406989

MIR206

microRNA 206;MIR206;microRNA 206

hsa-mir-206

6p12.2

ncRNA

OBJECTIVES: MicroRNA-206 (miR-206) is downregulated in many human malignancies, which correlates with tumour progression. This study characterized the contribution of miR-206 to the initiation and progression of human breast cancer. METHODS: Consecutive primary breast cancer patients who received radical resection were enrolled. Breast cancer tissue samples were obtained during surgery. MiR-206 levels in matched pairs of cancer tissue and normal adjacent tissue (NAT) samples were examined using quantitative reverse transcription-polymerase chain reaction. The relationship between miR-206 levels and clinicopathological characteristics and overall survival was also investigated. RESULTS: In 128 patients with breast cancer, miR-206 was downregulated in 119 (93%) tumour tissue compared with their matched NAT samples. Decreased miR-206 was significantly associated with advanced clinical stage and lymph node metastasis. Univariate and multivariate Cox proportional hazard regression analysis revealed that a low miR-206 level was an unfavourable prognostic factor for overall survival, in patients with breast cancer. CONCLUSIONS: This study indicated that miR-206 may be a good candidate as a novel prognostic indicator in breast cancer patients.

BACKGROUND/AIMS: MicroRNA-206 has been proven down-regulated in many human malignancies and correlated with tumor progression. However, the expression and functions of miR-206 in hepatocellular carcinoma (HCC) are still unclear. The aim of this study was to explore the effects of miR-206 in HCC tumorigenesis and development. METHODOLOGY: The expression levels of miR-206 were quantified by qRT-PCR in 147 surgically resected HCC and matched adjacent non-cancerous tissues, and correlated with clinicopathological factors. MTT, flow cytometric assay, and Transwell invasion and migration assays were used to test the proliferation, apoptosis, invasion, and migration of HepG2 HCC cells transfected with miR-206 mimics or negative control (NC) RNA-oligonucleotides. RESULTS: MiR-206 expression was significantly downregulated in HCC compared with matched non-cancerous liver tissues. Low level of miR-206 was associated with poor tumor differentiation, multiple tumor nodes, lymph node metastasis, and advanced TNM stage. In addition, transfection of miR-206 mimics in HepG2 cells was able to reduce cell proliferation, invasion, and migration, and promote cell apoptosis. CONCLUSIONS: These findings demonstrate that miRNA-206 could not only be useful as a novel biomarker but also serve as a potential target for gene therapy of HCC.

BACKGROUND AND AIMS: MicroRNA-206 has proven to be down-regulated in many human malignancies in correlation with tumour progression. Our study aimed to characterize miR-206 contributions to initiation and malignant progression of human osteosarcoma. METHODS: MiR-206 expression was detected in human osteosarcoma cell line MG63, human normal osteoblastic cell line hFOB 1.19, and paired osteosarcoma and normal adjacent tissues from 65 patients using quantitative RT-PCR. Relationships of miR-206 levels to clinicopathological characteristics were also investigated. Moreover, miR-206 mimics and negative control siRNA were transfected into MG63 cells to observe effects on cell viability, apoptosis, invasion and migration. RESULTS: We found that miR-206 was down-regulated in the osteosarcoma cell line MG63 and primary tumor samples, and decreased miR-206 expression was significantly associated with advanced clinical stage, T classification, metastasis and poor histological differentiation. Additionally, transfection of miR-206 mimics could reduce MG- 63 cell viability, promote cell apoptosis, and inhibit cell invasion and migration. CONCLUSIONS: These findings indicate that miR-206 may have a key role in osteosarcoma pathogenesis and development. It could serve as a useful biomarker for prediction of osteosarcoma progression, and provide a potential target for gene therapy.