1. SS18-SSX-regulated miR-17 promotes tumor growth of synovial sarcoma by inhibiting p21WAF1/CIP1
- Author
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Minami, Yusuke, Kohsaka, Shinji, 1000030431307, Tsuda, Masumi, Yachi, Kazuhiro, Hatori, Nobuaki, 1000090360908, Tanino, Mishie, 1000090435959, Kimura, Taichi, 1000050322805, Nishihara, Hiroshi, 1000020133738, Minami, Akio, 1000030322803, Iwasaki, Norimasa, 1000070261287, Tanaka, Shinya, Minami, Yusuke, Kohsaka, Shinji, 1000030431307, Tsuda, Masumi, Yachi, Kazuhiro, Hatori, Nobuaki, 1000090360908, Tanino, Mishie, 1000090435959, Kimura, Taichi, 1000050322805, Nishihara, Hiroshi, 1000020133738, Minami, Akio, 1000030322803, Iwasaki, Norimasa, 1000070261287, and Tanaka, Shinya more...
- Abstract
MicroRNA (miRNA) can function as tumor suppressors or oncogenes, and also as potential specific cancer biomarkers; however, there are few published studies on miRNA in synovial sarcomas, and their function remains unclear. We transfected the OncomiR miRNA Precursor Virus Library into synovial sarcoma Fuji cells followed by a colony formation assay to identify miRNAs to confer an aggressive tumorigenicity, and identified miR-17-5p from the large colonies. MiR-17 was found to be induced by a chimeric oncoprotein SS18-SSX specific for synovial sarcoma, and all examined cases of human synovial sarcoma expressed miR-17, even at high levels in several cases. Overexpression of miR-17 in synovial sarcoma cells, Fuji and HS-SYII, increased colony forming ability in addition to cell growth, but not cell motility and invasion. Tumor volume formed in mice in vivo was significantly increased by miR-17 overexpression with a marked increase of MIB-1 index. According to PicTar and Miranda algorithms, which predicted CDKN1A (p21) as a putative target of miR-17, a luciferase assay was performed and revealed that miR-17 directly targets the 3-UTR of p21 mRNA. Indeed, p21 protein level was remarkably decreased by miR-17 overexpression in a p53-independent manner. It is noteworthy that miR-17 succeeded in suppressing doxorubicin-evoked higher expression of p21 and conferred the drug resistance. Meanwhile, introduction of anti-miR-17 in Fuji and HS-SYII cells significantly decreased cell growth, consistent with rescued expression of p21. Taken together, miR-17 promotes the tumor growth of synovial sarcomas by post-transcriptional suppression of p21, which may be amenable to innovative therapeutic targeting in synovial sarcoma. more...
- Published
- 2014