Open AccessPAI ‐1, a target gene of miR‐143, regulates invasion and metastasis by upregulating MMP ‐13 expression of human osteosarcoma
Author(s) -
Hirahata Mio,
Osaki Mitsuhiko,
Kanda Yusuke,
Sugimoto Yui,
Yoshioka Yusuke,
Kosaka Nobuyoshi,
Takeshita Fumitaka,
Fujiwara Tomohiro,
Kawai Akira,
Ito Hisao,
Ochiya Takahiro,
Okada Futoshi
Publication year - 2016
Publication title -
cancer medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 53
ISSN - 2045-7634
DOI - 10.1002/cam4.651
Subject(s) - osteosarcoma , metastasis , gene knockdown , cancer research , downregulation and upregulation , transfection , lung cancer , biology , medicine , pathology , cell culture , cancer , gene , genetics , biochemistry
Despite recent improvements in the therapy for osteosarcoma, 30–40% of osteosarcoma patients die of this disease, mainly due to its lung metastasis. We have previously reported that intravenous injection of miR‐143 significantly suppresses lung metastasis of human osteosarcoma cells (143B) in a mouse model. In this study, we examined the biological role and mechanism of miR‐143 in the metastasis of human osteosarcoma cells. We identified plasminogen activator inhibitor‐1 ( PAI ‐1) as a direct target gene of miR‐143. To determine the role of PAI ‐1 in human osteosarcoma cells, si RNA was transfected into 143B cells for knockdown of PAI ‐1 expression. An in vitro study showed that downregulation of PAI ‐1 suppressed cell invasion activity, but not proliferation. Moreover, injection of PAI ‐1 si RNA into a primary lesion in the osteosarcoma mouse model inhibited lung metastasis compared to control si RNA ‐injected mice, without influencing the proliferative activity of the tumor cells. Subsequent examination using 143B cells revealed that knockdown of PAI ‐1 expression resulted in downregulation of the expression and secretion of matrix metalloproteinase‐13 ( MMP ‐13), which is also a target gene of miR‐143 and a proteolytic enzyme that regulates tumor‐induced osteolysis. Immunohistochemical analysis using clinical samples showed that higher miR‐143 expressing cases showed poor expression of PAI ‐1 in the primary tumor cells. All such cases belonged to the lung metastasis‐negative group. Moreover, the frequency of lung metastasis‐positive cases was significantly higher in PAI ‐1 and MMP ‐13 double‐positive cases than in PAI ‐1 or MMP ‐13 single‐positive or double‐negative cases ( P < 0.05). These results indicated that PAI ‐1, a target gene of miR‐143, regulates invasion and lung metastasis via enhancement of MMP ‐13 expression and secretion in human osteosarcoma cells, suggesting that these molecules could be potential therapeutic target genes for preventing lung metastasis in osteosarcoma patients.