MicroRNA-126 Inhibits Proliferation, Migration, Invasion, and EMT in Osteosarcoma by Targeting ZEB1.

Osteosarcoma (OS) is a tumor with rapid progression, high metastatic potential and poor clinical prognosis. This study was aimed to investigate the function of miR-126 in OS cells. The miR-126 expression in OS cell lines and OS tissues were explored by qRT-PCR. Then, the effects of miR-126 on proliferation, cycle, migration, invasion, and transforming growth factor (TGF)-β1 induced epithelial to mesenchymal transition (EMT) were assessed. Predicted by TargetScan, one of target genes for miR-126 was verified by luciferase activity assay. Meantime, the mRNA and protein expressions of ZEB1 were assessed by qRT-PCR and Western blot assay. Subsequently, the effect of ZEB1 silence on miR-126 down-regulated cells was also evaluated. Finally, the expressions of key kinases involved in c-Jun N-terminal kinase (JNK) and Janus-activated kinase (JAK)-1/signal transducer and activator of transcription (STAT)-3 pathways were detected by Western blot analysis. Result showed that miR-126 was down-regulated in OS tissues and cell lines. Overexpression of miR-126 significantly inhibited cell proliferation, migration, invasion, and TGF-β1 induced EMT. The effect of miR-126 knockdown was just the opposite. ZEB1 was predicted and verified as a target gene of miR-126. Meantime, the influence of miR-126 knockdown was abrogated by ZEB1 silence. Additionally, the phosphorylation levels of c-Jun, JNK, JAK1, and STAT3 were down-regulated in miR-126 over-expressed cells, and the effect of miR-126 knockdown was reversed by ZEB1 silence. In conclusion, miR-126 inhibits proliferation, migration, invasion and EMT in OS by targeting ZEB1 through inactivation of JNK and JAK1/STAT3 pathways. J. Cell. Biochem. 118: 3765-3774, 2017. © 2017 Wiley Periodicals, Inc.

Jiang R ，Zhang C ，Liu G ，Gu R ，Wu H ... -  《-》

miR-17-5p promotes proliferation and epithelial-mesenchymal transition in human osteosarcoma cells by targeting SRC kinase signaling inhibitor 1.

MicroRNA-17-5p (miR-17-5p) and epithelial-mesenchymal transition (EMT) have been reported to participate in the development and progression of multiple cancers. However, the relationship between the miR-17-5p and EMT in osteosarcoma (OS) is still poorly understood. This study was to investigate the effects of the miR-17-5p and its potential mechanism in regulating proliferation, apoptosis, and EMT of human OS. Quantitative real-time PCR was used to detect the miR-17-5p and SRC kinase signaling inhibitor 1 (SRCIN1) messenger RNA expression in OS specimens and cell lines. After transfection with miR-17-5p inhibitors, proliferation, apoptosis, migration, and invasion of OS cells were assessed by using the Cell Counting Kit-8, the annexin V-FITC apoptosis, wound-healing, and transwell assays. The SRCIN1 was validated as a target of the miR-17-5p through bioinformatics algorithms and luciferase reporter assay. Moreover, the expression of EMT markers, E-cadherin, N-cadherin, and Snail was identified by the Western blot analysis. MiR-17-5p was significantly upregulated in OS tumor samples and cell lines. It inhibited proliferation and EMT, and promoted apoptosis in OS. The SRCIN1 was identified as a direct target of the miR-17-5p. Silenced miR-17-5p could change the expression of EMT markers, such as upregulating the expression of E-cadherin, and downregulating the expression of N-cadherin and Snail through targeting the antioncogenic SRCIN1. These findings suggest that the miR-17-5p promotes cell proliferation, and EMT in human OS by directly targeting the SRCIN1, and reveal a branch of the miR-17-5p/SRCIN1/EMT signaling pathway involved in the progression of OS.

Zhao X ，Xu Y ，Sun X ，Ma Y ，Zhang Y ，Wang Y ，Guan H ，Jia Z ，Li Y ，Wang Y ... -  《-》

The microRNA‑708‑5p/ZEB1/EMT axis mediates the metastatic potential of osteosarcoma.

Feng T ，Zhu Z ，Jin Y ，Wang H ，Mao X ，Liu D ，Li Y ，Lu L ，Zuo G ... -  《-》

By targeting TRAF6, miR-140-3p inhibits TGF-β1-induced human osteosarcoma epithelial-to-mesenchymal transition, migration, and invasion.

Guo Q ，Zhang N ，Liu S ，Pang Z ，Chen Z ... -  《-》

MicroRNA-27a promotes proliferation, migration and invasion by targeting MAP2K4 in human osteosarcoma cells.

Osteosarcoma is a high-grade malignant bone neoplasm. Although the introduction of chemotherapy has reduced its mortality, more than 50% of patients develop chemoresistance and have an extremely poor prognosis due to pulmonary metastasis. Several molecular pathways contributing to osteosarcoma development and progression have recently been discovered. Various studies have addressed the genes involved in the metastasis of osteosarcoma. However, the highly complex molecular mechanisms of metastasis are still poorly understood. Recently, the decisive role of microRNAs in the regulation of molecular pathways has been uncovered. miRNAs may function as either oncogenes or tumor suppressors, depending on their target genes. miR-27a, a member of an evolutionarily conserved miRNA family, is abnormally increased in several types of cancers. It has been shown to be upregulated in osteosarcoma and plays a pro-metastatic role in osteosarcoma cell lines. However, the effects of miR-27a on osteosarcoma have not been clearly elucidated. The present study thus addressed the miR-27a sensitive mechanisms in osteosarcoma. In this study, three biological programs were used to predict whether MAP2K4 was a target of miR-27a. A specific miR-27a inhibitor was used to inhibit the endogenous activity of miR-27a in the human osteosarcoma cell line MG63. Cell proliferation, colony formation, migration and invasion assays were performed to assess the effects of miR-27a on the proliferation, metastasis and invasion of MG63 cells. The expression levels of several proteins evolved in the JNK/p38 signaling pathway were detected using western blot analysis. The luciferase activity of the wild-type pGL3-MAP2K4 3'UTR vector was significantly inhibited after the miR-27a precursor or the control precursor was transfected into the MG63 cells. However, the luciferase activity was not inhibited after transfection of the mutant pGL3-MAP2K4 3'UTR vector. The inhibition of miR-27a increased the luciferase activity of the wild-type pGL3-MAP2K4 3'UTR vector after MG63 cells were transfected with the miR-27a inhibitor or the control inhibitor. Thus, MAP2K4 is a potential target of miR-27a and can be directly regulated by miR-27a. Inhibition of miR-27a significantly suppressed cell proliferation after 72 hours compared to the negative control group. Inhibition of miR-27a significantly suppressed colony formation of the MG63 cells by 39 6%. Transwell migration and invasion assays demonstrated that the number of migratory and invasive cells transfected with the miR-27a inhibitor was reduced by 63.5% and 69.1%, respectively. After transfection of the miR-27a inhibitor into the MG63 cells, the level of phospho-JNK1 and phospho-p38 increased by 25% and 29%, respectively, along with the up-regulation of MAP2K4 protein. This is the first study showing that miR-27a can function as an oncogene by targeting MAP2K4 in the osteosarcoma MG63 cell line. Inhibition of miR-27a increases MAP2K4 expression, which in turn inhibits cell proliferation and migration through the JNK/p38 signaling pathway in MG63 cells. These findings may help us understand the molecular mechanism of miR-27a in the tumorigenesis of osteosarcoma and may provide new diagnostic and therapeutic options for the treatment of this neoplasia.

Pan W ，Wang H ，Jianwei R ，Ye Z ... -  《-》