Osteosarcoma is a kind of mesenchymal tissue tumor, which is highly invasive and metastatic. Pro-angiogenic factors and vascular endothelial cells play key roles in the angiogenesis and metastasis of osteosarcoma, and the interaction between vascular endothelial cells and osteosarcoma cells can affect the growth and metastasis of osteosarcoma. Anti-vascular therapeutics agents for osteosarcoma, including monoclonal antibodies, tyrosine kinase inhibitors and traditional Chinese medicines, can inhibit the progression of osteosarcoma. An in-depth study of the correlation between osteosarcoma and angiogenesis can provide new ideas for the study of vascularization of osteosarcoma and anti-vascular treatment of osteosarcoma.

Objective To explore the effect of timosaponin B-II ( TB-II) on the differentiation of neural stem cells (NSCs) into tyrosine hydroxylase (TH) positive neurons in neonatal rats. Methods The biological functions of self-proliferation and multi-differentiation of NSCs were identified by primary culture, cell proliferation counting,morphological observation and immunology. NSCs of SD rats were cultured in vitro and treated with different concentrations of TB-II (10 μg/ml,30 μg/ml ,100 μg/ml) for 7 days. Immuno-histochemistry was used to detect the effect of TB-II on the differentiation of NSCs into TH-positive neurons, and Western blot was used to detect the expression of TH protein in neurons. Results ( 1) The cultured cells had the ability to self-proliferation,expressed nestin protein and differentiated into neurons and glial cells. So the cultured cells were conformed to the biological function of neural stem cells. (2)Compared with the control group,the TH positive cell ratio of TB-II 30 μg/ml group and TB-II 100 μg/ml group increased ((10. 03± 1. 36)%),( 20. 01± 3. 37)%),(31. 32± 3. 98)%) ,the difference was significant ( t=6. 15, 16. 54,both P<0. 05). There was no significant difference between TB-II 10 μg/ml group and control group (P>0. 05). (3)Western results showed that the relative expression of TH protein in TB-II 30 g/ml group and TB-II 100 μg/ml group was higher than that in control group,the difference was statistically significant (con-trol group: (1. 02±0. 24),TB-II 30μg/ml group: (3. 64±1. 78),TB-II 100 μg/ml group: (5. 88±2. 34);t=12. 58,9. 15,both P<0. 05). There was no significant difference between TB-II 10 μg/ml group and con-trol group (P>0. 05). Conclusion TB-II can promote the differentiation of NSCs into TH-positive neurons.