A natural product phillygenin suppresses osteosarcoma growth and metastasis by regulating the SHP-1/JAK2/STAT3 signaling.

Osteosarcoma represents one of the most devastating cancers due to its high metastatic potency and fatality. Osteosarcoma is insensitive to traditional chemotherapy. Identification of a small molecule that blocks osteosarcoma progression has been a challenge in drug development. Phillygenin, a plant-derived tetrahydrofurofuran lignin, has shown to suppress cancer cell growth and inflammatory response. However, how phillygenin plays functional roles in osteosarcoma has remained unveiled. In this study, we showed that phillygenin inhibited osteosarcoma cell growth and motility in vitro. Further mechanistic studies indicated that phillygenin blocked STAT3 signaling pathway. Phillygenin led to significant downregulation of Janus kinase 2 and upregulation of Src homology region 2 domain-containing phosphatase 1. Gene products of STAT3 regulating cell survival and invasion were also inhibited by phillygenin. Therefore, our studies provided the first evidence that phillygenin repressed osteosarcoma progression by interfering STAT3 signaling pathway. Phillygenin is a potential candidate in osteosarcoma therapy.