Analysis of Selenium Levels in Osteosarcoma Patients and the Effects of Se-Methylselenocysteine on Osteosarcoma Cells In Vitro.

The form of selenium appears to be important for preventing cancer in humans. Here, we evaluated selenium levels in the serum and bone tissue samples from osteosarcoma patients using atomic absorption spectrometry. The in vitro effects of Se-methylselenocysteine (Se-MSC) on growth, cell cycle status, and apoptosis of osteosarcoma cells were assessed using the WST-1 assay, Hoechst 33342/propidium iodide staining, and flow cytometry, respectively. In osteosarcoma cases, the mean serum selenium levels in osteosarcoma tissue and normal bone were 0.08 mg/kg and 0.03 mg/kg, respectively (P < 0.05). Serum selenium levels in osteosarcoma and non-osteosarcoma cases were 0.09 mg/L and 0.08 mg/L, respectively (P > 0.05). Se-MSC-treated MG63 cells showed altered cellular morphology, decreased viability in a time- and dose-dependent manner, and an increase in the sub-G1 cell population. Se-MSC also downregulated Bcl-2 expression and upregulated Bax. Se-MSC inhibited the proliferation of the drug-resistant osteosarcoma cell line Saos-2/MTX300 and enhanced the inhibitory effect of pirarubicin on MG63 cells. Our data demonstrate that selenium levels are significantly higher in osteosarcoma tissue than normal bone tissue in osteosarcoma patients. The results also support the anticancer effects of Se-MSC in osteosarcoma. Further development of Se-MSC as an ancillary chemotherapy agent in osteosarcoma is warranted.

[Proteomics research of bufalin-induced apoptosis in osteosarcoma cell lines].

OBJECTIVE: To study the apoptosis inducing effects of bufalin on various human osteosarcoma cells and the concerning molecular mechanisms. METHOD: MTT assay was used to detect the growth inhibition rates of osteosarcoma cells U-20S, U-20S/MTX300, SaOS-2, IOR/OS9 treated with bufalin in different concentrations and times. The apoptosis of cells was observed flow cytometry 48 h following bufalin treatment. The proteomic techniques were used to separate and compare the treated and control groups 48 h after bufalin-incubation. Then, the proteomic results were validated by western blot. RESULT: Bufalin inhibited the growth of human osteosarcoma cells U20S, U20S/MTX300 (methotrexate resistant cells), SAOS2, IOR/OS9 in a dose- and time-dependent manner. The 72 h IC50 were (37.43 +/- 4.1), (32.24 +/- 5.3) nmol x L(-1) in U20S,U20S/MTX300 cells,respectivly. Flow cytometry showed that the apoptosis cells were increased following bufalin treatment. The protein expression profile showed 24 differentiated expression proteins. Among these proteins, the level of an anti-apoptotic protein, heat shock protein 27 (Hsp27) decreased significantly and the result was then validated by western blot. Ectopic expression of Hsp27 could reduce the bufalin-induced apoptosis remarkably in U20S and U20S/MTX300 cells. CONCLUSION: Bufalin could inhibit the cell growth and induce apoptosis on human osteosarcoma cells. The effect of bufalin may be related to the joint intervention with multiple protein targets. Among them, downregulation of Hsp27 plays a critical role in the bufalin-induced apoptosis in human osteosarcoma cells.

[In vitro screening of 32 traditional Chinese herbal extracts against U2OS human osteosarcoma cells].

OBJECTIVE: To test 32 traditional Chinese medicinal herbs with effects against osteosarcoma in vitro. METHODS: U(2)OS human osteosarcoma cell line was treated with the extracts of the Chinese herbs at various concentrations. The changes in cell proliferation in response to the treatment were examined by MTT assay, and the effects of these extracts against human osteosarcoma growth were compared. Morphological observation, flow cytometry and Annexin V were employed to detect the cell apoptosis after the treatments. RESULTS: According to the results of MTT assay, several of the 32 Chinese herbs, especially Venenum Bufonis and oxgall powder, were identified to produce growth inhibition against U(2)OS cells. Further study of the aqueous extracts of Venenum Bufonis and oxgall powder demonstrated their effects in inducing U(2)OS cell apoptosis, and Venenum Bufonis showed the strongest effect. In spite of the obvious growth inhibitory effect of oxgall powder, its extract induced cell apoptosis only at high concentrations. CONCLUSION: Several of the traditional Chinese herbs, especially Venenum Bufonis and oxgall powder, may inhibit the growth of U(2)OS cell line, and the results of this study pave the way for further identification of the effective components in the herbs that inhibit osteosarcoma growth both in vivo and in vitro.