【Objective】 To investigate the effect of hydrogen sulfide (H2S) alone or combined with cisplatin on osteosarcoma cells U2OS and the possible mechanism in vitro.【Method】 Osteosarcoma cells U2OS were treated with NaHS (a donor of H2S) at different concentration (0.2

0.4

0.6

0.8

1.0

2.0

3.0

4.0

and 5.0 mmol/L) alone or combined with cisplatin at 20 mg/L concentration for 24 h respectively

then cell viability was tested by cell counter kit-8. U2OS cells were treated with NaHS at 0.4

and 1.0 mmol/L concentration for 24 h respectively

and U2OS cells were treated with NaHS at 1.0 mmol/L concentration alone or combined with cisplatin at 20 mg/L concentration for 24 h

then the number of monoclone was counted by monoclonal formation experiment. U2OS cells were treated with NaHS at 1.0 mmol/L concentration combined with cisplatin at 20 mg/L concentration for 24 h

then the expressions of Bcl-2

Bax

and NFκB were evaluated by Western blot assay.【Result】 The effects of hydrogen sulfide on U2OS cells: At the concentration from 1 to 5 mmol/L

NaHS dose-dependently inhibited cell viability in U2OS cells. Compared with control group

the monoclonal number of 1 mmol/L NaHS group was declined significantly (P < 0.05). The effect of hydrogen sulfide combined with cisplatin on U2OS cells: U2OS cell viability was dose-dependently declined by NaHS at the concentration from 0.8 to 5 mmol/L combined with cisplatin at 20 mg/L concentration for 24 h. Compared with cisplatin group

the monoclonal number of NaHS+ cisplatin group was declined (P < 0.01). The expression of NFκB and the ratio of Bcl-2/Bax expression were declined in the NaHS +cisplatin group compared with cisplatin group.【Conclusion】 Hydrogen sulfide can inhibit the growth of U2OS cells at the concentration above 1.0 mmol/L and enhance the inhibition of cisplatin on proliferation of U2OS cells at the concentration above 0.8 mmol/L concentration by decreasing the transportation of NFκB to the nucleus and then increase the apoptosis of U2OS cells.