Hsa_Circ_0001947/MiR-661/DOK7 Axis Restrains Non-Small Cell Lung Cancer Development

DOK7, a target of miR-299-5p, suppresses the progression of bladder cancer

OBJECTIVE

Bladder cancer (BLCA) is the 6th most common malignancy in males. microRNA (miRNAs) can function as tumor suppressors or oncogenic factors, which are of significance in the progression of BLCA. This study explored the mechanisms by which miR-299-5p modulates DOK7 (Docking Protein 7) expression and the functional role of DOK7 in the progression of BLCA.

METHODS

The expression of the DOK7 in BLCA patient samples was examined by RT-qPCR (Real-time quantitative polymerase chain reaction), Western blotting and Immunohistochemical (IHC) staining. The malignant phenotype of BLCA cells upon DOK7 overexpression or silencing was assessed by functional assays including cell count kit-9 (CCK8), colony formation and 5-ethynyl-2'-deoxyuridine (Edu) staining assays, as well as Transwell migration and invasion assays. The miRNA regulators of DOK7 were identified through bioinformatics prediction, and the biological role of miR-299-5p/DOK7 axis was validated by functional assays. The impact of miR-299-5p/DOK7 axis on Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway was further examined by Western blotting.

RESULTS

DOX7 was significantly downregulated in BLCA tumor tissues compared with normal tissues. Ectopic DOK7 expression suppressed the proliferation, migration and invasion of BLCA cells. DOK7 overexpression also attenuated the tumorigenesis of BLCA cells in nude mice. miR-299-5p was a negative regulator of DOK7 expression in BLCA cells. miR-299-5p/DOK7 axis impaired the malignancy of BLCA cells through regulating the JAK signaling pathway.

CONCLUSION

Our data indicate that miR-299-5p/DOK7 axis suppresses BLCA progression possibly by regulating the JAK signaling pathway.

miRNAs and exosomal miRNAs in lung cancer: New emerging players in tumor progression and therapy response

Non-coding RNAs have shown key roles in cancer and among them, short RNA molecules are known as microRNAs (miRNAs). These molecules have length less than 25 nucleotides and suppress translation and expression. The functional miRNAs are produced in cytoplasm. Lung cancer is a devastating disease that its mortality and morbidity have undergone an increase in recent years. Aggressive behavior leads to undesirable prognosis and tumors demonstrate abnormal proliferation and invasion. In the present review, miRNA functions in lung cancer is described. miRNAs reduce/increase proliferation and metastasis. They modulate cell death and proliferation. Overexpression of oncogenic miRNAs facilitates drug resistance and radio-resistance in lung cancer. Tumor microenvironment components including macrophages and cancer-associated fibroblasts demonstrate interactions with miRNAs in lung cancer. Other factors such as HIF-1α, lncRNAs and circRNAs modulate miRNA expression. miRNAs have also value in the diagnosis of lung cancer. Understanding such interactions can pave the way for developing novel therapeutics in near future for lung cancer patients.

Expression profiling of circular RNA reveals a potential miR-145-5p sponge function of circ-AFF2 and circ-ASAP1 in renal cell carcinoma

OBJECTIVES

Circular RNAs (circRNAs) are involved in carcinogenesis, though their expression profile in renal cell carcinoma (RCC) is uncharacterized. The tumor suppressor gene miR-145-5p is expressed in RCC tissues, but its relationship with circRNAs is unknown. Thus, we aimed to identify differentially expressed circRNAs in RCC tissues and to explore the interaction between these circRNAs and miR-145 in the development of RCC.

METHODS

We performed high-throughput sequencing and bioinformatics analyses to examine the expression pattern of circRNAs in RCC. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to functionally annotate differentially expressed circRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) was used for sequence verification. Small interfering RNAs were employed to investigate the function and mechanism of circRNAs in RCC. The relationship between miR-145-5p and circRNAs was confirmed using luciferase, RNA immunoprecipitation (RIP), and biotin-coupled probe RNA pull-down assays.

RESULTS

Fifty-three circRNAs were significantly and differentially expressed in RCC compared to normal control tissue. Bioinformatic analyses indicated that two significantly upregulated circRNAs, circ-AFF2 and circ-ASAP1, had sequences corresponding to miR-145 response elements. Consistently, the luciferase reporter, RIP, and biotin-coupled probe RNA pull-down assays showed that circ-AFF2 and circ-ASAP1 may repress miR-145 by acting as sponges. circ-AFF2 and circ-ASAP1 were highly expressed in RCC patient-derived tumor samples; their overexpression correlated with poor prognosis and low miR-145 levels. Knockdown of circ-AFF2 or circ-ASAP1 in RCC cell lines inhibited proliferation, underscoring their oncogenic function. A circRNA-miRNA network was constructed for RCC using the differentially expressed circRNAs and projected miRNAs. Candidate genes were verified by RT-qPCR and western blot, indicating that circ-AFF2 and circ-ASAP1 may be connected to RCC proliferation and metastasis.

CONCLUSION

circ-AFF2 and circ-ASAP1 were upregulated in RCC and likely promote tumor progression by sponging miR-145. Therefore, both circRNAs should be investigated further as potential diagnostic and therapeutic targets for RCC.

Circ_0001947 promotes cell proliferation, invasion, migration and inflammation and inhibits apoptosis in human rheumatoid arthritis fibroblast-like synoviocytes through miR-671-5p/STAT3 axis

Background

Circular RNAs (circRNAs) have emerged as vital regulators in the development of rheumatoid arthritis (RA). In this study, we aimed to explore the functions and mechanisms of circ_0001947 in RA.

Methods

The expression of circ_0001947, microRNA-671-5p (miR-671-5p) and signal transducer and activator of transcription 3 (STAT3) was determined by quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. Cell Counting Kit-8 (CCK-8) assay, 5′-ethynyl-2′-deoxyuridine (EdU) assay, flow cytometry analysis, transwell assay and wound-healing assay were performed to assess cell proliferation, apoptosis, invasion and migration. The concentrations of inflammatory factors were examined with enzyme-linked immunosorbent assay (ELISA) kits. Dual-luciferase reporter assay was used to analyze the relationships of circ_0001947, miR-671-5p and STAT3.

Results

Circ_0001947 was upregulated in RA patients and RA-FLSs. Knockdown of circ_0001947 repressed cell proliferation, invasion, migration and inflammatory response and facilitated apoptosis in RA-FLSs. Circ_0001947 served as the sponge for miR-671-5p and the inhibitory effect of circ_0001947 in RA-FLS progression was reversed by miR-671-5p inhibition. STAT3 was the target gene of miR-671-5p. MiR-671-5p overexpression restrained RA-FLS growth, invasion, migration and inflammation and promoted apoptosis, but STAT3 upregulation reversed the impacts.

Conclusion

Circ_0001947 contributed to the progression of RA-FLSs by elevating STAT3 through adsorbing miR-671-5p.

Circ_0001947 is abnormally upregulated in RA synovial tissues and RA-FLSs.

Circ_0001947 silencing inhibits cell proliferation, invasion, migration and inflammatory response and induces apoptosis in RA-FLSs.

Circ_0001947 sponges miR-671-5p, which directly interacts with STAT3.

Circ_0001947 regulates RA-FLS progression via miR-671-5p/STAT3 axis.