Circular RNA CircMTO1 suppressed proliferation and metastasis of osteosarcoma through miR-630/KLF6 axis.

OBJECTIVE: Circular RNAs (circRNAs) could regulate gene expression which may induce tumor occurrence and progression. In the current study, we first investigated the expression of circMTO1 in osteosarcoma, and the underlying mechanism was further elucidated. PATIENTS AND METHODS: Circular RNA microarrays were used to identify the differential expression of circRNAs in osteosarcoma tissues and the corresponding normal tissues. qRT-PCR was used to examine the level of circMTO1 in osteosarcoma tissues and cell lines. In addition, circMTO1 overexpression was constructed using lentiviral transfection in cell lines. Subsequently, the Cell Counting Kit-8 (CCK8), cell migration and invasion, and flow cytometry were used to investigate the effect of circMTO1 on the biological functions of cells. The Western Blot and the recovery experiments were used to explore the potential mechanism. RESULTS: Here, we measured 20 circRNAs which were downregulated in osteosarcoma tissues using circRNA microarray. CircMTO1 expression was decreased in osteosarcoma cell lines. Besides, circMTO1 could inhibit cell proliferation, migration and invasion, and induced apoptosis in osteosarcoma cells. Bioinformatics analysis showed that circMTO1 serves as a sponge for miR-630 and KLF6 is a direct target of miR-630. Furthermore, circMTO1 functions through regulation of miR-630/KLF6 axis. CONCLUSIONS: Our study suggests circMTO1 could suppress osteosarcoma progression by regulating miR-630/KLF6 axis, which may highlight the diagnostic and therapeutic potential of these molecules in osteosarcoma treatment.

Targeting EZH2 by microRNA-449a inhibits osteosarcoma cell proliferation, invasion and migration via regulation of PI3K/AKT signaling pathway and epithelial-mesenchymal transition.

OBJECTIVE: Osteosarcoma (OS) is one common bone malignant tumor prevailing in young adults and children. It is increasingly recognized microRNA 449a (miR 449a) as an anti-tumor factor in various tumours. However, little is known about the biological significance of miR 449a in OS. The intent of our study was to seek the prognostic values of miR-449a in OS. PATIENTS AND METHODS: Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to examine the level of miR-449a expression in 48 pairs of OS tissues and para-cancerous specimens, and the relationship between miR-449a level and clinical features of OS patient prognosis was analyzed. Moreover, we measured the miR-449a expression levels in OS cells. Transwell assay was further performed to investigate whether miR-449a influenced MG63 cell migration and invasion, which was important for malignant metastases. RESULTS: Quantitative real-time polymerase chain reaction (qRT-PCR) analysis demonstrated a notable decrease of miR-449a expressions in OS. The declined miR-449a expression was relevant with the poor prognosis and malignant clinicopathologic characteristics of OS patients. Thereafter, the functional assay was performed to determine the role of miR-449a in OS progression. Results of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assays and transwell assays indicated that miR-449a overexpression significantly repressed OS cell proliferation, invasion, and migration. Furthermore, luciferase reporter assay showed that enhancer of zeste homolog 2 (EZH2) was a downstream target of miR-449a in OS cells. Additionally, Western blot analysis demonstrated that miR-449a exerted anti-OS functions via the regulation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway and epithelial-mesenchymal transition. We also indicated that miR-449a restoration could inhibit in vivo tumor growth. CONCLUSIONS: These results manifested that miR-449a may thus be used as a therapeutic target in OS treatments.

[Correlation between the retinal nerve fiber layer defects (RNFLD) and visual field defects in primary open-angle glaucoma].

The RNFLD and the visual field in 73 cases (124 eyes) of primary open-angle glaucoma were studied. It was found that the early RNFLDs were usually local, as combed-hair, slit-like, or wedge shaped defects, while in the medium or late stage, diffuse RNFL atrophy or mixed RNF-LD was the rule. In the group of localized RNFLDs, 8.8% of the patients showed no visual field anomalies, indicating that RNFL damages preceded visual field damages; in the rest of the patients, visual field defects corresponded with the RNFLD in 86.7% of the cases. In patients of the medium or late stage with mixed or diffuse RNFLD, nasal steps and isopter constriction were usually found that corresponded perfectly with the RNFLD.

[Clinical evaluation of indentation gonioscopy].

The chamber angles of 31 cases (44 eyes) of angle closure glaucoma were studied by Iwata indentation gonioscopy and Goldman gonioscopy. (1) In 39 (89%) of the 44 eyes, the extent of open filtering angle under the indentation gonioscopy was larger than the that under Goldmann gonioscopy. (2) Peripheral iridectomy was indicated in only 68% of the cases when examined by Goldmann gonioscopy, while all cases were performed peripheral iridectomies successfully as indicated by indentation gonioscopy. Therefore, indentation gonioscopy is very useful in the differentiation of functional apposition of the chamber angle from the pathological peripheral synechiae.