title: MiR-221 increases osteosarcoma cell proliferation, invasion and migration partly through the downregulation of PTEN.
abstract: Increasing evidence has demonstrated that microRNAs (miRNAs or miRs) are involved in cancer initiation and progression. Previous studies have indicated that miR-221 is one of the most consistently overexpressed miRNAs in multiple types of cancer. However, the role of miR-221 in osteosarcoma carcinogenesis and progression is not yet fully understood. Thus, the aim of the present study was to examine the expression of miR-221 in osteosarcoma and to determine the effects of miR-221 on the biological behavior of osteosarcoma cells. RT-qPCR revealed that the expression of miR-221 was significantly upregulated in the osteosarcoma tissues and osteosarcoma cell lines (p<0.05). In order to explore the role of miR-221 in osteosarcoma, the expression of miR-221 in the human osteosarcoma cell line MG‑63 was upregulated or downregulated by transfection with miR-221 mimic or miR-221 inhibitor, respectively. The results from RT-qPCR revealed that we had successfully generated MG‑63 cells in which miR-221 was either overexpressed or depleted. To investigate the effects of miR-221 on osteosarcoma cell proliferation, invasion and migration, a tetrazolium-based colorimetric assay, propidium iodide (PI) staining, a transwell migration assay and a wound healing assay were used in the present study. The results revealed that the proliferation, invasion and migration ability of the MG‑63 cells in which miR-221 was overexpressed was enhanced, and the proliferation, invasion and migration ability of the MG‑63 cells in which miR-221 was depleted was suppressed. The correlation between miR-221 and phosphatase and tensin homolog (PTEN) expression was investigated by RT-qPCR and western blot analysis. The results revealed that the downregulation of miR-221 significantly increased the expression of PTEN, whereas the upregulation of miR-221 significantly reduced the expression of PTEN. Taken together, our results suggest that miR-221 enhances the proliferation, invasion and migration ability of osteosarcoma cells partly by suppressing PTEN.
authors.affiliation: Department of Orthopedics, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Orthopedics, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China.
authors.forename: Fan
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Orthopedics, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China.
authors.forename: Quanming
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Department of Oncology, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226001, P.R. China.
authors.forename: Xiancheng
authors.initials: X
authors.lastname: Liu
mesh_terms: D001859:Bone Neoplasms / Q000235:genetics / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics*; D049109:Cell Proliferation / Q000235:genetics*; D015536:Down-Regulation / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006801:Humans; D035683:MicroRNAs / Q000235:genetics*; D009361:Neoplasm Invasiveness / Q000235:genetics* / Q000473:pathology; D012516:Osteosarcoma / Q000235:genetics* / Q000473:pathology; D051059:PTEN Phosphohydrolase / Q000235:genetics*; D014162:Transfection / Q000379:methods; D015854:Up-Regulation / Q000235:genetics
chemical_list: D035683:MicroRNAs; D051059:PTEN Phosphohydrolase; C525709:MIR221, human; C494929:PTEN protein, human