Abstract: Objective To investigate the effects of Distal-less homeobox 1 (DLX1) and bone morphogenetic protein 9 (BMP9) on inducing osteogeninc differentiation of human osteosarcoma cells. Mtethods The MG63 cells were infected with AdDLX1 and AdBMP9 alone or in combination, grouped as DLX1 group(AdDLX1+AdRFP)、DLX1+BMP9 group(AdDLX1+AdBMP9)、BMP9 group(AdBMP9+AdRFP)、RFP group(AdRFP). The expression of DLX1 and BMP9 were detected by RT-PCR and Western blot. The cell migration and invasion were analyzed by Transwell assay. Alkaline phosphatase(ALP) staining and numeration were used to detect the early osteogenic potential of MG63 cells, and the late osteogenic potential was detected by the alizarin red staining. The expression of osteopontin (OPN) protein was determined by Werstern blot assay. ResuLts The mRNA and protein expression of DLX1 and BMP9 were increased by AdDLX1 and AdBMP9（P＜0.05）. Transwell assay resμLts showed the cell migration and invasion of DLX1 group、DLX1+BMP9 group and BMP9 group were decreased, DLX1+BMP9 group was the most one (P < 0.05). The activity of ALP and calcium deposition as well as OPN protein were increased in DLX1+BMP9 group and BMP9 group, what’s more, these markers in DLX1+BMP9 group were more obvious (P < 0.05). Conclusions The combination of DLX1 and BMP9 could inhibit the malignant biological behavior and induce osteogenic differentiation of osteosarcoma cells.

Key words: osteosarcoma, DLX1, BMP9, cell migration, cell invision, osteogenic differentiation