Long noncoding RNAs (lncRNAs) play crucial roles in tumor development of 
osteosarcoma (OS). LncRNA PCAT6 was involved in the progression of multiple 
human cancers. However, the biological function of PCAT6 in OS remains largely 
unknown. We found that PCAT6 was elevated in OS tissues relative to that in 
their adjacent normal tissues. The upregulation of PCAT6 was positively 
associated with metastasis status and advanced stages and predicted poor overall 
and progression-free survivals in patients with OS. Functionally, silencing 
PCAT6 inhibited the proliferation, migration and invasion abilities of OS cells. 
Mechanistically, PCAT6, acting as a competitive endogenous RNA, upregulated 
expression of TGFBR1 and TGFBR2 to activate TGF-β pathway via sponging 
miR-185-5p. This study uncovers a novel underlying molecular mechanism of 
PCAT6-miR-185-5p-TGFBR1/2-TGF-β signaling axis in promoting tumor progression in 
OS, which indicates that PCAT6 may serve as a promising prognostic factor and 
therapeutic target again OS.