Knockdown of WIF1 in miR-552-5p-silenced MG63 and U2OS cells rescued cell proliferation, migration and invasion. (A) Reverse transcription-quantitative polymerase chain reaction revealed that WIF1 expression was restored to the control level in MG63 and U2OS cells with miR-552-5p knockdown. (B) Cell Counting Kit-8 results indicated that knockdown of WIF1 rescued the proliferation ability of MG63 and U2OS cells. Transwell assays demonstrated that knockdown of WIF1 rescued the (C) migration and (D) invasion ability of MG63 and U2OS cells. *P<0.05 and **P<0.01. miR, microRNA; NC, negative control; WIF1, Wnt inhibitory factor 1; siWIF1, small interfering RNA targeting WIF1.