CTGF increases matrix metalloproteinases expression and subsequently promotes tumor metastasis in human osteosarcoma through down-regulating miR-519d

// Hsiao-Chi Tsai 1 , Hong-Lin Su 1 , Chun-Yin Huang 2,3 , Yi-Chin Fong 4,5 , Chin-Jung Hsu 4,5 and Chih-Hsin Tang 6,7,8 1 Department of Life Sciences, National Chung Hsing University, Taichung, Taiwan 2 Department of Orthopaedic Surgery, China Medical University Beigang Hospital, Yun-Lin County, Taiwan 3 Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan 4 School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan 5 Department of Orthopedic Surgery, China Medical University Hospital, Taichung, Taiwan 6 Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan 7 Department of Pharmacology, School of Medicine, China Medical University, Taichung, Taiwan 8 Department of Biotechnology, College of Health Science, Asia University, Taichung, Taiwan Correspondence: Chih-Hsin, Tang , email: // Keywords : Osteosarcoma; MicroRNA; MMP; CTGF; Metastasis Received : April 13, 2014 Accepted : May 19, 2014 Published : May 21, 2014 Abstract Osteosarcoma, the most common primary malignant bone tumor, shows potent capacity for local invasion and distant metastasis. Connective tissue growth factor (CTGF/CCN2), a secreted protein, binds to integrins, modulates invasive behavior of certain human cancer cells. Effect of CTGF in metastasis of human osteosarcoma is unknown. We found overexpression of CTGF increasing matrix metalloproteinases (MMPs)-2 and MMP-3 expression as well as promoting cell migration. MicroRNA (miRNA) analysis of CTGF-overexpressed osteosarcoma versus control cells probed mechanisms of CTGF-mediated promotion of migration. Among miRNAs regulated by CTGF, miR-519d was most downregulated after CTGF treatment. Co-transfection with miR-519d mimic reversed CTGF-mediated MMPs expression and cell migration. Also, MEK and ERK inhibitors or mutants reduced CTGF-increased cell migration and miR-519d suppression. By contrast, knockdown of CTGF diminished lung metastasis in vivo . Clinical samples indicate CTGF expression as linked with clinical stage and tumor metastasis. Taken together, data show CTGF elevating MMPs expression and subsequently promoting tumor metastasis in human osteosarcoma, down-regulating miR-519d via MEK and ERK pathways, making CTGF a new molecular therapeutic target in osteosarcoma metastasis.