Downregulation of Homeobox B7 Inhibits the Tumorigenesis and Progression of Osteosarcoma. 
Homeobox B7 (HOXB7), a member of the HOX gene family, plays a role in tumorigenesis.  However, until now the expression status and role of HOXB7 in osteosarcoma remain unclear.  Therefore, the present study aimed to investigate the functional role and mechanism of HOXB7 in osteosarcoma.  Our results demonstrated that HOXB7 was overexpressed in osteosarcoma cell lines.  Downregulation of HOXB7 significantly inhibited osteosarcoma cell proliferation in vitro, as well as attenuated xenograft tumor growth in vivo.  Downregulation of HOXB7 also inhibited the migration and invasion of osteosarcoma cells.  Furthermore, downregulation of HOXB7 significantly suppressed the protein expression levels of p-PI3K and p-Akt in U2OS cells.  In summary, our data demonstrated that downregulation of HOXB7 inhibited proliferation, invasion, and tumorigenesis, partly through suppressing the PI3K/Akt signaling pathway in osteosarcoma cells.  Our findings provide new insights into the role of HOXB7 in osteosarcoma and new therapeutic targets for the treatment of osteosarcoma.