R. Results. The survival prediction model consisted of 9 miRNAs, namely, hsa-miR-1301, hsa-miR-940, hsa-miR-592, hsa-miR-3170, hsa-miR-876, hsa-miR-215, hsa-miR-934, hsa-miR-3920, and hsa-miR-216b. Survival of UCEC patients in the high-risk group was worse than that in the low-risk group ( $p<0.001$ ). The receiver operating characteristic (ROC) curve showed that the model had good predictive performance, and the area under the curve was 0.800, 0.690, and 0.705 for 1-, 3-, and 5-year survival predictions, respectively. There were differences in the degree of immune cell infiltration and immune activity between the low-risk and high-risk groups. The expression levels of the identified differentially expressed genes correlated with the susceptibility to multiple anticancer drugs. Conclusions. The survival prediction model constructed based on 9 m7G-related miRNAs had good predictive performance.

Overexpression of hsa_circ_0061817 Can Inhibit the Proliferation and Invasion of Lung Cancer Cells Based on Active Compounds

Objective. This study was aimed at investigating the expression level of hsa_circ_0061817 in lung adenocarcinoma cells and its effect on cell proliferation and invasion and the possible mechanism of hsa_circ_0061817 in lung adenocarcinoma. Methods. The overexpression plasmids of hsa_circ_0061817 (OE-hsacirc_0061817) were transfected into human lung A549 cells and mouse LLC-LUC cells, respectively. The cell viability was detected by CCK-8, and the cell proliferation was detected by cell clone formation assay and EdU assay. Transwell test was used to detect the ability of cell invasion, and apoptosis was detected by flow cytometry. WB was applied to determine the expression of apoptosis and epithelial mesenchymal transition- (EMT-) related proteins and also target proteins for observation the effect of OE-hsa_circ_0061817 on the growth of A549 cells in nude mice. Bioinformatics method was used to predict the binding microRNA (miRNA) of hsa_circ_0061817 and construct the regulatory network of competitive endogenous RNA (ceRNA) and functional analysis of miRNA target genes. Results. Compared with PLO-ciR group, the cell viability, proliferation, and invasive ability of A549 and LLC-LUC were significantly reduced in OE-hsa_circ_00061817 group, while the apoptosis increased in OE-hsa_circ_00061817 group compared to PLO-ciR group. WB results showed that the expression of caspase 3, caspase 7, caspase 9, and E-cadherin increased significantly, while the expression levels of vimentin and N-cadherin decreased severely. Most importantly, OE-hsa_circ_00061817 inhibited the growth of A549 tumor-bearing nude mice. According to TargetScan and mirBase databases, hsa_circ_0061817 may competitively bind hsa_mir-181b-3p, hsa-mir-337-3p, hsa-mir-421, and hsa-mir-548d-3p. The results of functional enrichment showed that miRNA target genes were involved in many cancer-related biological processes, including negative regulation of apoptosis, gene expression, transcriptional imbalance in cancer, transforming growth factor-β, and P53 signal pathway. Conclusions. Over expression of hsa_circ_0061817 inhibits the proliferation of lung adenocarcinoma A549 and LLC-LUC cells and may reduce the invasive ability of lung adenocarcinoma cells by weakening the process of EMT, which provides a new target for the prevention and treatment of lung adenocarcinoma.