Background:Various chemicals have been used as an adjuvant treatment for giant cell tumor (GCT). However, the comparative effect of these chemicals remains unclear.

Methods:Cell line from GCT patients characterized by gene markers Nanog and Oct ¾ expression with RT-PCR was obtained. GCT cells were treated with H2O2 1%, 3%, 5% and ethanol 75%, 85%, 95% for 10 minutes and in vitro doses of H2O2 (0.003%, 0.005%, 0.01%, 0.03 %, 0.1%, 0.3%) for 5 minutes and were incubated for 24 hours. Cell morphology, cell viability and cell toxicity were assessed.

Results:Viability of GCT cells decreased significantly after exposure to the dose of H2O2 1% (p = 0.046), H2O2 3% (p = 0.043), and H2O2 5% (p = 0.043). There was no significant difference for cell viability between 1%, 3% and 5% H2O2 concentrations. While in in vitro doses, 0.3% H2O2 concentration has the best effectivity in sterilizing GCT. There was a phenomenon of cell fixation after exposure of GCT cells to ethanol. RT-PCR demonstrated a decrease in the expression of Oct 3/4 and Nanog genes along with an increase in the concentration of H2O2. Flowcytometry using Annexin V showed cell death due to necrosis, with the highest concentration amounted to 0.3%

Conclusion: Giving local chemical adjuvants of H2O2 concentrations of 1%, 3%, and 5% in vitro had the same effectiveness in killing GCT cells. While the concentration of 0.3% H2O2 for 5 minutes is the optimal therapy in GCT sterilization in vitro with necrosis cell death mechanism.