TIKI2 suppresses growth of osteosarcoma by targeting Wnt/β-catenin pathway.

Osteosarcoma is the most bone-associated malignancy with high lethality. The current therapeutic strategy benefits little on the survival of patients. Studies have shown that aberrant activation of Wnt/β-catenin pathway is essential for the progression of osteosarcoma, implying that targeting this signaling may be an effective way of therapeutics. Recently, TIKI family has been identified as a new class of negative regulators for Wnt/β-catenin pathway. However, the implication of TIKIs with osteosarcoma has not been explored. Here, we constructed an adenoviral vector that expresses TIKI2 in osteosarcoma cells (Ad-TIKI2). TIKI2 expression was found to be reduced in osteosarcoma specimens and cell lines. In tested osteosarcoma cells, the activation of Wnt/β-catenin pathway was found to be inhibited by TIKI2 expression. Furthermore, the proliferation, colony formation ability, and invasion were all significantly suppressed in osteosarcoma cells infected with Ad-TIKI2. Finally, animal experiments further confirmed that TIKI2 restoration was able to inhibit the growth of osteosarcoma in vivo. Taken together, we provided evidence that reduced expression of TIKI family protein in osteosarcoma may participate in the progression of osteosarcoma and restoring its expression was able to impair the growth of osteosarcoma.